US3149339A - Stapler - Google Patents

Description

Sept. 22, 1964 o. H. JOHNSON STAPLER 2 Sheets-Sheet l Filed April 17, 1962 Sept 22, 1954 Y o. H. JOHNSON 3,149,339

STAPLER Filed April 1'7, 1962 2 Sheets-Sheet 2 FIG. 3.

OSCAR H. JOHNSON INVENTOR www ,/EY

United States Patent O 3,149,339 STAPLER Oscar H. llohnson, Holden, Mass., assigner to Parker Manufacturing Co., Worcester, Mass., a corporation of Massachusetts Filed Apr. 17, 1962, Ser. No. 188,048 4 Claims. (Cl. 1-49) This invention relates to a stapler and, more particularly, to apparatus arranged to drive wire staples for fastening and like purposes.

According to common practice, Staplers and stapling guns are provided with a spring-loaded hammer which drives a wire staple. The hammer is retracted against spring pressure by a hammer lifter which, at the upper end of the retraction stroke, engages a cam surface on a cap piece. This cap piece also serves to abut one end of the spring. Because of its complicated configuration, the cap piece is diicult to manufacture and is subject to rapid Wear. Also, the spring is the part of the stapler that is most liable to breakage and, yet, the known stapler constructions do not permit ready replacement of the spring. These and other diiculties experienced with the prior art devices have been obviated by the present invention in a novel manner.

It is, therefore, an outstanding object of the invention to provide a stapler which is capable of extremely long life and in which parts most likely to be damaged may be readily replaced.

Another object of this invention is the provision of a stapling gun having a wear-resistant cap member.

A further object of the present invention is the provision of a stapling apparatus with a cam and springretaining means of complicated configuration which is readily manufactured from sheet metal stampings.

It is another object of the instant invention to provide a stapler having a readily removable cap member.

It is a further object of the invention to provide a stapler having a means of engagement between the harnmer and the retractor which permits accurate release and minimum wear.

A still further object of this invention is the provision of a stapler having a novel spring-retaining means.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated in the accompanying drawings in which:

FIG. 1 is a side elevational view of a stapler embodying the principles of the present invention,

FIG. 2 is a vertical sectional view of the stapler taken on the line lI-II of FIG. 3;

FIG. 3 is an end elevational view of the stapler;

FIG. 4 is an exploded perspective view of a portion of the stapler;

FIG. 5 is a horizontal sectional view of the stapler taken on the line V-V of FIG. 2; and

FIG. 6 is a somewhat enlarged View of a portion of the invention.

Referring iirst to FIG. 1, which best shows the general features of the invention, the stapler, indicated generally by the reference numeral 1t), is formed with two spacedparallel side frames 11 and 12 which are embraced along corresponding normally-vertical straight edges by a U- shapedfront frame 13. The side frames are held in spaced parallel relationship by aframe channel 14 running along corresponding bottom edges.Bumper retainers 15 are also located between the side frames and the unit is provided with abase 16. Astaple guide 17 3,149,339 Patented Sept. 22, 1954 ice is located within theframe channel 14. A plastic handle 1S is located between the side frames. Anactuating handle 19 is pivoted between the side frames on apivot pin 21 and ashield 22 is mounted on the handle. Alock loop 23 is pivoted on the side frames and is adapted to engage aslot 24 formed in the handle. Ahammer 25 is located between the side frames within thefront frame 13 and is provided with astaple blade 26 fastened thereto and resting against the bight of the U-shapedfront frame 13. Aspring guide roller 27 is mounted within thestaple guide 17 and is rotatably mounted on a spring guide roller pin 2S. Ahammer lifter 29 is mounted on a pivot pin 31 as a lever between theside frames 11 and 12 and between downward-depending flanges formed on thehandle 19. Alatch 33 is mounted on the outside of each of the side frames by means or apivot pin 34. A staple-pressure slide 32 is mounted in thestaple guide 17. Theslide 32 is fastened within theframe channel 14 by means of slide rivets 35. Ahammer spring 36 rests in an upwardly-directed recess in the top of thehammer 25. Between theside frames 11 and 12 and within thefront frame 13 is also mounted acap member 37 consisting ofoutside laminations 38 and 39 within which are provided spring-coniininglaminations 41 and 42. Finally, fivelifter cam laminations 43, 44, 45, 46, and 47 are located between the spring-confininglaminations 41 and 42. Alatch spring 43 is associated with thelatch 33, while alifter spring 49 is mounted on a pivot pin 51 in thehandle 19. Astaple feed spring 52 is mounted within thestaple guide 17 and has one end attached to ahinge pin 53 while the other end is attached to theslide 32. Arubber bumper 54 is mounted on the upper side of theframe channel 14 and underlies thehammer 25.

