Screw cutting attachment for lathe

Screw cutting attachment for lathe

This mechanism, shown incorporated in an attachment for a standard lathe, was produced to supersede the dial indicator and standard nut mechanism on screw-cutting centre lathes. The engagement and disengagement of the nut with the lead-screw is controlled mechanically with the result that threading can be carried out, using tungsten carbide tools, at extremely high spindle speeds.

Patented in 1955 by John Farrow and developed by the donors, the device js used with the existing lead-screw and controls the engagement of a half nut by means of a disc rotated by a pinion in constant mesh with the lead-screw. The disc is slotted and engagement can only occur when a pin enters a slot. By means of a screening device the number of slots can be varied to produce pick-up positions to suit whole or fractional numbers of threads per inch. A precision release is operated by a trigger coming into contact with a stop.

Details

Category:
Hand and Machine Tools
Object Number:
1959-288
type:
lathes
credit:
Saunderson and Costin Ltd.