PASSIVELY ENGAGED UNIDIRECTIONAL FRICTION LOAD CONTROL DEVICE

Abstract

A passively engaged unidirectional friction load control device having a rope-encasing shell with two points of rope redirection therein to generate friction that varies with the mass of the load during a lowering procedure and minimizes friction during an unloaded raising procedure.

Claims

1. A passively engaged unidirectional descent control device comprising a shell, a first friction point, a second friction point, and an attachment component, wherein the shell is comprised of a spine, a first side, and a second side, with the spine being substantially planar, the first side of the shell being substantially planar and attached to a left portion of the spine such that the first side of the shell is oriented substantially perpendicular to the spine, the second side of the shell being substantially planar and attached to a right portion of the spine such that the second side of the shell is oriented substantially perpendicular to the spine and substantially parallel to the first side of the shell, whereby the first side of the shell, the spine, and the second side of the shell form an open sided U-shaped channel, the first friction point is located across a top edge of the spine, running substantially horizontally from the first side of the shell to the second side of the shell, thereby forming a bending edge, the second friction point runs from a central portion of the first side of the shell to a central portion of the second side of the shell, with the second friction point oriented substantially perpendicular to the first side of the shell and substantially perpendicular to the second side of the shell, and further being oriented substantially parallel to and spaced apart from the spine of the shell, forming a gap between the second friction point and the spine, and the attachment component is located at a bottom portion of the spine.

2. The device of claim 1 wherein the shell is manufactured from stainless steel.

3. The device of claim 1 wherein the first side of the shell comprises an aperture formed therethrough at a central portion of the first side of the shell, and the second side of the shell comprises an aperture formed therethrough at a central portion of the second side of the shell, with the aperture formed into the second side of the shell being aligned with the aperture formed into the first side of the shell, whereby the second friction point is configured to be removably inserted into the apertures of the first and second sides of the shell and secured therein.

4. The device of claim 3 wherein the second friction point is one of the group of a removable pin, a shackle, a swinging gate, and a carabiner.

5. The device of claim 1 wherein the second friction point is a fixed pin, with a first end of the fixed pin located at a central portion of the first side of the shell and secured thereto, and a second end of the fixed pin located at a central portion of the second side of the shell and secured thereto, whereby the fixed pin is oriented substantially perpendicular to the first and second sides of the shell.

6. The device of claim 1 wherein at least a portion of the first friction point is substantially rounded, and at least a portion of the second friction point is substantially rounded.

7. The device of claim 1 wherein the shell is formed from a single monolithic piece of material, with the sides of the monolithic piece of material bent to form the sides of the shell and a middle portion of the monolithic piece of material rolled to form the bending edge.

8. The device of claim 1 wherein one or more of the spine, sides, bending edge, and attachment component of the shell are separate elements that are fixedly attached to each other.

9. The device of claim 1 wherein the shell has a length of between 10 cm and 15 cm, the channel of the shell has a width of between 12 mm and 18 mm, the first side of the shell has width of between 3 cm and 5 cm, the second side of the shell has width of between 3 cm and 5 cm, the spine of the shell is substantially rectangular, and the attachment component is a ring integrated into a bottom edge of the spine of the shell.

10. The device of claim 1 wherein the shell has a length of 13 cm, the channel of the shell has a width of 15 mm, the first side of the shell has width of 4 cm, the second side of the shell has width of 4 cm, the spine of the shell is substantially rectangular, and the attachment component is a ring integrated into a bottom edge of the spine of the shell.

11. The device of claim 1 wherein the bending edge is a substantially rounded circular cylinder having a diameter of between 10 and 15 mm.

12. The device of claim 1 wherein the bending edge is a substantially rounded circular cylinder having a diameter of 13 mm.

13. The device of claim 1 wherein the attachment component is a reinforced aperture having an inside diameter of between 14 mm and 18 mm.

14. The device of claim 1 wherein the attachment component is a reinforced aperture having an inside diameter of 16 mm.

15. The device of claim 3 wherein the second friction point is a removable pin, said removable pin being made of stainless steel and having a substantially circular cross-section, a diameter of between 10 mm and 15 mm, and a push button release, whereby the removable pin is configured to be removably inserted into the apertures of the first and second sides of the shell and secured therein.

16. The device of claim 15 wherein the removable pin has a diameter of 13 mm.

17. The device of claim 3 wherein the apertures formed into the sides of the shell are substantially circular.

18. The device of claim 3 wherein the apertures formed into the sides of the shell are located between 22 mm and 28 mm from their respective center points to the spine.

