AU613685B2

AU613685B2 - Column hoists

Info

Publication number: AU613685B2
Application number: AU26678/88A
Authority: AU
Inventors: Don Grkovic
Original assignee: NINA VICTORIA GRKOVIC
Current assignee: Roelofs Robyn Ann
Priority date: 1987-12-08
Filing date: 1988-12-08
Publication date: 1991-08-08
Anticipated expiration: 2008-12-08
Also published as: AU2667888A

Description

~3?rS9 COMMONWEALTH OF AUSTRALIA Patents Act 1952 Ie Ir 1 I *e I

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I 4 iir, 4 Name of Applicant Address of Applicant: NINA VICZORIA GRKOVIC 2 Apex Heights, Australia Street, Balmoral Queensland, 4171, Actual Inventor Address for Service DON GRKOVIC GRANT ADAMS COMPANY, Patent Trade Mark Attorneys, 333 Adelaide Street, BRISBANE. QUEENSLAND. 4000

AUSTRALIA.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: "COLUMN HOISTS" The following statement is a full description of the invention including the best method of performing it known to the applicant.

THIS INVENTION relates to improvements in column hoists, which are suitable for lifting vehicles or other loads.

Column hoists for vehicles are generally of two alternative constructions. Hydraulic hoists use hydraulic rams to raise and lower the load platform.

The hydraulic hoses and seals are liable to failure and are expensive to manufacture or maintain. Screw-type hoists using travelling nuts which travel along rotating screws are also known. The screws are liable to wear and must be maintained and lubricated to prevent early failure. Due to the large friction losses between the screws and thc travelling nuts, the efficiency of those hoists is low.

It is an object of the present invention to provide a column hoist which is relatively inexpensive and simple to manufacture and maintain.

,It is a preferred object to provide a hoist which can be readily collapsed, for transport.

Other preferred objects of the present invention will become apparent from the following description.

In a broad aspect, the present invention resides in a column hoist for vehicles or other loads including: a pair of spaced, normally upright columns; a load platform provided on each column, guided for vertical movement by its respective column; respective pulley or sheave means rotatably mounted adjacent the upper and lower ends of each column; and a further pulley or sheave means provided on the first of the load platforms, wherein: a drive means is mounted at the upper end of the first column supporting the first load platform anid provided with a chain engaging pulley or sheave, t'he 2 'V I I I chain engaging pulley or sheave having formations to provide driving engagement with a chain means; a first chain means is anchored at one end to the upper end of the first column and successive runs of the first chain means pass around the further pulley or sheave means and the pulley or sheave means at the upper end of the first column and the first chain means pass around the further pulley or sheave means and the pulley or sheave means at the upper end of the first column and the first chain means is in driving engagement with the chain engaging pulley or sheave; and a second chain means interconnects the two load platform, so arranged that the two load platforms are simultaneously raised or lowered relative to the columns.

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Preferably at lea8t one counterweight is attached to the chain jv-cab®- To enable the invention to be fully understood, a preferred embodiment will now be described with reference to the accompanying drawings, in which: FIG. 1 is a side elevation view of a first embodiment of the hoist; FIG. 2 is a top plan view of the base frame of the hoist; FIG. 3 is a rear elevation view of one of the columns of the hoist, parts being omitted for clarity; FIG. 4 is a similar view of the other column; FIG. 5 is a plan view of one of the load platforms on its column; FIG. 6 is an exploded view of components of the column of FIG 3; FIG. 6A is an exploded view of the pulley assembly for the column of FIG. 4; FIG. 7 is an exploded view of the components of one of the load platforms; FIG. 8 is a plan view of a portion of the control unit for the arms of the load platform; FIG. 9 is a general view of a second embodiment of the hoist; FIG. 10 is a general view of the hoist folded .or transport; FIGS. 11 and 12 are respective perspective views showing the hinged mountings of the columns to the base frame; FIG. 13 is a perspective view of the chain drive assembly on the first column; FIG. 14 is a perspective view of the tail sheave on the second column; and FIG. 15 is a perspective view of a mechanical rrg rf ~1 s7 c; r.

nrr=~I i brake assembly which may be fitted to the hoist.

Referring to FIGS. 1 to 5, the column hoist of the first embodiment has a pair of columns 11, 12 hingedly mounted on a base frame 13.

The base frame 13 (see FIG. 2) is sustantially rectangular in plan and has side rails 14 interconnected by lateral stringers 15, and end rails 16 with hingedly mounted wings 17 which may be extended horizontally for improved stability of the hoist, or swung upwardly to a substantially vertical position to reduce the floor area of the base frame 13 for transport. In the vertical position, the wings may also support a second similar column hoist during transport.

