Patent Publication Number: US-3877548-A

Title: Car hoist

Description:
[4 1 Apr. 15, 1975 United States Patent 1 Hernick CAR HOIST 3,557,908 l/197l Villars................................187/854 3,724,602 2/1971 Hernick.............................187/854 t r 6 b r .Ma B S e m a r e m m a E v. r m .n H P HE V [22] Filed: Jan. 2, 1974 Assistant Examiner-James L. Rowland [21] Appl. No.: 429,530  
 [57] ABSTRACT A car hoist comprising runways, a lift mechanism disengageably engageable with the runways and operable to lift and lower them through a range of elevations, props for temporarily propping the runways at selected elevations within the range, and a jack carried 48 9 51 8 8M 7: 00 5 ;B 9 W3 B 44 m ml .s. 3&#34; mm B m 7 9 8 H &#34;5 m 8 u UHI OO Hr. Ha e s .L cl C .w UhF M M 555 [ll by each runway operable by the lift mechanism when the runways are propped to raise and lower the car relative to the runway.  
 [56] References Cited UNITED STATES PATENTS 2,112,481 3/1938 187/854 2,902,116 9/1959 Ridgeway et a1. l87/8.43 14 Claims, 6 Drawing Figures PATENTEUAPR 1 51975 SHEET 1 U}: 2  
 CAR HOIST The invention relates to car hoists as used for example. in automobile repair or service stations for lifting cars to convenient working levels.  
  Preponderantly, the hoists heretofore found at such stations were intended either to lift cars by their frames or to lift them by their wheels, the actual lifting being usually performed by a single, centrally disposed, ram. so-called. which included a cylinder buried in the ground and a piston raised and lowered in such cylinder by hydraulic or pneumatic forces.  
  Hoists designed to lift cars by their frames were provided with arms radiating from the top of the piston which were individually adjustable for engagement with selected portions of the car frame when the piston was raised. This type of hoist had the disadvantage that, while it left the car wheels freely accessible for service, it tended to obscure and obstruct the car bottom thereby restricting access thereto. Conversely. hoists intended to lift cars by their wheels were provided with runways onto which the cars were driven, the runways being spaced apart to allow access to the car bottom. In this case, as will be understood, the car wheels, being in engagement with the runways. were not generally available for service. Moreover, with this type of hoist complete access to the car bottom was not available without first propping the runways in an elevated position and thereafter retracting or lowering the ram piston back into its cylinder.  
  The invention accordingly seeks amongst other things to overcome the disadvantages aforesaid by providing an improved ear hoist which is comprised of a pair of runways for the car wheels and a lift mechanism including a single, central ram as aforesaid for lifting and lowering the runways, the hoist including means for propping the runways at an elevation as well as other means for raising the car wheels off the runways to render them available for service, the ram being optionally retractable.  
  More particularly, in order to raise the car wheels off the runways as aforesaid the invention visualizes equipping the runways with jacks disposed at the sides thereof to engage the car by its frame and to raise and lower it relative to the runways when they are propped in an elevated position.  
  Under these circumstances, the invention seeks broadly and generally to provide a car hoist of the char acter described whereby a car can, in one instance. be raised by its wheels to a first work position and, in another instance, additionally raised, only this time by its frame, to a second work position, the latter position serving to free the wheels from the runways so that repair or maintenance services may be carried out on them. The ram is optionally retractable to clear the space below the car.  
  Another object of the invention is to provide a car hoist of the character described equipped with jacks carried by the runways so that once the car has been raised and the runways propped in an elevated work position the jacks can then be operated to engage and lift the car relative to the elevated runways thereby freeing the car wheels for movement.  
  The invention has further regard to providing a car hoist withjacks as aforesaid which are themselves operable by the specific lift mechanism, namely, the ram;  
 LII  
 LII  
 this is another and more particular object of the invention.  
  A related object is to provide a car hoist with lift mechanism as aforesaid which is itself optionally retractable to a non-obstructive ground level position once the jacks have been operated thereby.  
  The various objects of the invention are achieved herein by providing a car hoist comprising runways on which a car is disposable for lifting and lowering thereby, said runways being spaced apart to accommodate the wheels of the car. a lift mechanism disengageably engageable with said runways and operable to lift and lower them as aforesaid through a range of elevations. props for temporarily propping said runways at selected elevations within said range. and a jack carried by each said runway operable by said lift mechanism when the runways are propped as aforesaid to raise and lower the car relative to the runway.  
