US2505187A - Hydraulic jack - Google Patents

Description

April 1950 E. c. JUERGENS 2,505,187

HYDRAULIC JACK Filed Dec. 5, 1946 2 Sheets-Sheet 1 IN V EN TOR;

April 25,

Filed Dec. 6, 1946 1950 E. c. JUERGENS 2,505,187

HYDRAULIC JACK 2 Sheets-Sheet 2 9b 9 25 'f i1 H 9k '1 25 I INVENTOR.

Patented Apr. 25, 1950 UNITED STATES PATENT OFFICE 2,505,187 HYDRAULIC JACK '7 Edwin C. Juergens, Chicago, Ill.

Application December 6, 1946, Serial No. 714,549

8 Claims.

This invention relates to improvements in hydrauliclifting jacks of the kind used for automotive vehicles, although not necessarily limited to such use.

Among the objectsofthe invention is to provide a simple and dependable hydraulic ram and a self-contained double acting pump mechanism for operating the same which can be readily manipulated by hand with a minimum of effort.

Another object is to provide a simplified and improved form of universal mounting for the bumper catch on the lifting column to permit the latter to accommodate itself automatically to tilting movements of, the bumper or other portions of the car with which it is engaged, thereby relieving the lifting column of the jack from excessive lateral bending stresses.

A further object is to provide an improved form of mounting for the bumper catch Support, permitting selective. adjustment of the latter at various points along the lifting column of the jack. I

Other objects and advantages of myinvention will appear from time to time as the following description proceeds:

The invention may best be understood by reference to the accompanying drawings, in which;

Figure 1 is a side view of a lifting jack constructed in accordance with my invention, with,

a portion of the lifting column broken away;

Figure 2 is a vertical sectionof the upperpart of the jack showing details of construction of the pump mechanism and drawn to a largerscale than Figure 1;

Figure 3 is a vertical section of the lower end of the jack drawn to the same scale as Figure 2, showing details of construction of the bumper catch and the lower endof the lifting column;

Figure 4 is a detailed .section of the bumper catch support taken on line 4--4 of Figure 1;

Figure 5 is a detailed section taken on the broken line 5-5 of Figure 4;

Figure 6 is a fragmentary perspective detailed for adjustably holding the saddle nut on the lifting column. I

Referring now to details ofthe embodiment of my invention illustrated in the drawings, the

lifting jack indicated generally at I0 comprises as its main elements a telescope lifting column II, a bumper catch I2, a hydraulic pump I3 at the top of said column, and a socketed foot member or pedestal '9 at the bottom of said column.

The lifting column II consists of an elongated ram cylinder I5 with a ram rod I6 reciprocally mounted therein, said ram rod having a piston head H at its upper end. The lower end of the ram rod extends through a suitable bushing I8 threaded in the bottom end of the ram cylinder and having suitable packing means herein comprising an O-ring I9 fitting into an interior annular groove 20 in the bushing I8. The pedestal 9 may be permanently secured to the bottom end of the ram rod by a ring 9a passing loosely through a hole IBa near the base of said ram rod and also passing through holes 912, 9b in said.

The upper end of the ram cylinder I5 7 is externally threaded on a lower extension 2I of pedestal.

a pump cylinder 22, which will hereinafter be more fully described.

The exterior surface of the ram cylinder I5 is formed with a plurality oflongitudinal spaced annular grooves 25,25 adapted to provide supporting abutments for the selective adjustment of the bumper catch I2 which will now be de-.

scribed.

The bumper catch indicated generally at I2 includes a C-shaped jaw 26 with parallel side walls 21, 21, mounted for universal tilting movement with respect to the lifting column I5 in a manner somewhat similar to and broadly disclosed in my earlier application, Serial No. 657,196, filed March 28, 1946. The jaw 26 has a lower forwardly projecting portion provided with a plurality of notches 28, 29, 30, and 3|, arranged to permit said bumper catch to accommodate itself to automobile bumpers of difierent sizes and shapes when the lower edge of the bumper is ennotches 28, 29, 30, and 3| in the lower part of the jaw, as shown in Figure 1.

