The present invention relates to panty briefs comprising a waist portion for enveloping a wearer, said waist portion being knitted together at an edge area in the bottom of the briefs in order to form a crutch area separating two non-united sections of the edge areas at the bottom of the briefs in order to form leg openings, said briefs being produced from a base web with elastic threads, which are distributed across the height of the waist portion, and which extend generally in the circumferential direction of the waist portion in order to provide an elastic contraction in the circumferential direction of the briefs.
It is known from the prior art to produce panty briefs by knitting with different patterns in order to obtain the best possible fit without the need of a finishing treatment of the briefs. In order to obtain a fit and an elastic contraction, it is possible to use different mesh types, tighter knitting and the like in stead of interknitting the elastic threads. The present invention relates to such panty briefs wherein elastic threads are used, and to a lesser extent the mesh type, for providing the fit.
While several solutions have been proposed in order to obtain a fit that makes the briefs as widely applicable as possible, so-called one-size briefs, the known briefs are associated with certain disadvantages.
In order to obtain briefs that will fit a relatively small wearer firmly, a large number of elastic threads are required in the circumferential direction. However, such briefs result in a very high contractive stress on a relatively large wearer. If the briefs are to fit the large wearer, they will be much to loose for a relatively small wearer. Especially in diaper fixation briefs this is a problem. In such briefs relatively strong elasticity is required in order to obtain satisfactory fixation of a diaper. Consequently, the larger wearer will have a very high risk of strong local contractive stress adjacent the elastic threads. This leads to irritations and may also hamper free blood circulation.
Solutions to the formation of one-size briefs have been proposed wherein a tack extending partially into the briefs is formed at varying distances across the height of the waist portion and at the lateral seams of the briefs. This tack in the waist portion at certain points at intervals across the height of the waist portion may be broken. Breaking a smaller or larger part of the tack makes it possible to produce briefs that fit a large or a small wearer. However, the briefs will comprise a relatively large amount of material being concentrated at the lateral seams. This will naturally cause small wearers to feel uncomfortable due to the elastic forces in the circumferential direction, which will press the folded amount of material against the wearer with high local contractive stress.
There is further a risk that a user may break an excessive part of the tack. This will cause the briefs to be unsuited for use by a relatively small wearer since too feeble elasticity occurs in the circumferential direction of the finished briefs. This will especially lead to problems in diaper fixation briefs.
From US-A-3,016,726 it is known to produce a panty brief with elastic threads only forming meshes along a portion of the extension of said threads. However, this is done in order to manufacture a product of less size that the ordinary size of a product produced at one machine. There is no proposal for the manufacture of a one-size product.
Briefs according to the present invention may be seen as a further development of flat knitted briefs described in US patent No. 3,656,324. Materials, knit types, mesh sizes, embodiments etc. disclosed in the US patent may consequently also be used in connection with the production of briefs according to the present invention. Alternatively, the briefs according to this invention may also be manufactured by circular knitting.
It is the object of the present invention to remedy the disadvantages of prior art briefs, especially prior art one-size briefs, and in particular briefs for diaper fixation, by disclosing briefs of the type mentioned in the introduction that may be manufactured with an elasticity permitting it to be used by relatively small and relatively large wearers without causing local contractive stress and without fitting too loosely.
This is obtained according to the present invention by briefs being characterised in that at least part of the elastic threads only form meshes along a portion of the extension of said threads in the circumferential direction of the briefs so as to form intermediate portions in which the base web is pressed in an outward direction for the formation of undulations.
Finished briefs in which part of the elastic threads are meshed with the other base web meshes of the waist portion of the briefs only over a portion of their extension will appear with undulations. The elastic threads distributed across the height of the waist portion will contact those areas, oriented in the vertical direction of the waist portion, with which they are interknitted. Owing to this the intermediate areas, which are not in contact with the elastic threads, will be pressed in an outward direction so that the briefs appear with the undulated waist portion, in which the undulations are oriented with their longitudinal direction in the vertical direction of the briefs. In the direction perpendicular thereto, i.e. in the circumferential direction, the undulations will provide sufficient elasticity for safe maintenance of the briefs when placing the briefs on a small wearer. If the briefs are worn by a large wearer, the undulations will, in popular terms, be straightened out. This will cause increased elasticity to arise in the circumferential direction. However, there will only be a relatively small change in the elastic contractive stress.
