CASTOR LOCK ASSEMBLY AND WHEEL CARRIAGE

PURPOSE: To prevent the swivel of casters and the rotation of wheels simultaneously by providing, at both ends of a frame in the form of a 'T' bar, locking rings placed on the tops of the wheels of the swivel casters, and causing the locking rings to be locked to and unlocked from the wheels by the vertical swing of the frame. CONSTITUTION: A wheeled carriage 10 has two each of swivel casters 40 and fixed casters provided at each of the four corners of the lower surface of a chassis 11, and the swivel casters 20 are freely locked by a caster locking assembly 30. The locking assembly 30 has a frame 31 taking the form of a 'T' bar with locking rings 43, 44 provided at both ends of a cross bar 35 extending in the transverse direction thereof. A cam follower 45 is secured to a bar 32 extending in the vertical direction of the frame 31, and a cam 55 abutting thereto is secured to one end of a cam shaft 50. The portion of a pedal 61 at the end of the cam shaft 50 is operated to rotate the cam 55 to lock and unlock the locking rings 43, 44 to and from wheels 25 via the frame 31.