US765562A - Hydraulic press. - Google Patents

Description

No. 765,562. PATBNTBD JULY 19, 1904. E. GROWE. HYDRAULIC PRESS. APPLIOATIOH FILED our 7, 1903 2 SHEETS-SHEET 1.

N0 MODEL.

(/VVE/V 70/? Edward C'rowe No. 765,562. PATENTED JULY 19, 1904. E. GROWE. HYDRAULIC PRESS. APPLICATION FILED 00127, 1903. N0 MODEL.

2 8HEETS SHEET 2.

To all whom, it may concern:

neerand chief draftsman, Kingof Great Britain, residing at Birchholm, Bushey Wood, Totley .Rise, countyof York, England, have invented certain new and useful Improvements in Hydraulic Presses, ofwhichthe following is a specification.

ling the operation-of hydraulic presses 'used for forging and for other purposes-such, for example, as bending and testing armor-plates, fianging, and the like; and the invention has for its objects to enable the valves controlling the action of the provement on the invention for which I made lifting cylinders C.

UNITED STATES Patented July 19, 1904.

PATENT OFFICE.

.EDWARD CROWE, OF SHEFFIELD, ENGLAND, ASSIGNOR OF ONE-HALF TO DAVY BROS.,'LIMITED, OF SHEFFIELD, ENGLAND, AN INCORPO- RATED COMPANY.

HYDRAULIC PRESS.

srncmrcarxon ibrming part of Letters Patent 'No. 765,562; dated July 19, 1904.

Application filed October 7, 1903.

- Be it known that I, EDWARD CRowE, engis a subject of the 'S hefiield, in the' This invention relates to means of control-- press to be worked directly; and promptly by hand without the necessity of using auxiliary hydraulic or other fluidpressure independent of' that whereby the press-head itself is operated and to enable the speed'of descent of the press-head onto the work to be regulated at will and the presshead to be arrested at any point in its descent.

.The presentinvention consists 'in' an imprevious application for Letters Patent, filed on the 15th day of' J une, 1903, Serial No. 161,538, and will begdescribed with reference to the accompanying drawings, in which i Figure 1 is a side elevation, partly in sec-, tion, of a portion of a hydraulic press; and Fig. 2 is a. sectional elevation of the valve mechanism of the'press, showing my improvement.

In the drawings, A is the main cylinder, and B the ram for imparting the working stroke to the press-head B, the return stroke being imparted by the pistons D, working in the The pipe connections, with the cylinders A and O, are controlled by valves arranged tooperate in such manner that pressure c'anbe alternatively supplied to the main .cy linderA for making the working stroke or. to the liftinga linders C for making the returnstroka-ofilie main and liftingcylinders-can be connected at the same time with theexhau st-ta'nk or with each other and the exhaust in'such manner as to allow the Serial No. 176,077. (No model.)

inder A and the exhaust-valve F there is provided a self-closing by-pass suction-valve G,

which while permitting the main cylinder A to draw from the exhaust during the free de-' scent of the press-head B will be closed immediately the descent of the press-head is checkeduin consequence of the tool meeting the'worlgso that pressure then brought to bear on the main ram B will cause the descent of the press-head to becontinued, but at a 1 slower speed.

The supply from the pumps P to the main cylinder A is under the control of a high pressure distribution-valve E, which also conwith the main cylinder A, this latter connection being opened to afford passage of water from C to A during the descent of the main ram B. The arrangement is such that the pump-pressure has constant access to the lifting-cylinder; but owing to their smaller areatrols the connection of the lifting-cylinders C as compared with the main cylinder the pressure in the lifting-cylinder is only able to pre- Vail, and thus lift the press-head B, when by the closure of the high-pressure distributionvalve E the supply of pressure is cut off from the main cylinder A. The exhaust from the main cylinder is under the control of the exhaust-valve -F, while the connectionof the main cylinder Awith the exhaust J for the j admission of water to .the main cylinder dur-' ing the idle part of the descent of the presshead B is permitted by the opening of the suction-valve G, (closed by the spring g,)

which controls a by-pass ppnnectipn with the.

exhaust J and permits of flow in only one di-' rection when the exhaustevalve-F is closed. .The upper e'ndpf the main cylinder A'is connected by a pipe at with the valve-box of the valves G and F and througha constantlyop'en passage f around the latter valve with a passage e, which communicates by way of the high-pressure distribution-valve E with the delivery-pipe p from the pumps P.

The pump delivery pipe p connects,through the pipes c c, with the lower ends'of the lifting-cylindersC, and in order to regulate the speed at which the press-head B descends onto its work and to enable the press-head to be arrested and held stationary at any point in its descent two valves M and N are provided on the branch pipe 0. Of these M is selfacting and while permitting water to flow from the C prevents any return flow. This valve M is on a by-pass to the other valve, N, which is adjustable and controlled, preferably, by a screw '92, worked by a handle 0. By varying the extent to which the valve N is opened the rate at which the water escapes from the lifting-cylinders C, and consequently the speed of descent of the press-head B, can be very eflectually regulated, while by closing the valve N the descent of the press-head will be arrested entirely.

