US1672561A - High-speed hydraulic press - Google Patents

Description

June 5, 1928. 1,672,561

w. ERNST HIGH SPEED HYDRAULIC PRESS Filed Sept. 29, 1926 2 Sheets-Sheet l SW 1. Tar-k 3 i 62 Ir 5 ll I r J-T 1| ,f belzibl' Walter Errufli June 5, 1928. 1,672,561

W. ERNST HIGH SPEED HYDRAULIC PRESS Filed Sept. 29, 1926 2 Sheets-Sheet 2 S ge Ilnk Boosier- Main C i nder- Boo s'l'cr Hale. Discharga 'Pum ject the Fatented June 5, 1928.

1 UNITED war, or MOUNT sum, 0x10, assronoa'r'o 'rna muons amass IANUFACTURING COMPANY, OF MOUNT GILEAD, OHIO HIGH-SPEED HYDRAULIC PRESS.

Application filed September 29, 1928. Serial No. 138,416.

This invention relates to hydraulic presses which are intended to be operated by fi u1d sup lied under pressure from a reversible variable delivery pump and has for an obprovision of simple and effic ent valve mechanism by which the propersequence of operations will be carried out antomatically or semi-automatically. Detail features of the invention will be apparent from the following description and t e appended claims. i

This invention relatesto certain improvements on applicants Patent 1,653,350, of December 20, 1927. i

In the drawings: Y

Figure 1 is a side elevation of one'type of press having embodied therein the present invention.

Figure 2 is a. vertical section through a valve mechanism constituting a part of the .invention.

Figure 3 is a diagrammatic view with two valve mechanisms shown in section showing the various connections from the pump to the operating mechanism of the press.

The invention may be embodied in various types of presses employed for various purposes, but is illustrated in connection with a press of the four column downward pressure type. 4 which may be formed of cast iron for the purpose of bringing the working surface to a convenient height. Above this is a heavy cast steel base B which receives the strains from the press. A- press head C is con- 4 nected to the base by-four strain rods D.

The main'downwa'rdly movable platen E is guided on the strain rods in the usual manner. There is also illustrated in Figure 1 a variable delivery reversible pump F and connections for operating the same which form no part of the present invention.

A pipe line 1 is shown as leading from the pump and has a branch 2 which communicates with two booster cylinders 3 which are intended to initiate the movement of the press ram. This line also has a connection 4 leading to a valve mechanism generally indicated at 5. From this valve mechanism a pipe 6 communicates with the main cylinder 7 above the press ram. From the upper part of this cylinder a pipe 8 communicates by the 'way of a valve mechaplate 36., the position of which may be adnism indicated generally at 9 with a surgetank 10, which has a pipe 11 communicating with the valve mechanism 5.

A second pipe 12 leads from the pump F and has a separate branch 13 communicating with the two ush back cylinders 14 which return the p aten to its upper position. This line 12 alsohas a line 15 which-com-- municates with a small'chamber underlying the stem of the valve mounted in t-he'valve mechanism 9 above mentioned- The pipe 12 also communicates with the valve mecha nism 5. i I

The valve mechanism 5 is particularly illustrated in Figure 2 but comprises a main casting 16 which is divided into four chambers 17, 18, 19, and 20. Apartition 21 between the chambers 17 and 18 is provided with a plurality of passages 23 and the partition '22- between the chambers 18 and 19 is provide'd with similar passages 24. A valve stem 26 is slidably mounted in the partitions 21 and 22 and carries at one end a head 27 lying in the chamber 19 and is adapted to close the openings 24 and at its other end a head 28 lying in the chamber 17 is adapted to close the openings 23. The valve stem is of such length that when one set oi openings is closed the other is opened.

There is shown a base A TAls'o slidably mounted in the'casing is a valve 29-which coacts with a valve seat 30 to control communication between the chambers 17 and 20. The upper end of this valve stem is guided in a bushing 31 set in the casing 16 and acting to retain a packing 32. The lower end of the valve stem has a pack-" ing 33 held in place by a cylindrical member 34 which is screwed into the casing 16.

- This member 34 has mounted therein a coil spring 35, and bears at one end against the valve'stem and at. its'other end against apisted by a screw 37 adjustably mounted in a cap 38 which is screw threaded on the open end of the member 34. In this manher the tension of the spring may be varied and the valve set to open at differing pressures. The valve mechanism 9 comprises a casing 39 having therein a passage 40 which is controlled by a valve {11. The stem 42 of this valve is separate and fits slidably in a short tubular member which is connected to the ms v y communicates with the chamber 17 will thus 7 vis set to deliver fluid end of'the pipe 15. Suitable packing 43 is provided and a small chamber 44 is formed in the tubular member just mentioned. A

perend against a fixed collar through which the valve stem 42 tends to hold the tion.

