US3531938A

US3531938A - Hydraulic jacks

Info

Publication number: US3531938A
Application number: US783034A
Authority: US
Inventors: Harold Frederick Resuggan
Original assignee: Webley and Scott Ltd
Current assignee: Webley and Scott Ltd
Priority date: 1967-12-21
Filing date: 1968-12-11
Publication date: 1970-10-06
Anticipated expiration: 1987-10-06
Also published as: GB1176040A; DE1814347A1; FR1603642A

Description

2 sheet s sheet 1 Fig.

H. F. RESUGGAN HYDRAULIC JACKS I II Oct. 6, 1970 Fiiad Da e. 11, 1968 INVENTOR AROLD F. RESUGGAN BY M w Wm Oct. 6, 1970 H. F. RESUGGANV HYDRAULIC J ACKS 2 Sheets-Sheet 3 Filed Dec. 11, 1968 United States Patent /67 Int. Cl. B66f 3/42,- F15b 15/18 US. C]. 60-52 6 Claims ABSTRACT OF THE DISCLOSURE A hydraulic jack having a cylinder provided with a piston and associated with a housing defining a hydraulic liquid reservoir and accommodating both a hydraulic reciprocatory pump and an oscillatory driving crank arm connected to the latter, a driving spindle being journalled in the housing and in driving connection with the crankarm, the latter resting driving assembly on an assembly table accommodated within the housing so as to be positioned to present a spindle receptive part in approximate axial alignment with the journalling arrangement of the housing, so as to facilitate engagement of the spindle with the crank-arm on insertion of the spindle through the journalling arrangement.

This invention relates to hydraulic jacks of the kind comprising a cylinder provided with a piston, a housing defining a hydraulic liquid reservoir accommodating both a hydraulic reciprocatory pump and an oscillatory driving mechanism connected to the pump, and a driving spindle received in spindle receptive parts of the housing and the oscillatory mechanism, the spindle being in driving engagement with the latter.

In known jacks of this kind, diluculty is encountered, during assembly, in connecting the spindle oscillatory mechanism or the latter with the pump, since the housing makes access to the oscillatory mechanism and the pump difiicult.

An object of this invention is to provide a jack of this kind which overcomes the above difiiculty and can be readily assembled.

In accordance with this invention, a hydraulic jack comprises a cylinder, a piston reciprocable in the cylinder, a reciprocatory pump, an oscillatory driving mechanism connected to the pump, a housing defining a hydraulic liquid reservoir and accommodating both the pump and the oscillatory mechanism, a driving spindle journalled in the housing and in driving connection with the oscillatory mechanism, and an assembly table accommodated in the housing to support the oscillatory mechanism in a position such that during assembly spindle receptive parts of the oscillatory mechanism and the housing are approximately axially aligned to facilitate introduction of the spindle.

The invention is now more particularly described with reference to the accompanying drawings, wherein:

FIG. 1 is a sectional side elevation of a jack according to the invention, shown before insertion of the driving spindle;

FIG. 2 is a fragmentary view similar to that of FIG. 1 but showing the spindle in its operative position;

FIG. 3 is a section on line 33 of FIG. 1, showing the spindle partially inserted in the housing; and

FIG. 4 is a fragmentary section similar to that of FIG. 3, showing the spindle in its operative position.

Referring to the drawings, the jack comprises a base block 11 having a circular internally tapped recess 12 formed in an upper face 13. A cylinder 15 screw engages in the recess 12 so as normally to extend axially ver- 3,531,938 Patented Oct. 6,, 1970 ice" tically from the base block, a sealing ring 16 being disposed between the block and the cylinder. A piston 10 is slidably mounted in the cylinder 15. The block has a liquid passage 17 extending downwardly from the recess 12 and opening into an oblique bore 18 drilled in a side of the block and terminating at that side in an enlarged part 1801 internally tapped and receiving in screwed engagement therewith a release valve 20. Delivery and release hydraulic liquid passages, 21 and 22 respectively, are drilled into the base block from the face 13 adjacent the cylinder 15, the delivery passage 17 and the release passage 22 opening into the enlarged part 18a so as to be communicated with the liquid passage 17 only with the release valve opened. A shallow elongated depression 24 is formed in the upper face 13 at which depression the passage 22 opens.

A hydraulic pump sub-assembly 25 is mounted adjacent the cylinder 15 over the depression 24 on the upper face 13 of the base block 11 and is normally accommodated in a housing 50 defining a hydraulic liquid reservoir 51. The depression 24 extends beyond the pump assembly 25 to connect the release passage 22 with the reservoir 51. The sub-assembly includes a body part 28 having a main bore 26 slidably mounting a plunger 27. A liquid chamber 29 is drilled from one side of the body part 28 to connect with the main bore 26 and houses a delivery valve 30 of the ball type. A drilled conduit 31 leads from the valve 30 to connect with the delivery passage 21 in the base block. The delivery valve closes the conduit 31 to the main bore except when pressure is higher in the main bore. A bore also extends perpendicularly toconnect with the liquid chamber 29 and accommodates an inlet valve 33 of the ball type, an inlet duct 35 serving to connect the valve with the reservoir 51. The inlet valve 33 closes the inlet duct 35 to the main bore 26 except when pressure in the duct is higher than in the main bore.

