Claims
- 1. A method of moving a plurality of tool-holding carriages to respective predetermined positions along an elongate guide member comprising:
- (a) sensing the position of each carriage with respect to said guide member by means of respective first sensors, mounted on the respective carriages, by generating from each of said respective first sensors a different discrete multicharacter digital signal for each different position of a respective carriage, and calculating therefrom the respective distances which said carriages must move in order to reach their respective predetermined positions;
- (b) moving at least some of said carriages toward their respective predetermined positions simultaneously in opposite directions along said guide member;
- (c) during step (b), sensing when each carriage has reached its respective predetermined position by sensing the movement of the respective carriage relative to said guide member, by means of a second sensor by generating therefrom a series of identical signal pulses whose number corresponds proportionately to said movement, and comparing said movement to each of said respective distances; and
- (d) locking each of said carriages to the guide member when the respective carriage has reached its predetermined position.
- 2. The method of claim 1 wherein step (b) comprises selectively engaging each of said carriages with a common drive member, and wherein step (c) comprises sensing the incremental movement of said drive member by means of said second sensor.
Parent Case Info
This is a division of co-pending application Ser. No. 07/202,974, filed on June 3, 1988.
US Referenced Citations (12)
Foreign Referenced Citations (2)
Number |
Date |
Country |
3426302 C |
Jan 1986 |
DEX |
2072563 |
Oct 1981 |
GBX |
Divisions (1)
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Number |
Date |
Country |
Parent |
202974 |
Jun 1988 |
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