Exhaust Fan for Bathrooms and the Like

The present invention relates to improved exhaust fans of the centrifugal type. Such fans are typically utilized to ventilate bathrooms and other living spaces in homes.

The improved fan of the present invention has a housing with a base wall. When the fan is typically installed on a joist above the ceiling of the bathroom, the base wall forms the top of the housing. Four side walls depend from the base wall. A baffle is positioned within the side walls to form a centrifugal fan scroll. One of the side walls has an exhaust port containing an exhaust outlet fitting.

In accordance with one aspect of the present invention, a venturi plate is positioned within the side walls to lie parallel to, but spaced from, the base wall so as to form a blower chamber for the fan. The venturi plate contains an inlet air opening. The portions of the venturi plate surrounding the opening are formed as a venturi leading into the blower chamber.

A strut means formed in the venturi plate spans the inlet air opening for mounting the fan motor. A centrifugal fan impeller is mounted on the output shaft of the motor so as to lie within the blower chamber. The strut means has a configuration resembling a shallow Y and is positioned in the opening so as to be removed from the portion of the opening adjacent the exhaust port, thereby to enhance the efficiency of the fan.

The venturi plate is retained in the housing, without the use of fasteners, by peripheral tabs that engage slots in the side walls of the housing. The venturi plate may be easily inserted and removed from the fan by use of the tabs and slots to permit wiring and for other reasons.

To enhance the ease and versatility of the installation of the improved fan of the present invention, the base wall and one of the side walls have reinforced holes for receiving a wiring conduit connector or other appliance used to connect the fan to the household wiring. Depending on whether the fan is to be wired from the top or the side, one or the other of the holes is utilized. The hole not utilized is covered by a flap, preferably formed as a portion of the housing. The use of knock-outs is thus avoided, while at the same time the fan is capable of being wired from either the top or side.

The reinforced holes are preferably located in a corner of the housing.

A corner separator separates the parts of the base wall and side wall with the reinforced holes from the remainder of the blower chamber. The wiring connections for the fan are contained in the portion of the housing so separated. The motor is connected by means of a conventional two-prong plug and receptacle, the receptacle being mounted in the corner separator and connected to the wiring.

In accordance with another aspect of the claimed invention, the exhaust outlet fitting contains an integral centrifugal fan outlet cutoff that enhances the operation of the centrifugal blower by providing a smooth air flow transition and reduced feedback. The exhaust outlet fitting is removably mounted in the exhaust port for ease of assembly and repair.

The bath fan of the present invention also lends itself to manufacture and assembly by programmable manipulators, and the like.

The invention will be further understood from the following detailed description taken in conjunction with the drawing in which:

FIG. 1 is a perspective view of the improved fan of the present invention with a typical associated louver;

FIG. 2 is an exploded view of the fan;

FIG. 3 is a bottom view of the fan, i.e. a view looking upward in FIG. 1, but with the louver removed;

FIG. 4 is a cross sectional view along line 4--4 of FIG. 3, the manner of assembly of a portion of the fan being shown in phantom;

FIG. 5 is a fragmentary cross sectional view showing the discharge conduit fitting and associated portions of the housing; and

FIG. 6 is a fragmentary side view taken along the line 6--6 of FIG. 3.

FIG. 1 shows fan 10 attached to louver 12. In use, fan 10 can be conveniently mounted in either the horizontal or vertical positions. Thus fan 10 is fastened along one side to a ceiling joist or subjoist or to a wall stud. Louver 12 extends below the ceiling or beyond the wall of a bathroom or other space. Fan 10 draws air in vents 14 of louver 12 and discharges it out exhaust outlet fitting 16.

Fan 10 includes housing 18. Housing 18 is formed of sheet metal or other suitable material of a thickness sufficient to provide the necessary structural strength to fan 10. The sheet is bent to the configuration shown in the figures and fastened at overlapping corner flanges, such as 20 and 22, and elsewhere, by any suitable means. Housing 18 has base wall 24 forming a top wall when fan 10 is oriented as shown in FIGS. 1, 2, and 4. Four side walls 26, 28, 30, and 32 depend from base wall 24. Side wall 30 contains integral flanges 34 by which housing 18 may be mounted to a joist or stud as by nails or screws extending through holes 35. The adjacent ends of side walls 28 and 32 may be bent to be along flanges 34, thereby to provide a strengthening double thickness to the flanges, as shown in FIG. 3. The integral flanges assist in installing fan 10.

