US3325995A - Jack - Google Patents

Description

C. L.. BUHRO June 20, 1967 JACK 2 Sheets-Sheet 1 Filed Feb.

IN VENTOR. ,Zia/ 70 /M 07g@ June 20, 1967 vCz. BUHRO n 3,325,995

JACK

Filed Feb. 5, 1965 2 Sheets-Sheet 2 M /55 n J .hf I 'M4 Il A f4 wf @65 5? /s/rraWA/EKS" United States Patent 3,325,995 JACK Charles L. Buhl-o, Racine, Wis., assigner to Walker Manunfacturing Company, Racine, Wis., a corporation of Delaware Filed Feb. 3, 1965, Ser. No. 430,036 1 Claim. (Cl. 60-51) This invention relates generally to hydraulic jacks and, more particularly, to hydraulic jacks of the type provided with auxiliary pumping means for rapidly supplying hydraulic fluid to the elevating or ram cylinders thereof.

It is a general object of the present invention to provide means for selectively communicating a source of compressed air or similar actuating fluid with the hydraulic fluid reservoir of a hydraulic jack assembly and with an auxiliary pumping device for rapidly pumping fluid from the reservoir to the jacks ram cylinder, whereby the time and effort required to elevate the jacks lifting lever or arm and load supported thereon is minimized to the extreme.

It is a more particular object of the present invention to provide means of the above character which is controlled by simple movement an actuating lever mounted on the jacks manipulating handle.

It is another object of the present invention to provide means of the above character which prevents compressed air from being trapped in the jacks fluid reservoir to facilitate rapid lowering of the jacks lifting lever.

It is another object of the present invention to provide means of the above character which is of an extremely simple design that can be easily assembled and economically manufactured.

In accordance with the principles of the present invention, the foregoing and other related objects and advantages are achieved through the provision of a novel valve construction which is adapted to be mounted directly upon the manipulating handle of a hydraulic jack of a type used in automotive vehicle repair shops and which is provided with an auxiliary pumping device that uses pressurized air as is commonly available in such repair shops to rapidly pump hydraulic fluid from the jacks fluid reservoir to its ram cylinder, thereby effecting rapid elevation of the jacks lifting lever without requiring oscillation or pumping of the jacks manipulating handle. The valve construction of the present invention is adapted to be connected directly to the aforesaid source of pressurized air and selectively communicate said source with both the auxiliary pumping device and the fluid reservoir of the jack assembly, whereby pressurized air is initially communicated to the fluid reservoir to force fluid into the jacks ram cylinder and thereby elevate the lifting arm into engagement with the load to be elevated, at which time the pressurized air is communicated to the auxiliary pump which serves to force hydraulic fluid from the fluid reservoir to the ram cylinder and thereby elevate the load upon the lifting lever. During the time pressurized air is being communicated to the auxiliary pumping device, pressurized air is continually supplied to the fluid reservoir by means of the subject valve construction such that during the suction stroke of the pumping device, hydraulic fluid will be forced into the pumping device `by reservoir pressure, thereby preventing any cavitation within the hydraulic ICC system and substantially improving the efliciency of the auxiliary pumping device. At such time as the valve means of the present invention is deactuated, the jacks fluid reservoir is vented to the atmosphere, whereby hydraulic fluid may readily flow from the jacks ram cylinder back to the fluid reservoir without en-countering any back pressure due to air trapped within the reservoir, thus permitting rapid lowering of the jacks lifting lever.

A more complete understanding of the present invention and other objects and features thereof will ybe obtained from the following detailed description taken in conjunction with the accompanying drawings, wherein:

FIGURE l is a schematic view of the valve assembly of the present invention as seen in operative association with a conventional hydraulic jack and auxiliary pumping means therefor;

FIGURE 1A is an enlarged schematic view showing a conventional check valve combination for preventing back flow to the reservoir and air pump;

FIGURE 2 is a longitudinal cross-sectional view of the auxiliary pumping means illustrated in FIGURE l;

FIGURE 3 is a top elevational view of the valve construction of the present invention;

FIGURSE 4 is a transverse cross-sectional view of the valve assembly illustrated in FIGURE 3; and

FIGURE 5 is a side elevational view, partially broken away, of the valve construction illustrated in FIGURE 3.

