US3410087A - Hydraulic jack - Google Patents

Description

L. L. ARNES Nov. 12, 1968 HYDRAULIC JACK 3 Sheets-Sheet 1 Filed March 17, 1966 //v VENTOR. 44, 07265 L. ARNES Nov. 12, 1968 Filed March 17, 1966 INVENTOR. A. 77755 0 40? W if ozwz/s,

United States Patent f 3,410,087 HYDRAULIC JACK Lyle L. Arnes, Racine, Wis., assignor to Walker Manufactoring Company, Racine, Wis., a corporation of Delaware Filed Mar. 17, 1966, Ser. No. 535,123 9 Claims. (Cl. 60-51) ABSTRACT OF THE DISCLOSURE In a hydraulic force applying device a pressure air mechanism is used to move the hydraulic mechanism to a load engaging position, to pressurize the hydraulic fluid, and to remove water accumulating in the hydraulic mechanism.

In air operated jacks an air cylinder, preferably of the type shown in US. Patent 3,218,980, is used to supply the power needed to operate the oil pump that raises the lifting arm of the jack, thus replacing manual pumping by a human operator. In such jacks it is necessary to provide suitable valving to control the air flow and it is desirable to provide means to remove water that condenses from the air used in operation of the device. Accordingly, it is the object of this invention to provide a water separator and valving means that is useful in air operated jacks or similar hydraulic systems. This valving is such that air is used to pressurize the oil reservoir and raise the jack during no load condition and automatically actuate the air pump when load resistance is reached. On lowering, the valving (including its operating mechanism) is such that air pressure is released just prior to release of oil pressure so that air pressure in the reservoir does not exceed oil pressure in the ram cylinder. The reservoir air during releasse is used to blast out water collected during the lifting cycle of the jack.

Other objects and features of the invention will appear upon consideration of the accompanying drawings in which:

FIGURE 1 is a perspective view of an air operated garage type hydraulic jack (with a top cover plate removed) embodying the invention;

FIGURE 2 is a top view of a portion of the jack of FIG. 1, and partly in section, as taken from position 2 in FIG. 1;

FIGURE 3 is a side view of the structure of FIG. 2 but with a side plate of the jack carriage broken away;

FIGURE 4 is an enlarged elevation of the water separator unit of this invention;

FIGURE 5 is a longitudinal section through the water separator along the line 55 of FIGURE 4;

FIGURE 6 is a cross section along the line 6--6 of FIGURE 4;

FIGURE 7 is a somewhat schematic cross sectional view of the end of the water separator to show the valving structure; and

FIGURE 8 is an enlarged view along the line 8-8 of FIGURE 2.

Referring to FIGS. 1-3, the portable garage jack 1 has a carriage 3 which is movable on wheels 5 so that the lifting head 7 on bellcrank lifting arm 9 can be positioned as desired. The arm 9 is moved up and down about its pivot pin 11 by an oil operated ram assembly or hydraulic unit :13 which is connected at one end to the arm 9 and pivoted at its other end at 15 to the side plates 17 of the jack. In manual operation the unit 13 would be operated by pumping movement of handle 18. In the present jack the hydraulic unit 13 is operated or pumped by an air pump unit 19, mounted on the carriage 3, which is preferably constructed in accordance with US. Patent No. 3,218,980. The pressure output of pump 19 3,410,087 Patented Nov. 12, 1968 is operatively connected to the oil pump or ram pressurizing means of hydraulic unit 13 by means of hose 20'.

In accordance with this invention air to operate the air pump 19 and to pressurize the oil reservoir (not shown) in hydraulic unit 13 (which air is the usual pressurized shop air available in garages, etc.), passes first through a water separator unit 21. As best seen in FIG. 3, air from inlet hose 23 which is attached to the shop pressure air supply and controlled by hand valve 25, enters the unit 21 at elbow 27 and leaves the unit 21 via hose 29 for the air pump 19 and via hose 31 for the oil reservoir in the hydraulic unit 13. The unit 21 is mounted on a hollow adapter rod 33 that replaces the normal manual pump mechanism in the inlet 13 and to which the hose 20 from air pump 19 is connected by fittings 35 (FIG. 3).

