Abstract: The process comprises forming a mixture containing a thermoplastic material and a cross-linking agent and causing the mixture to enter a die head. A pressure is exerted on the mixture in the die head along the axis of the die head so as to sinter the mixture. The die head is heated to a temperature lower than the temperature at which the cross-linking agent becomes substantially decomposed so as to cause fusion of the mixture and produce a formed material. The formed material is passed through a bath of molten salt downstream of the die head. The temperature of the molten salt is such as to achieve the decomposition of the cross-linking agent and the cross-linking of the formed material. A device is described for carrying out the process.

Abstract: The support jack comprises a cylinder and a piston which define therebetween a variable-volume chamber. An inlet aperture and an outlet aperture for control fluid are provided for the chamber. Escape passageways are provided in evenly-spaced relation about the rod of the piston and put the chamber in communication with the annular space between the fixed and moving component parts of the jack and open radially onto said space. These passageways create pressure drops which are higher than the pressure drops due to the annular space.

Abstract: The device is provided for a coupling which comprises an annular sealing element interposed and compressed radially between the socket of one pipe element and the male end of the other pipe element. The pipe elements are capable of having an angular deviation therebetween. The device comprises an annular shoulder integral with the male end which shoulder is disposed, in the assembled state of the coupling, between an inner flange at the entrance of the socket and the sealing element. A split ring surrounds the male end between the flange and the shoulder. Screws engaged with and extending through tapped passages arranged circumferentially around and carried by the flange bear against a face of the shoulder so as to apply the ring against the shoulder.

Abstract: This process for manufacturing spheroidal graphite cast iron pipes by centrifugal casting has the feature that the rate of the cooling of the liquid iron just centrifugally cast in a tubular layer is increased from a zone of the layer spaced away from the mould to the free inner surface of this tubular layer while the cooling of the liquid iron in the vicinity of the surface of the mould is slowed down.

Abstract: The coupling of two tubular elements is achieved by welding them together by energization of an electrical resistance element, the one element comprising a male end, the other a socket end. The coupling operation is carried out by means of a composite connecting piece comprising two rings which are fitted on one another, one acting as a support for a bifilar electrical resistance element and the other as a sheath. The electrical resistance element is thus uniformly coated in plastic material and is accurately centered, thereby ensuring uniform heating and welding. This coupling method is for use in coupling discharge pipelines for waste water and rain water and for conduits for industrial fluids.

Abstract: The machine comprises an openable moulding box which has a perforated top side and is in the form of two separable semi-moulds. A sand blowing head is movably connected to the machine stand by at least one pair of parallel connecting elements which form a deformable parallelogram structure. The head is capable of being moved away from the perforated top side or against the latter for blowing a mixture of sand and binder into the interior of the mould.

Abstract: The installation comprises two centrifugal casting moulds which are roughly parallel to each other and are movable by rotation of a common support between a mould preparing station, a pouring station and a pipe extracting station, which stations are disposed in such maner that one of the moulds is in the axial extension of the pouring station when the other mould is in the axial extension of the extracting station and vice-versa. The two moulds are carried by rollers mounted on the common support and the latter comprises a horizontal platform which is rotatable about a central vertical axis relative to which the two moulds are symmetrically arranged.

Abstract: The insulated pipe comprises an inner pipe and a foam of thermally insulating plastics material which adheres to the inner pipe and to an outer protective layer. The foam material covers the major part of the inner pipe but terminates at a distance from each end thereof in a portion having an inclined surface of frustoconical shape. The outer protective layer comprises a cover which is relatively rigid and terminates before reaching each frustoconical surface and a protective case for each frustoconical surface of the foam material. The case is at one end fixed to the cover and at the other end integral with the inner pipe. The case has sufficient elasticity to allow the foam to follow the expansion of the inner pipe while the cover remains immobilized.

Abstract: The method comprises applying on the surface of each of the parts a thin layer of a curable first mixture containing a first resin which cures slowly and is slightly exothermic and has a good adherence to said surfaces. A curable second mixture is then introduced in a space defined by the layers of the first mixture in the final position of the two parts. The second mixture contains a second resin which cures rapidly and is sufficiently exothermic to promote the curing of the first resin and normally has after curing a poor adherence to said surfaces but a good adherence to the first resin.