  Other objects of the invention more or less broad than the foregoing will become apparent from the hereinafter following description of the elements, parts and principles of the invention given herein solely by way of example with reference to the embodiment herein described and illustrated in the accompanying drawings wherein like reference numerals refer to like parts of the invention and wherein FIG. 1 is a perspective view of the car hoist construction according to the preferred embodiment of the invention;  
  FIG. 2 is an elevational view taken along lines lIIl in FIG. 1 and showing the mutually abutting engagement between a runway and the crossbar;  
  FIG. 3 is an elevational view similar to FIG. 2 but illustrating the jack being held in lifted position by said crossbar;  
  FIG. 4 is a perspective view of various cooperating parts of the car hoist in the area of one of its jacks;  
  FIG. 5 is a front perspective view of a vehicle being driven onto the runways when disposed at ground level, and  
  FIG. 6 is a front elevational view taken along lines VI--VI in FIG. 5 and showing the jack arms disposed over the top of the runways for engagement with the car frame.  
  The present preferred embodiment of a car hoist according to the invention is illustrated generally in FIG. 1. Shown therein is car hoist A embodying runways 22 on which a car (not shown) is disposable to be lifted and lowered therwith, said runways 22 being spaced apart to accommodate the wheels (shown schematically) of a car. Toraise and lower the runways there is provided lift mechanism L, to be more particularly described, which is disengageably engageable with said runways 22 to lift and lower them as aforesaid through a range of elevations. props P being provided for temporarily propping said runways 22 at selected elevations within said range. Once said runways 22 are propped in elevated position, jacks 44 carried by said runways 22 are respectively operable by said lift mechanism L in a manner which will be well understood to raise and lower them relative to the runways 22 and, in appropriate cases, to raise the car to thus free its wheels from the runways for repair or other like purposes.  
  More particularly, it will be recognized from FIG. I that said lift mechanism L includes a crossbar 6 which extends transversely of and underneath each said runway 2. said crossbar 6 being movable into an abutting relationship with said runways 22 to disengageably engage them as shown by solid line position in FIG. 2 in order to raise and lower them as shown. for example. by their positions relative to ground G in FIGS. 1 and 5. respectively. Specifically. said lift mechanism L fur ther includes a single. centrally disposed ram 8 comprising the conventional piston and cylinder combination. as commonly used in car hoist constructions. ram 8 carrying said crossbar 6 at its free end as at 10. Thus. it will be understood that said crossbar 6 can be selectively elevated and lowered by merely actuating said ram 8 to lift and lower said runways 2-2 through the range of elevations as aforesaid.  
  Of course. it need hardly be mentioned and must indeed be obvious that an acceptable hydraulic or pneumatic system including appropriate operating controls and so forth well known to the car hoist art will be provided for effecting actuation of said ram 8 and. hence. a description of such has been omitted in this submission as having no significant bearing on the innovative principles of the instant embodiment of the invention.  
  It is appreciated that said runways 22 as described may. at times. display a tendency to rock about said crossbar 6 because for example. of faulty centering of the car thereon and the invention contemplates that any of the suitable stabilizing means well known to the car hoist art may be provided in the hoist construction herein between said runways 22 and crossbar 6 to circumvent the possibility of such rocking action by said runways 2 2.  
  With more particular regard now to said props P. FIG. 1 illustrates them to be disposed, preferably. at the respective ends of each said runway 2. Specifically, each said runway 2 has a pair of props P associated therewith and in this embodiment. one of said pair. identified by reference numeral 12, is telescopable into a mating guide element 14 suitably disposed in the ground G. The exterior or free end of said prop 12 is secured to said runway 2 as at 16 for raising and lowering therewith. In addition. said prop 12 may include a plurality of spaced perforations 18 extending along its longitudinal axis to correspond to the range of elevations aforesaid for accommodating a pin 20 having a length significantly greater than the transverse dimension of said guide element 14. Said pin 20 when accommodated in said perforations l8 and extending from each side of prop 12 serves as a stop element to limit penetration of prop 12 into said guide element l4 whereby to support said prop l2 and. of course, the runway 2 at a required elevation. It will be understood that one end of each said runway 2 may be propped at various levels within the range of elevations aforesaid by merely selectively disposing said pin 20 in the appropriate perforation 18 in each prop 12. Obviously, a prop l2 and its co-operating elements may be provided at each corner of the present car hoist A. Alternately. the prop 12 on each runway 2 may have a companion prop at the opposite end of the same runway 2, identified by reference numeral 22, which extends above ground G in this preferred embodiment and also includes a plurality of spaced perforations 24 extending at appropriate levels along its height for accommodating a pin 26. Said stationary prop 22 is in turn, embraced by a slidable sleeve element 28 fixed to said runway 2 at 30 for raising and lowering therewith, said sleeve element 28 including ahole 32 which is capable of being selectively moved into registration with any one of said perforations 24 to mutually accommodate said pin 26; the net result is that said runway 2 can also be supported by said stationary prop 22 similarly to prop 12 at various levels within the range of elevations aforesaid.  
