Hoist controller

A hoist controller is the controller for a hoist. The term is used primarily in the context of electrically operated hoists, but it is apparent that the control systems of many 20th century steam hoists also incorporated controllers of significant complexity. Consider the control system of the Quincy Mine No. 2 Hoist. [ [http://files.asme.org/ASMEORG/Communities/History/Landmarks/5631.pdf Quincy No. 2 Mine Hoist (1920)] National Historic Engineering Landmark brochure, The American Society of Mechanical Engineers, 1984.] This control system included interlocks to close the throttle valve at the end of trip and to prevent opening the throttle again until the winding engine was reversed. The control system also incorporated a governor to control the speed of the hoist and indicator wheels to show the hoist operator the positions of the skips in the mine shaft.

The hoist controllers for modern electric winding engines have long included such features as automatic starting of the hoist when the weight of coal or ore in the skip reaches a set point, automatic acceleration of the hoist to full speed and automatic deceleration at the end of travel. [H.K. Burch and M.A. Witting, Automatic Operation of Mine Hoists, in [http://books.google.com/books?id=oioLAAAAYAAJ Trans. Amer. Inst. of Mining Engineers, Vol. LV] , 1016, page 10.] .Hoist controllers need both velocity and absolute position references taken, typically taken from the winding drum of the hoist. [A.R. Lilly, Hoist Controller, U.S. Patent 3,110,199 granted Aug. 30, 1960.] . Modern hoist controllers replace many of the mechanical analog mechanisms of earlier controllers with digital control systems.

For historical reasons, the operator of a hoist controlleris frequently known as a "winding engine driver"

References

Text left over from an older version of this page

In the mining sector in South Africa, the action of raising and lowering persons or material is facilitated, by means of an onsetter(person)underground "(on a certain landing level)" and a Banksman(person), working on the shaft-bank area. These persons communicate with the Winding Engine Driver(WED) by signalling on a locked bell system. These signals are interpreted by the WED as to what action is needed by the Onsetter and Banksman with regard to the movement of the conveyance(s).For example: The banksman will signal 1(one) to the WED and then the WED will control the machine in such a way that the conveyance will be raised at the shaft bank. The tone of the signal will differ from that of the onsetter, so that the driver will know from whom the signal is coming. There are many different signals rung in sequence. Each signal will have a different meaning to the WED. There are signals for raising, lowering, raising slowly, lowering slowly. A signal which informs the WED that the conveyance is clear and that the WED may proceed to perform whatever action He/She wants to perform at His/Her discretion. There are also signals informing the WED of what contents the conveyance is transporting, persons, material, explosives, long material attached to the bottom of the conveyance etc. These signals are standardised on all mines in South Africa, and have been approved by the government mining engineer (a person appointed by the minister of minerals and energy affairs). These signals are known as the Government Code of Signals. Special signals for a specific mine have to be approved by the regional director (an inspector of machinery appointed by the minister of minerals and energy affairs) and can only be used once approved. No other signals than these signals are allowed.