MODULAR TOOL FOR DRIVING FASTENERS

Abstract: A modular tool 110) functions to drive nails (N) or staples (S). The tool uses an air motor (11) having a housing (12), and has interchangeable magazines and handle assemblies (16,17) for nails and staples, respectively. The assemblies are selectively attached to the air motor via adapter plate means (13) mounted on the air motor housing.

Description: This invention relates to tools for applying fasteners and more particularly to pneumatic tools for driving such fasteners as staples and nails. In the manufacture of pneumatic stapling and nailing tools, it is typical to provide housings for such tools in the form of integral castings defining the cylinder body and integral handle therefor. Although it is known for the tools to be multi-purpose devices, e.g. as in U.S. 3,871,566, such castings are usually machined and fitted out to provide either a nailer or a stapler, as the case may be. Consequently separate stocks of service parts are held for each type of device notwithstanding that some parts might be made to be interchangeable between each type of device. Typically, though not exclusively, nailers are constructed such that the end of the tool handle remote from the working parts of the device is attached to the magazine, as seen for example in U.S. 3,708,096. The present invention specifically relates to a tool constructed in this manner and comprises an axially displaceable fastener driver which extends from a motor housing to a driving station, the housing containing an air motor operably coupled to the fastener driver, a magazine which delivers fasteners serially to the driving station and a handle supported at its far end by a connection to the magazine. It is characterised in that to enable the tool to selectively drive staples or nails it comprises an assembly of modular parts including the motor housing, the magazine and the handle, each thereof being detachable from the tool and interchangeable with others to suit the selected function of the tool as a staple or a nail driver, the staple and nail magazines being alternatively received and fastened on a common adaptor plate attached to and positioned at the end of the motor housing from which the fastener driver extends, and the respective handles being alternatively received and fastened on a side wall of the motor housing. The modular construction of the tool in accordance with the invention, permits it to be easily disassembled for maintenance, repair, or fastener changeover. The common air motor is provided with a number of unique features combining to produce not only a motive apparatus for a modular fastener tool, but an improved air motor for fastener tools. It will be appreciated that the tool provides these and many other advantages. By way of example, it is only necesary to manufacture one air motor for both staple and nail tools, the tools making use of common and interchangeable parts. This facilitates manufacture, parts inventory and repair. The invention will now be described, by way of example, with reference to the accompanying drawings, in which:- Figure 1 is an exploded, elevational view of a modular fastener tool according to the invention and showing both nailing and stapling components, Figures 2 to 4 are respective cross-sectional views of a feed motor for staple magazine, Figures 3 and 4 further showing details of a top loading staple magazine, Figure 5 is a cross-sectional side view of a nail magazine and follower apparatus according to the invention, Figure 6 is a cross-sectional view taken along lines 6-6 of Figure 5, Figure 7 is a cross-sectional view similar to Figure 6, but showing the following in a loading condition, Figure 8 is a cross-sectional view of a nail magazine taken along lines 8-8 of Figure 6, Figures 9 and 10 are cross-sectional views of the tool of Figure 1, in nailing configuration and showing the unactivated and activated positions thereof, respectively, Figure 11 is an elevation view, taken along lines 11-11 of Figure 9, and showing the access door to the tool's driving station, Figure 12 is a cross-sectional view showing the remote valve of the tool of Figure 9, Figure 13 is an enlarged cross-sectional view of the firing valve of the tool of Figure 1, Figure 14 is a cross-sectional view of the snap-in trigger of the tool of Figure 1, and Figure 15 is a cross-sectional view, taken along lines 15-15 of Figure 14. Turning now to the drawings, there is illustratively shown in Figure 1 a modular tool 10 which includes an air motor 11 (Figures 9 and 10), a motor housing 12, a bottom adapter plate 13, and interchangeable nail and staple magazine and handle assemblies 16 and 17, respectivley. Each handle and magazine assembly 16 and 17 includes a handle and a magazine, as shown, and each handle is provided with a forward plate F-1, F-2, repectively. These plates provide support for respective trigger assemblies, and define as well mounting flanges for attachment of the handle and magazine assemblies to the air motor 11. As such, these plates F-1, F-2 and the noted flanges are preferably integral parts of the respective handles. A safety trigger 14, safety 15 and a remote valve (such as valve 75 used in a nailer) are associated with the magazine and handle assemblies 16 and 17. such a tool 10 is useful, and when outfitted with the nail magazine and handle assembly 16, for driving nails into a surface of materials to be nailed together. Alternatively, modular tool 10 is useful, when outfitted with the stapler magazine and handle assembly 17 for driving staples into a surface or materials to be stapled together. As described, the modular tool 10 utilizes common parts for driving both nails and staples. Specifically, the modular tool 10 utilizes, as common parts, the air motor 11, the air motor housing 12, the adapter plate 13, the safety trigger 14, the safety 15, and the remote valve (such as valve 75). Interchangeable parts, depending on the type of fastener to be driven, include the respective magazine and handle assemblies 16 and 17, which are easily interchangeable with the common elements described above and as will be further described. As noted above, trigger 14, safety 15, and remote valve 75 may be supplied with each magazine and handle assembly, or interchanged therebetween. Air Motor Turning now to a further detailed description of the common components of the modular tool 10 as noted above, it will be appreciated that the air motor 11 includes a cylinder sleeve 25, firing valve 26 and piston 27 as can be clearly seen in Figure 10. The piston 27 is connected to a fastener driver 