US 2875678 A
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Description (OCR text may contain errors)
March 1959 w. SHEPHERD 2,875,678
VENTILATORS Filed July 6, 1954 4 Sheets-Sheet 1 g 4 28 W/ HI w mrm m W" Wim- I' 'M H l' hl hl ll M A J V lNVENTOR ATTORNEY March 3, 1959 w. SHEPHERD VENTILATORS 4 Sheets-Sheet 2 Filed July 6, 1954 INVENTOR WYLEY SHEPHERD ATTORNEY March 3, 1959 w; SHEPHERD 2,875,678
VENTILATORS Filed July 6, 1954 '4 Sheets-Sheet 5 WYLEY SHEPHERD Q J 5.
ATTORNEY United States Patent VENTILATORS Wyley Shepherd, Miami, Fla. Application July 6, 1954, Serial No. 441,236
3 Claims. (Cl. 98-43) This invention relates to means for ventilating buildings, and more particularly to roof ventilators having a casing adapted to be secured to a roof as an upright outlet extension of an opening through the roof and having a ventilating fan in the casing.
Roof ventilators, as known heretofore, have suffered from the great disadvantage that they did not effectively shut out the elements during periods of use as well as during periods of idleness. In a high wind or a driving rain storm, the roof ventilators known heretofore would often permit entry of rain water into the building to which they were attached, with resulting damage to the interior of the building. Alternatively, strong winds would often tear the roof ventilators of the prior art loose from their fastenings on the roof, or at the very least would blow back through the ventilator and force exhaust gases back into the building from which they were withdrawn.
In an effort to overcome the above disadvantages, a
number of expedients have been tried. For example, it has been proposed to provide roof ventilators with various types of hoods or coverings for protective purposes. Thus, in U. S. Patent No. 2,332,552, issued October 26, 1943, to Belanger, an assembly of hood and shutters was provided which was designed to exclude the elements; however, this expedient nevertheless permitted the entry of driving rain into the casing past the shutters which were open in use. Moreover, this structure was subject to back draft when in use, was liable to be torn from its mounting in a strong wind, and did not afford easy access to the drive motor when assembled. In U. S. Patent No. 2,55l,004, issued May 1, 1951, to Johnson, it was proposed that the hood be pivotally mounted; but this expedient was likewise unavailing, since the hood of Johnson did not exclude the elements when the ventilator was in use, nor did it afford easy access to the fan drive motor. Although a number of other attempts were made to overcome the foregoing difficulties and disadvantages of the prior art roof ventilators, none, so far as I know, were entirely successful when carried into practice commercially on an industrial scale.
Accordingly, it .is an object of my invention to provide a roof. ventilator which will exclude the elements when the ventilator is in use as well as when it is not in use. Another object of the invention is to provide a roof ventilator of which all the working parts are readily accessible from the roof side of the ventilator, thereby eliminating the awkwardness and hazard of using ladders or scaffolding to reach the working parts for repair and maintenance from within the building.
The invention also contemplates the provision of a roof ventilator in which the working parts are readily accessible without disassembly of any portion of the structure surrounding the working parts.
is a further object of the invention to provide a roof ventilator in which back draft due to strong winds will be reduced to a minimum.
Still another object of the invention is the provision of a roof ventilator which will not be susceptible of dislodgernent from its fastenings in a strong wind.
A still further object of the invention .is the provision of a roof ventilator adapted to serve either as an intake or an exhaust ventilator.
Yet another object of the invention is to provide a roof ventilator in which the air passageways are so arranged as to permit the movement of very great quantities of air without obstruction to its even flow.
it is also an object of my invention to provide a roof ventilator that is efiicient in operation, that is easily installed, operated and repaired, and that is economical of manufacture and rugged and enduring in construction.
Other objects and advantages will become apparent by the following description taken in conjunction with the accompanying drawings in which:
Figure 1 is a side elevational view of a roof ventilator according to the invention, showing the hood in closed position, which is the operative position of the ventilator.
Figure 2 is a view similar to Figure 1, but showing the hood in open position, which is the inoperative position of the ventilator.
Figure 3 is an elevational cross sectional view of a ventilator according to my invention, taken on the line 3-3 of Figure 5.
Figure 4 is a view similar to Figure 3, but taken on the line 4-4 of Figure 5.
Figure 5 is a cross sectional view of a ventilator according to the invention, taken from below on the line 55 of Figure 4, looking up.
Figures 6 and 7 are views similar to Figures 1 and 2, but showing a modified form of roof ventilator according to my invention.
