Patent Abstract:
A safety ladder that protects a climber from a fall is disclosed. The device provides a ladder having a plurality of rails and rungs, one of the rails being an elongated channel having multiple flanges surrounding a passageway, a pair of the flanges defining there between a gap. A locking member is configured to travel upwardly in the passageway, the locking member having a beam, a cam section at one end portion of the beam and an eyelet that is positioned outside of the passageway. A cable connects a climber to the connector section. The cam section is specially configured and forms an anchor with the channel in a locking position when a climber pulls down on the cable and locking member. The rail or rails flanges form an acute angle with the rungs.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    U.S. Provisional Patent Application Ser. No. 61/186,297, filed 11 Jun. 2009, is incorporated herein by reference. Priority of that application is hereby claimed. 
         [0002]    This is a continuation-in-part of U.S. patent application Ser. No. 11/675,897, filed 16 Feb. 2007, and incorporated herein by reference. PCT Application No. PCT/US2007/062326, filed 16 Feb. 2007, is incorporated herein by reference. U.S. Provisional Patent Application Ser. No. 60/774,294, filed 16 Feb. 2006, is incorporated herein by reference. Priority of that application is hereby claimed. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    Not applicable 
       REFERENCE TO A “MICROFICHE APPENDIX” 
       [0004]    Not applicable 
       BACKGROUND OF THE INVENTION 
       [0005]    1. Field of the Invention 
         [0006]    The present invention relates to safety devices for preventing inadvertent injury to a ladder climber by connecting the climber to the ladder with a harness arrangement that provides a locking member that slides in a vertically extended channel attached to the ladder during ascent and that forms an anchor in the event of a fall. More particularly, the present invention relates to an improved ladder safety apparatus that provides an elongated channel that extends upwardly along the ladder, the channel providing a passageway for holding a cam locking member, wherein the cam locking member can be pulled upwardly with little or no resistance but locks to provide an anchor when pulled downwardly such as when the climber falls. 
         [0007]    2. General Background of the Invention 
         [0008]    Workers are often required to climb to dangerous elevations such as when scaffolding is in use. It is known to bolt or otherwise rigidly attach an elongated vertically extended ladder to scaffolding so that workers can ascend dozens of feet (many meters) in the air in order to reach a selected level of a scaffolding. During this ascent, the climber is subjected to potential injury or death if he or she loses a firm grip on the ladder. 
         [0009]    Several patents have issued that relate generally to safety devices that help a climber when ascending a ladder. 
         [0010]    The following US Patents are examples of such devices, each being incorporated herein by reference: 
         [0000]    
       
         
               
               
               
             
           
               
                 TABLE 
               
               
                   
               
               
                 PAT. 
                   
                 ISSUE DATE 
               
               
                 NO. 
                 TITLE 
                 (MM-DD-YYYY) 
               
               
                   
               
             
             
               
                 2,616,609 
                 Tower Ladder Safety Device 
                 11-04-1952 
               
               
                 3,348,632 
                 Climbing Device 
                 10-24-1967 
               
               
                 3,523,591 
                 Climbing Safety Device 
                 08-11-1970 
               
               
                 3,885,647 
                 Climbing Safety Device 
                 05-27-1975 
               
               
                 4,085,818 
                 Plastic Ladder and Safety Device 
                 04-25-1978 
               
               
                 4,111,280 
                 Supporting Guide Rail for Ladder 
                 09-05-1978 
               
               
                   
                 Safety Device 
               
               
                 4,130,177 
                 Ladder Climber&#39;s Safety Device 
                 12-19-1978 
               
               
                 4,193,475 
                 Rigid Rail Safety Device 
                 03-18-1980 
               
               
                 4,269,284 
                 Sliding Clamp and Adaptor 
                 05-26-1981 
               
               
                 5,238,084 
                 Safety Device for Climbing Ladders 
                 08-24-1993 
               
               
                 6,161,647 
                 Fall Arresting Ladder Safety Device 
                 12-19-2000 
               
               
                 6,837,337 
                 Fall Arrest Safety Device 
                 01-04-2005 
               
               
                   
               
             
          
         
       
     