28 which reciprocates with the driven piston 27 for the purpose of driving fasteners into a surface. The firing valve 26 can be of any suitable type, but preferably is of the type which is described in detail in EP-A-0129351. The air motor 11 further includes a cylinder seal and retainer 29 having an inwardly turned circular flange 30 extending over the annular top end 31 of cylinder sleeve 25. The cylinder sleeve retainer 29 extends radially outwardly to engage the housing 12 and thereby supports the top end 31 of the cylinder sleeve within the housing. Also it will be appreciated that the flange 30, by way of engagement of the top end 31 of the cylinder sleeve 25, retains the cylinder sleeve against upward shifting movement within the housing. It will also be appreciated that the firing valve 26 includes a diverter 32 which serves as a firing valve seal across the top of the cylinder sleeve retainer 29. This prevents pressurized air from entry into the top of the cylinder sleeve 25 above the piston 27 until such time as trigger 14 is manipulated and pressure air above the firing valve 26 is relieved. Such relief permits the diverter 32 to move away from the cylinder sleeve seal and retainer 29 and, in particular, the inwardly turned flange 30 thereof. Thereafter, when the trigger 14 is released, the increased pressure above the firing valve 26 causes it to shift downwardly. The diverter 32 thus engages the flange 30 of the seal and retainer 29. This component acts as a buffer between the top end 31 of the cylinder sleeve 25, and the diverter 32 and prevents cylinder sleeve chipping and consequent leakage. Continuing on with the description of the air motor 11, the cylinder sleeve 25 is provided with a radially outwardly directed bracket 33, provided with an annular seal 34 for sealing an annular pressure chamber 35 from a lower chamber 36 within the housing 12. In this regard, it will be appreciated that the chamber 35 communicates through port 37 in the housing 12 with the handle chamber 38 which is constantly pressurized by means of an air fitting at the end of the handle (not shown). It is this pressure which, when admitted to the top of the cylinder sleeve 25, drives the piston 27 downwardly. The lower end 39 of the cylinder sleeve 25 comprises a smooth cylindrical outer surface 40 having no circumferential grooves therein. Cylindrical surface 40 is provided with a plurality of recesses 41 and with a plurality of ports 42 extending completely through the wall of the cylinder sleeve 25. A flat elastic band 43 is provided with projections 44. These are oriented to extend into the recesses 41, and to prevent axial movement of the band along the cylinder sleeve 25. The elastic band 43 has a reduced thickness portion 45 encircling the cylinder sleeve 25 on the surface 40 and covering the ports 42. This band, being elastic, permits air to exhaust from the ports 42 beneath a descending piston 27. Yet, when no air is being forced outwardly through the ports 42, the band portion 45 closes on the ports and prevents the ingress of air from outside the cylinder sleeve 25 into the cylinder sleeve through the ports. It will be appreciated that the shape of the cylinder sleeve 25 as shown, including the bracket 33, admit of cylinder molds which can be moved axially together for the purpose of molding the cylinder and axially away from each other for releasing the cylinder. Since there are no circumferential grooves required in the cylinder sleeve, it is unnecessary to utilize radially moving molds. Utilization of axially moving molds provides a better casting or parison which retains a round shape and requires either no machining or less machining to insure interior cylinder sleeve roundness. The firing valve used in the air motor 11 is best seen in Figures 9, 10 and 13. The detailed construction of the firing valve is disclosed in EP-A-0129351. In principle, the firing valve includes the diverter 32 which normally sits on the flange 30 atop the cylinder sleeve 25, all as shown in Fig. 9. This situation continues for as long as high pressure air is present in the chamber 47 surrounding the firing valve above the diverter 32 and the seal 48. Such high pressure air is transmitted to the chamber 47 through the pressurized air passageway 49, as will be further described. Once the passageway 49 is vented, the high pressure air in the chamber 47 is released and the valve is subjected to a pressure differential which suddenly lifts the firing valve, including the diverter 32, from the top of the cylinder. This admits the high pressure air in the surrounding chamber 35 over the piston for driving it downwardly. This high pressure air in handle chamber 38 has come through the port 37 into the chamber 35 where the high pressure air is transmitted through the passageways 50 located in the cylinder retainer 29. Once the air passageway 49 is pressurized, however, as by releasing the trigger, there is a pressure differential favoring the downward motion of the firing valve so that the diverter 32 seals off the top of the cylinder, permitting the piston to return. Considering now the details of the firing valve in Fig. 13, it is noted that the firing valve includes the diverter 32, the lower rolling seal 48, the upper rolling seal 51 and firing valve stem 52. A support member 53 is placed over the stem and holds the inward circumferential portion of the seal 48 against the diverter 32. The inward circumferential portions of the rolling seal 51 are held against the member 53 by means of an exhaust valve or firing valve retainer 54. Accordingly, it will be appreciated that the firing valve is a composite made up of a number of different elements which are secured together as noted. In the past, it has been typical to provide the exhaust valve with threads complimentary to threads provided on the firing valve stem whereby the retainer or exhaust valve can be screwed onto the stem for firing valve assembly. In such construction, however, it is necessary to machine threads in both the exhaust valve and the stem and to provide a turning motion of one part relative to the other in the assembly process. As best seen in Fig. 13, there are no threads on the firing valve stem 52 or on the exhaust valve 54. Instead, the exhaust valve 54 is provided with an inwardly tapered collar 55 which may be slotted at various portions around its periphery to provide some resiliency therein. The firing valve stem 52 is itself provided with inwardly turned detents 56 of complimentary shape to the collar or projections 55. The exhaust valve 54, when the firing valve 26 is assembled, is