US2204270A

US2204270A - Surge valve for hydraulic presses

Info

Publication number: US2204270A
Application number: US204971A
Authority: US
Inventors: Richard W Dinzl
Original assignee: WATSON STILLMAN CO
Current assignee: WATSON STILLMAN CO; WATSON-STILLMAN Co
Priority date: 1938-04-29
Filing date: 1938-04-29
Publication date: 1940-06-11
Anticipated expiration: 1957-06-11

Description

June 11', 1940.

R. w. DlNzl. 2,204,270

SURGE VALVE FOP. HYDRAULIC PRESSES Filed April 29, 1938 ATTORNEYS Patented June 11, 1940 UNITED STATES 2,204,270 SURGE VALVE FOR HYDRAULIC PRESSES Richard W. Dinzl, Westfield, N. J., assignor to The Watson- Stillman Co., Roselle, N. J., a co1'- poration oi' New Jersey Application April 29, 1938., Serial No, 204,971

2 Claims.

This invention relates to improvements in a hydraulic press of the type having an oil reservoir known as a surge tank? mounted over the main press cylinder, and a surge valve to control fiow between the tank and cylinder.

Important objects oi the invention are to provide, for such a press, a surge valve of improved design, and to provide a surge valve designed for quick and easy removal and replacement.

Other objects of the invention will appear herelnafter.

In the drawing,

Fig. 1 is a diagrammatic View showing, partly in elevation and partly in section, -a press apparatus embodying the invention;

Fig. `2 is an enlarged vertical sectional view of the surge valve device;

Fig. 3 is a horizontal section on the line 3-3 of Fig. 2*.; and

Fig. 4 is a view similar to Fig. 2, upon-a reduced scale, showing a modied form of the surge valve device.

Heretofore the arrangement and mounting of a surge valve have been such as to render` it very d-iicult to remove and replace the'v'alve.` Usually the valve'is disposed at the lower end of the port connecting the surge tank and the press cylinder and is adapted to close said port by upward shift. The seat for the valve is borne by a bushing. tted in the port. In order to remove the valve it is necessary to dismantle its mounting and remove said bushing so that the valve can be withdrawn upwardly through the port. This is a laborious operation and it keeps the press out of service for considerable time. The present invention provides an improved design and arrangement oi the valve, the valve mounting and the valve seat, providing for quick and easy removal and replacement of the valve.

The press, as indicated in Fig. 1, has a fixed lower press head I and a movable upper press head 2. A ram 3 bears the upper press head and is reciprocable in a xed main hydraulic press cylinder 4. Push-back plungers 5 depend from the head 2 and are reciprocable in fixed, hydraulic push-back cylinders 6. The upper head is advanced toward the lower head by hydraulic pressure in the main cylinder and retracted by hydraulic pressure in the push-back cylinders. A surge tank 1 mounted upon the main press cylinder has a bottom port 8 opening into the cylinder. This port is opened and closed by a surge valve device 9. At Illl there is'indicated a main control valve device. This device controls the operations of the press head advancing and retracting mechanisms and the operations of the surge `valve device.v

The surge valve device includes a vertical cylinder` Il with end flanges I2. The cylinder has a bore I3 of one diameter along the lower half `g; of. its length, and a bore, or counterbore, I4 of larger diameter extending from the bore I3 to the upper end of the cylinder. At its upper end the cylinder is closed by a head plate I5 having a sealed fit in the upper end of the counterbore. 10 A plunger-type valve I6 is fitted in the cylinder. The valve has a cylindrical shank portion I1 tted to reciprocate in the bore I3, and an integral pistony head portion I8 fitted to reciprocate in the counterbore I4. The length ofthe shank matel5 rially exceeds that of the bore I3 andthe depth ofthe piston head is materially less than the length of the counterbore. At its upper end the valvehas a deep central recess I9, and the under face of the head plate I5 has a shallow recess 20 20 opposed to recess I9. A coiled compression spring 2| has. its ends seated in said recesses and constantly urges the valve downward. The head plate has a central bore 22 for connection of a control pipe 23, and the cylinder has a side port 25 24, at the lower end of the counterbore, for connection `of a control pipe 25. The cylinder anges and `the head plate have registering bolt holes 26 receiving bolts 21, for securing the valve device in `place and also securing the head plate to the cylinder.v In the present instance there are four of these bolts equally spaced around the cylinder.

In the present instance thecasting forming the main press cylinder 4 valso forms the bottom 28 of the surgetank and has a raised fiat central 35 portion 29 Within the tank.` The port 8 extends through said. raised portion and is counterbored at its upper end to receive a metal ring 3l whose upper face forms a seat 32 for the surge valve. As shown, said seat may be flush with the upper surface 33 of the raised portion. Said surface 33 hasthreaded sockets 34 spaced around the port 8 to correspond to the spacing of the bolts 21 around the cylinder Il. The bolts are screwthreaded at both ends, and their lower ends are screwed into the sockets 34 to hold the valve device centered over the port. Spacer collars or washers 35 encircle the bolts and are interposed between the lower cylinder flange and the surface 33 to support the cylinder spaced above said surface. 'I'hereby space is afforded beneath the cylinder for lio-W of oil to and from the port 8. This laterally open space also affords access to the valve seat 32 and to the lower end surface 36 of the valve, for cleaning them. Said end surface of the valve is flat and smooth to seat fully upon the seat 32. Nuts 31 are screwed upon the upper ends of the bolts to hold the cylinder down upon the spacers 35 and also hold the cylinder head tight upon the cylinder.