       BRIEF SUMMARY OF THE INVENTION 
       [0011]    The present invention provides an improved ladder safety apparatus that features an elongated flanged channel that is attached to and that extends along a ladder to be climbed. A specially configured cam locking member travels in the channel and can be pulled upwardly with little or no resistance as the climber ascends the ladder. In one embodiment, the channel forms a rail of the ladder. In one embodiment, the channel is positioned in between a pair of ladder rails. 
         [0012]    If the climber loses his or her grip on the ladder and falls, the cam locking member immediately grips the channel, preventing downward movement of the cam locking member. A lanyard, rope, or cable can be used to attach the user to the cam locking member by fastening to a belt, vest or harness worn by the user. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0013]    For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein: 
           [0014]      FIG. 1  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention; 
           [0015]      FIG. 2  is a top view taken along lines  2 - 2  of  FIG. 1 ; 
           [0016]      FIG. 3  is a partial perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0017]      FIG. 4  is a partial perspective view of an alternative embodiment of the apparatus of the present invention; 
           [0018]      FIG. 5  is a partial perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0019]      FIG. 6  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention; 
           [0020]      FIG. 7  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention; 
           [0021]      FIG. 8  is a perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0022]      FIG. 9  is another perspective view of the preferred embodiment of the apparatus of the present invention; 
           [0023]      FIG. 10  is a fragmentary side view of an alternate embodiment of the apparatus of the present invention; 
           [0024]      FIG. 11  is a top view taken along lines  11 - 11  of  FIG. 10 ; 
           [0025]      FIG. 12  is a partial perspective view of the alternate embodiment of the apparatus of the present invention; 
           [0026]      FIG. 13  is an elevation view of the preferred embodiment of the apparatus of the present invention showing connectable vertical channel sections; 
           [0027]      FIG. 14  is a fragmentary view of the preferred embodiment of the apparatus of the present invention; 
           [0028]      FIG. 15  is a fragmentary view of the preferred embodiment of the apparatus of the present invention; 
           [0029]      FIG. 16  is a partial sectional view of the preferred embodiment of the apparatus of the present invention; 
           [0030]      FIG. 17  is a side view of an alternate construction of the locking member; 
           [0031]      FIG. 18  is a top view of the locking member of  FIG. 17 ; 
           [0032]      FIG. 19  is a perspective view of the locking member of  FIG. 17 ; 
           [0033]      FIG. 20  is side view of an alternate construction for the rail portion of the preferred embodiment of the apparatus of the present invention; 
           [0034]      FIG. 21  is a fragmentary side view of the embodiment of  FIGS. 17 and 20  of the apparatus of the present invention; 
           [0035]      FIG. 22  is a similar view; 
           [0036]      FIG. 23  is a fragmentary side view of the embodiment of  FIG. 20  of the apparatus of the present invention; 
           [0037]      FIG. 24  is an elevation view of another alternate embodiment of the apparatus of the present invention; 
           [0038]      FIG. 25  is a top view of the embodiment of  FIG. 24 ; 
           [0039]      FIG. 26  is a sectional view taken along lines  26 - 26  of  FIG. 24 ; 
           [0040]      FIG. 27  is a fragmentary view of the embodiment of  FIG. 24 ; 
           [0041]      FIG. 28  is a fragmentary view taken along circle  28  of the embodiment of  FIG. 24 ; 
           [0042]      FIG. 29  is a fragmentary view taken along circle  29  of the embodiment of  FIG. 24 ; 
           [0043]      FIG. 30  is a fragmentary view of the embodiment of  FIG. 24  and showing an alternate rail arrangement. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]    Ladder safety apparatus  10  is shown in  FIGS. 8 and 9  in use at a construction site having scaffolding  11  to which is attached an elongated vertically extended ladder  12 . The ladder  12  attaches to the scaffolding  11  using a plurality of brackets  13  and a bolted connection  14 , for example. Ladder  12  includes rails  15  and rungs  16 . 
