| Patents for Joseph Leathley Hall |
Patents 1 -
6
of 6
      |
| Picture | Number | Date | Patentee | Title |
 | GB-416,928 | Sep. 17, 1934 | J.L. Hall | Improvements in the hardening of the teeth of gear wheels |
 | GB-434,996 | Sep. 12, 1935 | J.L. Hall | Improvements relating to metal milling and like machines |
 | GB-438,549 | Nov. 19, 1935 | J.L. Hall | A new and improved screw-threading machine for forming taper threads |
 | GB-441,303 | Jan. 16, 1936 | J.L. Hall | New and improved screw-threading machine for forming taper threads |
 | GB-487,531 | Jun. 22, 1938 | J.L. Hall | Improvements relating to axially movable spindles of milling and like machine tools |
 | GB-509,945 | Jul. 25, 1939 | J.L. Hall, S. Lindon | Improvements in rotary driving connections between axially movable parts |
