US 3044689 A
Description (OCR text may contain errors)
July 17, 1962 L. L. ALLDRITT ETAL 3,044,689
VENTILATING FAN ASSEMBLY Filed May 8, 1958 INVENTORS LAWRENCE L. ALLDRITT DELLA MAY ALLDRITT A TTORA I EV United States 3,044,689 Patented July 17, 1962 lice ' Filed May s, 1958, Ser.'No. 733,886
3 Claims. 01. 230-273 The present invention relates to ventilating and cooling fan assemblies, and more particularly to 'belt driven fan assemblies intended and adapted for attic and wall mounting, in residences and oflice buildings and factories and other buildings, both of frame and masonry con- 7 struction.
An object of the invention is to provide a fan assembly structure for ceiling or attic or wall installation, which has a supporting and mounting structure of compact form and arrangement, thus requiring a minimum of space and depth of wall or frame for installation, so that the fan assembly can be substantially completely encompassed within the thickness of an average wall of a frame or masonry house, and so that in'attic installations a minimum of space will be required and the fan can be mounted to hang down inside the joists instead of resting upon and projecting above the joists.
A further object of the present invention is the provision of a ventilating fan and mounting therefor such that the parts are substantially balanced to distribute any strain from the fan and motor mounting and the drive belt therebetween. 7
Still another object of the present invention is the provision of a ventilating fan assembly having means resiliently mounting the rotatable fan member so as to avoid pounding or hammering of the fan unit.
Another object of the present invention is the provision of a fan and mounting structure which is simple to install and of which all parts can be easily reached for servicing and the like.
Finally, it is an object of the present invention to provide a ventilating fan assembly which will be easy and inexpensive to manufacture, simple to operate, maintain and repair, and rugged and durable in use.
Other objects and advantages of the present invention will become apparent from a consideration of the following description, taken in connection with the accompanying drawing, in which:
FIGURE 1 is a view in perspective showing the ventilating-fan of the present invention from the intake side;
FIGURE 2 is a view in edge elevation showing the fan and mounting structure; and
FIGURE 3 is an elevational view looking at the intake side of the mounting structure with the drive motor and rotatable fan unit removed.
Referring now to the drawing in greater detail, there is shown a ventilating fan assembly comprising a substantially rectangular flat plate having an upstanding flange 12 disposed on one side of the plane thereof entirely about the edges of the plate. Plate 10 is provided with a circular central opening 14 bounded by a venturi ring 16 integral with plate 10 and extending away from the plane of plate 10 on the side thereof opposite flange 12. Obviously, plate 10 with its flange and venturi ring may be constructed by forming opening 14, spinning out venturi ring 16, and bending up and welding flange 12.
Secured flat against the same side of plate 10 as flange 12 is a uniplanar integral Z-shaped torsion bar 18, which may be a steel rod of round bar stock bent at two places so as to have a straight mid-portion 20 and a pair of oppositely angularly related legs 22 and 24 which are straight and in the illustrated embodiment are parallel to each other. Each leg 22 and '24 is secured adjacent its ends to plate 10 by means of welds 26' so that leg 22 is disposed adjacent corner 30 of plate 10 and flange 12 while leg 24 is disposed adjacent diagonally opposite corner 32 of plate 10 and flange '12. The ends of leg 22 lie on opposite sides of an imaginary line 28 joining diagonally opposite corners 30 and 32, as do also the ends of leg 24 and the welds 26 adjacent those leg ends. If the points of securement of legs 22 and 24 to plate 10 on one side'of line 28 are joined by an imaginary line 34 and the points of securement oflegs 22 and 24 on the other side of line 28 are joined by an imaginary line 36, it will be noted that line 28 lies substantially.
mid-way between and substantially parallel to lines 34 and 36.
Secured in holes 38 through plate 10 is the mounting bracket for an electric drive motor 40 which is thus mounted on plate 10 on the same side of the plane of the plate as venturi ring 16. Motor 40 has a drive shaft 42 which extends through hole 44 in plate 10 and terminates on the flange side of plate 10 in a relatively small drive pulley 46.
