The molded plastic rectangular shutter support housing and the mounting cover frame of the two-piece foundation ventilator are provided with connector devices for removably maintaining the shutter support housing and the mounting cover frame in assembled condition and for permitting disassembly of the mounting cover frame and the shutter support housing, if desired. The connecting devices include integrally molded clip members on the mounting cover frame with inwardly extending locking portions positioned in overlying engagement with integrally molded flanges of the shutter support housing to permit the shutter support housing to be removed from the mounting cover frame by sliding the shutter support housing longitudinally in one direction along the mounting cover frame and for assembling the two parts together by longitudinally sliding the shutter support housing in the opposite direction along the mounting cover frame. Locking arms are integrally molded with the shutter support housing and cooperate with the locking clip members to maintain the shutter support housing in assembled condition with the mounting cover frame.

FIELD OF THE INVENTION 
This invention relates generally to a molded plastic two-piece foundation 
ventilator including a mounting cover frame and a shutter support housing, 
and more particularly to improved connector means for easily assembling 
and disassembling the mounting cover frame and the shutter support housing 
of the ventilator. 
BACKGROUND OF THE INVENTION 
For many years it has been the common practice to install ventilators in 
openings in building walls to provide for the flow of ventilating air 
through the enclosed crawl space beneath the floor of the building. In 
recent years, foundation ventilators have been provided with shutters 
which are thermostatically controlled so that they remain in an open 
position during warm weather when the temperature is above about 
70.degree. F., and the shutters move to a closed position when the outside 
temperature drops below a predetermined amount, such as 40.degree. F. This 
type of automatic foundation ventilator is disclosed in U.S. Pat. No. 
3,528,606. 
U.S. Pat. No. 4,274,330 discloses an automatic ventilator of this general 
type which includes a rectangular mounting frame that is first mounted in 
the foundation opening and the shutter support housing is then positioned 
in and fixed to the mounting frame. U.S. Pat. No. 4,587,892 discloses 
another automatic ventilator in which the mounting frame and the housing 
supporting the operating shutters are of molded plastic construction and 
are preassembled. The automatic ventilator of this patent is mounted in 
the wall opening in such a manner that the ventilator remains firmly 
seated in the opening with any expansion or contraction of the ventilator 
during use. 
It has been the common practice to preassemble the molded plastic shutter 
support housing and the mounting cover frame of the ventilator of U.S. 
Pat. No. 4,587,892 by integrally molding openings in the outwardly 
extending flange of the shutter support housing and molding mounting pins 
on the mounting cover frame to extend into and through the openings in the 
shutter support housing. The ends of the molded pins extending through the 
openings are then heated and flattened to fix the shutter support housing 
to the mounting cover frame. If the ventilator does not operate properly 
after it has been assembled in this manner, it is very difficult, if not 
impossible, to separate the shutter support housing and the mounting cover 
frame to carry out the required repairs or adjustments to the shutter 
operating mechanism, with the result that the entire automatic ventilator 
must be discarded. 
SUMMARY OF THE INVENTION 
With the foregoing in mind, it is an object of the present invention to 
provide a molded plastic two-piece automatic foundation ventilator which 
may be easily assembled into condition for mounting in a wall opening and 
which may be easily disassembled, should it become necessary to make 
adjustments or repairs to the ventilator after the shutter support housing 
and the mounting cover frame have been assembled. 
In accordance with the present invention, the molded plastic two-piece 
foundation ventilator includes a rectangular mounting cover frame of 
predetermined width and height sufficient to be mounted in a rectangular 
opening in a foundation wall. A rectangular shutter support housing of 
predetermined width and height of lesser dimensions than the predetermined 
width and height dimensions of the mounting cover frame is provided for 
attachment to the rectangular mounting cover frame prior to installation 
in the rectangular opening in the foundation wall. The shutter support 
housing and the mounting cover frame are maintained in assembled condition 
and are easily separated by providing integrally molded flanges extending 
outwardly from opposite sides of the shutter support housing and by 
integrally molded upstanding clip members along opposite sides of the 
mounting cover frame. The upstanding clip members include inwardly 
extending locking portions which are positioned in overlying engagement 
with the molded flanges of the shutter support housing to maintain the 
shutter support housing and the mounting cover frame in assembled 
condition and to permit easy disassembly of the shutter support housing 
from the mounting cover frame, if desired. 
