Canister cover heater for automotive vapor canister

• US 4,864,103 A
• Filed: 06/13/1988
• Issued: 09/05/1989
• Est. Priority Date: 06/23/1986
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Bishop, Robert P., Berg, Peter G., Offiler, Stephen B.
• Primary Examiner(s): Pellinen, A. D.
• Assistant Examiner(s): Gaffin, Jeffrey A.
• Application Number:
  US07/205,880
• Time in Patent Office: 449 Days
• Field of Search: 55/208, 55/269, 55/316, 55/387, 123/518, 123/519, 123/549, 219/202, 219/205, 219/206, 219/504, 219/505, 219/359, 219/375, 219/366
• US Class Current: 96/141
• CPC Class Codes: F02M 2025/0881 with means to heat or cool the canister
• CPC Class Codes: F02M 25/0854 Details of the absorption canister
• CPC Class Codes: F02M 31/13 Combustion air
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

A cover for an automotive vapor canister has a heat-spreading member heated by a self-regulating electrical resistance heater of positive temperature coefficient of resistivity for heating air which is periodically introduced into the canister for purging the canister. The cover has a first cover of thermally insulating material defining a thin inner air flow path section to pass air being introduced into the canister over the heat-spreading member for transferring heat to the air and to receive additional heat within the first cover and has a second cover of thermally insulating material defining a thin outer air flow path section overlying and connected with the inner air flow path section to pass the air over the first cover prior to being advanced into the inner flow path section for withdrawing said additional heat from the first cover to preheat the air and improve air heating efficiency.

Claims

1. A compact canister cover heater for a top air entry opening of an automotive vapor canister having a top vapor entry to the canister for heating air introduced into the top air entry to the canister to purge the canister comprising a U-shaped heat-spreading plate of a sheet metal material of relatively high thermal conductivity having a base and a pair of legs to extend around a top vapor entry of a vapor canister, a self-regulating heater disc element of an electrical resistance material of positive temperature coefficient of resistivity secured in heat-transfer relation to a central portion of one side of the base of the U-shaped heat-spreading plate, means for electrically energizing the heater disc element to generate and transfer heat to the heat-spreading plate, a first cover means of thermally insulating material secured over said one side of the heat-spreader plate and having ribs engaging said one plate side forming an enclosure around the heater disc element and defining a thin, U-shaped inner flow path section to pass air being introduced into the canister serially over the legs and base portion of the U-shaped heat-spreading plate for transferring heat to the air and to receive additional heat within the first cover means, the first cover means having an air inlet means therein at one end of said inner flow path section and providing an air outlet to the canister at an opposite end of the inner flow path section, and second cover means of thermally insulating material secured over the first cover means defining a thin U-shaped outer flow path section overlying the inner flow path section provided by the first cover means, the second cover means having an air entry opening at one end of the outer flow path section and communicating with the air inlet in the first cover means at an opposite end of the outer flow path section to pass the air over the first cover means prior to being advanced into the inner flow path section for withdrawing said additional heat from the first cover means to preheat the air and improve air heating efficiency.

2. A compact canister cover heater for a top air entry opening of an automotive vapor canister for heating air introduced into the canister to purge the canister comprising a heat-spreading stud of a metal material of relatively high thermal conductivity having an end and a peripheral heat-exchanging surface, a self-regulating heater disc element of an electrical resistance material of positive temperature coefficient of resistivity secured in heat-transfer relation to said stud end, means for electrically energizing the heater disc element to generate and transfer heat tot he heat-spreading stud, a first cover sleeve of thermally insulating material disposed around the heat-exchanging stud surface defining a thin cylindrical inner flow path section over the heat-exchanging stud surface, the first cover sleeve having openings in the periphery thereof at one end to pass air being introduced into the canister over the heat-exchanging stud surface for transferring heat to the air and to receive additional heat within the first cover sleeve, and a second cup-shaped cover member of thermally insulating material having a cup-bottom of the member secured to the stud and having a cup side wall fitted around the first cover sleeve, the cup-shaped cover member having ribs engaging the stud end forming an enclosure for the heater disc element and being attached to the first cover sleeve for defining a thin outer flow path section overlying and connected to the inner flow path section through said sleeve openings to pass the air over the first cover sleeve prior to being advanced into the inner flow path section for withdrawing said additional heat from the first cover sleeve to preheat the air and improve air heating efficiency.