simply placed over the stem 52 and pressed thereon, pressing together all of the previously described components including the seals 48, 51 and the support member 53. The exhaust valve 54 is pressed over the stem 52 until the projections of collar 55 engage in the detents 56, thereby snapping the exhaust valve 54 onto the valve stem 52 in a permanent position, and holding the firing valve components in a permanent position. Further considering the function of the air motor 11, and as previously stated, it will be appreciated that the firing valve 26 remains in its normal position as shown in Fig. 9 for so long as pressure is present in the chamber 47. High pressure air is conducted to the chamber 47 through the passageway 49 provided in the housing 12. This passageway 49 terminates in a port 60 which is located in a position to communicate with a port 61 in a handle 70 of a nailer such as that shown in Figs. 9 and 10. Remote Valve Each of the nailer and stapler configurations use a remote valve which is interchangeable therebetween. Due to the fact they are identical, only the remote valve 75 in the nailer will be described. Remote valve 75 is provided in the handle 70 (or in the handle of a stapler) for the purpose of conducting pressurized air through the ports 61 and 60 and passageway 49 to the chamber 47. Alternately, the remote valve may be actuated to vent to the atmosphere the ports 61, 60, and the passageway 49 together with the chamber 47 to initiate actuation of the firing valve 26 and of the air motor 11. While Figs. 9 and 10 show the general orientation of the remote valve 75, the details of the remote valve are best seen in Fig. 12. The remote valve includes a housing 76, an insert 77 and an actuator stem 78. The housing 76 is provided with grooves 79 and 80, accommodating respective O-rings 81 and 82, surrounding the housing. A plurality of ports 83 are spaced around the housing wall and extend therethrough in an area between the grooves 79 and 80. The lower end of the housing 76 is threaded, as at 84, and thus can be screwed into an opening or bore 85 in a handle 70, for example, of a nailer such as shown in Figs. 9 and 10 (or in the handle of a stapler as at 17 in Fig. 1). The bore 85 extends through the handle into the high pressure air chamber 38. The O-ring seals 81 and 82 serve to seal the housing 76 to the handle 70 within the bore 85, serve to seal off the passageway 86 from the high pressure chamber 38 in the handle 70, and serve to seal against leakage to atmosphere through threaded end 84 of housing 76. Passageway 86 extends through handle 70 and between the remote valve 75 and the air passageway 49, and is connected to such passageway via ports 61 and 60, as noted in Fig. 10. The housing 76 is further provided with a relatively smooth, internal bore 87 which may be slightly stepped as at 88 to provide a seating surface for the insert 77. Apart from this step 88 and the recesses 89 at the upper end of the housing 76, the housing 76 has a relatively smooth interior surface, free from circumferential machined grooves, seats, and the like. Located within the bore 87 is a circumferential spacer 90 which extends around the stem 78. O-ring seals 91 and 92 reside above and below the spacer, also circumferentially around the stem 78. Spacer 90 includes a plurality of ports 93, for passing pressurized air around the stem immediately adjacent the spacer through the ports 83 and to the passageway 86, and alternatively for venting the passageway 86 through the ports 83 and the ports 93, depending on the position of the stem 78, as will be described. The insert 77 has a groove 94 provided with an O-ring seal 95 for sealing the insert to the bore 96, which is a continuation of the bore 87 of the housing 77. The insert also has turned out projections 97, 98 which reside in recesses 89 when the insert 77 is pressed into the bore 96. The insert 77 is provided with a plurality of ports 99 communicating between the chamber 38 of handle 70 and a chamber 100 immediately surrounding the stem 78 internally of the insert. A spring 101 is placed between the stem 78 and the upper end of the insert 77 in order to constantly bias the stem in a direction which is to the left, as viewed in Fig. 12. It will be appreciated that the stem 78 has a plurality of surface discontinuities. For example, the stem 78, as shown in Fig. 12, has either a fluted or a turned down portion 102 at its lower end, and a fluted or turned down portion 103 at its upward end in the area or the spacer 90 and seal 92. It will be appreciated that when the stem 78 is extended by the spring 101 to its downwardmost position, the stem 78 engages the O-ring seal 91 and seals off the chamber 100 surrounding the stem 78 so that no pressurized air can escape along the reduced portion 102 at the lower end of the stem 78. At the same time, it will be appreciated that chamber 100 communicates through the ports 93 and 83 with the passageway 86 leading to the firing valve, as has been described. High pressure is available in the chamber 100 through the ports 99 and the high pressure chamber 38 in the handle 70 of a nailer, for example. When it is desired to drive a fastener, the stem 78 is actuated in a upward direction, or in a direction to the right as viewed in Fig. 12, against the bias of spring 101. This action causes stem portion 104 to move upwardly against O-ring 92 and thereby seals off the chamber 100 from the ports 93. At the same time, stem portion 105 is moved to the right or upwardly and unseats from the seal 91. Any pressurized air present at the ports 93 can be exhausted to atmosphere through the lower portion of the remote valve 75 via the reduced portion 102 of the stem 78. Accordingly, the passageways 86 and 49 are vented, together with chamber 47, through the remote valve 75. This permits the firing valve 26 to quickly lift from the retainer seal 29 of cylinder sleeve 25 for driving of the piston as has been described. It will be appreciated that the internal bores of the housing 76 are relatively smooth and do not require any special machining for valve seating. It will also be appreciated that all sealing within the remote valve 75 occurs as a result of the assembly of the seal 91, the spacer 90, the seal 92 and the insert 77, together with the stem 78 within the housing 76. The insert, and specifically its projections 97 and 98 cooperating with the recesses 89, serve to press the seals 91 and 92 and the spacer 90 together to provide the necessary sealing. Accordingly, it will be appreciated that the remote valve 75, when in its normal condition as shown in