From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Installation drawing for a 10 A3 clutch.
| Identifier | ExFiles\Box 129\2\ scan0087 | |
| Date | 1st November 1935 | |
| Handwritten Notes: .375/.41 3.775" 6 HOLES .3760 DIA EQUALLY SPACED. C'BORE TAPPED HOLES. PLAIN PORTION OF SETSCREW TO ENTER C'BORE & AS SHOWN. RECOMMENDED BRG. No S.K.F. 6205. (NOT SUPPLIED BY BORG & BECK) HUB CADMIUM PLATED. THIS ALTERATION IS NECESSARY FOR THE 11 A3 & SPRING DRIVE PLATE IS USED. 4 DRAIN HOLES 3/8 DIA. EQUALLY SPACED. NOTE:- 10" SPRING DRIVE PLATE SHOWN ABOVE & 10" RIGID DRIVE PLATE SHOWN BELOW. THE 11" SPRING DRIVE PLATE IS IDENTICAL WITH THE 10" EXCEPT FOR LENGTH OF HUB. SEE BORG & BECK DR'NG SK 30600/2. TO RELEASE CLUTCH APPLY PRESSURE IN THIS DIRECTION. PRESSURE REQD = 240LB AT TRUNNION CENTRE. NOTE:- A RETURN SPRING MUST BE PROVIDED ON PEDAL ARRANGEMENT TO MAINTAIN THIS CLEARANCE. HOLE DRILLED & TAPPED TO SUIT CUSTOMERS REQ'M'TS. NEW COVER WITH EXTENSION REQUIRED. CENTRE OF TRUNNION SHOULD BE PREFERABLY 3/32 ABOVE C/L OF CLUTCH SHAFT. AS ON STD 11" DWG. BODY DIMENSIONS. RELEASE BRG CARRIER IN "MAX WEAR IN" POSITION. C/L OF TRUNNION SHOULD BE AS NEARLY VERTICAL WITH CROSS SHAFT CENTRE AS POSSIBLE. THROWOUT FORK & CROSS SHAFT MUST CLEAR CLUTCH DURING ROTATION. ALSO APPLICABLE TO A.B. CONSTRUCTION. SALES DEPARTMENT. CASE HARDENED STEEL TRUNNION BLOCKS. MUST BE FREE ON PINS. EXISTING THROWOUT FORK. PREFERRED THROWOUT FORK. VIEW IN DIRECTION OF ARROW 'A'. HOFFMAN BRG No XLS. 1 3/4". Diagram Labels and Dimensions: 2.250 ± .005 PREFERABLE DIM. 1.125 ± .0025 1.575 ± .0025 .562 ± .001 2.750 ± .005 TO SUIT EXISTING THROWOUT FORK 3.375 PREFERABLE DIM. 1.687 1.500/1.4993 BORE OF CARRIER 12.312 / 12 3/16 / 12.310" DIA. OF CLUTCH 11.627 / 11.623 P.C. DIA. 5 3/4" MAX O.A. 1 27/32 ± 1/32 7/16 9/16 MAX RELEASE POSITION INITIAL ENGAGED POSITION 'WEAR IN' POSITION 5/16 MIN. 1/8 MIN. MAINTAIN THIS DIMENSION. 2 7/8" 1.275 1/8 MIN. 1/2" FULL SPLINE TO THIS DIMENSION. 1.439 O.D. OF EXTENSION / 1.438 .192/.190 1.247/1.246 DIA 1 1/4 DIA. S.A.E. 10 SPLINE SHAFT DIMENSIONS. 3.800 +.000/-.035 1.000/.995 1/64" Printed Text Block (Bottom Left): NOTE:- Flywheel friction face should be of good quality cast-iron & comparatively hard. The friction face should be fine, turned and polished and not "run-out" more than .005", & the face on flywheel to which the driving flange is attached should not "run-out" more than .003". It is important to see that the crank-shaft and clutch shaft are co-axial to suit construction. The application of this model clutch is based on the following data: Name of Firm......................... Car Model......................... No of Cyl...........Maximum Torque....... R.P.M............ Maximum Engine Speed.................. Open or Unit Construction................. Vehicle Type.................. Vehicle Capacity.............. Date................ This Clutch is of the non-adjustable type. Therefore some adjustment must be provided on the Pedal mechanism to compensate for friction facing wear. N.B. - Care must be taken to see that the driven plate is assembled in correct position, as illustrated, i.e., with chamfered spline of hub towards the rear. Oil, Grease or Paraffin must not be allowed under any circumstances to be brought in contact with the friction face. Title Block (Bottom Right): All Dimensions ± .015 Unless Otherwise stated. All Corners Free From Fraise. Work to Dimensions. Do Not Scale. This Print supersedes any issued Previous to Date Alteration Read. It is Our Property and must be returned upon request. This Part must not be sold to any other concern. F = Good Finish O = Rough G = Ground = Machine All Over THIS CLUTCH IS SUITABLE FOR A MAXIMUM SPEED OF 5000 R.P.M. BORG AND BECK CO. LTD. LEAMINGTON SPA. ENGLAND. DESCRIPTION. INSTALLATION 10 A3 CLUTCH PART No. SK.30604/6 DRAWN: T.A.W. 1-11-35 TRACED: -- CHECKED: J.D.G. PASSED: -- DATE ISSUED: 1-NOV 1935 MATERIAL SPECIFICATION No. OFF PER SET ALTERATION | No. | DATE ALTERATIONS READ UP | ||