EP0345175A1 - Self-blocking descender - Google Patents

Abstract

The descender according to the present invention comprises a one-piece body having the principal parts of a figure-eight descender, namely a first part (1) provided with a first hole (2), a second part (3) provided with a second hole (4), the two parts being connected by an intermediate part (5). According to the invention, the intermediate part (5) is curved such that its attachment zone (6) is angularly offset relative to the main axis (B-B) of the descender. An auxiliary hole (11) permits the passage of a karabiner for the angular orientation of the descender about the first hole (2). The angular orientation enables the braking obtained by the descender along the rope to be adjusted. <IMAGE>

Description

The present invention relates to descenders used in particular for the practice of mountaineering and speleology.

The descenders usually used are devices making it possible to slide along a rope while producing a certain braking. The user clings to the descender, the descender itself being adapted on a rope, so that the user can descend along the rope, the upper end of which is attached to a fixed point.

The descenders most generally used at present are called "descenders in 8". A descender in 8 comprises a one-piece body consisting of a first part pierced with a first hole, a second part pierced with a second hole, the first part and the second part being connected by an intermediate part connected to the first part by a connecting zone intended to be surrounded by a loop of rope, the two strands of which pass through the first hole; the second hole is used for hanging the user.

These known descenders are very safe, by the fact that the rope cannot in any case escape from the descender: when it has passed correctly through the descender, forming a half-loop around the attachment zone, it is understood that it it is impossible to remove the rope unless the half-loop can make the total turn of the user, or unless the user is separated from his descender. In the latter case, the rope is removed by making it go around the second part of the descender.

It is understood that the rope, by its curved shape passing through the first hole and making a half-loop around the attachment zone, rubs considerably against the walls of the descender when the descender slides along the rope. This results in relatively significant braking of the descender along the rope. However, this braking is insufficient to sufficiently slow the user down when he descends along the rope, and the user must provide additional braking using his hands rubbing on the rope. It follows that if, inadvertently or as a result of discomfort, the user's hands let go of the rope, braking becomes insufficient. The user then risks descending at too high a speed, likely to cause serious or even fatal trauma, and does not not stop at the end of the rope.

The object of the present invention is in particular to avoid the drawbacks of known descenders, by proposing a new descender structure which, while retaining the safety qualities of known descenders at 8, significantly increases the braking forces along the rope, provides sufficient braking to completely stop the sliding of the descender along the rope when the user releases the device and the rope completely, and allows the progressive adjustment of the braking forces by action of the user on the descender itself. According to the invention, these functions are provided by a one-piece descender comprising no mechanical annex movable relative to the body of the descender.

To achieve these and other objects, the descender according to the present invention comprises a one-piece body comprising the main parts of a descender at 8, the descender being used in the same manner as a descender at 8; according to the invention:
the intermediate part of the descender is curved so that its attachment zone is angularly offset around the first hole with respect to the line joining the holes,
- Gripping means are provided to allow adjustment at will of the angular orientation of the device around the axis of the first hole, this orientation producing a progressive adjustment of the braking forces of the descender along the rope.

In the release position, the attachment zone is angularly offset around the first hole relative to the line joining the two holes, or main direction of the rope; this arrangement very significantly increases the friction of the descender on the rope, and the braking force which it achieves, compared to the braking obtained by a descender at 8.

By correctly choosing the angular offset of the attachment zone relative to the line joining the two holes, during the construction of the descender, a braking force greater than the weight of the user is produced in the released position. Such a result is obtained when the angular offset is greater than approximately 70 °.

According to a preferred embodiment, the gripping means allowing the adjustment of the angular orientation of the descender relative to the main direction of the rope comprise a hole auxiliary, formed in the intermediate part of the descender, in the vicinity of the attachment area. The half-loop of rope passes around the area of attachment between the first hole and the auxiliary hole; the auxiliary hole can be used to pass a cord or a carabiner, which the user can then pull at will to produce the adjustment of orientation of the descender around the first hole.

According to another embodiment, the gripping means can be a lever secured to the descender body. Such a lever can be arranged in any position around the body.

According to one embodiment, the first hole comprises, in the vicinity of the attachment zone, a rectilinear wall. This arrangement ensures better blocking when the descender is used with a two-strand rope: the blocking is better balanced between the two strands of rope.