         [0045]    In  FIGS. 4-9 , an elongated vertical channel  17  is attached to ladder  12 . The vertical channel  17  can include web  18  and flange  19 ,  20  sections. Each of the flanges  19 ,  20  has a folded portion for producing a narrowed gap  23 . The flange  19  has folded portion  21 . The flange  20  has folded portion  22  as shown in  FIG. 5 . The gap  23  is sized to be smaller than the width of the cam section  38  of locking member  35  measured between flat sides  39 ,  40  (see  FIG. 2 ). In order to insert the locking member  35  into channel  17 , an oval shaped opening  24  and slot  25  are provided as shown in  FIGS. 4-5 . 
         [0046]    Channel  17  is connected to ladder  12  using fittings  26 . Each fitting  26  can include a u-shaped section  27  providing recess  28  and an ell shaped portion  29 . The ell shaped portion  29  and u-shaped section  27  can be integrally joined, being formed from a single piece of metal, flat bar or the like. One or more of the fittings  26  can be provided with perforated plates  30 ,  31  that are receptive of a locking pin  32  as shown in  FIG. 5 . The locking pin  32  can be retained with a chain  33  and attachment  34  as shown. 
         [0047]    The locking member  35  ( FIGS. 1-3 ) provides an elongated beam  36  having an eyelet  37  at one end portion and cam section  39  at the other end portion. The cam section  38  has two u-shaped surfaces  41 ,  42  that are joined at reference line  43 . A stop  44  on beam  36  prevents excess movement of the locking member  35  when a user pulls it upwardly such as when climbing the ladder  12  (see  FIG. 6 ). 
         [0048]    In order to prevent injury to a user or climber  48  (see  FIGS. 4-9 ), a strap, rope, or cable  45  can be used with a hook  47  to form an attachment between locking member  35  and a climber  48 . The climber  48  can be equipped with a harness  49 , or vest or belt or other suitable device that attaches to cable  45  so that if a climber  48  falls, the locking action of the locking member  35  with the vertical channel  17  provides an anchor that will support the weight of the climber  48  as shown schematically in  FIG. 9 . In  FIG. 7 , locking member  35  rotates in the direction of arrow  46  should the climber  48  lose his or her grip on ladder  12 . In such a case (see  FIG. 7 ), u-shaped surface  42  engages web  18  of channel  17  while u-shaped surface  41  engages folded portions  21 ,  22 . 
         [0049]      FIGS. 10-12  show an alternate configuration for a locking member, designated by the numeral  55 . Locking member  55  provides a beam  56  having an eyelet  57  at one end portion and a cam section  58  at its other end portion as shown. The cam section  58  has opposed flat sides  59 ,  60 . The cam section  58  has opposed surfaces that can be curved at  61 ,  62 . Stop  63  is welded to beam  56  using weld  64 . Otherwise, the locking member  55  can be interchanged with the locking member  35  of  FIGS. 1-9 . 
         [0050]      FIGS. 13-16  show an alternate configuration for vertical channel  17 , mainly connectable sections  17 A,  17 B,  17 C. The sections  17 A,  17 B,  17 C can be provided in differing lengths as shown in  FIG. 13 , referencing the dimension lines A, B and C. Each of the sections  17 A,  17 B,  17 C provides at its lower end portion a coupler  50 . The coupler  50  can provide a web  51  and opposed flanges  52 ,  53  as shown in  FIGS. 13-15 . The coupler  50  can be connected (for example, welded) to the lower end portion of any of the selected channels  17 ,  17 A,  17 B,  17 C. A portion (for example, about one half) of the coupler  50  is welded to the selected channel  17 ,  17 A,  17 B,  17 C leaving about one half extending below the selected channel, as shown in  FIG. 15 . In such a fashion, the upper end portion  54  of the selected channels  17 ,  17 A- 17 C can be fitted to the area under any one of the selected channels  17 A,  17 B,  17 C of  FIG. 13  to complete a splice. Thus, the upper end portion  54  of a channel section  17 A- 17 C is fitted into the bottom of the coupler  50  that is attached to the lower end portion of a selected channel section  17 A,  17 B,  17 C. 