Figure 8 is a sectional elevational view of the modified form of my invention, taken on the line 88 of Figure 9.
Figure 9 is a sectional view of the modified form of my invention, taken from below on the line 9-9 of Figure 8, looking up.
Figure 10 is an isometric view of a fan casing according to my invention.
Broadly stated, the present invention contemplates the provision of a roof ventilator having a casing adapted to be secured to a roof as an upright outlet extension of an opening through said roof and having a ventilating fan in the casing, and a hood over the casing to protect it from the elements. The hood may be mounted on the casing for pivotal movement about a substantially horizontal axis which may be disposed intermediate the horizontal length of the hood. The horizontal width and length of the hood may be substantially greater than the horizontal width and length of the casing; and the hood may be of downwardly concave shape so as to provide in effect a cap disposed over but spaced from the upper portion of the casing. The upper marginal portion of the'casing may be disposed as high as or higher than the lower marginal portion of the hood .to provide substantially complete protection from the elements. The hood may be provided interiorly with a downwardly projecting pyramidal deflector to facilitate the passage of air through the ventilator. The motor may be mounted on the outside of the casing and protected from the weather by the hood, or mounted on the outside of the hood and protected by a separate casing; but in either event, upward tilting movement of the hood will provide access to the motor, as well as to the other working parts.
Referring now to the drawings, Figure 1 shows in side elevation 21 first form of roof ventilator according to the invention, and comprising a trunk creasing 1 0 which hereinafter.
'fan ring 16 is mounted in the upper portion of casing and is nicely rounded upwardly to a substantially circular throat opening, as shown in Figures 3 and 4. It will of course be understood that fan ring 16 may also be inverted from its illustrated position, and may take a variety of ring forms. Extending across the throat of fan ring 16 is a pair of crossbars attached at either end to the fan ring and braced intermediate their lengths by oifsetbracing struts 2% which are attached at one end to the fan ring and at the other end to their respective crossbar 18.
Mounted firmly between the crossbars 18 is a bearing member-22 in which fan shaft 24 is journalcd for rotation about a vertical axis. At the upper end of fan shaft 24- are mounted a plurality of fan blades 26, so inclined that when fan shaft 24 turns in one direction, the air adjacent the blades 26 will be propelled in one direction, and that when shaft 24 turns in the opposite direction, the air will be propelled by the blades 26 in the opposite direction. At the opposite or lower end of fan shaft 24 is mounted a fan pulley 28, for apurpose to be described It will of course be .understood that the positions of the blades 25 and pulley 28 on shaft 24 may be reversed, so that the pulley is at the upper end of the shaft and the blades at the lower end.
Disposed along the upper marginal portion of a side of casing 16 is a substantially horizontal first hood support member 30, as seen from below in Figure 5. Merriber 30 extends laterally outwardly from the sides of easing iii, as shown by projection 32. In other words, the length of member 34? is substantially greater than the width of casing 10. Member 3% may be a bar or channel or other convenient structural form. The outer extremities of member 3% are provided with downturned ends 34 which carry substantially horizontal outwardly projecting pins 36, for a purpose to be described hereinafter.
At the opposite end of casing 10, adjacent an upper marginal portion thereof is a second hood support member 38, which also extends full Width of casing 10, and extends laterally therebeyond substantially equal distances on either side thereof, as at projections 40. Projections 40 are provided with downturned ends 42 bearing at their lower extremities outwardly projecting horizontal ears 44 which are provided with holes 46 for a purpose to be described hereinafter. Thus, it will be seen that ears 44 provide in effect downwardly offset terminal portions of second hood support member 38.
Pivotally mounted on pins 36 is a hood 48 having rounded end portions 50 and vertical sides 52. Hood 48 thus is generally downwardly concave. It will also be observed that the horizontal length of hood 48 is substantially greater than the horizontal length of casing '10; and that the horizontal width of hood 48, as represented approximately by the length of members 30 and 38, is substantially greater than the horizontal Width of casing 10. By virtue of the concavity and greater horizontal dimensions of the hood, it will be observed that the hood is at all points spaced a substantial distance from the casing, but that at the same time, the hood forms 'in effect a cap over and around the upper portion of the casing. It must also be noted that the lower marginal p'o'rtion of hood 48 extends at least as low as the upper marginal portion of casing 10, as represented by the upper edge of the casing itself or by the upper edge of fan ring 16. Indeed, in Figures 3 and 4, it will be noted that the upper marginal portion of the casing 10 extends somewhat above the plane of the lower marginal portion of hood-48.
