US2000208A - Sheet metal punch machine - Google Patents

Description

y 7, 1935. s. T. BALFE SHEET METAL PUNCH MACHINE Original Filed Dec. 11, 1931 5 Sheets-Sheet l I N V EN TOR.

flea/9e 7." Ba/f'z Q A TTORNEYJ May 7, 1935. G. T. BALFE SHEET METAL PUNCH MACHINE Original Filed Dec. 11, 1931 3 Sheets-Sheet 2 INVENTOR. G'earye 7 50/7 52,

ATTORNEY) y 1935- cs. T, BALFE 2,000,208

SHEET METAL PUNCH MACHINE Original Filed Dec. 11, 1951 I5 Sheets-Sheet 3 4 I N V EN TOR.

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gArrokNEx f Patented May 7,1935

PATENT OFFICE SHEET METAL PUNCH MACHINE Geom 'r. Balfe, mam, "16L, ma

Detroit Gasket 4; Manufacturing Company, Detroit, Mich, a corporation of Michigan right! application December 11, 1931, Serial No. 580,415, which intllnl is a division of Serial No.

479,734, September 4, 1930, now Patent No. 1,843,438. Divided and this application June 3, 1932, Serial-N0. 615,233

5 of, perforating sheet'material such as metal,

and more particularly to the forming of a large number of closely adjacent apertures in such a sheet, and in such a manner as not to remove any of the metal from the sheet and to give form and shape to the metal about the perforation.

An object of my invention is the manufacture of closely. perforated sheet metal plates rapidly and economically. The invention comprises a new type of machine for producing metal sheetsthus characterized and a new process of their manufacture.

It is shown as embodied in mechanism for producing a reticulated metal sheet having a particular type of perforation and wherein the sheet is punched from opposite sides to produce apertures including oppositely directed minute tangs closely spaced from one another throughout the entire surface area of the sheet on both sides thereof and arranged after a specific fashion.

There are numerous uses to which sheet metal so perforated may be placed. One use is as a base for a gasket structure such as. I have described and claimed in my copending application Serial No. 420,331, filed January 13, 1930, No. 1,776,140, issued September 16, 1930, which shows open ended protuberances having tangs projecting from the bottom thereof. Great difilculty has been experienced in perforating sheet metal as above described wherein tangs extend in opposite directions alternately throughout the width and length of the sheet.-

It is desirable that the tangs project from opposite faces in a uniform style and arrangement and that they be formed without otherwise fracturing the metal and that the sheet so perforated retain suflicient strength for the purpose for which it is to be employed.

Consequently I have provided a method of producing such sheets by which the perforations may be formed in succeeding rows, all perforations in a row being simultaneously formed, and the adjacent perforations of each row being formed from opposite sides of the sheet so as to produce spaced tangs along each row which alternately project from opposite sides to produce the aforenamed results.

My improved machine includes a plurality of individual punch unit members provided with male punches so disposed in the relative arrangement of the several units as to carry out the desired process. The several punch unit members are arranged to act upon a sheet of metal to form successive rows of perforations therein. 5

Preferably the pimch unit members are in the form of individual sheet steel discs having peripheral punch teeth and secured in a row in closely spaced arrangement upon a rotatable arbor. A similancooperating opposed arbor carrying similarly arranged discs is here illustrated with the discs of the two arbors enmeshed. Each disc, in its punch teeth, embodies a male die and a portion of a female die.

Arranged between each adjacent pair of discs is an individual sheet metal stationary stripper plate which serves to strip the metal sheet from the male dies of the rotating disc. These stripper plates are individually removable as are the discs and they are also arranged in pairs, spaced apart in the same plane, a pair between each pair of spaced discs on an arbor. Due to the enmeshed cooperation of the discs each pair of stripper plates is disposed between a pair of spaced discs on each arbor.

The stripper plates establish a planar guide for the metal sheet being acted upon by the discs. They also strip the plate after perforation from the discs. Each line or row of stripper plates, the edges of which form a. planar guide, act as an anvil for the opposed discs and cooperate with the female die portions 'of the adjacent rotatable discs to form the female dies.

A further object of the invention is to so pre sent the respective male and female dies of the discs to each other that a clearance between each male and female die is provided during their interengagement whereby the metal is tiepressed and perforated to produce tangs and the tangs given a form as the process continues.

An additional feature of the invention resides in the means employed for distributing a cooling agent, usually a lubricant such as oil, upon the die members, and the provision of means for wiping or cleaning the sheet metal after it has been acted upon by the die members, to remove any film of cooling material which may be coated or have collected thereon and thus present the finished material in condition for subsequent operations without further treatment.

Other meritorious features of my improved method and machine will be obvious from the following description taken in conjunction with the drawings wherein:

Figure l is a cross section on the line I-l of Figure 2.

