GB2437793A

GB2437793A - Rope control device

Info

Publication number: GB2437793A
Application number: GB0608790A
Authority: GB
Inventors: Christopher Mark Edmondson
Original assignee: Heightec Group Ltd
Current assignee: Heightec Group Ltd
Priority date: 2006-05-04
Filing date: 2006-05-04
Publication date: 2007-11-07
Anticipated expiration: 2026-05-04
Also published as: GB2437793B; GB0608790D0

Abstract

A rope control device provides a locking function and different frictional resistance depending on the direction of travel of the rope, comprising an eccentric pulley 1 and associated rope guide member 10. The pulley having a control handle 13 secured thereto for releasing the locking mechanism. The rope is threaded around plurality of rope guide members 10,11,12 each of which is mounted on a spindle 16,17,18 around which it can rotate in one direction but not in the opposite direction. When the rope is moved in one direction through the device the rope guides rotate reducing the frictional resistance to the passage of the rope, when moved in the opposite direction the rope guides remain fixed increaseing the frictional resistance to the passage of the rope. Preferably a pivotably mounted cover (6, fig 5) can be moved to expose the pulley and rope guides to allow roping or unroping thereof.

Description

I

Rope control device Rope devices are well known for controlling a load on a rope, cable web or other similar elongate load supporting member (collectively referred to hereinafter as rope') when abseiling or carrying out rescues of persons from height etc. Known devices provide friction to slow the passage of the rope and hence control the movement of the load. As the level of friction is fixed the device provides the same frictional resistance whichever way the rope is moved.

However this can cause problems when slack rope needs to be pulled through the device or it is used for hauling i.e. the rope is moved through the device in the opposite direction. The friction which is required for lowering is S...

* . still present and this impedes the passage of the rope, therefore devices which provide sufficient friction cannot be used efficiently for hauling in and * vice versa. The current solution to this problem is to have variable friction *5S which can be added or subtracted depending on the required use, this has the *.:. obvious drawback in that it requires input from the user who may be unskilled *: :: : or in a panic situation in the case of an emergency rescue.

The invention seeks to eliminate these problems by providing a device which offers resistance to the passage of the rope in one direction but reduced resistance in the other.

According to the present invention there is provided a rope device for controlling the lowering and/or raising of a load on a rope, the device comprising rope guide means comprising a plurality of rope guide members around which the rope can be threaded for guiding and controlling the passage of the rope through the device and attachment means for attaching the device to a further rope and/or an object/person to be lowered and/or raised, the rope guide means includes rope braking means comprising a first locking member movable between a rope jamming position wherein the rope is trapped between the locking member and an adjacent rope guide member and a release position wherein the locking member is spaced from said adjacent rope guide member, the rope guide means being arranged such that the first locking member is urged towards its rope jamming position when a rope is applied to the downstream end of the rope, the first locking member being selectively movable towards its release position in order to selectively control the movement of the rope through the rope guide means, at least one of said rope guide members being freely rotatable when urged in a first direction and including locking means preventing rotation of said at least one rope guide member when when urged in an opposite direction.

Preferably said rope guide member adjacent said braking means against which the locking member abuts is freely rotatable when urged in said first S...

* * direction and includes locking means preventing rotation when when urged in the opposite direction.

S S..

In one embodiment, each of said rope guide members of said rope guide *:*:.* means is rotatable in a first direction and includes respective locking means *::::* preventing rotation in an opposite direction.

Preferably said at least one rope guide means is adapted to be freely rotatable when a load is applied to an upstream end of the rope.

Thus the friction acting on the rope as it passes through the rope guide means can be different depending on which direction the rope is moving through the rope device.

Preferably the user may selectively thread the rope around a greater or lesser number of said rope guide means so as to increase or decrease the amount of friction acting on the rope.

Preferably the device comprises first and second mounting plates, the rope guide means being mounted on the first mounting plate and a second mounting plate being mounted on the first mounting plate for movement between a rope loading position wherein the rope can be located in the rope guide means and a closed position wherein the second mounting plate covers at least the gap between the first locking member and its adjacent abutment preventing removal of the rope from the braking means. Preferably said at least one rope guide member is mounted on a spindle extending normal to said first mounting plate. Preferably said locking means comprises one way clutch means allowing free rotation of said rope guide member with respect to said spindle in a first direction and preventing rotation of said at least one rope guide member with respect to said spindle in a direction opposite to said first direction. * I. * S S **S. *S.S

Preferably the first locking member of the braking means comprising a first * : cam or eccentric pulley pivotably mounted on the first mounting plate for * rotation about a rotational axis normal to said first mounting plate between its rope jamming position and its release position.. * * * S * * S.

* An embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings in which: Figure 1 is a front view of the rope control device according to the invention.

Figure 2 is a front view of Fig.1 with the cover plate removed and the braking mechanism in a first operative position Figure 3 is a front view of Fig.1 with the cover plate removed and with the braking mechanism in a second operative position Figure 4 is a front view of Fig. 1 with the cover plate removed and with the braking mechanism in a third operative position Figure 5 is a front view of Fig.1 with the cover plate moved to its rope loading/unloading position.

A preferred embodiment of the invention comprises a predominantly circular pulley I mounted eccentrically with relation to its centre on a spindle 3 secured normally on a flat portion of a first supporting plate 5. A second supporting plate 6 or cover plate is mounted parallel to the first supporting plate 5, the second supporting plate 6 being pivotally movable between a rope loading/unloading position and a closed position to allow rope 7 to be inserted and then retained in the device. The outer circumferential surface of the pulley I is provided with a groove to retain the rope around the circumferential surface of the pulley. *...

An aperture 8 corresponds with a similar aperture 9 in the second supporting plate 6 to allow a connector, such as a karabiner or screwlink, to be inserted to connect the device to a person or a secure anchorage point.

