GASKET HAVING A PLIABLE RESILIENT BODY WITH A PERIMETER HAVING CHARACTERISTICS DIFFERENT THAN THE BODY
A single piece gasket is disclosed having a skeletal member, typically metallic, and a pliable body. The pliable body includes a first portion having a first firmness and a second perimeter portion have a firmer consistency. When such a composite body is placed under compression, the perimeter will tend to limit the flow of the softer inner material past the firmer perimeter region or portion of the gasket. In this manner, creep or overrun of the less firm portion material will be reduced.
This application is a continuation U.S. patent application Ser. No. 13/469,603, filed May 11, 2012, and now issued as U.S. Pat. No. 9,701,388, which claims priority to U.S. Patent Application No. 61/484,879, filed May 11, 2011. These priority applications are herein incorporated by reference as well as U.S. Pat. Nos. 6,530,577; 6,695,320; and 7,229,516.
FIELD OF THE INVENTIONGaskets, including aircraft gaskets, having a perimeter of greater firmness than the non-perimeter, more tacky portion thereof.
BACKGROUND OF THE INVENTIONGaskets provide a mechanical seal that fills the space between two mating surfaces. They may be provided to prevent leakage from or into the pieces under compression. Gaskets typically can allow less than perfect mating surfaces on machine parts where they can fill irregularities. Gaskets are commonly produced from cutting sheet materials, such as gasket paper, rubber, silicon, metal, cork, felt, neoprene, nitrile rubber, fiberglass or plastic polymer, such as polychloro, trifloro ethylene.
Pre-cured polyurethane and antenna gaskets have been provided with aluminum skeletal carrier die cut to fit the workpiece, such as an aircraft antenna. The polyurethane provides an effective environmental sealant. It also demonstrates excellent cohesion after installation and provides a high degree of environmental protection, still allowing for easy removal of the workpiece.
Polyurethane provides a non-hazardous seal with no silicon oil residue before, during or after installation or removal. Moreover, polyurethane is not problematic with paint adhesion or preparation and there is no peripheral silicon contamination. Polyurethane provides a positive moisture barrier for easy workpiece removal and provides noise and vibration dampening.
In some applications, however, some polyurethane may creep under compression creating an overrun outside the gasket area. This may sometimes require manual removal.
SUMMARY OF THE INVENTIONVarious embodiments of Applicants' device are enclosed, which feature a single piece gasket having a skeletal member having a pliable body, wherein the pliable body typically includes a first portion having a first firmness and a second, perimeter portion, having a firmer consistency. When such a composite body is placed under compression, the perimeter will tend to limit the flow of the softer inner material past the firmer perimeter region or portion of the gasket. In this manner, creep or overrun of the less firm first portion material will be substantially reduced or eliminated.
Thus, in one version of Applicants' embodiment, a dual firmness body, such as a polyurethane body, will have a first firmness of a first portion of the body and a firmer consistency and resistant to compression over a perimeter or second region, which second or perimeter region typically conforms to the outer edges of the workpiece.
The pre-compression thickness of the embodiments set forth herein may be about 55 mil (range about 25-100 mil). Gasket 10a comprises of a resilient body 12, typically made from pre-cured polyurethane gasket material, such as KBS, Fort Worth, Tex., as disclosed in the patents that are incorporated by reference. Body 12 is seen to have a first portion 14 having a first firmness, such as a firmness between about 75 and about 150 (measured with a 37.5 g half cone penetrometer). The second firmer perimeter portion 16 is seen to comprise the outer perimeter of the gasket, which generally mimics the shape of the outer perimeter of the workpiece, in which second firmer perimeter portion 16 may have a durometer hardness “00” of between about 15 and about 75. The perimeter portion may be made from HT3326-5 and the body or inner portion may be made from a mix of P-1011 and U-1010. This will provide a gasket within the firmness range set forth in this paragraph.
