Patent GB-1274872-A (GB)
Title: Improvements in or relating to conveyor systems
Inventor: WILKINSON KEITH
IPC: B61B10/02
Filed: 1969-02-18
Abstract: 1,274,872. Conveyers; selective operation of points. GEO. W. KING Ltd. 5 Feb., 1970 [18 Feb., 1969], No. 8840/69. Headings B7L and B7N. A conveyer system comprises two conveyers each of the kind wherein load-carrying trolleys 10 are propelled along a fixed trolley track 12 by means of the engagement therewith of pusher dogs 17 which depend from an endless driven chain 13 disposed vertically above the track 12. Means are provided for transferring load-carrying trolleys 10, from the trolley track of one conveyer to the trolley track of the second conveyer, which means comprise a transfer track 23, Fig. 2, above which there is no endless chain 13 and the invention is characterized in that mobile transfer 25 is provided for moving the trolleys 10 along this length of track 23, the unit 25 being adapted to travel back and forth along a track 26 which is disposed alongside and parallel to the transfer track 23 of the conveyer 21 and the unit 25 includes a reversible electric motor 28<SP>1</SP> and an arm 34 which is adapted to project into the path of any trolley 10 present on the transfer track 23 and to be effective on movement of the unit 25 in one direction by pivoting in the direction of the arrow A (Fig. 3) to propel the trolley 10 along the length of the track 23. The track 26 comprises two parallel rails each made up of lengths of channel section members, which rails being supported at spaced points along their length by means of brackets 27 (Fig. 3) which are attached to brackets 28 carried by the tracks 12 of the conveyers 21, 22 and the transfer track 23. When a selected trolley 10 is to be transferred from the conveyer 21, a track switch 24, Fig. 3, is actuated by closure of a limit switch 39 by a selector carried by the trolley 10 so as to divert the trolley 10 on to the transfer track 23. As the trolley 10 moves off the track of the conveyer 21, it actuates a limit switch 40 so as to start the motor 28 of the transfer unit 25 and move the unit 25 towards the conveyer 21. As the unit 25 moves, the arm 34 contacts the lower part of the waiting trolley 10 and pivots so as to brush past the trolley 10. The unit 25 moves until it reaches a position wherein the arm 34 is restored by a spring 36 to its operative position against a stop 37 and is located behind the lower part of the waiting trolley 10. Then the unit 25 contacts a limit switch 43 which reverses the direction of the unit 25. The arm 34 is then maintained rigid by abutment with the stop 37 and propels the trolley 10 along the transfer track 23 to a point 13, Fig. 2, where any loads on the trolley 10 are clear of loads on conveyers 21 and 22. The unit 25 is halted at 13 until a free pusher dog 17 of the chain 13 of the conveyer 22 approaches the transfer zone. Then a limit switch 41 disposed adjacent to the conveyer 22 closes and starts the motor 28 of the unit 25 so as to move it along the track 26 parallel to the transfer track 23 towards the trolley track 12 of the conveyer 22. When a driving abutment 18 of the trolley 10 is contacted by the approaching free pusher dog 17, the unit 25 actuates a limit switch 42 which first stops and then reverses the unit 25 back to a rest position.