SLIDING SHEET

Abstract

 The patent application relates to a sliding sheet (11) comprising at least one first set up of threads (21), wherein the sliding sheet having an upper side (12) and an underside (13). The upper side (12) comprising a high friction region (15, 16) which has a first friction coefficient to human skin, and a low friction region (17) which has a second friction coefficient to human skin, wherein the second friction coefficient is lower than the first friction coefficient. Further, the high friction region (15, 16) having a first thread bond giving the first friction coefficient and the low friction region (17) having a second thread bond giving the second friction coefficient. Further, the individual threads in the first set of threads (21) extending over both the high friction region (15, 16) and the low friction region (17). This provides a sliding sheet that keeps together without abrasive joints at the same time as achieving the different friction regions through different types of thread bonds.

Description

Technical field

[0001] Present invention relates to a sliding sheet having an upper side and an underside, wherein the upper side comprises a high friction region with a first friction coefficient to human skin, and a low friction region with a second friction coefficient to human skin, wherein the second friction coefficient is lower than the first friction coefficient.

Background art

[0002] Sliding sheets are currently used primarily within health care, to facilitate a user to turn around in a bed through its own efforts. With user, is here meant a bedridden person, which for example because of illness, age and/or injury does not have the power to turn around in a bed that is bedded with a normal sheet. In order to facilitate for such a user to turn around on its own power, the sliding sheet has been developed. These have a low friction region where the fabric is of such type that it has significantly lower friction to human skin than a normal bed sheet has. As the fabric gives less friction than a normal sheet, it means that less power is needed by the user in order for him to turn around by his own power.

[0003] Fig. 1 shows a bed 1 in which a sliding sheet 2 according to prior art is bedded. Fig. 1 also shows a user 9 lying on top of the sliding sheet 2 in the bed 1. The upper side of the sliding sheet 2 has a low friction part 7 arranged between two high friction parts 5, 6. The high friction parts 5, 6 are of a fabric of such a type that it has higher friction to human skin than the fabric of the low friction part 7 has. The purpose of the high friction parts 5, 6 and their position at the edges of the sliding sheet is to prevent the user from slipping out of bed. The sliding sheet is not usually bedded directly on the bed 1, but the sliding sheet is normally laid on top of an ordinary bottom sheet 3. The sliding sheet can either cover the entire length of the bed or cover only a part of the length of the bed, such as the length of the bed normally covered by a torso of a user when the user is in bed, or the length of the bed that is usually covered by the length of the entire user. The sliding sheet 2 consists of a piece of fabric for the low friction part and a respective piece of fabric for the two high friction parts. These three pieces of fabric have then been joined together with joints 4. Either, the pieces of fabric are sewn together. In that case the joints 4 are seams. Alternatively, the pieces of fabric have been glued together, wherein the joints are glued joints. A disadvantage of such a joining is that the joint itself gives a level difference on the sliding sheet which can cause chafing and pressure injuries to the user.

Summary of the invention

[0004] An object of the present invention is to create a sliding sheet which has no joints or other level differences which may cause chafing of the user.

[0005] This object is achieved by a sliding sheet according to claim 1, that is, a sliding sheet comprising of at least one first set of threads, wherein the sliding sheet having an upper side and an underside. The upper side of the sliding sheet comprising a high friction region with a first friction coefficient to human skin, and a low friction region with a second friction coefficient to human skin. The second friction coefficient is lower than the first friction coefficient. The high friction region has a first thread bond giving the first friction number and the low friction region has a second thread bond giving the second friction number. Furthermore, the individual threads of the first set of threads extend over both the high friction region and the low friction region.

[0006] As the sheet has a first set of threads where the individual threads extend over both the high friction region and the low friction region, the sheet will hold together without the need of any kind of joint or seam between the high and low friction regions. The desirable difference in friction between high friction region and low friction region is achieved by having a first type of thread bond with high friction number to skin in the high friction region, and another type of thread bond that has low friction number to skin in the low friction region. In this way, a sliding sheet is formed with a clear difference in friction between high and low friction, which is at the same time free of joining elevations. The sliding sheet is made of fabric. The sliding sheet can be woven or made of warp fabric, for example. An additional advantage is that the fabrication of the sliding sheet can be done in one and the same manufacturing process. For the prior art sliding sheet, on the other hand, high friction parts and low friction parts will be manufactured separately, and then be put together in a joining process of any kind.

[0007] According to an embodiment, the first thread bond gives the first friction number in a first direction and the second thread bond gives the second friction number also in the first direction. According to another embodiment, the sliding sheet has two high friction regions, wherein the low friction region is located between the two high friction regions. The low friction region may be located between the two high friction regions if seen in the first direction.

[0008] The first direction is suitably the direction of the sheet which is approximately perpendicular to the direction of the sheet of which a human is intended to lie. By placing in the first direction, the low friction region between two high friction regions, it is facilitated that a person lying on the bed sheet can change position, thanks to the low friction region in the middle. At the same time, the two high friction regions at the edges prevent man from falling out of bed.

[0009] According to another embodiment, the low friction region is completely surrounded by high friction region. Then, the sliding sheet can always have a length of a standard sheet, or at least the sliding sheet can be made such as covering an entire bed, regardless of the size of the low friction region. The fact that the low friction region is completely surrounded by a high friction region means, in the case that the low friction region is square, that on all four sides of the low friction region there will be a high friction region. For example, if you want a low friction region only where a person's torso usually is located, you make a sliding sheet where the low friction region only is located there. If you want a low friction region over the entire length of the bed, you choose to make the sheet in that way. In total, such an embodiment means that you can skip the bottom sheet under the sliding sheet, since the sliding sheet, regardless of the size of its low friction region, can cover a whole bed.

