TANGLEY CALLIOPE RESTORATION PROJECT (part 21)
by Dr. Bill Black
THE ROLL FRAME OPERATION
The Tangley Calliope has a very heavy duty roll frame, especially the gears. PHOTO A shows front view of the frame removed from the machine. The tracker bar tubing has been cut off since the tubing is so old and hard some of it will need to be scrapped off the nipples. Photos and a careful diagram of the hose arrangement was made. Since the calliope has 41 playing notes on the stack (the top two notes on the keyboard are not stack operated) and the A roll arrangements have 58 playing notes (the other holes are for control functions), some of the holes in the tracker bar are octave coupled to allow the 41 notes on the machine to play the 58 notes on the A roll.
PHOTO B shows the back view of the roll frame.
PHOTO C shows the gear arrangement of the frame. In the center of this gear cluster you will see a sprocket type pulley which will be connected to the air motor by means of a ladder type chain. This drives a a smaller gear meshed to large gear on a main drive axle. The large gear (vertical gear) serves to drive the supply spool when the rewind mode is engaged. Also on the main drive axle is another small gear meshed with another small gear which is then meshed to a large gear on a drive axle which serves to drive the takeup spool. These two gears also serve to reduce the rpms of the takeup spool. This gear arrangement allows slow rpms for the takeup spool while the machine plays and much faster rpms for the supply spool during the rewind function.
The drive axles for the takeup spool and the supply spool are each equipped with a clutch arrangement to allow for shifting the power from the air motor back and forth between the takeup spool and the supply spool to allow for a play mode and a rewind mode.
In PHOTO D the lower section of the gear arrangement shows the drive axle for the takeup spool. The red arrow points to the clutch on the takeup spool axle. These clutches are controlled by a vertical rod with a small arm engaging a groove in the clutch. This arm moves the clutch into either an engaged or a disengaged position. The clutches are made so that when one is engaged the other is disengaged. The vertical rod which controls this function is connected to the rewind pneumatic which we talked about before. When the rewind pneumatic is open (no vacuum applied) the roll frame is in the play mode (lower clutch engaged and the takeup spool is powered). When the rewind pneumatic collapses, the vertical rod is pulled toward the pneumatic, the vertical rod rotates, the takeup spool clutch is disengaged and the clutch on the supply spool axle is engaged (PHOTO E, red arrow). This is now the rewind mode. At the end of the rewind on the roll, the play valve is triggered, vacuum is removed from the pneumatic and a spring pulls the pneumatic open, rotating the vertical rod in the opposite direction and the frame shifts back to the play mode.
The roll frame is also equipped with a brake system for both the takeup and the supply spool. This is to help keep the roll paper against the tracker bar and also to help keep the paper tight on the spools during the play and rewind functions.This mechanism operates by means of wheels attached to the drive axle and the supply spool axle. When the roll frame is in the play mode, a spring holds the brake shoe against the wheel on the axle which drives the supply spool thereby applying a drag on the supply spool. The helps to provide a tight wind on the paper.
When the roll frame is in the rewind mode, vacuum from the stack cutout is channeled to a pneumatic on the roll frame. This pneumatic pulls the brake shoe onto the wheel on the axle which drives the takeup spool. At the same time, the brake shoe on the supply spool is released. The drag from the brake shoe on the takeup spool causes the paper to have a tight wind on the paper as it rewinds.
Next month we will take it apart.
Dr. Bill Black is one of the nation's most knowledgeble Wurlitzer band organ experts. He has made recordings of many band organs and other mechanical music machines which are available for purchase in our CarouselStores.com website.