Patent Abstract:
A ladder support apparatus, the apparatus including a support body, one or more clamp mechanisms operatively mountable to the support body, for mounting the support body to a structure and a retention assembly operatively connected to the support body and, in use, being adapted to limit relative movement between the ladder and ladder support, the or each clamping mechanism including a clamp aπn mounted for movement relative to the support body in a clamping direction and a release direction, an actuator operable to control the operation of the clamp arm, the clamp mechanism being arranged so as to be able to adopt a preset mode in which the clamp arm is substantially freely moveable in both the clamping direction and the release direction, a set mode in which the clamp arm is inhibited from movement in either direction but can be moved incrementally by operation of the actuator and a pre-release mode in which the clamp arm is inhibited from movement in either direction but upon operation of the actuator when in the pre-release mode the clamp arm can return to its preset mode.

Full Description:
TECHNICAL FIELD 
     The present invention relates to apparatus for supporting a ladder when in use. 
     In use ladders are often arranged to lean against a wall or other part of a structure such as a building. This arrangement can often lead to situations where the user is put at risk through the danger of the ladder falling. 
     The present invention seeks to ameliorate the abovementioned disadvantage. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the present invention there is provided a ladder support apparatus, the apparatus including a support body, one or more clamp mechanisms operatively mountable to the support body, for mounting the support body to a structure and a retention assembly operatively connected to the support body and, in use, being adapted to limit relative movement between the ladder and ladder support, the or each clamping mechanism including a clamp arm mounted for movement relative to the support body in a clamping direction and a release direction, an actuator operable to control the operation of the clamp arm, the clamp mechanism being arranged so as to be able to adopt a preset mode in which the clamp arm is substantially freely moveable in both the clamping direction and the release direction, a set mode in which the clamp arm is inhibited from movement in either direction but can be moved incrementally by operation of the actuator and a pre-release mode in which the clamp arm is inhibited from movement in either direction but upon operation of the actuator when in the pre-release mode the clamp arm can return to its preset mode. 
     The retention assembly may include two ladder retention devices each adapted for association with a respective ladder stile each device including a bracket which is operatively connected to the support body and includes a plurality of guides arranged in spaced apart relation for receiving the ladder stile with which it is associated therebetween, the guides being arranged to enable relative movement between the ladder and the retention devices in the direction of the stiles but inhibiting relative lateral movement. Preferably the position of the guides is adjustable relative to one another. Preferably each clamp arm is mounted for relative linear movement with respect to the support body towards the support body in the clamping direction and away from the support body in the release position. 
     Each clamping mechanism includes a braking device which can provide resistance to the movement of the clamp arm. A control arm may be provided which is operable to engage the braking bar towards the braking bar into a non-braking position. In one form the actuator comprises a lever pivotally mounted so that pivotal movement thereof can cause the clamping mechanism to operate in its various modes. 
     A lift mechanism may be provided, attached to the support body for lifting the apparatus into a selected position on the ladder. The lift mechanism may be of any suitable form, however, in one preferred form the lift mechanism includes a flexible line such as a cable or rope operatively connected to the support body. A lift eye may be connected to the support body for the purpose of connecting the lift cable or rope. 
     A pulley may be provided to raise the support body, along the ladder. In a preferred form the line is passed once over an upper rung of the ladder and drawn upwards by pulling downward on an appropriate end of the line at a selected purchase such as for example a 1:1 purchase. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Preferred embodiments of the invention will hereinafter be described with reference to the accompanying drawings, and in those drawings: 
         FIG. 1  is a plan view of apparatus in accordance with one embodiment of the invention; 
         FIG. 2  is a detailed view of part of the apparatus shown in  FIG. 1 ; 
         FIG. 3  is a schematic view of part of the apparatus shown in  FIG. 1 ; 
         FIG. 4  is an end view of part of the apparatus shown in  FIG. 3 ; 
         FIG. 5  is a schematic side elevation of apparatus according to one embodiment in one operating mode; 
         FIG. 6  is a schematic side elevation of the apparatus shown in  FIG. 5  in another operating mode; 
         FIG. 7  is an end view of part of the apparatus; 
         FIG. 8  is a schematic side view of the apparatus shown in  FIG. 6  in a mode of operation; 
         FIG. 9  is a schematic side view of the apparatus shown in another operational mode; 
