Abstract:
A device for ascending or descending using the single rope technique. The device includes a clamping mechanism that has a plurality of clamping segments interconnected by a flexible spine arrangement. A release mechanism is coupled to the clamping mechanism. A reduction mechanism is coupled to the release mechanism. The reduction mechanism includes a body portion having a rope slot configured to accommodate the single rope and a housing portion disposed over the body portion. The housing portion includes a cammed groove configured to accommodate the single rope. The cammed groove is rotatably aligned with the rope slot. The reduction mechanism is movable with at least two degrees of freedom between the clamping position and the released position. The reduction mechanism is configured to frictionally engage the single rope in the released position.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a safety device, and particularly to a device for safely raising and lowering a person using the single-rope technique. 
     2. Technical Background 
     There are many types of work that require a climbing device to safely perform a given task. In tree care work, for example, pruning, branch cutting and similar tasks must be performed off the ground and in the tree itself. There are construction jobs that also require the user to work in elevated positions. Some users enjoy mountain climbing or rock climbing as a recreational pursuit. Whatever the activity, it is paramount that the persons engaging in activities such as these be able to ascend, work and descend, safely and effectively, without worry or concern. 
     In reference to  FIG. 1 , a diagrammatic depiction of the “two-rope technique” is shown. Here, a rope R is disposed over a support structure Sp. One end of the rope is coupled to an attachment point  2 - 2  of the apparatus  2 , is secured by clamp  2 - 1 , and extends toward the ground. The user is attached to the apparatus at the attachment point  2 - 2 . To ascend, the user pulls the rope R downwardly (See arrow A) at point “P” to pull the apparatus  2  upwardly (See arrow B) toward the support structure. At rest, the clamping structure  2 - 1  secures the user at some position off the ground. When the user wishes to descend, he depresses the release mechanism  2 - 3 ; the attachment mechanism works in conjunction with the clamp  2 - 1  to apply enough friction and control such that the user slides down the rope in safe manner. One drawback to the two-rope technique relates to the 2:1 mechanical advantage provided by the two-rope technique; while it is relatively easy to pull oneself up the rope, one only travels half as far. Some users do not like this technique and prefer the single rope technique instead. 
     Referring to  FIGS. 2A-2B , a diagrammatic depiction of the “single rope technique” is shown. In this case, one end of the rope R is anchored or secured to the ground. The rope R extends over the support structure Sp, and is secured by the clamp  1 - 1 . The attachment point  1 - 2  connects the user, or the user&#39;s harness, to the climbing apparatus  1 , but is not connected to the rope. The single rope technique therefore provides no mechanical advantage. There is a 1:1 relationship between the pulling distance and traveling distance because they are one and the same. One of the drawbacks associated with the single rope technique occurs when the user actuates the release mechanism. Briefly stated, once the clamp  1 - 1  is released, the user has a tendency to rapidly descend down the rope with little control. 
     Referring to  FIG. 2B , the approach commonly employed to overcome the above stated drawback is shown. In order to obviate the above stated drawback, the user wraps the rope around the clamp  1 - 1  to effect a technique that is appropriately referred to as a “rope wrap”  1 - 4 . In particular, when the user actuates the release  1 - 3 , she is holding the lower portion of the rope R tightly against the clamp portion  1 - 1  such that the rope wrap  1 - 4  increases the coefficient of friction as the rope R moves in the direction A over the clamp  1 - 1 . The applied friction slows the user&#39;s descent and allows the user to lower herself with greater control. 
     One drawback associated with the rope wrap technique occurs at the moment the user actuates the release  1 - 3 . There is a momentary drop, or jerk, that occurs when the release takes up some of the slack in the rope or line. This sudden movement is very unsettling to the user. Many users report a sense of panic and feel unsafe when this occurs. Another drawback to this approach occurs when the user descends to a new position to continue work. Once the user is in position, the release mechanism is disengaged and the clamp secures the rope. Next, the user must undo the rope wrap  1 - 4 . However, this step in the process typically causes another sudden drop. Once again, the user momentarily thinks that she is about to fall. Again, this sudden movement is unsettling and annoying. 