Referring now to the drawings, FIGURE l illustrates a portable hydraulic service jack, generally designated 10, of the type with which the valve assembly of the present invention is adapted to be operatively associated. In general, the jack 10 comprises an elongated main frame or carriage 12 having transporting wheels 14 at its forward end and a manipulating handle 16 pivotably mounted at its rear end. A longitudinally extending loadlifting lever or arm 18 is pivotably mounted upon a transversely extending pivot pin or shaft 20 and is provided with a load-engaging saddle 22 on the swinging or unattached end thereof. A hydraulic ram assembly, generally designated 24, is mounted within the carriage 12 and includes a reciprocal plunger or ram 26 which is pivotably connected to the lower rear side of the lifting lever 18 and is movable in one direction by the action of pressurized hydraulic fluid within the assembly 24 to elevate the lever 18 and saddle 22, and is movable in the opposite direction to lower the lever 18 and saddle 22. Hydraulic fluid is supplied through passage 29 to the ram assembly 24 from a fluid reservoir 2S that is located within the rear end of the carriage 12, which fluid is normally adapted to be pumped to the assembly 24 upon appropriate oscillatory movement of the manipulating handle 16, in a manner well known in the art.

Pressure in the ram assembly 24 may be released to lower the jack by means of a pressure release valve 29A in the pressure release line 29V that connects the ram assembly to the reservoir 28.

The hydraulic jack 10 is provided with an auxiliary pumping device, generally designated 30, which is adapted to be mounted `on the manipulating handle 16 and use pressurized air as is commonly available in vehicle repair shops to rapidly pump hydraulic fluid from the reservoir 28 to the ram assembly 24, thereby effecting elevation of the arm 18 and saddle 22 without requiring pumping of the handle 16. As seen in FIGURE 2, the

pumping device comprises an elongated hollow cylindrieal housing 32 which is closed at its opposite ends with end plugs 34 and 36. An elongated hydraulic pumping cylinder 38 extends outwardly from the end plug 36 within which one end of a cylindrical piston rod 40 is reciprocally mounted. The opposite end of the rod 40 is connected to a piston assembly 42 which is reciprocally mounted Within the housing 32 and serves to move the piston rod 40 within the pumping cylinder 38. Pressurized air is communicated to the pump assembly 30 through a suitable conduit 44, the cylinder 38 being connected to the uid reservoir 29 of the jack 10 by means of a suitable conduit 46. between conventional non-return `or check valves 47A and 47B that prevent back flow from the ram 24 and into the reservoir 28 (FIGURE 1A). As pressurized air is communicated through the conduit 44, the piston assembly' 42 reciprocates Within the housing 32, whereby the movement of the piston rod 40 within the cylinder 38 causes hydraulic fluid to be forced from the jack reservoir 28 to the ram assembly 24. Both the operation and construction of the auxiliary pumping device 30, together with a description of how the device 30 utilizes the existing valving provided in the jack 10, is more particularly shown and described in the application of Lyle L. Arnes for Pump, Ser. No. 345,325, led Feb. 17, 1964, now U.S. Patent 3,218,980, issued Nov. 23, 1965, which is assigned to the same assignee of the present invention and is incorporated herein by reference as a part of the descriptive portion of this application.

In accordance with the principles of the present invention, there is provided a novel valve mechanism, generally designated 48, which serves to selectively control the flow of pressurized air from the aforesaid source thereof to the auxiliary pumping device 30 and to the uid reservoir 28 of the jack assembly 10, whereby pressurized air is initially communicated to the reservoir 28 to force hydraulic uid into the jacks ram cylinder 24 and effect elevation of the lifting arm 18 and saddle 22. The valve mechanism 48 also selectively communicates pressurized air to the auxiliary pumping device 30 such that hydraulic uid is forced from the reservoir 28 to the ram cylinder 24 by the action of the pumping device 30 at approximately the time as the saddle 22 engages and begins to lift a preselected load, representatively designated herein by the numeral 50.

