Manual / Guide · 1980
200-, 206-, 209- and 211-Type Selectors and 10-, 26-, 32-Type Banks: Requirements and Adjusting Procedures — AT&T BSP 026-706-701 (1980)
66 pp. Western Electric step-by-step two-motion selectors (the WE 206 type)
Manual / Guide · 1980
66 pp. Western Electric step-by-step two-motion selectors (the WE 206 type)
SECTION 026-706-701 14, November 1980 BELL SYSTEM PRACTICES AT&TCo Standard Issue AND 2 11 -TYPE SELECTORS 200-, 206-, 209-, AND 10-, 26-, AND 32-TYPE BANKS REQUIREMENTS AND ADJUSTING PROCEDURES 2 GENERAL 2. REQUIREMENTS PAGE CONTENTS PAGE CONTENTS 1. 12. Single-Piece-Type Feeder Brush-Balanced Type With Two Welded Contacts 13. Single - Piece-Type . . . 3. APPARATUS .... 60 4. ADJUSTING PROCEDURES 61 Type With One Formed Tip 14. 15. 14 Single-Piece-Type Feeder Brush-Balanced 1. 206-Type Selector and 26-Type Bank 2. Method a Selector Manually 16. Two-Piece-Type Feeder Brush 17. Rotor 18. Bridging Brush 3. Alignment of Tips of Rotor Brushes Armature Backstop . . 19. 5. Position of Bridging Brushes On Terminals and Tension Retaining Pawl Position 7. Ratchet Wheel and Associated Parts (206- and 2 1 1 -Type Selectors Illustrated) 20. 8. Driving Pawl and Associated 206, and 211-Type Selectors) 9. . . 15 .... 16 Heel Spacing Between Brush Members of Heel Spacing 16 Between Brush Members and Bank Feeder Brushes 16 21. Nonbridging Brush 17 22. Bridging Brush 18 23. 425 Selector Holder in Place On Nonrigidly Mounted Selector on Flat-Type Mounting . (200-, Parts . 8 . 15 15 Adjacent Pairs 7 6. 14 6 7 Position .... and Feeder Brushes 5 4. .... Single-Piece-Type Feeder Brush-Nonbalanced Type With Two Formed Tips Figures Stepping 14 Feeder Brush-Balanced Welded Contact and One Type With Two Formed Tips of . 5 . . 10 Selector) 10 Rotor Brush Alignment 12 59 Plate 24. Driving Pawl and Associated Parts (209-Type 622A Selector Clamp in Place On Nonrigidly Mounted Selector On Channel-Type Mounting 59 Plate 10. 25. 1 1 . 13 Detachable Feeder Brush Method of Cleaning Adjacent Surfaces Magnet Core and Armature of .... 60 NOTICE Bell Not for use or disclosure outside the System except under written agreement Printed in U.S.A. Page 1 SECTION 026-706-701 PAGE CONTENTS 26. Method of Lubricating Rotor Bearing When 27. Method of Adjusting 28. Method of Adjusting Spring Stop Lubricating Hole is Not Provided Driving ... 61 64 1 . . day's use, shake the container of lubricant for approximately 30 seconds to ensure mixing of the ingredients. The proper method of Pawl Tension . each before 66 GENERAL shaking the lubricant consists of repeated, rapid turning of the container to an upside down position and back to the upright position. If lubricant is to be used from a 1-pint container, the lubricant must be mixed as just described before it is poured into the smaller container. Under storage conditions, the cover should be tight on the container. 1.06 One dip of KS-16832, L2, Lubricant, for the purpose of this section, is the amount This section covers 200-, 206-, 209-, and 211-type selectors and 10-, 26-, and 32-type 1.01 banks. This section 1.02 is reissued of lubricant retained on the KS-14164 brush after being dipped into the lubricant to a depth of approximately 3/8 inch and scraped once against the side of the container as the brush is removed. to: 3, and add a Part 4. • Modify procedure 2.12 for checking overthrow stop position Make-Busy Information: Before making any of the inspections or readjustments herein, ascertain whether or not it is necessary to make any of the circuits busy. Circuits which are so affected should be made busy in the approved manner, and the necessary relays should 1.07 • Rearrange the contents of Parts 2 and specified be held operated or nonoperated to isolate the • Modify procedure 2.15 for checking armature selector circuit. airgap. 1.08 Since this is a general revision, revision arrows This reissue does not affect have been omitted. Method of Connecting Selectors for Electrical Tests: For the methods of connecting the test set to the selector in checking the Equipment Test List. and readjusting to meet the electrical requirements specified herein, refer to Sections 026-706-711 and Reference shall be made to Section 020-010-711 covering general requirements and definitions for additional information necessary for the proper application of the requirements listed herein. 026-706-712. 