GB2613023A

GB2613023A - Carabiners

Info

Publication number: GB2613023A
Application number: GB2116825.7A
Authority: GB
Inventors: John Ward Peter; Sissins Stuart
Original assignee: Excalibur Wales Ltd
Current assignee: Excalibur Wales Ltd
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2023-05-24
Anticipated expiration: 2041-11-23
Also published as: GB202116825D0; GB2613023B

Abstract

A carabiner comprises a body having end portions between which is defined an opening. A gate (22) is carried on one of the end portions that can be moved to open or close the opening. A sheave (52) is carried for rotation with respect to the body about a sheave axis. A clutch (72) is operatively connected to the sheave (52), the clutch (72) being operable to allow substantially free rotation of the sheave (52) in a first direction of rotation and to resist rotation of the sheave (52) in a second, opposite direction of rotation. The clutch (72) may allow the sheave (52) to rotate in the second direction against frictional resistance.

Description

Carabiners This invention relates to carabiners. In particular, it relates to carabiners that incorporate a rolling element over which a rope can pass.

In this specification, the term "rope" will be used in the interest of concision. However, it should be understood that the disclosure applies not just to a textile rope, but extends also to 10 cable, tape, webbing, and so forth, unless the context requires otherwise.

Carabiners are invariably formed with smooth, curved inner surfaces over which a rope can pass smoothly and easily. However, there are occasions where a heavily loaded rope will experience an undesirable level of sliding friction as it passes over a carabiner, and for this reason, it is known to include a rolling element, such as a cylindrical roller or a sheave, on a carabiner to allow the rope to slide more smoothly. Examples of such carabiners are known from EP-A-3 293 405, the content of which is incorporated herein by reference.

The carabiners disclosed in EP-A-3 293 405 are useful and effective, but the applicants have realised that they may be improved upon, especially in applications in which the pulley is being used with a line that is loaded asymmetrically.

To this end, from a first aspect, this invention provides a carabiner comprising a body having end portions between which is defined an opening; a gate carried on one of the end portions that can be moved to open or close the opening; a sheave carried for rotation with respect to the body about a sheave axis, and a clutch operatively connected to the sheave that is operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave in a second, opposite direction of rotation.

For example, an embodiments of this invention can be used to guide a rope in a system for hauling loads over a height difference. The carabiner is configured such that during upward movement, the pulley rotates freely in the first direction of rotation. While a load is being held in place or lowered, control is enhanced by the friction that arises between the rope and the sheave, movement of which is resisted or prevented.

In some embodiments of the invention, the clutch allows the pulley to rotate in the second direction against frictional resistance. Alternatively, the clutch may lock to prevent rotation of the sheave in the second direction.

The clutch me be configurable to operate with different characteristics. It may be configurable between two or more of: a free condition, in which it allows substantially free rotation in both the first and the second directions; a unidirectional condition in which rotation in the second direction is resisted; and a bidirectional condition in which rotation in both the first and the second direction is resisted. It may be configurable between a frictional configuration in which the sheave can rotate in the second direction against frictional resistance and a locking configuration in which rotation of the sheave in the second direction is prevented. The clutch may be configurable to reverse the first and the second directions.

The carabiner body typically extends within a median plane. Typically, the sheave axis is coincident with the median plane. In alternative embodiments, the sheave axis may be offset from the median plane. For example, the sheave axis may be normal to the median plane.

The gate is typically pivotally connected to an end portion of the body such that it can pivot about an axis that is normal to the axis of rotation of the sheave.

Embodiments may include an aperture that extends through the body adjacent to the sheave. Preferably, the aperture is of sufficient size to accommodate a rope or another carabiner. The actual size may be determined by the load that a specific embodiment is intended to carry, and it may scale with the overall size of the embodiment. It may be that the aperture can accommodate an element of at least 5mm in diameter, 10mm in diameter, 15mm in diameter or 20mm in diameter.

The sheave may be disposed between the gate and the aperture. The body may include a boss through which the aperture is formed.

Embodiments of the invention may include two or more sheaves, one or more of which is operatively connected to a clutch, the clutch being operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave in a second, opposite direction of rotation. In such embodiments, the axes of rotation of the sheaves are typically, but not necessarily, parallel to one another.

In an alternative arrangement, a carabiner embodying the invention may have two sheaves adjacent to one another. In such cases, the axes of rotation of the sheaves may be coaxial.

The sheave or at least one of the sheaves typically has an outer surface with which a rope can make contact, the outer surface typically being concave in profile. The outer surface may be smooth or may be formed with a plurality of facets, grooves or teeth. In the latter case, the facets, grooves or teeth increase friction between a rope and the sheave when rotation of the sheave is resisted or prevented, while having minimal effect while the sheeve is rotating freely.