  Accordingly. when said runways 22 are raised by said lift mechanism L to an elevated position and propped therein as aforesaid it will be appreciated that said crossbar 6, having only an abutting engagement with runways 222, may then be disengaged therefrom as shown by its dotted line position in FIG. 2 by merely actuating said ram 8 to lower it and crossbar 6 from said abutting engagement with said runways 22, leaving the latter supported in elevated position solely by props l2 and 22.  
  Turning now to said jacks 44. each includes a post 34 as shown in FIG. 3 which is vertically movable relative to the runway 2 by which it is carried as shown by its solid and dotted line positions in the same view; said jack post 34 has arms 3636 pivotally attached thereto at its top as at 38-38 (FIG. 4) which are swingable either away from or over the top of said runway 2 to liftably and selectively engage the lateral frame parts of a car standing on said runways 22. In particular, each said runway 2 includes a fixed bearing 40 on the outside thereof in which said jack post 34 is normally held in suspended relation with respect to said runway 2 as shown by its solid line position in FIG. 2, said jack post 34 being, however, slidable in said bearing 40 for vertical movement relative to said runway 2 to engage and lift a car as aforesaid. It is to be understood, of course, that since said jack post 34 normally depends from runway 2 an appropriate well 42 (FIG. 1) will be provided in ground G to accommodate it when runway 2 is disposed at ground level.  
  To actuate each said jack 4, i.e.. to effect vertical sliding movement thereof, the invention visualizes engaging said jack post 34 with said crossbar 6, when the latter is disengaged from said runways 22, whereby subsequent lifting of said crossbar 6 will produce like movement of said jacks 44 and of the car relative to runways 22, provided. of course. that the arms 3636 of each jack have been suitably disposed for this purpose. More particularly, the invention contemplates said crossbar 6 as including trapping means 44, to be later described. selectively operable to effect engagement between said crossbar 6 and jack post 34 when the crossbar 6 is being raised. said trapping means 44 being operable in this embodiment only when.  
 said crossbar 6 is disengaged from said runways 22 to the extent that it is positioned below said jack post 34 as shown by its dotted line position in FIGS. 2 and 3. Accordingly. said trapping means 44 as shown in FIG. 4 includes a horizontally slidable footing device 46 cooperable with an opening 48 provided in said crossbar 6 for accommodating said jack post 34; said footing device 46 is movable from a retracted position of FIGS. 2 and 4 in which said crossbar 6 is movable relative to said jack post 34 so as to engage said runways 2-2 as aforesaid, and an extended position of FIG. 3 in which said footing device 46 is engaged by and with saidjaek post 34 enabling the latter to be lifted by said crossbar 6 to procure lifting of the car as aforesaid. In its extended position aforesaid and illustrated by dotted lines in FIG. 4 it will be recognized that said footing device 46 is positioned in occluding relation with respect tosaid opening 48 essentially to block passage of said jack post 34 thercthrough and thereby to effect the engagement between said crossbar 6 and jack post 34. In order. to effect movement of said footing device 46 between it retracted and extended positions aforesaid. said trapping means 44 also includes a fluid motor 50 of the conventional piston and cylinder type, for example. fixed to said crossbar 6 at 52. Said motor 50 in turn is connected by its piston 54 (FIG. 4) to said footing device 46 as at 56 and has ports 58 and 60 for energizing it with a pressurized fluid. Thus, it will be understood that upon energization of said motor 50 it will, in one instance, effect movement of said footing device 46 to its extended position aforesaid and, in another instance. effect movement of said footing device 46 to its retracted position aforesaid.  
