US2719296A - Magazine latching means for stapling machines - Google Patents

Description

Oct. 4, 1955 H. w. MARANO 2,719,296

MAGAZINE LATCHING MEANS FOR STAPLING MACHINES Original Filed Feb. 17, 1953 3 Sheets-Sheet 1 THE .1.

' lNVENTOR #523527- M M/IE/l/VO ATTORN EY Oct. 4, 1955 H, w, MARANQ MAGAZINE LATCHING MEANS FOR STAPLING MACHINES 3 Sheets-Sheet 2 Original Filed Feb. 17, l955 [NW l NIH]? h. Mnemm ATTORNEY Oct. 4, 1955 H. w. MARANO MAGAZINE LATCHING MEANS FOR STAPLING MACHINES Original Filed Feb. 17, 1953 5 Sheets-Sheet 3 INVENTOR HERBERT M M/rm/va BY 2 ATTORNEY United States Patent O MAGAZINE LATCHING MEANS FOR STAPLING MACHINES Herbert W. Marano, Summit, N. ,L, assignor to- Wilson Jones Company, Chicago, Ill., a corporation of Massachusetts Original application February 17, 1953, Serial ,No. 337,328. Divided and this application December 9, 1953, Serial No. 397,125

11 Claims, (Cl. 1---49) The present invention relates generally to an improved fastener driving device, and it relates in particular to an improved portable, hand-operated device which will drive a single fastener such as a staple, or the like, from a pre-formed cohered strip of such fasteners into wood, cardboard, plastic or other materials. The word staple as herein used will indicate fasteners of that general type.

This application is a division of application Serial No. 337,328, filed February 17, 1953.

Hand-operated stapling machines of the general type with. which the present invention is concerned are widely used, and consist generally of a spring-loaded plunger or ram having a depending staple-driving blade rnovable along a predetermined path, a magazine for holding a strip of staples with the foremost staple in the path of the driving blade, and a hand-operated mechanism for retracting and releasing the spring-loaded plunger whereby to effect the staple driving stroke.

The conventional heavy duty stapling gun of the aforementioned type is a highly inefiicient machine, inflexible, expensive to fabricate, subject to excessive wear, 1. .6 difficult to operate and service. The inefficiency of the conventional gun tacker has been found to be directly attributable to the eccentricity existing between the line. of force of the energy storing plunger driving spring and the line of force exerted by the plunger retracting and spring loading element. The torque imparted to. the plunger as a result of this eccentricity accounts for a m j P t o e e e gy xpe d in a ngv t e vi g spring and is dissipated in frictional losses, which in turn greatly contribute to the excessive wear of the stapling device and demands an expenditure of much more energy on the part of the operator than should be necessary in employing the stapling gun.

Another disadvantage encountered in the conventional gun tacker is its limitation to use with only one size staple, or its limitation within an extremely small range of sizes. The spring loading and actuating mechanism is such that the energy stored in the spring during each driving stroke is normally fixed and unalterable. The gun tacker requires a major conversion in order to readjust or change the amount of energy stored in the driving spring during the stapling cycle. The drawbacks of this construction are readily apparent in view of the fact that it is often desirable toswitch from one size staple to another and to apply the staples to different types of materials. Moreover, the optimum drive applied to the staples varies with the staple size and the material to which they are applied, and conventional devices make no provision for varying readily the driving force. Another undesirable characteristic of the conventional gun' tacker is the tendency of the staples in the magazine to jam. The guide which accommodates the strip of staples has upper confronting walls which are, of necessity, spaced at distance at least as large as the greatest diam.- eter of the wire formingthe staples. Since the diameter of this wire varies, it often happens that the staple strip pusher causes staples of lesser diameter. wire to mount each other and jam the guideway. Increasing the strength of the pusher spring is of no help since it merely further aggravates the jamming.