Depending from the upper interior-surface of hood 48 substantially centrally thereof is a generally pyramidal deflector 56, which is made up of four equally inclined triangular pieces of sheet material of which the apices meet at the lowest point on the deflector to form the nadir of the pyramid. From the positioning of this inverted pyramid directly above the fan, it will be obvious that air passages are provided which provide for the flow of air on all sides of the casing 10, both on the inside and on the outside thereof. For example, it will be obvious that the path of air leaving a building through the ventilator of the invention will resemble the path of Water in a fountain formed by directing a stream of Water straight up. Similarly, the path of air flowing into a building through the ventilator will be the exact reverse. In other words, the novel shape and relationship of parts just described provides a smooth and even air flow over an unobstructed course.
Mounted on a vertical side 52 of hood 48 is a motor casing 56 having a flat top and a single curved side wall; Casing 56 is open at its bottom, but otherwise completely encloses fan motor 58 which may be a conventional electric motor having conventional wiring circuits and switches, not shown. Motor 58 is fastened to a motor mounting plate 619 which in turn is adjustably carried by base plate 62 mounted on vertical sides 52, by means of threaded bolts 64. Adjustment of motor mounting plate 6?) toward and away from base plate 62, for a purpose to be described hereinafter, is afforded by adjusting nuts 66 which may be screwed up and down on threaded-bolts 64-. Motor 58 is vertically disposed and is provided with a downwardly depending drive shaft 68 having at its lower end drive pulley '76, for a purpose to be described hereinafter.
interconnecting fan pulley 28 and drive pulley 70 is a fan drive belt 72, which may be a V-belt or other conventional form of drive belt. Mounted on the inside of easing 1d and enclosing fan pulley 28 and the portion of drive belt 72 which is inside the casing is a fan beltcasing 74 which forms a first fan belt guard. This fan belt casing encloses the inner portion of the belt and the hole of the fan pulley substantially completely and protects them from dirt and extraneous matter or corrosive fumes which may be drawn into or expelled from the building. Mounted on the outside of the casing 10 and extending substantially between the casing and motor 58 is a second fan belt guard 76, which does not completely enclose the outer portion of the fan drive belt 72, but which is provided only with a top and sides. Guard 76 may desirably be formed from a single piece of sheet material simply by bending down the two side edges of the sheet which has previously been cut to tapered form in order to accommodate the convergence or divergence of the two runs of the drive belt occasioned by differential diameters of the fan pulley and the drive pulley. Thus, a second fan belt guard is provided which is effective to prevent or reduce damage to that portion of the drive belt which lies between casing 10 and hood 48.
The operation of the device of Figures 1 through 5 'is as follows:
When it is desired to exhaust air or other gases from a building on which the ventilator is mounted, motor 58 is actuated so that drive shaft 68 turns in a counterclockwise direction as seen in Figure 5. Fan blades 26 will then draw air up from the building and project it against deflector 54. Deflector 54 will distribute the air in all directions so that it will spread out horizontally from the axis of rotation of the fan in all directions. The air will then be deflected downwardly by sides 52 and end portion 50 of hood 48, and will pass into the outer air adjacent the sides of casing 10. Conversely, when it is desired to bring outside air into the building on which the ventilator is mounted, it is merely necessary to actuate the motor in the reverse direction, in which case blades 26 will draw air in through the revers'e'p'ath, In either event, it is obvious that a smooth, "fountain-like air flow is provided, which requires a minimum of power expenditure and enables the handling of the maximum quantities of air with the smallest possible ventilating unit. A primary feature of this fountain-like air flow is that air enters the ventilator from all sides thereof and passes out through the ventilator about all sides thereof. Thus, the stresses induced in the ventilator by the pressure of air passing therethrough are reduced to a minimum in the ventilator of the invention, since the air moving on all sides of the ventilator equalizes the pressures exerted thereby and substantially balances the strain induced by the moving air in the ventilator.
It Will also be observed-that with the hood down in operative position, as shown in Figure 3, driving rain cannot enter the ventilator unit even when the unit is in use. As is well known, rain drops blown by winds of hurricane force often travel substantially horizontally, with the result that they have no difiiculty entering most louvered air vent structures. However, in the structure of the present invention, in which the lower marginal portion of the hood extends on all sides of the casing 10 at least as far down as the upper marginal portion of that casing, even rain drops traveling horizontally cannot find entry to casing 10. By the same token, the profile of my novel ventilator is so reduced in elevational area and in height that strong Winds have much less tendency to loosen it from its fastenings on the roof. Moreover, the circuitous air paths afforded by my novel construction greatly reduce backdraft through the ventilator when it is being used as an exhaust unit; and the desirable streamline shape enabled by the use of these circuitous routes further reduces wind resistance of'the ventilator unit.
