Abstract:
A dryer seal. The seal is formed from an elongate multi-layer structure having a strip of fibrous material folded upon itself to establish a folded perimeter edge and a pair of outwardly projecting portions projecting away from the folded perimeter edge. A fibrous interior spacer layer is located between the outwardly projecting portions and a single attachment seam extends at an inboard location substantially parallel to said folded perimeter edge.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of and priority from provisional application 60/490,361 filed Jul. 25, 2003 the contents of which are hereby incorporated by reference in their entirety. 

   TECHNICAL FIELD 
   This invention relates to a dryer seal and more particularly to a dryer seal of simplified construction incorporating an arrangement of fibrous material forming a multi-layer sealing element secured together by a simplified stitching arrangement. 
   BACKGROUND OF THE INVENTION 
   Automatic clothes dryers typically include a housing (also known as a bulkhead) and a rotating drum supported within the housing. It is known to use seal elements in the form of rings of felt which may be disposed between the housing and the drum so as to bear against the drum as it rotates. The use of a sealing element is desirable to prevent air leakage between the drum and the clothes dryer cabinet which could detrimentally affect the air flow system of the dryer. It is known to utilize seals in the form of multi-layered ring structures incorporating a folded over exterior layer such as wool or wool blend nonwoven material with a spacer material such as polyester or polyester blend material held within the folded over exterior. The legs projecting outwardly from the folded edge form a sealing contacting relation with the rotating drum. In known past constructions of this type the spacer material was typically held in place by two seams with a first positioning seam running between the upper edge of the spacer material and one side of the folded over exterior and a second holding seam extending at an inboard position through all three layers so as to establish a coordinated stable structure. 
   In the past the use of a first positioning seam and a second holding seam was believed to be necessary to maintain the desired spatial relation between the folded over exterior and the internal spacer material. Maintenance of this spatial relationship is required in order to retain the desired thickness of material between the drum and the housing. In the event that the internal spacer becomes disengaged from or unduly skewed relative to the folded over exterior, the seal efficiency may be greatly reduced thereby permitting hot air to exit the dryer drum and travel into the cabinet. 
   SUMMARY OF THE INVENTION 
   This invention provides advantages and alternatives over the prior art by providing a dryer seal of substantially simplified construction which eliminates the need for double stitching while nonetheless providing desirable sealing characteristics. In particular the present invention provides a seal which functions in the desired manner of prior seals by using flared edges to maintain a sealing relation between a rotating dryer drum and the dryer cabinet. However, although the seal of the present invention operates in the same manner as known prior seals, it utilizes only a single connecting stitch line such as a lock or chain stitch between the folded over exterior and the internal spacer. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The following drawings which are incorporated in and which constitute a part of this specification illustrate an exemplary embodiment of the present invention and, together with the general description above and the detailed description set forth below, serve to explain the principles of the invention wherein: 
       FIG. 1  is a perspective view of an exemplary clothes dryer with the rotating drum and seal illustrated in phantom; 
       FIG. 1A  is an exploded cut-away view of a seal according to the present invention with the seal mounted around a bulkhead flange; 
       FIG. 2  is an end view of a dryer seal according to the present invention; 
       FIG. 3  is an elevation plan view of an elongate strip of multi-layered construction which may be attached end to end to form the dryer seal illustrated in  FIG. 2 ; and 
       FIG. 4  is a view taken generally through line  4 — 4  in  FIG. 3  illustrating the arrangement of layers and single stitch line. 
   

   While the invention has been generally described above and will hereinafter be described in connection with certain potentially preferred embodiments and procedures, it is to be understood and appreciated that in no event is the invention to be limited to such illustrated and described embodiments and procedures. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the broad principles of this invention within the true spirit and scope thereof. 
   DESCRIPTION 
   Reference will now be made to the various drawings wherein to the extent possible like reference numerals are utilized to designate corresponding components throughout the various views. In  FIGS. 1 and 1A , there is illustrated a dryer  10  including a cabinet body  12  housing a heated rotating drum  14 . As illustrated, the cabinet body includes a door opening  16  for loading clothing articles into the mouth of the drum  14 . The door opening  16  may be closed by means of a door  18 . 
