A STAPLING MACHINE

Abstract: A stapling machine is provided which has means visible from the exterior of the machine to provide an indication when the supply of staples within the machine is exhausted. In one embodiment the indicating means comprise an element (12) on the staple pusher (10), which pushes the staples (8) within the magazine, this element being visible, through a window (13), from the exterior of the machine. In an alternative embodiment a constant tension spring moves the pusher, and markings are present on part of the constant tension spring which becomes visible in a window provided for that purpose.

Description: "A STAPLING MACHINE" THE PRESENT INVENTION relates to a stapling machine and more particularly relates to a stapling machine intended to staple together a plurality of pieces of paper. According to one aspect of this invention there is provided a stapling machine, said stapling machine comprising means visible from the exterior of the machine to provide an indication when the supply of staples within the machine is exhausted. The indicator may be a projection carried by the staple pusher or may be a marking provided on a spring biassing the staple pusher. The spring may be a substantially constant tension spring formed of a spring strip wound partly into a spiral, means being provided to retain the spiral portion in a substantially predetermined position, said marking being on part of the spring that forms the exterior of the spiral portion as the supply of staples within the machine becomes exhausted. Conveniently the means visible from the exterior of the machine comprise a light source or other visible indicator controlled by an electric circuit which is completed when the last staple is ejected from the stapling machine. In order that the invention may be more readily understood, and 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 a stapling machine in accordance with the invention, FIGURE 2 is a view of some of the operative components of the stapling machine of Figure l, FIGURE 3 is a view of the operative components of an alternative stapling machine, FIGURE 4 is an enlarged view of part of the constant tension spring of Figure 3, and FIGURE 5 is an enlarged view, corresponding to Figure 4 showing an alternative embodiment. The stapling machine of Figure 1 comprises an upper housing 1, which contains a magazine for staples and which contains a mechanism, to be described in more detail hereinafter, to eject a staple, from the staple magazine, through an ejection slot. The front part of the housing 1, shown towards the left in Figure 1, carries beneath it an arm 2, which is pivotally mounted about a notional pivot point 3, the arm 2 carrying on its upper surface an anvil 4 adapted to deflect the ends of a staple ejected from the ejection slot when the staple has passed through a plurality of sheets of paper to be stapled together. A gap 5 is defined between the lower part of the housing 1 and the upper part of the arm 2 so that sheets of paper to be stapled together may be inserted in position in the gap, and may then be stapled together. The housing 1 contains a mechanism adapted to actuate a staple ejector blade 6 which can be seen in Figure 2. The staple ejector blade is moved downwardly so that the blade encounters a staple 7 which is provided at the end of a strip of staples 8. The end staple 7 is engaged with a plate 9 which defines part of the ejection slot. The strip of staples 8 are contained within the magazine and are pushed towards the ejection slot by means of a staple pusher 10 which is associated with a spring 11. The staple pusher 10 is provided with a laterally extending projection 12 which is visible, from the exterior of the housing, through a slot 13 formed in the housing 1. The slot 13 may have a transparent infill. The arrangement is such that when a fresh supply of staples is introduced to the magazine the projection 12 is at one end of the slot 13 and when the strip of staples 8 is exhausted the projection 12 is at the other end of the slot 13. Thus, by observing where the projection 12 is with regard to the ends of the slot 13 it is possible to determine whether the magazine of staples needs replenishing. The stapling machine of Figure 1 is actuated by means of an actuator element 14 or trigger which is located beneath the rear part of the housing 1, that is to say the part of the housing 1 located towards the right-hand side as illustrated in Figure 1. It is envisaged that the stapling machine of Figure 1 will be operated in the manner of a pair of pliers and will be grasped in one hand, with the palm of the hand resting on the upper surface of the rear part of the housing 1 as shown to the right-hand side of Figure 1, and with the fingers curled beneath of the -4- actuator element 14. By applying upward pressure to the actuator element 14, by tightening the grip of the fingers, the arm 2 will initially pivot upwards slightly so that paper inserted into the gap 5 is gripped, and subsequently the ejector 6 will be moved downwardly to eject the staple 7 through the ejection slot, the two arms of the staple passing through the paper and then being clinched together by the anvil 4. Referring now to Figure 3, in an alternative embodiment of the invention a magazine 15 is provided in the form of an open top channel dimensioned to receive a strip of staples 16. A staple pusher 17 is provided adapted to be inserted in the channel and slide along the channel thus biassing the staples 16 towards an ejection slot 18 defined by the front end of the magazine 15. The staple pusher 17 has an upstanding edge 19 which is adapted to be engaged by a cross piece 20 forming part of a constant tension spring 21. The cross piece 20 interconnects two spring strip portions 22,23 which each terminate with a respective spiral portion 24,25. A staple steady 26 is provided adapted to lie over the staples, the staple steady defining, in its under-surface, recesses adapted to receive the spiral portions 24,25. A window 27 provides visual access to this recess. An ejector blade 28 is provided adapted to move past the front end 29 of the staple steady and to drive a staple through the ejection slot 18. It is to be appreciated that as the staples 16 become exhausted the spring strips 22,23 are drawn into the spiral portions 24,25, thus moving the staple pusher 17 along the magazine 15 and biassing the staples 16 towards the ejection slot. As the supply of staples becomes exhausted a part of the strip 22, as shown in Figure 4, forms the exterior of the spiral portion 24. This part of the strip 22 carries a marking 30. The marking may be of a red colour and may have an inclined upper edge. Thus, initially, an unmarked part of the spring is visible through the window 27, but as the supply of staples becomes exhausted the marking 30 becomes visible in the window 27. As the supply of staples becomes totally exhausted the marking totally fills the window 27. In an alternative embodiment of the invention, as illustrated in Figure 5, a marking 31 is provided comprising a series of numerals. These numerals are displayed through the window 27 as the supply of staples becomes exhausted, to give a numerical indication of the number of staples remaining. It is to be appreciated that in an alternative form of stapling machine, for example an electrically powered stapling machine, the element which provides an indication as to the number of staples remaining may comprise means mounted on the staple ejector adapted to touch a micro switch when a predetermined staple has been ejected, such as the last staple or the last-but-one staple, the micro switch controlling a light or other indicator visible from the exterior of the stapling machine. Whilst the invention has been described with reference to a "pliers" type machine with reference to Figures 1 and 2 it is to be understood that the invention is equally applicable to a conventional desk-top machine.

Claims: AMENDED CLAIMS [received by the International Bureauon 8 May 1992 (08.05.92); original claims 1 and 2 amended; other claims unchanged (1 page)] 1. A stapling machine comprising a staple pusher to push staples within a magazine and a spring to bias the staple pusher, there being a marking provided on the spring, which marking is visible from the exterior of the machine to provide an indication when the supply of staples within the machine is becoming exhausted. 2. A stapling machine according to Claim 1 wherein the spring is a substantially constant tension spring formed of a spring strip wound partly into a spiral, means being provided to retain the spiral portion in a substantially predetermined position, said marking being on the part of the spring that forms the exterior of the spiral portion as the supply of staples within the machine becomes exhausted.

Inventors: ZIGLIOLI ANDREA, ZIGLIOLI, ANDREA
Applicants: OFREX GROUP HOLDINGS PLC
Application year: 1991
Main classification: B25C5
IPC codes: B25C5