Patent Grant
8011547
1. Field of the Invention
The present invention relates to linear fastener driving tools, and, more particularly, directed to portable tools that drive staples, nails, or other linearly driven fasteners. The invention is specifically disclosed as a gas spring linear fastener driving tool, in which a cylinder filled with compressed gas is used to quickly force a piston through a driving stroke movement, while also driving a fastener into a workpiece. The piston is then moved back to its starting position by use of a rotary-to-linear lifter, which again compresses the gas above the piston, thereby preparing the tool for another driving stroke. A driver member is attached to the piston, and has protrusions along its edges that are used to contact the lifter member, which lifts the driver during a return stroke. A pivotable latch is controlled to move into either an interfering position or a non-interfering position with respect to the driver protrusions, and acts as a safety device, by preventing the driver from making a full driving stroke at an improper time. In alternative embodiments, the fastener driving tool uses a different type of driving device, such as a mechanical spring, to force the driver into a driving stroke.
2. Description of the Related Art
An early air spring fastener driving tool is disclosed in U.S. Pat. No. 4,215,808, to Sollberger. The Sollberger patent used a rack and pinion-type gear to “jack” the piston back to its driving position. A separate motor was to be attached to a belt that was worn by the user; a separate flexible mechanical cable was used to take the motor's mechanical output to the driving tool pinion gear, through a drive train.
Another air spring fastener driving tool is disclosed in U.S. Pat. No. 5,720,423, to Kondo. This Kondo patent used a separate air replenishing supply tank with an air replenishing piston to refresh the pressurized air needed to drive a piston that in turn drove a fastener into an object.
Another air spring fastener driving tool is disclosed in published patent application no. US2006/0180631, by Pedicini, which uses a rack and pinion to move the piston back to its driving position. The rack and pinion gear are decoupled during the drive stroke, and a sensor is used to detect this decoupling. The Pedicini tool uses a release valve to replenish the air that is lost between nail drives.
What is needed in the art is a portable fastener driving tool that is electrically powered, but which uses a gas spring principle of operation to drive a fastener into an object, and also uses few moving parts, which allows for simplicity of operation and provides a substantially gas-tight system for containing the pressurized gas for the gas spring.
Accordingly, it is an advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle, in which the cylinder that contains the moving piston and driver is substantially surrounded by a pressure vessel (as a main storage chamber) to increase the storage space of the pressurized gases needed for the gas spring effect.
It is another advantage of the present invention to provide a fastener driving tool that uses a gas spring principle to provide a quick downward driving stroke, and uses a rotary-to-linear lifter having a cam-shaped perimeter surface and multiple cylindrical protruding pins that lift the fastener driver element and the piston back to the initiating firing (or driving) position.
It is a further advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle, in which the tool has a cylinder displacement volume and also includes a main storage chamber, and in which a volumetric ratio of the main storage chamber's volume with respect to the cylinder's displacement volume is at least 2.0:1.
It is still a further advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle, in which there is a “working storage volume” comprising a combination of a main storage chamber and a cylinder displacement volume, and in which there is no gas replenishment system on-board the tool for allowing a user to replenish the charge gases of the tool's working storage volume, thereby reducing opportunities for gas leaks.
It is yet another advantage of the present invention to provide a fastener driving tool that uses a gas spring principle that uses a rotary-to-linear lifter to move the driver back to its firing (or driving) position, in which there can be a variable driving stroke by use of multiple rotations of the lifter member.
It is still another advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle, in which, for a first embodiment, a movable latch is controlled by a solenoid to disengage from multiple teeth of the driver element during a driving stroke, but also will tend to engage the teeth of the driver element as a safety interlock, and also at the maximum driver element displacement just before a driving stroke is to occur, so that the movable latch engages the driver teeth until the user activates the tool.
It is still another advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle, in which, for a second embodiment, a gearbox is provided that is essentially self-locking from its output side, or has a one-way feature, and thus the gearbox/lifter combination holds the driver in position just before a driving stroke.
It is a yet further advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle which includes a system controller that allows operation in either a “bottom firing mode” or a “trigger firing mode.”
It is a still further advantage of the present invention to provide a fastener driving tool that operates on a gas spring principle in which the system controller has error correction capability, including the capability of recovering from a jam of the driver element, without having to completely disable the tool.
Additional advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned with the practice of the invention.
To achieve the foregoing and other advantages, and in accordance with one aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a hollow cylinder comprising a cylindrical wall and having a movable piston therewithin, the hollow cylinder having a first end and a second, opposite end, the hollow cylinder containing a displacement volume created by a stroke of the piston; (b) a guide body that is substantially adjacent to the second end of the cylinder, the guide body having a receiving end, an exit end, and a passageway therebetween, the receiving end being proximal to the second end of the cylinder, the guide body being configured to receive a fastener that is to be driven from the exit end; (c) a driver member that is in mechanical communication with the piston at a third end of the driver member, the driver member having a fourth, opposite end that is sized and shaped to push the fastener from the exit end of the guide body, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body after the piston moves toward the second end of the cylinder, and the driver member, when at a ready position, being withdrawn into the guide body after the piston moves toward the first end of the cylinder; (d) a main storage chamber that substantially surrounds at least a portion of the cylinder and is in fluidic communication with the displacement volume of the cylinder, wherein the main storage chamber and the displacement volume are initially charged with a pressurized gas; and (e) a lifter member that, under first predetermined conditions, moves the driver member from its driven position toward its ready position; wherein the cylinder and piston act as a gas spring, under second predetermined conditions, to move the driver member from its ready position toward its driven position, using the pressurized gas of both the main storage chamber and the displacement volume acting on the piston, while the driver member's fourth end contacts the fastener and moves the fastener from the exit end of the guide body.
In accordance with another aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a hollow cylinder comprising a cylindrical wall and having a movable piston therewithin, the hollow cylinder having a first end and a second, opposite end, the hollow cylinder containing a displacement volume created by a stroke of the piston; (b) a main storage chamber that is in fluidic communication with the displacement volume of the cylinder, wherein the main storage chamber and the displacement volume are initially charged with a pressurized gas; (c) a guide body that is substantially adjacent to the second end of the cylinder, the guide body having a receiving end, an exit end, and a passageway therebetween, the receiving end being proximal to the second end of the cylinder, the guide body being configured to receive a fastener that is to be driven from the exit end; (d) an elongated driver member that is in mechanical communication with the piston at a third end of the driver member: (i) the driver member having a fourth, opposite end that is sized and shaped to push a fastener from the exit end of the guide body, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body after the piston moves toward the second end of the cylinder, and the driver member, when at a ready position, being withdrawn into the guide body after the piston moves toward the first end of the cylinder, (ii) the driver member having at least one longitudinal edge that is substantially parallel to a direction of movement of the driver member between its driven and ready positions, (iii) the driver member having at least one plurality of spaced-apart protrusions along the at least one longitudinal edge; (e) a lifter member that exhibits a discontinuous contact surface that, at predetermined locations along the discontinuous contact surface, makes contact with the at least one plurality of spaced-apart protrusions of the driver member such that, under first predetermined conditions, the lifter member is moved in a first direction and thereby causes the driver member to be moved in a second direction from its driven position toward its ready position; and (f) a latch member that has a catching surface and a sliding surface, wherein: (i) under third predetermined conditions, the latch member is controlled by a separate device and is forced into a non-catching position such that its catching surface does not interfere with the at least one plurality of spaced-apart protrusions of the driver member, thereby allowing the driver member to move in a third direction from its ready position to its driven position; and (ii) under fourth predetermined conditions, during which the driver member is being moved in the second direction from its driven position to its ready position, the separate device releases the latch member so that the latch member is not forced into a non-catching position, the latch member is directed toward a catching position, however, the sliding surface of the latch member allows the at least one plurality of spaced-apart protrusions of the driver member to slide along the latch member without being stopped so long as the driver member remains moving in the second direction; wherein the cylinder and piston act as a gas spring, under second predetermined conditions, to move the driver member from its ready position toward its driven position, using the pressurized gas of both the main storage chamber and the displacement volume acting on the piston, while the driver member's fourth end contacts the fastener and moves the fastener from the exit end of the guide body.