From a second aspect, this invention provides a rigging system comprising a carabiner 15 embodying the invention from its first aspect and a rope that passes over at least one sheave of the carabiner, which rope cooperates with at least one other component, and which rope is connected to the aperture of the carabiner.

Advantageously, the carabiner is configured such that it includes a sheave that rotates freely when a load is being lifted, and are rotation of which is resisted or prevented from rotation 20 when a load is being lowered.

The rope may be connected to the aperture by sewing or tying. Alternatively, the rope may be connected to the aperture by an intermediate connector (e.g., a carabiner or a snap hook) that passes through the aperture. The other component may include one or more of a pulley, a carabiner that incorporates a sheave, or a further carabiner being an embodiment of this invention.

Embodiments of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings, in which: Figures 1 to 3 are views of a carabiner being a first embodiment of the invention; Figure 4 shows the embodiment of Figures 1 to 3 with a captive bar removed and the gate open; Figure 5 is a cross-section through the embodiment of Figures 1 to 4; Figures 6 and? are views of a second embodiment of the invention; Figures 8 and 9 are views of a third embodiment of the invention; Figures 10 shows an alternative sheave suitable for use in embodiments of the invention; Figure 11 is a sectional view of the sheave of Figure 10; and Figures 12 and 13 show the embodiments of Figures 1 to 9 in use in a rigging system.

With reference to Figures 1 to 3, a carabiner includes a body 10 formed as a single alloy forging or casting. (Alternative embodiments might be formed from steel and could be machined from a solid billet) To assist in the understanding of the function and disposition of the body 10, for the purpose of this description it will be divided into three hypothetical regions; an upper region between lines A and B in Figure 1, a middle region between lines B and C in Figure 1, and a lower region between lines C and D in Figure 1. The body is substantially symmetrical about a median plane P, shown in Figure 2 and corresponding to the Z-axis (that is, directly away from the viewer) of Figure 1.

With the exception of mounting formations for the captive bar (an optional feature of embodiments of the invention which will be described below) the upper region of the body 10 resembles closely to the corresponding part of a conventional carabiner, so will be described only briefly. In the upper region, the body 10 comprises an approximately C-shaped loop, having a back 12 and a curved end portion 14. The upper region has an opening 18 through which a rope or similar item can pass through the opening 18 into the upper region of the body 10.

The middle region comprises two substantially parallel legs 30, 32, having mutually-facing 25 surfaces 34, 36 that are approximately flat and parallel. The middle region is of greater depth in the Z-direction of Figure 1 than the upper region. A respective aperture of circular section is formed through each leg 30, 32, the middle region, the apertures being coaxial and lying within the median plane P. In the lower region, the two legs 30, 32 are joined by a boss 40. A becket aperture 42 passes through the boss 40, extending in a direction that is generally parallel to the axis of the 5 apertures in the middle region, and the median plane P. A projection 38 extends from the boss towards the middle region.

The carabiner further includes a gate 22 that is carried on the upper region 10. The gate 22 is biased to pivot towards a closed position (Figs 1 to 3) in which it completely closes the opening 18 thus which forms a continuous loop in the upper region. Upon release of a locking mechanism, the gate 22 can be pivoted towards an open position (Figure 4), in which the opening is partially unobstructed. As is well known to those in the technical field, there exists a very large range of alternative gates and locking arrangements, many of which will be suitable for use in embodiments of the invention. Also, as shown, the gate is pivoted close to the end closer to the intermediate region. However, it could alternatively be reversed and pivoted further from the intermediate region.

An axle 50 is provided at the middle section. The axle 50 passes through the apertures in the middle region and is retained there by being riveted within the apertures such that it cannot move with respect to the body 10. A sheave 52 is carried for rotation on the axle 50. The depth of the middle region of the body is sufficiently great that it encloses the sheave 52 is entirely between the mutually-facing surfaces 34,36 of the middle region. The sheave 52 has an outer surface 54 with which a rope can make contact, the outer surface 54 being concave in profile to guide the rope towards the centre of the sheave 52. The projection 38 is close to the outer surface 54 of the sheave 52 to prevent a rope being passed between the sheave 52 and the boss 40.

The sheave 52 includes a central through bore within which is a rolling-element bearing 56 or a bushing that supports the sheave for free rotation upon the axle 50. A key 70 is carried upon the axle, projecting radially from the axle and extending longitudinally approximately one third of the length of the axle within the sheave 52, but not in the region of the bearing 56. The key 70 interacts with a roller clutch assembly 72 that is located within the through bore of the sheave 52. The clutch assembly 72 has an outer race constrained for rotation with the sheave 52 and an inner race that is prevented from rotation on the axle 50 by the key 70.

