GB2231302A

GB2231302A - Improvements in or relating to a stapling machine

Info

Publication number: GB2231302A
Application number: GB8908011A
Authority: GB
Inventors: Robert Benes
Original assignee: Ofrex Group Holdings PLC
Current assignee: Ofrex Group Holdings PLC
Priority date: 1989-04-10
Filing date: 1989-04-10
Publication date: 1990-11-14
Anticipated expiration: 2009-04-10
Also published as: GB2231302B; GB8908011D0

Abstract

A stapling machine has a handle 12 and a spring-biassed staple pusher 23 to push staples, in a magazine 11, towards an ejection slot 19 where they are driven, in use, to engage an anvil 2 adapted to deflect the ends of the arms of the staple. The pusher 23 is connected to the handle by means of a pull-back strap 25 which is integrally moulded of a plastics material and has means engaging the operating handle 12 and means engaging the pusher 23. One of the engaging means comprises an enlarged head 27 at one end of the strap 25 to engage one side face of a bridge 32 defining a passage, with part of the strap passing through the passage, the strap having a projection 28, adapted to engage the other side face of bridge 32 at the other end of the passage. The anvil 2 is reversible. <IMAGE>

Description

IMPROVEMENTS IN OR RELATING TO A STAPLING MACHINE The present invention relates to a stapling machine.

According to this invention there is provided a stapling machine, said stapling machine comprising a base carrying an anvil adapted to deflect the ends of the arms of a staple, and, pivotally connected to said base, a staple magazine and an operating handle carrying a staple ejecting blade, the staple magazine including a spring-biassed staple pusher adapted to push staples to an ejection slot at one end of the magazine, the pusher being connected to the handle by means of a pull-back strap, the pull-back strap being integrally moulded of a plastics material and having means engaging the operating handle or an element carried therewith, and means engaging the pusher, one of said engaging means comprising an enlarged head at one end of the strap to engage an abutment at one end of a passage, with part of the strap passing through the passage, the strap having a projection adapted to engage an abutment at the other end of the passage.

Preferably the said passage is formed on the staple pusher.

Conveniently the abutments are formed on a bridge, which defines a passage there-under.

Advantageously the projection is in the form of a projection presenting a first face, directed towards the said enlarged end, which extends substantially perpendicularly to the axis of the pull-back strap and an inclined face extending away from the enlarged head.

Preferably two projections are provided, on opposed sides of the strap.

Conveniently the pull-back strap is moulded as an integral element of polypropylene.

Preferably the other end of the strap is provided with an enlarged head adapted to be inserted through an aperture and then engaged with the walls defining the aperture.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 is a perspective view of the stapling machine in accordance with the inventions Figure 2 is a cross-sectional view taken through the stapling machine of Figure 1, Figure 3 is an enlarged view of the end of the staple magazine of the stapling machine of Figure t Figure 4 is an enlarged side view of the end portion of the pull-back strap illustrated in Figure 3 > Figure 5 is a top perspective view of the staple steady of the stapling machine of Figure 1 and, Figure 6 is a perspective view of the other end of the pull-back strap.

Referring initially to Figures 1 and 2 of the drawings the stapling machine of the invention is of a substantially conventional design. The stapling machine presents a rectangular base 1 which carries adjacent one end thereof a reversible anvil 2. The base 1 is of hollow construction and the anvil 2 is mounted on a depending stud 3 which passes through an aperture in the base 1, the stud having an enlarged lower end, the portion between the enlarged lower end and the undersurface of the cover being surrounded by a biassing spring 4. A rubber support 5 is provided at the under surface of the base 1, the support 5 defining an aperture 6 through which the stud 3 may be actuated. On depressing the stud the anvil 2 may be rotated, and it is intended, in use, that the anvil may have one of two selected positions.In one position the anvil presents recesses such that the prongs of a staple are forced inwardly, whereas in the other position the anvil presents recesses such that the prongs of the staple are forced outwardly.

Mounted at the other end of the base is a substantially "U"-shaped channel member 7 which presents two upstanding arms 8, 9. The member 7 is secured to the base by means of a rivet 10, and the rivet also secures to the base a leaf spring 11, which extends upwardly and forwardly. Extending between the upstanding arms 7 and 8 is a pivot pin 10. Pivotally mounted on the pivot pin 10 is a staple magazine 11 and an operating handle 12, together with a staple steady 13.

The operating handle 12 defines, adjacent its forward end, a staple ejecting blade 14. The blade 14 has an aperture therein which receives a projecting finger 15 provided at the forward end of the staple steady 13.

The staple magazine 11 defines a guide path for staples to be ejected, the guide path being defined by two vertical plates 16 each located adjacent but slightly spaced from one of the side walls 17, 18 of the magazine. The plates 16 are dimensioned so that a strip of staples may be mounted over the plates, with the opposed legs of the staples located between the respective plate and adjacent side wall.

Adjacent the free end of the magazine 11 a staple ejection slot 19 is defined.

The two side walls 17, 18 are formed on opposed sides of a channel member. The base of the channel member has two upturned portions 20, 21 at axially spaced positions each defining an aperture which receives a respective end of a rod 22. Mounted for slideable movement along the rod is a staple ejector 23.

A biassing spring 24 engages part of the ejector 23 and surrounds that part of the rod 22 extending between the ejector and rearmost projection 20.

