GB2041876A

GB2041876A - Hydraulic Elevator

Info

Publication number: GB2041876A
Application number: GB7905087A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1979-02-13
Filing date: 1979-02-13
Publication date: 1980-09-17
Also published as: GB2041876B

Abstract

An hydraulic elevator comprising a base frame of legs 2 at an angle and cross member 5, having fitted wheels 22 and castors 23, onto which is mounted vertical tension 4 and compression 3 members connecting to a pivoting cantilever lifting boom 1 via a pivot 16 and extensible hydraulic ram 10. Operation of a piston integral with the ram 10 causes the lifting point 11 to rise or fall. The arc of travel through which the lifting point 11 passes under the action of the hydraulic ram 10 may be adjusted by means of a screw mechanism 13 attached to the ram 10 thereby maintaining the full hydraulic lift available irrespective of the size or initial height of the load. Additionally by removal of pivot bolts 18, 20 the ram may be removed from the device for jacking or other associated lifting or ramming tasks, independently. By removal of bolts 18, 19 the boom and vertical members 3, 4 may be rotated about their respective pivots 16, 17 enabling the device to be folded into a generally flat structure made rigid and wheelable by re-insertion of a bolt 18 through the aligned holes W, Y, Z provided for this purpose. <IMAGE>

Description

SPECIFICATION Hydraulic Elevator The invention is concerned with a load lifting device as may be used in a workshop or garage for hoisting, lifting or transporting heavy loads, removing heavy objects from inaccessible places or jacking massive items into advantageous positions.

An essential part of the invention is the improved versatility of a composite unit which has the capability of allowing its obvious usefulness to be extended without the introduction of complicated machinery. Included within this versatility is the ability of the device to be wheeled in its integral wheels, especially in its folded condition, to assist in convenient storage and also for the hydraulic ram with its integral pump to be simply detachable from the steelwork and used independently for supporting or jacking massive loads or exerting a static load for instance in the forcing apart of two pieces.

Particularly and in addition the invention incorporates a special screw mechanism attached to the integral hydraulic ram and pump which allows the range of movement of the device's lifting arm to be extended considerably beyond that allowed solely by the hydraulic travel of the ram.

The invention may be conveniently described, in its working condition as an elevator, as a structure manufactured from rolled steel sections, mainly of rectangular hollow and angle sections.

It comprises a base formed from two legs at an angle to one another with a cross member attached to them, having wheels at all four extremities, on which two pieces of section steel are mounted to support a pivot about which the compression upright rotates. This compression upright is at its upper end connected to two horizontal stays which sandwich it and through this assembly passes a pivot to which the lower part of the combined hydraulic ram and pump unit is attached. The other ends of the two horizontal stays are attached to two further uprights, the tension uprights, which connect the base at its acute end to the fuicrum for the boom.

Connection of these tension uprights at the lower end is via removable fasteners so as to allow disconnection for folding of the device. The top ends of the tension uprights pass symetrically one either side of the boom at its pivot point with a pivot pin passing through all three members and restrained from lateral movement. The boom extends forward from its pivot point along the longitudinal centre line of the device comprising double depth of section over that portion of its length subject to greater stresses. At the other end of the boom a means is provided for the attachment of loads.Attached by means of removable fastenings between the boom, as a position some fraction of its length forward from the pivot point, and the upper end of the compression upright, is the combined hydraulic ram and pump which exerts a force on the boom causing it to pivot about its fulcrum and raise or lower the free end together with the attachment means. This combined hydraulic ram and pump unit is simply detachable from the steelwork and may be used separately as an elevating unit in its own right or as a portable unit for exerting force in places or restricted access.

In order to increase the arc over which the boom may operate the combined hydraulic ram and pump unit is fitted with a mechanism which may be screwed into and out of the unit and thus allow the operator to utilise the full lifting range of the device.

The attached drawings illustrate the invention in the following manner: Figure 1 is a side elevation of a typical elevator incorporating the invention.

Figure 2 is a side elevation of this elevator illustrating it in its folded condition.

Figure 3 is a fragmented detail of the connection between the tension uprights and the legs, in side elevation.

Figure 4 is a fragmented detail of the compression upright support pieces with the steelwork in its folded condition.

Figure 5 is a front end view of the elevator.

Figure 6 is a fragmented detail of the combined hydraulic ram and pump unit showing the screw mechanism and the fixing method.

Figure 7 is a plan view corresponding to Figure 1.

