Patent ID: 6701650
Filing Date: 2004-03-09
Classification: B66D,G09F

Abstract:
A system for suspending a sign, comprising:a member for supporting said sign; a cord supporting said member; a motor unit having a reversible motor and a drum operated by said reversible motor, said motor unit engaging said cord such that said cord is wound around said drum for raising and lowering said sign; a switch, coupled to said motor unit, for providing first output control signals when an object contacts said switch; a motor control unit, coupled to said reversible motor, for controlling bi-directional rotation of said reversible motor, said motor control unit comprising: a detector, responsive to received actuating signals, for providing second output control signals; a sensor for detecting an overload condition on the reversible motor and for providing third output control signals; a forward-reverse relay; an on-brake relay; and a microprocessor, coupled to said switch, said detector, said sensor, said forward-reverse relay and said on-brake relay, said microprocessor receives said first, second and third output control signals and activates said forward-reverse and said on-brake relays to control said bi-directional rotation of said reversible motor; and a signal generating transmitter, physically separated from said motor control unit, for transmitting said actuating signals to said detector; wherein in response to said first output control signals, said motor control unit controls said reversible motor to reverse a first direction and operate in a second direction reversed to said first direction for a predetermined time period before stopping; wherein in response to said second output control signals, said motor control unit controls said reversible motor to operate in one of said first direction, said second direction and to terminate vertical motion of said sign; wherein in response to said third output control signals, said motor control unit controls said reversible motor to terminate vertical motion of said sign.