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).
Technical discussion on resolving accidental crashing with hand-controlled Maybach dogs by modifying gear face angles and corner radii.
| Identifier | ExFiles\Box 128\2\ scan0054 | |
| Date | 3rd March 1931 | |
| HS{Lord Ernest Hives - Chair}/LID.{A. J. Lidsey} FROM DA{Bernard Day - Chassis Design}/HDY.{William Hardy} X220 C. to R.{Sir Henry Royce} SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} C. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} DA{Bernard Day - Chassis Design}/HDY{William Hardy}/M3.3.31. HAND CONTROLLED MAYBACH DOGS. We thank you for your HS{Lord Ernest Hives - Chair}/LID{A. J. Lidsey}3/KT26231. giving the difficulties you have experienced with the Maybach dogs on 14-EX. ACCIDENTAL CRASHING. We should like to say that it appears to us that there is no prospect of avoiding the crashing engagements by reduction of face angle alone and that we shall have to radius the leading corners. We have some data from a car we have here (Riley) which may be of interest, and if it is anything to go by, indicates that there is some chance of finding a satisfactory compromise between too easy and insufficiently easy engagement. The top gear dogs of this car are backed off and radiused as shewn by the sketch, and when using them as Maybach dogs they are the equivalent of those for 3rd. speed on 14-EX. [Handwritten text from diagram] WITHOUT RADII DAMAGE WILL BE DONE TO THE CORNERS WITH SMALL FACE ANGLES FACE ANGLE BETWEEN 2 & 3° ENGINE RADII ON LEADING CORNERS ABOUT .08 PROFILE AT % DIA 3 DOGS 30° APPROX. APPROX MEAN DIA OF DOGS ON 14EX WERE THIS DOUBLE THAT OF THE RILEY 6 DOGS WOULD GIVE THE SAME ANGLE OF ENGAGEMENT WITH THE SAME FACE ANGLE | ||