513,081. Locks. PARKES & SONS, Ltd., J., BUTTER, F. J., and FRYER, E. C. March 31. 1938, No. 9806. [Class 44] The transversely slidable tumbler C of a lock is provided with tongues c<1>, c<2>, c<3>, c<4> by which it is guided on the bolt, a tension spring F engaging the tongues c<3>, c<4> and holding them normally in register with tongues e, e', parallel thereto, bent up from a plate E secured to the bolt at b<3>. Movement of the tumbler, by the key in either direction, Fig. 3, will move the tongues e<1>, c', e, c<4> out of register against the force of the spring F. In a modification, pivoted spring- urged arms bear against the tongues. In further modifications, a compression coil spring or a U-shaped leaf spring may replace the spring F.