US2899248A - Hydraulic pump - Google Patents

Description

J. MERCIER HYDRAULIC PUMP original FildNov'. 25, 1955 Jean Mefca'ef /ITTORNEX HYDRAULIC PUMP Jean Mercier, New York, N.Y.

Original appiication November 25, 1953, Serial No. 394,301, now Patent No. 2,817,955, dated December 31, 1958 Divided and this application December 30, 1957, Seriai No. 705,936

1 Claim. (Cl. 309-23) This invention relates to the art of actuating units, more particularly to a hydraulic pump for remotely controlling the actuation of a movable member.

It is among the objects of the invention to provide a hydraulic pump of the above type that has but relatively few parts, not likely to become deranged even with long use, that is relatively simple to construct and may be operated with but a relatively simple manipulation to deliver iluid under pressure to a hydraulically controlled unit without the need for pressure accumulators or the like, to effect displacement of such unit by an amount proportional to the displacement of the pump and which will furnish additional uid under pressure when required to complete the action of the hydraulically operated unit.

Another object is to provide a hydraulic pump of the above type having a piston with a resilient seal and in which the likelihood of injury to such resilient seal as it moves past ports in the pump, will be substantially prevented to avoid breakdown of such seal with resultant leakage and ineiciency of the pump.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. l is a longitudinal sectional View of the hydraulic pump and hydraulic unit controlled thereby in one extreme position,

Figs. Z, 3 and 4 are views similar to Fig. l of the pump in various positions of operation, and

Fig. 5 is a fragmentary sectional View on a greatly enlarged scale of the seal ring.

This application is a division of co-pending application Serial No. 394,301, tiled November 25, 1953, now Patent No. 2,817,955.

Referring now to Fig. l of the drawings, the hydraulic pump desirably comprises a substantially cylindrical casing 11 closed at one end as at 12 and having its other end open as at 13.

The casing 11 at its closed end 12 desirably has a transversely extending boss or enlarged portion 14 through which extends two transverse longitudinally spaced control ports 15 and 16, the inner ends 17 and 18 of which lead into the bore 19 of casing 11. The second control port 16 adjacent the closed end 12 of the casing desirably has a cavity 21 therein in which is positioned a valve, desirably comprising a ball 22 normally retained by a coil spring 23 against the annular shoulder 24 formed by such cavity to seal the inner end 18 of port 16.

Two additional longitudinally spaced transverse ports 26 and 27 designated the outlet port and inlet port respectively, also have their inner ends 28, 29 leading into the bore 19 of casing 11, said ports 26 and 27 being positioned between the open end 13 of the casing and the first control port 15 and are illustratively on the side of casing 11 opposed to control ports 15 and 16. As is clearly shown in the drawings, the end 28 of port 26 leads into an elongated annular groove 30 in casing 11.

Slidably mounted in the bore 19 of casing 11 is an elongated piston 31. In order to provide a dependable 2,899,248 Patented Aug. 1l, 1959 fluid tight seal between the outer surface of the piston 31 and the inner surface of the bore 19, the wall of said bore adjacent its open end 13 desirably has an annular groove 33 in which is positioned a resilient sealing member preferably an 0 ring 34.

The piston 31 desirably has an elongated annular groove 35 positioned adjacent its inner end 36, and a passageway 37, having one end 38 in annular groove 35 and its other end 39 in the inner end 36 of piston 31, connects said annular groove 35 with the portion of said bore 19 formed between such inner end 36 and the end Wall 12 of the casing and defining a chamber 41.

The piston 31 desirably has a second annular groove 42 adjacent annular groove 3S and positioned between such annular groove 35 and the outer end 43 of the piston, a resilient seal ring, preferably an O ring 44, being positioned in said second annular groove 42. The piston has a plurality of inclined passageways 45, each having one end exposed in the annular groove 42, and the other end exposed at the surface of the piston, the passageways affording relief of pressure against the 0 ring 44- in the manner to be described.