In accordance with yet another aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a hollow cylinder comprising a cylindrical wall and having a movable piston therewithin, the hollow cylinder having a first end and a second, opposite end, the hollow cylinder containing a displacement volume created by a stroke of the piston; (b) a main storage chamber that is in fluidic communication with the displacement volume of the cylinder, wherein the main storage chamber and the displacement volume are initially charged with a pressurized gas; (c) a guide body that is substantially adjacent to the second end of the cylinder, the guide body having a receiving end, an exit end, and a passageway therebetween, the receiving end being proximal to the second end of the cylinder, the guide body having an opening for receiving a fastener that is to be driven from the exit end; (d) an elongated driver member that is in mechanical communication with the piston at a third end of the driver member: (i) the driver member having a fourth, opposite end that is sized and shaped to push a fastener into an external workpiece, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body after the piston moves toward the second end of the cylinder, and the driver member, when at a ready position, being withdrawn into the guide body after the piston moves toward the first end of the cylinder; (ii) the driver member having a first longitudinal edge, (iii) the driver member having a first plurality of spaced-apart protrusions along the first longitudinal edge; and (e) a lifter member that exhibits an outer shape, in which its outer shape defines a perimeter of a surface: (i) the lifter member being rotated, under first predetermined conditions, by a drive member that is in mechanical communication with the lifter member, (ii) the lifter member having a plurality of extensions that protrude from the surface, and under the first predetermined conditions, the plurality of extensions are brought into mechanical contact with the first plurality of spaced-apart protrusions along the first longitudinal edge of the driver member during the return stroke, and thereby moves the driver member from its driven position toward its ready position, and (iii) the lifter member being positionable, under second predetermined conditions such that a portion of the perimeter of the lifter member and the plurality of extensions is not proximal to the first plurality of spaced-apart protrusions of the driver member, and thereby prevents the plurality of extensions of the lifter member from mechanically interfering with the first plurality of spaced-apart protrusions of the driver member during the driving stroke in which the driver member is moved from its ready position toward its driven position.
In accordance with still another aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a guide body that has a receiving end, an exit end, and a passageway therebetween, the guide body being configured to receive a fastener that is to be driven from the exit end; (b) a driver actuation device that has a first end and a second end, the second end being movable; (c) an elongated driver member that is in mechanical communication with the second end of the driver actuation device at a third end of the driver member: (i) the driver member having a fourth, opposite end that is sized and shaped to push a fastener from the exit end of the guide body, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body, and the driver member, when at a ready position, being withdrawn into the guide body, (ii) the driver member having at least one longitudinal edge and having a direction of movement between its driven and ready positions, (iii) the driver member having at least one plurality of spaced-apart protrusions along the at least one longitudinal edge; and (d) a lifter member that exhibits a discontinuous contact surface that, at predetermined locations along the discontinuous contact surface, makes contact with the at least one plurality of spaced-apart protrusions of the driver member such that the lifter member is moved in a first direction and thereby causes the driver member to be moved from its driven position toward its ready position; wherein: (e) the lifter member, under first predetermined conditions, forces the driver member to undergo a return stroke and move toward the ready position; and (f) the driver actuation device, under second predetermined conditions, forces the driver member to undergo a driving stroke and move toward the driven position.
In accordance with a further aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a hollow cylinder comprising a cylindrical wall and having a movable piston therewithin, the hollow cylinder having a first end and a second, opposite end, the hollow cylinder containing a displacement volume created by a stroke of the piston; (b) a guide body that is substantially adjacent to the second end of the cylinder, the guide body having a receiving end, an exit end, and a passageway therebetween, the receiving end being proximal to the second end of the cylinder, the guide body being configured to receive a fastener that is to be driven from the exit end; (c) an elongated driver member that is in mechanical communication with the piston at a third end of the driver member: (i) the driver member having a fourth, opposite end that is sized and shaped to push a fastener into an external workpiece, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body after the piston moves toward the second end of the cylinder, and the driver member, when at a ready position, being withdrawn into the guide body after the piston moves toward the first end of the cylinder; (ii) the driver member having a first longitudinal edge and having a direction of movement between its driven and ready positions, (iii) the driver member having a first plurality of spaced-apart protrusions along the first longitudinal edge; (d) a lifter member that, under first predetermined conditions, moves the driver member from its driven position toward its ready position, wherein: (i) the lifter member is rotated, under first predetermined conditions, by a drive shaft that is in mechanical communication with the lifter member; (ii) the lifter member has a plurality of extensions that protrude from a surface of the lifter member, and under the first predetermined conditions, the plurality of extensions are brought into mechanical contact with at least one of the first plurality of spaced-apart protrusions along the first longitudinal edge of the driver member, and thereby, under the first predetermined conditions, moves the driver member from its driven position toward its ready position, and (iii) the lifter member is positionable, under second predetermined conditions such that the plurality of extensions of the lifter member are prevented from mechanically interfering with the first plurality of spaced-apart protrusions along the first longitudinal edge of the driver member during the driving stroke in which the driver member is moved from its ready position toward its driven position; and (e) a driver actuation device that, under second predetermined conditions, forces the driver member to undergo a driving stroke and move toward the driven position.
In accordance with a yet further aspect of the present invention, a driving mechanism for use in a fastener driving tool is provided, which comprises: (a) a guide body that has a receiving end, an exit end, and a passageway therebetween, the guide body being configured to receive a fastener that is to be driven from the exit end; (b) a driver actuation device that has a first end and a second end, the second end being movable; (c) an elongated driver member that is in mechanical communication with the second end of the driver actuation device at a third end of the driver member: (i) the driver member having a fourth, opposite end that is sized and shaped to push a fastener from the exit end of the guide body, wherein the passageway of the guide body allows the driver member to pass therethrough toward the exit end during a driving stroke and toward the receiving end during a return stroke, the driver member, when at a driven position, protruding toward the exit end of the guide body, and the driver member, when at a ready position, being withdrawn into the guide body, (ii) the driver member having at least one longitudinal edge and having a direction of movement between its driven and ready positions, (iii) the driver member having at least one plurality of spaced-apart protrusions along the at least one longitudinal edge; and (d) a lifter member that exhibits a discontinuous contact surface that, at predetermined locations along the discontinuous contact surface, makes contact with the at least one plurality of spaced-apart protrusions of the driver member such that the lifter member is moved in a first direction and thereby causes the driver member to be moved in a second direction from its driven position toward its ready position during the return stroke; and (e) a movable latch member that: (i) does not prevent a movement of the driver member when the driver member moves in the second direction; (ii) under normal circumstance, does not prevent a movement of the driver member when the driver member moves in a third direction from its ready position to its driven position during the driving stroke; and (iii) under abnormal circumstances, prevents a movement of the driver member when the driver member moves in the third direction; wherein: (f) the lifter member, under first predetermined conditions, forces the driver member to undergo a return stroke and move toward the ready position; and (g) the driver actuation device, under second predetermined conditions, forces the driver member to undergo a driving stroke and move toward the driven position.
Still other advantages of the present invention will become apparent to those skilled in this art from the following description and drawings wherein there is described and shown a preferred embodiment of this invention in one of the best modes contemplated for carrying out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various, obvious aspects all without departing from the invention. Accordingly, the drawings and descriptions will be regarded as illustrative in nature and not as restrictive.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one preferred embodiment of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
The terms “first” and “second” preceding an element name, e.g., first pin, second pin, etc., are used for identification purposes to distinguish between similar elements, and are not intended to necessarily imply order, nor are the terms “first” and “second” intended to preclude the inclusion of additional similar elements.
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings, wherein like numerals indicate the same elements throughout the views.
