Abstract: The connecting end on a coupling sleeve has an annular flange which may be hoved to urge compression stress to an annular deformable sealing ring to establish a seal between the main pipe and coupling sleeve. A stop part flange is positioned to one side of a sealing couple and which may assume a fixed position relative to the wall of the main pipe against which the stop part rests. Pivoted link stretching elements on the coupling sleeve move the insertion end of the branch pipe outwards relative to the wall of the main pipe and provides structure for exerting a compression stress against the resilient sealing ring to effect a seal between the coupling and main pipe.

Abstract: Ball-cock made of plastic parts with a spherical shut-off element in a housing with at first end a nesting place for a sealing ring and at the other end an end flange with also a nesting place for a sealing ring, said end flange having a radially projecting peripheral rib snapping into a peripheral groove near the second housing end in the inside wall thereof, housing flange and end flange being each provided with a short cylindrical end stub sealingly accommodated in an outer housing of which the inside end wall determines a nesting place for one of the sealing rings, and which at the other end is shut off by an end flange determining a nesting place for the other sealing ring.

Abstract: Electroweldable pipe sockets and fittings by forming a first tube being internally sized and cooled and on the outer side provided with a groove, having preferably a raised edge part, winding an electrical conductor in the groove, and the outer side of the first tube with electrical conductor is coated with plastics thereby maintaining the internal size of the first tube by internal cooling and sizing. In this continuous process the speeds of the first tube and of the continuous tube leaving the coating extrusion stage are equal. In the coating extrusion stage a negative pressure is maintained between the first tube and the coating to be applied.

Abstract: A plastic bag of polyolefin material such as polyethylene, for packaging materials, comprising particles of less than 50 .mu.m, and a closed bag containing such materials and a foil material for such a bag.The foil wall of the bag is provided with venting apertures with smooth edges, obtained by laser radiation, having a maximum size of 50-100 .mu.m; the distance between the venting perforations is such that the tensile strength of the foil is substantially the same as the tensile strength of the similar non-perforated foil.In a low density polyethylene foil of a thickness of 130-190 .mu.m distance between the perforations of 80 .mu.m is more than 20 mm, in a linear low density polyethylene foil of about 50-110 .mu.m the perforation distance is at least 5 mm.The bag may consist of two perforated foil layers, the perforations being staggered with respect to each other.

Abstract: An electroweldable socket comprising a conducting wire or gauze near the inner wall of the socket, the socket being manufactured by feeding conducting metal wire or gauze to a transverse extrusion head of an extruder and cutting the pipe extruded from the extruder to a socket length.Conducting wire may be fed to the extrusion head after having been wound to a helical spiral, the helical spiral may also be formed in the extrusion head or supplied accommodated in an outer groove of a thin walled tube having a helically extending outer groove. The wire may also be supplied as a hose assembled from said wires.Gauze is supplied in a pipe form obtained from a strip.The wire may comprise sections of helical spirals of mutally different pitch.Windings or groups of windings may be short-circuited.The socket is provided with connections for connecting to an electrical source if a conducting wire is present.

Abstract: A pipe member having at one end a socket for the insertion of a further pipe member and a corrugation in the wall of the socket containing a packing ring of resiliently deformable material, and a retaining ring received in an internal recess in the packing ring has its packing ring formed with an outer peripheral portion to fit the contour of the corrugation and annular front and rear projections situated respectively axially in front of and to the rear of the retaining ring to co-operate with the inserted pipe member to form pressure shoulders between which the retaining ring is disposed in the central region of the packing ring, the pressure shoulders transmitting compressive forces to the outer peripheral portion of the packing ring, the outer peripheral portion of the packing ring extending over the two pressure shoulders and over the retaining ring to bear against the corrugation under compressive load.

Abstract: Pipe with socket end provided with an annular groove chamber containing a sealing ring supported by a support ring, which support ring compresses the sealing ring less than the final inserted spigot end. The support ring closes the groove and the sealing ring or the closed space is provided with lubricant.

Abstract: A cage construction for use in breeding fur-bearing animals such as mink, comprises a plurality of cages arranged on a stand, whereby each cage is provided with a breeding coop with an opening giving access to the cage. Each breeding coop is formed by a vertical plastic pipe open at both ends and having a substantially rectangular cross section, the pipe wall being formed by a central foam plastic layer and an outer and an inner solid surface layer. These layers are integrally connected.