US2674851A - Beam type hydraulic jack - Google Patents

Description

April 13, 1954 1 Filed July 7, 1952 R. E. WOOLEY BEAM TYPE HYDRAULIC JACK 5 Shets-Shet 1 a ma ze 2| mvzsmom ROBERT E. Woouav.

BY 6.1L

ATTORNEYS April 1954 R. E. WOOLEY BEAM TYPE HYDRAULIC JACK 5 Sheets-Sheet 2 Filed July '7, 1952 ROBERT E. WO0LEY,. INVENTOR.

BY 50L, M

ATTORNEYS April 13, 1954 R. E. WOOLEY BEAM TYPE HYDRAULIC JACK 5 Shee'ts-Sheet 5 Filed July 7, 1952 INVENTOR; ROBERT E. WOOLEY.

gain P ATTORNEYS Patented Apr. 13, 1954 BEAM TYPE HYDRAULIC JACK Robert E. Wooley, Charlotte, N. 0., assignor of one-half to Clifford E. Smythe, Charlotte, N. 0.

Application July 7, 1952, Serial No. 297,489

Claims. 1

This invention relates to hydraulic jacks, of the type used in automotive vehicle repair shops and which include a wheeled frame or carriage having a pivoted beam thereon, the frame being provided with handle levers for moving the jack from one place to another and, also, for raising and lowering the beam of the jack. More especially, this invention is concerned with improved means for directing hydraulic fluid under pressure to the lifter cylinder of a jack of the character described for raising the beam and saddle or cap to, in turn, raise an article, such as the axle of an automotive vehicle, resting upon said jack saddle.

Heretofore, beam-type hydraulic jacks have included a housing or reservoir for the hydraulic fluid having valve means for establishing communication between the reservoir and the usual hydraulic-cylinder and wherein a pair of pumps, including plungers working in corresponding sleeves or cylinders, were provided to direct the fluid from the reservoir to the hydraulic cylinder. These plungers have extended through a wall of the reservoir thereby requiring that packing glands of a sort be provided to insure that the fluid would not leak around the plungers. It has been necessary for the plungers to project out of the housing or reservoir in order to facilitate connecting the plungers to the jack operating handle levers and wherein universal joints were interposed in the connections for operating the valve means. This has necessitated periodic replacement of the packing material carried by the packing glands and, if the packing material was not replaced periodically, as is frequently the case, the hydraulic fluid would leak around said plungers and collect on the floor of the plant or shop in which the jack was being used.

It is therefore the primary object of this invention to provide a jack of the type described wherein the pumps and the operating parts therefore are entirely enclosed within the reservoir with connections above the normal level of the fluid contained in the reservoir and extending through the side walls of the reservoir to the lower end of the operating levers or handle levers of the hydraulic jack.

It is another object of this invention to provide a hydraulic jack of the type described with a cam operated pressure release or by-pass valve interposed in the connections "between the pumps and the main. or lifter cylinder with a return passageway communicating with the release valve and the reservoir and wherein means are provided to automatically move said cam operated valve from one position to another upon the jack saddle or cap being elevated to a predetermined limit and to thus permit any additional fluid which the operator may attempt to pump from the reservoir to the cylinder to return to the parts of the beam-type hydraulic jack under undue stresses.

It is still another object to this invention to provide a control handle disposed closely adjacent the usual handle on the operating levers of the hydraulic jack, with connections between said control handle and the cam for operating the pressure release valve with resilient means normally holding the valve in a closed position and, upon moving the valve control handle in one direction, the bypass or pressure release valve will be opened to thereby permit the fluid in the main hydraulic cylinder to return to the reservoir and to thereby lower the beam with the saddle thereon.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which Figure 1 is a side elevation of the improved beam type hydraulic jack showing the beam and saddle in a raised position;

Figure 2 is a top plan view of the structure shown in Figure 1;

Figure 3 is an enlarged view looking at the right hand end of Figure 1, but with the upper portions of the operating lever-s broken away;

Figure 4 is an enlarged elevation of the lower portion of Figure 3;

Figure 5 is an enlarged fragmentary top plan view taken substantially along the line 5-5 in Figure 1 with parts broken away and other parts being shown in section and also omitting the cover from the reservoir;

Figure 6 is an enlarged vertical sectional view taken substantially along the line 6-5 in Figure 5 showing, particularly, the structure of the valve mechanisms for controlling the flow of hydraulic fluid between the lifter cylinder and the reservoir;

Figure 7 is an enlarged vertical sectional view taken substantially along the line l-l in Figure 6 and showing the high speed pump cut-off valve and the high speed pump;

Figure 8 is a vertical sectional view at a reduced scale taken substantially along the line 8-8 in Figure 6 and showing the cam operated combination stroke-limiting and manually operable pressure release valve, the structure of the lifter cylinder and the pivotal connection between the frame of the hydraulic jack and the beam;

Figure 9 is a vertical sectional view at a reduced scale taken substantially along the line 99 in Figure 6, showing the low speed pump and associated valve means within the reservoir;

Figure 10 is an enlarged fragmentary vertical sectional view, mostly in elevation, taken substantially alon the line Ill-ill in Figure 2 and showing, particularly, the means for operating the combination stroke-limiting and release valve when the saddle and the corresponding beam have moved upwardly a predetermined distance;

Figure 11 is an enlarged vertical sectional view, mostly in elevation, taken substantially along the line H--H in Figure 2 and showing the opposite side of the handle lever from that shown in Figure 19;

Figure 12 is a vertical sectional View at'a reduced scale taken substantially along th line I2-l2 in Figure 6 and showing, particularly, the overload safety valve;

Figure 13 is an enlarged vertical sectional view taken substantially along the line l3l3 in Figure 10;

Figure 14 is an enlarged vertical sectional view taken substantially along the line i i-i l in Fig ure 12;

Figure 15 is an enlarged vertical sectional view taken substantially along the line Ill-15 in Fig ure l0.

