US2074148A - Multipost lift - Google Patents

Description

l. VON K. HOTT MULTIPosT LIFT March 16, ma?.

4 Sheets-Sheet 2 March 1s, 11937.

l. voml K. Ho'r'r A 2,074,148-

MULTIPOST LIFT Filed Aug. 15, 1935 4 She`ets-Sheet 3 h/f--f A TTD/WBK Malik 16 1937. l. voN K. HOTT Filed Aug. 15, 1935 Patented Mar. 16, 1937 PATENT Fris.

MULTIPOST LIFT poration of Ohio Application August 15, 1935, SerialNo. 36,377

2s claims. (01.254-93) This invention relates to a multi-post lift and is designed primarily for elevating a motor driven vehicle to permit access to be had to the underneath parts thereof for servicing the same. Some motor vehicles are substantially heavier at one end than at the other, this being particularly true of busses and trucks and when such a vehicle is placed on a multi-post lift, that is, a lift having two or more lifting elements, the weight of lO'the load will'be unequally distributed between the lifting `elements with the result that one or more of the lifting elements will move at a greater speed than the other element or 'elements and the vehicle supporting structure will be l5 tilted, sometimes to adangerous extent.

One object of the invention is to provide a `multi-post lift with simple and efficient means for `maintaining the load supporting structure in a substantially horizontal position, or subgoistantially at a predetermined angle to the hori- Zonta-l, during, the raising and lowering of the load regardless of the distribution of the weight of the load.

A further object of the invention is to provide `sucha lift with means for positively preventing any appreciable tilting of the load supporting structure l A further object of the invention is to provide a multi-post lift with means for causing the lifting elements to move `substantially in unison and for causing the distribution of the power to the several lifting elements in proportion to the loads thereon.

A further object of the inventionis to provide 'such a liftin which the excess power delivered to a lifting element having a relatively light-load will be transferred to a lifting element having a heavier load.

Other objects of the'invention will appear as the mechanism is described in detail.

In the accompanying drawings Fig. 1 is a plan view of an automobile lift of the free wheel type embodying my invention and partly broken away; Fig. 2 is a side elevation of such'a lift; Fig. 3 is a vertical sectional view taken through the lifting element to which fluid is initially delivered and through a portion of one of the cross-members;

i et is a vertical section of one of the other lifting elements, with a portion of the cross membei' in elevation; Fig. V5 isa section'taken on the line of Fig 3; Fig. 6 is a'section taken on the line -iiof Fig. 3; Fig. 'l is a section taken on the line 'i-l of Fig. 3, showing a portion of rr the cross, member in plan; Fig. 8 is a section "taken onthe line 8 8 of Fig. 3; Fig. 9 is a lift.

section-taken on thelineS-lof Fig. 8; Fig. 10

is a section takenon the line lil-ii] of Fig. 8; Fig. 11 is a detail view ofthe cable clamp;,=Fig.

.l2 is a diagrammatic view showing the uid connections betweentheseveral lifting elements -5 jFig..13 is adiagrammatio View showing thearrangement of the controlling cable; Fig. v14 is `a plan `view of a portion `of a lift.of the runway :type showinglthe invention applied thereto; Fig.

l5 is a section "taken on the line |,5--I5 of Fig. `10 lll; Fig. "16 is a section taken fon theline IB--Ii of Fig. .14; Fig..1'7,is atransverse is'ectiontaken on the line l'l-H of Fig. 14; and Fig. `18is;a side elevation of "a portionof a lift of therunway type.' Y 15 In theseldrawings Lhave illustrated one .em-

bodiment ofimyinvention, togetherwith'a minor `modification thereof, and have shown the same as applied to a four. post fluid operated autofmobilelift but "it will Vbe understood that this `particular embodimenthas been chosen for'the purposes of illustrationonly, that the invention Amay take various forms and imay be appliedto `lifts of various `kinds comprising two or more lifting elements.