Although any suitable means may be employed to effect longitudinal movement of the piston in the bore of the casing, as illustratively shown, such movement is accomplished by means of a screw 51 threaded through an opening 52 in a xed member 53 and having a rotataable connection 54 to the end 43 of the piston 31 so that rotation of the screw by handle 55 will effect longitudinal movement of the piston in the bore of the casing. The position of the piston may be indicated by means of a pointer 40 carried thereby and having an associated scale 40 calibrated in the manner to be described.

The outlet port 26 is desirably connected by means of a line 57 to a reservoir 58 for fluid. The line 57 is desirably connected through a line 61, having a one-way valve 62 therein, to the inlet port 27, the valve 62 permitting flow of fluid only from said reservoir into inlet port 27.

The outer ends 63 and 64 of control ports 15 and 16 are desirably connected by delivery line 65 to the port 66, preferably located in the end wall 67 of the cylinder 68 of a hydraulic unit, which may be located at some remote position, the cylinder 68 desirably having a port at 1ts upper portion controlled by a Valve 70. A piston 69 is slidably mounted in cylinder 68 and desirably has an annular groove 71 in its periphery in which a resilient O ring 72 is positioned to provide la dependable seal. The outer end of the piston is desirably connected through a suitable linkage to a lever 73, pivoted at its lower end as at 74 and desirably having a coil spring 75 aflixed to its upper end which normally urges the lever and hence the piston 69 connected thereto to the left as shown in Fig. l. The lever is suitably connected to the mechanism to be actuated, illustratively a sliding bulkhead door, for example, which normally is in open position and will be closed upon movement of the piston to the right in the manner hereinafter to be described.

The piston, the ports, and various annular grooves are so constructed and arranged that, as shown in Fig. l, when the piston is in its outermost position, the outlet port 26 will be in communication through annular groove 30 with annular groove 35 and the inner ends 17 and 18 of ports 15 and 16 will be in communication with the chamber 41, the inner end 36 of the piston 31 being spaced from such ports 15 and 16.

When the inner end 29 of port 27 is in communication with annular groove 35, due to the inward movement of the piston to the position shown in Fig. 3, the port 15 'will be sealed by the inner end 36 of the piston and as the resilient seal ring 44 will have been moved to engage the bore of the casing,- the port 26 will be sealed so that no fluid will ow therethrough.

Assuming that the pump 11 and reservoir 58 are on the vbridge o'f a ship above the lvel of the cylinder 68, with the pump inthe position shown i Fig: 1 a fluid such as il may be forced through valve 70 to charge the various lines and the interior' of the pump. The valve 70 is then closed and rthe system is ready foi' operation. To actuate the lever 73 to close, for example, a bulkhead door (not shown) the screw 51 is turned by handle 55 to move the piston 31 to the right. When the piston reaches the position shown in Fig. 2,- as port 26 will then be sealed with respect to passageway 37, by the ring 44, which is moved into engagement with the casing bore 19, further movement of the piston to theight will create a pressure on the uid in chamber 41. Such iluid will thereupon be forced through port 15 'and line 65 into port 66 of the hydraulic cylinder 68 to move the piston 69 therein to the right, thereby pivoting lever 7 3 against the tension of spring `75 to move the sliding bulkhead door toward closed position.

When the piston 31 has been moved from the position shown in Fig. 2 to the position shown in Fig. 3, the port 27 will be in communication with annular groove 35 and port 15 will be sealed. The volume of fluid from chamber 41 forced into cylinder 68 when lthe piston 31 is moved from the position shown in Fig. 2 to the position shown in Fig. 3 is the amount normally required to complete the closing of the bulkhead door. By Calibrating the scale 40 so that the pointer 40 indicates open when the piston 31 is in the position shown in Fig. 2 and closed when in the positionshown in Fig. 3, the position of the bulkhead door may readily be determined.