     What is needed, therefore, is an apparatus adapted to the single rope technique that overcomes the drawbacks described above. In particular an apparatus is needed that avoids the sudden drops associated with the rope wrap and the conventional single rope technique apparatus. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus adapted to the single rope technique that overcomes the drawbacks described above. The present invention is directed to an apparatus that provides control at all times such that the sudden jerks or drops associated with the rope wrap and the conventional single rope technique apparatus are substantially eliminated. 
     One aspect of the present invention is directed to a safety device for use in a single rope technique arrangement. The device includes a clamping mechanism including a plurality of clamping segments interconnected by a flexible spine arrangement. Each of the plurality of clamping segments includes a rope channel having a first aperture and a second aperture sized to substantially accommodate a diameter of the single rope. The first aperture is substantially offset from the second aperture. A release mechanism is coupled to the clamping mechanism. The release mechanism is configured to apply a first force to the flexible spine that substantially misaligns the rope channels of adjacent clamping segments in a clamping position and apply a second force that substantially aligns the rope channels of adjacent clamping segments in a released position. A reduction mechanism is coupled to the release mechanism. The reduction mechanism includes a body portion having a rope slot configured to accommodate the single rope and a housing portion disposed over the body portion. The housing portion includes a cammed groove configured to accommodate the single rope. The cammed groove is rotatably aligned with the rope slot. The reduction mechanism is movable with at least two degrees of freedom between the clamping position and the released position. The reduction mechanism is configured to frictionally engage the single rope in the released position. 
     Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings. 
     It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the description serve to explain the principles and operation of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagrammatic depiction of the two rope technique; 
         FIGS. 2A-2B  are a diagrammatic depictions of the single rope technique; 
         FIG. 3  is a diagrammatic depiction of the single rope technique in accordance with the present invention; 
         FIGS. 4A-4B  are exploded views of embodiments of the reduction mechanism depicted in  FIG. 3 ; 
         FIG. 5A  is a perspective view of the safety device depicted in  FIG. 3  with the reduction mechanism removed; 
         FIG. 5B  is a perspective view of the safety device depicted in  FIG. 3  with the reduction mechanism attached; 
         FIGS. 6A-6D  are perspective views illustrating a method for loading a rope into the reduction mechanism depicted in  FIGS. 4A-4B  in accordance with an embodiment of the present invention; 
         FIG. 7  is a detail perspective view of the safety device in accordance with an embodiment of the present invention; and 
         FIG. 8  is a detail perspective view of the safety device depicted in  FIG. 7  during a descent procedure. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to the present exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of the climbing mechanism of the present invention are shown in  FIGS. 3 ,  5  and  7 , and is designated generally throughout by reference numeral  10 . 
     As embodied herein, and depicted in  FIG. 3 , a diagrammatic depiction of the single rope technique in accordance with the present invention is disclosed. Specifically, a safety device  10  of the present invention includes a connector  12  that is coupled to a clamping apparatus  14  and a reduction mechanism  20 . The clamping mechanism is equipped with a release mechanism  16 . In practice, a single rope R is inserted into, and passes through, both the reduction mechanism  20  and the clamp apparatus  14 . Essentially, when the user releases the clamp apparatus  14 , the reduction mechanism is automatically engaged to substantially prevent the user from momentarily dropping. 
     Referring to  FIGS. 4A-4B , exploded views of embodiments of the reduction mechanism  20  diagrammatically depicted in  FIG. 3  are disclosed. The reduction mechanism shown in  FIG. 4A  includes a yoke  22  that includes a U-shaped body portion  22 - 1  having an elongated slot  22 - 10  formed therein. A shoulder  22 - 3  is formed at one end of the yoke body  22 - 1  and a connective boss  22 - 2  extends from the other end of the body portion  22 - 1 . The connective boss  22 - 2  has a narrower diameter than the yoke body  22 - 1  and thus a second shoulder  22 - 4  is formed at the yoke/boss interface. The connective boss  22 - 2  includes a pin aperture  22 - 20  that is configured to accommodate a retaining pin  23 . 
     The reduction mechanism  20  also includes a cammed bushing  24  that is configured to slide over the yoke body portion  22 - 1 . The cammed bushing  24  includes a rope ingress pocket  24 - 2 , a curvilinear diagonal slot  24 - 3  that forms the cammed surface  24 - 1 , and a rope egress pocket  24 - 4 . The function of each of these features is described below in greater detail. 
