US1773821A - Hydraulic accumulator - Google Patents

Description

MACK ET AL HYDRAULIC ACCUMULATOR Aug. 26, 1930.

Filed v001;. 24, 1928 2 Sheets-Sheet 1 Zn/en 501's Aug. 26, 1930. MACK ET AL I 1,773,821

umnwmc AGCUMULATOR Filed Oct. 24, 1928 2 Shoots-Sheet 2 Jrwenfar Patented Aug. 26, 1930 UNITED STATES MARTIN MACK AND WI LHELM GRbTZINGER, OF STUT'IGART -CANNSTATT, GERMANY HYDRAULIG'ACCUMULATOR Application filed October 24, 1928, Serial No. 314,824, and in. Germany September 28, 1928.

Our invention relates to hydraulic accumulators, more especially of the kind in which a piston is arranged for free reciprocation within the cylinder of the accumulator, being acted upon on one side by the liquid and on the other side by compressedair so as to separate the liquid and air spaces. In accumulators of this kind the valves'or slides which serve to throw the pressure liquid pump in and out of operation, are controlled by the piston, as it moves in the cylinder.

In accumulators of this kind, in order to save space, it has been suggested to mount the piston for free motion on a rod, which could be reciprocated by the piston only the distance which is required to control the valves. However, in these cases the controlling members still consumed an inadmissible space and were also exposed to mechanical damage.

It is an object of our invention to provide an accumulator of this kind, in which the.

space taken up by the controlling and safety devices is reduced to a minimum, while pipes connecting the accumulator with the valves and the like are dispensed withaltogether, all the controlling parts being protected in such manner as to be safe from injury. Nevertheless the valves may be operated by hand, if desired. I

We obtain this according to the present invention by accommodating the valves and the like inthe wall of the accumulator cylinder and preferably in the bottom thereof, com

munication between the valves and the interior of the cylinder being provided by corresponding conduits.

In the drawings aflixed to this specification and forming part thereof three forms of a hydraulic accumulator embodying our in- 0 vention are illustrated diagrammatically by way of example.

In the drawings, f Figs. 1-3 illustrate the first form, V Fig. 1 being an axial section of the accumu lator as a Whole, while Fig. 2 is an end view and Fig. 3 a development of a circular section parallel to the accumulator axis taken on the line AB in Fig. 2.

Fig.4 is an axial section of the bottom part of the second form, and

Fig. 5 is a similar view of the third form.

Referring first to Figs. 1-3, 1 is the accumulator cylinder, 2 is the compressed air space, 3 is the liquid space and 4- is the piston separating them. 5 is the piston rod and 6 and ,7 are two abutments fixed to the rod and serving, when acted upon by the movable piston 4, to displace the rod 5 in one or the other direction. In this case the rod 5 having a nut 8 mounted at its bottom end will act on the hollow control member 10. 9 is a stuffing box through which the rod 5 extends. On the outer end of the control member'lO is mounted a controlling disc 11 which projects above the pins of the valves, which are disposed in the bottom of the cylinder 1 with their axes in parallelto the cylinder axis.

The manually operated valve 12 serves for throwing the apparatus in and out of operation, respectively. 13 is a valve serving to connect-the liquid space 3 of the cylinder through conduit 14with another conduit 15 leading to the cylinder of a servomotor or to the means for reversing the valve of the pump (not shown) which forces liquid intothe cylinder through pipe 16. V 17 is a valve serving to connect the cylinder of the servomotor with the conduits 18 and 19, the latter serving as an exhaust. 20 is a safety valve which will connect the liquid space of the cylinder with the exhaust, whenever the apparatus should get out of order.

The operation of this device is as follows:

After the pump has forced a predetermined quantity of liquid into the liquid space 3, the piston 4 being displaced by the liquid will meet the abutment 6, thereby carrying along rod,5 and nut 8 andthrough this latter also the hollow control member 10 and disc 11. This disc will first act on the projecting pin of valve '13 and with the aid ofthe servomotor or the pump valve will stop the operation of the pump; If for any unforeseen reason the pump should still continue operating, disc 11 would then act on thepro-jecting pin of valve 20, whereby the accumulator would be opened towards'the exhaust.

1 On the pump having come to a standstill, the pressure liquid in the cylinder will gradually be consumed, the piston being gradually shifted towards the abutment 7 and carrying it along together with rod 5, Whereby nut 8 is moved into contact with the outer end of the control member 10, which is now moved to the left together with disc 11. The valve 13, being released by disc 11 will now be closed under the action of the pressure in the cylinder. In moving to the left, disc 11 will carry along the in of valve 17 by means of an abutment 21 n ounted on the pin, Whereby the liquid press; between the accumulator and the servomotor or the controlling piston is released so that this piston will move backwards under spring action and is enabled to throvv the pump in again.

In the modification illustrated in Fig. 4 the valves 13, 17 and 20 are disposed within the bottom of cylinder 1 in a position at right angles to its axis and are controlled by a control member 22 having cam faces formed thereon which are in contact with the valve pins. These cam faces are formed in such manner that vhenever the piston 4 approaches the right end position, Without, however, having reached it, the pin of valve 13 Will be lifted While valve 17 which controls he exhaust from the pump valve or controlling piston, is closed. \Vhile these valves are being acted upon, the pin of the safety valve 20 is still spaced from its cam on the controlling member so far that it will be lifted only if the other valves have been operated and the piston 4 should still continue on its stroke.

In the modification illustrated in Fig. 5 the valves are controlled by a slide 1O which is operated by the rod 5 as described With reference to Figs. l t, the valves being replaced by a system of conduits controlled by the slide 10 in a manner Well known per se.

\Ve wish it to be understood that We do not desire to be limited to the exact details of construction shown and described for obvious modifications Will occur to a person skilled in the art.

In the claims a'llixed to this specification no selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to ailasequently make claim to any modification not covered by these claims is expressely reserved.

W'e claim .i, Hydraulic accumulator comprising a. cylinder, a piston in this cylinder freely movable for reciprocation. valves in the bottom of said cylr ed means arranged for op eration b said piston. for controlling said valves.

2. Hydraulic accumulator comprising a cylinder. :1 piston. in this cylinder freely movable for reciprocation, valves in the bottom of said cylinder and a rod associated with said piston and movable axially in said cylinder, said rod being arranged to control said valves.

3. Hydraulic accumulator comprising a cylinder, a piston in this cylinder freely movable for reciprocation, valves including a safety device in the bottom of cylinder and means arranged for operation by said piston for controlling said valves.

l. Hydraulic accumulator comprising a cylinder, a piston this cylinder freely movable for reciprocation, valv "s e bottom of said cylinder and arranged at an angle to the cylinder axis and means arranged for operation by said piston for controlling said valves.

5. Hydraulic accumulator comprising a cylinder, a piston in this cylinder freely movable for rcclproca es in the bottom of said c" wec for operation by said piston said valves, said valves bei o be operated automatically and another manually operable valve in said cyli der bottom.

In testimony v ereof \ve affix our signatures.

MAI- TEN MACK. IVILHELM GROTZINGER.

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