Typical of the difficulties met in the manufacture of the conventional gun tacker is the fabrication of the staple exit guide. This guide, being subject to the maximum wear and abrasion, must be heat treated for reasonable service. However, since this guide is generally formed integral with the lower channel member of the gun tacker, its proper hardening without disturbing the channel member is a major problem and diflicult of proper attainment without a large percentage of rejects, There are many other drawbacks and disadvantages encountered in the conventional staple gun tacker in spiteof the fact that this device is universally and widely employed, and much efiort has been expended in its development.

It is, therefore, a principal object of the present inven tion to provide an improved fastener driving device.

Another object .of the present invention is to provide an improved portable hand-operated staple gun tacker.

Still another object of the present invention is to provide an improved staple gun tacker requiring a minimum of manual effort in its operation.

A further object of the present invention is to provide an improved staple gun taeker having a staple driving mechanism which is highly efiicient in the transmission of the energy expended by the operator in relation to the driving of the staple.

.Still a further object of the present invention is to provide an. improved staple gun taclcer which is capable of handlingstaples of a large range of sizes.

Another object of the prcsent'invention is to provide an improved staple gun tacl'ger in which the force imparted to the staples may be easily and simply manually adjusted.

Still another object of the present invention is to provide an improved magazine for the strip of cohered staples in which the jamming of the staples is eliminated. A further object of the present invention is to provide an improved staple gun tacker having a staple loading mechanism which permits the rapid and simple insertion of. a strip of staples.

Still a further object of the present invention is to provide an improved staple gun tacker having a novel staple exit channel which greatly facilitates the fabrication thereof. I The above and other objects of the present invention will become apparent from a reading of the following de: scription taken. in conjunction with. the accompanying d w ng whe n Figure 1 is an exploded view illustrating in perspective the. various. components entering into the assembly of an improved staple gun tacker in accordance with the present i enti n;

Figure 2 is a side transverse sectional view of the staple gun tacker in uncocked condition;

Figure 3 is a side transverse sectional view of the forward portion of the staple gun tacker in fully cocked condition immediately preceding the release of the staple driving plunger;

Figure 4 is a side detail view, partially in section and partially broken away, of the staple magazine and opening and loading mechanism illustrated in open position;

Figure 5 is a side elevational view of the improved staple gun tacker. in normal uncooked operative posiion;

Figure 6 isaside elevational view of the tacker showing the handle in the magazine opening position;

Figure 7 is. a sectional view taken along line 77 of A Figure 2 showing the driving force adjusting element in the high energy position;

Figure 8 is a sectional view taken along line 88 of Figure 3 showing the driving force adjusting element'in the low energy position;

Figure 9 is a sectional view taken along line 9--9 of Figure 2;

Figure 10 is a sectional view taken along line 10-10 of Figure 2; and

Figure 11 is a sectional view taken along line 1111 of Figure 2.

A staple gun tacker embodying features of the present invention includes a main body or frame member having an actuating handle hinged to its upper front edge, a staple magazine housing hinged to its lower rear edge and a channel shaped member secured to its front and defining a housing and guide for the staple driving plunger and spring. Slidably supported in the front channel is a plunger or ram having a horizontal shoulder and a depending driving blade which rides along the inner front face of the channel. An energy storing compression spring is confined between the upper face of the ram shoulder and a vertically spaced shelf and urges the plunger to its lowermost or advanced position. The plunger cocking and releasing mechanism comprises a horizontally hinged lifting lever whose free end engages the bottom face of the ram shoulder at a point colinear with the line of force of the ram driving spring, the lever having a longitudinal slot formed therein. A fulcrum is pivotally mounted in the upper part of the frame member and supports at its front end a depending cocking member terminating in a pointed end topped at its forward edge by a recessed portion defining a hook above which the edge inclines rearwardly defining a cam surface. The cocking member registers with the lifting lever slot, the hook normally engaging the front edge of said slot. The rear end of the fulcrum is link-connected to the actuating handle.

