| 摘要 |
699,730. Seats. HITTER CO., Inc. Jan. 15, 1953 [May 7, 1952], No. 1243/53. Class 52(ii) A dental &c. chair is provided with arm rests pivotal to a number of in-use positions and an out-of-use position; the pivotal movement comprising clutch surfaces and means being provided for clamping releasably such clutch surfaces. The arm rests, as shown, each comprise an arm surface 55 carried by an arm 53 mounted on an axis from a bracket 37 rigidly secured to the chair. The said axis comprises clutch members 61, 65 and a bolt 67 with a spherical head 69 seated in clutch member 65 and provided with a split nut 73 which may be tightened on the bolt by a screw 75. Contained within and pivoted at 85 to each arm 53 is a lever 83 which has a cam projection 105 coacting with a transverse groove in the face 79 of the nut 73. The lever 83 has at its upper end a handle 91 provided with a notch 99 engageable by a spring 101. Movement of the lever 83 in a clockwise direction by means of the handle 91 against the restraining action of of the spring 101 and notch 99 causes the projection 105 with its engagement with the nut 73 and the bolt 67, to move to separate the clutch members 61, 65 and so permit the arm rest to be moved into an adjusted position such as those shown in dotted lines in Fig. 2. |
