Mobile storage unit with holding brake and single status line for load and drive detection
The present invention is a mobile storage unit including an electric motor operably connected to wheels movably supporting the unit, and a motor brake operably connected to the electric motor. A shaft is rotatably mounted to the unit and supports the wheels on which the unit moves, and is engaged with an electric motor. The electric motor operates to rotate the shaft and the wheels to move the unit in the desired direction. Upon deactivation of the motor, the motor brake, which is also engaged with the shaft, operates to prevent any further rotation of the shaft to maintain the mobile storage unit in a specified location regardless of deflection of the surface on which the storage unit is positioned.
1. A mobile storage unit comprising:
a) a housing adapted to receive and retain items therein;
b) a shaft rotatably secured to the housing;
c) at least one wheel interconnected with the shaft for rotation therewith;
d) an electric motor operably connected to the shaft to rotate the shaft; and
e) a motor brake operably connected to the shaft,
wherein the motor brake is operably connected to a motor brake and status controller, and wherein the motor brake and status controller is operably connected to a main controller via a single status line.
2. The storage unit of claim 1 wherein the motor brake is connected to the electric motor.
3. The storage unit of claim 1 wherein the motor brake defines a recess therein within which the shaft is received.
4. The storage unit of claim 3 wherein the recess is positioned in alignment with a central opening extending through the electric motor in which the shaft is positioned.
5. The storage unit of claim 1 wherein the motor brake and status controller is configured to provide status signals to the main controller along the single status line concerning the connection of the motor brake and status controller to a load and to the main controller.
6. The storage unit of claim 1 wherein the motor brake is deactivated when a power supply is connected to the motor brake.
7. The storage unit of claim 1 wherein the motor brake is activated when a power supply is disconnected from the motor brake.
8. A method for controlling the movement of a mobile storage unit in a mobile storage unit system, the method comprising the steps of:
a) providing a storage unit including a housing adapted to receive and retain items therein, a shaft rotatably secured to the housing, at least one wheel secured to the shaft for rotation therewith, an electric motor operably connected to the shaft to rotate the shaft, and a motor brake operably connected to the shaft;
b) connecting a power supply to the motor brake to allow rotation of the shaft; and
c) providing a status signal from a motor brake and status controller to a main controller along a single status line connecting the motor brake and status controller to the main controller after connecting the power supply.
9. The method of claim 8 further comprising the step of connecting the power supply to the electric motor to rotate the shaft simultaneously with connecting the power supply to the motor brake.
10. The method of claim 8 further comprising the step of disconnecting the power supply to the motor brake to prevent rotation of the shaft after connecting the power supply to the shaft.
11. The method of claim 10 further comprising the step of disconnecting the power supply from the electric motor simultaneously with disconnecting the power supply from the motor brake.
12. The method of claim 8 wherein the step of providing the status signal comprises:
a) sending a signal concerning the status of a load connection to the motor brake and status controller along the single status line; and
b) sending a signal concerning the status of a connection between the motor brake and status controller and the main controller.
13. The method of claim 8 further comprising the step of altering the connection of the power supply to the motor brake in response to the signal sent from the motor brake and status controller to the main controller along the single status line.