US2557265A - Hydraulic press - Google Patents

Description

June 19., 1951 w. c. DENIISON, JR

HYDRAULIC PRESS 2 Sheets-Sheet 1 Filed Nov. 6, 1944 I l -1.-.I

INVENTOR.

N m G W June l951 w. c. DENISON, JR 2,557,265

' HYDRAULIC PRESS Filed Nov. 6, 1944 2 Sheets-Sheet 2 "Patented June 19,1951

" UNITED William 0. D9niiii:er&mwell, Ohio, assignor to The v Ohio, acorporation of Ohio a 'Application liovember e. 1944, s 562,24; 1 j;

This invention relates to improvements in hydraulic presses, and has to do particularly with the construction of the machine housing and the provision of a motor-pump unit supported therein.

One of the objects of the invention is the provision of a simpliiled construction for the purpose stated which shall be well adapted for quantity production at relatively low cost.

, Another object is the provision of a motorpump unit embodying a horizontal partition member separating the housing into an upper motor chamber and a lower pump chamber, and forming the means for mounting the unit in the housing. e

-' Another object is the provision of a cushioned mounting for the unit which shall absorb vibration and reduce noise.

A further object is the provision of an improved pressure relief valve which shall avoid chatter and shall drain 011 any leakage of pressure liquid back to the sump.

ZOther objects and features of novelty will appear as I proceed with the description of those elmbents oi the invention which, for the purposes of the present application, I have illusgtrated in the accompanying drawings, in which Fig. i is a side elevational view of a bench type hydraulic press embodying the invention f Fig. 3 is a detail vertical sectional view taken substantially on the line of Fig. 2, but on a. larger scale.

E Fig. 4 is a fental elevational view, partly vertical section, of a modified form of motorpump unit, and

Fig. 5 is a perspective view of manual control means which may be employed in connection with the invention.

Referring first to. Figs. 1. 2 and 3 of the drawings, I have sho therein a single casting including a main vertical portion it divided into a lower pump chamber ii and an upper motor chamber 52. This vertical portion of the housing is preferably substantially rectangular in horicylinder H which has a flange I at its lower end for the reception of fastenings I by means .of which the cylinder is secured to the housing.

A valve H for controllingthe flow of liquid to and from the power cylinder is attached to that 4 cum. (cute-In) 2 is a top plan view of the same. 30

parent from the drawings, the top ofthe machine housing is open exceptior a cross-brace It, in order-to provide ready access to the working parts and to promote ventilation for cooling. 8 Inthe bottom of the housing there is a forwardly projectinghorizontal portion 20 providing a work table 2| beneath the ram 22.

Manual-control means for operating the valve l'l comprises a vertical rod 23 which is movable up and down by the manipulation of two hand levers 24 which are pivotally mounted about a common axis 25 and are connected with rod 23 by a transverse bar indicated at 26. Any other suitable means for operating rod 23 may be sub- 15 stituted for'that herein disclosed. I

The chamber II is closed so far as its bottom 2 At the upper end of this chamber there is a horizontal ledge 21 which projects inwardly a I short distance from all four side walls. A substantially rectangular horizontal partition it rests upon this ledge.' For this purpose the 25 partition is formed with a flange 25 overhing the ledge and a perimetrical wall it so dimensioned as to leave a small space between it and the inner surface of ledge 27. A resilient gasket.

of the press, becauseit eliminates machining of the supporting and supported surfaces. Ma-

chining of these surfaces is not necessary for alignment purposes because accurate'alignment of the unit with respect to the housing is not required. The partition 28 may be tied to the ledge 21 by any suitable means, such as screws 32 extending through holes in flange it into threaded openings in ledge 21.

An electric motor 35 of the vertical type supplies the necessary power. It has a special lower bell 38 which is formed integral with partition 28, and in fact constitutes part of the partition.

From the lower side of the partition, concentric with the motor axis, a casing or frame flprojects downwardly, being rigidly supported upon the partition. A pump housing 38 is rigidly supported upon frame 31. The liquid pump enclosed within the housing 38 has a vertical shaft cylinder by studs or the like ll. As will be ap- 89 which is operatively connected by a suitable *3 coupling II with the vertical shaft ll of the motor. these two shafts being "thus disposed in cleanses pump housing It on one side, while the discharge from the pump is taken by another conductor 43 .which extends up to and is connected with a fitting 4| mounted in the partition 28. In the partition there is a cavity ll formed in the casting operation. Fitting 44 connects conductor 43' with this cavity. Directly above fitting 44 another fitting It is mounted in the partition and serves to connect cavity II with an upwardly extending conductor 41 which leads to the intake side of valve l'l. Exhaust liquid from valve I1 is transmitted through a conductor 48 which extends downwardly through partition 28 and into the sump. preferably terminating below the normal liquid level therein soas to avoid splash and aeration of the oil.

in order to control the pressure of the liquid delivered by the pump I provide a pressure relief valve which I mount preferably in the partition ll. To this end I form a bore ii in the partition which extends downwardly to the cavity 45 and a short distance below the cavity. I then form a slightly smaller bore II concentric with the first and extending the rest of the way through the partition. 52 is a plug mounted in the bore i and supported by the annular shoulder between bores It and 5!. The joint between this plug and the bore ii is preferably sealed by gasket '3. Plug 82 is hollow, being threaded at its lower end to receive a conductor 54 which extends down into the sump. Conductor ll communicates with an axial passage 55 through the plug at the top of which is a valve seat disposed within the cavity ll,

In the bore 50 I mount a casing II which has a shoulder it engaging a boss on the top of the partition, and a gasket 59 to seal the joint around the casing. A central bore '0 is formed in the casing in which is slidably mounted a plunger ti that is pressed downwardly by a coil spring 62, the upper end of which bears against an adlusting screw 63 that E threadably mounted in the casing above the bore 60. A look nut 54 serves to hold the screw 83 in adjusted position.

