596,589. Adjustable seats. WARREN McARTHUR CORPORATION. Jan. 2, 1945, No. 185. Convention date, Nov. 19, 1943. [Class 52(ii)] A seat 11 comprises a longitudinally adjustable seat frame 21 supported on a stretcher 18 together with locking means for securing the seat frame in the adjusted position. The locking operation is effected by a pin and slot engagement, the pin being engaged and disengaged by crank arms 52 attached to collars 51 secured to a crank shaft 44 rotatably mounted in brackets 43 and operated by the rotary motion of the handle 45. The seat frame 21 having slotted plates 24, 25 through which the crank shaft passes, is supported on rollers 58 mounted on the plug 56 and positioned by a collar 54. The stretcher 18 together with the plug 56, the brackets 43 and pin-supporting brackets 28 are mounted on a transverse rod 29. Perforated plates 34 forming the slots of the pin and slot coupling are secured to the slotted plates 24, 25. Springs 61 tension the seat and facilitate adjustment.