The high-pressure valve E is guided and operated by means of its spindle 6, whose diameter is equal to the mean between the greater and lesser diameters of the valve-seat, so that the valve when closed is in equilibrium, and therefore capable of being easily opened by means of the handing-lever L, as more fully described hereinafter;

The body of the exhaust-valve F is of two diameters, the portion above the annular passage f, already referred to, being of larger diameter' than that forming said passage. Above the body of the valve F is a chamber the exhaust J by way of an axial passage traversing the body of the valve F and controlled bya pilot-valve K, the pilot-valveface being of approximately the same diameter as the upper part of the valve-spindle If, so that the pilot-valve itself is balanced, and therefore easy to open.

The chamber in is in constant communication with the annular passage f by way of small holes or passages, as at 76', the collective area of the holes-lc than that of the orifice closed by the pilotvalve K that when the latter is open the water canv escape more action being as follows: Supposing the valves F and K to be closed, the former will be held firmly to its seat by the pump-pressure transmitted through the holes and acting on the top of valve F. On the pilot-valve K being opened the pressure tending to hold valve F to its seat will be relieved, and the pressure from the main press-cylinder A acting in the annular passage f upon the areaof the valve F, corresponding to the difference of its two diameters,, will cause the valve]? to rise until the area of the relief-passage through valve K is so diminished as to equal only the collective area of the holes is, and consequently pumps P into the lifting-cylinders.

the inner wall ofk, which communicates with bear upon the work.

being so much less quickly than it can enter, the

so long as there is suflicient pressure from the main press-cylinder A acting in the passage f the valve F will be caused to follow the upward movement of the pilot-valve K. When once valve F is wide open, there will cease to be any pressure in the system, and consequently there will be no resistance to overcome in closing valve F.

It is a feature of this invention that the ex-' haust-valve F and high-pressuredistribution valve E are both controlled directly by the same handing-lever L, which is fulcrumed at a fixed pointl and connected atopposite sides of the fulcrum by links 6 Z? with the valvespindles e and lairespectively, so that a movement of lever L in either direction. will open one of the valves and close the other. When the exhaust-valve F is closed, the high-pressure valve E will be held open by pressure acting upon its face, and to enable the valve E ver L or the valve-spindle a, so that before the movement'of lever L is transmitted to valve E in the direction to close that valve the valve F will have been raised from its seat sufiiciently'to relieve the pressure tend ing to hold valve Eopen. In consequence of this arrangement the valves E and F are under perfect control, and by proper manipulation of the handing-lever L they can both be held open at the same time, so as to allow the press-head B to descend onto the work and to hold the latter between the forging or other tools solely by its own weight, the water from the pumps escaping through the open exhaust-valve F, so that no other pressure than that due to the weight of the presshead and attached parts will be brought to This provision, as well as that by means of which the descent of the press-head can be regulated and arrested by means of the valve N, is of great value in enabling the work to be adjusted under the press without the necessity of interrupting the running of the pumps.

I claim 1Q In a hydraulic press, the combination of main and lifting cylinders, provisionrfor a common source of supply forboth, a selfclosing suction-valve adapted to permit the descent of the-r'press-head by gravity, a valve adapted to control connection :between the lifting-cylinders and the main. cylinder and to also control the supply of pressure from the source of power to the main cylinder and, when closed, confine the supply of said pressure to the lifting-cylinders, a valve for regulating the escape of water from the liftingcylinders, an exhaust-valve interposed between the main cylinder and the'exhaust,a

balanced pilot-valve seated in said exhaustvalve for controlling the operation thereof, and a hand-operated lever connected to said pilot-valve and to the pressure-distribution to be closed with ease the link l has a pinand-slot or equivalent connection withthe le:

valve, the connection of said valves with the lever being on opposite sides of the fulcrum thereof, whereby when the one valve is open the other valve .will be closed and vice versa, substantially as specified.

2. In a hydraulic press,the combination of v main and lifting cylinders, a common source ders, avalve for regulating the escape of water from the lifting-cylinders, an exhaustvalve interposed between the main cylinder' and the exhaust, a balanced pilot-valve seated in said exhaust-valve for controlling the operation thereof, and a hand operated lever connected to said pilot-valve and to the pressure-distribution valve, the distribution-valve having a loose connection with the lever. whereby the exhaust-valve is permitted to open slightly before the commencement of the closing movement of the pressure-distribution valve, substantially as specified.

3. In a hydraulic press the combination of main and lifting cylinders, provision for a common source-0f supply for both means for permitting the descent of the press-head onto the work by gravity, a self-acting non-return valve interposed in the supply-pipe to the lifting-cylinders and an adjustable hand-controlled valve on a by-pass to the saidxnon-return valve for the purpose of regulating the speed of descent of the press-head and arresting the same at any level, substantially as specified.

EDWARD GROWE.

Witnesses:

LUTHERJ. BARR. I BAIN L. CAMPBELL.

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