Referring now to
A “left” outer cover of the driver portion is indicated at 20. A “top” cover is indicated at 22, while a “front” outer cover or “housing” of the driver portion is indicated at 24. A “rear” cover for the handle portion is indicated at 26 (which is also the battery pack cover), while a “rear” cover of the magazine portion is indicated at 28. It will be understood that the various directional nomenclature provided above is with respect to the illustration of
The area of the first embodiment tool 10 in which a fastener is released is indicated approximately by the reference numeral 30, which is the “bottom” of the fastener exit portion of tool 10. Before the tool is actuated, a safety contact element 32 extends beyond the bottom 30 of the fastener exit, and this extension of the safety contact element is depicted at 34, which is the bottom or “front” portion of the safety contact element. Other elements that are depicted in
Reference numeral 60 indicates a magazine housing, while reference numeral 62 indicates a fastener track through which the individual fasteners run therethrough while they remain within the magazine portion 16. A feeder carriage 64 is used to feed an individual fastener from the magazine into the drive mechanism area, and a back plate 66 is used to carry an individual fastener while it is being driven. In the illustrated embodiment, the feeder carriage 64 positions a fastener to a position within the guide body that is coincident with the path of the driver member 90, so that when the driver 90 moves through a driving stroke, its driving end will basically intercept the fastener and carry that fastener to the exit end of the tool 10, essentially at the bottom portion 30 of the tool's exit area.
The first embodiment fastener driving tool 10 also includes a motor 40 which acts as a prime mover for the tool, and which has an output that drives a gearbox 42. An output shaft 44 of the gearbox drives a lifter drive shaft 102 (see
A printed circuit board that contains a controller is generally designated by the reference numeral 50, and is placed within the handle portion 12 in this embodiment. A trigger switch 52 is activated by a trigger actuator 54. As can been seen by viewing
The controller will typically include a microprocessor or a microcomputer device that acts as a processing circuit. At least one memory circuit will also typically be part of the controller, including Random Access Memory (RAM) and Read Only Memory (ROM) devices. To store user-inputted information (if applicable for a particular tool model), a non-volatile memory device would typically be included, such as EEPROM, NVRAM, or a Flash memory device.
Referring now to
Also within the fastener driver portion 14 are mechanisms that will actually drive a fastener into a solid object. This includes a driver 90, a cylinder “venting chamber” 94 (which would typically always be at atmospheric pressure), a driver track 98 (see
There is a cylinder base 96 that mainly separates the gas pressure portions of the fastener driver portion 14 from the mechanical portions of that driver portion 14. The venting of air from the cylinder venting chamber 94 passes through the cylinder base 96, as seen at a vent 150 (see
Lifter 100 is not designed with an entirely circular outer perimeter, but instead is arcuate and portions of its perimeter exhibit an eccentric shape of a cam (see
It should be noted that
The latch 120 that was briefly noted above is depicted on
In
It will be further understood that the main storage chamber 74 preferably comprises a fixed volume, which typically would make it less expensive to manufacture; however, it is not an absolute requirement that the main storage chamber actually be of a fixed volume. It would be possible to allow a portion of this chamber 74 to deform in size and/or shape so that the size of its volume would actually change, during operation of the present invention, without departing from the principles of the present invention.
In the illustrated embodiment for the first embodiment fastener driving tool 10, the main storage chamber 74 substantially surrounds the working cylinder 71. Moreover, the main storage chamber 74 is annular in shape, and it is basically co-axial with the cylinder 71. This is a preferred configuration of the illustrated first embodiment, but it will be understood that alternative physical arrangements could be designed without departing from the principles of the present invention.
Referring now to
In
In
In the configuration depicted on
As rotary-to-linear lifter 100 rotates counterclockwise (as seen in
In the illustrated embodiment of the first embodiment fastener driving tool 10, the rotary-to-linear lifter 100 makes two complete rotations to lift the driver 90 from its bottom-most position to its top-most position. (The upper position is also sometimes referred to herein as the “ready position.”) At the end of the second rotation, the parts will be configured as illustrated in
In
When the sensor 130 detects the fourth pin 114 a first time (in this embodiment), the control system turns off the solenoid 46, which will then allow the latch 120 to engage the right-hand teeth (in these views) of the lifter 100. Note that the solenoid can also be turned off earlier during the lift, if desired. When sensor 130 detects this pin 114 a second time (in this embodiment), the current to the motor 40 is turned off, and the motor thus is de-energized and stops the lifting action of the driver 90. As described herein, the solenoid 46 acts as a latch actuator.
Due to the gas pressure above the piston 80, the driver/piston subassembly will drift downward (in these views) a small distance until the tooth 126 contacts the latch surface 124. This is the position illustrated in
When it is time to drive a fastener, the next action in the illustrated first embodiment is to cause the motor 40 to become energized once again. This occurs by two independent actions by the user: in some modes of the invention, these two independent actions can occur in either order. (There is also an optional “restrictive mode” of operation, in which the two independent actions must occur in a specific order.) These two actions are: pressing the nose 34 of the safety contact element 32 against a solid surface, and depressing the trigger actuator 54. The trigger actuator will cause the trigger switch 52 to change state, which is one condition that will start sending current to the motor 40. The safety contact element 32 has an upper arm 134 (see
It should be noted that the rotary motion of the lifter 100 will cause a small upward movement of the driver 90 so that the latch 120 can easily disengage from the “last” tooth 126 of the driver 90. Thus, there will not be a binding action that might otherwise cause the mechanism to jam.
Now that all this has occurred, the latch 120 is in its disengaged position so that its catching surface 124 will not interfere with any of the teeth 92 along the right-hand side (as seen in
The pressure of the gas in the combined main storage chamber 74 and displacement volume 76 is sufficiently high to quickly force the driver 90 downward, and such pneumatic means is typically much faster than a nail driving gun that uses exclusively mechanical means (such as a spring) for driving a fastener. This is due to the “gas spring” effect caused by the high gas pressure within the main storage chamber 74 and displacement volume 76 that, once the driver is released, can quickly and easily move the driver 90 in a downward stroke.
As the driver 90 is being moved downward, the piston 80 and the movable piston stop 82 are forcing air (or possibly some other gas) out of the cylinder venting chamber 94 that is below the piston. This volume of air is moved through a vent to atmosphere 150, and it is desired that this be a low resistance passageway, so as to not further impede the movement of the piston and driver during their downward stroke. The gas above the piston is not vented to atmosphere, but instead remains within the displacement volume 76, which is also in fluidic communication with the main storage chamber 74.
One aspect of the present invention is to provide a rather large storage space volume to hold the pressurized gas that is also used to drive the piston downward during a driving stroke of the driver 90. There is a fluidic passage 152 between the upper portion of the cylinder and the main storage chamber 74. (In the illustrated first embodiment, the cylinder wall 70 does not extend all the way to the “top” cap 72.) It is preferred that the volume of the main storage chamber be larger than the total volume of the cylinder working spaces (i.e., the displacement volume) by a volumetric ratio of at least 2.0:1, and more preferably at least 3.0:1. This will allow for a powerful stroke, and a quick stroke.
The illustrated first embodiment of the present invention allows for both a quick firing (or driving) stroke time and also a fairly quick “lifting” time to bring the driver back to its upper position, ready for the next firing (driving) stroke. Both of these mechanical actions can sequentially occur in less than 340 milliseconds (combined time), and allow a user to quickly place fasteners into a surface. In one operating mode of the present invention, the human user can hold the trigger in the engaged position and quickly place a fastener at a desired location merely by pressing the nose (or “bottom”) of the tool against the working surface to actuate the fastener driver and place the fastener. Then the user can quickly remove the fastener driver tool from that surface, and move it to a second position along the work surface, while still depressing the trigger the entire time, and then press the nose (or bottom) of the tool against the working surface at a different position, and it will drive a fastener at that “different” position. This is referred to as a “bottom fire” capability, and when using the illustrated embodiment it can occur virtually as fast as a human can place the tool against a surface, then pick up the tool and accurately place it against the surface at a different position, and thereby repeat these steps as often as desired until emptying the magazine of fasteners. This type of mode of operation will be discussed in greater detail below in connection with the logic flow chart starting at
Referring now to
Also viewed on
Referring now to
This “catching” action of the latch 120 has more than one benefit. In the first place, the latch holds the tooth 126 (which is the “bottom tooth” along the right-hand side of the driver as seen in
More specifically, if the driver jams during a drive stroke, and if a person tries to clear the jam, and if there was no precaution taken to prevent the remainder of the stroke from occurring at that moment, then possibly an injury could occur when the driver 90 suddenly becomes released from its jammed condition. In other words, a fastener could be driven during the attempt to clear the jam, and that fastener would likely be directed somewhere that is not the original target surface. In the present invention, the latch 120 will have its solenoid 140 become de-energized once the jam occurs (because solenoid 140 will de-energize after a “timeout” interval occurs), and therefore the latch 120 will be engaged and the catching surface 124 will be in a position to interfere with the downward movement of the driver teeth 92. By use of this configuration, the driver could only move a short distance even if the jam was suddenly cleared, because the latch catching surface 124 will literally “catch” the “next” tooth 92 that unexpectedly comes along during a downward travel of the driver 90. This makes the tool much safer in situations where a complete driver stroke has not occurred.