In the four post lift-:here illustrated the lifting elements, or posts, are arranged in pairs near the respectiveends of thellift, the lifting elements f2!) and 2| being arranged at one end of the lift 'load supporting structure as a whole. 0

4 The mechanism'as a whole is mounted above `the supporting vsurface so that no excavation of any kind is necessary for the installation of the The lifting elements maybe of any suitable character but preferably they are fluid oper- 45 ated and, as here shown, each lifting element comprises a piston 28 which extends upwardly from a base 29 which is adapted to be mounted on and, if desired, rigidly secured to a suitable supporting surface, such as the licor or pavement of an automobile service station. Mounted on the piston 28 for vertical movement is a cylinder 30 which is closed at its upper end, as shown at 3|, and is provided near its lower end with suitable `packing 32 to prevent the escape `of fluid between 55 the cylinder and the piston. The interior diameter of the cylinder is somewhat greater than the exterior diameter of the piston to provide a space through which the fluid may flow from one end of the cylinder to the other. Arranged within the cylinder is a stop 33 adapted to engage a cooperating stop 34 at the upper end of the piston to limit the movement of the cylinder with relation to the piston. Stops 33 and 34 are in the form of short segments, the lower segments 33 being spaced apart a distance greater than the width of the segments 34 so that by imparting a partial rotation to the cylinder the latter may be released and removed from the piston.

The cross bars 24 and 25 are connected with the movable members or cylinders of the respective lifting elements and may be secured thereto in any suitable manner. In the arrangement here shown a bracket 35 is rigidly secured to each cylinder and extends laterally and downwardly therefrom, the inner end 36 of the bracket being shaped to fit about the end of the corresponding cross bar, to which it is rigidly secured, as by welding. The bracket 35 may be attached to the cylinder in various ways and, in the construction shown, the outer portion of the bracket is curved to fit about the adjacent side of the cylinder and is provided on each side with lugs 31 and 38 arranged one above the other. The lugs 31 are bolted or otherwise secured to cooperating lugs 40 carried by a band 4l which extends about the cylinder and is embraced by the bracket 35. The upper lugs 38 of the bracket are secured by bolts, or otherwise, to cooperating lugs 42 which are welded ldirectly to the cylinder. The cross members 24 and 25 may be of any suitable character but they must have sufficient strength to jointly support the load on the lift and inasmuch as the vehicle must be driven across one of these supporting members in order to place it in position above the rails 26 and 21 and is usually driven across the other supporting member in removing the same from the lift it is desirable that the cross members should be of a low construction and supported on or close to the supporting surface when the lift is in its lowered position. It is also desirable that the inner and outer walls of these cross members should be sloped to facilitate the movement of the wheels over the same. In the present construction each cross member is substantially semi-circular in cross section, see Fig. 8, which not only provides it with the sloping surfaces but also provides Within the same a channel which is utilized for a purpose which will be hereinafter explained. If desired, the cross member may be reinforced by a plate 43 arranged within the same and welded or otherwise secured to the respective side walls.

The longitudinal members 26 and 21 may be secured to the cross members in any suitable manner but in the construction here shown Ythe longitudinal members are in the form of H-bars and I have rigidly mounted brackets 44 on the cross bars, the brackets being preferably welded.

Each bracket has two projections 45 provided at their upper and lower edges with flanges 46 and spaced apart a distance slightly greater than the thickness of the web of the H-bar so that the projections may be inserted in the respective channels of the H-bar as shown in Fig. 9. The vertical portion of each projection of the bracket is slotted longitudinally, as shown at 41, and a bolt 48 is passed through the slotted projections and through the web of the H-bar. This bolt has a tapered head 49 which engages in the slot of one projection and carries a tapered washer 50 which engages in the slot of the other projection, the slots being preferably countersunk to receive the head and Washer. Thus by tightening down the bolt the two projections are not only clamped tightly against the web of the H-bar but they are expanded to force the flanges 46 into tight engagement with the upper and lower flanges of the H-bar.

