Patent Application
20090242604
The present invention relates generally to fastener-driving tools, and more particularly to a new and improved cap assembly of a fastener-driving tool having a new and improved switch mechanism incorporated therein wherein, for example, the new and improved switch mechanism comprises a two-position switch mechanism whereby when the switch mechanism is disposed at a first one of the two positions, the fastener-driving tool can be operated in a fully automatic continuous firing mode of operation by means of which the fastener-driving tool can continuously fire fasteners into a substrate or workpiece as long as the workpiece contact element is maintained at its engaged or depressed position against the workpiece or substrate, and as long as the trigger mechanism is likewise maintained at its actuated or depressed position, or alternatively, when the switch mechanism is disposed at a second one of the two positions, the fastener-driving tool can be operated in a one-shot firing mode by means of which the fastener-driving tool can only fire a single fastener either in accordance with, for example, a sequential-firing mode of operation or a bump-firing mode of operation. In addition, the new and improved cap assembly also has incorporated therein an adjustment mechanism such that when the switch mechanism is disposed at the first one of its two positions so as to permit the fastener-driving tool to be operated in its fully automatic continuous firing mode of operation, the rate at which the fastener-driving tool can be continuously fired can be adjusted.
Various different types of fastener-driving tools are of course well-known in the art. For example, the fastener-driving tools may be electrically or electronically powered or controlled, combustion-powered, pneumatically powered, or the like. In addition, the fastener-driving tools may effectively incorporate various structure therewithin which permits the fastener-driving tools to be operated in accordance with different firing modes of operation. More particularly, for example, in accordance with a first single-shot firing mode of operation, which is known in the industry and art as a sequential mode of operation, the depression or actuation of the trigger mechanism will not in fact initiate the firing of the tool and the driving of a fastener into a workpiece or substrate unless the workpiece-contacting element is initially depressed against the substrate or workpiece. Considered from a different point of view or perspective, in order to operate the fastener-driving tool in accordance with the sequential mode of operation, the workpiece contacting element must first be depressed against the workpiece or substrate followed by the depression or actuation of the trigger mechanism. Still further, once a fastener has in fact been driven into the workpiece or substrate, further or repeated depression or actuation of the trigger mechanism will not result in the subsequent driving of additional fasteners into the workpiece or substrate unless, and until, the workpiece contacting element is permitted to be effectively reset to its original position and once again disposed in contact with, and pressed against, the workpiece or substrate prior to the depression or actuation of the trigger mechanism each time the tool is to be fired so as to drive a fastener into the work-piece or substrate.
Alternatively, in accordance with a second single-shot firing mode of operation, which is known in the industry and art as a bump-firing mode of operation, the operator initially maintains the trigger mechanism at its depressed position, and subsequently, each time the workpiece contacting element is disposed in contact with, and pressed against, the workpiece or substrate, the tool will fire, thereby driving a fastener into the workpiece or substrate. Still yet further, in accordance with a third fully automatic continuous firing mode of operation, as long as the workpiece contact element is maintained in contact with, and pressed against, the work-piece or substrate, and as long as the trigger mechanism is maintained at its depressed position, the fastener-driving tool will automatically and continuously fire fasteners into the workpiece or substrate. Unfortunately, conventional fastener-driving tools do not have incorporated therewithin a simple mechanism for effectively altering the mode of operation of the fastener-driving tool between, for example, either one of the first or second single-shot firing modes of operation and the third fully automatic continuous firing mode of operation.
A need therefore exists in the art for a new and improved switch mechanism which can be easily incorporated into, for example, the cap structure of a fastener-driving tool, even in a retro-fitted manner, whereby the mode of operation of the fastener-driving tool can be easily, readily, and quickly selected or altered between, for example, a single-shot firing mode of operation and a fully-automatic continuous firing mode of operation.
The foregoing and other objectives are achieved in accordance with the teachings and principles of the present invention through the provision of a fastener-driving tool which is provided with a new and improved cap assembly which has incorporated therein a new and improved switch mechanism which permits the fastener-driving tool to be operated in one of two firing modes of operation. The new and improved switch mechanism comprises a two-position switch mechanism such that when the new and improved switch mechanism is disposed at a first one of its two positions, the fastener-driving tool will be able to operate in a fully automatic continuous firing mode of operation by means of which the fastener-driving tool can continuously fire fasteners into a substrate or workpiece as long as the workpiece contact element is maintained at its engaged or depressed position against the workpiece or substrate, and as long as the trigger mechanism is likewise maintained at its actuated or depressed position, or alternatively, when the new and improved switch mechanism is disposed at a second one of the two positions, the fastener-driving tool can be operated in a one-shot firing mode by means of which the fastener-driving tool can only fire a single fastener either in accordance with, for example, a sequential-firing mode of operation or a bump-firing mode of operation. In addition, the new and improved cap assembly also has incorporated therein an adjustment mechanism such that when the switch mechanism is disposed at the first one of its two positions so as to permit the fastener-driving tool to be operated in its fully automatic continuous firing mode of operation, the rate at which the fastener-driving tool can be continuously fired can be adjusted.