The plunger includes a skirt 36 within which is mounted a connecting rod 40, the latter projecting out of the main bore between clevis limbs 39 of a crank arm 41, and is pivotally connected to the limbs by a crank pin 42. The crank arm has a square (or otherwise non-circular) aperture 43 for receiving a crank spindle 44.

The body part 28 has an assembly table 45 adjacent the plunger 27 on which the crank arm 41 rests, during assembly of the jack, i.e. before the crank spindle 44 has been inserted in the crank arm 41.

The pump sub-assembly, including the crank arm, can be tested before being mounted on the base block 11 of the jack, thereby simplifying testing procedure.

The housing seats on the base block 11 and is slidably engaged with the cylinder 15,

seals

47, 48 respectively being provided between the housing and the block 11 and the housing and the cylinder 15. The housing 50 is slid into position after mounting of the pump sub-assembly 25 on the base block 11 and before connection of the crank spindle 44 with the crank arm 41.

The housing includes an inwardly projecting boss recessed internally of the housing to define a first bearing 53. A second bearing 54 is defined by a sleeve forming an integral part of the housing and disposed at the opposite side of the housing to the first bearing 53 and co-axial therewith.

The square aperture 43 in the crank arm 41 is positioned by the assembly table 45 on the pump assembly 25 in such manner that it registers with both bearing 53 and 54 when the housing is mounted on the base block 11 (as shown in FIG. 3).

The final step in assembling the jack involves engaging the crank spindle 44 in the aperture 43. The spindle has an end journal portion complementary to the first bearing 53 and a main journal portion 61 spaced from the portion 60 and complementary to the second bearing 54.

Between the

portions

60 and 61 is a square-section portion 62, complementary to the crank arm aperture 43, and an end part of the spindle adjoining the main journal portion 61 carries a head 64 for detachably mounting an operating lever (not shown). An O-ring 66 is carried in an annular groove of the main journal 61 to seal liquid within the reservoir 51 and a further annular groove 70 is provided for engagement with a screw to retain the spindle in the housing. The spindle portions are of progressively smaller width from the head 64, the end journal portion 60 being tapered to define a lead-in portion.

The lead-in portion of the spindle is inserted through the second bearing 54 and picks up the crank arm 41 by extension through the aperture 43. The spindle is then maneuvered until the square-section portion of the spindle engages in the aperture 43 when the spindle is pushed home. Pushing the square-section portion 62 through the aperture 43 so as to engage the

journals

60, 61 in their respective bearings, lifts the crank arm off the table 45 (as shown in FIG. 4).

In operation of the jack, oscillation of the spindle 44 causes reciprocation of the plunger 27 through the crank arm 41. On the upward stroke of the plunger, the delivery valve 30 is closed and the inlet valve 33 is open to permit drawing in of hydraulic liquid from the reservoir 51 through the inlet duct 35. On the downward stroke of the plunger, the inlet valve 33 closes and the delivery valve 30 opens to permit hydraulic liquid to be ejected from the main bore 26 through the conduit 31 to passage 21 and hence to the cylinder 15 to drive the piston 10.

To release the pressure in the cylinder 15 to permit retraction of the piston 10, the release valve 20 is rotated to connect the cylinder with the release passage 22, the depression 24 and hence with the reservoir 51.

I claim:

1. A hydraulic jack comprising a cylinder, a piston reciprocable in the cylinder, a housing defining a hydraulic liquid reservoir and accommodating both a hydraulic reciprocatory pump and an oscillatory driving mechanism connected to the pump, and a spindle received in spindle receptive parts of the housing and the oscillatory mechanism and in driving engagement, characterised by an assembly table accommodated in the housing and serving to support the oscillatory mechanism in a position such that during assembly, the spindle receptive parts of the oscillatory mechanism and the housing are approximately axially aligned to facilitate introduction of the spindle.

2. A hydraulic jack according to claim 1, wherein the assembly table is provided on a body of the pump.

3. A hydraulic jack according to claim 2, including a pump sub-assembly comprising the oscillatory mechanism and the pump body, the latter incorporating inlet and delivery valves and a reciprocable plunger, the plunger being pivotally connected to the oscillatory mechanism.

4. A hydraulic jack according to claim 1, wherein the driving spindle has a non-circular section portion complementary to the spindle receptive part of the oscillatory mechanism, and has a tapered lead-in portion to assist engagement of the spindle in the receptive part.

5. A hydraulic jack according to claim 1, wherein the spindle is journalled in two opposite sides of the housing.

6. A hydraulic jack according to claim 1, including a base part mounting the cylinder, the housing being slidably mounted on the cylinder in sealing engagement therewith and seating in sealed relationship on the base part.

References Cited UNITED STATES PATENTS 6,786 12/1875 Dudgeon. 1,969,408 8/ 1934 Kramer et 211. 2,018,506 10/ 1935 Walker.

FOREIGN PATENTS 924,686 3/1955 Germany.

EDGAR W. GEOGHEGAN, Primary Examiner US. Cl. X.R,. 254-93