US1689145A - Turntable lift - Google Patents

Description

Oct; 23, 1928.

P. J. LUNATI TURNTABLE LIFT Filed Feb. 6. 1926 2 Sheets-Sheet 1 Oct. 23, 1928.

v P. J. LUNATI TURNTABLE LIFT Filed Feb. 6, 1925 2 lSheets-Sheet 2 Patented Oct. 23, 19,28.

UNITED `STATES resins PATENT OFFICE.

PETER J'. LUNATI, 0F MEMPHIS, TENNESSEE.

TURNTABLE Lm'r.

Application -led February G, 1926. Serial No. 86,569.

and of which this application is in part a continuatioii.

One of the objects of myinvention is to provide an improved turntable lift.

Another object is to provide a safer fluid operated lift.

Another object is to provide a lift which is particularly responsive to application of fluid pressure. Another object is to provide a lift readily accommodated with the usual garage and service station equipment. y

Another object is to provide a lift which operates with relatively equal ease in cold weather and in hot weather.

' Another object is to provide a lift which may be raised rapidly but will descend slowly iii thev event of either accidental or intentional release of pressure. 3 Another object is air operated turntable'lift for automobiles..

Another object is to provide a lift-which acts differentially during upward and downward travel.

Another object is to provide a lift which is simple, reliable, and relatively inexpensive to operate and maintain.

to provide a `satisfactory Other objects and advantages ofthe inven tion will become apparent during the course of the following description.-

In the drawings I have shownone embodiment of the invention. In the showing Figure 1 is a central vertical longitudinal sectional view', parts being shown in elevation,

Figure 2 is a plan view, Figure 3 is an enlarged central vertica/l sec- -tional view taken at right angles to Figure 1,

' Figure 4 isa s etion on line 4-4 of Figure 3 Figure 5 is an enlarged section on line 5-5 of Figure 3,

Figure 6 is an section through the differential valve, and, Figure v7 is a detail section through the oil delivery pipe adjacent its upper end.

enlarged central vertical.

VIn general my hydraulic or fluid-pressure operated lift comprises a hollow stationary cylinder, having a closed bottom and open top,

and a movable hollow piston telescopically and rotatably mounted in the cylinder andcarrying the automobile supporting superstructure. The cylinder and piston are partly filled with an incompressible iuid such as o il, While air may be injected into the space in .tl'ie piston above the oil level to effect the raising of the 'piston regardless of the direc- 'tioii the super-structure is turned. While in depressed or raised position the piston and super-structure may be rotated about a vertical axis so that the lift will serve as a turntable. The lift is provided with'differentially acting means which serves automatically to permit the piston to be raised steadily with considerablerapidity but retards the return of the piston in the event the Huid pressure is accidentally or intentionally released.

Il ,eferring to the drawings'the numeral 10 designates a hollow piston having a Asuperstructure supporting casting 11 at its upper end. The casting 11 is provided with a cylindrical portion 12 which snugly fits'the upper end of the piston and is provided with supporting arms 13. The upper end of the piston is closed by a cap 14 secured by bolts 15 to flanges 16 carried by the casting 11. The cap 14 is provided with an opening normally closed by a screw threaded plug 17 for a purpose to be described.

Means are provided for supporting the vehicle by means of the piston described. As shown in Figures 1 and 2, beams indicated as a whole by the numeral 18 are arranged on opposite sides of the casting 11. These beams are provided with parallel central portions 19 riveted or otherwise secured tothe arms 13 whereby they are secured to the casting 11.

The beams are preferably formed o Lbeams and theupper bases of the central portions thereof are rivetedas at 20 to the cap 14.. Each of the beams is provided with an outwardly extending portion 21, as clearly shown in Figure 2, and the outwardly 'extending portions are riveted or otherwise secured as at 22 to vehicle supporting rails 23. These rails are provided with flat bases 24 and upstanding side lianges25 vto provide a channel construction.` "Ihe ends of the rails may be flared outwardly as at 26 to facilitate driving a vehicle upon them. Referring to designates an upper cylinder `section as a Figure 3, the numeral27 whole havin-g a depending sleeve portion 28 snugly fitting the piston as shown. The

upper portion 29 of the upper cylinder section is enlarged and provided at its upper and b lower ends respectively with annular flanges 30 and 31. Packing 32 is arranged within the cylindrical portion 29 and is engaged by the lower end of a gland 33. 'I'he glandy is provided at its upper end with an annular lflange 1u 34 and bolts 35 connect the flanges 30 and 34 to permit the gland to be adjusted to compress the packing 32, as will be understood.

