GB2126147A - Improvements in stapling machines - Google Patents

Abstract

A power-operated stapling machine comprises a plunger 16 which is moved downwards by the core 19 of the solenoid 20 to push an end staple 11a in a row of staples 11 through a stack of paper sheets and against an anvil 2 which bend the staples to hold the sheets together. The downward movement of the plunger 16 causes a link 29 to rock a lever 27 counter clockwise. This causes a wheel 26 to rotate the wheels 22, 23 clockwise whereby the wheels 22, 23 frictionally feed a row of staples 11 forwards until it catches up the rear end of the staples already in the machine. The machine operation is not interrupted meanwhile. Return movement of the plunger 16 promotes only an idle movement on lever 27. The lever 27 is connected to the wheel by a one-way clutch. A new row of staples is at once added to a guide bar 10 and is engaged by the second driving wheel 23. <IMAGE>

Description

SPECIFICATION Improvements in stapling machines This invention relates to power-operated stapling machines for stapling together stacks of paper sheets such as are produced by paper collating machines, or booklet making machines.

The invention is particularly concerned with such machines of the type comprising a staple-bending anvil, a guide, which is arranged to hold a row of staples detachably fixed to each other closely side by side, one end of the guide being movable towards and away from the anvil, a poweroperated plunger which, in operation, is intermittently reciprocated at one end of the guide, being moved in an operative stroke to press an end staple in the row through a plurality of paper sheets to hold the sheets together and then being moved in a return stroke, and means for moving the row of staples along the guide to present another staple to the plunger each time a preceding staple has been pressed against the anvil and the plunger has made its return stroke.

Collating machines, with which such poweroperated stapling machines are commonly used, have a holder for receiving stacks of collated sheets and to enable the stacks of sheets to be fixed together, either the collating machine has a power-operated stapling machine or a wire stitcher fitted to its holder. As an alternative, the stacks of sheets may be transferred from the holder to a separate stapling machine. Booklet making machines have a holder in which a stack of paper sheets is centrally stapled or wire stitched together and is then folded over along a line extending through the staple or staples or the wire stitches to form a booklet. A wire stitcher is a form of stapling machine which is fed with a continuous length of wire from which individual staples are formed by the machine.

Wire stitchers can operate continuously with a supply of wire from a roll, but these stitchers are extremely expensive. Stapling machines of the type initially described, which are supplied with pre-formed staples detachably fixed to each other closely side by side, are much cheaper, but in existing stapling machines of the kind initially described, the plunger is usually mounted on one end of an arm, the other end of which is pivoted to the guide, and in order to reload the guide with staples when a row of staples have all been used, it is necessary to interrupt the operation of the machine and move the plunger on its arm away from its operative position adjacent the guide to enable a new row of staples to be introduced into the guide in a direction transverse to that in which the staples are moved along the guide.In other forms of stapling machine of the kind initially described, some other operation is necessary to reload the stapling machine with staples, but in all cases the reloading makes it necessary to interrupt the operation of the machine.

When such machines are used in conjunction with collating machines, or booklet making machines, the interruptions which are necessary to reload the stapling machines with staples greatly decrease the output of the collating or booklet making machines. This tends to be frustrating for the operators of the machines.

The object of the present invention is to construct a stapling machine of the kind initially described in such a manner that the machine can be reloaded with staples without interrupting its operation.

To this end, according to this invention, in a power-operated stapling machine of the kind initially described, the other end of the guide is open to allow further staples to be fed to the guide without interrupting operation of the plunger, and the means for moving the staples comprises at least one friction driving wheel which, in operation, engages with a surface of the row of staples remote from the one end of the guide, and a driving wheel is rotated in a direction to push the staples frictionally along the guide, the driving wheel being arranged to engage with the surface of a new row of staples as it moves out of engagement with the end of the surface of a row of staples already held by the guide.