Fig. 12, transmits pressurized air in the handle 70 of a pneumatic tool to above the firing valve in order to maintain the tool in an inoperative condition. The remote valve may be actuated to cut off the high pressure air above the firing valve and to vent the chambers above the firing valve in order to actuate the firing valve in the air motor 11 for driving a fastener. Trigger Turning now to a description of the trigger for actuating the remote valve 75, attention is directed to Figs. 9, 10, 14 and 15, wherein a trigger assembly 110 is illustrated. The trigger for each of the nailer and stapler is identical and for purposes of brevity, only the trigger associated with a nailer will be described. The stapler trigger is mounted on plate F-2 just as the nailer is mounted with respect to plate F-1. Trigger assembly 110 includes a manually operable trigger lever 14, a safety interlock lever 112, and a trigger cover or retainer 113. As shown in the drawings, the trigger lever 14 is pivoted at the pin 114 and is biased about pin 114 by the spring 115, as viewed in Fig. 14. A pin 116 is mounted through the trigger lever 14. Safety interlock lever 112 is pivoted to trigger lever 14 by pin 116 and is biased by spring 117, as viewed in Fig. 14. The trigger retainer 113 is provided with latch members on each side thereof. In particular, the trigger retainer 113 includes two upwardly extending legs 119 and 120, each of which have a latching surface 121, as indicated by the hidden lines in Fig. 14. This latch surface 121 is designed for cooperation with the lug 122, also shown in dotted lines in Fig. 14. When the latch surface 121 is positioned above the lug 122 as shown in Fig. 14, the trigger retainer 113 is held at the ends of legs 119, 120 within the forward plate F-1. Retainer 113 also includes a latching surface 123 at the lower end thereof which extends downwardly and is yieldable for cooperation with abutment 124 of forward plate F-1. Thus, the latch surfaces 121 and 123 engage the lug 122 and abutment 124 respectively to secure the retainer 113 in place within the plate F-1. The retainer 113 also includes at the end of each leg an upstanding pin retaining surface 125. Surfaces 125 of the respective legs 119 and 120 serve to engage the respective ends 126 and 127 of pin 114 and retain the pin 114 in place against surfaces 128 and 129, respectively, of the forward plate F-1. As shown in Fig. 15, the forward end of the retainer 113 includes an upstanding lug 130 which is provided with a cam surface 131 thereon. When the trigger retainer 113 is snapped into place, the cam surface 131 engages the forward plate F-1 and causes the lug 130 to move inwardly until it can snap over the abutment 124 where surface 123 is engaged to retain the retainer in place. Returning momentarily to trigger lever 14, it will be appreciated that the trigger lever has two upstanding sides, 132 and 133 (Figs. 14 and 15) through which the pin 116 is mounted. It will also be appreciated that the interlock lever 112 extends between these sides and then drops through the trigger lever 14 at the termination area 134 of the manually engageable surface 135 thereof. The walls or sides 132, 133 are extended to form stop lugs such as at 136 (Fig. 14) to limit clockwise movement of the trigger lever 14. It will be further appreciated that the entire trigger assembly 110 can be easily removed from the tool by means of lifting the lower end 137 of the retainer 113 outwardly from the forward plate F-1. This causes a slight pivoting of the lug 130 by virtue of the engagement of the cam surface 123 on abutment 124 and permits the retainer to be pivoted rearwardly and away from the forward plate F-1. Once the lower end of the retainer 113 clears the forward plate F-1, the surface 121 can be pulled downwardly to clear the lug 122 and the retainer completely removed. This permits the pin 114 to be pulled downwardly and away from the forward plate F-1 over the lugs 122 and thus the entire trigger assembly 110 is easily removable from the tool. This clears an access for the remote valve 75 which can then be easily serviced or replaced as needed. Moreover, it will be appreciated that this permits the same trigger assembly 110 to be utilized for each different type of fastener magazine and handle combination to be used with air motor 11. Safety As perhaps best seen in Figs. 1, 9 and 10, the modular tool 10 is provided with a safety 15 which is identical for both nailer or stapler. Safety 15 comprises a formed wire safety member which extends downwardly from the housing 12 and adapter plate 13. The bottom most end 15a of the safety 15 is extended to such a distance as to project outwardly from the bottom-most area of the back and front plates of the magazines, as will be described. It will be appreciated that the formed wire safety 15 may extend down both sides of the magazine, forming a transverse bight at the lower end 15a (Fig. 11). Also, at the upper end of the safety 15 the formed wire extends upwardly into forward plate F-1 (a F-2 if a stapler is considered) and is held for reciprocal movement therein with the upper end of the safety 15 forming a bight 15b extending in a transverse direction for engagement of the bight with the safety interlock lever 112. Returning to Figs. 9 and 14, it will be appreciated that the when the modular tool 10 is in its at-rest condition, such as shown in Fig. 9, the bottom end 15a of the safety 15 projects below all other structure associated with the tool and thus the upper end or bight 15b is in its lowermost position with respect to the trigger. In this position, even if the trigger lever 14 is manually actuated, the air motor 11 will not function in view of the fact that the interlock lever 112 cannot be moved to the extent required for engagement with the stem 78 of the remote valve 75. Thus, the air motor cannot be operated unless the tool is placed adjacent a surface, such as a surface S (Fig. 10), to be stapled or nailed. When the tool 10 is moved against as surface S, such as shown in Fig. 10, the lower end 15a of the safety 15 engages the surface and is pushed upwardly. This moves the bight 15b upwardly a similar distance to a point where the safety interlock lever 112 is touching or is just below the stem 78. Thereafter, manual actuation of the trigger lever 14 in a counter-clockwise direction serves to further lift the safety interlock lever 112 against the stem 78 and to move the stem 78 up into the remote valve 75, thereby releasing high pressure air from above the firing valve 26 and venting the firing valve through passageway 49 and the