GB2128127A

GB2128127A - Stapler

Info

Publication number: GB2128127A
Application number: GB08228221A
Authority: GB
Inventors: Yasuo Yasuda
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-10-02
Filing date: 1982-10-02
Publication date: 1984-04-26
Also published as: GB2128127B

Abstract

The stapler has a base member 2 provided with an anvil plate 7, a staple magazine member 3 and a driving member 4 provided with a staple drive plate 29. The base member 2, staple magazine member 3 and the driving member 4 are pivotally secured together at their base ends by means of a pivot pin 1. A staple guide member 16 is mounted in the staple magazine member 3 for sliding movement in forward and backward directions while leaving a staple drive clearance 15 in the end of the staple magazine member 3. A staple feeder 19 is connected to the driving member 4 and is mounted in the staple guide member 16 for sliding movement in the forward and backward directions. A resilient member 14 is disposed around the pivot pin 1 with the resilient member being retained at its front bent end by the staple guide member 16 and at its rear bent end by the staple magazine member 3. The arrangement avoids jamming of staples and provides for easy ejection of any jammed staple whilst also enabling simple re-loading with fresh staples. <IMAGE>

Description

SPECIFICATION Stapler The present invention relates to a stapler for use in binding or stitching sheets, such as of paper, the stapler being of the kind having a base member provided with an anvil plate, a staple magazine member and a driving member provided with a staple drive plate all of which are pivotally secured to one another at their base ends by means of a pivot pin.

In a conventional stapler of this kind, a staple feeder feeds a series or strip of staples to bring the staples one by one into a staple drive clearance formed in the free end of the staple magazine member, wherefrom the staple is driven by the staple drive plate attached to the driving member to penetrate stacked sheets of paper laid on the anvil.

The staple is then deformed as it is pressed against the anvil plate on the base member thereby to stitch or bind the sheets of paper together. Often the staple drive clearance is inconveniently jammed by the staple which renders the stapler inoperative. Such jamming may be caused by inferior precision in fabrication of the stapler, damage, wear and other reasons. Once the staple drive clearance is jammed, it is difficult and troublesome to remove the staple which has been deformed or distorted and caught in the staple drive clearance.

Another problem arising with this kind of conventional stapler is that, since the staple feeder is always biased by a coil spring or the like towards the staple drive clearance, it is necessary to retract the staple feeder rearwardly by a dextrous hand and finger operation to overcome the force of the coil spring or other biassing means.

It is an object of this invention to provide a stapler which is improved to avoid the jamming of the staple drive clearance by a staple and to facilitate, if the clearance becomes jammed, the removal of the jamming staple.

Another object is to provide a stapler which permits easy loading of the staples by a novel feature employing a connecting member which connects the driving member and the staple feeder.

According to this invention, there is provided a stapler having a base member provided with an anvil plate, a staple magazine member and a driving member provided with a staple drive plate, the base member, staple magazine member and the driving member being pivotally secured at their base ends to one another by means of a pivot pin, characterised by comprising a staple guide member mounted in the staple magazine member for sliding movement in forward and backward directions whilst leaving a staple drive clearance in the end of said staple magazine member, a staple feeder connected to the driving member and mounted in the staple guide member for sliding movement in the forward and backward direction, and a resilient member disposed around the pivot shaft, said resilient member being retained at its front end by the staple guide member and at its rear end by the staple magazine member.

The above and other objects, features and advantages of the invention will now be explained by the following description of the preferred embodiment depicted in the accompanying drawings wherein: Figure 1 is a sectional side elevational view of a stapler in accordance with the invention showing the driving member swung slightly upwardly; Figure 2 is a sectional front elevational view of the stapler as shown in Figure 1; Figure 3 is a partly cut-away perspective detail view of parts of the stapler shown in Figure 1 with the base memberthereof omitted, and Figure 4 is a further partly cut-away perspective detail view of parts of the stapler shown in Figure 1 with the base member thereof omitted.

The stapler in accordance with the preferred embodiment of the invention as shown in the drawings has three major members: namely, a base member 2, a staple magazine member 3 and a drive mem ber 4 all of which are pivotally secured to one another at their base or rear ends by a pivot pin 1.

The base member 2 is channel-like of substantially inverted U-shape cross-section composed of a bottom wall 2a and two opposed side walls 2b upstanding from each side of the bottom wall 2a. An anvil support 5 is fixed between the side walls 2b at the free end portion of the base member 2. An anvil plate 7 is rotatably secured to the anvil support 5 by means of a pivot pin 9 fixed to the centre thereof and extending through the anvil support 5. Outward staple guide grooves 6 and inward staple guide groove 6' are formed in one and the other end portions of the upper surface of the anvil plate 7. A coil spring 10 is compressed between the anvil support 5 and the head 9' of the pivot pin 9.

The rear end portions of the side walls 2b are extended upwardly to provide opposed supporting walls 11 through which the pivot pin 1 extends with the pivot 1 pivotally securing the staple magazine member 3 and the driving member 4 together. A coil spring 12 is confined between the staple magazine member 3 and the bottom wall 2a of the base member 2.

The staple magazine member 3 is channel-like of substantially U-shape cross-section composed of a bottom wall 3a and two opposed side walls 3b. A pair of apertures, a front aperture 13 and a rear aperture 13', are formed in the rear end portion of the bottom wall 3a. The front aperture 13 retains the front bent end 14a of a resilient member 14 wound round the pivot shaft 1 whilst the rear aperture 13' retains the rear bent end 1 4b of the resilient member 14. A staple drive clearance 15 is formed between the front end of the bottom wall 3a and a front wall 3c of the staple magazine member 3.

