Connection system for heater strips

• US 4,312,121 A
• Filed: 01/26/1979
• Issued: 01/26/1982
• Est. Priority Date: 01/26/1979
• Status: Expired due to Term

• Current Assignee: Raychem Limited (TE Connectivity Limited)
• Original Assignee: Raychem Limited (TE Connectivity Limited)
• Inventors: Tweed, Donald G.
• Primary Examiner(s): Crosby, Gene P.
• Application Number:
  US06/006,772
• Time in Patent Office: 1,096 Days
• Field of Search: 29/611, 29/612, 29/613, 219/301, 219/535, 219/536, 174/65 SS, 138/33
• US Class Current: 29/611
• CPC Class Codes: F16L 53/38 using elongate electric heating elements, e.g. wires or ribbons
• CPC Class Codes: H02G 3/0616 Joints for connecting tubing to casing
• CPC Class Codes: H02G 3/088 Dustproof, splashproof, drip-proof, waterproof, or flameproof casings or inlets
• CPC Class Codes: H05B 3/06 Heater elements structurally combined with coupling elements or holders
• CPC Class Codes: Y10T 29/49083 Heater type
• CPC Class Codes: Y10T 29/49087 with envelope or housing

Abstract

An apparatus and method for electrically connecting a heater strip is described. The apparatus is characterized in that a deformable grommet assembly is placed around the heater strip, so that the grommet assembly can be deformed by a pressure plate so that it fits tightly against the heater strip. The grommet assembly can hold the heater strip away from a support surface of the pipe on which the heater strip is mounted and can hold the heater strip oriented perpendicularly relative to the support surface. A grounding plate can be provided for pressing a grounding element of the heater strip against the pressure plate.

An apparatus based on the same grommet assembly for electrically terminating a heater strip is also described.

Claims

1. An apparatus for electrically terminating at least two heater strips located on a support surface comprising:

(a) a deformable, electrically non-conductive grommet assembly for each heater strip, each grommet assembly being sized to fit circumferentially around one of the heater strips, each grommet assembly being oriented so as to hold an end of a heater strip away from the support surface;

(b) chambers in a side by side relationship, one chamber for each grommet assembly, each chamber supporting and substantially completely surrounding a grommet assembly; and

(c) means for deforming the grommet assemblies so each grommet assembly substantially completely fills its corresponding chamber and tightly seals against its corresponding heater strip.

2. The apparatus of claim 1 including means for limiting the amount each grommet assembly presses against its corresponding heater strip.

4. The apparatus of claim 1 in which each grommet assembly is oval-shaped and at least one such grommet assembly is removably supported in its chamber so that different grommets assemblies having the same exterior dimensions but sized to fit heater strips of different exterior dimensions can be placed in the chamber for such removable grommet assembly.

5. The apparatus of claim 1 in which each grommet assembly is oval-shaped.

6. The apparatus of claim 1 in which at least one grommet assembly comprises a single grommet.

7. The apparatus of claim 1 in which at least one grommet assembly comprises at least two grommets, the grommets be vertically stacked, at least one of the grommets being formed of a material different from the material from which another grommet is formed.

8. The apparatus of claim 1 in which the support surface is a pipe.

3. An apparatus for electrically terminating at least two heater strips located on a support surface comprising:

(a) a deformable, electrically non-conductive grommet assembly for each heater strip, each grommet assembly being sized to fit circumferentially around one of the heater strips, each grommet assembly being oriented so as to hold an end of a heater strip away from the support surface;

(b) chambers in a side-by-side relationship, one chamber for each grommet assembly, each chamber supporting and substantially completely surrounding a grommet assembly; and

(c) a single pressure plate for deforming the grommet assemblies so each grommet assembly substantially completely fills its corresponding chamber and tightly seals against its corresponding heater strip.