Figure 2 is a vertical section along the line 2-2 of Figure 1.

Figure 3 is a section along the line 3-3 of Figure 2.

Figure 4 is an enlarged section along the line 4-4 of Figure 2.

Figure 5 is a detail view in section showing the engagement of the die members. I

Figure 6 is a detail view showing the action of the die members upon the sheet of material being treated.

Figures 7, 8, 9 and 10 are detail views of the die member and associated parts.

My punch machine comprises a base or frame l0 having upright standards l2 and I4. These standards provide bearings for two opposed rotatable arbors 6 and I8. Each of these arbors is provided with gear wheels 28 and 22 which are of identical diameter and possess the same number of teeth. Arbor I8 is driven through gear 22 from a suitable power source as by means of a chain, and the two arbors l6 and I8, therefore, rotate at the same rate of speed.

Secured transversely across the front and rear of the uprights l2 and I4, as by means of screws 26, are spaced keyway members 28 and 88. Similarly disposed keyway members 32 and 34 are secured to the opposite sides of the upright standards in a like manner. A guide and feed plate 36 is secured by means of the bracket 38 to the keyway 28 and assists in feeding the metal strips between the shafts l6 and I8.

Keyed to the keyways 28, 30, 32 and 34 and freely surrounding or partially embracing each of the shafts I6 and I 8 to permit free rotation of the shafts with respect thereto, at closely spaced apart intervals along each of the said shafts, are my stripping discs 40 having keyways 40', as shown in Figures 7 and 10. The apertures 42, where a disc, as shown in Figure 7, is employed, are somewhat elongated for purposes to be hereafter brought out. Spacing discs or bearing washers 44 are keyed to the shafts l6 and I8 by means of keys 24 fixed to the arbors within the apertures 42 of stripping discs 40. These two discs occupy the same plane, but the spacing disc 44 is of infinitesimally greater thickness than the stripping disc 48. It may, however, assume various thicknesses as occasion may require.

The punching discs 46, about the circumference of which the punch teeth 48 are arranged are keyed to the shafts l6 and I8 and held in spaced relationship thereon by the spacing discs 44. As illustrated in Figures 3, 4 and 5, the teeth 48 of the two discs 46 on each side of each spacing disc 44 are disposed in staggered relationship to each other. The punch discs, of course, revolve as a unit with the arbor upon which they are mounted.

As already stated, the apertures 42 in the stripping discs 40 are slightly elongated as shown at 4| in order that their peripheral edge will be subjected to minimum pressure and frictional wear from the rotating spacing disc or bearing washers 44 which rode therein. This is shown best in Figure 5.

It will be seen from Figures 2 and 3 that the cooperating punch discs 46 keyed to the two shafts l 6 and l 8 occupy the same plane and mesh with one another. The male dies of one disc cooperate with the adjacent stripper discs to perforate the metal sheet. In the operation of the machine as the metal sheet is fed along the guide plate 36, it is caught by the teeth of the rotating punch discs. A bevel 58 is provided at the front of the straight edge portion of each of the stripping discs 40 to facilitate the ingress of the metal sheet. Inasmuch as the teeth 49 mesh and are being rotated in opposite directions, it will be seen that the sheet of metal will be punched alternately in opposite directions by each upper and lower pair of punch discs 46 as it progresses. It will also be seen that, inasmuch as the teeth 48 of the punch discs 46 which are located on opposite sides of the stripping discs 49 are staggered, the apertures punched in the sheet of metal and extending in a row will be staggered transversely across its width. The rows are punched and formed in succession.

The metal which is displaced to form the aperture is not removed from the sheet and since the punch teeth 48 are rotating at the moment they commence their punching operation on the sheet of metal, the punch produces a small tang in the metal on the side opposite that from which it is punched. It is this tang, in contradistinction to a clean cut aperture, which renders the resultant sheet of metal particularly adaptable as a base unit for the gasket described in my aforesaid application. The projecting tangs and the sides of the apertures are given a curved shape as shown in the copending application herein referred to and it is believed that this results from the rolling action of the teeth over the sheet, and that the sheet is first deformed and the metal partially shaped for the resulting aperture and tang before the metal is actually pierced and that following the piercing the tang is further bent and shaped.

Each row of stripping discs not only functions to strip the metal sheet from the rotatable discs but it also functions as an anvil to receive the thrust of the opposed row of rotating punch discs. In addition it also serves to cooperate with the female die portions of the adjacent row of rotating punch discs to form the complete female dies for the male dies of the opposed row of rotating punch discs.

A receiving plate 52 is mounted upon a second bracket 54 which is secured to the keyway 34 on the egress side of the punch machine, and the end of the straight edge portion of each of the stripping discs 40 is cut away as at 56 for the purpose of freeing up the sheet of metal as it issues from the rotating punch discs.