         FIG. 10  is a schematic side view of the apparatus shown in another mode; and 
         FIG. 11  is a schematic side elevation of apparatus according to another embodiment in one operating mode; 
         FIG. 12  is a schematic side elevation of the apparatus shown in  FIG. 1  in another operating mode; 
         FIG. 13  is a schematic side view of the apparatus shown in  FIGS. 11 and 12  in a mode of operation; 
         FIG. 14  is an end view of the apparatus as shown in  FIGS. 11 to 13 ; 
         FIG. 15  is a schematic side view of the apparatus shown in  FIGS. 11 to 14  in another operational mode; 
         FIG. 16  is a schematic side elevation of apparatus according to yet another embodiment in one operating mode; 
         FIG. 17  is a schematic side elevation of the apparatus shown in  FIG. 15  in another operating mode; 
         FIG. 18  is a schematic side view of the apparatus shown in  FIGS. 15 and 16  in a mode of operation; 
         FIG. 19  is a schematic side view of the apparatus shown in another operational mode; 
         FIG. 20  is a schematic side elevation of apparatus according to yet another embodiment in one operating mode; 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIGS. 1 and 2  of the drawings there is shown a ladder support apparatus generally indicated at  10 . As illustrated in  FIGS. 3 ,  6  and  11  the apparatus is adapted to be mounted to a ladder  12  which includes a pair of spaced apart substantially parallel stiles  14  with spaced apart rungs  16  extending therebetween. The apparatus is adapted to be clamped to a structure such as gutter  60  ( FIG. 6 ), scaffold member  260  ( FIG. 11 ), or any other suitable structure. The apparatus is adapted to limit the movement of the ladder when mounted thereto. 
     The apparatus  10  includes a support body  20  in the form of an elongated structure which when the apparatus is mounted to a ladder extends in a direction from one stile to the other and generally parallel to the rungs. 
     As best illustrated in  FIG. 2  the support body comprises a plurality of tubular components including outer sections  101  and  102  and inner sections  103  and  104 . Outer section  101  is smaller in length than section  102  and is adapted to support inner sections  103  and  104  which are arranged generally parallel to one another and in slightly spaced apart relation. Outer section  102  is adapted to receive inner sections  103  and  104  in telescopic fashion so that they can be slidably displaced therealong so as to provide for an adjustment of the length of the support body. The support body further includes a quick release locking device  105  which holds the sections in a fixed position relative to one another. The locking device  105  is adapted to cooperate with holes in the support body. A lifting link or eye  108  is provided to which a flexible line such as a rope or cord  109  can be attached. The lifting link  108  can be positioned in one of the holes  111  (only two are itemised) chosen so that the link is centrally disposed when the length of telescopic body is adjusted. Non-slip rubber pads  127  are provided in spaced apart relation along the body which inhibit damage to which the apparatus is to be clamped. 
     The apparatus further includes two ladder retention devices  110  each being adapted for association with a respective ladder stile. Each retention device  110  includes a bracket  112  which is secured to the support body. The devices  110  include guides  113 ,  114  and  115  which in a mounted position limits movement of the ladder. Guides  113  and  114  includes rollers  116  and  117  and bearing plates  118  and  119 . Guide  115  is in the form of a boss  120  having a bearing plate  121  associated therewith. The guides enable the apparatus to move along the ladder in the direction of the stiles whilst limiting substantial lateral movement of the ladder. Guides  114  and  115  can be adjusted along slots  123  and  124  in order to cater for different ladders. Guide  113  can be mounted in one of holes  125  to provide suitable position adjustment. 
     The support body can be drawn upwards by a flexible line in the form of lift rope  109  which is connected to a lift eye  108  in the middle of the support body to ensure even pulling force to both devices. 
     In the embodiment of  FIGS. 4 to 9  each device further includes a clamping mechanism  137  by which the apparatus can be releasably secured to a structure such as gutter  60 . In this embodiment the clamping device is adapted to be operated in a position remote from the apparatus when in use; that is the device can be operated from the ground or other surface upon which the ladder rests. The clamping mechanism  137  includes a clamp arm  138  in the form of a rod mounted to a support housing  171  on bracket  112 . The position of the support housing  171  relative to bracket  112  is clearly illustrated in  FIG. 4 . The support housing  171  has mounting apertures  141  and  142  in opposed side walls thereof through which the clamp arm  138  can extend. The clamp arm  138  is slidably moveable relative to the housing  131  through the apertures  141  and  142 . The clamp arm  138  has a clamping stop  177  mounted at one end thereof and a stop  178  at its other end. Clamping stop  177  is mounted on arm  173  which is spring loaded and can be rotated relative to clamping arm  138  for positioning of a pin in one of a series of grooves  174  in section  175  of arm  173  (see  FIG. 7 ). 
