US2988981A - Power roof ventilator - Google Patents

Description

June 20, 1961 J. JENN ETAL 2,988,981

POWER ROOF VENTILATOR Filed March 12, 1958 INVENTORS. Zoo/3 JI JAN/Y. JflMES W. Sewn 1:2.

United States t nt "ice 2,988,981 POWER ROOF VENTILATOR Louis J. Jen and James W. Schwier, Indianapolis, Ind.,

assignors to Jenn Air Products Company, Inc., Indianapolis, 'Ind., a corporation Filed Mar. 12, 1958, Ser. No. 720,854

1 Claim. (Cl. 98-43) I This invention relates generally to power roof ventilators, and in particular to a ventilator of this type arranged to discharge air at a maximum height above roof level with a minimum over-all extension thereabove.

Power roof ventilators are conventionally mounted upon a preconstructed curb and are arranged to extend upwardly from the roof level, it being desirable to discharge air from the ventilator at a substantial height above the roof level. This desirable feature is opposed by the further requirement that the height of extension above the roof level of the ventilator unit be maintained at a minimum. In the design of ventilators of the type referred to it is further desirable to provide a means for controlling the angular movement of the air flowing through the ventilator body prior to its; introduction into the impeller, or other air moving means proper. Control of this characteristic of the entering air stream is conventionally referred to as control of the prerotation ofthe air flowing through the ventilator. In the design of ventilators, particularly power operated roof ventilators, it is also desirable to isolate and prevent transmission of vibration from the air moving means and other movable parts to the exterior frame or body of the ventilator.

The primary object of the present invention, therefore, is to provide a power roof ventilator having the air moving means mounted at the top of the unit, above the supporting and driving means, thereby allowing the air to be discharged at a substantial distance above the roof level while maintaining a relatively low over-all ventiator unit height.

A further object of the present invention is to provide a power roof ventilator having a cap or rain cover supported by a grille which also acts as a guard against entry of birds or rodents into the ventilator.

It is a further object of the present invention to provide a power roof ventilator which incorporates a plurality of vanes extending transverse to the air path through the ventilator body and providing a mounting means for a driving device such -as an electric motor, the vanes thereby serving the dual function of providing a support and also controlling the prerotation of the air flowing through the ventilator unit.

A further object of the present invention is to provide a power roof ventilator in which the air moving'means and all other moving parts are suspended on a frame or body by means of a rubber-in-shear mounting, with metal to metal contact between the moving parts and the ventilator body being thereby eliminated.

The full nature of the invention will be understood from the accompanying drawings and the following description and claim:

FIG. 1 is a side sectional view of a vventilator embodying the present invention.

FIG. 2 is an enlarged, fragmentary view taken generally along the line 22 of FIG. 1.

FIG. 3 is a fragmentary, sectional view of a modified form of the ventilator.

Referring initially to FIGS. 1 and 2, there is shown at a preconstructed curb extending upwardly from the roof level indicated at 11. Overlying the annular curb is a support ring -12 which carries a metal member 1'3, having a stepped configuration in cross section. The upstanding marginal flange 14 of the member 13 has Patented June 20,1961

mounted thereon a steel band 16 by means of bolts 17. The bolts also serve to secure to the outer face of the band a cylindrical shell 18 which may be formed of aluminum or similar'corrosion resistant metal.

Welded to the band at spaced intervals therearound are support posts 19 which, as may best be seen in FIG. 2, are L-shaped in cross section. Adjacent their upper ends the support posts are bolted to the shell 18 by means of bolts 21.

Referring now principally to FIG. 2, it may be seen that each of the posts 19 has secured thereto by means of bolts 22 a facing plate 23. The surface of the plate, between the bolts 22 has bonded thereto a rubber cushioning block 24. The block may be formed of cushioning rubber or similar vibration insulating material. The opposite face of the rubber block has bonded thereto a facing plate 26 having threaded studs 27 extending therefrom and through appropriately positioned apertures in radially extending vanes 28. Nuts 29 threaded on the studs serve to lock the vanes to the facing plate 26. It will be understood that any desired number of supporting posts and radially extending vanes may be provided, only two being visible in FIG. 1.

The inner ends of the vanes are welded, or otherwise suitably secured to a tubular column 31 which extends upwardly through the ventilator and protrudes beyond the upper margin of the exterior shell 18. At each of its ends the column carries bearing members 32 which journal a drive shaft 33, thrust washers 34 fixed to the shaft serving to retain the shaft in position longitudinally. At its upper end the shaft carries mounted for rotation thereon a hub casting 36. By means of rivets 37 the hub supports an air impeller having a body section 38 from which radially extend a series of blades or vanes 39.

