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).
Leaflet detailing the specifications, diagrams, and operating instructions for variable speed gears.
| Identifier | ExFiles\Box 119\1\ scan0215 | |
| Date | 23th June 1939 guessed | |
| LEAFLET 394 CROFTS STANDARD DESIGN VARIABLE SPEED GEARS Improved Construction The construction of Frame and Shaft Bearings is such as to permit of ready Dismantling or Erection. End Pressure on the Driving Cones is balanced and taken by Ball Thrust Bearings specially housed between the Operating Levers. Don't use any kind of Dressing on the Vee Belt. Keep Faces of Discs free from Grease. See that all Nuts and Bolts are kept tight. Operate Speed Changing Screw ONLY when transmission is running. To tighten Belt, turn Spindle X in the direction indicated on plate fixed to frame of V.S. Gear. Lubrication of Bearings, Screw and Toggle Pins requires due attention. APPROXIMATE DIMENSIONS IN INCHES | Size of Machine. | A | B | C | D | E | F | G | H | J | K | L | M | N | R | S BB | S RO{C. C. Rose - Export Manager} | Dia. of Bolts. | No. of Bolts. | |---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---| | 5 | 5 3/4 | 4 | 10 | 17 1/2 | 3 1/2 | 11 1/4 | 11 | 23 1/4 | 3/4 | 4 1/2 | 8 5/8 | 2 1/2x12 | 7/8 | 6 7/8 | 13 1/2 | 15 | 3/8 | 4 | | 6 | 6 3/4 | 4 1/2 | 10 1/2 | 20 1/4 | 3 1/2 | 13 1/4 | 13 1/2 | 30 | 1 | 5 1/2 | 10 | 2 1/2x15 1/4 | 7/8 | 7 7/8 | 16 3/8 | 18 | 3/8 | 4 | | 9 | 9 1/4 | 6 | 12 1/2 | 28 3/4 | 6 1/4 | 19 | 18 1/2 | 39 | 1 1/4 | 7 | 13 1/2 | 3 1/2x20 | 1 | 10 5/8 | 22 5/8 | 24 3/8 | 1/2 | 4 | | 10 1/2 | 11 1/2 | 7 1/4 | 14 | 32 1/2 | 7 | 22 | 21 1/2 | 46 | 1 1/2 | 9 | 15 | 4x23 1/2 | 1 1/8 | 13 1/4 | 25 1/4 | 28 1/2 | 5/8 | 4 | | 12 | 12 1/2 | 8 3/4 | 15 | 35 1/2 | 7 1/2 | 24 | 23 1/2 | 48 | 1 1/2 | 9 | 16 1/2 | 5x25 1/2 | 1 1/4 | 15 1/4 | 27 1/2 | 30 1/4 | 5/8 | 4 | | 15 | 16 1/2 | 10 1/2 | 19 | 44 1/2 | 9 1/2 | 28 1/2 | 27 1/2 | 58 | 2 | 10 1/2 | 19 | 6x30 | 1 3/8 | 18 1/4 | 32 3/4 | 36 1/2 | 3/4 | 4 | | 18 | 19 1/2 | 12 | 22 | 51 | 11 | 31 1/2 | 30 | 64 | 2 | 12 | 20 | 6 1/2x33 | 1 1/2 | 21 5/8 | 35 1/4 | 39 1/2 | 3/4 | 4 | | 21 | 22 1/2 | 14 | 25 | 59 | 12 1/2 | 36 1/2 | 35 | 71 | 2 1/4 | 12 | 22 1/2 | 7x38 | 1 5/8 | 25 1/4 | 41 1/2 | 45 1/2 | 7/8 | 4 | | 25 | 26 1/2 | 16 | 30 | 68 | 15 | 41 | 39 1/2 | 75 | 2 1/2 | 15 1/2 | 25 1/2 | 8x43 | 2 | 29 1/4 | 46 | 50 | 1 | 4 | | 30 | 32 | 20 | 36 | 82 | 18 | 48 1/2 | 47 | 90 | 2 3/4 | 17 | 28 1/2 | 10 1/2x51 | 2 1/4 | 36 | 53 | 58 1/2 | 1 1/8 | 4 | | 36 | 39 | 24 | 58 | 102 | 22 | 57 | 57 | 98 | 3 1/2 | 17 | 35 | 11 1/2x62 | 2 1/2 | 41 1/2 | 63 | 65 | 1 1/8 | 4 | See Leaflet 6339/36 for Dimensions of Short Shaft Extensions and for Arrangement Diagrams. Dimensions given above are approximate only, and subject to alterations without notice. Standard arrangement includes Shafts extended equally on both sides, but shafts will be cut to suit customers' special requirements if stated in Inquiry or Order. The Paying-off Pulley is fitted to Variable Speed Shaft, which can be either shaft as required. The Chain Wheel or Hand Wheel on Operating Screw can be fixed on either end of screw. Hand Wheel is supplied with Standard Machines. Chain Wheel can be substituted if asked for when machine is ordered. The machine can be run in either direction. If makers are informed the relative position of the Machine to the Attendant's position, the Gear can be assembled in a manner to meet buyer's convenience. Buyers must decide which ratio will best suit their requirements, and order accordingly, as the Machine Belts are made specially to suit each of the various ratios. CROFTS (ENGINEERS) LTD. THORNBURY BRADFORD ENGLAND Telephone 4901 (6 lines) Telegrams : "Crofters, Bradford " | ||