PURPOSE: To enable simple and rapid regulation of a blade part gap, by a method wherein guiding is effected so that an inclination angle is variable on the one side of the upper part and the lower part of a ram is guide, and guiding is effected in a manner that through longitudinal movement of the ram on the other side, the inclination angle is changed.

CONSTITUTION: When a shaft 17 is rotated by a one complete turn with the aid of an electric motor, a ram 16 at both end parts of the front of which liners 25 are secured and to the both end parts of the rear of which liners 26 are secured is raised after it is lowered one time, a lower blade 22 is secured to a table 15 and an upper blade 23 to the ram 16. A linear 33 is supported by a holder 28, a recessed surface member 30, and a spherical member 32 of each of front upper guide devices 27 on both sides of a frame 10 so that an inclination angle is variable. With a handle 62 rotated, a fan-shaped gear 48 is rotated, an eccentric member 52 is rotated through a coupling rod 55 and a lever 53, and a guide member 58 is longitudinally moved. A recessed surface member 41 and a spherical member 32 are longitudinally moved through the elasticity of a disc spring 42 of a front lower guide device 40 in a manner to nip the ram 16 therebetween to change the inclination angle of the ram 16, and a gap (e) between upper and lower blades 23 and 22 is changed.