In existing mine hoists, much of the complex equipment needed for automatic control is located at the working levels in the mine where environmental conditions are poor. According to this invention, the complex equipment needed for automatic control of the hoist is located in the same room as the hoist drive where the environment is warm and dry. This is achieved through the use of control equipment of a type that responds to the coded pulses generated in the Bell Pull circuit in the way that the operator responds to the ringing of his bell or flashing of his light. In essence, this equipment duplicates the responses of the operator in that it counts pulses, distinguishes between sets of pulses, remembers this, exercises a degree of logic, and applies the information for control purposes. Moreover, it can be located in the same room as the hoist drive where it is dry and warm. The existing Bell Pull system or an equally simple circuit can now be used for sending the appropriate signals from the various mine levels to the control equipment. An operation selector is provided for selecting a mode of hoist operation between automatic or manual through a suitable connection with the Bell Pull circuit. When operation is manual control, the signals sent by the Bell Pull will, of course, be displayed to the operator.
展开▼