Referring now to FIGURES 3, 4 and 5, the valve mechanism 48 comprises a rectangular shaped valve housing 52 which is ydisposed interjacent -a pair of elongated converging handle members 54 `and 56 that comprise the major portion of the manipulating handle 16 of the yhydraulic jack 10. The housing 52 is rigidly supported interjacent the members 54 and S6 by means of a generally U-shaped bolt 58 that comprises spaced parallel leg sections `60 and 62 and an end section 64 which interconnects the ends of the sections 60 and 62. The leg sections 60 and 62 extend horizontally above and below the members 54 and 56, respectively, the section 62 also extending through a bore 66 that is formed in the lower end of the housing 52. The U-bolt 58, and hence the housing 52 which is supported upon the leg section 62 thereof, is secured to the handle members S4 and 56 by means of a mounting plate 68 that is formed with a pair of suitable bores'70 and 72 through which the ends of the leg sections 60 and 62 project, as best seen in FIGURE 3. The outer ends of the leg sections -60 and 62 of the bolt 58 are externally threaded and are hence adapted to receive suitable nuts 74 and 76, respectively, which, when appropriately tightened, secure the handley members 54 and S6, housing 52, U- bolt 58 `and mounting plate 68 in the unitary assembly illustrated in FIGURES 3 through 5.

The U-bolt 58 also serves to support an elongated actuating handle, generally designated 78, which extends substantially parallel to the upper sides of the handle members 54 and 56, as seen in FIGURE 5. The handle 78 comprises .a pair of spaced parallel side sections 80 and 82 and an upper section 84 which extends between the upper ends of the side sections and 82. The leg section 60 -of the U-bolt 58 extends through suitable aligned apertures in the side sections 80 and 82, whereby the handle 78 is pivotable about a horizontal axis defined by the leg section 60 to effect actuation of the valve mechanism 48, as will hereinafter be described.

Referring now to FIGURE 4, the housing member 52 is formed with a pair of spaced parallel and vertically extending bores 86 and 88 that are formed with enlarged diameter lower sections 90 and 92, respectively, which are closed -at their lower ends by suitable plugs 94 and 96, respectively. The lower sections 90 and 92 of the bores 86 and 88 are communicable with a transversely or horizontally extending bore 98 that is formed in the lower end of the housing 52. The bore 98 is communicable at one end with a pressurized air inlet conduit 100 that is connected to a suitable source of pressurized air (not shown) and is rigidly secured to the housing 52 by a suitable inlet tting 102l that is threaded within the end of the bore 98. A pair of elongated cylindrical piston or plunger members 104 and 106 are disposed within the bores 86 and 88, respectively, which members 104 and 106 are provided with frusto-conically shaped valve members 108 and 110 on the lower endsv Y springs 116 and 118 which extend coaxially of the upper endsV of the plunger members 104 and 106, respectively, which springs 116 and 118 are mounted on the upper ends of the members 104 and 106 and are retained thereon by a pair of Cotter pins 120 which extend through suitable openings in the upper ends of the members 104 and 106.'As seen in FIGURE 4, the lower ends of the springs 116 and 118 abut against a pair of retaining rings 122 which are press tted within annular recesses 124 and 126 circumjacent the upper ends of the bores 86 and 88, respectively, and serve to retain suitable O- ring sealing members 128 and 130 that are also disposed wit-hin the recesses 124 and 126, the members 128 and 130 providing air-tight seals between the interior of the bores 86, 88 and the outer peripheries of the plunger members 104 and 106. It will be seen that the lengths of the plunger members 104` and 106 are such that when the actuating handle 78 is depressed a predetermined amount, the upper section 84 of the handle 78 initially engages the plunger member 104 and causes the valve member 108 secured thereto to become unseated from the valve seat section 112. In a similar manner, whenv the actuating handle 78 is further depressed, the upper section 84 thereof engages the plunger member 106, thereby unseating the valve member 110 from the valve seat section 114. When the handle 78 is released, the coil springs 116 and 118 will'serve to bias the plunger members 104 and 106 upwardly to engage the valve members 108 and 110 with the valve seat sections 112 and 114, this action of the prings 116 and 118 also serving to bias the handle 78 to the position illustrated in FIGURE 5.

