WO1984001540A1

WO1984001540A1 - Machine punch

Info

Publication number: WO1984001540A1
Application number: PCT/US1983/001592
Authority: WO
Inventors: Randall P Krenz
Original assignee: Effective Systems Inc
Priority date: 1982-10-14
Filing date: 1983-10-14
Publication date: 1984-04-26
Also published as: AU2209083A; EP0122283A1

Abstract

A machine for punching, embossing and otherwise pressing a work piece, has a pressing element (31) mounted to a pressure transmitting platen (25) by means of a shaft (36) having at its remote end a magnetic attachment means (32) as the sole holding element. The pressing elements (31) may be positioned on the pressure transmitting plates (25) in an essentially infinite number of positions by the magnetic attachment means (32).

Description

MACHINE PUNCH I. DESCRIPTION

Field of the Invention This invention relates to a machine driven pressing element, and more particularly to a punch wherein the cutting pieces may be positioned on the pressure applying platen in an essentially infinite number of positions by a magnetic means of attachment.

Descriotion of the Prior Art Machine punches are well known in the art and typically employ a hydraulic or mechanical punch situated above a workpiece holding table. A punch carrying platen member situated above and parallel to the workpiece is movable downwardly by hydraulic or mechanical action. Punch assemblies are usually in the form of a short rod of steel with various shapes at one end for forming, perforating, embossing or cutting. They are attached to the lower side of the punch carrying platen member. Attachment is commonly achieved by welding the punch to the punch carrying platen member or by bolting the punch to one of a multitude of holes in the punch carrying platen member surface so as to position the punch assembly in the desired position relative to the workpiece.

When the punch assemblies are driven downward, it passes through the work and into a die carried on top of the workpiece table under the workpiece. The cut material then falls into a bin below the table.

Typically, punch machines are designed for punching thousands of units. When the volume is large, it is economically justifiable to weld a punching tool assembly directly to the punch carrying platen member. However, for smaller volume jobs, repositioning a punch tool on the punch carrying platen member is time consuming and expensive. Adapting a punch machine to a different use or a different material to be cut requires substantial modifications. Even punching machines with punch tools bolted to the punch carrying platen member have a limited number of possible positions for the tools. In operation, it is desirable to have a machine that may easily go from paper to cardboard to light metal to leather for materials, and be useful for forming, perforating, embossing or cutting. It is not economically feasible to alter the punch tool arrangement on the prior art machines, unless large quantities of material are to be punched. Summary of the Invention

The present invention consists of an improvement in punch machines, particularly in positioning of the individual punches.

Hereinafter, the invention will be described with respect to a punch; it being understood that the invention is also applicable to an embossing head or shaping head.

Conventional punch machines consist of a lower table that defines a workpiece support surface. An arm overhangs the workpiece support surface and carries a hydraulic or mechanical press. The press is arranged such that the driving means is extendable downwardly toward the workpiece table. A flat plate of steel (the platen) is attached to the driving means in a position parallel to the table. The platen member is available to attach various punching tools as will now be described.

The invention provides punching tool assemblies with their upper end attached to a powerful magnet which, in turn, is positionable anywhere on the platen. The improved punch tool assemblies include a rod or shaft with one end shaped or carrying a shaped element for whatever cutting, embosssing, perforating or forming operation is desired. The other end of the shaft is attached to a powerful permanent magnet by bolts, screws or magnetic attraction. The magnet itself has an upper flat face that is positionable anywhere on the platen. The punch tool assembly is arranged such that the shaft is perpendicular to both the workpiece table and the platen to minimize undesirable torquing.

An operator merely needs to position a die plate on the workpiece table with the multiple die shapes and positions selected as desired. The required punch assemblies are then magnetically attached to the steel platen in roughly the desired positions. The operator then moves the entire press downward in incremental steps until the shaped ends of the punch assemblies nearly meet their corresponding die positions. The operator can then tap the punch assemblies with a hammer, causing the magnetically held tool assembly to slip laterally just enough to move into the desired position.

Changing from one material run to another material run is greatly simplified by the invention. A new template with the die positions as required is exchanged for an old die template, and the punch assemblies are either removed for a new set or merely tapped into the new positions as desired. Such a punching machine could economically be changed from one work shift to another for different punch positions, material usages or punching operations. Specialty purpose punches can be used, such as heated punches for cutting plastics or embossing punches for decorating leather. The invention is particularly useful when multiple pressing element assemblies are positioned over a large workpiece surface. Multiple operations performed in one press requires the ability to move each pressing element assembly about the platen ro locations above the dies in the template.