The process for controlling the solenoid and the moments when the solenoid will either be energized or de-energized are discussed below in connection with the flow chart that begins on
With respect to various types of firing (or driving) modes, a “trigger fire” mode is where the user first presses the tool nose against a working surface, and then depresses the trigger actuator 54. It is the trigger being depressed that causes the drive stroke to occur in this situation. With respect to a “bottom fire” mode, the trigger is actuated first, and then the user presses the nose of the tool against a work surface, and it is the work surface contact that causes the drive stroke to occur. As discussed above, the user can continue to hold the trigger down while pressing against and releasing the tool from the work surface multiple times, and obtain quick multiple firing strokes (or driving strokes), thereby quickly dispensing multiple fasteners into the working surface at various locations.
There is also an optional “restrictive firing mode,” in which the nose of the tool must be first placed against a working surface before the trigger is pulled. If the sequence of events does not unfold in that manner, then the drive stroke will not occur at all. This is strictly an optional mode that is not used by all users, and certainly in not all situations.
With regard to alternative embodiments of the present invention, an exemplary fastener driving tool can be made with a main storage chamber volume of about twelve cubic inches and a cylinder displacement volume of about 3.75 cubic inches. This would provide a volumetric ratio of the main storage chamber versus the displacement volume of about 3.2:1. As discussed above, it is desirable for the volumetric ratio of the main storage chamber's volume to the displacement volume to be at least 2.0:1, and it could be much higher if desired by the fastener driving tool's designer.
The working pressure in the system could be around 120 PSIG, and should probably be at least 100 PSIG for a quick-firing tool. By the term “working pressure” the inventors are referring to the pressure in the displacement volume 76 (and main storage chamber 74) at the time the piston 80 is at its “ready” position, which is when it is at (or proximal to) its uppermost travel position as illustrated in
It should be noted that other gases besides air can be used for the main storage chamber and the displacement volume, if desired. While air will work fine in many or most applications, alternative gases could be used as the “charge gas,” such as carbon dioxide or nitrogen gas. Moreover, the use of nitrogen gas can have other benefits during the manufacturing stage, such as for curing certain adhesives, for example.
In the illustrated first embodiment, there is no fill valve on the fastener driving tool 10 at the storage tank (main storage chamber) 74. This is a preferred mode of the present invention, although an optional fill valve could be provided, if desired by a tool designer. The design of the preferred mode of the present invention is such that the charge gas should not significantly leak from the tool, and therefore a fill valve would not be required.
Another feature of the present invention is that a variable stroke is possible by causing the rotary-to-linear lifter 100 to be rotated a multiple number of times to create a shorter or longer firing (driving) stroke, if desired. In the illustrated first embodiment, the lifter 100 makes a complete rotation two times to lift the piston from its lower-most position to its top-most position. This number of rotations of the lifter could be increased to three times or four times if desired, or even could be decreased to a single turn for a shorter stroke tool, if desired.
Another possible variation is to use a composite sleeve for the internal cylinder wall 70, which would make contact with the seals of the piston 86. In addition, the outer pressure vessel wall 78 could also be made of a composite material, if desired. The use of a carbon fiber composite, for example, would decrease weight, but would maintain the desired strength.
Referring now to
Referring now to
Referring now to
Referring now to
A step 212 now determines the stability of the system electrical power supply. And then a step 214 initializes the interrupts that will be used for the controller. The controller is now ready to enter into an operational routine.
At a step 220, the control logic enters a “FIRST 1” routine. A decision step 240 now determines whether or not a “mode” selector switch has been activated. (Note, this mode switch would typically be only an optional feature for a driving tool 10, and many tools will not include this mode switch at all.) If the answer is NO, then the logic flow is directed to a decision step 222. On the other hand, if the mode selector switch was turned “on,” then the logic flow is directed to a step 242 in which the tool enters a “restrictive fire” routine. The logic flow is directed now to a decision step 244 that determines if the trigger has been pulled. If the answer is NO, then the logic flow is directed to a decision step 224. On the other hand, if the trigger has been pulled, then the logic flow is directed to a step 246 that will further direct the logic flow to the “STOP 1” function (or routine) at step 380 on
If the answer at step 240 was NO, the decision step 222 now determines whether or not the trigger has been pulled. If the answer is YES, the logic flow is directed to a step 230 in which the logic flow enters a “TRIGGER” routine. A step 231 turns on a “work light” which is a small electric lamp (e.g., an LED) that illuminates the workpiece where the fastener is to be driven.
A decision step 232 now determines whether or not a predetermined timeout has occurred, and if the answer is YES, a step 234 directs the logic flow to a “STOP 1” routine, that is illustrated on
If the timeout has not occurred at decision step 232, then a decision step 236 determines if the safety has been actuated. If the answer is NO, then the logic flow is directed back to the FIRST 1 routine 220. On the other hand, if the safety has been actuated at step 236, then the logic flow is directed to a step 238 that will send the logic flow to a “DRIVE” routine, which is on
If, either at step 222 or step 244, the trigger was not yet pulled, then the logic flow is directed to the decision step 224. When the logic flow reaches decision step 224, the logic now determines whether or not the safety has been actuated. This step determines whether or not the safety contact element 32 has been pressed against a solid object to an extent that actuates the sensor (e.g., limit switch 132), which means that the tool is now pressed against a surface where the user intends to place a fastener. If the answer is NO, the logic flow is directed back to the mode switch query at decision step 240. However, if the answer is YES, the logic flow is directed to a step 250 in which the controller enters a “SAFETY” routine.
Once at the SAFETY routine at step 250, a step 251 turns on the “work light,” which is the same lamp/LED that was discussed above in reference to step 231. A decision step 252 now determines whether or not a timeout has occurred, and if the answer is YES, the logic flow is directed to a step 254 that directs the logic flow to the “STOP 1” function at step 380 on
As can be seen by reviewing the flow chart of
Referring now to
On the other hand, if decision steps 264 and 270 are both answered affirmatively, then a step 280 clears the operational timers, and the logic flow is then directed to a decision step 282 that determines if the software code flow is within certain parameters. This is a fault-checking mode of the software itself, and if the system does not determine a satisfactory result, then the logic flow is directed to a step 284 that sends the logic flow to a “STOP” routine at a step 370 on
If the software code flow check is within acceptable parameters at decision step 282, then the logic flow is directed to a step 290 that turns on the motor, and then a step 292 that turns on the solenoid. A step 294 now starts the solenoid timer and a step 296 now starts the motor run timer. As will be discussed below, these timers will be periodically checked by the system controller to make sure that certain things have occurred while the solenoid is on and while the motor is running. Otherwise, after a predetermined maximum amount of time, the motor will be turned off and the solenoid will be turned off due to these timers actually timing out, which should not occur if the tool is being used in a normal operation, and if the tool is functioning normally.