A substantially channel shaped tray 18 extends substantially the length of the space frame along the longitudinal axis thereof. Mounting blocks i which rotatably support pulleys or sheaves 20, are provided adjacent each end of the tray 18.

Each column 11, 12 has a substantially Ushaped base plate 21 (see FIG. 6) which has substantially vertical side plates hingedly mounted on the side rails 14 of the base frame 13 by pivot pins 22.

The side plates 23 of the column 12 are shorter than the corresponding side plates 24 of the. column 11. This enables the column 11 to overlie column 12 when both are folded down to their transport positions substahtially parallel to the base frame 13.

Referring now to FIGS. 3, 4 and 6, each column i 11, 12 has a pair of parallel substantially vertical 4 30 column side plates 25 and tubular column members 26 fixed at their lower ends to the base plate 21 and interconnected at their upper ends by a rectangular top frame assembly 27, the top frame assembly being bolted to head plates 28.

An arrestor bar 29 is fixed at its upper end T i to the rear of the top frame 27 and depends substantially vertically therefrom.

A pair of bearing housings 30 are bolted to the top of the top frame 27 on column 12 and are fitted with bearings 31 which rotatably journal a shaft 32 connected to the output side of a gearbox 32a driven an electric motor 32b. A plurality of pulleys or sheaves 33 are rotatably mounted on the shaft 32 together with a chain pulley or sheave 34 which is non-rotatably keyed i1 0 to the shaft 32 by a key Referring to FIG. 6A, bearing housings 36 are mounted at the upper ends of the side beams 26 of the column 12 and they are provided with bearings, now shown, which rotatably journal a shaft 37 provided with pulley or sheaves 38, similar to the pulley and sheaves 33 on the column 11.

Referring to FIGS. i, 3, 4, 5 and 7, each column 11, 12 is provided with a respective load platform 39 which has a pair of removable telescopic side arvis 40 interconnected by a transverse stringer 41.

Each side arm 40 has a tubular inner section 42 provided with a bifurcated yoke 43 which has an aligned pair of holes 44 adapted to be aligned with a respective hole in the transverse stringer 41 to receive a removable locking pin 46 retained by a retainer pin 47. The outer end 48 of each side arm 40 has a series of holes 49 along its length which may receive a locking pin passing through aligned holes in the inner section 42 to enable the outer end 48 to be selectively locked in position.

A vertically adjustable load pad 50 is screw-threadably received in a hole 51 at the distal end of the outer end 48 of each side arm.

The extent of vertical travel of each load platform 39 is shown in FIG. 1.

Each load platform 39 has a traveller assembly 6 i I 52 which has a pair of spac..d parallel side plates 53 welded at their forward ends to the stringer 41 and t interconnected at their rearward ends by a substantially L-section tail bar 54. A front pair of rollers 55 which bear on the front faces of the side beams 26 of the two columns are rotatably mounted on pins 56 received in tubular housings 57 on the stringers 41. A second set of rollers 58 which bear against the rear faces of the side beams 26 are rotatably mounted on the ends of a axel member 59 fixed in a socket 60 defined by the side plates 53, the tail rail 54 and a pair of mounting plates 61 welded to the inner faces of the side plates 53. The mounting plates 61 are interconnected by a vertical brace 62.

Aligned holes 63 are provided in the mounting plates 61. and these receive a removable axel 64, located by a washer 65 and stud 66, which rotatably journals a plurality of pulleys or sheaves 67.

Referring to FIG. 8, the angular relationship between the side arms 40 and the stringer 41 on each load platform 39 can be adjustably set by a linkage 68 attached at one end to a bracket 69 on each side arm and passing through an adjustable lock 70 mounted on the stringer.

Referring now to FIGS. 1, 3 and 6, one end of a first chain 71 is attached to pair of anchor plates 72 (by a pin not shown) on the top frame 27 of column 11.

The first run of the chain extends down and around a pulley or sheave 67 on the traveller assembly 52 of the load platform 39 on column 11. The second run of the chain extends upwardly and over a first pulley or sheave 33 on the top of the column 11ii. The third run extends down and around a second sheave 67 on the traveller assembly 52. The fourth run extends up and over a second pulley or sheave 33 and a fifth run extends down 7 and around a third pulley or sheave 67 on the traveller assembly 52. The sixth run of the chain 71 extends up and around the chain pulley or sheave 24 which has shaped recesses 73 to provide driving engagement between the chain pulley or sheave 34 and the lengths of the chain 71. The seventh run of the chain 71 hangs freely from the chain pulley or sheave 34.

One end of a second chain 74 is attached to the traveller assembly 52 of the load unit 39 on column 11 and passes around the pulley or sheave 20 adjacent the base of that column, extends along the tray 18 and around the pulley or sheave 20 adjacent the base of the second column 12. The second chain 74 then extends up and around the pulley or sheave 38 at the top of column 12 and down to where the other end of the chain is attached to the traveller assembly 52 of the load platform 39 on the column 12.