-Referring more specifically to the drawings, the numeral 10 broadly designates the wheeled frame of a hydraulic beam-type jack which pivotally supports a beam assembly broadly designated at H and a handle assembly broadly designated at If. The frame It! comprises a pair of elongated side frame members or side plates it and is which are spaced from each other at their front ends by a shaft or axle it, reduced opposite ends of which slidably penetrate the side plates is and I5 and have front wheels ll and I8 rotatably mounted thereon.

A base plate iii has its opposite edges suitably secured to the proximal surfaces of the lower medial portions of the side frame members or plates id and i5 and spans the distance therebetween (Figures 3, 4, 5, and 8) The lower edges of a pair of transversely based ram guides 21, 2 I are suitably secured to the upper surface of the base plate 29 and each has an inwardly projecting rib or flange 22, 22 at the upper edge thereof which extends downwardly and rearwardly at an angle as is clearly shown in Figures 4, 8, and 10 for guiding a ram, to be later described.

Reservoir Suitable caster wheels 25 and 26 are rotatably mounted in respective brackets 2! and 28 suitably secured to the outer surfaces of the side plates i4 and 15 of the frame ill adjacent the rear ends thereof. The rear portions of the side plates l4, l5 are held in spaced relation to each other by a plurality of projections 3i (Figure 6) extending outwardly from a hydraulic fluid rmervoir 32 having a bottom 33, front and rear walls 34 and 3.5, respectively, and spaced side walls 36 and 31. The level of the hydraulic fluid in the reservoir 32 is shown by broken lines indicated at L in Figures '7, 8, and 12.

The top of the reservoir is closed by a closure plate 40 and between the closure plate and the upper edges of the walls 34 to 31, inclusive, is a gasket 4! of any desired material. The closure plate lil is removably secured to the walls 35 to 31, inclusive, as by screws 42. The reservoir 32 and the various parts contained therein form the most important features of the present invention and will be later described in detail.

It will be observed in Figures 5, 8, l0, and 12 that a lifter 'or main cylinder 4 is suitably sccured to, or integral with, the front wall 3d of the reservoir 32 and extends forwardly and upwardly at slight angle relative to the horizontal and has a hollow lifter position or ram 65 mounted for longitudinal sliding movement therein. The lifter piston is provided with a closur or abutment it adjacent the rear end thereof, the front surface :of which engages the rear end of a ram rod or pin ll. The cylinder 44 has suitable packing material 8 held therein by an annular gland screw t9 (Figure 8). The piston 45 also has a tubular dust shield 35a integral therewith which sli-dably engages the exterior surface of the thickerred outer portion of the cylinder The front endof the pin or plunger :37 is fixed intermediate the ends of a transverse guide bar to, 'to the lower surface of which a pair of guide bars 51 are suitably secured. The outer surfaces of the guide bars '5! engage the proximal edges of the flange portions 22 of the inverted 'L-shaped members 2 l. A transverse guidebar 52 is fixed to the lower surfaces of the blocks '51 and slidably engages the lower surfaces of the flange portions 22.

Beamassembly The beam assembly ll comprises links 53, 53 pivotally connected to opposite ends of the transverse bar Ell. The links 53, 53' extendrearwardly in Figures 5 and 3 and are vpivotally mounted between the proximal surfaces of the lower or front corner portions -of outer and inner beam levers or hell cranks 15$, 55, and 5 1, respectively, as at 56 (Figures 3, l, 8, and 10). The outer beam levers 5s, .54 are substantially triangularlyshaped and the inner beam levers 55, '55 are substantially 'L-shaped. The lower rear corner portions of the beam levers 5 3, 55, 54', and 55 in Figure 10, are penetrated by a common transverse tubular member 51, to which they are suitably secured, as by welding. The tubular member 5'! is oscillatably mounted on a bushing 655 which serves as a spacer between side plates is and 15 and through which a transverse shaft 55 extends. Opposite ends of the tubular member 5'5 slidably and oscillatably engage the proximal surfaces of the side frame members 54 and i5 and the opposite ends of the shaft 6% penetrate the side walls or frame members Id and I5 and are fixed therein, by any suitable means such as nuts 52.