In addition to the solenoid and motor run timers discussed above, a “dwell timer” is used to allow the tool to begin its normal operation before any further conditions are checked. This is accomplished by a decision step 298 on
Once the dwell timer has finished at step 298, the logic flow is directed to a decision step 300 that determines if the solenoid “on time” has been exceeded. If the answer is YES, the logic flow is directed to a step 302 that turns off the solenoid. This situation does not necessarily mean the tool is being misused or is not functioning properly, and therefore the logic flow does not travel to a “stop step” from the step 302. Instead, the logic flow is directed to a decision step 304, discussed below.
If the solenoid on time has not been exceeded, then the logic flow also is directed to the decision step 304, which determines if the cam limit switch has received a first signal. This is the limit switch 130 that detects the presence or absence of the fourth pin 114 of the lifter. If the tool of the illustrated embodiment is being used, the lifter 110 will make two complete rotations when lifting the driver and piston from their bottom-most positions to their top-most positions. Therefore, the cam limit switch 130 will receive two different signals during this lift. Step 304 determines if the first signal has occurred. If not, then a decision step 310 determines whether the motor timeout has occurred. If the answer is NO, then the logic flow is directed back to decision step 300. On the other hand, if the motor run timer has indeed timed out, then the logic flow is directed to a step 312 that sends the logic flow to a “STOP” routine at step 370. This would likely indicate that there is a problem with the tool, or a problem with the way the user is attempting to operate the tool.
Referring back to decision step 304, if the first signal from the cam has occurred, then the logic flow is directed to a step 306 that turns off the solenoid. This will allow the latch 120 to engage the teeth 92 of the driver 90, in case there has been some type of jam, or other type of unusual operation while the driver and piston are being lifted. It also allows the latch 120 eventually to properly engage the bottom-most tooth 126 of the driver, which is the normal operation once the driver and piston have been raised to their top-most (or firing) position.
The logic flow is now directed to a decision step 320 that determines whether a second signal has been received from the cam limit switch. If the answer is NO, then the logic flow is directed to a decision step 322 that determines whether or not the motor run timer has timed out. If the answer is NO, then the logic flow is directed back to decision step 320. On the other hand, if the motor timer has timed out, the logic flow is directed to a step 324 that directs the logic flow to the “STOP” routine at 370, and indicates that there is some type of problem.
Once decision step 320 determines that the second signal from the cam has been received, then the logic flow is directed to a step 330 that turns off the motor, then to a step 332 that starts a “reset” timeout referred to as “all switches on.” In this mode, it is either assumed that both the actuation (input) devices are still actuated, or at least that the controller needs to make an examination of those input devices to see what the proper status of the tool should be. Accordingly, the logic flow is directed to a decision step 340 that determines if the safety is still actuated. If the answer is NO, then the logic flow is directed to a step 342 that then sends the logic flow to the “FIRST 1” routine at step 220 on
The logic flow is continued on
The other type of STOP routine is the “STOP 1” routine at step 380. Once that occurs, a step 382 turns off the motor, turn off the solenoid at a step 384, and turn off the work light at a step 386. The STOP 1 routine will then clear the timers at a step 388, and a decision step 390 determines whether or not the trigger is still pulled. If the answer is YES, then the logic flow is directed back to the STOP 1 routine at step 380. If the trigger is not pulled at step 390, the logic flow is then directed to a decision step 392 that determines if the safety is still actuated. If YES, the logic flow is directed back to the STOP 1 routine at step 380. However, if the safety is not actuated, the logic flow is directed to a step 398 that sends the logic flow to the “FIRST 1” routine at step 220 on
Referring now to
A “right” outer cover or “housing” of the driver portion is indicated at 411. A “top” cover is indicated at 412, while a “front” outer cover of the driver portion is indicated at 413. A “rear” cover for the handle portion is indicated at 415 (which is also the battery pack cover), while a “rear” cover of the magazine portion is indicated at 416. It will be understood that the various directional nomenclature provided above is with respect to the illustration of
The area of the second embodiment tool 401 in which a fastener is released is indicated approximately by the reference numeral 417, which is the “bottom” of the fastener exit portion of tool 401. Before the tool is actuated, a safety contact element 418 extends beyond the bottom 417 of the fastener exit, and this extension of the safety contact element is depicted at 419, which is the bottom or “front” portion of the safety contact element. Other elements that are depicted in
Reference numeral 445 indicates a magazine housing, while reference numeral 447 indicates a fastener track through which the individual fasteners run while they remain within the magazine portion 407. A feeder carriage 448 (see
The second embodiment fastener driving tool 401 also includes a motor 427 (see
A printed circuit board (see
A three-position selector switch, acting as a “mode” control switch, is mounted on tool 401 at 441. This switch 441 allows the user (the tool's operator) to select an operating “Mode A” or an operating “Mode B”, or to turn the tool OFF. These operating modes are described in detail below, and in conjunction with logic flow charts in the drawings.
There also are one or more light-emitting diodes (LEDs) 443 mounted on tool 401, which provides an indication as to certain functions of the tool. This is described below in greater detail, in the description of the logic flow charts. There are also other input devices for the controller, however those input devices are not seen in
The controller at 435 will typically include a microprocessor or a microcomputer device that acts as a processing circuit. At least one memory circuit will also typically be part of the controller, including Random Access Memory (RAM) and Read Only Memory (ROM) devices. To store user-inputted information (if applicable for a particular tool model), a non-volatile memory device would typically be included, such as EEPROM, NVRAM, or a Flash memory device.
Referring now to
Also within the fastener driver portion 405 are mechanisms that will actually drive a fastener into a solid object. This includes a driver 490, a cylinder “venting chamber” 492 beneath the piston 458 (which would typically always be at atmospheric pressure), a driver track (not seen in this view; however, see
It will be understood that the precise positions for the teeth 92 and 491 could be different from those illustrated for the driver 90 or 490, without departing from the principles of the present invention. It will also be understood that the precise shapes of teeth 92 and 491 could be different from those illustrated for the driver 90 or 490, without departing from the principles of the present invention. It will be further understood that the longitudinal edges of the driver elements 90 and 490 do not necessarily have to be linear or straight, although a straight edge is probably the simplest to construct and use. Moreover, the longitudinal edges of the driver elements 90 and 490 do not necessarily need to be parallel to one another, or parallel to the longitudinal axis of the driver itself, although again, such parallel construction is probably the simplest to build and use.
There is a cylinder base 493 that mainly separates the gas pressure portions of the fastener driver portion 405 from the mechanical portions of that driver portion 405. The venting of air from the cylinder venting chamber 492 passes through the cylinder base 493, as seen at a vent 450 on
Lifter 400 can be designed with an entirely circular outer perimeter, or it can have a different shape. In the first embodiment of
The rotary-to-linear lifter 400 includes three cylindrical protrusions (or “extensions”) that will also be referred to herein as “pins.” The first such pin (“pin 1”) is designated 404, the second pin (“pin 2”) is designated 406, while the third pin (“pin 3”) is designated 408. (See,
It should be noted that
It should be understood that the “working side” of these three pins 404, 406, and 408 is on the opposite side of the lifter 400 in the view of
It should also be noted that pins 404, 406, an 408 are illustrated as having circular cross-sectional shapes, which is desirable for this embodiment, although other cross-sectional shapes could instead be used without departing from the principles of the present invention. For example, the pins could have a smooth arcuate outer surface along the portions that will come into contact with the protrusions or “teeth” of the lifter 490, and the remaining portion of the outer surface of the pins could exhibit a sharp angular cut-off edge, that for example, would have the appearance of a slice of pie. This alternative shape can apply both to the pins 104, 106, and 108 of the first embodiment and to the pins 404, 406, and 408 of the second embodiment, without departing from the principles of the present invention. Moreover, the pins do not necessarily need to protrude from the lifter surface at right angles.
In the first embodiment of
The latch 420 that was briefly noted above is depicted on
In
In
It will be further understood that the main storage chamber 454 preferably comprises a fixed volume, which typically would make it less expensive to manufacture; however, it is not an absolute requirement that the main storage chamber actually be of a fixed volume. It would be possible to allow a portion of this chamber 454 to deform in size and/or shape so that the size of its volume would actually change, during operation of the present invention, without departing from the principles of the present invention.
