US3622124A

US3622124A - Hydraulic lift jack

Info

Publication number: US3622124A
Application number: US38032A
Authority: US
Inventors: Kenneth R Sidles; Dwayne R Sidles
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-05-18
Filing date: 1970-05-18
Publication date: 1971-11-23
Anticipated expiration: 1988-11-23

Abstract

The lift jack has an upright cylinder operatively associated with a lift piston assembly, the full surface area of the underside of which is utilized in the raising of the piston assembly; and only a portion of the surface area of the top side is utilized in the lowering of the piston assembly. With fluid under a constant pressure and volume rate supplied from a single source, the piston assembly is slowly elevated with a maximum lifting pressure and quickly lowered with an appreciably reduced pressure.

Description

United States atet 11113,622,124

[72] Inventors Kenneth R. Sldles; 2,965,375 12/1960 Hamilton 254/93 R X Dwayne R.Sidles,both 01314 No. 15th St., 3,168,853 2/1965 Prince 91/167 Esthervllle, Iowa 51334 3,353.352 l 1/1967 Gardner 92/108 lzl 1 Appl 38032 Primary Examiner-Othell M. Simpson (22] Filed [45] Patented May 18, 1970 Nov. 23, 1971 [54] HYDRAULIC LIFT JACK 93 HP, 93 L; 60/52 HA, 52 HD; 92/108; 91/167 [56] References Cited UNITED STATES PATENTS Attorney-Rudolph L. Lowell preciably reduced pressure.

PAIENTEDuuv 23 l8?! 3,622,124

SHEET 1 [1F 2 m vewrom KENNETH A. 5/01. 5 DW/WNE P. 5/01. ES

HYDRAULIC LIFI JACK SUMMARY OF THE INVENTION The lift jack is of a simple and compact construction efficient in operation to exert a maximum lifting pressure with a slow lift and a reduced pressure with a fast drop from a fluid source of uniform volume and pressure. Where the object being lifted is blocked in an elevated position the fast drop action of the lift jack results in time and labor savings by virtue of its quick availability for successive lift operations such as are commonly required in a house moving operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the lift jack of this invention;

FIG. 2 is a longitudinal sectional view of the lift jack of FIG. 1 shown in a fully raised position and in assembly relation with a fluid control system;

FIG. 3 is a longitudinal sectional view of the lift jack in a partially raised position showing the flow of fluid therein during an elevating operation;

FIG. 4 is illustrated similarly to FIG. 3 and shows the flow of fluid through the lift jack during a lowering operation; and

FIG. 5 is a top plan view of the lift jack shown in FIG. 1.

DETAIL DESCRIPTION OF THE INVENTION With reference to FIGS. 1 and 2 of the drawings the lift jack of this invention, designated generally as 10, is shown as including a base member 11 to which is secured the lower end of an upright cylinder member 12. Extended axially of and within the cylinder 12 is a tubular fluid carrying member or manifold 13 that is also secured at its lower end to the base member 11. The manifold 13 has fluid openings 14 adjacent its upper end and a fluid opening 16 in its lower end that is in registration with a fluid passage 17 formed in the base member 11. A second fluid passage 18 in the base member is open to the lower end of the cylinder member 12.

Operatively associated with the cylinder member 12 is a piston assembly 19 that includes a piston unit 21 provided with a tubular piston rod 22 which is concentrically spaced about the fluid carrying manifold 13. The piston unit 21 has a central ring portion 23 located within and attached to the lower end of the piston rod 22 with its inner peripheral surface in sliding engagement with the outer peripheral surface of the fluid carrying member 13. An outer ring portion 24 of the piston unit 21 is positioned about and secured to the lower end of the piston rod 22 with the outer peripheral surface thereof in sliding engagement with the inner peripheral surface of the cylinder member 12.

The tubular piston rod 22 is guidably mounted for reciprocal movement relative to the cylinder member 12 by a closure means 26 for the upper end of the cylinder. This closure means includes a central ring or annular section 27 that is secured about and adjacent the upper end of the manifold member 13 so as to be in slidable engagement with the inner peripheral surface of the piston rod sidewall 28. An outer annular section 29 of the closure means 26 is secured within and adjacent the upper end of the cylinder member 12 for slidable engagement with the outer peripheral surface of the piston rod sidewall 28. It is seen, therefore, that the enclosure means 26 is f 1:: ed with a circular slot 31 of a width slightly greater than the thickness of the piston rod sidewall 28 so as to slidably receive the sidewall therein for retraction and extension of the piston rod 22 relative to the cylinder member 12.

