GB2151175A - Staple driving apparatus and magazines therefor - Google Patents

Abstract

A staple magazine having a guide rail (29) has a staple forming block (23) and a mounting element (28) on said rail for aligning the magazine in staple driving apparatus so that a front surface of said block can form a wall of a staple driving throat when the magazine is in the apparatus. The magazine has a cover which is operable to reload staples without removal of the magazine from the apparatus. The magazine can be removed from the apparatus without opening the cover. A staple feed arrangement on the rail 29 is adapted to advance a formed staple from the block (23) to a driving throat whilst an unformed staple is advanced onto the block (23). <IMAGE>

Description

SPECIFICATION Staple Driving Apparatus and Magazines Therefor This invention relates to staple driving apparatus and to a staple magazine for use in staple driving apparatus.

Staple elements are conventionally interconnected in series by a breakable bond. It is known to interconnect partially bound staple elements which are finally formed in the driving apparatus immediately before being driven into a workpiece. The staple clip can thus be flatter and occupy less space. A known staple forming and driving machine is shown in Heilman U.S. Patent 2,987,735. The Heilman mechanism is shown forming and driving staples from a flat clip.

Stapling tool used in continuous packaging applications requires mobility and a large staple storage capacity to eliminate inconvenient time delays for loading.

In this specification, the word "staple" is not limited to a fully formed fastening element but includes partially formed staple elements, e.g. those whose legs are not at right angles to the crown portion.

An object of the invention is to provide a staple magazine with which clearing of staple jams occurring in use with a staple driving tool can be easily and rapidly accomplished.

Another object of the invention is to provide a magazine which can be held against a staple guide thereby creating a staple driving throat through which the staples can be driven into the workpiece.

Another object of the invention is to provide a magazine with high loading capacity which is simple and convenient to operate.

According to one aspect of the invention, there is provided staple driving apparatus comprising a drive member for driving staples; a staple driving throat; and a removable staple magazine which includes a staple guide rail characterised in that the magazine has a mounting element attached to said rail for correct alignment of said rail in the apparatus and has a staple form block mounted on said rail for forming crown portions on said staples when driven by said drive member, and in that a front surface of said block forms a wall of said driving throat.

According to a further aspect of the invention, there is provided staple driving apparatus having a magazine characterised in that the magazine has a cover which is openable to reload staples without removal of the magazine from the apparatus and in that the magazine can be removed from the apparatus without opening of said cover.

According to another aspect of the invention, there is provided a staple magazine for staple driving apparatus having a driving throat, the magazine being characterised by a staple guide rail; a mounting element on said rail for aligning the magazine in said apparatus; and a staple form block mounted on said rail for forming crown portions on staples, a front surface of said block being adapted to provide a wall of said driving throat.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure lisa side view of a typical portable stapling tool equipped with a staple magazine according to one embodiment of this invention; Figure 2 is the end view of the magazine in the portable stapling tool; Figure 3 is a longitudinal section of the magazine showing parts in operation; Figure 4 is a partial sectional view of the magazine along line A-A of Figure 1; Figure 5 is a partial longitudinal view of magazine with cover open for loading; Figure 6 is a cross-sectional view along line B-B of Figure 4 showing latching and positioning locations; Figure 7 is a partial plan view showing parts for latching;; Figure 8 is a partial view along line B-B of Figure 4 showing latching parts disengaged for magazine removal; Figure 9 is a front view of the magazine inserted in locating guides in the portable stapling tool; and Figure 10 is an alternative cover catching system.

Figure 1 shows a pneumatically operated portable staple driving machine equipped with a magazine 26. The machine has a body 20 in which an air cylinder, valve, piston and rod are installed to force a forming and drive blade 21 (see Figure 6) downward through a staple throat formed by the region between a staple guide 22, being part of the stapling tool, and the front of a form block 23 which is part of the staple magazine. Figure 6 shows a staple 36 ready in the throat.

The air valve, piston, and other movable components in the body 20 are actuated by a manually operated trigger 24 when the body 20 has been connected to a supply of compressed air through air inlet port 19.

Although the drawing herein shows a pneumatically powered stapler, the magazine is equally applicable to a manuaily operated stapler such as the type shown in Heilman U.S. Patent 2,987,725. The magazine will also work efficiently in a stapler that drives the staples directly into separate workpieces for the purpose of holding them together without folding the legs under as in Heilman U.S. Patent 2,987,725.

Figure 1, Figure 4, Figure 7 and Figure 9 show the magazine mounted in a channel-like support member 25 that is attached to the stapler body 20.

The support member 25 contains a location pin 27 (Figure 7) to keep the magazine assembly 26 approximately centered within the support member 25.

The magazine includes an elongate channel-like rail 29 (Figures 3 and 9) whose base has an opening for receiving pin 27. Attached to the bottom of rail 29 is a mounting plate 28 to be used for positioning the front portion of the magazine. The plate 28 has portions 60 extending outwardly from respective sides of the rail 29 to be slidably disposed in slots 37. The portions 60 are formed upwardly so that the magazine can be positioned close to the workpiece and yet have a strong section 61 for support during the downward thrust of the former blade 21. The slot 37 is located so asto ensure that the magazine is both perpendicular and symmetrical to the forming and drive blade 21 and staple guide 22.

