The invention relates to a driving machine that drives a fastener, such as a nail, by cooperative action of two switch mechanisms, which include a first switch operated by a trigger and a second switch operated by a push lever that moves in response to an operation of pressing a front end of an ejection port of the fastener against a driven material. In the driving machine, a driving switching mechanism for switching between a single-shot driving operation and a continuous-shot driving operation is mounted to the trigger portion.
The commonly-known portable driving machine sequentially drives out fasteners that are loaded in a magazine from the front end of a driver blade by utilizing a driving source (power source), such as a compressed air system which uses air pressure by supplying compressed air from an air compressor to the driving machine main body, a gas combustion system in which the driving machine main body is equipped with a small gas cylinder for burning gas stored in the cylinder, an electric motor system in which the driving machine main body is equipped with a storage battery and an electric motor so as to use the driving force of the electric motor, and so on. For this type of driving machine, it is conventional to dispose a safety mechanism, as disclosed in Patent Literature 1, which constantly urges the push lever toward the side of the bottom dead center (the side of the driven material) with respect to the front end of the nose in the initial state, such that when the driven material is not in contact with the push lever of the ejection part front end, the striking driving part would not be activated even if the trigger is pulled. Such a system performs the operation while the front end of the push lever (contact arm) is pressed against the driven material. Therefore, it is possible to perform the so-called continuous driving operation in the case of sequentially driving multiple nails. That is, in the state where the trigger is not released after one nail is driven, the main body is moved to move and press the push lever against the next driving position, so as to sequentially and continuously drive multiple nails.
According to the technology of Patent Literature 1, the operation mode switching mechanism for switching between the single-shot driving mode and the continuous-shot driving mode is disposed on the push lever mechanism side instead of the trigger side. This system has the advantage that it does not complicate the structure inside the trigger, but the operation mode switching mechanism needs to be disposed near the upper end of the push lever and thus an installation space is required. Therefore, it may have adverse effects when the driving machine is to be made smaller and lighter. In addition, the inventors' study has found that in the case of the so-called two-switch system driving machine, in which the switches (valve mechanisms) of two systems, i.e., the trigger having a first switch for activating the striking driving means and a second switch that is turned on and off by the push lever, are disposed in parallel, installing the operation mode switching mechanism on the trigger part side may be advantageous as a whole.
Accordingly, in the invention, the switching mechanism for switching between the single-shot driving mode and the continuous-shot driving mode is disposed on the trigger part side of the driving machine, which performs the trigger operation through two switches and, in the state where the trigger remains to be pulled, moves the push lever from the bottom dead center to the top dead center, so as to enable the continuous-shot driving operation of fasteners. Furthermore, the invention reduces the number of parts on the push lever side that are for operating the second switch to simplify the configuration, so as to provide the driving machine with improved disassembly workability and assembly workability.
Representative features of the invention disclosed in this application are explained as follows. The invention provides a driving machine, which includes a driver blade that strikes a fastener such as a nail; a striking driving element causing the driver blade to reciprocate; a first switch for activating the striking driving element; a trigger operated by an operator to set the first switch to an ON state or an OFF state; a push lever supported to be movable in a direction parallel to a movement direction of the driver blade and moving in response to an operation of pressing a front end of an ejection port of the fastener against a driven material; and a second switch opened and closed by a movement of the push lever and set to an ON state when the push lever is at a top dead center and set to an OFF state when the push lever is at a bottom dead center. The driving machine drives the fastener with the striking driving element when the first switch and the second switch are both in the ON state. A driving switching mechanism is disposed for switching between a single-shot driving mode, which drives one fastener every time the trigger is pulled, and a continuous-shot driving mode, which drives the fasteners continuously by repeatedly pressing the push lever against the driven material and releasing the push lever in a state of keeping the trigger pulled. The driving switching mechanism is disposed on the trigger side. The trigger includes a trigger lever that is swingable around a swing shaft. The driving switching mechanism includes a movable member that is disposed in the trigger lever and is in contact with a plunger of the first switch. The movable member is movable relative to the trigger lever and can be positioned at one of a first position and a second position, wherein the first position is where the plunger is not operated by an operation of the trigger lever and the second position is where the plunger is operated by the operation of the trigger lever.