1 .03 1.09 Steady and Uniform Operation: selector operates steadily A and uniformly when it operates regularly under self-interruptions Asterisk (*): 1.04 Requirements are marked with an asterisk when to check for them would necessitate the dismantling or dismounting of apparatus or would affect the adjustment involved on other adjustments. No check need be made for not less than ten revolutions. requirements unless the apparatus or part is made accessible for other reasons or its performance indicates that such a check is advisable. at or about the time the rotor brushes engage the for these If the selector is wired so it cannot be rotated under self-interruptions, it shall be rotated under control of the relay wired to its interrupter contacts for at least ten revolutions. A slight hesitation or momentary change of speed brushes feeder regularly. is not objectionable if it recurs A distinctive click indicating the failure of the pawl to latch up over a tooth shall not be Preparation of KS- 16832, L2, Lubricant: This lubricant is provided in 2-ounce and A small wide-mouth container, such as the 2-ounce jar in which the lubricant is available, should be used as a receptacle from which to dispense the lubricant. If allowed to stand more than 1 day without agitation, the 1.05 1-pint containers. lubricant ingredients tend to separate; therefore, Page 2 present. It is satisfactory to rotate the selector for approximately 1 minute and to judge its operation by ten consecutive revolutions thereafter. 1.10 Selector Circuit: The selector circuit referred to herein ordinarily consists of the magnet coil. However, when apparatus such as a lamp, resistance, or relay, or any selector ISS combinations thereof is wired into the circuit to be in series with the selector coil during normal circuit operation, it shall be considered part of the For requirements 2.36 (Speed), selector circuit. 2.32 (High- Voltage Interrupter Contact Test), and 2.33 (Low- Voltage Interrupter Contact Test), the selector circuit shall be extended to include the interrupter contacts with spark protection. 14, SECTION 026-706-701 Position of Selector When Requirements Are Met: Unless otherwise specified, all requirements shall be met with the parts in the position which they assume after being operated 1.18 electrically. 1.19 All rotor brush requirements shall be met on both ends of the rotor brush assembly. High or low voltage refers to the potential 1.11 drop or closed circuit voltage across the selector circuit with the test set connected to the interrupter spring which is wired to the magnet coil. The specified potential drop must be regulated as far as possible by the use of the auxiliary battery used with the selector test set. A series resistance may be used to obtain the correct potential, when necessary, but this resistance must always be less than that which would be sufficient to correct for a difference of one cell. Numbering of Rotor Brushes: 1.12 rotor brush pairs are numbered from 1.20 "Running" and "Stepping": circuit In the requirements table, test clip data is given to indicate the method of connecting the test set to the selector in checking and readjusting to "For meet the requirements specified herein. Running" (previously "Requirements for Running") and "For Stepping" (previously "Requirements for Stepping") appear in the "Remarks" column and are associated with the test clip data. The data "For Running" is for use in cleaning and lubricating the selector and for checking requirements 2.36 The (Speed), left Test), 2.32 (High- Voltage Interrupter Contact and 2.33 (Low- Voltage Interrupter Contact to right, facing the front of the selector, beginning with the No. 1 pair which is the nearest to the Test) on those selectors where these requirements apply or wherever it is necessary to rotate the ratchet wheel. selector under self-interruptions or under control of the relay wired to its interrupter contacts. The Numbering of Interrupter Contact 1.13 Springs: The interrupter contact springs the interrupter spring nearest the spring stop which is spring No. 1. are numbered consecutively, starting at data "For Stepping" is for use in cleaning and lubricating in case the selector is not wired for operation on self-interruptions and in checking requirements 2.15 (Armature Airgap), 2.18 (Magnet Pull Test), 2.19 (Step Test), or wherever it is necessary to operate the selector step by step. Bank feeder brushes are those feeder 1.14 brushes which are part of the 10-, 26-, or 32-type bank. Detachable feeder brushes are those 1.15 feeder brushes which are mounted as a detachable unit by a stud used in place of the top selector mounting screw. 1.21 1.22 (Fig. 1) is a point on the driving arm beneath the pawl spring to which the driving pawl is Lamp and Dental proper cord is used for the available voltage. The standard point of measurement 1.16 Use of Portable Mirror: The 510C portable lamp and 376A dental mirror may be used in connection with the visual inspections specified in Part 2, Requirements. In using the 510C portable lamp, make sure the Moving Rotor Brushes by Hand: all cases where it is In necessary to move the rotor brushes by hand, do this by manually holding the armature against the core and grasping the free ends of the rotor brushes between the contact fastened. portion and the hub. 1.17 Selectors which do not meet the test requirements for 2.19 (Step Test), 2.36 (Speed), 2.32 (High-Voltage Interrupter Contact or 2.33 (Low-Voltage Interrupter Contact Test) shall be exercised for approximately 1 minute and then, if necessary, they shall be cleaned and Test), relubricated and then retested for these requirements. 