GB2293128A - Punching device - Google Patents

Abstract

A punching device comprises a housing 6 carrying a main punch body 8 in the form of a plate having a plurality of integral punch members 12 projecting downwardly in a staggered array. The punch members are tapered and have a waisted portion 12c which is narrower than an operative edge portion. The device comprises an operating handle 30 pivotally mounted on the housing 6 carrying drive pinions 32 engageable with the racks 10, so that by movement of the handle 30 the punch body may be raised and lowered. <IMAGE>

Description

Title: "Punching devices" Description of the Invention This invention is concerned with improvements relating to punching devices.

Punching devices are in common use, to punch a row of holes along one edge of material, such as a stack of paper, to enable the stack to be bound together, such as by a comb binder or a wire binder.

Conventionally available machines comprise a support means upon which the material to be punched may be located, a punch mechanism comprising a body, and a plurality of punch members carried by the punch body, the support means being provided with apertures to receive the punch members on passage through the material, and means to move the punch body between a retracted position in which the punch members are spaced from the support means and an advanced position in which the punch members extend through the apertures.

According to this invention there is provided a punching device comprising: (a) a support means upon which material to be punched may be located, (b) a punch mechanism comprising a body, and a plurality of punch members of rectilinear cross-section carried by the punch body, (c) the support means being provided with apertures to receive the punch members on passage through the material, and (d) means to move the punch body rectilinearly from a retracted position in which the punch members are spaced from the support means and an advanced position in which the punch members extend through the apertures, wherein the punch members are tapered, having a waist portion which is narrower than an operative edge portion at least in one dimension.

Preferably the waist portion of the punch members is narrower than the operative edge portion in two mutually perpendicular dimensions.

Advantageously the leading end face of the punch is concave.

Advantageously the punch body comprises a punch plate, means being provided to guide the punch plate for rectilinear movement between said retracted and advanced positions, and preferably the punch members are integral with the punch plate.

Preferably the operative edge portions of the punch members are staggered.

According to this invention there is also provided a punch body for a punching device of the kind set out above, the punch body comprising a plate comprising a plurality of integral punch members of rectangular cross-section, the punch members being tapered, having a waist portion which is narrower than an operative edge portion in at least one dimension.

Preferably the plate comprises rack formations provided adjacent opposite side edges of the punch plate.

There will now be given a detailed description, to be read with reference to the accompanying drawings, of a punching device which is the preferred embodiment having been selected for the purposes of illustrating the invention by way example.

In the accompanying drawings: FIGURE 1 is a perspective view of the device which is the preferred embodiment of the invention, parts thereof having been broken away for clarity; FIGURE 2 is a sectional view showing the device in a condition preparatory to a punching operation, with a locking means in an inoperative condition; FIGURE 3 is a view showing the locking means in an operative condition; and FIGURE 4 is an enlarged view showing individual punch members of the device.

The punching device which is the preferred embodiment of the invention comprises a housing 6 carrying a punch mechanism 7 comprising a main punch body 8 in the form of a plate for rectilinear sliding movement, the punch body comprising a driving rack 10 extending downwardly along each side, and a plurality of integral punch members 12 projecting downwardly in staggered array.

The punch body 8 is mounted above a support means 16, said support means providing a channel 18 in which a stack S of material such as sheets of paper may be located, a linear array of lower die apertures 20, and two linear arrays of superposed guide apertures 22 and 24, said three arrays of die apertures comprising one aperture in each array for each of the punch members 12.

The device comprises an operating handle 30, pivotally mounted on the housing 6, and carrying drive pinions 32 engageable with the racks 10, so that by movement of the handle 30 in the direction of the arrow A of Figure 1, the punch body 8 may be caused to move downwardly relative to the housing, between an upper, retracted position, shown in Figure 1, and a lower, advanced position, shown in chain dotted lines in Figure 3. Such movement of the operating member 30 causes the punch members to move within the guide apertures 22 and 24, through the stack of material S, and through the lower aperture 20, effecting the operation of punching a series of holes into the stack of paper.

The punch body additionally carries a plurality, specifically three, auxiliary punch members 12= each of which being mounted on the main body 8 by a dovetail formation in a manner in which the punch member 12a is capable of longitudinal sliding movement relative to the main body, being permitted to fall under gravity into a rest position (shown in full lines in Figures 2 and 3) defined by engagement between a shoulder 13 of the punch member 12a and a finger 15 of the punch body in which it is retained in position in line with the remainder of the punch members 12.

