Fastener-driving tool with improved feeding mechanims

Abstract: A fastener-driving tool (10) comprises a nosepiece (12), a mechanism (14) for driving a fastener (N) from the nosepiece (12) into a workpiece (W), and a mechanism for feeding an elongate strip (S) of collated fasteners (N) , such as nails having heads. An elongate track (60) admits the strip (S) and guides it so that a leading fastener (N′) is positioned to enter the nosepiece (12). A pusher (20) is moveable longitudinally along the track (60) over a range of operative positions, between a retracted position and an advanced position, and laterally between the retracted position and an inoperative position (Figure 7). The pusher (20) is biased longitudinally by a spring (140) so as to push the strip (S) along the track (60) , toward the advanced position, when the pusher (20) is in the range of operative positions. The pusher (20) is biased laterally by a spring (120) toward the inoperative position, in which it can be releasably latched. A button (100) is arranged to be manually depressed to release the pusher (20).

Description: This invention pertains to a fastener-driving tool, such as a nail-driving tool, of a type comprising a nosepiece, a driving mechanism for driving a fastener from the nosepiece into a workpiece, and a mechanism for feeding an elongate strip of collated fasteners so that the fasteners are fed successively into the nosepiece. Fastener-driving tools, such as nail-driving tools or staple-driving tools, may be pneumatically powered or combustion-powered tools. Pneumatically powered tools of the type noted above are exemplified in Howard et al. U.S. Patent No. 4,629,106, Nikolich U.S. Patent No. 4,549,344, Plunkett U.S. Patent No. 4,188,858, and Howard U.S. Patent No. 3,815,475. Combustion-powered tools of the type noted above are exemplified in Nikolich U.S. Patent Re. 32,452, Nikolich U.S. Patents No. 4,522,162, and No. 4,483,474, Wagdy U.S. Patent No. 4,483,473, and Nikolich U.S. Patent No. 4,403,722. Typically, the feeding mechanism of such a tool employs a spring-biased pusher, which must be manually held in a retracted position while an elongate strip of collated fasteners is being loaded into the tool. Such manipulations can be somewhat difficult for a user needing to load such a strip into the tool, particularly if the user is standing on a ladder or in cramped quarters. It would be highly desirable to provide such a tool with an improved mechanism for feeding an elongate strip of collated fasteners so that there would be no need for a pusher to be manually held when such a strip was being loaded into the tool. A spring biassed pusher mechanism is also known for stapling machines, for example those of US-A-3,049,715. This shows an elongate track along which staples are guided to a nosepiece under influence of a spring biassed pusher. The pusher may be laterally displaced to allow further staples to be inserted. According to this invention, a fastener-driving tool comprising a nosepiece, means for driving a fastener from the nosepiece into a workpiece, and means for feeding an elongate strip of collated fasteners including a leading fastener and a trailing fastener in such manner that the fasteners are fed successively into the nosepiece, the feeding means comprises: (a) an elongate track having an inlet end and an outlet end, which communicates with the nosepiece, for admitting the elongate strip into the inlet end with the leading fastener preceding the trailing fastener and for guiding the elongate strip along the elongate track in such manner that the leading fastener is positioned to enter the nosepiece from the outlet end, and (b) a pusher assembly including a support member guided in the elongate track, and adapted to move longitudinally along the elongate track over a range of operative positions, including a retracted position and an advanced position, as well as an inoperative position in which the pusher assembly is displaced so as to permit the elongate strip to be then admitted into the inlet end of the elongate track, the pusher assembly being adapted for pushing the elongate strip along the elongate track when the pusher assembly is in the range of operative positions, (c) a means arranged to bias the pusher assembly longitudinally toward the advanced position, characterised in that the feeding means further comprises (d) means arranged to bias a pusher supported by the support member laterally with respect to the support member to the inoperative position, and in which the elongate track is arranged such that, in the retracted position, the means for laterally biassing the pusher acts to automatically latch the pusher in the inoperative position, and also including unlatching means for moving the pusher laterally against the action of the biassing means into its retracted operative position. Along with the pusher, the feeding mechanism comprises an elongate track and several biasing and latching structures. In a preferred embodiment, which is used with an elongate strip of collated nails, the track has two laterally spaced, inwardly turned flanges, from which the strip is suspended by the nail heads. The pusher is adapted to move longitudinally along the track over a range of operative positions including a retracted position and an advanced position. Also, the pusher is adapted to move laterally between the retracted position and an inoperative position, in which the pusher is displaced to permit such a strip to be then admitted into the inlet end of the elongate track. The pusher is used for pushing the strip along the track when the pusher is in the range of operative positions. Various means are provided respectively