Not applicable.
This invention pertains to a device used, in conjunction with a rope, to stop a falling object and/or to lower an object in a controlled manner. In particular it pertains to a belay device used in the sport of rock climbing and, more specifically, to an auto-locking belay device.
In the sport of rock climbing, a belay device is used to protect a climber from injury in the case of a fall. Generally the climber wears a harness to which one end of a rope is attached. The rope passes through a belay device that is often attached to the harness of another person, the “belayer”. The belayer operates the belay device and typically remains at a stable point while the climber ascends. When the climber is “lead” climbing, the climber drags the rope up the rock as he ascends. At various points during the ascent, the climber clips the rope into metal loops (carabiners) that, in turn, are attached to the surface of the rock. When the climber is “top-rope” climbing, the rope extends down toward the climber from above. In the case of lead climbing, the belayer feeds out rope as the climber ascends. In the case of top-rope climbing, the belayer takes in rope as the climber ascends. In either case, if the climber falls, the belayer must grasp the rope securely by means of the belay device. The fall is therefore stopped by means of the belay device and the climber comes to rest suspended from above by the rope. Thereafter, the belayer may gently lower the climber to the ground by operating the belay device so as to gradually release tension on the rope. Anyone experienced in rock climbing is familiar with this practice and with the various forms of belay devices.
As mentioned, when lead climbing the rope is fed out from the belay device to the climber. If the climber is in a precarious position, he may need to quickly clip the rope into an attachment point In order to accomplish this move, the climber may require that as much as eight feet of rope be fed through the belay device almost instantly. When the climber is not able to obtain sufficient rope in one quick fluid movement, the climber is said to have been “short-roped”. Short-roping can actually cause the climber to fall by disturbing his balance. Since the primary objective of a belay device is to stop the fall of a climber, most devices contain a torturous path through which the rope runs. The frictional forces that develop as the rope travels through this torturous path serve to oppose the movement of the rope. This effect is beneficial to stop a fall but in direct opposition to the requirement that at times rope must be fed very quickly to the climber when he is lead climbing.
Over the years many devices have been developed to grip a rope and to control the rate of movement of rope, and many of these devices have been used for the purpose of belaying or for the very similar purpose of descending. Much of the patented prior art deals with descenders, many of which can also be used as belay devices. A descender is designed to lower a person or object in a controlled fashion.
The devices of the prior art can be broadly categorized into two classes:
The first class, manual belay devices, consists of relatively simple devices that contain no moving parts. These devices, many of which are very effective, rely entirely upon frictional forces developed within a torturous path through which the rope runs. A positive attribute of this class is that these devices are inexpensive since they are based on simple designs and contain no moving parts. On the negative side, these devices require action on the part of the belayer in order to stop a fall. If the belayer is inattentive or looses his grip, the result can be disastrous. Also on the negative side, it is difficult to feed rope quickly through these devices due to the torturous path of the rope. Examples include U.S. Pat. No. D413,786 to Graham, U.S. Pat. No. 5,217,092 to Potter, and U.S. Pat. No. 5,671,822 to Phillips.
The second class, auto-locking belay devices, consists of relatively more complicated designs, often with moving parts, that have the benefit of requiring no action on the part of a belayer in order to stop a fall. Often, such devices consist of one or more cams over which the rope runs. The cams either have an off-center axis of rotation or a variable radius that increases as the cam rotates. At least one such cam in each such device is usually designed such that, under normal climbing conditions, the rope slips over the surface of the cam and the cam remains stationary but, in the event the climber falls, the friction developed by the rapid passage of the rope along the cam surface causes the cam to rotate. Due to the shape of the cam, rotation thereof causes the rope to be pinched and stops the rope. These rotating cams are often spring loaded so as to resist rotation until a certain threshold frictional force has been achieved. A positive attribute of this class is that these devices require little or no action on the part of the belayer in order to stop a fall. On the negative side, these devices are relatively more expensive since they are more complicated designs and often have multiple moving parts. The presence of a moving part usually implies the requirement for manual labor in the assembly of that part which, in turn, implies relatively higher manufacturing cost Another negative attribute of this class, as with the first class, is that it can be difficult to feed rope quickly through these devices. The rapid pull of rope through the device, in essence, simulates the same conditions on the device as a fall, thus causing the cam to rotate and lock the rope. Examples of these auto-locking devices include U.S. Pat. No. 4,531,610 to Fertier et. al., U.S. Pat. No. 5,360,083 to Hede, U.S. Pat. No. 5,577,576 to Petzl et al., and U.S. Pat. No. 5,597,052 to Rogleja.