A vertically stepped triggering element is slidably supported by the frame in confronting relation to the front edge of the cocking member so that different portions of the trigger may be brought into alignment with the cocking element whereby to trigger the cocking mechanism at preselected points in its stroke and hence impart varying driving forces to the plunger as will be described in detail. A channel shaped staple guide is disposed on the base of the magazine housing and engages a slidable staple pusher which is urged forward by spring means. An elongated staple retaining element is hinged at its rear to the lower portion of the frame at point intermediate the ends of the frame and terminates at its front end in depending rearwardly facing hooks which slide along the base of the magazine housing and may engage tabs projecting laterally from the staple pusher. Spring means urge the staple retainer downwardly whereby to confine the staples stored on the staple guide. The forward side walls of the magazine housing are provided with elevated portions having forwardly directed recesses formed therein which, when the housing is in closed position, are engaged by a latch member consisting of an apertured plate slidably supported in the frame and having laterally projecting locking tabs extending through corresponding slots in the frame side walls. The latch member is spring-urged to the locked position, and the aperture therein registers with the pointed end of the cocking member which, when depressed by the raising of the actuating handle, travels between the front edge of the aperture and a rearwardly disposed stop, urging the latch member to its forward open position and releasing the magazine housing. The magazine housing swings downwardly as does the staple retaining member, the hooked ends of which engage the staple pusher carrying it to its retracted position and facilitating the loading of a strip of staples. Upon closing of the magazine housing, the staples are urged forward so that the foremost staple is brought against the driving blade and into its path upon the cocking of the plunger. An aperture is formed in the front bottom wall of the magazine housing and defines a staple exit opening. A

hardened staple exit channel is positioned above this opening and receives the brunt of the driving cycle.

Reference is now made to the drawings which illustrate a preferred embodiment of the present invention wherein the numerals 12, 12 generally designate a pair of laterally spaced, symmertical side walls having abutting upper and rear inwardly directed flanges 13, and opposing oval shaped openings 14, in which is positioned a finger grip 16 formed of rubber or other suitable material. The side walls 12, which define a supporting frame, have upper and lower projecting portions 17 and 18 respectively, which extend into and between side walls 19 of a front channel member 20 abutting said side walls and are secured thereto by means of the suitable screw and spacer assemblies illustrated, which pass through and are located between corresponding aligned holes formed in the channel side walls 19, and the frame member projections 17 and 18. Hinged to the lower rear corner of the frame member is a bottom magazine housing channel 21, having a pair of rear upwardly directed tabs 22, which embrace the lower rear corners of the side walls 12, and have holes formed therein aligned with corresponding holes formed in the side walls 12, said holes being secured by a suitable post fastener 23. The forward end of channel 21 has a front wall 24, the upper edge of which abuts the front lower edge of the front channel member 20 when the magazine channel is in closed position, and also has a pair of upwardly directed front tabs 26, whose forward edges fit into the confronting lower corner edges of channel 20 when the magazine channel 21 is closed. Also formed in the matching portions of the channel walls 19 and tabs 26, are recesses 27 and 28 respectively which define a continuous slot. A rectangular opening 29 is formed in the front of the bottom wall of the magazine channel 21. An actuating handle 30, having depending laterally spaced side walls 32, is hinged to the frame 12 by means of a post screw assembly 33 passing through holes formed in the front portion of the handle side walls 32 and corresponding openings formed in the frame projections 17 and front channel side walls 19, the front portion of the handle side walls embracing the upper portion of the front channel side walls 19.

A plunger 26 is vertically slidably disposed in the front channel 20, and includes a ram 37 and a depending driving blade 38. The ram 37 is formed of a sheet of metal and has a front wall 39, side walls or gussets 40, a bottom wall 41 formed of the inwardly directed tabs of the front wall 39 and gussets 40, and a rear wall formed of a I further extension of the front wall tab. The tabs forming the ram bottom wall 41 are secured by a centrally located rivet 42. Projecting forwardly from the upper portion of the ram front wall 39 are a pair of horizontally spaced detents 43 which bear against the upper edge of the depending driving blade 38 secured to the ram front wall 39 by suitable rivets 38a. It should be noted that the plunger is guided by a pair of inwardly directed ribs 44 formed in the front wall of channel 20 and the forward vertical edges 46 of the frame wall 12.

