Heating element arrangement for an electric blanket or the like

• US 6,713,724 B1
• Filed: 10/11/2002
• Issued: 03/30/2004
• Est. Priority Date: 10/11/2002
• Status: Expired due to Term

• Current Assignee: Perfect Fit Industries, Inc. (Littlejohn & Company LLC)
• Original Assignee: Perfect Fit Industries, Inc. (Littlejohn & Company LLC)
• Inventors: Carr, Sheldon P., Zimmerer, Richard
• Primary Examiner(s): Bennett, Henry
• Assistant Examiner(s): DAHBOUR, HENRY
• Application Number:
  US10/269,454
• Publication Number:
  US 20040069760A1
• Time in Patent Office: 536 Days
• Field of Search: 219/212, 219/211, 219/217, 219/528, 219/529, 219/544, 219/545, 219/549, 392/425, 392/432, 392/435
• US Class Current: 219/212
• CPC Class Codes: H05B 2203/003 using serpentine layout
• CPC Class Codes: H05B 2203/014 Heaters using resistive wires or cables not provided for in H05B3/54
• CPC Class Codes: H05B 3/342 heaters used in textiles

Abstract

An electrically operated heating device, such as an electric blanket, mattress pad, heating pad or throw having a pliable member, includes heating elements located within an interior defined by the pliable member which are configured to prevent breakage or disconnection of the heating elements in the event the pliable member is subjected to a concentrated load that applies tension to the heating elements. The interior of the pliable member includes a series of passages within which the heating elements are located. The heating elements have a non-linear configuration such that the overall length of the heating element contained within each passage has a length greater than that of the passage, which enables the heating elements to stretch and flex when the blanket portion is subjected to a concentrated load. The ends of adjacent heating elements are connected, such that the heating elements are defined by a single length of heating wire that is placed in a back and forth manner throughout the surface area of the blanket portion. The heating wire defines ends which are engaged with a power input for supplying electrical power to the heating elements.

Claims

1. A heating device, comprising:

a pliable member having first and second oppositely facing surfaces and defining a series of passages;

a connector member interconnected with the pliable member; and

an elongated heating element located within each passage, wherein the elongated heating element in each passage has a non-linear configuration such that the overall length of the elongated heating element contained within the passage exceeds the length of the passage, so as to enable the heating element to flex and stretch in response to a tensile force applied to the heating element;

wherein the elongated heating elements located within the passages are defined by a series of sections of a continuous elongated heating member that defines a pair of ends, wherein each end of the continuous elongated heating member is interconnected with the connector member, wherein each adjacent pair of heating elements is interconnected via a connector section of the continuous elongated heating member.

2. The heating device of claim 1, wherein each passage is defined by a pair of generally parallel sides such that the passage has a substantially constant transverse dimension throughout its length, wherein the heating element is positioned within the passage so as to have a repetitive non-linear configuration having an axial component and a transverse component.

3. The heating device of claim 2, wherein the heating element has a wave configuration throughout the length of the passage.

4. A heating device, comprising:

a pliable member having first and second oppositely facing surfaces; and

at least one elongated heating element located between the first and second oppositely facing surfaces, wherein the pliable member defines a series of passages and wherein an elongated heating element is located within each passage, wherein the elongated heating member in each passage has a non-linear configuration such that the overall length of the elongated heating member contained within the passage exceeds the length of the passage, so as to enable the heating element to flex and stretch in response to a tensile force applied to the heating element;

wherein each passage is defined by a pair of generally parallel sides such that the passage has a substantially constant transverse dimension throughout its length, wherein the heating element is positioned within the passage so as to have a repetitive non-linear configuration having an axial component and a transverse component; and

wherein the pliable member defines an interior within which the series of passages are located, and wherein the interior of the pliable member further includes a pair of spaced apart open end areas, wherein the passages open to the open end areas and wherein the heating elements of adjacent passages include a connector portion located in one of the open areas that extends between and interconnects the heating elements in adjacent passages.

5. The heating device of claim 4, wherein the heating elements are defined by a length of heating wire that extends in a back and forth manner through the passages and the open areas.

6. The heating device of claim 5, wherein the heating wire includes a pair of end portions that extend through one of the open end areas and that are engaged with a connector member secured to the pliable member.

