Dorman Smith fuses for fused plug. Copper-ended cylinders with screw thread to one end. Band of colour in centre, variously red, yellow or white.
Part of the Bob Gray collection of electrical objects.
At around the time this plug was made, competing types of plugs, which were not interchangeable, were made by companies such as Crabtree, MK, and Dorman Smith. This plug was designed to have an easy to replace fuse which also doubled up as the live, current-carrying pin. The fuse could be replaced using thumb and fingers without any tools at all. Although a convenient design, it was more expensive than the system which was eventually adopted as British Standard 1363 in 1947. The BS 1363 used a cheap fuse located within the plug whereas this type of fuse had to be heavily built with a brass screw thread on one end.