EP0009855A1

EP0009855A1 - Method and device for hoisting and suspending high level cantilevered structures

Info

Publication number: EP0009855A1
Application number: EP79300175A
Authority: EP
Inventors: James Borland
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-09-29
Filing date: 1979-02-05
Publication date: 1980-04-16

Abstract

Methods of hoisting and suspending high level cantilevered structures (14) such as frames boards and boxes particularly at inaccessible heights on a wall mounted support arm (5) which is brought into position through a bore (2) in the wall by means of a resiliently flexible tapered rod erection tool (1) projected through the bore from the vantage point inside the building and onto the end of which the support arm (5) is hoisted and sleeved over for manipulation through the wall.

The structure (14) is then hoisted and suspended on the support arm (5) either free hanging on the cantilever, or against the wall by using two secondary cables emerging from an orifice underneath at the backing plate (20) with the wall.

The support arm (5) cantilever is curved downward to reduce slip drag on the cables and the vertically downward pointing orifice (8) is flaired to afford unobstructed passage to cable joints and for locating purposes.

Description

This invention relates to methods of hoisting and suspending cantilevered structures at a high level on the wall surfaces of buildings.
The invention is particularly applicable to the erection at a high level on the walls of buildings of attack resistant enclosures, containing for example, surveillance cameras, alarm signalling equipment, security lighting and the like. It also applies to display sigris, advertising hoardings and almost anything which requires to be mounted on a vertical wall surface at a high level.
When erecting and servicing cantilevered structures at a high level it is usually necessary to use ladders, cranes, scaffolding and the like. This conventional equipment is expensive, can be obstructive and also dangerous to the personnel involved. The present invention seeks to provide a method of hoisting and suspending high level cantilevered structures which will remove the need for conventional kinds of equipment whilst still providing a safe and practical system which allows for subsequent removal for service or replacement of the structure and its contents.
In its broadest aspect, the invention envisages the use of a hoisting line passing through a long resiliently flexible hollow tapered rod which is projected through a bore in the wall at the height which it is desired to anchor the cantilevered structure which could be at some convenient floor level of the building.
The rod is so positioned that means to reel in and reel out the hoisting line are on the inside of the wall at one end of the rod, and the other end projects outwardly as a resiliently flexible cantilever from the outside. The arrangement generally resembles a fishing rod and line complete with reel. The hoisting line is extended to the ground and attached to a tubular support arm which is then hoisted until it sleeves over the curved cantilever of the resiliently flexible arm so being brought into suitable attitude for manipulation through the wall, to be secured in position. The rod and line is then removed and a winch line is passed through the support arm and extended to the ground or any accessible level where it is attached to the structure which is to be hoisted and suspended on the support arm. When hoisting of the structure is complete, it is held by clamping its suspension cables securely on the inside of the wall.
Methods of hoisting and suspending high level cantilevered structures, all of which embody the invention are illustrated in the accompanying drawings. These methods will now be described by way of example and with reference to the drawings in which:- Figures 1 to 4 show successive stages in the erection of the support arm. Figures 4 to 7 show methods of hoisting and suspending two types of structures. Figure 8 shows a heavy duty support arm with accessories. Figure 9 shows an attack resistant enclosure suspended on an attack resistant support arm for security applications. In Figure 1, an erecting tool comprising a long hollow resiliently flexible tapered rod 1, resembling a fishing rod, is projected through a bore in the wall 2, from the inside of the building. A hoist line 3 passes through the rod from the reel 4 at the inside end and emerges at the tapered end to be extended to the ground where it is passed through the proposed tubular support arm 5. A stopper 6 is then secured to the line where it emerges and the support arm is shown being hoisted. Precaution must be taken to avoid excessive swing by the support arm during its ascent to prevent collision with the wall, for example a strain line may be used, which is attached to the stopper and controlled from the ground.
Figure 2 shows the support arm fully hoisted and sleeved onto the tapered rod to give it a suitable attitude for manipulation into the bore in the wall when the erecting tool is withdrawn.
To improve the horizontal attitude, the support arm may be sleeved further onto the tapered rod by a - tubular extension 7 plugged into the flaired orifice 8 of the support arm with the hoisting line extended through so that the hoist line pull holds it in position and when the pull is released it falls away with the stopper 6. This method is shown in Figure 3.
Figure 4 shows the support arm 5 fully erected and clamped through the wall. The tapered rod erection tool has been removed, a power winch 9 has been brought into use with its hoisting cable 10 passing through the support arm and extended to ground level where it has been connected to the suspension cable 11 of the structure 12,-which may include electrical wires, by means of a coupling yoke 13 consisting of a train of miniature screw clamps. The structure is shown in the process of being hoisted.
