US3776537A

US3776537A - Loader for power presses

Info

Publication number: US3776537A
Application number: US00278405A
Authority: US
Inventors: V Smith; C Smith
Original assignee: Tappan Co
Current assignee: White Consolidated Industries Inc
Priority date: 1972-08-07
Filing date: 1972-08-07
Publication date: 1973-12-04
Anticipated expiration: 1990-12-04

Abstract

A manual loader is provided in the form of a rigid frame moved by hand from a loading position in front of the press to carry the stock into the same for working on loading fingers bridging the frame, each finger having two spaced aligned parts with depressible stops for pushing and pulling stock respectively to load and unload the same. The assembly permits adjustment of spacing of finger parts for stock width variation, lateral adjustment of the fingers, and vertical adjustment thereof. During unloading, the worked piece falls freely by gravity from the loader in approaching the loading position to receive another piece to be inserted in the press.

Description

United States Patent 1191 Smith et a1.

3,677,121 7/1972 Etchell.............................. 83/563 X LOADER FOR POWER PRESSES [75] Inventors: Victor P. Smith, Mansfield; Charles Primary ExaminerHarold D. Whitehead Assistant Examiner-Mark S. Bicks Attorney-Edwin E. Donnelly, Jr.

C. Smith, Lucas, both of Ohio [73] Assignee: The Tappan Company, Mansfield,

Ohio

[57] ABSTRACT A manual loader is provided in the form of a rigid frame moved by hand from a loading position in fro of the press to ca [22] Filed: Aug. 7, 1972 Appl. No.: 278,405

rry the stock into the same for working on loading fingers bridging the frame, each finger having two spaced aligned parts with depressible stops for pushing and pulling stock respectively to load and unload the same. The assembly permits adjustment of spacing of finger parts for stock width variation, lateral adjustment of the fingers, and vertical adjustment 269/13, 214/1 BB ..B65g 9 00 100/215, 218,45;

83/81, 82, 157, 205, 206, 278, 467, 563; 214/1 BB, 1 GD, 291

[52] US. [51] Int. [58] Field of Search......................

thereof. During unloading, the worked piece falls freely by gravity from the loader in approaching the be inloading position to receive another piece to serted in the press.

m m MA in.. was 9 my C D RE n N U m h 11 Claims, 4 Drawing Figures 2,176,543 10/1939 83/563 2,769,493 11/1956 Karsoe ..269/316X PATENTEUnEc 4197s sum 1 0r 2 l k WW PATENTEDUEC 4197s 776,537

sum 2 or 2 LOAD 37 LOADER FOR POWER PRESSES This invention relates, as indicated, to a power press loader and, more particularly, to a manual loader and unloader for mechanically powered presses that shear, punch, form or assemble metal or other material by means of tools or dies.

It is a principal object of the invention to provide such a loader in the form of a manually operated slide carriage for easy and efficient insertion and removal of sheet metal parts to and from such power press.

Another object is to provide such a loader which in its actuation by the operator limits the movement of the hands of the operator of the press to a safe distance in front of the bolster plate of the same and hence the point of operation in which the dies or tools are operative for shearing, punching, forming and the like.

It is a still further object of the invention to provide such a manual loader which is readily adjustable to handle sheet metal parts or stock of varying thickness, width and length, within the practical limits of the capacity of the press.

Another object is to provide such a loader in which the sheet metal part is automatically released to a discharge chute or the like in the act of withdrawing the loader, and in a manner facilitating a convenient accumulation of the worked parts.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

FIG. 1 is a perspective view in which a mechanical power press is shown fragmented, but with its bolster and bottom die assembly and a loader in accordance with the present invention fully illustrated;

FIG. 2 is essentially a top plan view of the bottom section of the press in which the loader is located and operative;

FIG. 3 is a simplified side view of one of two loading fingers used in the invention, with parts in section and a sheet metal part supported on the loading finger in the load position for insertion in the press; and

FIG. 4 is a similar side view with the finger in the withdrawn or unloading position and the discharge chute and finished part collecting means included.

Referring now to the drawings in detail, the invention concerns only the loading mechanism associated with the bottom or stationary part of the press 10, with the latter shown only in this area and recognizable as a type which has a vertically reciprocable upper die mechanically powered by any conventional means to work sheet metal parts and the like which are inserted in and withdrawn from the point of operation by an operator standing at the open front of the press.

More particularly, such bottom structure includes of course the bottom frame or bed structure 11 of the press on which there is supported the usual heavy bolster plate 12, a likewise heavy master shoe 13 of lesser width and length on the top of the bolster plate and, on top of the latter, in this-case, a rectangular tool 14.

For purposes of illustrating the invention, the press'is one intended to punch and shear shapes in a rectangular sheet metal part, and there is accordingly provided on the tool a bottom shoe 15 having openings such as 16 therein corresponding to the cutting parts of the reciprocating upper shoe, not shown.

