US2238968A - Hydraulic jack - Google Patents

Description

INVETOR H P- BRUMDER HYDRAULIC JACK Filed Aug l5' :L91sa AITORNEY- APY 22, 1941.

Patented Apr. 22, 1941 UNITEDv STATES PATENT OFFICE HYDRAULIC JACK Herbert P. Brumder, Chenequa, Wis., assignor to Blackhawk Mfg. Co., Milwaukee, Wis., a corporation of Wisconsin Application August 15, 1938, Serial No. 224,881

3 Claims.

wheels or the like. 4In an effort to produce durable.

jacks at'moderate cost, the manufacturers of some of these devices have heretofore resorted to' diecasting in the construction of the major parts, and ln order to obtain a compact assemblage some of these jacks are formed with the liquid supply reservoir surrounding the plunger barrel and with the pump cylinder and piston detachably associated directly with the base oi' the jack and disposed at an oblique angle relative to the axis ofmovement of the jack plunger. The hydraulic jacks of this latter type have proven quite satisfactory in use, `but rather tedious, to construct by the die-casting method because some of the valves 'and numerous ports were located within the relatively large and bulky base casting, and the rather delicate valve seats and liquid passages were diillcult to form and to machine. The

manufacturers of these Jacks were therefore confronted with many diilicultierin quantity production, and in the production of high grade Jack due to clogging of liquid passages or escape of actuating liquid.

A clear conception of an embodiment of my present invention, and of the manner of constructing and of utilizing a hydraulic jack built in accordance with my improvement, may be had by referring to the drawing accompanying and forming a part of thisspecification wherein like refer- 'ence characters designate the samel or similar parts in the several views.

Fig. 1 is a part sectional side elevation of one of my improved hydraulic jacks, the section being taken centrally through the pump and valve assembly; and

Fig. 2 is a transverse horizontal section through the jack of Fig. 1, taken along the line 2-2.

Although I have shown and described my invention herein as being specifically applied to a units which could be sold at moderate cost and In accordance with the present improvement, the.

jack barrel and the liquid supply reservoir surrounding the barrel, are formed integral with the base and are'connectible with each other for the transfer of liquid from the reservoir to the barrel and vice versa, through a single relatively large and easily formed passage. The valves and the relatively smaller suction', discharge and by.. pass ports of my improved jacks are `all disposed within a rather simple pump casing which is detachably secured to the base in open communication with the reservoir and with the single large passage yin the base casting. Thus, aside from facilitating manufacture of the assemblage, the controlvalves are made more readily accessible by mere removal of the pump from the base, and the entire jack is less apt to become ineffective hydraulically actuated automobile jack, it is not my intention to thereby unnecessarily restrict the scope and utility of the improved features.

Referring to the'drawing, the improved hydraulic jack assemblage` shown therein comprises in general a main support or base 5 having a plunger barrel 6 and a liquid reservoir forming wall 1 formed integral with the base and projecting upwardly therefrom; a plunger 8 movable approximatelyvertically within the barrel 6 and having a cup-shaped flexibleseal 3 at its lower end coacting with the bore I0 of the barrel; a

vclosure cap II detachably secured to the wall 1 'and enclosing the top ofthe liquid supply chamber or reservoir I 2, and coacting with the plunger 8 to guide the same; a pump casing or cylinder I3 detachably secured to the base 5 and having a central bore Il which is communicable through ports I 5, I6 with the reservoir I2 and withI the barrel bore I0, respectively; a relatively large single passage I 'l formed in the base 5 in axial alinement with the cylinder I3 and directly connecting the lower extremity of the bore I0 with an enlarged lower portion I8 of the pump discharge port I6; a by-pass duct I9 formed in the cylinder casing I3 and connecting the port portion I8 with the reservoir I2, and having therein a manually manipulable relief valve -2li; a pump piston 2l reciprocable within the casing bore I4' and an operating lever 22 pivotally suspended from the base 5 and wall 1 by means of a fulcrum pin 23, and coacting through a transverse pin 24 vsiilbh a. notch in the upper portion of the piston The base 5, barrel 6 and wall l, are re formed of suitable metal by die-casting? inflsl known manner, and' the borev I0 and annular which is adapted to be manipulated'fromnthe exterior of Ithe jack through handles 411. The