In the drawings, particularly in Figure 7, I have illustrated the slight elongation of the apertures 42 in the stripping discs 40, and have indicated this at 4|. The arbors are adjustable toward or from each other to provide for movement of one or both arbors. Preferably the upper arbor is made adjustable by means of spacer blocks mounted in the frame and supporting the bearing blocks. Suitable means are provided for firmly securing the arbor in any one of its adjusted positions, as for example, spacer blocks may be disposed in the frame above the bearing blocks, and by means of adjustable screws or bolts suitably tightened to hold the bearing blocks between the spacer blocks.

Any suitable adjusting means for the upper spacer blocks may be employed, and the spacer blocks will preferably be slidable in guides arranged on the frame.

Instead of employing stripper plates of the form shown in Figure 7, these may be made arouate or semi-circular, as shown in the drawings, and in detail in Figure 10. With such a construction, the upper and lower key ways will be made vertically adjustable on the frame so as to dispose the opposed meeting edges of the stripper plates in the proper vertical spaced apart relation. By using arcuate or semi-circular plates, any possibility of wear, due to friction between the plate and the piercing disc, is eliminated.

It will thus be seen that the arbors and stripper plates may be adjusted to vary the depth of the depression and the length of the tang as required.

It will be understood that, while the machine is operated at relatively high speeds, the treatment of the metal is gradual so far as the bending, piercing and forming operations are concerned. This will be readily understood from Figure 5, where there is a gradual bending to thecenter, piercing and a gradual forming at the center to bend the tang and form it.

It will be observed that the stripper plates 40 illustrated in detail in Figure 10 are provided with recesses 60 in the side edges thereof adjacent the lower edge. The recesses 60 receive the respective keyways 28, 30, 32 and 34 and are vertically adjustable towards or away from each other, by

reason of the said keyways being slidably mounted in a vertical direction on the frame of the machine.

I may use either a stripper member of the form illustrated in Figure 7, but prefer to use a stripper member 40 of the type illustrated in the drawings and in detail in'Figure 10. By employing a stripper member as shown in Figure 10 of this application, the respective stripper members are adjustable with respect to the arbors within very delicate limits without moving the arbors and it is only where spacing of the stripper members is extended that the arbors need be moved; at the same time a great saving in metal is obtained.

Referring to Figure 2, I disclose nozzles 63 and 64 at the feed in side of the machine adapted to throw a spray of lubricant and cooling medium upon the die members and associated parts. On the other side of the machine, I disclose a blast apparatus which acts to remove any cooling medium or lubricant which has formed as a film upon the perforated sheet. Thus the sheet is caused to pass beneath a blast hood 64' having an enlarged outlet and over a transversely disposed perforate grid 66 having a dimension substantially that of the blower outlet 65. The .grid 66 will support the perforated material and the action of the blast 64' is to force any lubricant upon the perforated plate or within the openings and projections downwardly into the outlet 67 communicating with the openings of the grid 66. A suitable suction fan is sometimes connected to the outlet 61 and, therefore, the sheet is not only acted upon on its upper surface by the blower, but is subjected to a suction on its undersurface so that a thorough cleaning is obtained. This suction apparatus is not essential, the blast delivered to the upper surface of the sheet being usually suflicient. The lubricant is delivered from the outlet 61 to a suitable collector, not

shown, whence it may be pumped back and reused. The blower and grid substantially enclose a. sheet of formed material delivered from the machine, being of sufficient transverse dimension for this purpose. The surface of grid 66 is flush with receiving plate 52 as shown in Figure 2.

It will be observed that the grid which preferably consists of a plurality of transversely or longitudinally spaced bars is substantially flush with the stripper plates forming therewith a continuous path, whereby the sheet is not subjected to any bending or otherwise distorted. Furthermore, the cleaning action takes place at once as a part of the continuous operation of forming the sheet being immediately subsequent to the delivery of the sheet from the die members.

A pan G8 is disposed at the base of the machine to collect any of the cooling medium which drips therefrom.

It is to be observed that by reason of the construction employed that the punching operation is a continuous process involving the steps of forming the depressions, piercing a portion of the bottom of each depression to produce thereby a tank and then simultaneously giving form and shape to the uncut wall of the depression and to the tang, whereby a protuberance having a tang extending beyond the plane of the sheet is formed.

