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).
Letter from The Fulton Company regarding the specifications and performance of three returned shutter thermostats.
| Identifier | ExFiles\Box 77\4\ scan0311 | |
| Date | 16th January 1923 | |
| Copy of letter from:- THE FULTON COMPANY, Knoxville, Tennessee, U.S.A. January 16, 1923. Rolls-Royce Ltd., Derby, England. Gentlemen, Reference Wd{Mr Wood/Mr Whitehead}5/NJ4123. Replying to your letter of January 4, in regard to the three shutter thermostats which you sent to us for charging, we have finished these up and made return shipment direct to you by parcel post on January 9. These were all included in one package, and we will send you an invoice at $1.90 each, which is the price we charged you for the Sylphons, so that you can get them through the customs. You understand of course that we do not expect you to pay this invoice. Our Engineering Department inform us that we could not quite meet the range specified in your letter, so we charged each differently, as marked on the tag attached to each instrument, which is as follows:- One charged with acetone - starts at 166°F.{Mr Friese} (74° Cent.) and makes .420" stroke at 171°F.{Mr Friese} (77° Cent.). One charged with C.P. Methyl Alcohol - starts at 177°F.{Mr Friese} (80 1/2° Cent) and makes .430" stroke at 183°F.{Mr Friese} (83 1/2° Cent). One charged with special denatured alcohol - starts at 188°F.{Mr Friese} (87° Cent) and makes .420" stroke at 198°F.{Mr Friese} (93° Cent). In all cases the thermostats were loaded with a dead weight of 35#. In production these temperatures would vary a few degrees up or down, but upper and lower limits could be held within 10° Cent., unless an unduly stiff spring were used, or the shutters had an undue amount of friction. Of course the less the shutter friction and the nearer constant the spring tension is throughout the stroke, the closer will be the operating range. In fact by suitable lever arrangement it is possible to make the spring tension almost uniform, or even a little stronger, say four or five pounds when the bellows is cooled down, which would compensate in large measure for the resilience of the bellows itself. We hope that these three instruments reach you in good (contd) | ||