A lower cylinder section 36 surrounds the piston 10 and is spaced therefrom7 as shown.

le The section 36 is threaded at its upper end for reception within a collar 37 having an annular flange 38 at its upper end by means of'- which it may be secured to the flange 31 by ,bolts 39. The cylinder section 36 is pro- 2o vided with a lower head 40 whichl may be provided with an upwardly extending threaded extension 41 adapted to engage within the lower end of the cylinder section. An air conduit 42 is preferably cast in the head 40,

25 as shown in Figure 3 and is provided with an upwardly extending opening 43 arranged axially of the piston and cylinder sections for a purpose to be described.

Air under pressure is delivered to the con.- '40 duit 42 through a pipe 44. This ipe`is connected by a T 45 with a. pair o i valves 46 and 47 (see Figure 1); The valve 46 is connected by a pipe 48 to a suitable source of compressed air, while the opposite end of the 35 valve 47 communicates with the'atmosphere.

The lower end of the piston 10 is substantially closedlby a head 49.. This head may be provided with a cylindrical portion 50 which is internally threaded to receive the threaded io lower end of the piston, and above the cylindrical portion 50 the piston head isprovided with an outstanding annular flange 51 adapted to contact with and slide along the walls of the cylinder section 36 to form a guide for L5 the piston. The head 49 is provided centrally thereof with a relatively large opening 52 and may be provided with a downwardly extending abutment 53 adapted to rest upon-the cylinder head 40 to support the piston and i i0 the elements carried thereby.

An air pipe 54 extends upwardl through the piston and cylinders axially t ereof, as shown., The lower end of the air pipe is threaded for reception within the opening 43,

L3 while the upper end of the pipe is open as shown in Figure 3. A spider 55 is provided near the upper end of the air pipe. This spider has a central hub 56 surrounding and ,secured to the air pipe and the arms of the 30 `spiderl are adapted to contact Iwith the inner lwalls of the piston to slide thereagainst. In the operation of the apparatus, oil contained within the piston and cylinder is adapted to How back and forth between the interiors thereof, and means in the form of a difvpiston head 49 and is of a length suliicient to extend a substantial distance above the piston head. As clearly shown in Figure 6, the opening 52 is materially larger in diameter than the cylindrical portion of the thimble, for a purpose to be described. The upper end of the cylindrical portion 59 is taperedas at 60 and is provided with cutj away pdr-tions 61 providing lips 62. An upper flange 63 surrounds the upper end of the cylindrical portion 69 and isv provided with a plurality of openings 64. In` assembling the device the upper flange 63 is placed in the position shown in Figure 6 of the drawings, whereupon the fingers 62 may be bent outwardly to the position illustrated in Figure 3 whereby the upper flange may be secured in position. It will be apparent that the internal diameter of the cylindrical portion 59 is slightly larger than the external diameter of the pipe 54 to provide a restricted space through which oilis adapted to flow when the piston is raised and lowered. It will be apparent that communication is afforded at all times between the piston and the interior of the lower cylinder section through the. space between the air pipe 54 and the thimble 57, and when the latter is in its downward position as illustrated in Figure 3, communication also is afforded through the openings 64. Due to the arrangement of the yflanges of the thimble, the latter is obviously adapted to partake of limited vertical movement and also is adapted to shift its position transversely of the axis of the pipe 54 for a purpose tobe described. 'I'hus the hollow stationary cylinder and hollowA movable piston form a twocompartment chamber which may be partly filled with a liquid so as to leave a pressure space for the introduction of a gas under pressure above the liquid level. The differential valve heretofore described controls the amount of communication between the chamber compartments and automatically governs the upward and downward travel of the piston as will be hereinafter explained.

In service the chamber formed by the cylinder and piston, preferably substantially filled with oil when the piston is in its llow- 'ered position, and the oil employed is preferably of a character suitable for lubricating the springs and other parts of the motorvehicle. In practice with the piston lowered, oil is preferably poured into the pistonjimtil the upper level of `v`the oil reaches Vth'ef'point indicated by the dotted Brief-'165 'in Figure 3. Oil is preferably replenisliegyvhe'n thel level reaches the point indicated by the dotted line 66. As previously stated the oil is preferably of a character adapted for lubricating different parts of the vehicle, and means is providedfor@ spraying the oil on the parts which it is desired to lubricate. As shown,

