US181936A - Improvement in ventilating-caps for pipes, chimneys - Google Patents

Description

F. GREAVES VENTILATING CAPS Fon PIPES, cHIMNEYs, sw.

Patented Se-pt.5,1876.

N.1a1,9se.

[al I.

N.PET= RS, PHoTq-LITHQGRAPMER. WASHINGTONy D f -UNITED STATES PATENT FFICE.

FRANKGREAVES, on BROOKLYN, NEW'YORK.

IMPROVEMENT IN VENTlLATlNG-CAPS FOR PIPES, CHIMNEIVSI, &c.

Specication forming part of Letters Patent No. 181,936, dated September 5, 1876 application led -November 12, 1873.

i To all whom it may concern:

Be it known that I, FRANK GREAvEs, of the city of Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Ventilator- Caps for Flues, Pipes, Ste.; and I do hereby declare that the following is a full, clear, and exact description thereof, and of its mode or manner of operation, reference being had to the accompanying drawings, and to the letters of reference marked thereon, and making a part of this specification.

The nature of my invention consists in the production of an improved ventilator cap or head for ues and pipes or chimneys, which will secure a constant upward draft through such ue, pipe, Ste., and preven't either upward or downward currents of air passing into and down such ue or pipe, to thereby inter- 'fere with or overcome the draft, and which can be used with complete success on ues or pipes standing by the side of, or terminating below the top-of, walls, 8vo., and near their base. Y

Figure l is a perspective view of my improved ventilator-cap with its secondary top, and Fig. 2 is a vertical cross-section of the same. Fig. 3 is a perspective view ot' the same cap with the secondary top removed, and Fig. et is a' vertical cross-section of the same,

A is a tube, which is put over or fitted tightly upon the iiue or pipe, and which should project some little distance-say, four to live inches-above the top, in the case of an eightinch flue or pipe. Covering such tube is a shield or deecting-cap, B, which is supported by standards b b so as to be about four inches above the top of such tube, and whi'ch is some- I what larger than the open end of the tube, so

l C, leaving an open space between the two of from three to four inches, which extends downward some four or tive inches below the top ot' the inner tube, and also extends upward in a straight line to about the line ofthe periphery or edge of the delecting-cap B, when it contracts inward or toward the center, and extends in such direction far enough to make its mouth C about the same size as the inner tube A. In the case of a downward current or blast oi' air, the contracted mouth C limits the quantity of air that can enter, and the deilecting-cap B, being larger than the top of the tube A, not only prevents such a blast entering into and passing down'theilue or pipe, but, in fact, causes such downward current to increase the draft of the Hue, as the air passes down and out of the opening d, carrying the smoke, 85o., down with it through such opening. Any upward current or blast of air outside of the flue is forced by means of the rim a` against the side ofthe outer tube C, which thus passes up and' mouth C of the outer tubeC should also be v substantially as large as the tube A, so as to permit unobstructed and free discharge of the products of combustion and air rwithout any tendency to backward movements of the same. The shield or cap B should also project over the sides ofthe tube A only sufcie'ntlyfar to prevent any downward current or blast entering such tube A, and the particular construction, as described, of the under side of such cap, so as to have no cavity or open space under it in or bywhich there can be any eddying or back action of the air or products of combustion, and so as to deect outward the upward current, is also regarded as highly advantageous and essential to the full satisfactory action of the device.

When the ventilator is to be used in positions where the natural draft is interfered with by cross-currents or eddies of air, as near high Walls, or when the lue opens or terminates near the bottom of such a Wall, I make use of a secondary cap, D, which is placed a little distance above the mouth C', and Which has a breadth about the same as the diameter or horizon tal Width of the outer tube C. Such secondary cap more eft'ectually prevents any down- Ward current interfering with or overcoming vthe draft, and has been proved by actual eX- periment to overcome the injurious effects produced by such Walls, creating or causing doWnward and cross currents of air, which, in most cases, seriously interfere With, if they do not practically render useless, ordinary ventilating-caps.

1. The inner tube A, outer or overlapping tube G, and deiiecting-cap B, With rim pro jecting over the lend of the tube A, combined With the angular deiiector a, substantially as F. GREAVES.

Witnesses:

S. D. LAW, A. T. GURLITZ.

Images