Abstract:
A stabilizing mechanism for rigid fixed and extension ladders that includes an anchorage assembly removably mounted to one of the rungs of a ladder. A linkage assembly is mounted to the anchorage assembly through a transversally and rotably mounted elongated base that permits the setting of linkage assembly in one of several angular positions. Two arched arm members are pivotally mounted to a plate and also, with two linkage arms that are pivotally mounted to a swivel bracket, this two linkage assembly permits the arch members to move coplanarly between two extreme positions. The arm members releasably embrace a support structure thereby providing a firm engagement of the ladder to the support structure. A stabilizing pad assembly includes two pads mounted to adjustable elongate members to engage surrounding surfaces for more stability. A release mechanism remotely disengages the ladder from the support structure after a user descends from the ladder. The engagement is kept by a locking mechanism that includes a pivoting mounted plate with a central opening A shaft rigidly mounted to the rigid plate coacts in the edge of the centered opening to permit the shaft to move in on direction only.

Description:
OTHER RELATED APPLICATIONS 
       [0001]    The present application is a continuation-in-part of U.S. patent application Ser. No. 12/144,444, filed on Jun. 23, 2008, which is hereby incorporated by reference, and which in turn is a continuation-in-part of U.S. patent application Ser. No. 12/060,331 (now abandoned) filed on Apr. 1, 2008, which is hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a stabilizing mechanism for ladders, and more particularly, to such a mechanism that permits a user to achieve a secure engagement remotely on a supporting object. 
         [0004]    2. Description of the Related Art 
         [0005]    In using straight ladders, typically a user leans a ladder against a supporting structure. The angle needs to be an adequate one to ensure the stability of the ladder. But in crowded areas, such as with urban utility poles, the space is limited. Thus, the desirability of having a mechanism for engaging a fixed structure, such as a pole, substantially vertically and parallel to the pole. Additionally, the arms assembly with the remotely releasable locking assembly ensures the safety of the users while providing a practical, efficient, and prompt manner of deployment. 
         [0006]    Several designs for stabilizing mechanisms for ladders have been designed in the past. None of them, however, includes a mechanism that can be readily actuated. The parent application provides for a similar mechanism but it lacks stability for some applications. 
         [0007]    Applicant believes that one of the related references corresponds to U.S. published application number 2010/0018803 A1 published on Jan. 28, 2010 listing Schwenket and Cinquemani as inventors. Schwenket and Cinquemani teach that apparatus  10  is put into contact with a supporting surface and to secure the calipers  28   a  and  28   b  of apparatus  10  around said surface, a user must climb the unsecured ladder and manually wrap chain  56  around the supporting surface and attach it to open hook  58 . 
         [0008]    However, it differs from the present invention because it does not offer the additional security to the user taught by the present invention. Schwenket and Cinquemani&#39;s application fails to disclose a locking system that is remotely actuated allowing the user to securely engage the ladder to the supporting surface while safely on the ground. In addition, the related reference does not teach of arms that are rotably able to move in order to provide engagements to other supporting surfaces (such as a roof or parapet wall). 
         [0009]    Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which: 
           [0011]      FIG. 1  represents an isometric view of mechanism  10  mounted to a ladder represented in phantom. 
           [0012]      FIG. 2  shows a bottom view of the mechanism shown in the previous figure. 
           [0013]      FIG. 3  illustrates an elevational view of the back of the mechanism with the cover of housing member  32  removed. 
           [0014]      FIG. 4  is an enlarged partial elevational view of member  25  seen from inside mechanism  10  with slidable claw  28  behind it. 
           [0015]      FIG. 4A  is an enlarged partial elevational view of members  25 ′ and claw  28 ′ from outside mechanism  10 . 
           [0016]      FIG. 5  is an enlarged partial isometric view of a portion of anchorage assembly  20  showing the engagement of pivoting claw  22  to member  25  which includes a cutout to permit the internal components to be seen. 
           [0017]      FIG. 6  shows an enlarged partial isometric view of anchorage assembly  20  showing ratchet assembly  110  coacting with pivoting claw  22 . 
           [0018]      FIG. 6A  illustrates a partial side elevational view of ratchet assembly  110 , showing a cross-section of housing  111 , ratchet pin  37  and pivot claw spring  113  coacting with engaging pin  115  in the retracted position. 
