GB1599277A - Punch and die sets - Google Patents

Description

(54) PUNCH AND DIE SETS (71) We, TIMSONS LIMITED, a British Company of, Perfecta Works, Bath Road, Kettering. Northamptonshire Nun 16 8NG, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to punches in machines (hereinafter called machines of the kind specified) and which include adjacent feed rolls rotating about spaced parallel axes and providing a feed path therebetween for a web of paper or other flexible sheet material, one of the rolls carrying a punch and the other a die, into or past which punch moves relatively to cooperate with the die to cut the web.The web may be in the form of a single thickness web or it may be in the form of a number of superposed webs which may be folded, and the expression "web" is to be deemed to cover both such cases.

The present practice in paper cutting machines is to use a one piece punch which projects from the outer surface of one roll of a pair of rolls and which cooperates with a die in the surface of the other roll. The paper is usually cut between the leading edges of the cooperating punch and die, considered in a direction of rotation of the rolls, of the punch and of the die. After some use, the leading edge of the punch wears so that the whole punch has to be replaced.

The object of the present invention is to provide in a machine of the kind specified for cutting flexible sheet material, particularly paper, a punch which is an improvement on those heretofore used.

According to the invention we provide in a machine of the kind specified, a punch, the punch comprising a main body portion having side faces extending longitudinally of the feed path and end faces extending transversely of said path, one or both of such end faces having secured thereto a cutter providing the cutting edge at that end of the punch.

One or both of the side faces of the main body portion may provide, or each provide respectively, a longitudinally extending cutting edge.

The arrangement has the advantage that the part of the punch that would otherwise wear more quickly can be replaced without the necessity of replacing the whole of the punch.

The cutter may be made from any suitable material, examples are manganese bronze, and hardened steel. The cutter may be secured to the main body of the punch by, for example, screws or adhesive.

The invention may be applied to machines of the kind specified arranged to cut a slot in the web or webs. The slot may extend laterally from a position inset from a longitudinal edge up to such edge of the web and in this case would be laterally open, or it may terminate at a position which is still inset laterally from the edge and in this case could be closed. The slot may have one boundary (its side) or one pair of boundaries (its sides) parallel to the direction of web movement along the feed path and another boundary (its end) or a pair of boundaries (its ends) perpendicular to said direction.The or each side of the slot would be cut, over the main part of its length, by a longitudinal cutting edge provided by the side face or faces of the main body portion of the punch, and the, or each of the, ends of the slot would be cut by the transverse cutting edge or edges provided by the replaceable cutter or cutters on the main body portion of the punch. At one or both ends of the slot a small part of the side of the slot would be cut by a cutting edge provided by a side face of the cutter at that end.

Adjustment means may be provided for adjusting the axial position of the rolls so that if an open-sided slot is being cut, wear on the longitudinal cutting edge of the punch can be taken up by appropriate relative axial adjustment of the rolls.

The invention will now be described, by way of example, with reference to the accompanying drawings wherein.

FIGURE 1 is a view in side elevation and in cross-section on the line 1-1 of Figure 2 of one embodiment of the invention suitable for cutting closed slots in sheet material; FIGURE 2 is a view in end elevation of the same embodiment in cross-section on the line 2-2 of Figure 1; FIGURE 3 is a view in side elevation of one of the punches incorporated in the embodiment of Figures 1 and 2, such punch being shown on an enlarged scale; FIGURE 4 is a view in cross-section of the punch on the line 44 1 of Figure 3; FIGURE 5 is a view in end elevation of the punch shown in Figure 3; and FIGURE 6 is a view similar to Figure 2 of a second embodiment of the invention suitable for cutting open-sided slots in flexible sheet material.

Referring firstly to Figures 1 to 5 of the drawings, flexible sheet material such as paper, cardboard or similar material in the form of a single web or in the form of a plurality of superposed webs is fed along a path 15 in the direction indicated by the arrow between cooperative rotatable members 10 and 11 which are driven respectively, as indicated by arrows 12 and 13, to provide the requisite feed to the flexible sheet mate rival.

