Page:Motors and motor-driving (1902).djvu/156

124 distance from the centre of shaft. As a result, the hammer is slightly depressed. Now forms portion of the bracket, and, consequently, when  is depressed it moves the bracket  slightly forward from the perpendicular, as seen in fig. 15. This, in turn, pushes forward the spindle, so that the digger at the end of it misses the shoulder , as shown in the diagram. A careful study of figs. 14 and 15 side by side, and the angles of the various arms and brackets, will show distinctly how their position is altered to accomplish the end in view. Fig. 17 shows a perspective view of the mechanism which will further help the reader.



Fig. 16 will assist the reader to understand the way in which the hammer climbs from cam to cam. It represents the end view of the two cams and the collar, with the hammer resting on the largest one,. It will be noticed that their circumferences coincide at one point, thus enabling H to slip from one to the other with facility. , the circular collar, is mounted truly on shaft, whereas and  are mounted upon it eccentrically.

We have now to describe the mechanism that operates the hammer, and to show more clearly the cams on which it acts.

The mechanism which operates the hammer is commonly known as the governor, and is clearly shown in fig. 17. This mechanism is attached to shaft. In figs. 14 and 15 the