Insect Screen

Abstract

An insect screen comprised of knitted synthetic yarns and having a knitted pattern incorporated therein. First and second groups of yarns, such as polypropylene, are knitted with the first group of yarns forming a grid or mesh while the second group of yarns form a pattern. Once the insect screen is knitted, the insect screen is subjected to a finishing operation. In finishing the insect screen is stretched and placed in tension using selvages formed of a third group of yarns. The tensioned insect screen is heated causing the yarns to at least slightly plasticize and causing heat fusion of at least some stitches. Thereafter the insect screen and yarns are cooled, resulting in the insect screen becoming more rigid and generally assuming the stretched configuration in the absence of stretching.

Description

FIELD OF THE INVENTION

The present invention relates to insect screens.

BACKGROUND OF THE INVENTION

Insect screens are widely used in windows, doors, porches, gazebos and the like. No one will argue that insect screens are not functional. Whether they are used in doors, windows or screened porches, insect screens make certain areas of a home habitable and enjoyable, especially during summer months and in areas where insects are prevalent.

Aside from functionality, little can be said for insect screens. They are not particularly aesthetically pleasing, nor are they even designed to be. But yet, insect screens are often used in and around areas of the home where a great deal of time and attention has been devoted to design and aesthetics.

Therefore, there is a need for a “designer type” insect screen, one that will not only fit in with fine or even extraordinary furnishings and interior design, but one that will even compliment and add to the aesthetics of a home.

SUMMARY OF THE INVENTION

A knitted insect screen is provided with a pattern incorporated into the insect screen.

In one particular embodiment, the insect screen is knitted from at least two groups of yarn. The first group of yarns forms a grid or mesh while the second group of yarns is knitted into a pattern that extends over an area of the insect screen.

Other objects and advantages of the present invention will become apparent and obvious from a study of the following description and the accompanying drawings which are merely illustrative of such invention.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front elevation view of an insect screen in a window.

FIGS. 2A and 2B are lapping diagrams for mesh yarn inlays.

FIG. 2C illustrates lapping diagrams for pillar stitched mesh yarns.

FIG. 2D illustrates the combination of yarn inlays and pillar stitched yarns of FIGS. 2A and 2B.

FIG. 2E illustrates patterning yarns showing pillar stitching in non-non-patterned areas and tricot stitching across two wales in patterned areas.

FIG. 2F illustrates patterning yarns showing pillar stitching in non-non-patterned areas and tricot stitching across three wales in patterned areas.

FIG. 2G illustrates patterning utilizing the patterning yarns of FIGS. 2E and 2F superimposed.

FIG. 3 is a threading diagram and stitch construction for an insect screen fabric using a 3 needle/3 needle technique.

FIG. 4 is a threading diagram and stitch construction for an insect screen fabric using a 2 needle/3 needle technique.

DETAILED DESCRIPTION

With further reference to the drawings, the insect screen of the present invention is shown therein and indicated generally by the numeral 100. Insect screen 100 is of a general mesh or grid construction. Integrated into the insect screen 100 is a pattern indicated generally by the numeral 101. Pattern 101 can include individual patterns spaced apart on the insect screen 100, as illustrated in FIG. 1, or can include one continuous pattern that extends over a substantial portion of the insect screen. Various patterns 101 can be incorporated. Typical examples of patterns are palm trees, leaves, landscapes, etc. Generally, insect screen 100 can be used in a wide variety of areas. For example, insect screen 100 can be used in doors, windows, porches, gazebos and other areas where desirable to prevent the ingress of insects. In the example shown in FIG. 1, the insect screen 100 is incorporated into a window frame 100A.

Insect screen 100 is of a knit construction. Yarns, such as synthetic yarns, are knitted together to form the basic mesh or grid construction as well as the pattern 101. Basically, at least two groups of yarns are utilized to form insect screen 100. A first group of yarns is knitted together to form the mesh or grid. This first group of yarns is sometimes referred to as mesh yarns. The mesh or grid can assume various shapes. Typically the mesh or grid will include tiny rectangular openings formed between yarns. In addition to the first group of yarns, or the mesh yarns, there is also a second group of yarns utilized to form pattern 101 that visually contrasts with the mesh or grid. These yarns may be referred to as patterning yarns.