     The clamp mechanism includes a releasable braking device  182  which in a braking position provides resistance to movement of the clamp arm  138  relative to the housing  171  in at least one direction. The braking device includes a braking bar  183  having an aperture  184  therein through which the clamp arm  138  passes. The braking bar  183  can adopt a braking position in which withdrawal of the clamp arm  138  from the housing  171  is resisted. 
     Spring  185  tends to urge braking bar  183  into a braking position in which relative movement between the clamp arm  138  and the housing  171  is resisted. A control arm  187  is adapted to engage braking bar  183  under the influence of spring  188  to urge the braking bar into a non-braking position. The control arm  187  can be held by catch element  189  as described hereinafter. 
     There is further provided an adjustment device  186  which is operable to enable incremental movement of the clamp arm  138  so that the stop  177  is drawn towards the housing. The adjustment device includes an actuating lever  181  arranged to cause movement of a drive link  190 . Spring  191  urges the drive link  190  into a selected operating position. The clamp arm  138  passes through an aperture  193  in the drive link  190 . 
     Initially the clamping mechanism adopts a pre-set mode as illustrated in  FIG. 5 . In this mode the actuating lever  181  is urged into a preset position by spring  195 . The arrangement is such that clamp arm  138  is substantially free to move relative to braking bar  183  and drive link  190  the actuating lever  181  causing the drive link  190  to abut and be retained against lip  192  and pin  197 . In this pre-set mode control arm  187  under the influence of spring  188  urges brake arm  183  into a non-braking position in which control arm  138  and can be moved in both directions relative to support housing  171 . In this present mode stop  178  can be removed enabling the arm  138  to be removed and replaced. It will be appreciated the configuration of the clamp arrangement can take other forms depending upon its application. For example the arms may be of different lengths and the clamping device of different shapes for use under eaves, tree trunks, poles and the like. 
     When the device is required to be clamped to a structure such as gutter  60  the clamping mechanism is caused to adopt a set mode as illustrated in  FIG. 6 . This is done before the device is raised to the position whereby it can be clamped to the gutter. It may be put in this mode prior to or initially when mounted to the ladder. In this set mode actuating lever  181  is pivotally displaced from its pre-set position so that the control arm  187  can be moved so as to be held by catch element  189 . In this position brake arm  183  is urged into a braking position under the influence of spring  185 . When in this position the brake arm  183  provides a resistance to movement of the clamp arm  138  in direction where stop  177  is displaced away from supporting housing  171  although movement in the other direction is still possible. 
     With the mechanism in the set mode the device can be drawn along the ladder from the base region thereof and positioned with a wall of the gutter disposed between stop  177  and the support body  102  of the device. This is illustrated in  FIG. 9 . Pivotal movement of actuating lever  181  causes drive link  190  to incrementally move the clamp arm  138  so that stop  177  is brought into abutment against the wall of gutter  60 . Abutment section  198  causes displacement of link  190  off members  192  and  197 . In this position the device firmly clamps the ladder to the gutter  60 . The pivotal movement of the actuating lever can be effected from the base region of the ladder by pulling of line  132  connected thereto. 
     To release the device, catch element  189  is disengaged from control arm  187  which is caused to engage shoulder  175  on actuating lever  181 . This is a pre-release position and is illustrated in  FIG. 10 . In this position the clamp arm  138  is yet to be released and the operator can descend the ladder. The abutment section  198  on actuating lever  181  causes drive link  190  to be displaced from lip  192  and pin  197  thereby effectively locking clamp arm  138  relative to the drive link  190 ; that it is the position of the drive link  190  which inhibits movement of the clamp arm  138  when clamped to the structure in this position. The clamp arm  138  could not move from this position even if the brake arm  183  adopted its non-braking position. By further pivotal displacement of actuating lever  181  using line  132  the control arm  187  is disengaged from the shoulder  175  on the actuating lever  181  whereupon it is caused to move under the influence of spring  188  to its pre-set position in which it acts on brake arm  183  so that it adopts the non-braking position. In this position lever  181  can move under the influence of spring  195  so that link  190  can return to the position shown in  FIG. 5  and the device can be manipulated until it can be freed from the gutter whereupon it can be returned to the base position of the ladder. 
     Referring to  FIGS. 11 to 15  there is shown another embodiment according to the invention with a modified form of catch element. The same numerals have been used to identify the same parts as shown in the earlier embodiments. In this embodiment the catch element  289  is pivotally mounted at pivot point  290  the same pivot point as for control arm  187 . An indexing member  292  is provided at one end of the catch element  289 . The indexing member  292  includes a knob  293  and a spring loaded pin  294  ( FIG. 14 ). 
