Abstract: A reversible ratchet mechanism comprises a cylindrical head having axially a center hole in which the cylindrical body of a torsion transmitting element is rotatably disposed. The cylindrical body is provided axially with a V-shaped slot in which a V-shaped pawl is fastened pivotally such that two arms of the V-shaped pawl form an angle smaller than the V-shaped slot. Two arms of the pawl are provided respectively on the top end thereof with a plurality of pawl teeth engageable with a plurality of axial teeth provided on an inner wall surface of the center hole of the cylindrical head. Fastened pivotally to the cylindrical body is a round rod which is located between the two arms of the pawl and is provided at the midsegment thereof with a spring-biased pin capable of urging either one of the two arms of the pawl depending on the angular position of the round rod, thereby resulting in the engagement of the pawl teeth with the axial teeth of the center hole of the cylindrical head.

Abstract: An improved hammer is composed of a handle and a head fastened to the one end of the handle. The head is provided centrally with a hole for receiving therein a threaded rod of the handle. The hole of the head is provided in the outer end thereof with a threaded area. Located at the side opposite to the threaded area is a polygonal area having a section polygonal in shape and greater than that of the threaded area. In addition to the threaded rod engageable with the threaded area of the head, the handle further comprises a casing of plastic material covering entirely the threaded rod and filling the gap formed between the threaded rod and the polygonal area of the hole of the head.