The two groups of yarns may be of the same color or shade. Alternatively, each group may include yarns of different or distinct colors or shades from the yarns of the other group. For example, the mesh yarns could be clear polypropylene yarns while the patterning yarns could be colored yarns or yarns that are more nearly opaque or black. This provides an additional visual contrast between the mesh or grid and pattern 101. Similarly, the two groups of yarns may be selected to exhibit other properties. such as composition, denier, ply, etc., that are different in one group than in the other group.

In the example shown in FIG. 1, insect screen 100 includes non-patterned areas 102 and patterned areas 104. In the non-patterned areas 102, the patterning yarn lies generally adjacent the mesh yarn. Thus, in the non-patterned areas, the mesh or grid is formed by both the mesh yarn and the patterning yarn. In patterned areas 104, the patterning yarn is diverted from the mesh yarn to form pattern 101. In a general sense the patterning yarn is extended across mesh or grid openings so as to partially close selected openings. This gives rise to a pattern effect.

FIGS. 2A-2G illustrate sequentially the basic construction of the insect screen 100. Each of FIGS. 2A-2G illustrate the same 10 course (C1-C10) by 5 wale (W1-W5) portion of insect screen 100 showing the dispositions of the various yarns used in forming the screen. A single course indicates the instantaneous location of the knitting machine needle array while forming screen 100. Each wale indicates the sequence of locations of a particular needle in the needle array during the formation of screen 100. A first group of yarns, referred to as the mesh yarns, include an array of zigzag yarns that zigzag back and forth across wales and along courses forming inlays 33 and 34, as shown in FIGS. 2A and 2B. The mesh yarns also include an array of connecting yarns that form connecting stitches 32 as shown in FIG. 2C. Connecting stitches 32 bind the zigzag yarns together.

The zigzag yarns comprise two sub-groups of yarns. The two sub-groups of zigzag yarns form opposing inlays, one as illustrated in FIG. 2A and the other as illustrated in FIG. 2B. Once the zigzag yarns are connected by the connecting yarns, it follows that tiny openings within the formed mesh are defined. In one example, the connecting yarns form pillar stitches 32 at selected locations to bind the zigzag yarns together, which in turn forms the mesh.

In forming the mesh or grid, the zigzag yarns of one sub-group extend across a predetermined number of courses along a wale and then turn and extend across a predetermined number of wales to the next course, and thereafter continue to extend along wales and courses in alternating fashion. For example, as shown in FIG. 2A, one of the zigzag yarns lies below needle location C1-W3, extends around the needle location to the left, extends along wale W3 to needle location C3-W3, turns and extends out of wale W3 and across wale W4 to needle location C4-W5. A zigzag yarn may, in some embodiments, start in every wale in course C1 and zigzag along wales and across courses in this manner, as illustrated in FIG. 2A. The zigzag yarns of the other sub-group are inlayed in opposition as can be seen by comparing FIGS. 2A and 2B. For example, in FIG. 2B, one of the zigzag yarns lies below needle location C1-W3, extends to the right of the needle location, extends along wale W3 to needle location C3-W3, and then turns and extends out of wale W3 and across wale W2 to needle location C4-W1. Thus, one sub-group of zigzag yarns forms inlays 33 that are open to one side, and the other sub-group of the zigzag yarns forms inlays 34 that are opposed and open to the opposite side. However, when the two inlays are superimposed, as occurs in the knitting process, the side openings are effectively closed to form the mesh and the tiny openings are bounded by the zigzag yarns.

FIG. 2D shows the yarn layout when inlays 33 and 34 and pillar stitches 32 are superimposed. The mesh or grid is clearly apparent in that each opening is bounded by a vertical element 105V and a horizontal element 105H. Vertical elements 105V are formed by pillar stitches 32 and portions of inlays 33 and 34 which run within each wale. Horizontal elements 105H are formed by the portions of inlays 33 and 34 that extend out of wale from one course to another course.

