Abstract: An object of the invention is to provide a structural foundation wherein a spiral pile for supporting the foundation can be fixed in such a stable manner as not to displace in the horizontal direction or not to subside in the vertical direction. The structural foundation can be easily installed on site with reduced costs for transportation and installment so as to support a structure or part of a structure.

Abstract: A purpose of the invention is to provide a spiral piece of steel having high mechanical strength and being capable of easily making smaller the pitch intervals of twisted portions (spiral blade portions) even without changing the twist angle, and also to provide an application product thereof and a method for manufacturing the spiral piece of steel.

Abstract: An object of the invention is to provide a manufacturing method and an apparatus for a twisted flat bar which can prevent the pitch from becoming inconsistent and makes it possible to process a long flat bar into a twisted flat bar. A flat bar (5) is sandwiched between two round bars (7), which are positioned so as to be inclined at the same angle in different directions relative to the longitudinal direction of the flat bar from the two sides, and the above described two round bars are rotated relative to the flat bar around the rotational axis in the longitudinal direction of the flat bar, and at the same time, the flat bar is moved in the longitudinal direction of the flat bar relative to the round bars.

Abstract: An object of the invention is to provide a manufacturing method and an apparatus for a twisted flat bar which can prevent the pitch from becoming inconsistent and makes it possible to process a long flat bar into a twisted flat bar. The manufacturing method for a twisted flat bar is characterized in that a flat bar (5) is sandwiched between two round bars (7), which are positioned so as to be inclined at the same angle in different directions relative to the longitudinal direction of the flat bar from the two sides, and the above described two round bars are rotated relative to the flat bar around the rotational axis in the longitudinal direction of the flat bar, and at the same time, the flat bar is moved in the longitudinal direction of the flat bar relative to the round bars.

Abstract: (57) Abstract: An object of the invention is provide a new pile for replacing conventional foundation piles so that piles can be driven into the ground with little vibration and noise and residents in the neighborhood are not bothered, and in particular, to provide a spiral steel pipe pile that can be smoothly driven into the ground even when the outer diameter exceeds 100 mm. The spiral steel pipe pile has a steel pipe (3), a spiral portion (4) gained by twisting flat steel having the same or a greater width than the outer diameter of the steel pipe, and a spiral slit (5) through which the spiral portion is inserted at the lower end of the steel pipe, and is characterized in that the spiral portion is inserted into the slit and the steel pipe and the spiral portion are welded together in such a state as to share the same center line, and a cover (6) in conical form is welded to the lower end of the steel pipe so that a hole in the spiral insertion portion is covered.

Abstract: To provide a thrust fork to arrest a resisting criminal without danger of being stabbed by an edge tool, a thrust fork main body (2) attached to an end of a handle portion (1) is provided with a forked rod (21), movable opening and closing rods (23), which have base end portions respectively pivoted to leading ends of the forked rod and freely swivel only inside the forked rod without outward movement, a returning element (24) to return the opening and closing rods (23) by a spring to an original position, and a constraining rope (26), both ends of which are engaged with leading ends of the opening and closing rods (23) respectively to form a ring 44 having a suitable size inside the forked rod, whereby the end of the forked rod is opened and closed via swiveling of the opening and closing rods.

Abstract: To provide a thrust fork to arrest a resisting criminal without danger of being stabbed by an edge tool, a thrust fork main body (2) attached to an end of a handle portion (1) is provided with a forked rod (21), movable opening and closing rods (23), which have base end portions respectively pivoted to leading ends of the forked rod and freely swivel only inside the forked rod without outward movement, a returning means (24) to return the opening and closing rods (23) by a spring to an original position, and a constraining rope (26), both ends of which are engaged with leading ends of the opening and closing rods (23) respectively to form a ring 44 having a suitable size inside the forked rod, whereby the end of the forked rod is opened and closed via swiveling of the opening and closing rods.