PURPOSE: To make a bit detachable from its holder more easily, and what is more, maintain stabilized excavation without producing any unsteadiness.
CONSTITUTION: A pair of fork-shaped interlocked seats 2 and 3, which are installed a bit 1, are joined with a receiving seat 4a, which is installed to a dented holder 4 in such a fashion that they may be separated by the relation between a dovetail slot and a dovetail. A removable pin 6 is fitted into the interlocked seat and the receiving seat in a direction intersecting a separation direction, which restrains the bit 1 to the holder 4 and connects them. As a result, the two restraint system based on the dovetail slot and the pin 6 restrain the bit to the holder, thereby securing the safety of the excavation bit during excavation. In addition to that, an elastic sleeve 5 is installed to a penetration hole which allows the pin 6 to penetrate into the receiving seat. This sleeve 5 elastically receives the load which exerts to the pin 6, thereby protecting the pin from flexibility deformation.
NAKANO KAZUTAKA
NAKAGAKI TOSHIYUKI
KUROKI KENJI
SKY ENTERP KK