The new manual loader is basically in the form of a horizontally sliding frame defined by parallel left and

right rods

17, 18 supported for such movement by bushings 19 mounted horizontally at the four corners of the tool and hence outward of the ends of the tool 14. At the front, the rods are interconnected by a bar 20, by adjustable brackets which will be described more in detail later, and a similar bar 21 interconnects the rods in comparable fashion adjacent their rear ends at the back of the press, so that a rigid rectangular frame is provided that can be easily pushed by an operator, with his hands on the front bar, from the loading position shown in FIG. 1, and in FIG. 2 as well, into the press and extracted or withdrawn by pulling or reversing such manual action. Each bracket used to connect the ends of the front or rear bars to the adjacent rod end portions comprises a block 22 slidable on the rod and secured in a given position of adjustment therealong by machine screws 23 which, of course, are actuatable to free the block for such sliding adjustment and then to lock the same in the desired position. Block 22 has attached thereto a vertically adjustable angle '25, the adjustment in this case being provided by slots 26 in the angle and bolts 27 passing through such slots.

The angle 25 thus vertically adjustably attached to each rod mounting bracket also carries a stop bolt which extends adjustably inwardly or in the direction of the working area of the press, with the front stop bolts designated by reference numeral 28 and those at the rear by reference numeral 29. The ends of the front and

rear bars

20, 21 are attached to the upper horizontal flanged parts of the angles 25, and it will therefore be appreciated that, first, the bars can by virtue of such attachment to the rods be adjusted both in and out on the same and vertically with respect thereto to accommodate different sizes and thicknesses of sheet metal parts to be worked. Moreover, the

stop bolts

28, 29 at the front and rear of the loader limit respectively the insertion and withdrawal movements of the loader by abutting the master shoe 13, as shown most clearly in FIG. 2.

The illustrated embodiment of the invention employs two loading fingers 30, although the number may vary, which extend between and are adjustably secured to the front and

rear bars

20, 21. Actually, each loading finger comprises a front bar length 31 and a spaced separate but aligned rear length 32, and the blanked bottom shoe 13 has parallel grooves 33 in which the fingers can move in and out with their top surfaces flush with the top surface of the blank or knock out die. It will now be clear that the adjustment of the front and rear bars along the side rods permits the spacing between the inner ends of the loading finger parts to be varied to accommodate pieces of sheet metal which vary in width.

Moreover, the loading fingers are adjustably securedto the front and rear bars to vary the lateral spacing of the same by means of depending guides 34 which engage respectively the longitudinal edges of the bars and are locked in a given position of such adjustment along the same by set screws 35 penetrating the outermost guide sections and having handles for convenient actuation. It will of course be understood that this permits a differently configured and sized tool to be used in the press, for example, with a different blank outline but with appropriately located grooves therein in which the loading fingers can move in and out as described.

With particular reference to FIGS. 2 and 3, wherein the loader is shown in the loading condition as indicated earlier, reference numeral 36 designates a rectangular piece of sheet metal which is to be cut and/or apertured inthe particular configuration desired corresponding to the blanks in the bottom shoe, through which the cut pieces can preferably be permitted to fall freely through the bottom of the press to a suitable scrap container, not shown.

The front parts 31 of the loading fingers carry adjacent their inner ends stops 37 pivoted in recesses 38 on pivots 39 near their outer ends, and they are normally biased by springs 40 so that their upper ends project above the top surfaces of the fingers. The rear finger parts 32 are similarly provided with stops 41 in recesses 42 on pivots 43 and biased by springs 44 upwardly at their forward or inner ends. These stops thus, in each loading finger 30, face each other, and it will be evident from FIG. 3 in particular that the

recesses

38, 42 are adequate to completely contain such stops when depressed by closure of the press. The interchangeable tool carries a forwardly projecting guide 45 with a bottom flange 46 to support the inner left comer of the sheet metal part and properly locate the edge of the same. Additionally, the front and rear bars have been adjusted relative to each other on the

rods

17, 18 so that the front and rear edge portions of the stock are supported on the spaced ends of the front and rear

loading finger parts

31 and 32, with the stock abutting the forward stops 37 at its outer edge. Once the various adjustments are made for this positioning of stock, it is a relatively easy matter for the operator to properly load the sheet metal piece in such location, for example, with a suction cup applicator. The operator then pushes the loader inwardly as disclosed to place the piece on the blanked part of the tool with pins 47 at the rear edge of the same provided for abutment by the leading edge of the sheet metal piece to stop this loading action.

If the sheet metal part to be worked is of relatively light gauge and yet appreciable length, one or more ramps, such as the one shown at 48 in FIGS. 1 and 2, can be added to the tool to preclude any interference as a result of gravity bowing of the sheet metal piece, that is, by lifting and guiding the latter to the working surface of the tool.

