GB2136772A - Hoist for, e.g., roof tiles - Google Patents

Abstract

A hoist for raising articles to a higher level, particularly roof tiles on to a rooftop comprises an elevatable boom (1), a trolley (2), which is capable of travel thereon and which is adapted to co-operate with pusher means (6) provided at one end of the boom (1) so as to transfer a load from the trolley (2) to a storage position at that end of the boom (1). The pusher means preferably comprises pivotal arms (7) mounted on the boom (1) which are adapted to co-operate with the trolley (2) such that contact with the trolley (2) causes the arms (7) to lift, thereby transferring a load from the trolley (2) to a storage area adjacent the end of the boom (1). <IMAGE>

Description

SPECIFICATION Hoist This invention relates to hoists, particularly but not exclusively to hoists for raising a batch of roof tiles from ground to roof top level.

In the tiling of roofs a considerable amount of time and effort is consumed in carrying the tiles up to the roof.

Often the tiles are simply carried in a hod by a man scaling a ladder to the roof. However only a limited number can be carried at any one time.

Alternatively the tiles are hoisted to the roof using for example a block and tackle.

It has also been proposed to use a powered hoist comprising an elevatable boom which can be raised to roof level, carrying a hood-like trolley device which can be loaded at ground level and sent to the upper end of the boom for unloading on to the roof.

The powered hoist arrangement requires one man on the ground to load the trolley and one man on the roof to unload the trolley or alternatively one man to first load the trolley, climb a ladder to the roof to unload the trolley, send it back for the next load and then descend the ladderto load the trolley again.

An object of the present invention is to obviate or mitigate the aforesaid disadvantages.

According to the present invention there is provided a hoist comprising an elevatable boom, a trolley which is capable of travel thereon and which is adapted to co-operate with pusher means provided at one end of the boom so as to transfer a load from the trolley to a storage position at that end of the boom.

Preferably the pusher means comprises pivotal arms mounted on the boom and the trolley is provided with cam follower means for engagement with cam surfaces on the underside of the pivotal arms.

Preferably also the boom includes a pivotal section which can be lowered on to a roof to facilitate removal of a load.

The invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 shows a side view of one end of the elevatable boom with a loaded trolley at the start of its travel; Figure 2 shows a side view of the other end of the elevatable boom with a load held in a storage position; Figure 3 shows a plan view of the end of the elevatable boom shown in Figure 1 except that the load has been omitted to enable detail of the trolley to be shown; Figure 4 shows a plan view of the end of the elevatable boom as shown in Figure 2 but with the load omitted so as not to obscure detail of the boom; Figure 5shows a plan view of the trolley in more detail; and Figure 6 shows a side view of the end of the boom shown in Figures 2 and 4 as it would be positioned with respect to a roof.

According to one embodiment of the invention a hoist comprises an elevatable boom 1, a trolley 2 which is capable of travel from one end of the boom 1 to the other on a guide track 3.

There is provided on the boom 1, pusher means 6 for transferring a load from the trolley to a storage position. The pusher means 6 comprise pivotal arms 7, which can pivot about a point 17 on the boom 1, and support arms 8 which are pivotally attached to the pivotal arms 17 at pivot point 18 and have end portions 9 which slide through sleeves 10.

The trolley 2 is provided with cam follower means 4 for engagement with cam surfaces 5 on the underside of pivotal arms 7 so as to cause raising of the arms 7 as the trolley 2 advances and thereby cause the arms 7 to lift a load from the trolley 2 and push it onto a storage position on the support arms 8.

The boom 1 has at one end thereof a drive unit 11 which, by means of a wire rope 12 and a pulley 13, can be used to cause the trolley 2 to travel from one end of the boom to the other. At the other end of the boom 1 there is provided catch means 14 for holding the load on the support arms 8 at the upper end of the boom 1. This co-operates with catch means 14a on the support arms 8 to lock them in position.

Limit switches 21 and 22 are provided so that stopping and starting positions of the trolley are accurately controlled. The upper limit switch 22 also prevents the trolley 2 being sent up to the top of the boom unless the arms 7 are in the lowered position i.e. resting on stops 25.

The boom 1 is at the other end provided with a pivotal section 15 which can be used to angle that end towards the roof top in order to facilitate removal of a load for use. Adjustment of the angle of this section is accomplished by use of a crank 26 acting through a screw-(27) and-nut (28) device to a pivot 19.

The hoist of this embodiment is suitable for raising batches of tiles to a roof-top for use thereon.

The hoist is positioned adjacent the building whose roof requires tiling and the boom 1 is assembled from a number of sections sufficient to exceed the height of the building. The boom 1 is then elevated to an inclined position so that the pivotal section 15 is overhanging the roof. A man on the roof then turns the crank 26 to adjust the angle of that section and fixes support stay 16 which includes baton hooks 1 6a to secure the hoist to the roof.

A load of tiles is then placed in the trolley 2 at ground level, the drive unit 11 is started and the trolley 2 ascends. The trolley 2 is of such a width that the tiles overhang the edges of the trolley 2 so that as the trolley 2 nears the top of the boom and causes the cam follower means 4 to engage the cam surfaces 5 of the pivotal arms 7 and raise them away from the stops 25, the tiles are pushed forward onto the support arms 8. At the end of its travel the trolley 2 has raised the arms 7 to an upright position and the catch means 14, 14a are engaged so that the tiles are held in a secure storage position even when the trolley is allowed to descend again.

A further feature of this embodiment is the provision of pulleys 23 which can be used for self-elevation of the boom using the drive unit 11, bracket means fitted to the edge of the roof (not shown) and a rope or cable fed through the pulleys and bracket to the drive unit.

Thus by virtue of this invention it is possible for a single man to set up the hoist and transfer batches of tiles to the roof with the minimum number of ascents and descents. A proposed procedure would be to assemble the hoist, climb to the roof, fix a bracket and rope to the edge of the roof, descend and fix the rope to the drive unit 11, elevate the boom 1, climb to the roof and secure the stay 16, descend and load the trolley. Thereafter he can send the trolley to the top of the boom 1 where the load is pushed onto a storage position, recall the trolley and load it ready to be called up when he has used the stored tiles at the other end of the boom. He can optionally carry an additional load of tiles himself when ascending to the roof and thereby have 3 loads available to him for use on the roof.

Various modifications can be made to the embodiment shown without substantially altering the operation of the hoist. For example it is conceivable that the arms 7 could be provided in-board of the track 3 with only minor consequential amendments to the structure of the trolley 2.

Claims (4)

1. A hoist comprising an elevatable boom, a trolley which is capable of travel thereon and which is adapted to co-operate with pusher means provided at one end of the boom so as to transfer a load from the trolley to a storage position at that end of the boom.

2. A hoist according to claim 1 wherein the pusher means comprises pivotal arms mounted on the boom and the trolley is provided with cam follower means for engagement with cam surfaces on the underside of the pivotal arms.

3. A hoist according to claim 1 or claim 2 wherein the boom includes a pivotal section which can be lowered on to a roof to facilitate removal of a load.

4. A hoist according to claim 1 and substantially as hereinbefore described with reference to the accompanying drawings.