Patent Application
20130087981
1. Field of the Invention
The present invention relates to a tool bit assembly and more particularly to a tool bit assembly for quickly alternating bits.
2. Description of Related Art
A conventional hand tool with connecting shaft includes a connecting shaft. The connecting shaft has a retaining hole opened at one end thereof A positioning bead is extruded on the inner wall of the retaining hole of the connecting shaft. A screw bit has a notch corresponding to the positioning bead and defined on the outer periphery thereof Under this arrangement, when a user wants to assemble the screw bit to the connecting shaft, the user inserts one end of the screw bit into the retaining hole and the positioning bead is engaged with the notch of the screw bit at the retaining hole, so that the screw bit is assembled to the connecting shaft; when the user wants to remove the screw bit from the connecting shaft, the user holds the connecting shaft and pulls out the screw bit from the retaining hole. However, the conventional hand tool with connecting shaft has two shortcomings as following:
First, when the oil is attached to the user's hand, it is difficult to pull out the screw bit from connecting shaft for alternating the other screw bit.
Second, although the positioning bead is engaged with the notch of the screw bit, the positioning bead might not be engaged with the notch of the screw bit completely and firmly so that the screw bit at the retaining hole of the connecting shaft might not be stable to operate.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional. Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
The main objective of the present invention is to provide an improved tool bit assembly.
To achieve the objective, a tool bit assembly for quickly alternating bits comprises a connecting shaft, a block, a positioning bead and a cover, a first groove defined on one side of the outer periphery of the connecting shaft, a second groove defined on another side of the outer periphery of the connecting shaft, a restricting member engaged with the second groove, a retaining hole axially opened at one end of the connecting shaft, a magnet and a first spring received in the retaining hole, the magnet located between the first spring and an opening of the retaining hole, a third groove opened on the bottom of the first groove, the third groove communicating with the retaining hole, the block mounted in the first groove and the shape of the block corresponding to the first groove, the block having a restricting part corresponding to the second groove, a fourth groove defined on one side of the block, the connecting shaft having a fifth groove corresponding to the fourth groove of the block, the fourth groove and the fifth groove formed a circle opening above the third groove and communicating with the third groove so that the positioning bead is moveably received in the space formed with the fourth groove, the third groove and the fifth groove, a cover encircling the connecting shaft, the cover having an incline surface at one end, the incline surface formed on the inside periphery of the cover and inclining toward an opening of the cover for compressing the positioning bead, a restricting ring mounted on the inside periphery of the cover, the connecting shaft encircled by a second spring, the second spring mounted between the connecting shaft and the cover, one end of the second spring abutting against the restricting member and the restricting part, another end of the second spring abutting against the restricting ring.
Under this arrangement, when a tool bit with a notch is inserted into the retaining hole by a user, the positioning bead is compressed toward the retaining hole by the incline surface of the cover and the positioning bead engages with the notch of the tool bit, thereafter the cover is positioned via the elasticity of the second spring so as to keep the positioning bead engaging with the notch of the tool bit, and the tool bit is inserted into the retaining hole of the connecting shaft firmly; when the user wants to release the tool bit from the retaining hole of the connecting shaft, the user moves the cover axially relative to the connecting shaft and the incline surface of the cover moves away from the positioning bead, thereafter the positioning bead moves up from the retaining hole so as to disengage with the notch of the tool bit and the magnet pushes the tool bit to release the tool bit from the connecting shaft via the recovering force of the first spring to push the magnet, furthermore after the positioning bead disengages with the notch of the tool bit, the magnet attracts the tool bit for preventing the tool bit from dropping down.
Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.
Referring to
Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