It is seen that the relationship of the first portion to the second portion is one of typically close, adjacent, contiguous integral and/or intimate relation of one portion with respect to the other along common face 23. That is to say, they lay adjacent one another and indeed may intermingle one portion to the other at least close to the boundary portion or common face 23 between the first and second portions. Moreover, it is seen with reference to
That is to say, Applicants provide for a number of cross-sectional configurations to the second, firmer perimeter portion 16, which are designed to provide both an effective seal and/or a visually pleasing perimeter. This is achieved, in part, by providing a second material at an outer perimeter having a firmer consistency, while being substantially integral with the first portion 14.
Some embodiments of Applicants' gaskets disclosed herein have configured second portions 16 as more generally described hereinbelow. The shapes may generally be described as: 10a tabular; 10b tabular (with raised lips); 10c curved (convex); 10d toothed or ribbed; 10e curved (concave); and 10f trapezoid.
In the embodiments illustrated, a flexible skeleton 18/20 is provided. The flexible skeleton 18/20 is in the embodiment illustrated in
In either form of flexible skeleton 18/20, it is seen that the skeletal member is usually substantially encapsulated in the resilient body 12 and may add strength to the gasket as well as integrity between portions 14/16 as, seen in the illustrations, the skeletons 18/20 typically extend substantially throughout first portion 14 and typically, at least partially, into perimeter or second portion 16.
Turning to
It is seen that the embodiment 10a illustrated in
In
The straight or regular cut gasket may be desired where there is only a slight bulge desired, post-compression, of the gasket at the workpiece perimeter. On the other hand, a slight overcut gasket may be provided to improve the aesthetics of the sealing adjacent the workpiece base and outer perimeter area see in
In
In other applications, the undercut of
By varying the shapes of the outer edges, including the cross-sectional shapes, in some cases a more effective seal may be provided, as may be needed in different applications. Further, the post-compression visual aesthetics of the seal may be enhanced.
It is noted that any of the embodiments 10a-10f may be straight cut, undercut or overcut as needed for effective sealing and/or aesthetic purposes. Moreover, it is seen that any of the embodiments may have a differential firmness wherein the softer first portion 14 has a first or greater tackiness than the outer portion 16, which may be firmer and less tacky.
The increased thickness of the second portions, as illustrated in embodiments 10b-10e, are believed to, in part, provide greater resistance to the migration of the soft material of first portion 14 and the prevention of overrun outside the outer perimeter of Applicants' dual firmness or composite gasket.
In
Turning to
A cap 53, including top divider 52, may be removed and, to start the procedure, skeleton 18/20 is placed across base 53 supported on the top edge of bottom divider 54 and extending partway past bottom divider 54 into space that will be filled with the second (firmer) composition. The first composition may then be poured pre-mixed in the snout S of the applicator A in known ways, and allowed to self-level to the desired height, here H 14 and H 16 being equal. Following curing, cap 53 and top divider 52 are removed leaving the cross-section illustrated in
With reference to
In
In
Turning to
Turning back to
All dimensions set forth herein are approximate and the ranges may be varied to suit specific applications.
Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. On the contrary, various modifications of the disclosed embodiments will become apparent to those skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover such modifications, alternatives, and equivalents that fall within the true spirit and scope of the invention.
Claims
1. A seal assembly for use between an aircraft base structure having a substantially flat face and an aircraft workpiece structure having an outer perimeter and a substantially flat face positionable adjacent the flat face of the aircraft base structure, the seal assembly comprising:
- an open body skeleton including a first substantially planar surface and a second substantially planar surface, the first surface and the second surface being generally parallel with each other and extending in length and width to form an outer perimeter for the skeleton, the skeleton having a thickness between the upper surface and the lower surface, the thickness being much less than the length and width of the first surface and the second surface;
- a flexible body comprising a pliable, resilient, deformable, gel body that surrounds and penetrates the skeleton before compression of the assembly between the aircraft base structure and the aircraft workpiece structure, the body including a first, inner portion and a second, outer perimeter portion, the first portion and the second portion being integrated with each other before being disposed on the aircraft base structure, the first portion having a first firmness and the second portion having a second firmness, the second firmness being greater than the first firmness, the second portion extending beyond the perimeter of the skeleton and generally conforming to the outer perimeter shape of the workpiece structure, at least the first portion of the body including a substantially flat first surface and a substantially flat second surface that are configured to be compressed between the aircraft base structure and the aircraft workpiece structure during operation, the first surface and the second surface of the skeleton being generally parallel to and lying between the first surface and the second surface of the body before compression.
