US2402669A - Cap for exhaust pipes and the like - Google Patents

Description

June 25, 1946.

CAP FOR EXHAUST PIPES AND THE LIKE Filed Jan. 1, 1943 l 3 3 I u h l l M I E511 HVVENTOR. 5 Pals/N 47- ro/ewEy in which:

Patented June 25, 1946 UNITED STATES PATENT OFFICE car FOR EXHAUST PIPES AND THE LIKE,

s01 R. Rubin, Los Angeles, Calif.

Application January 1, 1943, Serial No. 471,087

. 2 Claims.

, My invention relates to a cap means for exhaus pipes, ventilating flues, or the like.

One of the principal objects of this invention is to provide a cap meansof this class which will not allow a down-draft in the pipe, flue, or the like, on whichit is aflixed, irrespective of air or appear hereinafter, I have devised a cap means for exhaust pipes, and the like, which has certain novel features of construction, combination, and

arrangement of parts and portions, as will be hereinafter described in detail and particularly set forth in the appended claims, reference being hadto the accompanying characters of reference thereon, which form a part of this'application,

Fig. 1 is a fragmentary side elevation of an exhaust pipe or ventilating flue extending above the inclined roof of a building, and showing my exhaust cap, in a preferred form of construction,

facilitate the illustration; and,

Figs. 3, 4, 5, and 6 are diagrammaticside elevational views of the cap, showing by arrows different air conditions, or different directions of wind with respect to the cap, and showing the air exhausting capacities thereof under such dif ferent directions of the wind.

The exhaust pipe or ventilating flue I is of conventional construction and extends through and above the roof 2, which is shown in the drawing as inclined, the pipe or flue I being supported on and sealed with respect to the roof by the usual flashing member or cone 3.

My exhaust cap means is to be applied to the top of such exhaust pipe or fine. In this instance the exhaust cap means is provided with a separate supporting neck III which may telescope over the top and outside of the pipe Around the end of the skirt extending above the upper end of the neck a distance slightly greater than the distance of the lower end of the skirt below the upper end of the neck. The cross-sectional area between the neck ill and the skirt I I may be substantially that of the cross-sectional area of the neck, but, as shown, is slightly less than the latter. The hood I2, which is of flat cone shape, may be approximately twice the diameter of the pipe or neck, and also extends considerably be yond the open upperend of the skirt. The circumferential area of the opening between the upper end of the skirt andthe hood is substantially equal to or slightly greater than the crosssectional area of the skirt, so that the exhaust of the air beyond the upper opening of the skirt will not be choked.

The neck H], the skirt I I, and the hood [2 are all shown cylindrical or circular and are all arranged coaxially, and these elements are supported in'such relation by a plurality of straps J3, the same'strap securing all three elements togethen. Below the open end of the skirt is arranged a disc shaped bafile M, the same being secured to the neck It) by means of brackets 15. The bafile I4 is positioned such a distance below the lower end of the skirt II that the cross-sectional area between the skirt and the baflle is greater than the cross-sectional area between the neck and the skirt. The outer diameter of the baffle I4 is also greater than the diameter of the skirt, as shown. The positions of the baffle l4 below the skirt and the spacing of the-latter outwardly from the neck is such that wind which passes upwardly from below the baffie in a vertical direction, ora relatively sharp angle to the vertical direction, will be deflected outwardly from suchcap by the bafile. The spacing of the baflle below the skirt and the position of the upper end of the neck above the lower end of the skirt is such that a horizontal wind, or wind which makes only a slight angle with such horizontal direction, will rather be split and the major portion will pass around the neck. The relation between the several elements is such that the lower end of the skirt ll intersects or is positioned slightly below the line extending through or between the peripheral edge of the bafiie and the topof the pipe, or so that the lower edge of the skirt is positioned in such relation to the conical plane which is tangent to the peripheral edge of the ballle and the top of the neck, such plane being indicated by P in Fig. 1.

Different wind conditions or directions are upper end of the neck to is a skirt II, the upper shown in Figs. 1, 3, 4, 5, and 6, and these are indi- 3 cated, respectively, by A, B, C, D, and E in these figures.