When the motor 32b and gearbox 32a are operating to drive the shaft 32 to cause chain pulley or -heave 34 to pull in, i.e. reduce the length of chain 71 between the top of the column 11 and the traveller assembly 52 on the load platform 39 on that column, the second column 74 simultaneously causes the distance between the top of the column 12 and the traveller of the load platform 39 on the column 12 to be reduced so that the two load platforms are raised simultaneously.

Depending on the number of runs of chain (and therefore I the number of pulleys or sheaves 33, 67 on column 11), the relative lifting rate to motor speed and lifting capacity to rated output of the motor 32b can be varied, for example, an approximately 1.1 kw (11 horse power motor) can be sufficient to raise and lower a load of five tonnes on the hoist To provide safety should a run of either chain 71 or 74 occur, safety braking means are provided on 1 each load platform. A brake housing 75 is mounted on Sthe tail rail 54 of each traveller assembly 52 and slidably receives the arrestor bar 29 of the column on which the traveller is mounted. A locking pin 76 is rotatably journalled in aligned holes, not shown, in the side plate 77 of the brake housing 75. T'e pin 76 has a braking cam 78 within an eccentric bore 79 affixed thereto by a locking pin 80. Rotation of the braking cam 78 into engagement with the arrestor bar 29 will progressively lock the traveller against downward movement on the column 11, 12 on which it is mounted.

The braking pin 76 is operated by a braking arm 81 which has a yoke 82 secured to the pin 76 by studs 83. A pair of spaced side plates 84 are interconnected by a pin on which is rotatably mounted a pulley or sheave 86 which is urged into engagement with one of the runs of the chain 71 by a tension spring, not shown, provided between the braking arm 81 and a fixed mount on the traveller assembly 52. Tension in the chain run causes S 20 the roller 86 to urge the braking arm to a position where the braking cam 78 is free of engagement with the arrestor bar 29. If, however, the tension on the chain run should be lost, e.g. due to a failure in the chain, the tension spring will cause the braking arm to rotate the pin 76 to progressively urge the braking cam into braking engagement with the arrestor bar to apply a braking force to the traveller assembly 52 and thereby the load platform on the columm. (In a modified arrangement, not shown, the side arms 82 may be replaced by a single arm which at its forward end has a balance bar each provided with a respective pulley or sheave 86 respective outer runs of the chain 76. Should the tension be lost in either of the outer runs of that chain, then the tension spring will cause the braking cam to be applied to the arresting bar.) The braking I

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system for column 12 will be as described for a column 11 except the pulley or sheave 86 will bear on a run of the chain 74.

Referring now to FIGS. 9 and 10, the column hoist 110 of the second embodiment has a pair of columns 111, 112 mounted on a base frame 113. The base frame 113 has hinged "wings" 114 which may be folded (see FIG.

to reduce the area of the base frame for transport and to support a second, similar hoist, during transport.

Each column 111, 112 has a pair of parallel side beams 115, 116 which are provided with nylon guide/wear pads. A foot plate 117, 118 for each column is hingedly mounted on the base frame to enable the columns to be moved between a vertical working position (see FIG. 9 and a horizontal transport position (see FIG. 10). The hinges 119 for the first column 111 are longer than the hinges 120 for the second column 112 to enble the columns to be overlapped (see FIG. Bolts, (not shown), are used to releasably secured the foot plates 117, 118 to the base frame 113 when the hoist is in use.

A load platform 121 on each column 111, 112 has a pair of side arms 122 with a transverse stringer 123 arranged to engage the chassis or body of the vehicle being lifted. (Wheel engaging pads may be provided on the stringers, if preferred.) The outer ends of the platform have blocks 124 guided by the nylon guide/wear pads on the side beams 115, 116 on the two columns 111, 112.

Referring now to FIG. 13, a sheave 125 is keyed to the output shaft 126 of a reduction gearbox 127 driven by an electric motor 128. The shaft 126 is journalled in bearings 129 at the upper end of the first column 111. The sheave has formations (not shown) in its circumferential groove to drivingly engage the links of a chain 130. A curved bracket 131 prevents the chain from slipping from the sheave.

One end of the chain 130 is connected to the load platform 121 mounted on the first column 111. The chain passes ovor the sheave 125 and around a second sheave 132 which has a shaft 133 journalled in bearings 134 on the foot plate 117. (The central groove and the flats on the perimeter of the sheave ensure accurate location of the c'hain around the sheave.) The chain 131 then passes around a similar sheave 135 at the base of the second column 112, over a third sheave 136 at the top of the second column 112 and is attached at its end to the load platform 121 on the second column 1112. A counterweight 137 is slidably mounted on the first column 111 and is attached to the chain 130 to counterbalance, at least in part, the weight of the two load platforms 121 and any vehicle thereon.