From Figures 1 and 7 it can be seen that the elevator has a base structure completely fabricated from rectangular hollow section steel with two legs (2) at an angle and joined at one end and a cross member (5) fixed to these legs at right angles to the longitudinal centre line of the device. About this centre line the base is symmetrical. It will be noticed that wheels are fitted to the members described at their extremities, wheels on axles (22) in the case of the legs, and castors (23) in the case of the cross member. At the apex of the legs, attached to the underside, is an angle bracket (9) through which a pair of nuts and bolts (19) may be fastened to restrain the lower ends of the tension uprights (4) and hold the device upright.

Attached to the cross member (5) are two support pieces (7 s 8) which are also of rectangular hollow section. Through the lower portion of these supports passes a pin (17) which forms the pivot about which the compression upright (3) rotates in folding. One of the supports (7) also has a hole W drilled through its upper end which is used to locate a bolt (18) when the elevator is folded. Sandwiched by the supports (7 8 8) is the compression upright also with a hole in its lower end through which a pin (17) passes. With the device in a lifting condition, the compression upright (3) stands vertical above the base structure in the centre of the cross member (5) and having at its upper end two horizontal stays (6) attached rigidly.These horizontal stays are also attached rigidly at their other ends to a point part way along the tension uprights. With the compression upright in a vertical position the tension uprights are also approximately vertical.

The tension uprights (4) have a hole in one of their faces through which the retaining bolts (19) pass to connect this member with the angle bracket (9) when the device is erected. At the top end of the tension members (4) is a connection point for the pin (16) which forms the fulcrum for the boom (1). This pin (16) passing through both tension uprights (4) and the boom (1) between them, allows the boom to pivot about this point. The boom (1) comprises two lengths of rectangular hollow section steel, one being longer than the other, with the longer piece attached firmly above the shorter to form a beam of double depth for some portion of its length. At the end of the boom (1) and on the underside is connected a lifting means (11) which may take the form of a 'U' bolt.

Some way along the boom (1) is a hole Y which aligns with the hole W in the support piece (7) and hole Z in the tension uprights through which a bolt (18) passes when the device is in a collapsed position. The boom (1) also has a hole X through its lower member at some point close to the pivot end through which a removable pin (18) passes connecting the combined hydraulic ram and pump unit to the boom via a 'U' shaped bracket (14).

The combined hydraulic ram and pump unit is therefore connected via brackets (14 8 21) to the boom and the upper end of the compression upright by pivot pins (18 s 20) such that any extension of the hydraulic ram causes the boom to elevate while a contraction of the hydraulic ram causes the boom to lower, hence the means for attaching the load is either raised or lowered.

As can be seen from Figure 6 the combined hydraulic ram and pump unit is fitted with a threaded bar (13) which can screw into and out of the ram and is rotated by means of a tommy bar (12) which is free to slide through a hole in the thrust block (27) which is rigidly attached to the threaded bar. Connection of the combined hydraulic ram and pump unit to the device is by means of bolts (24 s 26). By first removing the tommy bar (12) from the thrust block (27), then unscrewing the top bolt (24) and the bottom bolts (26) the combined hydraulic ram and pump unit may be removed from the steelwork for use elsewhere.

Erecting the elevator from its collapsed position is carried out by removing the bolt (1 8) from holes Y, W and Z as shown in Figures 1 and 4 and pivoting the tension and compression uprights (4 8 3) about the pivot point (17) until in a generally vertical position. At this point the holes at the base of the tension uprights will align with holes in the angle bracket (9) and the two bolts (1 9) are inserted as in Figure 3. The boom (1) is then rotated about its pivot (16) until the 'U' shaped bracket (14) locates on the boom with hole X aligning with the holes V in the 'U' shaped bracket. The bolt (18), removed previously, is inserted through these holes and tightened. The elevator is now ready for work.

The load to be lifted must be securely fastened to the lifting means. Adjustment of the screw mechanism is carried out to ensure that the device will lift and lower the load to the desired height. This is achieved by rotating the tommy bar (12) in the required direction before raising the load by hydraulic action. To lift the load the end of the handle (28) having a special shape is used to screw in the hydraulic valve (29) and is then inserted into the pump lever (30) (see arrow on Figure 5 and also Figure 6) and pumped up and down which raises the forward end of the boom and hence the load. The load can then be lowered by removing the handle (28) from the pump lever (30) and using its shaped end to gently unscrew the hydraulic valve (29) which will cause the forward end of the boom and the load to lower.