1.23 To step the selector manually, apply sufficient pressure to the bottom of the armature, as shown in Fig. 2, to force it upward against the core and then release the armature. In some cases it may be necessary to apply the force with a snap in order to obtain a slight whip Page 3 SECTION 026-706-701 SELECTOR MOUNTING SCREW RETAINING PAWL (O SOLDERING TERMINALS CARD HOLDER RATCHET WHEEL BANK ROTOR BRUSHES (PAIRS NUMBERED FROM LEFT TO RIGHT) DRIVING PAWL BANK TERMINAL MAGNET CLAMPING SCREW (A) INDEX WHEEL MAGNET ADJUSTING LUBRICATING HOLE BUSHING MAGNET ADJUSTING LOCK NUT DRIVING ARM STUD ROTOR SHAFT SPRING NO. 2 COUTSIDE INTERRUPTER L— OVERTHROW STOP SPRING) (D) STANDARD POINT OF MEASUREMENT SPRING NO. I (INSIDE INTERRUPTER SPRING) BANK FEEDER BRUSHES INSULATOR SPRING STOP OUTER END (BACK) FRAME STIFFENING BRACKET INNER END (FRONT) DRIVING SPRING LUG TERMINAL NO. 2 TERMINAL NO. DRIVING SPRING BRACKET CLAMP DRIVING SPRING ARM MAGNET COIL I ARMATURE BEARING PIN ARMATURE BEARING BUSHING Fig. FRAME 1— 206-Type Selector and 26-Type Bank of the driving arm so the driving pawl will engage a tooth of the ratchet wheel. Where, because of limited space, the armature cannot be operated in this manner, it is permissible to step the selector by operating and releasing the driving arm taking care to grasp the driving arm. To do this, brace Page 4 the left thumb on the screws of the interrupter spring pileup and pull the driving arm with the fingers of the left hand. Take care to position the fingers on the lower half of the driving arm to avoid overstressing the arm. ISS (b) SECTION 026-706-701 14, Rotors (211-type selectors) shall be treated with No. 33 oiled sleeving. After Turnover (c) DRIVING ARM Bank terminals (200-, 206-, and 209-type selectors) shall be initially cleaned with No. 29 aloxite sleeving followed by treating with Subsequently, the bank No. 30 oiled sleeving. terminals shall be treated with No. 30 oiled • sleeving. (d) Bank terminals (211-type selectors) shall be treated with No. 30 oiled sleeving. (e) Rotors (200-, 206-, and 209-type selectors) shall be cleaned using No. 32 aloxite sleeving, followed by treating with No. 33 oiled sleeving. (f) Rotors (211-type selectors) shall be treated with No. 33 oiled sleeving. ARMATURE (g) Recommended Interval for Treatment of Bank Terminals and Rotors: Ordinarily bank terminals and rotors should not require treatment more frequently than at yearly For 200-, 206-, and 209-type selectors and associated banks, this interval may be intervals. Fig. 2 — Method of Stepping a Selector Manually extended if local conditions are such as to ensure that the parts are satisfactory during the extended On 211-type selectors and associated banks, the interval shall not exceed one year. Immediately after such treatment, the bank terminals equipped with precious metal shall be Where evidence of wear inspected for wear. of the precious metal in the brush track is interval. REQUIREMENTS 2. 2.01 (a) Cleaning The ratchet wheel and armature bearings and the surfaces of the magnet core and present, future treatments shall be made at 6-month intervals instead of 1 year. armature adjacent to each other shall be cleaned, necessary, in accordance with approved when 200-, 206-, 209-, (b) The interrupter contacts shall be cleaned, when necessary, in accordance with Section be The Lubrication (Selectors Only): 2.03 procedures. lubricated with and 211-type selectors shall KS-16832, L2, lubricant as follows. 069-306-801. (a) in Before turnover, the installer shall Treatment of Banks and Rotors: lubricate parts of the selector in accordance Bank terminals and rotors shall be treated accordance with Section 069-330-801. with Table A if more than 6 months has elapsed 2.02 Before Turnover (a) Bank terminals (32-type bank associated with 211-type selectors) shall be treated with No. 30 oiled sleeving. between the date of manufacture (as indicated by the date stamped on the selector frame in front of the magnet adjusting bushing locknut). (b) After turnover, the selectors shall be lubricated as specified in Table A at 3-year intervals except for those selectors subjected to Page 5 SECTION 026-706-701 high-temperature conditions such as may prevail near hot air ducts, radiators, etc. Selectors so situated shall be lubricated at 2-year intervals. However, the 2- and 3-year intervals may be extended if periodic inspections have indicated that local conditions are such as to ensure that the selectors will be adequately lubricated during the extended interval. TABLE A LUBRICATION Fig. 3(B)—The tips of