Pressure on a forked lever fulcrumed to the base of the machine, one end of which encircles the collar and the other end touching the lower stop lever, holds the clutch out of action. When the pressure of the forked lever against the collar is released, the clutch spring expands and the clutch rod moves the collar inward until the leather buffers are pushed against the inner surface of the driving pulley, causing the shaft to rotate.
After the machine has made a complete revolution, a pawl on cam No. 10 contacts the upper stopping lever and through the lower stopping lever forces the forked lever against the collar, throwing the friction out of action.
The Clutch Spring
The clutch spring is held in place by a small collar on the inside end of the clutch rod and a screw bushing on the outside, by which the tension of the spring is regulated. This tension should be sixteen to twenty pounds. A screw pin passes through a slot in the shaft, through the clutch rod, and into the opposite side of the collar. The outer end of the clutch rod is connected to the friction clutch by a screw which passes through the clutch rod. By taking off the clutch and hooking a balance spring in the screw hole in the rod and pulling out on the scale, the instant the rod moves the scale indicates the tension of the spring registered. One end of the clutch rod is connected to the collar on the shaft, and the other end is connected to the clutch. When the collar is moved the clutch rod also moves in the same direction.
When the clutch rod spring is adjusted to a tension of 16 to 20 pounds it gives about the right friction to carry the machine through all its operations where everything is working properly, but if anything sticks or makes the machine run hard, the clutch will slip.
Friction Clutch Adjustments
There are three positions of the starting and stopping lever: Starting, operation, and stopping. When pulled all of the way out the lever is in starting position. When the lever is in starting position, the eccentric screw in the starting and stopping lever pulls against the lug in the vertical lever and causes the upper lug to force the automatic stopping pawl off the upper stopping lever. This sets the machine in action. When the lever is half way out it is in operating position and allows the machine to start when a line is sent in. When the lever is pushed all the way in the clutch is thrown out of action and the machine is stopped.
When making any adjustments, have the lever in starting position (out as far as it will go). If the automatic stopping pawl is resting on the upper stopping lever, the adjustments could not be made, as the lower stopping lever would be forcing the forked lever against the collar, throwing the friction clutch out of action.
The friction clutch should be adjusted so as to have 15/32 of an inch between the collar and the shaft bearing. Place a 15/32 inch gage between the right-hand side of the collar and the left-hand side of the shaft bearing. If the distance is less than 15/32 of an inch, dress the leather buffers with a file. If the distance is more, place cardboard under the buffers to increase the thickness. On old-style machines this adjustment was made by two nuts, one on each side of the clutch rod. Putting cardboard under the buffers will not satisfactorily drive the machine if something else is wrong. If there is too much packing under the leathers the starting and stopping lever will have no effect on the clutch and the machine will not stop properly.
The upper stopping lever and the lower stopping lever are fastened by pin pivots to a steel shaft which passes through the vertical lever. This allows a limited up and down movement of the stopping levers. The shaft is held in position by a set screw in the top of the vertical lever bracket. When the machine is in action the forked lever must be free of the collar. If it is not, the clutch does not get the proper pressure on the inside of the pulley, because the forked lever would push against the collar and force the rod and clutch outward. To be sure the forked lever is free of the collar, adjust so there is 1/32 of an inch between the lower stopping lever and the forked lever. This adjustment is made by the screw in the lower part of the upper stopping lever.