for biasing the pusher longitudinally toward the advanced position, for biasing the pusher laterally toward the inoperative position, and for latching the pusher releasably in the inoperative position. In the preferred embodiment, the latching means comprises two vertically spaced edges disposed in fixed relation to the track. When the pusher is in the inoperative position, these edges are disposed to engage the pusher, so as to prevent the pusher from moving longitudinally toward the advanced position. Also, in the preferred embodiment, the latching means comprises a button having a stem mounted fixedly to the pusher so as to extend laterally from the pusher. The button is adapted to be manually depressed to disengage the pusher from the edges and to move the pusher laterally from the inoperative position into the retracted position. The button is moveable longitudinally with the pusher when the pusher is in the range of operative positions. Moreover, in the preferred embodiment, the latching means comprises a sleeve mounted around the button so as to permit lateral movement of the button and the pusher relative to the sleeve. The sleeve is mounted in moveable relation to the elongate track so as to be longitudinally moveable with the button and the pusher. Preferably, the means for biasing the pusher laterally toward the inoperative position comprises a coiled spring mounted operatively between the sleeve and the button and moveable longitudinally with the button, the sleeve, and the pusher. Preferably, the means for biasing the pusher longitudinally toward the advanced position comprises a negator spring having a forward end and a rearward end. The forward end is mounted in fixed relation to the elongate track. The rearward end is mounted operatively to the pusher. A particular embodiment of a fastener-driving tool in accordance with this invention will now be described with reference to the accompanying drawings, in which:- Figure 1 is a perspective view of a combustion-powered, nail-driving tool comprising an improved mechanism for feeding an elongate strip of collated nails having heads. Certain elements of the improved mechanism are shown in an advanced, operative position. Figure 2 is a fragmentary, perspective view showing the same elements in a retracted, inoperative position. Figure 3 is a fragmentary, sectional view taken along line 3-3 of Figure 2, in a direction indicated by arrows. Figure 4, on a larger scale, is a fragmentary, partly broken away, elevational view showing the aforenoted elements in an intermediate, operative position. Figure 5, on the same scale, is a fragmentary, partly broken away, elevational view showing the same elements in the retracted, inoperative position. Figure 6 is a fragmentary, sectional view taken along line 6-6 of Figure 4, in a direction indicated by arrows. Figure 7 is a fragmentary, sectional view taken along line 7-7 of Figure 5, in a direction indicated by arrows. Figure 8 is a fragmentary, sectional view taken along line 8-8 of Figure 6, in a direction indicated by arrows. Figure 9 is a fragmentary, sectional view taken along line 9-9 of Figure 7, in a direction indicated by arrows. As shown in the drawings, a combustion-powered, nail-driving tool 10 constitutes a preferred embodiment of this invention. Broadly, the tool 10 comprises a nosepiece 12, a mechanism including a driver 14 for driving a nail from the nosepiece 12 into a workpiece W when the tool 10 is actuated, and an improved mechanism for feeding an elongate strip S of nails N in such manner that the nails N are fed successively into the nosepiece 12. As shown, the nails N are collated in a known manner by collating tapes T and have D-shaped heads H. The nails N of the strip S include a leading nail N′ and a trailing nail N″. According to this invention, the feeding mechanism comprises a pusher 20, which is can be releasably latched in an inoperative position so as to facilitate loading such a strip of collated nails into the tool. The tool 10 has a housing and handle structure 22 comprising two housing and handle pieces 24, 26, which are assembled by screws 28 and by a metal channel 30 having two inwardly turned flanges 66, 68, that fit into grooves 36, 38, in the respective pieces 24, 26. These pieces 24, 26, may be advantageously molded from an engineering polymer. The piece 24 has a socket 42 accommodating a battery pack 44, which powers an ignition system (not shown) of the tool 10. The tool has switches (not shown) including a head switch, which is actuatable via a workpiece-contacting element 46, and a trigger switch, which is actuatable via a manually actuatable trigger 48. An elongate track 60, which is made from a metal extrusion, is mounted fixedly within the housing and handle structure 22. The track 60 has an inlet end 62 and an outlet end 64, which communicates with the nosepiece 12. The track 60 has two laterally spaced, inwardly turned flanges 66, 68. Near the inlet end 62, the track 60 has a lateral slot 70 in the flange 32 and in adjacent portions of the track 60. The housing and handle structure 22 has an elongate, vertically extending slot 74, which is enlarged at an upper, rear portion 76. The slot 74 is shaped to permit the strip S of collated nails N to be endwise inserted through the slot 74, into the inlet end 62 of the track 60, with the leading nail N′ preceding the trailing nail N″. The enlarged portion 76 of the slot 74 accommodates the nail heads H. As admitted into the inlet end 62 of the track 60, the strip S is suspended from the flanges 66, 68, by the nail heads H and is guided along the track 60 in such manner that the leading nail N′ is positioned to enter the nosepiece 12 