Inlays 33 and 34, may, as illustrated in FIGS. 2A and 2B, be repeated in every wale or they may be spaced apart one or more wales. Connecting yarns form stitches 32 along every wale in which a zigzag yarn turns around a needle location. In one embodiment, illustrated in FIGS. 2A and 2B, zigzag yarns form inlays 33 and 34 that are immediately adjacent one another, and the connecting yarns form pillar stitches 32 extending along every wale and connecting to the zigzag yarns at every needle location.

The size of the tiny openings in the mesh can be varied in several ways. For example, the size of the openings can be varied by varying the needle spacing or varying the length of the in wale run of the zigzag yarns.

The patterning yarn, or second group of yarns, is incorporated into insect screen 100 in two different ways as illustrated in FIGS. 2E-2G. First, in non-patterned areas 102, the yarns of the second group tend to follow the connecting yarns of the first group. That is, in non-patterned areas 102, the yarns of the second group extend alongside the connecting yarns of the first group, and also form pillar stitches 31A and 31B. Thus, in non-patterned areas 102, the yarns of the second group, or the patterning yarns, cooperate with the yarns of the first group to form the mesh or grid. However, in patterned areas 104, the yarns of the second group are diverted to form a pattern or series of patterns. Effectively, the patterning yarns are diverted such that they extend across openings in the mesh or grid, and at least partially close these openings such that when a substantial area of the screen 100 is viewed a pattern 101 is seen. When the second group of yarns is diverted for the purpose of forming the pattern 101, they are attached to other yarns in the insect screen 100 by tricot stitches 31AP and 31BP.

The yarns utilized in producing insect screen 100 may be beam or creel fed. Generally, yarns used to form stitches which consume approximately equal amounts of yarn continuously may be beam fed. That is, such yarns would be wound on the beam together ad fed generally uniformly from the beam. Yarns forming stitches or inlays with varying consumption rates during the knitting process are generally creel fed. Each yarn is supplied from a separate spool housed in the creel and fed from there to the knitting machine. Creel feeding such yarns prevents distortion of the grid or mesh structure of insect screen 100.

FIG. 3 illustrates one embodiment the insect screen 100 constructed by warp knitting on a Piezo Jacquard machine equipped with a fall plate and employing the 3 needle/3 needle inlay technique. The machine gauge is 12 needles per inch. The stitch construction, indicated generally by the numeral 30, shows a representative portion of screen 100 showing non-patterned areas 102 and patterned areas 104. The yarns and threading thereof utilized in forming screen 100 are illustrated in the threading diagram, indicated generally by the numeral 50. The stitch construction 30 that forms screen 100 illustrates the stitches and their relationships in the fabric that forms the screen 100.

Insect screen 100 comprises a generally rectangular mesh or grid structure formed along courses C1-C11 and across wales W1-W9. Patterned areas 104 are yarn structures that are integrated with the mesh or grid structure to form an aesthetic appeal while maintaining functional attributes. Non-patterned areas 102 comprise the grid or mesh structure. The 3 needle/3 needle inlay technique provides relatively high width stability to the mesh or grid structure of insect screen 100. For this embodiment, the openings in the grid or mesh structure are spaced approximately 14 openings per inch.

As mentioned before, yarns used to form insect screen 100 may be of various types, including synthetic yarns. In one embodiment, the yarns are polypropylene yarns, specifically 1/70/36 HESR 100% polypropylene solution dyed. A first group of yarns is utilized uniformly throughout the fabric to form the mesh or grid structure. Yarns of a second group are aligned with and form a part of the mesh or grid structure in non-patterned areas 102, but are diverted in patterned areas 104 to form the pattern or patterns structures. In one embodiment the yarns of the second group would preferably be creel fed so as to have little or no distortion of the mesh or grid structure. Yarns 52, 53, and 54 comprise the first group of yarns and are guided by ground guide bars L2, L3, and L4, respectively, to form the grid or mesh structure. Yarns 51A and 51B comprise the second group of yarns, guided by Jacquard guide bar L1A, L1B to alternately align with the mesh or grid in non-patterned areas 102 and selectively divert in patterned areas 104 to form pattern 101. As is appreciated by one of ordinary skill in the art, the guide bars are functional elements of a warp knitting machine that engage needles to form the various stitches and inlays to comprise the structure of a knitted fabric. Selectively diverting yarns 51A and 51B is effected by shifts of certain individual guides of Jacquard L1A and L1B using the piezo capability of the Jacquard.

