Abstract:
A controlled descent mechanism with a self locking feature. The mechanism includes a belt with an end for attaching to a higher elevation and a free end. The belt is routed between moveable pins within the mechanism and slides across the pins as it moves through the mechanism. The pins can be moved toward one another to induce a dynamic friction within the mechanism to slow the rate of belt movement. The mechanism includes an attachment location for a user harness, and can be used to lower the user while controlling the rate of descent. The mechanism includes a self locking feature to automatically arrest the descent of the user.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/477,571, filed on Jun. 11, 2003. The disclosure of the above application is incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to a fall protection system and more specifically to a rappelling mechanism for controlled descent.  
       BACKGROUND OF THE INVENTION  
       [0003]     People working from heights have been known to fall from workstations and hunters in trees have fallen out of tree stands. Today there are many types of fall protection systems intended to arrest the fall of a person. One of these mechanisms is a life line that is connected to a harness worn by the user and connected to a stationary object. Also there exists mechanisms that allow a person to control their descent as they rappel. Conventional rappelling devices generally require that the user has specialized knowledge or training in the use of the devices. Additionally, these devices are sometimes bulky, heavy and expensive. Many conventional rappelling mechanisms are not self locking and require the user to actuate the rappelling mechanism in order to stop or slow the rate of descent. What is needed is a fall protection system that will restrain the fall of an individual and also provide a rappelling mechanism that is less complicated and easier to use.  
       SUMMARY OF THE INVENTION  
       [0004]     In accordance with the teachings of the present invention, a fall protection system with a rappelling mechanism is disclosed. In one form, the present invention provides a fall protection system that incorporates a harness with a rappelling mechanism and a pouch for storing a length of webbing. In another form, the present invention provides a rappelling mechanism including a pair of lock plates, a pair of release plates, a release pin, a pair of short pins, and a pivot pin. Additional advantages and features for the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0006]      FIG. 1  is a front view of the controlled descent mechanism in accordance with the present invention;  
         [0007]      FIG. 2  is a sectional view taken along line  2 , 2  of  FIG. 1 ;  
         [0008]      FIG. 3  is a perspective view of a fall protection system in accordance with the teachings of the present invention;  
         [0009]      FIG. 4  is a perspective view of the pouch of  FIG. 3  showing a top portion;  
         [0010]      FIG. 5  is a perspective view of a release plate of the mechanism of  FIG. 1 ;  
         [0011]      FIG. 6  is a perspective view of a locking plate of the mechanism of  FIG. 1 ; and  
         [0012]      FIGS. 7 and 8  represent front and side views of an alternate rappelling mechanism according to the teachings of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0013]     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  
         [0014]     The following description of embodiments of a fall protection system and controlled descent mechanism are exemplary in nature and in no way intended to limit the invention, its applications or uses. Moreover, while the present invention is described in detail with reference to fall protection, it will be appreciated by those skilled in the art that the present invention is not limited to a fall, but may also be used wherever a controlled descent mechanism would be required.  
         [0015]     The rappelling mechanism  10  functions to selectively control the movement of the webbing  42  through the mechanism  10 . To this end, by coupling a harness  52  to the mechanism  10 , a user can selectively release or lock the harness to the webbing  42 . As shown in  FIG. 1 , the locking plates  12  and  14  are held together in a generally parallel configuration by the pins  26 ,  28 , and  30 . Additionally disposed between the locking plates  12  and  14  is the pivot pin.  
         [0016]     Similarly, the release plates  16  and  18  are parallelly configured and held together by pins  20  and  24 . As described below, the lock plates  12  and  14  are rotationally coupled to the pin  26 . Rotation of the release plates  16  and  18  with respect to the locking plates moves the locking pin  24  with respect to the short pins  20 ,  24 .  
         [0017]     With reference to  FIGS. 1 and 2 , a controlled descent or rappelling mechanism in accordance with the teachings of the present invention is generally illustrated as reference numeral  10 . Mechanism  10  includes a pair of lock plates  12 ,  14 , a pair of release plates  16 ,  18 , a pair of short pins  20 ,  22 , a locking pin  24 , a pivot pin  26 , a release pin  28 , an attachment pin  30 , and a cover  32 . Mechanism  10  is illustrated with a belt  40  inserted therein. An attachment webbing  42  is secured to attachment pin  30  and a release strap  44  is secured to release pin  28 .  
         [0018]      FIG. 3  illustrates a fall protection system  50  to include a harness  52  having a D-ring  54  attached thereto and a pouch  56  mounted thereon. Pouch  56  can be attached to harness  52  with a conventional hook and loop closure attachment. Harness  52  includes straps  60  with adjustment portions  62  and a locking mechanism  64  attached thereto. Adjustment portions  62  are provided with straps  60  to adjust the length of straps  60  when fitting harness  52  to a user. Locking mechanism  64  are adjustable with respect to straps  60  and lock onto straps  60  in order to form the harness  52  that can be secured to the torso of an individual. When harness  52  is strapped on an individual, D-ring  54  is preferably mounted in the back just above pouch  56  as best seen in  FIG. 3 . Attachment webbing  42  is secured to D-ring  54  of harness  52 . While harness  52  is illustrated as multiple straps  60 , it is also anticipated that the harness of the present invention could be a vest with straps  60  attached thereto to provide the same function as harness  52 .  
