PURPOSE: To reduce the cost of product as well as facilitate manufacturing moulds by a method in which the tumbler-housing chamber of a core to be slidably and rotatably attached to a cylinder is formed by setting a separate partition wall plate into the recession of a block-shaped mold.
CONSTITUTION: A given shape of a core 20 having a recession 29 and a recession 26, which is formed by a block-shaped mold 70 with a continuously waved recession 71, is provided. A given shape of a partition wall plate 28 whose upper part has the same shape as the periphery of the cylinder 21 is set into the recessions 29 of the core 20 to form a tumbler housing chamber 25. A tumbler is housed in the chamber 25, and the core 20 with sidebar and other given components are set in the cylinder an a turnable and slidable manner. The needs for forming the partition wall in the core can thus be eliminated in manufacturing mold, and the mold can thus be easily obtained. Damage to mold and occurrence of defect product can be prevented. Also, the accuracy can be raised and the cost can also be cut down.
YAMAMOTO TSUTOMU
YOSHINO SHIGERU
