96/01353 PC17AU95/00382
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TITLE A PROP
Field of the Invention
The present invention relates to a prop for supporting an article, and in particular, but not exclusively, to a prop for supporting building elements such as ceiling panels and cornices, and other structures such as cabinets while being fixed to a wall, ceiling or the like.
Background of the Invention In the construction of buildings it is often necessary to physically support various articles such as ceiling panels and cornices while those articles are being fixed onto the overall building structure. Typically this is accomplished by having a number of people either directly hold and support the article or support the article by use of poles. For example, when fixing ceiling panels to ceiling rafters typically two people will support the ceiling panel with broom handles while a third person nails or glues a ceiling panel into place. In the case of gluing, it is necessary for the support to the ceiling panel to remain until the glue sets. The use of two, three or more people to support a ceiling panel or other building article is an extremely inefficient use of resources.
It is known at times to temporarily nail battens across ceiling panels to support them whilst glue dries. However, this still requires other people to support the ceiling panels whilst the battens are nailed in place.
Wind up frames are available for raising and supporting ceiling panels while being fixed to rafters. However, such frames are expensive, cumbersome and relatively slow to use. Also, one frame is required for each ceiling panel which further adds to construction costs.
Similarly with the fixing of other articles such as prefabricated cabinets to walls a number of people may be required for an extended period of time to support the cabinet and hold it in place while being fixed to the wall.
Summary of the Invention
It is an object of the present invention to provide a prop for supporting an article which is of simple construction and easy to use.
In accordance with the present invention there is provided a prop for supporting an article comprising: an elongate shaft of adjustable length; and, a resilient element operatively associated with said shaft and disposed between opposite ends of said prop, whereby, in use, the length of said shaft can be adjusted so that said opposite ends of said prop contact said article and a supporting surface respectively with said resilient element in compression whereby said prop can apply a force in the direction of its length to said article.
Preferably said shaft comprises first and second elongate elements, and said first elongate element is telescopically extendable from and retractable into said second elongate element.
Preferably said resilient element is disposed between one of said elongate elements and an end of said prop.
Preferably said prop further comprises releasable locking means for releasably locking said first elongate element to said second elongate element to allow adjustment of the length of said shaft.
Preferably said prop further comprises a leg retained by and extending from said second elongate element and wherein
one end of said resilient element abuts one end of said leg, and a second end of said resilient element abuts a stop provided in said second elongate element.
Preferably a head is provided at one end of said prop for engaging said article.
Preferably said head is pivotally attached to said one end of said prop.
Preferably said head comprises an elongate beam.
Preferably said head is further provided with a finger retained by said beam and movable so as to protrude from a surface of said beam to engage said article.
In an alternate form, said head comprises first and second connected beams extending in different directions.
Preferably said first and second beams are of different length.
Preferably said prop further comprises a cable support detachably connectable to said shaft for supporting cables, ropes and the like.
Brief Description of the Drawings Embodiments of the present invention will now be described with reference to the accompanying drawings in which:
Figure 1 is an exploded sectional view of a first embodiment of a prop in accordance with the present invention; Figure 2A is a side view of a head component of the prop;
Figure 2B is a top view of the head shown in figure 2A;
Figure 3 is a side view of another form of a head component of the prop;
Figure 4 is a side view a cable supporting attachment for the prop; and, Figure 5 is a sectional view of a second embodiment of the prop.
Referring particularly to figure 1, it can be seen that a prop 10 in accordance with an embodiment of the invention comprises an elongate structure 12 of adjustable length disposed between opposite ends 14 and 16 of the prop 10, and a resilient element in the form of a coil spring 18 which is operatively associated with the elongate structure 12 and located between the structure 12 and end 16 of the prop.
The elongate structure 12 comprises a first elongate member in the form of tube 20 and a second elongate member in the form of tube 22. The outer diameter of tube 20 is smaller than the inner diameter of tube 22 so that tube 20 can be telescopically extended from or retracted into tube 22. Locking means in the form of an eccentric cam 24 is attached to an end of tube 20 opposite end 14.
The eccentric cam 24 comprises two discs 26 and 28 which can rotate relative to each other about an axis extending substantially perpendicular to the length of the tube 20. Disc 26 is fixed against rotation to tube 20. The axis passes through the centre of one of the discs 26 and through a point offset of the centre of the other disc 28. The diameter of the discs 26 and 28 is arranged so that when the discs 26 and 28 are in alignment they lightly engage the inner circumferential surface of tube 22 allowing relatively free sliding of tube 20 within tube 22. When tube 20 is twisted about its length relative to tube 22 the discs 26 and 28 rotate relative to each other and, due to the eccentric coupling of the discs become firmly
wedged within tube 22 thereby releasably locking the first tube 20 to the second tube 22 at a selected extension. By twisting tubes 20 and 22 relative to each other in an opposite direction the discs 26 and 28 can again be brought into alignment thereby unlocking the tubes 20 an 22 and allowing relative sliding therebetween.
Collar 30 is provided for coupling the tube 20 to the tube 22. The collar 30 has a diameter at end 32 nearest end 14 of the prop 10 of marginally greater than the outer diameter of tube 20 so as to allow free sliding of the tube 20 through the collar 30. Opposite end 34 of the collar is of a diameter in the order of the diameter of the outer circumferential surface of tube 22 so as to form an interference fit with the outer circumferential surface of tube 22. End 34 of the collar is pressed onto the outer circumferential surface of tube 22 to prevent the first tube 20 from being pulled wholly out of tube 22.
