GB191517265A - Improved Means for Effecting Remote Control of Apparatus Driven by Electric Motors. - Google Patents

Abstract

17,265. Pickett, F. N., and Igranic Electric Co. Dec. 8. Systems for controlling travel for a fixed distance or number of revolutions; controllers, drum, actuating-mechanism for. - Remote control of electrically-driven apparatus is obtained by a controller with auxiliary contacts operable between consecutive main contacts, each contact being connected to a corresponding contact on a similar controller or limit switch driven by the motor. The movable main contacts a<1> ... a<16>, Fig. 8, are carried on a drum or on radial arms, and engage with spring contact-fingers A' ... A<16>. The drum controlling the auxiliary contacts is built up of twenty-five disks g<1> .. g<25> each having sixteen cam-projections on its circumference, so that when the disks are assembled, the drum surface has sixteen cam-strips b<1> . . b<16>. These strips operate levers G<1> &c., which carry contacts H<1> &c., to connect the various contacts B', B<2>, &c., and the contact strip AB. The limit switch driven by the motor has main contacts C' .. C<13> and auxiliary contacts e<1> .. e<25>. The part of the drum 3 associated with the main contacts is divided diagonally in steps as shown in Fig. 8, so that one of the contacts C<1> .. C<16> is open at each position of the drum. Or the drum may have a number of cam-grooves, and spring-pressed contact levers are operated by projections falling into the grooves. The other part of the drum 3 has sixteen cam-grooves d<1> &c. for the operation of the switch levers E' &c. The lever E<1> carries a contact e<1>, which remains touching the contact D' until the rotation of the drum permits the projection on the lever to enter the cam groove d', thereby moving the lever to its ' off ' position. The other auxiliary contacts are operated in the same way. This system of connexions gives four-hundred positions of the search-light or other apparatus. To obtain the one hundred and thirty-fifth position, the controller is moved until the contacts a<5>, A<5> engage, and the cam b<5> operates the contact B'‹. The circuit of the actuating-coil 20 of the motor switch is completed through the contacts A<17>, a<17>, a<5>, A<5>, C<5>, C<17> until the limit switch moves to the position in which the contact C<3> is opened. The actuating-current then flows through the contact bar AB, contacts B<10>, e<10>, D<10>, D<1>. This circuit is broken when the limit switch reaches the position in which the contact e<10> moves away from the contact D<10>. If the limit switch overruns its proper position, a circuit is completed through the actuating-coil 21 of the reverse switch and one of the contacts D<d1>.. D<d25>.