EP0720964A1

EP0720964A1 - Auxiliary device of a hydraulic jack

Info

Publication number: EP0720964A1
Application number: EP95100077A
Authority: EP
Inventors: Jin Soo Park
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-01-04
Filing date: 1995-01-04
Publication date: 1996-07-10

Abstract

An auxiliary device of a hydraulic jack (10) of the present invention consists of a lower body (20) the outer surfaces of the side wall portions of which is formed with grooves (24); and an upper body (30) the inner surfaces of the side wall portions of which is formed with projections (32) engaged into the grooves (24) of the lower body (20). The auxiliary device of the present invention has an height adjusting mechanism.

According to the present invention, the rotation of the upper body (30) is prevented, and the device can be adjusted in height to locate the supporting part (33) thereof immediately below the lower end of a work piece for preventing the upper body (30) from being lifted in a no-loaded state.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an auxiliary device of a hydraulic jack, and more particularly to an auxiliary device, of which an upper body is stably lifted without rotation, and which can be disassembled into several parts to be easily moved, can be reliably used even upon breakdown of the hydraulic jack only by replacing the hydraulic jack, and can be adjusted in height to locate the supporting part thereof immediately below the lower end of a work piece for preventing the upper body from being lifted in a no-loaded state whereby increasing working efficiency.

2. Prior Art

Generally, a hydraulic jack is used for lifting a work piece or a structure of heavy load through a short distance, and there is known several types of hydraulic jack. A typical hydraulic jack will be described with reference to Korean Utility Model Publication No. 88-614 in below.
Referring to Fig. 1, a hydraulic jack 10 includes a cylinder 14 having an inner fluid chamber 12 and an outer fluid chamber 13 separated each other, and a hydraulic pump 15 for supplying working fluid from outer fluid chamber 13 to inner fluid chamber 12. Inner fluid chamber 12 and outer fluid chamber 13 are respectively communicated with hydraulic pump 15 through fluid paths formed in a base 11. A piston 16 having a piston rod 17 integrally fastened thereto is movably installed in inner fluid chamber 12 of cylinder 14. The upper end of piston rod 17 is formed with a supporting part 18, and outer fluid chamber 13 is filled with the working fluid.
A check valve 19 is positioned in the fluid path for preventing the counterflow of the working fluid pumped by hydraulic pump 15 from outer fluid chamber 13 into inner fluid chamber 12, whereby to cause piston 16 to be lifted. Also, in the fluid path, there is provided a returning screw including a steel ball(not shown) for returning the working fluid from inner fluid chamber 12 to outer fluid chamber 13.
In the conventional hydraulic jack constructed as described above, by positioning the jack immediately below a work piece or a structure being supported and pumping the working fluid from outer fluid chamber 13 into inner fluid chamber 12 by means of pump 15, piston 16 provided in inner fluid chamber 12 is upwardly moved.
Accordingly, piston rod 17 integrally fastened to piston 16 is also upwardly moved, and the supporting part formed in the upper end of piston rod 17 is lifted in a no-loaded state until it contacts with the lower surface of the work piece or the structure.
After the supporting part contacted with the lower surface of the work piece or the structure, it lifts up the work piece or the structure, and in this state, desired working or operation is performed against the work piece or the structure.
When the working or operation is completed and it is necessary to release the hydraulic jack, the return screw is rotated to open the fluid path for returning the working fluid from inner fluid chamber 12 to outer fluid chamber 13, and piston rod 17 is lowered into its original position.
However, in the conventional hydraulic jack constructed as mentioned above, because piston 16 is just fitted into inner fluid chamber 12 of cylinder 14 having cylindrical cross-section, it is impossible to prevent the rotation of the work piece or the structure being supported and an unexpected accident can be happened therefrom.
Additionally, since supporting part 18 formed in the upper end of piston rod 17 installed in cylinder 17 is lifted in the no-loaded state until it contacts with the lower surface of the work piece or the structure, working efficiency is reduced and time loss is increased.

