초록 ▼

In a theft deterrent security device for trailers and like equipment having a dual chamber brake system that operates with compressed air an electro mechanical device, such as servomotor or a solenoid, is mounted within the interior of the dual chamber brake system housing in which an expanded high

In a theft deterrent security device for trailers and like equipment having a dual chamber brake system that operates with compressed air an electro mechanical device, such as servomotor or a solenoid, is mounted within the interior of the dual chamber brake system housing in which an expanded high spring-rate spring biases and keeps a brake actuator in a locked "brakes on" position when there is no compressed air supplied to the system. The servo motor or solenoid is connected to members which in one position mechanically block movement of the brake actuator to prevent its normal operation even when there is compressed air available to the system and the high spring-rate spring is compressed. In a second position of the servo motor or solenoid the members do not block movement of the brake actuator and thereby allow normal operation of the brakes. The servo motor or solenoid is responsive to coded signals which control its position and which are normally available only to an authorized user. Alternatively, a remote controlled valve is included in the interior of the dual chamber brake system to block supply of compressed air to the chamber having the high spring-rate spring.

대표청구항 ▼

1. Apparatus for locking and unlocking the brake actuator of a dual chamber brake system that operates with compressed air, wherein the dual chamber includes a brake actuator in a first chamber and a high spring-rate spring in a second chamber, the brake actuator being movable in the axial direction

1. Apparatus for locking and unlocking the brake actuator of a dual chamber brake system that operates with compressed air, wherein the dual chamber includes a brake actuator in a first chamber and a high spring-rate spring in a second chamber, the brake actuator being movable in the axial direction to apply and release the brakes of the brake system; in the absence of compressed air the high spring-rate spring expanding to bias and keep the brake actuator in an axially forward position locking the brakes of the brake system, and wherein when there is compressed air in the second chamber the high spring-rate spring is compressed and allows retraction of the brake actuator from its forward position to unlock the brakes, the apparatus comprising:electro mechanical means responsive to a first coded signal for locking the brake actuator into the forward position preventing its movement axially, whereby the brakes are locked independently of the status of expansion or compression of the high spring-rate spring, the electro mechanical means being responsive to a second coded signal for unlocking the brake actuator thereby unlocking the brakes, said electro mechanical means being mounted within the first chamber of the dual chamber brake system, and said electro mechanical means including a servo motor operatively associated with a receiver decoder for receiving said coded signals, the servo motor having a first rotary position in one of clockwise and counterclockwise direction responsive to the first coded signal and a second rotary position in the opposite direction responsive to the second coded signal, locking means for mechanically preventing axial movement of the brake actuator away from its locked forward position in the first rotary position of the servo motor and for freeing the brake actuator for axial movement in the second rotary position of the servo motor, and connecting means for operatively connecting the servo motor with the locking means, and said brake actuator having a serrated portion, the locking means including a pair of members having serrated portions, and wherein in the first rotary position of the servo motor the serrated portions of the members engage the serrated portion of the brake actuator.