In the illustrated embodiment for the second embodiment fastener driving tool 401, the main storage chamber 454 substantially surrounds the working cylinder 453. Moreover, the main storage chamber 454 is annular in shape, and it is basically co-axial with the cylinder 453. This is a preferred configuration of the illustrated second embodiment, but it will be understood that alternative physical arrangements could be designed without departing from the principles of the present invention.
For example,
In
A cylinder base 796 separates the gas pressure portions of the fastener driver portion 714 from the mechanical portions of that fastener driver portion 714. The tool 710 can include a handle portion (not shown), a fastener magazine portion 407 (not shown), and a fastener exit portion 718. The remaining parts of tool 710 can be very similar, or identical, to other parts of the second embodiment tool 401, illustrated in
Referring again to
In
In the configuration depicted on
As rotary-to-linear lifter 400 rotates counterclockwise (as seen in
In the illustrated embodiment of the second embodiment fastener driving tool 401, the rotary-to-linear lifter 400 makes two complete rotations to lift the driver 490 from its bottom-most position to its top-most position. (The upper position is also sometimes referred to herein as the “ready position.”) At the end of the second rotation, the parts will be configured as illustrated in
At the end of the piston's normal upward movement, the “last” tooth along the right-hand side (as best seen in
When the sensor 430 detects the magnet 414 a first time (in this second embodiment), the control system turns off the solenoid 431, which will then allow the latch 420 to engage the right-hand teeth (in these views) of the lifter 400. Note that the solenoid can also be turned off earlier during the lift, if desired. When sensor 430 detects this magnet 414 a second time (in the second embodiment), the current to the motor 427 is turned off, and the motor thus is de-energized and stops the lifting action of the driver 490. As described herein, the solenoid 431 acts as a latch actuator.
In the second illustrated embodiment tool 401, the latch surface 424 is not in contact with the driver teeth 491 when the driver 490 has been moved to its “ready” position. In this second illustrated embodiment, the gearbox 428 has an attribute by which it essentially is self-locking from its output side (i.e., from its output shaft 429), and this prevents the lifter 400 from allowing the driver 490 to move “backward,” which is the “down” direction in
At the “ready” position for the driver 490, the latch 420 may be positioned such that it would interfere with the driver teeth 491 (i.e., in an “interfering position”) as a safety feature (i.e., in which the latch surface 424 would “catch” the teeth 491 of the driver 490, if the driver somehow would move downward). However, the gearbox/lifter combination does not allow the “last tooth” 426 to contact that latch 420 at this point in the tool's operation.
This is the position illustrated in
It should be noted that, for the second embodiment tool 401, the gearbox can be of yet another alternative construction. For example, instead of being self-locking from its output side, a “regular” gearbox could be used if provided with a “one-way” feature, such as an adjacent one-way clutch (or a one-way clutch constructed therewithin). In this manner, the driver 490 would still be prevented from moving down (in
When it is time to drive a fastener, the next action in the illustrated second embodiment is to cause the motor 427 to become energized once again, so that the lifter 400 rotates further in its original direction. This occurs by two independent actions by the user: in some modes of the invention, these two independent actions can occur in either order. (There is also an optional “restrictive mode” of operation, in which the two independent actions must occur in a specific order.) These two actions are: pressing the nose 419 of the safety contact element 418 against a solid surface, and depressing the trigger actuator 439. The trigger actuator will cause the trigger switch 437 to change state, which is one condition that will start sending current to the motor 427. The safety contact element 418 has an upper arm 434 (see
When both of these actions occur simultaneously, current is delivered to the motor 427 which will once again turn the rotary-to-linear lifter 400 a short distance. Also, the controller energizes the solenoid 431, which rotates the latch 420 a small angular distance clockwise (as seen in
Now that all this has occurred, the latch 420 is in its disengaged position so that its catching surface 424 will not interfere with any of the teeth 491 along the right-hand side (as seen in
The pressure of the gas in the combined main storage chamber 454 and displacement volume 457 is sufficiently high to quickly force the driver 490 downward, and such pneumatic means is typically much faster than a nail driving gun that uses exclusively mechanical means (such as a spring) for driving a fastener. This is due to the “gas spring” effect caused by the high gas pressure within the main storage chamber 454 and displacement volume 457 that, once the driver is released, can quickly and easily move the driver 490 in a downward stroke.
As the driver 490 is being moved downward, the piston 458 and the movable piston stop 459 are forcing air (or possibly some other gas) out of the cylinder venting chamber 492 that is below the piston. This volume of air is moved through a vent to atmosphere 450, and it is desired that this be a low resistance passageway, so as to not further impede the movement of the piston and driver during their downward stroke. The gas above the piston is not vented to atmosphere, but instead remains within the displacement volume 457, which is also in fluidic communication with the main storage chamber 454.
One aspect of the present invention is to provide a rather large storage space or volume to hold the pressurized gas that is also used to drive the piston downward during a driving stroke of the driver 490. There is a fluidic passage 452 between the upper portion of the cylinder and the main storage chamber 454. (In the illustrated second embodiment, the cylinder wall 451 does not extend all the way to the top end region 455.) It is preferred that the volume of the main storage chamber be larger than the total volume of the cylinder working spaces (i.e., the displacement volume) by a volumetric ratio of at least 2.0:1, and more preferably at least 3.0:1. This will allow for a powerful stroke, and a quick stroke; moreover, it provides for an efficient operating air spring.
The illustrated second embodiment of the present invention allows for both a quick firing (or driving) stroke time and also a fairly quick “lifting” time to bring the driver back to its upper position, ready for the next firing (driving) stroke. Both of these mechanical actions can sequentially occur in less than 340 milliseconds (combined time), and allow a user to quickly place fasteners into a surface. In one operating mode of the present invention, the human user can hold the trigger in the engaged position and quickly place a fastener at a desired location merely by pressing the nose (or “bottom”) of the tool against the working surface to actuate the fastener driver and place the fastener. Then the user can quickly remove the fastener driver tool from that surface, and move it to a second position along the work surface, while still depressing the trigger the entire time, and then press the nose (or bottom) of the tool against the working surface at a different position, and it will drive a fastener at that “different” position. This is referred to as a “bottom fire” capability, and when using the illustrated embodiment it can occur virtually as fast as a human can place the tool against a surface, then pick up the tool and accurately place it against the surface at a different position, and thereby repeat these steps as often as desired until emptying the magazine of fasteners. This type of mode of operation will be discussed in greater detail below in connection with the logic flow chart starting at
Referring now to
Also viewed on
As generally indicated on
Further alternative ways to force the driver 490 of
Referring now to
This “catching” action of the latch 420 has more than one benefit. In the first place, the latch remains in its interfering position as the piston 458 is lifted to its top or “firing” position. The driver 490 cannot be fired until the latch 420 is moved out of the way, as discussed above. On the other hand, if there is some type of jam or an improper use of the tool by a user such that the driver 490 does not totally complete its travel during a firing (driving) stroke, the latch 420 will also prevent a misfire from occurring at an inconvenient time.
More specifically, if the driver jams during a driving stroke, and if a person tries to clear the jam, and if there was no precaution taken to prevent the remainder of the stroke from occurring at that moment, then possibly an injury could occur when the driver 490 suddenly becomes released from its jammed condition. In other words, a fastener could be driven during the attempt to clear the jam, and that fastener would likely be directed somewhere that is not the original target surface. In the present invention, the latch 420 will have its solenoid 440 become de-energized once the jam occurs (because solenoid 440 will de-energize after a “timeout” interval occurs), and therefore the latch 420 will be engaged and the catching surface 424 will be in a position to interfere with the downward movement of the driver teeth 491. By use of this configuration, the driver could only move a short distance even if the jam was suddenly cleared, because the latch catching surface 424 will literally “catch” the “next” tooth 491 that unexpectedly comes along during a downward travel of the driver 490. This makes the tool much safer in situations where a complete driving stroke has not occurred.
