Backup apparatus for a hydraulic elevator brake control

A brake controller circuit for a braking device on a hydraulic elevator drive piston carrying an elevator car or a cable pulley, the braking device including a pair of brake arms for engaging and preventing movement of the hydraulic elevator drive piston, the drive piston being guided in a hydraulic elevator drive cylinder and acted upon by pressured fluid in the drive cylinder, the brake arms being rotatably mounted on the drive cylinder and moved by a brake drive actuated by the pressured fluid, the brake controller circuit comprising:

• an input means for connection to a source of electrical power;
• a normally open switch means and a coil connected in series with said input means;
• a brake control connected to said switch means for closing said switch means in response to an actuation signal to provide current flow in said coil from a power supply connected to said input means thereby actuating a brake drive to move brake arms into engagement with a hydraulic elevator drive piston;
• a buffer battery connected to said input means for receiving charging current from the power supply connected to said input means and for providing said current flow in said coil to actuate the brake drive in the absence of the power supply;
• and
• a capacitor connected to said input means for receiving charging current from the power supply connected to said input means and for providing said current flow in said coil to actuate the brake drive in the absence of both the power supply and said buffer battery.