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Publication numberUS2503347 A
Publication typeGrant
Publication dateApr 11, 1950
Filing dateSep 12, 1945
Priority dateSep 12, 1945
Publication numberUS 2503347 A, US 2503347A, US-A-2503347, US2503347 A, US2503347A
InventorsAlfred Miller Arthur
Original AssigneeMiller Products
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Hydraulic jack
US 2503347 A
Abstract  available in
Images(3)
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Claims  available in
Description  (OCR text may contain errors)

April 11, 1950 A. A. MILLER 2,503,347

HYDRAULIC JACK Filed Sept. 12, 1945 v 5 Sheets-Sheet 1 x IIIIIIIIIIIIIIII mm 15221227? ErZZiz/r ZZ/frezi [UV/Er April 11, 1950 I 'A. A. MILLER I HYDRAULIC JACK Filed Sept. 12-, 1945 3 Sheets-Shget 2- April 1950 A. A. MILLER I 2,503,347

HYDRAULIC JACK Filed Sept. 12, 1945 I 3 Sheets-Sheet 3 Patented Apr. 11 1950 [TED EPAT DFFIZLCE HYDRAULIC JACK Arthur Alfred. Miller,- Mcltllenry; 111;, assignor to Miller" Rroducts a copartnership' consisting of Arthur Alfred'iMiller and Thou? (Jharles: Casanov Application September 12, 1945, Serial No. 615,785

6(Claimsl2 (Cl. 254-422) The present invention-pertains toWeight raising "devices and moreparticularly'toan improved and efiicient type of a hydraulic jack wl'iicl ii is adapted to be manually" operated and released through the medium of a; hydraulic control to effect the raising and lowering'ofa load supportinghea'd. The jackheadis supported by a novel arrangement of-pivota-lly connected'lazy tongs links and stabilizing links, having hydraulically actuated operating blocks mounted intermediate the ends of selected upper and' lower-lazy tongs links to provide pivotal connections for the remaining lazy "tongs links and alsoproviding free ends forthe attachment'of 'the stabilizing links.

An object of theinventiondsthe provision of'a weightlifting device of simple and effective construction, including a: hydraulically operated lifting unit involving novelly" assembled" lazytongs links and stabilizing" links," whereby the"- objects and features contemplated are obtainable with economy and facility.

It is an' object ofthe invention to provide an improved andsimplified form of jack wherein the lazy tongs'lifting unit is adapted to 'be'operated by a hydraulic piston mechanism-which is conveniently positioned to "facilitate convenient operation thereof to'eifect both raising and lowering of the lift'ing unit.

Another object of the invention is the provision of a'lazy tongs'type ofjack provided with I hydraulic operating meansincluding a manually operable crank connection whereby the hydraulic operating" means may be'operated to raise'the lifting'unit' and 'wherein the hydraulic operating means'may be conveniently released toeifect a gradual and steady lowering of the lifting unit.

It is furthermore an object'of' this invention to provide a scissors type'jack'operable'by hydraulic means, thelifting and lowering operations of which are effected through the rotation and shifting of a: manually operated crank shaft control.

A furtherobject of the invention is the provision of a scissors or" lazy tongstype of lifting jack wherein crank operated hydraulic pump mechanisms are operable'for raising the jaclt and wherein lowering'ofthe jack is conveniently ef fected by the operationof a release means.

It'is an important object of this invention to provide a scissors-type of lifting jack operable I by hydraulic means, the operation; of which. is governed by r the manual rotation and; shifting of a control medium, therotation'of whicha'causes raising. of the jack: whilezshifting thereof permits retraction and gradualilowering of thetjack: 55

Another objectofthe invention is the provision of a hydraulic scissors typeof jack mechanism provided with a reinforced lifting head or saddle having side plates for enclosing portions of" the lazy tongs membersto serveas a shield therefor in either a-raisedor-'lowered position of the jack mechanism.

A further feature of 'theinvention is the pro'-' vision of a hydraulic type of scissorsjack wherein a-manuall'y operable crank handle is adapted to be removablyengaged with a' couplingunitfor either rotating-or shifting acrank mechanism to cause operation of the jack to either raise or lower the same through the control of the direction'of fl'ow of a liquid medium.

Another object of the invention is to provide a scissors typeof lifting jack operable by'hydraulicmeans wherein thepumping and release of liquid" for actuating the jack is governed by a manually operable crank shaft type of control which may be either rotated or shifted to respec tively cause raising or lowering of the jack through th'e'control of a fluid medium.

Another object of th'e'invention is theprovision ofa hydraulic'scissors jack wherein piston operated' control blocks and stabilizing links are pivotally, connected between the endsofupper and lower lazy tongsim'embers' tothe outerfree ends 'of which the stabilizing links arealso connected..