When it is desiredto have'access to thefan or motor for cleaning or repair, or when it is desired for any other reason to expose the working parts, the hood 48 is merely swung up, as shown in Figure 2. It will be observed that the hood pivots upwardly about its mounting pins 36, which forms a horizontal pivotal axis disposed intermediate the horizontal length of the hood and transverse thereto, with the hood in raised position, the fan is readily accessible; and since the motor is carried with the hood in a downwardly open casing 56, upward swinging movement of the hood renders motor 58 readily accessible without the inconvenience of working from below.
When it is desired to return the ventilator to operative condition, the hood is simply swung down again to its closed or forward position, in which it rests adjacent its swinging end but intermediate its horizontal length on horizontal ears 44, which are downwardly offset as aforesaid so that when the hood is resting thereon, the lower marginal portion of the hood will be disposed in a plane substantially parallel to the plane of the roof. In other words, the downward offset levels the hood. Wing nuts 78 are adapted to register through holes 46 and corresponding holes in the lower marginal portion of the hood, in order to hold the hood in its lowered position. Needless to say, the wing nuts must be loosened before the hood can be swung upwardly and must be re-engaged in order to hold the hood in its lowered position. Instead of holes 46, it will of course be apparent that wing nuts 78 could be pivotally mounted on hood 48 to swing into and out of outwardly opening slots in horizontal ears 44.
When the ventilator is in operation, pulleys 28 and 70 are drivingly connected by belt 72; and hence, when hood 48 is swung upward, it is obviously necessary to disengage the belt from one or another of the pulleys. To this end, I have mounted motor 58 in such a way that it will be movable inwardly or outwardly, toward or away from the fan. In order to effect this movement, adjusting nuts 66 are screwed inwardly or outwardly on threaded bolts 64. For example, when it is desired to move motor 58 inwardly to release belt 72 from pulley 70, the adjusting nuts 66 contacting the inner side of motor mounting plate 60 are screwed inwardly toward base plate 62. Plate 60 may then be moved inwardly; and if desired, nuts 66 on the outer or motor side of plate 60 may also be screwed inwardly on bolts 64 to hold motor 58 in its inward or ineffective position during upward swinging of hood 48. Conversely, when hood 48 is lowered and the ventilator is once more placed in operative arrangement, belt 72 will again be slipped ove'r pulley 70 and the nuts 66 on either side of plate 60 screwed outwardly to tension belt 72 between pulleys 28 and 70 and maintain motor 58 in its operative or driving position.
In Figures 6 through 9, I have shown a modified form of ventilator fan according to my invention in which, as also in the first embodiment, a trunk or casing 10' is adapted to be mounted on a roof 12 over an opening 14 therein, and in which a fan ring 16 is provided which bears crossbars 18' and bracing struts 20' which support bearing member 22 in which fan shaft 24' is journaled for rotation about a vertical axis. Fan blades 26 are carried at one end of shaft 24 and fan pulley 28' is carried at the opposite end of shaft 24'. First and second hood support members 30' and 38' are provided as before, with lateral projections 32 and 40' having downturned ends 34 and 42 respectively. As before, the first support member carries outwardly disposed pins 36' and the second support member carries outwardly projecting horizontal ears 44' provided with holes 46'. Hood 48' provided with rounded end portions 50, vertical sides 52 and pyramidal deflector 54 is pivotally mounted as before on pins 36'.
The embodiment of Figures 6 through 9 differs from the first embodiment chiefly as to the manner in which the motor is mounted. It will be noted that in the modified form, fan motor 58' ismounted directly on the side of casing 10' and is not provided with a separate motor casing. As before, motor 58 may be mounted on motor mounting plate 60' which in turn may be adjustably connected with base plate 62 by means of threaded bolts 64' and adjusting nuts 66 whereby motor 58' may be moved inwardly or outwardly to break or make driving connection with the fan. As before, the fan is driven through downwardly extending drive shaft 68 hearing drive pulley 70' at its lower end and drivingly engageable with fan pulley 28 by means of fan drive belt 72.
Belt 72' and pulley 28 are protected from dirt and corrosive fumes and extraneous material entrained in the air stream by fan belt casing 74 which is mounted inside casing 10. Inasmuch as motor 58 is not centered on the side of casing 10 but is mounted instead adjacent one corner of the casing, the belt casing 74' is not bisymmetric, but rather has one leg thereof longer than the other to accommodate mounting within the casing on a bias, as shown in Figure 9. To this end, the legs of casing 74' are terminated on a plane which is inclined to the major longitudinal axis of casing 74'. No belt guard is needed on the outside of casing 10'.