Fluid under pressure may be delivered to the several lifting elements in any suitable manner but I prefer to deliver all the fluid initially to one lifting element and to distribute the same from that lifting element to the other lifting elements. Preferably a single supply pipe 5I leads from a suitable source of supply of fluid under pressure, such as a reservoir |52, in which oil is stored under air pressure, to one of the lifting elements, in the present instance the element 20. This pipe extends upwardly through the piston and discharges into the cylinder above the head of the piston. The lifting element 2U is connected with each of the other lifting elements to provide for the distribution of the uid and, in the arrangement shown, cross conduits 52 connect the cylinders of the respective pairs of lifting elements and a longitudinal conduit 53 connects the two cross conduits 52. In this manner the cylinder of each lifting element is connected with the cylinder of each other lifting element'. The conduits'52 are shown as termi nating in Y-fittings 54 which extend partially about the respective cylinders and communicate therewith at separated points. When cil or other fluid is rst delivered to the initial cyl inder, of lift 26, it will flow downwardly between the cylinder and the piston and through the conduits 52 and 53 to the other cylinders and when all the cylinders have been filled the delivery of additional uid will exert substantially equal pressure on the several cylinders and will tend to move the same upwardly in unison. After the cylinders have been once lled with fluid they will remain filled between successive operations and fluid admitted to the initial cylinder will immediately exert pressure on all the cylinders. If the load on one lifting element is lighter than the load on another lifting element the lifting element having the lighter load will tend to move at a greater speed than the lifting element having the heavier load, thus causing the tilting of the load supporting structure, and I have therefore provided means for controlling the relative movement of the lifting elements and for causing the fluid to be distributed in proportion to the load on the several lifting elements.

For the purpose of so controlling the relative movements of the lifting elements and the distribution of power I have provided an auxiliary stop device which is connected with the several lifting elements and the movement of which is so controlled as to cause said lifting elements to move in substantial unison. This stop1 device preferably consists of one or more flexible members which may be of any suitable character and it is herein referred to as a cable. In the preferred construction a single endless cable is connected with each lifting element and its longitudinal movement is so controlled as to cause the lifting elements to move in substantial unison. In the construction shown each lifting element has secured thereto, near its upper end, a guide, such as a pulley 55, and has secured thereto, near its lower end, two guides, such as pulleys 55 and 51, the lower guides being arranged guide. Other guides 8l Lare mounted on :the

`cross members :24 and 251between the fendszof the same. A cable P58 is .threaded .about the .several guides onlthe lifting elements andtoni` the buckle 59. This arrangement ofthe `cablenprovides the same, adjacent to each lifting element, with 4an upwardly extendingjportionlwhich is looped about the upper guide VVV55. The two sides of the looped portion of .thecable extend Yabout the respective lower guides .56 andz1'and the intermediaterportions of the cableare carried through the channeled.'crosslbarsfi24 and and the channeled longitudinal members 26 and 2l' to the lower guides of the otherlifting elements. One side of each looped portion of the cable is held against movement, as byanchoring the same to an upright stationary standard Sil which, as shownin-Fig 3, is mounted 'on the base '29 which carries the piston 2B. In the present arrangement, the anchoring means comprises an arm (il `rigidly secured to the standard @d and having a hook-shaped portion 62 to receive the cable. A clamping member 63 is connected with the arm `(il by means of a screw 5.64 which forces the same into firm engagement with the cable. 'As the lifting elements move upwardly in unison the lowerguideswill approach the respective anchors :6| fand the upper guides will move away from those anchors, thus extending the loopsv of the cable abovelthe respective anchors. This upwardextension'of the loop is permitted by the feedingfof thelower portion of the anchored side of each cable loopto the unanchored side of another cableloop and therefore one lifting element cannot move `with a speed greater thanthe speed `at which the other lifting element moves. For example, when'the lifting elements 2l `and-23tare moving upwardly that portion of the anchored side of the .cable loop `of lifting element .23 `which passes `'about the guide 56 willbe fed-about the .guides on the cross members and about thelower guide 51 4of the lifting element 2| so astosupply additional cable to the loop of lifting elementzZI and :permit the upper guide of that Aelement to move upwardly, but obviously the lifting element .2| can move no fasterthamthe cableis'suppliedto it from the lifting elementx23 andtherefore the two lifting elements will move atthe same speed. If lifting element 2| carries a lighter load than the lifting elementl'it .willtendto move at a greater speed thanthe'liftingelementwil, dueto `the'fact that fluid powerisnormally supplied :to

the two lifting elements in equal amounts, but the cable will prevent the lifting element `12| moving at greater speed than the lifting element 2:3 and the excess fluid which is delivered to fthe lifting element 2l will `be transferred through the conduits 52 and 53to the lifting element 23, thereby supplyingthat lifting element with additional power to elevate its heavierload.

The cable will operatein Va similar imanner to cause the several lifting elements'tomovefdownwardly substantially in unison when the load is being lowered. Thelowerng Vof the lifting elements is effected by the vweight `:of the load-s thereon and the heavier load on'theLlifting element 23, in` the example ,above used, will tend :loop of i lifting element 23.