     The reduction mechanism  20  further includes a collar portion  12  that includes a central opening  12 - 2  that accommodates the connective boss  22 - 2 . Once the boss  22 - 2  is inserted into collar opening  12 - 2 , the collar  12  is seated on the shoulder  22 - 4  such that the pin aperture  22 - 20  is exposed. Once the collar  12  is in place, the retaining pin  23  is inserted into the exposed pin aperture  22 - 20  to complete the assembly  20 . Note that the collar  12  includes an opening  12 - 1  formed in the side thereof. The opening  12 - 1  is configured to accommodate a retaining pin (not shown in this view) that interconnects the reduction mechanism  20  and the clamp apparatus  14  (also not shown in this view). 
     Referring to  FIG. 4B , another embodiment of the reduction mechanism  20 ′ in accordance with the present invention is disclosed. In this embodiment, the yoke  22 ′ does not include a boss extending from the yoke body; rather, the yoke body  22 - 1 ′ has a single diameter from shoulder  22 - 3 ′ onward. In this case both the cammed bushing  24  and the collar  12  fit over the yoke body  22 - 1 ′. The pin  23 ′ connects the collar  12  to the body  22  such that the cammed bushing  24  is disposed between the shoulder  22 - 3  and the collar  12  with enough clearance to allow the cammed bushing  24  to rotate freely. Moreover, the clearance allows both the bushing  24  and the collar  26 ′ to slide somewhat along the longitudinal axis of the yoke body  22 - 1 ′ between the shoulder  22 - 3  and the pin  23 ′. Thus, the cammed bushing  24  operates with two degrees of freedom in carrying out its functions. The reader will note that an L-shaped release member  21  is shown in this view. The previous embodiment (See  FIG. 4A ) can employ the same or a similar release member  21 . 
     Referring to  FIG. 5A , a perspective view of the safety device  10  depicted in  FIG. 3  (with the reduction mechanism  20  removed) is disclosed. The device  10  is depicted in situ with the single rope R extending through the clamp  14 . The clamp  14  includes a spine  14 - 3  that is comprised of interconnected link elements  14 - 30 . The top link accommodates the retaining pin that couples the collar  12  to the remainder of the spine  14 - 3 . Moreover, each link  14 - 30  provides a connection point for each clamp segment  14 - 1 . In this view, the clamp  14  includes four clamping segments  14 - 1 . The clamping segments  14 - 1  are flanked on the top by a release tab  16 - 1  and on the bottom by a second release tab  16 - 2 , that together comprise the release mechanism. The release mechanism  16  is depicted as an L-shaped member that includes a handle portion  16 - 3 . Note that the vertical slot in the handle  16 - 3  also functions as the attachment point for the users harness. 
     Turning now to  FIG. 5B , a perspective view of the safety device  10  is disclosed, this time with the reduction mechanism  20  attached thereto. Here, the boss  22 - 2  is shown extending through the collar  12  with the retaining pin  23  in place such that the reduction gear  20  is coupled to the clamp  14 . In the detail view of  FIG. 5B , each clamp segment  14 - 1  is shown to include a top aperture  14 - 10  and a lower aperture  14 - 12 . The apertures ( 14 - 10 ,  14 - 12 ) are deliberately misaligned and off-center one from the other. When the device  10  is shown in the operating position shown in  FIGS. 5A-5B , the misaligned apertures ( 14 - 10 ,  14 - 12 ) clamp the rope R. 
