GB773299A - Transparency viewer - Google Patents

Abstract

773,299. Transparency viewers. MILLER, G. Sept. 28, 1955, No. 27594/55. Class 98(2) A transparency viewer in the form of a box-like member, containing a light bulb arranged at one side of a light diffusing plate includes transparency receiving and ejecting means combined with a switch, has guide tracks leading from a transparency receiving slot in one side of the boxlike member, and a spring mounted opposite the transparency receiving slot to resist the full entry of the transparency, and arranged to eject the transparency at least partially, when holding pressure thereon is released, the' spring being mounted in the circuit to the bulb to complete the circuit only when the transparency is held pressed thereagainst within the frame. As shown in Fig. 1, the boxlike member 11 has a viewing lens 12 mounted at one end thereof, and an inner framework 16 is slid in from the other end and secured in position by means of a spring catch 18. The inner framework 16 carries the holder 15 for an electric bulb 14, and includes a compartment 20 for a pair of electric batteries 21 connected by an electric circuit to the bulb holder 15. Registering slots 30, 31 in the box-like member 11 and the inner framework 16 respectively lead to guide ways 32 formed on opposite sides of inner framework 16. Weak springs 34 s,erve to press a transparency inserted through the slots 30, 31 against a light diffusing plate 13 also mounted in the inner framework 16. A bowed spring 26, Fig. 4, fixed at 27 to the inner framework 16, normally occupies its dotted-line position; but when a transparency 36 is inserted into the guideways 32, the spring is pressed downwards against a contact strip 28, thus completing the circuit to the bulb 14. The bulb 14 thus remains alight as long as the transparency is held in position, but when the transparency is released. it is partially ejected by action of spring 26 returning to its dotted-line position, breaking the circuit to the lamp 14 at the same time.