Technical Field

[001 ] The present invention relates to mechanical coupling mechanisms used especially for protection in the sport of climbing but also for other endeavors, and more specifically, to an improved carabiner that has a wear-resistant insert.

Background Information

[002] Carabiners are indispensable tools for any rock or mountain climber.

Among their many benefits, carabiners provide a secure mechanical connection between different objects in a variety of conditions encountered while climbing. For instance, rock climbers typically use many carabiners to quickly yet releasably couple one piece of equipment to another -as an example, a carabiner may be attached to protection such as a bolt, nut or cam, and a rope is then threaded through that carabiner or another one that is attached to it with webbing. Mountaineers use carabiners to quickly and releasably make an attachment between their climbing harness and a lead rope. Carabiners are also used as components of climbing equipment called

"quickdraws." These comprise two carabiners connected by a short sling of webbing and they are commonly used to connect a rope to fixed protection like bolts or to extend gear placements to reduce rope drag. These are just a few examples; there are hundreds more ways that carabiners are used in the sports of rock climbing and mountaineering.

[003] Similarly, carabiners are useful for the strong mechanical connections they provide in numerous other endeavors such as sailing.

[004] Given their ubiquitous use in many sports and other facets of everyday life, there are many different types and designs of carabiners. That said, a typical carabiner is defined by a frame - often a C-shaped member - and a gate that selectively opens and closes the opening into the C-shaped member. The gate is typically spring-loaded so that it is biased into the closed position and many carabiners include a lock that is capable of locking the gate closed for safety. With the gate closed, the carabiner defines a bounded internal region in which different objects may be attached or through which objects such as ropes are threaded. There are of course many, many different variations on these general structural and operational themes.

[005] The mechanical properties of carabiners and the materials that are used for the main body frame and the gate of the carabiner are important considerations. Most often, carabiners are made either of steel or aluminum alloys - the strength of the devices depend upon various factors such as the specific alloys used and the specific design of the carabiner and the gate. Most climbers prefer aluminum carabiners because they provide excellent strength characteristics and most especially because they are lighter than steel carabiners. Since most climbers carry numerous carabiners while climbing, saving weight is a very important consideration. That accounts in part for the popularity of aluminum carabiners. But in addition, aluminum carabiners are usually far more economical than their steel counterparts, further contributing to the frequent use of aluminum.

[006] It is important to always use carabiners in the proper manner. Among other considerations, a carabiner should never be loaded across its minor axis. That is, if we consider a C-shaped carabiner, the upright portion of the letter C is parallel to the long axis and the axis that is transverse to the long axis extends through the opening into the C, through the gate. Any load must be oriented along the long axis, not transverse to it.

[007] Although aluminum carabiners are widely used, the aluminum material used for the main frame has a significant limitation: the aluminum is relatively soft (at least compared to steel) and is prone to wear over time. Specifically, carabiners are very often used in situations where a climbing rope is passed through the device - the rope rests on or passes through the interior portions of the carabiner. Often, and intentionally, the rope moves through the carabiner, which remains relatively stationary. As this happens, the rope rubs on the interior surface of the carabiner. Of course, the abrasion and friction of the rope abrading against the carabiner causes wear in the carabiner and this abrasion increases with the load on the rope. This inherently weakens the carabiner and climbers know that their carabiners need to be replaced at regular intervals when they wear from rope abrasion. With quickdraws, rope movement through the carabiner is very common given the particular uses of the equipment. Many aluminum carabiners are anodized and the anodizing material is harder than the raw aluminum alloy. However, the anodizing material is applied only very thinly - perhaps 1/1000 ^th of an inch of material, and is still not as hard or wear-resistant as steel. While steel carabiners are heavier than their aluminum counterparts, they tend to wear less from rope abrasion, or at least more slowly, because the steel is harder than the aluminum alloys.

[008] Rope-worn carabiners present a safety concern because the climber may not have properly inspected the device to insure that it is in proper condition and may not therefore be aware of a reduction in the strength of the device.

[009] In view of the benefits derived from relatively light equipment such as aluminum carabiners, there is a need, therefore, for a carabiner that overcomes the limitations of existing devices and which is specifically less prone to wear from ropes and other devices that are attached to or threaded through the carabiner.