           [0019]      FIG. 7  is a partial side elevational view of the lateral side of frame assembly  24  and bracket  226  mounted therein supporting housing assembly  30  which in turn supports linkage assembly  40 . 
           [0020]      FIG. 8  is a partial cutout of a side view showing housing assembly  30  and linkage assembly  40 . 
           [0021]      FIG. 9  shows an isometric view of supporting arms assembly  60  showing the embodiment including rubber pads  65  and  65 ′. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0022]    Referring now to the drawings, where the present invention is a mechanism generally referred to with numeral  10 , it can be observed that it basically includes anchorage assembly  20 , rotable housing assembly  30 , linkage assembly  40 , supporting arms assembly  60 , stabilizing pad assembly  70 , and locking assembly  80  (as best seen in  FIG. 3 ). Mechanism  10  is removably mounted to a ladder  100 , as seen in  FIG. 1 . 
         [0023]    Anchorage assembly  20  is as best seen in  FIG. 1  preferably mounted on ladder  100  at a predetermined distance from one end and the other end resting on a supporting and substantially horizontal surface (not shown). Anchorage assembly  20 , as seen in  FIGS. 2 and 3 , includes frame assembly  24  which in turn includes longitudinal elongate members  25 ;  25 ′, which are kept at a parallel and spaced apart relationship with respect to each other by transversal elongate members  26 ;  26 ′ and transversal plate  27  including central aperture  27 ′. In one of the preferred embodiments, as best seen in  FIG. 4 , member  25  is a U-shaped bar for enhanced reinforcement and to provide a supporting surface for other components as it will be described below. Assembly  20  also includes a pair of slidable claws  28 ;  28 ′ and pivoting claws  22 ;  22 ′. The former are preferably mounted to the top rung in a ladder as shown in  FIG. 1 . Slidable claws  28 ;  28 ′ are spring biased and slidably mounted to the outer sides of elongate members  25 ;  25 ′ and include cutouts  29 ;  29 ′, respectively, that cooperatively receive rung  102  of ladder  100 . See  FIGS. 4 and 4A . As best seen in  FIG. 4 , claw  28  (and similarly claw  28 ′) is biased with slidable claw spring  227  (and similarly  227 ′). Member  25  includes slots  125  and  126  (and similarly  126 ′) for guiding headed pins  127  (and similarly  127 ′) and  128  (and similarly  128 ′), respectively. Thus, slidable claw  28  is biased to longitudinally extend outwardly to engage rung  102  and it can be retracted a predetermined distance when mechanism  10  is mounted to ladder  100 . 
         [0024]    Pivoting claw  22  (and similarly  22 ′) are pivotally mounted to the outer side of member  25  (and similarly  25 ′) and pivoting headed pin  122  (and similarly  122 ′) are allowed to travel along a curved path defined by arched slot  21  (and similarly  21 ′) as best seen in  FIG. 5 . Bias spring  121  is secured at one end to tab  123  rigidly mounted to the interior member  25 . The end of spring  121  (and similarly  121 ′) is mounted to pivoting pin  122  so that the latter is urged inwardly along the path of slot  21 . Pivoting claw  22  (and similarly  22 ′) includes cutout  23  (and similarly  23 ′) that is similar to cutout  29  (and similarly  29 ′). Cutout  23  (and similarly  23 ′) receives rung  102 ′, as best seen in  FIG. 1 . 