remote valve 75 to permit the firing valve 26 to lift off the cylinder seal 29 and thus allowing high pressure air to act against the piston 27, driving it and the driver 28 downwardly to drive a fastener. Drive Station Access Door As previously noted, the modular tool 10 is useful with a number of different fastener magazines and types of fasteners. Nevertheless, each of the fastener magazines is preferably provided with a front plate and a rear plate which define a path for the fastener driver and as well a driving station for each fastener just before it is driven. Each of the magazines also includes an access door to the driving station for the purpose of permitting jam clearance and the like. While it will be appreciated that the shape or size of the access door and its associated latching mechanism may vary according to the respective magazines, each of the access doors must be held positively in place by its associated latching apparatus so as to provide a precisely defined and unchanging driver path and fastener drive station. In this regard, it is has been noted that access doors in the past have either fitted loosely from their inception or wear loose. An access door and a latching apparatus for the tool 10 are provided in each of the respective magazines for securely fastening the access door in a precise position. Any wearing of the latching parts or of the access door is accommodated by the specific latching structure so that the latching apparatus tends to wear in rather than to wear out and become loose. The specific access door and latching mechanism is shown in Figures 9, 10 and 11. In Figure 10, it will be appreciated that the modular tool 10 is shown set up for use as a nailer having a magazine and handle assembly 16 and including a front plate 145 and a back plate 146. The front plate 145 is provided with an access door 147 pivoted by a pin 148 to the front plate. The front plate 145 includes two downwardly depending cam lugs 149 and 150 having tapering surfaces 151 (Fig. 10). The access door 147 is provided with upstanding lugs 152 mounting a pin 153 about which latching lever 154 is pivoted. Latching lever 154 has downwardly turned sides 155 and 156 which are adapted, such as by drilling, to retain the upper bight portion 157 of a resilient spring latching bail 158. Bail 150 has a lower bight portion 159. As will be appreciated from Fig. 10, the upper and lower bight portions have axes which are disposed inwardly toward the access door 147 from the pin or pivot 153 when the latch is closed. Thus, the latch comprises an over-center latch which tends to remain in the locked condition as shown. When it is necessary to open the access door 147, it is only necessary to pull the latching lever 154 downwardly or in a counter-clockwise direction as viewed in Fig. 10, thereby lifting the bight portion 157 and moving it forwardly so as to permit the lower bight portion 159 to be removed from the tapered cam surfaces 151 of the lugs 149 and 150. In Fig. 11, it will be seen that the bight portion 159 extends between the lugs 149 and 150 mounted on the front plate 145 and engages the rear surfaces of the access door 147, maintaining the door closed. When the bight 159 is wedged between the access door 147 and the cam surfaces 151 of the lugs 149 and 150, it will be appreciated that the access door 147 is urged into a closed position. As the bight portion 159 or other components of the latching apparatus wear, the bight portion 159 is simply pulled slightly further inwardly along the tapered surfaces 151, thereby continuing to maintain the access door 147 in a precisely positioned, locked condition. Moreover, it will be appreciated that the resiliency afforded by the curved latch bail 158 maintains a spring tension on the bight portion 159, tending to urge it inwardly and thereby provide a constant spring bias retaining the latch door 147 in a closed position. It will be appreciated that while the access door and latch associated with the modular tool, when set up as a nailer, has been described, the access door and latch for staples, or other types of fasteners as suitable, can be similarly constructed and used. Staple Feed Motor When set up as a stapler utilizing a staple magazine and handle assembly 17 (Fig. 1), a staple feed motor is provided for the purpose of urging staples forwardly to a drive station beneath the driver 28. In this connection, a staple magazine such as at 18 (Fig. 1) includes forward and rearward backing plates 19 and 20, respectively, for attachment to the adapter plate 13 of the housing 12 and defined therebetween a drive station 21 generally disposed as shown. A plurality of staples 22 is urged forwardly by carriage 23 toward such drive stations, the staples being covered by a pivotable staple cover 24 and retained thereby from falling out of the magazine 18. Turning now to Figs. 2-4, the details of the carriage 23 and the drive motor 165 will be described. The staple magazine 18 includes a staple rail 166 on which the staples 22 are disposed for sliding movement in the direction of arrow A as shown in Fig. 2. The carriage 23 includes a U-shaped staple follower or pusher 167 also fitting over the rail 166 for engaging the last staple S-1 in a line of staples 22. Attached to the carriage 23 and more particularly to the follower 167 is a manually operable tab 168 which can be engaged and pulled rearwardly for the purpose of insertion of additional staples into the magazine 18. The magazine 18 may include further guide members 169 and 170, for example, for the purpose of guiding staples on the rail 166 and for the further purpose of structural rigidity of the entire magazine 18. Secured to the carriage 23 by means of a bolt 171 threadably engaged with the body of the tab 168 is the staple feed or drive motor 165. This drive motor includes a pulley 172 surrounding a flat coil spring 173 secured to a post 173a at a spring end 174. The other end of the spring is secured, as at 175, to the pulley 172. A cable 176 is secured to a forward end of the magazine and is wrapped about the pulley in groove 177. When the tab 168 is engaged and pulled rearwardly, the pulley unwinds as a result of its attachment to the cable 176 as the pulley moves rearwardly. Such unwinding tends to coil up or tighten the flat spring 173. Thereafter, staples are loaded on rail 166 and the carriage is released to engage the last staple S-1 in a line of staples 22, thereby urging the entire group of staples forwardly toward the drive station 21. This particular construction of a feed motor eliminates the winding and unwinding of the