GB2192664A

GB2192664A - Self-blocking jamming cleat for a fixed rope

Info

Publication number: GB2192664A
Application number: GB08715493A
Authority: GB
Inventors: Paul Petzl; Pierre Petzl
Original assignee: PETZL ETS; Petzl SA
Current assignee: PETZL ETS; Petzl SA
Priority date: 1986-07-07
Filing date: 1987-07-01
Publication date: 1988-01-20
Anticipated expiration: 2007-07-01
Also published as: FR2600898A1; IT8767551A0; GB2192664B; DE3722280C2; ES2005895A6; FR2600898B1; GB8715493D0; IT1210835B; DE3722280A1

Description

GB2192664A 1 SPECIFICATION longitudinal direction of the median axis of

the catch, the slit passing through the whole wall Securing device with self-blocking jamming of the cam and having its outlet on the face cleat for a fixed rope opposite the gripping means in such a way as to allow the mud accumulated in the bottom The invention relates to a self-blocking secur- of the dish to, be completely evacuated.

ing device with a jamming cleat, operating in The continuity of the longitudinal evacuation conjunction with a fixed rope, and comprising: device slit in the axial direction prevents any - a body made of metallic material, equipped risk of the bottom of the dish becoming at one of its ends with a recess housing the 75 clogged up, and enables the gripping spikes to rope, have an efficient grip on the rope when the - a one-way blocking catch, mounted with catch is urged into the blocked position.

limited pivoting on a spindle fixedly united to Other advantages and features will become the body opposite the recess, the free end of more clearly apparent from the following de the movable catch being shaped into a jamm- 80 scription of an illustrative embodiment of the ing cam capable of blocking the rope against invention, given as a non- restrictive example the bottom of the recess of the body, only and represented in the accompanying - gripping means evenly distributed over the drawings, in which:

surface of the cam to prevent any sliding of Figure 1 is a perspective view of the self the jammer on the rope in the downwards 85 blocking securing device according to the in direction, vention, the catch being represented in the - a device for evacuating the mud or ice inactive neutralization position; which covers the jamming cam when a strong Figure 2 is an elevation view of the securing pressure is exerted by the catch against the device in the blocked position; rope, 90 Figure 3 shows a side view of the jamming - and means of attaching the body to the cam of the catch; user's harness. Figure 4 is a sectional view along the line If the securing device is used on a frozen IV-IV of Fig. 3; rope in mountaineering or on a rope clogged Figure 5 is a sectional view along the line up by mud in speleology, the jamming cam of 95 V-V of Fig. 3; the catch no longer blocks the rop efficiently Figure 6 represents a sectional view along against the recess. The gripping means be- the line VI-VI of Fig. 4.

come inoperative, and this may result in slip- In Figs. 1 to 6, a selfblocking securing de ping dangerous for the user's safety, notably vice 10 of the jamming cleat type is used in in the event of a fall. 100 mountaineering and in speleology for ascen According to a state-of-the-art jammer, the sion on a fixed vertical rope 12. The securing jamming cam is equipped with an ice evacua- device 10 commonly called a "jammer" is tion device, comprising a plurality of parallel made up of a body 14 achieved by folding an openings extending perpendicularly to the aluminium alloy sheet having a high mechanical longitudinal axis of the catch. The transverse 105 resistance. One of the lateral extremities of openings are located at regular intervals along the body 14 forms a U- shaped recess 16 in the cam, and require a large number of gripp- which the rope 12 slides, said recess 16 be ing teeth to be omitted to the detriment of ing bounded by a front guide wing 18 extend the jamming action. Only a part of the ice or ing parallel to the rear flange 20 of the body mud is evacuated by the openings, and there 110 14. The other lateral extremity of the latter is always remains the possibility of partial clogg- curved in the opposite direction on the same ing of the gripping teeth located in the interval side of the flange 20, and has passing between two successive openings. Certain through it a fixed spindle 22 secured to the diameters of ropes are moreover liable not to flange 20 by riveting.

catch correctly on the teeth of the gripping 115 A blocking catch 24 mounted with limited spikes depending on the width of the pivoting on the spindle 22 comprises a jamm transverse openings. ing cam 26, capable of blocking the rope 12 The object of the invention is to perfect the against the bottom of the recess 16 (Fig. 2).

securing device with self-blocking jamming The surface of the jamming cam 26 is pro- cleat to achieve total safety whatever the con- 120 vided with a plurality of protruding gripping ditions of use and the diameter of the fixed spikes, described in detail in Frenh Patent No rope. 2,311,213. The inclination of the spikes 28 The jammer according to the invention is ensures gripping on a rope 12 covered with characterized by the fact that the surface of ice or mud, without causing wear of the the cam equipped with gripping means pre- 125 sheath.

sents a dished profile designed to follow ex- The catch 24 is associated with a retaining actly the shape of the rope in the blocked lever 30 equipped with an operating lug 32 position of the catch, and that the mud evacu- designed to move the catch 24 to an end ation device comprises an axial slit extending neutralization position (Fig. 1), in which the in the botton of the dish according to the 130cam 26 is located away from the recess 16.

