Abstract:
Pile weatherstripping is provided by a flat pile of strands which are tensioned to spring outwardly to straight condition to provide a pile weatherstrip, when bent and inserted into a T-slot or other kerf in a member such as a window or door frame or sash. The tendency of the bent parts of the pile to spring away from each other facilitates retention of the pile after insertion into the slot. A locking fin, more rigid than the pile, is preferably used. This locking fin engages steps or edges in the throat of the slot thereby impeding withdrawal of the weatherstripping from the slot. One or more barrier fins may also be assembled with the strands constituting the flat pile. The pile can be operated in bending mode or in columnar compression (crushing mode). Bending mode operation can be over a bending range so as to accommodate a large range of clearance between a sash and a frame or other members which are sealed by the pile weatherstripping. Parts of the pile can have desired lateral spacing and angular orientation with respect to each other (contour) by using spacing and/or contour forming elements assembled with the flat pile. Since the pile is flat until installed, it is readily wound on reels for shipment and storage until installation. Installation may be accomplished by a roller which pushes the flat pile into the slot. The slot may be disposed at an angle or in a corner of the member to be sealed and facilitates sealing around the entire perimeter of a surface to be sealed such as the exterior surfaces of a window sash or a frame in which this sash is movable.

Description:
DESCRIPTION 
     The present invention relates to pile weatherstripping and more particularly to a pile weatherstrip which is formed by bending and insertion of a strip of side-by-side strands of flat pile into a kerf or other slot in a member for providing sealing action along a surface of the member through which the pile extends. 
     It is a feature of the present invention to provide pile weatherstripping which is formed from flat pile. Another feature of the invention is to provide pile weatherstripping which is operable in compression or in a bending mode. In the bending mode, the pile can bend over a range covering different size clearances between members to be sealed. A single size of flat pile can form weatherstripping which covers a large range which may be approximately 100 mils (0.100 inch) of clearance, or more. Still another feature of the invention is to provide weatherstripping which may be manufacturable at lower cost than weatherstripping which has been heretofore available, such as of the type shown in Johnson, U.S. Pat. No. 5,807,451, issued Sep. 15, 1998, or Miska, U.S. Pat. No. 4,288,483, issued Sep. 8, 1981. 
     Pile weatherstripping has conventionally been provided by piles which project upwardly into a brush, rather than are formed into a brush providing the pile seal upon insertion in the pile receiving slot. Even when strands are wound around a loop and cut into sections, the winding provides bush-like structure with bases or cores to facilitate holding the pile in the slot. See for example, the above cited patents and Metzler, U.S. Pat. Re. No. 30,359, issued Aug. 5, 1980. 
     The range of flexure of conventional pile weatherstripping may be limited when the sealing action is accompanied by the crushing of the pile. Such crushing mode operation can exert forces sufficient to bind the movable sealed unit, such as a sash of a window or door frame, which prevents opening of the window or door without more than desirable force. In other words, the stiff strands apply pressure on the sash and cause binding on the sides of the sash. The present invention provides a sash which can operate in a bending mode; providing sealing without significant crushing of the pile and enabling the pile to bend over a range, commensurate with the height of the pile, over the surface of the member through which the pile extends. The stiffness and height of the pile are therefore controllable. Moreover when barrier fins are used, the bending action also bends the fin rather than causes crenellation which detracts from the sealing action. 
     Pile weatherstrip provided by the invention may utilize a locking fin on the outside of the flat pile. The inside of the pile is defined by the parts, around the bend, formed when the flat pile is inserted in the slot, which parts face each other. With a locking fin, the force to insert the weatherstripping, preferably by rolling into the slot, is much less than the force to remove the weatherstripping. 
     In order to control compressive forces exerted by the pile in the crushing mode, the density of the pile (strands per given area) has been reduced, sacrificing the sealing action of the pile. Pile weatherstripping in accordance with the invention can be operated in the crushing mode if desired and without sacrificing the sealing action thereof. 