         [0025]    As best seen in  FIGS. 1 ,  6 , and  6 A, anchorage assembly  20  also includes two ratchet assemblies  110 ;  110 ′ to permit pivot claws  22 ;  22 ′ to be releasably locked at predetermined angular positions with respect to frame assembly  24 . In this extreme position, anchorage  20  is used to firmly mount mechanism  10  between two rungs  102  and  102 ′. The other extreme position has pivoting claws  22 ;  22 ′ at a retractable position that will permit the unobstructed positioning of assembly  20  between rungs  102  and  102 ′. Once positioned, pivoting claws  22 ;  22 ′ are moved through handle  19  to the other extreme position with cutouts  23 ;  23 ′ receiving rung  102 ′. Assemblies  110 ;  110 ′ include housings  111 ;  111 ′ mounted to transversal plate  27 , adjacent to elongate member  25 ;  25 ′ and  26 ;  26 ′,respectively. As best seen in  FIGS. 6 and 6A , where assembly  110  is shown (and assembly  110 ′ is similar), pin  37  is mounted substantially inside housing  111  with both ends protruding outwardly of housing  111 . One end of pin  37  includes V-shaped tip  137  and the other includes perpendicularly extending lever  237 . Tip  137  cooperatively engages ratchet cavities  132  to releasably keep pivoting claw  22  at a predetermined angular position. Upon the application of a force of a predetermined magnitude to handle  19 , pivoting claw  22  is allowed to rotate in one direction. In the other direction, however, V-shaped tip  137  prevents its movement unless disengaged by pulling lever  237 . Pivot claw spring  113  (and similarly  113 ′) coacts with engaging pin  115  (and similarly  115 ′) urging the latter outwardly until V-shaped tip  137  engages ratchet cavity  132 . To release the engagement, a user pulls from lever  237 . In this manner, anchorage assembly  20  is aligned between two rungs  102 ;  102 ′ causing cutouts  23 ;  23 ′ to receive rung  102 ′ (shown in  FIG. 1 ). Pivoting claws  22 ;  22 ′ are brought from an angular position with respect to frame assembly  24  to the extreme position where cutouts  23 ;  23 ′ are aligned with cutouts  29 ;  29 ′ (as shown in  FIG. 4 ), both sets housing rungs  102  and  102 ′ (as shown in  FIG. 1 ). 
         [0026]    Housing assembly  30  (as best seen in  FIG. 1 ) is rotably mounted to bracket  226  which in turn is mounted to frame  24 . Assembly  30  includes housing member  32  which extends transversally inside central aperture  27 ′. Pivoting pins  224 ;  224 ′ are journaled by brackets  226 ;  226 ′ as seen in  FIG. 7 . Semicircular end plates  228  (and a similar end plate at the other end of housing member  32 ) include several through holes  229  adjacent to its periphery. Casing  225  is mounted to member  25  and the former includes spring-loaded pin  223  that releasably protrudes through through holes  229 . Pin  223  is cammingly dislodged from through holes  229  upon the application of a force of a predetermined magnitude. 
         [0027]    Linkage assembly  40  has linkage member  42  having an elongated shape with two ends  41 ;  41 ′. Assembly  40  is rotably mounted to housing assembly  30 , as seen in  FIG. 2 . Linkage arms  44  and  44 ′ are pivotally mounted through pins  46  and  46 ′ to linkage member  42  at a predetermined distance from ends  41  and  41 ′, respectively, at one end of the linkage arms  44 ;  44 ′. The other ends of arms  44  and  44 ′ are pivotally mounted through pivot pins  47  and  47 ′ to arms  64  and  64 ′, respectively. Linkage arms  44 ;  44 ′ have been designated an L-shape in order to maximize the extreme open position of arched arm members  64 ;  64 ′. Linkage assembly  40  also includes shaft pins  66 ;  66 ′ which hold shaft  338  securely in place. 
         [0028]    Arm assembly  60  includes arched arm members  64 ;  64 ′. Arm ends  61 ;  61 ′ are pivotally mounted to plate member  62  at predetermined locations through pivot pins  69 ;  69 ′, respectively. Therefore, arms  64 ;  64 ′ pivot about pins  69 ;  69 ′ while, at the same time, their movements are restricted by the pivoting engagement of pivoting pins  47 ;  47 ′ of linkage arms  44 ;  44 ′, which in turn pivot about pivoting pins  46 ;  46 ′. Plate member  62  includes rivets  66  to secure double-threaded shaft  338 . Plate member  62  further includes teeth  63  which help increase the traction between mechanism  10  and a supporting object. Arms  64 ;  64 ′ are permitted to move between two extreme positions. Arm ends  68 ;  68 ′ include a slight curved shape to cooperatively and cammingly coact with an object (typically a pole, roof, tree, etc.) to cause the separation of arms  64 ;  64 ′. 