The jaw 26 is pivotally mounted on a trunnion strap 35 which consists of a sheet metal piece arched over a saddle nut 36 and having opposite upright side walls 31, 31 with outwardly extending studs 38 to which the side walls 27, 21 of the C-shaped member are pivotally connected. In the preferred form shown, the studs 38, as are produced .by punching apertures in the side walls 3'! of the trunnion strap and flanging the margins of said apertures outwardly, as shown in Figures 1, 4, and 5. After the side walls 21, 2'! of the C-shaped member 26 are pivotally mounted on the studs 38, the outer ends of the latter are placed outwardly at 36, 39, to holdthe C-shaped jaw permanently in pivoted relation on said studs.

The central arched portion of the trunnion strap indicated at 46 is provided with an aperture 4! through which the lifting column .15 projects with sufficient clearance at opposite sides thereof to permit lateral rocking movement or the trunnion strap relative to said lifting column.

The saddle nut 36 shown in detail in Figures 7 and 8 is generally cylindrical in form, with a bore 45 extending therethrough. at right angles to the axis of said nut. The lifting column 5' projects through the bore '45 with a relatively easyslidi-ng fit.

The arched portion 46 of the trunnion strap fits over the curved uppersurface of the saddle nut36, so as to permit limited rocking movement of the trunnion strap relative to the saddle nut on'a horizontal axis. Since the jaw 26 has rocking movement'with respect to the trunnion strap on a horizontal axis at right angles to the axis of saidsaddle nut, the jaw 26 has substantially universal tilting movement with respect to the lifting column 15.

In initially applyingth'e jack to an automobile bumper, the loweredge-of the bumper is engaged in =one or the otherof the notches 28, 29, 30 or 3|, and then by the relatively slight tilting movement of the jaw caused when the jack starts to raise, the upper portion of the bumper will become engaged against the abutment 32 of the jaw'so-asto lock the bumper against further tilting movement with respect to the jaw. Thus, in efiect, the bumper will becomea rigid extension-of the jaw 26, and the load on the bumper will be transferred to the center line of the liftingcolumn of the jack, so that the latter will be relieved of bending stresses which would "otherwise be imparted thereto.

A pair of retaining lugs 48, 48 are turned inwardly at the diametrically opposed front and rearedges of the side walls 31, 31. Said lugs normally are spaced a slight distance from the front and rear faces of the nut 36 at a point above the axis of the pivot studs 38, 38 so as to hold the nut loosely centered relative to the trunnion strap. A second pair-of lug l'il, 49 are bent inwardly and then reversely at'an'acute anglefrom the front edges of the side walls 31, 31 of the trunnion strap below the lugs 48, 48, so as to extend beneath the rear of the saddle hut, as shown in Figures 4 and 5. The lugs 49, 49 have a substantial clearance below the saddle nut so as to retain it loosely between the side walls 31,

310i said trunnion strap, but permitting limited 0 trunnion strap 55 consists of a relatively flat length of wire with its central portion 56 looped-so as to formalmost a complete circle, but terminating with relatively straight portions 51, 58. One of the terminal portions 5'! is slightly offset with respect to the other portion 58 so that said straight portions may cross each other in parallel planes as shown in Figure 9. The free ends of the straight portions 51 and 58 may be bent at right angles to the plane of the circular portion 56 to form finger pieces 51a and 5.841 respectively.

The looped portion 56 -,of the lock spring 55 is normally of such diameter as to fit under slight tension in any one of the grooves 25, with its periphery projecting beyond the outer surface of the ram :cylinder [5 so as to form an abutment upon which the lower face of the saddle nut 36 is supported. As shown in Figure 8, the rounded bottom surface of the saddle nut is preferably cut away toward one end thereof to form a substantially flat surface 66 surrounding the central bore 35 in the saddle nut, but leaving a semicircular recess defined by a depending shoulder 6| at the opposite end of the nut, in which the looped portion 56 of the lock spring his.

