In the third movement (see Fig. 21), the top motion is the same as the first and second, but the cylinder movement is distinct. A flat, iron casting which acts as a slide, is placed on each side of the machine. These slides are supported by small iron rollers, which are placed in brackets fixed to the frame of the machine. At the end of the slide, a brass cup for the cylinder and the spring hammer is fixed. A stud is attached to the slide. The rod connected to the clamp of the cam (or what is called the eccentric rod) extends upwards and is attached to an arm that is set-screwed on a shaft, but extends upwards. This movement is one of the best. The brackets that support the rollers are adjustable but seldom in the life of a harness do they require adjusting, for if the rollers are well oiled they last many years, because the friction is at the lowest possible point.
[Illustration: Fig. 21. Showing Overhead Lever Lift and Slide Cylinder Motion.]
In the fourth movement a square cradle lever is placed in brackets near the feet of the machine, and connected to the top of the griffe spindle by means of an arm attached to the end of the cradle lever. This is shown in the double-lift machine, Fig. 22. There is an arm at each side of the machine that is connected to the cradle lever. To the outer end of the lever the long lifting rod is attached. The length of the square lever is generally twenty-eight inches from fulcrum to connection of long lifting rod, and ten inches on the shorter end. This gives about a four-inch lift to the griffe. The cylinder is driven by an independent spindle motion. An iron spindle is attached to the frame that supports the cylinder. The spindle passes through two slide brackets fixed to the sides of the machine. Between the two brackets and set-screwed on the spindle is an extension with a stud attached to the top of it. On this stud, the connecting arm from the lever is placed. The lever is supported at the top of the same bracket that supports the square lifting lever. To the outer end of the lever the eccentric rod is attached, but instead of using a cam to give motion to the cylinder, one part of a double crank is used, the other portion is used for lifting the griffe.