     Another advantage of the flat pile weatherstripping provided by the invention is that it is adapted to be assembled by welding, for example, with a bead (a filament) which extends along the inside of the pile. The use of a locking fin facilitates distribution of ultrasonic welding energy and avoids burning of the strands. Locking fins thus afford a further advantage when used in weatherstripping provided by the invention. The lateral spacing of the bent parts (tufts) of the weatherstrip is a function of the diameter of the bead and the width of the T-slot. The compressibility of the pile, even in the crushing mode, may be selectable in accordance with the diameter of the bead and without sacrificing the density and sealing effectivity of the pile. Selectability of bead diameter is still another feature of the invention. 
     Weatherstripping provided by the invention may readily be made by winding processes which maintain the strands under tension so as to pre-stress or bias the strands to return to straight condition, thus providing a pile which tends to lie flat. Winding processes for making flat pile are similar to those used in weaving and may be of the type described in U.S. Pat. No. 4,022,642, issued May 1977 to Abel, and U.S. Pat. No. 1,895,293, issued January  1933  to Morton. 
     Another advantage of the invention is to provide weatherstripping which is easy to store and may be wound flat around a reel for shipping or storage. Furthermore, the winding can be at higher density and without capturing significant air, and thus the amount of linear footage that can be stored on a standard reel is substantially increased over conventional weatherstripping. Still another advantage of the invention is that the pile may be formed into a slot which may be other than perpendicular to a flat surface of the member to be scaled. The slot may be disposed at an angle less than 90 degrees and even in to a corner of the member. 
     Briefly described, a pile weatherstrip in accordance with the invention forms a flexible seal projecting from the member to be sealed when received in a holding slot in the member. The slot may, as conventional, extend longitudinally of the member. The slot has a throat which defines steps along opposite edges of the throat internally of the slot. The slot may be a kerf where the throat is provided by teeth which define the edges. A plurality of strands are stacked in side-by-side relationship to provide a flat pile. The strands have resiliency tending to maintain them straight, that is, perpendicular to a longitudinal axis, about which the flat pile defined by the strands is bent. Upon insertion into the slot, the strands are bent inwardly, along the axis which divides the pile into separate parts. These parts are tensioned, because of the tension in the strands, to spring outwardly. Preferably, a locking fin on the outside of the flat pile, is located internally of the slot, and engages the edges at the throat as the locking, fin spring outwardly, so as to retain the weatherstripping in the slot. End portions of the parts of the strands extend outwardly from the slot and define the flexible pile seal. 
    
    
     The foregoing and other features, objects, and advantages of the invention will become apparent from a reading of the following description in connection with the accompanying drawings in which: 
     FIG. 1 is a perspective view of a flat pile in accordance with the invention; 
     FIG. 2 is a cross sectional view showing the pile weatherstripping formed from the flat pile disposed in a slot; 
     FIG. 3 is a view similar to FIG. 2 showing the pile disposed in a kerf; 
     FIG. 4 is a view similar to FIG. 2 showing another installation of pile weatherstripping in accordance with the invention; 
     FIG. 5 is a view similar to FIG. 1 showing still another installation of weatherstripping in accordance with the invention, wherein the slot is disposed at a non-perpendicular angle to the surface of the member to be sealed; 
     FIG. 6 is a view similar to FIG. 1 showing the slot and weatherstripping installed in a corner of the member to be sealed; 
     FIGS. 7A,  7 B, and  7 C are schematic diagrams illustrating rolling of the flat pile weatherstripping to install same in the slot or kerf in the member to be sealed; 
     FIGS. 8A and 8B show a flat pile and the weatherstripping formed therefrom, respectively, in accordance with another embodiment of the invention; 
     FIGS. 9A and 9B show still another flat pile and the weatherstripping formed therefrom, respectively, in accordance with still another embodiment of the invention. 