heretofore used flat constant force spring which, due to its extension from a spring housing, was constantly being subject to the elements and the ambient environment of the stapler. Utilization of the pulley 172 secured to the carriage 23 and surrounding the motive spring maintains the drive in a cleaner and more smoothly functioning condition. Also, all of the drive elements can be mounted to the side of the magazine rather than on the top thereof to provide for top loading of staples onto the rail 166. Top Load Staple Magazine The specific details of the top loading staple magazine 18 are best seen in Figures 1 to 4. Magazine 18 is provided with a pivotable cover 24, rotatably pinned at a rear end of magazine 18 at pin 202 (Figs. 3 and 4). The forward end of cover 24 is similarly and coaxially pinned to magazine 18 at a forward end thereof, such pin, however, not appearing in the drawings. A spring 203 urges cover 24 in a counter-clockwise direction as viewed in Fig. 3. Cover 24 includes a side portion 204 and a top portion 205. When the cover is in its normally closed condition, portion 205 covers at least a portion of rail 166 and prevents any staples from moving off the rail, even when the tool 10 is turned upside down. Side portion 204 of cover 24 is generally straight in a direction from a forward end of the magazine rearwardly. Near the rear end of magazine 18, however, side portion 204 tapers inwardly, as at 206, toward rail 166. In Fig. 3, it will be appreciated that side portion 204 of cover 24 is sufficiently spaced from the follower motor pulley 172 so that the follower apparatus may freely move along rail 166. When it is desired to load additional staples onto rail 166, tab 168 is manually grasped and pulled rearwardly. This moves pulley 172 rearwardly where it engages inwardly tapered portion 206 of cover 24 and cams the entire cover outwardly to a piston P, as shown in the dotted lines of Fig. 3. In this position, top portion 205 of cover 24 is moved to the side of rail 166, and adequate clearance is provided for placing additional staples on rail 166. Once this is completed, follower 167 (Figs. 2 and 4) is released to push the staples on rail 166 in a forward direction. When pulley 172 clears tapered portions 206 of cover 24, the cover is spring biased back into operative position as shown in solid lines in Fig. 3. As shown in Fig. 1, a follower catch slot 207 is provided in rail 166 at a rearward end thereof. When the follower is pulled rearwardly for loading, and to a position where cover 24 is cammed open, element 208 of the follower apparatus can be urged upwardly into slot 207, thus holding the entire follower apparatus rearwardly, and cover 24 cammed open, for loading. Thereafter, tab 168 is pushed downwardly, element 208 clears slot 207, and the follower 167 engages the rearwardmost of the newly loaded staples on rail 166. At the same time, pulley 172 clears tapered portion 206 of cover 24, permitting the cover 102 to close. Accordingly, a top loading magazine is provided from which staples cannot inadvertently fall even when the tool 10 is operated in an inverted position. Nailer Magazine and Follower Details of the nail magazine 16a and nail follower apparatus are best seen in Figs. 1 and 5-8. Magazine 16a includes a nail magazine body 220 defining an elongated nail receptacle or nail path 221 for receiving and guiding a strip N of nail fasteners (Fig. 5) having a rearwardmost nail N-1. Nail strip N may be any commonly known pre-assembled, temporarily integral strip of nails as is well known in the industry. Path 221 is open at its forward end 222 and is in communication with drive station 219, similar to drive station 21 of the staple tool described herein, excepting of the appropriate configuration for nails as opposed to staples. Drive station 219 is defined by front plate 145 and rear plate 146 of magazine 16a. A drive station access door 147 is also provided having a latch means like that described above with respect to the staple magazine. Path 221 is also open at its rearward end 223 for receiving a strip of nails therein for loading. Body 220 is operatively associated with and connected to frame 224 for connection to handle 70, the frame 224 also provides guide or support structure for the nail follower apparatus to be described. In Fig. 5, a follower 230 has mounted thereto a follower blade 231. Tabs 232 and 233 on follower 230 can be grasped to pull blade 231 rearwardly for loading. Follower 230 includes top guides 234 and 235 disposed in sliding relationship with frame 224 to guide follower 230 in reciprocal directions back and forth along body 220. Follower 230 also includes side guides 236, 237 slidably engaging outer sides of body 220 to assist in slidably mounting follower 230 on magazine 16a. Guides 234-237 may be integrally formed with tabs 232, 233 to form an integral follower 230. Blade 231 is mounted to follower 230 for movement therewith within nail path 221. In addition, blade 231 is mounted to follower 230 for transverse movement as best seen in Figs. 6 and 7. A screw 240 is threaded to blade 231 and is spring loaded by spring 241 against side guide 236. Spring 241 normally urges blade 231 against the side of path 221 and to the top as viewed in Figs. 6 and 7. Screw 240 thus mounts the blade 231 to the follower 230. Also, blade 231 is provided with transversely extending projections 244 and 245 which extend outwardly from magazine body 220 and slidably between frame 224 and body 220 (Figs. 6 and 7) to serve as blade guides. A recess 242 is provided in magazine body 220 and a slot 243 is provided in frame 224. Recess 242 and slot 243 are disposed, generally, near rearward end 223 of the magazine 16a, and accommodate portions of the blade 231 when it is pulled rearwardly for nail loading, as will now be described. In use, follower 230 is attached to a constant force spring 247 housed in housing 246 (Fig. 1) for pulling follower 230 forwardly and against last nail N-1 of a strip N of nails. This biases nails serially into the drive station 219. When it is desired to load additional nails, tabs 232, 233 are grasped and the follower 230, together with blade 231, is pulled rearwardly. Blade 231 blocks nail path 221 until the blade 231 moves rearwardly to a point adjacent recess 242 and the blade portion supporting projections 244 and 245 is adjacent slot 243. At this point, spring 241 urges the blade 231 into recess 242. The portions of blade 231 supporting projections 244, 245 fall sideways into slot 243. In this position, transversely removed from path 221, the follower blade 231 does not block