Abstract:
A safety ladder that protects a climber from a fall is disclosed. The device provides a ladder having a plurality of rungs, 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 configured to form an anchor with the channel in a locking position when a climber pulls down on the cable and locking member.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     Priority of my U.S. Provisional Patent Application Ser. No. 60/774,294, filed 16 Feb. 2006, incorporated herein by reference, is hereby claimed. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT  
       [0002]     Not applicable  
       REFERENCE TO A “MICROFICHE APPENDIX” 
       [0003]     Not applicable  
       BACKGROUND OF THE INVENTION  
       [0004]     1. Field of the Invention  
         [0005]     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.  
         [0006]     2. General Background of the Invention  
         [0007]     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.  
         [0008]     Several patents have issued that relate generally to safety devices that help a climber when ascending a ladder.  
         [0009]     The following US patents are examples of such devices, each being incorporated herein by reference:  
                       TABLE                       PATENT       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  
       [0010]     The present invention provides an improved ladder safety apparatus that features an elongated channel that is attached to and that extends along a ladder to be climbed. A cam locking member travels in the channel and can be pulled upwardly with little or no resistance as the climber ascends the ladder.  
         [0011]     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  
       [0012]     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:  
         [0013]      FIG. 1  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention;  
         [0014]      FIG. 2  is a top view taken along lines  2 - 2  of  FIG. 1 ;  
         [0015]      FIG. 3  is a partial perspective view of the preferred embodiment of the apparatus of the present invention;  
         [0016]      FIG. 4  is a partial perspective view of an alternative embodiment of the apparatus of the present invention;  
         [0017]      FIG. 5  is a partial perspective view of the preferred embodiment of the apparatus of the present invention;  
         [0018]      FIG. 6  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention;  
         [0019]      FIG. 7  is a fragmentary side view of the preferred embodiment of the apparatus of the present invention;  
         [0020]      FIG. 8  is a perspective view of the preferred embodiment of the apparatus of the present invention;  
         [0021]      FIG. 9  is another perspective view of the preferred embodiment of the apparatus of the present invention;  
         [0022]      FIG. 10  is a fragmentary side view of an alternate embodiment of the apparatus of the present invention;  
         [0023]      FIG. 11  is a top view taken along lines  11 - 11  of  FIG. 10 ;  
         [0024]      FIG. 12  is a partial perspective view of the alternate embodiment of the apparatus of the present invention;  
         [0025]      FIG. 13  is an elevation view of the preferred embodiment of the apparatus of the present invention showing connectable vertical channel sections;  
         [0026]      FIG. 14  is a fragmentary view of the preferred embodiment of the apparatus of the present invention;  
         [0027]      FIG. 15  is a fragmentary view of the preferred embodiment of the apparatus of the present invention;  
         [0028]      FIG. 16  is a partial sectional view of the preferred embodiment of the apparatus of the present invention;  
         [0029]      FIG. 17  is a side view of an alternate construction of the locking member;  
         [0030]      FIG. 18  is a top view of the locking member of  FIG. 17 ;  
         [0031]      FIG. 19  is a perspective view of the locking member of  FIG. 17 ;  
         [0032]      FIG. 20  is side view of an alternate construction for the rail portion of the preferred embodiment of the apparatus of the present invention;  
         [0033]      FIG. 21  is a fragmentary side view of the embodiment of  FIGS. 17 and 20  of the apparatus of the present invention;  
         [0034]      FIG. 22  is a similar view;  
         [0035]      FIG. 23  is a fragmentary side view of the embodiment of  FIG. 20  of the apparatus of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]     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 .  
         [0037]     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 .  
         [0038]     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.  
         [0039]     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 ).  
         [0040]     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 .  
         [0041]      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 .  
         [0042]      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.  
         [0043]      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 .  
         [0044]     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.  
         [0045]     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 .  
         [0046]     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.  
         [0047]     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.  
         [0048]     The following is a list of parts and materials suitable for use in the present invention.  
       PARTS LIST  
       [0049]     Part Number Description 
         10  ladder safety apparatus      11  scaffolding      12  ladder      13  bracket      14  bolted connection      15  rail      16  rung      17  vertical channel      17 A vertical channel section      17 B vertical channel section      17 C 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  unshaped 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  unshaped surface      78  locking surface      79  tail/locking tab      80  wedge      81  opening      82  inclined surface      83  transverse surface      84  folded portion      85  folded portion        
 
         [0129]     All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.  
         [0130]     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.