Scissor lift descent control systems and methods

A lift device comprising:

• a base having a plurality of wheels;
• a battery arranged within the base;
• a retractable lift mechanism having a first end coupled to the base and being moveable between an extended position and a retracted position;
• a work platform configured to support a load, the work platform being coupled to and supported by a second end of the retractable lift mechanism;
• a linear actuator configured to selectively move the retractable lift mechanism between the extended position and the retracted position, the linear actuator having an electric motor;
• an electromagnetic brake coupled to the linear actuator and movable between an engaged position and a disengaged position;
• and
• a manual release device configured to manually move the electromagnetic brake from the engaged position to the disengaged position, wherein the electric motor of the linear actuator is biased into a shunted configuration, so that, in the event of the battery being fully discharged or a power failure and the electromagnetic brake is moved into the disengaged position by the manual release device, the electric motor acts as a generator to electromagnetically reduce a rotational speed of a rotor of the electric motor and, thereby, reduce a speed at which the retractable lift mechanism is moved toward the retracted position.

A lift device comprising:

• a base having a plurality of wheels;
• a battery arranged within the base;
• a retractable lift mechanism having a first end coupled to the base and being moveable between an extended position and a retracted position;
• a work platform configured to support a load, the work platform being coupled to and supported by a second end of the retractable lift mechanism;
• a linear actuator configured to selectively move the retractable lift mechanism between the extended position and the retracted position, the linear actuator having an electric motor;
• an electromagnetic brake coupled to the linear actuator and movable between an engaged position and a disengaged position;
• and
• a manual release device configured to manually move the electromagnetic brake from the engaged position to the disengaged position, wherein the electric motor of the linear actuator is configured such that, in response to the battery being fully discharged or a power failure, the electric motor acts as a generator to electromagnetically reduce the electric motor and, thereby, reduce a speed at which the retractable lift mechanism is moved toward the retracted position.