Abstract: A permanent form for placing a basement concrete wall includes a percolation layer and a water-conduit channel for discharging water leakage or the like from a basement concrete wall. If the basement concrete wall is placed using the form, the percolation layer is impregnated with cement paste of concrete, whereby the form and the basement concrete wall are joined to each other. Redundant water before hardening the concrete, water leakage after hardening or the like flows into the water-conduit channel through the percolation layer, flows downward through the water-conduit channel, and is discharged from the bottom of the form. In addition, heat from the basement concrete wall is cut off by a heat insulating layer provided on the side of the interior as viewed from the water-conduit channel.

Abstract: An electro-fusion fitting includes a body, and a magnetic alloy member which is continuous in the axial direction is embedded in the vicinity of a joint surface of the body. A shield member is arranged on the outer surface of the body in a portion where a cold zone is to be formed. The joint surface of the body and a joint surface of a member to be joined are brought into contact with each other. When a high frequency current is applied to the magnetic alloy member from a high frequency power supply by electromagnetic induction in this state, the magnetic alloy member generates heat, so that the body and the member to be joined are fused, and joined to each other. Since the shield member shields the electromagnetic induction, the magnetic alloy member in a portion where the shield member is provided does not generate heat, so that the cold zone is formed in the portion.

Abstract: A method for producing a synthetic resin union joint, the method including the steps of forming a union nut having a screw portion and a union sleeve of an elastically softenable material, the union sleeve having a union swivel end and a connecting end, heating a length of the union nut at least equal to a thickness dimension of the flange part but not extending to the screw portion so as to elastically soften the length of the union nut, abutting one end of a truncated cone-shaped expansion guide with an end face of the union swivel end, shifting and enlarging the length of the union nut along the expansion guide so as to pass over the union swivel end and so that the union nut passes over the guide, and returning the length of the union nut to its original configuration due to a restoring force of the elastically softenable material so as to be positioned within the union swivel end and the connecting end.

Abstract: Two plastic tubelike members on which an annular protrusion or an annular groove are respectively provided to be used as two constructive block members for assembling valve or joint devices are directly coupled to assemble such devices. Critical dimensional relationships on the coupling end having the annular groove are established wherein a deformation process can be controlled to engage the annular groove with the annular protrusion by a radially widening motion and an axially spring motion in elastic dynamics, while the coupling end having the annular groove is softened by heating to become elastic. High coupling accuracy can be secured with high coupling strength and durability.

Abstract: For the purpose of making a joint socket comprising at least two portions, namely a portion for receiving a plastic pipe end and another portion into which a rubber ring is fitted, a device for heating and softening a plastic pipe end and enlarging the radius of the softened pipe end to twice its size which includes, an inwardly slanted portion between a first outwardly slanted portion and a second outwardly slanted portion whose radius becomes smaller as it comes nearer to the front end thereof. As the result, the frictional resistance between an improved core and the radius enlarged softened pipe is reduced to a value which enables the device to be operated such that wall-thickened sockets can be made without loss of wall thickness subsequent to the radius enlarging process.

Abstract: For the purpose of making a joint socket comprising at least two portions, namely a portion for receiving a plastic pipe end and another portion into which a rubber ring is fitted, a method of heating and softening a plastic pipe end and enlarging the radius of the softened pipe end to twice its size which includes, an inwardly slanted portion between a first outwardly slanted portion and a second outwardly slanted portion whose radius becomes smaller as it comes nearer to the front end thereof. As the result, the frictional resistance between an improved core and the radius enlarged softened pipe is reduced to a value which enables the method to be carried out such that wall-thickened sockets can be made without loss of wall thickness subsequent to the radius enlarging process.

Abstract: A method of molding a connecting socket part on a synthetic resinous pipe, wherein a first internal groove is formed as to be able to seat stably a resilient packing therein, and a second groove also is formed inwardly of the first groove and simultaneously therewith. A resultant molding article is thereby formed in such a manner that the pipe axis of another pipe interconnected therewith is bendable within the above-mentioned second groove. Consequently the circumferential wall of the connecting socket part of the pipe has irregularities yielding to necessity. The metallic core mold used for making up the connecting socket part, for this reason, has a form including some segments which come together to form a surface equivalent in shape to the internal circumferential surface of the connecting socket part which is to be formed. The configuration of the segments thus formed contributes to the smooth operation of assembling the core metallic mold and of dismantling after conclusion of a single operation cycle.