With this arrangement, as the operator of the machine observes that the end of the row of staples held by the guide is approaching the at least one friction driving wheel, the operator can add a further row of staples to the guide immediately behind the rear end of the row of staples already held by the guide. Thus when the driving wheel reaches the end of the row of staples already held by the guide, it immediately moves into engagement with the leading end of the new row of staples so that this row of staples is fed forwards immediately behind the preceding row of staples and accordingly after the last staple in the preceding row has been presented to the plunger, the first staple in the succeeding row of staples is immediately presented to the plunger after the plunger has made its next return stroke.

There is accordingly no interruption whatsoever in the operation of the stapling machine.

Preferably the stapling machine is conventional in that the plunger is mounted on one end of an arm which is pivotally connected to the guide, and the guide has an extension on the side of the pivotal connection of the arm remote from the anvil.

The at least one friction wheel then acts on the staples which are held by the extension of the guide.

In a preferred arrangement, there are two friction driving wheels which are rotated simultaneously and in the same direction as each other and these driving wheels engage with the surface of the row of staples one behind the other.

The surface of the row of staples which is engaged by the driving wheel or wheels is most conveniently the upper surface, that is the outside surface of the base part of the staples between their two arms. The driving wheel or wheels may, however, alternatively engage with the undersurface of the row of staples if the guide is longitudinally slotted, or with one or both side surfaces of the row of staples.

When, as is preferred, there are two driving wheels, which act upon the row of staples one behind the other, the wheels are preferably driven by a mechanism which rotates them at a peripheral speed greater than the required forward feeding speed of the staples so that the wheels slip on the surface of the row of staples. With this arrangement, if, as the leading driving wheel approaches the rear end of a row of staples, the next row of staples added to the guide does not have its leading end against the rear end of the front row of staples, the next row of staples will be fed faster by the second driving wheel so that it catches up the preceding row of staples and when only the next row of staples is subsequently engaged by the driving wheels, the preceding row of staples will be continuously fed forwards by the pressure of the leading end of the next row of staples against them.

The driving wheel or wheels may be intermittently rotated by an oscillating lever, which acts through a one-way clutch and a power transmitting wheel. The lever is then oscillated by a link which is moved by a mechanism which acts on the plunger so that the driving wheel or wheels are turned each time the plunger is reciprocated.

An example of a stapling machine in accordance with the invention is illustrated somewhat diagrammatically in the accompanying drawings in which: Figure lisa side view of the machine with parts shown broken away to illustrate internal details; and Figure 2 is a cross-section through the machine as seen in the direction of the arrows on the line Il-Il in Figure 1.

The stapling machine comprises a base 1 carrying at one end a staple-bending anvil 2. Near the other end of the base 1 are a pair of upwardly projecting lugs 3, to the upper ends of which an arm 4 is pivotally connected by a pin 5.

As shown most clearly in Figure 2, the arm 4 is of downwardly open channel-shaped section and forms a housing within which a channel 6 is contained. The channel 6 is also pivotally connected to the lugs 3 by the pin 5 and can accordingly rock upwards and downwards relative to the base 1 with the arm 4. The channel 6 can also rock relative to the arm 4 but this rocking movement is restricted by a pin 7 which passes through and is fixed to the sides of the channel 6 and engages in slots 8, one of which is shown in Figure 1, in the sides of the channel-shaped arm 4.

The channel 6 has inwardly bent portions 9 at its bottom and these portions support a bar 10, which is of rectangular cross-section and which forms a guide for rows of staples 11.

A still further channel-shaped member 1 2 is fixed within the channel 6 and to the left of the lugs 3 as seen in Figure 1, forms a slot through which the rows of staples 11 pass between its bottom 13 and the upper surface of the guide bar 10.

The channel 6 together with the guide bar 10 is biased upwards, that is in a clockwise direction, relative to the base 1 by a U-shaped spring 14 and the channel-shaped arm 4 is biased upwardly relative to the channel 6 by a second U-shaped spring 1 5. This upward movement is restricted, as already mentioned, by the engagement of the pin 7, which is fixed to the channel 6, in the slots 8 in the sides of the channel-shaped arm 4.

The arm 4 carries, at its end remote from its pivot pin 5, a blade-like plunger 1 6 which extends downwards through a slot 1 7 in the channel 6 and the bottom end of which engages with an end staple 1 a in the row of staples 11.