It is an important object" of" this invention to provide i an improved and simplified form'of a hydraulic operated scissors. jack wherein the operationi-of lazy-tongs mechanisms are stabilized by a novel connection for stabilizing means andfa positioning of hydraulically controllediactuating connections intermediate the ends. of twooppo sitely positioned members of the l'azyiton'gs mech anisms, .wherebythe objects sought are adapted tobe realized .with economy and facility. I

Qther and; further important objects and features ofthis invention will be apparent from the-disclosures in the specification and'the accompanying drawingsi Onflthe drawings:

Figure iris aiside elevational view of scissors typeihydraulic jack illustrated in. collapsed. form and embodying=.th'e.iprinciples of this invention;

EigureZlis a sectionaliviewof the hydraulic operating. mechanismtaken on substantiallyline IIr-II of Figure V1, with parts shown inielev'ation and;withtparts= omitted and including a. drive coupling for connecting a crank handle with. a crank shaft of. thehyd'raulic mechanism;

Figure -3-is -alongitudinal central vertical section of the scissors jack in a partly raised position, and including a sectional view of the hydraulic control mechanism, with parts shown in elevation;

Figure 4 is an enlarged sectional view of the lower portion of the hydraulic control mechanism taken on line IVIV of Figure 3 with parts shown in elevation;

Figure 5 is a fragmentary sectional view of the lower right-hand portion of the hydraulic control mechanism with the coupling unit partly shown in section showing the hydraulic crank shaft control pulled outwardly by means of the operating crank handle to open the release valve controlling the discharge of the hydraulic liquid 1 medium out of the piston hack into the liquid reservoir to permit lowering of the jack;

Figure 6 is a fragmentary and elevational view of the upper portion of the jack to show the shape of the lifting head or saddle having shields or guard plates secured thereto to partially enclose the toggle mechanism;

Figure 7 is a transverse sectional detail view taken on line VII--VII of Figure 5; and

Figure 8 is a fragmentary longitudinal sectional view taken on line VIII-VIII of Figure '7 with parts shown in elevation and with the operating crank arm removed.

As shown on the drawings:

This invention relates to an improved and efficient type of a hydraulically operated lifting or raising jack adaptable for use in connection with the raising of automobiles, heavy trucks or for use in connection with the lifting or raising of other heavy devices or objects to hold the same in a raised position and act as a temporary support therefor. The improved jack mechanism is of the scissors or lazy tongs type wherein the lazy tongs unit is adapted to be conveniently raised and lowered by a manually operable hydraulic unit which governs the operation of a piston member connected for actuating the lazy tongs to cause either raising or lowering thereof depending upon the flow of the hydraulic medium into or out of the piston cylinder. The jack is furthermore adapted for raising or lowering a load of any selected weight at a speed depending upon the rate of rotation of a manually operable crank handle connected for operating the hydraulic control.

A novel feature of the present hydraulic jack is the mounting of a hydraulic unit in an inclined position to permit a crank handle to be readily attached and disposed in an inclined position so that the outer operating end thereof may be conveniently rotated to facilitate raising of the jack head or cradle and furthermore permitting convenient release of the hydraulic medium to permit gradual lowering of the jack head or cradle without making it necessary for an operator to stoop and crawl into inaccessible places to either position, operate or release the jack.

A novel feature of the present hydraulic jack is contained in the lazy tongs structure which has the operating blocks thereof mounted between the ends of pairs of toggle members to permit projectin ends of said members to be free for the reception of selected ends of equalizing links leaving the opposite ends of said equalizing links free to be pivotally connected intermediate the ends of the respective toggle members to which the operating blocks are secured.

The improved hydraulic scissors type jack herein disclosed comprises a bottom or base plate I having two spaced pairs of apertured bearing lugs 2 and 3 integrally formed thereon for respectively supporting bearing shafts 4 and 5, the outer ends of which are reduced in diameter to form suitable supports for the lower ends of members forming parts of a collapsible and expendable type of Weight lifting and lowering mechanism of the lazy tongs type.

The load lifting and lowering mechanism is supported on the base plate I and is of the scissors type including two oppositely positioned sets of lazy tongs or toggle frame members comprising a pair of lower lazy tongs links or toggle members 6 which have the lower ends thereof pivotally supported on the reduced ends of the base bearing shaft 4. A second pair of lower lazy tongs links or toggle members 7 have the lower ends thereof pivotally supported on the reduced ends of the base bearing shaft 5. The toggle members 6 and I on each side of the jack cross one another and project upwardly and outwardly in opposite directions as illustrated in Figure 3.

