1066 THE BELL SYSTEM TECHNICAL JOURNAL, NOVEMBER 1952 



Fig. 40 — A solderless wrapped connection on a wire spring terminal. 



Another A\Tapped connection of the solderless type on a similar termi- 

 nal is shown in Fig. 40. Studies indicate that solderless wrapped connec- 

 tions can be used with a wide variety of materials, including aluminum. 



It is interesting to note that a troublesome problem in wiring to the 

 new wire spring relay was soh^ed by the development of a new method 

 which itself has become an important de^'elopment with broad applica- 

 tions. The wrapped connection with or without subsequent soldering has 

 resulted in better, more uniform and less costly connections made in less 

 time than those made by previous methods. 



13. CONCLUSIONS 



A description has been given of a new type wire spring general purpose 

 relay for telephone switching systems. Although accurate manufacturing 

 costs will not be available for some time, the new relay is expected to 

 be substantially lower in cost. It provides major improvements in contact 

 performance, reduced power, faster operation and longer life. The new 

 relay also covers a wider field of application than any previous general 

 purpose relay in such characteristics as speed, slow release, marginal 

 operation, number of contacts, etc. 



Important economic advantages include lower manufacturing cost of 

 the relay itself and a reduction in switching systems costs resulting from 

 less equipment and reduced power. 



The new relay has shown considerable improvement in mechanical 

 life and in contact performance. The life of the relay is of the order of 

 one billion operations. These impro^'ements can be expected to reduce 

 the cost of maintenance of switching systems appreciably. 



The development of the new relay has called for a major cooperative 

 effort of many sections of Bell Telephone Laboratories, including such 

 departments as Switching Apparatus Development, Switching Systems 

 Engineering, Switching Systems Development, Research, Materials, 

 Chemical, etc. Without the cooperation of the many members of these 



