Control system for a platform lift apparatus

摘要

A platform lift apparatus moves objects vertically within a structure such as between floors of a residential or commercial structure. A drive train comprises a rotatable shaft having plural lift drums and a motor operatively coupled to the shaft to cause selective rotation thereof. Each of the lift drums has an associated lift tether coupled thereto and wound thereon. A platform is coupled to respective ends of the lift tethers to suspend the platform from the platform receiving portion of the main body. The platform is selectively movable by operation of the drive train to travel vertically relative to the main body and is substantially nested within the platform receiving portion when at an uppermost point of travel. At least one load sensor is operatively coupled to at least one of the lift tethers to provide a load signal corresponding to load on the associated one of the lift tethers.

主权项

1. A platform lift apparatus, comprising;
a main body having a platform receiving portion and a utility portion; a drive train substantially contained within the utility portion of the main body, the drive train comprising a rotatable shaft having plural lift drums and a motor operatively coupled to the shaft to cause selective rotation thereof, each of the lift drums having an associated lift tether coupled thereto and wound thereon; a platform coupled to respective ends of the lift tethers to suspend the platform from the platform receiving portion of the main body, the platform being selectively movable by operation of the drive train to travel vertically relative to the main body, the platform being substantially nested within the platform receiving portion of the main body when at an uppermost point of travel; at least a first load sensor operatively coupled to a first one of the lift tethers and a second load sensor operatively coupled to a second one of the lift tethers, the first load sensor providing a first load signal corresponding to load on the first one of the lift tethers and the second load sensor providing a second load signal corresponding to load on the second one of the lift tethers; and a control circuit operatively coupled to the motor and the first and second load sensors, wherein the control circuit takes at least one corrective action if a difference between at least the first and second load signals exceeds a predetermined load setting; wherein the control circuit causes the platform to travel upward by driving the motor to rotate the shaft in a first direction to wind the lift tethers onto the respective lift drums and causes the platform to travel downward by driving the motor to rotate the shaft in a second direction to unwind the lift tethers from the respective lift drums.