Turning now to a more detailed description of stitch construction 30 for the exemplary insect screen 100 of FIG. 3, the fabric is formed utilizing several stitch trajectories. Yarn 54 forms inlay 34 spanning 3 needle locations, and yarn 53 forms an opposed inlay 33 likewise spanning 3 needles. This 3 needle/3 needle inlay technique provides relatively high width stability to the grid or mesh structure. Both inlay 33 and inlay 34 each span three wales, or needle locations. For example, yarn 54, guided by guide bar L4, laps to the right about needle position C1-W3, then back to the left to lap C2-W1, then to the right to lap C2-W1, then to the left to lap C3-W1, and finally to the right to C5-W3. Inlay 34 repeats up across the courses, and the stitch is repeated for every wale. That is, an inlay 34 begins, in one embodiment as shown in stitch construction 30, at each of wales W1, W2, W3, W4, W5, W6, W7, W8, W9, and each inlay repeats across the courses. Thus, successive inlays 34 partially overlap preceding inlays 34 forming a portion of the grid or mesh structure. Similarly, yarn 53, guided by guide bar L3, forms an opposed inlay 33 by lapping, for example, to the left of C1-W4, then right to lap C2-W6, then left to lap C3-W6, then right to lap C4-W6, and finally left to C5-W4 to form a cycle of the inlay. As with inlay 34, inlay 33 repeats across courses with a yarn forming an inlay 33 beginning in every wale. It is appreciated that yarns 53 and 54 form opposed inlays 33 and 34 due to the opposed shogging of guide bars L3 and L4 to produce the conformation of the grid or mesh with relatively high width stability. Portions of yarns 53 and 54 running generally closely spaced and in a slightly angled fashion, in one embodiment, form horizontal elements 105H of the grid or mesh as described here before. The generally vertical elements 105V of the grid or mesh are formed by the partially overlapping portions that run sinuously up individual wales between the horizontal elements.

The mesh or grid is bound or stitched together by open pillar stitches 32 formed utilizing yarn 52 running up each wale. Pillar stitches 32 engage and wrap yarns 53 and 54 where they cross to provide the lengthwise stability of screen 100. In non-patterned area 102 yarns 51A and 51B, guided by Jacquard sections L1A and L1B, respectively, generally align with, and lay adjacent, yarn 52 running along the wales. In one embodiment, yarns 51A and 51B from open pillar stitches 31A and 31B, respectively, in unison with stitches 32 in non-patterned areas 102. Because of the changing nature of the stitches formed by yarns 51A and 51B, the yarns may be creel fed.

In patterned areas 104, yarns 51A and 51B are diverted to form open tricot stitches 31AP and 31BP crossing one or more wales. For example, yarn 51A binds other yarns at C1-W2, then laps leftward to C2-W1 binding and engaging yarns at that location, and finally laps rightward to C3-W2 to form open tricot stitch 31AP. It is to be noted that the portion of yarn 51A lapping from, for example, C2-W1 to C3-W2 crosses a portion of the mesh cell formed by vertical grid elements 105V formed along wales W1 and W2 and the horizontal grid elements 105H between C1 and C2 and between C4 and C5. Yarn 51A crossing a mesh cell creates part of a pattern area 104. Likewise, yarn 51B binds other yarns at C1-W3, angles leftward to bind other yarns at C2-W1, and finally angles rightward to form open tricot stitch 31BP. As with yarn 51A, it is appreciated that yarn 51A being thus diverted crosses one or more mesh cells and forms part of a pattern area 104 by partially closing an opening in the mesh. It is further appreciated that by selectively diverting yarns 51A and 51B at various locations in fabric, various pattern structures may be produced.

