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Publication numberUS1975249 A
Publication typeGrant
Publication dateOct 2, 1934
Filing dateNov 20, 1930
Priority dateNov 20, 1930
Publication numberUS 1975249 A, US 1975249A, US-A-1975249, US1975249 A, US1975249A
InventorsBradley John R, Christie Lindsay R
Original AssigneeDuff Patents Company Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Press
US 1975249 A
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Description  (OCR text may contain errors)

1934 .J. R. BRADLEY ET AL 1,9752% PRESS Filed Nov. 20, 1930 5 Sheet-$heet 1 Oct. 2, 1934. J. R. BRADLEY ET AL 1,975,249

PRESS Filed Nov.

5 Sheets-Sheet 2 4 4 M M M 7 N 4 a llllll IJIIIIITII L mmmmm m mwl lim w wu m J. R BRADLEY ET AL PRESS Filed NOVa 20, 1930 5 Sheets-Sheet 3 INV ENTORE Oct. 2, 1934. J. R. BRADLEY ET AL 7 1,975,249

' PRESS v I Filed Nov. 20, 1930 SShets-Sheet 4 etc 2,1934 J. R. BRADLEY, ET AL.

PRESS Filed NOV. 20, 1930 5 Sheets-Sheet 5 Patented Oct. 2, 1934 uurrso STATES PATENT reigns 5 Claims, (01. 153 21) The present invention relates broadly to the art of metal working, and more particularly to a press adapted for the punching, bending, shaping or the like of pieces of metal. Although the utility of the invention is not limited to the particular function which it performs, it will, for purposes of a clearer understanding, be hereinafter illus' trated and referred to as a bending press.

As the size of presses has gradually increased, the weight has been correspondingly increased, until large presses have reached such tremendous sizes and weights as to be extremely expensive, cumbersome and difficult of installation. One of the principal factors contributing to the increased weight has been the fact that it has heretofore been considered essential to construct the press housing of castings, and as the loads to which the castings have been subjected have increased, the area and general mass of the castings has been likewise increased.

It is one of the objects of the present invention to provide a press constructed almost entirely of structural shapes and members as distinguished from castings, whereby the weight and cost of the press as well as its size are all appreciably decreased. The installation and operation of the press is thus facilitated and the room required for a press of given capacity materially reduced. Not only is such reduction in size desirable from the standpoint of the mill in which the press is located, but it is desirable from the standpoint of press capacity itself. This is true for the reason that with structural shapes the different frame parts of the press are more compact, therei by facilitating access to the press not only for repair purposes but for the operation thereof.

With castings as heretofore utilized; there has also been existent the problem of proper mounting of the cylinders utilized for operating the press, the cylinders usually of necessity being supported or carried outside of the main body of the casting. In accordance with the present invention this difficulty is obviated for the reason that it is possible to so assemble the structural members as to provide room for certain of the cylinders within the bodily limits of the housing or frame itself. This constitutes a distinct advantage, as will be readily apparent, not only from the standpoint of compactness, but from the standpoint of protection afforded to the working parts of the mechanism.

It not infrequently happens that it is desired to operate upon material, such as sheets, plates, strips or the like having dimensions such that the ordinary press cannot perform the operations required due to the fact that the material cannot be bodily positioned within the'press itself. The size of the cast housings heretofore utilized has precluded the provision of end windows or openings of sufficient sizes to permit the passage therethrough of work. In accordance'with the present invention the end frames, being constructedof structural members, may be readily disposed so as to provide windows or openings therethrough through which work may be inserted or removed at the pleasure of the operator, thereby making it possible by an endwise movement of the work to utilize the press for performing bending, shaping or other operations on metal bodies of materially greater dimensions in one direction than the maximum distance between theend frames of the press.

Another object of the invention is to provide a press having improved operating connections not only possessing desirable features from the standpoint of press operation, but also from the standpoint of control and adjustment of the press.

It has also been found that presses as ordinarily constructed are open to the objection that a press of given capacity cannot be economically utilized for the performance of relatively minoroperations inasmuch as the mass to be moved and consequently the power expenditure is out of proportion to the results accomplished. The present invention provides a construction possessing desirable attributes in' this respect, since the number of operating means utilized, and consequently the power developed, may be varied at the pleasure of the operator in accordance with the work being performed. In this manner there is provided what may be termed a more or less universal press, the characteristic operation of which may always be kept more or less in step with the operations beingperformed.

