US1757737A - Cushion for sheet-metal presses - Google Patents

Description

May 6, 1930. F, R D'E 1,757,737

CUSHION FOR SHHEl METAL PRESSES Filed Feb. 9, 1929 3 Sheets-Sheet l May 6, 1930. F, JJRODg 1,757,737

CUSHION FOR SHEET METAL PRESSES Filed Feb. 9; 1929 s Sheets-Sheet 2 May 6, 1930. F, U, I'QODE v 1,757,737 CUSHION FOR SHEET METAL PRESSES Filed Feb. 9', 1929 s Sheets-Sheet s Patented May 6, 1930 UNITED STATES PATENT; OFFICE rnnnnron .7. BODE, or CHICAGO, ILLINoIs, ASSIGNQR 'ro manounrrn 'rooI. & use.

conranr, or CHICAGO, ILLINOIS, A CORPORATION or ILL IIoIs CUSHION FOR SHEET-METAL PRESSIlS Application filed February 9, 1929. Serial No. 338,816.

This-invention relates in general to cushioning devices for presses of the character'm which the metal is shaped by means of cooperating dies, one of which is reciprocable toward and away from the other, the work being clamped or held by means of a blank .or work holding element that co-operates,

with the reciprocable die member, the blank or work holder being resisted in Its movement in one direction by a pressure pad, the

latter being resisted by the said cushion, and one of the objects of the invention is to provide improved means for controlling the re: turn of the pressure pad whereby thelatter may be prevented from directly returning with the ram of the press or the co-operating die, when the latter starts to move away from the work. 7

A further object is to provide improved means for controlling the return of the pressure pad from a movable part of the press.

To the attainment of these ends and the accomplishment of other new and useful objects as willappear, the invention consifis in the features of novelty in substantiall the construction, combination' and arrangement of the several parts hereinafter more fully described and claimed and shown in the ac-- companying drawings illustrating this invention and in which Figure 1 is a view partly in elevation, partly in section and partly broken away of .a cushioning device of this character constructed in accordance with the principles of this invention.

Figure 2 is a detail 'view partly in elevation, partly in section, partly broken away, and with-parts omitted, showing the position of the partsfof the cushion when the ram. is in a raised position. A

, Figure 3 is a view similar to Figure 2, showing the position of the parts when the. a

Y the pipe 30 and a spring controlled valve operates with the die or work holding'ele" ment 14, the latter being mounted upon the bed of the press.

Beneath the press is arranged a cushion .embodying a cylinder 15 mounted upon a suitable support 16 which latter is in turn supported preferably from the bed of the press by means of hangers 17. Within the cylinder 15 is a reciprocable piston 18 to which a piston rod 19 is connected, and the piston rod in turn is connected with the pressure pad 20 upon which pins or projections 21 rest, and which pins pass through the bed plate and are connected with the co-operating blank or work holding element 22. j v

oThe ram 12 is reciprocable preferably by means of links 23 connected with a crank shaft 24 and connected to the shaft isa fly wheel 25.

All of the above referred to parts are of the ordinary and well known construction.

The cylinder 15 is provided with an outlet openmg 26 preferably arranged adjacent the bottom thereof and communicating with this opening is a valve casing or chamber 27 which Is provided with an opening 28 which serves as an inlet and an outlet for liquid to and from the cylinder'15 and the casing 27 is also providedwith an opening 29 which serves as an Inlet for liquid to the cylinder.

Communicating with the opening 28 is a pipe 30 which receives a supply of liquid 31 from a container or receptacle 32. A fluid so supply pipe '33 has communication with the container 32 preferably adjacent the top thereof and in the pipe 33 is arranged a pressure regulating valve 3 1 of any desired construction and a pressure indicating gauge 35. .The fluid enters the container 32 above the liquid 31, the height of the liquid bein'g indicated by an indicator gauge 36, and

forces the liquid from the container through the pipe 30 and through the opening 29 into 37 is provided for closing the opening 29 to prevent liquid from flowing out of the cylinder 15- and into the pipe 30, as'shown in Figure 3,..but will open to permit the liquid to flow from the pipe 30 and into the cylinder 15, as'shown in Figure 2.

A valve 38 is provided for controlling the regulating valve 47 and a oint of communication between the open mg 29 and the pipe 30 so that when the valve 38 is unseated as shown in Figure 2, liquid under pressure in the container 32 will flow into the.v cylinder, past the valve 38, through the openin 29 to raise the piston 18.

Then, however, %he valve 38 is seated as shown in Figure 3, liquid cannot flow into the cylinder 15 when the opening 28 is closed.

A valve 39 is provided for the opening 28 so that when the opening 28 is closed and the piston 18 is lowered, a pressure will be created upon the liquid in the cylinder 15, the tendency of the pressure being to force the liquid out of the cylinder back into the container 32. This will be prevented, however, by reason of the fact that the valve 37 will be closed under such pressure, and the liquid can only flow back into a the container 32 through the opening 28 when the valve 39 is unseated.

So long as the valve 39 is seated pressure will be built up on the liquid in the cylinder 15 and when such pressure exceeds the pressure by means of which the valve 39 is seated, the valve will be opened under such pressure and the liquid will escape from the cylinder back into the container.