         [0019]      FIG. 4  illustrates pouch  56  including belt  40  folded therein. Pouch  56  is intended to enclose a predetermined length of belt  40  in order to allow an individual that has fallen to rappel safely to the ground as described below. Belt  40  is shown in  FIG. 4  to be folded and overlaid within pouch  56  in order to allow belt  40  to self feed from pouch  56  during operation of fall protection system  50 .  
         [0020]     With reference to  FIG. 5 , release plate  18  is shown in greater detail. Release plate  18  is identical to release plate  16  and is shown to include a locking pin aperture  124 , a pivot pin aperture  26 , a release pin aperture  128 , and an attachment pin aperture  130 .  FIG. 6  illustrates locking plate  14  to include short pin apertures  220  and  222 , a locking pin slot  224 , and a pivot pin aperture  226 .  
         [0021]     When assembled, pivot pin  26  is shown in  FIGS. 1 and 2  to be interposed through pivot apertures  126  of pivot plates  16 ,  18 , and pivot apertures  226  of locking plates  12 ,  14 . Pivot pin  26  is interposed through apertures  126 ,  226  in such a manner as to allow locking plates  12 ,  14 , to rotate relative release plates  16 ,  18 . Short pin  20  is interposed within short pin apertures  220  and short pin  22  is interposed within short pin apertures  222 . Locking pin  24  is shown interposed through locking pin apertures  124  and locking pin slots  224 . Thus provided, locking pin  24  translates within locking pin slots  224  as lock plates  12 ,  14  rotate with respect to release plates  16 ,  18 . Belt  40  is positioned within mechanism  10  such that belt  40  threads through a space between short pins  20 ,  22 , around locking pin  24 , and back through the space between short pins  20 ,  22 . Attachment pin  30  is interposed within attachment pin apertures  130  and release pin  28  is interposed within release pin apertures  128  and secured therein. Locking pin  24 , release pin  28 , and attachment pin  30  are securely attached to release plates  16 ,  18 , thereby forming a rigid mechanism  10 . This attachment can be accomplished by an interference fit between release plates  16 ,  18  and locking pin  24 , release pin  28 , and attachment pin  30  wherein the ends of locking pin  24 , release pin  28 , and attachment pin  30  are splined, or by any other suitable means. Cover  32  is superposed about the moveable components of mechanism  10 . As presently preferred, cover  32  is constructed of injection molded plastic belt  40  is a seat belt webbing, and all other components of mechanism  10  are constructed of  4130  cold rolled steel.  
         [0022]     As best seen in  FIGS. 2, 5  and  6 , as release plates  16 ,  18  rotate counterclockwise with respect to locking plates  12 ,  14 , the locking pin  24  translates within locking pin slots  224  toward short pins  20 ,  22 . As locking pin  24  translates in this direction, belt  40  is cinched between the surfaces of locking pin  24  and short pins  22  and/or  20 . In this manner, counterclockwise rotation of release plates  16 ,  18  (see  FIG. 2 ), will cause locking pin  24  to tighten belt  40  against short pins  20 ,  22 . This prevents relative movement between belt  40  and locking pin  24 . As release plates  16 ,  18  are counter-rotated or rotated in a clockwise direction, the locking pin  24  rotates away from short pins  20 ,  22 , thereby unlocking belt  40 . This allows the belt  40  to travel through rappelling mechanism  10 . This clockwise rotation is accomplished by pulling on release strap  44  thereby exerting a force on release plates  16 ,  18  via release pin  28  in a downward direction with respect to  FIG. 2 . The amount of force required to release belt  40  is approximately 25% of the individuals body weight.  
         [0023]     In operation, the weight of a user will provide a downward reactive force W on attachment pin  28 , generally in the direction of arrow D. This force will rotate locking plates  16 ,  18  counter clockwise thereby locking belt  40  between locking pin  24  and short pins  20 ,  22 . Thus provided, belt  40  is self-locked after a user falls. To descend, the user pulls release strap  44  thereby moving locking pin  24  away from short pins  20 ,  22 . This permits the belt  40  to travel through the rappelling mechanism  10 . The amount of force applied by the user to release pin  28  has a component of force P in the direction of arrow D. As belt  40  travels through rappelling mechanism  10 , friction between belt  40  and pins  20 ,  22 , and  24  counter acts some of the downward reactive force W, thereby slowing the rate of descent and inhibiting a free fall of the user. The amount of force P applied by the user varies the amount of friction between belt  40  and pins  20 ,  22 , and  24  which, in turn, varies the rate of descent. Thus provided, a user can control the rate of travel of belt  40  through mechanism  10  by selectively regulating the amount of force P applied to release pin  28 . It would be appreciated by one skilled in the art that pins  20 ,  22 , and  24  could be provided with a frictional surface, and that belt  40  can be selected to provide a desired coefficient of static and/or dynamic friction during operation of fall protection system  50 .  