  Having regard to the foregoing, the invention further visualizes means for selectively locking said jacks 44 in lifted position whereby said crossbar 6 may then be disengaged therefrom by lowering said ram 8 to a nonobstructive ground level position, the net result being that not only are the car wheels freely accessible for service but also the car bottom. In particular, it is contemplated that each said jack post 34 be provided with a plurality of spaced perforations 62, two in this embodiment, extending along its longitudinal axis, each being registerable with opposed openings 6464 in said bearing 40 as best shown in FIG. 3. In addition, a pin 66 is provided for insertion through the registering openings 64-64 and one said perforation 62 to thus selectively lock said jack posts 34-34 and, of course, a car when engaged by its arms 3636 in lifted position aforesaid. It is to be understood. however, that the locking means for said jacks 44 aforesaid is merely auxiliary equipment which enables optional retraction of said lift mechanism L to a non-obstructive ground level position when and if the need arises for providing free access to the car bottom when supported by said jacks 4-4.  
  By way of summary, therefore, and beginning from the lowermost position of said runways 22, i.e., when the are at ground level, the operation of the car hoist A proceeds as follows:  
 said ram 8 is actuable to procure lifting of said runways 22 by said crossbar 6 to a predetermined height within said range of elevations where said runways 22 are then propped as aforesaid.  
  Thereafter, said crossbar 6 is lowered from engagement with said runways 22 to the dotted line position below said jack posts 34-34 shown in FIG. 2. In that event, said motors 5050 are then energized to cause said footing devices 46-46 to move to their extended position aforesaid to block passage of said jack posts 34-34 in said crossbar openings 4848. Afterwards, said crossbar 6 is then once again raised to where it becomes engaged by and with the ends of said jack posts 3434 to lift them contemporaneously to the solid line position of FIG. 3 to effect lifting of the car relative to said runways 22 as aforesaid as represented by the raised wheel (shown schematically) in the same view. Upon reversing the procedure aforesaid said runways 22 can once again assume their ground level position.  
 (FIG. 6).  
 What I claim is: 1. A vehicle hoist comprising:  
 runways on which a vehicle is disposable for lifting and lowering thereby, said runways-being spaced apart to accommodate the-wheels ofthe vehicle;  
 lift mechanism disengageably engageable with said runways and operable to lift and lower them as aforesaid through a range of elevations:  
 props for temporarily propping said runways at selected elevations within said range. and  
 a jack carried by each said runway disengageably engageable by said lift mechanism and thereby operable, when the runways are propped as aforesaid and said lift mechanism is disengaged from the runways, to raise and lower the vehicle relative to the runways at any elevation at which they may be propped.  
 2. A vehicle hoist as defined in claim I wherein:  
 said lift mechanism includes a crossbar which extends underneath cach said runway. and being clevatable to engage and raise said runways and alternately capable of being lowered to lower said runways. and  
 a ram for elevating and lowering said crossbar to lift and lower the runways through the range of elevations as aforesaid.  
 3. A vehicle hoist as defined in claim 2 wherein:  
 each said jack including a post which is vertically movable relative to the runway by which it is carried and has arms at its top for liftably and selectively engaging a vehicle standing on said runways, said crossbar including trapping means selectively operable to engage it with said post whereby to procure lifting of the jack and of the said vehicle when the crossbar is elevated as aforesaid.  
 4. A vehicle hoist as defined in claim 3 wherein:  
 said trapping means is operable as aforesaid when said runways are propped and the crossbar is lowered out of engagement with said runways.  
 5. A vehicle hoist as defined in claim 3 wherein:  
 said post is disposed at a side of the runway by which it is carried. and  
 its said arms are swingable over the top of the runway to engage and disengage the frame of the vehicle.  
 6. A vehicle hoist as defined in claim 5 wherein:  
 said post is disposed at the outside of the runway by which it is carried. I  
 7. A vehicle hoist as defined in claim 3 wherein:  
 said trapping means caried by said crossbar is selectively operable to engage the crossbar with said post as aforesaid or, alternately, to permit relative vertical movement between said crossbar and said post.  
 8. A vehicle hoist as defined in claim 7 wherein:  
  said trapping means includes a footing for said post which is selectively moveable between a post engaging position and a post releasing position permitting relative vertical movement between said crossbar and said post. 9. A vehicle hoist as defined in claim 3 including a bearing on a side of each runway in which the jack post is slidable for vertical movement relative to said runway.  
 10. A vehicle hoist as defined in claim 1 wherein: the said props are disposed at each end of each said runway. 11. A vehicle hoist as defined in claim 10 wherein: each runway has a pair of props associated therewith, one of said pair being secured to the runway for both stationary props and prop bearings are at the same end of the hoist.  
  14. A vehicle hoist according to claim 1 and including a lock operable to releasably lock each jack in a raised position relative to the respective runway.  
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