As thus far described, it is seen that when the piston assembly 19 is in its lowered position, shown in dotted lines in FIG. 1, the cylinder member 12 is divided by the manifold member 13 and the piston rod 22 into a pair of spaces 32 and 33, which are concentrically arranged about the manifold member 13. However, on extension of the piston assembly 19 outwardly from the cylinder member 12 (FIGS. 3 and 4) there is formed within the cylinder only a single space 34 through which the fluid carrying tube or manifold 13 is axially extended. The spaces 32 and 34 constitute expansible fluid chambers and the space 33 an expansible air chamber. The openings 14in the fluid carrying member 13 are thus open to the fluid chamber 32 and the fluid passage 18 in the base member 11 is open to the fluid chamber 34.

A lift sleeve 36 of a cylindrical shape is guidably mounted about the cylinder member 12 for relative longitudinal movement (FIGS. 3 and 5). Secured to and extended radially from adjacent the lower end of the lift sleeve is a load supporting platform 37. The upper end of the lift sleeve 36 is connected to the upper end of the piston rod 22 by a common cover plate 38 which is secured to the lift sleeve by weldments 39 and the piston rod by bolts 40. The piston rod 22 and the lift sleeve 36 are thus longitudinally and rotatably movable as a unitary assembly relative to the cylinder member 12.

The lifi jack 10 is hydraulically operated from a single pump 41 through a two-way hydraulic valve 42 (FIG. 1). The pump 41 may be driven by an electric motor or from the power takeoff of a truck or like vehicle. The inlet 43 of the pump 41 is connected by a line 44 with an oil reservoir 46. The outlet 47 of the pump 41 delivers oil under pressure to the control valve 42 for selective flow into one of a pair of

fluid lines

48 or 49 which are in fluid connection with the

fluid passages

17 and 18, respectively, in the base member 11. The control valve 42, which is of a conventional type, has an exhaust line 51 connected to the reservoir 46.

In the operation of the lift jack 10, assume the piston assembly 19 is to be elevated from its lowered position shown in dotted lines in FIG. 1. On movement of the control handle 52 of the control valve 42 to its dotted line position, indicated at 52a in FIG. 2, fluid under pressure from the pump 41 is supplied to the fluid line 49 for admission into the lower end of the cylinder member 12 (FIG. 3). This fluid acts against the under side of the total area of the piston unit 21 so that a maximum fluid pressure is obtained for extending the piston rod 22 to elevate the lift sleeve 36.

Concurrently with the admission of oil into the fluid chamber 34 of the cylinder 12 through the passage 17, oil is exhausted from the fluid chamber 32 and into the reservoir 46 through the openings 14 of the fluid carrying member 13, and then downwardly and outwardly from the member 13 into the passage 18, fluid line 48 and control valve 42 for flow through the exhaust line 51 to the reservoir 46. The elevation of the lift sleeve 36 (FIG. 2) is limited by engagement of the annular portion 24 of the piston unit 21 with the outer annular section 29 of the closure means 26 for the cylinder 12. The elevated position of the lift sleeve 36 is retained by returning the handle 52 of the control valve 42 to its full line position in FIG. 2.

To lower the lift sleeve 36 from its elevated position of FIG. 2, the handle 52 is moved to its dotted line position 52b so as to reverse the travel of the fluid through the

fluid lines

48 and 49. As a result, fluid under pressure from the supply line 48 (FIG. 4) is admitted into the fluid carrying member 13 for flow into the fluid chamber 32 so as to act only against the upper surface of the piston unit portion 23. Concurrently with the admission of fluid under pressure into the fluid chamber 32, fluid is exhausted from the fluid chamber 34 of the cylinder member 12 through the passage 18, fluid line 49, control valve 42 and exhaust line 51 into the reservoir 46. When the valve handle 52 is in its neutral full line position shown in FIG. 1, fluid from the pump 41 is bypassed through the valve 42 and the exhaust line 51 into the reservoir 46.

With the pump 41 providing a constant volume rate of fluid at a uniform pressure, the piston assembly 19 is moved downwardly at an accelerated rate. This action occurs by virtue of the piston rod 22 functioning as a movable cylinder relative to a stationary piston member constituted by the center section 27 of the closure means 26. However, in the elevation of the lift sleeve 36, the piston rod 22 and piston assembly l9 operate in a usual manner relative to the cylinder member 12 so as to utilize the overall area of the piston assembly 19 for elevating purposes. The lift jack 10 thus provides for a slow lift action with a maximum piston pressure and a fast drop action with a reduced piston pressure.

