US2478761A - Ventilator head - Google Patents

Description

7 Aug- 9, 19 G. A. HOUSEMAN VENTILATOR HEAD Filed Jan. 28, 1946 FI J FIC1.2-

3 Sheets-Sheet 1 lNveu'ror.

GtoRGt: A. Hoostmnu AT? 0 RNLY tXAMINtR A 8- 9, 1949- G. A. HOUSEMAN 2,478,761

VENTILATOR HEAD Filed Jan. 28, 1946 3 Sheets-Sheet 2 lNva w-o Cieoaee. A. Hous'tmeu HAMMER Aug. 9, 1949. s. A. HOUSEMAN 2,478,761

I VENTILATOR HEAD Filed Jan. 28, 1946 3 Sheets-Sheet 3 ATTORNEY Patented Aug. 9, 1949 EXAMINER VENTILATOR HEAD George A. Houseman, Bellfiower, CaliL, assignor to Kool-Vent Metal Awning Company of Louisiana, a partnership Application January 28, 1946, Serial No. 643,877

6 Claims.

My invention relates to ventilators and more particularly to Ventilator heads designed to be placed on the exit end of ventilator conduits extending through roof structures.

An object of my invention is to provide a ventilator head comprising a series of spaced nested frusto-conical shell members provided with internally positioned vertically extending rain deflecting flanges to serve the function of the outside weather-band or shield now in common use in similar prior art types of ventilator heads.

Another object of my invention is to provide a ventilator head comprising a series of similarly proportioned generally frusto-oonical shells of decreasing sizes arranged in spaced nested relationship with the assembly terminating in a cone-shaped cap whereby a downward draft of wind is deflected across the peripheral air exhaust openings defined by adjacent shells of the ventilator head assembly whereby the downward stream of wind will produce a partial vacuum or aspirating force on the ventilator head to increase the rate of flow of air from the inside of a building on which the ventilator head is mounted,

through the discharge openings of the peripheral ventilator head.

Another object of my invention is to provide a ventilator head comprising an assembly of spaced, nested, generally frusto-conical shells of diminishing diameters capped by a cone-shaped shell frustum shells which vanes constitute means for rotating the head assembly under the power of wind that strikes the ventilator head. A still further object is to design a construction of vanes that is designed also to create low-pressure areas along the rear surfaces of the same when they are in motion, which low-pressure areas induce tile flow of air through the peripheral openings defined by adjacent nested shells of generally frusto-conical shape.

Other objects and advantages of my invention will appear from a reading of my detailed description to follow when read in connection with figures of my drawings which illustrate ventilator head constructions embodying my invention.

In the drawings, Figure 1 is an elevational view of a preferred form of a ventilator head embodying my invention.

Figure 2 is a plan view of the ventilator head illustrated by Figure 1.

Figure 3 is an enlarged fractional view of a portion of the ventilator head illustrated by Figure 1.

Figure 4 is a, diagrammatic view illustrating a mode of operation of the ventilator head.

Figure 5 is a diagrammatic view illustrating a mode of operation of the ventilator head.

Figure 6 is a diagrammatic view illustrating a mode of operation of the ventilator head.

Figure '7 is a diagrammatic view illustrating a mode of operation of the ventilator head.

Figure 8 is an elevational view of a rotatable type ventilator head embodying my invention.

Figure 9 is a fragmentary plan view of the ventilator head illustrated by Figure 8.

Figure 10 is a cross sectional view taken on line I0-lfl of Figure 8 and,

Figure 11 is a fragmentary view of a portion of the structure illustrated by Figure 8.

Referring to Figure 1 of the drawings, numeral l0 designates a conduit which is adapted to be extended through and fastened to a roof structure such as the roof structures R shown in the diagrammatic views, Figures 4-7. Three stays or bracing members that are tilted toward one another and spaced 120 degrees apart are secured (riveted) at their lower ends to the upper end of the air conduit [0 by means of rivets 12. A series of conical frustum shells i3 of diminishing sizes are arranged in spaced nested formation and riveted to the stays II by means of rivets [2 passed through the upstanding flange portions of the frustum shells I3 which flange portions may be called rain stop flanges l4. Asshown in Fig. 1 these flanges are substantially cylindrical or more nearly cylindrical parts of the annular shells l3, extending upwardly from the latter and essentially integral therewith. See Fig. 3 for detail. A conical cap I5 is fastened to the upper ends of the stays H by means of rivets [2 in spaced nested formation with the uppermost frustum shell l3.

