Elevator car brake

An elevator system comprising an elevator car, an elevator car hoisting apparatus which includes a hoisting rope and a braking apparatus for gripping the hoisting rope comprising:

• a) an inner brake shoe and an outer brake shoe, the shoes having facing braking surfaces and outer non braking surfaces, the inner brake shoe being stationarily mounted and the outer brake shoe movably mounted such that the outer shoe braking surface can move toward the inner shoe braking surface;
• b) a push plate having a first and second surface, the push plate connected in fixed relationship to the outer brake shoe and the first surface facing the brake shoes such that the first surface is closest to the non braking surface of the inner brake shoe;
• c) a compressible spring means positioned in between the push plate first surface and the non braking surface of the inner brake shoe such that when the push plate is being pushed on the second surface toward the inner brake shoe the spring means is compressed and the outer brake shoe moves away from the inner brake shoe and when the push plate is not being pushed on the second surface, the spring means expands and pushes the push plate away from the inner brake shoe and the outer brake shoe moves toward the inner brake shoe and grips the hoisting rope;
• and
• d) a motorized rotatable cam shaft having a cam surface positioned such that when the motor is engaged the motor rotates the cam shaft such that the cam surface pushes against the push plate second surface pushing the push plate toward the inner brake shoe, compressing the spring means and moving the brake shoes apart and when the motor is not engaged the cam shaft does not push on the push plate second surface.