Longwall shearer tracking system

US4466667A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• Peter D. Poulsen · Grants Pass, US
• Richard J. Stein · Huntsville, US
• Robert E. Pease · Huntsville, US

Key dates

• Filing date: Nov 15, 1982
• Grant date: Aug 21, 1984
• Expiry date: Nov 15, 2002

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21C35/08
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A tracking system for measuring and recording the movements of a longwall shearer vehicle (10) includes an optical tracking assembly (B) carried at one end of a desired vehicle path and a retroreflector assembly (A) carried by the vehicle. Continuous horizontal and vertical light beams are alternately transmitted at (38) by means of a rotating Dove prism (58) to the reflector assembly (A). A vertically reciprocating reflector (34) interrupts the continuous light beams and converts these to discrete horizontal and vertical light beam images transmitted at (68) at spaced intervals along the path. A second rotating Dove prism (64) rotates the vertical images to convert them to a second series of horizontal images while the first mentioned horizontal images are left unrotated and horizontal. The images are recorded on a film (74, 104). An overlay (106) with X and Y co-ordinates may be utilized to view the images and provide a graphical representation of the vehicle's path along the longwall coal face.