| 摘要 |
673,466. Control of D.C. motors. EATON AXLES, Ltd. July 16, 1948. [Aug. 1, 1947] No. 19132/48. Addition to 655,636. Class 38 (iii). [Also in Group XXIV] The system for controlling the operational movement of a shifting mechanism as claimed in the parent Specification, has the switch common to the circuits of both motor field windings provided with an additional contact or contacts corresponding to intermediate positions of the nut member on the screw, said additional contact or contacts being respectively connected with a member or members in make- and-break relationship with a contact of the series switch of the energized field of the motor, the nut member being effective to break the circuit on reaching a predetermined position. When a control lever 28 is ina neutral position, in which it engages contact 84, no current is supplied from battery 26 to motor 12. Movement of the arm 28 to engage contact 60 energises the motor for forward operation, current being supplied through limit switch-arm 40 and field winding 22. The motor drives a screw-and-nut mechanism, the nut carrying a pin which engages a notch 86 to pivot a contact lever 64 and engage contacts 70, 74. At the limit of its forward movement the nut opens switch 40-52, the load being shiftable from this extreme position to either the other limit position or the neutral position by engaging the arm 28 with contact 62 or contact 84, the field winding 20 being energizable for reverse rotation. Specification 616,533, [Group XXIV], also is referred to. |