To insertthe magazine 26 into the machine, the magazine is set over the locating pin 27 so the pin can pass through the opening in the bottom of the rail 29. The rail 29 is positioned with member 25 with the outside extremities of the mounting plate 28 resting on the lower portion of member 25. The magazine 26 can now be moved forward a short distance until the mounting plate 28 enters the slot 37 in the support member 25 and comes to rest with the front of the form block 23 against the staple guide 22. The cavity created therebetween is the drive throat through which the staple can be driven.

To keep the drive throat at the correct size, the magazine 26 is held forward by a latching bar 31, as best shown in Figure 7. The latching bar 31 is mounted in holes through two pivot pins 32.

Compression springs 33 on the latching bar 31 keep the bar forward by use of retaining washers 34 and retaining pins 35.

When the latching bar 31 is in position at the end of the magazine rail 29, the compression springs 33 keep a forward resilient force on the rail 29 thereby holding the magazine 26 against the staple guide 22.

Should an abnormally large staple 36 arrive at the throat, the magazine 24 will move backwards as the staple 36 exerts a transverse force on the lower portion of the form block 23. The magazine 26 will again move forward to its original position after the staple 36 is completely driven out of the machine.

As best shown in Figure 8, the magazine 26 can be disengaged by forcing the latching bar 31 toward the bottom of the machine. The pivot pins 32 will rotate slightly and the latching bar 31 slides back through the pins 32. The compression springs 33 keep a forward force on the bar 31. The latching bar 31 slides out of the detent portion 42 at the end of the staple rail 29 and clears the lower portion of the rail 29. The magazine is now free to move backward for clearing jams or complete removal from the machine. To relatch the magazine 26 in the machine, the assembly is set over the locating pin 27 and slid into the slot in the support member 25. The latching bar 31 can be pulled backward against the force of the compression springs 33, and lifted upward into the detented portion 42 of the staple rail 29.The latching bar 31 nests into the detent 42 and forces the magazine assembly 26 forward to rest against the staple guide 22. It is not necessary to remove the roll of staple elements 40 from the magazine before removing or inserting the magazine assembly 26.

Although a latching bar is presently preferred it is possible to provide a similar element, not having the bar shape shown in Figure 7 and Figure 8, to hold the magazine biassed toward the driving throat.

Such a latching element need only be attached to the staple driving apparatus and adapted to be releasably hooked onto the rail. The latching may contactthe rail or staple plate at a position along the side instead of around the end depending on the length and the configuration of the rail.

As best shown in Figure 9, a staple plate 41 having a horizontal base with opposite longitudinal upstanding side portions is mounted on rail 29. A strip of staple elements 40 rests on the base transverse to the upstanding portions for alignment with forming and drive blade 21. A cover 38 having a shape such as to enelose a coil of staple elements is pivotally mounted on the rearward end of plate 41 by a shaft 39 passing through the side portions thereof.

Attached to the front portion of cover 38 is a mounting bracket 51 (see Figure 3). Transversely disposed within bracket 51 is a shaft 52. A latch 50 is pivotal about the shaft 51 and is held in a clockwise position by a torsion spring 53. The latch 50 has an extension transversely beyond the edge of cover 38.

The end of the extension has a hook 54 to seat under a retaining block 55 which is attached to the upstanding portion of plate 41 thereby securely latching the cover 38 to the plate 41. The top of latch 50 has a portion that can be pushed to cause counterclockwise rotation about shaft 52 to unlatch the cover 38.

After loading the roll of staple elements 40, the cover 38 can be pivoted clockwise over the roll and the inclined edge of the hook portion 54 contacts the block 55 causing counterclockwise rotation of the latch 50. As the cover continues to move toward the plate 41, the end of the hook 54 will slip over the block 55 and pivot under the lower surface of the block 55 due to the force exerted by the torsion spring 53. The cover 38 will now be securely latched to the plate 41 thereby containing the roll of staple elements 40 within the cover 38.

An alternate latching system is shown in Figure 10. A bar 56 is attached to the vertical extensions of plate 41 so as to span across the area that supports the staples. A leaf spring 57 is attached to a central portion of cover 38 by suitable means such as rivets 58. The end of leaf spring 57 has a bent portion 59 that hooks under the bar 56 to retain the cover in a closed position. To release the cover 38 for rotation to an open position, the leaf spring 57 can be pressed inwardly until the bent portion 59 clears the bar 56.

Figures 3,4 and 9 show the internal parts of the magazine assembly 26 that feed the staples into the forming and driving area. The form block 23, staple rail 29, and the mounting plate 28 are fastened together with screws 45 to hold all items in a symmetrical position. A staple pusher 46, a pusher pin 47, and a pusher spring 48 are held in place with a retainer 49 on mounting plate 28. The stapler pusher 46 and pusher pin 47 will move horizontally when a force is exerted against an angled face 47A of the pusher pin 47.

