Patent Publication Number: US-6215110-B1

Title: Formable heater tape assembly

Description:
This application is a continuation of application Ser. No. 09/022,236 filed Feb. 11, 1998 now U.S. Pat. No. 6,057,531. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a heater tape assembly. 
     2. Description of the Related Art 
     Heater wire for heating an object to be heated, e.g., an antenna reflector, may be attached in a desired pattern to a relatively large sheet of thermally conductive foil using an adhesive. The foil is typically cut to a desired shape and the heater wire is laid in a serpentine or other desired pattern on the foil. An adhesive on one side of the foil holds the heater wire in place and also attaches the foil to an object to be heated. Such an assembly requires that the foil be precut to the shape of the area to which the foil is to be applied on the object to be heated. Typically, different foils with different shapes are required to be used with different objects to be heated. This therefore in turn requires that a relatively large inventory of foils with different shapes be maintained. 
     What is needed in the art is a heater assembly which allows a user to apply a heater wire to an object to be heated with virtually any desired pattern and without precutting the heater assembly. 
     SUMMARY OF THE INVENTION 
     The present invention provides a heater tape assembly with a heater wire disposed between two flat tapes which are bonded together and have a plurality of notches in the side edges thereof to allow the heater tape assembly to bent in a plane parallel to the flat tapes. 
     The invention comprises, in one form thereof, a heater tape assembly for heating an object to be heated. An elongate first tape has a pair of opposing side edges and a first surface extending between the side edges. The first tape also has a plurality of first notches which extend into the first surface from a respective side edge thereof. An elongate second tape has a pair of opposing side edges and a pair of opposing second and third flat surfaces extending between the side edges. The second tape also has a plurality of second notches which extend into the second and third flat surfaces from a respective side edge thereof. The second notches in the second tape are substantially aligned with respective first notches in the first tape. The second flat surface is bonded with the first surface of the first tape. The third flat surface has an adhesive thereon for bonding to the object to be heated. At least one heater wire is interposed between the first surface of the first tape and the second surface of the second tape. The notches in the first and second tapes allow the heater tape assembly to be bent in a plane substantially parallel to the first and second flat surfaces. 
     An advantage of the present invention is that the heater tape assembly may be bent to form to almost any desired surface with any desired shape. 
     Another advantage is that the opposite ends of the heater wire may be connected with a source of power at a common end of the heater wire assembly. 
     Yet another advantage is that the notches may be formed in the side edges of the heater tape assembly with a number of different shapes and still provide the desired functionality of allowing the heater tape assembly to be bent in a plane parallel to the flat surfaces of the tapes. 
     Still another advantage is that the notches may be kiss cut in the side edges of the heater tape assembly without cutting the backing, thereby allowing the backing to be easily removed without tearing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 is a fragmentary, top view of one embodiment of the heater tape assembly of the present invention with notches in the form of slits; 
     FIG. 2 is a side, sectional view taken along line  2 — 2  in FIG. 1; 
     FIG. 3 is a fragmentary, top view of the heater tape assembly shown in FIGS. 1 and 2, illustrating bending of the heater tape assembly and corresponding relative movement of the notches; 
     FIG. 4 is a fragmentary, top view of another embodiment of the heater tape assembly of the present invention with notches in the form of V-shaped notches; 
     FIG. 5 is a side, sectional view taken along line  5 — 5  in FIG. 4; 
     FIG. 6 is a fragmentary, top view of the heater tape assembly shown in FIGS. 4 and 5 with the backing removed, illustrating bending of the heater tape assembly and corresponding relative movement of the notches; and 
     FIG. 7 is a fragmentary, top view of another embodiment of the heater tape assembly of the present invention with a single heater wire looping back on itself. 
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to FIGS. 1-3, there is shown an embodiment of a heater tape assembly  10  of the present invention. Heater tape assembly  10  includes an elongate first tape  12 , an elongate second tape  14  and at least one heater wire  16 . 
     First tape  12  includes a pair of opposing side edges  18  with a first surface  20  extending therebetween. First surface  20  includes an arcuate center portion  22  located between two flat portions of first surface  20  on either side thereof which extend to opposing side edges  18 . First tape  12  includes a plurality of first notches  24  which extend into first flat surface  20  from a respective side edge  18 . In the embodiment shown, each first notch  24  is in the form of a slit which extends from a respective side edge  18 . Each side edge  18  includes a plurality of slits  24  which are spaced apart along a longitudinal extension of heater tape assembly  10 . Each slit  24  in a side edge  18  is disposed in substantial alignment with a slit  24  in an opposing side edge  18 . 