Pivotally connected by means of a pivot stud 8 to each of the lower toggle members I, at a point a short distance from the shaft 5, is the lower end of a lower stabilizing link 9, the upper end of which is pivotally engaged on a pivot stud l0 carried in the lower projecting end of an upper lazy tongs link or toggle member H, two of which are provided. The upper ends of the two lazy tongs links or toggle members II are pivotally supported on the reduced ends of an upper shaft l2 which projects through apertures in two spaced looped or U-shaped flanges i3 spaced from an intermediate or middle reinforcing flange I4. The spaced flanges l3 and I4 form an integral part of a jack lifting head or saddle l5. The lifting head I5 is constructed of a sheet metal plate having portions thereof folded upon itself to provide the downwardly projecting flanges l3 and 14 as illustrated in Figure 6.

Each of the upper lazy tongs links or toggle members I I has a pivot stud 16 supported thereon a short distance inwardly from the upper end thereof. Pivotally supported on the stud i6 is the upper end of an upper stabilizing link H, the lower end of which is pivotally supported on a pivot stud I8 carried by the upper projecting end of one of the lower lazy tongs links or toggle members I. It will thus be noted that the lower and upper sets of stabilizing links 9 and H are mounted so that one end is pivotally connected intermediate the ends of either one or the other of the toggle members 1 or II while the other ends of said stabilizing links are pivotally connected to projecting ends of the respective toggle members I or I l as clearly illustrated in Figure 1.

Also supported in the depending flanges E3 of the jack head I5 is another upper shaft l9, positioned opposite and parallel to the upper shaft I2 on the jack head. Pivotally engaged on the outer reduced ends of the upper shaft I9 are the upper ends of a pair of upper lazy tongs links or toggle members 20 which extend downwardly and cross on the inside of the upper toggle members II. The lower ends of the two upper toggle members 20 are pivotally engaged on trunnions or gudgeons 2| which are integrally formed on opposite ends of a lower toggle operating block 22. The trunnions 2! of the lower toggle operating block 22 are rotatably engaged in openings provided near the upper ends of the lower toggle members I a short distance inwardly from the studs 18 as shown in Figure 1, thereby pro- 55; viding an arrangement in which the-lower: ends of the upper stabilizing-links Iiiaren'sonnected to the upper projecting; ends-of the =lower toggle membersnl' beyond the=-point of support for: the lowerrtoggle operating block 22.

'I he lower toggle operating block 22 is recessed to: receive a retaining wedge unit 2131 hich ispassaged-i to 1 register with: a transverse opening inatheblock 2-2 to rec'ei-ve the outer end of a.

hydraulicallyoperated piston rod on plunger; 24% 10' securely loohed therein; The outer: end portion: of the piston rod 24 iscircumferentially grooved at 25*? to: receive an; internal ring forming: an. integral part of the wedge-unit z, which is of a splitln construction to facilitate engagement thereof around the grooved end of the/piston'irodi 2's: as: illustrated in'Figure 3:

The scissors or: togglemechanisms for: a-ctue ating: the jack head includes an: upper-a toggleoperating: block 2'6 which' is' formed with: integral 2O outwardly projecting end 1 trunnions or: gudgeons 2-7; The trunnions' 2 1 are rotatablyengaged in: openings provided in the lower portions! of the upper togglemembers I lsat a short distance inwardly-from the studs lilliwhich: are supported in: the lower projecting ends. of. the togglemem. hers H to serve as supports for, the upper ends. of'the lower stabilizing links-9 as showndn Figure 1i It willthus be-notedthatthe-jack: head. iS'is adapted to be'operatedby lazy tongs or the r scissors type'arranged in two groups or: sets on opposite sides of the jack head and including: upper and lower sets of stabilizing linksconnccted to projecting ends of the toggle memberszfiand.

l i and to-points'between the supporting-ends of said toggle members and the points..where\-- the supporting trunnions of the lazy tongsaoperating blocks engage through the toggle imemberss'li and; Hi

Theupper toggle operating block.261-is-trans-v 4O versely recessed and is welded or otherwise rigidly secured around the exterior of a. hydraulic cylinder -28 'Which. is mounted: in a an inclined: po. sition and slidably'receives theupper endofrthe piston rod 24. The piston rod; 2143 isaalso' supported in an inclined position as illustrated-tin Figure .1 3 and projects through-suitable packing: in a closure -cap29= which is.:tightly.-threadedfion: the lowerexteriorly threaded end of the cylinder ze toinsure'a tight'joint. Rigidly secured ion the inner or upper end of the pistonrrod 21!: isaanpis ten 30" which is adapted. to beoperated by a: hydraulic operating fluid; such: as oil; water or any other: suitablefluid adaptablefor useas a liquid medium for actuating the. piston andithei piston rod to cause operation.ofztheitoggle mechanisms tov raise the jack. head.

