US 2830525 A
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.April 15, 1958 w. E.vw|l HrrE ATTACHMENT FOR CHIMNEY TOPS Filed May 23, 1955 United States Patenti "1() 2,830,525 ATTACHMENT FOR CHIMNEY TGPS Walter E. Wilhite, Spokane, Wash.
Application May 23, 1955, Serial No. 510,308
3. Claims. (Cl. 98-67) My presentl invention is an attachment for chimney tops, flues, and the like, and is particularly adapted for improving the draft conditions within a chimney.
l The greatest problem experienced with chimneys and ues is poor draft conditions. This may either be in lack of draft or too much draft. The lack of draft is caused by air currents being deilected down the chimney by higher kobjects such as buildings, surrounding hills, etc., or' a less often recognized cause wherein the ilue gases are chilled or cooled before they have opportunity to pass up and out of the chimney, thus creating a down pressure. Obviously, when the ue gases are cold, it is necessary for the fire to push a column of heavy air ahead of them in order to escape up the chimney. This is the primary cause of certain types of fireplaces and other ilues smoking when the re is first kindled. This downdraft or no draf obviously causes the smoke and gases to escape from the rebox. These poor draft conditions have a secondary undesirable effect which results in causing the chimney or flue to collect carbon deposits which tend to ignite and burn out periodically.
It is therefore one object of this invention to provide an attachment for chimneys which will eliminate all of the aforementioned diiiiculties.
Another object of this invention is to provide an attachment for chimney tops which may 'be easily installed without the use of tools or cement, and is particularly constructed and arranged to anchor itself to the chimney when applied thereto.
Still another object of the invention lies in the provision of an attachment for chimney tops which may be installed thereupomregardless of the variations in sizes and shapes among a number of chimneys.
These and other objects of the invention will become apparent during the course of the following description.
In the accompanying drawings, I have shown a preferred form of the present invention for the purpose of illustration only and not for the purpose of limiting the scope of my present invention, except insofar as it is dened in the appended claims. Like numerals are employed to designate like parts in the accompanying drawings, wherein:
Figure 1 is a perspective view of a chimney top upon which one of my chimney attachments is installed;
Figure 2 is a vertical cross section substantially on the plane of line 2-2 of Figure 1 and upon an enlarged scale;
Figure 3 is a horizontal cross section taken on the plane indicated at -line 3--3 of Figure 2 and upon a further enlarged scale;
Figure 4 is a further enlarged fragmentary vertical cross section as at the plane of line 2--2 of Figure l showing the insulation and retaining band;
Figure 5 is a plan view of a circular form attachment;
Figure 6 is a View similar to Figure 3 of the circular attachment shown in Figure 5; and
Figure 7 is a perspective view of the attachment shown in Figures 5 and 6.
Referring now more particularly to the drawings, it
will be seen that the numeral 10 denotes a chimney of v the type which is commonly constructed of brick for residential purposes, and the numeral 11 denotes my improved attachment for chimney tops.
The attachment preferably is formed having an upwardly tapered circumferentially continuous inner shell 12 which is produced from a flexible resilient metal such as galvanized iron, and it will be seen that the shell is open at its upper and lower ends. The shell 12 is circumferentially continuous and may be square, rectangular, or round, as desired.
Secured to the upper end of the shell 12 by means of an interlocking rolled or welded sealed connection, I provide a downwardly ilared skirt 13 which is provided with an inturned. cylindrical ange 14 which extends downwardly into the open upper end 0f the shell 12 and by a rolled connection or weld rigidly unites the shell and the skirt against displacement, one from the other.
It will be noted in Figure 2 that the shell and the skirt have therebetween a progressively increasing space toward'their lower ends, and also the shell is substantially longer than the skirt. In actual practice, the height of the skirt is l2 inches while the length of the shell is 24 inches. These dimensions, however, may vary according to the size of the chimney or ue upon which the attachment is to 'be used. The lower end of the shell 12 is substantially greater in diameter than the width of the flue of the chimney 10 so that it will conform to the cross-sectional configuration of the iue as seen in Figure 3.