A pull-back strap 25 is connected to the staple pusher 23 and is also connected to the staple steady 13.

A leaf spring 26 is connected to the interior of the operating handle 12 to bias the staple steady 13 downwardly.

As thus far described, the stapling machine is of substantially conventional design, but as will become apparent, the pull-back strap is of a novel design.

In the described embodiment of the invention the pull-back strap 25 is moulded of a plastics material, such as polypropylene. One end of the pull-back strap is shown, in side elevation, in Figure 4. It can be seen that the illustrated end of the pull-back strap presents an enlarged head 27, of greater width than the rest of the strap. Slightly spaced from the enlarged head 27 are two projections 28, 29 provided on opposite sides of the pull-back strap, which effectively increase the thickness of the pull-back strap. Each projection presents a vertical flat face 30 directed towards the enlarged head, and a sloping or chamfered face 31 directed towards the rest of the pull-back strap 25.

It is envisaged that the pull-back strap will be connected to the staple pusher 23 by sliding the free end of the pull-back strap beneath a bridge 32 formed on the staple pusher 23. As the strap is inserted in position the cam face 31 of the strap engages one face of the bridge. Pressure applied to the strap causes the strap to deform, to permit the projection 28, 29 to pass under the bridge. When the pull-back strap has been inserted in position, the enlarged head 27 will engage one side face of the bridge 32, which effectively defines a passage to receive the strap 25, the passage being only slightly wider than the strap itself. When the enlarged head 27 engages one side face of the bridge, one of the faces 30 on the projection 28 or the projection 29 will engage the other side face of the bridge 37, thus preventing the strap from being withdrawn from the mounted position.It does not matter which way up the strap is when the strap is introduced into the space under the bridge 32.

The other end 33 of the pull-back strap, as shown in Figure 6, is of planar configuration but has a "spade" end. This end is dimensioned to be inserted through an aperture 34 provided for that purpose in the staple steady 13, as can be seen in Figure 5. The aperture is of substantially "T" configuration and the head 33 is dimensioned so that it can be inserted through the aperture when the plane of the head is aligned with the stem of the "T". However, the width of the strap is such that when the head 33 has been passed through the aperture 34, the strap may be rotated within the area defined by the head of the "T" and then the head 33 may be brought into engagement with the partof the staple steady 13 adjacent the head of the "T".

Projections 35 are provided on the upper surface of the staple steady 13 to ensure that the head 33 of the pullback strap remains in engagement with the part of the steady surrounding the aperture, as intended.

The stapling machine will operate in a conventional manner. Staples will be mounted on the plates 16, and the staple pusher will be biassed by the spring 24 to urge staples towards the ejection slot 19.

As the operating handle 12 is depressed the staple ejection blade 14 will press the end-most staple through the ejection slot and the legs of the staple will be deflected appropriately by the anvil 2. When the handle is released the spring 11 will serve to lift the staple magazine, to permit a further piece of paper to be inserted in position, and the spring 26 provided on the handle will engage the upper surface of the staple steady 13, thus biassing the ejection blade 14 to an elevated position, permitting the staple pusher 23 to push the strip of staples in the magazine forwardly, so that another staple is aligned with the ejection slot.

When the staples in the magazine have been exhausted, the handle 12 may be pulled upwardly, and the pull-back strap will then automatically pull the staple pusher 23 to a retracted position, permitting fresh staples to be inserted into the magazine.

It will be appreciated that the pull-back strap is moulded as a single element of plastics material, and is thus cheap to manufacture. It will also be appreciated that the pull-back strap can readily be mounted in position, as described, incurring only a minimum manufacturing cost.

Claims

1. A stapling machine, said stapling machine comprising a base carrying an anvil adapted to deflect the ends of the arms of a staple, and, pivotally connected to said base, a staple magazine and an operating handle carrying a staple ejecting blade, the staple magazine including a spring-biassed staple pusher adapted to push staples to an ejection slot at one end of the magazine, the pusher being connected to the handle by means of a pull-back strap, the pull-back strap being integrally moulded of a plastics material and having means engaging the operating handle or an element carried therewith, and means engaging the pusher, one of said engaging means comprising an enlarged head at one end of the strap to engage an abutment at one end of a passage, with part of the strap passing through the passage, the strap having a projection adapted to engage an abutment at the other end of the passage.

2. A stapling machine according to Claim 1 wherein the said passage is formed on the staple pusher.

3. A stapling machine according to Claim 1 or 2 wherein the abutments are formed on a bridge, which defines a passage there-under.

4. A stapling machine according to any one of Claims 1 to 3 wherein the projection is in the form of a projection presenting a first face, directed towards the said enlarged end, which extends substantially perpendicularly to the axis of the pull-back strap and an inclined face extending away from the enlarged head.

5. A stapling machine according to any one of the preceding Claims wherein two projections are provided, on opposed sides of the strap.

6. A stapling machine according to any one of the preceding Claims wherein the pull-back strap is moulded as an integral element of polypropylene.

7. An arrangement according to any one of the preceding Claims wherein the other end of the strap is provided with an enlarged head adapted to be inserted through an aperture and then engaged with the walls defining the aperture.

8. A stapling machine substantially as herein described with reference to and as shown in the accompanying drawings.

9. Any novel feature or combination of features disclosed herein.