AU2005229759A1 - Protective Shelter for Hoist - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Name of Applicant: Actual Inventors Address for service is: PCH Access Pty Ltd Paul Gregory Adrian Gibson WRAY ASSOCIATES Level 4, The Quadrant 1 William Street Perth, WA 6000 Attorney code: WR Invention Title: Protective Shelter for a Hoist The following statement is a full description of this invention, including the best method of performing it known to me:- -2-

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"Protective Shelter for Hoist" Z Field of the Invention 00 oO This invention relates to a hoist incorporating a protective shelter.

The invention has been devised particularly, although not necessarily solely, for N 5 hoists used on construction sites for delivery of materials and equipment

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between two locations, one elevated with respect to the other.

Background Art On construction sites, it is often necessary to convey materials and building equipment between the ground and elevated locations. Mobile hoists, which have transport and operative conditions, are often used for this purpose. Such a mobile hoist comprises a base which is configured to provide a stable support for the hoist when in the operative condition and which is provided with wheels for engaging the ground when the hoist is in the transport condition. Typically, a rocker arrangement is provided to facilitate movement of the hoist between the operative and transport conditions. The hoist includes a hoisting platform moveable along a tower extending from the base.

The hoist typically incorporates controls for its operation, the controls being accessible to a hoist operator at ground level. With this arrangement, there is a danger that materials and equipment being conveyed on the hoisting platform could possibly fall and cause injury to the hoist operator. Additionally, any materials and equipment falling from the elevated location overhead could also possibly strike the operator.

The present invention seeks to provide a way of protecting a hoist operator from falling material and equipment, whether that be from the hoist platform or from an overhead elevated location.

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Disclosure of the Invention Z According to a first aspect of the invention there is provided a hoist comprising a OO tower, a hoisting platform moveable along the tower, and a protective shelter for providing overhead protection to an operator of the hoist, the protective shelter a 5 comprising a canopy extending outwardly from a location adjacent the tower.

The protective shelter preferably further comprises a wall from which the canopy extends, the wall being located adjacent the tower.

NPreferably, the hoisting platform is moveable along one side of the tower and the protective shelter is located on the opposed side of the tower to the hoisting platform.

With this arrangement, the operator is isolated from the hoisting platform by both the wall and the canopy.

Preferably, the hoist is provided with a control station at which the operator is positioned for operation of the hoist, the control station being disposed within the confines of the protective shelter.

The protective shelter may be moveable between operative and stored conditions. For this purpose, the canopy and the wall may be constructed as a unit. In the operative position, the protective shelter provides protection to the operator at the control station. In the stored position, the protective shelter is retracted to facilitate transportation of the hoist.

Preferably, the control station includes a control panel incorporating controls for operation of the hoist, the control panel being mounted on the wall of the protective shelter.

Preferably, the wall and the canopy are of a construction affording protection to the operator at the control station while at the same time providing some visibility therethrough for monitoring the hoisting platform as it is raised or lowered. The wall and canopy may, for example, incorporate a mesh barrier through which the hoisting platform is visible.

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00 Brief Description of the Drawings The invention will be better understood be reference to the following description of one specific embodiment thereof as shown in the accompanying drawings in which: Figure 1 is a perspective view of a hoist according to the embodiment in Noperation on a construction site, with the protective shelter in an operative condition and the hoisting platform in a lowered condition; Figure 2 is a view similar to Figure 1, with the exception that the hoisting platform is in a raised condition; Figure 3 is a side elevational view of the hoist shown in Figure 2; Figure 4 is a perspective view of the hoisting platform from one side thereof; Figure 5 is a perspective view of the hoisting platform from another side thereof; Figure 6 is a perspective view of a cat head mechanism fitted to the upper end of the tower of the hoist; Figure 7 is a similar view to Figure 6, with the exception that it is viewed from an opposed side thereof; Figure 8 is a fragmentary perspective view of the hoist in an operative condition with an operator standing at a control station protected by the protective shelter; Figure 9 is a view similar to Figure 8, with the exception that the operator is away from the control station and the protective shelter is in a stored Z position; 00 Figure 10 is a perspective view of a gate for an accessway for the hoisting S 5 platform, the gate being shown in a retracted condition corresponding to opening of the accessway; Figure 11 is a view similar to Figure 10, with the exception that the gate is Sshown in an extended position corresponding to closing of the accessway; Figure 12 is a schematic view illustrating the hoist in a transport condition, wherein the hoist is attached to a towing vehicle and the protective shelter is in the stored condition; Figures 13, 14 and 15 are schematic side views illustrating progressive movement of the hoist from the transport condition towards an operative condition; and Figure 16 is a schematic side view of the hoist in the operative condition.