Referring now to FIGURES 4 and 5, a pair of spaced parallel uid outlet bores 132 and 134 are formed in a medial section of the housing 52 and are communicable at their inner ends with the bores 86 and 88 directly `above the valve seat sections 112 and 114. The bores 132 and 134 are respectively communicable with an air conduit 136 which is connected to the uid reservoir 28 of the jack 10, and with the conduit 44 which communicates pressurized air to the pumping device 30, the conduits 136 and 44 being secured to the housing 52 by means of suitable fittings 138 and 140 which are threaded within the outer ends of the bores 132 and 136, respectively. It will be observed that when the plunger members 104 and 106 are disposed in a position illustrated in FIGURE 4, the valve members 108 and 110 block communication between the inlet bore 98 and -tfhe fluid outlet bores 132 and 134, and when the handle 78 is depressed, the Valve members 108 and 110 will be disengaged from the valve seat sections 112 and 114, thus communicating the inlet bore 98 with the outlet bores 132 and 134.

As best seen in FIGURE 5, formed in the housing 52 adjacent the bore 86, is a vertically extending passage 142 which is communicable at its lower end with the bore 132. The passage 142 is formed with a reduced diameter section 144 that defines an annular valve seat 146 against which a spherical valve member 148 is resiliently engaged by a valve spring 150 that extends coaxially within the upper end of the passage 142. Disposed within the upper end of the spring 150 is a vertically extending cylindrical pin or shaft 152 which includes a hemispherical upper end section 154 that is engaged with the upper section 84 of the actuating handle 78. It will be noted that the force exerted on the valve member 148 by the spring 150 is such that when the handle 78 is arranged in the position illustrated in FIGURE 5, the fluid pressure within the reservoir 28 of the jack assembly 10 is sufficient to unseat the` valve member 148 from the section 146 and thereby cornmunicate the reservoir 28 with the atmosphere; however, when the actuating handle 78 is partially depressed, the spring 150 will engage the valve member 148 with the valve seat section 146 with sufficient force to prevent the Valve member 148 from being unseated while pressurized air is being communicated to the fluid reservoir 28, as will hereinafter be described.

In operation, assuming that the air inlet conduit 100 is connected to a suitable source of pressurized air, and that the outlet conduits 44 and 136 are connected to the auxiliary pumping device and the fluid reservoir 28 of the jack assembly 10, respectively, as the manipulating handle 78 is initially depressed, the spring 150 is compressed such that the spherical valve member 148 is engaged with the valve seat section 146 to prevent the valve bore 132 from communicating with the atmosphere. Simultaneously, the plunger 104 is forced downwardly within the bore 86, thereby disengaging the valve member 108 `from the valve seat section 112, whereby pressurized lair being communicated to the housing 52 through the inlet conduit 100 and bore 98 is communicated through the enlarged section 90 of the bore 86 and into the outlet bore 132, from where this pressurized air is communicated through the conduit 136 to the fluid reservoir 28 of the jack 10. As pressurized air is transmitted to the uid reservoir 28, the hydraulic fluid within the reservoir 28 is forced into the ram cylinder 24, whereby the load-lifting lever 18 is elevated to a position engaging the load 50, as indicated by the phantom lines in FIGURE l. As the lifting arm 18 engages the load 50, the actuating handle 78 is depressed further, whereby the plunger 106 is forced downwardly within the bore 88 to disengage the valve member 110 from the valve seat section 114, whereby pressurized air is communicated from the bore 98 into the bore 134, which air is then transmitted through the conduit 44 to actuate the pumping device 30. The device 30 will operate to draw hydraulic fluid from the reservoir 28 and force it into the ram assembly 24.

