Automatically controlled mirror

Claim 2

An automatic control unit for the coordinated operation of each of two external tractor/trailer mirrors said automatic control unit comprising: pivoting means for independently pivoting each mirror in response to predetermined control signals; encoding means for generating and sending said control signals to the pivoting means, said encoding means being responsive to a turning angle of the tractor with respect to the trailer, said encoding means further including; an optical encoder which cooperates with an extendable cable whereby, during a turning operation, said cable is extended in proportion to the turning angle, with said optical encoder generating control signal pulses in response to the length of the extended cable; and switch means for selectively activating said pivot means in response to the direction of the turn whereby the direction of pull of said extendable cable respectively engages the switch means in order to pivot one of the two mirrors, the device thus providing a constant view of the rear of said trailer at all times while making a turn or backing.

Claim 3

A system according to claim 1, wherein both the left and the right mirrors on the tractor are mounted on two brackets, one at the top and one at the bottom of each so as to allow each mirror to swivel, further including a stepper motor affixed to a gear box and wherein the shaft of the gear box is affixed to the top shaft of each mirror.

Claim 4

A system according to claim 1, wherein a control panel which is accessible to the driver including an electrical switching means, a jog left and jog right switch for each mirror, which are used for initial adjustment and for panning an area for hazards; wherein the control panel contains stepper motor controllers and also means for overriding the encoder.

Claim 5

A system according to claim 1, wherein the encoder means comprises an encoder box and wherein the optical encoder takes analog movements from the extendable cable and converts them to digital signals which correspond to the amount of in or out movement of the extendable cable wherein said pivoting means comprises stepper motors, and said digital signals are fed to stepper motor controllers, which in turn drive the stepper motors; wherein the extendable cable is a spring loaded stranded metal cable extending from a take up reel and is pulled around a pulley including first and second layers; wherein one layer is turned by the movement of the stranded metal cable and on the second layer rides a v-belt which is used to turn the optical encoder and the stranded metal cable is pulled around another pulley and exits the encoder box and is hooked to the center of the front of the trailer; wherein the switch means comprises two micro switches which are located inside the encoder box at the stranded metal cable exit and cooperate with two exit rollers which are moved as the stranded metal cable is forced left or right because of a left or right turn of the tractor and thereby give directions as to which stepper motor to turn.