19. The device of claim 3 wherein the apertures formed into the sides of the shell are located between 18 mm and 22 mm from their respective center points to the bending edge.

20. The device of claim 3 wherein the apertures formed into the sides of the shell are located 25 mm from their respective center points to the spine, and the apertures formed into the sides of the shell are located 20 mm from their respective center points to the bending edge.

Description

DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1A is a side plan view of the first side of the shell of the device of the present invention.

[0029] FIG. 1B is a side plan view of the second side of the shell of the device of the present invention.

[0030] FIG. 1C is a rear plan view of the spine of the shell of the device of the present invention.

[0031] FIG. 1D is a top plan view of the top of the shell of the device of the present invention.

[0032] FIG. 2A is a side plan view of the first side of the shell of the device of the present invention in which a removable pin is utilized as the second friction point.

[0033] FIG. 2B is a side plan view of the second side of the shell of the device of the present invention in which a removable pin is utilized as the second friction point.

[0034] FIG. 2C is a rear plan view of the spine of the shell of the device of the present invention in which a removable pin is utilized as the second friction point.

[0035] FIG. 2D is a top plan view of the top of the shell of the device of the present invention in which a removable pin is utilized as the second friction point.

[0036] FIG. 3 is a plan view of one manufacturing embodiment of the device of the present invention, wherein the device is stamped out of a monolithic piece of stainless steel, and the sides are capable of being bent perpendicular to the spine and the top portion of the spine is capable of being rolled into the bending edge.

[0037] FIG. 4 is a stylized plan side view of the device of the present invention showing the movement of the rope when the device is used to lower an object. (Note: the representations of the rope, the load holding device, and the person being rescued are not to scale.)

[0038] FIG. 5 is a stylized plan side view of the device of the present invention showing the movement of the rope when the device is used to raise an object. (Note: the representations of the rope and the load holding device are not to scale.)

[0039] FIG. 6A is a plan side view of the device of the present invention in use, with a load securing device to be lowered attached thereto at the attachment point. (Note: the representations of the rope, the load holding device, the rescuer, and the person being rescued are not to scale.)

[0040] FIG. 6B is a plan side view of the device of the present invention in use, with the device unloaded and ready to be raised. (Note: the representations of the rope, the load holding device, and the rescuer are not to scale.)

DETAILED DESCRIPTION OF THE INVENTION

[0041] The descent control device 1 of the present invention embodies a solution to the above-stated problem, providing a device 1 having two friction points 172, 174 incorporated into a shell 100 configured to partially encase a portion of rope 10.

[0042] In the preferred embodiment, the shell 100 is comprised of a substantially planar spine 110, a substantially planar first side 120, and a substantially planar second side 130. See FIGS. 1A though 1C. The first side 120 of the shell 100 is attached to the left edge of the spine 110 in a substantially perpendicular orientation to the spine 110, and the second side 130 of the shell 100 is attached to the right edge of the spine 110 in a substantially perpendicular orientation to the spine 110, with the first and second sides 120,130 of the shell 100 being oriented substantially parallel to each other. This configuration results in the shell 100 having an open U-shaped channel 140 formed by its spine 110 and first and second sides 120,130 of the shell 100. See FIG. 1D. The channel 140 is appropriately sized to accommodate the thickness of a rope 10.

[0043] Across the top edge 112 of the spine 110, running substantially horizontally from the top portion 122 of the first side 120 of the shell 100 to the top portion 132 of the second side 130 of the shell 100, is a bending edge 150. The bending edge 150 should be substantially rounded and serves as a bending point (the first friction point 172) for the rope 10.

[0044] A second friction point 174 runs from a central portion 124 of the first side 120 of the shell 100 to a central portion 134 of the second side 130 of the shell 100, with the second friction point 174 oriented substantially perpendicular to the first side 120 of the shell 100 and substantially perpendicular to the second side 130 of the shell 100, and further being oriented substantially parallel to and spaced apart from the spine 110 of the shell 100, such that the gap 142 between the second friction point 174 and the spine 110 is sufficient to accommodate the thickness of the rope 10. The second friction point 174 should be substantially rounded and serves as a second bending point for the rope 10.

[0045] Located at the bottom edge 114 of the spine 110 is an attachment component 160, configured to provide a point of attachment of the load holding device 20 to the shell 100.

