US2809494A - Hydraulic jack - Google Patents

Description

Oct. 15, 1957 G. T. MATSON ET AL HYDRAULIC JACK 2 Sheets-Sheet 1 Filed Dec. lf?, 1955 'BY' l Oct. 15, 1957 G. T. MATsoN ErAL 2,809,494

HYDRAULIC JACK Filed Deo. 17, 1955 2 Sheets-Sheet 2 INVENTOR. Richard L. Matson Giiberi T. Maison Attorneys nited States Patent HYDRAULIC JACK Giibert T. Matson and Richard L; Matson, Seattle, Wash.

Application October 17, 1955, Serial No. 540,770

1 Claim. (Cl. 60452) This invention relates to hydraulic jacks, and pertains more especially to a jack of the type commonly known as a cribbing jack, and namely a jack which takes its purchase from cribbing blocks, henceis designed so that the head on which the-object to belifted is sustained occupies a position at the low limit of its lift travel as close as possible to the plane of the base surface which seats upon the cribbing blocks.

lt is a particular object, therefore, to devise a hydraulic jack in which the vertical spacing between said base and head, at the low point of the latters-travel, is appreciably less than has been the case with previously existing cribbing jacks.

It is a further object to provide a hydraulic jack in which the hydraulic uid is containedvin a reservoir disposed to occupy a position alongside the cylinder in which the lifting ram is received, with said reservoir being open at the top, and wherein this top opening is closed by a removable block made separate and apart from the jack proper and which serves the added function of a valve chest bored and linished to contain the valvel mechanisms which control the working of the jack.

lt is a still further-and particular object to provide a hydraulic jack of the character described peculiarized in that the pump for the jack is also carried by said mounting block so as tofpermit these parts to be removed intact should any need arise for the servicing thereof.

As a further object still the invention aims to provide a hydraulic jack usingneoprene O-rings in lieu of'conventional packing glands for sealing the open ends of the cylinders which contain the lifting ram and the pump piston.

With the above ends in view and further aiming to provide a hydraulic jack which is easy and convenient to use, of rugged construction, and generally a more efficient I jack in the perfomance of the Work for which it is intended, the invention consists in the novel construction and in the adaptation and combination of parts hereinafter described and claimed.

In the accompanying drawings:

Figure l is a longitudinal vertical sectional view with parts in elevation reprmenting a hydraulic jack constructed to embody the preferred teachings of the present invention, and illustrating the manner of using by portraying, in dotted lines, cn'bbing blocks and an object being lifted.

Fig. 2 is a top plan view of the jack with a part broken away; and

Fig. 3 is an enlarged-scale fragmentary perspective view with parts broken away and shown in section to illustrate the mounting block with the valve mechanisms housed therein.

Referring to said drawings, there is provided a hydraulic cylinder designated by the numeral cast into a body which includes a flange 11, preferably of a rectangular plan conguration, serving as a base on which the jack takes its purchase. Such ange is disposed in close proximity to the upper end of the cylinder. At diametri- ICC cally opposite sides ofy the cylinder the flange `issurmounted by reinforcing ribs 12 and 13 extending parallel to one another, and spanning the opening between ysuch ribs, one adjacent one-end and the other Vadjacent the other end of the base, are bars 14 and 15- which vserve as handles for the jack.

Reciprocably mounted in the cylinder isa ram =16.ex tending through an O-ring 17 of neoprene or Vother like or suitable material. On its housed lowereend the ram carries av packing cup 1S backed bythe usual-washer 19, and on its exposed upper end the raml hasra half-round ball 20 formed with a circumscribing groove--2r1. VA attopped bearing cap 22 surmounts theV wrm-having on its underside a boss 23. presenting a socket into which-the terminal ball-20 seats, and at'diametrically opposite sides the boss 23 carries cap screws'24 arranged and adapted to have their innerA end project into the groove 21 .so as to hold the cap uponthe ram. The cap admits to a-moderate degree-of universal motion upon the terminal ball, and the setting given the cap screws 24 is such asto-hold the cap against dislodgment without restraining the same against said moderate motion.

y26 denotesV a shell-which is made an integral .part of the body casting to occupy a position `below the base flange 11 and to oney side of the cylinder. lAdajcent the bottom end of the chamber contained by such shell-there is a combination supply and return opening drilled through the wall which divides ythe chamber from the cylinder, and such opening is tapped to receive a nipple 27. f Also extending between the cylinder and the chamber at'the upper end of the latter is a passage-way 28.

Said chamber, which serves as an oil reservoir, `is open at both top and bottom. For the Vbottom lopening there is provided a closure plate 30, and as a closure for the top opening there is provided a block body 31, each being bolted in place with a respective underlying Y sealing gasket.

