Weather seal construction including a weather-strip

Abstract

A weather-strip construction includes a frame member and a cover member and a weather-strip. The cover member mates with the frame member and the weather-strip forms a weather seal between the frame member and the cover member. The weather-strip includes a foamed sealing portion. The weather-strip is secured to either the frame member or the cover member. The foamed sealing portion of the weather-strip provides the weather seal and extends continuously along either the frame member or the cover member depending to which one it is attached and extends along any sharp corners continuously without interruption such that a continuous weather seal is formed between the cover member and the frame member.

Description

BACKGROUND OF THE INVENTION

The present invention relates to weather-strips and in particular relates to weather-strips that have a sealing member made from a foamed polymer.

Presently there are several materials being used to make foamed weather-strips for residential windows and doors. These materials produce very satisfactory weather-strips. Such weather-strips have a foamed sealing member and an attaching member that is used to secure the sealing member to the door or window. Typically the attaching member is made of a solid polymer.

One material used for the foamed sealing member in weather-strips is SANTOPRENE®. SANTOPRENE® is an elastomeric thermoplastic rubber which may be foamed to produce extruded cylindrical and other profiles. The characteristics and properties of SANTOPRENE® are described in U.S. Pat. Nos. 4,130,535 and 4,311,628 assigned to Monsanto Company. Foamed extrusion of SANTOPRENE® is discussed in U.S. Pat. No. 4,898,760 (all of which are herein incorporated by reference in their entirety). SANTOPRENE® includes a co-extruded skin that is bonded to the foamed SANTOPRENE®.

Although SANTOPRENE® makes a satisfactory foamed weather seal, the SANTOPRENE® based weather-strip must be cut when forming a weather seal at a 90 degree corner of the window or door or the frame with which the window or door mates. A new section of SANTOPRENE® based weather-strip must then be positioned at the corner, positioned 90 degrees from the previous placed weather-strip. The SANTOPRENE® based weather-strips although abutting each other, do not form a continuous weather seal at the 90 degree corner. Bending the SANTOPRENE® based weather-strip results in a bulge, pucker or wrinkle at the 90° corner which then results in the door or window not sealing properly against the weather-strip.

SUMMARY OF THE INVENTION

The present invention includes a weather-strip construction for providing a weather seal, the weather-strip comprising a frame member having a cover member for mating with the frame member when moved toward the frame member, the weather seal being disposed between the frame member and the cover member, the weather seal having at least one sharp corner. The weather-strip has a foamed sealing member extending along the perimeter of the cover or frame member and continuously through the sharp corner without interruption and without a substantial bulge, wrinkle or pucker such that the foamed sealing member forms a continuous weather seal between the cover member and the frame member due to its uninterrupted extension.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of the weather-trip of the present invention.

FIG. 2 a is a perspective view of the weather-strip in a casement window.

FIG. 2 b is a perspective view of the weather-strip in a door.

FIG. 3 is an enlarged perspective view of the circled area 3 in FIG. 2.

FIG. 4 is a sectional view of another embodiment of the weather-strip of the present invention.

FIG. 5 is a sectional view of yet another embodiment of the weather-strip of the present invention.

FIG. 6 is a sectional view of still another embodiment of the weather-strip of the present invention

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention includes a weather-strip generally indicated at 10 in FIG. 1. The weather-strip 10 is capable of forming a weather seal around a sharp corner without a bulge, pucker or wrinkle so that a cover member such as a door or window will form a weather seal along its entire length when the cover member is moved and pressed against a frame member. The door and window constructions contemplated are hinged doors and casement windows. By casement windows is meant those window sashes that are either hinged or pivot from an open position to a closed position. Such windows may move about a vertical or horizontal axis between an open and a closed position. Casement windows also include “fixed windows” that were made as a casement window but to which the hardware to move the window has not been attached or has been removed and the window when installed is fixed in a closed position with the weather-strip providing a weather seal.

By sharp corner is meant a corner making an abrupt bend as compared to a rounded bend. Such corners on doors and windows are typically approximately 90 degrees although other angles such as 60 degrees are also contemplated. Generally angles much greater than 90 degrees do not produce sharp corners while angles less than 90 degrees always do.

By a weather seal is meant that the door or window when in a closed position with the frame member compressively engages the weather-strip continuously throughout its length with no substantial gaps through which air may flow. It is understood that no bulge, wrinkle or pucker results at a sharp bend of the weather-strip in a weather seal engagement of the present invention since this would result in discontinuous contact. The weather seal continues through the sharp corner due to the continuous extension of the weather-strip without interruption as discussed subsequently.

By bulge, pucker or wrinkle is meant that the weather-strip at the sharp corner rises substantially above, or creases at the sealing plane of the weather-strip when it runs along a straight path. The words bulge, pucker or wrinkle may be used interchangeably herein and refer to the same phenomenon.

