LADDER STABILISING DEVICE
FIELD OF THE INVENTION
The present invention relates to stabilising devices. It has been developed primarily as an adjustable stabilising device for ladders and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.
BACKGROUND OF THE INVENTION
Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.
Known ladder stabilising devices have included rigid struts or other support structures releasably attachable to the foot of a ladder. One such device is illustrated in US Patent 4,798,263. While providing some degree of stability, these devices afford no restraint to the top portion of the ladder.
Attempts have been made to provide support for the ladder top but these devices have generally been specifically designed for that purpose and so provide no stability for the foot portion. These devices have included specialised wall hook brackets which must be first secured in position and so are often unsuitable. Other devices have included rigid hooks extending from the top end of the ladder, intended specifically for engaging the ridge of a roof.
It is an object of the present invention to overcome or ameliorate one or more of the disadvantages of the prior art, or at least to provide a useful alternative.
It is an object of the present invention in its preferred form to provide a ladder stabilising device, which can be conveniently attached to the ladder to provide stability to either or both the top or bottom portions as required.
DISCLOSURE OF THE INVENTION
According to the invention there is provided a ladder stabilising device including:
a securing means engagable with a ladder side rail at any one of a plurality of locations along said rail; and a support strut supportively engagable with a support fixture and lockingly engagable with said securing means in any one of a plurality of ladder support configurations with respect to said securing means.
Preferably, the securing means is a clamp releasably engagable with the side rail and the support strut is rotatably and slideably adjustably engagable with the clamp.
The strut preferably includes a proximal portion engagable with the clamp and a distal portion extending away from the proximal portion. The proximal portion preferably extends in an axial direction and the distal portion extends away from the axial direction. In another preferred form, the proximal portion is hingedly connected to the distal portion.
The invention also provides a ladder including a stabilising device as described above.
BRTEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:
Figure 1 is an isometric view of a ladder including four first embodiment stabilising devices according to the invention, shown applied to both the top and foot portions of the ladder;
Figure 2 is a side view of the top portion of the ladder shown in Figure 1 illustrating a stabilising device supportively engaged with a gutter support fixture;
Figure 3 is a front view of a ladder including three stabilising devices according to the invention;
Figure 4 is an enlarged front view of part of Figure 2 showing the ladder stabilising device in greater detail and illustrating its orthogonal degrees of freedom for adjustment relative to the ladder;
Figure 5 is a side view of the stabilising device shown in Figure 4, illustrating the rotational adjustability of the support strut;
Figure 6 is an enlarged sectional view taken on line 6-6 of Figure 4;
• Figure 7 is a view taken on line 7-7 of Figure 6;
Figure 8 is a side view of the top portion of the ladder of Figure 1 but showing the stabilising device supportively engaged with a parapet;
. Figure 9 is a side view of the top portion of the ladder of Figure 1 but showing the stabilising device supportively engaged with a skillion roof;
Figure 10 is a side view of the top portion of the ladder of Figure 1 but showing the stabilising device supportively engaged with a roof ridge;
Figure 11 is a plan view of the top portion of the ladder of Figure 1 but showing the stabilising device supportively engaged with a wall;
Figure 12 is a front view of the stabilising device shown in Figure 11;
Figure 13 is a plan view of the top portion of the ladder of Figure 1 but showing the stabilising device supportively engaged with a pole;
Figure 14 is a front view of the stabilising device shown in Figure 13;
Figure 15 is a front view of a second embodiment of the invention showing a hinged support strut;
Figure 16 is a front view of a third embodiment of the invention showing a straight support strut;
Figure 17 is a front view of a fourth embodiment of the invention showing the support strut with a telescopic arm;
Figure 18 is a front view showing a support strut being used to support an article;
Figure 19 is a cross-sectional view of a fifth embodiment of the invention adapted for incorporation as part of the original ladder showing a C-shaped ladder side rail with an integral t-shaped retaining formation;
Figure 20 is a side view of the ladder shown in Figure 19;
Figure 21 is a cross-sectional view of a sixth embodiment of the invention adapted for incorporation as part of the original ladder showing a C-shaped ladder side . rail with an integral t-shaped retaining groove.
Figure 22 is a side view of the ladder shown in Figure 21;
Figure 23 is a cross-sectional view of a seventh embodiment of the invention adapted for incorporation as part of the original ladder showing a standard C-shaped ladder side rail with a retaining slot formed therein;
Figure 24 is a view of a section of the ladder side rail shown in Figure 23, showing the slot; and
Figure 25 is a cross-sectional view of an eighth embodiment of the invention adapted for incorporation as part of the original ladder showing an I-shaped ladder side rail with an integral t-shaped retaining groove.