the rear end of path 221 and a strip N of nails can be loaded from the rear end 223 of magazine 16a into the recess or path 221 and past blade 231. Once the strip N of nails is loaded, screw 240 is pushed inwardly to release blade 231 from recess 242 and slot 243. The follower 230, with blade 231 now in path 221, moves forwardly with blade 231 engaging the last nail N-1 to push the entire nail strip N forwardly to drive station 219 where the nails can be serially driven. Also, it will be appreciated that the blade 231 positively engages and holds the last nail N-1 in the drive station 219. There are no transverse recesses for blade 231 at the drive station 219 and thus the last nail is positively held, with no chance of tilting or falling backwards along path 221 in the magazine. At the same time, the rearward transverse recess 242 and slot 243 receives blade 231 to clear path 221 for loading. Accordingly, nails can be loaded from the rear end of magazine 16a without removal of the follower rearwardly from the magazine. Modular Tool Returning now to the modular aspects of the tool 10, it will be appreciated that each of the magazines and handle assemblies 16 and 17 are easily and interchangeably secured to the housing 12 by means of the adapter plate 13 and respective forward plates F-1, F-2. Specifically, the adapter plate 13 further includes a depending lug 185 and provides means by which the front and back plate of a magazine, such as the front plate 145 and the back plate 146 of a nailing magazine as shown in Fig. 10, can be secured to the bottom of a housing 12 in the adapter plate 13 by means of the bolt 186. The upper ends of the front and back plates 145, 146 extend upwardly into the adapter plate 13 for rigidity purposes. Also, it will be appreciated that the handles for the respective magazines, such as the handle 70 as shown in Figs. 9 and 10, are secured to the housing 12 by any appropriate means such as bolts (not shown) extending into the housing casting from the flanges of plates F-1 or F-2. In this regard, it will be appreciated that the handle 70 provides a stop abutment 188 (Fig. 14) for engagement by the stop lug 136 of the trigger lever 14. The handle for the staple magazine and for the magazines of any other fasteners are similarly constructed so as to be easily attachable to the housing 12, the remote valves 75 being supplied with each handle but also being interchangeable as between the respective handles. It will also be appreciated with respect to the nailing magazine and handle assembly 16 that the nail magazine extends upwardly from the horizontal in the range of 30°to 45°, while the handle extends upwardly in the approximate range of 5° to 20° from the horizontal, i.e., from the perpendicular to the drive axis as defined by the fastener driver 28 and the axis of the cylinder sleeve 25 of the air motor 11. At the same time, it will be appreciated that the handle and magazine of the staple assembly 17 extend approximately perpendicularly to the drive axis as defined by the fastener driver 28 and the longitudinal axis of the cylinder sleeve 25. Accordingly, it will be appreciated that the modular tool 10 provides a tool for the driving of the nails or staples for other types of fasteners without the loss of the particular configurations of the handles and magazines for nailing or stapling, respectively, while at the same time providing a secure safety together with a large number of interchangeable parts which are utilized for the modular tool 10, irrespective of whether set up to drive nails or staples. It will be understood by any one skilled in the art that, in use, tool 10 can assume any orientation. Thus, terms such as upper, lower, downwardly, upward, and the like, are used in association with the accompanying figures solely for purposes of clarity of description.

Claims: A pneumatic tool for driving fasteners comprising an axially displaceable fastener driver which extends from a motor housing to a driving station, the housing containing an air motor operably coupled to the fastener driver, a magazine which delivers fasteners serially to the driving station and a handle supported at its far end by a connection to the magazine, characterised in that to enable the tool to selectively drive staples or nails it comprises an assembly of modular parts including the motor housing (11), magazine (16a) and the handle (70), the magazine and handle being detachable from the tool and interchangeable with others to suit the selected function of the tool as a staple or a nail driver, the staple and nail magazines (16a or 17) being alternatively received and fastened on a common adaptor plate (13) attached to and positioned at the end of the motor housing (11) from which the fastener driver (28) extends, and the respective handles (70) being alternatively received and fastened on a side wall of the motor housing. A modular pneumatic tool as in Claim 1 wherein the front of each magazine is constituted by a front plate (145) and a back plate (146) and the adaptor plate has a depending lug (185) to which the said back plate (146) is secured. A modular pneumatic tool according to Claim 2 wherein the back plate of the nail magazine is weldless. A modular pneumatic tool according to any preceding claim wherein each handle is furnished at the forward end with a mounting plate (F1 or F2)which is detachably received on the motor housing side wall. A modular pneumatic tool according to Claim 4 wherein each handle mounting plate is provided with a recess (Fig. 14) configured for operatively receiving, and yieldably releasing, a trigger (14) for operating the air motor. A modular pneumatic tool according to any preceding claim wherein the motor has an operating cylinder defined by a sleeve (25), a sleeve retainer means (29) encircling the upper end of the sleeve having a flange (30) disposed over the sleeve's top annular edge (31) and a firing valve (26) co-operating with the sleeve retainer means for selectively sealing the upper end of the cylinder and for admitting pressurised air thereto. A modular pneumatic tool according to Claim 6 wherein the cylinder (25) has exhaust ports (42) in a lower area thereof including check valve means (40, 41, 43) for permitting passage of air out of the cylinder through the exhaust ports but preventing ingress of air into the cylinder through the ports, the check valve means comprising a smooth cylindrical portion of the sleeve external wall (40) defining the ports, recesses (41) disposed in the external wall proximate the ports, and a flat elastic band (43) encircling the sleeve and having