The hydraulic. cylinder. 281 projects 1ongi--- tudinally and centrally through-lthe upper portion of ahydrauli-c housing or jacket3il e and is tightly sealedin collars- 32'. and 33 which areintegrally formed on opposite ends of! the upper central portions of 1 the end walls of the housing 3!. The upper end of the cylinder: 28 projects through the housing sleeve 33 andzis' exteriorly same ha-s'beenemptied.

threaded to receive a'closure. cap 34:.toseal the upper. end of the cylinder.

The hydraulic housing'3l is provided with a. chamber 35 which isfilled with a-hydraulic opacrating liquid such as oil which forms ajacketv around the cylinder 28 where it projects through. the housing.

Normally thejacl: head [5 is inits=lowermost position as illustrated-in Figure i, so that the hydraulic piston rod-2'4 is:-in'-itsoutlermostposi tion=-with1 the pistom 30%:1'n tne lower: end of: the

cylinder 28 sothat substantially all of the'op'en=- ating 'fluid is discharged i from the-lower sideof? the piston 303 outwardly through a-- combination:

fluid feed and discharge-pipe36, the outer end? of which is connected by a pipe'coupl-ing Biwhich is engaged in a sleeve 38 integrallyformedi on the lower central portion: of one-end of the hydraulic housing 3 Tightly connected-- to the inner endof the pipe coupling 3 is one:- end of a fluid pipe 39 which is disposed within the fluid chamber 35 and'has the=sec0nd end thereof'pro jecting into a'valve housing wiwhich -is* integrally formed or cast in a lower corner of the fluid housing 3!'- and is disposed.at right anglestha fluid-pump cylinder 4|; Thefluid pumpcylinder: l! is integrally connected by-means of a web fl" toasecond pump cylinderfi43; onee end ofiwhich is-integr-ally connected at ri'ght -angles to a second valve 1 housing A l: which -is also integrallyformed in one ofthe cornersofi the housingdl in align ment with the valve housing 48 and spaced therefrom as-shown-in Figured. I

llhe valve housing 40' is provided- Withe -liquid receiving" chamber id-which opens through one end ofthe housing 3 I andis -closed by a-threaded plug 46. Seated against the inner end of the closure plug 15 is one end 0? a valvecontrol spring t1, the innerend -of which seats against a ball valve l8 to' normally. hold the same seated in a valve seat d9 formed in the valve housing llii Alsoseated against the bal1'valve-48-"' is'-oneend of a control spring 59 which-is disposed 'within a passage or chamber in the valve housing4E3 and communicates with the inner' end of the pump chamber within the cylinder-41 The sec ond endof the control spring fi'il engagesaga-insta second intakeball valve 51 to normally holdthe same seated against anauxiliary valve seat 52 to normally close'a fluid intake passage-or port 53 provided in the inner end of the-valve housing 49- as clearly-illustrated in Figure-4;

In a similar manner the second valve housing; M; in the. housing 31, is--provided witha fli'iid' chamber 54 the outer end of 'which opens throughan openingin an end wall of the housing 3 I and is closed; by meanszofxa threa'ded' closure-"plug 55 i Engagedi against the inner end of. the closure plug 55 is; one end' of: a: maint control-t spring. 5'65 which-:issdisposedin the chamber 523 andihasssthec opposite end? thereof. engaged iagainst azmain.iballi:v valve: 5'!- which 1 is adapted to: be normallyaheld; seated againsttai mainu valve: seat: 5&1- to; close-1 off .i the chamber; 54 from the chamber-y at the innerx end. of: the chamber Ell-of the pump cylinder.- 43'. Disposed within'; the. chambers at the. end. 2 of the pump chamber 59 i-is an. auxiliary controluspring; 6&3. one endlof which seats against. aflmain: ball. valve 51 while. the-rather. end seats. against an. auxiliary balLvalve. 61 to. hold thesame against an auxiliary valve seat 62' for controllinga ,fillii.

intake passage orport 63; provided. in the inner end of the valve housing 44 to permit fluid to be suctioned through the passage '63" to fill the pump chamber 59* to refill the same after the" To permit the operating fluid to be pumped from the chamber 54'- into tliechamber- 4 5' and theninto the outlet pipe-3 9 a'connecting or-trans fer pipe fid isprovided with one end of-"said'pipe being connected 'to the-'valve'housing M to com municate withthe chamber 54 therein while the other end' of said pipe 63- is= connected to the valve housing ine-to communicate with' thee-chain berl 45i' therein';