SUMMARY OF THE INVENTION

The present invention has been made to overcome the above described problems of the conventional hydraulic jack, and accordingly it is a primary object of the present invention to provide an auxiliary device of a hydraulic jack which prevents an upper body from being rotated to minimize the possibility that an unexpected accidents may be happened, and which can be disassembled into several parts to be easily moved and to be reliably used even upon breakdown of the hydraulic jack only by replacing the hydraulic jack.
Another object of the present invention is to provide the auxiliary device of a hydraulic jack which has a simple structure, can be easily manufactured thereby to improve working efficiency and productivity and to reduce manufacturing cost.
Still another object of the present invention is to provide the auxiliary device of a hydraulic jack which can be adjusted in height for locating the supporting part thereof immediately below the lower end of a work piece or a structure to prevent the upper body from being lifted in a no-loaded state thereby to increase working efficiency.
According to one aspect of the present invention, there is provided an auxiliary device of a hydraulic jack comprising: a lower body including a base having a cut-out portion, and an inner case integrally formed on the upper surface of the base and having an "U" shaped cross-section to define a space for receiving the hydraulic jack between the side wall portions thereof, the outer surfaces of the side wall portions of the lower body being formed with grooves; and an upper body including an outer case having an "U" shaped cross-section to cover the outer surface of the inner case, and having a supporting part provided adjacent the upper end of the upper body for supporting a work piece and a supporting piece fitted into the cut-out portion for supporting the work piece, the inner surfaces of the side wall portions of the upper body being formed with projections engaged into the grooves of the lower body.
According to another aspect of the present invention, the outer case of the upper body has a quadrilateral cross-section to enclose the inner case of the lower body.
By the above features of the invention, rotation of the upper body is prevented, which minimizes the possibility that an unexpected accidents may happen, and the device of the present invention can be disassembled into several parts to be easily moved and to be reliably used even upon breakdown of the hydraulic jack only by replacing the hydraulic jack.
According to another aspect of the present invention,
the auxiliary device is provided with a height adjusting mechanism for adjusting the height of the upper body and the supporting piece.
According to another aspect of the present invention,
the height adjusting mechanism consists of the upper body having a plurality of engaging holes formed in the bottom wall portion thereof; and a separate work piece supporting member having a projection selectively engaged into the engaging hole and a supporting piece for supporting the work piece.
According to another aspect of the present invention,
the engaging holes and the projection have an inclination.
According to another aspect of the present invention,
the height adjusting mechanism consists of the upper body and the lower body each having a plurality of pin holes; and a height adjusting pin selectively passing through the pin holes.
According to another aspect of the present invention,
the height adjusting mechanism consists of the upper body having a plurality of fitting holes formed in the upper end thereof; and a separate adaptor being formed with a plurality of fitting pins respectively fitted into the fitting holes and having an adjusting screw threaded into it.
According to another aspect of the present invention,
the height adjusting mechanism consists of the upper body being formed with two quadrilateral holes which are formed in the upper end of the upper body and spaced each other by a distance, and a flange portion adjacent the quadrilateral hole; and a height adjustor having a quadrilateral rod portion integrally formed and downwardly extending, and a plurality of throat portions formed in the rod portion spaced each other by the distance.
By the above features of the present invention, auxiliary device of a hydraulic jack can be adjusted in height for locating the supporting part thereof immediately below the lower end of a work piece or a structure to prevent the upper body from being lifted in a no-loaded state thereby to increase working efficiency.
According to still another aspect of the present invention, there is provided an auxiliary device of a hydraulic jack comprising: a lower body including a base having a cut-out portion, and two partition wall portions integrally formed on the upper surface of the base to define a space for receiving the hydraulic jack therebetween and having an inclined surface, the inner surfaces of the partition wall portions of the lower body being formed with grooves; and an upper body having a supporting part provided adjacent the upper end of the upper body for supporting a work piece, a supporting piece fitted into the cut-out portion for supporting the work piece, and projections which extend downwardly from the lower surfaces of the supporting part and includes an inclined surface which engaged with the inclined surface of the lower body, the outer surfaces of the side wall portions of the upper body being formed with other projections engaged into the grooves of the lower body.
By the above feature of the invention, rotation of the upper body is prevented, which minimizes the possibility that an unexpected accidents may happen, and the device of the present invention can be disassembled into several parts to be easily moved and to be reliably used even upon breakdown of the hydraulic jack only by replacing the hydraulic jack.