By operating the motor 128, the sheave 125 causes the chain to raise tbq load platform 122 on the first column 11l, and simultaneously, raise the load Platform 122 on the second column 112, the chain passing around the sheaVies 132, 135 and 136. Reversing the motor causes the load platforms 122 to be lower'ed.

in a modified form, of the invention (not shown), the free end of the chain 130 is connected to the counterweight 137 and the chain passes over the sheave 125 and around sheave 132, the load platform 121 on the first column being attached to the downward run of the chain between the two sheaves.

For heavy load---, the multiple sheave assemblies may be provided on each column so that the chain passes over each assembly several times, and to reduce the vertical Velocity of the load platforms for a given driving speed of the motor 128.

A mechanical brake assembly 150 (see FIG. may be provided for each load platform 121. A carrier 151 is mounted on arms 152 on the load platform and slidably supports a n 153 which can engage aligned holes 154 on the adjacent beam 115 of the column 111, 112.

A tension spring 155 urges the pin 153 towards locking engagement with the holes but is opposed by the tension in the chain 130 which is engaged by the fingers 156 of a yoke 157 on the pin 153. If the tension is released, should the chain 130 even fail, the pin 153 will engage the holes 153 and lock the load platforms 121 to their respective columns.

Various changes and modifications may be made to the embodiments described without departing from the scope of the present invention defined in the appended l claims.

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Claims

1. A column hoist for vehicles or other loads, including: a pair of spaced, normally upright columns; a load platform provided on each column, guided for vertical movement by its respective column; respective pulley or sheave means rotatably mounted adjacent the upper and lower, ends of each column; and a further pulley or sheave means provided on the first of the load platforms, wherein: a drive means is mounted at the upper end of the first column supporting the first load platform and provided with a chain engaging pulley or sheave, the chain engaging pulley or sheave having formations to provide driving engagement with a chain means; a first chain means is anchored at one end to the upper end of the first column and successive runs of the first chain means pass around the further pulley or sheave means and the pulley or sheave means at the upper end of the first column and the first chain means pass around the. further pulley or sheave means and the pulley or sheave means at the upper end of the first column and the first chain means is in driving engagement with the cha;;,n engaging pulley or sheave; and a second chain means interconnects the two load platforms, so arranged that the two load platforms are simultaneously raised or lowered relative to the columns.

2. A column hoist according to Claim 1 wherein the second chain means is connected at one end to the first load platform, passes successively around tho "ley and sheave means at the lower end of the first column and then at the lower and upper ends of the second column and is connected at its other end to the second of the load platforms. 13 -A (?j

3. A column hoist as claimed in Claim 1 or claim 2 wherein: the drive means includes a motor and gearbox 4 Mounted at the upper end of one of the columns; and the chain engaging pulley or sheave is fixed on a shaft conn~rected to the aitput of the gearbox.

4. A column hoist as claimed in Claim 2 or Claim 3 wherein: each column has a pair of spaced, substantially vertical side beams; and each load platform has a traveller with respective pairs of front and rear rollers which bear on the respective side beam to guide the load platform as they are raised and lowered. S I

5. A column hoist as claimed in any cne of Claims 1 to 4 wherein: the or each Toad platforin has a pair of :4substantially l arallel side ax,, with respective load engaging pads.

6. A column hoist as claimed in any 0 Claims 1 to 5 wherein: the columns are hingedly mouat,;; i base frame and are movable to subs tantal .ly zi,-ontal 6positions, one .f the columns overlies the the columns.

7. A column hoist as claimed in Claim 6 wheretn: the base f rame is provided with hingedly mounted wings adjacent each end, the wings being movable between a substantially horizontal operating position imparting stability to the column hoist and a substantially vertical travelling position where they can support a second similar column hoist.

8. A column hoist as claimed in any one of Claims 1 to 7 wherein: an arrestor bar depends from the upper end of each column; and I i i i; a respective eccentrically mounted braking cam is mounted. on each end of the load platform, or on each of the load platforms and I o)perably connected to a sensor means which detects tne tension in the chain means, so arranged that each braking cam is urged into braking engagement with its arrestor bar when the tension in the chain means falls below a preset level.

9. A column hoist substantially as hereinbefore described with reference to FIGS 1 to 8, or FIGS 9 to 15, of the accompanying drawings. DATED this eighteenth day of March 1991. NINA VICTORIA GRKOVIC, By her Patent Attorneys, GRANT ADAMS COMPANY. r re a r I It te V