For the purpose of insuring the steady pumping of a fluid from the fluid chamber 35 of the housing 3|, two alternately operating pump mechanisms are provided including the pump cylinders 4| and 43 hereinbefore described. Slidably mounted in the pump chamber 64 of the pump cylinder 4| is a pump piston stem or rod 65 which projects out of one end of the cylinder 4| and has rigidly secured on the projecting end thereof a pump head 66 having engaged around the inner side thereof one end of a coiled spring 61, the inner end of which engages around a portion of the pump cylinder 4| and seats in a recess provided in a plate 68 having openings therein to permit the plate to be engaged around the pump cylinders 4| and 43 as illustrated in Figure 4. Slidably engaged in the chamber 59 of the pump cylinder 43 is a pump piston stem or rod 69, the outer end of which projects from the pump cylinder and has rigidly secured thereon a piston head 19. Engaged around the projecting end of the pump cylinder 43 is a coiled spring 1|, one end of which seats against the inner side of the piston head 10 while the other end seats in a recess provided in the plate 68.

The two pump piston units are alternately operable to alternately draw the pumping fluid from the chamber 35 through the intake ports 53 and 63 into the respective pump chambers 64 and 59 when the pump piston rods move outwardly in their respective cylinders by the action of the piston control springs 6'! and II, one of which is compressed when the other is expanded as shown in Figure 4. The piston control springs jointly act to hold the piston heads 66 and 19 in contact with a double cruciform type of crank shaft unit comprising a crank shaft 15 journaled in suitable bearings provided on the housing 3| and extending outwardly from the interior of the housing 3| through a packing unit 12.

Rigidly formed on the crank shaft 15 within the chamber 35 are two spaced diametric double cranks l3 and 14 which form an integral part of the crank shaft 15 and are disposed at right angles with respect to one another so that the crank 13 is positioned to coact with the piston head 66 while the crank 14 coacts with the piston head 10 when the crank shaft is rotated to cause alternate operation of the twin pumps. The crank shaft 15 slidably projects through the packing unit 12 and is normally held in its innermost position by means of a coiled control spring 16 which is coiled around the crank shaft within the chamber 35 of the housing 3| with one end of said spring being engaged against a flat portion of the packing unit 12 while the inner end of said spring seats against a control disk 11 which is rigidly secured on the crank shaft 15 adjacent the crank 74 as illustrated in Figure 4.

The crank shaft 15 which drives the twin pump mechanisms for pumping the hydraulic fluid into the lower end of the hydraulic cylinder 28 to cause operation of the jack is adapted to be manually rotated. For the purpose of rotating the crank shaft I the outer projecting end thereof has a coupling head I8 attached thereto by means of a sleeve 19 which is secured to the crank shaft 15 by means of a set screw 80 or other suitable fastening means. Rigidly secured longitudinally within the coupling head 18 are two diametrically opposite and parallel stop pins 8|. The coupling head is chambered and has the outer end thereof closed by means of a wall which is provided with a central opening 82 and with a diametric slot 83 which crosses the opening 82 as clearly illustrated in Figure '7.

For the purpose of rotating the crank shaft 15, a removable crank handle 84 is provided, the outer end of which is shaped with a crank extension and a hand grip (not shown) of the ordinary type to permit rotation of the crank handle 84. The driving or attachment end of the crank handle 84 is provided with a diametrically positioned driving pin 85, as shown in Figure 5, and said pin is adapted to be projected through the diametric slot 83 as the end of the crank handle 84 is projected through the central opening 82 of the coupling head 18.

When the crank handle 84 is rotated, the driving pin 85 will engage behind the pins 8| in the coupling head to cause rotation of the coupling and the crank shaft 15 together with the cranks 13 and 14. The cranks "I3 and 14 coact with the respective piston heads 66 and 10 to cause alternate operation of the pump piston rods 65 and 69 whereby the fluid in the chamber 35 of the hydraulic housing 3| is alternately drawn through the ports 53 and 63 to be pumped into the respective chambers 45 and 54 and then through the pipe 39 to enter the hydraulic cylinder 28 below the piston 30 to gradually move the same upwardly in the cylinder 28. The piston 30 draws the piston rod 24 inwardly to cause the toggle operating block 22 to be drawn toward the toggle block 28 thereby causing operation of the toggle members as well as the stabilizing links to gradually and evenly raise the jack head l5 to a desired height.