Best Mode(s) for Carrying Out the Invention Referring to the drawings, there is shown a hoist 1 according to the embodiment.

The hoist 1 has been devised particularly, although not solely, for use on construction sites and is readily transportable from one site to another. In this regard, the hoist 1 has an operative condition in which it can be used to perform hoisting operations (as shown in Figures 1, 2 and and a transport condition in which it can be towed from one site to another (as shown in Figure 12).

The hoist 1 according to the embodiment will be described in relation to use on a construction site in conjunction with scaffolding 2 erected at the site. The scaffolding 2 includes an elevated platform 3 to, and from, which building materials and equipment can be conveyed by way of the hoist 1. The scaffolding ,n -6- O 2 includes a side barrier 4 adjacent the platform 3 and an access gate 5 in the side barrier 4 to provide access to the hoist. The scaffolding 2 also incorporates 0 Z an outwardly extending guard rail 7 adjacent the location at which the hoist 1 is oO intended to be positioned. The guard rail 7 provides a barrier at one side of the hoist 1 and also operates in conjunction with a part of the hoist, as will be explained later.

In N The hoist 1 comprises a base structure 11 and a tower 13 projecting from the

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I base structure. A hoisting platform 15 is supported on the tower 13 for movement therealong between lowered and raised positions.

The tower 13 comprises a frame structure 17 having longitudinal frame elements, several of which define tracks 18 along which a carriage 19 forming part of the hoisting platform 15 can move. The carriage 19 incorporates flanged rollers 21 engageable with the tracks 18 for rolling movement therealong.

The hoisting platform 15 comprises a frame 23 to which the carriage 19 is attached. The frame 23 supports a platform floor 25 and two opposed sidewalls 27, 28. The carriage 19 is disposed adjacent sidewall 28 on the outer side thereof, as shown in the drawings.

The other two sides of the hoisting platform 15 are open to provide a first accessway 31 and a second accessway 32 in opposed relation to each other.

The first accessway 31 provides access to the hoisting platform 15 when it is at ground level and the second accessway 32 provides access to the hoisting platform when it is raised to a level corresponding to the scaffolding platform 3.

The hoist 1 has a gate 33 for opening and closing the first accessway 31. The two accessways 31, 32 are each provided with a removable barrier line 34 to deter entry. The raised hoisting platform 15 is accessible from the scaffold platform 3 through the access gate 5 in the scaffolding 2, as best seen in Figure 2. The access gate 5 is opened in order to provide access to the hoisting platform 15 when it is in the raised condition, after of course removal of the respective barrier line 34.

q -7- O The hoist gate 33 comprises a barrier 41 slidably moveable between retracted and extended conditions corresponding to opening and closing of the gate. In 0 Z Figure 1 of the drawings, the barrier 41 is shown in its retracted condition oO corresponding to opening of the gate, and in Figure 2 the barrier 41 is shown in the extended condition corresponding to closing of the gate.

In The barrier 41 is supported for sliding movement between the extended and Sretracted conditions by a support structure 43, as first seen in figures 10 and 11.

I The support structure 43 is carried on an arm 45 secured to the tower 13.