Another embodiment entails the use of the 2 needle/3 needle inlay technique as illustrated in FIG. 4. The description of the yarns and construction as regards the yarns 61A, 61B, and 62 forming stitches 41A, 41AP, 41B, 41BP, and 42 is identical to that of FIG. 3 for yarns 51A, 51B, and 52 forming stitches 31A, 31AP, 31B, 31BP, respectively. Insect screen 100 in this embodiment differs from the embodiment illustrated in FIG. 3 in regards to inlays 43 and 44 formed by yarns 53 and 54 guided by ground bars L3 and L4, respectively. Inlay 44 spans only two wales, or needle locations while inlay 43 spans three wales, or needle locations. For example, yarn 64 laps rightward around C1-W7, then leftward around C2-W6, then rightward around C3-W6, then leftward around C4-W6, and finally rightward to C4-W7 to form inlay 44 spanning two wales, or needle locations. Yarn 63 laps leftward around C1-W3, then rightward around C2-W5, then leftward around C3-W5, then rightward around C4-W5, and finally leftward to C4-W3 to form inlay 43 spanning three wales, or needle positions. As in the case of inlays 33 and 34 in FIG. 3, inlays 43 and 44 in FIG. 4 each commence, in one embodiment, in each wale and run along wales across courses as described. It is appreciated that the 2 needle/3 needle inlay technique provides relatively lower widthwise stability of insect screen 100 as compared to the earlier-described embodiment that employs the 3 needle/3 needle inlay technique, albeit with a lower yarn consumption. Further, 2 needle/3 needle inlay technique may provide stiffer horizontal, or widthwise, elements 105H in insect screen 100 due to the shorter wale-to-wale yarn traverses included in inlay 33. Additionally, the 2 needle/3 needle inlay technique provides cleaner, more balanced in width and length mesh or grid openings.

The embodiment described above utilizing the 2 needle/3 needle inlay technique also provides mesh or grid opening spacing of about 14 openings per inch. Other opening spacings can be produced. For example, employing an 18 gauge single Jacquard machine and using 3 needle/3 needle or 3 needle/4 needle inlay techniques can produce insect screen 100 with an opening spacing of about 20 openings per inch. It is appreciated that a wider inlay technique, such as a 3 needle/4 needle limits machine speed relative to narrower inlays. Another example is employing a Rascheltronic machine with 28 needles per inch, or 28 gauge, with a 2 needle/3 needle inlay technique to produce insect screen 100 with opening spacing of about 30 openings per inch.

Turning now to the method of forming insect screen 100, it is appreciated that the screen is knitted and subsequently subjected to one or more finishing operations. To facilitate handling insect screen 100 during finishing operations, opposed side selvages are integrally knitted onto the screen. The side selvages are utilized to attach opposed sides of insect screen 100 to pins or hooks of a conveyor that forms a part of the finishing system. The side selvages stretch insect screen 100 and maintain the screen in tension on the conveyer as the conveyor moves the screen through the finishing process. After finishing, the side selvages are removed from insect screen 100.

In one embodiment, finishing operations include stretching and tensioning insect screen and subjecting the screen to a heated environment for a certain period of time. This is accomplished using finishing ovens where the conveyor conveys the tensioned insect screen 100 through the ovens. Such finishing systems are well known to those of ordinary skill in the art. In one embodiment, where polypropylene yarns are utilized to construct insect screen 100, the oven is set at about 330° F. and the screen is retained in the oven for approximately one minute. The melting point of polypropylene yarns is about 330° F., and the softening point is about 290° F. Heating the yarns that comprise insect screen 100 plasticizes the yarns and heat fuses the stitches. This causes insect screen 100 to be “set”, meaning that after being removed from the conveyor, the screen generally assumes the same area it assumes when stretched in tension on the conveyor. Moreover, plasticizing the yarns and heat fusing the stitches tends to make insect screen 100 more rigid.

As mentioned above, insect screen 100 is tensioned by the side selvages when connected to pins or hooks of the conveyor that moves through the heated area. It is preferable to construct the side selvages of yarns having a higher melting point than the yarns utilized to form insect screen 100. This will generally preclude the side selvages from being melted during the finishing operation by heat transmitted from the pins or hooks of the conveyor thereby enabling screen fabric 100 to be held throughout the finishing operation.

The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

Claims

1. A device for use in doors, windows and enclosures, comprising:

a. a knitted insect screen;

b. the insect screen including first and second groups of knitted yarns;

c. the first group of knitted yarns forming a grid in the insect screen;

d. a pattern knitted into the insect screen and wherein the second group of yarns forms the pattern; and

e. wherein the knitted insect screen is mounted within a frame.

