To tighten and loosen a bolt while once stopping a form in an apparatus for automatically tightening and loosening the bolt nut of a split form molding a long concrete product to achieve the miniaturization and cost reduction of the apparatus.
A tightening and loosening truck 9 loaded with a tightening and loosening tool 19 and made freely movable in the moving direction of a form 1 is arranged above a form feed truck 6. The rotary support 5 of the fed form is detected by a stop signal emitting detector 36 to stop the form at the tightening and loosening position under the tightening and loosening truck 9. Next, the tightening and loosening truck 9 is moved while referring to position data such as a bolt pitch preliminarily inputted on the basis of the stopped rotary support 5 to perform tightening and loosening work within a predetermined range. When bolt tightening and loosening work is completed, the feed of the form is resumed and, continuously, when the rotary support 5 of the next form is detected, the same operation is repeated and the bolt tightening and loosening of the whole of the form is performed.
NAGASAWA YOSHIFUMI
AYUSAWA KUNIHIKO