Various other features and attendant advantages of the present invention will be more fully appreciated from the following detailed description when considered in connection with the accompanying drawings in which like reference characters designate like or corresponding parts throughout the several views, and wherein:
Referring now to the drawings, and more particularly to
In addition, it is also seen that, in accordance with the principles and teachings of the present invention, a new and improved cap assembly, generally indicated by the reference character 200, is adapted to be fixedly secured to the upper housing portion 102 by means of, for example, a plurality of suitable bolt fasteners 110, and still further, and likewise in accordance with the principles and teachings of the present invention, a new and improved switch mechanism, generally indicated by the reference character 300, is adapted to be movably disposed within, and with respect to, the new and improved cap assembly 200 in order to selectively determine the particular mode of operation in which the fastener-driving tool 100 is operating, that is, whether or not the fastener-driving tool 100 is being operated in accordance with its fully automatic continuous firing mode of operation by means of which the fastener-driving tool can continuously fire fasteners into a substrate or workpiece as long as the workpiece contact element 112 is maintained at its engaged or depressed position against the workpiece or substrate, and as long as the trigger mechanism 114 is likewise maintained at its actuated or depressed position, or alternatively, whether or not the fastener-driving tool 100 is being operated in accordance with its one-shot firing mode by means of which the fastener-driving tool can only fire a single fastener either in accordance with, for example, a sequential-firing mode of operation or a bump-firing mode of operation.
With reference now being made to
With reference now being specifically made, for example, to
It is to be noted that while the pair of exhaust air signal ports 250 are defined within the cap gasket 216 upon opposite sides of the piston exhaust air port 248, the provision of the pair of exhaust air signal ports 250 is for structurally symmetrical purposes only in that only one of such pair of exhaust air signal ports 250 will actually be fluidically connected to the piston exhaust air signal port 242 defined within the cap member 210. In other words, the cap gasket 216 has been constructed so as to be entirely symmetrical about its longitudinal axis so that regardless of whether it is oriented with its upper surface portion, as viewed in
Continuing still further, and with reference continuing to be made to
With reference lastly being additionally made to
As will become more fully appreciated hereinafter with respect to the operative description of the present invention in connection with, and as illustrated within,
More particularly, with reference still being made to
A first purpose served by means of the cap member 314 is that it effectively serves as a handle by means of which, for example, the tool operator can move the changeover control pin 302 between its leftward and rightward positions. The second purpose served by means of the cap member 314 is that it effectively serves as a stop mechanism in that the cap member 314 will engage an external surface portion of the cap member 210 such that the changeover control pin 302 cannot be moved beyond its leftmost position, defining the single-shot firing mode of operation of the fastener-driving tool 100, and thereby become separated from the cap assembly 200 as a result of effectively being pushed completely through, and out from, the bore 286 defined within the cap assembly 200. In a similar manner, it is also seen that the left external surface portion of the changeover control pin 302 is provided with an outwardly extending or projecting lug 318, and this lug 318 similarly serves as a stop mechanism, as a result of engaging or contacting an interior portion, not shown, of the cap member 210 so as to prevent the tool operator from moving the changeover control pin 302 beyond its rightmost position, defining the fully automatic continuous firing mode of operation of the fastener-driving tool 100, whereby, again, the entire switch mechanism 300 could become separated from the cap assembly 200. Lastly, it is also seen that an external surface portion of the changeover control pin 302, located at a substantially axially central portion thereof, is provided with a cut-out region 320 for a purpose which will be more fully explained hereinafter.