an oil supply pipe 67 is arranged in the upper en d of the piston. This pipe has an enlarged screw threaded portion 68 extending through a threaded opening in the'cap 14. The oil supply pipe carries any oil receptacle 69 at its lower end. This receptacle is clearly shown in Figures 3 and 4, being preferably arcuate in shape. Within the receptacle 69 the supply pipe is provided with openings 70 to permit oil'to flow from the receptacle into the interior of the pipe. A flexible hose 71 communicates with the upper end of the oil supply pipe, and a manually controlled spraying nozzle 72 is connected to the outer end of the flexible hose. In order that oil may be atomized at the nozzle 72, the pipe 67 is provided above the level of the oil within the piston with openings 7 3, as shown in detail in Figure 7.

When the device is installed for operation, the lower portion thereof is preferably embedded in a concrete foundation or well 74- as indicated in Figure l. This foundation is provided with an enlarged recess 75 to provide access to the bolts 35 and 39, and to the packing gland, and above the recess 75 the foundation is provided with a pit 76 to receive the rails 18. The top 77 of the foundation is arranged flush with the surface of the surromiding ground, substantially in contact with the lower faces of the supporting rails to permit a vehicle to be driven upon the rails, as will be obvious.

The operation of the apparatus is as follows: Y Oil is supplied to-the chamber within the cylinder piston by removing the plug 17 and inserting a funnel or supply hose throughl the .opening in which the plug normally is arranged. Oil is supplied to the chamber until it reaches the level indicated by fthe dotted line 65. The plug is -then replaced and the apparatus is ready for operation. When Ia -vehicle is in position on the 'rails and it is desired to elevate the piston, the valve 47 .is closed and the valve 46 opened to supply compressed air to the interior of the piston. This air will flow through lthe pipe 44 and conduit 42 and since the latter communicates with the pipe 54, it will be apparent that air under pressure wlll be supplied to the pist'gn above the level of the oil therein'. The air under pressure el evates the piston, and as the latter rises, it will be apparent that oil must flow from the piston compartment to the cylinder compartment. This How of oil 'ispermitted by the differential valve through the 'space between the pipe 54 and the cylindrical portion 59 of the thimble. Obviously when the piston is being lifted the thimble will assume the position shown in Figure 3 of the drawings whereby oil also may flow through the openings 64. Thus relatively unobstructed flow of oil is'permitted on the upward travel of the piston'and, in consey quence, the piston may be raised rapidly, the iow of oil through the valve, however, serving to render the movement smooth and uniform. Upward movement of the piston will be limited by contact between the flange 51 and the lower end ofthe upper cylinder section,- as will be obvious. When this upper position is reached the valve 46 may be closed. As the piston rises, it will be apparent that the level of theoil therein will drop with respect to the piston until it reaches a position a material'distance below the receptacle 69. Since the receptacle 69 is arranged beneath the oil when the piston is lowered, it will be apparent that it will remain full of oil when the piston is elevated. The operator may then spray the springs or other parts of the vehicle by operating the nozzle 72. The pressure of the air within the piston causes oil to be forced into the pipe 67 through the openings 70, andvatomization of the oil at the nozzle is effected by` supplying air under pressure directly to the interior of the pipe 67 through the openings 73. In practice, the receptacle 69 is sufficiently large to hold an ample supply of lubricating oil. When it is desired to lower the device, the Valve 46 remains closed and the valve 47 is opened, thus releasin .the air in the piston to the atmosphere. s soon as the piston starts its downward movement, a pressure differential is created between the interior of the piston and the interior of the lower cylinder section which causes the thimble57 of the dif? ferential valve to move upwardly whereby the lower flange thereof contacts with the lower face of the piston head 49. Thus the only communication afforded between the piston and cylinder will be through the space lbetween the pipe 54 and the interior of the thimble, and since this space is very limited the downward movement of the piston will be retarded. Thus it will beapparent that the piston is prevented from dropping rapidly, thereby eliminating danger of inJury to any workman who Vmay be Working beneath the vehicle.q The arrangement ofthe thimble in the position shown in Figure 3, however, permits the piston to be rapidly raised, depending. upon the pressure of the air at the source.v As oil is used for lubricating purposes by operation of the nozzle 72, it will be apparent that the level of the oil will gradually fall. When this level reaches the position Indicated by the dotted line 66 it preferably is freplenished, oil being supplied 'until the level again is broughtvup to the point indicated by the dotted line 65. The volume of oil normally represented by A the space between the dotted lines 65 and 66 has been found in practice to be suiicient to lubricate about one hundred vehicles, and consequently it will be apparent that it is nlelcessary to replenish the oil only occasiona y.

