GB2240361A

GB2240361A - Camming type climbing aid

Info

Publication number: GB2240361A
Application number: GB9100064A
Authority: GB
Inventors: Hugh Irving Banner
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-01-24
Filing date: 1991-01-03
Publication date: 1991-07-31
Also published as: GB9001603D0; GB9100064D0

Abstract

The climbing aid comprises a cam arrangement 11 mounted at one end of a support bar (12, Fig. 2) which has a rope attachment (13) and an operating arrangement (14) for the cam arrangement for inserting it in and withdrawing it from a rock crack and spring means (15) to deploy the cam arrangement to an operative position in the crack in which the climbing aid is jammed by the cam arrangement against movement under rope loading, in which the support bar is fabricated by forging and has thicker cross section 31, 32 at the locations of the cam arrangement and the rope attachment connected by lightweight, thinner web sections 33. <IMAGE>

Description

CLIMBING AID This invention relates to climbing aids of the kind intended to be lodged in rock cracks and jammed therein to support a climbing rope.

Such aids are known for example from GB-1,588,317, Jardine, and my earlier application, GB-2,193,902.

The Jardine device has a cam arrangement mounted at one end of a support bar which has a rope attachment point at the other end. There is an operating arrangement for the cam arrangement which closes up the cam arrangement so that it can be inserted into a rock crack and spring means to deploy the cam arrangement to an operative, opened-out position in the crack in which the aid is jammed by the cam arrangement against movement under rope loading.

The operating arrangement in the Jardine patent comprises an operating bar which is slidably mounted on the support bar in a slot which extends lengthwise thereof intermediate the cam arrangement location at one end and the rope attachment point at the other. The operating bar is connected to the cam arrangement by operating wires.

In the arrangement of GB-2,193,902 the support bar is replaced by a flexible wire loop and the operating bar is replaced by a pull ring or by a bar that works outside the wire loop. The improved flexibility of this arrangement as compared with the stiff Jardine support bar enables the aid to cope with sudden movements and so make it less likely to be jerked out of its rock crack location. A stiff support bar is also liable to break or become permanently twisted in certain loading conditions, and this happens particularly at the points of weakness, namely where the cam arrangement bearing and the rope attachment eye have been drilled out, and where the slot for the operating bar has been machined out of the solid bar stock used in the manufacture.

The wire loop arrangement of GB-2,193,902 is also clearly of lighter construction than the Jardine arrangement and easier to pack and carry - an advantage not without significance in rock climbing.

However, the wire loop arrangement also has its disadvantages, one of which is that the wire can kink.

There is no danger of failure when this happens, but it renders the aid useless, and it must be replaced. Hence there is a need for the more robust, bar form of the aid.

The present invention provides such a bar form of the climbing aid which does not suffer from the aforementioned disadvantages.

The invention comprises a climbing aid of the kind comprising a cam arrangement mounted at one end of a support bar which has a rope attachment and an operating arrangement for the cam arrangement for inserting it in and withdrawing it from a rock crack and spring means to deploy the cam arrangement to an operative position in the crack in which the climbing aid is jammed by the cam arrangement against movement under rope loading, in which the support bar is fabricated by forging and has thicker cross section at the locations of the cam arrangement and the rope attachment connected by lightweight, thinner web sections.

The aid may have, intermediate the said locations, an apertured section receiving the operating arrangement which apertured location is also of thicker cross section.

The operating arrangement comprises a lever arrangement pivoted on the support bar the distal end(s) of the lever arrangement being connected by wire or rod to the cam arrangement.

The climbing aid may comprise two pairs of cams, one pair on each side of the support bar, mounted on a spindle passing through a bearing aperature in the thicker cross section cam arrangement supporting section.

Embodiments of climbing aids according to the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a front view of a first embodiment; Figure 2 is a side view of the embodiment of Figure 1; Figure 3 is a cross section of the support bar of the aid of Figure 1 and 2; Figure 4 is a view on the line IV-IV of Figure 3; and Figure 5 is a front view of a second embodiment.

The drawings illustrate climbing aids of the kind comprising a cam arrangement 11 mounted at one end of a support bar 12 which has a rope attachment eye 13 and an operating arrangement 14 for the cam arrangement 11 for inserting it in and withdrawing it from a rock crack and spring means 15 to deploy the cam arrangement 11 to an operative position in the crack in which the climbing aid is jammed by the cam arrangement 11 against movement under rope loading.

The support bar 12, more clearly seen in the first embodiment in Figures 3 and 4, is fabricated by forging, for example from steel, and has thicker cross section at the locations of the cam arrangement 11 (31) and the rope attachment eye 13 (32) connected by lightweight, thinner web sections 33.

Intermediate the said locations 31 and 32, in the first embodiment, is an apertured section 34 receiving the operating arrangement 14. This apertured section 34 is also of thicker cross section. The operating arrangement 14 comprises a lever arrangement pivoted on the support bar 12, the distal ends of the lever arrangement being cammed by wire or rod 16 to the cam arrangement 11.

Because the operating arrangement is now pivotal, instead of being slidably mounted on the support bar, as taught by Jardine, the apertured section 34 can be of limited extent as compared with that required by Jardine's patent, and this, together with the thickening permitted by the forged fabrication rather than machining from bar stock, greatly increases the strength of the support bar in this crucial region.

The aid comprises two pairs of cams 21,22 and 23,24, one pair on each side of the support bar 12, mounted on a spindle 18 passing through a bearing aperture in the thicker cross section cam arrangement supporting location 31. The thicker section at this location 31 which can by virtue of the forged construction be some 25% thicker than when machined bar stock is used, is substantially stronger and much less liable to failure.

The rope attachment eye 13, also by virtue of the forged construction, is much stronger, again by virtue of a 25% thickness advantage.

Figure 5 illustrates a second embodiment which is generally similar to the first, but here the aperture in the section 34 is avoided altogther by forming the lever arrangement in the form of yokes pivoted on a pin 51 extending through a bore drilled across the support bar 12.

Claims

1. A climbing aid of the kind comprising a cam arrangement mounted at one end of a support bar which has a rope attachment and an operating arrangement for the cam arrangement for inserting it in and withdrawing it from a rock crack and spring means to deploy the cam arrangement to an operative position in the crack in which the climbing aid is jammed by the cam arrangement against movement under rope loading, in which the support bar is fabricated by forging and has thicker cross section at the locations of the cam arrangement and the rope attachment connected by lightweight, thinner web sections.

2. A climbing aid according to claim 1, having intermediate the said locations an apertured section receiving the operating arrangement which apertured section is also of thicker cross section.

3. A climbing aid according to claim 1 or claim 2, of which the operating arrangement comprises a lever arrangement pivoted on the support bar the distal end(s) of the lever arrangement being connected by wire or rod to the cam arrangement.

4. A climbing aid according to any one of claims 1 to 3, comprising two pairs of cams, one pair on each side of the support bar, mounted on a spindle passing through a bearing aperture in the thicker cross section cam arrangement supporting location.