2 GB2192664A 2 The clearance of the cam 26 then enables the dish to be evacuated when a strong pressure rope 12 to be inserted in the recess 16 when is exerted by the catch 24 against the rope the securing device 10 is fitted. This neutrali- 12.

zation position of the catch 24 is stable and The axial continuity of the evacuation slit 50 the retaining lever 30 is latched and locked 70 in the direction of the median axis of the permanently onto the body 14 opposite the catch 24 prevents any risk of the bottom of recess 16. the dish becoming clogged up, and enables Unlocking of the retaining lever 30 must the spikes 28 to have an efficient grip on the take place when the securing device 10 is rope 12, whatever the conditions of use. The used (Fig. 2). A torsion-type return spring is 75 presence of the single axial slit 50 requires a fitted on the spindle 22, and urges the catch minimum number of spikes 28 to be omitted 24 in a clockwise direction until the jamming along the median axis XX'. In the embodiment cam 26 comes into contact w ith the rope 12. represented in Fig. 3, three aligned spikes 28 The flange 20 has two circular holes 36, 38 have been omitted, whereas the rest of the and an oblong orifice 40 located facing an 80 teeth remain symmetrical with respect to the orifice 42 forming part of the front wing 18. median axis. This results in reliable gripping by A snap-hook 44 attaching the user's harness the spikes 28 whatever the thickness of the passes through the pair of orifices 40, 42 rope 12 used.

(Fig. 4) and prevents the rope 12 from com- According to an alternative embodiment (not ing out of the recess 16. 85 represented), the spikes 28 gripping the rope The securing device 10 ensures safety when 12 can be replaced by a plurality of parallel ascending the roped 12, either self-securing ribs protruding from the surface of the cam the user, or securing a team-mate during a 26 and extending transversely in a perpendicu rescue operation. The reaction of the recess lar direction to the axial slit 50.

16 on the rope 12 when upwards sliding of 90 The blocking catch 24 with evacuation slit the body 14 takes place causes anticlockwise 50 can be adapted to any other type of rope pivoting of the catch 24 around the spindle jammer, for instance in which the base of the 22 to an unblocked position in which the rope body 14 is extended by a hand-grip enabling 12 is released by the cam 26. Unblocking of the user to progress more easily along the the catch 24 takes place against the force of 95 rope 12.

the return spring 34, and allows free sliding

Claims

on the rope 12 in the upwards direction. CLAIMS

Should the user fall, or a strong downwards 1. A self-blocking securing device with a pull be exerted, the catch 24 is driven jamming cleat, operating in conjunction with a clockwise by the rope 12 to the locking posi- 100 fixed rope, and comprising:

tion (Fig. 2), in which the jamming cam 26 - a body made of metallic material, equipped blocks the rope 12 against the bottom of the at one of its ends with a recess housing the recess 16. This results in a self-locking effect rope, of the catch 24 on the fixed rope 12, which - a one-way blocking catch, mounted with stops the failing movement or any other force 105 limited pivoting on a spindle fixedly united to directed in the downwards direction. The op- the body opposite the recess, the free end of eration of a securing device 10 of this kind is the movable catch being shaped into a jamm well known to those skilled in the art, and it ing cam capable of blocking the rope against is not necessary to specify the various possi- the bottom of the recess of the body, Ile bilities of use. The presence of the inclined 110 - gripping means evenly distributed over the spikes 28 on the jamming cam 26 prevents surface of the cam to prevent any sliding of any sliding of the jammer in the downwards the jammer on the rope in the downwards direction, on a rope 12 which is frozen or direction, covered with mud. - a device for evacuating the mud or ice According to the invention, the jamming 115 which covers the jamming cam when a strong cam 26 of the blocking catch 24 presents a pressure is exerted by the catch against the dished profile capable of following exactly the rope, rounded shape of the rope 12 in the blocked and means of attaching the body to the position of the jammer. The gripping spikes user's harness, wherein the surface of the 28 form a set of teeth evenly distributed over 120 cam equipped with gripping means presents a the whole surface of the dish. The bottom of dished profile designed to follow exactly the the dish has a slit 50 with rounded opposite shape of the rope in the blocked position of sides, arranged longitudinally along the median the catch, and that the mud evacuation device axis XX' of the catch 24. The length of the comprises an axial slit extending in the bottom axial slit 50 extends over a large part of the 125 of the dish according to the longitudinal direc cam 26, and its thickness is a few millimet- tion of the median axis of the catch, the slit ers. The slit 50 passes through the whole passing through the wall of the cam and com wall of the cam 26, and comes out opposite ing out opposite the gripping means in such a the spikes 28 in such a way as to allow the way as to allow the mud accumulated in the mud or ice accumulated in the bottom of the 130 bottom of the dish to be completely evacu- 3 GB2192664A 3 ated.
2. The self-blocking securing device according to claim 1, wherein the axial evacuation slit is formed by an oblong opening hav- ing a small thickness in relation to the width of the jamming cam.
3. The self-blocking securing device according to claim 1 or 2, wherein the gripping means are made up of a set of spiked teeth evenly distributed in the dish of the cam on either side of the axial slit.
4. A self-blocking securing device substantially as hereinbefore described with reference to the accompanying drawings.
5. Any novel feature or combination of features described herein.

Published 1988 at The Patent Office, State House, 66/71 HighHolborn, London WC 1 R 4TP. Further copies may be obtained from The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

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