Having described substantially all of the structural components comprising the new and improved cap assembly 200 of the present invention, as well as substantially all of the structural components comprising the new and improved fastener-driving tool mode of operation switch mechanism 200, an operation of the fastener-driving tool 100, when the same is being operated in either its fully automatic continuous firing mode of operation, or in its single-shot firing mode of operation, will now be described as a result of reference being additionally made to
For example, line pressure, supplied to the fastener-driving tool 100 by means of the compressed air line 108 operatively and fluidically connected to the compressed air source, will be supplied to the reservoir port 236 of the cap member 210 through means of the reservoir port 232 defined within the diaphragm member 204, and the trigger port 234 of the cap member 210 through means of the trigger port 230 defined within the diaphragm member 204. It is noted that the line pressure fluidically connected to the trigger port 234 of the cap member 210 would normally tend to flow outwardly through the trigger port 234 to atmosphere, however, since the trigger mechanism of the fastener-driving tool 100 has not as yet been depressed or actuated, such line pressure air cannot actually be exhausted through the trigger port 234, and in fact, since the trigger port 234 defined within the cap member 210 is fluidically connected to the diaphragm control port 238 as a result of the annular space defined between the external peripheral surface portion of the spool valve 254 and the internal peripheral surface portion of the bore 252 defined within the cap member 210, as well as the relative disposition of the annular O-ring members 266, 268 with respect to the trigger port 234 and the diaphragm control port 238, line pressure air will tend to flow through the diaphragm control port 238 of the cap member 210 and toward the diaphragm member 204 so as to pressurize the diaphragm member 204 and move the same downwardly. In addition, it is noted that line pressure will also be supplied to the inside of the tool whereby such line pressure tends to flow within the space defined between the diaphragm member 204 and the rubber gasket 202, and toward the piston cylinder of the fastener-driving tool 100, as schematically illustrated by means of the oppositely oriented arrows A,B within
It is noted, however, that when the various component parts of the fastener-driving tool 100 are disposed at their respective positions as illustrated within
However, when the fastener-driving tool 100 is desired to be fired so as to fire or discharge fasteners outwardly therefrom in accordance with its fully automatic continuous firing mode of operation, and assuming that the workpiece contact element of the fastener-driving tool 100 has been disposed in contact with and depressed against the workpiece or substrate, then when the trigger mechanism of the fastener-driving tool 100 is pulled or depressed, air is exhausted through means of the trigger mechanism and the trigger port 234 defined within the cap member 210 such that the air pressure disposed above the diaphragm member 204 is now effectively reduced or exhausted, it being remembered that the trigger port 234 is in fluidic communication with the diaphragm control port 238 by means of the annular spacing defined between the external peripheral surface portion of the spool valve 254 and the internal peripheral surface portion of the bore 252 defined within the cap 210, as well as a result of the relative disposition of the annular O-ring members 266, 268. Accordingly, since the coil spring member 212 does not exert a sufficiently strong biasing force, by itself, against the diaphragm member 204, so as to maintain the diaphragm member 204 at its lowered or depressed position as has been illustrated within
At the same time that the line pressure, as schematically illustrated by means of the oppositely oriented air flows A,B are actuating the working piston downwardly, such line pressure also begins to flow upwardly through the diaphragm 204, that is, more particularly, through the fluid passageway 208 of the upstanding post 206, and the piston exhaust air port 244 defined within the cap member 210. While some of this line pressure is vented to atmosphere from the piston exhaust air port 244 through means of the V-shaped exhaust passage 246, a portion of such line pressure air is also fluidically conducted upwardly through the piston exhaust air port 248 defined within the cap gasket 216. Continuing further, this portion of the line pressure air is further conducted through the aforenoted passageway, not shown, defined upon the undersurface portion of the cap cover 218 so as to effectively be routed back downwardly toward and through the left one of the air signal ports 250 defined within the cap gasket 216 and thereby, in turn, be fluidically conducted into the piston exhaust air signal port 242 defined within the cap member 210 as can also be seen in
It is also seen that the leftmost end portion of the needle valve 276 is disposed within a stepped-down or radially inwardly diminished portion 290 of the needle valve housing 272, however, sufficient annular space is defined between the leftmost end portion of the needle valve 276 and the stepped-down or radially inwardly diminished portion 290 of the needle valve housing 272 so as to, in effect, permit a control signal, denoted by means of the arrow 292, to be fluidically conducted toward, and there-by act upon, the right end face 294 of the spool valve 254. Part of such control signal air also enters the plenum chamber port 240, and together, the air volumes will act upon the spool valve 254 so as to begin to move the spool valve 254 toward the left so as to ultimately attain the position illustrated within