the bridging brushes shall overlap the line of contact of the Gauge by eye. (The rotor brush members are 0.013 inch thick.) AXIS OF ROTOR SHAFT AMOUNT PART Right (b) nonbridging brushes by 0.025 inch ±0.015 inch. 1 dip at end of rotor Rotor Bearing Fig. 1 (A) Left 1 dip at end of rotor Rotor Bearing Right 1 dip, distributed Armature Bearing between both sides Fig. 1 (B) of the bearing Left 1 dip, distributed Armature Bearing between both sides Ratchet 4 dips, distributed over the teeth of the ratchet wheel 2.06 while the selector is being rotated the No. NON-BRIDGING LINE OF of the bearing Fig. Wheel (Fig. 1 (C) Overthrow Stop Fig. 1 (D) 1 dip, applied between the overthrow stop and the driving pawl while CONTACT BRUSHES BRIDGING BRUSHES 3 — Alignment of Tips of Rotor Brushes Clearance Between No. 1 Rotor Brush and Driving Arm: The clearance between 1 brush and the driving arm with the rotor brush assembly in the position it assumes after being operated electrically and with the sideplay of the armature taken up toward the right as viewed from the front shall be the selector is held Min 0.015 inch operated 2.04 Record of Lubrication: During the Note: period of installation, a record shall be kept The rotor brush members are 0.013 inch thick. by date of the lubrication of the selector; and this record shall be turned over to the telephone company with the equipment. If no lubrication has been done, the record shall so state. 2.05 Alignment of Tips of Rotor Brushes Fig. 3(A)—The trailing edges or tips of all nonbridging brush members shall be in approximate (±0.010 inch) alignment. The reference line used as a basis for this measurement To check this requirement proceed as follows: Operate the selector electrically until the No. 1 rotor brush is adjacent to the top edge of the driving arm. (1) (a) (2) Take up the sideplay of the armature the right as viewed from the front. (3) Observe the clearance of the No. 1 rotor brush and the top edge of the driving arm. to shall be parallel to the axis of the rotor shaft. Gauge by eye. Page 6 ISS (4) 2.07 SECTION 026-706-701 (a) the rotor brush assembly. armature against the backstop, the retaining pawl disengaged, and the play of the rotor assembly taken up alternately in the backward and forward directions, bridging brushes shall Armature Bearing Pin Position (Armature Bearing Pin Without Clamp Plate): The armature bearing pin shall be approximately centered with respect to the sides of the frame and securely held in position by the frame stiffening bracket and bracket clamp. 2.08 14, Check the requirement on both halves of Armature Endplay: Bridging Brushes: Fig. not touch adjacent terminals. 5(A)— With the See (c). Gauge by eye. MAGNET COIL The armature shall have an endplay on its shaft of DRIVING SPRING Min 0.005 inch DRIVING SPRING LUG Gauge by eye and feel. DRIVING SPRING ARM To check this requirement, move the armature from one side to the other and observe the clearance between the armature bearing brushings and the ARMATURE BACK STOP lugs of the frame. l—(A) 2.09 Fig. Clearance Between Rear Corners of Armature and Lugs of the Frame: 4(D)— The clearance between the rear corners of the armature and the lugs of the frame shall Fig. 4 — Armature Backstop Position be NON - BRIDGING BRUSHES Test—Min 0.003 inch Readjust—Min 0.005 inch BRIDGING BRUSHES Use the 74D gauge. • To check this requirement, move the armature toward one lug as far as possible and insert the 74D gauge in the gap between the armature and this lug to measure the clearance at the rear corner. Using the 376A dental mirror, observe the clearance. Move the armature toward the other lug, and recheck at that lug. LEADING EDGE 2.10 Armature Backstop Position: (A)— At the time of turnover, the armature backstop shall be positioned on the selector so the straight portion of the stop designated (B) in Fig. 4 inclines MA) Fig. 4 Fig. 5 — Position of Bridging Brushes on Terminals upward to the right. Gauge by eye. (b) Nonbridging Brushes: Fig. 6(A) Test— With the armature against the backstop, 2.11 Position of Rotor Brushes on Terminals Bank the retaining pawl disengaged, and the play of the rotor assembly taken up alternately in Page 7 SECTION 026-706-701 the backward and forward directions, the tips (trailing edges) of nonbridging brushes shall be BANKMin 1/64 inch from the respective edges of the bank terminals. See (c). BANK TERMINALS Gauge by eye. Readjust— With the armature against the backstop, the retaining pawl disengaged, and the rotor assembly rotated in a backward direction to take up the play between the driving pawl and any ratchet wheel tooth, the tips (trailing edges) of all nonbridging brushes shall be (A) Fig. 6 — Retaining Pawl Position and Tension 1/32 inch Gauge by eye and proceed as follows. from the leading edges of their respective bank terminals. See (c). (1) Operate the selector (step by step) to the required positions. Gauge by eye. Take up the play between the driving pawl and any ratchet tooth by moving the rotor in a backward direction and then (2) The bank terminals are approximately 1/64 inch thick. releasing the rotor. This requirement shall be checked on all nonbridging brushes when the brushes are on the bottom terminals and also on the pair of nonbridging brushes nearest the index wheel when these brushes are at the middle and uppermost positions of the bank. (c) In checking, apply pressure against the (3) (4) Grasp the upper end of the driving arm between the thumb and forefinger. Move the driving arm gently from side Binding will be indicated if the driving pawl does not return to approximately to side. its original position. driving spring arm where the driving spring is attached to ensure that the armature is against the backstop. Overthrow Stop Position: Fig. 7 (A)— With the armature against the backstop 2.12 [see requirement 2.11(c)] and the rotor assembly The clearance between the driving pawl and the overthrow stop shall be such that the motion of the rotor brush assembly at the brush (b) tips is rotated in a backward direction to take up the play between the driving pawl and any ratchet tooth: (1) not bind between (2) (a) The driving pawl shall the ratchet wheel and the overthrow stop. This requirement shall be checked at four positions of the ratchet wheel with the rotor brushes in a vertical position and a horizontal position in each half cycle of the rotor. Page 8 maximum 1/32 inch. Gauge by eye and proceed as follows. Disengage the retaining pawl. Operate the armature manually and slowly See release it against the backstop. requirement 2.11(c). Rotate the rotor brush assembly in the direction of rotation and note the motion of the brush assembly at the brush tips. ISS (3) 14, SECTION 026-706-701 Repeat this check with the opposite ends The application of the gauge may be facilitated of the brushes contacting the bank terminals. by using a small loop of twine looped around the pawl and the end of the gauge. Driving Spring Tension: Fig. 8(A) and 9(A) The driving spring tension, measured at the standard point of measurement as the driving pawl drops over a ratchet wheel 2.14 RETAINING PAWL — RATCHET WHEEL tooth, shall be within limits specified in the charts SPACING WASHER (C) furnished with the section. (B) Note: ROTOR BRUSH HUB OVERTHROW STOP r tA) Fig. 8(B) and 9(B)— The outside interrupter spring shall not be in contact with the driving arm stud when the above requirement met. is 1 DRIVING Use the 79B gauge, and proceed as follow. PAWL FEEDER BRUSH (SINGLE PIECE (1) TYPE) Place the toothpick between the interrupter springs just below the contact point to force the outside interrupter spring away from possible DRIVING ARM contact with the driving arm stud armature is fully operated. SPRING STOP INSIDE INTERRUPT (2) OUTSIDE INTERRUPTER SPRING when the Apply the 79B gauge to the standard point of measurement, and hold the gauge horizontally. Fig. 7— Ratchet Wheel and Associated Parts (206- (3) and 211 -Type Selectors Illustrated) Measure the tension at the instant the driving pawl drops over the next tooth of the ratchet wheel. 2.13 Retaining Pawl Position and Tension Fig. 7(B)—The retaining pawl shall just drop over the radial face of the ratchet wheel teeth when the armature is operated manually and slowly released against the backstop. See requirement 2.11(c). (a) It (4) is advisable to check the measurement two or three times because of the possibility of the gauge twisting at the point where it is attached to the driving arm. Armature Airgap: 2.15 200-, 206-, and 2 11 -Type Fig. 4(C) Selectors Gauge by eye. With the magnet electrically operated on low voltage, the gap between the armature and the backstop shall not exceed 0.030 inch. (a) This requirement shall be checked in at least four positions of the ratchet wheel approximately 90 degrees apart. Use the 92J gauge. Fig. 7(C)—The tension of the retaining pawl against the ratchet wheel teeth measured at the bend in the pawl shall be (b) Test —Min 40 grams, max 80 grams Readjust —Min 50 grams, max 70 grams Use the 79C gauge. With the magnet electrically operated on low voltage and the overthrow or whip removed, the airgap between the armature and magnet core shall be such that the driving pawl will engage all ratchet wheel teeth throughout a complete revolution. This requirement shall be checked in all positions of rotation. (b) Page 9 SECTION 026-706-701 thereby eliminating overthrow or whip of the armature arm. RATCHET WHEEL OF MEASUREMENT steps fC) (A) is met if the selector when the finger pressure has been The requirement (3) STANDARD POINT removed and the magnet de-energized. 