     Second tape  14  includes a pair of opposing side edges  26  and a pair of opposing second and third flat surfaces  28  and  30  extending therebetween. Second flat surface  28  is bonded with first flat surface  20  of first tape  12 . More particularly, first flat surface  20  and/or second flat surface  28  includes an adhesive thereon allowing first tape  12  and second tape  14  to be bonded together. Opposing side edges  26  of second tape  14  substantially align with opposing side edges  18  of first tape  12 . Second tape  14  includes a plurality of second notches (not numbered) which extend into second and third flat surfaces  28  and  30 , respectively, from a corresponding side edge  26 . The second notches formed in second tape  14  are disposed in substantial alignment with respective first notches in first tape  12 . That is, the second notches in second tape  14  lie immediately under and in alignment with first notches  24  of tape  12  shown in FIG.  1 . Third flat surface  30  includes a thin layer of adhesive thereon for bonding to the object to be heated, such as an antenna reflector or pipe (not shown). 
     First tape  12  and second tape  14  may be formed from any suitable material. In the embodiment shown in FIGS. 1-3, first tape  12  and second tape  14  are each constructed from metallic foil which provides a relatively high strength and allows good thermal conduction from heater wire  16  to the object to be heated. The metallic foil may include reinforcing fibers therein, such as fiberglass reinforcing fibers  32  shown partially in FIG.  1 . 
     Heater wire  16  is interposed between first surface  20  of first tape  12  and second surface  28  of second tape  14 . More particularly, heater wire  16  is at least partially surrounded by arcuate center portion  22  of first surface  20  and is interposed between arcuate center portion  22  and second flat surface  28  of second tape  14 . In the embodiment shown, heater wire  16  includes a plurality of wire strands  34  which are encased by an extruded, plastic layer of insulation  36 . Heater wire  16  is not in communication with any of first notches  24  formed in first tape  12  or the second notches formed in second tape  14 . In other words, each pair of aligned notched in first tape  12  and second tape  14  extending from a side edge  18 ,  26  does not extend to arcuate center portion  22  or heater wire  16 . Heater wire  16  is therefore prevented from directly contacting a user or other object. In the embodiment shown, heater tape assembly  10  has a longitudinal axis  38  and heater wire  16  is disposed substantially coincident with longitudinal axis  38 . 
     First notches  24  formed in first tape  12  and the correspondingly aligned notches formed in second tape  14  allow first tape  12  and second tape  14  to be bent in a plane substantially parallel to first surface  20  and second flat surface  28 . More particularly, and referring to FIG. 3, notches  24  formed in first tape  12  and the correspondingly aligned notches formed in second tape  14  include opposing side walls (not numbered) which move relative to each other when heater tape assembly  10  is bent in the plane parallel to second flat surface  28 . As shown in FIG. 3, a notch on the side toward which heater tape assembly  10  is bent closes or overlaps, while the notch on the opposite side from which heater tape assembly  10  is bent opens. Without using notches in first tape  12  and second tape  14 , the tapes may crumple on the side toward which the heater tape assembly is bent and tear on the side away from which the heater tape assembly is bent. Such crumpling or tearing of the tapes is obviously not desirable. Depending upon the extent to which heater tape assembly is bent, a notch on the side toward which the heater tape assembly  10  is bent may substantially close, or may even overlap as shown in FIG.  3 . 
     In the embodiment of heater tape assembly  10  shown in FIGS. 1-3, first tape  12  and second tape  14  have a width extending between opposing side edges  18  and  26  of between approximately 1 to 2.5 inches. However, it will be appreciated that a particular width may be selected depending upon a specific application such that heater tape assembly  10  is allowed to bend or flex by allowing relative movement of notches  24 . 
