GB975777A - Control systems for conveyors - Google Patents

Abstract

975,777. Endless conveyers. STAMICARBON N.V. Dec. 24, 1962 [Dec. 22, 1961], No. 48585/62. Heading B8A. Endless conveyer belts A, B, C, D, E, F may be started in sequence as the result of signals of different frequencies transmitted on common circuit 9 (Fig. 3). A starting switch 31 (Fig. 3) of a main control box 39, starts a driving motor (not shown) of the belt A by means of a relay 48. This results in a contact 50 being closed and this energizes a transmitter 7. Thus a signal of given frequency is transmitted on the circuit 9. A receiver 10 of a control box 40 (bottom half of Fig. 3) associated with the conveyer B responds to this signal (none of the receivers 10 of the control boxes 40 respective to conveyers 3-6 responds to the signal). A motor-starting relay 48 is thereby energized to start the driving motor of the endless conveyer belt B. The starting of the conveyer B results in the operation of a contact-breaker 19 driven from a roller 44 coacting with the belt B. This has the effect of periodically interrupting the signal of a transmitter 11 to which only a receiver 12 in the control box 39 responds. Thus a signal light 26 operates periodically and indicates whether the belt B is operating and also indicates the existence of belt slip. A timing mechanism operates in conjunction with the contact breaker so as to actuate a cut-out switch for the belt if slip should exceed a certain amount. Starting of the belt B also closes a contact 53 so as to energize a transmitter 8 in the control box 40. A signal of such frequency as to activate a receiver in the control box 40 of the belt C, is thereby fed to the line 9, and so on. If a transmitter or receiver of one of the belts B-F is defective, the main switch 35 of the corresponding control box is placed in its upper position (i.e. the position shown in Fig. 3-for normal automatic working as described above, the switch 35 is in its lower position). The transmitter 11 is thus energized continuously (instead of periodically due to the contact breaker 19). The belt at the defective station is manually controlled by a switch 33 while the upstream belts are controlled by the switch box of the next belt upstream. The downstream belts are controlled as before by the control box 39. All the belts may be controlled manually by lifting a switch 34 of the control box 39 to an " up " position (this is shown in the " down " position in Fig. 3). Undue accumulation of coal on any conveyer operates a cut-out switch 42 which may be operated by electrical capacity.