Arivet 55 extends through the side flanges of thefront frame 13 and through corresponding apertures in all of the laminations. At one end, the rivet is provided with an aperture through which extends alock spring 56 of a well-known type.

As is evident in FIG. 4, the twolaminations 38 and 39 of thecap 37 are exactly alike, thelamination 38 being provided with anaperture 57 to receive therivet 55. It is formed with anotch 58 having a downwardly-directededge 59 which engages and rests on the upper edge 6i) of the bight of the channel-Shapedfront frame 13. It iS provided with a rearwardly-directedabutment 61 having a downwardly-directededge 62 which rests on an upper horizontal edge of the side frame 11 (see FIG. l). The spring-confininglaminations 41 and 42 are mirror images of one another. Thelamination 41 is provided with an aperture 63 adapted to receive therivet 55 and an aerture 64 is adapted to receive arivet 65 which holds thelaminations 41, 42, 43, 44, 45, 46, and 47 together as a unitary body. It is also provided with anotch 66 dening a downwardly-directededge 67 similar to theedge 59 of thelamination 38; theedge 67 rests on theupper edge 60 of the bight of thefront trarne 13. Thelamination 41 is also provided with anaperture 68 for receiving apivot pin 69, as will be described more fully hereinafter. Thelamination 41 is provided with a downwardly-directedleg 71 having anotch 72 along one edge. The portion of theleg 71 underlying thenotch 72 is bent to provide a curved portion 73 which extends inwardly of the stapler. Thelamination 42 is similar to thelamination 41 but is provided with acurved portion 74 which is curved in the opposite direction, i.e., toward thelamination 41. The outer vertical edges of thecurved portions 73 and 74 are located adjacent one another and the two curved portions form a generally tubular construction which embraces the top of thespring 36. Thelifter cam laminations 43, 44, 45, 46, and 4 7 are all exactly alike and are stamped out of thin sheet metal, as are all the laminathe machine at rest.Y staple guide 17 by removal ofthebase 16, the staple-prestions for that matter. l the lifter cam laminations and is provided with anaperture 75 adapted to receive therivet 65 and with an aperture '7 6 adapted to receive therivet 55.

Thelamination 43 is also provided with anotch 77 dening a downwardly-directed edge ,7S which rests on theupper edge 60 of the bight of thefront frame 13. Thelamination 43 is provided with an aperture 7? adapted to receive thepivot pin 69. As is best evident in FIG. 5, therivet 65 is used to lock together all of the laminations except theoutside laminations 38 and 39. Thepivot pin 69 is provided with a large central portion which en-` gages the apertures V68 and '7g in thelaminations 41 and 43 and similar apertures in the lamination-.S y44, 45, 46, 47, and 42; thiscentral portion is also forged at the ends to lock these members together in the manner of a rivet. ln addition, the pivot pin is provided with reduced portions S1 which engagecorresponding notches 82 in the side; frames 11 and 12. This arrangement is best shown in FlG.*6 wherein thenotch 82 is shown as consisting of acurved edge 33 having the same radius of curvature as the reducedportion 81 of thepivot pin 69. Tangential horizontal edges extend outwardly from the curved edge S3 and intersect twostraight edges 84 and S5. Edge S4 Yis exactly perpendicular to the edge of the side frame 11 while the edge 8S is generally vertical.

