US3581499A

US3581499A - Quick raise adapter

Info

Publication number: US3581499A
Application number: US823284A
Authority: US
Inventors: John M Barosko
Original assignee: Tenneco Inc
Current assignee: McNeil Corp
Priority date: 1969-05-09
Filing date: 1969-05-09
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01
Also published as: CA939328A

Abstract

A U-shaped annular cup is disposed in a flow passage between the ram and center tube of a two speed hydraulic jack and acts as a seal during the pumping cycle and as a one-way valve during the release cycle which connects the pressure end of the ram to the reservoir via the center tube.

Description

United States Patent 1 References Cited UNITED STATES PATENTS 5/1947 Buffington et 11/1959 Bremeretal.......

[72] Inventor John M. Barosko Kenosha, Wis. 823,284

App]. No. Filed 277/205 277/205UX 60/52H.A.

2.420929 2,913,269 3,134,232 5/1964 Barosko 1221 May 9. 1969 [45] Patented June 1, 1971 {73] Assignee Tenneco lnc.

Primary ExaminerEdgar W. Geoghegan Houston, Tex.

AttorneyHarness, Dickey & Pierce [54] QUICK RAISE ADAPTER 7 Claims, 6 Drawing Figs. [52] US.

ABSTRACT: A U-shaped annular cu e ram and center tube of a two s acts as a seal durin as a one-way valve during the release h t d nn wa k We a b .w 1 u w a r 8 0 v Ph ...FlSb 15/18, F16, 15/48 60/52 [51] [50] Field of (H.A.),97 1-1 54.6 (M); 92/; 1 10, 168,240;

cycle which connects the 91/412; 277/205 pressure end of the ram to the reservoir via the center tube.

uick miss ADAPTER BRIEF SUMMARY OF THE INVENTION It is the purpose of the invention to simplify and improve the structure and operation of a hydraulic force applying device. It finds special application in a two speed jack, such as the one shown in my U.S. Pat. No. 3,l34,232, where it enables the space between the center tube and the ram to be used as a part of a pressure release flow passage and thereby simplifies the hydraulic circuitry required to properly operate the jack. The invention includes a combination seal and valve means, preferably in the form of an annular U-shaped ring or cup, that is located to control pressure flow between the high speed and low speed faces of the ram.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross section of a simplified form of two speed jack embodying the invention as taken along the line 11 of FIG. 2;

FIG. 2 is a cross section along the line 2-2 of FIG. 1;

FIG. 3 is a cross section along the line 3-3 of FIG. 2 with the pump added;

FIG. 4 is a schematic section illustrating the hydraulic circuitry used in the jack of FIGS. 13,

FIG. 5 is an enlarged view of the structure within the circle Sin FIG. 4; and

FIG. 6 is a longitudinal cross section of a modified form of the invention.

DESCRIPTION OF THE INVENTION The jack 1 of FIGS. 1-5 has a base 3 which supports a tank or outer housing 5 that is closed on its top by a fluid tight connection cap or tank nut 9. The tank nut 9 has an internally threaded skirt 11 into which is threaded the top end of a cylinder 13 whose bottom end is threaded at I5 into the threaded sidewall of a recess 17 in the base 3. An open-ended center tube 19 is also carried by the base 3, being threaded into the wall of an aperture 21, and extends to a lesser height than the cylinder 13 but is coaxial with it and with the tank 5. The space between the tube 19 and the cylinder 13 forms a working chamber 23 for the ram 25 and its suitably packed piston head 26; and the space between the cylinder 13 and the tank 5 forms an annular reservoir 27 for hydraulic liquid. The ram 25 has an internal bore 29 which receives the center tube 19 and is somewhat larger in diameter than the tube to form an elongated annular passage 3] inside the ram and around the outside of the tube. The ram 25 extends through and is supported in an aperture 33 in the tank nut 9, the joint being made fluid tight by a suitable seal or packing 35. The top end 37 of the ram is raised and lowered by control of hydraulic pressure within cylinder 13 acting upwardly on its bottom end.

