Method and apparatus for controlling a transfer car from a remote station

Apparatus for controlling from a remote outside location, a transfer car adapted for travel in a path between limit positions in a closed operating space defined by protective walls and having a drive means, comprising:

• a rotary shaft extending through said wall,
• an inner drum fixed to said shaft within said space,
• an outer drum fixed to said shaft on the outside of said wall,
• a first cable length connected at one end to said transfer car and having the opposite end portion wrapped around said inner drum,
• a second cable length having one end wrapped around said outer drum, its outer end fixedly supported and having a fall therebetween supporting a weight element connected to a sheave that is raised and lowered in a vertical path by said cable fall
• whereby said shaft and inner and outer drums move in one direction when said first cable length is pulled by said transfer car and in the opposite direction when said second cable length is pulled by said weight element moving downward as said transfer car moves in the opposite direction, and
• means responsive to the position of said weight element for de-energizing said drive means when said transfer car reaches a predetermined position in said closed operating space.

A method for automatically halting the travel in forward and reverse directions at remotely adjustable predetermined limit positions, of a transfer car having a drive means and being located in a closed operating space within protective walls comprising the steps of:

• converting linear motion of said transfer car in its forward direction between said limit positions into rotation in one direction of a shaft extending through said wall
• operating a first switch means outside of said wall to stop said drive means, in response to a preselected number of turns of said shaft in said one direction whereby said transfer car is automatically halted at one of its predetermined limit positions,
• converting linear motion of said transfer car in its reverse direction between said limit positions into rotation in the opposite direction, of said shaft,
• operating a second switch means outside of said wall to stop said drive means in response to a preselected number of turns of said shaft in said opposite direction whereby said transfer car is automatically halted in its other predetermined limit position.