The operation of the modified device of Figures 6 through 9 is as follows:
The operation of the fan by the motor is the same as in the previous embodiment. When access is desired to the working parts for the purposes of cleaning or repair, wing nuts 78 may be loosened as before and the hood swung upwardly about the substantially horizontal axis extending between pins 36. Since motor 58 is mounted on the side of casing 10', the motor does not move with the hood; and hence it is not necessary to disengage drive belt 72 from drive pulley 70'. When the hood is in its upwardly swung position, both the fan within the casing and the motor mounted on the outside of the casing will be readily accessible. The purpose of mounting motor 58' adjacent a corner of the casing 10' rather than centered on a side thereof will now be apparent, since in this position, mounted a substantial distance from the pivotal axis provided by pins 36, the motor will be surrounded by much more working space than if it were mounted closer to the pivotal axis of hood 48. Of course, motor 58' could be mounted the very farthest from the pivotal axis by mounting it on the same side of the casing as second hood support member 38; however, there would then tend to be interference between the motor and the adjacent rounded end portion 50 of the hood. Finally, when hood 48 is returned to its lower position, it will as before come to rest on horizontal ears 44 andbe held down thereagainst by wing nuts 7 8'.
Thus it will be seen that in the second embodiment I have provided a roof ventilator in which maximum accessibility to the working parts is provided by upward swinging of the hood, and in which the hood, when in lowered position, serves not only to provide air passageway on all sides of the casing by virtue of its horizontal lateral outward extension in all directions therefrom, but also serves completely to shield the motor from the elements,'there'by eliminating the need for a separate motor casing outside'the fan casing.
Although the present invention has been described in conjunction with preferred embodiments, it is to be understood that modifications and variations may be resorted to without departing from thespirit and scope of the invention, as those skilled in the art will readily understand. Such modifications and variations are considered to be within the purview and scope of the invention and appended claims.
'1. A roof ventilator comprising in combination a rectangular casing open at its top and bottom adapted to bemounted on a roof over an openingtherein, a rectangular fan ring mounted in said casing and having a circular central opening defined by a venturi ring extending upward from and integral with'said fan ring, a fan mounted for rotation in said casing about a vertical axis concentric with said opening, a motor mounted on said casing and having driving connection with said fan, a downwardly concave rectangular hood mounted on said casing, the upper marginal edge of said venturi ring extending a substantial distance above'the lower marginal edges of said hood, all four inner-side walls of said hood being spaced a substantial distance outward from the side walls of said rectangular casing to permit free flow of air downwardly outward on all four sides of said casing, and a pyramidal deflector mounted on the under side of said hood above said fan, said deflector having four equally inclined triangular sides of which the apices meet at the lowest point on said deflector, the base of each said triangular side being parallel to an upper edge of said rectangular casing.
2. Aroof ventilator comprising in combination a rectangular casing open at its top and bottom adapted to be mounted on a roof over an opening therein, a fan rotatably mounted in said casing, and a downwardly concave rectangular "hood mounted on said casing, all 'four inner sidewalls of said rectangular hood being spaced a substantial distance outward from the side walls of said rectangular casing to permit free flow of air downwardly outward on all four sides of said casing, and means for mounting said hood on said casing comprising a pair of bars of substantially greater length than the width of said casing, fastened along their medial portions to opposed upper edges of said casing and defining outwardly extending flanges along said opposed upper edges, the outer ends of said bars extending across said substantial distance between said side walls of said rectangular casing and said inner side walls of said rectangular hood, one-of said bars having means at its outer ends on which said hood is mounted for vertical swinging movement, and the other of said bars having means atits outer ends on whichsaid hoodrests 'whenin lowered position.
3. The invention of claim 2, the lower marginal edges of said hood extending a substantial distance below said bars.
References Cited in the file of this patent UNITED STATES PATENTS 715,169 Stanley Dec. 2, 1902 776,642 Budd Dec. 6, "1904 1,604,448 Hosch Oct. 26, 1926 1,614,190 Dyer Ian, 11, 1927 2,198,420 Winton Apr. 23, 1940 2,218,348 Boyer Oct. 15, 1940 2,332,552 Belanger Oct. 26, 1943 2,551,004 Johnson May 1, 1951 2,571,513 Ammerman Oct. 16, 1951 2,638,835 Strawsine May 19,1953 2,684,621 Cook July 27, "1954