Drafting machine

Claim 1

A DRAFTING HEAD SURFACE COMPRISING A DRAFTING HEAD SUPPORT MOVABLE IN ALL DIRECTIONS ON THE SURFACE OF A DRAWING BOARD WHILE MAINTAINING A LINE OF SAID SUPPORT IN PARELLEL RELATION AT ALL TIMES, A SHAFT HAVING A BORE ROTATABLY MOUNTED ON SAID SUPPORT, A DRAFTING HEAD PLATE FIXED TO SAID SHAFT, A CUP HAVING A BORE IN THE BOTTOM THEREOF MOUNTED ON SAID SHAFT IN FIXED RELATION, A PAWLOPERATING WHEEL HAVING A BOSS PROJECTING THEREFROM ROTATABLY MOUNTED ON SAID CUP, SAID CUP AND SAID BOSS OF SAID PAWL-OPERATING WHEEL BEING PROVIDED WITH SLOTS THEREIN, A DRAFTING HEAD ROTATING KNOB MOUNTED ON SAID CUP, A CONTROL BAR POSITIONED IN SAID CUP AND EXTENDING DIAMETRICALLY INTO THE SLOTS OF SAID CUP AND BOSS OF SAID PAWLOPERATING WHEEL, A LEVER PIVOTALLY MOUNTED IN SAID BORE OF SAID SHAFT AND BEING CONNECTED TO SAID CONTROL BAR, A LINK MOUNTED IN SAID DRAFTING HEAD PLATE AND CONNECTED TO SAID LEVER, AND A PAWL OPERATIVELY CONNECTED TO SAID LINK WHEREBY SAID PAWL CAN BE OPERATED BY ROTATION OF SAID PAWL-OPERATING WHEEL, A DISC MOUNTED ON SAID DRAFTING HEAD SUPPORT FOR COOPERATION WITH SAID PAWL TO RETAIN SAID DRAFTING HEAD IN FIXED RELATION TO SAID DRAFTING HEAD SUPPORT, A CAM PUSH-BUTTON MOUNTED ON SAID DRAFTING HEAD OPERATING KNOB HAVING ITS CAM SURFACE COOPERABLE WITH SAID LEVER IN ONE DIRECTION, AND A SPRING OPERABLE TO MOVE SAID PAWL INTO OPERATIVE POSITION WITH RESPECT TO SAID DISC.