An abutment 18 is mounted on the top of the arm 4 adjacent the plunger 16 and is acted upon by a movable core 19 of a solenoid 20. When the solenoid 20 is energised, the core 19 moves downwards and swings the arm 4 downwards about its pivot pin 5. The downward movement of the left-hand end of the arm 4 is transmitted by the spring 1 5 to the channel 6 and thence to the guide bar 10 so that this assembly, including the plunger 1 6 is swung downwards towards the anvil 2 against the action of the spring 14. Before this movement takes place, a stack of papers is inserted between the bottom end of the staple 1 a and the anvil 2 and the downward movement of the channel 6 together with the guide bar 10 ceases when the underside of the portions 9 engage with the top of the stack of paper sheets.

At this stage of the operation of the machine, the downward movement of the arm 4 together with the plunger 1 6 continues relative to the channel 6 against the action of the spring 1 5 and this causes the plunger 1 6 to force the staple 1 a through the stack of paper sheets until the tips of its arms engage with the anvil 2 and bend them over to cause the staple 1 1 a to fix the stack of sheets together.

The solenoid 20 is then de-energised and the springs 14 and 1 5 then cause the parts of the machine to move back into positions shown in Figure 1. At this stage of the operation, the row of staples 11 is moved towards the left along the guide bar 10 to move a new staple into the position of the staple 11 a where it is presented to the action of the plunger 1 6 so that the stapling machine is ready for a subsequent cycle of operations when the solenoid 20 is again energised.

Most of the construction of the machine so far described and the whole of its mode of operation is conventional.

However, in conventional machines, the pivot pin 5 passes through the guide bar 10 which terminates at the position of the lugs 3. Because of this, the portions 9 of the channel 6 are not required in order to hold the guide bar 10 in position. When all the staples in the row 11 have been used, it is necessary to move the solenoid 20 laterally away from the abutment 18 and to swing the arm 4 with the channel 6 upwardly about the pivot pin 5 relative to the guide bar 10 so that a new row of staples can be inserted over the top of the guide bar 10 in a position to the left of the lugs 3. The row of staples is urged towards the left as seen in Figure 1 by a spring-biased slider which slides on the guide bar 10 to the right of the row of staples 11 and this slider acts on the right-hand end of the row of staples which lies just above the spring 14.After the new staples have been added, the arm 4 and the channel 6 are swung downwards again and the solenoid 20 is moved back into position. Ali these reloading operations take a considerable amount of time so that there is an interruption in the operation of the machine.

To avoid this interruption, in the machine shown in the drawings, the guide bar 10 is, as already described, supported by the portions 9 of the channel 6 and its extends between the lugs 3 to the right, as seen in Figure 1 beyond the righthand end of the base 1. The channel 6 has two projecting side portions 20, one of which is shown at 21 in Figure 1. A pair of rubber driving wheels 22 and 23 are mounted on spindles 24 and 25 between the side portions 21 and the bottom parts of the peripheries of the driving sheels 22 and 23 engage with the upper surface of the row of staples 11 on the guide bar 10.

The driving wheels 22 and 23 are themselves intermittently rotated by a power-transmitting wheel 26. The power-transmitting wheel is itself intermittently rotated by a lever 27 which is connected to the wheel 26 through a one-way clutch by means of which movement of the lever 27 in a counter-clockwise direction is transmitted to the wheel 26 and thence to the wheels 22 and 23 to cause them to rotate in a clockwise direction, but return movement of the lever 27 in a clockwise direction is idle and is not transmitted to the wheel 26.

The upper end of the lever 27 is pivotally connected by a pin 28 to a link 29, which is itself pivotally connected by a pin 30 to the top righthand corner, as seen in Figure 1, of the arm 4.