Housing 18 has curved sheet 37 fastened to walls 28, 30, and 32 that serves to form a centrifugal fan spiral or scroll in housing 18.

In accordance with one aspect of the present invention, housing 18 is so formed to provide ease and versatility to the installation of fan 10 and particularly the wiring thereof. Fan 10 may be connected, without knockouts, to a wire cable or conduit containing wire either from the top or the side. To this end, housing 18 has hole 36 in a base wall 24. When fan 10 is oriented as shown in FIGS. 1, 2 and 4, hole 36 accommodates a downwardly extending conduit or wire cable. Hole 38 is provided in side wall 28 to accommodate a horizontally extending conduit or wire cable. Each of holes 36 and 38 is provided with an annular reinforcing flange 40 for coaction with the wiring coupling to provide the necessary structural strength to the wiring-housing connection, and as required by various electrical codes. The annular flanges, such as that indicated by 40 in conjunction with hole 36 in FIG. 2, may be formed by folding back material from the center of the hole along the periphery of the hole to provide an additional thickness of the sheet material forming housing 18.

To close off the hole 36 or 38 not being used, flap 42 is provided in the sheet of material from which housing 18 is formed. During assembly of housing 18, flap 42 is bent to lie inside the housing, as shown in FIG. 2. If hole 36 is used to connect the wiring, flap 42 remains in the position shown in FIG. 2 to cover hole 38. If hole 38 is used to connect the wiring, flap 42 is bent to over hole 36, as shown by the arrow in FIG. 2.

Through the above-described arrangement, wiring connection in either the vertical or horizontal direction can be made to fan 10, thereby facilitating installation of the fan. The use of knock-outs can be avoided, while at the same time, the unused opening in housing 18 is closed to retain the closure integrity of housing 18, also as required by various electrical codes.

The corner of housing 18 containing holes 36 and 38 is separated from the remaining portions of housing 18 by corner separator 44. Corner separator 44 has vertical wall 46 lip or, flange 48, split vertical side flanges 50a and 50b on either side, and horizontal flange 52. Flange 52 mounts a conventional two-prong electrical receptacle 54 with lead wires 56.

After connection of housing 18 to the household wiring, the household wires are connected to lead wires 56 in a suitable manner, as by the use of twist connectors or the like. The ground wire of the household wiring may be connected to the adjacent portions of housing 18 by grounding clip 58 mounted on wall 26. Or, the ground wire may be connected to housing 18 by a grounding screw inserted into extruded hole 59 in base wall 24.

Walls 26 and 28 are provided with somewhat drop shaped slots 60 and 62 for mounting corner separator 44 in housing 18. Side flanges 50a on either side of vertical wall 46 are inserted through slots 60, 62 by means of bent corners 64 so as to lie on the outer surface of side walls 28 and 26, as shown in FIGS. 3, 4 and 6. Side flanges 50b remain on the inside of sidewalls 38 and 26, as shown in FIGS. 4 and 6. The wiring connections are thus neatly separated from the remaining portions of the interior of housing 18 and the spiral or scroll configuration of the housing maintained. As fan 10 is customarily shipped with corner separator 14 assembled, one of side flanges 50b is provided with tab 66 that facilitates removal of separator 44 prior to connection to the wiring.

Corner separator 44 also serves to maintain flap 42 in the desired position. When flap 42 is in the position shown in FIG. 2, the flap is retained by horizontal flange 52 in the manner shown in FIG. 3. For this purpose, flap 42 is longer than vertical wall 46. When flap 42 is bent to be along base wall 24, it fits between flange 48 of corner separator 44 and base wall 24 when corner separator is installed.