An end cap 36 of relatively high friction material such as rubber is placed over the end of tube 20 at end 14 of the prop 10.
Stop 38 is provided intermediate the length of tube 22 which protrudes from the inner circumferential surface of tube 22. Most conveniently, the stop 38 can be in the form of a plurality of rivets fastened to the tube 22. The stop 38 provides an abutment for one end of the coil spring 18. The length of the tube 22 below the stop 38 and the length of the coil spring 18 are arranged so that the spring 18 when in abutment with stop 38 is retained wholly within tube 22.
Leg 40 has an upper end 42 which is inserted into tube 22 at an end opposite tube 20. End 42 also has a increased diameter portion 44 being of a diameter less than the inner diameter of tube 22 which forms an abutment for the
opposite end of the coil spring 18. Collar 45 of similar construction and function to collar 30 but of reverse disposition is provided about leg 40 for coupling leg 40 to tube 22. End cap 47 of a high friction material such as rubber is pressed onto leg 40 at an end adjacent end 16 of the prop 10.
Depending on the actual use of the prop 10, end cap 36 can be replaced with one of a number of different heads, examples of which are illustrated in Figures 2A, 2B and 3. With particular reference to figures 2A and 2B head 46 comprises a beam 48 provided with a pivot connection 50 in the vicinity of its mid point to a cap 52 which is designed to fit over end of tube 20 after the end cap 36 has been removed. The beam 48 has an upper planar surface 54 for. engaging an article to be supported, such as for example a ceiling panel. A finger 56 is slidably retained within a recess 58 formed in the beam 48. The finger 56 can be moved so as to protrude from surface 54 or alternately so as to lie beneath or at least flush with surface 54. A small notch 60 is formed inboard of the end of finger 56 which can protrude from the surface 54. The notch 60 can engage the edge of panel like articles such as ceiling panels.
An alternate head 46' is shown in figure 3. Head 46' comprises the first and second beams 62 and 64 which extend from a common region 66 in different directions. Pivot point 68 is provided in the vicinity of the common region 66 which couples the head 46' to an cap 70 designed for fitting over end of tube 20 when the end cap 36 is removed. As seen from figure 3, beams 62 and 64 are of different length, although they can of course be of the same length. An arcuate notch 72 is formed between the arms 62 and 64 in the common region 66.
Head 64' is particularly well suited for applications where it is desired to for example support a cabinet against a wall so as to allow the permanent fixing of the cabinet to the wall.
A detachable cable support 74 (refer figure 4) can be attachably connected with the tube 20 for supporting the cables and the like, for example of power tools. The cable support 74 comprises a base 76 having a plurality of integrally formed hooks 78 extending from one surface thereof. A plurality of spring clips 80 are formed on the other side of the base 76 for engaging in holes 82 predrilled in the tube 20 (ref Fig. 1) . The support 74 can be coupled to the tube 20 by inserting the spring clips 80 into the corresponding holes 82. Similarly, the cable support 74 can be removed by merely pulling away from the tube 20.
In an alternate embodiment shown in figure 5, the resilient element 18 of the prop 10 is located between tube 20 in the eccentric cam 24. In this embodiment, the coil spring 18 is retained within a short tube 84 which is slidably retained within an end of tube 20 opposite end 14 of the prop 10. Coil spring 18 abuts a lower end of a tube 84 adjacent the eccentric cam 24 and at its opposite end abuts the bottom of tube 20. In this embodiment, the end cap 47 is fitted over the end of tube 22 opposite tube 20 and the leg 40, and collar 44 of the embodiment shown in figure 1 are dispensed with.
In order to use the prop 10 to support for example a ceiling panel for fixing to a roof structure, typically the head 46 shown in figure 2 is attached to tube 20 and the length of the prop 10 adjusted and locked so as to be slightly greater than the distance between the ceiling panel and an underlying support surface such as the ground. The overall length of the prop is then decreased by pulling
on the tube 22 to cause compression of the coil spring 18. The downward pull on the tube 22 is then released allowing the coil spring 18 to extend so as to push the head 46 against the ceiling panel. A second and/or further props can be similarly used to hold the ceiling panel in place.
Accordingly by virtue of the coil spring 18 or any other resilient element employed, the prop 10 resiliently supports the ceiling panel and consequently applies pressure/force to the ceiling panel. The pressure or force applied can be varied by changing the degree of compression of the coil spring 18. This is achieved by adjusting the length of the shaft 12 to provide the desire of degree of spring compression when the prop 10 is placed between the ceiling panel and the ground.
When it is required to hold prefabricated cabinets or cupboards against a wall for fastening the head 46' can be attached to the end of tube 20 so as to engage a front and underneath surface of the cabinet.
Now that embodiments of the invention have been described in detail it will be apparent to those skilled in the relevant arts that numerous modifications and variations may be made without departing from the basic inventive concepts. For example, the resilient element described in the embodiments is in the form of a coil spring 18. However, other types of resilient elements including self contained pneumatic pistons can be used. Further, different types of feet may be attached or otherwise connected with end 16 of the prop so as to increase a surface area of contact between end 16 and the ground or to make the prop 10 self supporting, for example a foot may be in the form of a plate pivotally attached to end 16 or take the form of a tripod attached to end 16. In addition, other types and configurations of locking means other than the eccentric cam 24 can be used and heads 46, 46' of any
desired shape and configuration may be attached to end 14 of the props 10. All such modifications and variations are deemed to be within the scope of the present invention the nature of which is to be determined from the foregoing description and the appended claims.