Brief Description of the Drawings The detailed description of the invention, including a preferred embodiment, is hereinafter described with specific reference being made to the drawings in which:

Figure 1 is a perspective view of a hydraulic punch machine, including pressing element assemblies of the invention;

Figure 2 is an enlarged partial side view of the punch machine through lines 2-2 of Figure 1; and Figures 3A, 3B and 3C are side views of pressing element assemblies of the invention with the attachment means shown in phantom.

Detailed Description of the Invention Figure 1 depicts a typical hydraulic punch machine. Workpiece table 10, consisting of legs 11 and cross braces 12, defines upper workpiece surface 13. To allow for material punched from a workpiece 15 to be discarded, upper workpiece surface 13 must be substantially open. Slats 14 are spaced on workpiece surface 13 at desired intervals to create a planar surface support allowing material to fall through the gaps formed between slats 14. Slats 14 are preferably formed of steel square tubing to provide strength and a firm support surface.

Die template 16, formed with shaped holes 17 in preselected positions, is placed on top of the surface formed by slats 14. Any slat 14 that is immediately below a shaped hole 17 is moved slightly so waste cut-out material can pass to a discard bin (not shown).

Punch machine support brace 18, consisting of heavy tubular support 19, is attached to table 10. Arm 21 extends at a right angle from tubular support 19 and carries driving means 22. Driving means 22 can include mechanical presses, such as screw presses, eccentric presses, crank presses and hydraulic presses. Figure 1 depicts driving means 22 operated by hydraulic pressure.

The hydraulic press includes hydraulic cylinder

23 mounted to arm 21 and piston 24 extending downward towards upper workpiece surface 13. Punch carrying platen member 25, in the form of large, flat steel, iron or other ferromagnetic plate, is rigidly attached to piston 24 such that punch carrying platen member 25 is parallel to upper workpiece surface 13. Two guide posts 26 and 27 are affixed to platen 25 at spaced locations. Posts 26 and 27 are, in turn, journaled through guides 28 and 29 which are attached to heavy guide plate 30. The guide plate 30 is attached to arm 21 such that punch carrying platen member 25 is rigidly supported and remains in a parallel plane to upper workpiece surface 13 when under load.

Hydraulic cylinder 23 is preferably double- acting, such that fluid pressure can be supplied to drive piston 24 downward and also return piston 24 and punch carrying platen member 25 to a raised position. Suitable hydraulic cylinders 23 are available from J. E. Braas Company, Eden Prairie, Minnesota. A suitable hydraulic pump means is available from J. M. Grimstad Incorporated of Minneapolis, Minnesota. Hydraulic pressure is supplied by a hydraulic pump 44 and control means 37 of the types well known to those skilled in the art of presses. These units do not form a part of the invention. Control means 37 is joined to switches 45, 46, 47 and 48 and controls the output from hydraulic power source 44.

Magnetic punch assemblies 31 of the invention include a heavy, powerful, permanent magnetic member 32 which has a flat upper face 33 and a parallel lower flat face 34. Cutting members 35 are formed of short rods or shafts 36, preferably of steel, with shaped head 38 present at the lower end for cutting, embossing, perforating or deforming. Upper end 39 of shaft 36 is attached to magnet 32.

One method of attaching the upper end of shaft 36 to magnet 32 is by drilling a countersunk hole 40 in the magnet and attaching magnet 32 to shaft 36 by a threaded screw 41 as shown in Figure 3A. Flat-headed countersunk screw 41 is employed, such that no part of screw 41 projects above magnet upper face 33. A suitable magnet is a four-pole ceramic cup assembly available from the Permag Company of Eden Prairie, Minnesota. A magnet under Permag catalog number PMC-7502T with a pull of 96 pounds and a diameter of 2.5 inches is preferred.

An alternate method of attachment is to weld a steel; iron or other ferromagnetic metal plate 42 to upper end 39 of shaft 36 as shown in Figure 3C. The upper surface of plate 43 then contacts lower surface 34 of magnet 32 and is held in position magnetically. With such a construction, all plates 42 can be of the same size to fit one size of magnets. Fewer, and only one size magnet, would be needed for multiple punch applications. Still another method of attachment, shown in Figure 3B, is to drill a hole in magnet 32, inserting shaft 36 and employing a set screw 20 through the magnet into shaft 36.