Thus, in operation of the machine, every time the arm 4 is pressed downwards by the core 1 9 of the solenoid 20 to perform a stapling operation, the link 29 rocks the lever 27 in a counterclockwise direction and this causes the wheel 26 to rotate the wheels 22 and 23 in a clockwise direction and owing to the frictional engagement of these wheels with the top surface of the row of staples 11, they push the row of staples 11 towards the left. The peripheries of the wheels 22 and 23 move much further during each stapling operation than is necessary for the row of staples 11 to move towards the left to present a new staple to the plunger 1 6 and accordingly the wheels 22 and 23 slip on the upper surface of the row of staples.

As the staples are used up in successive stapling operations, the right-hand end, as seen in Figure 1, of the row of staples will eventually move to the left beyond the line of contact between the wheel 23 and the row of staples. As soon as the operator of the machine sees this happen, a further row of staples is slipped over the top of the guide bar 10 which extends further towards the right than is shown in Figure 1. The new rod of staples is then fed manually to the left until its leading end is engaged by the driving wheel 23.

During this time the staples already in the machine will continue to be moved towards the left step by step after each stapling operation by the driving wheel 22. As soon as the leading end of the new row of staples is engaged by the driving wheel 23, this row will be moved further than the row of staples engaged by the driving wheel 22 since there will at first be no slippage between the periphery of the driving wheel 23 and the upper surface of the row of staples.

Accordingly the leading end of the new row of staples 11 will rapidly be moved into engagement at the rear end of the preceding row of staples and this happens before the rear end of the preceding row of staples has moved beyond the driving wheel 22. In consequence as the driving wheel 22 moves out of engagement with the rear end of the preceding row of staples, it will immediately move into engagement with the leading end of the new row of staples and all the staples will once more be moved forwards, that is to the left as seen in Figure 1, by the intermittent rotation of the two driving wheels 22 and 23.

There is thus no interruption whatsoever in the operation of the machine by the solenoid 20 as new rows of staples are added to the machine. In consequence the machine can operate continuously for an indefinite period when stapling together successive bundles of papers which may be supplied to it manually or may be supplied into the paper holder of a collating machine or bookletmaking machine in which the stapling machine is incorporated.

Claims (7)

1. A power-operated stapling machine comprising a staple-bending anvil, a guide which is arranged to hold a row of staples detachably fixed to each other closely side by side, one end of the guide being movable towards and away from the anvil, a power-operated plunger which, in operation, is intermittently reciprocated at the one end of the guide, being moved in an operative stroke to press an end staple in the row through a plurality of paper sheets to hold the sheets together and then being moved in a return stroke, and means for moving the row of staples along the guide to present another staple to the plunger each time a preceding staple has been pressed against the anvil and the plunger has made its return stroke, wherein the other end of the guide is open to allow further staples to be fed to the guide without interrupting operation of the plunger, and the means for moving the staples comprises at least one friction driving wheel which, in operation, engages with a surface on the row of staples remote from the one end of the guide, and a driving mechanism by which the driving wheel is rotated in a direction to push the staples frictionally along the guide, the at least one driving wheel being arranged to engage with the surface of a new row of staples as it moves out of engagement with the end of the surface of the row of staples already held by the guide.

2. A stapling machine according to Claim 1 in which the plunger is mounted on one end of an arm which is pivotally connected to the guide, the guide having an extension on the side of the pivotal connection of the arm remote from the anvil and the friction wheel acting on the staples on the extension of the guide.

3. A stapling machine according to Claim 1 or Claim 2, in which there are two friction driving wheels which are rotated simultaneously and in the same direction as each other and the driving wheels engage with the surface of the row of staples one behind the other.

4. A stapling machine according to Claim 3, in which the driving wheels engage with the outside surface of a base part of the staples between side arms of the staples.

5. A stapling machine according to Claim 4, in which the driving wheels are driven by a mechanism which rotates them at a peripheral speed greater than the required forward feeding speed of the staples so that the wheels slip on the surface of the row of staples,

6. A stapling machine according to Claim 5, when dependent upon Claim 2, in which the driving wheels are intermittently rotated by an oscillating lever acting through a one-way clutch and a power transmitting wheel, the lever being oscillated by a link which is pivotally connected to the arm.

7. A stapling machine according to Claim 1, substantially as described with reference to the accompanying drawings.