TRAFFIC CONTROL TELEPHONE SYSTEMS Circuit - Sam Hallas

More documents

Recommendations

Info

Page 30 (c) The total travel of the stepping pawl (U) shall not be less than 1¾ nor more than two teeth of the ratchet wheel (W). (d) The movement at the end of the stepping pawl (U) shall be such that it will obtain full engagement with the teeth on the ratchet wheel (W) at all times. (e) The holding pawl (Q) shall fall reliably into each tooth of the ratchet wheel (W) as it is advanced by the stepping pawl (U) with a maximum backlash of 0.005 inch. Holding Spring and Code Wheel (a) When the code wheel (E) is revolved by hand the cup-shaped part of the holding spring (K) shall clear the inside of the code pins (C) and time arm by not less than 0.005 inch, and shall clear the lower surface of the enlarged part of the code pins and nuts by not less than 0.015 inch. (b) When the code wheel (E) is advanced by the armature (O) the holding spring (K) shall clear the code pins (C) and the time arm in its outward motion by not less than 0.005 inch. (c) The code wheel (E) and code pins (C) shall be located so that after each group of impulses in its own particular code the holding spring (K) shall, on the release of the armature (O), engage with each code pin in turn so that the pin is held in the cup and retains the code wheel in that position until advanced by the next group of impulses or the releasing impulse. The holding spring (K) in normal position shall press against the insulating stud on the rocker arm (S) with a pressure of 1 gramme minimum to 3 grammes maximum. (d) The holding spring (K) shall be adjusted to lie flat along the whole length of the buffer and the tension against the buffer measured at the end of the buffer shall not exceed 10 grams. (e) Altering the Selector from 17 to 27 Step Code. To change the setting from 17 to the 27 step code, loosen slightly the two code wheel screws (F) holding the code wheel (E) on the shaft. Step the ratchet wheel (W), by operating the armature (O) by hand, to the 27th step and hold it. Then rotate the code wheel on the shaft so that the contact spring makes contact with the first ringing terminal and the permanent code pin will be in position to be engaged by the holding spring (K). Tighten firmly the two code wheel screws (F). Contact Spring (a) When the selector is mounted in a horizontal position or in a vertical position with the armature (O) at the bottom, the contact spring (Z) shall be raised by the ringing terminals by not less than 0.02 inch when in the ringing position.
(b) The contact spring (Z) in the normal position shall press against the code wheel (E) with a pressure of ? gramme minimum to 1 gramme maximum. (c) The contact spring (Z) when one step before or beyond the ringing terminals shall not make contact with them. Spiral Spring (a) When the selector is mounted in a horizontal or in a vertical position with the armature (O) at the bottom, the tension of the spiral spring (AB) shall be sufficient to restore the code wheel (E), either to the normal or to the time receiving position, whenever the rocker arm (S) comes into its normal position during the operation of the selector and the code wheel is not in such a position that it will be held by the holding spring (K) engaging with the code pins (E) or time arm lug. For this test the contact spring on the code wheel shall be advanced by operating the armature by hand:- 1. One step beyond the normal position. 2. One step beyond each ringing terminal. 3. One step beyond the time ringing terminal. In each case the armature shall be released slowly. Retractile Spring on Rocker Arm (a) The tension of the retractile spring (R) on the rocker arm (S) including the tension of the holding spring shall be sufficient to restore the rocker arm to normal at all times when no current is flowing through the selector and also to meet the tests specified in the electrical requirements. Armature and Magnet Cores (a) The centre line of the magnet (AJ) shall be equally distant from the cores (AK) within 0.02 inch either side. (b) The armature lever shall clear all adjacent parts except the rocker arm (S) throughout its entire stroke. The allowable vertical or horizontal play shall not permit the lever to touch such parts. (c) The end play of the armature shaft, the ratchet wheel shaft, the rocker wheel shaft and the holding pawl, shall not be greater than 0.01 inch, Page 31
Page 2 and 3: TRAFFIC CONTROL TELEPHONE SYSTEMS C
Page 4 and 5: CONTENTS Part Title Page 1 Key Syst
Page 6 and 7: swing of the meter needle either si
Page 8 and 9: One No. 4002-B Selector Key Case (c
Page 11 and 12: wires. This change of polarity is t
Page 13 and 14: Case), K2 terminal (Time Sending Se
Page 15 and 16: Where satisfactory operation cannot
Page 17 and 18: one is available (if not, with an o
Page 19 and 20: PART 2 4001-A SELECTOR KEY Selector
Page 21 and 22: The keys are easily removed from th
Page 23 and 24: Letter. Name. S.T.C. Code. A Impuls
Page 25 and 26: 4. When the key is normal the tip o
Page 27 and 28: the time terminal. During selective
Page 29 and 30: Cycle of Events on Receiving a Code
Page 31: Mechanical Requirements To assist i
Page 35 and 36: Letter Name 4301-A 4304-A 4305-B A
Page 37 and 38: General PART 4 4001-B SELECTOR TEST
Page 39 and 40: 4001-B Selector Test Set, Schematic
Page 41 and 42: General PART 5 DIAL SYSTEM, SELECTI
Page 43 and 44: The speak key also connects the con
Page 45 and 46: normal, Relay IR is held operated a
Page 47 and 48: here that from SC bank contacts 29
Page 49 and 50: from Line switch SC banks 1 and 2 a
Page 51 and 52: Line Test Set . . . . . . Designed
Page 53 and 54: Line Voltage Curves Fig. 14. The op
Page 55 and 56: General PART 7 LINE TEST SET-LU.310
Page 57 and 58: Operating Instructions 1. Voltage M
Page 59 and 60: the particular line to the earthed
Page 61 and 62: Operate CVK, note meter reading on
Page 63 and 64: 10. Impulse Ratio Check on Selectiv
Page 65 and 66: 12. Telephone Communication. (See F
Page 67 and 68: Page 65
Page 69 and 70: Armature Travel Armature travel is
Page 71 and 72: Contact Sequence The standard conta
Page 73 and 74: chloride or trichlorethylene. The t
Page 75 and 76: PART 9 ADJUSTMENT AND MAINTENANCE D
Page 77 and 78: 9. Armature Restoring Springs:— T
Page 79 and 80: Oil dag should be applied as above
Page 81 and 82: 3. Pawl Spring Tension 3.1 With the
Page 83 and 84:
8.6 The wipers shall exert a pressu
Page 85 and 86:
2.2 The wipers shall rotate smoothl
Page 87:
Registered Office: CONNAUGHT HOUSE
show all

TRAFFIC CONTROL TELEPHONE SYSTEMS Circuit - Sam Hallas

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?