As best seen in FIGS. 57, the water separator assembly 21 includes means to remove water from the air so that it does not flow to the air pump 19 or the reservoir of hydraulic unit 13 and valving that delivers air first to the reservoir and then when lifting head 7 engages the load, to the air pump unit 19. The unit 21 includes a tubular housing shell 37 that has a tank nut 39' at the inlet end and a valve block 41 at the outlet end. An aperture 43 in nut 39 connects the air inlet fitting 27 to the interior of tube 45 which is threaded at one end in nut 39 and at the other end in block 41. The wall of the tube 45 has cross holes 47 in it adjacent the inlet end so that air can blast into the annular tank space or chamber 49. The abrupt change in direction as air flows through holes 47 separates the water from the air and deposits it in the bottom of tank 49.

As seen best in FIGURE 7, the air in tank 49 can enter a passage 53 in block 41 which opens into passage 55 that communicates with the hose 31 which leads to the oil reservoir in the hydraulic unit 13. When pressure in passage 55 exceeds a certain value (due to contact of the head 7 with a load), it forces the slide valve 57 in passage 55 downwardly against the resistance of spring 59 that is housed in an enlargement 61 of passage '55 and reacts against apertured adjustment screw 63 that is threaded into the valve block 41. Valve 57 has a shoulder 65 that carries an O-ring 67 so that it seals off section 61 when the valve is in the seated position of FIGURE 7. When the valve member 57 moves down its reduced diameter section 69 lines up with a passage 71 at the end of tube 45 so that air can flow around it and enter passage 73 in the block 41 which feeds air to hose 29 that leads to the air pump 19. This operates the pump 19 to actuate the hydraulic unit 13 and lift the load.

In order to release the pressure within hydraulic unit 13 and lower lifting head 7 and the load, the release rod 75 of the unit 13 is moved to the right as seen in FIGURE 2. Force for this movement is applied to a foot pedal 77 which is pivoted on the carriage 3 and which is connected to a tie rod 79 so that depression of the pedal moves the rod to the right in FIGURE 2. As seen in FIGS. 2 and 8 the rod 79 extends loosely through an oversize hole 81 in a strike plate 83 and applies force to the back of it (i.e., to the right in FIG. 2) by means of nut 85 that is threaded on the end of the rod. One end of the strike plate 83 is loosely connected to the threaded end of the release rod 75 by means of nuts 87 threaded on the rod. Release movement of the release rod 75 to the right in FIGURE 2 when the strike plate 83 is pulled to the right is resisted, however, by a relatively heavy spring (not shown) inside the hydraulic unit 13. At the beginning of release movement the strike plate 83, therefore, rocks about its connection to the, tie rod 79 and pushes the projecting end 89 of a plunger 91 to the right as seen in FIGS. 2, 7, and 8. The plunger end 89 extends through an oversize aperture 93 in the block 41 which is an extension of the larger aperture 95 containing the plunger 91 which is pressed by a relatively light (as compared with the release rod spring) spring 97 based on apertured adjustment screw 99 against O-ring 101 to seal oil the inlet end of aperture 93. Unseating of plunger 91 by movement to the right enables air in the oil reservoir of the unit 13 to back track through hose 31, passages 55 and S3, tank 49, passages 47, passage 103 that opens into passage 71 and aperture 95, and passage 93 to atmosphere carrying with it excess water that may have accumulated in tank 49. This occurs prior to operation of the release rod 75 and continued movement of the tie rod 79 to the right due to depression of the foot pedal 77 pulls the rod 75 far enough to release pressure on the ram in unit 13 and lower the jack. Because of the relationship just described the air pressure in the oil reservoir will not exceed the oil pressure in the ram cylinder of unit 13 at the time of load release and there is no danger of air bubbles being blown into the ram cylinder.

As seen best in FIGS. 5 and 6 the block 41 of water separator 21 has an opening 105 whereby the unit is mounted on rod 33 of the hydraulic assembly 13. The screw 107 threaded into the block 41 holds the unit 21 in place.