Located in the upper end of the channel 20 is a shelf 47 having lateral extensions 48 registering with corresponding slots 49 formed in the upper projecting portions 17, 17 of frame walls 12. Depending centrally from the shelf 47 is a spring-engaging stud having a stepped cylindrical head 50. A pair of concentric helical compression drive springs 50a, 50b are entrapped between the underside of shelf 47 and the upper face of the ram bottom wall 41, urging the plunger 36 to its lowermost or advanced position. The upper ends of the springs 50a, 50b engage the stud stepped head 50, the springs 50a, 50b, the head 50 and the rivet 42 being coaxially disposed. A torsion spring 51, whose arms bear against the cross wall of handle 30 and the upper face of shelf 47, is mounted on the bolt 33 and urges the handle 30 to its normal intermediate position, see Figure 2.

The plunger actuating mechanism includes a lifting lever 52 0f channel shaped cross-section having rearwardly ex? tending. vertical tabs provided with aligned openings engaging a bolt 52a which is supported by the frame walls 12and,.in turn, rotatably supportsthe liftinglever 52,. The front end of the lifting lever 52 hasa forwardly projecting arm 53 having a convex upper face which engages subv stantially the center of the head of the rivet 42. The horizontal wall of the lever 52 has a longitudinal slot.54formed therein. Positioned directly below the lifting lever arm 53 isa cushion assembly consisting of a pair of superimposed plates 56; the lateralendsof which engage and extend into corresponding horizontal slots 57 formed in. the front channel sidewalls 19 flush with theouter margins thereof, and a rubber pad 58 mounted atop the plates 56, the assembly being secured by a rivet 59. It should be noted that the lifting lever, cushion assembly, driving blade and plunger, and the driving spring mechanism are so dimensioned and disposed that the lower edge of the blade 38 is. at the levelof. the lower edgeof the magazine channel frontwall 24 when the mechanismis inits normal. at rest position.

In. order to effect the stapledriving stroke, thereis provided. a pair of horizontally spacedparallel fulcrum arms 6.0 which are rotatably supported between the upper parts of the frame walls. 12 by means of a screw post 61 passing through aligned holes formed between the ends of arms 60 and in the frame walls 12. The rear ends. of the arms 6.0 are connected through a suitable pivot and spacer and by links 63 to a screw post 64 supported by the side walls of the actuating handle 30. Hinged to and depending from the forward ends of thearms. 60 is. a cocking member 66, which ispositioned intermediate the arms 60 by means of Suitable spacers. engaging a pin 67 which registers with holes formed in the upper part ofcocking member 66 and the forward part of the arms 60. A torsion spring 68, mounted about the post 61, has its arms confined between the lower edges of arms 60 and the. rear edge. of cocking member 66 to swing the lower end of. the. member 66 forwardly, The cocking member 66 terminates at its lower free end in a point defined by a frontv inclined cam edge 69 and a back inclined cam edge 70. Above the front cam edge 69 and separated therefromby a recessed portion 71 defining a hook, is an upwardly, rearwardly in.- clined cam edge 72.

In normal inoperative position, the lower. end. of the cocking member 66 passes through the slot 54 in the lifting lever 52, the hook 71 engaging the front edge of the slot 54. An adjustable triggering element 73 is provided, having a transverse arm provided with upper and lower stepped bottom edges 74 and 76 respectively, and rearwardly extending finger tabs 77, and is. transversely slidably supported by rectangular vertically extending recesses 78 formed in the frame face forward edges 46. A spring member 79, supported on the front channel walls 19 by a suitable post 79a, resiliently retains the member 73 in the recesses 78. While the lower edge of triggering element 73 is illustrated as having but two steps, this edge may have a larger number of steps or be inclined, as will be readily understood from the foregoing,