[0046] In one embodiment, the second friction point 174 is a removable pin 200. See FIGS. 2A though 2D. The first side 120 of the shell 100 comprises a first aperture 126 located in the central portion 122 of the first side 120 of the shell 100, and the second side 130 of the shell 100 comprises a second aperture 136 located in the central portion 134 of the second side 130 of the shell 100. The first aperture 126 is aligned with the second aperture 136. The removable pin 200 is removably inserted into the first aperture 126 and second aperture 136 and is securable at both ends. The pin 200, when removed from the shell 100, allows the rope 10 to be loaded into the channel 140 of the shell 100, and when the pin 200 is secured to the sides 120,130 of the shell 100 it holds the rope 10 within the channel 140 of the shell 100. The bending of the rope 10 around the removable pin 200 is the second bending point 174 for the rope 10, creating additional friction.

[0047] In other embodiments, the second friction point 174 may be a shackle, a carabiner, or another removable object that can be removed to allow the loading of a rope 10, and then replaced to secure the rope 10 in the shell 100. The same first and second apertures 126,136 are used to accommodate these alternative components.

[0048] In yet other embodiment, the second frictional point may be a fixed rounded pin. The first end of the fixed pin is located at the central portion 124 of the first side 120 of the shell 100, and the second end of the fixed pin is located at the central portion 134 of the second side 130 of the shell 100. In this embodiment, the free end of the rope 10 must be inserted into the channel 140 of the shell 100 and passed into and through the gap 142 between the fixed pin and the spine 110 of the shell 100.

[0049] With regard to the shell 100, the shell 100 can be made of any high strength material including but not limited to steel, aluminum, or carbon fiber. In the preferred embodiment, stainless steel is chosen due to its high strength to weight ratio, its resistance to degradation from the elements and from repeated exposure to friction, and its ease of manufacturing. The shell 100 could be made any length, but in the preferred embodiment it is approximately 13 cm long, which gives it an adequate lever arm to rotate into its engaged and disengaged positions while minimizing its weight and the materials necessary to manufacture it. The channel 140 of the shell 100 could be made any width as long as the width is sufficient to accommodate a rope 10 of sufficient strength to safely lower the load. In the preferred embodiment the channel 140 has a width of approximately 15 mm to accommodate the most commonly used diameters of rescue and arborist ropes 10, which are between 11 mm and 12.5 mm in diameter. A 15 mm channel width allows either diameter rope 10 to be used safely without risk of binding while minimizing weight and materials. The first and second sides 120,130 of the shell 100 could be of any width. In the preferred embodiment each side has a maximum width of approximately 4 cm. This maximum width is located proximate to the top edge of the shell 100 and to the central portion of the shell 100. This width accommodates the location of the second friction point 174 while leaving a sufficient distance to the opening of the channel 140 for strength. The overall shape of the sides 120,130 of the shell 100 could be any shape. In the preferred embodiment, the sides 120,130 have a generally rectangular shape at their superior ends (closest to the top edge of the shell 100), with rounded corners for maximum strength where the friction of the rope 10 is greatest, and have a tapered shape on the inferior end (closest to the bottom edge of the shell 100) to minimize weight and material use, as well as to maximize mobility of the attachment device 30 with which the shell 100 interacts. In the preferred embodiment the spine 110 of the shell 100 is substantially rectangular. In the preferred embodiment the attachment component 160 is a ring, integrated into the bottom edge 114 of the spine 110 of the shell 100. In one embodiment the shell 100 may be formed from a single monolithic piece of material, with the sides bent to form the sides 120,130 of the shell 100 and the bending edge 150. See FIG. 3. In other embodiments, the spine 110, sides 120,130, bending edge 150, and attachment component 160 may be separate components that are then fixedly attached to each other. In yet other embodiments some subset of the components may be constructed from a monolithic piece of material, which others are separately manufactured and then fixedly attached.

[0050] With regard to the bending edge 150, the top edge 112 of the spine 110 of the shell 100 should be sufficiently rounded to minimize damage to the rope 10 and serve as a friction point 172. As long as this surface is sufficiently blunt as to not damage the rope 10 as it moves over said surface, it could have any shape and diameter. In the preferred embodiment, the bending edge 150 is rounded to a circular cylinder having a diameter of approximately 13 mm. The circular cylinder allows the smoothest bending of the rope 10, and a 13 mm diameter represents at least as great a diameter as that of the rope 10 that is bent around it, to minimize the risk of damage to the rope 10. The most commonly used diameters of rescue ropes 10 are 11 mm and 12.5 mm and therefore a 13 mm diameter safely accommodates both sizes of rope 10 while limiting weight and materials. In other embodiments, the bending edge 150 could have a substantially rectangular or hexagonal or octagonal cross section; provided that the edges are rounded, any such regular (or irregular) configuration may be used.