BRIEF DESCRIPTION OF THE DRAWINGS

The above object, and other features and advantages of the present invention will be more apparent after a reading of the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a sectional view of a hydraulic jack of the prior art;
FIGs. 2 is an exploded perspective view of an auxiliary device of a hydraulic jack in accordance with one embodiment of the present invention;
FIG. 3 is a sectional view of the auxiliary device and the hydraulic jack being in an assembled state;
FIG. 4 is a cross-sectional view of the auxiliary device and the hydraulic jack taken along line A-A of Fig. 3;
FIGs. 5 and 6 are exploded and sectional views illustrating an upper body and a lower body in accordance with another embodiment of the present invention.
FIGs. 7 to 16 are perspective and sectional views illustrating an auxiliary device in accordance with still another embodiments of the present invention, having height adjusting mechanism; and
FIGs. 17 to 19 are exploded, perspective and sectional views illustrating an auxiliary device of a hydraulic jack in accordance with a still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGs. 2 to 4, there is illustrated an auxiliary device of a hydraulic jack in accordance with one embodiment of the present invention. As described in the preface of this specification, a hydraulic jack 10 includes a cylinder 14 having an inner fluid chamber 12 and an outer fluid chamber 13 separated each other, and a hydraulic pump 15 for supplying working fluid from outer fluid chamber 13 to inner fluid chamber 12. Inner fluid chamber 12 and outer fluid chamber 13 are respectively communicated with hydraulic pump 15 through fluid paths formed in a base 11. A piston 16 having a piston rod 17 integrally fastened thereto is movably installed in inner fluid chamber 12 of cylinder 14. The upper end of piston rod 17 is formed with a supporting part 18, and outer fluid chamber 13 is filled with the working fluid. Since the hydraulic jack of the present invention operates in the same way as the hydraulic jack of the prior art, description about the operation of the hydraulic jack will be omitted in preferred embodiments of the invention.
The auxiliary device of the present invention includes a lower body 20 and an upper body 30. In a base 21 of lower body 20 is formed a cut-out portion 22 in which a supporting piece 34 of upper body 30 is received as will be described in detail in further below. In the center portion of base 21, there is integrally formed an inner case 23 which has an "U" shaped cross-section to define a space for receiving hydraulic jack 10 in an upright manner. The respective outer surfaces of the side walls of inner case 23 are provided with dovetail grooves 24 which are opposed to each other.
Upper body 30 which surrounds the outer surface of inner case 23 of inner body 20 has an outer case 31 which has an "U" shaped cross-section corresponding to that of inner case 23. The respective inner surfaces of the side walls of outer case 31 are provided with a dovetail projections 32 corresponding to dovetail grooves 24.
Also, on the upper end of outer case 31 of upper body 30 is formed a supporting part 33 which is positioned adjacent to the upper end of piston rod 17 of hydraulic jack 10. Supporting piece 34 is horizontally extended from the lower end of outer case 31 of upper body 30.
In the auxiliary device of the present invention constructed as described above, upper body 30 and lower body 20 are assembled each other, and hydraulic jack 10 is received in the space to position its base 11 onto base 21 of lower body 20 and supporting part 33 of upper body 30 onto upper end of piston rod 17 of hydraulic jack 10.
When hydraulic jack 10 is used, supporting part 33 or supporting piece 34 of upper body 30 are positioned immediately below the lower end of a work piece or a structure being supported, and piston 16 provided in cylinder 14 is lifted by the actuation of pump 15.
By the upward movement of piston 16, piston rod 17 is lifted, and upper body 30 is also upwardly moved in a no-loaded state until contacting the lower surface of the work piece or the structure.
As the upper end of piston rod 17 contacts with the lower surface of the work piece or the structure, the work piece or the structure is lifted, and in this state, desired working or operation is performed against the work piece or the structure. According to the auxiliary device of the present embodiment, since lower body 20 and upper body 30 are firmly engaged with each other by dovetail projection 24 and dovetail groove 32, the rotation of upper body 30 is effectively prevented and the possibility that an unexpected accident may be happened is minimized.
When the working or operation is completed and it is necessary to release the hydraulic jack, a return screw is rotated to open the fluid path for returning the working fluid from inner fluid chamber 12 to outer fluid chamber 13, piston rod 17 is lowered into its original position, and upper body 30 is also downwardly moved along lower body 20 to return to its original position.
FIGs. 5 and 6 are exploded and sectional views illustrating an auxiliary device of a hydraulic jack in accordance with another embodiment of the present invention.
The construction of this embodiment is the same as the first embodiment except in that an inner case 23a of a lower body 20a is formed to have an "U" shaped cross-section to define a space for receiving a hydraulic jack 10 in an upright manner and an upper body 30a surrounding the outer surface of inner case 23a of inner body 20a is formed to have a square cross-section.
By the above construction of this embodiment, upper and lower bodies 30a and 20a have a simple structure, can be easily manufactured, and thereby working efficiency and productivity are improved and manufacturing cost is reduced.
FIGs. 7 to 16 are perspective and sectional views illustrating an auxiliary device of a hydraulic jack in accordance with still another embodiments of the present invention, having a mechanism for adjusting the height of a supporting member depending upon the height of a work piece or a structure.