A staple guide member 16 of substantially Ushape cross-section is mounted between the side walls 3b of the staple magazine member 3 for relative backwards and forward sliding movement.

The staple guide member 16 is engaged and re tained at its rear end 16' by the front bent end 1 4a of the resilient member 14. The staple guide member 16 has a bottom wall 16a in which formed are a pair of elongate holes 17,17' spaced apart in the longitudinal direction of the staple guide member 16. These elongate holes receive stoppers 18,18' which are short lugs formed by cutting and raising corresponding portions of the bottom wall 3a of the staple magazine member 3.

A staple feeder 19 is mounted slidably on the staple guide member 16 and is a channel-like member of substantially inverted U-shape crosssection providing a top wall 19a and two opposed side walls 19b. Each side wall 1 9b is received within a respective gap 20 which is formed between respective side walls 3b and 1 6b of the staple magazine member 3 and the staple guide member 16 so that the staple feeder 19 is slidable backwards and forwards along the length of the staple guide member 16. A coil spring 21 is loaded and retained between the top wall 19a of the staple feeder 19 and the bottom wall 3a of the staple magazine member 3.

A retaining tab 22 protrudes from the central portion of rear end of the top wall 19a, and a connecting plate 24 is provided at one end with an aperture 23 which is adapted to engage with the retaining tab 22. The connecting plate 24 has two opposed projections 25 each extending laterally from one side edge of the plate 24 near the one end having the aperture 23. The lateral projections 25 are slidably received in elongate slots 26a formed in each sidewall 3b of the staple magazine member 3.

The lateral projections 25 are slidable also along opposed elongate grooves 26b which are formed as extensions of the elongate slots 26a. The connecting plate 24 is pivotally secured at its other end to opposed side walls 27b of a staple pressing member 27 mounted in the driving member 4.

The staple pressing member 27 is of substantially inverted U-shape cross-section providing the aforesaid side walls 27b and a top wall 27a. A tab 28 projecting from the centre of the free end of the top wall 27a is received by an elongate hole 30 formed in a staple drive plate 29 fixed to the driving member 4.

The side walls 27b are each provided at their rear end with a notch 31 which receive and engage the pivot shaft 1. The staple pressing member 27 is biased away from the top wall of the driving member 4 by a leaf spring 32 acting between the top wall 27a of the staple pressing member 27 and the top wall of the driving member, which also is of inverted U-shape cross-section.

In use, as the driving member 4 is pivotally moved upward around the fulcrum constituted by the pivot pin 1, the connecting plate 24 is pulled by the driving member 4 so that the retaining tab 22 of the staple feeder 19 is retained and pulled by the aperture 23 formed in the connecting plate 24. In consequence, the staple feeder 19 is slid rearwardly overcoming the force of the coil spring 21 to afford a space for holding and mounting of a series or strip of staples on the staple guide member 16 in the staple magazine member 3. Thus, the space for loading the staples is automaticaly and simply provided by swinging the driving member 4 upwardly as stated.

Afterthe loading, the series of staples are pressed forwardly, i.e. toward the staple drive clearance 15, by the staple feeder 19 which tends to resume the initial position by the resetting bias force of the coil spring 21. Then, as the driving member 4 is pressed down, the staples are severed from each other and driven one by one to stitch or bind sheets of paper by the force exerted by the staple drive plate 29 fixed to the driving member 4.

In the event that the thus driven staple tends to jam the staple guide clearance 15 for any reason, the staple guide member 16 is forced back automaticaily by the reaction force exerted by this jammed staple, thereby overcoming the force of the resilient member 14, so that this staple can be ejected easily by a further actuation of the staple drive plate 29 to clear the jammed staple out of the staple drive clearance 15.

Although the invention has been described through specific terms, it is to be noted here that the described embodiment is not exclusive and various changes and modifications may be incorporated without departing from the scope of the invention.

Claims

1. A stapler having a base member provided with an anvil plate, a staple magazine member and a driving member provided with a staple drive plate, said base member, staple magazine member and said driving member being pivotally secured at their base ends to one another by means of a pivot pin, characterized by comprising a staple guide member mounted in the staple magazine for sliding movement in forward and backward directions whilst leaving a staple drive clearance in the end of said staple magazine member, a staple feeder connected to the driving member and mounted in the staple guide member for sliding movement in the forward and backward directions, and a resilient member disposed around said pivot shaft, said resilient member being retained at its front end by said staple guide member and at its rear end by said staple magazine member.

2. A stapler according to claim 1 further characterised in that said resilient member has a bent end at its front end and has a bent end at its rear end.

3. A stapler according to claim 1 or claim 2 further characterised in that a coil spring is loaded between said staple feeder and the end of said staple guide member.

4. A stapler according to any one of the preceding claims further characterised in that the staple guide member is of substantially U-shape crosssection and the staple feeder is of substantially inverted U-shape cros-section.

5. A stapler according to any one of the preceding claims further characterised in that the staple magazine member is of substantially U-shape crosssection.

6. A stapler according to any one of the preceding claims further characterised in that a connecting plate is pivotally secured at its one end to a rear portion of said driving member and slidably secured at its other end to said staple magazine member.

7. A stapler according to claim 6 further characterised in that a retaining tab is formed on the upper surface of said staple feeder at the rear end portion thereof and is engageable with said other end of said connecting plate.

8. A stapler substantially as hereinbefore described with reference to the accompanying drawings.