Shaped heads 38 of cutting members 35 may be in any shape as are known in the art. In operation, preformed die template 16 is positioned on top of slats 14 of workpiece table 10. Die templates can be constructed of plywood with shaped holes 17 positioned wherever desired. Slats 14 are then moved so that shaped holes 17 of die template 16 are not directly over any slat 14 as shown in Figure 2. In this manner, a punch can pass cleanly through the material and die template 16 without striking a slat. Waste cut-out material then passes through the gap formed between the slats and falls to the floor in a bin.

Punch element assemblies 31, with required shaped heads or pressing elements 38, are then selected by the operator. Each, in turn, is then affixed to the lower surface of punch carrying platen member 25 by upper face 33 of magnets 32. After roughly positioning the magnetic punch assemblies, the operator causes driving means 22 to move the platen 25 down in incremental steps until magnetic punch assembly 31 nearly touches die template 16.

To do so, the operator turns on air or hydraulic pump 44 and adjusts switch 45 which selects a run cycle or incremental cycle. The incremental cycle moves the punch carrying platen member in small increments of about one inch each time up and down switch 46 is depressed. Final positioning is readily achieved by tapping magnets 32 with a hammer, causing them to move on punch carrying platen member 25 until they are immediately above their corresponding shaped holes 17 of the template.

OPERATION The operator then raises the hydraulic piston and punch carrying platen member and places the workpiece material in position. Line 49 supplies fluid under pressure for the piston downstroke, line 50 pressurized fluid for the upstroke to raise the piston. Switch 45 is adjusted to a run cycle. Two palm buttons 47 and 48, separated for safety, are depressed, causing the punch carrying platen member and punches to descend. Release of either or both palm buttons 47 and 48 causes the punch carrying platen member to rise to a fully open position. When hydraulic pressure is applied, the punch carrying platen member, including the pressing element assemblies, contact the workpiece material to form, perforate, emboss or cut as was required.

To change the punch machine from one use to another, all an operator has to do is to change die template 16 and add or substract punch element assemblies 31, positioning them as described above.

Although the invention has been described in reference to driving means using hydraulic pressure, punching pressure may be supplied by any means. The punch element assemblies can be used for any number of purposes and may be wired to create heat cutting punches suitable for use in plastics.

Of course, aligning edges may be advantageously used in conjunction with the machine to align the workpiece as desired.

Claims

ll. WHAT IS CLAIMED IS;

1. In a punch machine comprising a machine base carrying a workpiece table, the table defining a workpiece support surface, a punch carrier platen member parallel to said support surface and means to drive said punch carrier platen member toward said workpiece support surface, the improvement comprising: punch element assemblies constructed and adapted to be positionable to said punch carrier platen member so as to extend toward said workpiece surface, said assemblies comprising a rod having an upper end and a lower pressing element end; and a magnet means having an upper flat face and a lower surface, said upper rod end attached to said lower magnet surface such that said rod is perpendicular to said magnet upper face, said punch element assemblies being magnetically and adjustably positionable on said punch carrier platen member such that said lower pressing element may be positioned at any location above said workpiece support surface.

2. In a hydraulic press comprising a support base, an upper workpiece surface, a double-acting hydraulic means, including a cylinder and a piston arranged to descend toward said workpiece surface, said piston including a punch carrying platen member mounted parallel to said workpiece surface, the improvement comprising: a punch element assembly comprising a shaft having upper and lower ends; a magnet means attached to the upper end of said shaft, said magnet including an upper flat face perpendicular to said shaft attachable to said punch carrying platen member; and a cutting member integrally formed on the lower end of said shaft.

3. A punch assembly for use in machine presses, comprising: a shaft having an upper end and a lower end shaping means; and a magnet means having a lower surface and an upper flat face adapted to be magnetically attachable to a driving means of said press and to be jointed to said upper shaft end such that said shaft is perpendicular to said magnet upper face.

4. The punch assembly of claim 3 wherein said upper end of said shaft is magnetically attached to said magnet, said upper end of said shaft including a flat plate surface perpendicular to said shaft length.

5. The punch assembly of claim 4 wherein said shaping means comprises a cutting blade.

6. The punch assembly of claim 4 wherein said shaping means comprises an embossing head.

7. The punch assembly of claim 4 wherein said shaping means comprises a forming head.

8. The punch of claim 3 wherein said upper end of said shaft is joined to said magnet means lower surface by a countersunk screw extending through said magnet means into said shaft such that no portion of said screw extends above said magnet means upper face.

9. The punch of claim 3 wherein said upper end of said shaft extends into the magnet means and is held in a fixed position by a set screw.