from the outlet end 64 of the track 60. The pusher 20 is disposed within the slot 74 and is adapted to move longitudinally through the slot 74, along the track 60, over a range of operative positions including a retracted position and an advanced position. At its upper end 78, the pusher 20 extends between the track flanges 66, 68. Thus, the pusher 20 is adapted to move longitudinally between the retracted and advanced positions, which are operative positions of the pusher 20. Also, the lateral slot 70 in the track 60 permits the pusher 20 to move laterally between the retracted position and an inoperative position, in which the pusher 20 is displaced to permit the strip S of collated nails N to be then admitted into the inlet end 62 of the track 60. As admitted thereinto, the strip S can be then moved along the track 60 until the leading nail N′ reaches a similar strip (not shown) admitted previously or until the leading nail N′ reaches the nosepiece 12, as shown in Figure 4. However, when the pusher 20 is in the range of operative positions, the pusher 20 prevents such a strip from moving inwardly or outwardly past the pusher 20. As explained below, the pusher 20 is biased longitudinally toward the advanced position. Thus, when the pusher 20 is in the range of operative positions, the pusher 20 is biased so as to push the trailing nail N″ of the strip S so as to push the strip S along the track 60, toward the advanced position. As explained below, the pusher 20 is biased laterally toward the inoperative position. Thus, when the pusher 20 is in the retracted position, the pusher 20 moves laterally from the retracted position, as permitted by the track slot 70, into the inoperative position. A latching means is provided, which latches the pusher 20 releasably in the inoperative position. The latching means comprises two vertically spaced, rearwardly facing edges 90, 92, which are defined by the housing and handle piece 26. The edges 90, 92, are disposed in fixed relation to the track 60. As shown in Figures 4 and 7, when the pusher 20 is in the inoperative position, the edges 90, 92, are disposed to engage the pusher 20 so as to prevent the pusher 20 from moving longitudinally toward the advanced position. As shown therein, the edge 90 engages an upper portion 94 of the pusher 20, and the edge 92 engages a lower portion 94 of the pusher 20. Also, the latching means comprises a button 100 having a stem 102, which is integral with the button 100, and which is mounted fixedly to the pusher 20 so as to extend laterally from the pusher 20. The button 100 and the stem 102 may be advantageously molded, in one piece, from an engineering polymer. The stem 102 extends through an elongate slot 104 in the housing and handle piece 26 without binding between the stem 102 and such piece 26. The button 100 is adapted to be manually depressed to disengage the pusher 20 from the edges 90, 92, and so as to move the pusher 20 laterally from the inoperative position into the retracted position, which is an operative position of the pusher 20. Thus, when the pusher 20 is in the range of operative positions, the button is moveable longitudinally with the pusher 20. Moreover, the latching means comprises a sleeve 110, which is mounted around the button 100 so as to permit lateral movement of the button 100 and the pusher 20 relative to the sleeve 110. The sleeve 110 has a non-circular hub 112, through which the stem 102 extends, and which extends through the elongate slot 104 so as to permit longitudinal movement of the sleeve 110 relative to the housing and handle piece 26. Thus, the sleeve 110 is mounted in moveable relation to the elongate track 60 so as to be longitudinally moveable with the button 100 and the pusher 20. A coiled spring 120 is disposed around the stem 102 of the button 100, so as to be axially compressed between an outer, annular surface 118 of the sleeve 100 and an inner, annular surface 122 of the button 100. The spring 120 biases the button 100 so as to bias the pusher 20 laterally toward the inoperative position. Thus, when the pusher 20 is in the retracted position, the spring 120 moves the pusher 20 into the inoperative position, in which the pusher 20 is latched releasably, unless and until the button 100 is depressed so as to permit the pusher 20 to move longitudinally along the elongate track 60 toward the advanced position. As shown in Figures 6 and 7, a tubular element 130 is mounted in parallel relation to the stem 102 of the button 100, around an annular shoulder 132 formed integrally on the pusher 20. The tubular element 130 may be advantageously molded from an engineering polymer. A negator spring 140 is provided, which biases the pusher 20 toward the advanced position. The spring 140 has a forward end 144, which is mounted fixedly to the housing and handle structure 22, near the nosepiece 12, via a pin 144. The spring 140 has a rearward end 146, which is mounted operatively to the pusher 20 by being affixed to the tubular element 130 in such manner that the spring 140 tends to wind around the tubular element 130 as the pusher 20 moves longitudinally toward the advanced position and to unwind as the pusher 20 moves oppositely. The spring 140 can flex sufficiently in lateral directions to accommodate lateral movement of the pusher 20 between the retracted and inoperative positions. The improved mechanism according to this invention is not restricted in its applicability to a nail-driving tool or to a combustion-powered tool. It is contemplated that such a mechanism may be readily adapted to a pneumatically powered, nail-driving tool or to staple-driving tool, which may be pneumatically powered or combustion-powered.