. spindle 42 is embraced by a packing 45 which the reservoir chamber l2 through one or more openings 25. The cup-seal 9 may be clamped to a disk 2S coacting with the lower end of the plunger i8, by means of a nut 2l; and the upper extremity of the plunger 8 is provided with an adjustable screw head 28 of usual construction. The detachable upper closure cap l l is adapted to coact with the head 28 as shown in Fig. l, when the latter is in -lowermost position, and this cap i l may be provided with suitable packing it coacting with the plunger 3. The outer wall l may be provided with integral ears 3@ in which the pvot pin 23 is mounted and which also reeniorce the inclined socket 3l within which the cylinder casing it is confined, and this wall l may also be connected to the base 5 by reenforcing ribs 32 likewise formed integral with these elements.

The cylinder casing i3 Within which all of the control valves are confined. may also be formed as a die-casting,` and is conned within the socket 3l with its medial portion completely surrounded by liquid in the supply reservoir I2. The pump casing i3 is provided at its lower end with a reduced portion 33 snugly fitting a counter-bore in the base 5, and with a plane lower end surface coacting with an adjacent surface of the base casting; and the upper end p0rtion 34 of the casing i3 is of enlarged diameter and snugly ts the bore of the socket 3|. cylinder casing I3 is normally detachably clamped in position bv-means of a-ring nut'35, and the piston 2l which is slidable within the bore l@ of the casing i3, is embraced by a packing 36 and a packing retainer nut 37 which prevent escape of liquid along the piston. As previously indicated, the piston 2l is reciprocable by means of the pin 24 carried by the lever socket 22, and a handle 38 may be secured to this socket and constitutesa part of the actuating lever. lower end of the piston 2I is also provided with a cup shaped seal 39 which cooperates with the packing 36 to prevent leakage'.

'The pump discharge port I 6 which connects the pump bore I4 with the large base passage I'I, has a ball discharge valve 4U confined therein above the by-pass'port I9, by means of a spring or snap ring in a well known manner; and the pump inlet or suction port I5 which'drectly connects the pump bore I4 with the reservoir I2, has a ball suction valve 4I confined therein by a similar snap ring. fWhile the discharge port I6 is rectilinear throughout its entire length, Vthe suction port I5 is preferably formed of two rela-` tively inclined sections one of which is` parallel to the bore I4. and the other of which is approxi.- mately parallel to the by-pass port I9, so as -to permit convenient formation of all of the ports I5, I6, I8, I9 by die-casting operations. AThe ball by-pass valve 20 which is also confined within the cylinder casing I3 and is removable therewith, is adapted to be pressedgagainst its seating to close the-port 19 when the pump is being operated, by means of a spindle 42 having screw thread coaction with a threaded element 43, and

The

Thev

is retained in place by the element d3, and when the pump is inactive and the spindle d2 is manipulated to release the by-pass valve 2l] liquid subjected to' pressure within the bore Ill and passage Il will be quickly relieved of such pressure by the escape of excess liquid through the ports i8, I 9 to the reservoir l2. In order to properly position the port i9 and the by-pass valve 20 relative to the spindle l2 when the cylinder casing I3 is placed within the socket 3l, the cylinder casing i3 may be provided with a recess adapted to coact with a key d6 formed integral with the base 5, as shown in Figs. l and-2, and this key i6 will positively prevent rotation of the pump cylinder.