It will be observed in Figures 3 and 4 that the lower portions of the beam levers 5E, 55, 54 and 55' are spaced from each other, but the upper ends of the outer beam levers 5 and 54' converge inwardly and engage the outer surfaces of the respective inner beam levers 55 and 55. The upper ends of the beam levers 54, 55, 5'4, 55' are disposed between respective bifurcated portions 63 and 63' of a weight supporting cap or saddle broadly designated at '84 'and'which further comprises a transverse portion which spans the distance between the bifurcated portions '53 and 63 and is integral therewith. The cap or saddle 64 also includes a substantially circular portion 66 which is cast integral with the portions 63, 3 an '6 It will be observed in Figure 1 that the bifurcated portions 63 and 63' are substantially triangularly-shaped, the upper ends of the beam levers 54, 55, 54, and 55' being pivotally connected to the upper rear corners of the bifurcated portions 63 and 63, as at 61. The upper ends of parallel links 10 and 10' are pivotally connected, as at II, to the lower front corners of the respective triangularly-shaped bifurcated portions 63 and 63'. The lower portions of the parallel links In and 10' extend downwardly between the outer beam levers or bell cranks 54, 54 and the respective side frame numbers I4, and I5- and are pivotally connected, as at I2, to the side frame members or plates I I, and I5. Each of the parallel links I0, and I has a forwardly projecting spring anchor portion 13 integral therewith (Figures 3, 4, and 10) to each of which the upper end of a tension spring 14, I4 is connected. Each tension spring I4, I4 extends downwardly and rearwardly at an angle and is connected to a suitable spring anchor I project ing inwardly from the proximal surfaces of the 'respective side frame members or side plates The tension springs 14, M are provided for the well known purpose of returning the saddle 64 and the beam II to lowered positions upon the fluid being released from the lifter cylinder 44 in a manner to be later described. In order to assist in maintaining the beam levers or bell cranks 54, 55, 54 and 55' in proper spaced relation to each other and to lend the rigidity thereto, a transverse beam cover plate 76 is provided, opposite edges of which are disposed closely adjacent the proximal surfaces to the side plates or side frame members I4, I5. The beam cover plate I6 is suitably secured to the rear or upper surfaces of the beam levers or bell cranks 54, 55, 54', and 55' by any suitable means such as welding (Figures 1, 2, 3, -5, and The beam cover plate I6 also assists in preventing dirt or foreign matter from collecting on the parts therebeneath.

Handle assembly It will be observed in Figures 1, 2, 10, and 11 that the hydraulic fluid reservoir 32 is also covered by a removable hood I1, which is shaped to conform to the configuration of the upper and rear edges of the side frame members I4, I5 and is suitably secured thereto, as by screws 80. The hood TI enhances the appearance of the jack and prevents dirt from accumulating on the parts therebeneath. Opposite side portions of the hood 'I! are cut away to form slots BI, 6| through which a pair of operating lever or handle lever extensions 82, 82' loosely extend. The extensions SI and 8| are parts of the handle assembly I2. The lower ends of the handle lever extensions 82, 92' are bifurcated to form respective slots 03, 83' therethrough.

The upper portions of the handle lever extensions 82, 82' have the lower ends of respective handle operating levers 84, 84' suitably secured therein, as by screws 85. The lower portions of the handle levers or operating levers 84, 86' are held in proper spaced relation by a brace 86 suitably secured thereto. The handle levers 84, 84' converge upwardly and are suitably secured to opposite sides of a handle block 81 having a handle 90 integral therewith.

Referring to Figures 5, 10, 11, and 13, it will be observed that the bifurcated lower ends of the handle levers or operating lever extensions 82 6 and 82' each has a hub member 9I suitably se-' cured thereto, as by welding, or which hub member may be cast integral therewith. The hubs SI loosely penetrate the side plates E4, I5 (Figure 13). Each of the hubs 9I is provided with an outer tapered bore 92 and inner straight bore 93. The tapered bores 92 of the hubs 9I are mounted on corresponding tapered portions 94 of a transverse pump operating shaft 95. The pump operating shaft 95 is oscillatably mounted in floating bushings 96, the proximal ends of which are flush with the proximal surfaces of side walls 36, 37 of the reservoir 32. These bushings 96 are loosely mounted in the side walls 36, 31. The straight bores 93 of the hubs 9I are oscillatably mounted on the outer portions of the bushings 96.

The outer ends of the hubs 9I are engaged by washers IOI which are tightened against the hubs 9I by nuts I02 threadably mounted on reduced opposite ends of the transverse pump operating shaft 95. It will be noted that the hubs M are keyed, as at I 03 (Figure 13), to the corresponding tapered portions 94 of the transverse pump 0perating shaft 95. A sleeve or tubular member I05 is also fixed on the medial portion of the shaft 95, as by a key I04 and set screws I06. Opposite ends of the sleeve I05 slidably and oscillatably engage the proximal surfaces of the side walls 36 and 37 of the reservoir 32.

It will be observed in Figures 5 and 9 that the sleeve I05 has a pair of longitudinally spaced radially extending arms I0! integral therewith, to the outer end of each of which a pair of links I I0 are pivotally connected, as at I I I. The links 0 extend downwardly and rearwardly at an angle and are pivotally mounted on a common transverse shaft II2 which slidably penetrates enlarged portions H3 and H4 (Figures 7, 9, and 13) of forwardly and rearwardly extending plungers or piston rods I I 5 and I I 6, respectively, which are disposed in parallel spaced relation adjacent the bottom of the reservoir 32. These plungers II5, II 6 are parts of respective high speed and low speed ram actuating pumps P-I It will be observed in Figures 5, '7, and 9 that the front portions of the pump piston rods II5, I I6 are mounted for longitudinal sliding movement in respective substantially tubular guide members I26 and I2I, the rear ends of which are closed and the reduced front ends of which thr closed and the reduced front ends of which threadably penetrate the rear wall 35 of the reservoir 32. Each of the pitson rods II5 and H6 has a longitudinally extending channel or passageway I22 in the rear portion thereof and a transverse passageway or port I23 to permit in gress and egress of air and/ or fluid in back of the corresponding piston rods II5 and H6.