         [0051]      FIGS. 17-23  show an alternate construction for the rail  65  and locking member  71 . The channel  65  has web  66  and flanges  67 ,  68  that provide an overall generally c-shaped transverse cross section. As with the channel  17  of  FIGS. 4-9 , folded portions  84 ,  85  can be provided on flanges  66 ,  67 . A locking member opening  69  in channel  65  is an oblong opening  69  that enables locking member  71  ( FIG. 19 ) to be added to the space or gap  70  that is in between the flanges  67 ,  68 . The oblong opening  69  is sized and shaped to receive the cam section  74  of locking member  71  including its tail or locking tab  79 . The tail or locking tab  79  is not found on the locking member  35  of the preferred embodiments of  FIGS. 1-16 . 
         [0052]    Locking member  71  provides a beam  72  and eyelet  73 . The eyelet  73  is (as with the preferred embodiment) a location for the attachment of a safety cable  45  and hook  47  thereto. 
         [0053]    The improvements to the channel  65  and locking member  71  shown in  FIGS. 17-23  work in the same manner as was shown and described with respect to  FIGS. 1-16 . The improvement of  FIGS. 17-23  provide locking tail or locking tab  79  and its engagement with the wedge  80  that is attached (for example, welded at opening  81 ) to web  66  of rail  65 . 
         [0054]    As with the preferred embodiment of  FIGS. 1-16 , the locking member  71  provides a cam section  74  having sides  75 ,  76  and u-shaped surface  77 . Locking surface  78  provides a tail or locking tab  79  as shown in  FIGS. 17-19 . This tail or locking tab  79  engages wedge  80  as shown in  FIG. 22  should a climber  48  inadvertently fall. 
         [0055]    The wedge  80  has inclined surface  82  and transverse surface  83 . If the climber  48  falls, as in  FIGS. 5-9  and related text herein, the cable  45  attached to eyelet  73  will pull down on the eyelet  73 , creating a moment in beam  72  so that it rotates (see arrow  46 ,  FIG. 7 ) locking tab or tail  79  engages web  66  at surface  83 . As the climber  48  falls downwardly, the locking member  71  will travel a short distance until locking tail or locking tab  79  stops upon wedge  80  transverse surface  83 . The wedges  80  can be spaced apart for example, between about 12 and 24 inches (30 and 61 cm), and preferably about 18″ (46 cm) apart. The locking member openings  69  can be spaced between about 24 and 36 inches (61 and 91 cm) apart, and preferably about 32″ (81 cm) apart. The wedges  80  can, for example, be about ⅛″-1 inch (0.32-2.5 cm) wide, ⅛″-2″ (0.32-5.1 cm) high and 1/16″-⅛″ (0.16-0.32 cm) thick at their upper edges. The width of space  70  can be around 1″ (2.5 cm) for example. 
         [0056]      FIGS. 24-30  show an additional alternate embodiment of the apparatus of the present invention designated generally by the numeral  90 . Ladder safety apparatus  90  provides a ladder  91  having spaced apart rails  92 ,  93 . The rails  92 ,  93  are connected by rungs  94 . Each of the rails  92 ,  93  have side flanges that form an acute angle  95  with the rungs  94 . In  FIGS. 26 and 27 , each rail  92 ,  93  can be similarly constructed. Each rail  92 ,  93  is comprised of an inner section  96  and an outer section  97 . The inner section  96  is shown in  FIG. 27 . Inner section  96  includes side flanges  99 ,  100  that form an acute angle with each rung  94 . Inner section  96  also includes web  98 . Each flange  99 ,  100  provides curved end portions  102 ,  103  as shown in  FIG. 27 . A gap or opening  101  is provided in between the curved end portions  102 ,  103 . 
         [0057]    The outer section  97  is shown in  FIG. 26 . Outer section  97  has a web  104  and side flanges  105 ,  106  attached thereto. Flanges  107 ,  108  are short flanges. Flange  107  is attached to flange  105 , forming an angle of about 90 degrees with flange  105 . Similarly, flange  108  forms an angle of about 90 degrees with side flange  106 . A gap or opening  109  is provided in between the short flanges  107 ,  108  as shown in  FIG. 26 .  FIGS. 28 and 29  are fragmentary views of the ladder safety apparatus in  FIG. 24 .  FIG. 29  shows slot  116  and opening  115  in rail  92 ,  93 . 
         [0058]      FIG. 30  shows an alternate arrangement of a ladder safety apparatus, designated generally by the numeral  110 . In  FIG. 30 , each rung  111  attaches to a rail  112 . Each rung  113  attaches to a rail  114 . A central rail  117  is placed in between the rails  112 ,  114  as shown. Rail  117  can be of the same construction as the rail  92  or  93  of  FIGS. 24-29 , having the same cross section as shown in  FIGS. 26 and 27 . 
         [0059]    The following is a list of parts and materials suitable for use in the present invention. 
       PARTS LIST 
       [0060]      
         [0000]    
       
