Dental chair with a switch actuating arm rest

Claim 1

A dental chair comprising: a. a back unit, a seat unit and a base unit each of which is operatively associated with a corresponding reversible motor means and wherein the back unit is pivotally movable relative to the seat unit, the seat unit is longitudinally tiltable relative to the base uniT and the base unit is vertically adjustable, b. an arm rest pivotally mounted on said back unit for manual pivotal movement to a first position extended upwardly along one side of said back unit and to a second position projected forwardly from said one side of the back unit, and c. an electrical control circuit for said motor means including a single switch device on said back unit having an actuating lever movable, in response to the movement of said arm rest to the first position therefor to a first circuit closing position to simultaneously operate said motor means in one direction of rotation to move said units to relative positions providing for the support of a person in an upright seated position, and movable, in response to the movement of the arm rest to said second position therefor to a second circuit closing position to simultaneously operate said motor means in an opposite direction of rotation to move said units to relative positions providing for the support of a person in a reclined position, and d. normally closed limit switches in said control circuit corresponding to said motor means and mounted on the chair for engagement by corresponding ones of said units to automatically stop said motor means to define said relatively moved positions of said units.