An injection-molding method for manufacturing a sleeve (1) comprising a cylindroconical body comprising at least one deformable bellows portion (2) arranged in line with a base (3), by means of tooling comprising a mold (8) formed of at least two portions (81, 82) defining a mold cavity and a core that can be inserted into the mold cavity, and comprising a first cylindroconical portion (11) provided externally with a helical thread that is complementary to a helical thread of the mold (8) and a second portion (15) that is complementary to a recessed portion of the mold (8), said method comprises a step of filling the mold spaces left free between the core and the inside of the mold cavity (9), a step of opening the mold (8) during which, or at the end of which, the second portion (15) of the core is moved axially in a direction parallel to the winding axis (XX′) of the threads of the helical thread going away from the first portion (11) of the core, and a step of driving relative turning movement of the sleeve (1) and of the first part (11) of the core.

The dust proof sleeve comprises a rubber tubular bellows part (1) with an opening at both ends for sliding onto an element fitted with the dust proof sleeve. The bellows part (1) comprises an accordion-shaped undulated wall with circumferential peaks (2) and circumferential valleys (3). The dust proof sleeve further comprises at least one reinforcement (4), which is arranged at least along a part of the circumference of the bellows part (1) and adjoins the circumferential shape of the bellows part (1). The at least one reinforcement (4) is at least partly integrated in the bellows part (1) by vulcanization. The invention further comprises a dust proof sleeve production mould and a dust proof sleeve production method.

The present invention provides a die assembly for molding a resin-made insert having a sleeve that is inserted into an intake port of an internal combustion engine. Each sleeve has one inlet and two outlets. The die assembly includes an inner die and an outer die. The inner die includes an inlet side part and an outlet side part. The inlet side part and the outlet side part mold an inner peripheral surface of the sleeve in an assembled state, and are removed in mutually opposite directions. By means of this assembly, a sleeve having a complicated structure and shape can be molded easily.

An injection-molding method for manufacturing a sleeve (1) comprising a cylindroconical body comprising at least one deformable bellows portion (2) arranged in line with a base (3), by means of tooling comprising a mold (8) formed of at least two portions (81, 82) defining a mold cavity and a core that can be inserted into the mold cavity, and comprising a first cylindroconical portion (11) provided externally with a helical thread that is complementary to a helical thread of the mold (8) and a second portion (15) that is complementary to a recessed portion of the mold (8), said method comprises a step of filling the mold spaces left free between the core and the inside of the mold cavity (9), a step of opening the mold (8) during which, or at the end of which, the second portion (15) of the core is moved axially in a direction parallel to the winding axis (XX) of the threads of the helical thread going away from the first portion (11) of the core, and a step of driving relative turning movement of the sleeve (1) and of the first part (11) of the core.

The present invention provides a die assembly for molding a resin-made insert having a sleeve that is inserted into an intake port of an internal combustion engine. Each sleeve has one inlet and two outlets. The die assembly includes an inner die and an outer die. The inner die includes an inlet side part and an outlet side part. The inlet side part and the outlet side part mold an inner peripheral surface of the sleeve in an assembled state, and are removed in mutually opposite directions. By means of this assembly, a sleeve having a complicated structure and shape can be molded easily.

A device for producing a silicone rubber cupping appliance is provided. The device includes a nozzle, an internal mould core, a separable slide comprising at least two separable slide blocks; and a blowing-demoulding unit. A mould cavity used for moulding the silicone rubber cupping appliance is formed between the slide and the internal mould core. One end of the nozzle is connected to a channel that transports liquid silicone rubber material, and another end of the nozzle is connected to the mould cavity. The blowing-demoulding unit is connected to the mould cavity through a blow duct opening which is set at a contact surface of the internal mould core and the mould cavity.

A system for injection molding a part includes a plate, first and second primary mold slides, first and second secondary mold slides and at least a first core post. The first and second primary mold slides define an exterior of a first portion of a molded part and are movable relative to each other between an open position and a closed position. The first and second secondary mold slides define an exterior of a second portion of the molded part and are movable relative to each other between an open position and a closed position. A first core post defines an interior of the first portion of the molded part. The first and second secondary mold slides are operative to secure the molded part as the first and second primary mold slides are moved from their closed position to their open position, as the molded part is expanded under a source of pressurized air and as the first core post is withdrawn from an interior of the molded part.