In this embodiment, the clutch assembly operates to allow rotation between its inner and outer races (and therefore between the sheave 52 and the axle SO) to take place in a first direction with little resistance. The clutch assembly 70 substantially prevents rotation between its inner and outer races in the opposite direction, although there may be an amount of lash that permits a limited amount of such movement. Thus, the sheave 52 can rotate within the body in a first direction but not in a second, opposite direction.

A captive bar 60 is provided at the upper region. Mounting formations for the captive bar 60 are provided in the upper region. These include a counterbored, threaded hole 62 that extends through the back 12 and a hole 64 between the opening 18 and the middle region.

The counterbored hole 64 and the hole 62 are coaxial, in the median plane P, and angled at approximately 30° to the axle 50. The captive bar 60 has a head 66 having a drive slot and a threaded portion close to the head. The captive bar 60 can be inserted through the threaded hole 62 in the back 12 such that the threaded portion enters the hole 64. It can be tightened in place using a suitable tool engaged with the drive slot in the head 66.

Specific features of this embodiment include: * a rope or other element passing over the sheave 52 moves freely in one direction (in which the sheave rotates freely) and moves with resistance in the opposite direction (in which rotation of the sheave is resisted or prevented) A second embodiment of the invention is shown in Figures 6 and 7. As with the first embodiment, for the purpose of this description this alternative embodiment will be divided into three hypothetical regions; an upper region between lines E and F in Figures 6 and 7, a middle region between lines F and G in Figure 6 and 7, and a lower region between lines G and H in Figure 6 and 7.

The lower region of this embodiment is essentially the same as the combined lower and 25 middle regions of the first embodiment. The upper region of this embodiment is essentially the same as its lower region, except that it is inverted. Thus, the second embodiment has two sheaves 152, 152' and two corresponding becket apertures 142, 142'.

This embodiment may be constructed in several configurations, including: * one sheave 152 being able to rotate freely in either direction on it sheave axis and the other a sheave 152' carried for rotation with respect to the body about a sheave axis, and a clutch operatively connected to the sheave 152' that is operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave in a second, opposite direction of rotation; * a clutch operatively connected to both of the sheaves 152, 152' that is operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave 152, 152' in a second, opposite direction of rotation; wherein: o the direction of free rotation of the two sheaves 152, 152' is the same; or o the direction of free rotation of the two sheaves 152, 152' is opposite.

The body 110 of this embodiment has a back 112 that interconnects the first and the third regions. Opposite the back, an upper leg 130 that extends from the upper region towards the lower region, and a lower leg 130' extends from the lower region towards the upper region.

An opening is defined between the upper and lower legs 130, 130'. A gate 122 is carried on the lower leg 130' to pivot in the median plane of the carabiner. In a closed position, the gate 122 makes contact with the upper leg 130, thereby closing the opening. Upon manipulation of a locking mechanism, gate 122 can be displaced against a resilient biasing force to partially open the opening between the upper and lower legs 130, 130' such that a rope can pass through the opening to be enclosed within the body 110.

A third embodiment is shown in Figures 8 and 9. This embodiment is a variation of the first embodiment, the significant difference is that two sheaves 252, 252' are carried on the axle 250, the sheaves being capable of rotation on the axle 250 independently of one another. In this embodiment, the sheaves 252, 252' are of similar size, but this is not essentially so. A divider plate 256 passes between the sheaves 252, 252'. One end of the divider plate is received in a slot in the boss 240. From there, it extends between the sheaves 252, 252', where it has a hole through which the axle 250 passes, and a further hole through which the captive bar 260 passes. The plate 256 and the captive bar 260 create two separate passages through which a rope can pass over a respective one of the sheaves 252, 252'. The combination of free and resisted rotation of the sheaves 252, 252' is the same as described in relation to the preceding embodiment In any of the above embodiments, one or more of the sheaves 52 may be substituted with a sheave that has an outer surface that is not smooth, an example being shown in Figures 10 5 and 11. The sheave 80 of Figure 12 has an outer surface 82 which is concave in profile and is formed with a multiplicity of facets 84 that meet one another at vertices 86 such that the outer surface 82 is polygonal in section. In this example, there are eight facets 84. The effect of this modification is that friction between the sheave 80 and a line passing over it is enhanced, so increasing frictional drag on the rope when rotation of the sheave is prevented 10 (or resisted, as the case may be) while having little effect on the ability of the line to move over the sheave 80 while the sheave 80 is rotating freely.

