Process and apparatus for the continuous obtainment by displacement of cylindrical or prismatic hollow bodies produced with fibre-reinforced synthetic resins

Claim 2

Improvements in or relating to a process for the continuous manufacture by displacement of an elongated hollow body with fibre-reinforced synthetic resins, obtained by the continuous winding of fibrous elements impregnated with synthetic resin over an elongated mandrel previously covered with resin impregnated support fibres placed parallel to the longitudinal axis of said mandrel, comprising the steps of: a. rotating the mandrel about an axis parallel to the longitudinally extending direction thereof; b. providing a plurality of feed stations for supplying said support fibres; c. rotating said plurality of feed stations about said axis in unison with said mandrel and simultaneously feeding said support fibres from said feed stations to said rotating mandrel; d. impregnating said support fibres with a liquid resin after they leave said feed stations but before they contact the mandrel; e. placing said resin impregnated support fibres longitudinally over the continuously rotating mandrel as it rotates in unison with said plurality of feed stations to thus form a fibrous substructure which rotates with the mandrel; f. displacing the rotating fibrous substructure thus obtained longitudinally along the length of said mandrel in a direction away from the feed stations by pulling on the substructure while preventing relative rotary movement between said substructure and said mandrel;

Claim 3

g. winding a plurality of continuous resin impregnated fibrous elements around said rotating fibrous substructure as it is supported on and being displaced longitudinally along the mandrel to form an elongated hollow body, whereby the fibrous elements extend spirally around the hollow body to form a layer of given thickness; h. treating the wall of the holow body thus obtained to eliminate trapped air; f. controlling and correcting defects in the wall of the hollow body; i. moving said hollow body past a first heating station to at least partially cure and harden the resin; j. providing a resin distributor head at a location which is spaced downstream from both the heating station and the discharge end of the mandrel; k. applying a layer of resin of desired thickness to the interior surface of the hollow body by means of said distributor head as said hollow body is moved therepast; l. moving said hollow body past a second heating station which is located downstream of said distributor head to cure and harden the inner layer of resin; and m. severing said hollow body into sections of desired length.

Claim 4

g. winding a plurality of continuous resin impregnated fibrous elements around said rotating fibrous substructure as it is supported on and being displaced longitudinally along the mandrel to form an elongated hollow body, whereby the fibrous elements extend spirally around the hollow body to form a layer of given thickness; h. treating the wall of the holow body thus obtained to eliminate trapped air; f. controlling and correcting defects in the wall of the hollow body; i. moving said hollow body past a first heating station to at least partially cure and harden the resin; j. providing a resin distributor head at a location which is spaced downstream from both the heating station and the discharge end of the mandrel; k. applying a layer of resin of desired thickness to the interior surface of the hollow body by means of said distributor head as said hollow body is moved therepast; l. moving said hollow body past a second heating station which is located downstream of said distributor head to cure and harden the inner layer of resin; and m. severing said hollow body into sections of desired length.

Claim 5

Improvements in or relating to an apparatus for the continuous manufacture by displacement of a hollow body with fibre-reinforced synthetic resins, comprising: frame means; an elongated mandrel rotatably mounted adjacent one end thereof on said frame means so that said mandrel projects outwardly from said means in a cantilever manner, said mandrel being supported for rotation about a longitudinally extending axis; first drive means operatively interconnected to said mandrel for rotating same; a spool-frame fixedly joined concentrically to said mandrel for rotation therewith, said spool-frame being positioned adjacent said one end of said mandrel and having a plurality of spools supported thereon for feeding a plurality of longitudinal support fibres axially along the periphery of said mandrel to thereby form a fibrous substructure which rotates in unison with said mandrel; guiding means rotatable with said spool-frame and disposed for guidably deflecting the support fibres after they are removed from the spools but prior to the fibres being positioned adjacent the periphery of said mandrel; tank means disposed adjacent said guiding means and containing therein a synthetic resin so that said guiding means and the support fibres guided thereon are submerged in said tank means during rotation of said spool-frame and mandrel; means for winding one or more fibrous elements impregnated with synthetic resin around the rotating fibrous substructure which is supported on and extends longitudinally of the rotating mandrel, said last-mentioned means including stationary support means spaced from said mandrel, said fibrous element body guided from said stationary support means to said mandrel so as to be wound around the fibrous substructure thereon, whereby said fibrous substructure and said fibrous element form a hollow body; means for eliminating air trapped in the wall of the hollow body; pulling means for engaging the hollow body and pulling same in its longitudinal direction for displacing said hollow body relative to said mandrel in the longitudinal direction of said mandrel away from said spool-frame, said pulling means including first and second clamping units which are spaced apart from one another in the longitudinal direction of the mandrel, each of said clamping units having movable clamping means adapted for engagement with the hollow body; second drive means drivingly interconnected to each of said clamping units for rotating said clamping units synchronously with said mandrel about the rotational axis thereof; third drive means drivingly interconnected to each of said clamping units for causing linear reciprocation thereof in a direction substantially parallel to said rotational axis; each clamping unit including a first part which is mounted for linear reciprocating movement parallel to said longitudinal direction and is restrained from rotation, said third drive means being drivingly interconnected to said first part; and each said clamping unit also including a second part rotatably supported on said first part for rotation about said rotational axis, said second drive means being drivingly interconnected to said second part, and said clamping means being mounted on said second part and disposed for engagement with said hollow body to thereby rotate simultaneously with said hollow body in response to mandrel rotation as said hollow body is being displaced longitudinally of said mandrel.