At its lower end the drive shaft has mounted thereon a pulley 41 connected by means of a V-belt 42 to a pulley 43. The pulley 43 is mounted on the output shaft of an electric motor 44. The motor is mounted by means of bolts 46 on one of the vanes 28. The bolts extend through appropriate slots 47 in the vanes to provide for belt tension regulating adjustment of the position of the electric motor.

Mounted on the upper margin of the shell 18 is a plate 48 having a central aperture defined by an upturned flange 49 providing an inlet orifice for the impeller. The connection between the shell and the plate 48 is provided by bolts 51 which also serve to secure to the shell a suitably formed, annular grille 52. The outer margin of the grille is secured by means of bolts 53 to a concavo-convex cover or rain cap 54 which overlies and encircles the impeller.

From the foregoing it will be evident that the support posts and the outer shell attached thereto provide a tubular exterior frame. The radially extending vanes, having a vibration insulating mounting, support the drive shaft in a position such that its axis coincides with the longitudinal axis of the ventilator body. One of the vanes serves as a mounting means for the electric motor driving the impeller. The motor and impeller together with other moving parts of the ventilator are thus suspended on and vibrationally insulated from the ventilator frame or body.

In operation, the motor rotates the impeller to draw air past the radially extending vanes, through the inlet orifice, and discharges the air through the annular discharge opening provided between the cap and the upper margin of the ventilator body.

By appropriately tilting or positioning the major plane of the vanes it will be evident that the incoming air flowing through the ventilator body may be given an angular prerotation either in the same direction as or against the direction of rotation of the impeller, or the vanes may be maintained aligned with the longitudinal axis of the ventilator body, as shown in FIG. 1, to thereby reduce rotation of the incoming air. The vanes 28 thus not only provide a mounting for the drive shaft and .the motor, but .in addition also 'provide a means for controlling the prerotation of the air flowing through the ventilator unit.

The annular grille 52 supports the overlying cap and also performs the additional function of providing a guard for 'the air discharge opening. The support of the motor and the motion transmission means for the drive shaft below the impeller permits the air discharge opening of the ventilator unit to be located at a maximum height above the roof level with a minimum over-all extension of the ventilator'unit above the roof level.

Referring now to FIG. 3, there is shown fragmentarily a modified form of the ventilator utilizing a fan rather than a centrifugal impeller. In this form of the ventilator a shroud 48a is mounted on theouter shell 18a and encloses a fan having blades 39a, the fan being mounted on the upper end of the drive shaft 33a for rotation thereby. The cap or rain cover 54a has a concavo-convex configuration similar to the cap referred to with reference to FIG. 1, but is additionally provided with a depending cup-shaped member 56 whose curved inner surface serves to direct the air to the discharge opening with a minimum of turbulence. The grille 52a serves to support the overlying cap and also to provide a guard for the discharge opening in identical fashion to the grille described with reference to FIG, 1.

The operation of this modified form of the ventilator is identical to that of the ventilator described previously and differs from it only in the provision of the air directing surfaces necessary when the air moving means takes the form of a rotary fan.

While the invention has been disclosed and described in some detail in the drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons skilled in this art and within the broad scope of the invention, reference being had to the appended claim.

The invention claimed is:

A power ventilator comprising a tubular body adapted to be mounted upright on a roof surface, a central shaft disposed longitudinally Within said body, a plurality of radial vanes within and secured to said body and supporting said shaft, an annular plate mounted on said body at the top thereof and defining an air inlet orifice through which said shaft extends, air moving means mounted for rotation on the portion of said shaft extending beyond said orifice and adapted to draw air through said body and past said inlet orifice, a concavo-convex cap overlying said air moving means and having its margins laterally spaced from said body to provide an annular air discharge opening, .power means for driving said shaft supported on one of said vanes, said vanes being generally aligned with the direction of air movement through said body to thereby control the prerotation of air entering said inlet orifice.

References Cited inthe file of this patent UNITED STATES PATENTS 2,157,609 Hopkins May 9, 1939 2,322,302 Martinson June.22, 1943 2,728,541 Hansel Dec. 27, 1955 2,735,611 McLean Feb. 21, 1956 2,868,105 Knutson et al. Jan. 13, 1959 2,875,678 Shepherd Mar. ,3, 1959

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