Joints for polymeric pipe

• US 5,958,172 A
• Filed: 03/10/1998
• Issued: 09/28/1999
• Est. Priority Date: 01/30/1995
• Status: Expired due to Fees

• Current Assignee: Jerry C. Levingston
• Original Assignee: Jerry C. Levingston
• Inventors: Levingston, Jerry C.
• Primary Examiner(s): SELLS, JAMES D
• Application Number:
  US09/037,484
• Time in Patent Office: 567 Days
• Field of Search: 156/250, 156/256, 156/258, 156/293, 156/304.1, 156/304.2, 156/304.5, 156/304.6, 156/308.2, 156/309.6, 156/309.9
• US Class Current: 156/258
• CPC Class Codes: B29C 65/02 by heating, with or without pressure
• CPC Class Codes: B29C 65/2076 perpendicularly to the plane comprising the parts to be joined
• CPC Class Codes: B29C 65/305 involving the use of cartridge heaters
• CPC Class Codes: B29C 65/7802 Positioning the parts to be joined, e.g. aligning, indexing or centring
• CPC Class Codes: B29C 66/02242 Perforating or boring
• CPC Class Codes: B29C 66/1142 Single butt to butt joints
• CPC Class Codes: B29C 66/1162 Single bevel to bevel joints, e.g. mitre joints
• CPC Class Codes: B29C 66/5223 for forming corner connections or elbows, e.g. for making V-shaped pieces
• CPC Class Codes: B29C 66/52231 with a right angle, e.g. for making L-shaped pieces
• CPC Class Codes: B29C 66/5224 for forming fork-shaped connections, e.g. for making Y-shaped pieces
• CPC Class Codes: B29C 66/52241 with two right angles, e.g. for making T-shaped pieces
• CPC Class Codes: B29C 66/52298 said socket being composed by several elements
• CPC Class Codes: B29C 66/5344 said single elements being substantially annular, i.e. of finite length, e.g. joining flanges to tube ends B29C66/5346 takes precedence
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/81422 being convex
• CPC Class Codes: B29C 66/81423 being concave
• CPC Class Codes: B29C 66/818 characterised by the cooling constructional aspects, or by the thermal or electrical insulating or conducting constructional aspects of the welding jaws or of the clamps characterised by the heating means B29C65/24; comprising means for compensating for the thermal expansion of the welding jaws or of the clamps
• CPC Class Codes: B29C 66/91421 of the joining tools
• CPC Class Codes: B29C 66/919 characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/91921 : in explicit relation to another temperature, e.g. to the softening temperature or softening point, to the thermal degradation temperature or to the ambient temperature
• CPC Class Codes: B29C 66/91935 : lower than said fusion temperature
• CPC Class Codes: B29C 66/91945 : lower than said glass transition temperature
• CPC Class Codes: B29D 23/008 : T-joints
• CPC Class Codes: B29K 2023/04 : Polymers of ethylene
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/065 : HDPE, i.e. high density polyethylene
• CPC Class Codes: B29L 2031/243 : Elbows
• CPC Class Codes: B29L 2031/246 : T-joints
• CPC Class Codes: Y10T 156/1066 : Cutting to shape joining edge surfaces only

Abstract

A method for forming a branch in a pipe made of polymeric material which permits a strong joint to be formed at the branch to another pipe. A system for carrying out the method includes heaters which soften the polymeric material in a highly localized manner. A forming member is pulled through the softened material to deform the pipe wall and form a branch. A method for making reinforced pipe joints in which pipe sections are force fit into each other is also disclosed.

