Патент USA US2409446код для вставки
l 2.1 %” 1946 ’ 2,409,444 v .. is!) STATES PATENT I 0 2,409,444 FFlCEY CLOCK LUBRICANT John D. Morgan, South Orange, and Russell E. ' Lowe, East Orange, N. I... assignom to Cities Service Oil Company, poration of PennsylvaniNew York, N. Y., a cor No Drawing. Application August 14, 1944. Serial No. 549,494 ‘ . ' » 2 Claims. ‘(or 252-494;) ‘This invention relates to lubricants and more particularly to compositions for lubricating elec tric clocks, chronometers and similar precision timing devices. ' r - 2 ‘ country and are readily available on the open market. The production or our lubricant does not depend, thereioraupon the availability 01' ingredients which must be imported from abroad, The small synchronous electric motors, and as as do many timepiece and other special oils, and sociated gear trains, which constitute the timing 5 the product can be made and sold at a compara units of most electric clocks and similar chronoé ' tively low cost. phic devices. raise lubrication problems which One speci?c example or a lubricant which is not answered by any 01' the normal time well suited to the lubrication of elec piece oils, nor even by many of the special oils 10 particularly tric clocks and similar devices has the following which are prepared for this speci?c work. As a uenerel rule the bearings and other moving parts ~ Percent by weight of these motor units are lubricated but once, at Tricresyl phosphate. _..-....-.._..-....-..--_---..-..- 0 the time oi manufacture, and the lubricant must Di butyl phthalate ____________________ __-..__ 20 lost for the full life of the device. It is accord I5. Tri ethylene glycol di-Z-ethyl butyrate-r_--_ 30 inaly cmential that the lubricant shall be chem- ' The resulting oil-like product has'a kinematic ically stable to a high degree, resisting oxida tlon and polymerization, both of which chemical ' viscosityloi 13.49 centistokes at 100° F., a value formula: ' v which is recognized as substantial at this high catine‘ values. A further requirement is that the 20 temperature and as being entirely adequate for the lubrication oi.’ electric'clock bearings. When lubricant must have an extremelyvlow volatility the temperature of the liquid is dropped to --l0° so that it will not evaporate during the life of F., its viscosity increases to a value of only 380.4 the timing mechanism and leaving the bearings centistokes, which for this temperature is fairly and other parts dry. Obviously in service of this low. Both the pour point and the cloud point hind it is very important that the lubricant shall - 25 of the liquid are at some temperature below not attack the bearings, pivots. and gears. and ‘ —60° 11., thus indicating that the composition that it should tend to protect those parts from does not begin‘ to separate into its components corrosion by the water vapor. and oxygen oi’ the nor to freeze at any temperature at which elec atmosphere.v In addition to all of the foregoing. is essential thatthe lubricant shall not react 30 tric clocks can be expected-to operate. It will be evident from the foregoing that the viscosi_ with or dissolve the painted and lacquered dials ties of our ?uid may be said to be low, that they » and other parts 01' a clock mechanism which ac-' remain relatively constant over a wide range of tion would tend to destroy the utility of both the temperature. and that these properties are well cficvice and the oil itself. within the viscosity-temperature speci?cations ‘The principal object or the invention is to pro vide a lubricating oil which. is chemicallv stable 35 laid, down by the leading manufacturers of elec trio clock mechanisms for lubricants vfor their over estencied. periods of time. has a relatively reactions tend to change the viscosity and lubri- . timing mechanisms; . ' ‘low viscosity over a wide range of temperatures. ' The volatility oi’ the composition is extremely .hich is non-corrosive to metals used in the‘ low. Upon test in an open cup. a sample 01' our wustruction of electric clocks. and has no sol 49 ?uid showed a loss 01' only'lour tenths of one per ‘i‘dl’lt or chemical effect upon the paints and lac cent after being held at a temperature of 160° liuere normally‘ used in such devices. F. for 500 hours. , y ‘it is a further object of the invention to pro The chemical stability of the ?uid is excellent. vide a time piece lubricant which is better adapt is. or course, free, 01' gum when ?rst prepared, ed to meet lubrication requirements of synchrof 5 It and long exposure at high temperature does not nous electric clocks than any of the lubricants seem to produce any undesirable residues. A thin now available for this purpose. and which may ?lm oi the liquid was held at a temperature of manufactured at a comparatively low cost 160° F., for example, forsome 300 hours-after from synthetically prepared lnrzredients that are which it showed no tack development or other readiiy available in the domestic market. indication of deterioration. At more moderate We have discovered that very satisfactory 50‘ temperatures of the order of normal room. tem lucants can be prepared from mixtures of tri peratures, there is no evidence of oxidation and phosphate: di butyl phthalate; and tri gumming, even after very extended periods of ex ethyiene glycol di~2-ethyl butyrate. These in posure. ' crements are all prepared synthetically in mm on A further feature of the advantage of this 2,409,444. a . lubricant is its very low spread factor. Thus, the liquid tends to stay in the place in whichit is put and not to creep away to surrounding‘ sur faces. We have found, for example, that the lubricant does not tend to spread away from the main shaft of the timing unit to the dial of an electric clock, nor to_oreep around the'edge of 4 within the following range: tricresyl phosphate 40 to 60 percent; di butyl phthalate 25 to 15 percent; tri ethylene glycol dl-2- etc. 35-25 per cent, the percentages being by weight.‘ All of these compositions have good lubricating prop erties, are stable and resist gum-forming tend encies for long periods of time, and have little or no action uponlithographic paints. The per centages of the individual ingredients may be The solvent action of the lubricant upon lithc- Y adjusted, to bring out one or another of these 10 graphic paints and lacquers was tested by im properties for‘the purpose of meeting the special mersing llthographed clock dials in the lubricant } requirements of individual problems. time and at temperatures‘ for extended periods of Having described our invention what we well in excess 01' normal summer heat. ' At the claim is: conclusion or these tests the dials showed no ill 1. A lubricant consisting essentially of a mix» e?ects. The lubricant exhibited no tendency to 15 ture of from 40 to 60 percent of tricresyl phos remove the lithographic paint, or to soften it in phate, from 25 to 15 percent of di butyl phthalate, the least. and from 35 to 25 percent of triethylene glycol The ?uid has no corrosive action upon steel,» di-2-ethylbutyrate, all of said percentages being copper, and brass or other metals normally used by weight. 20 in clock manufacture. In fact its presence on 2. A lubricant for electric clocks and the like pivots, bearings, etc., serves to prevent rusting consisting of about 50 percent by weight of tri and atmospheric corrosion. ' cresyl phosphate, about 20 percent by weight oi! The foregoing composition is an ideal lubricant di butyl phthalate, and about 30 percent by for lubricating electric clocks and the like, be weight of triethylene glycol di-2-ethylbutyrate. the case, etc. ' - cause of its unique properties that particularly suit it for that type of service. We have found, however, that other desirable lubricants may be prepared from mixtures of these same ingredients 1 JOHN D. MORGAN. RUSSELL E. LOWE.