    
    
     Referring to FIG. 1, there is shown a stack of strands which form a flat pile  10 . The strands are tensioned outwardly so that the strands tend to lie flat in the pile  10 . The pile may be made of a polyolefin yarn, preferably polypropylene, which is ultrasonically weldable. A monofilament thread or bead  12  extends along the center of the pile on the inside  14  thereof. This monofilament may be a polyolefin material or any other ultrasonically meltable and weldable material such as nylon. Opposed to the bead  12 , on the outside  16  of the pile  10 , is a locking fin  18  also of ultrasonically weldable material. This fin may be thicker than the strands forming the pile, while the resilience is of the fin  18  greater (more rigid) than the pile. The requisite resiliency may be obtained by selecting the thickness of the fin  18 . The fin is centered along the center of the pile  10  (a longitudinal axis along the center of the width of the pile). An ultrasonic horn is preferably used to compress the bead  12  against the fin  18  thereby compressing the pile along the center axis thereof, and melting the bead, pile and locking fin  18 , thereby welding them together and assembling them into the flat pile weatherstrip  20 . If desired, a barrier fin  22  of a width which may be equal to the width of the pile as shown or greater than the width of the pile or even somewhat less than the width of the pile, so as to enhance the sealing action of the pile. This fin  22  may be referred to as a glide fin. 
     Another similarly sized glide fin (not shown) may be provided on the outside  16  of the pile  10  between the pile and the lock fin  18 . All these fins are of ultrasonically weldable material and are assembled into the flat pile weatherstripping by adhering the bead  12 , pile  10 , lock fin  18  and the glide fins to each other, preferably by ultrasonic welding. 
     The pile tends to be a flat pile because of the tension in the strands of the pile which is permanently set when the strands are wound or woven during formation of the pile. 
     FIG. 2 illustrates a frame or member  24 , such as a sash or window frame, having a T-slot  26 . The member  24  may, for example, be an extrusion of plastic material, usually vinyl, which forms the sash or frame of a window in which the pile  20  is installed. The T-slot  26  has a throat or neck  28  of a width greater than the diameter of the bead  12 . Under the neck  28  are steps  30 . The flat pile is bent about the bead  12  into parts (sides)  32  and  34  which flare away from each other. The angular extent of the flare, or the angle between the parts  32  and  34 , is determined by the width of the slot  26 , and the diameter of the bead  12 . 
     The lock fin  18  enters the slot  26  and engages the steps  30  under the neck  28  of the slot. The engagement is along the edges of the lock fin  18 . Accordingly, when the weatherstrip is bent and inserted into the slot  26 , it is installed in a way to impede removal. In order to remove the weatherstrip  12 , a hook blade may be inserted into the slot  26 , past the neck  28  to engage and depress the lock fin along one side thereof so as to allow the weatherstrip  20  to be pulled from the slot. Otherwise, the lock fin  18  permanently locks the weatherstrip in the slot  26 . 
     The weatherstrip  20 , as shown in FIG. 2, is designed to operate in a bending mode. When in that mode, weatherstrip is capable of forming a seal over an operating range as for example, indicated by the dash lines  38 . The weatherstrip  20  is therefore able to accommodate a large range of clearance between the member  24  and another member which is movable toward and away from the extrusion member  24 . This operating range may, for example, be 100 mils, or more. Thus a single weatherstrip size may be used to accommodate a large range of closing clearances as between a window sash and frame. 
     The weatherstrip  20  may, as shown in FIG. 4, be operable in compression or crushing mode, where the parts or sides  32  and  34  extend generally perpendicular to the surface of the extrusion member  24 . Such a more perpendicular relationship than shown in FIG. 2 is obtained by reducing the distance between the bead  12  and the side walls of the throat, that is the spacing between the bead and the side walls of the throat. This may be accomplished with a smaller width T-slot  26 . As the width of the slot axis is reduced, the pile becomes more perpendicular in the slot. In the compression or crushing mode, the operating range, that is the distance between the dash lines  38 , is smaller than in the case where the weatherstripping is configured to operate in the bending mode as shown in FIG.  2 . 
     Referring to FIG. 3, the weatherstrip  20  is shown installed in an extrusion member  40  having a kerf  42 , which is a slot having teeth or grip edges  44  extending along the kerf slot  42 . The lock fin  18  engages the grip edges  44  when the pile  20  is received in the kerf  42 . 
