PURPOSE: To obtain the dental treatment chair suitable not only for general adults but for the aged, children, etc., as well by constituting the chair of a base part back sheet fixed with a freely luffable back sheet mounted to the dental treatment chair and an upper movable back sheet mounted freely advanceably and retreatably in the upper part of this sheet.
CONSTITUTION: The upper movable back sheet 2 can be moved to a proper position if an operator presses one hand to the upper back sheet 2 and presses the sheet vertically as shown by arrow Y while pressing a movable adjustment button 34 with the finger of the other hand. The upper movable back sheet 2 can be fixed to this point when the operator detaches the finger of the one hand from the movable adjustment button 34 in a suitable position. A stopper 33 consisting of a projecting body fits into a stopper groove 23 hollowed on the surface of a sliding bar 21 by returning a spring 37 when the sliding bar 1 is inserted into a through-hole 38 of a sliding guide 31. The upper movable back sheet 2 is then fixed in a specified position.
NIIJIMA TOSHIYUKI
NOGUCHI KUNITOSHI