Summary of the Invention

[010] The present invention relates to a carabiner having improved longevity due to the incorporation of a wear-resistant surface on the interior of the carabiner where ropes and the like typically cause wear and abrasion of the carabiner. The wear- resistant material may be formed of an insert that is attached to the interior surface of the carabiner with any conventional means of attachment, including for example bonding with adhesives or with friction fit. The wear-resistant material may further be applied as a coating applied to the load bearing surface of the carabiner. The carabiner body is a conventional device that is most typically fabricated from an aluminum alloy and the wear-resistant insert is a material that is harder than the aluminum, such as alloys of steel and/or ceramics, and has greatly improved wear characteristics. The insert adds negligible weight to the carabiner and therefore increases the life of the device without detracting from the usability of the device.

Brief Description of the Drawings

[01 1 ] The invention will be better understood and its numerous objects and advantages will be apparent by reference to the following detailed description of the invention when taken in conjunction with the following drawings.

[012] Fig. 1 is a side elevation view of a carabiner according to the present invention incorporating a wear-resistant insert.

[013] Fig. 2 is a cross sectional view of the carabiner illustrated in Fig. 1 , taken along the line 2 - 2, showing the carabiner with the gate removed. [014] Fig. 3 is a cross sectional view of the carabiner shown in Fig. 1 , taken along the line 3 - 3 of Fig. 1 , so that the view is transverse to the cross sectional view of Fig. 2.

[015] Fig. 4 is an exploded perspective view of a carabiner according to the present invention, showing the carabiner and the wear-resistant insert but omitting the gate.

[016] Fig. 5 is a perspective view of the carabiner of Fig. 4, showing the wear- resistant insert in place and attached to the carabiner main body.

[017] Fig. 6 is a cross sectional view of a first alternative embodiment of a carabiner according to the present invention in which two separate wear-resistant inserts are utilized, the view of Fig. 6 analogous to the cross sectional view of the embodiment shown in Fig. 2.

[018] Fig. 7 is a cross sectional view of a second alternative embodiment of a carabiner according to the present invention in which a relatively longer wear-resistant insert or coating is utilized.

Detailed Description [019] Preferred embodiments of the carabiner 10 according to the present invention are illustrated in the figures. The carabiner 10 illustrated herein is typical of an aluminum alloy carabiner but it will be readily understood by those of skill in the art that there are innumerable shapes and configurations used for carabiners and that there are many different types of "gates" used. The invention detailed herein is not limited to any particular shape or type of carabiner, but is instead applicable to all carabiners within the scope of the invention.

[020] The illustrated carabiner 10 is defined by a main body 12 having a generally C-shape with an opening 14 into the open interior portion 16 of the main body 12. All carabiners also include a gate 18 that closes the opening 14 - the gate is usually spring loaded or in some other way biased toward the closed position so that the opening is normally closed. The gate 18 shown in Fig. 1 is a wire-type gate that is attached to body 12 with its two ends oriented adjacent one another to facilitate a spring force on the wire. The gate 18 is attached to the carabiner at end 20 - the gate 18 extends between the end 20 and the opposed end 22 of the main body so that when the gate 18 is in the closed position the open interior portion 16 defines a completely bounded opening. In use, ropes, webbing and other devices are threaded through the bounded opening of the carabiner defined by the open interior 16. Because the gate is closed in normal use, a rope is retained within the open interior 16 of the carabiner 10. As alluded to above, there are many types of gates that are used in carabiners, including locking-type gates. [021 ] For purposes herein, the C-shape of carabiner 10 defines a lower curved portion 24 that is defined as the lower curved portion of the letter C, and an upper curved portion 26, which is the upper curved portion of the letter C. While there are many, many different types and shapes of carabiners and manners in which they are used, regardless of the specific shape the interior surface of the lower curved portion 24 is the primary surface on which ropes impinge, and this part of the interior surface is thus the primary wear surface or primary load bearing surface that typically wears first and most significantly from use.

[022] The carabiner according to the present invention includes a wear-resistant insert 30 that is attached to the carabiner 10 and which covers the primary load bearing surface, that is, interior surface 28. The interior surface 28 is thus defined by the wear- resistant insert in a carabiner 10 that includes the insert. The wear-resistant member 30 is fabricated of a material that has increased hardness relative to the hardness of the material that is used to fabricate main body 12 of the carabiner, and has improved wear- resistance. The wear-resistant member 30 is considered a separate part from the carabiner body. As noted above, anodizing material on an aluminum carabiner is harder than the aluminum in the body. However, the wear-resistant member used herein is a separate member that is attached to the body of the carabiner, which may be anodized. A carabiner 10 that incorporates a wear-resistant insert 30 has improved life span because the ropes and the like that are threaded through open interior portion 16 and bear on the interior surface 28.