As illustrated in FIG. 1, the weather-strip 10 of the present invention includes a sealing member 12 and an attaching member 14. The sealing member 12 acts as a seal between the cover member (window sash 21 of the window 16 or door 17) and the frame member 18 as illustrated in FIGS. 2a and 2b. The weather-strip 10 may be mounted on the window sash 21 or on the window frame 18 as illustrated in broken lines in FIG. 2a. In FIG. 2b, the weather-strip is illustrated as attached to a stop 23 of the door frame 18. The attaching member 14 attaches the weather-strip 10 as discussed subsequently.

The sealing member 12 is made of an ethylene propylene diene monomer (EPDM) rubber that is foamed and cured. By cured is meant that the EPDM is crosslinked. When EPDM is foamed, a skin is formed on the outer surface of the extrudate providing both an esthetically pleasing surface and a durable sealing surface. The skin is an integral part of the extrudate being formed as the extrusion progresses and is formed from the same polymer that is being foamed. The skin is typically a thin layer with no cells visible in the skin to the naked eye. The skin aids in reducing the bulge, pucker or wrinkle that might otherwise be formed at the sharp corner if using a foamed SANTOPRENE® with skin. The sealing member extends through the sharp corner continuously, that is, it is not cut and then the ends bonded together. In continuing without interruption through the sharp corner, without a substantial bulge, pucker or wrinkle, the sealing member forms a continuous seal through the sharp corner. A low friction coating may be applied to the skin for particular applications to reduce friction.

The foamed EPDM has good resistance to compression set and is resilient (capable of returning to its original shape after having been compressed) so as to be well suited for use as a weatherseal. Other components may also be mixed with the EPDM for various purposes but EPDM will still be the major polymeric component of the foamed sealing member. In the spirit of this disclosure other materials that exhibit similar performance characteristics to EPDM foam can be substituted for the EPDM without discrediting the novelty of this invention.

The sealing member is foamed using standard extrusion foaming techniques. A standard single screw extruder can be used. Extruders having a 24:1 L/D to 48:1 L/D ratio are suitable for producing the foamed EPDM sealing member of the present invention. The melt temperature of the extrudate should be in the range of 300 degrees Fahrenheit to 450 degrees Fahrenheit. The EPDM is foamed using a blowing agent. The blowing agent can either be a chemical blowing agent or water.

A cross section of the sealing member 12 extrudate is illustrated in FIG. 1. The geometry of the cross-section of the sealing member extrudate 12 corresponds to that of the cross-sectional profile of the lateral land at the face of the die (not shown). The dimensions of the foamed extrudate are enlarged when exiting the die (not shown) and the extent of such enlargement is a function of the process conditions, the rate of extrusion (screw speed, rpm), and density of the extrudate formed. Such processing parameters are well within the ability of one skilled in the art. As understood various types of cross sectional profiles are possible with foamed EPDM.

As illustrated in FIG. 1, the sealing member may also have tubular hollow 30 formed during extrusion. The tunnel 30 in some situations is useful to increase the softness of the sealing member when the sealing member is foamed at a higher density. The hollow 30 compensates for the higher density foam. In one example, the sealing member had a diameter of approximately 0.225 inches and the hollow 30 had a diameter of approximately 0.100 inches. The wall thickness α between the wall 31 of the hollow 30 and the outer surface 32 of the sealing member 12 was approximately 0.0625 inches. The wall thickness α may vary decreasing with more dense foams while increasing with less dense foams, depending on a variety of factors. It should be understood that the hollow 30 is not necessary and the sealing member may be made without the hollow 30 as illustrated in FIG. 6.

The density of the foamed EPDM will vary depending on the characteristics of the window or door, but will range approximately from 1.0 to 30 lbs/ft³ and typically may range from 5 to 25 lbs/ft³.

The attaching member 14 in one embodiment is also made of EPDM but in a solid non-foamed extrudate. The function of the attaching member 14 is to attach the weather-strip 10 to the cover member 16 by insertion into a kerf 22 formed in the cover member 16 as illustrated in FIG. 3. In practice the kerf 22 is a slot cut into the wood or in the case of a polymer-based cover member a molded or cut slot. Therefore the cross sectional profile of the attaching member 14 is such that it should be easy to insert the attaching member 14 into the kerf 22 and once inserted into the kerf 22, the attaching member 14 is difficult to remove and acts as an anchor for the weather-strip. The attaching member 14 is progressively inserted into the kerf 22a and is bent at corner 28 and then into kerf 22b, the particular sequence employed not being important. As illustrated in FIG. 1, the attaching member includes a plurality of barbs 24 that are positioned to engage the walls of the kerf 22 and act against withdrawal of the attaching member 14. Other types of attaching members which have a point projecting in a direction reverse to insertion to produce resistance from withdrawal are within the scope of the present invention.