In the accompanying drawings we have shown for purposes of illustration only, a preferred embodiment of the present invention. In the drawings:

Figure 1 is a side elevational View partly broken away, of a press constructed in accordance with the present invention;

Figure 2 is an end elevational view, partly broken away and on an enlarged scale, of the press illustrated in Figure 1;

Figure 3 is a top plan view of the press of Figures land 2; V

Figure 4 is a detail sectional View, on an enlarged scale and partly broken away, along the line IV-IV of Figure 1, the operating cylinders being removed;

Figure 5 is a detail sectional view, similar to Figure 4, along the line V-V of Figure 1;

Figure 6 is a detail sectional View on the line VIVI of Figure 2;

Figure '7 is a vertical sectional view, partly broken away and partly in elevation, along the line VII--VII of Figure l;

Figure 8 is a detail sectional view, partly broken away and partly in elevation, along the line VIII--VIII of Figure 2, looking in the direction of the arrows.

Figure 9 is a view similar to Figure 2, but partly broken away and illustrating diagrammatically the operating characteristics for the press; and

Figure 10 is a partial side elevational view of the structure illustrated in Figure 9. 1

Referring more particularly to the drawings,

ends of the bottom girder 4 are secured in any desired manner.

Similarly, each pair of posts at their upper portion is connected by a transversely extending plate or cross-beam 7 in substantially the same horizontal plane as the top girder 3 to which the ends of the upper girder 3 are connected. Said top and bottom girders together with their crossbeams at the ends, each form supporting element of substantially H shape in which the girders are arranged to support the upper and lower dies and the actuating mechanism for one of the dies. The upper girder 3, illustrated in detail in Figures 4 and 5 comprises spaced plates 8 and 9 built up to form a girder of box section. These plates are secured to the transverse plate '7 by means of corner angles 10 effective not only for tying the parts together, but for stiffening the same. Overlying the plates 8 and 9 and further assisting in completing and strengthening the top girder, are plates 11 of different lengths and serving to form a truss as will be more apparent from Figures 1 and 3 of the drawings. The top plates 11 are tied to the box girder plates by flange angles 12. These plates are provided with registering openings 14 at predetermined spaced intervals facilitating access to pull back cylinders, as here inafter more fully described.

Carried by the bottoms of the box girder plates 8 and 9 are bottom plates 15 similarly secured to the box girder plates by flange angles 16. Extending vertically of the box girder plates and serving to stiffen the same are web angles 17 of such length as to have a driving fit between the flange angles 12 and 16.

Secured to the plates 15 and directly underlying the upper box girder 3 and overlying the bottom girder 4, are hydraulic cylinders 18, each cylinder being located substantially below an opening 19 in the bottom plates and in turn registering with the openings 14 before referred to. Positioned within each of the cylinders is a piston 20 operatively secured in any desired manner to the upper flange of an H beam 21, whereby movement of the pistons in one direction will be effective for lowering the H beam, and movement in the opposite direction effective for raising such H beam.

Secured to the under side of the H beam is a male die 22 of a shape depending upon the work which the press is to do, the die herein shown as having a relatively sharp bending edge 23. With the H beam in lower position, the bending die 22, indicated in dotted lines in Figure '7 is effective for bending material M supported on a female die 24 carried by the bottom girder 4.

" The female die is herein illustrated as'comprising a pair of standard rails mounted in normal position and secured in the desired spaced relationship by tie bolts 25 around which are spacer sleeves 26, the rails in turn being bolted in position on the bottom girder by a clamping plate 27 located therebetween and cooperating with the base flanges of the rails.

It will be apparent to those skilled in the art that a die constructed of rails as herein described not only provides an extremely inexpensive structure, but one which may be readily adjusted for causing bending at different angles. Thus by merely removing the bolts 25 and the spacer sleeves 26, and substituting new bolts and sleeves, any desired adjustment of the rails themselves may be obtained.