   As will be well known to those of skill in the art, the cabinet body  12  typically includes a bulkhead flange  20  ( FIG. 1A ) surrounding the door opening and projecting into the interior of the cabinet body. The bulkhead flange  20  is disposed generally around a reduced diameter drum opening  22 . An outer wall portion  24  of the drum is disposed in surrounding relation to the flange or ring  20 . 
   As shown, a seal  30  is disposed around the bulkhead flange  20  between the outer wall portion  24  and the bulkhead flange  20 . As will be appreciated by those of skill in the art, dryers are typically vacuum systems. In operation the seal  30  prevents the draw of cool (non-heated) air from around the drum. With this flow path blocked, air is drawn more efficiently into the drum from a heated element area for use and eventual vent discharge. 
   As will be described in greater detail hereinafter, the seal  30  includes a folded over exterior  36  and an internal fibrous spacer  38 . As the dryer is operated the drum  14  may experience a degree of oscillation up and down. The exterior  36  and spacer  38  define legs which may flair out or compress as required to adjust for this up and down oscillation and thereby maintain contacting sealing relation with the moving drum. 
   Although dryer seal arrangements using seals having flared ends were previously known, according to the present invention an improved construction for the seal  30  is provided which eliminates the need for multiple seams holding the spacer material in place. Thus, substantial efficiency is provided without sacrificing the ability to hold the spacer material in place (thereby avoiding dislocation or skewing) or giving up the ability to maintain contacting relation between the seal  30  and the oscillating drum  14 . 
   Referring to  FIGS. 2–4 , it may be seen that the dryer seal  30  is preferably of substantially circular construction. According to one potentially preferred practice the dryer seal  30  is formed by adjoining the opposing ends of an elongate sealing structure  32  by use of end to end stitching  34  or other attachment means such as ultrasonic welding and the like as may be known to those of skill in the art. 
   Referring simultaneously to  FIGS. 2 and 3 , according to one contemplated embodiment the sealing structure  32  is formed by folding an outer layer  36  around an interior spacer layer  38  and applying a single stitch line  40  through the layered structure so formed thereby securing the components in place relative to one another. As illustrated, the stitch line  40  is disposed at an inboard location relative to the folded over edge of the outer layer  36 . Such an arrangement thereby forms a single bulbous pocket structure  44  in which a proximal end  46  of the interior spacing layer  38  is held. 
   According to an exemplary formation practice, the outer layer  36  is a needle punched nonwoven textile material formed from entangled fibers of wool or wool blend material such as wool and polyester or other synthetic fiber. Recycled grey wool material may be particularly desirable. In such a construction, the wool provides a degree of natural lubricity which may aid in avoiding premature damage. In one exemplary construction the outer layer  36  is a needle punched grey wool felt having a thickness of about 0.13 inches. However, it is likewise contemplated that other materials and/or constructions may be utilized if desired. 
   The interior spacer layer  38  is preferably a needle punched nonwoven of polyester. In one exemplary construction this interior spacer layer is needle punched polyester having a thickness of about 0.17 inches and a mass per unit area of about 12 ounces per square yard. However, it is likewise contemplated that other materials and/or constructions may be utilized if desired. 
   The stitch line  40  which defines the inboard boundary of the pocket  44  is preferably formed by a chain stitch or lock stitch construction although other stitching arrangements as may be known to those of skill in the art may likewise be utilized. In one exemplary construction the stitch line incorporates a stitch density of about 5 to about 13 stitches per inch. However, it is likewise contemplated that other stitching arrangements may be utilized if desired. The stitch joints formed preferably exceed the tear strength of the felt. 
   As previously indicated and illustrated in  FIGS. 1A and 4 , the portions of the outer layer  36  and interior spacer layer  38  which project outwardly from the pocket structure  44  define legs which can be compressed or flared as required to adjust for oscillation of the drum  14 . Thus, contacting sealing relation between the seal and the drum is maintained during such oscillation. 
   While the present invention has been illustrated and described in relation to certain potentially preferred embodiments and practices, it is to be understood that such embodiments and practices are illustrative and exemplary only and that the present invention is in no event to be limited thereto. Rather, it is contemplated that modifications and variations to the present invention will no doubt occur to those of skill in the art upon reading the above description and/or through a practice of the invention. It is therefore contemplated and intended that the present invention shall extend to all such modifications and variations which incorporate the broad principles of the present invention within the full spirit and scope thereof.