Patent Publication Number: US-2021172250-A1

Title: An apparatus for restraining movement of a ladder

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to provisional application No. 62/614,863 entitled “An Apparatus For Restraining Movement Of A Ladder” filed on Jan. 8, 2018, which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present invention generally relates to the field of safety devices and more particularly, is directed to an apparatus for restraining the movement of the ends of a ladder to help prevent the ladder from moving and causing injury to a person standing on the ladder or someone in close proximity to the ladder. 
     BACKGROUND 
     Ladders are typically used to gain access to elevated locations or surfaces and come in various shapes and sizes. 
     As illustrated in  FIG. 1 , a step ladder is a free standing structure with wide flat steps  1  positioned between one of two pairs of legs  2  and  3  which are hinged at a top  4 . Step ladders are used to safely reach relatively low elevated locations or surfaces. 
       FIG. 2  illustrates a further embodiment of a ladder that is comprised of a pair of parallel side rails  21  and  22  that are held together by a plurality of spokes or steps  23 . Ladders of the type illustrated in  FIG. 2  are typically used to reach higher locations and surfaces than the customary step ladder. 
     For still higher locations and surfaces, an extension ladder such as illustrated in  FIG. 3  is used. An extension ladder is comprised of two sections  31  and  32 , such as the type illustrated in  FIG. 2 , arranged so that they fit together or extends on a sliding mechanism almost to the full length of the two sections. Thus, extension ladders provide a range of height adjustment dependent on the height of the location or surface to be reached. 
     A great deal of care must be exercised when using ladders of any type due to the likelihood of falling. Ladder related accidents, such as falls, can lead to serious injury. 
     The consequences of falls are magnified by the height of the structure on which a ladder is used. For example scaling a ladder to reach the roof of a building represents a substantial risk of falling. More importantly, the risk is increased if the ladder is not restrained from moving at it lower and upper ends. The present invention addresses this safety concern. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The novel features of the present invention are set out with particularity in the appended claims, but the invention will be understood more fully and clearly from the following detailed description of the invention as set forth in the accompanying drawings in which: 
         FIG. 1  illustrates one embodiment of a step ladder as known in the prior art; 
         FIG. 2  illustrates one embodiment of a ladder as known in the prior art; 
         FIG. 3  illustrates one embodiment of an extension ladder as known in the prior art; 
         FIG. 4  is a top view of one embodiment of an apparatus for restraining the movement of a ladder in accordance with the present invention; 
         FIG. 5  is a top view of a further embodiment of an apparatus for restraining the movement of a ladder in accordance with the present invention; 
         FIG. 6  is an illustration of the embodiment of the present invention as shown in  FIG. 4  in use on a roof; 
         FIG. 7  is an illustration of the embodiment of the present invention as shown in  FIG. 5  in use on a roof; and 
         FIGS. 8-10  are dimensional construction diagrams of the embodiments of the present invention as shown in  FIGS. 4 and 5 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment of the present invention will be described with further reference to the drawings. 
       FIG. 4  illustrates one embodiment of an apparatus for restraining the movement of a ladder in accordance with the present invention. 
     As shown in  FIG. 4 , the apparatus comprises a plate  40  having a plurality of apertures or holes  41  which allow plate  40  to be temporarily nailed or otherwise secured, for example, to the edge of a roof as shown in  FIGS. 6 and 7 . 
     Plate  40  also includes a ladder retraining tab  42  which projects outward from the edge of plate  40 . 
     The apparatus further includes a slotted ladder lock bar  43  which is attached to plate  40  with one or more fasteners  44 . Fasteners  44  can be tighten down to secure bar  43  in one of a number of lateral positions about plate  40  as indicated by arrow  45 . 
     Bar  43  also has a ladder retraining tab  46  which projects out from plate  40 . 
     As also illustrated in  FIG. 4 , a pair of anchor points  47  and  48  is provided which form a rotatable retainer to which a strap, rope or other device may be attached for holding the apparatus during transport or carrying to a roof top for installation. 
     When a ladder is leaned against a building with plate  40  in place, the side rails of the ladder, for example rails  21  and  22  as shown in  FIG. 2  (or the side rails of ladder  31  as shown in  FIG. 3 ) are positioned between ladder retaining tabs  42  and  46  and the location of lock bar  43  is adjusted accordingly along arrow  45  to prevent the top end of the ladder from moving. Lock bar  43  may then be secured in position by fasteners  44 . Thus, the elevated end of the ladder can be stabilized, making the ladder safer to use. 
     The present invention may also be used to stabilize the lower end of the latter in a similar fashion. 
       FIG. 5  illustrates a further embodiment of an apparatus for restraining the movement of a ladder. In this embodiment, a pair of pivoting ladder rail locks  51  and  52  is used to secure the side rails of a ladder as shown in  FIG. 7 . 
     Rail locks  51  and  52  have respective pivot points  53  and  54  which, by way of example only, may be formed of a nut and bolt combination or a rivet. Thus, rail locks  51  and  52  rotate about these pivot point so that the rail locks can be rotated into place in order to secure the side rails of the ladder to the apparatus as shown in FIG.  7 . Thus, the end of the ladder is locked to the apparatus in order to prevent lateral movement of the ladder. 
     Rail locks  51  and  52  include a hole  55  which overlaps a corresponding hold  56  when the rail locks are moved into place to lock the side rails of the ladder. Pins  57  and  58  may then be inserted through the respective holes to prevent the rail locks from moving. As shown in  FIG. 5 , pin  57  is already inserted in its respective holes  55  and  56 . 
     To insure that the pins  57  and  58  do not become lost or misplaced, they are secured to the apparatus with respective cords  59  and  60  as shown in  FIGS. 5 and 7 . Cords  59  and  60  may be made of steel braided cable incased in plastic or other suitable materials. 
       FIGS. 8-10  dimensionally illustrate the construction of the embodiments of applicant&#39;s apparatus for restraining movement of a ladder as shown in  FIGS. 4-7 . 
     The various elements of the apparatus may be fabricated from a number of materials, including metals, plastics and composites as one of ordinary skill in the art would understand. 
     While the foregoing specification teaches the principles of the present invention, with examples provided for the purpose of illustration, it will be appreciated by one skilled in the art from reading this disclosure that various changes in form and detail can be made without departing from the true scope of the invention.