• - la figure 1 représente un descendeur en 8 traditionnel, et son mode d'utilisation normale ;
• - la figure 2 représente un descendeur selon la présente invention, en vue de face ;
• - la figure 3 représente une vue en coupe selon le plan A-A de la figure 1 ;
• - la figure 4 représente le descendeur de la présente invention en position de blocage ;
• - la figure 5 représente le descendeur de la présente invention en position de coulissement avec freinage ;
• - la figure 6 illustre un autre mode d'utilisation en relais autoblo­quant pour descente ; et
• - la figure 7 illustre un mode d'utilisation du descendeur selon l'invention comme un descendeur en 8 classique.

Other objects, characteristics and advantages of the present invention will emerge from the following description of a particular embodiment, given in relation to the attached figures, among which:

• - Figure 1 shows a traditional descender 8, and its normal mode of use;
• - Figure 2 shows a descender according to the present invention, in front view;
• - Figure 3 shows a sectional view along the plane AA of Figure 1;
• - Figure 4 shows the descender of the present invention in the locked position;
• - Figure 5 shows the descender of the present invention in the sliding position with braking;
• - Figure 6 illustrates another mode of use in self-locking relay for descent; and
• - Figure 7 illustrates a mode of use of the descender according to the invention as a conventional descender 8.

As shown in FIG. 1, a conventional descender in 8 comprises a first part 1 pierced with a first hole 2, a second part 3 pierced with a second hole 4. The first part 1 and the second part 3 are connected by a intermediate part 5, the assembly forming a one-piece body. The intermediate part 5 is connected to the first part 1 by a connecting zone 6.

In normal use, shown in Figure 1, the descender at 8 is positioned on a rope 7: the upper strand 8 of rope once passes through the first hole 2, makes a half-loop 9 around the attachment area 6 , goes back into the first hole 2 and goes out to form the lower strand 10. We see that the upper strand 8 and the lower strand 10 do not intersect in the first hole 2. A carabiner 11, or other attachment device, is passed into the second hole 4 for hooking the user. In normal use, the user must hold with one hand at least the lower strand 10, and possibly the upper strand 8. If the user releases the two strands, the braking of the rope when the descender at 8 is passing is insufficient.

We see that, in the descender at 8, the first hole 2 and the second hole 4 define the main axis BB of the descender, the axis being substantially parallel to the general direction of the rope 7, or direction of the upper strand 8 and of the lower strand 10. This direction is generally vertical, during use.

As shown in FIG. 2, the descender according to the present invention comprises, like a descender at 8, a first part 1 pierced with a first hole 2, a second part 3 pierced with a second hole 4, an intermediate part 5 connecting the first part 1 and the second part 3, the intermediate part 5 connected to the first part 1 by a connecting zone 6, the assembly forming a single piece. The first hole 2 and the second hole 4 define the main axis of the descender.

As shown in FIG. 2, the intermediate part 5 of the descender according to the invention is curved so that its attachment zone 6 is angularly offset around the first hole relative to the line BB joining the two holes 2 and 4. We have schematically represented in the figure the general direction AA of the attachment zone 6, and the angle D of offset between the axis AA and the main axis BB of the descender.

Gripping means are provided to allow the angular orientation of the descender to be adjusted around the axis of the first hole 2. In the embodiment shown, these gripping means are consisting of a simple auxiliary hole 11, formed in the intermediate part 5, in the vicinity of the connecting zone 6. It can be considered that the connecting zone 6 extends between the auxiliary hole 11 of the intermediate part 5 and the first hole 2 of the first part 1 of the descender body.

Preferably, the curvature of the intermediate part 5 develops in the plane of the descender, that is to say that the descender is substantially planar, so that its use can be adapted as well to right-handed users as to left-handed users, without showing any difference in behavior.

There is shown in Figure 3 a sectional view along the plane A-A of the descender of Figure 1, showing such the descender is substantially planar.

Other embodiments are possible for the gripping means. One can for example design a lever, integral with the first part 1 of the body, and accessible to the user to tilt, either by traction or by pressure, the descender around the axis of the first hole 2. The lever can, for example, be arranged as an extension of the attachment zone 6, on the left-hand side of FIG. 2, or on the opposite in the first part 1; a lever on the left is actuated by pulling downwards, a lever on the right would be actuated by pushing upwards, producing in both cases a rotation of the descender anticlockwise.

In the embodiment shown in FIG. 2, the hole 2 comprises, in the vicinity of the attachment area 6, a substantially planar wall 12. This wall forms a planar area capable of receiving two strands of rope side by side, balancing friction as will be explained later.