Claims

1. A method for forming a reinforced joint of polymeric material comprising the steps of:

selecting a first pipe section made of polymeric material, the first pipe section having an outer diameter and an inner diameter;

selecting a second pipe section made of polymeric material, the second pipe section having an inner diameter substantially corresponding to the outer diameter of the first pipe section;

forcing the first pipe section longitudinally into the second pipe section, the second pipe section expanding upon reception of the first pipe section therein and securely gripping the first pipe section thereby to form a first reinforced joint element;

selecting a third pipe section made of polymeric material, the third pipe section having an outer diameter and an inner diameter;

selecting a fourth pipe section made of polymeric material, the fourth pipe section having an inner diameter substantially corresponding to the outer diameter of the third pipe section;

forcing the third pipe section longitudinally into the fourth pipe section, the fourth pipe section expanding upon reception of the third pipe section therein and securely gripping the third pipe section thereby to form a second reinforced joint element;

cutting the first reinforced joint element generally transversely in a plane which is skewed relative to the longitudinal axis of the first reinforced joint element, the first reinforced joint element having an end face lying generally in the plane;

connecting the first reinforced joint element to the second reinforced joint element thereby forming a reinforced joint which is angled.

2. A method as set forth in claim 1 wherein the steps of selecting the first and third pipe sections each include the step of selecting a pipe section having an inner diameter substantially equal to unreinforced pipe to which the joint is to be connected.

3. A method as set forth in claim 2 further comprising the step, prior to the step of connecting the first and second reinforced joint elements, of cutting the second reinforced joint element generally transversely in a plane which is skewed relative to the longitudinal axis of the second reinforced joint element, the second reinforced joint element having an end face lying generally in the plane, and wherein the step of connecting the first and second reinforced joint elements comprises the step of fusing the end face of the first reinforced joint element to the end face of the second reinforced joint element.

4. A method as set forth in claim 1 wherein:

the step of cutting the first reinforced joint element comprises the step of cutting at least one other reinforced joint element from the first reinforced joint element, the other joint element having end faces lying in planes which are nonparallel;

and wherein the step of connecting the first and second reinforced joint elements comprises the steps of arranging the other reinforced element between the first and second reinforced joint elements and joining together the reinforced joint elements to build up a turn in the joint.

5. A method as set forth in claim 1 wherein:

the step of cutting the first reinforced joint element comprises the step of cutting multiple reinforced joint elements from the first reinforced joint element, the multiple reinforced joint elements each having end faces, at least some of the multiple reinforced joint elements having end faces lying in planes which are nonparallel;

and wherein the step of connecting the first and second reinforced joint elements comprises the steps of arranging the multiple reinforced elements, end face to end face, between the first and second reinforced joint elements and joining together the reinforced joint elements to build up a turn in the joint, and joining the end face of each of the multiple reinforced joint elements to the adjoining face of the adjacent reinforced joint element.

6. A method as set forth in claim 1 further comprising the steps of:

selecting a fifth pipe section made of polymeric material, the fifth pipe section having an outer diameter and an inner diameter;

selecting a sixth pipe section made of polymeric material, the sixth pipe section having an inner diameter substantially corresponding to the outer diameter of the fifth pipe section;

forcing the fifth pipe section longitudinally into the sixth pipe section, the sixth pipe section expanding upon reception of the fifth pipe section therein and securely gripping the fifth pipe section thereby to form a third reinforced joint element;

cutting the second reinforced joint element in a plane which is skewed to the longitudinal axis of the second reinforced joint element, the end face of the second reinforced joint element lying in the plane;

and wherein the step of connecting the first and second reinforced joint elements comprises the step of fusing the end face of the first reinforced joint element to the end face of the second reinforced joint element;

the method further comprising the steps of,

cutting the fused first and second reinforced joint elements in a plane which is nonparallel with the plane of either of the end faces of the first and second reinforced joint elements to form an end face of the fused first and second reinforced joint elements lying in the plane, and

fusing the end face of the fused first and second reinforced joint elements to an end face of the third reinforced joint element.

7. A method as set forth in claim 6 further comprising the step of cutting the third reinforced joint element in a plane which is skewed to the longitudinal axis of the third reinforced joint element, the end face of the third reinforced joint element lying in the plane.

8. A method as set forth in claim 1 wherein the inner diameters of the second and fourth pipe sections and outer diameters of the first and third pipe sections are substantially constant along the entire lengths of the pipe sections.