Referring now to FIGs. 7 and 8, there is illustrated height adjusting mechanism. The height adjusting mechanism of the present embodiment consists of an upper body 30 having a plurality of rectangular engaging holes 35 defined in the bottom wall thereof, and a separate work piece supporting member 36. As shown in the drawings, supporting member 36 has a projection 37 which is formed on the upper end thereof and extends downwardly, and a supporting piece 38 which is formed on the lower end thereof and extends transversely. Therefore, by selectively engaging projection 37 into engaging hole 35, the height of work piece supporting member 36 can be easily adjusted.
Referring to FIGs. 9 and 10, a plurality of pin holes 40 are provided in an upper body 30 and a lower body 20, through which height adjusting pin 39 is passed. In this embodiment, by grasping upper body 30 in a desired height, aligning pin holes 40 formed in respective upper body 30 and lower body 20 and inserting height adjusting pin 39 into pin hole 40 to maintain height adjusting pin 39 on supporting part on the upper end of a piston rod 17, the height of upper body 30 can be easily adjusted.
Referring now to FIGs. 11 and 12, there is illustrated another height adjusting mechanism. The height adjusting mechanism of this embodiment consists of an upper body 30a having a plurality of rectangular engaging holes 35a defined in the bottom wall thereof, and a separate work piece supporting member 36a. As shown in the drawings, supporting member 36a has a projection 37a which is formed on the upper end thereof and extends in an angle, and a supporting piece 38 which is formed on the lower end thereof and extends transversely. Therefore, by selectively engaging projection 37a into engaging hole 35a, the height of work piece supporting member 36a can be easily adjusted.
Referring now to FIGs. 13 and 14, there is illustrated still another height adjusting mechanism. The height adjusting mechanism of this embodiment consists of an upper body 30a having a plurality of fitting holes 41 defined in the corner portion thereof, and a separate work piece adaptor 44 having pin portions 42 integrally formed on the lower surface thereof and a threaded hole formed in the center portion thereof, and an adjusting screw 43 threaded into the threaded hole. In this embodiment, by fitting pin portions 42 into respective fitting holes 41, rotating adjusting screw 43 and holding it to a desired level, the height of adaptor 44 can be easily adjusted.
In FIGs. 15 and 16, there is illustrated a still another height adjusting mechanism. The height adjusting mechanism of this embodiment consists of an upper body 30b having two square holes 45 spaced each other, and a separate adaptor 48. Adaptor 48 includes a rod portion 46 which has a square cross-section and extends downwardly from it's lower surface and throat portions 47 which are separately formed on rod portion 46 and have the space corresponding to the distance between the two square holes 45. In this embodiment, by inserting square rod portion 46 through square holes 45 and rotating square rod portion 46 in an appropriate angle, the height of adaptor 48 can be easily adjusted.
Referring now to FIGs. 17 and 19, there is illustrated an auxiliary device of a hydraulic jack in accordance with still another embodiment of the present invention.
An auxiliary device of this embodiment includes a lower body 200 and an upper body 300. In a base 210 of lower body 200 is formed a cut-out portion 220 in which a supporting piece 340 of upper body 300 is received. Adjacent the opposed edge portions of base 210, there are integrally formed partition walls 230 between which a space for receiving a hydraulic jack 10 in an upright manner is defined. Each partition walls 230 have a guiding surface 250 which is inclined. The respective inner surfaces of the partition walls 230 are provided with dovetail grooves 240 which are opposed to each other.
Upper body 300 which is positioned on lower body 200 has a supporting part 330 on its upper portion and a supporting piece 340 on its lower portion which extend in opposite direction each other. The respective outer surfaces of the side walls of outer case 31 are provided with dovetail projections 320 corresponding to dovetail grooves 240.
Supporting part 330 has projections 350 which downwardly extend from the side surface thereof and have an inclined surface with which the inclined surface 250 of lower body 200 is engaged. The inclined surface 250 of lower body 200 functions to limit the downward movement of upper body 300. By the above construction of this embodiment, upper and lower bodies 300 and 200 have a simple structure, can be easily manufactured, and thereby working efficiency and productivity are improved and manufacturing cost is reduced.
As described in the above, according to the present invention, there is provided an auxiliary device comprising a lower body including dovetail grooves and having an "U" shaped cross-section, and an upper body including dovetail projection and having an "U" shaped cross-section. By the construction of the present invention, an upper body is stably lifted without rotation whereby it is possible to minimize the possibility that an unexpected accidents may be happened, and the auxiliary device can be disassembled into several parts to be easily moved, can be reliably used even upon breakdown of the hydraulic jack only by replacing the hydraulic jack.
Also, according to the present invention, there is provided a height adjusting mechanism by forming a plurality of pin holes in the lower body and upper body into which a height adjusting pin is passed or defining a plurality of engaging holes in the upper body into which the supporting piece of a supporting member is engaged, and thereby the auxiliary device of the present invention can be adjusted in height to locate the supporting part thereof immediately below the lower end of a work piece or a structure for preventing the upper body from being lifted in a no-loaded state whereby increasing working efficiency.
While the present invention has been described with reference to a few specific embodiments, it is apparent that other forms could be adopted by those skilled in the art. For example, dovetail projection and dovetail groove of the upper and lower body can be changed into quadrilateral shape, and height adjusting mechanism can be modified into several forms. Accordingly, the scope of the invention is to be limited only by the following claims.