A carabiner embodying this invention is typically used as part of a rigging system in combination with other functional components and an interconnecting rope. An example, shown in Figures 12 and 13, is a lifting system that offers a mechanical advantage. The body of a first carabiner 300 similar to the first embodiment of the invention is suspended from a fixed anchorage (not shown) with its body extending upward from the aperture 42. An end portion 310 of a rope 312 is secured through the aperture 42 of a second carabiner 302 similar to the first embodiment of the invention, by sewing, tying or by an intermediate carabiner or other connector, the body extending downwardly from the aperture 42. The rope extends from a termination in the aperture 42 of the second carabiner 302 upwardly to pass over a sheave of a link 320 of the type disclosed in GB-A-2 391 902. From there, it extends downward to pass around the sheave of the second carabiner 302 and then up to pass over the sheave of the first carabiner 300. From there, a free length 314 of the rope extends. A load to be lifted is connected to the second carabiner 302. A downward pull on the free length of the rope causes the load attached to the second carabiner 302 to be lifted with a 2:1 mechanical advantage. Controlled release of the rope allows the load to be lowered. The carabiners are configured such that their sheaves rotate freely when a load is being lifted, to offer minimal resistance to the rope. The sheaves apply a frictional drag to the rope when a load is being lowered so providing a user with additional control over the load.

Note that the first carabiner could be replaced by a carabiner similar to the third above-described embodiment of the invention that has two sheaves. In that case, the snap link 320 can be omitted, and the rope is instead looped over a sheave of the first carabiner.

Claims

Claims 1. A carabiner comprising a body having end portions between which is defined an opening; a gate carried on one of the end portions that can be moved to open or close the opening a sheave carried for rotation with respect to the body about a sheave axis, and a clutch operatively connected to the sheave that is operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave in a second, opposite direction of rotation.
2. A carabiner according to claim 1 in which the clutch allows the pulley to rotate in the second direction against frictional resistance.
3. A carabiner according to claim 1 in which the clutch lock to prevent rotation of the sheave in the second direction.
4. A carabiner according to any preceding claim in which the clutch is configurable to operate with different characteristics.
5. A carabiner according to claim 4 in which the clutch is configurable between two or more of: a free condition, in which it allows substantially free rotation in both the first and the second directions; a unidirectional condition in which rotation in the second direction is resisted; and a bidirectional condition in which rotation in both the first and the second direction is resisted.
6. A carabiner according to claim 4 or claim 5 in which the clutch is configurable between a frictional configuration in which the sheave can rotate in the second direction against frictional resistance and a locking configuration in which rotation of the sheave in the second direction is prevented.
7. A carabiner according to any preceding claim in which the clutch is configurable to reverse the first and the second directions.
S. A carabiner according to any preceding claim in which the carabiner body extends within a median plane.
9. A carabiner according to claim 8 in which the sheave axis is coincident with the median plane.
10. A carabiner according to any one of claims 1 to Sin which the sheave axis is normal to the median plane.
11. A carabiner according to any preceding claim in which the gate is pivotally connected to an end portion of the body such that it can pivot about an axis that is normal to the axis of rotation of the sheave.
12. A carabiner according to any preceding claim that includes an aperture that extends through the body adjacent to the sheave.
13. A carabiner according to claim 12 in which aperture can accommodate an element of at least between Smm and 20mm in diameter.
14. A carabiner according to claim 12 or claim 13 in which the sheave is disposed between the gate and the aperture.
15. A carabiner according to any one of claims 12 to 14 in which the body includes a boss through which the aperture is formed.
16. A carabiner according to any preceding claim that includes two or more sheaves, one or more of which is operatively connected to a clutch such, the clutch being operable to allow substantially free rotation of the sheave in a first direction of rotation and to resist rotation of the sheave in a second, opposite direction of rotation.
17. A carabiner according to claim 19 in which the axes of rotation of the sheaves are parallel to one another.
18. A carabiner according to claim 19 in which the axes of rotation of the sheaves are coaxial.
19. A carabiner according to any preceding claim in which the sheave or at least one of the sheaves has an outer surface with which a rope can make contact, the outer surface being concave in profile.
20. A carabiner according to claim 16 in which the outer surface is smooth.
21. A carabiner according to claim 16 in which the outer surface is formed with a plurality of facets, grooves or teeth.
22. A rigging system comprising at least one carabiner according to any preceding claim and a rope that passes over at least one sheave of the carabiner, which rope cooperates with at least one other component, and which rope is connected to the aperture of the carabiner.
23. A rigging system according to claim 22 in which the carabiner is configured such that it includes a sheave that rotates freely when a load is being lifted and rotation of which is resisted or prevented from rotation when a load is being lowered.