         
               
               
             
           
               
                   
               
               
                 Part Number 
                 Description 
               
               
                   
               
             
             
               
                 10 
                 ladder safety apparatus 
               
               
                 11 
                 scaffolding 
               
               
                 12 
                 ladder 
               
               
                 13 
                 bracket 
               
               
                 14 
                 bolted connection 
               
               
                 15 
                 rail 
               
               
                 16 
                 rung 
               
               
                 17 
                 vertical channel 
               
               
                     17A 
                 vertical channel section 
               
               
                     17B 
                 vertical channel section 
               
               
                     17C 
                 vertical channel section 
               
               
                 18 
                 web 
               
               
                 19 
                 flange 
               
               
                 20 
                 flange 
               
               
                 21 
                 folded portion 
               
               
                 22 
                 folded portion 
               
               
                 23 
                 gap 
               
               
                 24 
                 oval shaped opening 
               
               
                 25 
                 slot 
               
               
                 26 
                 fitting 
               
               
                 27 
                 u-shaped section 
               
               
                 28 
                 recess 
               
               
                 29 
                 ell shaped section 
               
               
                 30 
                 perforated plate 
               
               
                 31 
                 perforated plate 
               
               
                 32 
                 pin 
               
               
                 33 
                 chain 
               
               
                 34 
                 attachment 
               
               
                 35 
                 locking member 
               
               
                 36 
                 beam 
               
               
                 37 
                 eyelet 
               
               
                 38 
                 cam section 
               
               
                 39 
                 flat side 
               
               
                 40 
                 flat side 
               
               
                 41 
                 u-shaped surface 
               
               
                 42 
                 u-shaped surface 
               
               
                 43 
                 reference line 
               
               
                 44 
                 stop 
               
               
                 45 
                 cable 
               
               
                 46 
                 arrow 
               
               
                 47 
                 hook 
               
               
                 48 
                 climber 
               
               
                 49 
                 vest 
               
               
                 50 
                 coupler 
               
               
                 51 
                 web 
               
               
                 52 
                 flange 
               
               
                 53 
                 flange 
               
               
                 54 
                 upper end portion 
               
               
                 55 
                 locking member 
               
               
                 56 
                 beam 
               
               
                 57 
                 eyelet 
               
               
                 58 
                 cam section 
               
               
                 59 
                 flat side 
               
               
                 60 
                 flat side 
               
               
                 61 
                 u-shaped surface 
               
               
                 62 
                 u-shaped surface 
               
               
                 63 
                 stop 
               
               
                 64 
                 weld 
               
               
                 65 
                 channel 
               
               
                 66 
                 web 
               
               
                 67 
                 flange 
               
               
                 68 
                 flange 
               
               
                 69 
                 oblong opening 
               
               
                 70 
                 slot/gap 
               
               
                 71 
                 locking member 
               
               
                 72 
                 beam 
               
               
                 73 
                 eyelet 
               
               
                 74 
                 cam section 
               
               
                 75 
                 flat side 
               
               
                 76 
                 flat side 
               
               
                 77 
                 u-shaped surface 
               
               
                 78 
                 locking surface 
               
               
                 79 
                 tail/locking tab 
               
               
                 80 
                 wedge 
               
               
                 81 
                 opening 
               
               
                 82 
                 inclined surface 
               
               
                 83 
                 transverse surface 
               
               
                 84 
                 folded portion 
               
               
                 85 
                 folded portion 
               
               
                 90 
                 ladder safety apparatus 
               
               
                 91 
                 ladder 
               
               
                 92 
                 rail 
               
               
                 93 
                 rail 
               
               
                 94 
                 rung 
               
               
                 95 
                 angle 
               
               
                 96 
                 inner section 
               
               
                 97 
                 outer section 
               
               
                 98 
                 web 
               
               
                 99 
                 flange 
               
               
                 100  
                 flange 
               
               
                 101  
                 gap/opening 
               
               
                 102  
                 curved end portion 
               
               
                 103  
                 curved end portion 
               
               
                 104  
                 web 
               
               
                 105  
                 flange 
               
               
                 106  
                 flange 
               
               
                 107  
                 flange 
               
               
                 108  
                 flange 
               
               
                 109  
                 gap/opening 
               
               
                 110  
                 ladder safety apparatus 
               
               
                 111  
                 rung 
               
               
                 112  
                 rail 
               
               
                 113  
                 rung 
               
               
                 114  
                 rail 
               
               
                 115  
                 opening 
               
               
                 116  
                 slot 
               
               
                 117  
                 central rail 
               
               
                   
               
             
          
         
       
     
         [0061]    All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. 
         [0062]    The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.

Technology Classification (CPC): 4