week 6: mechanism of carrying tea doll

-->

Today I would show you “cost of Karakuri doll” so I asked the museum about it, but there are few information. Therefore I will talk about carrying tea doll’s mechanism in this week, sorry.

Mechanisms of a carrying tea doll

The inside of a Karakuri doll seems to have been made with a wood, a thread, and a whisker of a whale (materials of a spring).

A doll does the following movement:

1. A spring is wound up first, and then a doll is in the state that stands still.
2. If a master puts a tea cup on the tray which the doll supports, the doll will begin to advance and the legs of the doll begins to move forward and backward.
3. If the doll comes in front of a visitor, the head of the doll will lean forward, that is, the doll bows.
4. Then, if a visitor takes up a teacup, the doll will stop, and the leg motion will also stop.
5. If a visitor drinks up tea and puts the teacup back on the tray again, the doll will rotate 180 degrees.
6. Then, the doll stands with the head straight.
7. The doll begins to advance toward the place where the master is, ie, a starting point. The legs of the doll also move again forward and backward.
8. If the doll comes back to the master and the master takes away an empty teacup from the tray, the doll will stop moving and the legs also.

Mechanism of feet moving back and forth

When the eccentric disk (that is A) rotates, the horseshoe end of component B which is between in A without clearance oscillates. This is a positive motion cam. That is the leg of the Karakuri doll connecting with B moves forward and backward. Moreover, since the phases of the eccentric disk of legs on either side are shifted 180 degrees, a leg on either side moves forward and backward by turns.

Mechanism of a turn

It is about the bottom of the doll. This picture shows the front and the back. A lever has a prop in the lower part and the upper end of the lever is always pulled clockwise with the thread and the board spring. That is, the upper end of the lever is always pulled back. The upper end of the lever is connected with the handle of the front wheel through the coupling rod, using thread. The direction of the front wheel is forward when the protrusion of the rotation disk does not touch with the tip of the lever. If the protrusion of contacts and moves the tip of to the front, will rotate the clockwise and the doll will turn to the right. If the protrusion of leaves from the lever, wheel will rotate anticlockwise and a doll will turn to the right. This combination of this wheel and the lever is the cam mechanism.

We can make carrying tea doll with kit, so why don’t you make it?

http://otonanokagaku.net/magazine/vol16/index.html

(Reference)

http://translate.google.co.jp/translate?hl=ja&sl=en&u=http://www.museum.kyoto-u.ac.jp/english/materials/chakumiDolleng.html&prev=/search%3Fq%3DKarakuri%2Bdoll%26start%3D10%26hl%3Dja%26safe%3Doff%26client%3Dfirefox-a%26hs%3DzQb%26sa%3DN%26tbo%3Dd%26rls%3Dorg.mozilla:ja-JP-mac:official%26biw%3D1001%26bih%3D624&sa=X&ei=zZD_UISSKdHYkgX5joGoBQ&ved=0CDEQ7gEwADgK