Disposed in and secured to the bottom wall of the magazine channel 21 is a channel-shaped staple guide 80, whose upwardly directed side walls 81 have parallel longitudinal slots 82 formed therein. The forward ends of the guide. side walls 81 have depending legs 83 which overhang the rear wall of the opening 29 and extend to the lower edge thereof. An apertured upright tab 84 is positioned at the front end of the staple guide bottom wall, the other end of which is provided with a rearwardly extending port-ion terminating in an uprighttab 86 having a horizontal slotformed therein. A pusher member 88, having depending side walls provided with longitudinal slots 89, slidably. straddles the guide 80, the slots 89 being aligned withv the guide slots 82. The pusher member 88 is also provided with horizontal cross walls, the rear one of which has a: depending apertured tab 90. A cross bar 91, having a longitudinal tubular guide opening 92, is positioned in the guide and pusher 88, projecting laterally through and beyond the aligned slots 82 and, 89. A guide rod 94 passes through the openings in tabs 84, 86 and 90, and the pusher tubular opening 92, and has its flattened rear end upset at tab 86 to complete the assembly. Mounted on, and coaxial with, the guide rod 94 is a helical compression springv 96 confined between the confronting faces of guide tab 86 and pusher tab to urge the pusher 88 to its advanced position.

A staple-confining and pusher-retracting member 100 of inverted channel. shape is provided, and has an upper wall 101 and depending side walls 102 adapted to straddle thepusher member 88 and nest in the magazine channel 21. The confining member 100 is hinged to and between the lower portions of frame walls 12 by means of a screw post 100a passing through aligned openings formed in upward extensions 103 to the rear portions of. side walls 102 and corresponding. openings formed in the frame walls 12, The front ends of side walls. 102 are provided with forwardly projecting Shanks 104 terminate ing in depending rearwardly openhooks 106 which ride along the inner longitudinal bottom edges of the channel 21 and are adapted to engage the portions of the pusher bar 91 projecting beyond the pusher slots 89. Furthermore, a rearwardly flanged upright tab 107 is positioned towards the back edge of. the confining member upper wall 101.

A latch or locking member 110 of horizontal platelike configuration is slidably supported at the level. of the recess 27 formed in the front channel side walls 19 by means of a plurality of laterally projecting tabs 112, 111, 112 slidably engaging a similar number of slots 113v of longer extent formed in the frame side walls 12. The centermost tabs 111 project through their associated slots 113 beyond the outer faces of side Walls 12, whereas the front and rear tabs 112 only extend to the plane. of these faces. Formed in the latch member 110, in vertical alignment with the cocking member 66, is alongitudinal rec.- tangular aperture 114, the forward edge of which is provided with. an upwardly rearwardly inclined tab 116. A stop member 117 is disposed directly above the locking member 110 and is supported in fixed position by means of a pair of laterally extending ears 118 engaging cor.- responding openings 118a in the frame side walls 12. The forward edge of the stop member 117 is provided with a forwardly inclined depending tab 117a projecting into the locking member aperture 114 at a point intermediate the ends thereof in lockedposition. A pair of helical tension. springs 119 engage at one end openings 120 formed in the rear portion of locking member 110 and at the other end spin-121 supported by holes formed in the upper corners of retaining member side wall extensions 103. The springs 119 are normally upwardly deflected from their straight line path by the retaining member upright 107 and serve the. multiple purpose of urging the locking member 117 to its close position and the confining member 100 downwardly and counterclockwise, asseen in- Figure 4.

A channel shaped. staple exit member 122 isformed of a. hardened steel and is disposed at the forward end of the magazine channel 21, registering with the exit aperture 29. The forward wall 123 of the exit member abuts the inner face of the magazine channel front wall 24 and is provided at its upper edge with a forwardly projecting lug 126 which abuts the upper edge .of channel front wall 24 and registers with a recess 127 formed in the lower edge of the front wall of front channel member 20. The rear portion of the side walls ofv the staple exit member is directed laterally arcnately outwardlyandforcibly engages the confronting rear edge of magazinechannel aperture 29. Projecting vertically from the side walls of the exit channel are tabs 128 which extend above the corresponding edges of the magazine channel side walls. The staple exit member 122 is hardened prior to assembly and, due to its configuration, distortion will be outward which is favorable since a preloaded condition is set up when it is assembled into forward end of magazine channel 21. The curved end faces of the member 122 abutting the rear edge of aperture 29 secures it therein, correcting an inward distortion that might manifest itself after the heat treating process. In the exceptional case, where the distortion of the side walls of member 122 is laterally outward, then the side walls of the magazine channel 21 will forcibly engage the exit member side walls suitably, preloading the same. Moreover, the abutting faces of the walls 24 and 123 are secured by a tack weld. It should be noted that the forward vertical edges of the staple guide 81 are spaced from the inner face of the wall 123 of exit member 122 a distance sufficient to permit easy passage of the driving blade 38.