According to another feature of the invention, the striking driving element moves a piston that is connected to the driver blade by compressed air, and the first switch is a switching valve of an air flow path, which serves as a trigger to supply the compressed air to the piston, and is operated by the trigger lever. Moreover, the second switch is a switching valve interposed in series in the air flow path and performs opening and closing operations by the movement of the push lever. Here, in the single-shot driving mode, after the fastener is driven, the movable member moves from the second position to the first position, such that the first switch is not operated. Thereby, while the operator keeps the trigger pulled, even if the driving machine is moved and the push lever is pressed against the next driving position, the striking of the fastener is not carried out. On the other hand, in the continuous-shot driving mode, after the fastener is driven, the movable member remains at the second position to maintain the first switch in an operable state. Accordingly, while the operator keeps the trigger pulled, the driving machine is moved and the push lever is pressed against the next driving position to carry out the striking operation of the fastener. Thus, the fasteners can be driven sequentially.
According to another feature of the invention, the movable member is a swing type arm and is swingable by a predetermined angle around a rotating shaft that is disposed in the trigger lever. A direction in which a swing end of the trigger lever extends from the swing shaft and a direction in which a swing end of the movable member extends from the rotating shaft are opposite directions, and a switching member may be disposed in the trigger lever to allow or prevent swing of the movable member. The switching member is of a rod type that is disposed substantially in parallel to the rotating shaft. A guiding groove is disposed to partially overlap a swing range of the movable member when viewed in an axial direction of the rotating shaft, and the switching member is moved inside the guiding groove in a longitudinal direction of the movable member. The switching member can set one of a single-shot position and a continuous-shot position, wherein the single-shot position is where the movable member is movable between the first position and the second position, and the continuous-shot position is where the movable member is fixed to the second position.
According to yet another feature of the invention, in the single-shot driving mode, if the trigger is operated after the push lever is pressed against the driven material, the movable member moves from the first position to the second position due to contact with the push lever to be able to move the plunger of the first switch. On the other hand, if the trigger is operated before the push lever is pressed against the driven member, because the movable member and the push lever are in a non-contact state, the movable member remains at the first position and is not able to move the plunger of the first switch. In addition, when the fastener is driven in the single-shot driving mode, the movable member and the push lever are released from a contact state by releasing the push lever from a state of being pressed against the driven material, and the movable member returns to the first position from the second position by a force of an urging spring.
According to the invention, the driving switching mechanism is disposed on the trigger side. Thus, the configurations of the push lever mechanism, the push valve on the second switch side, and so on can be simplified to facilitate the disassembly or assembly work. Moreover, the driving switching mechanism is disposed on the trigger side, particularly, on the trigger lever. Therefore, the device main body can be made compact to achieve a driving machine that is easy to use. The aforementioned and other novel features of the invention can be understood through the description of the specification and the figures below.
Hereinafter, embodiments of applying the invention to a nail driving machine that uses a compressed air system as the driving source are described with reference to the figures. In all the figures for illustration of the embodiments, members having the same function are assigned with the same reference numerals and the repeated descriptions will be omitted. Moreover, in the following embodiments, for convenience, the vertical and horizontal directions are defined as shown in the figures based on a state where the driving machine is disposed to make the direction in which the fastener is driven vertically downward. Nevertheless, the actual direction of driving nails may be the horizontal direction or other directions.
The magazine 80 is disposed in a manner that the longitudinal direction thereof (feeding direction) is slightly oblique with respect to the ejection direction, and is disposed in a manner that an end on a nail discharge side is attached to the nose member 4 and an end on a nail supply side is on a side away from the nose member 4 and located rearward and obliquely upward with respect to the handle part 2b. The magazine 80 feeds nails (not shown) connected by a tensile force of a spiral spring (not shown) to the side of the nose member 4. The figure illustrates a state where a feeder knob 83 is pulled to a position near the rear end of the magazine 80 in the feeding direction.
