Patent GB-108279-A (GB)
Title: Improvements in Driving and Control Mechanism of Planing and like Machines.
IPC: B23D7/00
Filed: 1917-03-27
Abstract: 108,279. Igranic Electric Co., (Cutler-Hammer Manufacturing Co.). March 27, 1917. Addition to 18017/15. Controllers with auxiliary switches and no volt release; electric braking; systems for controlling reciprocating motion.-In a motor control system for obtaining reciprocating motion for a planer or like machine as described in the parent Specification, the electro magnetic main switch is provided with auxiliary switches adapted to vary the holding circuit of the switch, to complete the shunt field circuit of the motor, and to effect dynamic braking by closing the shunt field circuit and the armature circuit through braking resistances, either upon a failure of voltage or operation of the stopping switch. The circuit of the main switch is completed through contacts on the controller so that the main switch cannot be energized after de-energization until the controller has been returned to its " off " position. The operation of the arrangement shown in Fig. 1 is as follows : With the line switch L and the reversing switch 2 closed, the closure of the starting switch 16 completes the circuit of the main switch 1<e> thus : Line L<1>, lead 20, switches 12, 16, 17, operating coil of switch 1, lead 31, and line L<2>. The armature of the main switch is then attracted to close the switches 1<c>, 1<d>, 1<e> and open the switches 1<a>, 1<b>. The armature circuit of the motor is completed thus : Line L<1>, leads 20, 22, resistance r<2>, lead 23, resistance r<3>, series field f, leads 24, lower pole of switch 2, lead 25, resistance r, lead 26, resistance r<1>, lead 27, interpole winding f<1>, armature a, leads 28, 29, upper pole of switch 2, lead 30, switch 1<e>, lead 31, and L<2>. The shunt field circuit is completed as follows :-line L<1>, leads 20, 32, 33, switch 13, leads 34, 35, shunt field f<2>, lead 36, switch 1<c>, lead 31, and line L<2>. The magnet of the main switch 1<e> remains energized when the switch 16 is released through a lead 47, resistance r<6>, switch 1<d>, lead 48, switch 17, lead 46, operating coil of the switch 1, lead 31 and line L<2>. The controller then operates to short-circuit progressively the resistances r, r<1>, r<2> and finally short-circuit the series field f and resistance r<3> and open the switch 13 when the shunt field circuit is completed from the lead 32 as follows :-Lead 37, 38, switch 2a associated with the switch 2, leads 39, 40, resistance 14, lead 35 and so on. When the reversing switch 2 is open and the switch 3 closed, the resistance r is excluded from the armature circuit, and when the switch 13 is opened, the resistance 15 is introduced into the shunt field circuit instead of the resistance 14. To effect dynamic braking when the switch 2 is closed, the main switch 1<e> and the auxuliary switches 1<c>, 1<d> opened, and the auxiliary switch 1<a>, 1<b> closed, the following circuits are established (1) lower terminal of motor M, leads 28, 29, upper pole of switch 2, lead 30, switch 1<a>, resistance r<4>, leads 50, 24, lower pole of switch 2, lead 25, resistance r, lead 26, resistance r', lead 27, interpole field f<1> to upper terrninal of motor M. The shunt field circuit is completed thus :-Lower terminal of field winding f<2>, lead 36, switch 1<b>, lead 51, resistance r<5>, upper terminal of field winding f<2>. When the switch 3 is closed the armature circuit of the motor during braking will be as follows :-Lower terminal of motor M lead 28, lower pole of switch 3, leads 24, 50, resistance r<4>, switch 1<a>, lead 30, upper pole of switch 3, lead 26, resistance r<1>, lead 27, interpole field f<2>, and upper terminal of motor M.