209-Type Selectors OVERTHROW STOP The airgap between the armature and core shall be such that the driving pawl will engage any tooth of the ratchet wheel when a 0.010-inch gauge is placed between the armature and the magnet core and the selector is electrically This requirement energized on low voltage. shall be checked in all positions of rotation. (c) FRAME Fig. 8 — Driving Pawl and Associated Parts (200-, 206-, and 211-Type Selectors) Use the KS-6909 gauge, and eliminate the overthrow or whip as described in (a). RATCHET WHEEL RETAINING PAWL 2.16 Driving Pawl Tension and Position: Driving Pawl Tension The tension of the driving pawl against the ratchet wheel or pawl guide, measured at the bend near the ratchet wheel end of the pawl with the armature in the electrically operated (a) (A)— STANDARD POINT OF MEASUREMENTDRIVING PAWL position, shall be OVERTHROW STOP PAWL GUIDE Test—Min 90 grams, max 150 grams Readjust—Min 100 grams, max 140 grams DRIVING ARM STUD Use the 70J gauge applied at the right-hand side DRIVING ARM of the pawl. Driving Pawl Position OUTSIDE INTERRUPTER SPRING (b) The sides of the driving pawl along its length shall be parallel with the sides of the ratchet Fig. 9 — Driving Pawl and Associated Parts (209-Type wheel. Selector) Gauge by eye. Gauge by eye, and remove the overthrow or whip as follows. (c) Fig. shall 9(D) —The driving edge of the pawl be parallel to the axis of the rotor brush assembly. (1) Apply sufficient pressure against the back of driving pawl to prevent the armature from operating when the magnet is electrically energized. (2) Remove the finger pressure gradually, permitting the armature to operate slowly, Page 10 Gauge by eye. Check this requirement by observing the motion of the pawl as it is clamped between the ratchet wheel tooth and the overthrow stop by intermittently forcing the rotor brush assembly in the direction ISS of rotation and noting whether or not there a twisting motion of the pawl. (d) Fig. is 7(G)—The tip end of the driving pawl shall in no case extend beyond either edge of the ratchet wheel. 14, SECTION 026-706-701 charts furnished with the section is applied, the magnet shall be capable of drawing up the armature so the driving pawl falls into the next tooth when the pull of the driving spring is selector supplemented by the pressure specified in the charts applied horizontally with a push-gram gauge at a point opposite the standard point of measurement. To check this requirement, operate the selector electrically for a complete revolution and then Use the 79B or C gauge. check at four positions approximately 90 degrees apart after stepping the selector electrically to these positions. Pawl Guide 2.17 Selectors: (a) Position, Note: When checking 209-type selectors, if any difficulty is experienced in meeting this requirement it may be due to heating of the magnet coil, in which case the magnet should be allowed to cool. 209-Type Fig. 9(E) With the rotor brush assembly rotated forward to take up all rotary following conditions shall be met. play, 2.19 the Step Test: Fig. 8(A) and 9(A)— The selector shall be capable of taking a full step where the rotor brushes step onto the feeder brushes when the load on the driving spring is The driving pawl shall advance the rotor increased by the application of the tension specified assembly only one step with each operation of the armature. in the charts furnished with the section applied at (1) (2) As the armature is slowly released manually from its operated position, the tip of the driving pawl shall clear the top of the tooth adjacent to the tooth which the pawl is about the standard point of measurement in a horizontal direction opposed to the pull of the driving spring. This requirement shall be met at both ends of the rotor brushes. Use the 79B or 79C gauge. to engage. Gauge by eye. (b) With the rotor brush assembly rotated backward to take up all rotary play, the following condition shall be met. (1) As the armature is slowly released manually from its operated position before the tip pawl strikes the radial face of the tooth to be engaged, it shall contact the front slope of the adjacent tooth. of the Rotor Brush Alignment: Fig. 10 (A)— The junction between each pair of rotor brush springs shall line up with the center line of the associated bank feeder brush within 0.014 inch when the brushes are in the position in which they are about to pass onto the feeder brushes. In case the bank feeder brushes have been cut away, this requirement shall apply to the first row of 2.20 bank terminals. Gauge by eye. Gauge by eye. 2.18 Magnet Pull Test: Fig. 8(D) and 9(F)— When the low voltage specified in the Bank terminals and single-piece-type feeder brushes are 0.014 inch thick. Page 11 SECTION 026-706-701 ROTOR BRUSH on the center line of the feeder brush and close to the crotch, the two prongs shall leave the CENTER LINE OF FEEDER BRUSH rotor at the same time. Gauge by eye. 11(A)— The points of contact between Fig. (c) the feeder brushes and the rotor brush hub FEEDER BRUSH shall be Min 0.015 inch within the outside edge of the rotor brush hub. 10 Fig. 2.21 — Rotor Brush Alignment Feeder Brush Position: Gauge by eye. Each feeder brush shall meet the requirement listed in Table B for the particular type of feeder brushes The single-piece-type feeder brushes are 0.014 inch thick. Each spring of the chromium-plated, involved. 