Shutter slat configuration

A shutter assembly is made of adjacent interlocked extruded plastic slats having a hollow generally rectangular body with extending tongue and channel interlocking members. Provision is made for locking slats in mated position against longitudinal movement and for a metallic end bearing surface providing long wear under heavy use. The slat structure is ribbed to remove rain water that may tend to pass through a shutter and for adding strength and can receive strengthening rods as desired in a mating internal female cell structure.

TECHNICAL FIELD 
This invention relates to shutters or blinds made of a plurality of 
adjacent interlocking slats, and more particularly it relates to the slat 
configuration. 
BACKGROUND ART 
Rolling shutters constructed of a plurality of interlocking slats are well 
known in the art as evidenced by the following U.S. Patents: 
Krueger--U.S. Pat. No. 2,235,220--Mar. 18, 1941 
Piana--U.S. Pat. No. 3,642,050--Feb. 15, 1972 
It is known as taught in U.S. Pat. No. 4,042,005--Hammerstein--Aug. 16, 
1977, and U.S. Pat. No. 4,173,247--Piana--Nov. 6, 1979 to form slats of 
extruded plastic materials in various configurations. 
However, all such known prior art configurations have various problems and 
deficiencies solved by the present invention. 
One basic requirement of a shutter is to keep out wind and rain. Because a 
plurality of slats are in contiguous contact at upper and lower edges a 
crease is formed into which water tends to accumulate as it runs down the 
outside shutter surface and to blow inside the shutter. This problem has 
not effectively been solved by prior art slat configurations. 
Another problem of prior art slat configurations is that they are difficult 
to confine in end channels and tend to wear, bend or otherwise become 
damaged with extensive movement. 
Another problem of prior art shutter configurations is that the individual 
slats tend to shift longitudinally and thus can bind or become damaged as 
they are raised and lowered. 
Another problem with prior art shutter assemblies, particularly those using 
extruded plastic slats, is that the outer weather surface is weak and can 
become distorted in the presence of heavy winds. 
Still another problem with some complex prior art shutter assemblies is 
that they are not readily cleanable both inside and outside because of 
inaccessible creases or complex surfaces into which dirt may accumulate. 
It is therefore an object of this invention to correct the foregoing 
problems in prior art shutters and to produce improved shutters capable of 
long maintenance free use. 
Further features, objects and advantages of the invention will be made 
evident throughout the following drawing, description and claims. 
DISCLOSURE OF THE INVENTION 
Accordingly there is provided by this invention an improved slat 
configuration which interlocks in a shutter assembly to resolve the 
aforesaid problems of the prior art. 
The slat is preferably made in the form of an extruded plastic hollow body 
generally rectangular in cross section. Opposed side walls form interior 
and exterior shutter surfaces. Mating tongue and channel interlocking 
elements extend from the two ends of the rectangular body. The outer 
shutter surface of each slat has a zig-zag surface configuration providing 
a plurality of ribs on each slat to permit water running down the exterior 
shutter surface to drip off the ribs. Preferably a rib terminates near the 
lower edge of the slat to let water drip off instead of running down the 
surface past the seam between two adjacent slats. 
The interior of the hollow rectangular body is divided into three 
successive closed cells formed by two integral panel members extending 
across the hollow body from wall to wall. The intermediate cell is longer 
than the outer cells and has two flanges extending internally from the 
walls near each end of the longer cell. 
This structure accordingly receives in frictional contact with the interior 
of the hollow body and the flanges a skeletal strengthening rod if desired 
along the length of selected slats, such as an H-shaped aluminum 
extrusion. Furthermore, a special metallic, preferably tempered aluminum, 
.pi.-shaped end fitting frictionally fits with legs inserted between the 
flanges and the ends of the intermediate cell (over the strengthening rod 
if desired) and extends from the ends of the slats. This end fitting 
serves as a bearing surface to ride in a guiding channel. 
For purposes of preventing sliding of the slats relative longitudinally 
relative to each other a locking arm extends from the .pi.-shaped end 
fitting over the interlocked end members of two interlocked slats. The 
interlock structure is such that the slats are assembled by longitudinally 
inserting the tongue of one slot into the channel of the adjacent slat. 
The end locking arm therefore confines the mated interlock members to 
avoid any substantial longitudinal displacement of the slots. 
To permit rolling up of the slats for storage, the tongue and channel 
members having mating semi-cylindrical elements. The cylinder of the 
tongue member is connected by a slotted panel to the hollow body to allow 
the shutter to pass some sunlight and air in a semi-closed position.

