Load-minimizing, trolley arrester apparatus and method
A system comprising a cable held in suspension and a trolley traveling along the cable relies on a brake to control velocity and limit net downhill acceleration of the trolley. The trolley may include a brake pad positioned to contact the cable. At the downhill end of the ride, the lever actuating the brake is caught and lifted by a capture ring, thus relieving the braking load on the trolley. Also, the trolley engages a comparatively modest, second resistance mechanism, such as, for example, a system of springs, that gradually increases in resistance with distance of motion of the trolley thereagainst, bringing the trolley to a gradual halt at a rate to improve comfort of a rider and reduce acceleration forces (loads) on the trolley.
1. A method to minimize loads of arrest in a trolley, the method comprising:
providing a trolley having a frame and traveling along a cable suspended from supports proximate first and second ends of the cable;
initiating, proximate the first end of the cable, relative motion of the trolley with respect to the cable in response to a gravitational force;
applying, automatically, by the frame, acting on a brake, a braking force between the trolley and the cable to control the speed of the trolley along the cable;
approaching, by the trolley, the second end of the cable;
relieving, proximate the second end of the cable, the braking force during a continuation of the motion of the trolley with respect to the cable;
the relieving, further comprising engaging, by the frame, a capture element, reducing automatically the braking force applied by the frame, by pivoting about an axis orthogonal to a direction of the cable, thereby lifting a load carried by the trolley, in response to movement of the trolley; and
transferring a first portion of kinetic energy corresponding to the trolley into a deflecting element deflecting along the direction of the cable.
2. The method of claim 1 , wherein the trolley further comprises said frame, a sheave mount pivotably connected to the frame, and a sheave, rotatably mounted to the sheave mount to roll along the cable, the sheave and sheave mount suspending the frame below the cable.
3. The method of claim 2 , wherein applying the braking force comprises pivoting the frame with respect to the cable in a first direction.
4. The method of claim 3 , wherein relieving the braking force comprises pivoting the frame in a second direction, opposite the first direction.
5. The method of claim 4 , further comprising transferring a second portion of the kinetic energy corresponding to the trolley into lifting the frame and load suspended therefrom.
6. The method of claim 5 , wherein the deflecting element comprises at least one spring and an engagement member interfacing between the frame and the at least one spring.
7. The method of claim 6 , wherein the engagement member comprises said capture element pivotably suspended therefrom.
8. The method of claim 7 , wherein the frame comprises a guide extending away from the remaining portion of the frame and guiding the frame into an engagement with the capture element.
9. The method of claim 8 , wherein relieving further comprises lifting of the guide by the capture element along a path reflecting pivoting of the capture element.
10. The method of claim 9 , wherein the guide further comprises a yoke having a vertex and extensions forming an opening therebetween, the opening receiving the capture element and the extensions guiding the capture element toward the vertex.
11. The method of claim 1 , wherein applying the braking force comprises pivoting the frame with respect to the cable in a first direction.
12. The method of claim 1 , wherein relieving the braking force comprises pivoting the frame in a second direction, opposite the first direction.
13. The method of claim 1 , further comprising transferring a second portion of the kinetic energy corresponding to the trolley into lifting the frame and a load suspended therefrom.
14. The method of claim 1 , wherein the deflecting element comprises at least one spring and an engagement member interfacing between the frame and the at least one spring.
15. The method of claim 14 , wherein the engagement member comprises said capture element pivotably suspended therefrom to automatically control the frame position in response to continuing movement of the trolley along a direction of the cable.
16. The method of claim 15 , wherein the frame comprises a guide extending away from the remaining portion of the frame and guiding the frame into an engagement with the capture element.
17. The method of claim 15 , wherein relieving further comprises lifting of the guide by the capture element along a path reflecting pivoting of the capture element.
18. The method of claim 15 , wherein the guide further comprises a yoke having a vertex and extensions forming an opening therebetween, the opening receiving the capture element and the extensions guiding the capture element toward the vertex.
19. A method to minimize loads of arrest in a trolley, the method comprising:
providing a trolley traveling along a cable suspended from supports proximate first and second ends of the cable;
initiating, proximate the first end of the cable, relative motion of the trolley with respect to the cable in response to a gravitational force;
applying a braking force between the trolley and the cable to control the speed of the trolley along the cable;
approaching, by the trolley, the second end of the cable;
relieving, proximate the second end of the cable, the braking force to effect continuous motion of the trolley with respect to the cable;
the relieving, further comprising pivoting a capture element, about an axis orthogonal to the direction of the cable and in response to engagement thereof, by a guide portion of the frame;
the relieving, wherein the guide portion is formed as a yoke comprising extensions extending from a vertex thereof to capture the capture element therewithin and guiding the capture element toward the vertex;
the relieving further comprising lifting the guide portion by the capture element along a path corresponding to pivoting of the capture element; and
transferring a first portion of kinetic energy corresponding to the trolley into a deflecting element deflecting along a direction of the cable.
20. A method to minimize loads of arrest in a trolley, the method comprising:
providing a trolley traveling along a cable suspended from supports proximate first and second ends of the cable;
initiating, proximate the first end of the cable, relative motion of the trolley with respect to the cable in response to a gravitational force acting on a load applied to the trolley;
applying, automatically, by the frame, acting on a brake, a braking force between the trolley and the cable to control the speed of the trolley along the cable without human intervention therealong;
approaching, by the trolley, the second end of the cable;
maintaining continuing motion of the trolley along the cable by relieving, automatically, proximate the second end of the cable, the braking force;
the relieving, further comprising engaging, by the frame, a capture element, pivoting about an axis orthogonal to the direction of the cable, thereby reducing the braking force by applying a lifting force to the frame to relieve the load, in response to movement of the trolley against the capture element; and
transferring, a first portion of kinetic energy corresponding to the trolley into a deflecting element deflecting along a direction of the cable.