         [0024]     When a fall protection system is desired, an individual is secured within harness  52  such that pouch  56  is located adjacent the individuals rear torso region. Attachment webbing  42  is secured to D-ring  54  thereby providing a positive attachment between rappelling mechanism  10  and harness  52 . Pouch  56  is preferably located on a portion of harness  52  that is below rappelling mechanism  10 , as seen in  FIG. 3 . Straps  60  are securely tightened around the person&#39;s torso and leg regions using lock mechanisms  64  and adjustment portions  62 . In the event of a fall, the weight of an individual is translated through D-ring  54  and attachment webbing  42  to attachment pin  30 . This downward force on attachment pin  30  as seen in  FIG. 2 , causes locking pin  24  to rotate counterclockwise towards short pins  20 ,  22  thereby locking the rappelling mechanism  10 . With rappelling mechanism  10  locked, belt  40  will not translate therethrough, thereby arresting the user&#39;s fall. For a controlled descent to the ground or other recovery location, release strap  44  is pulled such that locking pin  24  is moved away from short pins  20 ,  22  and belt  40  is allowed to slowly translate between locking pin  24  and short pins  20 ,  22 . The rate of descent is controlled by the amount of downward force P exerted on release pin  28  via release strap  44 , as discussed above. During descent, the rate of descent can be lowered by exerting less force P on release pin  28 . Thus provided, fall protection system  50  allows an individual to control their rate of descent after a fall.  
         [0025]     With reference to  FIGS. 7 and 8 , an alternate rappelling mechanism  70  according to the teachings of the present invention is disclosed. The rappelling mechanism  70  is configured to releasably engage a flat webbing  72  as previously described. The rappelling mechanism  70  has a walking pin support frame  74  which is configured to align three walking locking pins  76 ,  78 , and  80 . Coupled to the center locking pin  80  is a release arm  82 . The rappelling mechanism  70  is configured to be positioned along a length of webbing  72  and further fixaby coupled the harness  52 . In this regard, the rappelling mechanism  70  is disposed between the harness  52  and a fixed point so as to allow a user to manually adjust the distance between the harness  52  and the fixed point along the webbing  72 .  
         [0026]     The locking pin support frame  74  has a pair of generally parallel lock pin support bars  84  and  86 . The lock pin support bars  84  and  86  slidably receive the three walking locking pins  76 ,  78 , and  80 . As best seen in  FIG. 8 , the webbing  72  is serpentinely fed about locking pins  78  and  80 . Further, the webbing  72  is fed between the interfacing surfaces of locking pins  76  and  80 . It should be noted that the locking pins  76 ,  78 , and  80  are slidable along the locking pin support bars.  
         [0027]     The orientation of the locking pins in conjunction with the webbing  72  locks the webbing  72  and prevents relative movement of the webbing with respect to the locking pins  76 ,  78 , and  80 . The locking pins  76 ,  78  and  80  are generally cylindrical and can have an outer surface with a constant radius. Disposed transversely through each pin is a pair of holes which slidably accept the lock pin support bars  84  and  86 . It is envisioned the rappelling mechanism  70  can further have a suitable injection molded plastic housing and at least one web guide  71  to maintain the mechanism  70  in a preferred orientation.  
         [0028]     The lever release arm  82  has a handle portion  90  and a camming portion  92 . The camming portion  92 , which is formed of two parallel members  91 , has first and second bearing surfaces  94  and  96  which contact locking pins  76  and  78 . Members  91  define a through hole  93  that rotatably interfaces with the outer surface  95  of locking pin  80 . Rotation of the lever release arm  82  rotates the camming portion  92  with respect to the locking pin  80  and causes the first and second bearing surfaces to apply pressure to surfaces of locking pins  76  and  80 . This pressure causes the locking pins  78  and  80  to translate and separate from locking pin  76  along the locking pin support bars. In this regard, while locking pin  76  is pressed against the stop by the lock pin support bar&#39;s formed end or stop  98  and  100 , locking pins  78  and  80  translate along the locking in support bars. The mechanism is configured so the amount of separation of the locking pins  76 ,  78  and  80  is proportional to the angle of rotation of the release lever. Upon the loading of the webbing  72  from a user&#39;s weight, the webbing  72  pulls the three locking pins  76 ,  78 , and  80  into engagement with the pair of stop members  98  and  100  formed on the locking pin support bars. Specifically, in loading the lock pin support bar toward locking pin  78 , the webbing  72  forces lock pin  78  into the center locking pin  80  which in turn forces and traps the webbing  72  into lock pin  76 . Lock pin  76  is stopped and held in position by the lock pin support bar&#39;s formed end or stop  98  and  100 . In this position, the mechanism  70  is in a locked condition and will not payout any webbing  72  until the release lever is pulled.  
         [0029]     The speed of the decent is controlled by the magnitude of the forces on release arm  82 . To descend slowly, a small rotation is applied to the release arm  82 . To descend faster, forces to cause more rotation of the release arm  82  are applied. The removal of forces to the release arm  82  will cause the mechanism  70  to be again put into the locked condition.  
         [0030]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.