1. Technical Field
This invention relates to ladder access control kits and ladder assemblies including access control apparatus.
2. Background Art
It is often desirable to prevent unauthorized users from climbing on a ladder which extends from one location to a desired but unauthorized location. For example, a ladder may extend from the ground to a tree-mounted stand for hunting. Another example is a ladder which extends from the ground to the upper platform of an above-ground swimming pool. Other ladders are secured to a man-made structure to allow an authorized user access to a boat in a marina or to perform maintenance or otherwise access a vertically displaced portion of the man-made structure.
The following U.S. patent documents describe various ladder anti-climbing or blocking devices and assemblies: 2002/0092704; U.S. Pat. Nos. 5,832,755; 5,441,126; 5,343,977; 4,579,197; 4,450,937; 4,181,195; 4,126,206; 3,968,857 and 3,225,863.
At least one problem associated with many of the prior art ladder anti-climbing or blocking devices and assemblies is that such devices and assemblies are ineffective in providing a compact, simple and inexpensive solution to the problem of blocking unauthorized climbing on ladders.
An object of the present invention is to provide a ladder access control kit and ladder assembly including access control apparatus which are relatively compact, simple and inexpensive yet effectively block unauthorized users from climbing on ladders.
In carrying out the object and other objects of the present invention, a ladder access control kit is provided. The kit includes a planar barrier and a first member including a first support structure to movably support the barrier and a first attachment mechanism to secure the first support structure at a first side of the ladder. The barrier is movable within a plane of the barrier between an access position to allow access to the ladder and a blocking position to prevent access to the ladder when the first attachment mechanism secures the first support structure to the first side of the ladder and the first support structure movably supports the barrier. The kit also includes a second member including a second support structure and a second attachment mechanism to secure the second support structure at a second side of the ladder spaced apart from the first side of the ladder. The kit further includes a locking device to fasten the barrier to the second support structure in a locked condition of the device and in the blocking position of the barrier when the first support structure movably supports the barrier and the first and second attachment mechanisms secure their respective support structures to the sides of the ladder to prevent unauthorized access to the ladder.
The barrier may move by rotating about a pivot axis perpendicular to the plane of the barrier. The first support structure may include a pivot to allow the barrier to pivot about the pivot axis.
The barrier may include an aperture formed therein wherein the locking device includes a bolt having extended and retracted positions. The bolt is in its extended position in the aperture in the locked condition to fasten the barrier to the second support structure in the blocking position when the locking device is supported on the second support structure. The aperture may comprise an elongated slot wherein the kit can be utilized with ladders of different widths. The aperture may extend completely through the barrier wherein the second member further includes a shield which covers a distal end of the bolt in the extended position of the bolt.
The locking device may be supported on the second support structure either above or below the barrier when the barrier is in its blocking position to prevent unauthorized users from climbing on the ladder while allowing authorized users to unlock the locking device. The locking device may be a keyed locking device wherein the kit further comprises a key to unlock the locking device.
Further in carrying out the above object and other objects of the present invention, a ladder access control kit is provided. The kit includes a planar barrier including an elongated slot formed completely therethrough wherein the kit can be utilized with ladders of different widths. The kit also includes a first member including a first support structure to movably support the barrier and a first attachment mechanism to removably secure the first support structure to a first side rail of the ladder. The first support structure has a pivot to allow the barrier to pivot about a pivot axis perpendicular to the barrier within a plane of the barrier between an access position to allow access to the ladder and a blocking position to prevent access to the ladder when the first attachment mechanism secures the first support structure to the first side rail of the ladder and the first support structure including the pivot pivotally supports the barrier. The kit further includes a second member including a second support structure, a shield and a second attachment mechanism to removably secure the second support structure and the shield to a second side rail of the ladder. Still further the kit includes a keyed locking device including a bolt having extended and retracted positions. The bolt is in its extended position in the slot and the shield covers a distal end of the bolt in a locked condition of the device to fasten the barrier to the second support structure in the blocking position when the first and second attachment mechanisms secure their respective support structures to the side rails of the ladder, and when the first support structure including the pivot pivotally supports the barrier. The kit further includes a key to unlock the locking device.
Still further in carrying out the above object and other objects of the invention, a ladder assembly including access control apparatus is provided. The assembly includes a ladder and a first member including a first support structure and a first attachment mechanism which secures the first support structure to a first side of the ladder. The assembly also includes a second member including a second support structure and a second attachment mechanism which secures the second support structure to a second side of the ladder spaced apart from the first side of the ladder. The assembly further includes a planar barrier supported by the first support structure to move within a plane of the barrier between an access position to allow access to the ladder and a blocking position to prevent access to the ladder. Still further the assembly includes a locking device which fastens the planar barrier to the second support structure in a locked condition of the device in the blocking position of the barrier to prevent unauthorized access to the ladder.
The locking device may be a keyed or combination locking device.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
a is an environmental view of a first embodiment of an access control kit after being assembled and secured to a ladder to form an assembly including a barrier locked in its blocking position (solid lines) by a locking device located below the barrier to prevent an unauthorized user from climbing up the ladder and having access to a tree stand and also showing an access position of the barrier (phantom lines);
b is a marine environmental view of a different embodiment of the access control kit after being assembled and secured to a ladder to form an assembly with the locking device located above the barrier to prevent an unauthorized user from climbing from an upper level to a lower level down the ladder;
c is yet another environmental view of a third embodiment of a kit similar to the embodiment of
a is a bottom perspective view, partially broken away, of one embodiment of a locking device for use with the kit or assembly of
b is a view similar to the view of
Referring to
The first embodiment of the ladder access control kit includes a planar barrier 10 and a first member 12 including a first support structure 14 to movably support the barrier 10. The first member 12 also includes a first attachment mechanism 16 to secure the first support structure 14 at a first side or rail 20 of a ladder 22. The barrier 10 is movable within a plane of the barrier 10 between an access position (phantom lines in
The kit of the first embodiment also includes a second member 30 having a second support structure 32 (
The kit of the first embodiment also includes a locking device which may be a keyed locking device 40 or a combination locking device 40″′ as shown in
In other words, the first embodiment of the present invention can be thought of as a lockout kit or apparatus adapted to be attached to a ladder such as the ladder 22 which extends to the tree-mounted stand 42 used for hunting as shown in
As previously mentioned, the barrier has a closed or blocking position (solid lines in
As previously mentioned, the kit or apparatus of the first embodiment includes the first and second members 12 and 34, respectively, having their attachment mechanisms 16 and 34 for attaching their support structures 14 and 32, respectively, to the side pieces or rails 20 and 36 of the ladder 22. In the first embodiment, the attachment mechanisms 16 and 34 of the first and second members 12 and 30, respectively, are removably secured to the side rails 20 and 36 of the ladder 22 by conventional u-bolts 35, nuts 39, plates 37 and washers 38 as best shown in
As previously mentioned, the locking device locks or fastens the barrier 10 to the second support structure 32. The locking device is either a keyed or a combination lock 40 or 40″′ as shown in
The bolt 46 extends through an elongated slot 48 of the barrier 10 in its extended position when the device 40 is locked thereby locking the barrier 10 to the second support structure 32. The bolt 46 moves to its retracted position when the device 40 is unlocked. The device 40 fastens the barrier 10 to the second structure 32 by means of the key 44 (i.e.,
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.