The devices described in the above mentioned patents, do not disclose, teach or illustrate the unique structure, function and advantage of the subject belay device.
The belay device and the belayer are critical to the sport since a climber's life is dependent both on the ability of the device to do its job and the attentiveness and reactions of the belayer. Some ideal characteristics of a belay device are:
These desired attributes can lead to design features that are in conflict with each other. For example:
The essence of the present invention is an improved belay device, for use in the sport of rock climbing, which performs well with respect to all critical characteristics. The subject invention achieves an optimal balance of these critical design characteristics.
In view of the foregoing, it is a primary object of the present invention to provide a belay device that achieves an optimal balance of desired performance characteristics that can often be in conflict with one another. Of particular note is the fact that this device is small, able to grip the rope very firmly, yet requires minimal force to lower a climber in a controlled fashion.
Another object is that the device requires little or no action on the part of the belayer in order to stop a fall. If the belayer releases his grasp on the present invention altogether, a fall will be stopped. Alternatively, the belayer may continue to hold the device during a fall, provided he does not obstruct the movement of the rope locking mechanism.
Still another object is that the device is inexpensive relative to its performance features. The present invention contains only one simple moving part It has a rope locking ring which can rotate around a central axle. It has no elaborate cams of varying radius. As will become apparent when reviewing the included figures, the hole through which a carabiner is received during operation, also serves to secure a front face plate.
Still another object is that the device provides a simple means for a fallen climber to be lowered to the ground in a gradual and controlled fashion. With the present invention, the belayer may lower a climber simply by exerting a relatively small force on a small, yet comfortable, lowering handle; the rate of descent being in direct proportion to the force exerted by the belayer.
Still another object is that the device grips a rope securely, even in the case of a fall of a heavy climber.
Still another object is that the device does not cause undue wear on a rope. The path of the rope through the present invention contains only smooth surfaces and all turns are of gradual curvature. The device contains no teeth or rough surfaces with which to grip the rope.
Still another object is that the device is relatively small and lightweight.
Still another object is that the device contains a relatively smooth rope path that allows the belayer to feed out rope very quickly.
These and other objects of the subject invention will become apparent to those familiar with the different types of belay devices when reviewing the following detailed description, showing novel construction, combination, and elements as herein described, and more particularly defined by the claims, it being understood that changes in the embodiments to the herein disclosed invention are meant to be included as coming within the scope of the claims, except insofar as they may be precluded by the prior art.
The Protruding Cylindrical Core (18) fits within a Central Hole (34) of a Rope Locking Ring (36). The Rope Locking Ring (36) contains an Upper Ring Rope Channel (38) and a Lower Ring Rope Channel (40). When positioned ready for use, the respective inner ends of the Upper Ring Rope Channel (38) and Lower Ring Rope Channel (40) match with the outer ends of the Base Rope Channel (20), forming one continuous channel through which a rope, not shown, may be threaded. When a rope is not present, the Rope Locking Ring (36) can rotate freely around the Protruding Cylindrical Core (18). The width of the Rope Locking Ring (36) is the same dimension as that of the Protruding Cylindrical Core (18). The Upper Ring Rope Channel (38) and Lower Ring Rope Channel (40) have the same depth as the Base Rope Channel (20). Consequently, the back portion of the Rope Locking Ring (36), behind the Upper Ring Rope Channel (38) and Lower Ring Rope Channel (40), is a Continuous Ring (42) of a width that equals the width of the Back Axle Portion (28). The Rope Locking Ring (36) has a Handle (44) extending outward and positioned so as to lie above the Base Carabiner Attachment Arm (12). The Rope Locking Ring (36) also contains a Curved Channel (46), which passes entirely through the width of the Rope Locking Ring (36) and is generally positioned near the edge of the Rope Locking Ring (36) opposite from the Handle (44). Additionally, the Rope Locking Ring (36) contains a Recessed Area (47) in order to minimize weight.
A Cover (48) comprises a Circular Cover Plate (50) from which extends a Cover Carabiner Attachment Arm (52). The Cover Carabiner Attachment Arm (52) has a Cover Carabiner Hole (54) with the same diameter as the Base Carabiner Hole (30). A Cover Connecting Pin Hole (56) passes through the Circular Cover Plate (50) and is positioned on an outer point on the Circular Cover Plate (50) generally opposite from the Cover Carabiner Hole (54).
A Connecting Pin (58) passes through the Base Connecting Pin Hole (32), Curved Channel (46), and Cover Connecting Pin Hole (56). The Curved Channel (46) allows the Connecting Pin (58) to pass through the Rope Locking Ring (36) without interfering with the rotation of the Rope Locking Ring (36) needed to lock the rope.