Locking arms are integrally molded with the flanges of the shutter support 
housing and extend outwardly therefrom and include locking portions 
extending at least partially around and outside of the upstanding clip 
members on the mounting cover frame to prevent accidental inward flexing 
movement of the flanges so that the locking portions of the clip members 
are prevented from moving out of overlying engagement with the flanges of 
the shutter support housing. The locking portions of the locking arms 
permit sliding movement of the shutter support housing in one direction 
relative to the mounting cover frame so that the locking arms move out of 
partially encircling relationship outside of the clip members and permit 
easy disassembly of the shutter support housing from the mounting cover 
frame, when desired. Upstanding stabilizing ribs, in the form of guide 
rails, are integrally molded along opposite sides of the mounting cover 
frame and are positioned adjacent the opposite sides of the molded flanges 
of the shutter support housing to aid in sliding the shutter support 
housing into assembled position on the mounting cover frame. The guide 
rails also prevent sidewise movement between the shutter support housing 
and the mounting cover frame.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
The present foundation ventilator is illustrated in FIG. 1 in position in a 
rectangular opening of predetermined width and height in a brick wall 11 
in any suitable manner, such as by a mounting screw 12 (FIG. 1). The 
foundation ventilator is formed of molded plastic two-piece construction 
and includes a rectangular mounting cover frame, broadly indicated at 15, 
and a rectangular shutter support housing, broadly indicated at 16. The 
rectangular mounting cover 15 is of a predetermined width and height which 
is adapted to be mounted in the rectangular opening of the foundation wall 
11 and the rectangular shutter support housing 16 is also of a 
predetermined width and height of lesser dimensions than the predetermined 
width and height dimension of the mounting cover frame 15. 
The mounting cover frame 15 includes respective upper and lower inwardly 
extending opposite side walls 17, 18 and spaced opposite end walls 19, 20 
(FIGS. 5 and 6). A peripheral flange 22 is integrally molded with the 
outside of the mounting cover frame and is adapted to extend around and 
cover the opening in the foundation wall 11 when the foundation ventilator 
is mounted therein, as illustrated in FIG. 1. A rear wall 23 is integrally 
molded along opposite sides with the upper and lower side walls 17, 18 and 
at opposite ends with the end walls 19, 20. The central portion of the 
rear wall 23 is provided with molded openings adapted to be covered by a 
screen 24, suitably attached to the rear wall 23 and covering the openings 
therein. 
The rectangular shutter support housing 16 includes respective upper and 
lower inwardly extending side walls 25, 26 and spaced-apart inwardly 
extending opposite end walls 27, 28. A rear wall 30 is integrally molded 
around its peripheral sides and ends with the side walls 25, 26 and the 
end walls 27, 28 (FIG. 9) and includes integrally molded rectangular 
openings formed therein. A suitable screen 29 is attached to the inner 
surface of the rear wall 30 and covers the openings therein. The shutter 
support housing 16 pivotally supports opposite ends of temperature 
responsive shutters, indicated in dotted lines at 31 in FIG. 2. The 
temperature responsive shutters 31 may be of the type shown and described 
in commonly owned Witten U.S. Pat. No. 4,587,892, which are automatically 
opened and closed by temperature control means in a control box, indicated 
in dash-dot lines at 32 in FIGS. 1 and 2, and in solid lines in FIG. 9. 
The control box 32 is suitably attached to the end wall 28 of the shutter 
support housing 16. 
In accordance with the present invention, means is provided for removably 
maintaining the shutter support housing 16 and the mounting cover frame 15 
in assembled condition and includes integrally molded upper and lower 
flanges 35, 36 extending outwardly from opposite sides of the respective 
upper and lower opposite side walls 25, 26 of the shutter support housing 
16. Integrally molded opposite end flanges 37, 38 also extend outwardly 
from the corresponding end walls 27, 28 of the shutter support housing 16. 
Upstanding stabilizing ribs, in the form of respective upper and lower 
guide rails 40, 41, are integrally molded along opposite sides of the rear 
wall 23 of the mounting cover frame 15. These guide rails 40, 41 are 
positioned adjacent the opposite outer sides of the molded opposite 
flanges 35, 36 of the shutter support housing 16 to aid in sliding the 
shutter support housing 16 into assembled position on the mounting cover 
frame 15, in a manner to be presently described. An integrally molded stop 
rail 42 extends upwardly from the rear wall 23 of the mounting cover frame 
15 and provides a stop to limit sliding movement of the shutter support 
housing 16 in one direction along the mounting cover frame 15 when 
contacted by the outer edge of the outwardly extending flange 38. 
Upstanding spaced-apart clip members 45 are integrally molded with the 
upper guide rail 40 and corresponding clip members 46 are integrally 
molded with the lower guide rail 41 and extend outwardly therefrom. The 
clip members 45, 46 each includes inwardly extending locking portions 
positioned in overlying engagement with the corresponding integrally 
molded flanges 35, 36 of the shutter support housing 16, as best 
illustrated in FIGS. 3 and 4, to maintain the shutter support housing 16 
and the mounting cover frame 15 in assembled condition and to permit the 
shutter support housing 16 to be removed from the mounting cover frame 15 
by sliding the shutter support housing 16 longitudinally along the 
mounting cover frame 15 until the corresponding flanges 35, 36 move out of 
engagement with the inwardly extending locking portions of the 
corresponding clip members 45, 46, in a manner to be presently described. 
Upper locking arms 48 are integrally molded with the upper flange 35 of the 
shutter support housing 16. Lower locking arms 49 are integrally molded 
with the lower flange 36 of the shutter support housing 16 (FIG. 2). The 
locking arms 48, 49 extend outwardly from the upper and lower side flanges 
35, 36 and include locking portions extending in parallel spaced 
relationship to the side flanges 35, 36. The locking portions extend along 
the outside of the corresponding clip members 45, 46 when the shutter 
support housing 16 is in assembled condition with the mounting cover frame 
15 to prevent inward flexing movement of the upper and lower side walls 
17, 18 and the corresponding flanges 35, 36 to thereby maintain the 
locking portions of the clip members 45, 46 in overlying engagement with 
the flanges 35, 36 of the shutter support housing 16. 