The pistons 20 before described are effective for accomplishing the downward movement of the H beam 21 and producing the working stroke of the press. For effecting a return movement of the parts, there is provided the pull back cylinder 28 cooperating with each of the hydraulic cylinders 18 and directly secured thereto in superimposed relationship. Mounted in each of the pull back cylinders is a piston 29, the upper end of which cooperates with a cross head 30 from which extend tie rods 31. These tie rods are herein illustrated as extending through the openings 19, through openings 32 in the base flanges 33 of the hydraulic cylinders and through suitable aligned openings in the piston heads 34 and the upper flange of the H beam 21, the upper and lower ends of the rods 31 being secured respectively to the yokes 30 and the H beam 21. Due to this construction, when fluid is admitted to the lower ends of the pull back cylinders, the pistons therein will be raised to the position illustrated in Figure 8, and the bending die drawn from its dotted line position of Figure '7 to its full line position ready for a succeeding bending operation.

It is to be noted that we have herein illustrated the H beam, which may be considered as constituting the platen or plunger of the press, as adapted to be moved by the combined action of five hydraulic cylinders 18 suitably spaced length wise thereof, and as movable to upper position by an equal number of pull back cylinders. For obvious reasons it is desirable to synchronize the movement of the hydraulic pistons in the various cylinders, and to this end I provide a shaft 35 ex tending lengthwise of the platen and mounted in suitable bearings 36 carried thereby. At each end, the shaft 35 is provided with a pinion 3'7 adapted to mesh with a rack 38 secured to a bracket 39 carried by a suitable brace 10 extending transversely between the pairs of corner posts 5. By reason of this construction, the opposite ends of the platen are caused to move substantially equal amounts, any differences being such as permitted only by torsion in the shaft 35. By making the shaft of proper dimensions, however, such torsion may be substantially eliminated.

Cooperating with and opposed to the brackets 39 are similar brackets 41 having bearing plates 42 adapted to cooperate with guide plates 43 on 1.:

deflection during the operation of the press, they.

are preferably of built up construction. To this end we preferably provide laterally extending Wings 44 preferably integral with the transversely extending plates 6 and '7 before referred to, the

entire plate being punched out to provide the windows or unobstructed spacesbefore described.

For stiffening the end plates, they may have secured thereto tapered plates 45 bolted or riveted in position through the medium of corner angles 46 on their outer sides, these corner angles extending the full height of the end plates, and by inner angles 4'7 adjacent the transverse plates '7 and similar angles 48 adjacent the transverse plates 6. Disposed 0n the opposite sides of the end plates from the tapered plates 45 are angles 49 similar to the anglesfl6 and extending the full height of the end plates. These angles are so mounted that their inwardly projecting flanges lie in the plane of the tapered plates 45 as will be clearly apparent more particularly from Figure 6 of the drawings, whereby they define the sides of the end windows. It will thus be apparent that there are provided corner posts which are braced in each of four directions, thus providing the necessary strength and stiffness without resort to cumbersome castings as heretofore utilized. The smaller space required for such structural posts makes possible the end Windows through which material may befed to or removed from the press,

In Figures 9 and 10 of the drawings there are illustrated connections by means of which the desired operation of the press may be easily obtained. In Figure 9 there is indicated a tank 50 constituting a suitable source of fluid supply having a pipe 51 leading to the inlet of a pump 52. The outlet 53 of the pump is branched, the branch 54 leading to a release valve 55the outlet of which has a connection 56 to the inlet of the pump and effective when the release valve is open for by-passing the pump and thereby preventing the generation of pump pressure in the system. The other branch 5'7 of theoutlet 53 leads toa check valve 58 of such construction as to freely permit the passage of fiuid therethrough in the direcion indicated by the arrow 59, but preventing the passage of fluid in the opposite direction.

The outlet 60 of the check valve communicates with a T 61 having a connection 63 leading to the lower ends of the pull back cylinders 28. The T also has a connection 64 leading to a twoway control valve 65. With the valve in one position it will permit fluid to flow from the pull back cylinders by way of connections 63, T 61 and connection 64 to pipes 66 leading to the hydraulic cylinders 18, thus permitting the pull back cylinders to discharge into the hydraulic cylinders,

while with thc'valve in its other position, it will permit fluid to flow from the hydraulic cylinders by way of the pipe 66 to a return line 6'7 discharging into the tank or reservoir 50.

