Note: Descriptions are shown in the official language in which they were submitted.
~1 ~4661
VERTICAL RISE AU~_.J~1V~: LIFT
R~I~T~t~Rfl~ND ~F ~I'iTT~ Y~.LLUN
This invention relates to ; ~ ~ uv~ -nts in vehicle
hoists or lifte for use in garages, servlce stations and
the li Re .
The prior art has provided a variety of hoiets and
lifts for use in the servicing of various types of land
vehicles. In general, it i8 considered very desirable to
provide linkage-type hoist equipment having a vertical
rise ~r~hil;tY while r-;nti~;n;ng the vehicle being lifted
in a horlzontal plane and at the same time achieving this
without the use of auxiliary cables or chains or external
posts or similar devices. There have been numerous
attempts by other8 to provide equipment satisfying these
requirements which is at the same time commercially viable
but the known prior art attempte have not been fully
successf ul .
STr~'~RY OF TTTR INVl;~NTION,
2 0 The preeent invention provides a vehicle lif ting
system employing, in a preferred embodiment, a
parallelogram linkage mechanism which provides the
required levelling action to m~;nt~in the support surface
or runway for the vehicle or equipment being hoieted in a
horizontal plane. At the ~ame time, the invention, in its
preferred form, provides a unique vertical path lifting
and lowering action by virtue of a special linkage
mechanism which is capable of automatically moving the
vehicle support surface or runway relative to the upper
portion of the lifting parallelogram mechanism in order to
achieve the above-noted vertical path lifting and lowering
action .
BRIEF IlT ~L KT~luN QF TTT~ VTT~T~ OF nR~WTNt3S - -
In drawings which illustrate an embodiment o~ the
invention:
Fig. 1 is a perspective view of a vertical rise
vehicle lift according to the invention;
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Fig . 2 i3 a perspective view of one of the lif ting
parallelograms and as80ciated m^~h~ni ~c (partially in
exploded view);
Fig. 3 is a perspective view of a portion of the lift
partly broken away to show the underlying structure;
Fig. 4 is a top plan view of the complete vehicle
lift; and
Fig. 5 is a side elevation view of a slightly
modified elmubodiment of the vehicle lift.
DET~Tr.~n r)~qr~TPTION OF ~;r~:~k~ ;MROD,TM~NT
Ref erring now to the drawings, the vertical rise
lifting hoist 10 ;n~ e~ a spaced apar~ parallel pair of
assemblies 12 which are secured together in spaced apart
parallel relationship by cross-ties 13. Each asse,m,bly 12
includes a lifting parallelogram 14, each lifting
parallelogram 14 having a runway 16 longitudinally movably
mounted to the upper extremity thereof. The two runways
16 are sized and spaced apart 80 that when the hoist is in
its lowered position, a vehicle may be driven onto the
runways 16 by way of fixed floor ramps 18.
With reference to Fig. 2, one of the two lifting
parallelograms 14 is shown in detail. I,ifting
parallelogram 14 includes elongated base link 20 having a
pair of lifting lege 22 pivotally mounted adjacent
opposing ends thereof via suitable pivot mounting pins 24.
The upper ends of the liftlng legs 22 are connected by way
of pivot pins 26 to the opposing ends o~ the elongated top
link 28.
The two lifting legs 22 of each lifting parallelogram
are caused to pivot about their respective pivot pins 24
by means of hydraulic actuators 30, each hydraulic
actuator being pivotally connected between suitably
arranged pivot points on the base link 20 and on the
respective lifting legs 22. As the hydraulic actuators 30
are retracted and .o~ct~n~le~, the lifting legs are caused to
pivot clockwise and counterclockwise about their
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respective pivot axes as indicated by arrows A. As this
pivoting action takes place, the top link 28 of the
lifting parallelogram also moves in a corresponding
arcuate path while at the same time remaining level and
5 parallel to the base link 20, (the latter at all times
resting flat on the horizontal floor of the repair shop or
garage) .
In order to provide the vertical lifting action in
accordance with the invention, the runways 16 are each
10 mounted for lengthwise ,v~ ~nt relative to the upper
extremity of the associated lifting parallelogram 14. In
particular, each runway 16 is mounted for translational
m~vl ^nt longitudinally of its aseociated parallelogram
upper link 28. This tran31ational movement i8 enabled by
15 virtue of spaced pairs of rollers 3 6 mounted to the
outboard ends of the upper pivot pins 26. These rollers
36 support the associated runway 16 via elongated spaced
pairs of generally l~r-shaped trackways 37 formed in each
runway 16 for l~.~,v. nt thereof parallel to link 28 in the
20 manner be~t illustrated in Fig. 3. The runway structure
need not be described in further detail, it being
sufficient to say that runways 16 are sufficiently strong
and rigid to support the vehicle being lifted, the ligting
forces being transmitted via the rollers 36 to the
25 trackways 37 in which the rollers 36 are located
Another important component of the vertical lift
mechanism comprises the ~o-called scissor links 38. These
scissor links 38 are pivotally connected at pivot points
37 to the midpoints of the associated lifting legs 22.
3 0 The upper ends o:~ the scissor links 3 8 are pivotally
connected at pivot points 39 to the associated runways 16.
sy virtue of the arrangement shown, as the lifting legs 22
are pivoted upwardly and downwardly by their respective
hydraulic actuators 30, the scissor links 38 pivot
35 relative to lifting legs 22 and interact with t~e runways
16 to cause the latter to travel lengthwise of the
associated upper links 28 of the lifting parallelograms 14
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such that the runways 16 move upwardly and downwardly
approximately along vertical paths illustrated by double
ended arrow3 V in Figs. l and 5. The relative lengths of
the several linkages for any given situation can readily
5 be determined by a very simple kinematic analysis and this
analysis can easily be carried out by anyone having a good
grasp of basic engineering drawing techniques.
The embodiment shown in Fig. 5 differs from that
shown in Figs. 1-4 mainly by having two extra pairs of
10 scissor links 38, i.e. one pair for each lifting leg 22
which may provide additional stability.
Also shown in association with the hydraulic
actuators 30 are locking ~ ~h~n; FlmC' 32 which comprise
relatively movable elements connected respectively to the
15 lifting legs 22 and the base link 20 and having
ratchet-like teeth which can move relative to one another
in the upward lifting direction but which lock firmly at
any given point thus preventing lifting legs 22 from
pivoting downwardly accidently as in case of a failure of
20 the hydraulic system (not shown) which controls the
hydraulic actuators 30. These locking ~ h~nlomq 32 muæt
be physically disengaged before the hoist can be lowered
thus providing a ~qubstantial degree of equipment safety.
It might also be noted here that, as shown in Figs.
25 1 and 4, a pair of jack a~qsemblies 40 are shown as
bridging the two runways 16 in spaced apart relationship
adj acent the f ront and rear ends of these runways . These
j ack assemblies, which are optional equipment, are
utilized for lifting individual portions of the vehicles
30 supported on runways 16 a~q for example, when one wishes to
change tires or the like.
The vertical lifting action achieved by the present
invention has a number of advantages readily apparent to
those skilled in the art including the fact that the
35 entire lifting hoist may be utilized in an area occupying
substantially less space than would be the case with
comparable prior art design~q.
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Preferred embodiments of the invention have beerL
described and illustrated by way of example. Those
skilled in the art will realize that various modifications
and change8 may be made while still remaining within the
5 spirit and 3cope of the invention. Hence the inven~ion is
not to be limited to the embodiments as described but,
rather, the invention encompas~es the full range of
equivalencies as def ined by the appended claim8 .