Furthermore, the contractive stress will not be positioned in single spots. Instead there will be an even distribution of the elastic contractive stress on the wearer across the entire circumferential direction of the briefs. Thus, the briefs may be used by a small wearer, in which case the undulations give rise to the required elasticity, and by a larger wearer, in which case increased elasticity will occur due to the stretching of the elastic threads by the straightening of the undulations. The briefs are easy to use as they require no preceding preparation. Furthermore, the briefs will always be suited for use by a large or small wearer no matter if they have previously been expanded to their maximum extension.
The briefs according to this invention will not cause a large amount of material to occur at certain areas such as at the lateral seams, which might give rise to irritating contractive stresses on the wearer and which might also make the briefs aesthetically unattractive due to the bulges occurring at these large amounts of material.
As the briefs will in any use give a largely uniform elastic tension that may be determined in advance by the number of elastic threads, the briefs will be particularly suitable as diaper fixation briefs. It will be possible to manufacture the briefs by flat knitting on traditional dual track Raschel machines or by circular knitting on traditional circular knitting machines.
In the present application the term waist portion refers to those parts being designed to envelop the wearer and extending all the way down to the crutch area between the two leg openings. The elastic threads may thus be placed across the entire height of the briefs, including areas for a waist-band for surrounding the waist of the wearer and an elastic edge area adjacent the leg openings. Thus, also waist-bands and leg cuffs will appear with the undulations and be adaptable to wearers of different sizes. In order to obtain suitable elasticity it has turned out to be advantageous in the briefs for adults to use between 10 and 20 elastic threads, preferably between 14 and 18 elastic threads.
The invention will now be explained in further detail with reference to the accompanying drawings in which
Figure 1 shows a substantially rectangular front piece 1 of briefs according to the invention manufactured by flat knitting. The rectangular front piece 1 is provided overlaying a largely corresponding rear piece 2 being only visibly at leg openings 3, which are arranged on either side of an interknitted crutch area 4 at the bottom of the briefs. The briefs 1 comprise a waist portion 5 designed to envelop the wearer. The front piece 1 and the rear piece 2 are interknitted along lateral edge areas 6 to form a lateral seam 7.
The interknitting of the edge areas 6 corresponds to the interknitting made in the crutch area 4.
The front piece 1 and the rear piece 2 are manufactured in endless lengths on a conventional knitting machine, e.g. a Raschel knitting machine in which one of the needle tracks is used for manufacturing the front piece 1 and the other needle track is used for manufacturing the rear piece 2. The endless lengths are cut across to form separate briefs. This cut is performed in meshproof cutting lines (not shown) at either lateral edge.
At the top of the waist portion 5 a waist-band 8 is formed enveloping a waist opening 9. The waist-band 8 is produced in a matter known per se by means of a large number of elastic threads 10.
The briefs are manufactured with a number of elastic threads 11 generally extending in the circumferential direction of the waist portion. In the embodiment shown this means that the elastic threads 11 extend between the edge areas 6 of the front piece 1 and the rear piece 2, respectively. The elastic threads are able in a manner known per se to provide elastic contraction in the circumferential direction of the briefs. This ensures that the briefs fit firmly to the wearer.
Elastic threads will normally as a whole or in part constitute part of the base web of the front piece 1 and the rear piece 2, which are formed with a net-like open mesh structure. This mesh structure is well-known to a person skilled in the art and, therefore, will not be described in detail. It is also well known to use elastic threads interknitted with the base web throughout the circumferential direction of the waist portion. These known elastic threads are designated by 11'.