[023] If the main body 12 is aluminum or an aluminum alloy, the wear-resistant insert 30 is a material that has increased hardness and wear-resistant properties relative to the aluminum.

[024] The wear-resistant insert 30 is formed so that it mates with the curved interior surface of the carabiner body onto which the insert is attached. The insert 30 may be attached to carabiner 10 in a number of appropriate manners. These include friction fit, crimping, bonding with appropriate adhesives, a combination of friction fit and bonding, with physical attachment such as screws and other similar fasteners, and, depending on the materials used for both the carabiner and the insert, welding. With reference to Fig. 3, it may be seen that the cross sectional configuration of the main body 12 is somewhat hourglass shaped. The insert 30 may be formed in a semicircular shape and the shape of the lower curved portion 24 of carabiner 10 is cooperatively formed so that the insert 30 is friction fit over the lower curved portion 24. Adhesive may be used to bond the insert to the carabiner. The adhesive should be appropriate to insure a strong bond between the insert and the main body in all conditions. Since frictional forces from a rope bearing on the insert can lead to elevated temperatures, the adhesive should maintain a strong bond over a broad temperature range. The insert may also include inwardly projecting tabs or bosses or other similar structures that engage cooperatively shaped and located recesses on the carabiner body to retain the insert in place on the carabiner.

[025] Similarly, the insert may be attached to the main body by crimping the insert to the main body, and adhesive or fasteners may be used together with a crimped-on insert. The attachment strength of a crimped-on insert may be enhanced when inwardly projecting tabs on the insert engage cooperative recesses on the body. An insert may further completely encircle the main body and be attached with an adhesive or with a fastener; this type of insert is most easily accomplished when the main body is cylindrical in cross section.

[026] There are many materials that may be used for wear-resistant insert 30, including for example, a variety of steel alloys and other metals and metal alloys, ceramics, etc. The insert 30 adds relatively little weight to the carabiner 10 because the insert itself is relatively small and thin. The preferred light-weight aluminum carabiner 10 may thus have improved wear characteristics and long life without significant increase in weight. As the carabiner is used, ropes and other devices that extend through the carabiner interior 16 bear on the surface of the insert 30, which has greater resistance to wear caused by friction and other forces. [027] A second illustrated embodiment of a carabiner 10 according to the present invention is shown in cross section in Fig. 6. In this embodiment, a second wear resistant insert 40 having a second, upper interior bearing surface 28 may be attached to the main body 12 at upper curved portion 26, which defines a secondary load bearing surface of the carabiner. Although the upper curved portion 26 of the carabiner 10 is less often used as an attachment point and thus as surface that is prone to wear, sometimes it is advantageous to improve wear-resistance at the upper curved portion 26. The wear-resistant inserts 30 and 40 may be attached to the main body 12 in any of the manners described previously.

[028] A third embodiment of a carabiner 10 incorporating a wear resistant insert 50 with an interior bearing surface 28 is shown in Fig. 7. In this case, the wear-resistant insert 50 covers substantially the entire inner bearing surface of the carabiner between ends 20 and 22. This has the advantage of provide increased wear resistance over the entire interior surface of the carabiner that could be damaged by wear. The insert 50 could be a separate insert piece as detailed above with respect to the embodiments previously described, or could be defined by a coating material applied to the interior- facing surface portion of the main body 12 rather than a separate insert piece. As noted above, many if not most aluminum carabiners are anodized and the anodizing material is harder than the raw aluminum alloy. If the wear-resistant insert 50 is defined by a coating applied to the main body, the coating contemplated herein is an added layer of material that is both thicker and harder than an anodized coating, for example, a ceramic material. Moreover, the coating is specifically oriented on the carabiner to cover the wear surface.

[029] As another example of how the carabiner 10 according to the present invention provides benefit, carabiners (usually with quickdraws) are often attached directly to bolt hangers. Bolt hangers are typically steel and have an opening into which the carabiner is engaged. The hard steel of the bolt hanger can easily damage an aluminum alloy carabiner. However, when the carabiner includes a wear resistant insert as contemplated herein the wear and damage caused by the bolt hanger is significantly reduced.

[030] While the present invention has been described in terms of preferred and illustrated embodiments, it will be appreciated by those of ordinary skill that the spirit and scope of the invention is not limited to those embodiments, but extend to the various modifications and equivalents as defined in the appended claims.