In operation, when it is desired to raise the head 7 of the jack 1 the operator opens valve which connects air hose 23 to air line pressure. The air flows down tube 45 in separator 21 and passes out through holes 47 so that water is separated out into tank 49, and then enters passage 53 to how through passage 55 into hose 31 to pressurize the oil reservoir in the unit 13. This pressure causes the arm 9 to lift under the no load condition. Some action of the pump 19 occurs during this period due to leakage by the valve 57. When the load is engaged the pressure in the reservoir increases abruptly and this is reflected in increased air pressure on the plunger 57 which moves against spring 59 to let full air pressure flow by reduced valve section 69 from tube 45 to reach hose 29 and operate the air pump 19. When the lifting arm 9 and the load reaches the desired position the operator releases the air valve 25 and lifting stops and holds.

When it is desired to lower the load, the operator depresses the pedal 77 which pulls the tie rod toward him (to the right) and teeters strike plate 83 to push plunger end 89 inwardly and unseat plunger 91 so that air in the reservoir can back flow to atmosphere through blowoti passage 93 carrying water in tank 49 with it. Continued pressure on the foot pedal causes the plate 83 to pull the release rod in a direction to relieve pressure in the ram cylinder of hydraulic unit 13 and lower the load and then the arm 9 back to the position of FIGURE 1.

Modifications may be made in the structure shown without departing from the spirit and scope of the invention.

I claim:

1. In an air operated hydraulic pressure producing device having an air operated pump and a hydraulic operated ram assembly including a hydraulic reservoir and a pressure release member, a valve mechanism having an inlet for connection to a source of pressurized air and an air pump outlet and a reservoir outlet, air passage means in said mechanism for flow of air from said inlet to said outlets, said passage means including an open section between said inlet and said reservoir outlet so that air may continuously flow therein, valve means responsive to pressure at the reservoir outlet for controlling fiow through the passage means to the air pump outlet and operative above a predetermined pressure to provide flow to said air pump outlet and below said pressure to obstruct such flow, said valve mechanism and said passage means comprising an elongated housing having an air inlet at one end and a valve block at the other end, a second valve means for controlling flow through a portion of said passage means which connects said open section to a blowoff outlet, said air pump outlet and said reservoir outlet being formed in said valve block, said valve means being provided in said valve block, a tube forming a part of said passage means and connecting said inlet to said valve block, said housing including a tank chamber surrounding said tube and said tube having cross openings for air flow into said tank chamber, said block containing a cross passage connecting the end of the tube to the tank chamber.

2. A construction as claimed in claim 1, wherein said valve block includes a first passage connecting said tube to said air pump outlet and a second passage intersecting said first passage, said second passage being connected to said reservoir outlet, said valve means comprising a spring pressed slide valve in said second passage, said slide valve having a reduced diameter section alignable with said first passage upon movement of the slide valve by pressure at the reservoir outlet to connect the air inlet to the air pump outlet.

3. A construction as claimed in claim 2, wherein said valve block includes a blowoff outlet opening to atmosphere, said valve block including a third passage connected to said blowolf outlet, a spring pressed plunger in said third passage and normally closing said blowoif outlet and including a force receiving projection accessible from outside the valve block, said passage means connecting said tank chamber and said reservoir outlet to said third passage so that upon unseating of said plunger back pressure from 5: id reservoir outlet can carry water from said tank chamber through said bio-wolf outlet.

4. In combination with a hydraulic operated ram assembly including a raw, a hydraulic reservoir connected for pressurizing the ram, an air operated pump also con nected for pressurizing said ram, and a pressure release member connected for releasing pressure from said ram, a valve mechanism having an inlet for connection to a source of pressurized air and an air pump outlet connected for operating said pump and a reservoir outlet connected to pressurize said reservoir, air passage means in said mechanism for flow of air from said inlet to said outlets, said passage means including an open section between said inlet and said reservoir outlet so that air may continuously flow therein, valve means responsive to pressure at the reservoir outlet for controlling flow through the passage means to the air pump outlet and operative above a predetermined pressure to provide fiow to said air pump outlet and below said pressure to obstruct such flow, a second valve means for controlling flow through a portion of said assage means which connects said open section to a blowolf outlet, a common means for operating said pressure release member and applying said force to said second valve means, said common means and said second valve means being arranged to apply said force and operate said second valve means prior to operation of said pressure release member.

