Cuckoo Clock Bellows
The air current from the bellows enter thru opening No.1, passing into a small air chamber, the air then emerges thru the narrow slit, No.2 and escapes in puffs between lips Nos. 3 and 4. The puffs are due to the fact that the air currents from No. 1 strikes upon a bevel lip No. 4 and breaks into a flutter, the puffing sound thus produced consists of a confused mixture of many faint sounds. The air column No. 5 of the pipe can resound only to one of these tones, the resonance of the air column, brought about in t~is way, constitutes the tone of the pipe.
Cracks in the pipe can be sealed with glueing a small patch of ordinary paper over the cracks. Sometimes the orifice becomes clogged with dust, or the edge may become rough. By inserting a very thin file or watch mainspring, the lip may be cleaned or smoothed. If the width of the orifice is enlarged, it will change the tone. The tone can also be changed by altering the position of block No.6. By decreasing the air chamber, a higher pitched note is the result, or by increasing the length of the air chamber, a lower pitched note will be had.
The lead weight, No.7, is to increase the air pressure when the bellows are released. If too much weight is used, the action of the bellows will be too fast, forcing the air out too quickly, causing a whistling sound. The bellows must be lifted to full capacity in order to get clear long notes.