Claim 6

Improvements in or relating to an apparatus for the continuous manufacture by displacement of a hollow body with fibre-reinforced synthetic resins, comprising: frame means; an elongated mandrel rotatably mounted adjacent one end thereof on said frame means so that said mandrel projects outwardly from said means in a cantilever manner, said mandrel being supported for rotation about a longitudinally extending axis; first drive means operatively interconnected to said mandrel for rotating same; a spool-frame fixedly joined concentrically to said mandrel for rotation therewith, said spool-frame being positioned adjacent said one end of said mandrel and having a plurality of spools supported thereon for feeding a plurality of longitudinal support fibres axially along the periphery of said mandrel to thereby form a fibrous substructure which rotates in unison with said mandrel; guiding means rotatable with said spool-frame and disposed for guidably deflecting the support fibres after they are removed from the spools but prior to the fibres being positioned adjacent the periphery of said mandrel; tank means disposed adjacent said guiding means and containing therein a synthetic resin so that said guiding means and the support fibres guided thereon are submerged in said tank means during rotation of said spool-frame and mandrel; means for winding one or more fibrous elements impregnated with synthetic resin around the rotating fibrous substructure which is supported on and extends longitudinally of the rotating mandrel, said last-mentioned means including stationary support means spaced from said mandrel, said fibrous element body guided from said stationary support means to said mandrel so as to be wound around the fibrous substructure thereon, whereby said fibrous substructure and said fibrous element form a hollow body; means for eliminating air trapped in the wall of the hollow body; pulling means for engaging the hollow body and pulling same in its longitudinal direction for displacing said hollow body relative to said mandrel in the longitudinal direction of said mandrel away from said spool-frame, said pulling means including first and second clamping units which are spaced apart from one another in the longitudinal direction of the mandrel, each of said clamping units having movable clamping means adapted for engagement with the hollow body; second drive means drivingly interconnected to each of said clamping units for rotating said clamping units synchronously with said mandrel about the rotational axis thereof; third drive means drivingly interconnected to each of said clamping units for causing linear reciprocation thereof in a direction substantially parallel to said rotational axis; each clamping unit including a first part which is mounted for linear reciprocating movement parallel to said longitudinal direction and is restrained from rotation, said third drive means being drivingly interconnected to said first part; and each said clamping unit also including a second part rotatably supported on said first part for rotation about said rotational axis, said second drive means being drivingly interconnected to said second part, and said clamping means being mounted on said second part and disposed for engagement with said hollow body to thereby rotate simultaneously with said hollow body in response to mandrel rotation as said hollow body is being displaced longitudinally of said mandrel.

Claim 7

An apparatus according to claim 2, wherein said third drive means causes said first and second clamping units to be simultaneously linearly displaced in opposite directions, said clamping means as associated with each unit being automatically engageble with the hollow body when the respective clamping unit is being linearly displaced away from the mandrel, said clamping means being disengaged from the hollow body when the respective clamping unit is being linearly displaced toward the mandrel, whereby the first and second clamping units alternately engage and pull the hollow body as they are simultaneously reciprocated back and forth in opposite directions.

Claim 8

An apparatus according to claim 3, wherein said second part comprises a ring which surrounds said hollow body and has said clamping means supported thereon, said clamping means including a plurality of clamp movably supported on said ring and spaced circumferentially therearound so as to clampingly engage said hollow body at a plurality of circumferentially spaced locations.

Claim 9

An apparatus according to claim 2, including a guide structure fixed to said mandrel closely adjacent the periphery thereof and disposed downstream of said guiding means for deflecting the support fibres which are fed to said mandrel so that the support fibres extend axially of said mandrel and are positioned closely adjacent the periphery thereof.

Claim 10

An apparatus according to claim 2, including heating means disposed adjacent the mandrel for curing and hardening the synthetic resin.

Claim 11

An apparatus according to claim 6, wherein said heating means is disposed in the interior of said mandrel adjacent the discharge end thereof.

Claim 12

An apparatus according to claim 2, including resin feed-head means for applying a layer of resin to the interior surface of the hollow body, said resin feed-head means being located a selected distance from the discharge end of said mandrel, conduit means extending axially through said mandrel and connected to said feedhead means for supplying resin thereto, and means associated with said hollow body at a location downstream of said feed-head means for accelerating the curing of the inner resin layer.

Claim 13

An apparatus according to claim 2, including means defining a heating zone disposed adjacent the mandrel to at least partially cure and harden the resin applied to said fibres, a resin distributor head means located a selected distance from the discharge end of said mandrel for applying a layer of resin to the interior surface of the hollow body, and a heat-insulated conduit means connected to said distributor head means for supplying resin thereto, said conduit means extending axially through the interior of said mandrel and through a heating zone defined by said heating means.