We claim:

l. A hydraulic lift jack comprising:

a. a base member,

b. a cylinder secured to and projected upwardly from said base member,

c. an upright fluid-carrying member with a fluid opening at each end thereof secured to said base member and projected axially upwardly through said cylinder,

d. a lift assembly including a pair of circular inner and outer sleeve members concentrically arranged relative to said fluid-carrying member with the inner member within the cylinder and the outer member positioned about and in guidable engagement with said cylinder,

e. a piston member for said cylinder secured to the lower end of said inner sleeve member with said fluid-carrying member slidably extended therethrough,

f. a closure means for the upper end of said cylinder having a circular slot therein for slidably receiving therethrough the sidewall of the inner sleeve member,

g. a source of fluid under pressure, and

h. means for supplying the fluid from said source to the underside of said piston member concurrently with the exhaust of fluid from said inner sleeve member downwardly through said fluid-carrying member, when said lift assembly is to be elevated, and for supplying fluid from said source upwardly through said fluid-carrying member and into said inner sleeve member to the upper side of that portion of the piston member defined by the cross-sectional area of the inner sleeve member concurrently with the exhaust of fluid from the underside of the piston member, when said lift assembly is to be lowered.

2. A hydraulic jack comprising:

a. a base member,

b. a cylinder secured to and projected upwardly from said base member,

c. a piston assembly for said cylinder including a tubular piston rod and a piston member secured to the lower end of said piston rod,

d. a lift member guidably mounted about said cylinder for relative longitudinal and rotatable movement,

e. means connecting together said lift member and piston rod for unitary movement,

f. a closure means for the upper end of said cylinder member having circular slot therein for slidably receiving therethrough the sidewall of said piston rod,

. an upright fluid carrying member secured to said base member axially of said cylinder member and slidably extended through said piston member and into said piston rod for attachment of the upper end thereof to said closure means, said fluid carrying member having a fluid opening at each end thereof,

. a source of fluid under pressure, and

. means for supplying fluid from said source into the lower end of said cylinder for application against the lower side of said piston member concurrently with the exhaust of fluid from within the piston rod downwardly through said fluid-carrying member, when said lift member is to be elevated, and for supplying fluid from said source upwardly through said fluid-carrying member and into said piston rod for application against the upper side of that portion of the piston member defined by the cross-sectional area of the piston rod concurrently with the exhaust of fluid from the lower end of the cylinder, when said lift member is to be lowered.

3. The hydraulic jack according to claim 2 wherein:

a. said closure means includes a central circular portion secured to said fluid-carrying member having an outer peripheral surface in slidable engagement with the inner peripheral surface of the sidewall of said piston rod, and an annular portion secured to said cylinder having an inner peripheral surface in slidable engagement with the outer peripheral surface of the sidewall of said piston rod.

4. A hydraulic jack comprising:

a. a base member,

b. a cylinder projected upwardly from said base member, c. a piston assembly including a pair of concentrically arranged inner and outer sleeve members, said outer sleeve member mounted about and in bearing engagement with said cylinder member and said inner sleeve member located in a concentrically spaced relation within said cylinder member,

d. means connecting said sleeve members at the upper ends thereof for unitary longitudinal and rotatable movement relative to said cylinder,

e. closure means for the upper end of said cylinder having portions in slidable engagement with inner and outer surfaces of the sidewall of said inner sleeve member,

a piston member for said cylinder secured to the lower end of said inner sleeve member, said piston member having a central opening therein,

g. a fluid manifold secured to said base member and projected axially of said cylinder upwardly through the central opening in said piston member and into said inner sleeve member for attachment to one of said portions of said closure means, said fluid manifold having a fluid opening at each end thereof,

h. a first fluid supply and exhaust line connected to the lower end of said cylinder member,

i. a second fluid supply and exhaust line connected with the opening at the lower end of said manifold, and

j. a source of fluid under pressure,

it. means for selectively controlling the supply of fluid to and the exhaust of fluid from said first and second fluid lines, whereby said piston assembly is elevated when fluid under pressure from said first line is applied against the underside of said piston member concurrently with the exhaust of fluid from within said inner sleeve member downwardly of said manifold and through said second fluid line, and is lowered when fluid under pressure from said second line is directed upwardly of said manifold and into said inner sleeve member to act against the upper side of only that portion of the piston member which closes the lower end of the inner sleeve member, concurrently with the exhaust from the lower end of said cylinder through said first fluid line.