The release valve 55 is suitably carried by the frame of the press in such manner that the valve stem 68 thereof may cooperate with a pivoted lever 69 carrying the counterweight '70. Secured to the lever 69 is a cable '71 passing upwardly over a pulley 72 and thence downwardly over a second pulley '73 on the box girder 3 to a weight '74, heavier than the counterweight '70 and effective for overcomingthe same. As the press reaches its upper position, the upper surface of the H beam or platen 21 will engage. the weight '74 and lift the same, thus releasing tension on the cable '71 and permitting the counterweight to move downwardly and open the release valve 55, thus bypassing the pump 52 and releasing pressure from the system. At this time, however, descent of the platen will-be prevented by the pull back cylinders, the fluid being trapped in these cylinders through the medium of the check valve 58. This condition will continue until such time as it is desired to set thepress into operation. At such time, the control valve 65 will be operated to connect the pull back cylinders to the hydraulic cylinders so that the pull back cylinders will discharge into the hydraulic cylinders permitting the platen to descend by gravity. After this movement has been initiated, the platen 21 will withdraw from supporting relationship with the,

weight '74 which will in turn be effective for overcoming the counterweight) and closing the release valve 55 whereby the pump by-pass is closed and the pump pressure directed into the hydraulic cylinders 18 for forcing the platen down- Wardly.

t such time as the down stroke has progressed to the desired point, an adjustable stop screw '75 carried by the platen 21 will engage a bell crank '76 and swing the same about its pivotal mounting '77 to release the tail '78 thereof from holding engagement with a lever '79 having a pivotal mounting 80. Connected to the lever is a cable 81 to one end of which is secured a weight 82, the opposite end passing upwardly over a pulley 83 and around a pulley 84 and then attached to the cable '71. When the tail '78 moves out of engagement with the lever '79, the weight 82 is effective for overcoming the weight '74, lifting the same and thus enabling the counterweight '70 to open the release valve 55. In this manner the down stroke of the platen is automatically stopped at a predetermined time depending upon the adjustment of the stop screw 75. Suitable adjustment of this screw enables the stroke of the press to be lengthened or shortened at the will of the operator as will be readily apparent.

In case of necessity, the operator may check the down stroke at any desired interval by means of the trip handle 85. Outward movement of this handle against the spring 86 will be effective for swinging the bell crank '76 and releasing the lever '79.

When it is desired to lift the male die, the operator bears down on the handle portion 87 of the lever '79, thereby lifting the weight 82, closing therelease valve 55 and reestablishing fluid pressure in the system, the control valve 65 at this time having been turned to such position as to permit the hydraulic cylinders to discharge therethro-ugh into the return connection 67, whereby the pressure of the pump will be effective only in the pull back cylinders." It will be apparent that the downward movement of the handie portion 8'7 of the lever '79 causes it to move past the bell crank lever which immediately snaps into holding engagement therewith under the influence of the spring 86.

We have herein illustrated all of the hydraulic cylinders as cooperating with a single platen. From Figure 2 of the drawings, however, it will be apparent that the connection 66 from the control valve has an independent connection 66 to each of the hydraulic cylinders, each of which connections is controlled by an individual valve 88. Thus if desired, any number of the hydraulic cylinders may be quickly out out of operation to effects. corresponding change in the capacity of the press. The invention also lends itself to a division of the platen 21 into a plurality of parts each under the control of an individual hydraulic cylinder or under the control of any number of hydraulic cylinders, thus giving a number of individual presses each of the desiredcapacity for the performance of a particular operation. In such case a suitable change in the number of control valves may be made so as to provide for the desired automatic control of any. cylinder or group of cylinders.

Advantages of the invention arise from the provision of a structural frame and particularly from the provision of such a frame having end Windows and from the provision of a box girder within which the pull back cylinders may be positioned.

Further advantages arise from the provision of a press including a plurality of hydraulic cylinders or other operating means of such construction and so mounted that any number may be utilized at will independently of the others, or simultaneously therewith for the operation either I, I of a single platen or a plurality of different platens.

Still other advantages obtainable from a female die of the construction referred to, and from the automatic control features whereby automatic shut-01f on the down stroke of the press is obout departing either from the spirit of the invention or the scope of our broader claims.

