Load-minimizing, trolley arrester apparatus and method

Abstract

A system comprising a cable held in suspension and a trolley traveling along the cable relies on a brake to control velocity and 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.

1 . A method to minimize impulse 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 during a continuation of the motion of the trolley with respect to the cable; 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 a 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 a rider 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 a capture element pivotably suspended therefrom. 
     
     
         8 . The method of  claim 7 , wherein the frame comprises a guide portion 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 the 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 rider 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 a capture element pivotably suspended therefrom. 
     
     
         16 . The method of  claim 15 , wherein the frame comprises a guide portion 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 the 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 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 during a continuation of the motion of the trolley with respect to the cable;   transferring a portion of kinetic energy corresponding to the trolley into a deflecting element deflecting along the direction of the cable; and   resolving, by the deflecting element, momentum received from the trolley, in a continuously variable direction beginning at a first direction transferring substantially no momentum along the cable and ending at a second direction transferring substantially all momentum along the direction of the cable.   
     
     
         20 . A method to decelerate a trolley, the method comprising:
 controlling speed of a trolley descending on a cable by applying a braking force;   arresting the trolley by
 capturing a guide portion of the trolley by a capture element pivotably suspended from the cable, 
 relieving the braking force by lifting the guide portion according to the pivoting of the capture element, and 
 converting a portion of kinetic energy corresponding to the trolley into deflection of a spring.