Abstract: An electric motor has a detachably mounted gear cover and a reduction gear located within the gear cover. One pressure member is inserted into the gear cover through an opening formed through the gear cover and urged against another pressure member to squeeze a choke coil and a connection plate. A high current is flowed through the pressure members for a short time to weld the choke coil and connection plate together through resistive heating.

Abstract: A magnetic head having a head unit for contacting a magnetic medium comprises at least a pair of magnetic cores which are arranged in the head unit which face each other on sides of a magnetic gap for recording and/or reproducing signals. A spacer is included for maintaining a space between one of the magnetic cores and another member, which may be the other magnetic core or a shield member. The spacer includes a usable life detection device for providing an indication of wear on the head unit which is interrupted when the head unit is worn down to predetermined depth. A device for electrically sensing an interruption of the indication is provided so that a usable lifetime of the head unit can be determined.

Abstract: A motor terminal device comprises a storage case having an engaging section and installed on the motor side and a storage cover having an engaged section which can be engaged with the engaging section. The storage case stores external connecting terminals and electrical components, while the storage cover has a projecting pressers located in a position corresponding to the electrical components to secure the electrical components by pressing. The external connecting terminals have a latch hole and the storage case has a latch projection. Detachment of external connecting terminals is prevented as the latch projection is engaged with the latch hole.

Abstract: A brush holding structure for guiding a brush to a commutator is supported in a motor case. The structure includes an insulator plate attached to the motor case. The insulator plate is provided with guide means for guiding the brush in a direction which is inclined to a radial direction of the commutator within a plane including the axis of the commutator. The structure further includes a plate-like spring which has, at both ends, coil portions for winding up. An intermediate part of the plate-like spring presses the brush against the commutator to hold the brush in contact with the commutator without any play.

Abstract: A gear backlash adjusting mechanism includes a worm wheel having a gear tooth that engages the gear tooth of a worm. The gear tooth of the worm wheel is curved or tapered upwardly in the axial direction toward one end of the worm wheel. An adjusting apparatus permits the distance between the gear tooth of the worm wheel and the gear tooth of the worm to be adjusted so that the amount of backlash between the gear tooth of the worm wheel and the worm can be adjusted.