Before entering into my description of the modes of operation of the ventilator head, the function of the rain stop flange I4 may be noted. It is only in an instance where the wind W blows in a horizontal direction or in an upward direction that rain can be blown up the upper surface of the conical frustum shells l3. Under these conditions the rain stop flanges l4 prevent the wind from blowing films of water up the sloping sides of the shell elements l3 and into the central openings where otherwise it might fall down through the air conduit l0 and into the building on which the ventilator head is mounted.

The diagrammatic view, Figure 4, illustrates the normal mode of operation or my ventilator head, an operation under conditions where the wind W is blowing in a horizontal direction. In this Figure 4, as well as in Figures 5, 6 and 7, I use long arrows to designate the direction of movement of a wind W and short arrows to designate the direction of flow of the exhaustin air A.

When the wind W strikes my ventilator head in a horizontal direction of travel, parts of the wind stream W are deflected up the sloping sides of the shells l3 and over the central upper openings of the shells l3 while parts of the streams of wind W are divided and circle around opposite sides of the central openings of the frustum shells 13. All of the above mentioned portions of the wind stream W tend to create a partial vacuum within the ventilator, thus tending to withdraw exhaust air A out of the ventilator head and carry it on with the external air currents out through the peripheral openings between the shells I3.

This suction or aspirating phenomenon is due to the fact that the air pressure on the sides of moving streams of wind W will have subatmospheric pressures, a fact well known to all engineers who have made studies of wind movements. This same aspirating or vacuum effect of the wind W is brought into play in the modes of operation illustrated by figures 5-7 of my drawings.

When the wind is deflected upwardly through fractional portions of the circular exhaust air passages defined by adjacent frustum shells, it pushes exhaust air ahead of it and 'out through opposite sides of the circular opening. When wind travels across a fractional portion of the circular air passage, exhaust air is drawn out by the wind stream and carried along with it. That is to say, the exhaust air is caused to move into the wind stream and join up with it in directions of travel ranging from a direction normal to the direction of travel of the wind down to a direction leeward of the wind stream.

When the wind blows downwardly, as shown in Figure 6 and Figure '7 of the drawings, exhaust air is drawn out around the entire number of circumferential openings and throughout the entire circumferences of the openings.

It will thus be seen that even when the wind W blows in an upward direction, as shown by Figure 5 the wind W does not oppose the upward flow of the exhaust air A but creates a suction over and around the central openings of the frustum shells l3. Hence even in this case the Wind causes air to be withdrawn from the building through the ventilator.

It should be borne in mind that under normal conditions the air inside the building upon which the ventilator heads are mounted will be hotter than the surrounding air and would have a tendency to rise due to the fact that it is lighter than the surrounding air. Such a mode of operation under conditions when there was no wind at all would be an operation due to simple convection.

My diagrammatic views, Figures 4-7, illustrate how the force of wind W is made use of in assisting the simple flow of the exhaust air A, that is to say the air withdrawing or evacuating force of the wind W exerted on the upwardly travelling stream of exhaust air A.

Figure 6 of the drawing illustrates a condition under which the wind W strikes the ventilator head in a downwardly slanting movement. Even though none of the wind W moving in this direction of movement travels between the shells [3 it does, however, create an evacuating force over portions of the peripheral openings defined by adjacent frustum shells l3. The reader will appreciate this statement by keeping in mind the fact that the portion of the peripheral opening, defined by the adjacent frustum shells l3 that is presented to the side of the wind stream W travelling across such openings, is presented to a subatmospheric pressure area of the wind stream W as explained above.

In the mode of operation of the ventilator head, illustrated by Figure 7, the stream of wind W is shown as moving in a vertically downward direction. Under this condition of operation the complete peripheral opening areas defined by the adjacent frustum shells 13 are presented to subatmospheric pressure areas of the stream of wind W. In this mode of operation, as clearly shown by the small arrows, the exhaust air A is sucked out of the peripheral openings throughout the entire circumferences of the same.