The piston 10 is adapted to rotate in the upper cylinder section, as well as to reciprocate, and accordingly the apparatus is adapted to be employed as a turn table. In some cases, the apparatus will be installed inservice stations or the like in a corner, and under such conditions the vehicle may beA driven forwardly upon the rails, and after the lubricating or other work is completed, the piston may be rotated through an arc of 180 to permit the vehicle to be moved forwardly off the rails.

In the manufacture of the apparatus it has been found that the ipe 54 is not always accurately centered in t e piston and cylinder, and accordingly the thimble 57 is adapted to move laterally within reasonable limits to accommodate itself to the position of the pipe 54. 'The air pipe is anchored only at -its lower end, as will be apparent, and accordingly the spider 55 isprovided for maintaining the upper end of the air pipe in proper position. The arms of the spider are.

adapted to slide against the inner walls of the piston when the latter is raised and lowered, and will retain the upper end ofthe air pipe in its roper axial position at all times. The spi er is arranged directly be neath the oil rece tacle 69 when the piston is in its lower, osition so that there will be no interference etweenthese elements. It will be apparent that the oil receptacle is adapted l to revolve about the air pipe 59 when the ap-A paratus is employed as a turn table.

As previously pointed out, the oil in the piston 10 should be replenished when the level of the oil drops below the point indicated by the line 66. When a level below this pointv is reached, obviously the receptacle 69 will not be'iilled with oil. it will be noted that under such conditions Y the spraying apparatus yis adapted to serve as a signal to the operator that the oil in the iston should be replenished. When therey 1s no il in the receptacle 69, the opening of the valve 72 merel `results in projecting compressed air from t e nozzle instead of a spray of oil. In actual practice, the volume represented between the lines and 66 is suiicient to lubricate aboutl one hundred vehicles and accordin 1y it is not often necessary toreplenish t e oil in the piston'.

It is to be understood that the form of the invention herewith shown and describedis to be taken as a preferred example 4of the same and that various changes in the'shape, size and arrangement of parts may be resorted to without departing from the sp1r1t of Therefore,l

the invention or the scope of the subjoined claims.v

As a result of the various features hereinbefore set forth my lift possesses a number of im ortant advantages among which are the fo lowing: The piston may be elevated, held under air pressure at any elevation and lowered, irrespective of the direction the super-structure is turned. By using air as the pressure agent the "lift is particularly responsive to the application and removal of ressure because the ai'r is without mass and 1s instantly subject to control; furthermore,v

because kthe air is practically unaffected by temperature changes, it is as mobile in winter as in slimmer and consequently the power required to apply the pressure is always substantially constant. Another advantage of the use of air-is that the lifting equipment may be operated from the same source Vthat is used to inflate tires and do the other air pressure work about a garage or service sta'- tion. The oil serves to fill a considerable part of the chamber and to raise vthe relatively stationary pressure surface up toward the head of the movable piston. Thus the` materially the hazard of accidents to persons and property, although, by the use of the differential valve, this .advantage 'may be obtained without materially retarding the action upon the raising operation.

I claim: 1. Apparatus of the character described comprismg a cylinder, a piston mounted to reciprocate vertically therein, vehicle supporting means mounted on the upper end of said piston, a pipe'for introducing Huid pressure into the interior of said cylinder through the bottom thereof to lift said piston, and automatic means associated with the pipe for retarding downward movement of I ,sa1d lease to permit substantially unretarded upward movement of said iston.

(piston when the luid pressureis rev said last named means being adapted `2'. Apparatus o the 'character described comprising a cylinder, a piston mounted to reciprocate vertically therein, vehicle supporting means mounted on the upper end of said piston, a pipe for introducing fluid pressure into the. interior of said piston through the lower end thereof to lift said piston, and

a member carried by said piston and movable to one position to retard downward movement thereof, said member being movable to another position to permit substantially unretarded movement of said piston upwardly.