A push lever 40 is disposed at a front end of the nose member 4. The push lever 40 is a movable mechanism that is movable in a predetermined range in the same direction as the ejection direction and the opposite direction with respect to the nose member 4, and moves upward in response to an operation of pressing the front end of the nose member 4 against the driven material. By two operations, i.e., the condition where a front end member 41 that constitutes the push lever 40 is pressed against an object (the driven material) into which the nail is to be driven and the pulling of a trigger lever 11, the operator is able to activate the striking driving element that generates the reciprocating motion to drive the nail.
A trigger 10 is disposed on the lower side near a base of the handle part 2b toward the body part 2a. A guard member 45 made of a synthetic resin for covering a movable portion of the push lever 40 is disposed near the lower side of the trigger 10 on the side of the body part 2a.
Inside the driving machine 1, a cylindrical cylinder 50, a piston 8 that is capable of sliding (reciprocating) up and down in the cylinder 50, and a driver blade 9 connected to the piston 8 are disposed. The driver blade 9 is for striking a fastener, such as a nail, and is disposed to extend downward from the lower end side of the cylindrical cylinder 50. The driver blade 9 may be manufactured integrally with the piston 8 or separately.
The cylinder 50 is slightly movable in the downward direction by the force of the compressed air and slidably supports the piston 8 on the inner surface. A return air chamber 55 that accumulates compressed air for returning the driver blade 9 to a top dead center is formed on a lower outer periphery of the cylinder 50. A plurality of air holes 51 are formed in an axial center portion of the cylinder 50, and a check valve 52 is provided there. The air holes 51 allow the compressed air to flow in only one direction from the inner side of the cylinder 50 to the return air chamber 55 on the outer side. Moreover, an air passage 53 that is constantly open to the return air chamber 55 is formed on the lower side of the cylinder 50. A piston bumper 57 is disposed at the lower end of the cylinder 50. The piston bumper 57 has a through hole in the center, into which the driver blade 9 is inserted. The piston bumper 57 is composed of an elastic body, such as rubber, for absorbing the excess energy of the rapid downward movement of the piston 8 after nail driving.
The piston 8 is disposed to be vertically slidable in the cylinder 50. The driver blade 9 is formed integrally with the piston 8 so as to extend downward from the approximate center of the lower surface of the piston 8. Thus, the inside of the cylinder 50 is divided into a piston upper chamber 7a and a piston lower chamber 7b by the piston 8. The upper chamber 7a of the piston 8 is formed under a head cap 69, which abuts on the upper end of the cylinder 50. The head cap 69 is disposed on the lower side of a valve holding member 70. A spring 54 that urges the cylinder 50 downward is disposed on the outer periphery of the cylinder 50.
At the time of driving, when a first switch 20 and a second switch 30 are turned on by an operation of the trigger 10, high pressure air flows into a space 67 from the accumulation chamber 61 and moves an exhaust valve 68 to the lower side to close an opening 70a of the valve holding member 70 so as to close an air passage 66 that communicates the piston upper chamber 7a with the atmosphere. Simultaneously, when the first switch 20 and the second switch 30 are turned on, the high pressure air from the accumulation chamber 61 is also supplied to a main valve chamber 56. Thus, the pressure on the upper surface of a flange portion 50a of the cylinder 50 rises rapidly and the cylinder 50 moves slightly to the lower side in the ejection direction against the force of the spring 54 that holds the cylinder 50 while urging the cylinder 50 upward. Then, since the upper opening of the cylinder 50 and the head cap 69 are separated and form a gap, the compressed air flows from the accumulation chamber 61 into the piston upper chamber 7a at once. The inflow of the compressed air causes the piston 8 and the driver blade 9 to move down rapidly, and the driver blade 9 slides in an ejection passage 4b to drive the nail (not shown) that has been fed into the ejection passage 4b to the driven material.
