US2431548A - Staple supporter for stapling machines - Google Patents

Description

Nov. 25, 1947. A. LERlcsscN STAPLE sUPoRTER FQR STAPLING MACHINES Filed Sept. 22, 1945 f4/bawdy Patented Nov. 25, 1947 STAPLE SUPPORTER FOR STAPLING MACHINES Arvid I. Ericsson, Chicago, Ill., assigner to Signode Steel strapping Company, Chicago, Ill., a corporation of Delaware Application September 22, 1945, Serial No. 618,048

3 Claims.

This invention relates to Staplers, and more particularly to a staple hammer which provides support for the staples against collapse, crumpling, or mutilation as they are driven into the Work.

In the use of staplers, and particularly staple 'ha-inmers, staples often collapse and become crumpled while being driven into the work, so that they are ineliective and unsightly and must be replaced. This causes inconvenience, loss of time, and in some cases waste of material being stapled or, if the staples are not replaced, the appearance is poor. The present invention provides means in the stapler which supports the staple against collapse as it is being driven into the work.

'It is an object of this invention to provide a stapler having means to prevent collapsing of a staple being driven into an Object. v

It is another object to provide a stapler which will drive a staple securely into the work even though the staple does not enter the work squarely.

Other objects will appear from the `following description, reference being had to the accompanying drawings, in which:

Fig. 1 is a side elevational view of a staple hammer incorporating my invention;

Fig. 2 is an enlarged fragmentary sectional view of the head portion of the stapler illustrated in Fig. l, showing the parts in one position;

Fig. 3 is a View similar to Fig. 2, but showing the parts in a second position;

' Fig. 4 is a view similar to Figs. 2 and 3, but showing the parts in a third position;

Fig. 5 is a vertical sectional view taken along the line 5-5 of Fig. 3; and

Fig. 6 is an enlarged fragmentary View taken along the line 6--6 of Fig. 1.

This invention as illustrated is applied to a staple hammer of the general type disclosed in Henry Keil Patentv No. 2,345,267, issued March 28, 1944, although it will be understood that the invention may be applied to staplers of other types.

For the sake of brevity and clearness, the structure and operation of the invention are described below as though the stapler were always in substantially the position illustrated in theA drawings, with the staple driving head portion thereof substantially vertical for driving a staple downward-'- ly, although actually the stapler may be employed in any position.

AThe staple hammer comprises a head portion I and a hollow handle portion I2 which serves as a Staple magazine. Staples I4, which may be detachably secured together in a stick as common in the art are urged toward the forward end of the handle portion I2 by a spring disposed in a spring housing I6 carried by the handle portion. At the forward end of the handle portion I2, the staples pass over a staple guide I8 dening with the handle a gateway I9 corresponding to the shape of the staples and opening into a guideway 26 disposed at right angles to and extending upwardly from the handle portion I2. The guideway 20 has a width only sufliciently larger than the width of the staple to enable the staple freely to slide therein and a depth suflicient to receive only a single staple. The guideway 20 is formed in the striking member 26 which is slidably engaged on the guide 24 (formed on the head of the stapler) by means of rearwardly extending side ilanges 28 and inwardly extending rear flanges 39 at the rear ends of the flanges 28 embracing the guide 24. The forward face of the staple guide I8 lies in the plane of the bottom of the guideway 20. The striking member 26 normally projects below the handle portion I2, so that the guideway 2B therein normally extends below the lower end of the staple guide I8. Thus the guideway 2D is progressively moved downwardly upon downward movement of the handle portion I2. A staple driving member 32 is disposed in the guideway 20 with its lower end normally disposed above the staple gateway I9,

The driving member 32 has a sliding t in the guideway, and its bottom edge is adapted to engage the head of a staple I4 in the guideway to drive the staple downwardly into the work. An inertia member 34 may be connected to the driving member 32, and suitable mechanism may be associated therewith to increase the driving force of the member 32, particularly at the end of its stroke. Arms 36 secured to the handle portion I2 at each side thereof serve as stop means to limit relative movement between the striking member 26 and the driving member 32 and inertia member 34. Lugs 38 are provided on the striking member 2S which are engageable with the arms to limit relative upward movement of the striking member. A rack 40 at one side of the striking member which forms part of the mechanism of the inertia member 34 is engageable with one of the arms 3'6. to limit relative downward movement of the striking member. The bottom oi the inertia member 34 is engageable with the arms 36 to limit relative downward movement of the driving member 32 and inertia member 34, and a spring 42 is provided to return the members 25, 32, and 34 to their normal positions.

When a staple is to be driven, as into the work 44, the stapler is swung so that the bottom of the striking member 26 is brought forcefully against the work, and thus is moved upwardly relative to the handle. portion l2 and driving member 32;.