Therefore, in order to vary or control the resistance pressure of the liquid in the cylinder 15 against which the piston 18 and pressure pad 20 must act to resist the movement of the die or work holding element 22,.ineans are provided for varying the pressure exerted upon the valve 39 to hold the latter seated.

In the present form of the invention such means embodies a cylinder-'40 which is con-' nected with the stem 41 of the valve 39. Supported by the valve casing by means of members 42 is a cross head or member 43 in which a pipe 44 is anchored. To one end of the pipe 44 is connected a piston 45 which operatesin the cylinder 40. The pipe 44 opens through the piston 45 to deliver fluid between the piston and the bottom of the cylinder. To the pipe 44 is connected a pipe 46 through which fluidunderany desired pressure is conveyed from any suitable source of supply. Within the pipe 46 is a pressure pressure indicating gauge 48.

As the fluid pressure is admitted into the cylinder 40 through the piston 45 the cylinder will be moved with respect to the piston and the valve 39 will be seated to be held against such seat by the fluid pressure in the cylinder 40.

Therefore. in order to vary the pressure against which the valve 39 must be unseated, it is only necessary to vary the fluid pressure through the pipe 46 and in the cylinder 40.

Assuming the piston 18 in the cylinder 15 to be descending from its uppermost position and the valve 39 being seated at a predetermined pressure, it will be manifest that when .the piston descends the valve 37 will be closed and the pressure upon the liquid in the cylinder 15 created by'the piston 18 will be exerted upon the valve 39.

When the pressure in the cylinder 15 overcomes the. pressure in the cylinder 40, the valve 39 will be unseated and the liquid will flow through the pipe 30 back into the container 32, assuming the valve 38 to be closed.

After the piston has reached the limit of its lowermost movement and when the pressure in the cylinder 15 is overcome by the pressure in the cylinder 40, the valve 39 will be seated and the piston 18 will remain in itslowermost position until the liquid from the container 32 is again forced back into the cylinder 15 through the opening 26. This will occur when the valve 38 is opened. Assuming the valve 38 to be open, as shown in Figure 2, and the .valve 39 to be closed, it will be manifest'that the liquid will flow from the pipe 30, past the valve 38, through the opening 29, past the valve 37, through the opening 26 into the cylinder 15 to raise the piston 18.

The admission der 15 to raise the piston 18 may be controlled at any predetermined point in the cycle of operation of the press, but. the valve 38, which controls the return of the'piston 18, is preferably operated at a time in the cycle of operation of the press so as to prevent the piston 18 and the pressure pad 20 from immediately following the ram and die 13 when the latter start to ascend. In other words so that the piston 18 will be retained sh aft 51 that is journaled in a suitable bracket of the liquid into the cylin- 52. On the end of the rod 49 is an adjustable collar 53 with which a portion 54 of the arm 50 is adapted to engage.

Connected'also with the shaft 51 is another arm 55 and this arm" is connected by means of a link 56 with an arm 57 of'a bell crank lever,the.latter being pivotally supported as at 58 to a bracket 59. The other arm 60 of the bell crank lever is connected by means of a link 61 to an arm 62 on a rock shaft 63. Connected with the rock shaft 63 is an arm 64 that engages between spaced shoulders or collars 65 on the stem 66 of the valve 38. A spring 67 is connected by-one end with the arm 62 and is anchored to a fixed support by its other end. The normal tendency of the spring 67 is to move the valve 38 in a di rection to seat or close the latter.

If desired, the rod49 may be in two sec- The only exit under these conditions for the liquid from the cylinder is through the maticall opening 28, but as this opening is'closed by the valve 39 under a predetermined resistance pressure, it will be manifest that the only escape forJthe liquid from the cylinder 15 when'the valves 37 and 38 are-closed, will be through the opening 28.

It is thought that the operation of this vdevice will be clearly understood from-the foregoing and without any further explanation.

The valve 38, however, will be unseated by the engagement of the shoulder or collar 53 with the arm at a predeterminedtime in.

the cycle of operation of the press, that is after. the ram has started to ascend, the collar 53 being adjusted to engage and rock the arm 50 at such point. This will raise the arm 50 and also the arm 55 causing the link 56 to raise the arm 57 to shift the arm 60 to cause the link 61 to rock the shaft 63 in a direction to unseat the valve 38 against the stress of the spring 67.

When the ram 12 starts to descend, the shoulder or collar 53 will have a tendency to move away from the arm 50, but the spring 67 will cause the arm 50 to follow the collar 53 and will close the valve 38. The valve 38 will be closed before the ram reaches the limit of its downward movement and for this reason the rod 49 slides loosely through the arm 50.

While the preferred form of the invention has been herein shown and described, it is to be understood that various changes may be made in the details of construction and in the combination and arrangement of the-several parts, within the scope of the claims, without departing from the spirit of this invention.