Claims: A fastener-driving tool (10) comprising a nosepiece (12), means (14) for driving a fastener (N) from the nosepiece (12) into a workpiece (W), and means for feeding an elongate strip (S) of collated fasteners including a leading fastener (N') and a trailing fastener (N'') in such manner that the fasteners are fed successively into the nosepiece (12), the feeding means comprising: (a) an elongate track (60) having an inlet end and an outlet end, which communicates with the nosepiece (12), for admitting the elongate strip (S) into the inlet end with the leading fastener (N') preceding the trailing fastener (N'') and for guiding the elongate strip (S) along the elongate track (60) in such manner that the leading fastener (N') is positioned to enter the nosepiece (12) from the outlet end, and (b) a pusher assembly including a support member (110) guided in the elongate track (60), and adapted to move longitudinally along the elongate track (60) over a range of operative positions, including a retracted position and an advanced position, as well as an inoperative position in which the pusher assembly (20) is displaced so as to permit the elongate strip (S) to be then admitted into the inlet end of the elongate track (60), the pusher assembly being adapted for pushing the elongate strip (S) along the elongate track (60) when the pusher assembly (20) is in the range of operative positions, (c) a means (140) arranged to bias the pusher assembly (20) longitudinally toward the advanced position, characterised in that the feeding means further comprises (d) means (120) arranged to bias a pusher (20) supported by the support member (110) laterally with respect to the support member to the inoperative position, and in which the elongate track (60) is arranged such that, in the retracted position, the means (120) for laterally biassing the pusher (20) acts to automatically latch the pusher (20) in the inoperative position, and also including unlatching means for moving the pusher (20) laterally against the action of the biassing means (120) into its retracted operative position. A fastener-driving tool according to claim 1, wherein the unlatching means includes a button (100) mounted fixedly to the pusher (20) and extended laterally from the pusher (20), the button (100) being adapted to be manually depressed to disengage the pusher from the latching means (90, 92) and to move the pusher (20) laterally from the inoperative position into the retracted position, the button (100) being moveable longitudinally with the pusher (20) when the pusher is in the range of operative positions. A fastener-driving tool according to claim 2, wherein the support member includes a sleeve (110) mounted around the button (100) so as to permit lateral movement of the button (100) and the pusher (20) relative to the sleeve (110), the sleeve being mounted in moveable relation to the elongate track (60) so as to be longitudinally moveable with the button (100) and the pusher (20). A fastener-driving tool according to claim 3 wherein the means for biasing the pusher (20) laterally toward the inoperative position includes a coiled spring (120) mounted operatively between the sleeve (110) and the button (100) and moveable longitudinally with the button (100), the sleeve (110), and the pusher (20). A fastener-driving tool according to any one of the preceding claims, wherein the means for biasing the pusher longitudinally toward the advanced position includes a negator spring (140) having a forward end and a rearward end, the forward end being mounted in fixed relation to the elongate track (60), the rearward end being mounted operatively to the pusher (20). A fastener-driving tool according to any one of the preceding claims and adapted for driving nails having heads, wherein the elongate track (60) has two laterally spaced, inwardly turned flanges (66, 68) for suspending the elongate strip (S) of nails from the flanges (66, 68) by their heads.

Inventors: HOWELL SCOTT A, HOWELL, SCOTT A.
Applicants: ILLINOIS TOOL WORKS, ILLINOIS TOOL WORKS INC.
Application year: 1992
Main classification: B25C1
IPC codes: B25C1, B25C5