3. Apparatus of/ the character described comprising a cylinder, a piston mounted to land provided in its lower end with an opening communicating with said cylinder, vehicle supporting means carried by the upper end of said piston, a vertical pipe secured at its lower end to said cylinder and projecting upwardly into said piston lthrough the opening therein, means for supplying pressure to the lower end of saidpipe, and means carried by the lower end o said piston f or restricting communication between said pis` ton and said cylinder when said piston 1s moving downwardly and for permitting substantially unrestricted passage of lluid between said piston and said cylinder when said piston is moving upwardly. A

5. Apparatus o the character described comprising a vertical cylinder, a hollow piston mounted to reciprocate in said cylinder and provided with a head arranged above said cylinder, said piston being provided in its bottom portion with an opening communicating with the interior of said cylinder, said piston and said cylinder being adapted to contain a liquid, vehicle sup orting means carried by the upper end o said piston, means for introducing air under pressure into said piston above the level of the liquid therein, a 'pipe having'its lower end proJecting into said piston through the head thereof,

^ an open topped receptacle carried by said i with c aim pipe beneath the level of the liquid in said piston when the latter is in lower position,

said receptacle communicating with said pipe,

and a valve arranged in saidpipe above the head of said piston. Y'

6. A paratus constructed in accordance 5 wherein said pipe isp vided with a relatively small opening arranged above the level of the liquid in said'piston when the latter is in lower position.

7. Apparatus of the character described comprising a vertical cylinder, a hollowpiston mounted to reciprocate in said fcylinder and provided with a head arranged there- 'piston mounted to reciprocate in the cylinder,

mounted stationary cylinder, a hollow piston through the cylinder and the lower end of above, said piston being provided in its bottom portion with an opening communicating with the interiorr of said cylinder, said piston and said cylinder Vbeing adapted to contain a liquid, vehicle supporting means carried by the upper end of said piston, means for introducing air under pressure into said piston above the level of the liquid therein, a pipe projecting through the head of said piston, the lower end of said pipe projecting beneath the level ofthe oil in said piston and being provided with an opening, said pipe'being further provided with an opening communicating with the interior of said piston above the level of the oil therein, and a valve arranged' in said pipe above the head of said piston.

8. A turntable lift comprising a stationary closed-bottom cylinder, a hollow closed-top the cylinder and pistonforming a pressure chamber, a liquid partly' filling the chamber to form a fluid pressure space between the top of the piston and the level of the liquid,

a connection extending through the lower end 9" of the piston and the liquid for communicatinfr fluid pressure to said space, automatic dierentially acting means to retard the return of the piston upon release ofpressure and to permit the relatively unretarded action of the piston upon application of pressure, and a vehicle supporting super-structure carried by the piston.

9. A turntable lift comprising a vertically having one end closed and the other end open mounted to reciprocate in the cylinder, the piston and cylinder forming a chamber adapted to be partly filled with a liquid, a liuid pressure connection communicating the piston with the chamber above the liquid therein whereby fluid under pressure may be admitted to the ychamber to liftthe piston, a diiferentially acting valve operating automatically upon release of pressure to retard the return of the piston, and a vehicle supporting super-structure carried by the piston. 10. A hydraulic lift comprising a piston, a vehicle supporting super-structure carried by the piston, a cylinder for telescopically receiving the piston, an external source of fluid pressure, a pipe extending upwardly through the lower end of the piston for communicating the fluid pressure thereto to lift the same, and means acting automatically upon release of pressure to retard the return of the piston. 11. A hydraulic lift comprising a cylinder, a hollow piston mounted to reciprocate in the cylinder and forming therewith a closed chamber adapted to be partly filled with a liquid, pipe connections vextending through the cylinder below the bottom of the piston for applying pressure Huid between the piston and the surface of the liquid to elfect the 13o lifting of the piston, means associated with the pipe and acting automatically and differentially upon application and release of to be partly filled with a liquid, a pipe passing through the lower end of the piston andl the liquid to connect an external source oi. fluid pressure to the space in the chamber between the piston and the surface of the liquid, a differential valve automatically controlling the opening in the bottom of the piston to regulate the flow of liquid therethrough under conditionsbf fluid pressure and release of pressure, and a vehicle supporting superstructure carried'by the' piston. v

13. A turntable lift comprising a hollow piston closed adjacent the top and open at the bottom, a vertical stationary cylinder fortelescopically receiving the piston and forming therewith a two-compartment chamber, one compartment being in the piston and the other in the cylinder, a liquid partly lilling the chamber and movable from one compartment into the other as the piston rises and falls, a connection for aifording couimunication between an external source of fluid pressure and the chamber above the liquid level therein whereby pressure'may be built up between the liquid and the piston to raise the piston, said connection including a pipe projecting upwardly from the cylinder through the open end ofthe piston to a point above the surface'of'the liquid, a valve 'in -the open end of the dpiston, the valve acting 1 automatically and lierentially .to permit relatively freeilow of liquid lfrein the piston compartment Yof the cylinder compartment as the piston rises and retarding the flow of liquid Vfrom the cylinder compartment to the piston compartment as the piston falls, and a vehicle supporting super-structure carried by the piston.

