| 摘要 |
<p>519,612. Lathe &c. centres. TSCHERNE, A. June 2, 1939, No. 18178. [Class 83 (iii)] In an automatically adjustable dead centre for a lathe, grinding machine &c. the centre 3 screws at 4 in the casing 1 which is insertable in the tailstock, a torsion spring 6 tending to rotate the centre in the direction which screws it out of the casing. Stops 9, 10 limit this rotation and one end of the spring is attached to an adjustable collar 8 to vary its initial strain. When the work-piece in the lathe &c. expands due to heating, the additional axial pressure causes the centre to rotate slightly with the work, thereby screwing it further in the casing to relieve the pressure. On cooling, the spring rotates the centre in the opposite direction to maintain the axial pressure. The centre 3 may screw directly in the tailstock.</p> |