2-piece-type feeder brush is approximately inch thick, and each spring of the nonchromium-plated, 2-piece-type feeder brush 0.009 TABLE B is FEEDER BRUSH REQUIREMENTS (d) BANK FEEDER BRUSHES 0.007 inch thick. The unformed portions of the feeder and rotor brushes shall clear each other at all SINGLE PIECE SINGLE PIECE TWO positions of the rotor by PIECE TYPE TYPE TYPE (FIG. 12, 13. 14) (FIG. 15) (FIG. 16) (a) (a) Min 0.010 inch (a) Gauge by eye. (e) (b) (d) (d) (d) (e) (e) (e) (f) (f) (f) DETACHABLE FEEDER BRUSHES SINGLE PIECE SINGLE PIECE TWO TYPE TYPE (FIG. 15) (FIG. 16) (a) (d) (f) (f) (g) (g) 0.010 inch. Gauge by eye. (f The contacting portion of the feeder brushes shall make contact with and be approximately to the face of the rotor brush hub (a) parallel (c) throughout a complete revolution of the rotor brushes and shall meet the following requirements with relation to the periphery of the hub. (b) (d) Fig. 7(F)—That part of the feeder brush over which the rotor brushes pass shall be alignment with the bank terminals within PIECE TYPE (FIG. 14) (a) in (d) (1) (g) Single-Piece-Type Feeder Brushes: Fig. 12, 13, 14, 15— The contacting portion of the tip shall not extend beyond the periphery (a) Fig. 7(D)— The prongs of the feeder brush shall not touch the spacing (b) Fig. 7(E)—When the feeder brush is pushed away from the rotor with pressure applied Page 12 of the hub more than 0.015 inch. washers on the rotor at any point in the revolution of the rotor. Gauge by eye. (2) Two-Piece-Type Feeder Brushes: 16— The contacting portion of the Fig. ISS 14, SECTION 026-706-701 tip shall not extend beyond the periphery of the measured on the prong just below the contact hub. or tip, — With one end of the rotor brushes resting on the fifth row of bank terminals, the (g) shall be Test Min 20 grams, max 45 grams Readjust Min 25 grams, max 40 grams Gauge by eye. — Use the 70J gauge and proceed as follows: center line of that part of the feeder brush over which the rotor brush passes shall line up with the junction of the associated pair of rotor brush (1) springs within 0.010 inch. 60 degrees from the upper vertical part of Step the selector electrically to a position where the rotor brushes are approximately the frame. Gauge by eye. 2-piece-type feeder brush is approximately 0.009 (2) Block the rotor brush assembly by placing the 0.012-inch blade of the 74D gauge between the right side of the selector frame and the end of the rotor projecting beyond inch thick, and each spring of the nonchromium-plated, the nut. The single-piece-type feeder brushes are 0.014 inch thick. Each spring of the chromium-plated, 2-piece-type feeder brush is 0.007 inch thick. Note: the Newer-type selectors may not accept gauge designation. Adjust 0.012-inch accordingly. CLAMPING NUT (3) SPACING WASHERS Place a toothpick between the left side of the frame and the adjacent end of the rotor above the shaft. (4) Measure the tension of the front prong. (5) Remove the gauge blade and toothpick. (6) DETACHABLE Step the selector electrically 180 degrees, and repeat the check. FEEDER BRUSHES (b) ROTOR BRUSH HUB Fig. 12(B), 13(B) and 14(B)-The rear prong shall reliably contact the rotor brush hub. Gauge by eye and feel. • To check this requirement, block the rotor brush assembly as covered in (a) and apply the KS-6320 Fig. 11 orange stick to the rear prong to check that the prong is making contact with the hub. — Detachable Feeder Brush Feeder Brush Tension 2.22 Single-Piece-Type Feeder Brushes Single-Piece-Type Feeder Brushes per Fig. per Fig. 12, and 14 (a) (c) Fig. 12(A), 13(A), 15 13, and 14(A)—The tension of the front prong of the feeder brush against the associated rotor brush hub, Fig. 7(E)—The tension of each feeder brush against the associated rotor brush hub measured at a point on the center line of the feeder brush and close to the crotch shall be Page 13 SECTION 026-706-701 Test —Min 65 grams, max 90 grams Readjust —Min 70 grams, max 90 grams Use the 70J gauge, and check as follows: (1) Step the selector electrically to a position SPACING WASHER where the rotor brushes are approximately 60 degrees from the upper vertical part of ROTOR BRUSH HUB the frame. Block the rotor brush assembly by placing the 0.012-inch blade of the 74D gauge between the right side of the selector frame and the end of the rotor projecting beyond (2) Fig. 12 — Single-Piece-Type Feeder Brush — Balanced Type With Two Welded Contacts the nut. Note: the Newer-type selectors may not accept Adjust gauge designation. 