The barrier 41 comprises an upper rail 47 and a lower rail 49 interconnected by end members 51. The upper rail 47 is slidably supported in a sleeve 53 and the lower rail 49 is slidably supported in a sleeve 55, the two sleeves 53, 55 forming part of the support structure 43, as best seen in figures 10 and 11. The barrier 41 has some lateral movement when in the extended position, allowing it to move vertically to a limited extent. The lateral movement can arise through a loose sliding fit of the two rails 47, 49 in their respective sleeves 53, 55, as well as through some flexibility in the rails themselves. The limited vertical movement available in the barrier 41 when in the extended condition is utilised for releasably retaining the barrier 41 in the extended position corresponding to closing of the gate. In this regard, the outer end of the upper rail 49 is provided with a downwardly depending lug 57 which can engage against the guard rail 7 on the opposed side thereof the accessway 31. With the lug 57 located against the guard rail 7, the free end of the barrier 41 is supported and also retained in the extended position. When it is desired to open the gate, it is merely necessary for an operator to lift the barrier 41 so as to release the lug 57 from the guard rail 7, thereby allowing the barrier to be retracted and the gate thus opened.

The hoist gate 33 together with the guard rail 7 partly encloses the area of the ground below the lifting platform 15. The enclosure of the ground area is completed by the hoist itself and also the adjacent scaffolding 2. This assists in preventing access to the ground area below the lifting platform 15 when the latter is raised above the ground.

00 A drive means 61 is provided for moving the hoisting platform 15 along the tower 13. The drive means 61 comprises a drive motor and gearbox assembly 63 operably connected to the hoisting platform 15 through a pulley and cable assembly o The drive motor and gearbox assembly 63 includes a single-phase electric motor S69. A control switching system is provided for controlling operation of the motor, including its direction of rotation.

The cable and pulley system 65 includes a cable (not shown) one end of which is connected to a winding drum 66 driven by the motor and gearbox assembly 63, and the other end of which is connected to a cat head 73 located at the top of the tower 17. The cat head 73 incorporates two pulley wheels 75, 77 which form part of the cable and pulley system 65, as best seen in figures 6 and 7.

The motor and gearbox assembly 63, as well as the winding drum 66 are incorporated in the base structure 11.

The hoisting platform 15 also includes a pulley 79 which forms part of the cable and pulley system 65. The pulley 79 is mounted on the carriage 19, as best seen in Figure The cable (not shown) of the cable and pulley assembly 65 extends from the winding drum 66 upwardly to pass around pulley wheels 75, 77 in the cat head 73 and then downwardly to pass around pulley wheel 79 on the lifting platform and then upwardly again to anchoring point 78 on a load cell 80 mounted on the cat head 73.

With this arrangement, winding of the cable onto the winding drum 66 causes the hoisting platform 15 to travel upwardly along the tower 13. Subsequent -9unwinding of the cable from the winding drum causes the hoisting platform 15 to return downwardly along the tower 13.

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z 00 The load cell 80 is responsive to tensile loading of the cable and provides a signal to a control circuit which monitors and compares the signal against a reference which has been set to correspond to a maximum safe load condition for the hoist. Where the load on the hoist is at or below the safe load condition, N the control circuit generates a first signal representative of this condition. In this embodiment, the first signal operates a visual indicator such as a green light Owhich informs the hoist operator of the safe load condition. Where the load on the hoist, as determined by the load cell 80, exceeds the reference by a prescribed "allowable" overload, a warning signal will be generated, thereby alerting the operator to the overload condition so that there is an opportunity to take remedial action if considered necessary. In this embodiment, the overload condition is deemed to be within a range of 100% to 105% of the acceptable safe load condition. The warning signal is indicated in this embodiment by generation of an audible alarm and activation of a visual alarm, such as an amber light.

Where the load condition exceeds the maximum acceptable safe load by a prescribed amount, such as by being in excess of 105% of the maximum safe load condition, the control circuit generates a signal which interrupts operation of the motoring gearbox assembly 63 and which also initiates audible and visual alarms.

The various indicators (eg lights and alarms) identifying the operational status and load on the hoisting platform 15 are incorporated into a control panel 81 location at a control station 83. The control panel 81 also incorporates the control switching system for controlling operation of the electric motor 69, including its direction of rotation.

The control station 83 is located on the opposed side of the tower 13 to the hoisting platform 15, as is evident from the drawings. In this way, an operator is somewhat remote from the hoisting platform 15 during a lifting operation for safety but nevertheless is able to watch the hoisting operation as it proceeds.

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In the drawings, the operator is shown in outline and identified by reference numeral 87.