Due to the generally conical shape of my ventilator head, the central portion of the stream of wind W that strikes the cap [5 is deflected but slightly out of its downward vertical travel, with the result that this portion of the stream of wind W is made further use of in withdrawing the exhaust air A out of the ventilator head. That is to say this central portion of the stream of wind W that strikes the cap I 5 travels all the way down the slanting sides of the ventilator head performing its air withdrawing operations as it passes over each peripheral opening between the frustum shells I3.

The surrounding volume of the wind stream W also joins in with the above described central volume of deflected wind W in a manner to increase the suction force at the peripheral openings defined by adjacent frustum shells l3.

In all of the above described modes of operations some of the air A is drawn into the streams of wind W from directions nearly paralleling the streams of wind W as is done in some prior art types of ventilator heads.

In the rotatable type ventilator head illustrated by Figures 8-11 of the drawings the air conduit 20 is made substantially the same as the air conduit H] of the above described conduit head.

Attached to the conduit 20- are two pairs of lower bearing supports 2| on which the lower externally threaded bearing socket 22 is welded. The concave glass bearing insert 23 is removably positioned in the bearing socket 22 and is held in operating position by means of the expanded internally threaded sleeve 24 which is screwed down onto the socket 22 after the insert 23 has been placed in it. By means of this glass bearing insert friction obviously is substantially reduced.

Two pairs of upper bearing supports 25 are fastened to the top end of the conduit 20 by means of rivets 35 which are employed also for attaching the lower bearing supports 2| to the conduit 20 and employed in other places of the structure as means for joining elements together.

The thrust collar 21 is secured to a shaft 29 by means of a set screw 28 to prevent the rotatable ventilator head assembly from being lifted up out of the sleeve 24.

The center bearing 26 through which the shaft 29 is extended is preferably made integral with the upper bearing supports 25. The lower end of the shaft 29 is rounded at 30 and is adapted EXAMINER to be supported by a glass bearing insert 23. The shaft 29 is made of hard steel.

The rotatable head assembly proper includes the shaft 29. The head assembly is comprised of a series of bell-shaped or generally frusto-conical shells 33 of diminishing sizes, each of which is provided with a rain stop flange 34 which serves the same purpose as the rain stop flange ll of the above described preferred form of ventilator head. They are of the same general shape and form as flange 14, shown in Fig. 3. The assembly terminates at the top, as shown herein in a bellshaped cap 33 which is also positioned in spaced nested relationship with the uppermost generally frusto-conical shell 33. All of the shells 33 and bell-shaped caps 36 are mounted on the three angle stays 32 which are bent inwardly at their lower ends to attach to a hub member or collar 3| which is rigidly fastened to the shaft 29 by means of set screws 28. As clearly shown in Fig. 8, the stay members 32 are extended radially outward from the hub or collar 3i and then bend upwardly to extend generally axially and convergingly to the cap 36. The annular shells 33 and the cap 36 are all attached to and supported by these stays, as shown clearly in Fig. 8. Attachment may be by any conventional means such as riveting or welding.

The shaft 29 and the rotatable head structure above described that it carries is adapted to rotate as a unit under the power of wind W that strikes the vanes 31 that are extended across the peripheral openings defined by adjacent pairs of the bell-shaped roof members, frustum shells 33 and bell caps 33. Each vane 31 is riveted to the cap 36 and all of the frustum shells 33 positioned below it by means of rivets 35.

The long arrows shown on the drawings designate the flow of wind W while the short arrows designate the flow of exhausting air A. The short arrows shown in Figure of the drawings are intended only to show the flow of air A caused by the movement of the vanes 35. The reader should keep in mind that this rotatable form of my ventilator head also functions in the same manner as the simple cone-shaped style of ventilator head, as described above.

