Rotary orthoptic instrument

Claim 1

A ROTARY ORTHOPTOR ADAPTED TO BE HAND-HELD COMPRISING: AN ELONGATED TUBULAR CASING OPENABLE AT ONE END AND INCLUDING A DETACHABLE CAP FOR CLOSING SAID END, THE OTHER END OF THE CASING TERMINATING IN A NECK HAVING A BORE THERETHROUGH LONGITUDINAL OF SAID CASING; AN ANNULUS MOUNTED AT THE OUTER END OF SAID NECK WITH IS AXIS TRANVERSE TO THE LONGITUDINAL AXIS OF THE CASING, THE WALL OF SAID ANNULUS BEING PIERCED WITH A HOLE THERETHROUGH COAXIAL WITH SAID BORE; A PRISM-HOLDING CYLINDRICAL BARREL ROTATABLY MOUNTED WITHIN THE ANNULUS WITH IS AXIS COAXIAL WITH THE AXIS OF THE ANNULUS; A CIRCULAR GEAR ON THE OUTER RIM OF THE BARREL FOR ROTATING THE LATTER WHEN THE GEAR IS ROTATED; A PRISM FASTENED IN THE BARREL FOR ROTATION THEREWITH; AN ELECTRICAL MOTOR FIXED IN THE CASING WITH ITS SHAFT LONGITUDINALLY ORIENTED THEREWITHIN; A DRIVE SHAFT ROTATABLY MOUNTED IN SAID BORE AND HAVING INNER AND OUTER ENDS, THE INNER END BEING ADJACENT THE MOTOR ROTOR SHAFT AND THE OUTER END PROTRUDING INTO SAID ANNULUS TO BE ADJACENT SAID CIRCULAR GEAR; DRIVE MEANS COUPLING SAID ROTOR SHAFT TO SAID INNER END; A GEAR FIXED ON SAID OUTER END AND ENGAGING SAID CIRCULAR GEAR; AND CONTROL MEANS FOR STARTING AND STOPPING SAID MOTOR, THE LATTER, WHEN ENERGIZED, CAUSING SAID PRISM TO ROTATE.