Patent ID: 7898124

Claim:
A step-by-step motor able to carry out up-and-down transmission comprising: a housing formed with an accommodating chamber in an interior, said accommodating chamber having inside provided with a projecting edge formed therein with a recessed chamber, said housing having a topside bored with an insert hole communicating with said recessed chamber, said insert hole having an inner wall provided with positioning guide grooves, said recessed chamber having one side wall bored with an engage groove, said accommodating chamber having an inner wall formed with a recessed groove communicating with said engage groove, said accommodating chamber having opposite sides respectively disposed with a positioning insert groove, said housing cut with a notch at one side; a top rod inserted in said insert hole of said housing, said top rod having a lower portion provided with male threads, said top rod fixed with lengthwise projections on an outer wall, said lengthwise projections respectively fitted in said positioning guide grooves of said housing, said top rod further having a wall disposed with a cut recess; a circuit board installed in said accommodating chamber of said housing, said circuit board provided with conducting strips to be received in said recessed groove of said housing, said conducting strips having a position-limiting switch fixed at one end, said position-limiting switch positioned in said engage groove of said housing, said position-limiting switch secured thereon with a sidewise rod to be inserted in said cut recess of said top rod, said circuit board having two opposite sides respectively set with a socket; a magnet received in said accommodating chamber of said housing, said magnet bored with an insert hole in a center, said insert hole fixed therein with a connecting member with an insert hole, said insert hole of said connecting member formed with female threads in an interior, a bearing connected to an upper side of said magnet by said connecting member; a coil unit assembled in said accommodating chamber of said housing, said coil unit composed of a right-handed coil and a reverse coil superposed on each other, said right-handed coil and said reverse coil having their line terminals connected to a socket; and a cover covered on a bottom of said housing.