Abstract: The sealing element comprises an annular active portion of elastomer material adapted to be compressed radially between the outer surface of a male end and the wall of a cylindrical recess in a socket in which the male end extends and means for anchoring the sealing element in the socket, the active portion comprising an outer annular face, an inner annular face and an end face having, when the sealing element is at rest, a minimum inside diameter exceeding the outside diameter of the male end and a maximum outside diameter exceeding said minimum inside diameter by an amount exceeding the radial clearance between the recess and the male end. The end face is connected to each one of the annular faces of the active portion by a circular edge, and, when the sealing element is in the free state, in axial section, the rise or dip of the arc generating the end face is at the most equal to 1/5th of the length of the associated chord.

Abstract: The machine comprises a housing, a casting mould rotatably mounted in the housing and a device for axially placing and maintaining a core against the end of the mould. The device comprises an element for urging the core against the mould, a releasable mechanism for fixing the core to the element and means for shifting the element between a position in which it urges the core against the mould and a withdrawn position. According to the invention, the mechanism is movable on the housing between a position in which it fixes the core to the element when the latter applies the core against the mould and a withdrawn position, the arrangement being such that the mechanism can follow, between its withdrawn position and its other position, the movement of the means for shifting the element. A return element is provided for returning the mechanism to its withdrawn position.

Abstract: The device comprises cooling water spraying systems extending throughout the length of the mould for cooling the latter. At least one additional local cooling water spraying element is slidably mounted on a guide bar through a slide. The bar is parallel to the mould and the local spraying element is adjustable in position on the bar for each casting for further cooling a selected part of the mould.

Abstract: In a spraying container structure, before the sealing and blowing operations there is mounted in the valve body comprising a housing and a cover which is provided with a temporary sleeve, a closure member which is adapted to cooperate with a sealing element to close the valve. The closure member is maintained in the valve open position in the valve body during the production of the container.

Abstract: The valve is of the type having a body and a butterfly valve closure member. One of these parts has an annular sealing element which is retained in a cavity with which it defines an annular chamber. The other part has an annular surface for contacting the sealing element when the valve is closed. A conduit puts the chamber in communication with the upstream side of the closure member when the latter is in its valve closing position. According to the invention, an exhaust conduit is provided for putting the chamber in communication with the downstream side of the closure member when, and only when, the closure member is not in its valve closing position.

Abstract: Machine for injecting and blowing a plastics material into hollow bodies. It comprises a rotary polygonal-sided turret which carries on each side a set of support members for the plastics material which are made to pass step-by-step to an injection station for injection of a blank and a blowing station for blowing the material into a hollow body in passing through intermediate stations including a transfer station. A rotatable oven structure having sockets rotatable step-by-step about an axis of the oven structure is located adjacent the transfer station for transferring the sets from the turret to the oven structure and, after a complete rotation about the oven structure axis, transferring the sets from the oven structure to the turret. Each turret side and each socket of the oven structure receives a respective one of the sets which is fixed to the turret or oven structure in a removable manner to allow the mentioned transfer.

Abstract: This process for manufacturing spheroidal graphite cast iron pipes by centrifugal casting has the feature that the rate of the cooling of the liquid iron just centrifugally cast in a tubular layer is increased from a zone of the layer spaced away from the mould to the free inner surface of this tubular layer while the cooling of the liquid iron in the vicinity of the surface of the mould is slowed down.

Abstract: This installation has an extracting carriage provided with an extracting tongs. The extracting carriage is provided with means for driving the extracting tongs in rotation at the same speed as the mould. Consequently, in the extraction of large diameter cast iron pipes not intended to be annealed there is no risk of the pipes becoming oval.

Abstract: The control device comprises an electric motor whose rotor drives a rotary spindle which shifts the closure member of a valve. Means are provided for detecting the stoppage of the rotation of the spindle. Switching means for opening the supply circuit of the motor are responsive to the detecting means so as to stop the supply when the spindle stops rotating.

Abstract: The composite pipe union comprises a body of glass fibres embedded in a thermosetting plastics material. The body has at least two tubular end portions having a generally cylindrical shape. A metal case formed of two assembled half-shells surrounds the body and the latter adheres to the case throughout the provision of a film of a material ensuring said adhesion and interposed between the body and the case.

Abstract: A device is disclosed for braking the rod of an electric motor driven valve when the electric motor is put out of action and releasing the rod when the motor is brought into action. It includes a magnetic core integral with the stator of the motor and a magnetic armature capable of being attracted by the core to release the rod when the motor is supplied with current. Spring means automatically returns the device to its rod braking position when the supply of current to the motor is cut off.