         [0029]    In an alternate embodiment shown in  FIG. 9 , distal ends of arms  64 ;  64 ′ of arm assembly  60  include rubber pads  65  and  65 ′ that are pivotally mounted thereon. Some functions for rubber pads  65  and  65 ′ include enhancing the frictional engagement to the supporting surface and to avoid scratching the contact surface. This embodiment for arched arms  64 ;  64 ′ is useful for flat surfaces such as roofs, overhangs, parapet walls, roof eaves, and the like. 
         [0030]    Locking assembly  80  is housed within frame assembly  24 ; as seen in  FIG. 3 . Locking assembly  80  releasably locks double-threaded shaft  338 . The embodiment as shown in  FIG. 3A  and includes sub-housing  340  that is rigidally mounted to housing  30 . Double-threaded shaft  338  is centrally located and passes perpendicularly through central opening  338 ′. Double-threaded shaft  338  includes a portion that has fin thread  346  as seen in  FIG. 8 . Chamferred nails  337 ;  337 ′ which are located on the distal ends of locking members  81 ;  81 ′, ratchedly engage fin thread  346  so that shaft  338  can move in one direction only. Locking members  81 ;  81 ′ are spring biased against shaft  338 . To release the bias of locking members  81 ;  81 ′, against shaft  338 , the embodiment shown in  FIG. 3A  has linkage arms  343 ;  344  and  345  articulated to transmit a pulling force imparted through cord  92 . Actuating pins  333 ;  333 ′ are perpendicularly mounted to linkage member  343 ;  344  through guiding slots  342 ;  342 ′ to keep the movement of the articulated linkage members  343 ;  343 ′ over a predetermined distance. Actuating pin  333 ′ is coupled to coil spring  334  which exerts a force that biases actuating pin  333 ′, moving locking member  81  to the locking position. Locking member  81 ′ complements locking member  81  by engaging double-threaded shaft  338  from the opposite direction. Thus, locking members  81 ;  81 ′ create a secure engagement to double-threaded shaft  338 . The end result is locking arched arm members  64 ;  64 ′ into a desired position. Locking member  81 ′ is coupled to actuating pin  333 ′ which is mounted to linkage arm  344  and biased to linkage arm  345 . Conventional thread  347  of double-threaded shaft  338  mates with the internal thread of knurled knob  335  which is selectively brought against housing member  32  to lock shaft  338  in place. Knob  335  when brought against member  32  prevents shaft  338  from moving in the ratcheted direction. 
         [0031]    Locking assembly  80  is actuated by cord  92  is mounted at one end to tab  332  in sub-housing  340 . Tab  332  is on an end of linkage arm  343  and when cord  92  is pulled, linkage arm  343  is rotated about pivot pin  348  which in turn moves actuating pin  333 ′ along slot  342 ′. This causes locking member  81  to be pulled away from shaft  338 . Actuating pin  333 ′ pushes coil spring  334  into a retracted position. Coil spring  334  allows locking member  81  to move away from shaft  338  in a controllable and secure pace. When cord  92  is pulled, linkage arm  343  urges transversal linkage arm  345  which urges linkage arm  344  since they are coupled with each other. As transversal linkage arm  345  urges linkage arm  344 , actuating pin  333  moves laterally across slot  342  pulling locking member  81 ′ away from double-threaded shaft  338  thereby unlocking locking member  81 ′ from double-threaded shaft  338 . Upon the release of cord  92  locking members  81 ;  81 ′ again engage shaft  338 . 
         [0032]    As best seen in  FIG. 1 , stabilizing pad assembly  70  is mounted to the lateral sides of longitudinal elongate members  25  and  25 ′. Stabilizing pad assembly  70  includes pad ends  71  and  71 ′, which are brought in contact with a supporting surface to provide a more secure engagement. Stabilizing pad assembly  70  also includes stabilizing elongate members  72  and  72 ′ which are connected to pad ends  71  and  71 ′. Stabilizing elongate members  72  and  72 ′ are also connected to top pads  73  and  73 ′. Stabilizing pad assembly  70  is locked into desired stabilizing position by turning locking knobs  74  and  74 ′. When a predetermined force is applied on top pads  73 ;  73 ′, stabilizing springs  75 ;  75 ′ compress pad ends  71 ;  71 ′ into the supporting surface. When stabilizing springs  75  and  75 ′ are distended, by unlocking knobs  74 ;  74 ′, stabilizing pad assembly  70  is disengaged from the supporting surface. 
         [0033]    The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.