The attaching member 14 can be made of EPDM and in one embodiment is made from an EPDM having a Shore A Hardness of approximately 75. EPDM having other hardness ratings along with other types of polymers such as polypropylene or polyethylene can be used. The material for the attaching member 14 needs to be rigid or at least semi-rigid enough to be capable of insertion into the kerf 22 and have sufficient integrity to resist being withdrawn from the kerf 22. The material also needs to be compatible with the EPDM of the sealing member in terms of its ability to be bonded with the sealing portion or to be co-extruded with the sealing portion. Bonding is typically accomplished through the use of a suitable adhesive or by heat weld or heat seal.

The attaching member may also have a cord or string (not shown) disposed within, the cord or string running longitudinally through the attaching member. The cord or string prevents stretching of the attaching member.

The weather-strip of the present invention can also be attached to the cover member using an adhesive or through a strip attached to the sealing member that in turn is adhesively attached to the cover member as illustrated in FIG. 6. The embodiment 310 includes a sealing member 312 and an adhesive strip 314 having a backing 316 and a layer of adhesive 318. The embodiment 310 is secured directly to the cover member through the use of the adhesive.

Another embodiment of the present invention is illustrated in FIG. 4. The embodiment in FIG. 4 includes a sealing member 112 similar to the sealing member illustrated in FIG. 1. The sealing member is attached to an attaching member that has an “L”-shaped cross sectional profile. The attaching member also includes barbs 124 which are positioned in a direction so that the attaching member can be inserted into a kerf (not shown), but resists removal of the attaching member from the kerf once inserted into the kerf. The attaching member 114 includes a cap portion 126 and a leg portion 127. The leg portion extends from one side of the cap portion thereby forming the “L” cross sectional profile. The cap portion 126 of FIG. 4 is wider than the cap portion illustrated in the embodiment of FIG. 1, therefore when the weather-strip 110 is bent at a sharp corner, a bulge may result. To eliminate the bulge, the cap portion may be cut without cutting the sealing member 112 starting at or near a distal end 129 and cutting to where the leg portion 127 meets the cap portion 126 or vice versa. In some situations, depending on the thickness and the elasticity of the material used for forming the attaching member 114, the cap 126 may have to be notched such that a portion is removed.

Another embodiment of the present invention is illustrated in FIG. 5. The embodiment 210 includes a sealing member 212 similar to the sealing members discussed with respect to FIGS. 1 and 4. The attaching member 215 includes a leg portion 225 that extends from the cap portion 226 bent in an “L” shaped manner such that the distal end portion 227 is substantially parallel to the cap portion 226. It will be appreciated that the embodiment 210 engages a kerf (not shown) that is located on the surface 90 degrees from the surface from which the sealing portion 212 extends.

Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention.

Claims

1. A weather-strip construction for providing a weather seal comprising: a frame member; a cover member for mating with the frame member; a weather-strip for forming a weather seal between the frame member and the cover member, the weather-strip having a foamed portion having an integrally formed skin and being secured to either the frame member or the cover member, the foamed portion extending along either the frame member or the cover member and extending along a sharp corner of either the frame member or the cover member continuously without interruption such that a weather seal is formed between the cover member and the frame member.

2. The weather-strip construction of claim 1 wherein the foamed portion is made from a cured ethylene propylene diene monomer.

3. The weather-strip construction of claim 1 wherein the cover member is a window sash.

4. The weather-strip construction of claim 1 wherein the cover member is a door.

5. The weather-strip construction of claim 1 and further including an at least semi-rigid attaching portion to which the sealing member is attached and the at least semi-rigid attaching portion attaching the sealing member to either the cover member or the frame.

6. The weather-strip construction of claim 1 wherein the at least semi-rigid attaching portion is made from a cured ethylene propylene diene monomer.

7. The weather-strip construction of claim 1 and wherein the sealing member is adhesively attached to either the cover member or the frame.

8. A method for forming a weather seal between a cover member and a frame member wherein the cover member swings to a closed position with the frame member, the method comprising; providing a weather-strip having a foamed portion with an integrally formed skin as an outer surface securing on either the frame member or the cover member wherein the foamed portion such that the foamed portion extends through at least one sharp corner without forming a substantial bulge, pucker or wrinkle so that a weather seal is formed at the sharp corner due to the uninterrupted extension of the foamed portion there through

9. The method of claim 8 wherein the foamed portion is made from a cured ethylene propylene diene monomer.

10. The method of claim 8 wherein the cover member is a window.

11. The method of claim 8 wherein the cover member is a door.

12. The method of claim 8 wherein the foamed portion is attached to an at least semi-rigid attaching portion that extends through a slot formed within the cover member or the frame member.

13. The method of claim 12 wherein the attaching portion is made from cured ethylene propylene diene monomer.

14. The method of claim 8 wherein the sealing member is adhesively attached to either the cover member or the frame.