After the operating piston 30 has been moved upwardly in the hydraulic cylinder 28 by the pumping of the hydraulic fluid into the lower chamber of said cylinder, the raised jack head I5 will stay in its elevated position until the fluid below the piston 30 is released and is permitted to gradually flow outwardly through the pipe 36 and then through the pipe 39 into the chamber 45 of the valve housing 40 and through the connecting pipe 63 into the chamber 54 of the valve housing 44.

In order to permit the hydraulic fluid to escape from the chamber 54 of the valve housing 44, a fluid release mechanism is mounted within the fluid chamber 35 of the housing 3| and is supported in an interiorly threaded sleeve or collar 86 which is integrally formed on the valve housing 44 as clearly illustrated in Figures 2 and 4. The fluid release mechanism includes a valve block 81 having an externally threaded stem 88 integrally formed on one end thereof and threaded into the sleeve 86 to communicate with the chamber 54 in the valve housing 44. A release ball valve 89 is engaged in the valve block 81 and is normally held seated in a closed position against a valve seat 90 by means of a coiled spring 9|, one end of which seats against the ball valve 89 while the other end is engaged against a transverse diametric pin 92 in the threaded stem of the valve block 81 as illustrated in Figure 4.

The release valve block 81 is provided with a discharge chamber or passage 93 with which diametrically opposed discharge openings or ports 94 communicate to permit the discharged fluid to pass back into the chamber 35 of the housing 3| as shown in Figure 4. Slidably mounted in a passage provided in the valve block 81 is a discharge valve control pin or stem 95 which projects into the chamber 93 against the ball valve 89. One end of the control pin 95 projects from the block 81 into contact with a cam 96.

forming :a part of avalvecontrolfingerwr arm 19'! which is pivotally= -supported onla ;pivot pin 98. The pm 198 'is mounted :between :a pair :of plates 99 secured 'i'Ol'l wopp'osite =-sides of :the valve :block :8! and projecting beyond one :end :thereof to :provide a' space ifor :the controlw-cam 96 to rotateiin. Rotation of-ithecam Stir-causes operation of the control pin=555 and thereleaseball valve Bil-when the control finger'Blis swung outwardly from the full lineiposition:illustrated ine'Figure'A by the outward movement ofithe control disk "H.

' Outward movement of the controldiskfl 1' occurs when the crank shaft 15 iis slidablyfmoved outwardly against the action of 'the 30011811 -spring I6 when aipull is fmanuall-y :exerted fonthez'crank handle 'il l causing the pins-:85 to-engage against the end wall of the couplingih'ead fistopullthe coupling head 1 and the crank shaft -75 from the positions illustrated in'EigureZ into the positions illustrated in Figure in which the spring "i6 is compressed and in which-the disk Tl :swings or rocks the control finger 9? from the position shown in Figure 4 into the-operating :position shown in Figure :5. The cam 95 thus acts on the control pin 95 and causes the ball valve 88 to'move into its open position thereby-{permitting the fluid Whichis being forced=out of the lower .end of the hydraulicvcylin'der 2-3-tobe discharged through the-chamber '93 and the discharge port 94 backinto-the chamber 35-:of the housing-3| for reuse.

When the crank shaft "is ipulledioutwardly to causeopening of the .release-valvei89, the return i of the control fluid *backrinto the chamber permits "a-gradual 'even lowerin'g of the jack head '55 from a raised position into-1a lower position during which time the head'raising :lazy tongs mechanism and thestabilizing links asso ciated therewith are adapted vto be gradually moved back into their normal rcollapsed-positions, as illustrated in Figure 1,-to-permit the jack mechanism to be removed :from beneath .an tob- J'e'ct after being lowered.

For the purpose of gaining admittance -:to the mechanisms :mounted within thehydraulic housing 3-l said housing .is provided with .an opening which is tightly closed by means-of a removable closure seal plate 1.0! secured-to-the housing by means of screws "or other suitable fastening means.

Referring to Figure 6, -a zp-rotectingguard :is provided for the scissors jack, and this guard consists :of a pair-of-sid'e plates-or hood sections use, the upper ends of which are bent'over to engage beneath the side "margins of the jack head R5 to which the upper flanges of the side plates are rigidly secured. Theguard plates I02 serve to protect the lazy tongs mechanisms and also afford a safety means .toiprotect the lazy tongs mechanisms by preventing anything from getting between "the"members of'lazy tongs operating mechanisms to prevent proper operation thereof. The guardplates i 02 have been omitted from tall of the figures except "Figure Binorder to :more clearly disclose the various mechanisms of the-scissors jack. -It will, of course, beunderstood that the guard plates maybe omitted when not needed or said guard plates may .form -an integral .part of the jack hea'd 2115.