Considering now the operation of the improved stapling gun; in order to load the gun, the actuating handle 30 is raised in the direction of the arrow, Figure 6, causing the fulcrum arm 60 to rotate counterclockwise. The point of the depending cocking member 66 is thereby forced downwardly into the aperture 114 of the locking member 110. The locking member lower forward cam edge 69 engages the tab 116 and the rear cam edge 70 engages the stop tab 117 urging the locking member 110 forward and the locking tabs 111 from the close position in the recesses 28 to their open position out of these recesses and into the adjacent recesses 27. The springs 119, acting through the retaining member 100, swing the magazine channel 21 to its fully open position as seen in Figure 4, the lower edges of hooks 106 riding along the bottom Wall of the magazine channel 21. As the magazine channel 21 is swung outwardly, the hooks 106 engage the laterally projecting portions of the pusher bar 91 withdrawing the staple pusher member 88 to its retracted position and compressing the feed spring 96. A strip of staples may then be placed on the staple guide 80, and the magazine channel thereafter swung to its closed position, the locking tabs engaging the locking recesses 28. The hooked ends 106 of the retaining member 100 are thus returned to the forward end of the magazine channel 21, allowing the pusher member 88 to slide forward, engaging the rear staple of the strip and, by virtue of the spring 96, urging the strip of staples forward and the foremost staple against the inner face of the driving blade 38. The springs 119, acting on the upright 107, urge the confining member 100 downwardly, which maintains a pressure on the top side or bridge of the staples when loaded on the staple guide and thereby greatly inhibits the jamming of the staples.

In performing the stapling operation, the actuating handle 30 is pressed downwardly toward the frame member 12, thereby rotating the fulcrum arms 60 clockwise, as seen in Figure 3, and raising the cocking member 66. The hooked portion 71 of the cocking member 66 passing through lifting lever slot 54, engages the lower face of the lifting lever 52 and rotates the lifting lever 52 clockwise about pin 52a. The forward edge 53 of the lifting lever 52, acting on the rivet head 42, raises the plunger 37 and, as the lower edge of the driving blade 38 is elevated above the level of the strip of staples, the foremost staple is advanced into the vertical path of the driving blade 38 under the urging of spring 96. In the raising of the plunger 36, the energy storing springs 51 are compressed and loaded. As the fulcrum arm 60 is rotated clockwise and the cocking member 66 thereby raised, the forward upper cam edge 72 of the cocking member comes into contact with and engages the lower edge 74 or 76, as the case may be, of the triggering element 73. The triggering element lower edge, acting on the cam edge 72 (see Figure 3), swings the cocking lever 66 rearwardly as it is raised until the forward edge of the hook portion thereof 8 is retracted beyond the forward edge of the slot 54 in the lifting lever 52, releasing the lifting lever 52 and the plunger 36. The loaded spring is thus permitted to expand and send the plunger forcibly downwardly, the blade 38 engaging the bridge of the staple in its path, shearing it from the cohered strip and driving it home. The shock of the descending plunger and lifting lever is cushioned by the rubber pad 58.

After the completion of the staple driving stroke, the handle 30 is released and the entire mechanism returned to the starting position, as shown in Figure 2, being urged thereto by the springs 51 and 68.

