Obstruction detection means for material handling device

Claim 1

In an automatic storage system for material-units which comprises a bin structure including an aisle with bins disposed at multiple stations along the aisle, a stacker vehicle movable in the aisle and including a lateral platform movable laterally of the stacker vehicle for transferring a material-unit between the vehicle and a selected bin, a power operator connected with the lateral platform, and controlling the operation thereof and a probe means adjacent the platform and rigidly mounted to said platform capable of controlling said power operator comprising: a probe assembly pivotally mounted on and as a part of said probe means adapted to be pivotally moved through a portion of the selected bin, the axis of swing formed by the pivot mount is fixed relative to the probe means a first switch rigidly mounted on and a part of said probe means and electrically connected to said power operator and adapted to enable operation of said power operator when said bin is unobstructed, a second switch rigidly mounted on and a part of said pivotally mounted probe assembly and electrically connected to said power operator and adapted to prevent operation of said power operator when said bin is obstructed, a switch actuating probe element rigidly mounted on one end of and a part of said pivotally mounted probe assembly and biased out of contact with but capable of being forced into contact with and thereby actuate said second switch and prevent operation of said power operator when said bin is obstructed and said obstruction is contacted by said probe element during the pivotal movement of said probe assembly, a switch actuating surface on the other end of said probe assembly capable of contacting and thereby actuating said first switch to enable the operation of said power means when said probe assembly completes its pivotal movement through said selected bin without encountering an obstruction, actuating means coupled with the probe assembly to cause pivotal movement thereof into the selected bin, said actuator comprising an electrical magnet with reciprocal armature and motion transmitting means operatively connected between said armature and said probe assembly for causing pivotal motion thereof in response to movement of said armature, means for energizing said electromagnet previous to energizing said power operator, whereby said probe assembly is first pivotally actuated into said selected bin and said power operator is de-energized to prevent operation thereof when said movable probe element engages an obstruction in said bin and said power operator is energized to enable operation thereof when said probe element moves through a portion of said selected bin and completes its pivotal movement without engaging an obstruction.