The handle portion and drivingV member move.

downward relative to the striking member, and the driving member 32 also moves downwardly relative to the handle portion l2, engaging the staple I4 in the guideway 2U and driving it into the work 44. The driving member 32 moves downwardly faster than the handle portion l2l and guide 24, but the relative speeds are such. that the forward end of the handle portion contacts the work before the driving member. The staple i4 thus moves downwardly relative to the guide 24, but a portion thereof remains engaged' in the guideway 20 until the staple is fully driven into the work. When the staple has been driven, the striking member 26 is removed from contact with the work and the parts are returned to their original or normal positions by the spring 42. Asv

the driving member 32 moves upwardly beyond the staple gateway I9, another staple i4 is urged into the guideway 25. This staple may then be driven in the manner already described. Structural and operational details of the stapler as so far described are disclosed in the aforesaid patent, and reference may be had thereto for a full explanation.

The width of the guideway 2i) is such that the outer surfaces of the legs of a staple I4 are substantially in contact with the side walls thereof, and the width of the driving member S2, of course corresponds to the width of the guideway. The legs of the staple I4 thus are supported against moving or collapsing outwardly as the staple is driven downwardly in the guideway 2B and into the work 44.

To prevent the legs of the staple from movingv or collapsing inwardly as it is driven into the work, a movable support member is provided at the lower end of the striking member 25. The forward wall of the striking member 26 adjacent the bottom thereof is formed to provide a recess forwardly of and opening into the guideway 2G. The width of the recess 45 corresponds to the distance between the inside. of the legs of a staple I4, so that a portion 29a of the bottom wall of guideway 2e extends along each side of the recess 45 to support a staple as the guideway 2l) passes the recess 45. The width of each portion a thus corresponds to the thickness of a leg of the staple. A pin 48 extends through the recess 45 with its ends secured in the side walls thereof. rIhe movable support member 55 is pivoted on the pin 48. The member 5l) is bifurcated to provide spaced stop portions 52 at the upper end thereof, and a toe portion 54 is formed at the lower end thereof. A spring 55 on the pin 48 between the stop portions 52 has one end bearing-on the forward or end wall of the recess 45 and the other end engaging the toe portion 54. The spring normally holds the support member 50 with the toe portion extending through the guideway 2t and the stop portions 52 engaging the end wall of the recess. The stop portions 52 thus limit pivotal movement of the support member under the influence of the spring 56, and there fore the position of the toe portion 54 in the guideway 2G. The toe portion extends the width ofthe recess, having a length substantially equal tothe distance between the staple legs and .t-l-

ting snugly between the legs. The end surfaces of the toe portion 54 thus support the staple legs against moving or bending inwardly when the staple straddles the toe portion.

The lower surface 58 of the toe portion 54 is rounded or otherwise shaped so as to clear the work 44v as the support. member 50L pivots on the pin 48..

The upper surface of the toe portion 54 is formed to provide a` cam, illustrated as comprising an upper cam surface 6B extending at an angle downwardly into the guideway 2l! when the support member is in its normal position, and a lower cam surface 62 extending at such an angle to the cam surface 60 as to be more or less horizontal in normal position. As will be clear from Figs. 2 to. 5, when the staple I4 is driven downwardly by the driving member 32, the legs of the staple are engaged between the end surfaces of the toe portion 54 and the side walls of the guideway 29 in the striking member 2.6. The legs of the staple, are thus supported against bending or buckling either inwardly or outwardly, and the engagement of at least a portion of the staple in the guideway 2D prevents movement thereof forwardly or rearwardly. The staple legs are most likely to buckle or bend whenv they first come into Contact with the work 44, particularly if a relatively hard material is encountered. The disposition of the support. member 5B at the bottom of the striking member,y closely adjacent the work, provides support against buckling of the staple at the point where it is most necessary.

As the staple moves into the work, thehead of the staple contacts the support member 5S, rst engaging the upper cam surface 55 on the toe portion 54, and the downward movement causing the support member 58. to pivot againstthe force of the spring 56 so as to swing the toe portion` 54- partially out of the guideway 2E. This movement brings the upper cam surface 52 into a downwardly and rearwardly angled position, and continued downward movement of the head of the staple further pivots the support member to move the toeportion 54y entirely out of the guideway 2l) and out ofthe path of the headv or cross-bar of the staple, which can thenv move downwardly so that thestaple m-ay'be fully driven into the work 44. It will be clear that until the head. of theA staple car-ns the toe portion 5,4 entirely out of the guideway 2U, the toe portion supports thev legs; of the staple. closely adjacent to the work 44 against inward col-lapse.