It should be pointed out that when the triggering element is in the position shown in Figure 7, the higher stepped edge 74 engages the cocking member cam surface 72 and releases the plunger when it has been raised to a greater height than when the triggering element is in the position shown in Figure 8 and the lower edge 76 engages the cam surface 72. Since, in the former case, more compression is imparted to the springs 51 and hence more energy, a heavier driving stroke is effected when the triggering element is in the position illustrated in Figure 7, and a lighter stroke is effected when the triggering element is in the position shown in Figure 8. It is also important to observe that since the lifting lever 52 engages the ram 37 at a point and in a direction colinear with the axis of the compression springs 51, there is a minimum of torque and hence an increase in energy efficiency and a decrease in the frictional wear due to the wasted energy dissipated as a result of this torque.

While there has been described and illustrated a preferred embodiment of the present invention, it is apparent that numerous alterations and omissions may be made without departing from the spirit thereof.

I claim:

1. A stapling device comprising a body member, a staple magazine mounted on the lower portion of said body member and movable relative thereto between a closed position and an open position permitting access to the interior of said magazine, a latch element movable between lock and unlock positions and normally engaging said body member and said staple magazine and releasably locking said staple magazine in closed position, a staple driving mechanism disposed in said body member, a handle mounted on said body member and adapted to actuate said staple driving mechanism when moved between first and second predetermined positions and a lost motion mechanism providing engagement between said handle and said latch member and urging said latch member to unlock position when said handle is moved to a third predetermined position outside the path between said first and second predetermined positions.

2. A stapling device in accordance with claim 1, wherein said staple magazine is hinged to said body member and is provided with a latching recess and said latch element is slidably supported in said body member and movable into and out of engagement with said latching recess to define lock and unlock positions respectively.

3. A stapling device in accordance with claim 2, including spring means urging said latching element into lock position.

4. A stapling device in accordance with claim 2, wherein said handle is hinged to said body member and is rotatable between said predetermined positions, said third predetermined position being above said first and second predetermined positions.

5. A stapling device comprising a body member, a staple magazine hinged to said body member and having a recess formed therein and being movable between open and closed positions, a latching element slidably supported on said body member and movable into and out of engagement with said recess when said staple magazine is in closed position to define lock and unlock positions, spring means urging said latch element into lock position, a staple driving mechanism mounted in said body member, a handle hinged to said body member and adapted to actuate said staple driving mechanism and unlocking means adapted to move said latching element into unlock position when said handle is raised above a predetermined point relative to said body member.

6. A stapling device in accordance with claim 5, wherein said latching element comprises a horizontal plate having an opening formed therein which has front and rear edges, and there is provided a stop member mounted in said body member adjacent said opening, and said unlocking means includes a lever pivoted at a point between its ends to said body member, one end of said lever being linked to said actuating handle and an arm depending from the other end of said lever and terminating in a tapered end adapted to register with said latch element opening and engage an edge thereof and said stop member.

7. A staple driving gun comprising a body member, a staple drive actuating handle hinged to the upper portion of said body member, a staple magazine hinged to the lower portion of said body member and provided with a catch element, a latch member disposed in the lower portion of said body member and movable into and out of engagement with said catch element, and a lost motion mechanism providing engagement between said latch member and said actuating handle and urging said latch member out of engagement with said catch element when said actuating handle is moved to a predetermined position.

8. A staple driving gun in accordance with claim 7,

wherein there is provided spring means urging said magazine to its open position.

9. A staple driving gun in accordance with claim 7, wherein said actuating handle is movable from a normal intermediate position downwardly to efiect a staple driving stroke and upwardly from said intermediate position to urge said latch member to its unlocked position, and spring means are provided to normally urge said latch member to its lock position.

10. A staple driving gun in accordance with claim 7, wherein there are provided a stop member horizontally spaced from a confronting edge of said latch member and a depending arm movable by said handle and in vertical alignment with the space between said confronting edge and said stop member and terminating at its lower end in a wedge-shaped portion adapted to register with said space upon the raising of said handle to urge said latch member to its unlock position.

11. A staple driving gun in accordance with claim 10, wherein there are provided a staple driving means, spring means urging said driving means to its advanced position, said depending arm being in releasable engagement with said driving means and adapted to raise said driving means upon depression of said actuating handle, and a triggering element urging said arm out of engagement with said driving means upon said driving means being raised to a predetermined level.

No references cited.

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