The arrangement just described is such that the lockspring may be applied to any one of the annular grooves 25, on the lifting column depending upon the initial vertical position desired for the bumper catch. In applying the lock spring, the thumb pieces 5111,5811 are arranged to project rearwardly between the spaced side walls 21, 21 of the=C-shaped clamp 26, as shown in Figure 5. The saddle nut 36 may then be lowered until the bottom face '60 of said saddle nutengages the lockrspring as shown in Figures 3 and 4. In this position .itwill be observed that the depending semi-circular shoulder 6| 5111'- rounds the forward end of the looped portion 56 of said lock spring so as to prevent the latter from becoming accidentally displaced from its groove 25' whenever there isbanyfload imposed on the saddle nut. Moreover, it 'is necessary to lift the saddle nut with its depending shoulder 6| out of iregisteringrelation r-with'the lock spring whenever it is desired to readjust the position of the lock spring into another groove 25. Such readjustment can then bewreadily accomplished by compressing'the'finger pieces 51a, 58a a sufiicient distance to release the looped portion 56 0f the lock spring and thensliding the latter along the ram cylinder '15 to a newregistering position in another groove 25. By releasing the thumb pieces 61a, 5821 the tension of the lock spring will cause it to become seated in "the desired groove, ready to serve as an abutment for the saddle nut in its newly adjusted position.

Referring now thehydraulic pump mechanismjindicated generally at l3, the pump cylinder 22 extends upwardly in :alignment with the ram cylinder IS with zit-is :connected as previously described. Said pump cylind'er is surrounded rby a substantially :concentric cylindrical casing 65 with a bottom plate '66 and-.a cover plate 61 which together define a chamber 68 forming a hould supply tank orrreservoir for the pump. In the form shownzherein, the bottom plate 66 of the tank .has :a central aperture 68 through which the lower extension 2! of the pump cylinder extends. Said 'bottom1plate is secured in place between a downwardly facing shoulder .69 .on the :pump :cylinder and the upper end of the ram cylinder l5 when the partsiare'in 7 assembled position :as :shown .in figure 2.

In the form shown herein ztheilower end of the cylindrical casing 65 fits around a flanged ram s seal such as an O-ring 86b interposed therebetween. The upper. end of said cylindrical casing fits around the lowerperiphery of the cover plate 61 with a suitable, packingmember such as an O-ring 61a interposed ,therebetween.

The pump cylinder 22 has an axial cylinder bore I8 opening to its upper end within which is threaded a depending sleeve portion II of the cover plate 61. Said cover plate has an axially extending bore I2 through which the piston rod I3 of the pump projects. Said piston rod is of substantially smaller diameter than the bore ID of the pump cylinder and has a piston I4 at its lower end. The arrangement is such that the piston rod and its piston define a variable pressure chamber I6 in the bore I below the piston head I4, and a second variable pressure chamber II of reduced cross-sectional area in the space above the piston I4 between said piston rod and the side walls of the cylinder bore III.

The piston rod I3at its upper end is pivotally connected to a pump handle I4. Said pump handle is rockably supported on top of the cover plate 61 by means of a link I5 which is pivoted at its lower end on a pin I6 in a recess II and at its lower end to a pivot pin I8. The arrangement is such that the link I5 provides a floating fulcrum for the pump handle so that the piston rod I3 may reciprocate axially of the pump cylinder while the pump handle is being manipulated.

The pump cylinder 22 has an inlet port 88 at its bottom end communicating through a vertical passage 8| and an intersecting horizontal passage 82 with the lower end of the liquid tank 68. In the form shown herein the vertical passage BI is formed by drilling a bore 83 longitudinally of the lower extension 2I of the pump cylinder and inserting a plug 84 intermediatetheends of said bore. The plug 84 also forms a seat for a spring pressed check valve, 85 in the passage 8| which permits fiow of liquid by suction into the lower chamber I6 of the pump cylinder from the reservoir 68 but preventing the flow of liquid in the opposite direction.

The piston I4 has a port 81 opening to its bottom face and communicating with a laterally opening passage 88.1eading to the upper side of said piston. The port 81 is normally closed by a spring pressed check valve 89 so as to permit liquid to flow from the chamber 16 below the piston into the chamber 11 above said piston but preventing the flow of liquid in the opposite direction.

The pump cylinder has an outlet port 99 opening from its upper end and leading through an upright passage 9I, and an offset passage 92 below the bottom of cylinder bore I0 into a discharge passage 93 extending through the lower extension 2! of the pump cylinder. A spring pressed check valve 95 is mounted in one of the passageways just mentioned, as for instance in the passage 93 so as to permit the flow of liquid from the upper chamber 11 of the pump cylinder into the upper end of the ram cylinder I5 but preventing the fiow of liquid in the opposite direction.