0.012-inch accordingly. (3) Place a toothpick between the left side of the frame and the adjacent end of the rotor above the shaft. SPACING WASHER (4) Measure the tension. ROTOR BRUSH HUB When checking the tension of the No. 1 brush, the 70J gauge cannot be used. Therefore, the requirement on this brush is met if the tension as determined by Fig. 13 — Single-Piece-Type Feeder Brush — Balanced using the KS-6320 orange stick, is approximately the same as the tension of another brush which meets the requirement when checked with the 70J gauge. feel, Type With One Welded Contact and One Formed Tip (5) (6) (B) Remove the gauge blade and toothpick. Step the selector electrically 180 degrees, and repeat the check. SPACING WASHER ROTOR BRUSH HUB Two-Piece-Type Feeder Brushes per *(d) Fig. 16 With adjacent brushes held away, the spread of the contact ends of the 2-piece-type brushes shall be approximately 3/8 inch. part of the retaining pawl Fig. 14 — Single-Piece-Type Feeder Brush — Balanced is The clamped 3/8 inch wide. Gauge by eye. Type With Two Formed Tips 2.23 Rotor Brush Tension: The tension of each member of a brush pair, measured at a point approximately midway between the prongs of the brush member with the brushes on the Page 14 ISS / V 14, SECTION 026-706-701 SPACING WASHER ROTOR BRUSH HUB SPACING WASHER' ROTOR BRUSH HUB' Fig. 15 — Single-Piece-Type Feeder Brush — Nonbalanced Type With Two Formed Tips topmost row of terminals, shall be within the limits specified in charts furnished with the section. Use the 70J gauge, and proceed as follows. (1) Step the selector electrically so the brushes are on the topmost row of terminals. Block the rotor brush assembly by placing the 0.012-inch blade of the 74D gauge between the right side of the selector frame and the end of the rotor projecting beyond the nut and a toothpick between the left side of the frame and the adjacent end of the rotor above the shaft. (2) Note: the Fig. 16 — Two-Piece-Type Feeder Brush prong shall not be away from the feeder brush more than 0.005 inch. In case the bank feeder brushes have been cut away, this requirement shall apply to the first row of bank terminals. Gauge by eye. In doubtful cases, touch the prongs of the brushes with the end of the KS-6320 orange stick and note whether or not both prongs make contact with the bank feeder brush or bank terminal in cases where the feeder brushes are not away. The feel of the tool will be an aid to the visual check for the requirement. Newer-type selectors may not accept gauge designation. Adjust 0.012-inch accordingly. (3) Apply the 70J gauge between the prongs member. of each brush BRUSH (4) (5) Remove the blade and toothpick. Step the selector electrically 180 degrees, and repeat the check. NO. 6 BRUSH NO. 5 BRUSH NO. 4 BRUSH NO. 3 BRUSH NO. 2 Note: On selectors equipped with detachable BRUSH NO. I feeder brushes, it will be satisfactory to check this requirement with the rotor brushes on the detachable feeder brushes instead of on the topmost row of terminals. 2.24 Rotor Brush Prong Contact: 17(B)— At least one of the two prongs of each individual brush member shall make contact with the associated bank feeder brush. The other FEEDER BRUSHES FRAME - Fig. Fig. 17 — Rotor and Feeder Brushes Page 15 SECTION 026-706-701 Toeing of Bridging Brushes: 2.25 Fig. 18 (A)— When a bridging rotor brush is not contacting with the feeder brush or bank terminals, both pairs of trailing edges of tips of the brush shall toe out. The maximum separation between each pair of tips shall not exceed 0.010 inch when the brush members are making contact with each other. BANK BANK TERMINALS — Gauge by eye. Note: (A) At least one pair of contacting surfaces of the brush shall ROTOR BRUSHES make contact with each other. Fig. BRIDGING 19 — Heel Spacing Between Brush Members of BRUSH Adjacent Pairs (A) Gauge by eye. The bank terminals are 0.014 inch thick. In case the bank feeder brushes have been cut Fig. 18 — Bridging Brush away, this requirement shall apply to the first row of bank terminals. 2.26 (a) Heel Spacing Fig. 19(A)—The clearance between brush members of adjacent pairs when the brushes are in contact with the bank terminals shall be Min 0.030 inch Gauge by eye. The bank terminals are 0.014 inch thick. This requirement shall be checked on the topmost row of terminals. On selectors equipped with detachable feeder brushes, it will be satisfactory to check for this requirement on the detachable feeder brushes. Fig. 20 — Heel Spacing Between Brush Members and Bank Feeder Brushes (b) Fig. 20(A)—The heels of the rotor brush members shall clear the sides of the bank feeder brushes just before the engage the feeder brushes by rotor brushes Endplay 2.27 Min 0.015 inch Page 16 The rotor brush assembly shall have endplay on its shaft of a perceptible (sight or