00 The control station 83 is located within a protective shelter 91 intended to provide protection from falling objects. The protective shelter 91 comprises a wall 93 positioned adjacent the tower 13 and a canopy 95 extending outwardly from the wall 93. With this arrangement, the operator 87 is isolated from the hoisting N platform 15 by both the wall 93 and the canopy 95. The wall 93 and canopy

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incorporate a mesh barrier 97 which affords protection to the operator 87 at the Ocontrol station while at the same time providing some visibility through the mesh for monitoring of the hoisting platform 15 as it is raised or lowered.

The control panel 81 is mounted on the wall 93 for easy access by the operator 87.

The protective shelter 91 comprising the wall 93 and the canopy 95 is constructed as a single unit 99 which is moveable between operative and stored positions. In the operative position, the unit 99 functions as the shelter to provide protection to the operator 87 at the control station. In the stored position, the unit 99 is retracted to facilitate transportation of the hoist. The unit 99 is mounted on a frame structure 96 attached to the tower 13 for pivotal movement between the stored and operative conditions. The frame structure 96 includes an angled frame section 98 against which the wall 93 locates when the protective shelter 91 is in the stored condition. Locking arrangements (not shown) are provided for selectively locking the unit 99 in the stored condition and the operative condition, as the case may be.

The base structure 11 is configured for operation in two modes, one of which provides stable support for the hoist 1 when in the operative condition and the other of which supports the hoist 1 in its transport condition for towing from one location to another. Specifically, the base structure 11 includes a footing 101 for supporting the hoist in the stable manner when the latter is in the operative condition, and wheels 103 for engaging the ground when the hoist is in the Uq -11- Stransport condition. A rocker arrangement 105 is provided to facilitate movement of the hoist between the operative and transport conditions.

0 00oO The cat head 73 incorporates a hitch 107 for coupling the hoist 1 to a towing vehicle 109, as shown in Figure 12 of the drawings. The towing vehicle 109 may incorporate a lifting mechanism 111 to provide lift for the purposes of coupling the hoist 1 to the vehicle 109 and to also assist in moving the hoist between the C transport and operative conditions should such assistance be necessary.

In Movement of the hoist 1 from the towing condition as shown in Figure 12 to the Soperative condition as shown in Figure 16 is illustrated sequentially in intervening Figures 13, 14 and From the foregoing it is evident that the hoist according to the embodiment has a number of significant safety features, including in particular the provision of protection for the hoist operator from objects falling from overhead or from the hoisting platform.

Modifications and improvements can be made without departing from the scope of the invention.

Throughout the specification, unless the context requires otherwise, the word "comprise" or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

Claims (7)

1. 3. A hoist according to claim 1 or 2 wherein the hoisting platform is moveable along one side of the tower and the protective shelter is located on the opposed side of the tower to the hoisting platform.
2. 4. A hoist according to claim 1, 2 or 3 wherein the hoist is provided with a control station at which the operator is positioned for operation of the hoist, the control station being disposed within the confines of the protective shelter. A hoist according to any one of the preceding claims wherein the protective shelter is moveable between operative and stored conditions, whereby in the operative position the protective shelter provides protection to the operator at the control station and in the stored position the protective shelter is retracted to facilitate transportation of the hoist.
3. 6. A hoist according to claim 5 wherein the protective shelter is mounted on a frame structure for pivotal movement between the operative and stored conditions.
4. 7. A hoist according to claim 5 or 6 wherein the protective shelter is selectively lockable in the operative or stored conditions. -13-
5. 8. A hoist according to any one of claims 2 to 7 wherein the control station includes a control panel incorporating controls for operation of the hoist, the control panel being mounted on the wall of the protective shelter.
6. 9. A hoist according to any one of claims 2 to 8 wherein the wall and the canopy are of a construction affording protection to the operator at the control station while at the same time providing some visibility therethrough for monitoring the hoisting platform as it is raised or lowered. A hoist according to claim 9 wherein the wall and canopy mesh barrier through which the hoisting platform is visible.
7. 11. A hoist substantially as herein described with reference to the drawings. incorporates a accompanying Dated this Eighth day of November 2005. PCH Access Pty Ltd Applicant Wray Associates Perth, Western Australia Patent Attorneys for the Applicant