Integrally molded upstanding stop means is associated with the other end of 
the mounting cover frame 15 and is positioned to engage the shutter 
support housing 16 and maintain the same in assembled condition. The 
upstanding stop means includes integrally molded upstanding spaced-apart 
cam pins 50 (FIGS. 2 and 5), each including an upper inclined cam surface 
to permit the shutter support housing 16 to ride upwardly and over the 
upstanding cam pins 50 when the shutter support housing 16 is being moved 
into assembled condition with the mounting cover frame 15. As illustrated 
in FIG. 2, the stop pins 50 are positioned in corresponding slots formed 
in the flange 37 when the shutter support housing 16 is in assembled 
condition with the mounting cover frame 15. Also, as illustrated in the 
right-hand end of FIG. 2 and in FIG. 6, upstanding stop pins 51 are 
integrally molded with the rear wall 23 and adjacent the stop rail 42. 
These stop pins 51 are positioned in corresponding slots in the flange 38 
when the shutter support housing 16 is in assembled condition with the 
mounting cover frame 15. 
Method of Assembly 
After the screen 29 has been attached to the inside of the rear wall of the 
shutter support housing 16 to cover the openings therein, the temperature 
responsive shutters 31 are installed and the temperature control box 32 is 
attached to the right-hand end of the shutter support housing 16. Then, 
the screen 24 is attached to the rear wall 23 of the mounting cover frame 
15 to cover the openings therein. The shutter support housing 16 is then 
aligned with the guide rails 40, 41 extending along opposite sides of the 
mounting cover frame 15 with the leading edges of the flanges 35, 36 being 
guided beneath the clip members 45, 46, as illustrated in FIG. 7. 
Longitudinal sliding movement is imparted to the shutter support housing 
16, from left to right in FIG. 7, so that the leading pair of locking arms 
48 is moved to a position between the spaced-apart upper and lower clip 
members 45, 46, as shown in FIG. 8. Inward pressure is then applied 
against the shutter support housing 16 to force the upper and lower 
flanges 35, 36 to move inwardly beneath the trailing clip members 45, 46 
so that the corresponding locking portions extend in overlying engagement 
with the flanges 35, 36, as illustrated in FIG. 8. 
Further sliding movement imparted to the shutter support housing 16, from 
left to right in FIG. 8, moves the locking arms 48, 49 in position 
adjacent the locking clips 45, 46 with the locking portions of the locking 
arms 48, 49 extending along the outside of the clip members 45, 46 when 
the leading edge of the flange 38 engages the stop rib 42. The locking 
portions of the locking arms 48, 49 thus maintain the locking portions of 
the clip members 45, 46 in overlying engagement with the flanges 35, 36 of 
the shutter support housing 16. When the shutter support housing 16 is 
being moved into assembled condition with the mounting cover frame 15, as 
shown in FIG. 9, the end wall 27 and the end flange 37 of the shutter 
support housing 16 will be forced outwardly to move over the inclined 
upper cam surfaces of the lock pins 50 to prevent sliding movement of the 
shutter support housing 16 from right to left in FIG. 9 and to thereby 
maintain the shutter support housing 16 and the mounting cover frame 15 in 
assembled condition. 
Should it be necessary to disassemble the shutter support housing 16 from 
the mounting cover frame 15, to repair or adjust the temperature 
responsive shutters 31, or for any other reason, it is only necessary to 
spring the end wall 27 and the end flange 37 outwardly a sufficient 
distance to clear the upper end of the lock pins 50 and then sliding 
movement from right to left may be imparted to the shutter support housing 
16, as illustrated in FIG. 8, to free engagement of the locking arms 48, 
49 with the corresponding clip members 45, 46. The medial portions of the 
opposite sides of the shutter support housing 16 may then be flexed 
inwardly to move the flanges 35, 36 out of engagement with the locking 
portions of the clip members 45, 46 so that further sliding movement from 
right to left can be imparted to the shutter support housing 16. Further 
sliding movement of the shutter support housing 16 from right to left, as 
illustrated in FIG. 7, will cause the flanges 35, 36 to move out of 
engagement with the righthand clip members 45, 46 so that the shutter 
support housing 16 will be completely free of the mounting cover frame 15. 
After any adjustment is made to the temperature responsive shutters 31, 
the shutter support housing 16 may be again assembled with the mounting 
cover frame 15 in the manner previously described. 
Thus, the present invention provides means for removably maintaining the 
shutter support housing 16 and the mounting cover frame 15 in assembled 
condition and permits easy disassembly of the shutter support housing 16 
from the mounting cover frame 15, if desired. 
In the drawings and specification there has been set forth the best mode 
presently contemplated for the practice of the present invention and 
although specific terms are employed, they are used in a generic and 
descriptive sense only and not for purposes of limitation, the scope of 
the invention being defined in the claims.