DESCENT CONTROL DEVICE

Abstract

The invention relates to a descent control device comprising a housing, wherein the housing comprises a rope entrance (2) and a rope exit (3) located at opposite sides of the housing (1), a channel (5) having at least one curvature of at least 180 degrees, for accommodating the rope (4) internally in the housing, and an element (5) arranged in the centre of the curvature, limiting the inner radius of the channel. The element is eccentric rotatable between a free position and a stop position, and provided with an arm (6) protruding out through the housing for controlling the rotating between free and stop position. The channel in the curvature is more narrow along substantially its whole length when the element is in stop position than in free position.

Claims

1. Descent control device comprising a housing, wherein the housing comprises a rope entrance (2) and a rope exit (3), a channel (5) having at least one curvature of at least 180 degrees, for accommodating the rope (4) internally in the housing, an element (6) arranged in the centre of the curvature, limiting the inner radius of the channel, the element is eccentric rotatable between a free position and a stop position, the element is provided with an arm (8) protruding out through the housing for controlling the rotating between free and stop position, wherein the channel in the curvature is more narrow along substantially its whole length when the element is in stop position than in free position.

2. Device according to claim 1, characterized in that a peripheral edge of the element (6) is curved closely corresponding the curvature of the channel (5) in the housing, and that a remaining peripheral edge of the element has a reduced curve.

3. Device according to claim 2, characterized in that the remaining peripheral edge (7) of the element is flat.

4. Device according to claim 2 or 3, characterized in that the remaining peripheral edge (7) of the element (6) faces the curvature of the housing when the element is in free position, and that at least parts of the remaining peripheral edge of the element is rotated out of the curvature when the element is in stop position.

5. Device according to any one of the preceding claims, characterized in that the peripheral edge of the element curved corresponding the curvature, has protrusions and/or recesses (10), preferably protrusions/recesses perpendicular to the channel.

6. Device according to any one of the preceding claims, characterized in that the housing has protrusions and/or recesses (9) in a side constituting an outer radius of the curvature.

7. Device according to any one of the preceding claims, characterized in that the housing further comprises a member arranged eccentrically rotatably close to the wall of the housing, between the inlet and outlet of the rope.

8. Device according to any one of the preceding claims, characterized in that the housing further comprises an asymmetric member (13) arranged rotatably close to the wall of the housing, between the inlet and outlet of the rope.

9. Device according to any one of the preceding claims, characterized in that the curvature is at least 270 degrees.

10. Device according to any one of the preceding claims, characterized in that the housing further comprises limitation means (17) arranged on the outside of the housing, limiting the minimum distance between the arm and the housing.

11. Device according to claim 10, characterized in that the housing has a protruding part (16) on the outside, and in that in the limitation means comprises a spring loaded stopper (17), projecting along the side of the housing from the protruding part (16) towards the arm protruding out of the housing.

12. Device according to any one of the preceding claims, characterized in that the peripheral edge of the element is engaging the rope in the channel when the element is in free position.

13. Device according to any one of the preceding claims, characterized in that the inlet (2) and the outlet (3) are located at opposite sides of the housing (1).

Description

DESCRIPTION OF FIGURES

[0037] A preferred embodiment of the invention will now be described, by way of example, with reference to the following figures:

[0038] FIG. 1 shows a descent control device according to the invention, wherein a lid is removed and an eccentric element is in a stop positon, and

[0039] FIG. 2 shows corresponding to FIG. 1, wherein the element is in a limited free position,

[0040] FIG. 3 shows details of an eccentric element with an arm, and

[0041] FIG. 4. shows the housing of the device in FIGS. 1 and 2 in perspective.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0042] A preferred embodiment of a descent control device according to the invention is shown in the figures. The device comprises a housing 1, a rope entrance 2 and a rope exit 3, wherein the rope exit 3 and rope entrance 2 are located at opposing sides of the housing 1, leaving the rope direction out of the housing to be parallel to the rope direction into the housing. The housing is provided with narrow channels 2a, 3a for accommodating the rope both at the entrance 2 and exit 3, in order to ensure that the rope is straighten out when inside the device. FIGS. 1 and 2 show a rope 4 accommodated in the channels and running through the device, FIG. 4 shows the housing without the rope.

[0043] The housing is further provided with a channel 5 having at least one curvature of at least 270 degrees. In FIG. 4 the angle α of the curvature is shown, having 0 degrees at the beginning of the curvature and about 270-300 degrees at the end of the curvature. When the device is used for lowering, the rope 4 will enter the beginning of the curvature and leave the at the end of the curvature, and vice versa when the rope is drawn through the device for adjustment or preparation for a new use.