7. The heating device of claim 6, wherein the pliable member is formed of a fabric material and wherein the heating device comprises an electrically operated blanket, heating pad or throw.

8. In an electrically operated heating device including a pliable member having an interior within which one or more elongated heating elements are located, the improvement comprising one or more passages within the interior of the pliable member, wherein an elongated heating element is located within each passage and is configured such that the heating element has a non-linear wave-type configuration and defines an overall length greater than a length defined by the passage, to alleviate stress on the heating element resulting from application of a tensile force to the heating element, wherein the interior of the pliable member includes a pair of open end areas between which the passages extend, wherein a pair of adjacent heating elements include a connector portion located in one of the open end areas that extends between and interconnects the pair of adjacent heating elements.

9. The improvement of claim 8, wherein the adjacent passages are separated by a wall having an edge that borders one of the open end areas, and wherein the connector portion of the pair of adjacent heating elements extends into the open end area outwardly of the wall edge so as to define an end loop that prevents engagement of the connector portion with the wall edge when a tensile force is applied to one of the adjacent heating elements.

10. The improvement of claim 8, wherein the pliable member comprises a first layer and a second layer, wherein the second layer is connected to the first layer in spaced apart locations such that open areas between the connections between the first and second layers define the passages within which the heating elements are located.

11. In an electrically operated heating device including a pliable member having an interior within which one or more elongated heating elements are located, the improvement comprising one or more passages within the interior of the pliable member, wherein an elongated heating element is located within each passage and is configured such that the heating element has a non-linear configuration and defines an overall length greater than a length defined by the passage, to alleviate stress on the heating element resulting from application of a tensile force to the heating element, wherein the pliable member comprises a carrier member defining first and second layers that are interconnected together so as to define the passages between the first and second layers, and further comprising a pair of outer layers between which the carrier member is located.

12. A method of positioning one or more elongated heating elements within an interior defined by a pliable member forming a part of an electrically operated heating device, comprising the steps of dividing the interior of the pliable member into separate passages, non-removably placing each heating element within one of the passages in the interior of the pliable member, wherein the heating elements are placed such that each heating element has a non-linear configuration and a length greater than that of the passage, to alleviate stress in the heating element resulting from tensile forces applied to the heating element, and enclosing the heating elements within the separate passages.

13. The method of claim 12, wherein each heating element is placed within the passage such that the heating element has a wave-type configuration.

14. The method of claim 13, wherein the step of placing the heating elements within the passages is carried out by connecting each heating element at one of its ends to an adjacent heating element via a connector portion located outwardly of the passages within which the adjacent heating elements are located.

15. A method of positioning one or more elongated heating elements within an interior defined by a pliable member forming a part of an electrically operated heating device, comprising the steps of:

placing each heating element within a passage associated with the interior of the pliable member such that each heating element has a non-linear wave-type configuration and a length greater than that of the passage, to alleviate stress in the heating element resulting from tensile forces applied to the heating element; and

connecting each heating element at one of its ends to an adjacent heating element via a connector portion located outwardly of the passages within which the adjacent heating elements are located

wherein the step of placing the heating elements within the passages is carried out such that the heating elements are formed of a single length of heating wire positioned such that the connector portions between adjacent sections of the heating wire located within adjacent passages are located outwardly of the passages within an open area that establishes communication between the adjacent passages.

16. A heating device, comprising:

a pliable member having first and second layers that define oppositely facing surfaces, wherein the first and second layers extend between spaced apart closed ends and define a series of internal passages that extend between the spaced apart closed ends; and

a series of elongated heating elements, wherein each heating element is non-removably disposed within one of the passages, wherein the elongated heating element in each passage has a non-linear configuration such that the overall length of the elongated heating element contained within the passage exceeds the length of the passage, so as to enable the heating element to flex and stretch in response to a tensile force applied to the heating element.

17. The heating device of claim 16, wherein the elongated heating elements located within the passages are defined by a series of sections of a continuous elongated heating member that defines a pair of ends, wherein each end of the continuous elongated heating member is interconnected with a connector member interconnected with the pliable member, wherein each adjacent pair of heating elements is interconnected via a connector section of the continuous elongated heating member.