The piston rods II5 and I I 6 are of substantially the same diameter and the front end of the piston rod I I 5 has a suitable piston I24 and piston cup [24a fixed thereon which are mounted for longitudinal sliding movement in a high speed pump cylinder I25. The cylinder I25 issuitably secured, as by welding, to the rear surface of a valve body I26 shown as an enlarged or thickened transverse portion integral with the front wall 36 of the reservoir 32. It will be noted that the valve body I26 is spaced slightly above the upper surface of the bottom wall 33 of the reservoir 32 to form a passageway I 21 therebetween for purposes to be presently described. g

A low speed pump cylinder I30 is also suitably secured to the rear surface of the valve body I25, as by welding. It will be observed in Fi ure -9 that the front end of the piston rod 1 It also serves as a piston and is mounted for longitudinal sliding movementin the low speed pump cylinder I36, the rear portion of the low speed pump cylinder I38 being enlarged and having suitable packing material I32 held therein by a gland screw 33 to thereby prevent the fluid from escaping from the rear end of the low speed pump cylinder I39. It is to be understood, however, that the level L of the hydraulic fluid may be substantially above the level of the cylinders I and I353 as shown, if desired. As a matter of fact, the level of the hydraulic fluid in the reservoir 32 may be the same as the lower surface of the tubular member I05, if desired.

Valve mechanisms The pumps P-I an P-2 are respectively termed as a high speed pump and a low speed pump, since the high speed pump cylinder I25 has a relatively larger diameter than the low speed pump cylinder and, accordingly, the high speed pump plunger or piston red I I5 is instrumental in raising the saddle $4 at a relatively higher speed with a given number of strokes of the operating levers 84, 3 3' of the handle assembly I2 than the low speed pump piston rod II 8. It is evident that a substantially greater amount of hydraulic fluid is displaced by the piston I24 and the piston cup IZ-a upon each active stroke thereof than is displaced by the low speed pump piston rod I I6 upon each active stroke thereof.

In order to direct hydraulic fluid into the cylinders I25, I upon inactive or rearward strokes thereof and to subsequently direct fluid under pressure from the cylinders I25, I38 to the lifter cylinder 4d, it will be observed in Figures 7, 8 and 9 that the front wall 3 and the enlarged valve body portion I26 thereof are provided with a horizontal passageway I therein which communicates with the interior of the lifter cylinder 4d. The valve body I26 also has a pair of horizontal passageways -I4I, I42 therein which communicate with the respective pump cylinders I 25, I38.

The valve body IZE has two sets of three axially alined vertically extending passageways, chambers, or bores therein one set of which is indicated at I33, M4, and I45 and the other set of which is indicated at I48, Hi1, and M8 reading from the uppermost to the lowermost bores. The bores I43, 1st, and I45 progressively decrease in diameter and the lowermost passageway or bore I45 communicate with the passageway I21 beneath the valve body I25.

The passageways or bores I46, I41 and I48 also progressively decrease in diameter and the lower bore or passageway I443 also communicates with the passageway I27 beneath the valve body I26. The upper ends of the bores I43, I46 are closed by respective threaded plugs I5I, I52. The horizom tal passageways MI, I42 communicate with the respective intermediate vertically extending passageways or bores I44, m. The shoulders formed at the junctures of the respective passageways I44, I45, and I'll, I43 normally support check balls or valve members I53 and I54, respectively. The shoulders formed by the respective passageways I43, I44, and I46, I41 also support respective check balls or valve members I55 and IE3. ,The check balls I53 and .I 54 may also be termed as respective high speed pump and lowv speed pump suction valves and the check balls I55 and IE5 may also be termed as respective high speed pump and low speed pump discharge valves.

It will be observed in Figure 8 that the lifter cylinder passageway I40 is substantially L-sha-ped and the valve body I26 has a horizontal transverse passageway Ifil therein, the medial portion of which communicates with the vertical leg of the substantially L-shaped passageway I40 and opposite ends of the passageway I6!) also communicates with the large upper bores or passageways I43, I45 (Figure 6).

Referring to Figure 7, it will be observed that the valve body I25 has a relatively small passage way I62 therein which communicates with the passageway MI and also communicates with an enlarged passageway or chamber I63 in which a high speed pump pressure release valve I64 is mounted. The lower end of the high speed pump pressure release valve I64 is preferably conicallyshaped and is normally urged to close the passageway IE2 by a compression spring I65 which surrounds a reduced stem portion of the high speed pressure release valve I64. The upper end of the chamber or passageway I63 is closed by a threaded plug I66 which may be adjusted to vary the pressure of the spring I65.