     Referring now to FIGS. 4-6, there is shown another embodiment of a heater tape assembly  40  of the present invention, including a first tape  42 , second tape  44  and heater wire  46  which are similar to first tape  12 , second tape  14  and heater wire  16  shown in the embodiment of heater tape assembly  10  in FIGS. 1-3. However, first tape  42  and second tape  44  each include a plurality of notches therein in the form of V-shaped notches  48 , rather than slits  24  as shown in FIGS. 1-3. When heater tape assembly  40  is disposed substantially straight, as shown in FIG. 4, each V-shaped notch  48  of first tape  42  and second tape  44  has opposing side walls (not numbered) which are disposed at an angle α therebetween of between approximately 80° to 100°. This angular relationship has been found to be adequate to allow proper closing of one notch in a side edge and opening of a corresponding notch in an opposing side edge during bending of heater tape assembly  40  as shown in FIG.  6 . 
     First tape  42  of heater tape assembly  40  is also provided with at least one outside flat surface  50  having a flat display area  52  thereon. Flat display area  52  provides an area for displaying visual indicia  54  thereon. The visual indicia may, e.g., correspond to specifications or data associated with heater wire  46  within heater tape assembly  40 . To wit, it will be appreciated that after heater wire  46  is interposed between and bonded to first tape  42  and second tape  44 , data which may have been printed on heater wire  46  is no longer visible to a user. The visual indicia may correspond, e.g., to the wire size, voltage rating or other data of interest to a user. Display area  52  allows heater wire  46  to be entirely covered, while at the same time allowing the corresponding technical data to be displayed as visual indicia  54  therein. 
     Heater tape assembly  40  also includes a backing  56  having a pair of opposing side edges  58  which are disposed adjacent to opposing side edges of first tape  42  and second tape  44 . Backing  46  has a fourth flat surface (not numbered) extending between opposing side edges  58  and adjacent to second tape  44 . The fourth flat surface of backing  56  is detachably bonded with the underlying or third flat surface  62  of second tape  44 , whereby backing  56  may be easily pulled apart from second tape  44 . Backing  56  does not include any notches therein, as does first tape  42  and second tape  44 . 
     Notches  48  within heater tape assembly  40  are formed by the process of kiss cutting each of first tape  42  and second tape  44  without cutting backing  56  (see FIG.  5 ). That is, after first tape  42 , second tape  44  and backing  56  are attached to each other, V-shaped notches  48  are formed by kiss cutting first tape  42  and second tape  44  without the cutter penetrating backing  56 . In this manner, each triangular piece  60  which is complimentary to each V-shaped notch  48  remains intact with backing  56 . When a user desires to use heater tape assembly  40 , backing  56 , with triangular pieces  60  attached thereto, are separated and detached from second tape  44  and discarded. Heater tape assembly  40  may then be applied to the object to be heated with an adhesive which covers third flat surface  62  of second tape  44 . 
     FIG. 7 illustrates yet another embodiment of a heater tape assembly  70  of the present invention. Heater tape assembly  70  includes a first tape  72 , a second tape thereunder (not numbered) and a plurality of notches in the form of slits  74  extending through both first tape  72  and the second tape. The plurality of notches such as slits  74  can be formed, e.g., from a stamping process or using a carpet knife or pair of scissors. The primary difference between heater tape assembly  10  shown in FIGS. 1-3 and heater tape assembly  70  shown in FIG. 7 is that heater tape assembly  70  includes a single heater wire  76  which loops back on itself and has opposing ends  82  which terminate adjacent to a common end  78  of first tape  72  and the second tape. More particularly, heater wire  76  extends from a first common end  78  to a second common end  80  of heater tape assembly  70  and loops back on itself near common end  80  such that opposing wire ends  82  terminate at the same common end  78 . Heater wire  76 , in the embodiment shown, is in the form of a shielded heater wire having a core conductor  84 , a layer of extruded plastic insulation  86  around core  84 , and a grounding shield  88  around layer of insulation  86 . By providing opposite wire ends  82  of heater wire  76  which terminate at a common end  78  of heater tape assembly  70 , heater wire  76  may be easily connected to the line and neutral sides of a source of power. In the embodiment shown in FIG. 7, the looping portions of heater wire  76  lie adjacent to each other. However, it is also possible to twist the looping portions of heater wire  76  within first tape  72  such that any fields produced by heater wire  76  are substantially canceled. Moreover, it is also possible to place a looped and insulated core conductor within a single grounding shield extending through heater tape assembly  70 . 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.