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).
Page describing new industrial processes for cadmium plating and wire annealing, with a partial article on spring stress calculations.
| Identifier | ExFiles\Box 56\2\ Scan061 | |
| Date | 1st January 1929 | |
| (Continued from page ...) position for an equivalent compression by an amount may be as great as or g[reater] than a half pitch of the p[o]lar coil. At an instant on[e] wave later, the condition [is] exactly reversed. Thus, the stress range statically amount to 15,900 lb. per s[q. in.] the stress range in vib[ration] operation may vary be[tween] zero and solid stress, or greater than the latter, de[pend]ing upon the amount of i[mpact] due to coil clash. To be a little more s[pecific] about this stress range[,] stresses on the spring [at its] natural period was 10,750 vibrations per minute r[eads as] follows: Stress, Lb. per S[q. in.] Spring compressed solid With valve open With valve closed When this spring is vib[rating] severely in its own perio[dic] coils which are closed and [the spr]ing will be stressed 69,0[00] sq. in., or even more, depe[nding] upon the impact value [of the] coil clash. At the same in[stant] a coil at the opposite end [of the] spring will be opened up [a cer]tain amount, due to the motion. If the latter c[oil is] opened up an amount [which] will make its pitch at th[at in]stant equal to its pitch [when] the spring is in a free or unloaded condition, the[n the] stress range will be 69,0[00] per sq. in. or more. This, [how]ever, is a very extreme ca[se]. It is especially importa[nt to] remember that the rapidit[y with] which this stress range is [passed] through is of an order greater than camshaft [speed]. For example, in the case [of the] spring mentioned, which [has a] natural period of 10,750 f[i]brations per minute, the abnormally high stress will pass from the maxim[um to] the minimum value in 0.[...] sec., or in the time for the [...] to assume a position exact[ly out] of phase with its former [...]tion. From the foregoing c[...]sion it can be seen that [...] January, 1929 New Wire Device for Cadmium Plating A NEW type of anode, with wire cylinder container, for users of Udylite process in cadmium plating has been developed by the Udylite Process Co., Bellevue Avenue, Detroit. The anodes are made in the shape of a sphere and are used in a wire cylinder container which has a hook for suspension in the plating solution. As old anode balls are used up, new ones are dropped in at the top, When corroded balls grow smaller they work toward the bottom of the container, leaving room at the top for fresh supplies. Advantages claimed for the method are that the anode area never changes; there are no studs to remove; there is no metal to pick out of the tank, and both anodes and container are clean and accessible. The anodes of pure metal are cast in the form of balls of 2-inch diameter, weighing approximately 1¼ pounds each. To equip the wire containers, five-eights of a pound of anodes are required to each inch of container, which are made in seven standard lengths ranging from 18 to 36 inches. New Annealing Pot for Wire THE Fuzon annealing pot for wire, product of the Chicago Steel & Wire Co., is of welded stainless steel construction and is said to reduce annealing costs almost 50%. Although it weighs only 660 pounds, it takes the place of a cast steel pot and only requires the heating of 2660 pounds of metal, whereas the cast steel pot required 5300 pounds. At the annealing point of wire, which is 1350 to 1400 degrees F.{Mr Friese}, this stainless steel shell has scarcely taken color and consequently there is no sign of scale on surface or interior, so the life of the pot is extended almost indefinitely. The Fuzon pot is about 7 feet high and has an outside diameter of about 24 inches. The body is made of 18% chromium with 8% nickel stainless iron. It has a wrought steel base plate seven eights of an inch thick and a wrought steel collar on top about one inch thick. Eight carbon steel rods, one half inch in diameter, are welded to the collar and to the base to take the lift. A steel plate is welded inside so coils of wire can easily be removed and not catch in the corrugations of the outside shell. The shell is of 14 gauge stainless iron, first formed and then riveted—the riveting being primarily for the purpose of retaining the proper shape and not to afford extra strength. One of these pots that has been in and out of the furnace approximately 75 times and up to the annealing point for several hundred hours showed no signs of crack or fracture under the microscope at the points where the stainless iron is welded to mild steel. | ||