After the sheet metal piece has thus been moved to the point of operation of the press, the latter is mechanically operated in the usual manner to reciprocate the upper cutting die, for example, against the piece to cut the same and then retract. The operator then pulls the loader forwardly and, in this action, the now raised stops 41 of the rear loading finger parts 32 engage the back edge of the piece and carry it forward as shown in the phantom outline in FIG. 4. It will be noted that the spacing of the rear stops 41 relative to the ends of the front parts 31 of the loading fingers is such that the front of the sheet metal piece is no longer supported on the latter.

As will also be evident, the distance between these rear stops 41 of the loading fingers and the adjacent free ends of the parts 32 on which they are located is such that these ends are behind the center of gravity of the piece and, accordingly, in such withdrawal or unloading operation, as soon as the worked piece clears the press, it falls by gravity onto a discharge chute 49 carrying the same to a stack collector 50.

The loader is thus ready to receive the next sheet metal part to be worked in the same manner.

As shown by the dashed outlines in FIG. 2, the operation of the loader itself by hand is limited in any event to a distance of several inches in front of the bolster plate by virtue of the front stop bolt engagement with the shoe 13. Likewise, the rear stop bolts 29 limit the withdrawal of the loader.

For convenience of illustration, the press has not been shown as equipped with any form of interlock or other safety, and it will be understood by those skilled in the art that any suitable form of device of this character would normally be incorporated. For example, a conventional barrier guard can be used just in front of the bottom shoe;electrical interlocks, requiring, for example, that both hands of the operator be used to power the press would be another example assuring operator safety.

What the loader does is to give the operator a loading station well forward of the press from which he can insert the stock without normally approaching the point of operation. This advantage obtains in forming operations obviously as well, and the loader can handle preformed parts as well as flat pieces as shown in the drawings, with various finger configurations.

We, therefore, particularly point out and distinctly claim as our invention:

1. A manual loader and unloader for power presses, comprising a frame having front, rear and side portions, means for mounting the sides of said frame for sliding generally horizontal movement thereof relative to the bottom section of the press, at least one transverse loading finger means attached to the front and rear portions of the frame to be moved thereby through the working area of the press, said loading finger means having front and rear parts spaced a predetermined first distance apart at their respective inner ends, and stop means carried by such finger parts adjacent their inner ends and spaced apart a predetermined second distance, said first distance being such that the piece to be worked can be supported for loading at its leading and trailing sections on the two finger parts, with the latter against front finger part stop means and the former spaced from the rear finger part stop means, whereby pushing the frame relatively into the press causes said loading finger means to advance the piece to the loaded position, while retraction of the frame brings the rear finger part stop means into engagement with the leading section of the piece for withdrawal of the latter, said second distance being such that the piece is supported unstably in such withdrawal only by the rear finger part and falls freely therefrom for unloading as the frame is returned to its forward loading position.

2. The apparatus set forth in claim 1, wherein the loading finger parts are adjustably attached to the front and rear portions of the frame for variably locating the finger means along the same.

3. The apparatus set forth in claim 1, wherein the front and rear portions of the frame are vertically adjustably connected to the respective side portions, thereby to vary the elevation of the loading finger means relative to the frame sides.

4. The apparatus set forth in claim 3, wherein the connections of the front and rear frame portions to the side portions are also adjustable longitudinally of the latter.

5. The apparatus set forth in claim 1, wherein the frame carries adjustable front and rear stops to engage stationary parts of the press and thereby limit the in and out sliding movement of the frame.

6. A manual loader and unloader for power presses, comprising a generally rectangular frame, means for mounting said frame on the bottom section of the press for in and out sliding movement between work loading and loaded positions, plural front finger parts attached to and extending inwardly from the front portion of the frame, plural rear finger parts attached to and extending likewise inwardly from the rear portion of the frame, pusher stop means carried by the front finger parts, and pulling stop means carried by the rear finger parts, the front and rear finger parts being spaced apart at their respective inner ends and adapted cooperatively in the loading position to support a workpiece thereon bridging the space therebetween and against the pusher stop members, thereby to be inserted in the press by inward movement of the frame to the loaded position, and withdrawal of the frame causing the pulling stop means to extract the workpiece from the press.

7. The apparatus set forth in claim 6, wherein the pulling stop means are located to engage the workpiece and move the same only after such predetermined withdrawal that it is supported only on the rear finger parts and falls freely therefrom as the frame is returned to the loading position.

8. The apparatus set forth in claim 7, wherein the pushing and pulling stop means are normally resiliently biased upwardly from within recesses in the finger parts and are depressible fully therein when engaged by working means of the press in closure of the same.

9. The apparatus set forth in claim 7, wherein the front and rear finger parts are of equal number and in respective alignment with each other.

10. The apparatus set forth in claim 7, wherein the frame carries front and rear stops projecting inwardly to abut stationary parts of the press and thereby limit the in and out movement of the frame.

11. The apparatus set forth in claim 7, wherein the front and rear finger parts can be adjusted vertically and along the width of the frame.