Plunger it has a conical lower extremity 65 forming a valve piece which is adapted to engage the seat 56. part of the conical surface extending into the passage 55 when the valve is closed, and part of it remaining above the seat. That part which remaim above is exposed at all =times to whatever pressure of liquid exists in cavity 45. In addition, I may slightly reduce the diameter of the plunger above the conical surface 65 in order to .provide an annular shoulder .6 as a further surface normally exposed to the pressure in cavity 45. From this description it will be apparent that when the pressure in cavity 45 rises to a predetermined height, its action upon the exposed part of the conical surface it and upon the shoulder 66 will cause the plunger to rise in opposition to the spring 82. As soon an, inasmuch as reduced area of the plunger is exposed to the liquid pressure normally, the spring I! may be smaller'and of less strength than would ordinarily be required to handle a given pressure. In the event that any pressure.

liquid leaks past the plunger, that is upwardly along its outer wall, the oil which collects in the bore." can drain out through a passage 1 drilled axially through the plunger. 1

In Fig. 4 I have illustrated a somewhat different motor-pump unit. In this modification the motor has a lower bell II which, as in the first described form, is integral with a partition 'Il ha'ving ailange ll similar to and functioning in partition ii and is discharged through a passage It also formed in the partition. The pump per se forms no part of the present inventionand therefore is not disclosed in detail herein. The inlet passage 15 is connected with the sump by a conductor 11, while the live liquid flowing through passage 16 is carried to the control valve I'I by a conductor It similar to conductor 41.

In this form of the invention I employ a pressure relief valve which is mounted in the partition in communication with the liquid delivery passage I6 and is adapted to by-pass liquid back into the sump. In this modification there is a single casing 18 which projects through the up per and lower walls of the partition and intermediate of its length consists merely of vertical der 83 on the plunger. The plunger 84 is pressed downwardly toward seat 8| by a spring 85. There is a by-pass 86 similar to by-pass and a drain passage 81 similar to passage 61. The purpose and operation are the same as in the first described form of the invention.

In the foregoing description I have necessarily gone somewhat into detail in order to explain fully the particular embodiments of the invention herein illustrated, but I desire it to be understood that such detail disclosures are not to be construed as amounting to limitations except as they may be included in the appended claims.

as the plunger leaves the valve seat it, that part of the plunger which was formerly enclosed by the valve seat also becomes exposed to the liquid pressure in cavity 45. Hence, after the valve is opened a reduced pressure will serve to maintain Having thus described my invention, I claim:

1 In a hydraulic press, a housing having a vertical portion and integral lower and upper forwardly projecting horizontal portions spaced apart, said lower horizontal portion comprising a work table, a power cylinder and control valve carried in said upper horizontal portion, the lower part of said vertical portion forming a closed chamber providing a sump, a ledge extending inwardly from the sides of said verticalportion at an intermediate point in its height, a motor and pump unit supported by said ledge with the motor above the ledge and the pump therebelow, and liquid connections from said pump to said control valve and from said control valve back to said closed pump chamber.

2. In a. hydraulic press, a housing having a vertical portion and integral lower and upper forwardly projecting horizontal .portions spaced apart, said lower horizontal portion comprising a work table, a power cylinder and control valve carried in said upper horizontal portion, the lower part Of said vertical portion forming a closed chamber providing a sump, a ledge extending inwardly from the sides of said vertical portion at an intermediate point in its height, a motor and pump unit supported by said ledge with the motor above the ledge and the pump therebelow, and liquid connections from said pump to said control valve and from said control valve back to said closed pump chamber, the motor and pump unit having vertically aligned shaft means for direct transmission of power from the motor to the pump.

3. In a hydraulic press, a housing having a vertical portion and integral lower and upper forwardly projecting horizontal portions spaced apart, said lower horizontal portion comprising a work table, a power cylinder and control valve carried in said upper horizontal portion, the lower part of said vertical portion forming a closed chamber providing a sump, a ledge extending inwardly from the sides of said vertica1 portion at an intermediate point in its height, a'motor and pump unit supported by said ledge with the motor above the ledge and the pump therebelow, liquid connections from said pump to said control valve and from said control valve back to said closed pump chamber, and resilient packing interposed between said ledge and the supported surface of said unit. I

4. In :a hydraulic press, a housing having a vertical portion and integral lower and upper forwardly projecting horizontal portions spaced apart, said lower horizontal portion comprising a work table, a power cylinder and control valve carried in said upper horizontal portion, the lower part of said vertical portion forming a, closed chamber providing a sump, a ledge extending inwardly from the sides of said vertical portion at an intermediate point in its height, a motor and pump unit supported by said ledge with the motor above the ledge and the pump therebelow, liquid connections from said pump to said control valve and from said control valve back to said closed pump chamber, and a common shaft for said motor and pump unit extending vertically through said partition.

WILLIAM C. DENISON, J R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,745,800 Kramer Feb. 4, 1930 1,800,333 Wertz Apr. 14, 1931 1,904,864 Jongedyk Apr. 18, 1933 1,934,155 Deventer Nov. 7, 1933 1,934,189 Grier Nov. 7, 1933 2,086,295 Ernst July 6, 1937 2,139,373 McKinley et a1. Dec. 6, 1938 2,158,478 Parker May 16, 1939 2,273,214 McConaghy Feb. 17, 1942 2,319,232 Holmes et a1. May 18, 1943 2,383,153 Parsons Aug. 21, 1945 2,393,406 Parsons Jan. 22, 1946 FOREIGN PATENTS Number Country Date 9,012 Australia of 1927 527,919 Great Britain Oct. 18. 1940 683,535 France of 1930

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