A multi-usage electric tool with angle-changeable grip and a plurality of interchangeable tool heads, comprising:
- a grip, an upper end of the grip being disposed with a power socket for connecting with an external power source, a portion of the grip being formed as a stem, a lower end of the grip being formed with an inclined face;
- a main body, an upper end of the main body being formed with an inclined face corresponding to the inclined face of the grip, the main body being movably connected with the grip at a central portion, whereby the grip is rotatable relative to the main body to change an angle between the grip and the main body, a power motor being installed in the main body, a driving shaft of the motor extending out of the main body, and an engaging mechanism being disposed at a lower end of the main body;
- an electric tool head, a lower end of the tool head being replaceably connected with an electric tool, a power transmission mechanism being received in the tool head, an upper end of the tool head being disposed with an engaging mechanism for assembling with or disassembling from the engaging mechanism of the main body, the power of the driving shaft being transmitted by the power transmission mechanism to the lower end of the tool head;
- and
- a removable locking ring that extends around an end of the main body to which the tool head is to be secured,
- wherein an outer periphery of the lower end of the main body includes a plurality of fixing blocks that extend radially outwardly therefrom, each of said fixing blocks having an engaging surface that faces away from the tool head when the tool head is secured to the main body by the locking ring,
- wherein an inner wall of the locking ring includes fixing slope plates extending radially inwardly therefrom, a number of said fixing slope plates equaling a number of said fixing blocks and a lower side of each fixing slope plate that faces the tool head when the tool head is secured to the main body by the locking ring being formed with an inclined face, said inclined face being arranged to tightly engage an upper end face of a respective fixing block when said locking ring is fitted over the main body such that said fixing plates pass through gaps between said fixing blocks, and then are rotated to cause respective said inclined faces and engaging surfaces to engage each other,
- wherein said tool head has extending therefrom a plurality of clamp claws having outwardly extending projections, said clamp claws being positioned in said gaps between the fixing blocks as the tool head is brought into engagement with the main body, and secured in the gaps upon rotation of the locking ring,
- wherein engagement of said inclined faces of the fixing plates and said engaging surfaces of the fixing blocks causes an end of the locking ring to press against said outwardly extending projections to secure the main body on the tool head, and
- wherein at least several clamp claws include radially extending stopper ribs that engage vertical sides of the fixing plates for preventing the locking ring from rotating beyond a position at which the tool head is secured to said main body.