US2627722A - Hydraulic jack - Google Patents

Description

Feb. 10, 1953 D. JOHNSTON 2,627,722

HYDRAULIC JACK Filed Jan. 29, 1947 2 SHEETS- SHEET 1 Doz/6L H5 JOHNSTON, /Wwv gul,

Feb. 10, 1953 D. JOHNSTON 2,627,722

HYDRAULIC JACK Filed Jan. 29. 1947 2 sHEETs-SHEET 2 ,27 y Il 57M Il 6 24 55 30 ,I 5y Il X 1 l l l l l 1 H y l,

66 l I f l 74/ 77/ 6g /25/ f 45/ /4L)/4654\l56/ if? 58) 5/5 Pi 4 q 55 /338 EW* 41?; 7 D y/ u n 32 f/ 33 56 ///E/vroe.'

57 poum/a5 JOHNSTON) 27 39 0; 37 /0 28 VW M Patented Feb. l0, 1953 UNITED STATES PAT ENT @FFE CE HYDRAULIC JACK Douglas Johnston, Huntsville, Ala'., assigner to General Fluid Machinery Company', Huntsville, Ala., a. corporation of Alabama.

Application January 29, 1947,'S'erialNo. 725,013

5 Claims. 1.

The present invention relates to a hydraulic jack.

It is an object of the invention to provide a hydraulic jack wherein leal@ in the hydraulic mechanism are largely prohibited and wherein thedesign is such that a solid steel'base may be used to reduce the likelihood of leakage. A further object is to provide a particularly desirable valve construction wherein there are brass inserts to form the valve seats foreach of the` valves, and wherein all of the valvesY are located in a single opening and are accessible through this opening for replacement. Another object is to provide inserts for the valve arrangement, including seat members and spacers thatminimize the number of diiierent parts required.

A further object is to provide a jack of this' type wherein the ramA can-be mounted in the center of the base and the valves disposed in a single opening at one side of the base.

In the drawings: v

Fig. 1 is a plan view of the jack;

Fig. 2 is a vertical section on the line 2-2 of Fig. 1; v

Fig. 3 is a vertical sectional view taken on the line 3 3 of Fig. 1;

Fig. l is a horizontal section looking downwardly on the line 4;-4 of Fig. 3;v

Fig. 5 is an enlarged sectional view of the valve construction shown'in thelower part of Fig. 3;

Fig; 6 is a horizontal section through'the valve construction, taken on the line 6-6 of Fig. 3; and

Fig. 7 is a front elevation of the jack, with the ram partly broken away.

The jack includes a base' lil that may be formed of steel in one solid piece; This base Ie has a cut-out in its upper surface into which a cylinder Il is threaded. A cap I2 is threaded into the upperend of this cylinder, it having a hexagonal wrench fitting portion as shown in Fig. 1. An oil reservoir tubing I3 fits between the cap I2 Yand the base I and is sealed thereto to hold a-supply of `oil, as indicatedlinrFig. 2.

The cylinder vI I lsli'dably receives ia piston head I towhich .a'tubularmember IGiis attached. This tubular'member is threaded to receive a jack screw Il whichmay'be turned and thereby adjusted in andqout with respect tothe cylindrical portion I6. The screw has a head! I3' on it which may be disposed beneath the work to be lifted. The head I5, cylinder I6.' screw Il and head IS- constitute the ram of the jack and are centrally located on the base; Thefhead l5 has the usual sealing means onitsbottom'surface, so that hydraulic fluidforced"belowfthis vsealingfmeans 2t) will lift the ram. The cap I2, above the cylinder II, receives apacking ring' held in place by threaded` rings 2| screwed intothe cap I2 that compress the packing ring and maintain it in contact with the cylinder It. As the head I is larger indiameter than the cylinder i6, the head will engage the lower ring 2|, at the upper end of the stroke, and loe'v prevented from` moving out of the base.

As'noted, the tubing I3 provides, with the cylinder I I, the base` Ill and the cap I2, an annular oil reservoir 22. The'space within the cylinder l I and the base, below the'head I5, constitutes an operating cylinder 23 for the jack.

Thel base is provided with an opening 21% that isdrilled thereint'o from the back part of the base. Aslopingcontinuation 25 of this opening M-leadsto the front of the'base and has varying diameters, as will appear.

The reservoir 22 has a passage 2l leading into the end 25 of the opening' 2t". It has another passage 28 that leads intojthe valve opening 212 towardV the other' end thereof. Between these two passages, there is a passage Ertl-lat leads into the operatingcylinder 23.

Upstanding from a middle part of the opening 24, there is a vertical port 3S thatopens into a pressure-cylinder 3 [threaded-into the top surface of thebaseft'o onefside of the reservoir 22. This member 3'I receives an operating plunger 32 having 'a packing gland` cap 33 attached to its end'.l The plunger rod 32 passes through the cap 33, and is' pivoted to a rocking lever 35. The rocking lever is, in turn, pivoted to a vertical lever 36 that is pivoted between brackets 3l on the top' ofthe base. These pivot arrangements comprise'removable pins held in place bycotter pins, as shown. The lever 35 lhas asockettl' at its outer end. A pin do passes through the socket. Itv will be seen that, when a handle, indicated at H, isrinsertedin the'socket, and the lever 35 is rocked up and down, the plunger will be moved up and'down.