"to `cause the' same to :move .downwardly :atta greater speed than the lifting element 12| :which Vcarries Vthe lighter load, but'rduring this downwardmcvement the cable 58 is moving inea :di-

rection yreverse to that above described :and fit .is .fed zfromthe loop portion- `of the lifting zelement 2l to the anchored portion of theic'able loop of lifting element 23. Thelower-guides .of .the lifting element 23 are supportedbyithe cable `and therefore that' lifting element .can move only asfast as the cable isfedfrom `thelifting element .2! `to `the anchoredportion of 'the :cable In this manner the movement `of ,each lifting element is controlled wby the movements `of the other lifting elements Vand when :the cable is properly adjusted none of thelifting elements can have movement .with

relation to the others. vAny:relative:movement of the lifting elements which may lresult f from slackin the ,cableor otherwise, will be so slight that `it will cause `no substantialtilting Aof vthe 3 load. supporting structure. which the load supporting structureis normally In an installationdn inclinedit will be retained at thepre'determined angle throughout .the operation of the lift.

`Whenthe invention is applied to lalift of :the runway type, that is, toalift 'which is-provided with tracks or runwaysonto which `the wheels `of lthe' vehicle are driven, the only change nec- `essaryis supplying theload supporting structure with runways instead` of `with axle supporting rails. YIf desired, the longitudinal -members .26 andi-21 may be retained andatlie runways mounted on `the cross members 24 and 5.25. i-However,

`inthe-interest.ofeconomy and'to veliminate unnecessary obstructions beneath thetvehicleIzpre- .fer that .the runways should themselves constitute `longitudinal `connecting members, thereby .Ienabling the connecting members 26 `and 21 to abey dispensed with. .The loadsupp-orting `struc-- Vtur-e is, of course, provided withtwo runways,

one near `each side'thereof, and in I-ligs.` 14 and 1'8 -I have shown only one of the two' runways.

fthereillustrated the runway 65 is supported at 'its respective ends `on the crossi members .24 and S125 `and it 'is `provided with alongitudinal rein-v forcing bar 66, secured at its lower side, which isrrigidly secured at its respective ends to brack- The reinforcing member .66, is here .vides a channel toreceive theflongitudinal stretch yof the cable58-and thelongitudinal conduit 153. "Usually `the runwayis'provided at itsrespective Aendswith 'rampsll to facilitate the movement of Vthe vehicle onto the same.

While I have shown and described one einbodirnent of my invention Iwish it to be understood that I do not desire to be limited to the 4:details.thereof as various modifications may oc- :cur'toraperson skilled in the art.

V-lIaving'now fully vdescribed my invention, what .I claim asnew and desire to secure by Lette-rs Patent is:

L1. Ina multi-post lift comprising at .leasttwo lifting elements spaced one from the other,v a load supporting structure carriedby said `lifting ielements, and; meansfor supplying-zpower' to `said :lifting elements, a devicetfor :preventingthefrelative movement of said lifting elements including controlling means having parts connected with the respective lifting elements for bodily movement with relation thereto, and means sup- 5 ported independently of said lifting elements and cooperating therewith to control the movement of said controlling means with relation to said lifting elements.

2. In a multi-post lift comprising at least two l0 lifting elements spaced one from the other, a load supporting structure carried by said lifting elements, and means for supplying power to said lifting elements, flexible means connected with said two lifting elements for longitudinal movement with relation thereto and controlled in accordance with the loads on the respective lifting elements to prevent one lifting element from moving a greater distance than the other lifting element moves.

3. In a multi-post lift comprising at least two lifting elements spaced one from the other, a load supporting structure carried by said lifting elements, and means for supplying power to said lifting elements, flexible means connected with said two lifting elements for longitudinal movement with relation thereto and controlled in accordance with the loads on the respective lifting elements to prevent a lifting element having a lighter load from moving a greater distance than a lifting element having a heavier load and to cause excess power supplied to the lifting element having the lighter load to be diverted to the lifting element having the heavier load.

4. In a multi-post lift comprising at least two lifting elements spaced one from the other, a load supporting structure carried by said lifting elements, and means for supplying power to said lifting elements, a cable extending between said two lifting elements, means adjacent to each lifting element for anchoring said cable to a stationary part, and guides connected with said lifting elements for movement therewith and engaging said cable between the anchored portions thereof, said guides being so arranged with relation to said anchoring means as to cause the two lifting elements to move substantially in unison.