The process for controlling the solenoid and the moments when the solenoid will either be energized or de-energized are discussed below in connection with the flow chart that begins on
It will be understood that the latch 120 or 420 could be controlled by a device other than a solenoid, without departing from the principles of the present invention. For example, the solenoid 140 or 440 could be replaced by motor, or some type of air or hydraulic valve, if desired. Moreover, the latch action could be linear rather than rotational (pivotable), if desired.
With respect to various types of firing (or driving) modes, a “trigger fire” mode is where the user first presses the tool nose against a working surface, and then depresses the trigger actuator 439. It is the trigger being depressed that causes the driving stroke to occur in this situation. With respect to a “bottom fire” mode, the trigger is actuated first, and then the user presses the nose of the tool against a work surface, and it is the work surface contact that causes the driving stroke to occur. As discussed above, the user can continue to hold the trigger down while pressing against and releasing the tool from the work surface multiple times, and obtain quick multiple firing strokes (or driving strokes), thereby quickly dispensing multiple fasteners into the working surface at various locations.
There is also an optional “restrictive firing mode,” in which the nose of the tool must be first placed against a working surface before the trigger is pulled. If the sequence of events does not unfold in that manner, then the driving stroke will not occur at all. This is strictly an optional mode that is not used by all users, and certainly in not all situations.
With regard to alternative embodiments of the present invention second embodiment, an exemplary fastener driving tool can be made with a main storage chamber volume of about 11.25 cubic inches and a cylinder displacement volume of about 3.75 cubic inches. This would provide a volumetric ratio of the main storage chamber versus the displacement volume of about 3.0:1. As discussed above, it is desirable for the volumetric ratio of the main storage chamber's volume to the displacement volume to be at least 2.0:1, and it could be much higher if desired by the fastener driving tool's designer.
The working pressure in the system could be around 120 PSIG, and should probably be at least 100 PSIG for a quick-firing tool. By the term “working pressure” the inventors are referring to the pressure in the displacement volume 457 (and main storage chamber 454) at the time the piston 458 is at its “ready” position, which is when it is at (or proximal to) its uppermost travel position.
It should be noted that other gases besides air can be used for the main storage chamber and the displacement volume, if desired. While air will work fine in many or most applications, alternative gases could be used as the “charge gas,” such as carbon dioxide or nitrogen gas. Moreover, the use of nitrogen gas can have other benefits during the manufacturing stage, such as for curing certain adhesives, for example.
In the illustrated second embodiment, there is no fill valve on the fastener driving tool 401 at the storage tank (main storage chamber) 454. This is a preferred mode of the present invention, although an optional fill valve could be provided, if desired by a tool designer. The design of the preferred mode of the present invention is such that the charge gas should not significantly leak from the tool, and therefore a fill valve would not be required.
Another feature of the present invention is that a variable stroke is possible by causing the rotary-to-linear lifter 400 to be rotated a multiple number of times to create a shorter or longer firing (driving) stroke, if desired. In the illustrated second embodiment, the lifter 400 makes a complete rotation two times to lift the piston from its lower-most position to its top-most position. This number of rotations of the lifter could be increased to three times or four times if desired, or even could be decreased to a single turn for a shorter stroke tool, if desired.
Another possible variation is to use a composite sleeve for the internal cylinder wall 451, which would make contact with the seals of the piston 458. In addition, the outer pressure vessel wall 456 could also be made of a composite material, if desired. The use of a carbon fiber composite, for example, would decrease weight, but would maintain the desired strength.
Referring now to
The seals 482 and 484 are designed to hold the oil 488 within the annular space 186 indefinitely, or at least to lose the oil only at a very slow rate. In a preferred mode of the invention, the seals have a “slick” coating material to provide a long operational life. In the illustrated embodiment, an exemplary material for this coating is XYLAN™, which is a TEFLON™ material that includes molybdenum powder.
The driver element 90 of tool 10 and the driver element 490 of tool 401 both retract into their respective working cylinder areas 71 and 453. This is a unique arrangement, in that some of the driver's latching protrusions (or “teeth”) 92 and 491 also retract into the working cylinder areas 71 and 453. This is made possible by the positioning of the respective lifters 100 and 400, and by the shapes of the driver elements 90 and 490, and also by the sealing arrangement of the pistons 80 and 458, discussed in the previous paragraphs.
It will be understood that the fastener magazine portion 16 of tool 10 and the fastener magazine portion 407 of the tool 401 are essentially optional features. In other words, the fastener driving tools 10 and 401 could be constructed to act as “single-shot” devices, and no magazine would be provided for such a tool. Alternatively, the tools 10 and 401 could be provided with a standard detachable magazine, but the tools themselves could also be constructed to work in a “single-shot mode” such that a single fastener is placed in the tool 10 or 401, near its front end or tip (e.g., near 30) and that single fastener is then driven by tool 10 or 401. In this mode, the magazine 16 or 407 could be dismounted from the tool 10 or 401 during the single-shot procedure; later, the magazine 16 or 407 could be re-mounted to the tool 10 or 401, and the collated fasteners in the magazine could then be driven by the tool, as desired by the user.
Referring now to
Referring now to
Referring now to
Referring now to
Referring now to
A step 512 now determines the stability of the system electrical power supply. Then a step 514 causes an electrical output to blink one or more LEDs (light-emitting diodes) 443 on tool 510, so the user is made aware that the tool 510 has entered its “startup” mode of operation. Step 514 also initializes the interrupts that will be used for the controller, and the controller is now ready to enter into an operational routine.
A decision step 516 now determines if the safety has been actuated (i.e., whether the safety contact element 418 has been pressed against a solid object to an extent that actuates the sensor, e.g., limit switch 432). Step 516 also determines if the trigger 439 has been pulled. If the answer is YES for either of these questions, then the logic flow is directed to a step 520. If the answer is NO for both of these questions, then the logic flow is directed to another decision step 518.
Step 518 determines whether or not the LEDs 443 have flashed a predetermined maximum number of times. If the answer is YES, then the logic flow is directed to step 520. If the answer is NO, then the logic flow loops back to step 514.
At a step 520, the control logic enters a “BEGIN” routine. A decision step 540 now determines whether or not the current operating mode is the “RESTRICTIVE” mode. This determination involves inspecting the current state of the selector switch 441 which, as noted above, has three positions: “Off”, “Mode A”, or “Mode B”. This three-position switch 441 is part of an exemplary arrangement of the second embodiment of the fastener driving tool 401, and in this description of the second tool embodiment, Mode A and Mode B are also referred to as a “Restrictive Mode,” and a “Contact Actuation Mode.”
If the current operating mode is not the RESTRICTIVE mode, then the logic flow is directed to a decision step 522. On the other hand, if the current mode is the RESTRICTIVE mode, then the logic flow is directed to a step 542 in which the tool enters a “restrictive fire” routine. The logic flow is directed now to a decision step 544 that determines if the trigger has been pulled. If the answer is NO, then the logic flow is directed to a decision step 541. On the other hand, if the trigger has been pulled, then the logic flow is directed to a step 546 that will further direct the logic flow to the “STOP 1” function (or routine) at a step 680 on
If the logic flow at decision step 544 resulted in a NO result, the logic flow at decision step 541 determines whether or not the safety has been actuated. If the answer is NO, then the logic flow is directed back to the “restrictive fire” routine, just before step 544. However, if the answer is YES, the logic flow is directed to a step 543, in which the controller turns on the “work light,” which is a small electric lamp (e.g., an LED) that illuminates the workpiece where the fastener is to be driven.
A decision step 545 now determines whether or not a “sequential mode timeout” has occurred, and if the answer is YES, the logic flow is directed to a step 547 that directs the logic flow to the “STOP 1” function at step 680 on
If the answer at step 540 was NO, the decision step 522 now determines whether or not the trigger has been pulled. If the answer is YES, the logic flow is directed to a step 530 in which the logic flow enters a “TRIGGER” routine. A step 531 turns on a “work light,” which is the same lamp/LED that was discussed above in reference to step 543.