FIGS. 4 and 5 show the normal use of the descender according to the present invention. In this normal use, the user is, as for a descender at 8, connected to the descender by a hooking device passing through the second hole 4. One can for example pass a carabiner in the second hole 4, the carabiner being hooked to the user's shoulder harness. The figures show a use with a double rope. Use can also be effective on a single rope. The upper arm 8 of the rope passes through the first hole 2, forms a half-loop 9 around the attachment zone 6, passes back through the hole 2 and escapes to form the lower strand 10. However, as shown in FIG. 4, the strands of rope cross in the first hole 2, moreover the crossing takes place in a determined direction, defined in FIG. 4, so that the upper strand 8, which at its exit of semi-loop around the area of attachment 6 is closest to the second hole 4, must cross the lower strand 10 over this lower strand in the first hole 2.

An auxiliary gripping device, for example a strap 13 or a carabiner, is passed through the auxiliary hole 11. In the absence of traction on the auxiliary strap 13, the descender is positioned as shown in FIG. 4, under the effect of the traction exerted by the weight of the user attached to the second hole 4: the main axis BB of the descender is then in a substantially vertical position, aligned with the strands 8 and 10 of rope. Crossing the ropes then produces effective braking, preventing the descender from sliding along the rope. This braking is effective enough to prevent any sliding when the angle D formed by the main axis B-B of the descender and by the axis A-A of the attachment zone 6 is at least equal to 70 °. A smaller angle produces less braking, which may however be enough to avoid accidents. A greater angle produces very effective braking, which it is necessary to counter by a more important maneuver of the descender.

By pulling down on the strap 13, as shown in FIG. 5, the user can tilt the descender relative to the mean axis of the strands 8 and 10 of rope. It is then observed that the strands of the rope decrease slightly at the level of the first hole 2, and the braking provided by the descender on the rope decreases. Braking therefore depends on the orientation that the user gives to the descender along the rope, the braking adjustment being substantially continuous between a maximum braking value in the self-locking position shown in FIG. 4, and a relatively low braking value in the position shown in Figure 5.

It can be seen in FIG. 4, in the case of the use of a double rope, that the flat wall 12 ensures the placing of the two strands of the lower part 10 of rope against the flat wall 12, balancing the braking exerted on both strands.

Two other examples of the use of the descender according to the present invention are shown diagrammatically in FIGS. 6 and 7.

In FIG. 6, the descender is used to establish a relay making it possible to brake a descending rope and to block it automatically; its release requires traction on the strap passing through the auxiliary hole, as shown by the arrow in the figure.

In FIG. 7, the same descender according to the present invention is used as a conventional descender in 8. For this, the user hooking carabiner is passed not through the second hole 4 but through the auxiliary hole 11.

The present invention is not limited to the embodiments which have been explicitly described, but it includes the various variants and generalizations thereof contained in the field of claims below.

Claims (5)

1 - Descender comprising a monobloc body consisting of a first part (1) pierced with a first hole (2), a second part (3) pierced with a second hole (4), the first and the second part being connected by an intermediate part (5) connected to the first part (1) by a connecting zone (6) intended to be surrounded by a half-loop (9) of cord, the two strands of which pass through the first hole ( 2), the second hole (4) being used for hanging the user, characterized in that:
- the intermediate part (5) is curved so that its attachment zone (6) is angularly offset around the first hole (2) relative to the line (BB) joining the first hole (2) and the second hole (4 ),
- gripping means (11) are provided to allow the angular orientation of the descender to be adjusted around the axis of the first hole (2),
so that the angular orientation adjustment produces a braking adjustment of the descender along a rope (7) when the strands of rope are crossed in the first hole (2), the strand (8) closest to the second hole passed over the other strand in the first hole (2). 2 - Descender according to claim 1, characterized in that the angle formed by the axis (A-A) of the attachment zone (6) and the main axis (B-B) of the descender is greater than 70 °. 3 - Descender according to one of claims 1 or 2, characterized in that the gripping means comprise an auxiliary hole (11) formed in the intermediate part (5) of the body, in the vicinity of the attachment zone (6), for the passage of a strap (13) or a carabiner activated by traction. 4 - Descender according to one of claims 1 or 2, characterized in that the gripping means comprise a lever secured to the body and projecting from the body for its manipulation by the user. 5 - Descender according to any one of claims 1 to 4, characterized in that the first hole (2) comprises, in the vicinity of the attachment zone (6), a substantially planar wall capable of receiving two strands side by side of rope.

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