5. In a multi-post lift comprising at least two lifting elements spaced one from the other, a

load supporting structure carried by said lifting elements, and means for supplying powerl to said lifting elements, a cable extending between said two lifting elements, means adjacent to each lifting element for anchoring said cable to a stationary part, and guides connected with said lifting elements for movement therewith and engaging said cable between the anchored portions thereof, one of said guides being arranged above the anchoring means adjacent to one lifting element and another of said guides being arranged below the anchoring means adjacent to the other lifting element, whereby the first mentioned guide can move upwardly no faster than the last mentioned guide moves upwardly.

6. In a multi-post lift, a plurality of lifting elements, a load supporting structure carried by said lifting elements, means for supplying power to said lifting elements, upper and lower guides connected with one of said lifting elements for movement therewith, a lower guide connected with the second lifting element for movement therewith, a cable having a portion looped about the upper guide of the rst mentioned lifting element, means for anchoring one side of said v5 cable at a point below said upper guide, the other side of said cable extending about4 the lower guides of both lifting elements, and means for anchoring said cable at a point above the lower guide of said second lifting element.

7. In a multi-post lift, a plurality of lifting elements, a load supporting structure carried by said lifting elements, means for supplying power to said lifting elements, upper and lower guides connected with the respective lifting elements for movement therewith, and a flexible controlling device comprising a plurality of sections, each section being anchored to a stationary part adjacent to one of said lifting elements, extending upwardly from its anchor about the upper guide of that lifting element, then downwardly and about the lower guide of that lifting element, thence about the lower guide of another lifting element and being anchored to a stationary part above the last mentioned guide.

8. In a multi-post lift, a plurality of lifting elements, a load supporting structure `carried by said lifting elements, means for supplying power to said lifting elements, guides connected with said lifting elements for movement therewith, a ilexible controlling device having portions extending about the respective guides and movable therewith, and means for holding said exible device against bodily movement in the direction of its length.

9. In a multi-post lift comprising four lifting elements arranged at the corners of a rectangular figure, a load supporting structure carried by said lifting elements, and means for supplying power to said lifting elements, a flexible device having parts connected with the respective lifting elements for movement therewith, and means to control the movements of said parts of said flexible device to prevent one lifting element being moved a greater distance than another lifting element is moved.

l0. In a multi-post lift, a plurality of separately movable lifting elements, a load supporting structure carried by said lifting elements, means for supplying power simultaneously to said lifting elements, a single cable connected with all of said lifting elements for movement thereby in the direction of its length, means for automatically controlling the movement of the cable to cause the same to retard the movement of any lifting element which tends to move at a greater speed than another lifting element, and means for so connecting said power applying means with said lifting elements that excess power will be diverted from said retarded lifting element to said other lifting element.

11. In a multi-post lift, a plurality of fluid operated lifting elements, a load supporting structure carried by said lifting elements, iiuid conduits connecting said lifting elements one with the other, means for supplying fluid under pressure from a source of fluid supply to one only of said lifting elements, and means for causing said fluid to be distributed from said one lifting element to the other lifting elements in proportion to the loads on the several lifting elements.

12. In a multi-post lift, a plurality of fluid operated lifting elements, a load supporting structure carried by said lifting elements, means for normally supplying fluid under pressure to said lifting elements, guides carried by and movable with the respective lifting elements, a single cable extending about a plurality of said guides and movable thereon by the movement of said lifting elements, and means for controlling the movement of said cable to .cause the same to' act 2,07451481 on said guides to-cause thelifting elements with which said guides are connected to move in unison.

13. In a multi-post lift, a plurality of fluid operated lifting elements, a` load` supporting structure carried by saidliftingelements, means for normally supplying fluid under pressure to said lifting elements,.guides carried by and movable with'therespective-lifting elements, an endless cable extending about a plurality of said guides, .and means for controlling the movement of said cable to cause-the. lifting elements with whichiit isconnected to move in unison.

14. In` a multi-post. lift, a plurality o-f fluid operated lifting. elements,` a` loadV supporting structure carried by said lifting elements, means for. normally supplying fluid under pressure to said lifting elements, guides .carried by and movableV with the respective lifting elements, an endless-cable extending tautly about a plurality of saidlguides, portionsLoffsaid cable being movable on said guidesby theimoyernent` of said lifting elements, andlmeans for holding other portions of said-cable against movement.