9. A housing for electrically connecting first and second heater strips on a pipe comprising:

(a) a mounting bracket adapted to sit on the exterior surface of the pipe, the mounting bracket having at least two flanges extending axially along the exterior surface of the pipe for placement of clamping means on each flange and around the pipe for maintaining the mounting bracket in a selected position on the pipe, the mounting bracket having exit means for the heater strips, the exit means being oriented for maintaining the ends of the heater strips away from the surface of the pipe, the mounting bracket also having an entrance hole for each heater strip so that the heater strips can be inserted into the housing;

(b) a first deformable, electrically non-conductive sealing means for placement around the first heater strip and a second deformable, electrically non-conductive sealing means for placement around the second heater strip, each sealing means having a hole therethrough aligned with the exit means through the mounting bracket, each hole through a sealing means corresponding to the size and shape of a heater strip;

(c) elements defining a chamber for holding each of the sealing means in side-by-side relationship, the elements being supported by the mounting bracket; and

(d) means for deforming each of the sealing means so that each sealing means substantially completely fills its chamber and tightly seals against its corresponding heater strip.

10. The housing of claim 9 including means limiting the amount that each sealing means presses against its corresponding heater strip.

11. The housing of claim 9 in which the sealing means is a grommet assembly having opposing flat faces oriented substantially parallel to the pipe.

12. The housing of claim 11 in which the elements defining the chambers comprise a base plate having holes therethrough, each hole through a base plate being aligned with the exit means through the mounting bracket, the base plate being at least as thick as the grommet assemblies and supported by the mounting bracket, and a grommet support for each flat face of each grommet assembly.

13. The housing of claim 11 in which each grommet assembly is oval-shaped.

14. The housing of claim 11 in which at least one grommet assembly comprises a single grommet.

15. The housing of claim 11 in which at least one grommet assembly comprises at least two grommets, the grommets being vertically stacked, at least one of the grommets being formed of a material different from the material from which another grommet is formed.

16. The housing of claim 9 wherein at least one heater strip comprises a grounding element, the housing including means for grounding the grounding element of a heater strip.

17. The housing of claim 16 in which the means for grounding comprises a grounding terminal on the mounting bracket.

18. The housing of claim 16 in which the means for grounding comprises a grounding plate for compressing a grounding element against the deforming means, both the grounding plate and the deforming means being formed of electrically conductive material.

19. The housing of claim 9 in which the entrance holes of the mounting brackets are oriented so that each heater strip can be brought into the housing in a direction generally parallel to the pipe.

20. The housing of claim 19 in which the mounting bracket has an inner surface which is radiused so that each heater strip can be gently bent so that its end extends generally perpendicular to the pipe.

21. A method for electrically connecting first and second substantially flat heater strips mounted on a support surface, each heater strip having at least one conductor, the method comprising the steps of:

(a) selecting a housing comprising;

(i) a mounting bracket adapted to sit on the exterior surface of the support surface, the mounting bracket having exit means for the heater strips, the exit means being oriented for maintaining the ends of the heater strips away from the support surface, the mounting bracket also having an entrance hole for each heater strip so that the heater strips can be inserted into the housing;

(ii) a first deformable, electrically non-conductive sealing means for placement around the first heater strip and a second deformable, electrically non-conductive sealing means for placement around the second heater strip, each sealing means having a hole therethrough aligned with the exit means through the mounting bracket, each hole through a sealing means corresponding to the size and shape of a heater strip;

(iii) elements defining a chamber for holding each of the sealing means in side-by-side relationship, the elements being supported by the mounting bracket; and

(iv) means for deforming each of the sealing means so that each sealing means substantially completely fills its chamber and tightly seals against its corresponding heater strip;

(b) bending each heater strip so that each extends substantially perpendicular to the support surface;

(c) passing the bent heater strips through the exit means of the mounting bracket, through the chamber and through the sealing means of the housing;

(d) placing the mounting bracket with the heater strips extending therethrough on the support surface;

(e) deforming each sealing means so that each sealing means completely fills its chamber and seals tightly against the heater strip; and

(f) electrically connecting each conductor of each heater strip.

22. The method of claim 21 in which the step of electrically connecting comprises connecting conductors of each power strip to a heater source.

23. The method of claim 21 in which the step of electrically connecting comprises connecting conductors of one heater strip to conductors of another heater strip.

24. The method of claim 21 in which each heater strip comprises a grounding element and including the step of grounding the grounding element of each heater strip between an electrically conductive grounding plate and the means used for deforming each sealing means, the deforming means also being electrically conductive.