[0044] The width of the channel 5 in the curvature is limited by a rotatable element 6 arranged in the centre of the curvature. The element has an outer peripheral edge closely corresponding the shape of the curvature, but the part outside the curvature has a reduced curve, shown as a flat part 7 in the Figures. This part may have another shape deviating from the shape of the curvature, and being reduced compared to the shape of the curvature. The element 6 is supported eccentric, and thus the rotation axis is not in the centre of the curvature and the position of the element will effect the width of the channel 5.

[0045] When the element 6 is rotated to a position wherein the part 7 having a reduced curve faces the curvature, the channel 5 is sufficiently wide to allow the rope to pass through the device with only minimal friction. This position is referred to as a free position. However, when the element 6 is rotated clockwise in the Figures, to a position whereby the shape of the element corresponds to the shape of the curvature, the channel 5 will be too narrow along substantial parts or the whole of the channel to let the rope 4 pass, and thereby the lowering will stop. This position is referred to as the stop position, and the element is shown in stop position in FIG. 1. As described above, the stop position will depend on the forces acting on the rope, that is the weight of the person or parcel being lowered.

[0046] As the channel 5 will be narrowed along substantial parts or the whole length, the forces acting on the rope 4 will be distributed along the rope, and the risk for damages and breaks are substantially reduced compared to prior art where only parts of the channel were narrowed upon rotation of the element.

[0047] The element 6 arranged inside the curvature is provided with an arm 8 protruding out of the housing. By moving the arm 8, the element 6 will rotate, and thus the width of the channel 5 and thereby the rate of the rope 4 through the device, may be adjusted by adjusting the arm. When the arm 8 is aligned with the housing 1, the element 6 will be in free position and the rope 4 may pass through the device. When the arm 8 is protruding out from the housing, preferably from the curvature, the element 6 is in stop position. This is an advantage as the user may hold the device including the arm 8, by one hand and clamp the arm 8 close to the housing 1, which will hold the element 6 in the free position letting the rope 4 pass through the element with only minimum friction. If the user releases the arm 8, or removes his/her hand, the element 6 will rotate towards stop position and the arm 8 will be swung out form the housing, and the lowering will stop, as described above. By returning the arm 8 toward the free position along the housing, the lowering will start again.

[0048] In FIG. 2 the element 5 is shown in a limited free position, allowing a rope 4 to pass through the channel 5. When the rope 4 is moving through the device, it will engage the element 6 in such a way that if the arm 8 is not held in position by the user, the friction between the element 6 and the rope 4 will create sufficient force to rotate the element 6 towards a stop position. In FIG. 1 the element shown in FIG. 2, is rotated to the stop position for maximum forces acting on the rope. The rope 4 is clamped towards the opposite channel wall of the housing, and not able to pass through the controller shown in FIG. 1. The harder the rope 4 is pulled, the harder the element 6 will be forced to rotate, the more the element 6 rotates clockwise, the narrower the width of the channel 5 becomes, and the harder the rope 4 will be clamped. This will ensure that the lowering stops if the user is not active, loses the grip of the device, or becomes unconscious.

[0049] The shown housing is further provided with limitation means to limit the rotation of the element 6, and thus set the maximum rate of the rope less than the rate of the rope when the element is in the free position. In the shown embodiment, the limitation means are arranged on the outside of the housing, and comprises a protruding part 16 of the housing, wherein a spring loaded stopper 17 is fastened. The stopper 17 protrudes along the side of the housing from the protruding part 16 towards the arm 8. As described above, when the arm 8 is along the side of the housing, the element 6 is rotated to its free position and the rope 4 is running through the housing. When the stopper 17 is in its protruded position, the arm 8 will abut the stopper as shown in FIG. 2, and the element 6 may not be rotated totally into its free position. In this way the stopper 17 prevents maximum rate of the rope by adjusting the minimum distance between the arm and the housing.

[0050] The stopper 17 is preferably spring loaded, and may be pulled back towards the protruding part 16, into a retract position, if the user wants to go beyond recommended rate. The length of the stopper 17 may be adjusted to regulate the maximum rate through the device, as the rotation of the arm 8 will be more prevented by a longer stopper as the stopper protrudes along the side of the housing, towards the arm. This may also be achieved by retracting the stopper partly to a desired length. This may, of course also be regulated in other ways, for instance by using a thicker rope 4.

[0051] FIG. 3 shows details of the element 6 with the arm 8, wherein the element is flipped from the position shown in FIG. 1 and FIG. 2, whereby the face turning up in FIG. 3 is facing down in FIGS. 1 and 2. The peripheral edge of the element is shaped corresponding to the curvature, and provided with protrusions and/or recesses 10. These protrusions and/or recesses will engage the rope and rotate the element towards stop position, and finally stop the movement of the rope through the channel once the element reaches stop position. The remaining part of the peripheral edge 7, is flat in the shown embodiment. The transition between the remaining peripheral edge and the peripheral edge being curved as the curvature, in the rotating-direction towards stop position (shown to the left in FIG. 3), may be designed protruding as a nose 19, whereby the nose 19 will enter the channel in the beginning of the curvature 5 when the element is in stop position as shown in FIG. 1.