According to the present invention, part of the elastic threads 11 are only partially interknitted with the base web along the extension of the thread in the circumferential direction of the waist portion. In the embodiment shown the threads 11 are formed by yarn in the form of highly elastic elastan interknitted with the base web to alternately form four meshes and extend freely across the subsequent four meshes formed in the base web.
Across the height of the waist portion a total of sixteen elastic threads 11 are used. The threads 11 are only shown on the front piece 1 but corresponding threads will be arranged on the rear piece 2. The threads 11 will give the briefs undulations to be explained later with reference to figures 3 to 5. The undulations will permit the briefs to be used with satisfactory elasticity on a small wearer and a large wearer.
It is in the interknitting of the elastic threads 11 into the waist portion 5 that the briefs according to the present invention differ from the briefs of the prior art. The actual interknitting of the elastic threads is shown in the knitting diagram in figure 2. It is understood that the knitting diagram of figure 2 is only partial and that it is possible to vary the extension of individual areas. Thus, the waist-band 10 may be wider or smaller, and the edge area 12 located in immediate vicinity of the leg openings 3 may also have different extensions.
It appears from the knitting diagram that the elastic threads 11 in the area 13 extending in the vertical direction 14 of the briefs 1 form meshes 15 with the remaining, base web 16, and then follow an area 17 likewise oriented in the vertical direction 14 of the briefs where the threads 11 are not interknitted with the base web 16. The base web is formed with a net-like knitting of textured yarns, e.g. produced from nylon or polyester or elastan yarns.
In the waist band area 10 elastic yarns 18 are used in large numbers in order to form in a manner known per se a very elastic waist-band.
It is understood that the areas 13 and 17 extend across the entire height of the waist portion 1, i.e. also in the area of the waist-band 10. After knitting, the briefs will appear with undulations shown with an exaggeration in figure 3.
Figures 3 to 5 show schematically how the threads 11 and the base web 16 appear in different situations of use. Figure 3 shows a situation in which the briefs are finished and have been submitted to a fixation process known per se. In this situation the briefs are ready for use. Figure 4 illustrates a situation in which the briefs are partially stretched. i.e. a situation in which the briefs are put on a small wearer. Figure 5 shows a situation in which the briefs are widely stretched. i.e. a situation in which the briefs are put on a large wearer.
It is seen in figure 3 how undulations 19 are formed in the base web 16 of the briefs. The undulations have crests 20 in the areas 13 where the elastic threads 11 are interknitted with the base web 16. There are vales 21 in the areas 17 where the elastic threads 11 are not interknitted with the base web 16. As the elastic threads 11 are highly elastic threads, it is possible to submit them to a very substantial elongation without the exerted elastic power being increased substantially.
In the situation shown in figure 4 the elastic threads 11 are elongated, and the undulating base web 16 is partially straightened. Thus, the elasticity of the base web itself does not give much contribution to the elastic force when the briefs are used on a small wearer. This elastic force is primarily provided by stretching of the elastic threads 11.
Figure 5 shows a situation in which the base web is stretched and extends substantially parallel with the elastic threads 11. In this situation stretching occurs both in the elastic threads 11 and in the base web 16. As the base web 16 is formed with an open net-like structure, this base web 16 will have a certain elastic force. However, it is well known to a person skilled in the art that the elasticity occurring in the base web may very easily be regulated by the use of different mesh types.
It will be possible to vary the briefs of the invention. Thus, it will be possible to place the elastic threads 11 so that they extend obliquely from the crutch area in an upward and outward direction in a meandering pattern. In this manner the elastic threads may have a position corresponding to the lateral edges of a diaper. This will make the briefs particularly useful as diaper fixation briefs. Because not only a pressure effect along the lateral edges of a diaper is obtained but also elasticity in the circumferential direction of the briefs so that they fit firmly around the waist of the wearer. However, the briefs will also be useful as diaper fixation briefs with elastic threads 11 extending in the circumferential direction in the manner illustrated in figure 1.
It will also be possible to manufacture the briefs by circular knitting. In this embodiment no lateral seams will appear. The most important feature, viz. the partial mesh formation by means of the elastic threads 11, will also be found in such an embodiment.