In Fig. l the wind, represented by the arrow designated A, is shown as directed horizontally from the side. The air will impinge against the pipe or neck 1 below the skirt and will be split and deflected to the opposite sides, and only a small part of the air will rise into the skirt. The air directed above the skirt will pass below the hood from one side of the skirt to the other. The latter air will cause an up-draft both in the pipe I and in the skirt.

The direction of the wind in Fig. 3 is designated by B, it being directed at an angle from the side and from above. The air will impinge against the top of the hood and will be deflected as indicated by B The air directed toward the forward side or portion of the hood will be deflected downwardly toward the side of the cap, as indicated by 13 and the principal portion will be directed downwardly past the baflie. A portion of the air will be directed over the top of the bafile, as indicated by B and will tend to draw air from the bottom of the skirt. The air passing downwardly beyond the edges of the hood, and also downwardly from the skirt, will tend to draw air from the top and bottom of the skirt, as indicated by B and B respectively. This will create an updraft in the pipe or neck.

In Fig. 4, the wind, designated 0, is shown as assuming a downward path directly against the top of the hood. The hood will cause such downcurrent to pass by the cap, shown by C creating a vacuum primarily at the top of the skirt and perhaps a slight vacuum at the bottom of the skirt, as indicated by C and C respectively.

The rarefied condition of the air at both ends of the skirt will cause an up-draft in the pipe or neck. Heretofore exhaust caps have been made 7 wind, designated D, is at an angle from below. The principal portion of the air will assume a path toward the top of the skirt, as indicated by D and the air will pass over the top of the skirt to the opposite side of the hood. Such passage of theair will cause a rarefied condition at the top of the skirt and produce an up-draft in the pipe "or neck. Since the outer edge of the baille extends beyond the skirt, any 'air passing between the baflle and the lower end of the skirt will be split by the pipe or neck and tend to flow around the latter, as indicated b D rather than pass upwardly into the skirt. A small portion of such air, however, may pass upwardly into the skirt and will cause a slight additional vacuum at the upper end of the pipe or neck and assist in the up-draft therein.

In Fig. 6 of the drawing, the wind is shown as passing directly upwardly along the outer side of the pipe. This condition may take place when the exhaust pipe or ventilating flue is located at the side of a steep pitched roof, or when the pipe is located near a parapet wall or in the corner of such walls. In this instance, the baffle will cause the wind to be diverted outwardly and assume a direction indicated by E This will cause rarefied conditions; at the upper and lower ends of the skirt and result in an updraft in the pipe or neck, as indicated, respectively, by E and E Though I have shown and described a particular construction, combination, and arrangement of parts and portions and have described particular theories of action inrelation to different wind conditions, I do not-wish to belimited to the same, but desire to include in the scope of my invention the construction, combination, and arrangement substantially asset forth in the appended claims. r I

I claim: I

1. In an exhaust cap of the class described, a supporting tubular neck for the top of an exhaust pipe, a co-axial skirt surrounding and spaced outwardly therefrom with its upper and lower ends positioned respectively above and below the opening at the upper end of the neck, a hood positioned and spaced above the upper end of the skirt, a baflle spaced below the lower endof the skirt and extending laterally from the neck, the lower edge of the skirt lying substantially within the conical surface extending between the outer edge of the baffle and the upper edge of the neck, and means for securing the neck, skirt, and hood in said spaced relation.

2. In an exhaust cap of'the class described, a supporting tubularneck for the top of an exhaust pipe, a coaxial skirt surrounding and spaced outwardly therefrom with its upper and lower ends positioned respectivel above and below the opening at the upper end of the neck, a hood positioned and spaced above the upper end of the skirt, a battle spaced below the lower end ofthe skirt and extending laterally from the neck, the lower edge of the skirt lying substantially within the conical surface extending between the outer edge of the bafile and the upper edge of the neck, and means for securing the neck, skirt, and hood in said spaced relation. w

Y SOL R. RUBIN.

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