Note: Descriptions are shown in the official language in which they were submitted.
This invention relates to a hydraulic floor jacl< oF the type
which rolls on the floor to engage under a vehicle and lif-t it.
The existing jacks of th~ above type have ao far been rnade with
a rigid frame and solid wheels resulting in a construction of fixed and
substantial length which is cumbersome to use in many places where
there is limited floor space to maneuver. Besides, wi-th the solid
,lheels~ the full load must be carried by the wheels and the axles
thereof. This requires a solid and heavy construction which does not
allow or is not conducive to a narrow shape or form to engage in narrow
spaces such as between a set of fore and aft wheels o~ a tandem wheel
and axle asssmbly of a truck.
It is a general object of the present invention to provide an
hydraulic floor jack of the above type which avoids the above mentioned
disadvantages.
It is a more specific object of the present invention to provide
an hydraulic floor jack of the above type which is articulated to allow
maneuvering in limited floor space and to operatively occupy very little
floor space of its own beside the floor space occupie~ by the vehicle
under which it is used.
~0 It is another obj~ct of the present inventi,on to provide an
hydraulic floor jack of the above type which is constructed and arranged
to produce a narrow forrn engageable in narrow spaces such as be-tween
the aforementioned wheels of a vehicle.
It is a further object of the present invsntion to provide an
hydraulic floor jack o~ the above type which is of lighter and relative-
ly less expensive construction.
It is a more specific further object of the present invention
to provide an hydraulic floor jack of the above type which is constructed
to transmit the load thereon directly from the base of the hydraulic
cylinder to the floor indepandently of the whsels and to thersby
achieve a lighter cons-truction.
It is still anoth~r object of the prssent invsntion to provids
an hydraulic ~loor jac~ which includes articulatsd ssctions to
minimi~e the encumbrancs thsrsof anL which allows actuation of -ths
jack in any predsterminsd articulatsd position.
Ths above and other obj~cts and advantagss of the pressn-t `
invention will be better understood oith refersnce to the following
dstailsd description of a prsfsrred smbodiment thsrsof which is
- illustrated, by way of exampls, in ths accompanying drawings, in
which:
1~ Figure 1 is a psrspective visw of an hydraulic floor jack
according to the prssent invsntion;
Figurs 2 is a top visw of the jack of Figurs 1;
Figure 3 is a sids visw ~f the sarne jack showing in dottsd linss
a rsar frams section in fully slsvatsd position, angularly rslativs to
the front frame section; and
Figure 4 is a diagrammatic visw of the hydraulic circuit and a
detailsd view of the associatsd slsmsnts.
Ths illustrated hydraulic floor jack comprisss a frams formed of
a front frame ssction 1 and a rsar frame ssction 2, each of narrow
rectangular frame structure, as can be sesn in Figures 1 and 2. Ths
frame structure of the front section 1 includes transvsrse ends 3 and
4 joined to longitudinal sidss 5 and 6. Similarly, the frams structure
of the rear section 2 includes transverss ends 7 and 8 and longitudinal
sides 9 and lû.
A wheel axle ll extends through ths tubular side 3 of ths front
section l and rotativsly carries a pair of whsels 12 on its outwardly
projecting snds. As shown, each whssl 12 is providsd with an inflatabls
tirs 13 or othsrwise flexible tires. A pair of fest 14 are fixsdly
secured as by wslding to the same end o~ ths front ~rams section 1 as
the transverss snd 4 to carry ths frame structurs of this section off
ths floor coopsratively with the whsels 120
A solid bass 15 is fixadly sscursd by lugs 16 to downwardly
project a predetarrnine.' and limi-ted height from the floor ,uch as to
allow this base -to rest on the ground upon flexing of the tires le
upon loading on the jack. The base 15 registers with tha
rectangular opening defined by the frame structLIra 3, 4, 5 and 6 and at
the end thereof adjarent the flexibl~ tir~ whesls 12. An hydraulic
cylinder 17 is secured upright on the basa 15 and has an intarna! piston
18 having an outer projecting head 19 of smaller diamster than the
remainder of the piston to form an upward male projoction. A pair
of studs 20 upwardly project from tha longitudinal sides ~ and G
lû respectively. A pair of axtensions 21 and 22 are engagsd over each
stud 20 by engagamQnt of tha lattar in a corresponding famala bottom
portion of the extensions. The la-tter are adaptad to fit over the
upper male head 19 of the jack piston to provide an eXtQnsiOn to the
latter .
The rear frame section 2 is provided witil a pair of lugs 23 which
ars pivoted by a transverse pivot pin 24 to the frame structurP of ths
front section 1. The pin 24 extends inside the tubular transverse end 4.