Associated with each auxiliary punch member 12a is a locking device 40, each locking device comprising a locking member 42 pivotally mounted on pivot 44 and movable between an inoperative position, shown in Figure 2, and an operative position shown in Figure 3, spring means 46 being provided to urge said locking plate 42 to said operative position, in which the locking plate is interposed between the punch body 8 and the auxiliary punch member 12a. as is shown in Figure 3, in a way such that on lowering of the punch body 8, the auxiliary punch acts as though it is solid with the punch body 8.

Each locking device 40 comprises an operating member 50 pivotally mounted on a casing 52 of the device, and which may be lifted by the insertion of a figure into a recess B to cause a pin 54 to engage behind an arm 56 of the plate 42, to move the locking device against the action of the spring 44 to its inoperative position.

The operating member 50 when in the retracted position shown in Figure 2, corresponds to the associated auxiliary punch member being inoperative.

With the locking device inoperative, on lowering of the punch body 8 by use of the handle 30, the punch plate 8 and all of the punch members are lowered, a spring 23 preventing the auxiliary punch member from being carried downwardly into engagement with the stack S. On lifting of the punch body the auxiliary punch is engaged by the finger 15 and lifted. During such movement, the locking device is retained in its inoperative position, with the arm 56 riding against the pin 54.

However the spring 23 may be omitted, whereupon the auxiliary punch member 12a (when the locking member is in its inoperative position) will be carried into engagement with the stack S with the integral punch members 12, but will not exert any punching pressure thereon and will remain stationary whilst the integral punch members 12 pass through the stack in a punching operation, whilst any other auxiliary punch member 12a which is not in alignment with the stack S will pass through the apertures 22, 24, and 20 with the other punch members 12.

Thus, when the locking device is inoperative, the operating member 50 remains stationary relative to the housing whilst the punch mechanism moves between its retarded and advanced positions.

When it is desired to bring an auxiliary punch member into operation, the operating member 50 is pressed into the position shown in Figure 3, the spring 46 causing the locking member 40 to move into its operative position, in which it fills the space between a downwardly facing shoulder 17 of the punch body and an upwardly-facing shoulder 13 of the auxiliary punch member, causing the auxiliary punch member to behave as a solid member with the punch body, so that as the punch body is lowered, the auxiliary punch member compresses the spring 23 and passes through the stack of sheets S and through the die aperture 20 in a punching operation.

In this way one or more auxiliary punch members 12a may be taken out of operation to enable a stack of sheets of relatively small size to be provided with apertures along one side edge, but being spaced appropriately from the top and bottom edges. Alternatively, for use with a stack of sheets of full size, the auxiliary punches may all be brought into operation.

As is shown in Figure 4, all of the punch members 12 and 12a are tapered, having a waist 12e which is narrower than the head 12d in at least the larger dimension (i.e. that dimension along the length of the row of punches, as is shown in Figure 4) and advantageously optionally also in the perpendicular dimension. Preferably the tapering is as illustrated curvilinear in nature, although may of course be straight, enabling the punch members more readily to be withdrawn from a stack of sheets upon which a punching operation has been carried out, with reduced frictional forces, and advantageously the leading end faces of the punches are concave.

Attention is drawn to the specification of Application No. 9421086.1 (Serial No. 2280396) from which this application has been divided, and to the specification of Application No. (Serial No. ) also divided therefrom.

Claims (8)

1. A punching device comprising: (a) a support means (16, 18) upon which material to be punched may be located; (b) a punch mechanism (7) comprising a body (8), and a plurality of punch members (12, 12 carried by the punch body; (c) the support means (16, 18) being provided with apertures (20) to receive the punch members (12, 12E) on passage through the material; and (d) means (10, 30, 32) to move the punch body (8) from a retracted position in which the punch members (12, 12a) are spaced from the support means (16, 18) and an advanced position in which the punch members extend through the apertures; characterised in that of the punch members (12a) are tapered, having a waist portion which is narrower than an operative edge portion at least in one dimension.

2. A punching device according to Claim 1 wherein the waist portion of the punch members is narrower than the operative edge portion in two mutually perpendicular dimensions.

3. A punching device according to one of Claims 1 and 2 wherein a leading end face of the punch is concave.

4. A punching device according to any one of the preceding claims wherein the punch body comprises a punch plate, means being provided to guide the punch plate for rectilinear movement between said retracted and advanced positions.

5. A punching device according to Claim 4 wherein the punch members are integral with the punch plate.

6. A punching device according to any one of the preceding claims wherein the operative edge portions of the punch members are staggered.

7. A punch body for a punching device according to Claim 1, the punch body comprising a plate comprising a plurality of integral punch members of rectangular cross-section, the punch members being tapered, having a waist portion which is narrower than an operative edge portion at least in one dimension.

8. A punch plate according to Claim 7 wherein spaced rack formations are provided adjacent opposite side edges of the punch plate.