In operation, a belayer rotates the Cover (48) around the Connecting Pin (58) exposing the Upper Ring Rope Channel (38), Base Rope Channel (20), and Lower Ring Rope Channel (40). A rope, not shown, is threaded through all rope channels with the rope portion toward the belayer entering the device at the outer extreme of the Lower Ring Rope Channel (40), and the rope portion toward the climber exiting the device at the outer extreme of the Upper Ring Rope Channel (38). The Cover (48) is then rotated into a closed position in which the Cover Carabiner Hole (54) is positioned directly in front of the Base Carabiner Hole (30). An open end of a locking carabiner, not shown, is threaded through the belayer's harness, not shown; then through both Base Carabiner Hole (30) and Cover Carabiner Hole (54). The carabiner is then closed and locked.
After the device has stopped the fall of a climber, the belayer may slowly lower the climber by exerting force on the Handle (44). The Handle (44) is operated so as to slowly rotate the Rope Locking Ring (36) in a clockwise fashion, thereby removing the pinching force on the rope in the two Rope Pinch Transition Regions (61). In order to feed rope out quickly to a climber, the belayer can exert a slight pressure on the Rope Locking Ring (36) while feeding rope, thereby briefly preventing rotation of the Rope Locking Ring (36).
A very novel and unobvious feature of the subject invention is that the rope actually passes through the axis of rotation of the device. This feature not only yields a smaller and stronger device, but it also allows for the presence of two rope pinch points. Anyone familiar with the physical principle of leverage will realize that, the smaller the distance between the axis of rotation of the device and the rope pinch area, the stronger the grip force of the device. The fact that this device allows the rope to pass through the axis of rotation, yields a device with a very small distance between the axis of rotation and the rope pinch area. This, in turn, yields a device that is both smaller and stronger than those of the prior art. Those prior art auto-locking belay devices that contain rotating parts all have solid axles that form the axis of rotation. Consequently, the rope path in these prior art devices must be directed around these solid rotational axles. Relative to the present invention, these prior art designs result in a larger distance between the axis of rotation and the rope pinch area, thus yielding devices that must be larger than the subject invention in order to achieve the same grip force as the subject invention. Additionally, the fact that the rope path passes through the axis of rotation enables the device to have two rope pinch areas as shown by the two Rope Pinch Transition Regions (61).
The Curved Channel (50) also provides novel and unobvious functionality. This feature not only yields a relatively small device, it prevents excessive forces from damaging the rope. The Curved Channel (50) allows the Connecting Pin (58), which connects the Base (14) and Cover (50), to reside within the dimensions of the Rope Locking Ring (36) without interfering with the rotation of the Rope Locking Ring (36). Without this Curved Channel (50), the Connecting Pin (58) would have to reside outside of the dimensions of the Rope Locking Ring (36), yielding a larger Base (14) and Cover (50), thereby requiring a larger device. The Curved Channel (50) can also be dimensioned to form a mechanical stop. In this configuration, rotation of the Rope Locking Ring is stopped when the Curved Channel (50) contacts the Connecting Pin (58), thus preventing excessive forces from being entirely transmitted to the rope at the rope pinch point. This feature increases safety by ensuring that the rope will not break or be damaged by such extreme forces.
Thus the reader will see that the improved belay device of the invention provides a rugged economical device that optimizes the desired performance characteristics. The improved belay device is simple in design, highly effective, and is simple to operate. With respect to the sport of rock climbing, it can function either as a belay device or as a descender. It can also be used in a variety of situations to lower an object in a controlled fashion.
While the above description contains many specifics, these should not be construed as limitations on the scope of the invention, but rather as exemplification of two embodiments thereof. Each piece described within the aforementioned embodiments could be changed in form in ways that would not affect its function. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.
Provisional application No. 60/501,311 filed on Sep. 9, 2003.
Number | Name | Date | Kind |
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641809 | Tillottson | Jan 1900 | A |
4333551 | Shefrin | Jun 1982 | A |
4531610 | Fertier et al. | Jul 1985 | A |
4883146 | Varner et al. | Nov 1989 | A |
5217092 | Potter | Jun 1993 | A |
5360083 | Hede | Nov 1994 | A |
5577576 | Petzl et al. | Nov 1996 | A |
5597052 | Rogleja | Jan 1997 | A |
5671822 | Phillips | Sep 1997 | A |
D413786 | Graham | Sep 1999 | S |
6843346 | LeBeau et al. | Jan 2005 | B1 |
Number | Date | Country | |
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20050051385 A1 | Mar 2005 | US |
Number | Date | Country | |
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60501311 | Sep 2003 | US |