During normal use of my improved jack assemblage, the reservoir chamber l2 andthe other confinedl spaces of the jack are supplied with liquid as shown in Fig. l, and when the plunger il is in lowermost position, the by-pass valve 2u .would ordinarily be closed. The lever handle 38 may thenbe oscillated to reciprocate the pump piston 2l, and as this piston is elevated, liquid will be withdrawn from the supply chamber I2 through the port i5 and past the suction valve lil into the pump bore l@ beneath the piston 2l. When the piston 2l is subsequently forced downwardly, the liquid in the pump displacement chamber will be forced through the discharge port it past the delivery valve ill and through the passage ll into the bore i8 beneath the plunger cup seal d, thus causing the plunger 8 to rise. Repeated reciprocation of the pumppiston 2l will obviously cause the plunger 8 to rise 'higher and higher, until the seal 9 passes the relief opening 25, whereupon the plunger movement will automatically ceaseand excess liquid will escape from the bore l to the supply charn- 'l From the'foregoing detailed description it will l be apparent that the present invention provides an extremely simple, compact and durable jack assemblage which can be readily constructed' and which is moreover conveniently manipulable. The mapor parts of the improved jack may obviously be effectively produced by die-casting because of the fact that the base 5 has no complicated and unduly restricted ports and passages therein, and further because of the fact that all of the relatively small ports as well as all of the valves are confined directly within the pump casing I3. This pump cylin'dercasing is readily removable from the confining socketl 3| together with the valves 2l), 40, 4I, and the relatively small ports in the pump. casing will likewise permit convenient manufacture of this casing by diecasting. The imp'rovedV assemblage embodies no ports or passages which are not freely accessible at all times for inspection and cleaning, and proper assembly of the pump and base isobviously facilitated by the provision of the key 46 for insuring proper alinement of the spindle 42 with the by-pass valve 20. The improved jack assemblage may moreover be'malntained tight independently of the jack parts, and all of the n parts may be quickly assembled to complete the structure. All of the elements of the improved jack may obviously be readily formed and machined, and an abundant supply of liquid from therese'rvoir l2 to the pump and to the jack is constantlyavailable. i

,It should be understood that it is not desired to limit this invention to the exact details of construction or to the precise mode of operation, herein shown and described, :for various medincations within the scope of the claims may occur to persons skilled in ,the art.

I claim: i

1. A jack comprising, an upwardly extending plunger barrel and an annular reservoir formed integral with and surrounding said barrel, said barrel Aand reservoir having an inclined upwardly open socket in open communication at its medial portion with said reservoir and the lower end of which communicates directly with the lower extremity of said barrel through a large passage formed concentric with the socket, a pump cylinder having opposite ends slip iitted within the lower and upper ends of said socket and being provided with a central piston bore, one side of the bottom of said piston bore being connected of which communicates directly with the lower extremity ci said barrel through a large recf tilinear passage formed concentric with the socket, a pump cylinder having opposite ends tted within the lower and upper ends respec- Ytively of said socket and being provided with a central piston bore, one side-.of the bottom of said piston bore being connected with said concentric passage by a, rectilinear port having a discharge valve therein and the other side of said bottom being connected to said reservoir by an angular port having a suction valve therein while the portion of said rectilinear port between said discharge valve and said passage communicates through an outwardly directed by-pass port hav'- ing a by-pass valve therein directly with said reservoir, all of said ports being formed wholly within said cylinder and lying in a common plane means for positively preventing rotation of said cylinder about its own axis when disposed within said socket, and a spindle movable from theexterior of said reservoir in axial alinement with said by-pass valve poit for manipulating said by-pass valve.

3. A jack comprising, an upwardly extending plunger barrel surrounded by an annular reservoir formed integral with said barrel, said barrel and reservoir having an inclined upwardly open socket in open communication at its medial porwith said concentric passage by a rectilinear port having a discharge valve therein and the other side of said bottom being connected to said reservoir by an angular port having a suction valve therein while the portion of said rectilinear port between said .discharge valve and said passage communicates through an outwardly directed bypass port having a by'pass valve therein directly with said reservoir, all of said ports being formed wholly within said cylinder and lying in a cornmon plane, and means operable from the ex-` tion with said reservoir'and the lower end of which communicates directly with the lower extremity of said barrel through a large rectilinear passage formed concentric with the socket, a pump cylinder having lower and upper ends slip fitted within the lower and upperends respec-l tively of said socket and being provided with a central piston bore, one side of the bottom of said piston bore being connected vwith said ,concentric passage by a rectilinear port having a discharge valve therein and the other side of said bottom being connected to said reservoir by anangular port having a suction valve therein while the portion of said rectilinear port between said discharge ,valve and said passage communicates outwardly directly with said reservoir through a bypass port having a by-pass valve therein, all of P. BRUMDER.

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