TRAFFIC CONTROL TELEPHONE SYSTEMS Circuit - Sam Hallas
TRAFFIC CONTROL TELEPHONE SYSTEMS Circuit - Sam Hallas
TRAFFIC CONTROL TELEPHONE SYSTEMS Circuit - Sam Hallas
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contact with the dome of the inner buffer, the clearance between the buffered<br />
spring and the dome of the outer buffer to be 10 to 20 mil<br />
7.3 The pressure required to separate the contacts with the buffered spring<br />
resting on the outer buffer shall be 150 grammes minimum 250 grammes<br />
maximum, measured at contact. (Readjust 160 grammes minimum 240<br />
grammes maximum).<br />
7.4 With the armature in the unoperated position, the combined pressure of<br />
the two springs resting on the inner buffer shall be 10 grammes minimum<br />
measured behind contact.<br />
7.5 With armature operated the buffered spring shall rest on the dome of the<br />
outer buffer with a pressure of 30 grammes minimum measured at the<br />
contact. (Readjust 32 grammes minimum).<br />
7.6 The contact opening shall be such that the electrical tests are met and the<br />
contacts shall not be out of alignment by more than 1/4 diameter of contact.<br />
8. Wipers<br />
8.1 In positions No. 1 and 25 the line of contact of the nonbridging wipers<br />
shall lie within the limits of 1/3 to 2/3 the width of the contact from the<br />
entering edge. The centre line of the bridging wipers shall lie between the<br />
centre line and the leaving edge of the contact, to be judged by the eye.<br />
(The position on the first bank contact is obtained by adjusting the position<br />
of the wiper assembly on the hub, on the 25th contact the adjustment<br />
is obtained by adjusting the gland). When standing on the centre contacts<br />
the centre of the crimp on non-bridging wipers and the centre line of the<br />
contact area of the bridging wipers shall lie between the entering and leaving<br />
edge of the bank contacts.<br />
8.2 The tips of the bridging wipers when standing on any contact shall be not<br />
less than 7 mil clear of the plane through the leaving edge of the previous<br />
contact. This requirement also applies to wiper tips in the first position<br />
after leaving the bank.<br />
8.3 Before checking the wiper positions on any contact it is necessary to take<br />
up any overthrow by lightly forcing back the ratchet wheel against thepawl<br />
tip by hand. Force must not be used while making this check.<br />
8.4 With the rotor assembly moved sideways in any position, no portion of<br />
the wipers other than the tips shall touch the bank contacts.<br />
8.5 When the wipers are clear of the bank contacts there shall be no gap<br />
perceptible to the eye at the outermost contact points. Between the innermost<br />
contact points there may be a gap not greater than 8 mil.<br />
(Readjust 6 mil.)