Piping 38 leads from the control valve device lil to the main press cylinder, and the pipe 23, leading to the upper port 22 of cylinder Il, is connected to this piping. Other piping` 39 leads from the control valve device to the push-back cylinders 6. To the piping 39 the pipe 25, leading to the side port 2li of the surge valve cylinder is connected. The structure ofthe control valve device and the means for operating it are not shown as they form no part of the present invention.

When the control valve device ID is operated to relieve hydraulic pressure in the push-back cylinders, through the piping 39, the upper press head will descend by gravity. Until a die D borne by said head is brought to bear upon the work W this gravity descent will continue and the thrust of the descending push-back plungers 5 will maintain pressure upon the oil in the piping 39 and also in the connected pipe 25. This pressure, delivered by pipe 25, will actupon the under side of the piston head I8 of the surge valve and hold thefvalve up in open position, against the resistance of the spring 2|. Therefore, as the ram 3 descends, oil can ilow from the surge tank through port 8 and into the main press cylinder to pre-fill the latter.

Simultaneously with the said withdrawal of oil from the push-back cylinders the control valve device l0 admits oil through the piping 3B to the main press cylinder and also through the pipe 23 to the upper end of the surge valve cylinder. However, pressure cannot build up in the press cylinder and in the upper end of the surge valve cylinder while the surge valve is held open. When, however, descent of the press head is arrested by contact of the die D with the work, the pressure in the push-back cylinder and in the

piping

39 and 23 quickly falls. Consequently the pressure at the under side of the piston head of the surge valve drops and the spring 2l closes the surge valve. Pressure then develops in the main press cylinder to perform the pressure operation. The pressure in the press cylinder is transmitted through the piping 38 and 23 to the upper side of the piston head of the surge valve and is assisted by the spring pressure to hold the surge valve closed. As the area at-the upper end of the surgevalve subject to said pressure materially exceeds the area at the lower end of the valve subject to the pressure the valve is iirmly held down upon its seat.

For retraction of the upper press head the control valve device is operated to relieve pressure in the main cylinder 3 through the piping 38 and admit pressure through the piping 39 to the pushback cylinders. Thereby, through the pipe 23, pressure is relieved at the upper side of the piston head of the surge valve and pressure is admitted through pipe '25 to the under side of said piston head to force the surge valve upward to open position.

When it is required to remove the surge valve device for servicing or replacement either the nuts 3l or the bolts 21, or both, may be unscrewed and the

pipes

23 and 25 disconnected from the cylinder. 'Ihe entire surge valve device can then be easily removed upwardly from` the surge tank and from the valve seat 3l. Replace ment of the device can obviously be accomplished easily and quickly.

In the modified form of the surge valve device, shown in Fig. 4, the port 22 and the pipe 23 are omitted and the valve I6 is provided with a longitudinal central passage 49 leading from its lower end to the recess I9 in its upper end. Through this passage hydraulic pressure is conducted from the press cylinder d to the upper side of the piston head of the valve, for holding the valve seated.

What I claim is:

1. In a hydraulic press of the type set forth, including a press cylinder, a surge tank over said cylinder and having at its bottom a port connecting it with the press cylinder, and a surge valve for closing and opening said port, a seat for said valve facing upwardly and surrounding said port, a mounting for said valve comprising a cylinder, the valve being shiftable in the latter cylinder by iiuid pressure and supported by the cylinder for Vertical reciprocation to close upon said seat by downward movement and open by upward movement, and releasable fastening means detachably holding said valve cylinder in place within the surge tank, the valve cylinder being supported spaced above the bottom of the surge tank for lateral' ow therebeneath to and from said port, said seat and the seating face of the valve being located for lateral access through the space beneath the valve cylinder, and the valve and valve cylinder being constructed and arranged for removal as a unit from said seat and surge tank.

2. In a hydraulic press of the type set forth, including `a press cylinder, a surge tank over said cylinder and having at its bottom a port connecting it with the press cylinder, and a surge valve for closing and opening said port, a seat for said valve facing 'upwardly and surrounding said port, a mounting for said valve comprising a cylinder, the valve being shiftable in the latter cylinder by iluid pressure and supported by the cylinder for vertical reciprocation to close upon said seat by downward movement and open the port by upward movement, means supporting the valve cylinder spaced above the bottom of the surge tank for lateral flow therebeneath to and from said port, and releasable fastening means detachably holding said valve cylinder in place Within the surge tank, the valve and valve cylinder being constructed and arranged for removal as a unit from said seat and surge tank.

RICHARD W. DINZL.