     Referring to FIG. 5, there is shown a slot  48  disposed at an acute angle to the surface of the extrusion member  46  from which the pile  20  extends. The pile operates in a bending mode over a large clearance range where the sash surface  50  approaches the surface of the extrusion member  46 , which may be a window frame. As shown in FIG. 6, the pile weatherstripping  20  may be used in the corner of a member, such as the corner of a window frame formed by side and bottom extrusion members  52  and  54 . The pile  20  is received in a T-slot  56 . As the sash  58  approaches the frame, the weatherstripping  20  bends at the corner of the sash  58  providing a seal. The weatherstrip may be a continuous weatherstrip which extends around the corner  55 . Then the T-slot  56  is internally of the members  52  and  54 . A single weatherstrip may then be used to seal the bottom  54  and the sides  52  of the frame. 
     FIGS. 7A,  7 B, and  7 C illustrates the installation of the weatherstrip  20  by means of a roll in wheel  60  which is journaled in bearings  62 . The edge  64  of the wheel may be concave so as to ride on the bead  12 . As the extrusion and weatherstrip  20  move together past the wheel  60 , and the wheel  60  is brought down into the slot  26 , the weatherstrip  20  is bent as shown in FIG.  7 B. There the lock fin  18  is still within the neck  30  of the slot  26 . 
     As the wheel  60  is brought down further into the slot, as shown in FIG. 7C, the lock fin  18 , due to its resiliency and greater rigidity than the pile  10 , springs laterally outward and locks the weatherstrip  20  in the slot  26 . 
     FIGS. 8A and 9A show flat weatherstrips  70  and  72 , which are similar to the weatherstrip  20  and like parts are identified with like reference numerals. Pile contouring fins  74  and  76  in the form of strips of material which is resilient but more rigid than the pile  10  are assembled into the flat pile. More particularly, the contour fins  74  and  76  are strips which are centered with respect to the pile  10  (midway between the outer edges of the pile  10 ), and are sandwiched between the pile or the slide fin  22 , when that fin  22  is used on the inside of the pile, and the bead  12 . These contouring fins are assembled with the pile, lock fin  18  and bead  12  as a unitary assembly, preferably by ultrasonic welding. The material of the contouring fins  74  and  76  may be the same as used for the lock fin  18 . Preferably the rigidity of the contouring fins  72  and  74  is between the rigidity of the pile and the rigidity of the lock fin. 
     The contouring fin  74  is arcuately shaped and retains the arcuate shape when the weatherstrip  70  is inserted in the slot  26  as shown in FIG.  8 B. The contouring fin  74  defines the contour or flare of the sides  32  and  34  of the pile  10 , which generally follow the contour of the contour fin  74 . The installation of an arcuate contouring fin  74  is shown in FIG.  8 B. 
     The installation of the weatherstrip  72  in the T-slot  26  in the member  24  is shown in FIG.  9 B. The contouring fin  76 , like the fin  74 , is of a width less than the width of the flat pile  10  and centered between the outer edges  71  and  73  of the pile. The contouring fin  76 , like the fin  74 , is of sufficient width to extend out of the slot  26  when the pile is installed in the slot. The contouring fin  76  is wavy in cross section, that is, it has side arms  78  and  80  of convex shape extending from a central section  82  of convex shape. The concave side arms  78  and  80  are spaced further from the edges of the T-slot  26 , at the surface of the member, than is the case for the arcuate shaped contouring fin  74 , and thus defines a somewhat shallower flare or contour than the contouring fin  74 . By selecting the radius of the arc, both of the contouring fin  74  or of the arms  78  and  80  of the contouring fin  76 , the amount of feathering or tapering of the pile parts  32  and  34  and the amount of initial bending of the flat pile, and its desired contour, is obtainable. From the foregoing description it will be apparent that there has been provided improved pile weatherstripping, and particularly flat pile weatherstrips, which may operate either in bending or compression modes and assume desired shapes upon installation. Additional shapes of the pile and other variations and modifications thereof, within the scope of the invention, will become more apparent to those skilled in the art. Accordingly the foregoing description and drawings should be taken as illustrative and not in a limiting sense.