DESCRIPTION OF A PREFERRED EMBODIMENT 
As may be seen in the cross section view of a single slat 10 used to form a 
shutter assembly set forth in FIG. 1, a preferably plastic extrusion 
provides a hollow body section 11 of generally rectangular shape. 
Extending from opposite ends of the hollow body are the respective mating 
tongue 12 and channel 13 interlocking members. 
The slat has an outer weather surface 14 of zig-zag surface configuration 
to provide a plurality of protruding ribs 15, 16, 17 on each slat. It may 
be seen that these ribs permit rain to run down the outer surface and drip 
from the ribs, thereby decreasing the chances for water to accumulate at a 
seam between two slat where it can be blown inside the shutter. This 
ribbed structure also provides strengthening of the outer surface so that 
if it is hit by foreign objects such as tree limbs or rocks, damage to the 
shutter is less likely. The inner surface of the slat assembly is 
substantially straight, so that it can be readily cleared. The inner 
hollow body of the slat has three successive closed cell regions 20, 21, 
22 (22A and 22B) formed by two integral panel members 23, 24 extending 
across the hollow body between the side walls. The intermediate cell 
region 21 is longer than the outer cell regions 20, 22 and has a pair of 
internally extending flanges 25, 26 or 27, 28 near each end of the cell 
adjacent the walls 23, 24 respectively. 
These flanges 25-28 serve to strengthen the rigidity of the slat, but more 
important they serve as a frictional female receptacle for receiving the 
two members shown in FIGS. 2 and 3, as seen by the view of FIG. 4. 
Thus, the .pi.-shaped bearing and locking member 30 of FIG. 2 has two legs 
31, 32 with barbs 33 for holding the legs in the end of the slat. Thus 
flanges 25-28 and walls 23, 24 of the slat respectively form two female 
receptacles for receiving the legs 31, 32 in frictional engagement and 
mating registration. 
The bearing portion of member 30 comprises the ridge 35 which is adapted to 
ride in a mounting frame or channel 36 (FIG. 4A). Thus, the member is 
preferably made of an extruded and tempered aluminum. Thus, the slats and 
shutter assembly are simply mounted and guided without problems 
encountered in channelling the ends of the slat housing 10. 
In addition the locking arm 38 extends from the .pi.-shaped member 30 for 
riding down over the cells 22A, 22B and channel 13 to serve as a locking 
member to confine the tongue member 12 without significant end play so 
that the adjacent slat members cannot slide relative to each other, as 
best seen from FIG. 4. The configuration of the channel 13 is such that 
opening 40 accommodates the panel section 41 of the tongue extension 12 
for a degree of vertical motion along the length of the slat body, but 
requires the adjacent slats to be assembled by sliding together from the 
ends. Thus, with lock members 30 in place at each end of a slat the slats 
cannot move longitudinally relative to each other but can move over a 
range of positions vertical to the slat body. 
This permits the panel 41, with slots 42 to be disposed at the juncture of 
two adjacent slats 10 if desired to permit entry of some light and air 
through the slots 42. In such position the substantially diametrical 
flange 44 of tongue member 12 will rest on the mating flat inner surface 
of the L-shaped channel extension member 45. The flange 44 and L-arm then 
produce a weather seal ridge assembly. 
At the opposite end of the range of movement between adjacent slats as seen 
from 10B and 10C of FIG. 4, the semi-cylindrical tongue portion 50 rests 
in the mating semi-cylindrical surface 51 of the channel member 13. Thus 
the flat surfaces of the L-shaped channel member 45 preferably slightly 
tilted up at angle 52 will engage the flat surface 53 of the upper end of 
the generally rectangular slat body 11 to form a substantially closed 
mated seam 54 (FIG. 4) between two adjacent slats where flange 41 serves 
as a weather barrier stop to prevent water from passing through the 
shutter assembly. 
As seen from FIGS. 3 and 4, a metal, preferably tempered aluminum rod 60 of 
generally H-shaped configuration or the like, frictionally fits into the 
intermediate cell 21 between the respective flange paris 25, 26 and 27, 
28. This strengthens the slats where necessary against bending, giving 
longer slats considerable rigidity, and yet is compatible with the use of 
the bearing and locking member 30 frictionally mounted in the same cell 
21. 
It is evident therefore that an improved shutter slat configuration and 
shutter assembly is provided by this invention providing superior 
operation over the prior art. 
By the zig-zag step down outer surface configuration of the slats formed by 
ribs 15, 16, 17 or the like, shutters can be made more weather proof than 
those of the prior art. 
Because of the end bearing and locking members 30 shutters are made long 
wearing with extensive use and easy to confine in framing channels and the 
shutter slats cannot move laterally to cause binding and problems of end 
leakage, etc. 
Also the outer and inner shutter surfaces are easy to clean with simple 
surfaces and without accumulation of dirt. 
In addition the slats and shutters made therefrom are strong enough to 
withstand heavy storms and impact without leakage or damage. 
Therefore this invention has for the first time incorporated a plurality of 
novel features into a coacting combination which affords new functions and 
performance not heretofore available in the art without the specific novel 
contributions of this invention. 
INDUSTRIAL APPLICATION 
Extruded plastic slats for forming shutter assemblies of the roll down type 
are provided with several advantageous features of withstanding impact, 
keeping out water leakage and presentation of simple surface areas for 
each in cleaning. Interlocking assembly structure provides for partial 
opening with limited air and light transversal and weathertight closed 
position. The slats have an improved end bearing assembly for simplified 
framing for long life with extensive use. Also the slats are confined to 
prevent end play and are adapted to receive strengthening internal rods 
optionally where long slats or added strength are required.