# US 5,346,379 A · Extruding device for extruding plastic tubing with a measuring device for measuring the wall thickness of the plastic tubing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,346,379 A - Document ID: US5346379A - Status: Granted - Kind: A - Application number: 07/962,385 - Filed: 1992-10-16 - Granted: 1994-09-13 - Earliest claimed: 1991-10-17 - Assignees: Conpro GmbH - Inventors: Volkmar R. Wolfl; Ulrich Neumann - Web page: https://patentgrep.com/patent/US5346379A ## CPC - G01B 21/08: for measuring thickness - B29C 48/09: Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels - B29C 48/903: {externally} - B29C 48/92: Measuring, controlling or regulating - G01B 5/0002: {Arrangements for supporting, fixing or guiding the measuring instrument or the object to be measured} - G01B 5/068: {of objects while moving (G01B5/066 takes precedence)} - B29C 48/885: External treatment, e.g. by using air rings for cooling tubular films - B29C 48/905: {using wet calibration, i.e. in a quenching tank} - B29C 48/908: {characterised by calibrator surface, e.g. structure or holes for lubrication, cooling or venting} - B29C 48/912: {of tubular films} - B29C 48/919: {using a bath, e.g. extruding into an open bath to coagulate or cool the material} - B29C 2948/92152: Thickness - B29C 2948/92428: Calibration, after-treatment, or cooling zone - B29C 2948/92571: Position, e.g. linear or angular - B29C 2948/92923: Calibration, after-treatment or cooling zone - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00) ## Abstract An extruding device for extruding plastic tubing includes an extruder with an outlet and a cooling device connected to the outlet of the extruder. The cooling device has a water-filled chamber and a vacuum tank that is directly connected downstream to the water-filled chamber such that a sealed passage for the plastic tubing between the water-filled chamber and the vacuum tank is provided. The water-filled chamber has a water-filled cooling part and a water-filled measuring part. A water- and vacuum-conveying connection is provided between the measuring part and the vacuum tank. A calibrating sleeve with an inner wall surface is connected within the cooling part and is completely immersed in water for cooling purposes. The calibrating sleeve pulls the extruded plastic tubing against its inner wall surface. A measuring device for measuring the wall thickness of the plastic tubing is connected with the measuring part. The measuring part has at least one ultrasonic measuring head that is radially positioned relative to the plastic tubing. The measuring head measures the plastic tubing through the water within the measuring part. ## Claims ### Claim 1 An extruding device for extruding plastic tubing comprising: an extruder with an outlet; a cooling device connected to said outlet of said extruder, said cooling device comprising a water-filled chamber and a circulating cooling element in the form of a vacuum tank directly connected downstream to said water-filled chamber such that a sealed passage for the plastic tubing between said water-filled chamber and said vacuum tank is provided; said water-filled chamber having a water-filled cooling part and a water-filled measuring part; a water- and vacuum-conveying connection between said measuring part and said vacuum tank; a water-cooled calibrating sleeve with an inner wall surface connected within said cooling part and completely immersed in water, said calibrating sleeve pulling the extruded plastic tubing against said inner wall surface; and a measuring device, for measuring the wall thickness of the plastic tubing, connected within said measuring part, said measuring device comprising at least one ultrasonic measuring head radially positioned relative to the plastic tubing, said measuring head measuring the plastic tubing through the water within said measuring part. ### Claim 2 (depends on 1) An extruding device according to claim 1, wherein said connection comprises a sliding seal for adjusting the water level within said measuring part. ### Claim 3 (depends on 1) An extruding device according to claim 1, wherein said measuring part has a vacuum-tight cover that is openable for providing access to said measuring device. ### Claim 4 (depends on 1) An extruding device according to claim 1, further comprising a line connected between said vacuum tank and said cooling part for refilling the water level within said cooling part with water flowing from said vacuum tank. ### Claim 5 (depends on 1) An extruding device according to claim 1, wherein said calibrating sleeve has an end section coordinated with said measuring device, said end section having at least one passageway for ultrasonic waves of said measuring head. ### Claim 6 (depends on 5) An extruding device according to claim 5, wherein said end section has a plurality of said passageways arranged over the circumference of said end section and wherein a plurality of said measuring heads are stationarily coordinated with said passageways. ### Claim 7 (depends on 5) An extruding device according to claim 5, wherein said end section is separated from said calibrating sleeve by an intermediate space. ### Claim 8 (depends on 7) An extruding device according to claim 7, wherein said measuring head is rotatable and reversible about the plastic tubing in said intermediate space. ### Claim 9 (depends on 7) An extruding device according to claim 7, wherein said measuring head is rotatable and reversible about the plastic tubing above said intermediate space. ### Claim 10 (depends on 7) An extruding device according to claim 7, wherein said intermediate space has a width that is slightly greater than a width of said measuring head. ### Claim 11 (depends on 5) An extruding device according to claim 5, further comprising an axial guide for guiding said measuring head when axially advanced in a rotating and reversible fashion about the plastic tubing over a given angular range and wherein said passageway extends spirally over said angular range. ### Claim 12 (depends on 5) An extruding device according to claim 5, comprising two measuring heads that are axially advanced in a rotating and reversible fashion about the plastic tubing over a given angular range and are staggered relative to one another axially and over said angular range, and wherein each said measuring head has coordinated therewith one said passageway in the form of a groove extending over a portion of said angular range to be covered by said measuring head, with said grooves axially staggered relative to one another. ### Claim 13 (depends on 1) An extruding device according to claim 1, further comprising a frame for supporting said measuring device, said frame radially movably connected to said measuring part. ### Claim 14 (depends on 1) An extruding device according to claim 1, wherein said measuring device is slidable in the axial direction of said calibrating sleeve past an end section thereof. ### Claim 15 (depends on 1) An extruding device according to claim 1, wherein said cooling part further comprises nozzles for agitating the water in said cooling part. ### Claim 16 (depends on 7) An extruding device according to claim 7, wherein said measuring head is rotatable about the plastic tubing in said intermediate space. ### Claim 17 (depends on 7) An extruding device according to claim 7, wherein said measuring head is reversible about the plastic tubing in said intermediate space. ### Claim 18 (depends on 7) An extruding device according to claim 7, wherein said measuring head is rotatable about the plastic tubing above said intermediate space. ### Claim 19 (depends on 7) An extruding device according to claim 7, wherein said measuring head is reversible about the plastic tubing above said intermediate space. ### Claim 20 (depends on 5) An extruding device according to claim 5, further comprising an axial guide for guiding said measuring head when axially advanced in a rotating fashion about the plastic tubing over a given angular range and wherein said passageway extends spirally over said angular range. ### Claim 21 (depends on 5) An extruding device according to claim 5, further comprising an axial guide for guiding said measuring head when axially advanced in a reversible fashion about the plastic tubing over a given angular range and wherein said passageway extends spirally over said angular range. ### Claim 22 (depends on 5) An extruding device according to claim 5, comprising two measuring heads that are axially advanced in a reversible fashion about the plastic tubing over a given angular range and are staggered relative to one another axially and over said angular range, and wherein each said measuring head has coordinated therewith one said passageway in the form of a groove extending over a portion of said angular range to be covered by said measuring head, with said grooves axially staggered relative to one another. ### Claim 23 (depends on 5) An extruding device according to claim 5, comprising two measuring heads that are axially advanced in a rotating fashion about the plastic tubing over a given angular range and are staggered relative to one another axially and over said angular range, and wherein each said measuring head has coordinated therewith one said passageway in the form of a groove extending over a portion of said angular range to be covered by said measuring head, with said grooves axially staggered relative to one another.