EP0108598A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method & apparatus for forming a double walled thermoplasctic tube with integral bells and tube produced thereby
Assignee: Individual
•
Filing: 1983-11-01
•
Granted: —
•
Expires: 2003-11-01
Abstract
Abstract Double-walled thermoplastic tubes, with corrugated ' outer walls (18) and smooth inner walls (24) are formed with integral bell sections spaced along the tube. The outer, corrugated wall is formed with a bell section. One of the walls (18) is pierced between the ends of the bell section (34) to allow the escape of air, and the inner wall (24) is pressed outwards into engagement with the bell section (34) of the outer walls (18).
Inventors
- 👤 Manfred Arno Alfred Lupke
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 04:21
CPC Classifications
B; B29; B29D; B29D23/00; B29D23/18; B26; B26F; B26F1/00; B26F1/0015; B26F1/0061; B26F1/0069; B29C; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/0016; B29C48/03; B29C48/09; B29C48/13; B29C48/16; B29C48/18; B29C48/21; B29C48/25; B29C48/30; B29C48/303; B29C49/00; B29C49/0015; B29C49/0021; B29C49/28; B29C49/30; B29C49/38; B29L; B29L2016/00; B29L2023/00; B29L2023/003; B29L2024/00; B29L2024/003; B29L2031/00; B29L2031/60; B29L2031/601
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
108 words
A method of forming a double walled thermoplastic tube by extruding a first tube into travelling mold, molding the first tube in the mold to form a corrugated outer wall, and extruding a second tube into the first tube to form a smooth inner wall, the method being characterized by the steps of: molding integral bell sections into the outer wall; piercing one of the tubes between the ends of each outer wall bell section so as to allow the escape of air from between the inner and outer walls; and pressing the inner wall into continuous contact with the outer wall along each outer wall bell section.
Claim 2
Independent Claim
108 words
A method of forming a double walled thermoplastic tube by extruding a first tube into travelling mold, molding the first tube in the mold to form a corrugated outer wall, and extruding a second tube into the first tube to form a smooth inner wall, the method being characterized by the steps of: molding integral bell sections into the outer wall; piercing one of the tubes between the ends of each outer wall bell section so as to allow the escape of air from between the inner and outer walls; and pressing the inner wall into continuous contact with the outer wall along each outer wall bell section.
Claim 3
Dependent Claim
21 words
A method according to claim 1 characterized by piercing one of the walls adjacent the upstream end of each bell section.
Claim 4
Dependent Claim
43 words
A method according to claim 2 characterized in that the inner wall is first pressed against the outer wall adjacent the downstream end of each bell section and then progressively towards the upstream end as the bell section progresses with the travelling mold.
Claim 5
Dependent Claim
25 words
A double walled thermoplastic tube with a corrugated outer wall and a smooth inner wall, characterized by integral double walled bells interposed in the tube.
Claim 6
Dependent Claim
25 words
A double walled thermoplastic tube with a corrugated outer wall and a smooth inner wall, characterized by integral double walled bells interposed in the tube.
Claim 7
Independent Claim
153 words
An apparatus for forming a double walled, thermoplastic tube with a corrugated outer wall (18) and a smooth inner wall (24), the apparatus including a travelling mold (10) with a corrugated cavity (20), extruder means (14) for extruding a first tube (18) into the mold cavity and a second tube (24) into the first tube, means for molding the first tube (18) to form a corrugated outer wall and means for forming the second tube into a smooth inner wall, the apparatus being characterized by means for forming integral bells in the double walled tube, comprising the combination of:- means (34) for molding integral bell sections into the outer wall (18); piercing means (40 - 58) for piercing one of the tubes between the ends of each outer wall bell section; and pressing means (62; 120-142) for pressing the inner wall into continuous contact with each bell section (34) of the outer wall.
Claim 8
Independent Claim
153 words
An apparatus for forming a double walled, thermoplastic tube with a corrugated outer wall (18) and a smooth inner wall (24), the apparatus including a travelling mold (10) with a corrugated cavity (20), extruder means (14) for extruding a first tube (18) into the mold cavity and a second tube (24) into the first tube, means for molding the first tube (18) to form a corrugated outer wall and means for forming the second tube into a smooth inner wall, the apparatus being characterized by means for forming integral bells in the double walled tube, comprising the combination of:- means (34) for molding integral bell sections into the outer wall (18); piercing means (40 - 58) for piercing one of the tubes between the ends of each outer wall bell section; and pressing means (62; 120-142) for pressing the inner wall into continuous contact with each bell section (34) of the outer wall.
Claim 9
Dependent Claim
25 words
Apparatus according to claim 5 characterized in that the piercing means (40 - 58) are located adjacent the upstream end of each bell section (34).
Claim 10
Dependent Claim
60 words
Apparatus according to claim 6 characterized in that the pressing means (62; 120-142) comprise a presser (98; 140) at a fixed distance along the mold cavity (20) from the extruder means (14) and presser actuating means (84-94; 120-132) for moving the presser outwardly into engagement with the inner (24) as the downstream end of a bell section passes the presser.
Claim 11
Dependent Claim
30 words
Apparatus according to claim 7 characterized in that the presser actuating means (84-94; 120-132) also includes means (102-106; 144) for rotating the presser about the interior of the second tube.
Claim 12
Dependent Claim
15 words
Apparatus according to claim 8 characterized in that the presser comprises a roller (98; 140).
Claim 13
Dependent Claim
16 words
Apparatus according to claim 9 characterized in that the presser actuating means (84-94) are pneumatically operated.
Claim 14
Dependent Claim
78 words
Apparatus according to claim 9 characterized in that the presser actuating means comprise: a rod (144) extending from the extruder means (14) to the pressing means and connected to the pressing means (126-142) such that rotation of the rod rotates the presser (124-142) and axial movement of the rod (144) displaces the presser along the mold cavity (20); and cam means (122) engaging the presser (132) to displace the roller (140) outwardly upon axial movement of th'e presser.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.