When it is desired to elevate the ram 25, a pump 39 on the base 3 may be suitably reciprocated, as by pivoted pump handle 411. On the suction stroke oil is drawn to the pump chamber 13 from reservoir 27 through a pump suction passage 45 in the block, unseating ball check valve 47 in the passage 45. Assuming that a release valve 49 is in a seated or closed position and that there is no load on the top end of the ram, on the pump stroke oil in pump chamber 43 will seat check valve 47 and unseat check valve 50 in a connection passage 51 in the block 3 to enter a quick raise passage 53 in the block that opens inside the bottom end of center tube 19. Continued pumping of oil with the jack in no-load condition will cause oil flow into center tube 19 to thereby apply pressure to the top end of ram bore 29 and rapidly raise the ram 25 into contact with the load, there being means of this invention sealing annular passage 31 as will be later described. During the quick rise period of the ram 25, oil from the reservoir 27 can fill the rapidly expanding pressure chamber 55 below the bottom end of the ram and inside cylinder 13 by unseating a ball check valve 57 in a cross passage 59 that connects the pump section passage 415 with the main load passage 61, the latter opening into the bottom of chamber 55 inside the cylinder 13.

When the ram contacts the load, the pressure in the system will increase so that ball check valve 63 in cross passage 65 will unseat to connect pump chamber 43 with the main load passage 61. Thus, oil pressure is applied to the entire crosssectional area of the ram 25 and the load is lifted, or force is applied, as desired. Bypass hole 66 in cylinder 13 connects pressure chamber 55 to reservoir 27 when the ram is fully extended to prevent overstressing.

When it is desired to lower the ram 25, the release valve 49 is unseated to connect quick raise passage 53 to release passage 67 in the block. Oil can then flow from the inside of center tube 19 to the reservoir 27. Oil can also flow from pressure chamber 55 up through annular passage 31 past the sealing means 69 of this invention into the center tube 19. Thus, oil pressure on the ram is removed and the oil is returned to the reservoir so that upon reseating of the release valve 49 the jack 1 is ready for another lift.

The sealing means 69 is best seen in FIG. 5 and comprises a retaining ring 71, an annular spacer 73, and a U-shaped rubberlike or resilient packing ring 75. The ring 71 is threaded into the sidewall 77 of a recess 79 in the bottom of the ram 25 and supports the base portion of the flexible seal ring 75, the spacer ring 73 engaging the other side of the base. The outer lip 75B of the seal ring 75 engages the wall 77 and the inner lip 75A engages the center tube 19. The retainer ring 71 has a central aperture 81 which is larger than the tube 19, and in effect, forms a continuation of annular passage 31, the bottom of the aperture 81 opening into pressure chamber 55. However, oil flow from the annular passage 31 into the aperture 81 and chamber 55 is blocked by the inner lip of the seal ring which will be compressed tightly against the center tube 19. Thus, oil pressure in tube 19 will act on the top end of bore 29. Reverse oil flow in the direction of the arrows in FIG. 5 is permitted, however, when it is desired to lower the jack as the oil flow can then simply bend the inner seal lip away from the tube 19 as illustrated to flow up passage 31 and then down through tube 19. The seal ring, therefore, serves the additional function of a check valve that provides for two speed jack elevation when it is closed and for oil discharge when it is open.

FIG. 6 shows a modified arrangement in which the seal means of this invention is mounted on the center tube instead of the ram. In this figure parts corresponding to those in FIGS. 15 are given the same reference numbers plus one hundred. All details of the hydraulic power and control circuit for the jack 101 of FIG. 6 are not shown, for the sake of brevity, since in structure and principle, they may be substantially the same as those already described. The jack of FIG. 6 is similar to the one described in my US. Pat. No. 3, l 34,232.

In FIG. 6 the seal means 169 comprises a retainer 171 which is threaded on the top end of the center tube 119 and has openings (not shown) in it to form a continuation of annular passage 131. The retainer engages the base of the U-shaped rubber seal ring 175 and has an upper shoulder 176 that engages the top of the inner lip of the seal to hold the seal in place at all times. The outer lip of the seal 175 engages the wall of bore 129 and when there is pressure on top of it will expand to prevent oil from flowing through passage 131. When the top of the bore 129 is connected to the reservoir so that it is at a lower pressure than passage 131, the outer lip will bend inwardly to unseal the passage 131 and permit the ram to be lowered as previously described.