The vanes 31 do not completely prevent wind W from passing through the ventilator head especially when this rotatable type of ventilator head is rotated slowly by the wind force. When the wind strikes the concave surfaces of the vanes it dissipates some of its kinetic energy into the useful work of rotating the rotatable portion of this rotatable type ventilator head. The force of the wind imported to the vanes 31 on the left side as seen in Figure 10 is more than enough to move the vanes 31 on the right side against the wind W because the vanes 31 on the right side present their convex surfaces to the wind W. The rotating vanes 31 tend to create low-pressure areas over their rear surfaces. These low-tressure areas induce flows of exhausting air A out of the peripheral air exit openings between the shell members, frustum shells 33 and bell-shaped cap 36. While the use of wind power is generally relied upon to rotate this type of ventilator head it is to be understood that my invention in the rotatable type of ventilator head envisions a structure arranged to be driven by a belt, driving chain or the like, connected to a source of power such as an electric motor. With such a modification included in my structure, on a still day would discharge due to simple convection, that is to say, due to the fact the air inside of the building on which the ventilator head would be mounted would be heated to a higher temperature than the air outside the building.

Both the form of my ventilator head illustrated by Figures 1-3 and the rotating type of ventilator head illustrated by Figures 8-11 will operate under conditions where there is no wind more efficiently than the common prior art type of ventilator head which employs the wide wind band on the outside of it to prevent rain from being blown down into it. In ventilator head construction made according to the teachings of my invention I do away entirely with these external wind bands. I rely upon the small vertically extending peripheral rain stop flanges designated by numeral 14 in preferred form of my ventilator head and designated by numeral 34 in my rotating type of ventilator head as a means of preventing rain water from going down through my ventilator heads. These rain stop flanges define the central openings of the ventilator head shell members. The entire upwardly sloping surfaces of the shell members function as baffles to prevent rain from entering the ventilator heads. All that the rain stop flanges have to do is to prevent films of water from being blown through the central openings of the shell members making up my ventilator heads.

It is to be understood that the drawings forming a part of my patent specification are included for the purpose of illustrating structures that embody the principles of my invention and that my invention is not to be limited to the structure therein illustrated but only to be limited by the language of my claims to follow.

Having thus described my invention I claim:

1. In a ventilating device of the character described, the combination of a cap member and a. series of spaced and overlapping generally frustoconical annular shell members of graduated sizes and similar general outline arranged in ascending order of size from the smallest adjacent said cap member to the largest most remote therefrom, a plurality of circumferentially spaced and upwardly converging bars serving as stay members securing said cap and shell members in spaced relationship and in axial alignment and uniting them into a unitary assembly, said stay members also having integral elements at their lower ends converging axially and attached to a shaft member arranged axially of said shell and cap assembly. and means supported by a ventilator conduit element for mounting said shell and cap assembly for free rotation, including a friction-reducing bearing element for supporting said shaft member.

2. A device as in claim 1 having a series of concavo-convex vanes secured to the outer peripheries of said shell members and extending generally axially of said assembly to impel rotation under the impact of external air currents.

3. A device as in claim 1 wherein the frictionreducing bearing element comprises a glass hearing insert.

4. The device as claimed in claim 1, wherein the shells and the cap shell are made bell shaped.

5. A ventilator head comprising a vertically extending air conduit, a head assembly co-axlally rotatably mounted with respect to said air conduit and in communication with the same, by means of a shaft fastened to the head assembly in coaxial position with the same and a centrally positioned bearing connected to said air conduit in which the shaft is rotatably mounted the head assembly comprising a plurality of communicat- I ing nestedfspaced, frustum shaped, tubular shells connected to a set of upwardly extending circumferentially spaced stays beginning with a base shell into which the conduit extends and a cap shellmounted on the upper ends of the stays in nested spaced relationship with the top tubular shell and a plurality of vanes attached to and clrcumferentially spaced around the head assembly and extending outwardly from the same, the vanes extending continuously from the bottom shell to the cap shell and being adapted to rotate the head assembly under wind power, each of the vanes extending outwardly from one or more of the shells in a vertical direction and a radial direction with respect to the axis of rotation of the head assembly, each of the vanes terminating in a portion curved away from its radial direction of extension.

6. The device as claimed in claim 5 wherein the shells are provided with internally positioned up- REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,257 Kenney July-22, 1839 4,487 Collins Apr. 25, 1846 851,289 Horvath Apr. 23, 1907 1,977,934 Bolton Oct. 23, 1934 2,427,413 Miller Sept. 16, 1947 FOREIGN PATENTS Number Country Date 22,697 Great Britain 1895 63,373 Germany July 16, 1892 659,445 France Feb. 4, 1929

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