| 摘要 |
A zipwire trolley 1 having a plurality of zipwire engaging rollers 7,8, a swivelable brake block 12 adjacent to one of the rollers, the brake block having a zipwire-engaging cam surface 15 by which the roller can be at least partially lifted off the zipwire 9 when the trolley is moving in a rearward direction (figure 3), the cam surface being disposed between a pair of sidewalls 16,17 and acting as a brake surface adapted to grip the zipwire as the block swivels in response to rearward movement of the trolley, thereby preventing or inhibiting further rearward movement of the trolley by transferring the weight of the user of the trolley from the roller to the brake block. The brake block may also be adjustable to cope with different size zipwires or wearing of the block (figure 6). The brake block may contain a lever arm (figure 7, 26) to disengage the brake block to allow rearward movement. |