Figure 5 shows the structure fully hoisted and suspended in a free hanging mode which is particularly applicable to attack resistant enclosures 14. The coupling yoke 13 has been drawn through the support arm 5 and the suspension cable has been securely clamped to the panel on the interior wall surface where it has emerged from the support arm, before being released from the hoisting cable. Electrical connections are then made if applicable. The reverse procedure applies when lowering the structure for service or replacement.
Referring now to Figure 6, the structure being hoisted is a frame 15, which could be a display sign or advertising board or the like. An arm 16 extends out from the balance point on the top edge of the frame. To the end of this arm is attached the main suspension cable 11 of the structure. The length of this arm from the back of the frame to the point of attachment is slightly greater than the horizontal distance from the wall surface to the support arm orifice.
Two secondary suspension cables 17 each equidistant from the arm on opposite sides thereof, are attached to the top edge of the frame structure. Two lines 18 emerge from an orifice 19 on the underside of the support arm at the wall backing plate 20, and are attached one to each of the secondary suspension cables 17.
The frame is hoisted by the main suspension cable in the same manner as in the previous example and the extensive lines 18 attached to the secondary suspension cables are used to keep the structure 12 clear of the wall during its ascent by control from the ground.
When the coupling yoke 13 reaches the support arm orifice 8, the structure is held there temporarily whilst the two secondary lines 18 are wound in until the attachement yoke 21 to each of the secondary suspension cables is clearly drawn through the support arm 5. The cables 17 are then released from the lines 18 and connected to the hoisting winch in such a manner that all three suspension cables are used to bring the frame structure into position hard against the wall as shown in Figure 7. The three suspension cables are then securely clamped where they emerge at the inner end of the support arm before being released from the winch. Electrical connections may then be made if required. This method is the three point suspension linkage mode and is particularly applicable to the erection of frames, boards and boxes which must be sustained in position against the wall surface and require to be lowered at regular intervals for service and replacement, which is accomplished by the reverse procedure to that described.
The support arm 5 referred to throughout is shown in its simplest form in Figures 1 to 7. It consists of a suitable length of strong pipe or tubing and that part protruding out from the wall when in use is curved downward and its vertically downward pointing orifice 8 is flaired to remove obstruction to the hoistline coupling yoke 13 on passing through and to help locate the dowel, of needed, of the suspended structure.
There is also a secondary orifice on its underside at the backing plate 20 with the wall which is used in the three point suspension mode described.
The curvature of the arm minimises slip drag friction on the hoisting and suspension cables on passing through in the same manner as does the resiliently flexible rod 1 used to hoist and erect the support arm.
A backing plate 20 locates the support arm against the wall and seals the bore on the outer surface and the internal end seals the bore on the outer surface and the internal end of the pipe which passes through the bore is made to accommodate a plate and lock nut 22 or other fastening means to secure the support arm in position through the wall. The bore drilled through the wall need be sufficient only to accommodate the pipe passing through with a little tolerance for manipulation. If the wall is of thin fabric construction then the support arm is secured by fixing to an interior wall beam.
For heavy duty applications such as the suspending of workmen's platforms, the support arm is reinforced between its backing plate and outer end by twin beams 23. This is shown in Figure 8. A hook coupling 24 loaded with the platform elevating tackle, for example, is hoisted as previously described until it engages in the slot 25 by ratchet action when the pull on its suspension cable 11 is relaxed. To disengage the coupling the pull is restored to lift the ratchet link clear of the slot and by pulling on strain line 26, controlled manually from the ground, the link is held clear as it is lowered past the end of the support arm.
Figure 9 shows a support arm adapted for high security purposes. It is used in conjunction with the attack resistant enclosure 14 suspended in the free hanging mode as depicted in Figure 5. When in position for use, the protruding part is inclined downward and is straight throughout its length from the backing plate 20 to the downward pointing orifice 8. It is delta finned 27 along its length which together with the downward incline makes the support arm resistant to all forms of attack including roping.
The cubiform attack resistant enclosure 14 is suspended by one of its corners which is the apex of the enclosure. In this form it presents deflecting sloping sides and edges to attack by projectiles and the like from the ground, and because it is free hanging it will swing resiliently when hit.
The enclosure comprises a visor 28 through which the enclosed camera or lighting is applied. It consists of three laminated glass plates arranged together in such a manner that impact on any one will not allow it to collapse inwardly but will be sustained in position by the other two.
The visor is surrounded by a ring of thin stiff rods 29. These project outward from the enclosure and converge at an effective distance ahead of the visor 28. They add to the difficulty of blinding it out.
To improve resilience to attack the enclosure, the enclosed equipment itself can be resiliently suspended within. This would permit, for example, a camera to remain relatively motionless whilst the enclosure swings in response to attack.
Because of the inaccessible height at which the equipment can be erected, close quarter attack by an assailant is discounted.
As in all other applications of the invention, the attack resistant enclosure with contents can be lowered at any time for service and replacement by operation from the vantage point by the support arm on the inside of the wall.