[0052] FIG. 4 shows details of the housing, and in the shown embodiment, the side of the housing, limiting the outer radius of the curvature and facing the element in the curvature, is also provided with recesses and/or protrusions to further increase the friction between the rope and the housing. In the shown embodiment the side of the housing facing the curvature is provided with two recesses 9, arranged about 45 degrees from the beginning of the curvature, that is the angle α is about 45 degrees in FIG. 4.

[0053] When the device is used, the element 6 will turn towards the stop position (clockwise in FIGS. 1 and 2) and prevent the rope 4 from passing through the device, and the lowering will stop. When the user wants to start lowering again, she/he presses the arm 8 towards the housing until the element 6 allows the rope 4 to pass through the channel 5. As long as the user assures that the manipulation arm 8 is held away from the stop position, the lowering will continue.

[0054] In a preferred embodiment, the device is provided with another separate system for reducing the rate of the rope through the device, inside the housing. The second system comprises a member 13 rotatably arranged close to the wall of the housing, thereby creating a second channel 12 for the rope between the member 13 and the housing. The member 13 is preferably asymmetrical, and thus friction acting on the rope depends on the rotation degree of the member. The same effect may be achieved by arranging the member to rotate eccentric.

[0055] In the shown embodiment, the member 13 of the second system is designed as a cylinder having an outer surface with protrusions and/or recesses, the cylinder is arranged to rotate eccentric. Further, the member 13 is provided with an arm 14 rotating clockwise towards the wall of the housing when the member is in a brake position. When the member 13 is in a free position the arm 14 is protruding away from the wall of the housing, and the rope will pass between the cylinder wall and the housing wall. This is shown in FIG. 1. When the member 13 is in brake position, the arm 14 is aligned with the housing wall prolonging the channel 12 for the rope to pass through, and as the member 13 is trying to rotate even further, the arm 14 will exert force on the rope. The member 13 is shown in brake position in FIG. 2.

[0056] When the rope is running through the housing during lowering, that is the rope is running in through the inlet 2 and out through the outlet 3, the rope will interact with the member 13, and rotate the member 13 from free to brake position. The second system will thus limit the maximum rate through the brake regardless of the curvature and element 6 described above. When the rope is running through the housing in opposite direction, such as during adjustments and resetting for a new use, the rope will interact with the member 13 and rotate it counterclockwise from brake to free position, and thus the adjustment or resetting will be easier.

[0057] In the shown embodiment, the housing is further provided with a solid protruding part 20 between the second system and the curvature. The rope 4 must pass through the second system and around the protruding part 20 before entering the curvature. In the shown embodiment, one side of the solid part constitutes a part of the channel 5 in the curvature, and the other side of the part constitutes a part of the channel 12 between the member 13 of the second system and the housing.

[0058] As said above, the element 6 is arranged rotatable in the housing 1. This may be performed in many ways which will be obvious to a skilled person. In the shown embodiment, a round axle protrusion 11 on the housing 1 fits inside a round axle hole in the centre of the element 6, and the element may rotate around the axle protrusion 11. Rotating the arm 8 will rotate the element 6 around the axel protrusion 11. In the same way, the member 13 is arranged rotatable in the housing 1. This may be performed in many ways which will be obvious to a skilled person, but in the shown embodiment, a round axle protrusion 15 on the housing 1 fits inside a round axle hole in the centre of the member 13, and the member may rotate around the axle protrusion 15 until the arm 14 of the member bears against the rope 4.

[0059] The device is designed for a given rope 4, as the width of the channel 5 and 12 must be adjusted to the thickness of the rope, in order to achieve the desired function. The softness of the rope, meaning the reduction of the thickness upon radial pressure will also be important during design of the device. The thickness and height of the protrusions and recesses 9, 10 of the element and housing must also be chosen according to the rope. The relationship will be obvious to a person skilled in the art.

[0060] In the shown embodiment of the device, the housing 1 is provided with a slot 18 for attaching a strap to carry the user. The strap should run through the slot in conventional ways to attach a strap. In an alternative not shown embodiment, the housing is provided with a corresponding hole for attaching a carabine hook to be attached to the strap carrying the user.

[0061] The friction between the rope and the housing in the second system, depends on the material, shape of the member, distance between the member and the housing, surface smoothness of the rope, surface smoothness of the member etc. During the manufacture of the descent control device, parameters of the rope and rope channel are selected to provide the correct minimum and maximum rappel rate.

[0062] The example above is given to illustrate the invention and should not be used to interpret the following claims limiting. The scope of the invention is not limited by the example give above, but the following claims. Modifications and amendments of the invention, being obvious to a person skilled of the art, should also be included in the scope of the invention.