GB551756A - Improvements in roller chain sprocket wheels - Google Patents

Abstract

551,756. Chain wheels. KLAUCKE, H. Sept. 3, 1941, No. 11273. [Class 80 (i)] Consists in a sprocket wheel, for use with roller chains having side plates, which will compensate for inequalities of pitch in certain links of the chain due to wear and ensure that the chain as a whole will operate on a true pitch circle. According to the invention, alternate teeth of the wheel are of conventional form, those between them being shorter and having their profile faces sloping at a greater angle to a normal, the conventional teeth being adapted to be straddled by the pin links and the blunter teeth by the roller links. Fig. 1 shows a wheel all the teeth 18 of which are of conventional form and in which, due to wear, the pin links 14 have become elongated in pitch causing an increase of the distance between the centres of the rollers 16 with the result that the rollers ride higher on the teeth. Wear does not have the same effect on the roller links 20 and therefore pin and roller link pitches have become unequal with the result that the forward roller of each roller link is caused to ride even higher on the teeth than the rear roller link and therefore the chain does not run on a true pitch circle. In Fig. 2 it is seen that the forward roller 26 does not even engage its tooth and carries no load at all. In Fig. 4 is shown the long conventional teeth 32 alternating with the shorter and blunter teeth 34 the latter being relatively broader at the base so that the rollers will, when new, seat therein. As the pitch of the pin links increases and the teeth and rollers wear, the chain as a whole runs on a larger pitch circle, but it is still a true circle. A method of obtaining the shape of the teeth 34 by plotting from successive roller positions on the teeth 32 is described with reference to Figs. 5, 6 (not shown).