The improved "hydraulic jack is admirably adapted for raising light ori heavy loads, which after being raised maybe-gradually and uniformly lowered at a constant rate by the release "of %the fluid control valve unit, ithe opening of which is controlled by the shifting or slidable )movement of the crank i-tshaft 1:5. When the shaft This rotated iby'meansof the crankhandl-e 84, the fluid pump mechanisms are actuatedto cause the :fiuid to be pumped into the hydraulic L5 cylinder 2-8 to move the pistoniheadtfi upwardly in said cylinder to actuate the toggle-members sand the stabilizing links of the llazy -tongs unit to cause *raising of the jack head M to any desired-height within thelimitsifor which thejack 10 is designed.

-Itwi11 thusbe noted that an important feature -of the hydraulic rjack'is the provisionof a hy- -\dr-aulic control unit comprising a crank shaft which -is rotatable --for causing pumping .of the 115 fluid toicause operation of the-piston rodito raise the jack head. The crankshaft is furthermore longitudinally:shiftable by exerting an outward pull-on-the crank shaft against the actioniof the control springtocause cam o-peration of the re- :20 lease ball valve to permit release of the sum from the-hydrauliccylinder and aigradualeeven .lowering'of the iackhead and the toggleimechanisms supporting the same.

While :an improved type of hydraulic control 125 unit-is associated with the lazy tongs or scissors jack unit, it will of course be .understood that the'hydraulically operated piston mechanism may be replaced by an operating screw, the rotation of which maybe accomplished by .adirect con- 39 nection thereto of a suitable' crank handle or by imeansiof a reduction gear unit and :an auxiliary crank handle drive such vas the operating drive unit illustrated in imy copen'ding application wfor -,patent for a Scissors jack, filed-June 21, 1945, '35 U. S. -Serial No.-.600,'763.

:Another important feature of the present invention is the :provision of a lazy tongssjack "unit wherein the toggle members .are -mounted for *raising and lowering the jack ahead, said itogg'le 40 members being arranged with the actuating blocks mounted off center or between the ends 'of selected pairs ;of the toggle members while the-stabilizing links-areeachmounted with one endiconnected to a ,projecting end of one of the toggle members on which the actuating blocks are supported while-the other end of thestabiliz- .ing A link is 5 pivotally connected another o'fzsaid block supporting toggle members at a -pointiintor-mediate the ends thereof.

It will furthermore be understood that various other details of construction -may be varied through a wide range without departing from the principles of this invention, and it is, therefore, not the purpose to limit-the :patent granted 55 "hereon otherwise than necessitated by the scope .of the appended claims.

-I claimasmy invention:

Alazy tongs I-jack device comprisinga base, :a jack head, a pair-of lower lazy tongs vmembers pivotally connected to thesbase apair of upper lazy tongs :members pivotally connected to .the

j a'ck head, an operating block connected to ione Y of thelower:'1azy ton-gs 'membersintermediate the ends thereof and pivotally connected to one end of one of the upper lazy tongs members a-second block connected to-thesecondupperlazy tongs .member intermediate the-endsthereofiand to one rend-of the second lower lazy tongs member, "a

"driven member co-ac-tin with .said blocks, =.driving means for operating the driven member -to move the blocks toward one-another-to actuate the lazy tongs members-to raise the jackheads release :mechanism, and an 0peratin'g :means ifor =only 'Pshifting the driving :means to cause the same to operate the :release mechanism toicause 11' separation of the blocks and gradual lowering of the lower and upper lazy tongs members to lower the jack head.

2. A lazy tongs jack device comprising a base,

a jack head, a pair of lower lazy tongs members pivotally connected to the base, a pair of upper lazy tongs members pivotally connected to the jack head, an operating block connected to one of the lower lazy tongs members intermediate the ends thereof and to one end of one of the upper lazy tongs members, an upper stabilizing link connected to one end of the lower lazy tongs members to which the block is connected and having the other end connected to the second of said upper lazy tongs members intermediate the ends thereof, a second operating block connected to the second of said upper lazy tongs members between the ends thereof and to one end of the second of said lower lazy tongs members, a lower stabilizing link having one end connected to one end of th second of said upper lazy tongs members and the other end pivotally connected between the ends of the first of said lower lazy tongs members, a driven member supported by the blocks, a driving means for actuating the driven member to move the blocks toward one another to cause raising of th jack head,

and a release mechanism operable by the driving means to cause lowering of the jack head.

