| 摘要 |
1,063,404. Keysenders. INTERNATIONAL STANDARD ELECTRIC CORPORATION. May 14, 1965 [May 20, 1964], No. 20431/65. Heading H4K. An asymmetrical direct current code keysender breaks the loop to the exchange by means of one set of contacts before connecting up the code elements by means of a separate set of contacts each time a key is operated. Each key of the key set controls contact sets such as all, a12 and r1. Contact sets for n keys are shown. The contact sets rl to rn are arranged in series with the transmit-receive circuit St through which the normal calling loop is made. When a key is operated its associated contact r operates first to break the loop before the other associated contacts a connect the code. As shown in Fig. 3 the contact sets of each key are provided by an encapsulated ball armature K which bridges rods 1 and 2 to provide contact set r or bridges rods 3, 4 and 5 to provide contact sets a. The ball K is of magnetic material and its position is controlled by an electromagnet or by a ring magnet embracing the capsule and connected to a push-button. |