Exhaust outlet fitting 16 may be made from plastic or other suitable material. Exhaust outlet fitting 16 includes damper 70 for preventing reverse flow of air into fan 10. Exhaust outlet fitting 16 also includes baffle 72, shown most clearly in FIG. 4 that matches the configuration of the inlet end of fitting 16 to that of the venturi plate, hereinafter described, when the latter is installed in housing 18. The inlet end of fitting 16 includes flange 74 that fits in slot 76 in housing wall 26, as shown in FIGS. 2 and 5 to retain one side of exhaust outlet fitting 16 in the housing. Exhaust outlet fitting 16 also includes sealing flange 78 adjacent the inlet end. Flange 78 includes integral outlet cutoff 80 for the spiral or scroll of the centrifugal blower, as shown most clearly in FIG. 5. Such a configuration assists in forming a smooth scroll for the fan, lessens feedback and enhances the operation of the centrifugal fan. Outlet fitting 16 is conveniently retained in the exhaust port of housing 18 by clip 82 that passes through opening 84 in wall 32. With flange 74 in slot 76, clip 82 is slid sideways in the opening 84 so that the hooked end of the clip engages bar 86 to retain the fitting in housing 18.

As noted above, curved sheet 37, fastened to walls 28, 30, and 32 forms a centrifugal blower spiral or scroll in housing 18 extending from outlet cutoff 80. Vertical wall 46 of corner separator 44 and a portion of wall 26 also form the scroll, as shown most clearly in FIG. 3.

Housing 18 is spanned by venturi plate 100 that provides both an air inlet for the fan and supports the blower motor. Venturi plate 100 contains inlet opening 102 that connects vents 14 of louver 12 to the blower chamber formed between plate 100 and base wall 24 of housing 18. The periphery of opening 102 is formed as an inlet venturi to the chamber by flange 104, as shown most clearly in FIG. 4.

A plurality of struts 106 span opening 102 to support motor 108 for blower impeller 110. As shown in FIG. 3, struts 106 are positioned to avoid the area of outlet cutoff 80, thereby to avoid any reduction in the efficiency of the blower. To this end, the struts have the configuration of a shallow Y or T, as shown in FIGS. 2 and 3. The output shaft 112 of motor 108 extends through hole 114 in struts 106 to receive impeller 110. The motor is mounted to struts 106 by bolts 116. Bolts 116 extend through holes 120 in struts 106 to receive nuts 122.

Venturi plate 100 has peripheral flanges 124a-d. Flange 124d includes a pair of tabs 126 and 128 and flange 124b includes tab 130. Tabs 126 and 128 engage slots 132 and 134 in wall 32 and tab 130 engages slot 136 in wall 28 to position venturi plate in housing 18. Venturi plate 100 is installed by inserting tabs 126 and 128 in slots 132 and 134, as shown in phantom in FIG. 4. Venturi plate 100 is then swung in the direction of the arrow in FIG. 4 until tab 130 lodges in slot 136. Flanges 124a-d lie proximate to side walls 26-32. Tabs 126, 128 and 130 and slots 132, 134, and 136 fully secure venturi plate 100 in housing 20, since the weight of motor 108 serves to retain the tabs in the slots. However, a retaining screw may be inserted in holes 138 and 140 of wall 28 and flange 124b, if desired.

Venturi plate 100 includes opening 142 that exposes receptacle 54 in horizontal flange 52. Motor 108 is connected to the lead wires 56 by inserting plug 144 on lead wires 146 into the receptacle, as shown in FIGS. 3 and 4. Venturi plate 100 assists in retaining corner separator 44 in housing 18.

Venturi plate 100 also includes slots 148 that engage spring wires 150 for holding louver 12 on fan housing 18.

A stiffening ridge 152 is provided on venturi plate 100 adjacent tab 130. Venturi plate 100 may be pushed up, when viewed as in FIG. 4, and wall 28 bowed outwardly to remove tab 130 from slot 136 to release venturi plate 100 from the housing to permit wiring of fan 10 and for other reasons. Or, a screwdriver 154 shown in FIG. 3 may be inserted in opening 156 against the edge of flange 124b and used as a lever or pry bar to release the tab from the slot. Side walls 28 and 32 contain projections 160 adjacent the ends thereof, as shown most clearly in FIG. 3. The projections may be in the form of extruded holes. They serve to space the plaster board of the ceiling or wall from the side walls so that the walls can flex to release the venturi plate.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing and distinctly claiming the subject matter which is regarded as the invention.