The block body performs the function of a valve chest containing valve mechanisms controlling the directional flow of hydraulic fluid drawn from the reservoir by =the action of a pump, suchpump comprising a piston 32 working in a cylinder 33. The cylinder threads into a surface boss 34 provided upon the topside ofthe chest. There are three valve chambers inthe chest, designated by 35, 36 and 37. Each of the chambers 35 and 37 are produced by drilling horizontally into the body of the chest from the outer end wall of the latter, with the former appreciably deeper than the latter. The chamber 36 is drilled from a side wall so as to lie to the front of the chamber 37 on a drill axis traversing the chamber 35. Respective ball checks, as 40 and 41, are received in the valve chambers 35 and 36, being urged by the action of springs, as 42 and 43, into normal closed engagement against ports located at the inner ends of the chambers. The springs take their purchase against Allen-headed plugs, as 44 and 45, threaded into the outer ends of the respective drill holes. Said end-wall port of the charnber 35 connects by a passage 46 and a suction pipe 47 with the bottom end of the reservoir. T wo-openings are provided in the side wall of this valve chamber, one connecting by a passage 48 with the bottom end of the pump cylinder 33 and the other connecting by a passage 49 with the port which is formed in the end wall of the valve chamber 36. This valve chamber 36 also has two openings in its side wall, one connecting by a passage 50 and a combination supply and return pipe 51 with the nipple 27, and the other connecting by a passage 52 with a port which is formed in the end wall of the valve chamber 37. A manually operated needle valve 53 seats against the latter port, and in the side wall of such valve chamber there is provided a port which opens by a passage 54 into the reservoir.

The pump cylinder 33, like the ram cylinder 10, has its upper end sealed by an elastic O-ring 5S. The eX- posed head end of the pump piston is pivotally connected, as at 56, with a hand lever 57. A fulcrum pin 5S con- Vnects the inner end of this lever with a mounting link 59 pivoted, as at 60, to a rib 61 formed upon the top of the valve chest, and removably sleeved on the lever is an extension 62. The free end of this extension presents a slotted socket, and there is formed upon the exposed head of the needle valve 53 for mating engagement with said socket a stud counterpart 63 thereof.

Itis thought that the manner of operation is apparent. Upward motion of the pump piston by activation of he pump handle draws hydraulic uid through pipe 47 into the valve chamber 35 and the pump .cylinder 33, whereupon downward motion of the piston by reverse activation of the handle seats the ball check 40 and forces the suction charge of iluid past the ball check 4l into the valve chamber 36 and thence through pipe S1 into the ram cylinder 10. Repeated pumping actions lift the ram f progressively to any desired height within the scope of its permitted rise. The port which connects the passageway 28 with the ram cylinder constitutes a stop limiting the upward travel of the ram. An opening of the needle valve 53 perforce allows fluid within the ram cylinder to return through pipe 51 to chamber 36 and thence by passage 52, chamber 37, and passage 54 to the reservoir.

The advantages of the invention, it is thought, will have been clearly understood from the foregoing detailed description. Minor changes will suggest themselves and may be resorted to without departing from the spirit of the invention, wherefore it is our intention that no limitations be implied and that the hereto annexed clams be given a scope fully commensurate with the broadest int Y to the casting as a removable closure for said top opening of the reservoir, an open-top pump cylinder carried by the block in surmounting relation thereto, a pump piston in said pump'cylinder projecting by its upper end through the top opening of the pump cylinder, a pumping lever attached to said projecting upper end of the pump piston and fulcrumed to one end of a link having its other end attached to the block body, a suction pipe and a combination supply and return pipe contained within the reservoir each attached by their upper ends to the block body in communication with related cells of the latter and with the lower end of said suction pipe exposed to the oil within the reservoir at the base of the latter and with the lower end of the combination supply and return pipe attached to said threaded end of the nipple, two check-Valve mechanisms housed in related cells of the block body operable upon activation of the pump to cause hydraulic uid to be drawn from the reservoir through said suction pipe into the block body and thence forced through the combination supply and return pipe into the ram cylinder, and a hand-operated valve adapted to be normally closed andV also housed in a related cell of said block body and acting when Yopened to cause hydraulic uid within the ram cylinder to discharge through the combination supply and return pipe, by-pass the Vcheck-valve mechanisms and returnY to the reservoir, the removable mounting of said block body permitting said pipes, the pump cylinder, its piston, the operating handle therefor, and the link, together with the several valve mechanisms, to be removed from and applied to the casting intact as an assembled unit, said casting having a removable plate giving access to the reservoir for detaching said combination supply and return pipe from and'attaching the same to the nipple when the block body is being removed from and applied to the casting, respectively.

References Cited in the tile of this patent UNITED STATES PATENTS 743,508 Hornung Nov. 10, 1903 1,571,602 Roberts Feb. 2, 1926 2,018,506 Walker Oct. 22, 1935 `2,170,464 Rosenberry Aug. 22, 1939 2,214,257 Pfauser Sept. 10, 1940 2,352,390 Kirkland' June 27, 1944 2,540,578 Hall et al Feb. 6, 1951 2,548,902 Mueller Apr. 17, 1951 2,636,348 Murray Apr. 28, 1953 2,664,073 Pine Dec. 29, 1953

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