PREFERED EMBODIMENTS OF THE INVENTION
Referring to the drawings, the ladder stabilising device includes a securing means in the form of a clamp 1. The clamp is releasably engagable with the side rail 2 of a ladder 3 at any one of a plurality of locations along the rail. A support strut 4 is supportively engagable with a support fixture and is lockingly engagable with the clamp 1 in any one of a plurality of support configurations with respect to the ladder so as to suit the particular support fixture. In this case, the struts 4 are shown supportively engaged with both the ground 5 and a gutter support fixture 6. The strut 4 is rotatably and slideably adjustably engagable with the clamp 1 as best shown in Figures 4 and 5.
Throughout the various embodiments and illustrated applications, corresponding features have been given corresponding reference numerals.
In a first preferred form as shown in Figure 4, the support strut 4 includes an axially extending proximal portion 7 engagable with the clamp 1 and a distal portion 8 extending at an angle away from the axial direction of the proximal portion.
In another embodiment shown in Figure 15, the proximal portion 7 is hingedly connected to the distal portion 8 by a knuckle joint 9. In this embodiment, the proximal and distal portions are releasably lockable in any one of a plurality of angular
confϊgurations using a ratchet device or any other suitable mechanisms as are well known.
In a further embodiment shown in Figure 16, the support strut is straight. In another embodiment shown in Figure 17 the support strut has an extendable telescopic distal portion 10.
As shown in Figures 6 and 7, the preferred 'universal' type clamp includes a bracket 11 for at least partial encirclement of the ladder side rail 2. The bracket includes a plurality of interior abutment surfaces 12 engagable with the ladder side rail. The bracket also includes a releasable fastening means in the form of a clamping screw 13 for securing the bracket to the ladder side rail. A locking sleeve 14 is also included on the bracket. The sleeve is lockingly engagable with the support strut 4 by way of complementary locking splines 15 and clamping screw 16.
In use, any required number of stabilising devices are affixed to the ladder by positioning the clamps 1 on the ladder side rails 2 and securing them in the desired positions by clamping screw 13. The support struts 4 are then adjusted to supportively engage the desired support structure such as a gutter 6, wall 17, parapet 18, pole 19 or other support fixture as shown in the accompanying drawings. Once engaged with the desired support fixture, the support strut or struts stabilises the ladder in its desired configuration.
The support strut 4 may also be used to support articles such as tools or paint tins
20, as shown in Figure 18.
The 'universal' type clamping arrangements shown in Figures 6 and 7 are particularly suited for incorporation in an after market version of the stabilising device which can be used as an accessory to existing ladders. However, it is also envisaged that the device could be incorporated as part of an original ladder. In such applications it may be desirable to replace the more cumbersome 'universal' type clamp with another neater design that is specifically adapted for a particular ladder rail section and which may be captively retained with the ladder if required. Examples of just a few of many suitable configurations are shown in Figures 19-24.
Referring firstly to Figures 19 and 20 there is shown a ladder having a specially modified side rail that may be of a general C-section as shown (or a box section as
illustrated by the broken lines). The modified rail includes an integrally extruded T- sectioned formation 24 that extends from a side face of the rail. The clamp 1 is modified to include an undercut slot 25 that corresponds with the T-formation 24. The T and slot are sized to permit sliding of the clamp 1 along the rail to any desired position. The clamp is then locked with the T-foraiation by means of any suitable fastener such as is shown at 26. Ideally, this fastener would incorporate some form of quick release lever so that special tools are not required. Alternatively, the clamp could be replaced by a securing device that is held captive by the T-formation 24 with locking of the securing means at a preselected position being achieved, for example, by passage of a releasable spring biased pin through one of a plurality of locating holes formed on the ladder rail.
A similar alternative is shown in Figures 21 and 22. In this case, the ladder rail extrusion is modified to incorporate an undercut T-shaped slot 25 which is adapted to receive the head of a bolt-like connector 27 that can be held captive therein by insertion from one end of the rail. The connector 27 would be securable with the clamp 1 by means of a fastener 26 of a similar kind to that shown in Figure 20 or by means of a spring pin locating device o.f the kind described above.
Yet another alternative is shown in Figures 23 and 24. In this embodiment, a standard C-shape or box section rail is used, but the rail is modified by machining or the like to include a clamp retaining slot 28. The slot could extend over a majority length of the rail, or could comprise a series of spaced slots.
Finally, Figure 25 shows a further alternative which shows an I-section rail modified to incorporate an undercut T-slot of the kind shown in Figures 21 and 22.
It will be appreciated that the illustrated embodiments of the device are applicable to both the top and foot portions of a ladder. It is relatively easy to use and reduces the risk of accidental sideways or outwards movement of the ladder.
Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention can be embodied in many other forms.