The valve body I26 is provided with an overflow discharge port or orifice I61 which communicates with the chamber or passageway I53 for a purpose to be later described. The valve body 26 is also provided with a substantially L-shaped passageway I10 (Figure the horizontal leg of which communicates with the intermediate vertical passageway I41 and the ver-- tical leg of which communicates with .a vertically extending passageway or overload safety valve chamber I'M. A valve seat H2 is formed at the juncture of the passageways Ill] and Ill and an overload safety valve, in the form of a check ball I14, is normally urged against the valve seat I12 by a compression spring I15. The lower end of the compression spring I35 engages a disk I15 which bears against the check ball I74 and the upper end of the compression spring I15 engages the lower surface of a threaded plug or screw I I? threadably mounted in the upper end of the chamber or passageway III. The plug I'll pro vides for adjustment of the pressure exerted on the ball I12 by the spring I15.

A particularly important feature of the present invention is a unique cam controlled combination automatic stroke limiting and manually operable pressure release valve which serves to release hydraulic fluid from the lifter cylinder 44 and to return the hydraulic fluid to the reservoir 32 when the operator desires to lower the saddle 64 and beam assembly II. This cam controlled release valve also functions to automatically return hydraulic fluid to the reservoir which may be pumped into the valve body I26 by the high speed pump piston I24 or the low speed pump piston rod I I 6 when the saddle 64 has been raised to a maximum limit to thereby prevent placing the beam assembly II and the associated movable parts under undue stresses.

To this end, the valve body I26 also has a centrally disposed bore or passageway I therein (Figures 6 and 8) in which a valve shank IBI is mounted for vertical sliding movement. The valve shank IEI is preferably circular in cross section and has a reduced intermediate portion I82 and a conically-shaped pressure release valve portion I83 on the lower end thereof which, at times, seats against the open upper end of the vertical leg of a substantially L-shaped passage.-

I80 at a point below the juncture of the shank I 8I and the intermediate portion I82 thereof.

The pressure release valve I83 is normally held in lowered or closed position as in Figures 6, 8, and 12 by an abutment I87 shown in the form of an adjustment screw which slidably penetrates the front end of a lever I90 and bears against the upper end of the shank IBI. The lever I99 is oscillatably mounted intermediate its ends, as at I9I, between the upper ends of a pair of ears I92 which extend downwardly and are formed integral with valve body I25. A roller or cam follower I93 is mounted in the bifurcated rear end of the lever I99 and bears against an eccentric or cam I94 keyed or otherwise fixed on a transverse cam shaft I95, one of which is oscillatably mounted in a bushing I96 (Figure 1.4) fixed in a boss portion I91 projecting inwardly from the side wall I5.

The shaft I95 is also oscillatably mounted in a bushing 200 suitably secured, as by a pressed fit in a shouldered tubular bearing member 2ilI which threadably penetrates the side wall I4 of the reservoir 32. The right-hand end of the shaft I95, in Figure 14, bears against the wall I5 and the shaft I95 is prevented from moving to the left, in Figure 14, by a collar 292 adjustably secured on the shaft I95 and bearing against the inner surfaces of the bushing 290 and the bearing member 2IlI.

The bushing 290 has a circular groove 293 in the inner wall thereof in which an O ring 204 is disposed to thereby prevent hydraulic fluid from leaking around the shaft I95. The shaft I95 and the cam I94 are normally urged in a clockwise direction, in Figures 8 and 12, by any suitable means such as 'a torsion spring 295 which surrounds the right-hand portion of the cam shaft I95 (Figure 14). One end of the spring 295 is connected to the boss portion I 91 of the side wall I5 and its other end is connected to a collar 206 adjustably secured on the shaft I95.

The left-hand end of th cam shaft I95 (Figure 14) has one end of a crank arm 2I0 fixed thereon which extends forwardly and has a follower or roller 2 mounted thereon which is normally urged into engagement with the outer surface of a substantially U-shaped or horseshoe-shaped cam element or lever 2I3. The U- shaped cam element is disposed within the slot 83, as in the lower end of the handle lever or operating lever extension 82 shown in Figures 10, 11, and 13. The lower end of the cam element 2 I3 i pivotally mounted, as at 2I4, on the operating lever extension 82 and curves upwardly in a semi-circular manner and partially circumscribes the corresponding hub 9 I.

The upper or free end of the cam element 2I3 is engaged by a roller or follower 2I5 mounted in the upper end of a cam operating lever 2I9. The cam operating lever 2I6 is also oscillatably mounted intermediate its ends, as at 2I'I, in the slot 83 in the lower portion of the operating lever extension 82. .It will be most clearly observed in Figure 11 that one of the side walls defining the limit of its upward movement,

the slot 83 in the operating lever extension 82 has an arcuate slot 229 therein, through which a pivot pin 22! carried by the cam operating lever 2 I 6 loosely extends.

The lower end of a link 223 is pivotall mounted on the pivot pin 22I (Figures 5 and 11) and extends upwardly adjacent the inner surface of, and in parallel relation to, the handle lever 84. The upper end of the handle lever 84 of the handle assembly I2 has a slot 224 therein (Figure 1) and the block Bl has a groove or cavity 22% therein (Figure 2) which coincides with the slot 224. A. beam or saddle lowering handle or beam release lever 225 projects through the slot 224 and into the cavity 224a in the block I3! and.

is pivotally mounted therein, as at 239.

The upper end of the link 2223 is pivotally connected intermediate the ends of the beam or saddie release lever 225, hence, the lever 225 is normally urged forwardly or away from the jack handle 99 by the torsion spring 295 heretofore described (Figure 14).

