GB2157355A

GB2157355A - Anchoring device for mountain climbers

Info

Publication number: GB2157355A
Application number: GB08506096A
Authority: GB
Inventors: Curt Svensson
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-03-12
Filing date: 1985-03-08
Publication date: 1985-10-23
Also published as: SE8401345D0; GB8506096D0; SE441568B; SE8401345L

Abstract

The anchoring device, for releasable anchoring in rock cracks, comprises a central wedge (3) and two sliding members (5,5') on each side of the wedge. The wedge and the sliding members are arranged at one end of respective corresponding shanks (1,4,4'). The central shank (1) which carries the wedge and, via a load-bearing eyelet (2), also carries the outer load, is displaceable with the aid of a finger grip (7), with respect to the shanks (4,4') which carries the sliding 4' members. The device is anchored by transverse force and corresponding frictional force which arise from a traction force in the eyelet (2). <IMAGE>

Description

SPECIFICATION Anchoring device for mountain climbers The present invention relates to a device for releasable anchoring in cracks or slots, for example of the type having parallel walls. The device is based on wedging action and is intended for use in rock climbing, i.e. for anchoring in rock crevices to provide a support for the climbing rope or life line.

A device for said purpose, and which is similarly based on wedging action, is disclosed in European Patent Publication No.

00047232. Said device has, however, been found to be difficult to release from parallelsided cracks after having been subjected to a load. Furthermore, the device is composed of many different parts and is complicated to produce.

Other similar, but less developed, devices are disclosed in French Patent Publications Nos. 2396562 and 2 440 206.

The purpose of the present invention is to provide a device which is easier to release and is less complicated, and is also more simple to manufacture than the device disclosed in the above-mentioned European Patent Publication No. 0047 232. The present invention achieves this purpose with the device claimed in claim 1.

The invention is described in detail in the following and with reference to a preferred embodiment illustrated in the drawings, wherein: Figure 1 shows the device when it, in compressed position is inserted in a rock crevice; Figure 2 shows the device in affixed, expanded and loaded position in the rock crevice; and Figure 3 shows the separate parts of the device in disassembled state.

With reference to Fig. 3, the device comprises an inner stiff, and preferably rigid, straight load-bearing shank 1, having, at one end thereof, an eyelet 2 for accomodating an outer load and, at the other end, a wedge 3 widening in the direction away from the eyelet 2. At each side of the inner shank 1, there are outer shanks 4, 4' having, at one end thereof, sliding members 5, 5'. Said sliding members are intended to slide, with low friction, alongside the opposing sides of the wedge 3, and to become firmly wedged between the wedge 3 and the rock crevice when a load is applied to the eyelet 2. In order to achieve the least possible friction between the wedge 3 and the sliding members 5, 5', the common sliding surfaces are covered with a lubricant, preferably a permanent lubricant based on graphite.

In view of it being desirable to attain the maximum possible friction between the outer sides of the sliding member 5, 5' and the rock crevice said sides are provided with serrations.

With the object of joining the outer and inner shanks to a unit, and in such manner that the sliding members 5, 5' can be displaced alongside the wedge 3, the device comprises fastening members in the form of a first pin 6 provided with internal threads and a corresponding second pin 6' having external threads, on the one hand, and a finger grip 7 having external threads and which similarly acts as a joining pin, on the other. The pins 6, 6' are intended to be inserted in corresponding openings 8, 8' in the outer shanks 4, 4' and then to be partly screwed together, which is made possible by the fact that a longitudinal open slot 9 is provided in the inner shank 1. The finger grip 7 is similarly intended to be inserted in openings 10, 10' in the outer shanks 4, 4' and in a longitudinal open slot 11 in the inner shank 1.The opening 10 has internal threads which fit with the external threads on the finger grip 7. The length of the slot 11 is adapted so that the slot, interacting with the finger grip 7 running therein, provides suitable end positions for the movement of the sliding members 5, 5' in relation to the wedge 3.

A compression spring 1 2 in the form of a coil spring is intended to be inserted in the slot 9 and to bear against the pins 6, 6', when screwed together, so that the wedge 3 on the shank 1 is urged downwardly between the sliding members 5, 5'. to push them apart and to hold them in position against the walls of the rock crevice even when there is no pulling load acting in the eyelet 2. The diameter of the compression spring is somewhat larger than the thickness of the shank 1. To avoid the spring then becoming wedged between the shanks 4, 4', grooves are formed in these shanks. One such groove 1 3 is illustrated, in shank 4', the corresponding groove in shank 4 being hidden.

In use, the device is held in one hand, the index finger and middle finger being in contact with the finger grip 7 on each side of the shank and the thumb pressing on the extreme outer end of the shank 1, at the eyelet 2. By pushing with the thumb, the force of the spring 1 2 is overcome, whereby the device is set in the position shown in Fig. 1. An elastic ring (not shown in the drawings), for example of rubber, suitably surrounds the shanks 4, 4' and 1 at the level of the pins 6, 6', whereby the sliding members 5, 5' in all positions, including the position shown in Fig. 1, will press against the wedge 3 on the shank 1. In the position shown in Fig. 1, the distance between the sliding members 5, 5' is at a minimum and they can then be inserted in a suitable position in the rock crevice. By subsequently releasing the pressure from the thumb and finally releasing the device completely, the device will assume the working position shown in Fig. 2. Due to the small taper angle of the wedge 3 and the low friction between the wedge 3 and the sliding members 5, 5', the device will safely lock in the rock crevices, even when a heavy load is applied to the sling 14 inserted in the eyelet 2. When desired, the device can be simply released from the crack by pushing upwards on the extreme outer end of the stiff shank 1. This can be done without strain due to the fact that the wedge 3 exerts only low friction against the sliding members 5, 5', instead of working directly against any of the sides of the rock crevice.

Claims

1. An anchoring device for mountain climbers for releasable anchoring in rock crevices, comprising (a) an inner stiff, straight shank having a load-bearing eyelet at one end, and a wedge widening in a direction away from the eyelet at the other end; (b) two outer shanks longitudinally displaceably arranged alongside two opposite sides of the inner shank, said outer shanks being provided at one end with a finger grip, and at the other end with a sliding member, said sliding members being arranged to slide with low friction along the opposite sides of the wedge and to be firmly wedged between the wedge and a rock crevice when a load is applied to the eyelet; (c) a resilient member extending in the longitudinal direction of the shanks and arranged to draw the wedge between the sliding members to push them apart and to hold them in position against the walls of the rock crevice even when no load is acting in the eyelet; (d) joining members which join the outer and inner shanks as a unit, whereby the outer shanks and adjoining sliding members can be displaced with the aid of the finger grip along the inner shank, between two end positions, to achieve a reduction of the distance between the sliding members upon insertion of the device in a rock crevice.

2. An anchoring device according to claim 1, wherein the inner shank comprises a longitudinal slot which holds the resilient member.

3. An anchoring device according to claim 2; wherein the resilient member is a helical compression spring which bears against said joining members and is arranged to lie in said longitudinal slot.

4. An anchoring device according to any one of claims 1 to 3, wherein the inner shank has a longitudinal slot recess to receive movably said finger grip common to the two outer shanks and thus movable between two end-oftravel positions.

5. An anchoring device for mountain climbers for releasable anchoring in rock crevices, such device being constructed and adapted to operate substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.