On its external peripheral face, the shell l2 is provided with an upwardly tapered sleeve 15 of insulation material such as berglass o1' vermiculite. This insulation sleeve 15 is maintained in proper encircling relationship to the shell 12 by means of an annular band 16 of flexible resilient metal which has a depending flange 17 at its lower end disposed on a shorter radius than the balance of the band and in face to face engagement with the peripheral face of the sleeve 12. The band is secured to the sleeve 12 by means of staples i8 or other convenient securing means, and contines the insulation sleeve 15 in face to face engagement with the sleeve 12.
In Figures 5, 6, and 7, I have shown the attachment with a frusto-conical skirt 13, and in this structure the sleeve 12 will also initially be frusto-conical. However, the body material of the sleeve 12 and the band 16 is such that it may be shaped by hand to tit into a square or rectangular flue (as seen in Figure 7), and its resiliency attempts to return the sleeve to its normal circular configuration and thus the resilient pressures exerted by the lower end of the inner shell 12 assist in securing the attachment to the chimney and substantially seal therebetween.
It will be noted that no cement or other adhesive material is required for securing the attachment to the chimney since the inner shell 12 is of such a length that it will extend into the flue liner 10a of the chimney and its own resiliency will maintain the attachment thereon Iby frictional engagement therewith.
If found desirable, a sealing compound may be applied at the lower marginal edge of the skirt 1.3 as indicated at 19 to prevent moisture from owing under the attachment, and gases which may possibly escape between the flue liner 10a and the skirt l2 by reason of a crack or other deformity may be confined against discharge thereunder.
The reduced mouth or upper end of the attachment, as well as the upwardly tapered skirt 13, prevent downldrafts in the chimney by deecting outside airow upwardly as it strikes the skirt 13, and by increasing the velocity of flue gases as they discharge through the upper Patented Apr.1.s, 195s opening of the sleeve 12`by reason of its reduced diameter. This kcauses abetter flue action, eliminating the deposit of carbon to a great extent on the walls of the ue, preventing smoking from the tirebox, and because of the better flue action, facilitating combustion of the fuel.
Having thus described my invention, I claim:
l. The combination with a chimney havinga tubular ue, of an attachment therefor .comprising adownwardly flared openended circumferentially continuous skirt having its lower end resting upon the upper end ofs-aid chimney; said skirt having an inturned cylindrical flange at its upper end defining areduced opening therein; an open ended upwardly tapered resilient flexible annular inner shell coaxially arranged with relation to said Skirt and'having its open upper end secured in encircling seal-v ing engagement with said. ange; said shell being substantially longer than said`skirt and extendingdownwardly therefrom into said flue .and its lower end being of sufficient diameter with respect to said tlue to con-v form thereto and frictionally grip and seal` at its lower end to said ue by reason of the pressures -exerted by the'resiliency of said shell; and an insulatingsleeve encircling said shell in face to face relationship and-terminating spaced from the ends thereof.
2. The combination with achimney lhavinga quadrilateral tubular ue, of an attachment'therefor comprising an open ended upwardly tapered resilient exible initially' circular inner'shell extending'downwardly into the ue of said chimney and being suiciently greater in diameter at its lower end than the width of said ue to conform thereto and be secured therein by the pressure applied to the walls of the chimney ue by the resiliency of said shell; a downwardly ared open ended circumferentially continuous skirt secured at its upper end in encirclingfsealing engagement with said inner shell and defining a reduced opening; said'skirt being substantially shorter than ysaid shell and 'resting upon the upper end of saidchimney tosupport saidattachment.
3. The invention as dened' in claim 2 and further characterized by anfinsulating sleevey encircling said shell in face to face relationship and terminating spaced from the ends thereof.
References Cited in the file .of this patent UNITED STATES yPATENTS 191,230 Entwisle May 429, 1877 1,633,687 Subert .June 28,: 1927 1,700,018V Blanchard Jan. 29, 1929 2,408,665. Lovely .Oct. l, 1946 2,660,105 Sabin, Jr Nov. 24, 1953 2,680,402A Adelt June 8, 1954