5. A construction as claimed in claim 4 including a strike plate connected to said pressure release member and to said second valve means and a rod means for applying operating force to said plate, said second valve means being movable at less force than said pressure release member whereby it is operated by said strike plate prior to said pressure release member.

6. In combination with a hydraulic operated ram assembly including a ram, a hydraulic reservoir connected for pXGSSUIiZiUlg the ram, an air operated pulmp also connected for pressurizing said ram, and a pressure release member connected for releasing pressure from said ram, a valve mechanism having an inlet for connection to a source of pressurized air and an air pump outlet connected for operating said pump and a reservoir outlet connected to pressurize said reservoir, air passage means in said mechanism for [low of air from said inlet to said outlets, said passage means including an open section between said inlet and said reservoir outlet so that air may continuously flow therein, and valve means responsive to pressure atthe reservoir outlet for controlling flow through the passage means to the air pump outlet and operative above a predetermined pressure to provide flow to said air pump outlet and below said pressure to obstruct such flow, said valve mechanism including a tank chamber communicating with said air passage means, said air passage means including angled flow portions acting to separate water from the air and deposit in said tank chamber, said valve mechanism including a blowoif outlet opening to atmosphere for passage of water from said tank chamber, said passage means including a portion connecting said open section to said blowoff outlet, and second valve means controlling flow through said portion and arranged to provide flow through said portion upon application of a predetermined force to said second valve means, and a common means for operating said pressure release member and said second valve means, said common means and said second valve means being arranged to apply said force to operate said second valve means prior to operation of said pressure release member.

7. In combination with a hydraulic operated ram assembly including a ram, a hydraulic reservoir connected for pressurizing the ram, an air operated pump also connected for pressurizing said ram, and a pressure release member connected for releasing pressure from said ram, 21 valve mechanism having an inlet for connection to a source of pressurized air and an air pump outlet connected for operating said pump and a reservoir outlet connected to pressurize said reservoir, air passage means in said mechanism for flow of air from said inlet to said outlets, said passage means including an open section between said inlet and said reservoir outlet so that air may continuously flow therein, valve means responsive to pressure at the reservoir outlet for controlling flow through the passage means to the air pump outlet and operative above a predetermined pressure to provide flow to said air pump outlet and below said pressure to obstruct such flow, said valve mechanism including a blowoif outlet opening to atmosphere and said passage means including a portion connecting said open section to said blowotf outlet, water separation means associated with said open section and portion, and second valve means controlling flow through said portion and arranged to provide flow through said portion upon application of a predetenmined force to said second valve means.

8. In combination with a hydraulic operated ram assembly including a ram, a hydraulic reservoir connected for pressurizing the ram, an air operated pump also connected for pressurizing said ram, and a pressure release member connected for releasing pressure from said ram, a valve mechanism having an inlet for connection to a source of pressurized air and an air pump outlet connected for operating said pump and a reservoir outlet connected to pressurize said reservoir, air passalge means in said mechanism for flow of air from said inlet to said outlets, said passage means including an open section between said inlet and said reservoir outlet so that air may continuously flow therein, valve means responsive to pressure at the reservoir outlet for controlling flow through the passage means to the air pump outlet and operative above a predetermined pressure to provide flow to said air pump outlet and below said pressure to obstruct such flow, said valve mechanism including a tank chamber communicating with said air passage means, said air passage means including angled flow portions acting to separate water from the air and deposit it in said tank chamber, said valve mechanism including a blowoft outlet opening to atmosphere for passage of Water from said tank chamber.

9. A construction as claimed to claim 8 wherein said passage means includes a portion connecting said open section to said blowoff outlet, and second valve means controlling flow through said portion and arranged to provide flow through said portion upon application of a predetermined force to said second valve means.

References Cited UNITED STATES PATENTS 1,103,036 7/1914 Clark 91-29 2,403,912 7/1946 Doll 60-52 X 1,885,894 11/ 1932 Campbell 137-203 2,511,541 6/1950 Purcell 60-52 2,573,993 11/1951 Sedgwick 60-52 X 3,216,196 11/1965 Sund 60-51 3,258,921 7/ 1966 Prescott 6 0-52 3,325,995 6/1967 Buhro 60-51 ALAN COHAN, Primary Examiner.

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