NEW GENERAL PURPOSE RELAY 1043 



the same number of ))arts ])ut together in the same manner. Hy usiiifz; 

 a Iditional \'arieti(\s of cards and wire spi-iiij); assemblies tlie total iininher 

 of eontaet combinations which are i)ossible with the basic design is 

 many times larger than the 300 indicated aboN'e. 



Other examples of coded parts which are assembled in a standardized 

 manner are the coils, core plates and restoring sjjrings. Although coils 

 vary greatly as to turns, resistance, etc., all are a.ssembled to the coi'es 

 t)y the sam{> procedure, using itlentical spoolheads. The three \alues of 

 armature trax'el are controlled by selection of core plates with the proi)er 

 size of openings, but all core plates are assembled alike. Similarly, the 

 restoring springs are pro\'id{Hl in se\'en \'arieties including six different 

 thicknesses and seven predefiections to give the desired restoring force, 

 but these \'ariations do not affect the assembly operations. 



Standardized assembly of coded parts is of value, not only in reducing 

 the cost of hand assembly operations, but also in providing a more uni- 

 form product and as a principle which may make machine assembly 

 practicable. 



9. RELAY ADJUSTMENT 



Since adjustment expense accounts for a considerable part of the 

 manufacturing costs of older type relays, special efforts were made in 

 the design of the AF relay to reduce the need for adjustment. As a result 

 several types of adjustment used with other relays have been eliminated 

 completely and the remaining adjustments have been simplified. All 

 individual contact adjustment has been eliminated and only two types 

 of factory adjustments are made with the AF relay. These include adjust- 

 ment of the restoring spring to control armature back tension and a 

 gang adjustment of the stationary contacts to control the points in the 

 armature travel at which the contacts operate. Even these adjustments 

 are needed for only a fraction of the relays as close control of the tol- 

 erances in manufacture often causes the back tension and contact operate 

 points to fall within acceptable limits as the relays are assembled. 



The gang adjustment of the stationary contacts is made by bending 

 the arms of the core plate, thereby changing the position of the front 

 molded section of the stationary wire assembly which rests on the ends 

 of the arms. Each arm may be bent by means of a screwdriver inserted 

 in the slot as shown in Fig. 16. Rotation of the screwdriver in a counter- 

 clockwise direction causes the upper end of the core plate arm to move 

 to the left, carrying with it the upper end of the stationary wire assembly, 

 including the stationary contacts. This reduces the gap between these 