The staple elements 40 come to lie over the form block 23 one at a time. As the form and drive blade 21 is forced transversely downward over the form block 23, the leading portion thereof strikes the angled face 47A on the pusher pin 47 and forces it backwards. A shoulder on the pin 47 in turn forces the stapler pusher 46 backwards against the spring force of the pusher spring 48. The front portion of blade 21 contacts each lateral leg of the end staple element 40a (Figures 3 and 4) and folds each side leg thereof downward over the form block 23 in front of the retracted pusher 46 to make an angle of approximately 90" to the crown. As the blade 21 retracts to its original upper position, the pusher pin 47 is released and is able to move forward again.

The compression spring 48 forces the pusher 46 forward and therefore advances the formed staple 36 by contact with the legs which are now in front of the pusher 46. The formed staple 36 is fed into the cavity created between the staple guide 22 and front portion of the form block 23, ready to be driven into the workpiece on the next stroke of the form and drive blade 21.

On each successive stroke of the blade 21,the same sequence occurs: staple 36 is driven; pusher pin 47 and pusher 46 retracted; staple element 40a has legs formed at 900; and resulting staple fed forward into staple guide 22.

As the pusher 46 moves the formed staple 36 forward, the remaining staple elements 40 on the roll are pulled forward by a bonding material, such as a strip of tape or a layer of adhesive. This bonding material is sheared by the form and drive blade 21 as the staple 36 is forced out of the staple guide 22 and into the workpiece.

Staple driving tools adapted for forming and driving staples from a roll package have a distinct advantage over conventional "stick" staple tools in the reduced physical size for large capacities as well as longer runs before reloading is required.

The particular type of staple forming and driving mechanism shown in the drawings is purely by way of illustration to show the purpose and applicability of the staple magazine and the usefulness of this invention which is not limited to use with any one particulartype of staple driving machine ortool.

Various changes and modifications of this invention may be made, as will appear to those skilled in the art, and such changes and modifications as are within the teaching of this invention are to be included therein as defined by the claims appended hereto.

Claims (16)

1. Staple driving apparatus comprising: a drive member (21) for driving staples; a staple driving throat; and a removable staple magazine which includes a staple guide rail (29) characterised in that the magazine has a mounting element 28 attached to said rail 29 for correct alignment of said rail in the apparatus and has a staple form block (23) mounted on said rail (29) for forming crown portions on said staples when driven by said drive member (21), and in that a front surface of said block forms a wall of said driving throat.

2. Apparatus according to claim 1 characterised by a staple guide member mounted on a body of said apparatus to form a further wall of said driving throat.

3. Apparatus as claimed in claim 2 characterised in that said magazine is movable transversely of said staple driving blade movement and away from said guide member to expand said driving throat for allowing staples of various sizes to be driven therethrough.

4. Apparatus according to claim 2 or 3 characterised by a member on said body adapted for slidably supporting said staple magazine.

5. Apparatus according to any one of claims 2 to 4 characterised by means for biasing said magazine toward said driving throat

6. Apparatus according to any one of the preceding claims characterised by means for releasably securing said magazine in said staple driving apparatus.

7. Apparatus according to claim 6 characterised in that said securing means comprises a latching element on said supporting member for engaging said magazine, and means biasing said element and said magazine toward said driving throat when said element is engaged with said magazine, so that said magazine is removable from said apparatus when said element is disengaged from said magazine.

8. Apparatus according to claim 7 characterised in that said latching element is pivoted on said apparatus and engageable with an end of said rail.

9. Apparatus according to any one of claims 6 to 8 characterised in that said securing means can be released to allow removal of the magazine without unloading of the magazine.

10. Apparatus according to any one of the preceding claims characterised by a staple pusher (46) mounted on said rail (29) for pushing a formed staple towards said throat.

11. Apparatus according to claim 10 characterised by biasing means (48) for biasing said pusher towards said throat.

12. Apparatus according to any one of the preceding claims characterised by a staple plate (41) mounted on said rail for symmetrical alignment of a staple over said form block (23).

13. Apparatus according to claim 12 characterised by a staple cover (38) mounted over a part of said staple plate.

14. Staple driving apparatus having a magazine characterised in that the magazine has a cover which is openable to reload staples without removal of the magazine from the apparatus and in that the magazine can be removed from the apparatus without opening of said cover.

15. A staple magazine for staple driving apparatus having a driving throat, the magazine being characterised by: a staple guide rail (29); a mounting element (28) on said rail for aligning the magazine in said apparatus; and a staple form block (23) mounted on said rail (29) for forming crown portions on staples, a front surface of said block being adapted to provide a wall of said driving throat.

16. A staple magazine characterised by: a staple guide rail (29); a staple form block (23) at one end of said rail; and a staple feed arrangement on said rail, the feed arrangement being arranged to advance a formed staple from the block to a driving throat whilst an unformed staple is advanced onto said block.