2. The assembly of claim 1, wherein the skeleton is a woven flexible material.
3. The assembly of claim 1, wherein the skeleton is metallic.
4. The assembly of claim 1, wherein the first portion of the body has a durometer hardness, as measured by a 37.5 g half cone penetrometer, of between 75 and 150.
5. The assembly of claim 1, wherein the second portion of the body has a “00” durometer hardness of between 15 to 75.
6. The assembly of claim 1, wherein the first portion of the body has a firmness of between 75 and 150, as measured by a 37.5 g half cone penetrometer, and wherein the second portion of the body has a “00” durometer hardness of between 15 to 75.
7. The assembly of claim 1, wherein the first portion of the body is a polyurethane gel.
8. The assembly of claim 1, wherein the flexible body has a thickness between the first surface and the second surface of the first portion, and the thickness of the flexible body before compression is approximately twice that of the skeleton.
9. The assembly of claim 1, wherein the flexible body is approximately 30 mils thick before compression.
10. The assembly of claim 1, wherein the perimeter of the skeleton extends into the second portion of the body.
11. The assembly of claim 10, wherein the second portion of the body penetrates the skeleton.
12. The assembly of claim 1, wherein the skeleton is configured to make electrical contact with at least one of the aircraft structures when the body is compressed.
13. The assembly of claim 1, wherein the second portion of the body is tabular.
14. The assembly of claim 1, wherein the second portion of the body is convex.
15. The assembly of claim 1, wherein the second portion of the body is concave.
16. The assembly of claim 1, wherein the second portion of the body is toothed.
17. The assembly of claim 1, wherein the second portion of the body is trapezoidal.
18. The assembly of claim 1, further including an adhesive portion configured for placement between the body and at least one of the workpiece or the base.
19. The assembly of claim 1, further including an elastomeric perimeter gasket member configured to lay adjacent and be in contact with the second portion of the body.
20. The assembly of claim 1, wherein the second portion of the body is undercut.
21. The assembly of claim 1, wherein the second portion of the body is straight cut.
22. The assembly of claim 1, wherein the second portion of the body is overcut.
23. The assembly of claim 1, wherein the second portion of the body includes a substantially flat first surface that is generally parallel to the first surface of the first portion of the body.
24. The assembly of claim 23, wherein the first surface of the second portion and the first surface of the first portion lie in the same plane.
25. The assembly of claim 1, wherein the second portion of the body includes a substantially flat second surface that is generally parallel to the second surface of the first portion of the body.
26. The assembly of claim 25, wherein the second surface of the second portion and the second surface of the first portion lie in the same plane.
27. The assembly of claim 1, wherein the body is configured such that the aircraft workpiece structure contacts and compresses the inner portion and the outer portion of the body when the body is compressed.
28. The assembly of claim 1, wherein the inner portion of the body has an inner perimeter.
29. The assembly of claim 28, wherein the inner portion of the body is thinner than its inner perimeter.
30. The assembly of claim 29, wherein the inner portion of the body is thinner than the second portion.
31. The assembly of claim 28, wherein the inner perimeter has a firmness that is greater than the first firmness.
Type: Application
Filed: Jul 11, 2017
Publication Date: Oct 26, 2017
Inventors: Jeff Busby (Millsap, TX), Kent Boomer (Aledo, TX), Matt Boyd (Fort Worth, TX), Michael Dry (Fort Worth, TX), Douglas Smith (Weatherford, TX)
Application Number: 15/646,888