Abstract: The present invention provides a drill for making a dilled hole having a high circularity. The axial asymmetric edge drill has a chisel portion formed in the tip center so that the chisel portion center matches with the drill shaft center. At least one of the cutting edges is in an axial asymmetric position with another cutting edge across the drill shaft center. The outline of the edges of the drill forms a circular arc.

Abstract: A movable automatic bolt driving apparatus sequentially drives a plurality of bolts positioned substantially in line on flanges of elongated concrete molding frame segments for producing columnar concrete products. The apparatus has a vertically movable bolt driver unit and an air-cylinder unit. When the bolt driver unit drives a bolt in a state that the socket and the bolt are non-concentrically engaged with each other, the air-cylinder unit causes to properly reposition the bolt driver unit. At least a part of the bolt driver unit, which is normally disposed vertically, is pivotable with a horizontal pivotal axis orthogonal to the moving direction of the apparatus. The apparatus also has a flange follower for guiding the bolt driver unit. At least a part of the flange follower, which includes a roller having a vertical rotating axis, is pivotable about a vertical rotational axis.

Abstract: A simply constructed web tension meter is of reduced dimensions capable of preventing an object material from being displaced during a web tension measuring operation. The meter consists of a hollow body provided with an inlet port to which a fluid supply source is connected. An ejection port is opposed to one surface of the object material with a clearance left therebetween. An internal pressure measuring port, and a web tensioning unit are provided with a pressure measuring device joined to the internal pressure measuring port. This meter further includes as necessary another hollow body provided with an upstream port connected to a fluid supply source, and discharge ports opposed to the other surface of the object material with a clearance left therebetween. A web tension controller consists of the same web tension meter as mentioned above in an object material handling apparatus, and a web tension regulator regulates the tension imparted to the moving object material.