Referring to PEG. 2, it can be seen that the lower end of thehammer lifter 29 is provided with a hook S6 which engages a rectilinear recess S7 in the hammerl, the recessl being rather shallow so that the hammer does not Contact any portion of the hammer-lifter 29 except thehook 86.

Thelamination 43 is provided with a downwardly-directedcam notch 88 defined by two vertical edges d and 91 and an inclined edge 92. Thelamination 43 is also provided with two downwardly-directedabutments 93 and 94 which are spaced and parallel and are joined by kahorizontal edge 95. Y Y Y Y The operation of the stapler will now be readily understood, in view of the above description. When the stapler is not in use, thehandle 19 is in a generally horizontal position adjacent the plastic handle 18 and is held in that position by thelock loop 23 engaging theslots 24 in the downwardly-directed flanges or thehandle 19. During operation, however, the handle occupies kthe upper position (free of the` lock loop 23) shown in FTGS. l and 2. FIG. 2 shows the stapler without staples in place and with When staples are inserted inthesure slide 32 is urged to the left by the spring $2. The user grasps the stapler by placing his hand around thehandle 19 and theplastic handle 1S and squeezes them together. This causes thelifter 29 to move upwardly y against the pressure of thespring 36. Thehook 86 on the.

Ythe staple blade by theslide 32. As theVlifter 29 moves upwardly, carrying thehammer 25 and thestaple blade 26 with it, the upper end of the lifter eventually strikes thecap 37, particularly thelaminations 43, 44, 45, 46, and 47 thereof. The main body of thelaminations 41 and 42 cover thenotch 88 of the'central laminations, thus providing a box-like opening of approximately the width of the lifter. Thelifter 29 moves lwithin the opening and slides along the vertical edge 8S', eventually striking the inclined edge 92. Its upper end is forced to the left (in FIG. 2), thus forcing its lower end (having the hook $6)k to the right. Eventually, the camming action removes thehook 86 entirely from therecess 27 Vof thehammer 25 and the hammer moves downwardly under the impetus of the pressure of the spring l36. Thestaple blade 26 strikes the foremost staple and forcesit Thelamination 43 Vis typical of downwardly into the material against which thebase 16 is pressed. The hammer in its downward movement strikes therubber bumper 54, thus absorbing some of the shock. The main bodies of the spring-conining laminations 41 and 42 form sides for the recess defined by theabutments 93 and 94 on thelaminations 43 et al. and the edges 95V thereof. These provide a downwardly-directed box-like structure which encloses the upper end of the spring '36 and prevents it from moving within the stapler. In'addition, thecurved portions 73 and 74 of the'laminations 41' and 42 embrace the upper end of the spring, the manner in which this is done being shown in FIG. 2. It should be noted that thespring 49 forces the hoolr S6 into the Vrecess S7 of thehammer 25, but the distance the hook may proceed is limited by the bottom of the recess. This means that only a pre-determined amount ofmovement is necessary at the top of thelifter 29 to remove the hook from the hammer andy release it for downward movement.

Now, when it is desired to replace thespring 36, it is only necessary to remove thecap member 37. This is done by removing thelock spring 56 and the rivetSS. Then, theoutside laminations 38 and 39 may immediately be lifted out, after which the central body formed by the spring-contininglaminations 41 and 42 and thelifter cam laminations 43, 44, 45, 46, and 47 may be lifted out as a unitary body by pivoting them about thepivot pin 69 and sliding this pin out of thenotch 82. One of the interesting aspects of this construction is that the elongated, downwardly-depending portions of theoutside laminations 3S and 39 exactly ll the space within the channel-shapedfront frame 13 that is not occupied by theside members 11 and 12, since these laminations have the same thickness as the side members. This is shown clearly in FIG. 5. In other words, the side laminations and the side members form a single at surface in which the remainder of the laminations may slide. These downwardly-depending parts of theoutside laminations 33V and 39 also serve as added support'for theleg 71 and the corresponding leg on the spring-confininglaminations 41 and 42, so that the upper end of thespring 36 is couined in a rigid recess; this is important in View of the large lateral forces produced by the spring during a stapling cycle.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form'herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent,