Claims

1. Methods of hoisting and suspending high level cantilevered structures on the wall surfaces of buildings characterized by a support arm (5) which is hoisted and manipulated into position through a bore in the wall (2) by means of an erection tool(l) projected through the bore. The support arm is the means on which the structure (12) is hoisted and suspended, either free hanging on the outwardly protruding end of it or by three point linkage which holds the structure (12) against the wall.

2. An erection tool as claimed in claim 1 comprising a resiliently flexible rod (1) which is hollow and tapered to its projecting end and through which a hoisting line passes from a winding reel (4) at its base and onto the tapered end of which the support arm (5) can be sleeved.

3. A support arm (5) as claimed in claim 1 which is tubular and extends through the wall when in use where it is clamped in position, and that part protruding outward from the backing plate (20) with the wall to form a cantilever, is curved or inclined downward to a vertically downward pointing flaired orifice (8). There is also an orifice or twin orifices (19) on its underside at the backing plate (20).

4. A vertically downward pointing flaired orifice as claimed in claim 3 which affords unobstructed passage to the coupling yoke (13) which connects the hoisting cable (10) to the suspension cable (11) of the structure (12) and for locating auxilliary parts such as the tubular extension (7).

5. A coupling yoke as claimed in claim 4 which consists of a number, dependent on strength required, of miniature screw clamps, each one coupling a strand on one cable to a strand on the other and arranged in sequence so that one joint follows the other.

6. A support arm as claimed in claim 3 which is reinforced with twin cantilever beams (23) and onto the end of which a hook coupling (24) can be linked by ratchet action.

7. A support arm as claimed in claim 3 in which the cantilevered part in inclined downward in use and has three delta shaped fins (27) along its length and radially equidistant to each other. The depth of the fins increases along its length outwards.

8. A delta finned support arm as claimed in claim 7 onto which a cubiform enclosure (14) is hoisted and freely suspended by one of its corners. It comprises a visor (28) consisting of three laminated glass plates or the like at right angles to each other which are so arranged that when impact is applied to any one, it is supported in position by the other two.

9. A cubiform enclosure as claimed in claim 8 inside which the contents are resiliently suspended on the same suspension cable.

10. A visor as claimed in claim 8 which is surrounded by a ring of thin stiff rods (29) which project outward and converge at an effective distance in front of the visor.