Abstract: A device for adjusting the position of a drive element for automatically opening and closing a sliding door which is automatically opened upon stepping on of a mat switch by a customer who intends to enter a store and is automatically closed upon releasing of the mat switch by the customer who entered the store. The drive element of the automatically opening and closing sliding door is adjusted by merely once manually opening and closing sliding door. The drive elements such as limit switches are slidably mounted, not on the sliding door but on an endless wire such as an endless belt. Thus, adjusting the drive element so that the sliding door may stop just upon completely opening or closing of the door when mounting such an automatic sliding door can be rapidly and readily accomplished.

Abstract: An electric contact actuating mechanism for an automatic door comprising a rotary operator having a rotary shaft and interlocked with a door-driving device, a desired number of working arms fitted on the rotary shaft of the rotary operator so that they may be separately rotated relative to the rotary shaft when the rotational force applied thereto exceeds a predetermined value, working elements mounted on the respective working arms, responsive switch elements provided on a base member so that they may be actuated when the working elements approach thereto, and a stopper provided on the base member for stopping the rotation of the working arms; and thereby enabling the adjustment of its electric contact to complete by one shuttling operation of the door when installed.