3. A lazy tongs jack device comprising a base, a jack head, a pair of lower lazy tongs members pivotally connected to the base, a pair of upper lazy tongs members pivotally connected to the jack head, an operating block connected to one of the lower lazy tongs members intermediate the ends thereof and to one end of one of the upper lazy tongs members, an upp Stabilizing link connected to one end of the lower lazy tongs members to which the block is connected and having the other end connected to the second of said upper lazy tongs members intermediate the ends thereof, a second operating block connected to the second of said upper lazy tongs members between the ends thereof and to one end of the second of said lower lazy tongs members, a lower stabilizing link having one end connected to one end of the second of said upper lazy tongs members and the other end pivotally connected between the ends of the first of said lower tongs members, a driven member supported by the member to operate the hydraulic means, and a Q hydraulic release mechanism operable to cause release of the hydraulic means and lowering of the jack head when the control handle is actuated to shift the shaft member into engagement with the release mechanism.

4. A lazy tongs jack device comprising a jack head. a base, crossed toggle members connecting the head and base, operating blocks connected to opposite pairs of the toggle members between the ends thereof, stabilizing links having one end of each thereof connected to an end of one of the toggle members and the other end connected intermediate the ends of an opposite toggle member, hydraulic means for operating the blocks to cause raising of the jack head, a crank shaft, operating means for rotating the crank shaft to cause operation of the hydraulic means and elevation of the jack head, a hydraulic release mechanism connected with the hydraulic means, and a control carried on the crank shaft 12 for operating the hydraulic release mechanism to cause lowering of the jack head when the crank shaft is shifted by the operating means.

5. A hydraulic jack mechanism comprising crossed toggle members, a jack head supported thereon, guards carried thereby, a block member supported on two of said toggle members intermediate the ends thereof, a piston rod connected with said block member, a piston on said rod, a hydraulic cylinder enclosing the piston, a second block member on the hydraulic cylinder and connected to two other toggle members intermediate the ends thereof, a fluid housing connected to the hydraulic cylinder, pipe connections between the hydraulic cylinder and the fluid housing a plurality of fluid pump mechanisms in the housing, a fluid intake and outlet valve for each of the pump mechanisms, a fluid release valve unit in the housing, a control shaft rotatably and shiftably mounted in the housing, crank members on the control shaft for alternately operating the pump mechanisms to cause fluid to be pumped into the hydraulic cylinder to operate the piston and piston rod to cause movement of said block members toward one another to raise the jack head, a control disk mounted on the control shaft within the housing, a spring on said control shaft engaging said control disk to hold the control shaft in its innermost position to position the cranks in operating engagement with the pump mechanisms, a coupling unit connected with a projecting end of the control shaft, and a crank handle removably engaged in the coupling unit and adapted to be rotated to cause rotation of the control shaft and the crank members to pump fluid into the hydraulic cylinder to actuate the piston and piston rod to raise the jack head, said crank handle adapted to be pulled to shift the control shaft against the action of the spring to cause the control disk to operate the release valve mechanism to permit return of the fluid from the hydraulic cylinder back into the fluid housin and permit gradual lowering of the jack head.

6. In a scissors type jack including a base, a lifting head, crossed lazy tongs members supporting the head on the base, operating means connected with diagonally opposite upper and lower lazy tongs members intermediate the ends thereof and leaving one projecting end of each of said selected lazy tongs members free, and stabilizing links pivotally connected to the free projecting ends of said selected lazy tongs members and to points intermediate the ends of said selected lazy tongs members.

ARTHUR ALFRED MILLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,135,440 Cremieu-Javal Apr. 13, 1915 1,723,131 Burkholder et al. Aug. 6, 1929 1,736,202 Larson Nov. 19, 1929 1,859,830 Kummel May 24, 1932 1,954,558 Conrad Apr. 10, 1934 2,097,032 Marlowe Oct. 26, 1937 2,176,636 Meacham Oct. 17, 1939 FOREIGN PATENTS Number Country Date 667,423 France June 17, 1929 732.613 France Dec. 28, 1932

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2716537 *Jun 8, 1949Aug 30, 1955Gen Motors CorpScissors jack
US2936132 *Feb 2, 1956May 10, 1960Loewy Eng Co LtdCoiling or de-coiling apparatus for metal strip with collapsible drum
US4624448 *May 28, 1985Nov 25, 1986Lawman Dennis JLow profile, high rising lifting mechanism
US8191865May 17, 2005Jun 5, 2012Stertil B.V.Device and system for lifting a motor vehicle
US8523146May 10, 2012Sep 3, 2013Stertil Koni UsaDevice, system, and method for lifting a motor vehicle
DE1107384B *Jun 14, 1956May 25, 1961Koettgen & CieHubeinrichtung fuer Hubwagen
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Classifications
U.S. Classification254/122, 417/440, 417/539, 254/93.00H
International ClassificationB66F3/24
Cooperative ClassificationB66F3/245
European ClassificationB66F3/24D