inward projections (44) disposed within the recesses, the band covering the ports for sealing same against the ingress of air and being movable in an outward direction to permit egress of air from the cylinder, the projection retaining the band axially on the sleeve wall. A modular pneumatic tool according to Claim 6 or Claim 7 wherein the firing valve includes a firing stem (52) and an exhaust valve (54) secured to the stem, the exhaust valve and the stem having respective co-operating recesses (56) and yieldable projections (55), and providing an axial snap-together connection preventing axial movement of the exhaust valve relative the stem. A modular pneumatic tool according to any of Claims 6, 7 or 8 wherein the sleeve retainer means (29) extends radially between the cylinder and the motor housing and secures the sleeve (25) from movement toward the firing valve (26). A modular pneumatic tool according to Claim 5 or any claim appendant thereto wherein said trigger (110) comprises a trigger retainer member (113) yieldably snapped into the said recess, a trigger lever (14) pivoted at a forward end thereof to a support member (114), and a safety interlock lever (112) pivoted at a rearward end thereof to a rearward end of the trigger lever (14) and for engaging a movable control stem (78) of a remote pneumatic control valve (75) of the tool for actuation of the air motor (11). A modular pneumatic tool according to Claim 10 comprising a remote valve (75) for actuating the air motor (11), said valve operatively co-operating with said trigger and the valve having a housing (76), a valve insert (77), a valve stem (78), first integral means (91, 92) for sealing the stem to the housing, second integral means (95) for sealing the insert to the housing, and third integral means (80, 81) for sealing the housing to the tool. A modular pneumatic tool according to Claim 11 wherein a respective remote control valve (75) is housed in each handle, being operatively connected through air passageways (61, 60 & 49) to the air motor when the handle in which it is disposed is mounted on the tool. A modular pneumatic tool as claimed in Claim 11 or Claim 12 wherein the first integral sealing means of said remote valve (75) includes at least one O-ring (91, 92) and a spacer (90) engaging the O-ring, the O-ring being captured between the stem (78) and the housing (76) and between the spacer (90) and the housing (76). A modular pneumatic tool as claimed in Claim 13 wherein the spacer (90) is ported (see 93) to pass pressurised air from a position around the stem, through the spacer and into the tool for controlling the remote valve. A modular pneumatic tool as claimed in either Claim 13 or Claim 14 wherein the insert (77) is a press fit into the housing and compresses the first integral sealing means (91 , 92) against the housing, spacer and stem. A modular pneumatic tool according to any one of Claims 13, 14 or 15 wherein the housing (76) defines a smooth cylindrical interior surface adjacent the first integral sealing means and the spacer. A modular pneumatic tool according to any preceding claim wherein the fastener magazine (16a, 18) has an access door (147) pivotally mounted in the front plate for providing access, and latch means (154, 158) for releasably securing the access door in a closed position, the latch means comprising a latch lever (154), a bail (158) mounted on the lever for over-centre latching, the bail having a bight portion (159) and tapered bight receiving recesses (149, 150) mounted to the front plate adjacent the access door, the bight portion extending across the door and into the tapered recesses and wedging between the door and the tapered recess for securing the door in a closed position. A modular pneumatic tool according to Claim 17 wherein the fastener magazine has a fastener feed motor (165) for driving a fastener follower (167), the motor including pulley means including a rotatable pulley (172), a cable (176) wrapped about the pulley and secured at at least one end onto a stationary portion of the tool, and a coiled spring (173) in the pulley for urging rotation of the pulley to drive the follower. A modular pneumatic tool according to Claim 17 or Claim 18 wherein the staple magazine (18) has a fastener slide rail (166) for receiving staples therein, a staple cover (24) over the slide rail, the cover being pivoted at one side to the staple magazine along an axis extending along a bottom portion of the magazine, and cam means engaging the cover (24) pivoting same outwardly and exposing the slide rail for loading staples onto the slide from a position above and along the magazine. A modular pneumatic tool according to Claim 19 wherein the staple cover (24) has an inwardly tapering portion (206) proximate the staple rail, the pulley means (172) engaging the staple cover at the tapering portion, pivoting same outwardly, and exposing the staple slide rail for loading staples onto the slide from a position above and along the magazine when the feed motor (165) is pulled rearwardly for staple loading. A modular pneumatic tool according to Claim 20 further including cam means on the magazine, the cam means engaging the staple cover. A modular pneumatic tool according to Claim 17 having means (220) in the nail magazine defining a nail path (221) into the driving station, and nail follower blade means (231) movable in the path for pushing nails toward and into the driving station, wherein a last nail (n-1) to be driven is positively held in the driving station (219) by the follower blade means (231) disposed in the nail path (221). A modular pneumatic tool according to Claim 22 further including a recess (242) in the nail path at a rear end of the magazine, the follower blade means (231) mounted for transverse movement perpendicular to the nail path wherein the follower blade means is retractable into the recess when positioned at a rear end of the magazine, to permit loading of nails into the magazine, the nail path being generally symmetrical along its length forwardly of the recess into the drive station. A modular pneumatic tool according to Claim 23 wherein a follower (236) is biased outwardly of the nail path (221) and into the recess (242) when adjacent thereto. A modular pneumatic tool according to any of Claims 1 to 17 having nail and staple respective magazine and handle assemblies (16, 17) selectively and interchangeably attachable to the adaptor plate means (13).

Inventors: HAIL, ROBERT JOSEPH, MASSARI, DONALD J., JR.
Applicants: SENCO PRODUCTS, INC
Application year: 1985
Main classification: B25C1
IPC codes: B25C1, B25C5