The upper of the two rotary members seen in the drawing carries at least one punch 14 which is secured to a side face of a pair of rolls 10a, 10b which engage the upper surface of the sheet material on each side of the slot to be cut by the punch 14, such slot being of closed form, i.e. rectangular.

The punch cooperates with a die 1 lc forming part of the rotary member 11, the remaining components of which comprise rolls lia, 11 b for engaging the undersurface of the flexible sheet material. The die 1 Ic has at least one die cavity 30, the longitudinal edges and transverse edges of which cooperate with the corresponding longitudinal edges and transverse edges of the punch to effect cutting of the sheet material by a shearing action. The extent of inter-penetration of the punch into the die cavity 30 will be determined by characteristics of the material to be cut, e.g. its thickness, and may be adjusted as required by adjusting the radial position of the punch on the side face of roll 10a.For convenience the die 1 lc may be made as a part which is structurally separate from the rolls gila, llb but it will be understood that, if desired, all these parts may be formed integrally with each other and the circumferential face may be cut to form the die cavity 30.

Thus far described the apparatus is conventional and hence details have been omitted such, for example, as the journals on which the rotatable members are mounted, the means for adjusting the radial position of the punch and the separation of the axes 31 and 32, and any ejector mechanism which may be required to ensure that pieces cut out from the flexible sheet material are ejected from the die cavity. Further, it will be understood that although for convenience only a single punch cooperating die cavity is shown, a plurality of these may be provided at angularly spaced positions around their respective rotatable members 10 and 11.

The invention is specifically concerned with improvements in the punch 14 tcf which reference will now be made. The punch comprises a main body portion 20 which, as seen in Figure 4, may be of channel-shape in cross-section, although it could be of solid form if desired. The punch has longitudinal cutting edges 18 defined by the intersection of its top surface 33 and laterally and inwardly inclining portions 34 of its side faces which are formed adjacent to its upper face 33 and provide relief with respect to the lower main portion 35 of the side faces.

Instead of providing transverse cutting edges at the ends of the punch on the body portion 20, the latter has secured thereto replaceable cutters 21 and 22 which provide respectively transverse cutting edges 16 and 17. These are defined by the intersection of top faces 36 and 37 and the upper parts 38 and 39 of the end faces of the cutters, which upper parts incline inwardly to provide relief geometrically similar to that provided by the face portions 34. The term "upper" is used herein for convenience to denote that part of the face adjacent to the cutting edge.

The edge faces 25 and 26 of the cutters are also inclined inwardly to provide relief corresponding to that provided by the face portion 34 of the body of the cutter, the extremities of the longitudinal cutting edges of the punch being provided by the intersection of these inclined faces 25 and 26 with the top faces 36 and 37 of the cutters and forming continuations of the longitudinal cutting edges 18.

The longitudinal edges of the punch are found in practice to wear very much more slowly than the transverse cutting edges 16 and 17 which cut the ends of the slot.

Consequently it is advantageous to be able to replace the cutters 21 and 22 by new cutters when wear takes place, the cutting edges 18 of the main body outlasting two or possibly three sets of cutters 21 and 22.

The cutters are detachably secured to the ends 24, 25 of the body 20 in any suitable manner, for example by machine screws 28, location being established by means of a dowel 27 and cooperating hole in the cutter.

It will of course be appreciated that although reference has been made to cutting a closed rectangular shaped slot, the ends of the slot may be of otherwise than rectilinear form and this can readily be accomplished by utilising cutters of which the cutting edges 16 and 17 have the required non-rectilinear shape, the ends of the die cavity 30 being also correspondingly shaped.

If it is required to cut a slot which is open at one side, then only one of the longitudinal cutting edges 18 is operative. An embodiment suitable for this purpose is illustrated in Figure 6 in which parts corresponding to those already described are designed by like references, the preceding description being deemed to apply. In this case the die cavity or die cavities 30 may be formed in the roll 1 la instead of in a separate die 1 lc, although the latter expedient could be employed if desired.

