Tom Purvis, a renowned artist, and Alfred C. Mayo founded Purma Cameras Ltd. in 1935. David Brock of Brock Fireworks gave financial help to launch the company in London. Their office was at Brock House, Langham St, London W1.
The cameras of the Purma brand were 127 roll film viewfinder cameras with innovative gravity controlled shutters, based on the company's patents of 1935 and 1936, designed by founder A.C. Mayo. Purma cameras and accessories were sold by R. F. Hunter of London.
The most common, the Purma Special was made almost entirely of Bakelite, apart from the glass lens, plastic viewfinder optics and shutter & spring mechanisms. Styling was apparently due to Raymond Loewy’s London Office.
There were several interesting features;
The focal plane is curved, with a solid metal, curved focal-plane shutter with three speeds, controlled by a weight, which varied the slit-width. The shutter is cocked using a pear-shaped lever on the top edge, above the lens; the slit width/shutter speed depends on which way up the camera is held. Horizontal gives medium speed, vertical with winding knob down gives slow, and vertical, knob up, fast. See the Living Image site for photos of the shutter.
The lens is sprung to telescope out of the body when the screw-on lens cap is removed. Capping (and so collapsing) the lens locks the shutter release - which, unusually, is on the photographer's left.
the ever-ready case opens upwards from underneath the lens, unlike most cases, which open forward from the back.
The Purma is said to be the first camera to have plastic optics, although this is in the viewfinder only.