2. The device of claim 1 wherein the first and second groups of yarns of the knitted insect screen comprise polypropylene yarns.

3. The device of claim 1 wherein the yarns form stitches that are heat fused.

4. The device of claim 3 wherein the first and second groups of yarns include plasticized yarns.

5. The device of claim 3 wherein the insect screen includes patterned areas and non-patterned areas, and wherein in the non-patterned areas the second group of yarns generally lie adjacent yarns of the first group and the first and second group of yarns form the grid, and in the patterned areas the second group of yarns divert from the first group of yarn and form the pattern.

6. The device of claim 3 wherein the first group of yarns includes a first subgroup of yarns that zigzag and at least partially overly each other to form openings in the grid; and the first group of yarns further including a second subgroup of yarns that bind the yarns of the first subgroup together.

7. The device of claim 6 wherein the yarns of the first subgroup are inlayed and the yarns of the second subgroup form connecting stitches with the yarns of the first subgroup.

8. The device of claim 7 wherein the yarns of the second group form both tricot and pillar stitches.

9. The device of claim 6 wherein in some areas of the insect screen the yarns of the second group generally align with the yarns of the first group that form the grid, and in other areas the yarns of the second group divert from the first group of yarns to form the pattern.

10. The device of claim 9 wherein the insect screen includes patterned areas and non-patterned areas, and wherein in the patterned areas the yarns of the second group form tricot stitches, and in the non-patterned area the yarns of the second group form pillar stitches.

11. The device of claim 3 wherein the first group of yarns includes two sub-groups that form opposed inlays.

12. A method of knitting and forming an insect screen, comprising:

a. knitting a first group of yarns and forming a fabric mesh; and

b. with a second group of yarns knitting a pattern into the fabric mesh to form an insect screen having a knitted pattern.

13. The method of forming the insect screen of claim 12 wherein the yarns are synthetic yarns and including heating the insect screen and plasticizing the yarns of the insect screen.

14. The method of forming the insect screen of claim 12 wherein the yarns are synthetic yarns and including forming heat fused stitches that connect yarns.

15. The method of claim 12 including stretching the insect screen to a selected size; directing the stretched insect screen into a heated area; holding the stretched insect screen in the heated area for a selected time; and cooling the insect screen such that the insect screen remains substantially the same size in the absence of stretching.

16. The method of claim 12 wherein the yarns are synthetic yarns and including forming side selvages on the insect screen and utilizing a third group of yarns for forming the side selvages having a melting point temperature higher than the melting point temperature of the first and second group of yarns.

17. The method of claim 12 including mounting the insect screen having the knitted pattern in a frame.

18. The method of claim 12 wherein the insect screen includes patterned areas and non-patterned areas and the method includes the second group of yarns adjacent the first group of yarns in the non-patterned area, and in the patterned areas diverting at least some of the yarns of the second group of yarns to form a pattern.

19. The method of claim 15 including heating the insect screen for a sufficient period of time to plastically relax the insect screen.

20. A method of knitting and forming an insect screen, comprising:

a. knitting a first group of synthetic yarns to form a mesh;

b. knitting opposed side selvages onto the mesh with a second group of synthetic yarns where the melting point of the second group of yarns is higher than the melting point of the first group of yarns; and

c. heating the insect screen, plasticizing the mesh, and fusing yarns that intersect in the insect screen.

21. The method of claim 20 including utilizing the side selvages to tension the mesh and heating the mesh while tensioned and cooling the insect screen.

22. (canceled)

23. The method of claim 20 wherein the first group of yarns includes a series of inlayed yarns that at least slightly overlap to form at least a part of the mesh; and a series of connecting yarns for connecting the inlayed yarns.

24. The method of claim 23 wherein the first group of yarns includes two sub-groups and including forming opposing inlays utilizing the two sub-groups of yarns.

25. The method of claim 20 wherein the second group of yarns includes a series of yarns that connect to the mesh and which form a pattern on the mesh.

26. (canceled)

27. The method of claim 20 including mounting the insect screen in a frame.