A load can be raised to a height in excess of the normal hydraulic travel by simply lifting as described above then placing the load onto a surface some mid-way towards the high surface then readjusting the screw mechanism and continuing lifting.

To fold the device for storage first unscrew and remove the bolt (18) securing the 'U' shaped bracket (14) to the boom and rotate the boom over its pivot until its free end rests upon the floor then unscrew and remove the two bolts (19) at the base of the tension uprights. The vertical steelwork is then hinged forward about the pivot (17) until the hole Y in the boom is made to align with hole W in the support piece (7) and hole Z in the tension upright then the bolt (18), previously removed from the 'U' shaped bracket, is inserted through holes W, Y, Z.

The combined hydraulic ram and pump unit is removed from the structure for use elsewhere by removing the two bolts (26) at its base and removing the 'U' shaped bracket by undoing the screw (25) and sliding the tommy bar (12) through the thrust block (27) then removing the bolt (24) retaining the 'U' shaped bracket.

Claims

1. An elevator operated by the hydraulic principle comprising a base frame of two angled leg members attached to a cross member extending mostly forward thereof and symmetrical about a longitudinal centre line having a wheel fixed to each of the four extremities of these members thereby making the structure mobile, to which is attached, at the centre point of the cross member, a vertical compression member bearing at its upper end an integral hydraulic pump and ram unit attached by means of a pivot, with two vertical tension members, parallel to the compression member and attached to it by a horizontal member at some point along its length and secured to the apex of the leg members where they meet, extending upwards to a point through which a pivot, also passing through the boom at its rear most end, sandwiched between the two tension members, allowing the boom to rotate relative to the tension members, the boom being on the longitudinal centre line of the elevator extending forwards of the pivot and having at its forward end a means for attaching loads, intermediate along its length, a further connection point by which is attached the upper end of the ram unit is provided, the ram therefore connecting between the boom and the upper end of the vertical compression member at a point forward of the pivot, whereby operation of the pump, integral within the hydraulic ram, causes extension or retraction of the ram's cyiinder which, in turn, causes angular movement of the boom about its pivot and raising or lowering of the means for attachment of loads.

2. An elevator as claimed in Claim 1 wherein the combined hydraulic pump and ram is fitted with a screw mechanism enabling adjustment of the spacing between the base of the ram and its point of connection with the boom, and thereby the angle of the boom, by turning a screwthreaded shaft connected to the boom, within a nut connected to the ram thereby altering the height of the means of attachment of loads without operation of the hydraulic cylinder.

3. An elevator as claimed in Claims 1 and 2 wherein the combined hydraulic pump and ram unit may be removed from the elevator, by withdrawal of the bolts provided for this purpose, such that it may be used for lifting, jacking or ram duties as a unit in its own right.

4. An elevator as claimed in any one of the Claims 1 to 3 wherein the vertical tension members and compression member pivot together relative to the base structure, about a pivot at the base of the compression member, from their normally vertical position parallel to the forward extending angled leg members.

5. An elevator as claimed in Claim 4 when dependent upon any one of Claims 1 to 3 wherein the boom may be pivoted relative to the extension and compression members into a horizontal position so as to lie paraliel with them and the base structure upon their pivoting to a horizontal position.

6. An elevator as claimed in any one of the preceding Claims wherein insertion of the bolt removed from the boom/hydraulic ram connection point may be inserted through holes in the boom, tension members and upstanding support brackets, which align upon folding, in order to secure the folded structure in a rigid condition suitable for movement without obstruction on its own wheels in this folded condition,

7. An elevator as claimed in any one of the preceding Claims wherein the pivot, by which the vertical compression member is attached to the base, passes also through two upstanding brackets attached directly to the cross member one either side of the compression member equidistant from the centre of the cross member.

8. An elevator as claimed in any one of the preceding Claims wherein the screw-thread mechanism attached to the combined hydraulic pump and ram unit is provided with a tommy bar for turning and adjusting of the screw-thread.

9. An elevator as claimed in any one of the preceding Claims wherein the means for attachment of loads comprises a load lifting eye or hook.

10. An elevator as claimed in any one of the preceding Claims wherein the boom comprises two members attached vertically above one another over part of their length.

11. An elevator as claimed in any one of the preceding Claims wherein at least two of the wheels are on castors providing steerage of the unit.

12. An elevator as claimed in any one of the preceding Claims wherein the structure is welded together such that failure of any individual weld will not cause sudden catastrophic collapse of the structure.

1 3. An elevator substantially as herein described with reference to and as illustrated in the accompanying drawings.