Claims

An auxiliary device of a hydraulic jack comprising:
a lower body including a base having a cut-out portion, and an inner case integrally formed on the upper surface of the base and having an "U" shaped cross-section to define a space for receiving the hydraulic jack between the side wall portions thereof, the outer surfaces of the side wall portions of the lower body being formed with grooves; and
an upper body including an outer case having an "U" shaped cross-section to cover the outer surface of the inner case, and having a supporting part provided adjacent the upper end of the upper body for supporting a work piece and a supporting piece fitted into the cut-out portion for supporting the work piece, the inner surfaces of the side wall portions of the upper body being formed with projections engaged into the grooves of the lower body.
An auxiliary device of a hydraulic jack as claimed in Claim 1, wherein the outer case of the upper body has a quadrilateral cross-section to enclose the inner case of the lower body.
An auxiliary device of a hydraulic jack as claimed in Claims 1 or 2, wherein the auxiliary device is provided with a height adjusting mechanism for adjusting the height of the upper body and the supporting piece.
An auxiliary device of a hydraulic jack as claimed in Claim 3, wherein the height adjusting mechanism comprises the upper body having a plurality of engaging holes formed in the bottom wall portion thereof; and a separate work piece supporting member having a projection selectively engaged into the engaging hole and a supporting piece for supporting the work piece.
An auxiliary device of a hydraulic jack as claimed in Claim 4, wherein the engaging holes and the projection have an inclination.
An auxiliary device of a hydraulic jack as claimed in Claim 3, wherein the height adjusting mechanism comprises the upper body and the lower body having a plurality of pin holes; and a height adjusting pin selectively passing through the pin holes.
An auxiliary device of a hydraulic jack as claimed in Claim 3, wherein the height adjusting mechanism comprises the upper body having a plurality of fitting holes formed in the upper end thereof; and a separate adaptor being formed with a plurality of fitting pins respectively fitted into the fitting holes and having an adjusting screw threaded into it.
An auxiliary device of a hydraulic jack as claimed in Claim 3, wherein the height adjusting mechanism comprises the upper body being formed with two quadrilateral holes which are formed in the upper end of the upper body and spaced each other by a distance, and a flange portion adjacent the quadrilateral holes; and a height adjustor having a quadrilateral rod portion integrally formed and downwardly extending, and a plurality of throat portions formed in the rod portion spaced each other by the distance.
An auxiliary device of a hydraulic jack as claimed in Claim 1, comprising:
a lower body including a base having a cut-out portion, and two partition wall portions integrally formed on the upper surface of the base to define a space for receiving the hydraulic jack therebetween and having an inclined surface, the inner surfaces of the partition wall portions of the lower body being formed with grooves; and
an upper body having a supporting part provided adjacent the upper end of the upper body for supporting a work piece, a supporting piece fitted into the cut-out portion for supporting the work piece, and projections which extends downwardly from the lower surfaces of the supporting part and includes an inclined surface which engaged with the inclined surface of the lower body, the outer surfaces of the side wall portions of the upper body being formed with other projections engaged into the grooves of the lower body.