     Referring to  FIG. 11  the device is shown in the preset position. In this position the spring loaded pin  294  abuts against a face of the support housing wall  171 . In this position all other elements are arranged in the position as shown in  FIG. 5  with reference to the first embodiment. 
     In order for the device to adopt the set position element  289  is rotated in the direction of arrow A in  FIG. 11  until the pin under the influence of the spring associated therewith is located against the end of the housing  171  thereby preventing its return. Rotation of the element  289  into the position shown in  FIG. 12  causes the control arm  187  to rotate into the position shown in  FIG. 12  thereby activating braking bar  183  in the same fashion as described with reference to the first embodiment. The element  289  holds the arm  187  in the position shown in  FIG. 12 . Pivotal movement of lever  181  in this position causes incremental movement of the clamp arm  138  in the same manner as described with reference to the first embodiment. 
     To effect the pre-release position element  289  is returned to its original position but control arm  187  is retained by stop  178  on lever  181 . To release the device lever  181  is pivotally displaced thereby facilitating the return of control arm  187  to its original position. 
     Referring to  FIGS. 16 to 19  there is shown another embodiment according to the invention with yet a further modified form of catch element. Again the same reference numerals have been used to identify the same parts as shown in the earlier embodiments. In this embodiment the catch element  389  has a slot  394  in the element which can enable pivotal movement about pivot mount  390  as well as movement along the slot  394 .  FIG. 16  illustrates the device in the preset mode with the elements functioning in the same fashion as shown in  FIG. 5  with reference to the first embodiment. To adopt the set position catch element  389  is pivotally moved in the direction of arrow A in  FIG. 16  to the position shown in  FIG. 17 . The catch element  389  can lock over pin  197  on support housing  171  thereby holding the control arm  187  while actuating lever  181  is being activated to incrementally move the clamp arm  138  ( FIG. 19 ). 
     Prior to descent the operator releases catch element  389  by pivotal movement thereof by releasing it from pin  197  and moving it into a forward position as shown in  FIG. 16 . The control arm  187  is held by stop  178  so that the mechanism is in its pre release mode. Upon descent activation of lever  181  by line  132  releases the mechanism as described earlier. 
     A manually operable apparatus is illustrated in  FIG. 20 . In this embodiment the clamping mechanism  237  of the apparatus can be releasably secured to scaffold member  260 . The clamping mechanism  237  includes a clamp arm  238  in the form of a rod mounted to support housing  271  on bracket  247 . The support housing  237  is similar in structure to that described earlier. The clamp arm  238  is mounted in a similar fashion to that described earlier. The clamp arm  238  has a clamping stop  277  at one end thereof. 
     The clamp mechanism includes a releasably braking device  282  which in a braking position provides resistance to movement of the clamp arm  238  relative to the housing  271  in at least one direction. The braking device includes a braking bar  283  having an aperture  284  therein through which the clamp arm  238  passes. The braking bar  283  can adopt a braking position in which withdrawal of the clamp arm  238  from the housing  271  is resisted. 
     Spring  285  urges the braking bar  283  into a braking position in which relative movement between the clamp arm  238  and the housing  271  is resisted in one direction. 
     There is further provided an adjustment device  286  which is operable to enable incremental movement of the control arm  238  so that stop  277  is drawn towards the housing. The adjustment device  286  includes an actuating lever  281  arranged to cause movement of a drive link  290 . Spring  291  urges the drive link  290  into a braking position. 
     There is further provided a locking lever  222  which is engageable with the drive link  290  at section  294 . 
     In the position shown in the drawing, the clamping bar is clamped to the scaffold member  260 . In this position, the clamping bar is locked against movement which would loosen the clamping bars grip on the scaffold member. In order to move the clamping arm incrementally towards the scaffold member actuating lever  281  and locking lever  222  are pivotally displaced downwardly as shown in the drawing thereby causing incremental movement of the control arm  238 . When the clamping arm is in the position shown in the drawing the actuating arm and locking lever are released and the locking lever engages with a tooth  297  on control arm  238 . To release the mechanism firstly a slight downward pressure, is put on actuating arm  281  thereby releasing the locking lever which can be depressed so that it clears control arm  238 . By then raising the actuating arm and locking lever the braking bar is caused to adopt its release position so that the clamping arm can be displaced relative to the housing. 
     The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. 
     Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise”, and variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or step or group of integers or steps. 
     Finally, it is to be understood that the inventive concept in any of its aspects can be incorporated in many different constructions so that the generality of the preceding description is not to be superseded by the particularity of the attached drawings. Various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention.

Technology Classification (CPC): 4