The nose member 4 guides the nail (not shown) and the driver blade 9 such that the driver blade 9 is in proper contact with the nail to be able to drive the nail into a desired position of the driven material. The nose member 4 includes a cylindrical portion 4a that has therein the ejection passage 4b for guiding the nail and the driver blade 9, and a flange portion 4c that closes the opening at the lower side of the body part 2a. Moreover, the push lever 40 that is vertically movable is disposed along the outer surface of the ejection passage 4b. The ejection passage 4b is formed to extend from the through hole formed in the flange portion 4c at the upper end to an ejection port (not shown) at the lower end, and a feeding port (not shown) for feeding nails from the magazine 80 is provided in the middle of the path.
The magazine 80 is arranged side by side to the handle part 2b. The magazine 80 is loaded with connected nails (not shown) that are connected in a strip. The connected nails are pressed toward the side of the ejection passage 4b by a coil spring or the like mounted in the magazine 80 to be driven one by one into the driven material by the driver blade 9.
The handle part 2b is the portion to be held by the operator. In a connection portion between the handle part 2b and the driving machine 1, as shown enlargedly in
The trigger 10 is a mechanism that is operated directly by the operator, and performs switching between opening and closing of a trigger valve (to be described later) via a trigger plunger 21 of the first switch 20. Here, the trigger 10 is pivotally supported by the housing 2 to be swingable by a predetermined angle around a swing shaft 12. Nevertheless, the trigger 10 may also be a slide type trigger that moves in parallel to the vertical direction or may use other movable members to operate the trigger plunger 21.
The second switch 30 includes a push lever valve (to be described later) that allows or blocks flow of compressed air from the first switch 20 to the main valve chamber 56 by the push lever 40. The push lever 40 is movable in the direction of the arrow 48. Movement of the front end member 41 of the push lever 40 indicated by the arrow 48 is transmitted as vertical movement of a push lever plunger 31 on the side of the second switch 30 via a connection arm 42. The push lever 40 includes the front end member 41, the connection arm 42, a connection member 43, and a sleeve 44. These may be separate components, or part of or all of these components may be formed integrally. In addition, regarding the configuration of the push lever 40, some components may be omitted or other components may be added as long as the second switch 30 can be operated when the nose member 4 is pressed against the driven material. When the main body of the driving machine 1 is pressed against the driven material and causes the push lever 40 to move to a retracted position, i.e., the front end 41a is at a top dead center position, the second switch 30 allows the compressed air to flow from the side of the first switch 20 to the side of the main valve chamber 56. When the push lever 40 is at a normal position (a bottom dead center position), the second switch 30 is in a blocking state.
Next, operations of the first switch 20 and the second switch 30 are described with reference to
The first switch 20 mainly includes a substantially cylindrical trigger bush 23, the trigger plunger 21 disposed in the trigger bush 23, and a substantially spherical valve member 25. The trigger bush 23 is screwed into a female screw formed in the cylindrical hole 2c by a male screw 23b that is formed on the outer peripheral side near the lower side. A packing 29 is interposed in the upper end portion of the trigger bush 23. The valve member 25 is housed in a first valve chamber 26 that communicates with the accumulation chamber 61 and the air passage 58, and blocks or opens the passage of air by opening or closing a stepped opening 24 formed on an inner diameter portion of the substantially cylindrical trigger bush 23. The opening 24 is an edge of a step portion that opens downward from the first valve chamber 26. The opening 24 has a diameter smaller than a diameter of the valve member 25. The valve member 25 is constantly urged, as indicated by the arrow 62, by the force of the compressed air from the side of the accumulation chamber 61. Accordingly, when the valve member 25 receives the downward pressure caused by the pressure of the compressed air in the accumulation chamber 61 via a through hole 27, the valve member 25 is engaged with the opening 24 and the first valve chamber 26 is closed. That is, the first switch 20 becomes a closed state (OFF).