When the various components of the new and improved cap assembly 200 and the new and improved switch mechanism 300 are then disposed at their respective positions illustrated within
Eventually, however, as the working piston is fully returned to its uppermost original or start position, exhaust air, previously disposed above the working piston and being forced upwardly as a result of the working piston moving through its return stroke, is no longer conducted through the piston exhaust air signal port 242 and the annular space defined between the left end external surface portion of the needle valve 276 and the internal surface portion of the needle valve housing 272, and accordingly, the control signal 292 is no longer generated. Therefore a relatively low pressure region now exists between the left end portion of the needle valve housing 272 and the right end portion of the spool valve 254. In addition, the spool valve 254 has attained its leftmost position, as illustrated within
Lastly, with respect to the operation of the fastener-driving tool 100 in its fully automatic continuous firing mode of operation, depending upon the extent to which the needle valve 276 is threadedly engaged within, or threadedly disengaged from, the needle valve housing 272, the rate of oscillation of the spool valve 254, and therefore, the rate of firing of the fastener-driving tool 100, can be varied. More particularly, it is to be noted that the radially inwardly diminished internal peripheral surface portion 290 of the needle valve housing 272, as well as the external peripheral surface portion of the leftmost end portion 277 of the needle valve 276, are progressively tapered such that when the needle valve 276 is progressively unthreaded with respect to, or out from, the needle valve housing 272, the annular space defined between the radially inwardly diminished internal peripheral surface portion 290 of the needle valve housing 272 and the external peripheral surface portion of the leftmost end portion 277 of the needle valve 276 is progressively increased thereby effectively enhancing the volume, strength, and speed of the control signal 292, and therefore the rate of oscillation of the valve spool 254, whereas, to the contrary, when the needle valve 276 is progressively threaded into the needle valve housing 272, the annular space defined between the radially inwardly diminished internal peripheral surface portion 290 of the needle valve housing 272 and the external peripheral surface portion of the leftmost end portion 277 of the needle valve 276 is progressively decreased thereby effectively diminishing the volume, strength, and speed of the control signal 292 and the rate of oscillation of the valve spool 254. These relatively faster and slower adjustment modes are also schematically illustrated within
Lastly, when it is desired to operate the fastener-driving tool 100 in its single-shot firing mode of operation, the changeover control pin 302 of the new and improved switch mechanism 300 is moved in the direction extending from the lower right as viewed within
However, as the working piston tends to move back upwardly and generate the control signal 292 through the piston exhaust air signal port 242, as has been previously noted, since the left end portion 296 of the spool valve 254 is no longer effectively aligned with the cut-out region 320 of the changeover control pin 302, but, to the contrary, is effectively aligned with, and will contact, the solid portion 322 of the changeover control pin 302, any control signal generated through means of the air signal port 242 will not have any significant impact upon the spool valve 254, that is, such control signal will not move the valve spool 254 toward the left since spool valve 254 cannot in fact attain the position illustrated, for example, within
Therefore, in order to effectively recycle the fastener-driving tool 100 in order to permit the fastener-driving tool 100 to undergo another fastener-firing cycle, after the trigger mechanism, for example, has been depressed or actuated so as to fire the fastener-driving tool 100 as a result of the fluid circuitry disclosed within
Thus, it may be seen that in accordance with the principles and teachings of the present invention, there has been provided a fastener-driving tool which is provided with a new and improved cap assembly which has incorporated therein a new and improved switch mechanism which permits the fastener-driving tool to be operated in one of two firing modes of operation. The new and improved switch mechanism comprises a two-position switch mechanism such that when the new and improved switch mechanism is disposed at a first one of its two positions, the fastener-driving tool will be able to operate in a fully automatic continuous firing mode of operation by means of which the fastener-driving tool can continuously fire fasteners into a substrate or workpiece as long as the workpiece contact element is maintained at its engaged or depressed position against the workpiece or substrate, and as long as the trigger mechanism is likewise maintained at its actuated or depressed position, or alternatively, when the new and improved switch mechanism is disposed at a second one of the two positions, the fastener-driving tool can be operated in a one-shot firing mode by means of which the fastener-driving tool can only fire a single fastener either in accordance with, for example, a sequential-firing mode of operation or a bump-firing mode of operation. In addition, the new and improved cap assembly also has incorporated therein an adjustment mechanism such that when the switch mechanism is disposed at the first one of its two positions so as to permit the fastener-driving tool to be operated in its fully automatic continuous firing mode of operation, the rate at which the fastener-driving tool can be continuously fired can be adjusted.
Obviously, many variations and modifications of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.
