Air filter apparatus

A removable, washable air filter apparatus is formed with two V-shaped rectangular mesh filters held in place side by side within a housing with the vertices of the V filters draining grease and moisture into a removable pan. A mounting bracket maintains the pan in position to receive extracted grease and moisture without impeding air flow through the exposed filter mesh. The top edges of the housing have outwardly formed flanges for removably mounting the housing by means of overlying swivel retainers provided around the periphery of mating flanges on an intake opening of a ventilation hood or air duct.

This invention relates to air filter apparatus used at the air intake of 
air ducts, and power ventilated hoods of the ducted or ductless 
recirculating type. 
Standard flat filters of metal or plastic mesh are widely used in ducts and 
hoods over ranges, fryers, broilers and other cooking equipment with the 
draft or suction of a fan or blower pulling moisture laden air through 
mesh filters with the grease and moisture in the air from cooking vapors 
becoming deposited on the surfaces of the mesh filters. A grease and 
moisture laden atmosphere as is common with grilling, broiling and frying 
will quickly cause a mesh filter to become partly clogged with grease and 
moisture to the extent that the air flow through the filter is impeded 
cutting the efficiency of the hood or air duct system. 
Metal mesh filters are easily washable, but this is not practical or 
practiced at frequent intervals. Clogging filters with resultant loss of 
air flow lead to higher temperatures of fan and blower motors with further 
efficiency loss and even fire hazard in cases of grease laden wiring, 
motors, fans and ducts, hence, one can understand and appreciate the 
desirability and even the necessity for air filters that will maintain 
high efficiency for longer time with easy removability and cleanability. 
With these and other factors in mind my invention was conceived to provide 
a simple removal air filter apparatus utilizing standard inexpensive flat 
rectangular mesh filters, V formed and removable, within an easily 
removable housing and further with a removable pan to receive the dripping 
grease and moisture from the V formed filters. This further enhances the 
efficiency and utility of my filter apparatus as the National Fire 
Protective Association Code No. 96 and other safety and regulatory codes 
require vapor removal with mesh filters and in ducted hoods said filters 
must be installed at an angle of not less than 45 degrees from the 
horizontal and must be equipped with a drip pan or tray beneath the lower 
edge of the filters. Also one can appreciate the desirability of the pan 
to prevent grease drippings from draining on foods being cooked below. It 
will be further noted that my disclosure with two V formed filters at one 
air inlet doubles the filter area that would normally be provided if just 
one flat rectangular filter was utilized over a flat horizontal air inlet 
as is standard practice with range hoods. 
With my filter apparatus a standard activated charcoal flat filter can be 
easily installed horizontally above the two V formed filters and maintain 
its original efficiency for a much longer period of time than with a flat 
mesh filter installed horizontally against a flat activated charcoal 
filter as the flat mesh filter allows the activated charcoal filter to get 
grease and moisture across its surface, greatly reducing its efficiency 
and air handling capability, and as such activated charcoal filters are 
not washable, same must be replaced whenever its gets grease and moisture 
over is surface. 
With the foregoing and other objects in view, my invention comprises 
certain novel constructions, combinations, and arrangements of parts as 
will be hereinafter fully described, illustrated in the accompanying 
drawings, and more particularly pointed out in the appended claims.

Referring to the drawings in detail: 
FIG. 1--Parts 1 and 1A are the front and rear housing closure members 
respectively, spaced apart and held together by angle members 2 and 2A, 
preferably resistance welded, at their respective corners to 1 and 1A. A 
removable cross member 3 overlies the abutting edges of V formed metal 
mesh filters 4 and 4A which are placed side by side in the housing and 
held fixedly by overlying crossmember 3 with bolts 3A holding outer 
flanged portions to front and rear housing closure members 1 and 1A 
respectively. Extending flat tongue portions 7 and 7A hold outer top frame 
portions 5 and 5A in place so horizontal flange portions of angle members 
2 and 2A may seal against the underside of an air intake opening of a 
power hood or air duct which is provided with overlying swivel type 
retainers around the periphery to retain the housing closure members in 
place. Extending from and attached to the rear housing closure 1A is 
support member 8 with attached formed clip member 9 having a lateral 
formed offset 9A and a lateral formed half round portion 9B holding the 
upward extending rear lateral half round formed portion 6B of back 6A of 
sliding pan 6. It will be noted that back 6A of pan 6 may be slidably 
removed or inserted underneath clip 9 and in front of support 8 from 
either side of the filter apparatus and that same cam be centered under 
the vertices of the mesh filters 4 and 4A to receive and contain drippings 
from the V filters as shown in FIGS. 3 and 4. 
FIG. 2--Filters 4 and 4A with their perimeter supports or frames 5 and 5A 
are held in place by overlying support member 3 at their abutted edges, by 
tongues 7 and 7A at their outer edges and at front and rear by housings 1 
and 1A. 
FIG. 3--Pan 6 with extending front handle 6C with rear slide mounting is 
fixedly positioned below vertices of formed V filters 4 and 4A. 
FIG. 4--Inverted V angles 11 attached or post welded to the inner sides of 
front and rear closures 1 and 1A respectively support and retain the inner 
V portions of mesh filters 4 and 4A. These inverted V angles also serve to 
seal the inner frames 5 and 5A of the filters just as the inward formed 
angle portion 1B of front housing 1 and the inward formed angle portion 1C 
of rear housing 1A support and retain the outer V portions of mesh filters 
4 and 4A as well as seal the outer V portions of frames 5 and 5A. Half 
round formed member 10 provided with extended portions 10A serves as a tie 
bar or reinforcing member between front housing 1 and rear housing 1A as 
extending portions 10A are welded or secured to inward formed horizontal 
angle portions 1D and 1E respectively. 
It will be noted that with the two side by side mesh filters in their 
position within the housing with the overlying inverted V formed tie bar 
screwed to the front and rear housing members 1 and 1A by screws 3A, all 
of the mesh area of both V filters is exposed for maximum filter area and 
that the intake area at the top of the housing as shown in the top view of 
FIG. 2 is considerably less than the total mesh intake area. Further with 
overlying swivel clips or retainers provided on an air intake opening of 
an air duct or hood the top flanges 2 and 2A permit easy installation or 
removal of the entire apparatus by means of the swivel retainers mounted 
to the underside of the duct or hood in a manner to permit their swiveling 
over the flanges 2 and 2A to retain the filter apparatus in place in a 
relatively air tight manner. 
While I have described the preferred embodiments of my invention and 
illustrated same in the accompanying drawings, certain minor changes or 
alterations may appear to one skilled in the art to which this invention 
relates during the extensive manufacture of same, and I therefore reserve 
the right to make such alterations or changes or shall fall within the 
scope of the appended claims.