MOLD DRIVING SHAFT FRICTION CLAMP
The object of the friction clamp is to prevent the mold disk from vibrating when advancing to the casting or ejecting position, and is found attached to the mold driving shaft and held by a pin in the mold gear arm. The lost motion in several pinions from which the mold disk gets its action, will cause the disk to vibrate when stopping ready to advance on the vise stud blocks, unless it is held by the clamp which acts as a brake.
When the mold disk has made the one-quarter and three-quarter revolutions it must remain in that position, or the locking studs, coming in contact with the rims of the stud block, would wear.
The friction clamp which overcomes the vibration is made in two sections, with a leather lining, and connected to the mold turning shaft. A spring, washer, and lock nut add to its construction. The pin in the mold gear arm to which it is also connected prevents it from turning with the shaft. Do not have more friction than necessary, for if there is too much, the main clutch could not drive the machine, as the strong friction on the clamp would overcome the pull of the clutch spring.
Retiming Mold Gears
There are various methods of retiming the gears of the mold disk drive in case it is necessary to pull the disk forward while the machine is out of normal.
One method is to observe the position of the mold turning segments. Remember that the short segment causes the mold to revolve one-quarter revolution, or from normal to casting position. The long segment causes the mold to revolve three-quarters revolution, or from casting to ejecting position. The mold disk turns counter-clockwise. Place the gears in mesh so the punch marks on the gears register. Lock the mold slide in position. The drive pinion makes one complete revolution for each quarter revolution of the mold disk, and it goes on the connection pin at any complete revolution. Hold out on the drive pinion and turn the disk and drive pinion by hand the distance indicated by the amount of the segments which have passed the square block drive pinion. When the connecting pin enters the hole in the drive pinion, with the mold in the estimated position, the disk should be in time. Be sure the mold which is being used is the one which is placed in this position. For example, if the short segment and half of the long segment have passed the square block drive pinion, the mold should be turned one-half the distance from casting to ejection position. To observe what part of the segment is past the pinion, look directly underneath the frame of the machine which supports the mold turning shaft.
Another method of putting the disk in time is to disregard the position of the cams, connect the mold slide, and bring the disk, with the mold that is being used, into ejecting position. Hold the mold turning pinion away from the pin that connects it to the shaft, so that the disk will not revolve as the machine is set in motion. Pull out on the starting and stopping lever, thus letting the machine run around to normal position. Be sure that the disk locking studs are parallel with the stud blocks before starting the machine.
It is only necessary to let the vise down, disconnect the mold lever from the slide, and put the disk and drive pinion in time.