Preferably means are provided for effecting relative axial adjustment between the rotatable members 10 and 11 to enable that one of the longitudinal cutting edges 18 which is in operation to be moved closer to the corresponding longitudinal edge of the die cavity 30 when wear takes place.

If the formation to be cut is of a form such that the flexible sheet material requires cutting at one end only, e.g. if it is an openended and open-sided slot, such as may be required in the production of thumb-index pages for books, then a cutter such as 21 would be provided only at the leading end of the punch. If the formation to be cut were a tongue which remains attached to the sheet at one end, then the top surface 33 of the punch would preferably be relieved towards its trailing end and the trailing end of the die cavity would omit any cutting edge, a single cutter such as 21 being secured to the leading end of the punch body.

WHAT WE CLAIM IS: 1. In a machine of the kind specified a punch, the punch comprising a main body portion having side faces extending longitudinally of the feed path and end faces extending transversely of said path, one or both of such end faces having secured thereto a cutter providing the cutting edge at that end of the punch.

2. A punch as claimed in claim 1 wherein one or both of the side faces of the main body portion provide, or each provide respectively, a longitudinally extending cutting edge or edges.

3. A punch according to claim 2 wherein each of the side faces of the main body portion which provide a cutting edge has an upper portion inclining inwardly to provide relief with respect to the adjacent cutting edge provided by such side face, and wherein the, or each, cutter includes an end face and side faces, upper portions of which are inclined inwardly in a like manner.

4. In a machine of the kind specified a punch substantially as hereinbefore described with reference to and as shown in Figures 3 to 5 of the accompanying drawings.

5. A machine of the kind specified for cutting flexible sheet material substantially as hereinbefore described with reference to and as shown in Figures 1 to 5 of the accompanying drawings or modified as shown in Figure 6.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. at one side, then only one of the longitudinal cutting edges 18 is operative. An embodiment suitable for this purpose is illustrated in Figure 6 in which parts corresponding to those already described are designed by like references, the preceding description being deemed to apply. In this case the die cavity or die cavities 30 may be formed in the roll 1 la instead of in a separate die 1 lc, although the latter expedient could be employed if desired. Preferably means are provided for effecting relative axial adjustment between the rotatable members 10 and 11 to enable that one of the longitudinal cutting edges 18 which is in operation to be moved closer to the corresponding longitudinal edge of the die cavity 30 when wear takes place. If the formation to be cut is of a form such that the flexible sheet material requires cutting at one end only, e.g. if it is an openended and open-sided slot, such as may be required in the production of thumb-index pages for books, then a cutter such as 21 would be provided only at the leading end of the punch. If the formation to be cut were a tongue which remains attached to the sheet at one end, then the top surface 33 of the punch would preferably be relieved towards its trailing end and the trailing end of the die cavity would omit any cutting edge, a single cutter such as 21 being secured to the leading end of the punch body. WHAT WE CLAIM IS:

1. In a machine of the kind specified a punch, the punch comprising a main body portion having side faces extending longitudinally of the feed path and end faces extending transversely of said path, one or both of such end faces having secured thereto a cutter providing the cutting edge at that end of the punch.

2. A punch as claimed in claim 1 wherein one or both of the side faces of the main body portion provide, or each provide respectively, a longitudinally extending cutting edge or edges.

3. A punch according to claim 2 wherein each of the side faces of the main body portion which provide a cutting edge has an upper portion inclining inwardly to provide relief with respect to the adjacent cutting edge provided by such side face, and wherein the, or each, cutter includes an end face and side faces, upper portions of which are inclined inwardly in a like manner.

4. In a machine of the kind specified a punch substantially as hereinbefore described with reference to and as shown in Figures 3 to 5 of the accompanying drawings.

5. A machine of the kind specified for cutting flexible sheet material substantially as hereinbefore described with reference to and as shown in Figures 1 to 5 of the accompanying drawings or modified as shown in Figure

6.