     Referring to  FIGS. 6A-6D , perspective views illustrating a method for loading the rope R into the reduction mechanism  20  depicted in  FIGS. 4A-4B  is disclosed. In  FIG. 6A , the ingress opening  24 - 2  of the cammed bushing is aligned with the oblong slot  22 - 10  of the yoke member  22 . A portion of the rope R is inserted into slot  22 - 10  and the opening  24 - 2 . In  FIG. 6B , the user rotates the bushing in the direction indicated by the arrow such that the cammed surface  24 - 1  substantially closes the slotted opening  22 - 10 . In  FIG. 6C , the user continues the process as the cammed surface  24 - 1  slides over the cylindrical yoke body  22 - 1 . This rotational action of the cammed bushing forces the rope to move upwardly into the slot  22 - 10 . In  FIG. 6D , the rope loading process is essentially completed. At this point, the rope R has moved along the entire edge of the cammed surface  24 - 1  and has been locked into the egress pocket  24 - 4 . In this locked position, the rope R extends through the ingress pocket  24 - 2 , the slot  22 - 10  and the egress pocket  24 - 2 . When the reduction mechanism is disposed at an oblique angle relative to the rope R, the rope is engaged by the edges of the bushing body at both pockets ( 24 - 2 ,  24 - 4 ). As the reduction mechanism is rotated, the rope R tends to bend in an S-curve to thus increase the friction applied at the pockets ( 24 - 2 ,  24 - 4 ). When the reduction mechanism is positioned substantially normal to the longitudinal axis of the rope R, the pockets ( 24 - 2 ,  24 - 4 ) are substantially aligned to minimize the applied friction. 
     Referring to  FIG. 7 , a detail perspective view of the climbing mechanism in accordance with an embodiment of the present invention is disclosed. In this view, the user can freely advance the mechanism up the rope by pushing up on the bottom handle  16 - 3 . When the user takes this action, the clamping elements  14  and the reduction mechanism  20  angle slightly down toward the “unlocked” position. At the same time, the reduction mechanism  20  is disposed substantially normal to the longitudinal axis of the rope R and is therefore disengaged allowing near frictionless movement up the rope. When the user applies her weight to the device, by sitting back in her harness, the clamping elements and the reduction mechanism angle up to the clamped position. This action by the user misaligns the apertures of the clamp segments  14 - 1  and the reduction mechanism, clamping the rope and substantially prevent any downward movement along the rope R. 
     Referring to  FIG. 8 , a detail perspective view of the safety device  10  during a descent procedure is disclosed. Here, the user squeezes the top release tab  16 - 1  and the bottom release tab  16 - 2  together, the bottom handle  16 - 3  and release tab  16 - 2  are held in their proper angular orientation by the user&#39;s weight, which is applied to the bottom of the handle  16 - 3  (i.e., the user&#39;s point of connection). By squeezing of the release tabs together, only the top release tab is depressed downwardly. This action releases the grip of the clamping elements  14 - 1  on the rope, and allows the rope to slide freely through the clamp  14 . However, before the rope is able to slide, the reduction mechanism rotates to its fully engaged position. Accordingly, with the reduction mechanism fully engaged and adding friction to the system, the user descends down the rope in a smooth and controlled manner. Thus, the safety device of the present invention substantially eliminates the drawbacks associated with conventional single rope devices. In other words, the sudden drops and jerking motions characteristic of the conventional devices are substantially eliminated or dampened. Moreover, the present invention allows the user to descend with a wide range of speed; and therefore, this feature provides the user with a feeling of greater control. 
     Briefly stated, the clamp segments  14 - 1  allow the rope to pass freely there through, but the reduction mechanism  20  applies enough frictional force to substantially reduce the descending speed. The reader will note that the reduction mechanism  20  provides three degrees of freedom in controlling the movement of the rope R. The collar  12  allows the reduction mechanism  20  to move in an angular direction θ with respect to the rope (y-axis). As explained above, the cammed bushing  24  is provided with some clearance space between the collar  12  and the shoulder  22 - 3  such that it can move along the longitudinal axis of the reduction mechanism (x-axis) (between the shoulder  22 - 3  and the collar  12 ). In addition, the cammed bushing  24  is configured to rotate about the longitudinal axis of the reduction mechanism (x-axis). Clearly, the major control action taken by the user is squeeze the release mechanism to thereby cause the reduction mechanism  20  to rotate upwardly (i.e., about 60 degrees), but the other two degrees of freedom allow the bushing  24  to move incrementally and adaptively to provide a fine tuning of sorts that gives the user a greater degree of control over the descending process. As a result, the user descends in a smooth and controlled manner without any sudden and disconcerting drops or jerking motions. 
     All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. 
     The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. The term “connected” is to be construed as partly or wholly contained within, attached to, or joined together, even if there is something intervening. 
     The recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. 
     All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention and does not impose a limitation on the scope of the invention unless otherwise claimed. 
     No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
     It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. There is no intention to limit the invention to the specific form or forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined in the appended claims. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.