In the embodiment of FIGS. l5 there is sliding of the inner lip of the seal 75 on the outside of the center tube 19 during ram elevation and in the embodiment of FIG. 6 there is sliding of the outer seal lip on the wall of bore 129 during ram elevation. Pressure on the top of the seal automatically expands it into sealing contact and overcomes the effects of any wear due to this relative movement. During lowering of the ram, the lip is held substantially out of contact with the center tube or ram so that wear occurs only during the lift portion of the cycle.

Iclaim:

1. In a hydraulic force applying device, means providing a working chamber and a reservoir for hydraulic liquid, a ram member movable in the working chamber and having a pressure end defining a pressure chamber within the working chamber, an aperture terminating within the ram member and opening into the pressure chamber out of the pressure end, a fixed position tube member within the aperture and opening at one end into the aperture and having a second open end, said tube being smaller than the aperture to provide a flow passage between the tube and the wall of the aperture, hydraulic pumping and circuit means connected to the reservoir for pumping and delivering hydraulic liquid under pressure to the second end of the tube and to the pressure chamber and including release valve and passage means for selectively connecting the second end of the tube to the reservoir, and oneway seal means on one of said members and engaging the other and operated by pumping pressure to seal off said flow passage, said seal means being movable to open said flow passage when the pressure in said pressure chamber substantially exceeds the pressure in the tube member.

2. A device as set forth in claim 1 wherein said seal means includes a retainer attached to one of the members and a U- shaped resilient seal element supported on the retainer and having a lip resiliently engaging the other of the members to seal off said flow passage, the lips of the U-shaped seal extending away from said pressure chamber.

3. A device as set forth in claim 2 wherein said seal means is attached to the ram member adjacent its pressure end.

4. A device as set forth in claim 2 wherein said seal means is attached to said tube member adjacent said one end.

5. In a two speed hydraulic jack, an elongated longitudinally movable ram member having a pressure receiving end and an internal bore opening out of said end, a tube member extending inside said bore and having an opening into said bore but spaced from the wall thereof to provide a flow passage connecting the pressure end with the tube member opening, means for selectively connecting the inside of the tube to a source of hydraulic liquid at pumping pressures and to a hydraulic liquid reservoir, means for connecting the pressure end of the ram member to a source of hydraulic liquid at pumping pressures, and a combination seal and one-way valve means in said flow passage to seal it against hydraulic liquid flow from the tube member to the pressure end but provide for hydraulic liquid flow from the pressure end to the tube member.

6. A device as set forth in claim 1 wherein said seal means comprises a U-shaped resilient seal element supported by one of the members and having a lip resiliently engaging the other of the members to seal off said flow passage, the lips of the U- shaped seal element extending away from said pressure chamber.

7. In a hydraulic jack, a movable ram having a high speed face and a low speed face and a flow passage connecting the faces, and a U-shaped resilient seal member in said passage providing resilient valve and seal means in said passage and acting to prevent flow of hydraulic liquid from the high speed face to the low speed face but permitting flow from the low speed face to the high speed face.

Claims

1. In a hydraulic force applying device, means providing a working chamber and a reservoir for hydraulic liquid, a ram member movable in the working chamber and having a pressure end defining a pressure chamber within the working chamber, an aperture terminating within the ram member and opening into the pressure chamber out of the pressure end, a fixed position tube member within the aperture and opening at one end into the aperture and having a second open end, said tube being smaller than the aperture to provide a flow passage between the tube and the wall of the aperture, hydraulic pumping and circuit means connected to the reservoir for pumping and delivering hydraulic liquid under pressure to the second end of the tube and to the pressure chamber and including release valve and passage means for selectively connecting the second end of the tube to the reservoir, and one-way seal means on one of said members and engaging the other and operated by pumping pressure to seal off said flow passage, said seal means being movable to open said flow passage when the pressure in said pressure chamber substantially exceeds the pressure in the tube member.

2. A device as set forth in claim 1 wherein said seal means includes a retainer attached to one of the members and a U-shaped resilient seal element supported on the retainer and having a lip resiliently engaging the other of the members to seal off said flow passage, the lips of the U-shaped seal extending away from said pressure chamber.

6. A device as set forth in claim 1 wherein said seal means comprises a U-shaped resilient seal element supported by one of the members and having a lip resiliently engaging the other of the members to seal off said flow passage, the lips of the U-shaped seal element extending away from said pressure chamber.