Tapered Joint for Securing Cone Arm in Hole Opener

A hole opener comprising:

• a body extending along a rotational axis;
• a plurality of pockets formed in the body and angularly arranged about the rotational axis of the body, wherein each of the plurality of pockets includes a forwardly-positioned shoulder pocket section, a rearwardly-positioned tapered pocket section and a base opening axially extending through a wall of the corresponding pocket that receives a fastener therethrough;
• a plurality of cone arms, in which each of the cone arms include a cone head attached to an arm and in which the arm includes a forwardly-positioned shoulder arm section, a rearwardly-positioned tapered arm section, and a rearwardly-facing opening axially extending through the rearwardly-positioned tapered arm section that receives the fastener;
• wherein, when each of the plurality of cone arms is inserted into a corresponding one of the plurality of pockets and the corresponding fastener is tightened, the rearwardly-positioned tapered arm section is securely drawn into the rearwardly-positioned tapered pocket section of the pocket to create an pre-loaded fit therebetween and the forwardly-positioned shoulder arm section of the respective cone arm mates with the forwardly-positioned shoulder pocket section of the respective pocket.