Corer and method using same

A corer, comprising:

• a connecting sleeve;
• a power lever connected to the connecting sleeve;
• a hook cylinder having an upper end inserted into the connecting sleeve;
• and
• a cutting hook connected to a side of the hook cylinder;
• wherein a full-length opening is vertically formed on a side wall of the hook cylinder;
• an upper end of the hook cylinder is detachably connected to the connecting sleeve, and an arc slot perpendicular to the full-length opening is provided on a side of a lower end of the hook cylinder;
• and a plurality of teeth are arranged on a lower end surface of the hook cylinder along a circumferential direction;
• a cross section of the hook cylinder at both sides of the opening on the side wall is an arc surface;
• the cross section of the hook cylinder is fitted with a circular cross section of a connecting rod of the cutting hook;
• a radian of the cross section of the hook cylinder is consistent with a radian of an arc of an outer wall of the connecting rod of the cutting hook;
• the connecting sleeve is a funnel-shaped cylinder which comprises a cylindrical upper portion, a conical connecting portion and a cylindrical lower portion;
• a set of clamping slots are provided on an inner side surface, corresponding to an opening of the hook cylinder, of an upper portion of the connecting sleeve;
• the clamping slots are configured to clamp a handle of the cutting hook;
• an included angle between the clamping slots is 10-25 degrees;
• and
• a pair of bolt holes is symmetrically provided on a side wall of the upper portion of the connecting sleeve;
• a plurality of bolts for rotating the connecting sleeve are arranged in the bolt holes.