With the constructionV described, the staple i4 is prevented from bucklingv and becoming crumpled orl mutilated. so that. it cannot perform its intended securing function. Such collapse of the staple mightv result from a blow of the stapler in which one side of the striking member contacts the work before the. other; so that the staple enters; the work' at an, angle, froml inclusion :in the work 44. ofi a relatively hard material resisting,A penetration by the staple, or other causes. Since the. construction described prevents col-y lapsing of the. stapleA legs, and since the driving memberv 32 has full engagement with the upper surface. of thehead of the staple. to provide sub-` stantially equalv distribution of the driving force, the staple. legs must enter the work in substantially straight condition, and the staple is driven smoothly into. securing position.

Having thus described my invention, what I' claim asY new and desire t0 secure by Letters Patent is:

1. A hammer type stapler comprising a staplelv magazine, a head secured to the forward end of the magazine, a striking mem-ber movable vertically across the front face of the head, a staple guideway formed in the striking member into which staples are fed from the magazine, a staple driver carried by the head and movable relative to the striking member through the staple guideway, and means for feeding staples one at a time from the magazine into the guideway below the driver, characterized by a recess formed in the lower end of the striking member and open to the staple guideway, a staple supporter pivotally mounted within said recess, said supporter comprising a member having a rear face formed of a pair of adjacent cam surfaces disposed at an angle relative to each other, said member having a pair of opposed side surfaces engageable by the legs of a staple in the staple guideway, said side surfaces and the walls of the staple guideway serving to prevent collapse of the legs of the staple as it is driven into the work, and means biasing said member so that it normally projects across the guideway with the uppermost of the Icam surfaces positioned in the path of a staple, whereby during the operation of the stapler the head of a downwardly moving staple rst engages the upper cam surface to swing said member downwardly about its pivotal mounting so as to bring the second of said cam surfaces across the staple guideway for further pivotal movement of said member by the moving staple.

2. A hammer type stapler comprising a staple magazine, a h'ead secured to the forward end of the magazine, a striking member movable vertically across the front face of the head, a staple guideway formed in the striking member into which staples are fed from the magazine, a staple driver carried by the head and movable relative to the striking member through the staple guideway, and means for feeding staples one at a time from the magazine into the guideway below the driver, characterized by a recess formed in the lower end of the striking member and open to the staple guideway at its discharge end, a staple supporter pivotally mounted within said recess, said supporter comprising a member having a rear face formed of a pair of adjacent cam surfaces disposed at an angle relative to each other, said mem-ber having a pair of opposed side surfaces engageable by the legs of a staple in the staple guideway, said side surfaces extending upwardly from the discharge end of the guideway to co-act with the walls thereof to prevent collapse of the legs of the staple as it is driven into the work, and means biasing said member so that it normally projects across the guideway with the uppermost of the cam surfaces positioned in the path of a staple, whereby during the operation of the stapler the head of a downwardly moving staple first engages the upper cam surface to swing said member downwardly about its pivotal mounting so as to bring the second of said cam surfaces across the staple guideway for further pivotal movement of said member by the moving staple.

3. A hammer type stapler comprising a staple magazine, a head secured to the forward end of the magazine, a striking member movable vertically across guideway formed in the striking member into which staples are fed from the magazine, a staple driver carried by the head and movable relative to the striking member through the staple guideway, and means for feeding staples one at a time from the magazine into the guideway below the driver, characterized by a recess formed in the lower end of the striking member and open to the staple guideway at its discharge end, a staple supporter pivotally mounted within said recess, said supporter comprising a member having a rear face formed of a pair of adjacent cam surfaces disposed at an angle relative to each other, said member having a pair of opposed side surfaces engageable by the legs of a staple in the staple guideway, said side surfaces extending upwardly from the discharge end of the guideway a distance less than the length of a staple leg to co-act with the walls of the staple guideway to prevent collapse of the legs of the staple as it is driven into the work, a stop formed on said member and adapted to abut against the wall of the recess opposite its opening to the guideway, and spring means biasing said stop against the wall so that said cam surfaces normally project across the guideway with the uppermost cam surface positioned in the path of a staple, where-by during the operation of the stapler the head of a downwardly moving staple rst engages the upper cam surface to swing said member about its pivotal mounting so as to bring the second of said cam surfaces across the staple guideway for further pivotal movement of said member by the moving staple.

ARVID I. ERICSSON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 608,699 Michener Aug. 9, 1898 1,309,731 Hawkins July 15, 1919 1,815,066 Maynard July 21, 1931 1,962,874 Polzer June 12, 1934 2,117,743 Polzer May 17, 1938 2,281,232 Cavanagh Apr. 28, 1942 the front face of the head, a staple

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