1. A stapler, comprising (a) a frame comprising a section of U-shaped crosssection having a bightY and two side flanges dening an elongated chamber, l

(b) a hammer slidable in the chamber,

(c) a spring residing in the chamber and engaging the hammer at one end, and

(d) a cap member mounted in the chamber, the capV member being formed with a spring recess in which the other end of the spring resides, and

(e) a readily releasable fastener means holding they ledge which rests on the end edge of the bight of the frame.

2. A stapler, comprising (a) a frame comprising a section of U-shaped cross-section having a bight and two side anges dening an elongated chamber,

(b) a hammer slidable in the chamber,

(c) a spring residing in the chamber and engaging the hammer at one end, and

(d) a cap member mounted in the chamber, the cap member being formed with a spring recess in which the other end of the spring resides, and

(e) a readily-releasable fasterner means holding the cap member in the chamber and permitting ready removal of the cap member, the fastener means comprising a removable rivet extending through the side ianges of the frame and through the cap member, the fastener means also including a pivot pin extending through the cap member and residing in slots in the frame.

3. A stapler as set forth in claim 2, wherein the cap member is formed with a group of iirst laminations, each having a notch forming part of a cam recess and a notch forming part or" the spring recess, a second lamination on either side of the group of rst laminations, each second lamination having a leg with a curved portion, the curved portions forming a socket in which the spring resides, and a third lamination against each second lamination and engaging opposed surfaces of the chamber, all of the laminations having coextensive edges adapted to rest on the edge of the bight of the said front frame.

4. A stapler as recited in claim 3, wherein each third lamination is provided with an elongated leg which resides between the leg of the adjacent second lamination and the said surface of the chamber to support the leg of the second lamination against lateral pressure from the spring.

References Cited in the le of this patent UNITED STATES PATENTS 2,309,628 Crosby Feb. 2, 1943 2,341,530 Crosby Feb. 1S, 1944 2,412,620 Kipp Dec. 17, 1946 2,746,044 Cusumano May 22, 1956 2,775,765 Klopstock Ian. 1, 1957

Claims (1)

1. A STAPLER, COMPRISING (A) A FRAME COMPRISING A SECTION OF U-SHAPED CROSSSECTION HAVING A BIGHT AND TWO SIDE FLANGES DEFINING AN ELONGATED CHAMBER, (B) A HAMMER SLIDABLE IN THE CHAMBER, (C) A SPRING RESIDING IN THE CHAMBER AND ENGAGING THE HAMMER AT ONE END, AND (D) A CAP MEMBER MOUNTED IN THE CHAMBER, THE CAP MEMBER BEING FORMED WITH A SPRING RECESS IN WHICH THE OTHER END OF THE SPRING RESIDES, AND (E) A READILY RELEASABLE FASTENER MEANS HOLDING THE CAP MEMBER IN THE CHAMBER AND PERMITTING READY REMOVAL OF THE CAP MEMBER, THE FASTENER MEANS COMPRISING A REMOVABLE RIVET EXTENDING THROUGH THE SIDE FLANGES OF THE FRAME AND THROUGH THE CAP MEMBER, THE FASTENER MEANS ALSO INCLUDING A PIVOT PIN EXTENDING THROUGH THE CAP MEMBER AND RESIDING IN SLOTS IN THE FRAME, THE CAP MEMBER HAVING A LEDGE WHICH RESTS ON THE END EDGE OF THE BIGHT OF THE FRAME.

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