Referring again to Figures 10 and 11, it will be observed that the crank arm 2H3 has one end of a link 29I pivotally connected thereto. The link 23I is shown in the form of a link chain in Figures 10 and 11 and extends forwardly and is pivotally connected to the beam lever or hell crank 54, as at 232 (Figure 10), by means of a clevis 233 threadably embedded in a connecting link member 234 to which one end of the link chain is pivotally connected. This clevis 233 is provided to facilitate accurate adjustment of the link 23I so that, when the saddle approaches the substantially as shown in Figure 1, the link chain forming the link 23I will then become taut and will move the crank arm 2I9 and shaft cam I in a counterclockwise direction in Figure 10, whereupon the cam I94 will move from the solid line position to the broken line position shown in Figure 8 thereby permitting pressure release valve I83 to move upwardly under impetus of the compression spring I85. It is evident that this will cause any fluid directed under pressure to the passageway I4Il (Figures 6 and 8) to merely return to the reservoir through the passageways I 84, I 89 and I86: successively.

Method of operation Assuming the beam assembly II to be in the horizontal or lowered position shown in Figure 8, the further assuming that the beam pressure release lever 225 is in its normal position, the cam or eccentric I94 is then in the solid line position shown in Figure 8 and the pressure release valve I89 is also in the closed position shown in Figure 8. The operator then positions the saddle 64 beneath the articles to be raised thereby whereupon the handle lever assembly I2 is manually oscillated to, in turn, oscillate the shaft 95.

It is evident that oscillation of the shaft 95 cause the tubular member or sleeve I95, the arms IG'I, the links I I9, the transverse pivot shaft H2, and the pump piston rods II5 and H6 to reciprocate. Now, during the time that the saddle 64 is elevated from it lowermost position until it engages a load, the high speed pump piston I24 performs the work of forcing fluid from the reservoir to the main or lifter cylinder 44 since the pressure of the spring I95 (Figure 7) is such that the high speed pump pressure release valve or cut-out valve I64 will remain seated until pressure of the fluid passing through aovasc-r 11 the passageways Mi, as caused by the piston 24, is suificient to unseat the valve member I65, in which instance, the excess fluid displaced by the piston E24 will flow through the passageway 352 and N3, successively, and will be discharged through the port I57 back into the reservoir 32.

However, until the load carried by the beam assembly ii is increased up to a predetermined point, upon each active or forward stroke of the piston rods H and H6, fluid is forced through the respective passageways it! and H12 into the respective intermediate chambers or passageways I l-l and t ll.

Of course, upon each inactive stroke of the piston rods H5 and H6, the valve members or check balls 53 and its will be forced upwardly and unseated, due to the suction caused by the piston ll l and the piston rod 5 l6, and will thereby permit fluid to flow from the reservoir 32, through the passageway l2? beneath the valve body lZfi, through passageways and its (Figure 6) and the respective passageways hi l, Hi! and 151', 152, into the respective cylinders l25, I30.

As the piston 12% and piston cup l24a move in an active stroke toward the valve body :2 the amount of fluid displaced thereby is substantially greater than the amount of fluid displaced by the relatively smaller piston rod lit and, therefore, the ball $55 will be unseated, by the force of the fluid flowing into the intermediate chamber or passageway E55, and will thereby permit fluid to flow into the passageway or bore Hi3 and then through the passageways Hill and Hill, successively, to the main or liftercylinder Thus, the high speed pump P-l causes the beam assembly l i and the saddle 6d thereon to move upwardly at a relatively fast rate in the course of each active stroke or" the piston rods H5 and H6.

If the low speed pump P-2 was not provided, it is evident that the force required, on the handle 90 by the operator, would be increased considerably upon the saddle engaging and lifting a relatively heavy article. However, as heretofore stated, upon the fluid flowing through the passageway Mi approaching a predetermined pressure, the cut-out valve led is unseated thereby permitting excess fluid to flow back into the reservoir 32. When this occurs the relatively smaller amount of fluid forced through the passageway Hi2 upon each active stroke of the low speed pump piston rod H6 causes the ball I58 to move upwardly or to become unseated while the ball H55 in Figures 6 and 7 remains seated. Fluid under pressure then flows through the passageways IE2, Ml, MS, Hill and Hill, successively, into the lifter cylinder 44 to thus lift the load carried by the saddle 64.

In order that the beam assembly H and intervening parts connected to the lifter cylinder 44 are not placed under undue stresses due to overloading the saddle S4 of the litter piston 45, when the pressure of the fluid in cylinder 44 becomes greater than the pressure of spring F55 against the safety valve I12, the latter is unseated (Figures 6 and 12). Thus, the fluid above overload balls E55 and lSB causes the same to remain seated although further active strokes are imparted to the high speed pump piston I24 and cup 1250 and the low speed pump piston rod i Mi. Of course, the threaded plug H! is adjusted to cause the compression spring H5 in Figure 5 to exert a predetermined pressure on the overload safety valve ll2 and, upon this pressure being exceeded by the fluid in the cylinder 44 and 7 12 in the passageways ltil and M6 (Figures 6 and 9) the check wall or overload safety valve 12 is then unseated with succeeding active strokes of the low speed pump piston H6. In this event, fluid flows through the passageways ldl, H6 and 1H, successively, and is then discharged through the orifice I13 (Figure 12).

