Radiator having PTC electric resistance heating elements and spring-biased fin arrangement

• US 5,057,672 A
• Filed: 06/29/1989
• Issued: 10/15/1991
• Est. Priority Date: 07/15/1988
• Status: Expired due to Term

• Current Assignee: Apparate und Heizwiderstande GmbH Rheinstrasse
• Original Assignee: Apparte und Heizwiderstande GmbH
• Inventors: David, Josef, Bohlender, Franz
• Primary Examiner(s): Bartis, Anthony
• Application Number:
  US07/373,906
• Time in Patent Office: 838 Days
• Field of Search: 219/530, 219/540, 219/541, 219/504, 219/505, 219/375, 219/374, 219/202, 219/365, 392/360, 392/347, 392/379, 392/491, 338/22 R
• US Class Current: 219/540
• CPC Class Codes: F24H 1/009 for vehicle systems
• CPC Class Codes: F24H 3/0405 using electric energy supply, e.g. the heating medium being a resistive element; Heating by direct contact, i.e. with resistive elements, electrodes and fins being bonded together without additional element in-between F24H3/06, F24H3/08, F24H3/10 take precedence
• CPC Class Codes: F24H 3/0429 For vehicles
• CPC Class Codes: F24H 3/0435 Structures comprising heat spreading elements in the form of fins
• CPC Class Codes: F24H 3/047 Multiple-piece frames assembled on their four or more edges
• CPC Class Codes: F24H 3/0476 Means for putting the electric heaters in the frame under strain, e.g. with springs
• CPC Class Codes: F24H 9/1872 PTC
• CPC Class Codes: H05B 3/141 Conductive ceramics, e.g. metal oxides, metal carbides, barium titanate, ferrites, zirconia, vitrous compounds

Abstract

An improved radiator suitable for use with internal combustion engines in motor vehicles is provided. The invention converts conventional radiators, which ordinarilly provide heat to passenger compartments through exchange of heat built up in the coolant, into electrically operable radiators with electric resistance heating elements, commonly PTC resistors. The PTC resistors have self, temperature-regulating properties which prevent over heating. Additionally, sheet metal strips in heat-transmitting contact with the PTC resistors and spring elements acting on the sheet metal strips provide an efficient heat transfer mechanism whereby heat from the resistors is transferred without the self-regulating resistors constantly shutting off.

Claims

1. A radiator comprising:

a plurality of first frame bars and a plurality of second frame bars, said plurality of first and second frame bars defining a planar mounting frame, said planar mounting frame retaining a plurality of elongate heat-emitting elements, said heat-emitting elements extending parallel to one another in the plane defined by said mounting frame, each said heat-emitting element being engaged on opposite sides by a plurality of fins formed of a material having good heat-conducting properties and extending in substantially parallel planes transversely of the length of said heat-emitting elements between two respective ones of the latter or between respective ones of the latter and two first bars of said mounting frame, respectively;

each of said heat-emitting elements comprising two sheet metal strips extending in parallel planes, and a plurality of electric PTC resistors disposed therebetween at spaced locations in surface contact with, and electrically connected to, said sheet metal strips;

said plurality of fins each having ends which are adjacent heat-emitting elements or one heat-emitting element and one of said first frame bars of said mounting frame, or one heat-emitting element and a support strip, said support strip disposed between adjacent heat-emitting elements;

each of said first frame bars comprising a rigid outer rail member extending parallel to an inner web movable relative thereto, said inner web contacting the ends of the adjacent fins, and a spring means disposed between said outer rail member and said inner web and supported on said outer rail member for biasing said inner web into engagement with said ends of adjacent fins; and

said sheet metal strips being electrically insulated from one another, said strips having their ends electrically insulatively retained in said second frame bars of said mounting frame extending perpendicular thereto, at least one end of at least some of said sheet metal strips being provided with a respective electric terminal element for connecting said PTC resistors to a power supply.

2. The radiator of claim 1, wherein said sheet metal strips are retained in said second frame bars of said mounting frame for limited movement transversely of the length of said metal sheet strips in the plane defined by said mounting frame.

3. The radiator of claim 2, wherein each of said spring means consists of an elongated, corrugated spring strip;

and

said PTC resistors are retained at space locations between said sheet metal strips by a strip formed of an electrically insulating material and provided with openings for receiving said PTC resistors therein, the thickness of said insulating strip being not greater than that of said resistor elements.

4. The radiator of claim 2, wherein said parallel extending fins are fixedly connected to one another adjacent at least one of their ends.

5. The radiator of claim 4, wherein said fins are fixedly connected at least to a respective one of said sheet metal strips with which they are in abutment.

6. The radiator of claim 5, wherein said fins are rigidly connected to a respective one of said inner webs.

7. The radiator of claim 5, wherein said fins are fixedly connected to said support strip.

8. The radiator of claim 7, wherein said second frame bars of said mounting frame are made of an electrically insulating material.

9. The radiator of claim 8, wherein each of said spring means consists of an elongated, corrugated spring strip.

10. The radiator of claim 9, wherein said PTC resistors are retained at spaced locations between said sheet metal strips by a strip formed of an electrically insulating material and provided with openings for receiving said PTC resistors therein, the thickness of said insulating strip being not greater than that of said PTC resistors.