The trigger plunger 21 is held to be movable vertically below the valve member 25. A front end part 21c of the trigger plunger 21 is a working piece for moving the valve member 25. A cross part 21b is formed near the center and a cross-sectional shape of the cross part 21b perpendicular to the axial direction is substantially cross-shaped, and since there exist a cylindrical inner wall portion of the trigger plunger 21 and a predetermined space, air is allowed to flow in the axial direction. Thus, when the opening 24 is opened, the air flows in the axial direction of the trigger plunger 21 to be discharged to the side of the air passage 58 from an opening 28. When the lower end of the trigger plunger 21 is pressed upward by the trigger 10 (refer to
The second switch 30 mainly includes the substantially cylindrical push lever plunger 31 that is press-fitted into the cylindrical hole 2d, the push lever valve 34 disposed in the push lever plunger 31, and a coiled plunger spring 35 that urges the push lever valve 34 in a predetermined direction. The push lever valve 34 is a valve for switching to block or allow flow of the compressed air from the air passage 58 to the air passage 38 in response to the operation of the push lever 40. A push lever bush 33 extends substantially vertically and has a tubular shape that has a passage therein. The second valve chamber 36 is a cylindrical space that serves as a movement space of the push lever bush 33. A flange-shaped portion of the push lever valve 34 abuts on an opening 37 formed at the upper end of the second value chamber 36 to block the airflow (the state of
The push lever valve 34 moves in the vertical direction to open or close the opening 37 at the upper end of the push lever bush 33. About half of the push lever valve 34 is housed in the space on the upper side of the cylindrical push lever bush 33 and the push lever valve 34 moves to close or open the opening 37. Here, the shape of the push lever valve 34 is illustrated by the perspective view of
One end of the plunger spring 35 is held on the side of the housing 2 and the other end is in contact with the upper surface of the flange portion of the push lever valve 34, so as to urge the push lever valve 34 downward. The push lever plunger 31 moves vertically together with the push lever 40 to move the push lever valve 34. A flange part 31b having a diameter that expands to form a flange shape is formed at the lower end of the push lever plunger 31. A coiled spring 32 is interposed between the upper surface of the flange part 31b and a lower end surface 33b of the push lever bush 33 to urge the push lever plunger 31 downward.
When the trigger 10 is pulled in the state of collaboration with the push lever 40, the compressed air accumulated in the accumulation chamber 61 is supplied to the main valve chamber 56 and the exhaust valve 68 (both refer to
In this embodiment, as a premise, the trigger operation is achieved with use of two switches (valve mechanisms), i.e., the first switch 20 and the second switch 30. A “single-shot driving mode” and a “continuous-shot driving mode” are achieved by devising the configuration of the trigger 10. The “single-shot driving mode” is to drive the fastener every time the trigger 10 is pulled while the “continuous-shot driving mode” is to move the main body of the driving machine 1 vertically to continuously drive the fasteners when the trigger 10 remains to be pulled. In both modes, as long as the push lever 40 is not pressed against the driven material, namely, the push lever 40 is not positioned at the top dead center, the striking operation is not performed.
In the “single-shot driving mode,” after one driving is completed, once the trigger 10 is temporarily released and is set to a trigger-off state, the next driving is not performed unless the trigger lever 11 is pulled again (of course, a requisite condition is the state where the push lever 40 is pressed against the driven material when the next driving operation is performed). In other words, in the state where the operator keeps the trigger 10 pulled without releasing it after completing the first driving, even if the main body of the driving machine 1 is moved to press the push lever 40 against the next driving position of the driven material, the first switch 20 is not set to the ON state. Thus, for the “single-shot driving mode,” it is necessary to release the trigger operation once the driving of one nail is completed.
In the “continuous-shot driving mode,” in the state where the operator keeps the trigger 10 pulled without releasing it after completing the first driving, when the operator moves the main body of the driving machine 1 and presses the push lever 40 against the next driving position of the driven material, the operator can drive the nail at that time. Therefore, in this embodiment, if the operator keeps the trigger 10 pulled without releasing it after completing the driving, the first switch 20 can be maintained in the ON state and flow of the compressed air can be opened and blocked by the side of the second switch 30.