The openin'g'll receives a series of valves, valve seat `inserts'and spacers. At the left end of the opening in Figs. 5 and 6, there is a valve seat insert 45. The opening2d is preferably cylindrical, and the insert has an outside cylindrical surface'that slides'into the opening 2li and substantially'seals therewith. The insert' has a valve lseat recess wand an annular projection il at the-other end, with a'flui'd passage 4B axially throughV the insert. A ball vali/e541 is 'engageable with the' valve' seat.

There isa gasket" lfthatfiits'around the ex-l tension 41. To the right of the gasket, there is a cylindrical spacer sleeve 52. This sleeve has an inner, shouldered opening whereby it may receive a coil spring 53 and a ball Valve 54, and may conduct uid from end to end. It also has a plurality of lateral ports 55 at suitable points around Aits periphery.

Next to the right of the spacer, there is another valve seat element that is identical with the element 45. Then there is a gasket 56 and another spacer 51 that is identical with the spacer 52.

There is a spring actuated ball check valve 58 that may be received in the sleeve and which cooperates with the valve seat of another valve seat element 59.

Next, there is another gasket 68 followed .by two spacers, 6I and 62. The right end of the spacer 62 receives a washer' 53, against which a solid spacer 64 is engaged. This spacer 54 acts against a gasket 61 identical with the gasket 5I. The assembly is held by a threaded plug 55 that has a wrench receiving opening 65 therein. It may be seen that all of the spacers, gaskets, and valve seat elements are thus held in position firmly When the plug 65 is tightened into place, and that the several gaskets are spread into sealing relationship with the walls of the opening 2 `4.

In the extension of the opening 24, there is a manually movable plunger 68 that is threaded into a packing lgland fitting 69 that, in turn, is threaded into an enlargement of the opening 25 of the base, and is adapted to compress packing 10. The plunger 68 has a head 1I that is received in an enlarged socket portion 12 of the opening 25. This head 1I is shaped to be received in an internal opening in the end of the handle H, that also engages within the sleeve 38 of the operating lever. The head has a cross pin 14 that is similar to the cross pin 40 in the socket 38.

The disposition of the valve parts provides that the valve 50 Will be held against its seat 46 in the seat member 45 by the plunger 68, when the plunger is turned down by rotation of the head 1 I. This prevents communication from the port 21 that extends to the reservoir to the other parts of the opening.

The opening 28 leads through the ports 55 of the spacer 6I into the interior of these spacers, and thence may ilow up against the ball valve 58. The passage 29, that communicates into the pressure cylinder 23, connects into the spacer 52 and through the ports 55 thereof to establish communication of the pressure cylinder with the space between the two valves 50 and 54.

The interior of the operating cylinder 3l communicates through the port 30 with the interior of the spacer 51 to the left of the valve 58 and to the right of the valve 54. There are a sufficient number of ports 55 around each spacer to insure communication from the several passages, as indicated.

At a desired elevation along the casing I3, there is a ller plug 16 through which hydraulic liquid may be inserted. This plug establishes a proper liquid level.

Operation When it is desired to use this jack to lift some Work, the jack is disposed under the work with the jack screw I1 screwed out manually to establish engagement or approximate engagement between the head I8 and the work to be lifted. Thereupon, a suitable pipe handle H, with the necessary notch to engage over the pin 40, is inserted in the socket 38. When the handle is lifted,

the plunger 32 is elevated, establishing a low pressure condition back of the valve 58. This causes the hydraulic fluid to be drawn through the passage 28 from the reservoir 22, unseating the valve 58 in this process, so that, when the plunger 32 reaches its top point, the cylinder 3| is properly charged with hydraulic fluid. Upon subsequent depression 'of the hand lever and the plunger 32, the oil thus drawn in is forced outwardly from the cylinder 3l. The valve 58 then seats, checking the flow-back of this oil into the reservoir. The oil under pressure, however, unseats the valve 54 against its spring and passes out the ports 55 into the passage 29 of the cylinder 23, where it can act below the ram head I5. It thus causesthe head to be raised. When the plunger reaches the bottom of its stroke, the pressure thus applied is relieved and the valve 54 reseats, checking the outflow of such oil. Thereupon, the cycle is repeated `until the work is elevated as far as desired.

When it is desired to lower the jack, the handle is removed from the socket 38 and is inserted over the head 'II of the plunger 58. It is turned to unscrew the plunger and withdraw it from the valve 50 which has been maintained on its seat by the plunger 68. The pressure of the ram downwardly on the hydraulic duid in the cylinder 23 causes this iluid then to iiow past the valve 50 into the passage 21 and back into the reservoir, so that the jack is lowered.

