Abstract: A pipe-drilling fitting for a medium-conveying pipe, comprising a housing which has a drilling stub, which can be fitted at an angle to the pipe axis, for drilling into the pipe wall, and a branch stub which is arranged at an angle to the drilling stub, a rotationally actuable cutting bush being arranged in the drilling stub, the cutting bush and the drilling stub having mutually complementary screw threads, and at least one sealing means for sealing the medium-conveying pipe with respect to the outside being provided between the drilling stub and the cutting bush, in which fitting the sealing means is arranged in the cutting bush on an external diameter which is significantly smaller than the internal diameter of the complementary screw threads.

Abstract: A fitting of weldable thermoplastic material for connecting pipe elements or other fittings. The connection is obtained by welding by means of at least one heating element arranged at the surfaces of the members to be welded together. At least one weld indicator defined by a hollow space in the fitting is provided. The hollow space defines a first opening at the inner surface of the fitting and a second opening at the outer surface of the fitting. The first opening is covered by the heating element and the second opening defines a portion of reduced width, the portion of reduced width defining a retaining or cooling surface facing the interior of the hollow space. The second opening serves as an outlet opening for the melt. During welding, melt is conducted into the hollow space by the generated welding pressure. The melt solidifies when it reaches the retaining and cooling surface and only a small portion of the melt is conducted through the outlet opening for indicating a problem-free welding connection.

Abstract: A system for heat-sealing thermoplastic conduits involves a thermoplastic sleeve surrounding an electrically conductive heating wire arranged in a coil. A bridging conductor is located adjacent the heating element, but is separated from it by an insulation layer of predetermined thickness. When the sleeve is heated by supplying electric power to the heating element, the entire heating element generates heat during a first phase in which fusion pressure is applied between the sleeve and pipes being connected. The bridging connector is forced into contact with selected coils of the heating element to initiate a second phase. In the second phase, the heat produced in the area of the selected coils is automatically reduced by short circuiting such coils.

Abstract: A heating wire embedded in any one of several types of shaped elements is fed current by an electrical control apparatus for a time interval which is a function of the ohmic resistance of the wire and the type of shaped element. The type and resistance are automatically determined in advance by measurement of the wire impedance which indicates type and of the ohmic resistance. Welding time is selected from a predetermined directrix depending on resistance, and the directrix itself is chosen on the basis of type by the impedance measurement. A count representative of the time is stored in a counter and pulsed down to zero while current is delivered.

Abstract: A system for heat-sealing thermoplastic conduits involves a thermoplastic sleeve surrounding an electrically conductive heating wire arranged in a coil. A bridging conductor is located adjacent the heating element, but is separated from it by an insulation layer of predetermined thickness. When the sleeve is heated by supplying electric power to the heating element, the entire heating element generates heat during a first phase in which fusion pressure is applied between the sleeve and pipes being connected. The bridging connector is forced into contact with selected coils of the heating element to initiate a second phase. In the second phase, the heat produced in the area of the selected coils is automatically reduced by short circuiting such coils.

Abstract: A coupling assembly for joining together the ends to a pair of tubes, particularly suitable for use with plastics material, includes a pair of flange bushings, a sealing arrangement effecting a centering function and two semicircular shells having a U-shaped inner cross-sectional profile, each of the shells being provided with a resilient pawl which joins the shells together circumferentially about the coupling assembly. The sealing arrangement includes a centering ring and an inner sealing ring with the outer diameter of the centering ring performing in cooperation with the inner contour of the shells a centering function for the sealing arrangement. This centering function prevents displacement of the sealing arrangement during assembly and operation and permits the utilization of different types of seals and of smooth end faces of the flange bushings.

Abstract: A coupling for smooth pipe includes a housing, a sleeve nut threaded onto the housing, a gasket inside the housing and a thrust and locking ring structure within and between the housing and sleeve nut. The housing has a tapered inner surface to compress the gasket. When the nut is threaded onto the housing, the ring structure is axially moved by a shoulder on the nut to compress the gasket. The nut then radially deforms tongues on the locking ring structure to grip the pipe.

Abstract: In forming a mat, a continuous length of wire is fed between a winding plate and a pair of laterally spaced parallel spindles located closely above the plate. The winding plate is adjustable relative to the spindles so that the wire forming the mat can be held gently between the spindles and the plate. A feed member is pivotally mounted for supplying the wire in a continuous alternating manner first to one spindle and then to the other. Each spindle has a helically formed wire guide followed by a screw thread. The wire fed to the spindles is directed into the screw threads by the wire guide. The spindles are rotated in opposite directions to obtain the desired feeding action. The mat is built up from a plurality of juxtaposed wire sections connected at their opposite ends by return bends. Welding members are movably positionable relative to the mat being formed to provide welding of the wire sections together on both sides of the mat.