A decision step 532 now determines whether or not a predetermined “trigger timeout” has occurred, and if the answer is YES, a step 534 directs the logic flow to a “STOP 1” routine, that is illustrated on
If the timeout has not occurred at decision step 532, then a decision step 536 determines if the safety has been actuated. If the answer is NO, then the logic flow is directed back to the BEGIN routine 520. On the other hand, if the safety has been actuated at step 536, then the logic flow is directed to a step 538 that will send the logic flow to a “DRIVE” routine, which is on
If, at step 522, the trigger was not yet pulled, then the logic flow is directed to the decision step 524. When the logic flow reaches decision step 524, the logic now determines whether or not the safety has been actuated. This step determines whether or not the safety contact element 418 has been pressed against a solid object to an extent that actuates the sensor (e.g., limit switch 432), which means that the tool is now pressed against a surface where the user intends to place a fastener. If the answer is NO, the logic flow is directed back to the mode switch query at decision step 540. However, if the answer is YES, the logic flow is directed to a step 550 in which the controller enters a “SAFETY” routine.
Once at the SAFETY routine at step 550, a step 551 turns on the “work light,” which is the same lamp/LED that was discussed above in reference to step 531. A decision step 552 now determines whether or not a “safety timeout” has occurred, and if the answer is YES, the logic flow is directed to a step 554 that directs the logic flow to the “STOP 1” function at step 680 on
As can be seen by reviewing the flow chart of
Referring now to
On the other hand, if decision steps 564 and 570 are both answered affirmatively, then a step 580 clears the operational timers, and the logic flow is then directed to a decision step 582 that determines if the software code flow is within certain parameters. This is a fault-checking mode of the software itself, and if the system does not determine a satisfactory result, then the logic flow is directed to a step 584 that sends the logic flow to a “STOP” routine at a step 670 on
If the software code flow check is within acceptable parameters at decision step 582, then the logic flow is directed to a step 590 that turns on the motor, and then a step 592 that turns on the solenoid. A step 594 now starts the solenoid timer and a step 596 now starts the motor run timer. As will be discussed below, these timers will be periodically checked by the system controller to make sure that certain things have occurred while the solenoid is on and while the motor is running. Otherwise, after a predetermined maximum amount of time, the motor will be turned off and the solenoid will be turned off due to these timers actually timing out, which should not occur if the tool is being used in a normal operation, and if the tool is functioning normally.
In addition to the solenoid and motor run timers discussed above, a “dwell timer” is used to allow the tool to begin its normal operation before any further conditions are checked. This is accomplished by a decision step 598 on
Once the dwell timer has finished at step 598, the logic flow is directed to a decision step 600 that determines if the solenoid “on time” has been exceeded. If the answer is YES, the logic flow is directed to a step 602 that turns off the solenoid. This situation does not necessarily mean the tool is being misused or is not functioning properly, and therefore the logic flow does not travel to a “stop step” from the step 602. Instead, the logic flow is directed to a decision step 604, discussed below.
If the solenoid on time has not been exceeded, then the logic flow also is directed to the decision step 604, which determines if the cam limit switch has received a first signal. This is the Hall effect sensor 430 that detects the presence or absence of the magnet 414 of the lifter. If the tool of the illustrated embodiment is being used, the lifter 410 will make two complete rotations when lifting the driver and piston from their bottom-most positions to their top-most positions. Therefore, the cam limit switch 430 will receive two different signals during this lift. Step 604 determines if the first signal has occurred. If not, then a decision step 610 determines whether the motor timeout has occurred. If the answer is NO, then the logic flow is directed back to decision step 600. On the other hand, if the motor run timer has indeed timed out, then the logic flow is directed to a step 612 that sends the logic flow to a “STOP” routine at step 670. This would likely indicate that there is a problem with the tool, or a problem with the way the user is attempting to operate the tool.
Referring back to decision step 604, if the first signal from the cam has occurred, then the logic flow is directed to a step 606 that turns off the solenoid. This will allow the latch 420 to engage the teeth 491 of the driver 490, in case there has been some type of jam, or other type of unusual operation while the driver and piston are being lifted. It also allows the latch 420 eventually to properly engage the bottom-most tooth 426 of the driver, which is the normal operation once the driver and piston have been raised to their top-most (or firing) position.
The logic flow is now directed to a decision step 620 that determines whether a second signal has been received from the cam limit switch. If the answer is NO, then the logic flow is directed to a decision step 622 that determines whether or not the motor run timer has timed out. If the answer is NO, then the logic flow is directed back to decision step 620. On the other hand, if the motor timer has timed out, the logic flow is directed to a step 624 that directs the logic flow to the “STOP” routine at 670, and indicates that there is some type of problem.
Once decision step 620 determines that the second signal from the cam has been received, then the logic flow is directed to a step 630 that turns off the motor, then to a step 632 that starts a “reset” timeout referred to as “all switches on.” In this mode, it is either assumed that both the actuation (input) devices are still actuated, or at least that the controller needs to make an examination of those input devices to see what the proper status of the tool should be. Accordingly, the logic flow is first directed to a decision step 634, which determines whether the operator mode selector switch 441 is set to the Restrictive Mode, and if not, the logic flow is directed to a decision step 640 (discussed below).
If the answer is YES at step 634, the logic flow is directed to a decision step 635 that determines whether or not the reset timeout has occurred. If the answer is YES, then the logic flow is directed to a step 636, and the tool is then enters the STOP1 routine at step 680 on
Back at step 634, if the current selector switch mode was not Restrictive, then the logic flow is directed to a decision step 640 that determines if the safety is still actuated. If the answer is NO, then the logic flow is directed to a step 642 that then sends the logic flow to the “BEGIN” routine at step 520 on
The logic flow is continued on
The other type of STOP routine is the “STOP 1” routine at step 680. Once that occurs, a step 682 turns off the motor, turn off the solenoid at a step 684, and turn off the work light at a step 686. The STOP 1 routine will then clear the timers at a step 688, and a decision step 690 determines whether or not the trigger is still pulled. If the answer is YES, then the logic flow is directed back to the STOP 1 routine at step 680. If the trigger is not pulled at step 690, the logic flow is then directed to a decision step 692 that determines if the safety is still actuated. If YES, the logic flow is directed back to the STOP 1 routine at step 680. However, if the safety is not actuated, the logic flow is directed to a step 698 that sends the logic flow to the “BEGIN” routine at step 520 on
In the above detailed description, there are a number of various timeouts that may occur during the operation of the tools built according to the present invention. As of the writing of this patent application, all of the timeout intervals are set for three (3) seconds. However, each of the timeouts is designed so as to be independently settable by the system designer, in case it becomes desirable to alter one or more of the individual timeout intervals (i.e., to a time value other than three seconds). Normally this would be done in software code (stored in the memory circuit), used to instruct the processing circuit in its operations, although hardware timers could instead be used.
It will also be understood that the logical operations described in relation to the flow charts of
It will be further understood that the precise logical operations depicted in the flow charts of
Other aspects of the present invention may have been present in earlier fastener driving tools sold by the Assignee, Senco Products, Inc., including information disclosed in previous U.S. patents and published applications. Examples of such publications are U.S. Pat. No. 6,431,425; U.S. Pat. No. 5,927,585; U.S. Pat. No. 5,918,788; U.S. Pat. No. 5,732,870; U.S. Pat. No. 4,986,164; and U.S. Pat. No. 4,679,719.
All documents cited in the Background of the Invention and in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.
The foregoing description of a preferred embodiment of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Any examples described or illustrated herein are intended as non-limiting examples, and many modifications or variations of the examples, or of the preferred embodiment(s), are possible in light of the above teachings, without departing from the spirit and scope of the present invention. The embodiment(s) was chosen and described in order to illustrate the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to particular uses contemplated. It is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
While this invention has been described with respect to embodiments of the invention, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
The present application claims priority to provisional patent application Ser. No. 60/977,678, titled “FASTENER DRIVING TOOL USING A GAS SPRING,” filed on Oct. 5, 2007.
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