With the piston 31 in the position shown in Fig. 3 if, for example, due to a fall in. temperature there should be a contraction of the iiuid in the system, the lever 73 will` not be pivoted suiiciently to etect full closing of the bulkhead door. To determine if the door is actually closed as indicated by the pointer 40 associated with the piston, the screw 51 is turned slightly to attempt to move the piston further to the right. If the door is closed, the screw will be diicult to turn. If the door is not fully closed, the screw will turn readily and the Vresultant furlther movement to th'e right 'of the piston 31 in chamber 41 to the position shown in Fig. 4 will Yforce additional fluid through port 16, through line 65 into cylinderr68 to pivot lever 73 an additional amount. By reason of the :oneway valve 62 in line y61, no fluid will escape from the chamber 41 through passageway 37, annular groove 35 and port 27.

As the pointer 40 has moved past closed position as shown in Fig. 4, 4it may readily be moved back to this position and the chamber 41 recharged with uid without affecting the bulkhead door. This is readily accomplished by turning screw 51 in direction to move the piston 31 to the left. As both ports 15 and 16 are sealed, the former by the end 36 of the piston 31, and the latter by ball valve 22, a suction will be created in chamber 41 which will cause fluid to be sucked from reservoir 58, through line 61, valve '62, which is opened by such suction, port 27, annular groove 35 and passageway 37 into chamber 41 to ll the latter. Such suction -action is effected by merely turning the screw 51 so that the piston 31 will be moved to the left a distance insufficient to open the port 15, i.e. to the position shown in Fig. 3.

When this has been done the pointer is now properly positioned so that subsequent actuation of the piston 31 will properly indicate the position of the bulkhead door.

To open the bulkhead door, it is merely necessary to move the piston 31 Afurther to the left from the position shown in Fig. 3 by rotating the screw 51. As the end 36 of the piston 31 moves past port 15 to open the latter, due to the pressure on the fluid in the hydraulic cylinder 68, caused by the action of spring against lever 73 and piston 69, the uid in cylinder 68 will be forced into chamber 41 and the door will move toward open position being fully opened when the piston is in the position shown in Fig. 2.

In the event that the fluid in the system had expanded due to a rise in temperature, when the piston had originally been moved to the right to close the door, the pointer 40 would not have reached fully closed position when the screw 51 became diicult to turn. This would indicate to the operator the need to calibrate the pump which would automatically be accomplished by moving the piston 31 toward the position shown in Fig. l. When the ring 44 reaches the position shown in Fig. 2, due to the fluid pressure on the side of the O ring adjacent annular groove35 caused by the action of spring 75, the O ring would tend to be extruded slightly into annular groove 30 toward port 26. As this occurs, a path for the ilid will be provided beneath the O ring through passageways `45 and hence the pressure against the `O ring will be relieved without injury thereto which might otherwise be caused if no such pressure relief was provided and materialextrusion occurred of the C ring into passageway 26.

As the piston 31 reaches the position shown in Fig. l with the annular groove 35 in communication with annular groove 30, the excess fluid in the system may readily flow through passageway 37, annular grooves 35 and 30, port 26 'and liner57 to reservoir 58. Thus, upon the next actuation 'of the pump, the pointer 40 will be properly Ycalibrated with respect to the position of the bulkhead door'.

Although the hydraulic pump has been illustratively described as the actuating means for a bulkhead door, it is of course to be understood that it can be used to control any movable hydraulically operated unit such as the rudder of a ship.

As many changes could be made in the above construction, and many apparently widely dilerent embodiments of this invention could be made without departing from the scope ofthe claim, it i's intended that all matter contained in the above description or shown in the accompanying drawings shall be vinterpreted as illustrative and not -in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United .at a portion thereof longitudinally spaced from said annular groove, whereby when said piston is moved in said casing bore in direction tir-st to bring the outer end of the passageway into communication with the-port, the pressure on said yseal ring will be relieved to prevent material extrusion thereof through said port.

References Cited in the file of this patent UNITED STATES PATENTS 831,603 p Davis ---c Sept. 25, 1906 .Lans

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