US3129316A - Heating element for eliminating ice from a roof - Google Patents

Description

April 14, 1964 F. N. GLASS ETAL 3,129,316

HEATING ELEMENT FOR ELIMINATING ICE FROM A ROOF Filed July 30, 1962 2 Sheets-Sheet 1 4 Cmrnf {Arms 10 lab/I Int WAR/V/A G FERRIS N. GLASS LLOYD J. KREISER .INVEN'TORS Alba.

April 1 1964 F. N. GLASS ETAL HEATING ELEMENT FOR ELIMINATING ICE FROM A ROOF Filed July 50, 1962 2 Sheets-Sheet 2 FERRl-S N. GLASS J. KREISER INVENTORS LLOYD United States Patent 3,129,316 HEATING ELEMENT FOR ELIMINATING ICE FROM A ROOF Ferris N. Glass, 4100 Park Lane Road, and Lloyd J.

Kreiser, 2650 Holiday Hills Road, both of Traverse City, Mich.

Filed July 30, 1962, Ser. No. 213,182 1 Claim. (Cl. 219--19) The present invention is associated with conventional overlaid roof construction, and provides a heating element which can be interposed between the overlaid conventional elements. The fastenings normally used to secure these conventional elements are also used to secure the heating element in position, with the standard location or the fastenings being maintained. Normally these heating devices will be disposed along the eave portion of the building, as it is here that the formation of ice begins to develop to a suflicient extent to cause water to back up underneath the shingles and enter the building. It is by no means new to mount a heating element in this area, as it has been common practice to stretch a length of electrical resistance wire along an eave trough, or adjacent to it. The principal features of the present invention center in the arrangement which is readily structurally incorporated in the standard overlaid roofing assembly, and which results in the uniform distribution of heat over a considerable area. The several features of the invention will be analyzed in further detail through a discussion of the particular embodiments illustrated in the accompanying drawings. In the drawings:

FIGURE 1 presents a perspective view of a complete heating unit, showing the normally uppermost side with the usual markings for assisting the workman on installation.

FIGURE 2 is a perspective view of the under side of the unitshown in FIGURE 1, with a portion of the cover removed to expose the insulated heating element.

FIGURE 3 is a section on an enlarged scale on the plane IIIIII of FIGURE 2.

FIGURE 4 illustrates a connecting strip usable on interconnecting a series of the heating units shown in FIG- URE 1.

FIGURE 5 is a sectional elevation at a point of junction between successive heating elements.

FIGURE 6 is an expanded view showing the overlaid structure of the roof at the eave, and illustrating the man ner in which the heating unit is interposed between the standard roof elements.

A heating unit embodying the preferred form of this invention is illustrated in FIGURES 1, 2, and 3. This device includes an aluminum sheet 10 of a thickness and hardness selected to receive nails manually driven through it without pre-drilling. Ordinary cold-rolled aluminum sheet stock of low alloy content, and of approximately thousandths of an inch in thickness, will serve very efiectively. Nails can easily be driven through this thickness, and it can be bent readily to a fairly sharp radius without cracking. The material of the sheet 10 should be of high thermal conductivity, and aluminum seems to be the most satisfactory for this purpose. Copper would also be acceptable, but the cost is normally somewhat greater.

A length of insulated resistence wire 11 is preferably adhesively secured to the panel 10 along a serpentine path as shown in FIGURE 2. A layer of adhesive as indicated at 12 may be applied generally to the central portion of the sheet 10, with the heating element laid in position on it, after being pre-formed into the desired configuration. It is important that the marginal area shown at 13 be left clear along its full length, as nails will ultimately be driven through this area to secure the heating unit in position. Even though the resistance wire 11 does not extend throughout the sheet 10 (because of the unoccupied marginal area), the thermal transmission of the aluminum will deliver the heat out over the full area of the sheet 10 at a fairly uniform intensity. The amount of voltage supplied to the heating element 11 will vary with the length of it, and also with the amount of heat that it becomes necessary to supply to a particular installation in order to maintain the roof free of ice formations.

To complete the structure of the heating element itself, it is preferable to incorporate a sheet of foil or some heat-resistant material as a cover 14, this cover being secured adhesively to the sheet 10 with the heating element interposed between the cover and the sheet. The same adhesive which secures the cover in position may also bond the heating element, or the cover may be bonded in selected locations so that the cover itself holds the heating element in place.

FIGURES 4 and 5 show an arrangement for connecting a series of these heating units for installation along a long stretch of roof. This particular form of interconnection is well known in the sheet metal art, and is based upon the connector 15 shown in FIGURE 4, with the central portion formed to the cross section illustrated in FIGURE 5. The reverse bends 16 and 17 on the units 18 and 19, respectively, may be interengaged with the strip 15 to structurally connect these as shown. With the strip 15 formed of thermally conductive material, the heat transfer across this junction is accomplished with acceptable efficiency. The element 18 may even be a mere extension sheet of aluminum without incorporating an electrical resistance element. In this manner, an area of somewhat less heat intensity may be provided where the heat requirements are somewhat decreased.

Referring to FIGURE 6, the cave structure illustrated in this view includes a substructure generally indicated at 20, which usually is composed of rough boards. Roofing paper 21 is normally overlaid over this substructure, and the heating element 22 may be laid directly on top of this roofing paper. Separate fastenings as shown at 23 may be used to hold this heating element in position, and the edge opposite from these fastenings may be turned over as shown at 24 to embrace the edge of the cave as shown. Separate fastenings as shown at 25 and 26 may be incorporated at this edge bend. A heating unit disposed further up the roof would not be formed in this manner, this portion simply being left flat. Shingle layers as shown at 27 and 28 are then overlaid upon the heating element 22, with the fastenings normally used to secure these in position traversing the same general marginal area 13 as the fastenings 23.

In the modification shown in FIGURE 6, the ends of the heating wire 11 are brought together at a junction box 29 mounted on the sheet 11 and engaging a hole in the substructure 20, and serving as a terminal for the conduit 30. The ends 31 and 32 of the indicated element 11 are suitably interconnected with conventional circuit wiring (not shown) to a source of electric potential. In the arrangement shown in FIGURE 1, a connector 33 is incorporated in the heating unit, and this connector would normally be disposed opposite a hold in the substructure to perform a function similar to that of the box 29.

The particular embodiments of the present invention which have been illustrated and discussed herein are for illustrative purposes only and are not to be considered as a limitation upon the scope of the appended claim. In this claim, it is our intent to claim the entire invention disclosed herein, except as we are limited by the prior art.

We claim:

In combination with the cave portion of a roofing asr 4 sembly which includes overlapped covering pieces of circuit means supplying an electric potential to said standard Width secured in position by parallel rows of heating element, nails, said eave portion having a hole traversing the subsaid circuit means including connector means disstructure thereof, a heating device comprising: posed opposite said hole; and

a sheet of aluminum of substantial thickness and a 5 a foil cover for said heating element, said cover being hardness selected to accept nails driven through the secured to said sheet, and said heating element besame; ing interposed between said cover and said sheet. an insulated electric resistance heating element secured to the underside of said sheet'throughout the length References Clted m the file of thls patent of said element along a serpentine path, said sheet 10 UNITED STATES PATENTS having continuous opposite marginal portions unoc- 2,507,039 Miner May 9 1950 cupied by said heating element and disposed to re- 2,546,743 Harrison Mar. 27, 1951 ceive said nails, said heating element being disposed 2,932,711 Adams 12, 0 i the pa between said rows of nails, 3,010,007 Theodore et a1 21, 6

said marginal portions being marked on said sheet; 5 3,022,412 W t b 20, 1962

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