The pump mechanism above described operates as follows: upon the up-stroke of the piston I4, the valve 89 is closed and the piston draws liquid into the lower chamber 16 through the valve 85 and port 88, and simultaneously forces the liquid in the upper chamber 11 through the port 98 and check valve 95 into the upper end of the ram cylinder I5. Upon the down stroke, liquid passes through port 81 and check valve 89 into the upper chamber 11, and since the cross sectional area of'the latter chamber is less than that of V the lower chamber I6, the excess liquid is iorced through the port into the ram cylinder. Thus the pump is of the double action type, pumping during both strokes of the piston.

Manually control means are provided for releasing pressure in the upper end of the ram cylinder I5 and returning the liquid into the liquid reservoir 68 when it is desired to lower the jack. Such means includes a knurled control nut 93 threaded in a bore 94 at one side of the bottom plate 66 for operating a valve member 95 herein consisting of a ball, which closes a port 98 communicating with a passage 91 leading to the upper end of the ram cylinder I5. The bore 95 also has a passage 88 leading to the bottom of the reservoir 68.

In the form shown, a spring 95a. is interposed between the valve member 95 and the stem of said control nut, which spring is sufiiciently strong to close the check valve 95 against any pressures normally efiective in the ram cylinder, when the control nut is fully screwed into the bore 94.

When it is desired to retract the ram rod into the ram cylinder for lowering the automobile, or for storing the jack away in its fully telescoped position, the control nut 93 is unscrewed a sufiicient degree to open the valve port 96 and permit the fluid in the upper end of the ram cylinder to return into the reservoir 68. The rate of telescopic movement of the jack can be readily con.-

trolled by regulating the control nut, as desired- In case any excessive pressures are generated in the ram cylinder, as for instance when the ram has reached the lower limit of its movement, the spring 95a engaging ball valve 95 operates automatically as a relief valve to permit the escape of fluid from the ram cylinder into the reservoir 68.

A horizontal disc-like plate 99 is mounted in the reservoir 68 above the flanged rim 66a of the bottom plate 66 and is provided with a plurality of relatively small apertures I88, I88 to forma baflie plate which serves to minimize the foaming of liquid adjacent the relief bore 98 and,

the intake port 82 during the operation of the pump. I also provide a filler plug I8I which is threaded in tap hole I82 in the top plate 61. The

filler plug IOI is normally closed and sealed by a washer I03 so as to confine the operating liquid wholly within the casing 65, but said filling plug may be removed when it is desired to replenish any liquid lost by leakage.

It will be understood further from the foregoing description of the hydraulic system that the hydraulic ram, pump, and supply reservoir are all self-contained so that the jack may be used repeatedly without replenishment of liquid. For proper operation, the reservoir 88 should be made large enough to hold suflicient liquid for filling the ram cylinder when it is in fully extended position as well as all of the operating chambers andpassages of the pump, and in addition, a substantial air space should be provided for expansion above the maximum level of the liquid in the reservoir 68 so that an excessive degree of partial vacuum will not be produced in said reservoir when the ram is in its fully extended position.

Although I have shown and described a certain embodiment of my invention, it will be understood that I do not wish to be limited to the exact construction shown and described, but

75 that various changes and modifications may be iii'adveitiieut departing from-- th spi-i'it and seepe of the mvenuen as dfined in the" appended claiins. V

remim: 1. In a jack, a cylindrieal lifting c'oliiiiinhaving a plurality er afi'niilar gmev s in spaced: mat

tioir thfalong a bumper. catch ihliidirig a suppertmg nut slidably mounted on said coluiiin;

and an adjustable abutment iiiember'for said iiiit comprising asingle' continuous loopedspringmein-ber' selectively engageable in said grooves under tension, and having-iiiaiiuall'y compressi le I terminal portions for releasing said sprin mem berf apdadjusting it to another groove:

2; ma jack; acylindrica'l lifting column new me aplurality of annular'grooves iiispacedire lation therealong, a bumper catch-including a supporting nut slidabl'y mounted on said column,

and an adjustable abutmentmen'iber for said nut comprising a loopedspring; inernber sel'c itively engageablein said groovesunder tension, having manually compressible terminal portions for'iel easing said' looped member at will andadjusting it selectively into another of said an"- nular grooves, and said nut having a shoulder depending from itsunder face for preventingdisplaceinei t of said'loope'd member from engaging positionina proximate groove-While said nut is in supporting; engag'ementviiith said looped memt ier. I v V 3.- Ina jack, a cylindritial' lifting coluiiin having a3 plurality of annular'grooves' insp'aced re'-- lation't-lier'ealong; a" bumper catch including a supporting nut slidably-mouiited nsaid column,

andan adjustalele' abutment" member for saidnu-t' comprising alooped spring; member seleotively-engageable in one-f said grooves under:

tension,- and haVi-hg manually compressible-ter minal portions for releasing saidlooped niein ber at will for adjusting it into another of said annular grooves, and s'a'id'nuthaving a depending" annular shoulder extending partially aroundits' under. face for fitting about and preventing displacement of said looped member from eng-a'g-- ing position in aproximate" groove while said" nutis insupporting engagementwith s'ai'd'ldoped' member.

4. Ina jack, aliftingeolumn, a saddle nutthereon-havin a.cy1indrical upper bearing surface; aatrunnionsti'apxhaving an arched central? portion engaging said bearing surface; and dew pending side portions Witlfi laterally extending pivotal. studs thereon, said; arched"? portion hav-r ing an aperture therethrough prniittirigilirriited;

reciting; movement of said? strap on said; saddle mm antk a} load"; supporting" member: pivota'l ly' mountedon; said studs for r o'cking'movementi on anaxis transverse to the-axis oft rocking: move ment; of said: trunnionstrapson'said saddle nut:

5}. In a: jack, lifting: columh-,-. asaddle nut thereoi i having a1 cylindrical ui rperbearing sure face, aitrunnion strap-having: an arched central portion engaging said bearing surfaceaand'de" pending; side portions with laterally extending pivotalstuds thereon, said arched portion havingv an-aperture therethrough permitting limited;

rocking: movement of said strap on said saddle nutg a loadsupportiiig 'r'henibei pivotally inount ed on: said studsl foirocking movement on an axis: transverse."td' thet-axiswor"rocking movement 7 of said trunnioristrapeoii said saddle nut; and said trunnion strapfalsozhaving retaining lugsiextending-imivardly from opp'osit'side edges "of" said side-portions at opiaos-ite ends of said nut f'o'r liiniting'i axial? movement ofzsaid niit relative tozsaid strap;

6;. In a: jack; a lifting; column, a saddle" nut thereenhavin'g a cylindrical upper-bearing surfacea trunnionvstrapshaving an arched central portion engaging said; bearing surface, and depending side= portions: with. laterally extending 1 pivotal studsithereori;.saidvarched portions having an: aperture: thiethrough perniitting. limited rocking movement of said'strap on 'said saddle nutgtaload supporting'm'ember pivotally mountedon said .studsibrrockingi movement on an axis transverse tO' theYaXiS of rockinamovement of' strap on said saddle nut; and a; load: supporting member pivo'tall y-z, mounted; 0112 said studs for rocking moveiii'nt' o'n anaxis transverse-to the axis of rocking: niovnintaof said trunnion strap onsaid saddleinut.

81in aja'ckga lifting column} a; saddle nut thereon. having; a; cylindrioal upper bearing sur-' face," a'. trunnion strapeonsistingof a: fiat metal pie'e having: an arched central. portion engag ing said bearing surface, and depend'ing 'portions' with; laterally extending; pivotal studs" thereon,

formed'integrally with sa'id strap by punching flanged aperturesiin saidc s-ideegioi tions; said arched portion. having: an; aperture there'through per mittin's; limited w nking-movementof said strap on said saddle nut; and: a lo'ad'" supporting: meme be pivotany? mounted on sam -studs for rocking movementton an axis transverse t6 the-axis of rocking movement of said trunnion strap onsaid saddle nut.

' C. JUER GENS REE-ERENGES' CITED; Tsefonewie refers-dessert of record in the file c'if this patent:

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