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.

Conventionally the apertures provided in the support means are such as to enable holes to be punched on the entire length of one edge of (e.g.) a stack of sheets of A3 paper, and difficulty is encountered when it is desired to utilise the device in relation to a stack of sheets of smaller size, e.g. A4 paper, since it is in general desirable that holes are not punched close to top and bottom edges of the stack of sheets.

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 carried by the punch body,

(c) he support means being provided with apertures to receive the punch members on passage through the material, and

(d) means to move the punch body 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 at least one of the punch members (hereinafter referred to as being an auxiliary punch member) is mounted on the punch body for longitudinal sliding movement relative thereto, locking means being provided in relation to said auxihary punch member which is movable between an inoperative condition in which said auxiliary punch member is capable of longitudinal movement relative to the punch body in a retractive direction and an operative condition in which such movement is prevented.

In this manner, by locating said auxiliary punch member in an appropriate position in a longitudinal array of punch members, said auxiliary punch member may be utilised, where it is desired to provide a relatively long array of holes, by movement of the locking means into its operative condition, and may be "taken out" by movement of the locking means to its inoperative condition where it is desired to provide a shorter array of holes.

Preferably the locking means is resiliently urged, such as by spring means, into its operative condition, operative means being provided to permit the locking means to be moved to its inoperative condition.

Preferably said operative means is adapted for manual operation, such as by finger-operation.

Preferably the other (non-auxiliary) punch members are fixed in relation to the punch body, preferably being integral therewith, and preferably each auxiliary punch member is mounted on the punch body in such a manner that, on movement of the punch body towards its advanced position, said auxiliary punch member is carried initially towards material located by the support means, and thereafter remains stationary whilst the punch body continues to advance, producing movement of the auxiliary punch member relative to the punch body in a retractive direction.

Preferably the punch device comprises means whereby each auxiliary punch member when at rest adopts a lowermost position, preferably a position in which it is in line with the remainder of the punch members.

Preferably the locking means is provided by a member mounted for movement on the punch body, preferably for pivotal movement, between an inoperative position and an operative position in which it affords an abutment between the punch body and the auxiliary punch member, so that the auxiliary punch member moves in a unitary manner with the punch body, and the non- auxiliary punch members.

Preferably the punching device comprises a plurality of such auxiliary punch members, conveniently three.

According to this invention there is also provided a punching device comprising a punch plate comprising a body portion and a plurality of punch members integral with the body portion, the plate being provided with rack formations, the device comprising pinion means engageable with the rack formations to enable the punch plate to be moved in a punching operation

Preferably the device also comprises non-integi ' punch ^ embers carried by the body portion.

Preferably spaced rack formations are provi dji osit : r : edges of the punch plate, and advantageously the punc ev. ϊses twin pinions which may be driven by power means, but whic x>r otated, to carry the punch plate to an advanced position, by a manually- uidle.

Preferably the punch plate is mounted in guide means - ding movement between retracted and advanced positions.

Preferably the punch members are tapered, having a \ tion which is narrower than an operative edge portion in at least one on, preferably two dimensions extending mutually at right angles.

In this manner the punch members, on being driven throu s-ack of sheets in a punching operation, may more readily be withdrawn thro-. the sheets with reduced stiction.

Preferably the tapering from the waist portion is curvilinear.

According to this invention there is also provided a punch body carrying a plurality of punch members, the punch members being tapered, having a waist portion which is narrower than an operative edge portion in at least one dimension, preferably two dimensions, extending mutually at right angles.

Advantageously the punch body is in the form of a plate and some at least of the punch members are integral with the punch plate.

Preferably at least one of the punch members is mounted on the punch body for movement relative thereto.

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 12a. 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 12c _. 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.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in the terms or means for performing the desired function, or a method or process for attaining the disclosed result, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.