We claim:

1. A bending press having a frame comprising upper and lower supporting elements of substan tially H shape built up of structural shapes,

formed of two cross-beams and a girder connected to the intermediate portions of the crossbeams, posts built up of structural shapes connected to the ends of cross-beams of the supporting elements, a die member supported on the girder of each element, and means on one of the elements for actuating the die member associated therewith.

2. A bending press having four spaced apart I posts built up of structural shapes, a lower supporting element of substantially H shape built up of structural shapes, formed of two crossbeams and a girder connected to the intermediate portions of the cross-beams, each end of each cross-beam being connected to one of the posts, an upper supporting element of substantially H shape built up of structural shapes, formed of two cross-beams and a box-girder connected to the intermediate portions of the cross-beams of said upper supporting element, each end of each cross-beam of the upper supporting element being connected to one of the posts, a stationary die member secured to the girder of the lower supporting element, a movable die member above the fixed die member, and means on the box girder for supporting and moving the movable die member relative to the fixed die member.

3. A bending press having four spaced apart posts built up of structural shapes, a lower supporting element of substantially H shape built up of structural shapes, formed of two cross-beams and a girder connected to the intermediate portions of the cross-beams, each end of each crossbeam being connected to one of the posts, an upper supporting element of substantially H shape built up of structural shapes, formed of two cross-beams and a box-girder connected to the intermediate portions of the cross-beams of said upper supporting elements, each end of each cross-beam of the upper supporting element being connected to one of the posts, a stationary die member secured to the girder of the lower supporting element, a movable die member above the fixed die member, a hydraulic cylinder connected to the bottom of the box girder, a piston in said cylinder connected to the movable die member, a pull back cylinder above the hydraulic cylinder within the box girder, a pull back piston within the pull back cylinder extending upwardly within the box girder, a cross head on the outer end of the pull back piston within the girder, and pull back rods connected to the cross head and the movable die member.

l. A bending press having four spaced apart posts built up of structural shapes, a lower supporting element of substantially l-l shape built up of structural shapes, formed of two cross-beams and a girder connected to the intermediate portions of the cross-beams, each end of each crossbeam being connected to one of the posts, an upper supporting element of substantially H shape built up of structural shapes, formed of two cross-beams and a box-girder connected to the intermediate portions of the cross-beams of.

said upper supporting elements, each end of each cross-beam of the upper supporting element being connected to one of the posts, a stationary die member secured to the girder of the lower supporting element, a movable die member above the fixed die member, a plurality of hydraulic cylinders connected to the bottom of the box girder, a piston in each of said cylinders connected to the movable die member, a pull back cylinder above each of the hydraulic cylinders within the box girder, a pull back piston within each of the pull back cylinders extending upwardly within the box girder, a cross head on the outer end of each pull back piston within the girder, and pull back rods connected to each of the cross heads and the movable die member.

5. In a press, a stationary die, a movable die, a piston and cylinder for operating the movable die, a pull back piston and cylinder for retracting the die, a fluid pressure supply for continuously supplying fluid, fluid connections between said supply and the two cylinders, valve means in said fluid connections for connecting either cylinder with the fluid pressure supply and exhaust the fluid from the other cylinder, a release valve in said fluid connections arranged to by-pass the fluid around the cylinders when opened, and means associated with the movable die arranged to open the release valve When the die has moved apredetermined distance in either direction, to stop the movement of the die, regardless of the pressure in either cylinder, Without shifting the first valve means and without stopping the flow from the fluid pressure supply.

JOHN R. BRADLEY. LINDSAY R. CHRISTIE.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2848034 *May 19, 1955Aug 19, 1958Ohio Commw Eng CoVariable pressure fluid actuated brake beam compensation
US3023799 *Oct 18, 1957Mar 6, 1962Robert G LetourneauPress
US3835682 *Sep 21, 1972Sep 17, 1974Mannesmann Meer AgHydraulic presses
US5067340 *May 3, 1989Nov 26, 1991Macgregor Donald CPrecision press brake
DE3943349C2 *Dec 29, 1989Aug 23, 2001Amada CoBlechbiegemaschine
Classifications
U.S. Classification72/20.1, 72/441, 72/453.6, 100/256, 100/269.8, 100/214
International ClassificationB21D5/02
Cooperative ClassificationB21D5/02
European ClassificationB21D5/02