[0051] With regard to the second friction point 174, in the embodiment utilizing a removable pin 200, the removable pin 200 allows the rope 10 to be loaded, secures the rope 10 into the device 1, and bends the rope 10 to create friction. The removable pin 200 may be made of any material that is high strength and has an adequate coefficient of friction with the types of rope 10 to be used in the device 1, and of any size. In the preferred embodiment the removable pin 200 is a stainless steel pin having a circular cross-section with a diameter of 13 mm, with a push button release. Stainless steel has a high strength to weight ratio, is resistant to degradation from the elements and from repeated exposure to friction, and is simple to manufacture. Other materials are also contemplated. The circular cross-section allows the smoothest bending of the rope 10 and the 13 mm diameter is greater than the diameter of the most common sized ropes 10 used for rescue, to minimize the risk of damage to the rope 10. The most commonly used diameters of rescue ropes 10 are 11 mm and 12.5 mm and therefore a 13 mm diameter would safely accommodate both of them while limiting weight and materials. A push button release pin allows for easy removal and replacement while remaining secure. In a variant, the second friction point 174 may be a swinging gate, a carabiner, a shackle, or some other removable component, having substantially rounded edges.

[0052] The apertures 126,136 of the sides 120,130 of the shell 100 may be of any size that is sufficiently large to accommodate the removable second friction point object 174, and sufficiently small as to not compromise the strength of the sides 120,130 of the shell 100, and of any shape with at least 180 degrees being rounded. The locations of the apertures 126,136 could be anywhere along the sides 120,130 of the shell 100 as long as they are sufficiently distanced from the bending edge 150 to allow for the rope 10 to completely bend up to 180 degrees over the removable second friction point object 174 before bending again over the bending point. In the preferred embodiment, the apertures 126,136 are circular and have diameters of approximately 13 mm. This is to accommodate a 13 mm pushbutton removable pin 200, as described above. In other embodiments, differently sized and shaped apertures 126,136 may be used. The apertures 126,136 may be located any distance from the spine 110 of the shell 100; in the preferred embodiment the apertures 126,136 are located approximately 25 mm at their center points from the spine 110. This distance provides a clearance between the inside edge of the removable pin 200 and the spine 110 of approximately 18 mm, which is adequate clearance for the rope 10 to be free running between the pin 200 and the spine 110 of the shell 100 when the rope 10 is disengaged. In addition, in the preferred embodiment the apertures 126,136 are located with their center points approximately 20 mm from the bending edge 150. The distance of 20 mm allows the rope 10 to bend completely around the removable pin 200 and straighten before bending the opposite direction around the bending edge 150, which maximizes the bending angles and thus the friction and tension reduction. Similar positioning of the apertures 126,136 may be used in the embodiments comprising alternate variants to the removable pin 200.

[0053] With regard to the attachment component 160, any component allowing for the attachment of the device 1 to the load holding device 20 is contemplated. In the preferred embodiment, the attachment component 160 is a reinforced aperture having an inside diameter of approximately 16 mm through the lowest portion of the spine 110 of the shell 100. This allows for any number of different types of connectors 30 (e.g., carabiners, screw links, soft attachments, etc.) to be used to attach the descent control device 1 to the load holding device 20.

[0054] The device 1 may be used as depicted in FIGS. 6A and 6B. In one embodiment, the device 1 may be used to perform a rescue of a person 50 stranded on a ski lift chair. When performing a rescue using the device 1, a rescuer 40 throws a rope 10 over a portion of the ski lift chair near the person 50 needing rescuing, with the result that both ends of the rope 10 are in possession of the rescuer 40. The rescuer 40 then attaches a load holding device 20, for example, a rescue seat, to one end of the rope 10, and inserts the other end of the rope 10 through the device 1, with the lower portion of the device 1 oriented upwards, and then attaches the load holding device 20 to the attachment component 160 of the device 1. See FIG. 6B. The rescuer then hauls on the free end of the rope 10; the rope 10 passes freely through the device 1 and the load holding device 20 is raised to where the person 50 needing rescuing is located. See FIG. 6B. The person 50 climbs into the load holding device; the combined weight of the load holding device 20 and the person 50 causes the device 1 to flip over, such that the lower portion of the device 1 is now pointed downwards. See FIG. 6A. The rescuer 40 then plays out the rope, which passes through the two friction points 172, 174 of the device, and slowly lowers the person 50 in a controlled manner. See FIG. 6A. Other uses for the device 1 are also contemplated by the present invention.

[0055] While the preferred embodiments of the present invention have been described, modifications can be made and other embodiments may be devised without departing from the spirit of the invention.