What is claimed as new is 1. In a press, a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a cylinder and piston movable relatively one with relation to the other, a liquid column for supplying liquid to the cushion, an outlet through which liquid is discharged from the cushion, variable resistance pressure creating means for controlling said outlet, and autocontrolled means for supplying liquid om said column to said cylinder around the said resistance pressure creating means.

2. In a press, a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a cylin der and piston movable relatively one with relation to the other, a liquid column for supplying liquid to the cushion, an outlet through which liquid is discharged from the cushion, variable resistance pressure creating means for controlling said outlet, and means for supplying liquid from said column to said cylinder around the said resistance pressure creating means.

3. In a press, a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a cylinder and piston movable relatively one with relation to the other, a liquid column for supplying liquid to the cushion, an outletthrough which liquid is discharged from the cushion, variable resistance pressure creating means for controlling said outlet, means for supplying liquid from said column to said cylinder around the said resistance pressure creating means, and means controlled by a movable part of the press for controlling the second recited means.

4. In a press, a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a cylinder and piston movable relatively one with relation to the other, a liquid column for supplying liqpid to the cushion, an outlet through w ich liquid is discharged from the cushion, fluid pressure controlled variable resistance pressure creating means for controlling said outlet, and automatically controlled means for supplying liquid fromsaid column to said cylinder around the said resistance pressure creating means.

'5. In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction and embodying a cylinder and piston movable relatively one with relation to the other, a liquid supply for supplying liquid to the cushion, an outlet through which the liquid is discharged from the cushion, fluid pressure. controlled variable resistance pressure creating meansfor controlling said outlet, and automatically controlled means whereby liquid may be supplied from I said liquid supply to said cushion around the ionaround said resistance pressure creating means, means for controlling the last said passage, and means for varying at will the said fluid pressure.

7. In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad inone dircction,a liquid supply for supplying liquid to the cushion, a discharge passage from the cylinder communicating with said supply, fluid pressure controlled variable pressure creating means for controlling said discharge passage, a passage forming communication between the said supply and said cushion for delivering liquid to the cushion around said resistance pressure creating means, means for controlling the last said passage from a movable part of the press, and means for varying at will the said fluid pressure.

8. In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a liquid conduit, two passages forming communication between said cushion and said conduit, fluid pressure controlled variable resistance pressure creating means for controlling one of said passages, mechanical means for controlling the other of said passages, and means for varying at will the said fluid passage, all of said passages leading around the other passage.

9. In a press a pressure pad, an hydraulic V cushion for resisting the movement of the pad in one direction, a liquid conduit, two passages forming communication between said cushion and said conduit, fluid pressure con- 5 trolled variable resistance pressure creating means for controlling one of said passages, mechanical means for controlling the other of said passages, and means for varying at will the said fluid pressure.

10. In a ress a. pressure pad, an hydraulic cushion or resisting the movement of the pad in one direction, a liquid conduit, two passages forming communication between said conduit and the respective passages, a

-- fluid pressure controlled variable resistance pressure creating means, two valves for conpressure creating means for controlling one of said passages to the flow of the liquid in one direction with respect to the cushion, the other of said passages leading around said sure creating means for controlling one of said passages to the flow of the liquid in one direction with respect to the cushion, the

other of said pam'ages leading around said pressure creating means, two valves for con-. trolling the last said passage, each opening to the flow of the liquid in one direction, one of the last said valves operating automatically under the pressure of the liquid, and means operable from a movable part of the press for actuating the other of the valves which control the last said passage.

12. In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a liquid conduit, two passages forming communication between said conduit and the respective passages, a fluid pressure controlled variable resistance pressure creating means for controlling one of said passages to the flow of the liquid in one direction with respect to the cushion, the other of said passages leading around said pressure creating means, two valves for controlling the last said passage, each opening to the flow of the liquid in one direction, one of the last said valves operating automatically under the pressure of the liquid, means for actuating the other of the valves which control the last said passage, and meansfor varying at will the fluid pressure against which the said resistance pressure creating means is operable.

13.- In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a liquid conduit, two.

passages forming communication between said conduit and the respective passages, a fluid pressure controlled variable resistance pressure creating means for controlllng one of said passages to the flow of the l1 qu1'd 1n one direction with respect to the cushion, the other of said passages leading around said pressure creating means, two valves for con trollin the last said passage, each opening to the flow of the liquid in one directlon, one of the last said valves operating automatically under the pressure of the liquid, means tending normally to close the other of the valves which control the last said passage,

and means for opening the last said valve at a predetermined time in the cycle of operation of the press.

14. In a press a pressure pad, an hydraulic cushion for resisting the movement of the pad in one direction, a liquid conduit, two passages forming communication between said conduit and the respective passages, a fluid pressure controlled variable resistance pressure creating means for controlling one of said passages to the flow of the l1 qu1d 1n one direction with respect to the cushion, the other of said passages leading around said pressure creating means, two valves. for controlling the last said passage, each opening to the flow of the liquid in one direction, one of the last said valves operating automatically under the pressure of the liquid, means tending normally to close the other of the valves which control the last said passage, and means for opening the last said valve from a movable part of the press.

In testimony whereof I have signed my name to this specification, on this 21st day of January A. D., 1929.

FREDRICH J. RODE.

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