a: e n w e

Claims

1. A hydraulic lift jack comprising: a. a base member, b. a cylinder secured to and projected upwardly from said base member, c. an upright fluid-carrying member with a fluid opening at each end thereof secured to said base member and projected axially upwardly through said cylinder, d. a lift assembly including a pair of circular inner and outer sleeve members concentrically arranged relative to said fluidcarrying member with the inner member within the cylinder and the outer member positioned about and in guidable engagement with said cylinder, e. a piston member for said cylinder secured to the lower end of said inner sleeve member with said fluid-carrying member slidably extended therethrough, f. a closure means for the upper end of said cylinder having a circular slot therein for slidably receiving therethrough the sidewall of the inner sleeve member, g. a source of fluid under pressure, and h. means for supplying the fluid from said source to the underside of said piston member concurrently with the exhaust of fluid from said inner sleeve member downwardly through said fluid-carrying member, when said lift assembly is to be elevated, and for supplying fluid from said source upwardly through said fluid-carrying member and into said inner sleeve member to the upper side of that portion of the piston member defined by the cross-sectional area of the inner sleeve member concurrently with the exhaust of fluid from the underside of the piston member, when said lift assembly is to be lowered.

2. A hydraulic jack comprising: a. a base member, b. a cylinder secured to and projected upwardly from said base member, c. a piston assembly for said cylinder including a tubular piston rod and a piston member secured to the lower end of said piston rod, d. a lift member guidably mounted about said cylinder for relative longitudinal and rotatable movement, e. means connecting together said lift member and piston rod for unitary movement, f. a closure means for the upper end of said cylinder member having a circular slot therein for slidably receiving therethrough the sidewall of said piston rod, g. an upright fluid carrying member secured to said base member axially of said cylinder member and slidably extended through said piston member and into said piston rod for attachment of the upper end thereof to said closure means, said fluid carrying member having a fluid opening at each end thereof, h. a source of fluid under pressure, and i. means for supplying fluid from said source into the lower end of said cylinder for application against the lower side of said piston member concurrently with the exhaust of fluid from within the piston rod downwardly through said fluid-carrying member, when said lift member is to be elevated, and for supplying fluid from said source upwardly through said fluid-carrying member and into said piston rod for application against the upper side of that portion of the piston member defined by the cross-sectional area of the piston rod concurrently with the exhaust of fluid from the lower end of the cylinder, when said lift member is to be lowered.

3. The hydraulic jack according to claim 2 wherein: a. said closure means includes a central circular portion secured to said fluid-carrying member having an outer peripheral surface in slidable engagement with the inner peripheral surface of the sidewall of said piston rod, and an annular portion secured to said cylinder having an inner peripheral surface in slidable engagement with the outer peripheral surface of the sidewall of said piston rod.

4. A hydraulic jack comprising: a. a base member, b. a cylinder projected upwardly from said base member, c. a piston assembly including a pair of concentrically arranged inner and outer sleeve members, said outer sleeve member mounted about and in bearing engagement with said cylinder member and said inner sleeve member located in a concentrically spaced relation within said cylinder member, d. means connecting said sleeve members at the upper ends thereof for unitary longitudinal and rotatable movement relative to said cylinder, e. closure means for the upper end of said cylinder having portions in slidable engagement with inner and outer surfaces of the sidewall of said inner sleeve member, f. a piston member for said cylinder secured to the lower end of said inner sleeve member, said piston member having a central opening therein, g. a fluid manifold secured to said base member and projected axially of said cylinder upwardly through the central opening in said piston member and into said inner sleeve member for attachment to one of said portions of said closure means, said fluid manifold having a fluid opening at each end thereof, h. a first fluid supply and exhaust line connected to the lower end of said cylinder member, i. a second fluid supply and exhaust line connected with the opening at the lower end of said manifold, and j. a source of fluid under pressure, k. means for selectively controlling the supply of fluid to and the exhaust of fluid from said first and second fluid lines, whereby said piston assembly is elevated when fluid under pressure from said first line is applied against the underside of said piston member concurrently with the exhaust of fluid from within said inner sleeve member downwardly of said manifold and through said second fluid line, and is lowered when fluid under pressure from said second line is directed upwardly of said manifold and into said inner sleeve member to act against the upper side of only that portion of the piston member which closes the lower end of the inner sleeve member, concurrently with the exhaust from the lower end of said cylinder through said first fluid line.