In this connection, it is to be observed-that the stripper plates which form a part of the female die members effectively aid not only in the shaping and forming operation, but also to maintain undistorted the space between the respective projections, so that the plane of the sheet is not changed. I

I desire to refer particularly to Figure 2 and Figures 5 and 6. It is to be observed upon reference to Figure 5 that the intermeshing teeth 48 engage each other, whereby a clearance is provided. Thus, in Figure 5, it will be noted that initially the point of the male die bears against the right side of the female die, leaving a space between the left sides of the respective die members. As the rotary motion of the die members progresses, the space between each side of the male die and each side of the female die becomes equal and then the tooth point moves toward the left side of the female die, whereby a space is created between the right side of each die. In this manner, the metal is first deformed or depressed and thereafter perforated and the metal at the bottom of said depressed portion is formed into a tang extending beyond the plane of the sheet. In other words, the initial action of the die members is to depress the metal forming closed protuberances and thereafter the bottom of such protuberances is pierced and perforated by the teeth of the dies and the metal of such bottom is not removed, but instead formed into a tang which, as stated, is beyond the plane of the material and the protuberance. This rolling motion after the piercing of the sheet not only gives form to the tang, but to the depressed portion or protuberance as well.

The metal or other strip material may be fed in lengths or continuously from a roll and it will be seen that all of the operations are consecutive to produce the finished product, and that any creases or bends in the sheet are ironed out in its passage throughthe machine by reason of the stripper plates.

In some cases I may dispense with the suction fan belowthe grid.

In addition to cleaning the sheet of films of the cooling medium which may collect thereon, the cleaning apparatus acts to remove any metal particles and other undesirable matter on the sheet. Thus the hood and grid presenting opposed enlarged openings effectively enclose the sheet while traveling therethrough and prevent any particles from escaping and injuring workmen.

While the above generally described method of punching sheet metal in this particular way and the mechanical elements utilized for thatpurpose are both novel, various other means for carrying out my method, as well as various modifications of the assembled structural units will be apparent to those skilled in the art and for that reason I intend to limit myself only within the scope of the appended claims.

This is a division of my copending application Serial No. 580,415, filed December 11, 1931, which,

in turn, is a division of application Serial No.

479,734, filed Sept. 4, 1930, Patent No. 1,843,438, Feb. 2, 1932.

To reiterate the process of this invention, it comprises making the gasket reinforcing material by presenting the sheet metal to engagement with a rotating tooth member, piercing the metal at each point of engagement of the tooth with the sheet and forming openings and walls extending laterally from the sheet about the openings and continuing the piercing operation and cutting a narrow portion of the metal in advance of each tooth at one side of each opening substantially in the plane of rotation of the teeth and pressing the severed metal laterally of the sheet and forming an elongated wall at said side of the opening which consistutes a. deformable tang for engaging the gasket material.

The gasket will be made by applying layers of the gasket material upon a substantially coextensive sheet of the sheet metal prepared in accordance with this invention and compressing the same together, whereby the tangs will penetrate the gasket material layers and be deformed either below the plane of the outer surface of the gasket layers, or forced entirely through the gasket layers and bent over at substantially right angles to lie in the plane of the outer surfaces of the gasket layers or the top edges of the deformed tangs will lie substantially in the plane of the outer surface of each gasket layer.

I claim:

1. A machine of the class described comprising opposed die members, and a cleaning instrumentality comprising a blower and a grid disposed adjacent the die members for cleaning a sheet of material immediately it passes from the die members, said grid being substantially flush with the path of travel of the sheet from said die members.

2. A machine of the class described comprising opposed die members, and a cleaning instrumentality comprising a perforate grid with a blower and a suction means on opposite sides thereof and disposed adjacent the die members,

said cleaning instrumentality acting on opposite sides of a sheet for cleaning the sheet of material immediately it passes from the die members, said grid being substantially flush with the path of travel of the sheet from said die members.

3. A machine of the class described comprising opposed die members, and a pneumatic cleaning instrumentality disposed adjacent thereto for cleaning a sheet of material immediately it passes from the die members, said instrumentality comprising a grid disposed flush with the path of travel of the sheet from the die member 4. A machine of the class described comprising opposed die members, a pneumatic cleaning instrumentality disposed adjacent thereto for cleaning a sheet of material immediately it passes from the die members, said instrumentality comprising a blower acting on the upper surface of the sheet, and a grid over which the sheet passes and forming a continuation of the path of travel of the sheet, means for supporting a sheet in its travel past the die members, said grid being substantialy flush therewith.

5. A machine of the class described comprising die members, a cleaning instrumentality comprising a blower arranged in close relation to said die members, and a plate associated with the blower for supporting a sheet after it has been acted upon by the die members, said plate being arranged to present a substantially unobstructed path to the sheet in its travel from the die members past the blower.

6. A machine of the class described comprising die members and a cleaning instrumentality comprising a blower disposed at one side in close relation to said die members, and a perforate support for a sheet ejected from said die members, said support being substantially flush with means associated with the die members for supporting the sheet while being acted upon thereby.

'7. A machine of the class described comprising die members adapted to operate on sheet material passed in working relation thereto, a blower for acting on said sheet material after it leaves the die members, and a perforate supporting plate for the sheet material disposed in proximity to said blower whereby the supporting plate supports the material while being acted on by said blower.

GEORGE T. BALFE.

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