| 摘要 |
1,255,722. Indexing; making indexing tables; Jointing. GIDDINGS & LEWIS Inc. 17 June, 1969 [26 June, 1968], No. 30664/69. Headings B3A, B3B and B3V. A method of setting and fixing locating bushings 17 in an index table 10 comprises assembling the table 10 in a first required angular position relative to its base 11 and with shot pin means 15 mounted in the base operatively engaged in a bushing 17 which is itself loosely located in an oversize bore 35 in the underside of the table 10, injecting a hardenable cement, e.g. an epoxy resin, into the annular clearance volume 34 surrounding the bushing and allowing the cement to harden before withdrawing the pin 15; succeeding bushings are similarly fixed, the angular relocation of the table 10 being carried out using an autocollimator 55 cooperating with a precision polygonal member 53 mounted on the table at its rotational centre. Slots 50 in the end face of the bushing 17 allow for excess cement to escape into a supplementary clearance volume 51, completion of the injection of the cement being indicated by a rise in pressure as the cement enters the slots 50. Damaged or worn bushings can be removed by pulling on the threaded collar 48 seated above the bushing and the bushings can be replaced without additional machining of the bore 35. |