Next, the structure of the trigger 10 is described with reference to
For the trigger 10 of this embodiment, the rotating shaft 14 is disposed within a swing radius of the trigger lever 11, and the trigger arm 13 is disposed to be swingable with a small swing radius from the rotating shaft 14. The direction in which the trigger lever 11 extends from the swing shaft 12 (refer to
The trigger arm 13 is formed with the upper surface 13a and a rear piece 13b. The upper surface 13a is in contact with or is separated from the trigger plunger 21. The rear piece 13b can be pressed by the finger from the rear side so as to rotate the trigger arm 13. Here, although not illustrated in the figure, a spring means may be disposed for urging the trigger arm 13 to move in a predetermined direction, e.g., to the first position of
Hereinafter, a method for switching between the “single-shot driving mode” and the “continuous-shot driving mode” is described with reference to
When the stopper 17 is rotated again in the direction of the arrow 19b from the state of
Next, the operations of the trigger 10, the first switch 20, and the second switch 30 during the driving operation are described with reference to
Next, when the main body of the driving machine 1 is moved and the front end member 41 of the push lever 40 is pressed against the driven material, the connection arm 42 of the push lever 40 moves to the upper side, as indicated by the arrow 76a, and thus the push lever plunger 31 moves the push lever valve 34 upward, by which the opening 37 is opened. Therefore, the compressed air flows in the direction of the arrow 64 and thus the nail can be struck. In this way, even if the trigger lever 11 is pulled first as shown in
When the striking of the nail is carried out, the reaction thereof causes a reaction force to be transmitted to move the driving machine 1 to the side opposite to the driving direction. Therefore, the push lever 40 is separated from the driven material by the reaction force and returns to the state of
Next, the striking method for a situation where the push lever 40 is pressed against the driven material first in the “continuous-shot driving mode” is described with reference to
When the striking of the nail is carried out, the reaction thereof causes a reaction force to be transmitted to move the driving machine 1 to the side opposite to the driving direction. The push lever 40 moves away from the driven material due to the reaction force. Hence, the push lever 40 is moved in the direction of the arrow 76b by the urging force of a spring 46 (refer to
Next, the operation of the “single-shot driving mode” is described with reference to
Next, the striking operation of the “single-shot driving mode” is described with reference to
When the striking of the nail is carried out, the reaction thereof causes a reaction force to be transmitted to move the driving machine 1 to the side opposite to the driving direction. Thus, the push lever 40 moves away from the driven material due to the reaction force. Hence, the push lever 40 is moved in the direction of the arrow 76b by the urging force of the spring 46 (refer to
According to this embodiment, the driving switching mechanism is disposed on the side of the trigger lever 11. Therefore, the configuration of the invention can be easily achieved by only modifying the trigger 10. Moreover, because the driving switching mechanism can be implemented by the trigger arm 13, the change rod 16, and the guiding groove 15, the compact switching mechanism can be achieved with a simple mechanism.
Although the invention has been described above based on the embodiments, the invention should not be construed as limited to the aforementioned embodiments, and various modifications may be made without departing from the spirit of the invention. For example, in the embodiment described above, the driving switching mechanism is achieved by using the swing type trigger arm that is disposed on the rotating shaft 40. However, other types of movable members, such as a slide type movable member, may be used as the trigger arm and the switching mechanism may be disposed thereon. Moreover, the above embodiment illustrates a case of using the compressed air as the striking driving element. Nevertheless, the first switch and the second switch may be implemented by electric switch mechanisms, so as to use a combustion type gas or an electric motor.
Number | Date | Country | Kind |
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2016-012859 | Jan 2016 | JP | national |
This application is a continuation application of and claims priority benefit of a prior application Ser. No. 15/413,421, filed on Jan. 24, 2017, now allowed. The prior application Ser. No. 15/413,421 claims the priority benefit of Japanese Patent Application No. 2016-012859, filed on Jan. 26, 2016. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein and made a part of this specification.
Number | Date | Country | |
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Parent | 15413421 | Jan 2017 | US |
Child | 16798437 | US |