The operation of the device may be described as follows. It is assumed that it is desired to operate the press. The pump under pressure through The branch 4 of this line which slides so that this spring stem 42 in its lower posithe' line 1.

receive fluid under pressure and the valve stem 26 will slide to the right in Figure 8 so thatthe valve head 28 closes communicashown in this figure.

tion between the chambers 17 and 18 as At the same time,

-- fluid under pressure will pass through the through the valve casing 9 branch pipe line 3 and thus start 1 '29 will then be moved downwardly from the valve seat 30, opening communica- "chamber 1 main cylinder 7. As soon as the fluid under "high pressure enters the main cylinder 7,

' 8 will close the valve 41 2 I to the booster cylinders upper portion of the main cylinder 7, but the suction exerted through the pipe 8 will lift the valve 41 off its seat against the force of gravity and permit liquid to flow from the surge tank 10 and pipe 8 into the upper. portion of the main cylinder 7 behind the press mm. This action will continue until the ram meets suflicient resistance to build up the pressure in the pipe line 1 to a point where it is sufficient to overcome the force of the spring 35. The valve away tion between the chambers 17 and 20 and the chamber 20, and pipe 6 into the the back pressure exerted through the pipe and prevent this fluid from returning to the surge tank'at this time. The parts will remain in this position until the pressing operation is completed.

Thereafter, either automatically or .man

ually, the pump will be reversed and discharge fluid under pressure into the pipe line 12. The branch 13 of this line will con duct fluid to the push back cylinders 14 and immediately begin returning the ram'to its' normal upper position. At the same time the fluid entering the chamber 19 will move the valve stem 26 to the left so that the head 27 will close communication between the chambers 19 and 18. At this time the fluid under pressure will also pass through the branch 15 to the under side of the valve stem 42 and exert suflicient pressure thereon to lift the valve 41 off of its seat and permit the movement of the press. I ram downwardly. This, of course, tends to produce a vacuum in the ass from the pipe 4 through the 1 directly to the tank 10. As soon as the press ram reaches.

its upper normal position, the pump may be stopped manually or automatically or re versed to begin a new pressing operation.

It is to be noted that during this return movement, the booster rams willalso be moving upward in the booster cylinders 3 and the fluid contained in these cylinders will be forced through the pipe line 2 and branch 4 into the chamber 17 and thence into chamber 18 and through the pipe 11 to the surge tank.

It is obvious that the invention is independent of any specific type of pump so long as it is adapted to be reversed and afford a variable delivery. WVhile especially adapted to a high speed press, the invention may be applied to presses of many kinds without departing from the spirit thereof. It is obvious that features of the invention may be modified as regards their specific embodiment and it is to be remembered that the invention is limited only by the scope of the appended claims.

I claim as my invention:

1. In a hydraulic press mechanism having main, booster, and pushback cylinders, a press ram operated thereby and a surge tank; operating means which comprises a pipe line for conducting fluid under pressure to the booster cylinders, connections from the main cylinder to the surge tank including a valve which automatically opens when the fluid enters the booster cylinders, and connections from said pipe line to the main cylinder including a second valve which opens when the pressure in said pipe ine reaches a predetermined point and admits fluid under pressure from'said pipe line main cylinder.

2. In a hydraulic press mechanism having main, booster, and push back cylinders, a press ram operated thereby and a surge tank; operating means which comprises a pipe line for conducting fluid under pressure to the booster cylinders, connections from the main cylinder to the surge tank including a valve which automatically opens when the fluid enters the booster cylinders,

.and connections from said pipe line to .the

main cylinder including a second valve which opens when the pressure in said pipe predetermined point and ad-.

line reaches a mits fluid under pressure from said pipe line directly to the main cylinder.

3. In a hydraulic press mechanism having main, booster, and push back cylinders, a press ram operated thereby and a surge reaches a predetermined point and admits fiuid under pressure from said pipe line directly to the main cylinder, a. pipe line for admitting fluid under pressure to the push back cylinders to return the press rum,

in the second pipe line for opening the first named valve and permitting fluid to returnfroin the main cylinder to the surge tank, and another valve opened by pressure in said second pipe line and interposed in connections between the booster cylinders and the surge tank which permits fluid to return to the surge tank from the booster cylinders at this time.

In testimony whereof, I have hereunto ubscribed my name. means operated by the fluid under pressure:

WALTER ERNST.

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