In servicing the jack, the principal members subject to wear are readily accessible. When it is desired to remove the ram, the threaded members 2| and the packing ring are withdrawn. Then the ram may be pulled out, and, if it is necessary to replace the washer 20, the same may be readily done by removing its retaining screw as indicated by the drawing. Thereupon these parts may be conveniently replaced.

In similar fashion, the operating plunger 32 may be removed, as the several levers are held together by cotter pins. When the pins are removed, the gland nut 33 may be unscrewed and the plunger drawn out through the packing and its parts repaired. If need be, the whole cylinder 3I may be unscrewed and repaired or replaced.

The valve yarrangement provides for very easy service with a minimum number of different types of repair parts. This comes about because, in the rst place, all of the valves are immediately :accessible when the plug lE55 is withdrawn. Also, the valve seat inserts 4and spacer sleeves are all duplicates, so that only two types of such parts are required. The gaskets 5I are conventional. All of the ball valves are identical. The pressure relieving means, consisting of the plunger E8 and associated p-arts, are self-compensating for all normal Wear because of the threaded arrangement.

What is claimed is:

l. In a jack, a base, a hydraulic fluid reservoir, an operating cylinder, a ram in the operating cylinder, a pressure cylinder, a pressure producing means in the pressure cylinder, :an elongated, cylindrical opening of constant cross section extending at least partially through the base and having van entrance at one surface of the base, a first passage from the opening to the reservoir, a second passage from the opening to the pressure cylinder, -a third passage from the opening to the operating cylinder, a fourthpassage from the opening to the reservoir, removable Valve means in the opening between theirst and second passages. removable valve means in the opening between the second and third passages, and removable valve means in the opening between the third and fourth passages.

2. In a jack, la base, a hydraulic uid reservoir, an operating cylinder, a ram in the operating cylinder, a pressure cylinder, a pressure producing means in the pressure cylinder, an opening in the base having an entrance at one surface of the base, :a rst passage from the opening to the reservoir, a second passage from the opening to the pressure cylinder, a third passage from the opening to the operating cylinder, a fourth passage from the opening to the reservoir, valve means in the opening between the rst and second passages, valve means in the opening between the second and third passages, and valve means in the opening between the third and fourth passages, said valve means being disposed longitudinally within the opening in yabutting relationship.

3. In a jack, a base bounded by a plurality of intersecting surfaces, a hydraulic fluid reservoir, an operating cylinder, a ram in the operating cylinder, a pressure cylinder, a pressure producing means in the pressure cylinder, an opening extending at least partially through the base and having one end thereof terminating lat a surface so as to provide an entrance into the opening, a rst passage from the opening to the reservoir terminating at la surface of the base so as to provide an entrance into the first passageway, a second passage from the opening to the pressure cylinder, a third passage from the opening to the operating cylinder terminating at a surface of the base so as to provide an entrance into the third passageway, a fourth passage from the opening to the reservoir terminating at a surface of the base so -as to provide an entrance into the fourth passageway, a fth passage from the opening to a surface of the base, valve means in the opening between the first and second passages, valve means in the opening between the second and third passages, valve means in the opening between the third and fourth passages, manually operative valve actuating means in the fifth passage, and means closing the entrances of the opening and the passages.

4. In a jack, a base bounded by :a plurality ofv intersecting surfaces, a hydraulic iluid reservoir,

an operating cylinder, a ram in the operating cylinder, a pressure cylinder, a pressure producing means in the pressure cylinder, a straight opening extending at least partially through the base and having an entrance at one surface of the base, three separate lateral passages connecting the opening with the reservoir, the pressure cylinder and the operating cylinder, respectively, and substantially identical valve means disposed in the opening in labutting relationship so as to control the flow between adjacent lateral passages, each of said valve means including a valve seat, a valve element cooperable with the valve se-at, and a spacer, the valve seats being interchangeable, the valve elements being interchangeable, -and the spacers being interchangeable.

5. In a jack, a base bounded by a plurality of intersecting surfaces, a hydraulic iiuid reservoir, an operating cylinder, a ram in the operating cylinder, a pressure cylinder, a pressure producing means in the pressure cylinder, a straight opening extending at least partially through the base and having an entrance at one surface of the base, four separate lateral passages connecting the opening with the reservoir, the pressure cylinder, the operating cylinder, and the reservoir, respectively, and substantially identical valve means comprising a valve seat, a valveV element cooperable with the valve seat. and a spacer disposed in the opening so as to control the :dow between adjacent lateral passages.

DOUGLAS JOHNSTON.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,011,213 Lemp Dec. 12, 1911 1,388,602 Rotteleur Aug. 23, 1921 2,032,309 Rechard et al. Feb. 25, 1936 2,042,727 Mueller June 2, 1936 2,306,012 Campbell Dec. 22, 1942 2,393,405 Page Jan. 22, 1946 2,412,414 Mueller Dec. 10, 1946 2,439,796 Dearsley Apr. 20, 1948 2,447,650 Haumerson Aug. 24, 1948

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