* A first rope guide member 10 is mounted on a spindle 16 secured normally on the first supporting plate 5 adjacent to the pulley 1. A second rope guide member 11 is mounted on a spindle 17 and a third rope guide member 12 is mounted on a spindle 18 which are secured normally on the first supporting plate spaced from the first rope guide member 10 such that they are substantially in a straight line. Rope guide members 10, 11 and 12 are equipped with blocking means, such as a clutch bearing, such that they may rotate in one direction only.

A control handle 13 comprising as elongate flat plate is secured to the pulley I parallel to and adjacent to the first supporting plate 5. An abutment member or bollard 4 is mounted on the control handle 13, normally to the control handle 13 so that the rope 7 leaving the pulley I passes between the bollard 4 and the rope guide member 11.

The pulley 1, the first rope guide member 10 and control handle 13 together constitute a primary braking mechanism while the bollard 4 and rope guide member 11 constitute a second braking system.

In use the second supporting plate 6 is moved to is rope loading/unloading position and a rope 7 is threaded anti-clockwise around the pulley I moving away from the downstream end 14 of the rope 7 (i.e. the end of the rope to which the load is to be applied). The rope 7 is then passed between the pulley I and the first rope guide member 10. Next the rope passes between the rope guide member 10 and rope guide member 11, then between rope guide member 11 and rope guide member 12 before leaving the device.

When a load is applied to the downstream end 14 of the rope 7, the frictional force created by the rope 7 around the pulley I will cause the pulley I of the primary braking mechanism to pivot in an clockwise direction, thus locking rope 7 securely between point surfaces on the pulley I and rope guide member 10. * S * S S * S.

In order to release the rope 7 the control handle 13 is pressed towards the first and second supporting plates 5, 6 moving the pulley in an anti clockwise direction. Once the control handle 13 has been pressed to release the rope 7 the rope can move through the device. When urged in their respective directions by the frictional force created by the rope, the rope guide members 10, 11 and 12 are prevented from rotating by their locking means, providing additional friction to assist in controlling the passage of the rope.

During the release of the primary braking mechanism, further movement of the control handle towards the first and second plates 5, 6 moves the bollard 4 towards the rope guide members 11 clamping the rope securely therebetween. Thus, the bollard 4 will allow the device to brake the rope to a complete halt if the control handle is operated in panic.

If a load is applied to the upstream end 15 of the rope 7, the frictional force created by the rope 7 around the pulley I will cause the pulley I of the primary braking mechanism to pivot in an anti clockwise direction, thus releasing rope 7 and allowing rope to be drawn through the device. Said frictional force around pulley I being insufficient to operate the secondary braking system. When urged in their respective directions by the frictional force created by the rope, the rope guide members 10, 11 and 12 rotate freely, assisting the passage of the rope when a load is applied to the upstream end. However, the rope guide members 10,11 and 12 are prevented from rotating when the rope passes through the device in the opposite direction, thus providing greater friction in such direction. * S. * S * S... S... * S S... * *5 * a * a.. S

S

S * S * S 5 * S. 55. * S S...

Claims

Claims 1. A rope device for controlling the lowering and/or raising of

a load on a rope, the device comprising rope guide means comprising a plurality of rope guide members around which the rope can be threaded for guiding and controlling the passage of the rope through the device and attachment means for attaching the device to a further rope and/or an object/person to be lowered and/or raised, the rope guide means includes rope braking means comprising a first locking member movable between a rope jamming position wherein the rope is trapped between the locking member and an adjacent rope guide member and a release position wherein the locking member is spaced from said adjacent rope guide member, the rope guide means being arranged such :. that the first locking member is urged towards its rope jamming position when :..::: a rope is applied to the downstream end of the rope, the first locking member S...

being selectively movable towards its release position in order to selectively control the movement of the rope through the rope guide means, at least one *. of said rope guide members being freely rotatable when urged in a first * ** direction and including locking means preventing rotation of said at least one rope guide member when urged in an opposite direction. S..

S

2. A device according to claim I wherein the rope guide member adjacent the braking means against which the locking member abuts is freely rotatable when urged in a first direction and includes locking means preventing rotation when urged in the opposite direction.

3. A device according to claim I wherein each of the rope guide members of the rope guide means is rotatable in a first direction and includes respective locking means preventing rotation in an opposite direction.

4. A device as claimed in any preceding claim at least one rope guide means is adapted to be freely rotatable when a load is applied to an upstream end of the rope.

5. A device according to claim 1 wherein the user may selectively thread the rope around a greater or lesser number of the rope guide means so as to increase or decrease the amount of friction acting on the rope.

6. A device as claimed in any preceding claim comprising first and second mounting plates, the rope guide means being mounted on the first mounting plate and a second mounting plate being mounted on the first mounting plate for movement between a rope loading position wherein the rope can be located in the rope guide means and a closed position wherein the second mounting plate covers at least the gap between the first locking member and its adjacent abutment preventing removal of the rope from the braking means. S. * S

7. A device as claimed in any preceding claim wherein at least one rope guide S...

member is mounted on a spindle extending normal to the first mounting plate. * S. * * S

SSS S

8. A device as claimed in any preceding claim wherein the locking means * ** comprises one way clutch means allowing free rotation of the rope guide member with respect to the spindle in a first direction and preventing rotation * of the at least one rope guide member with respect to the spindle in a direction opposite to the first direction.

9. A device as claimed in any preceding claim wherein the first locking member of the braking means comprises a first cam or eccentric pulley pivotably mounted on a first mounting plate for rotation about a rotational axis normal to the first mounting plate between its rope jamming position and its release position.

10. A device substantially as herein described with reference to the accompanying drawings.