15,. In a multi-post lift, a plurality of fluid operated lifting elements, a load` supporting structure carried' by said lifting elements, means for supplying fluid under pressure to said lifting elements and for-diverting portions of said fluid from one lifting elementto another lifting element, guides carried by and movable with the respective lifting elements, a single cable extending abouti a plurality of said guides and movable thereon bythe movement of 1said lifting elements, and-means for` controlling the movement of said cable to cause'tlie same to so act on the lifting elements with which said guides are connected as to retard the movement of any of said lifting elements which tends to move at a greater speed within another of-said-lifting elements and to cause fluid to be diverted from the retarded lifting element to the other lifting element.

16. In a multi-post lift, four fluid operated lifting elements arranged atthe corners of a rectangularfigure,` aloadsupporting structure carried by said lifting elements; means for supplying luidiunder pressure to said lifting elements normally insubstantially equal amounts and for diverting portionsof said fluid from one lifting element to another lifting element, a guide carried by-and movable witheach lifting element, a single lcable extending about all four of said guides and movable thereon by the movement of said lifting elements, and" means for'controlling the movement of said cable to cause the same to retard the movement' of any of said lifting elements which tends to move at a greater speed than another of said lifting elements and to cause fluid to be diverted from the retarded lifting element to said other lifting element.

17. In a multi-post lift, four fluid operated lifting elements arranged at the corners of a rectangular ligure, a load supporting structure carried by said lifting elements, means for supplying fluid under pressure to said lifting elements normally in substantially equal amounts and for diverting portions of said fluid from one lifting element to another lifting element, a guide carried by and movable with each lifting element, an endless cable extending about all four of said guides, portions of said cable being movable on said guides by the movement of said lifting elements, and means for holding other portions of said cable against movement. Y

18. In a multi-post lift, a plurality of separately movable lifting elements, a load supporting structure carriedVv by said lifting elements, means for supplying; power simultaneously to said lifting elements, guidescarried by the respective lifting.

elements, acable` extending about said guides, and'means for controlling the movement of said cable to. cause it to resist the movement of one lifting element with relation to another lifting element.

19; In afmulti-postlift, a plurality of separately movable lifting elements, a load supporting structurercarried'by said lifting elements, means for supplying zpowersimultaneously to said lifting elements, a-guide Icarried by eachlifting element, a cable "carried by said liftingvelements and having portionslooped'about the respective guides, and meansforholding one Side of each looped p0rtion'ofi saidcable against movement.

20. In'a multi-post lift, a plurality of separately movablelifting elements, aload supporting structure. carriedbysaidlifting. elements, means for supplyingA power simultaneously to said lifting elements,` an upper-guide and a pair of lower guides carriedlby each lifting element, a cable having portions looped about the respective upper guides, yeach side of each looped portion of said cable1extending about one of the lower guides of that lifting element to the lower guide of Vanother lifting: element, a stationary member adjacent to each. liftingV element, and meansfor anchoring one .side'of.eachllooped'portion of said cable to one of said'` stationary. members.

21. In l.a multi-'post lift, a plurality of fluid operated..lifting elements, a load supporting structure carried by said lifting elements, fluid conduits1 connecting saidlimiting elements one with 4 the `other,.means for supplying fluid under pressure from asource of fluid supply to one of said;l

lifting"y elements, an upper guide and a pair of lower: guides carried by each lifting element, a cable having?, portions looped about the upper guidesiof the respective lifting elements, each side=ofteach;looped.portion of said cable extendingv aboutialower guide of its lifting element to the lower: guide of `another lifting element, a stationarymemberladjacent to each lifting element, andmeans for anchoring Vone side of each looped portion of saidcable to one of` said stationary members'.

22. In amulti-post lift, a plurality of stationary upright pistons; a cylinder mounted on each piston` for verticalmovement with relation thereto, a load supportingV structure carried by said cylin'ders,4v meansifor 'supplying fluid under pressure touone only ofi said cylinders, conduits movable with-saidV cylinderstoconduct fluid` from one duits connecting said lifting elements one with said cylinders to automatically retard the movement of any cylinder which tends to move at a greater speed than another cylinder and to cause fluid to flow from the retarded cylinder to said other cylinder.