14. A hydraulic lift comprising a cylinder, a hollow piston .adapted to reciprocate and turn in said cylinder, said piston and Said cylinder beingadapted to contain a liquid, said piston being provided with a restricted opening communicating with said cylinder below the -level of the liquid therein, and means locatedpon the axis` of the piston for introducing above the "level of the liquid therein and in any turned position thereof.

15. A hydraulic lift comprising a. cylin' der, aV hollow piston adapted to reciprocate Y pressure fluid into said piston fl in said cylinder,

piston being provided in its lower end with a restricted opening communicating with said cylinder, a pipe extending upwardly through said piston and said cylin-V der being adapted to'contain a liquid, said and spaced from said restricted opening and having its upper end arranged above'the level of the liquid in said piston, and means for supplying pressure fluid to the lower end of said pipe.

16. A hydraulic lift comprising a cylinder, a hollow piston adapted to reciprocate in said cylinder, said piston and said c linder being adapted to contain a liquid,-sai piston being' provided in its lower end with a restricted opening, said cylinder being provided with an air passage, a pipe carried by said cylinder and communicating at its lower end with said air passage, said pipe extending upwardly through and spaced from the walls oi' said restricted opening and having its upper end arranged'above the level of the'li'quid in said piston, and means for supplying comtion, said cap b eing provided with an axial opening, an axial air pipe carried by said lower cylinder section and projecting upwardly through said opening to a point above the level of the liquid in said piston, and means for introducing pressure fluid into the lower end ofsaid pipe, said cap being adapted to engage the lower end of said upper cylinder section to limit the upward movement lof said piston.

18. A turntable lift comprising an auto- 'ou upper cylinder mobile supporting superstructure, a closedv bottom cylinder, a hollow piston mounted to.

move longitudinally in the cylinder and turn unrestifictedly about the axis thereof and carrying the superstructure, .the cylinder and piston forming a chamber for a liquid andv l the piston being closed to form a fluid pressure space above the liquid, and iiuid presl sure connections communicating with 'the fluid pressure space within the piston above the liquid level in any turned position of the piston.

19. A 'turntable lift comprisinga hollow piston carrying a vehicle support, a cylinder for telescopically receiving the piston and permitting unrestricted rotation piston and cylinder forming a liquid and uid pressure chamber, a liquid partly iilling Y the chamber, and .a sourcevof fluid pressure communicating with the chamber Vabove the liquid levelduring all positions of the piston. 20. A turntable lift comprising a vertical thereof, the ,Y

iso

Y Y x i -Y-`stationary cylinder adapted to be embedded the cylindenand have unrestricted rotation on the axis thereof, means in the piston having a pressure surface substantially stationary relative to the cylinder, an external source of fluid pressure, a pipe connection extending upwardly through the lower end of the piston for lntroducing fluid from the external source into the piston between the closed top thereof and the stationary pressure means regardless of the vertical and rotational position of the piston, and a vehicle supporting superstructure carried by the piston.

21. A turntable lift comprising a cylinder having a closed bottom, a hollow movable piston with a closed end andan open end mounted telescopically and rotatably in the cylinder, the open end. being within the cylinder so that the piston and cylinder form a closed chamber, a liquid partly filling the chamber to leave a pressure space within the piston between its closed end and the surface of the liquid, a fluid pressure pipe secured to the bottom of the cylinderiand extending Vthrou h .the /liuid into the pressure'space where y a flui under pressure may be injected 1`nto the pressure spaceto elevate the piston, and a vehicle supporting superstructure carried by the piston.

22. A turntable lift comprising a vehicle supporting superstructure, a cylinder, a'

superstructure-carrying piston telescopically arranged in the cylinder and adapted for unrestricted rotation about the axis thereof, a fluid connection through which pressure is applied from below the piston to lift the same and through which pressure is released to effect lowerin of the piston in any position to which the piston is turned, a manually controlled valve in the fluid connection for effecting theapplication and release of fluid pressure, and means cooperating with the fluid connection and functioning automatically and free from manual control upon release of fluid pressure to retard the return of the piston.

In testimony whereof I aiix my signature.

PETER J. LUNATI.

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