At such time as the load 50 is elevated to a predesired height, the actuating handle 78 may be released, whereby the springs 116 land 118 will bias the actuating handle 78 to the position illustrated in FIGURE 5 and will serve to resiliently bias the plungers 104 and 106 upwardly such that the valve members 108 and 110 are engaged with the valve seat sections 112 and 114 defined within the bores 86 and 88, respectively. As the handle 78 is thus released,

the force exerted on the spherical valve member 148 by the spring will be relieved, whereby the valve member 148 may be unseated by any slight back pressure within the fluid reservoir 28 so that the reservoir 28 is vented with the atmosphere to permit the hydraulic fluid within the ram assembly 24 to flow easily back into the reservoir 28 and thus permit rapid lowering of the arm 18.

Although particular reference has been made herein to use of the valve construction 48 of the present invention as applied solely in combination with the jack assembly 10 and auxiliary pumping device 30, it is to be noted that the principles of the present invention are not intended to be limited to this sole application -and that the claim appended hereto which is not specifically directed toward this combination is not to be construed as being limited thereto.

While it will be apparent that the present invention is calculated to fulfill the objects above stated, it will be appreciated that the valve construction 48 is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claim.

What is claimed is:

In an hydraulic jack having an hydraulic ram assembly for moving a load and a reservoir for hydraulic fluid, an air operated pumping device for forcing hydraulic fluid under pressure from the reservoir to the ram assembly to move a load, a valve assembly having -a housing comprising means including an inlet passage for connection to a source of air under pressure, said valve assembly housing having a first outlet connected to said reservoir to furnish air under pressure to said reservoir, said valve assembly housing having a second outlet connected to said pumping device to furnish air under pressure to said device, said valve assembly housing having a first reservoir valve passage including a valve seat and a second reservoir air passage communicating with said first outlet, said first reservoir valve passage communicating on one side of said seat with said inlet passage and `on the other side of the seat with said second reservoir air passage, a reservoir valve plunger reciprocable in said first reservoir valve passage and having a valve portion engageable with said seat to block air flow from said inlet passa-ge to said second reservoir air passage, said valve assembler housing having a first air .pump valve passage including a valve seat and a second air pump air passage communicating with said second outlet, said first air pump Valve passage oommunicating on one side of its valve seat with said inlet passage and on the -other side of its valve seat with said second air pump air passage, an air pump valve plunger reciprocable in said first air pump valve passage and having a valve portion engageable with said seat to Vblock air flow from said inlet passage to said second air pump air passage, resilient means yieldably urging both said valves to seat on their respective valve seats, said valve assembly housing including a third reservoir vent passage connecting said second reservoir air passage with the atmosphere outside the Valve assembly housing, said third reservoir vent passage including a vent valve and a vent valve seat for controlling air flow through said vent passage, spring means yieldably urging said Vent valve to seat on the vent valve seat, a valve operator mounted adjacent the valve housing and movable toward and away from the housing, said spring means and said reservoir valve plunger and said `air pump valve plunger each having a portion projecting outwardly of the valve assembly housing and engageable with said operator and movable by it, said spring means and said reservoir valve plunger being operatively engaged and said air pump valve plunger being out of operative engagement with said valve operator when said valve operator is in a first position and movement of said operator toward a second position compressing said spring means to yieldably hold said vent valve on its seat and unseating said reservoir plunger valve to connect said air inlet passage with said first outlet so that air is furnished to said reservoir and said vent valve is 7 S closed, said air pump valve plunger remaining seated dur- References Cited ing movement of the operator from said rst to secon UNITED STATES PATENTS positions, said valve operator operatively engaging sai air pump valve plunger at and beyond said second posigregolre 9 g4( tions and continuing to operatively engage said spring 5 1903887 4/1933 Wwer 60-52 X means and said reservoir valve plunger to connect said air 2699958 1/1955 B l 'let "137 E28 inlet passage with said second outlet so that air is furnished eac X to said air operated pumping device while said air inlet FOREIGN PATENTS passage remains connected to said rst outlet and said vent 346,684 4/1931 Great Britain valve is held on its seat whereby said reservoir is pres- 10 surized by said source of air before said air pumping de- JULIUS Et WEST, primary Examiner. vice is operatedr by said source of air.

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