Overspeed safely brake
An overspeed brake system is described to engage a safety cable and subsequent brake system once a threshold speed is reached. An overspeed safety kit may be installed on an elevator system or lift car, to identify a threshold speed and engage a brake lever to activate a braking system. One or more brake engagement devices may be applied to limit the force on the brake lever during a fall, thereby preventing potential damage to brake components, while cushioning the deceleration.
1. An overspeed brake system comprising:
a safety kit configured to engage a safety cable to slow a downward movement of a lift car when a threshold speed is reached;
a vertical shaft connected to and positioned beneath the overspeed safety kit, wherein the safety cable passes through the safety kit and along the vertical shaft;
a guide maintaining a position of the vertical shaft relative to the lift car, wherein the guide at least partially surrounds the safety cable and a circumference of the vertical shaft; and
a brake engagement device connected to the vertical shaft and a brake lever, wherein, upon engagement of the safety kit and the safety cable, the brake engagement device causes the brake lever to engage a brake system to stop the downward movement of the lift car, and wherein the brake engagement device reduces a force on the brake lever during an engagement of the brake system.
2. The system of claim 1 , wherein the vertical shaft is a telescoping shaft comprising an outer rail and an inner rail, which are slidably movable to adjust a length of the telescoping shaft.
3. The system of claim 2 , wherein the brake engagement device comprises a connecting element linking the outer rail and the inner rail of the vertical shaft via a shear pin, wherein the shear pin, prevents an adjustment to the length of the telescoping shaft until a breaking point of the shear pin is met.
4. The system of claim 1 , wherein the brake engagement device comprises a rod and spring positioned within one or more brackets attached to the vertical shaft.
5. The system of claim 4 , wherein the spring has a compression force of 70-120 pounds.
6. The system of claim 1 , wherein during a fall, the brake engagement device prevents the lift car from dropping more than six to seven inches before engaging the brake system.
7. The system of claim 1 , wherein the guide magnetically attaches to the lift car, and partially or fully surrounds the vertical shaft.
8. The system of claim 1 , wherein the safety cable is 8, 9, or 10 mm in diameter.
9. The system of claim 1 , wherein the safety kit comprises an overspeed governor to identify the threshold speed and engage the safety cable.
10. The system of claim 1 , wherein the safety kit further comprises one or more controls for manually activating the safety kit.
11. The system of claim 1 , wherein the safety kit is configured to disengage the safety cable upon an upward movement of the lift car.
12. An overspeed braking method comprising:
guiding a safety cable along a vertical path using a safety kit and a vertical shaft connected to and positioned beneath the safety kit, wherein the safety cable passes through the safety kit and along the vertical shaft;
engaging the safety cable to slow a downward movement of a lift car when the safety kit detects a threshold speed, wherein the safety kit configured to engage the safety cable;
maintaining a position of the vertical shaft relative to the lift car using a guide that at least partially surrounds the safety cable and a circumference of the vertical shaft and
upon engagement of the safety cable, activating a brake engagement device connected to the vertical shaft, wherein the brake engagement device causes a brake lever to engage a brake system to stop the downward movement of the lift car, and wherein the brake engagement device reduces a force on the brake lever during an engagement of the brake system.
13. The method of claim 12 , wherein the vertical shaft is a telescoping shaft comprising an outer rail and an inner rail.
14. The method of claim 13 , further comprising linking an outer rail and an inner rail of the telescoping vertical shaft with a connecting element such that adjustments to the length of the vertical shaft is prevented until a breaking point of the connecting element is met.
15. The method of claim 12 , wherein the guide magnetically attaches to the lift car.
16. The method of claim 12 , wherein the brake engagement device engages a brake detection system such that the lift car drops no more than seven inches.
17. The method of claim 12 , further comprising identifying the threshold speed for engaging the safety cable using an overspeed governor.
18. The method of claim 12 , further comprising manually activating the safety kit to engage the safety cable.
19. The method of claim 12 , further comprising disengaging the safety cable upon an upward movement of the lift car.