The present invention relates to a ratchet screwdriver and, more particularly, to a ratchet screwdriver having a small size ratchet mechanism and providing enhanced operational convenience.
A conventional ratchet screwdriver can be coupled with a bit and can be adjusted to change the torque output direction to provide enhanced operational convenience. FIG. 8 shows a conventional ratchet screwdriver including a handle 1′ and a ratchet mechanism 2′ mounted to a front end of the handle 1′. The ratchet mechanism 2′ includes a shank 21′ at a front end thereof for coupling with a bit. A switch ring 22′ is mounted around the handle 1′ and can be rotated to adjust the torque output direction or free rotating direction of the shank 21′.
With reference to FIGS. 8 and 9, the handle 1′ receives a rod 11 in a center portion thereof. A compartment 12′ and a positioning member 13′ are mounted in a front end of the handle 1′. The ratchet mechanism 2′ has a diameter corresponding to that of the front end of the handle 1′. The ratchet mechanism 2′ is mounted around the rod 11′ and includes a ratchet gear 23′ coupled to the shank 21′ to move therewith. A catch 24′ is mounted to each of a left side and a right side of the ratchet gear 23′ and is biased by a spring 25′. The switch ring 22′ includes two pressing portions 221′ respectively pressing against the catches 24′. The switch ring 22′ further includes three positioning grooves 222′. When the positioning member 13′ is engaged in the middle positioning groove 222′, both of the catches 24′ engage with the ratchet wheel 23′ such that the shank 21′ can output a torque when rotated in either of the clockwise direction and the counterclockwise direction. When the positioning member 13′ is engaged in the left positioning groove 222′ or the right positioning groove 222′, only one of the catches 24′ engages with the left or the right positioning groove 222′, such that the shank 21′ can output a torque only when rotated in the clockwise or counterclockwise direction.
However, the compartment 12′ must be large enough to receive the ratchet mechanism 2′, resulting in a heavy ratchet screwdriver with a large front end. With reference to FIG. 10, to increase the use convenience, a plurality of bit holes 14′ is defined in a bottom face of the handle 1′ and windows 15′ are defined in an outer periphery of the handle 1′. Bits 3′ can be stored in the bit holes 14′, allowing easy carriage. Furthermore, the bits 13′ can be seen via the windows 15′, and the bit 3′ to be used can be moved out of the corresponding receptacle 14′ by a finger extending through the corresponding window 15′. However, users having fat fingers can not excess the bits 3′ via the windows 15′ having a small width, which is inconvenient to use.
USPTO Backgrounds
USPTO Backgrounds