Mounted for rotation coaxially ofopening 14 on midportion 20 is a fan 48 having a coaxial fan shaft 50 rotatable in a bracket 52 fixedly secured on mid-portion 20. On the free end of fan shaft 50 opposite fan 48 from bracket 52 is a relatively large fan pulley 54 drivingly interconnected with drive pulley 46 by a conventional drive belt 56. It should be particularly noted that drive belt 56 extends in the same general direction as line 28 and that drive shaft 42 is disposed at all times between lines 34 and 36, either on or a very small distance on either side of line 28. It should also be noted that fan shaft 50 is perpendicular to but spaced from mid-portion 20, which is to say that theaxis of rotation of fan 48 and the torsional axis of mid-portion 20 are spaced apart a substantial distance. Also, fan 48 being substantially heavier than fan pulley 54, the centroid of the rotatable fan unit is spaced a still greater distance from the torsional axis of mid-portion 20. It will further be observed that the angle between mid-portion 20 and the line 28 is very small and substantially less than 45", so that longitudinal stresses imparted through drive belt 56 will be borne by mid-portion 20 largely in axial tension or compression.
Considering the fan and its mounting as a resilient structure of limited flexibility, it will also be seen that the axial stresses in mid-portion .20 will to some extent be relieved by angularly related legs 22 and 24 somewhat in the manner of a clip spring and these stresses and forces will be equally distributed throughout the fan and its frame by the location of the secured ends of legs 22 and 24 on opposite sides of line 28. Moreover, the securement of legs 22 and 24 as above described also assures that the weight of fan 48 and the other factors tending to misalign fan shaft 50 from its coaxial relationship in opening 14 will be largely borne in torsion by mid-portion 20 in a very firm but somewhat resilient manner thanks to the oppositely angular disposition of legs 22 and 24 relative to mid-portion 20, so that these forces and stresses will be evenly distributed about plate 10 and flange 12. Finally, it will be noted that the provision of flange 12 about rectangular plate 10 creates a structure which would inevitably have a tendency to rack or twist about line 28 were it not for the mounting of torsion bar 18 as above described.
In view of the foregoing disclosure and discussion, it will be obvious that all of the initially recited objects of the present invention have been achieved.
Although the present invention has been described and illustrated in connection with a preferred embodiment, it is to be understood that modifications and variations may be resorted to without departing from the spirit of this invention, as those skilled in this art will readily understand. Such modifications and variations are considered to be within the purview and scope of the present invention as defined by the appended claims.
What is claimed is:
1. A ventilating fan assembly for installation in buildings, comprising a substantially rectangular flat plate having a circular central opening with a venturi ring extending outwardly on one side of the plane of the plate and a marginal flange extending outwardly on the other side of the plane of the plate, an integral uniplanar Z-shaped torsion bar having a straight mid-portion terminating at its ends in a pair of legs oppositely angularly related to the midportion, each leg being secured adjacent each of its ends to the flange side of the plate on opposite sides of a line joining diagonally opposite corners of the plate, the midportion extending across the opening, a fan mounted on the mid-portion for rotation coaxially of the opening, an electric motor mounted on the same side of the plate as the venturi ring and having a drive shaft extending through a hole in the plate, and means disposed on the flange side of the plate and drivingly connecting the fan with the drive shaft.
2. A ventilating fan assembly as claimed in claim 1, the drive shaft being disposed between lines interconnecting the ends of the legs disposed on each side of said line joining diagonally opposite corners of the plate.
3. A ventilating fan assembly for installation in buildings, comprising a substantially rectangular plate having an outer marginal flange and a circular opening through the plate, an integral uniplanar Z-shaped torsion bar having a straight mid-portion terminating at its ends in a pair of legs oppositely angularly related to the mid-portion, each leg terminating at one end in an end of the midportion and being spaced at the other end a substantial distance from the mid-portion, each leg being secured adjacent each of its ends to the plate on opposite sides of a line joining diagonally opposite corners of the plate, the mid-portion having a length greater than the diameter of the opening and extending across the opening, a fan mounted on the mid-portion for rotation coaXially of the opening, an electric motor mounted on the plate and having a drive shaft, and means drivingly connecting the fan with the drive shaft.
References Cited in the file of this patent UNITED STATES PATENTS 2,746,674 Alldritt et a1 May 22, 1956 2,708,373 Werner May 17, 1955 2,874,898 Bayhi Feb. 24, 1959