It has already been described how the link 23l (Figures 10 and 11) will permit the combination stroke limiting valve and manually operable pressure release valve 83 to move upwardly in Figure 8 when the beam assembly 5 i has reached its optimum raised position, to thus permit any further fluid pumped into the passageway M8, by either the high speed pump piston H5 or the low speed pump piston M5, to return to the reservoir 32 through the orifice W6 in Figure 8.

Now, when the operator desires to lower the saddle, and, of course, the beam assembly ll, it is merely necessary for the operator to grasp the control handle or lever 225 and move the same toward the jack handle 9%. This causes the link 223 to move downwardly thereby moving the levers 213 and 216 in a clockwise direction in Figure 10 and in a counter-clockwise direction in Figure 11. Thus, the cam shaft Hi5 and its crank arm 2H3 move in a counter-clockwise direction in Figures 8, 10 and 12, whereupon the pressure of the fluid in the passageways Hi0 and 183, caused by the load on the lifter piston 45, will unseat the combination stroke limiting and pressure release valve 133 thereby permitting the saddle and the beamassembly H to move downwardly as the lifter piston 55 recedes into the lifter cylinder 44, since the fluid then flows from the cylinder 4d, through the passageways l lt, Hi l and Hit, successively, and passes back into the reservoir 32 through the orifice I88. It is evident that the tension springs "i l also assist in lowering the beam assembly ll when the valve H83 is unseated.

It is thus seen that there is provided an enclosed valve assembly and pump unit, which enclosure also serves as the reservoir for the hydraulic fluid thereby insuring that the hydraulic fluid will not leak from within the reservoir 32. This obviates the necessity of providing connections to the high speed pump piston rod H5 and the low speed pump piston rod it which are disposed exteriorly of the reservoir 32, such as universal joints or gears, as have heretofore been required. Of course, this also obviates the necessity of providing packing glands and packing material at the points at which the piston rods 1 l5 and l 16 have heretofore passed through walls or a wall of the reservoir of the type heretofore employed.

As heretofore stated, the manually operable means for controlling the combination stroke limiting and pressure release valve W3 is one of the primary features of the present invention in that such means is simply constructed in such a manher that it will operate efficiently over a relatively long period without need of repair and is read- 7 ily controlled by the operator without necessity of the operator removing his hands from the jack handle 96.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

Iclaim:

1. An improved hydraulic actuating means including a fluid reservoir having a valve mechaplunger movable longitudinally in said pump.

cylinder, guide means spaced from the pump cylinder for supporting said plunger, a rocker shaft journaled in the reservoir above the plunger, a hand lever fixed on the rocker shaft exteriorly of the reservoir for imparting movement to the rocker shaft, a crank fixed on the rocker shaft, a link pivotally connected at one end to said crank and pivotally connected at its other end to a portion of said plunger between the pump cylinder and the guide means, a lifter cylinder extending outwardly from the reservoir and communicating with said valve mechanism and having an annular packing material in its outer end, said valve mechanism having means responsive to movement of said plunger for directing fluid under pressure from the reservoir into said lifter cylinder, a lifter piston longitudinally movable in said lifter cylinder, an annular fiange on the outer end of said lifter piston, a tubular dust shield carried by the annular flange and surrounding said lifter piston, said dust shield slidably engaging the exterior surface of said lifter cylinder, a pressure release valve interposed in said valve mechanism, a transverses cam shaft journaled in the reservoir and disposed adjacent the pressure release valve, a cam fixed on the cam shaft, spring means normally urging the, cam in one direction to maintain the pressure release valve in closed position, a U- shaped cam elementpivoted on said hand lever adjacent said cam shaft, a cam lever pivoted on said hand lever and having one of its ends engaging the free end of the U-shaped cam element, a link connected to the other end of said cam lever, a valve control handle pivoted adjacent the free end of the hand lever and to which the other end of said link is pivotally connected, and a crank arm fixed to one end of said cam shaft exteriorly of said reservoir and having a follower thereon normally biased against the U-shaped cam element by said spring means.

2. In a hydraulic pump apparatus for actuating a lifter element, a pump having a reservoir provided with side walls and front and rear walls, a lifter cylinder carried by said front wall, a lifter piston connected to the lifter element and being mounted for longitudinal movement in said lifter cylinder, a valve body carried by the front wall of said reservoir, a pump cylinder fixed to the valve body, a pump piston longitudinally movable in said pump cylinder, guide means for said piston spaced from said pump cylinder, a rocker shaft journaled in said side walls of said reservoir, a hand lever fixed to said shaft exteriorly of the reservoir, a first valve means in the valve body for drawing fluid into the pump cylinder upon each inactive stroke of the pump piston, a second valve means disposed in the valve body for directing fluid from the pump cylinder to the lifter cylinder on each active stroke of the pump piston, a pressure release valve movably mounted in said body and said valve body having a passageway communicating with the interior of the lifter cylinder and also communicating with the pressure release valve; the combination of a crank fixed on said rocker shaft within said reservoir, a first link pivotally connected at one end to a medial portion of said pump piston at a point between the pump cylinder and said guide means and pivotally connected at its other end to said crank, cam means including a cam shaft journaled in the side walls of said'reservoir, an eccentric cam fixed on said cam shaft, a valve lever pivotally supported by said valve body, means on one end of the valve lever engaging said cam and means on the other end of said valve leverengaging said pressure release valve, spring means normally urging the cam in one direction to maintain the pressure release valve in closed position, a substantially U- shaped cam element pivotally supported by said hand lever, a cam lever oscillatably mounted on said hand lever and having one of its ends engaging the free end of said U-shaped cam element, a link connected to the other end of said hand lever, and extending in parallel relation thereto,:

a valve control handle pivotally supported by said hand lever and to which the other end of said link is pivotally connected, a second crank fixed to one end of said cam shaft exteriorly of said reservoir and having a follower thereon normally biased in engagement with said U-shaped cam element by said spring means, and a normally relaxed pliable second link connected atone end thereof to said second crank and being connected;

at its other end to the lifter element whereby, upon said lifter element being raised a given distance, the pliable link will be pulled taut to move the follower on the second crank out of engagement with said U-shaped cam element to move the cam on the cam shaft in the opposite direction from that in which it is biased by said spring means to release said pressure release valve and thereby to release fluid from within the lifter cylinder and, also, whereby movement of the valve control handle will move the U-shaped cam element against the cam lever to also release the pressure release valve.

3. In a fluid pressure pump for controlling the position of a ram, said pump having a fluid reservoir and first valve means connecting said reservoir with said ram for directing fluid from the reservoir to the ram with operation of said pump, said pump also including a longitudinally reciprocable fluid pressure transmitting plunger mounted for longitudinal movement in said reservoir and being supported for longitudinal movement at at least two spaced points in said reservoir, a rocker shaft disposed above the level of said plunger and being journaled in said reservoir, a crank fixed on said rocker shaft, and a hand lever fixed to said rocker shaft exteriorly of said reservoir; the combination of a first link pivotally connected at one end thereof to said crank and being pivotally connected at its other end to said plunger at a point between the spaced means supporting said plunger, a pressure release valve interposed between the ram and the reservoir, a cam adjacent said pressure release valve, a cam shaft journaled in said reservoir and on which said cam is fixedly mounted, spring means normally urging the cam in one direction to maintain the pressure release valve in closed position, a substantially U-shaped cam element pivotally supported at one end thereof on said hand lever, a cam lever pivoted on said hand lever and having one of its ends engaging the free end of the substantially U-shaped cam element opposite from the end thereof which is pivotally connected to the hand lever, a second link connected to the end of said cam lever opposite from the end thereof which engages the U-shaped cam element and extending in substantially parallel relation to said hand lever, a valve control handle pivotally supported by said hand lever at a point remote from the rocker shaft and to which the end of said second link remote from the cam lever is pivotaliy connected,

and a crank arm fixed; to one end of said cam shaft exteriorly of said reservoir and having a follower thereon normally biased in engagement with the curved portion of said U-shaped cam element by said spring means whereby movement of the valve control handle will permit said spring means to move the cam lever, the U-shaped cam element and the crank arm to release the pressure release valve for releasing the fluid from the ram 4. In a structure according to claim 3, a pliable link connected at one end thereof to said lastnamed crank arm and being connected at its other end to the ram whereby, upon said ram being moved a predetermined distance the pliable link will be pulled taut thereby and move the crank arm out of engagement with the U-shaped cam. element to thereby move the cam on the cam shaft in the opposite direction from that in which it is normally urged by the spring means to release said pressure release valve for releasing fluid from said ram.

5. In a fluid pressure pump for controlling the position of a ram, said pump having a fluid reservoir and first valve means connecting said reservoir with said ram for directing fluid from the reservoir to theram with operation ofsaid pump, said pump also including a hand lever for operating said pump and disposed exteriorly of said reservoir; the combination of a pressure release valve interposed between the ram and the reservoir, a cam adjacent said pressure release valve, a cam shaft journaled in said reservoir and on which said cam is fixedly mounted, spring means normally urging the cam in one direction to maintain the pressure release valve in closed position, a substantially U-shaped cam element pivotally supported at. one end thereof on said hand lever, a cam lever pivoted on said hand lever and having one of its ends engaging the free end of the substantially U-shaped cam element opposite from the end thereof which is pivotally connected to the hand lever, a link connected to the end of said cam lever opposite from the end thereof which engages the U-shaped cam element and extending in substantially parallel relation to said hand lever, a valve control handl'e pivotally supported by said hand lever at a point remote from the cam shaft and to which the end of said link remote from the cam lever is pivotally connected, and a crank arm fixed to one end of said cam shaft exteriorly of said reservoir and having a follower thereon normally biased in engagement with the curved portion of said U-shaped cam element by said spring means whereby movement of the valve control handle will move the cam lever, the U-shaped cam element and the crank arm to release the pressure release valve for releasing the fluid from the ram.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 26,318 Wootten Nov. 29, 1859 1,455,224 Paoli May 15, 1923 1,485,138 Johnson Feb. 16, 1924 1,653,276 Harris Dec. 20, 1927 1,728,088 Vickers Sept. 10, 1929 2,039,895 Green 1 May 5, 1936 2,439,796 Dearsley Apr. 20, 1948 2,577,539 Page Dec. 4, 1951

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