Patent GB-936201-A (GB)
Title: Improvements in or relating to hearing aids
Inventor: COHEN MICHAEL
IPC: G02C11/06
Filed: 1958-11-12
Abstract: 936,201. Hearing aids. ARDENTE ACOUSTIC LABORATORIES Ltd. Nov. 9, 1959 [Nov. 12, 1958], No. 36377/58. Class 40 (4). A hearing aid of the air conduction type has a receiver disposedin a first casing and a microphone disposed in a second casing, components in the two casings being electrically connected together by flexible conductors and the casings being mechanically connected together via compliable spacer means. The distance between two casing parts coupled together by the compliable spacer means is less than the dimensions of the compliable spacer means in directions transverse to said distance. Supported on the ear alone.-The receiver casing 1, Figs. 1, 2, is in two parts 5, 6 and encloses a volume control 11, Fig. 14, an on-off and tone control switch 14, a transistor amplifier 83 and a pivotally mounted holder 13 for a mercury cell. A tube 3 connects a receiver 95 to an earplug 4. Contacts of the switch 14 are printed on the face of a sheet 85 of rigid insulating material. The microphone casing 2, Figs. 12, 13, is a lidless rectangular box having a rectangular hole 71 in its base. The edges of the hole 71 are rabbeted to accommodate a baffle plate 77. The microphone is in a brass housing 78 to which the first stage 79 of a transistor amplifier is attached. The structure for coupling the casings 1, 2 together includes a first coupling member 100, Figs. 15, 16, having a plate portion 102 with two arms 103 bent in one direction from opposite sides and two lugs 104 bent in the opposite direction from opposite ends, the lugs being formed with screw-threaded holes 105. A second coupling member 101, Figs. 17, 18, consists of a rectangular plate 107 having its two ends bent over to form flanges 108 having screw-threaded holes 109. There are also three rectangular sheets of foamed plastic or foamed rubber which comprise the compliable spacer means. The first sheet 115, Fig. 14, is cemented to the portion 102 of member 100. The second sheet 116, Fig. 19, is cemented to portion 102 with the arms 103 piercing the sheet 116. The third sheet 117 is cemented to plate 107 of member 101 between the flanges 108. In assembling the members, the exposed face of plate 107 is placed on the exposed face of sheet 116 and the ends 106 of arms 103 are bent around the sides of the plate 107 and the ends of the sheet 117. The sheets 115 to 117 and members 100, 101 are centrally pierced for the passage of flexible conductors. Screws passing into the holes 109 in the flanges 108 secure the compliable spacer means to the cover 6. The lugs 104 fit into recesses in the casing 2 and fixing screws pass through holes 80 into the holes 105 in the lugs 104. An alternative casing 2, Fig. 22, has a small hole 120 where the base 70 meets the wall 74. In an alternative arrangement, Fig. 26, casing 130 holds a receiver 126, casing 132 holds a microphone 129 and middle casing 131 contains a mercury cell 127 and other components 124. Adjacent casings are coupled by compliable spacer means. In a further embodiment an earplug 131 is formed with a cup-shaped recess 132 to receive a casing 133 which houses a receiver. Casing 133 is coupled by a rubber link or other compliable coupling means to a casing 135 in which are mounted the microphone 129 &c. Spectacles frame.-One arm 125, Fig. 27, of a spectacles frame is formed at its rear end as a casing and in the arm are disposed a receiver 126, mercury cell 127 and other components 124. At the rear end of the arm is disposed another casing 128 containing a microphone 129. The casings 125, 128 are coupled together by a rigid tube 140, Fig. 25, wrapped in a foamed rubber sheet 141, the opposite ends being inserted in the ends of casings 125 and 128. Other compliable coupling means may be used.