A locking rod 25 is slidabls endwise in the transvers~ ands 7
and 8 and is biased by a spring 26 forwardly toward the front frame
~0 section. Tha for'ward end of the locking rod 25 operatively projects
forward from the transvers~ end 7 to operatively engage into one of a
plurality of holes 27 angularly positioned around the transversa end
4. For instance, in this case, thera ara 3 into the transverse end 4
angularly arranged at predetermined anglQs to lock the rear ~rame
section 2 at say 0, 45 or 100 degreeq of angular elevation relative to
the front frame section. For instance, the 0 degree position is
shown in full lines and the 100 dsgree position is shown in dotted lines
in Figure 3. The outer and o~ the locking rod 25 is provide,d with a
pull knob 28 to selectively unlock the rod by pulling thereon against
~o tha bias of the spring 26 until the front end th~reof disQngages the
hole 27 in which it was.
A pair of lags 29 ara fixedly secllred to the outer and of the
- 4 -
5~
rear frame section 2 to support the sarre gsnerally level with -tha front
frame section 1. A handle socket 30 outwardly projects and opens from
the transverse end 8 in registry with a bore diametrically through this
transverse end 8.
A valve unit 31, shown in details in Figure 4, is fixedly
secured to the rear frame structure between the longitudinal sides ~ an~
10 thereof. The valve unit 31 is prc)vidsd with a twice r,ount~rbored
aperture therein defining a smaller diameter cylindrical chamber 32,
a larger diameter cylindrical chamber 33, and a still larger outer
lb chambsr 34. These chambers serially communicate with each other and wit.h
an inlet passage 35 at the end of the smaller chamber 32. A ball 36
is axially biased by a spring 37 to close the inlet passage 35. A ball
38 is axially biased by a spring 39 to close the passage between the
chambers 32 and 33. The outer end of the spring 39 is seated in a movable
cup 40 whieh is held in placa by a threaded ,lug or cap ~1. This arran-
gement produces a cascaded check valve adapted to be operated by a pump
42. The latter includqs a piston 43 axially displaceable in a bore 44
radially communieating with the small.er cylindrical chamber 32. A
cylindrical cap 45 forms an axial extension of the hydraulic cylinder
2û bore. A piston rod 46 is secured to the pistwn 4" and outwardly
projects frorn the cap 45~ A post 47 is fixed to the valve unit 31.
A pump act~lator arm 48 is pivoted at one end on the post 47 through a
pivot 49 and i5 provided at the other end with a hanclle socket 50 to
receiva one end of a handle 51.
The inlet passage 35 is connectad by a pipe or tube 52 to an
hydraulic fluid reservoir 53 also rno~nted on the rear frame section
2. An outl~t passage 54 at one end communicates with the larger
cylindrical ehambsr 33 and at the other end ra-lially communicates with
a high pressure fluid passage 55 eonnected by a tube or hose 56 to the
hydraulic cylinder 17 through a passage 57 in the base 15.~ A pressure
`` release passage 58 communicates at one end with the high pressure fluici
passage 55 in offset position relative to the flow patll between the outlet
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.. . . .. , . _ . . .. . . . .. . .. . . . . ... .. . .
'~,
~J~
passage.54 and the.hydraulic cylinder 17. A pipe 59 connects the
pressure release passage 58 to th~- ressrvoir 53.
~ prl-ssure release valve 60 is operati.vel.y connec-ted to the
passage 55 and includes a needl~ 61 adapted to axially movn in thi~
passage and close thc pressure release passage 58. The nesdl~ 61 is
provided on the inner end of a member having an int~rmt,'iate threaded
portion 62 and`an outer socket end~portion 63. This valve is opened
or closed by appropriate rotation ~f th_ ~ockst portion 63 by ths
handlc 51 which must be engagad in the handle socket 30 for that
purpose. Upon rotation9 the threaded pnrtion cause axial displacement
of tho needle 61 to either open or close the pressure release passage
58. When this valve is opened, the hydraulic fluid pressure if any
in the cylinder is released into the reservoir 53 through the concluits
57, 56, 55, 58 and 59.
When the valve is clnsod? the pumping by engagement of the
handle 51 in the handle socket 50 produces hydraulic fluid to be sucked
in the chamb~r 32 and therea~ter expelled into ths larger chamber
33 and the outlet passage 54 toward the hydraolic cylinder 17 for
each suction ancl expulsion stroke of the piston 43. Thus, the
pressure may be built up to lift a vehicle enyaged by the piston head
19 .
Il; must be noted that the locking rod 25 allows to secure the
rear frame section 2 in any predetermined position such as to be able
to operate the pump 42 and the pressure re].ease valve 60 in any
elevated position of the rear section.
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