| 摘要 |
606,272. Sets for deaf persons. BURGESS, A. F. (Zenith Radio Corporation). Aug. 23, 1945, No. 21597. [Class 40 (iv)] An earphone assembly intended primarily for use with a deaf aid instrument comprises an earpiece made of resilient material to fit into the auditory canal and carrying the earphone. The sound aperture of the earphone assembly 6, Fig. 2, has a flanged boss 10 which fits into a recess in a holder 4 where it is retained by a spring ring 8 engaging over the flange and located in a groove 9 in the recess; This holder is made of moulded material and has a projecting cylindrical portion 19 with a flange 11 so that a soft rubber earpiece 1 can be fitted over it and securely retained. When in use the assembly is supported by the earpiece 1 projecting into the auditory canal, where it is held by flanges 15, 16. The flared portion 17 closes the external opening of the ear and the passage of sounds in an outward or inward direction, other than through the central duct, is prevented by the closed cavities formed between the flanges 16, 15 and 17. A dust filter may be incorporated in the earphone assembly 6 and the spring ring 8 may be replaced by a suitably shaped spring clip, Fig. 9 (not shown). |