23. In a multi-post lift, two pairs of fluid operated lifting elements arranged near the respective ends of said lift, a load supporting structure carried by said lifting elements, conduits connecting the lifting elements of each pair one with the other and with the lifting elements of the other pair, means for supplying fluid under pressure to one only of said lifting elements, a single cable connectedpwith the several lifting elements and movable therewith, and means for controlling the movement of said cable to cause it to retard the movement of any of said lifting elements which tends to move at greater speed than another of said lifting elements.

24. In a multi-post lift, two pairs of stationary pistons extending upwardly from a supporting surface near the respective ends of said lift, cylinders mounted on the respective pistons for vertical movement with relation thereto, cross members connecting the lower ends of the cylinders of the respective pairs and arranged to be located close to said supporting surface when said cylinders are in their lowermost positions, a longitudinal member connecting said cross members, conduits connecting the cylinders of each pair one with the other and with the cylinders of the other pair, means for supplying fluid under pressure to said cylinders, a single cable connected with all of said cylinders and movable therewith, and means for controlling the lengthwise movement of said cable to cause the same to retard the movement of any cylinder which tends to move at a greater speed than another cylinder. 25. In a multi-post lift, two pairs of stationary pistons extending upwardly from a supporting surface near the respective ends of said lift, cylinders mounted on the respective pistons for vertical movement with relation thereto, cross members connecting the cylinders of the respective pairs and arranged to be located close to said supporting surface when said cylinders are in their lowermost positions, a longitudinal member connecting said cross members, said members having longitudinal channels, conduits extending through said channels and connecting said cylinders one with the other, a cable extending through said channels and having portions connected with the respective cylinders, and means for controlling the longitudinal movement of said cable to cause the same to retard the movement of any cylinder which tends to move at a greater speed than another cylinder.

26. In a multi-post lift, two pairs of stationary pistons extending upwardly from a supporting surface near the respective ends of said lift, cylinders mounted on the respective pistons for vertical movement with relation thereto, cross members connecting the cylinders of the respective pairs and arranged to be located close to said supporting surface when said cylinders are in their lowermost positions, a longitudinal member connecting said cross members, conduits connecting the cylinders of each pair one with the other and with the cylinders of the other pair, means for supplying fluid under pressure to said cylinders, an upper guide and two lower guides carried by each cylinder, other guides carried by said cross members, an endless cable extending about Y the upper and lower guides of each cylinder and about the guides of said cross members, a stationary member adjacent to each cylinder, and means for rigidly connecting said cable with each stationary member.

27. In a multi-post lift, two pairs of stationary pistons extending upwardly from a supporting surface near the respective ends of said lift, cylinders mounted on the respective pistons for Vertical movement with relation thereto, a bracket secured to the lower portion of each cylinder, channeled cross members secured to the brackets of the respective pairs of cylinders, a longitudinal member secured to said cross members, conduits extending through said channeled cross members and connected with the respective cylinders, a longitudinal conduit connecting the rst mentioned conduits, means for supplying fluid under pressure to said cylinders, an upper guide and two lower guides carried by each cylinder, other guides carried by said cross members, an endless cable extending about the upper and lower guides on said cylinders and about the guides on said cross members, the transverse portions of said cable extending through the respective cross members, and means adjacent to each cylinder to hold a portion of said cable against lengthwise movement.

28. In a multi-post lift, two pairs of stationary pistons extending upwardly from a supporting surface near the respective ends of said lift, cylinders mounted on the respective pistons for vertical movement with relation thereto, a bracket secured to the lower portion of each cylinder, channeled cross members secured to the brackets of the respective pairs of cylinders, a channeled longitudinal member extending between said cross members, a bracket secured to each cross member and having an expansible portion extending into the adjacent end of said longitudinal member, means for expanding said portions of said brackets and securing the same t0 said longitudinal member, conduits extending through said cross members and connected with the respective cylinders, a conduit extending through said longitudinal member and connected with the first mentioned conduits, means for supplying uid under pressure to said cylinders, upper and lower guides carried by each cylinder, other guides carried by said cross members, an endless cable extending through said channeled members and about the several guides, and means for holding a portion of said cable near each cylinder against lengthwise movement.

ION VON K ERT HOTT.

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