[0010] According to an embodiment, the second thread bond has fewer thread passages from the upper side to underside, or from underside to upper side, per surface area than the first thread bond. It is true that depending on how often the threads in the at least the first set of threads change place between upper and underside, different friction coefficients are achieved on the upper side. Lower friction is obtained when the threads do not go up and down so much through the fabric but may be lying unaffected. This means that a thread bond where the threads more seldom changes place between upper and underside has a lower friction coefficient than a thread bond where the threads more often changes place. Different friction coefficients can also be obtained by using threads with different friction coefficients, in the weave example, for example, one type of thread for warp and another type of thread for weft can be used. In this way, you can, for example, increase the friction difference between the high and low friction region. However, even if you have the same type of thread in all threads, you can get different friction coefficients depending on how the threads are tied together, that is, what thread bond they have. The surface referred to in the "surface area" is, of course, the surface of the sliding sheet, for example on the upper side.

[0011] According to a first embodiment, the sliding sheet is a woven sliding sheet consisting of the first set of threads extending substantially in the first direction, and a second set of threads extending substantially in a second direction, perpendicular to the first direction, wherein the first thread bond and the second thread bond are accomplished by bonding the first set of threads with the second set of threads.

[0012] According to a variant of this first embodiment, the first set of threads is at a relatively greater extent positioned on top of the second set of threads, when included in the second thread bond, than when they are included in the first thread bond.

[0013] By producing the sliding sheet such that the first set of threads, included in both the low friction and the high friction region, lies on top of the second set of threads to a greater extent in the low friction region than in the high friction region, the lower friction desired in the low friction region, is accomplished. Lower friction is obtained when the threads do not go up and down so much through the fabric but may be lying unaffected. In particular, low friction in the first direction is obtained in the case that the first set of threads runs in the first direction, as it becomes slippery in the direction of the threads as long as they may be lying unaffected, i.e. without passage to the underside. The fact that the first set of threads is located on top of the threads of the second set means that they are located on the upper side of the sheet.

[0014] According to a variant of the first embodiment, the first thread bond and the second thread bond have the same k-value. The k-value is a measure of the thread binding capacity, that is, its ability to contain threads. The k-value of the bond is calculated as k = R/g where R is the report number and g is the number of passages for a warp thread in a report. A passage means when a thread changes side from upper side to underside, i.e. right side, to underside, i.e. wrong side of the sheet. A report refers to the size of a unique weave pattern, i.e. how big the pattern is before it repeats. The report number refers to how many weft threads passed in the warp direction in a report, i.e. before the weave pattern is repeated. By making the sliding sheet so that the first thread bond and the second thread bond have the same k-value, problems with the fabric shrinking or expanding differently in the low friction region versus the high friction region is avoided, which is the risk when the high friction region and the low friction region having different k-values. If the low friction region and high friction region shrink differently, for example, during laundry, wrinkles can occur which can cause chafing or pressure injuries to the user.

[0015] According to another variant of the first embodiment, the first thread bond and the second thread bond have the same report number and the same number of passages in a report for the first set of threads. Additionally, by having the same report number and number of passages, a stable fabric is in an easy way achieved, with a low risk of occurring folds as thread tension and thread thickness can be the same for both warp threads and weft threads. On the other hand, if the report number and number of passages are different between the high friction region and the low friction region, although the k-value is the same, the fabric still can be made stable by just setting one or both of the thread tension and the thread thickness differently for the low friction region and the high friction region. This is not necessary if you also choose thread bindings that have the same report number and number of passages.

[0016] According to another variant of the first embodiment, the first thread bond is a Panama 4*4-bond and the second thread bond is a Satin 7/1-bond. This has been shown providing good stability in the fabric at the same time as providing a desired clear difference between the high friction and low friction region. Satin 7/1 is a satin type that provides long float stitches at the same time as providing a stable fabric. Float stitches are referred to as the distance that the first set of threads extends on top of the highest number of threads in the second set of threads, before the first set of threads goes down below the second set of threads again. Because it gives long float stitches, it gives good glide, thus low friction.

[0017] According to another variant of the first embodiment, the threads of the first set of threads have a third, relatively low friction coefficient, while at least the threads of the second set of threads extending over the high friction region have a friction coefficient greater than the third friction coefficient. By not only having different thread bonding in the high friction region relative to the low friction region, but also having different friction in the first set of threads relative to the second set of threads, even greater difference in friction between the low friction region and the high friction region is obtained.

[0018] According to a second embodiment, the sliding sheet is a warp-fabric-produced sliding sheet, made of the first set of threads forming a first type of stitch giving the first thread bond in the high friction region, and forming a second type of stitch which provides the second thread bond in the low friction region. Thus, in a warp-fabric-produced sliding sheet there is only the first set of threads and no second set of threads as in the woven sheet.

[0019] According to a variant of this second embodiment, when a single thread in the first set of threads is in the low friction region, it is lying as longest on top of more second threads in one sweep, than the same single thread makes as longest in the high friction region. By choosing first and second thread bonds so that individual threads lie in this way, there is a clear difference between low friction region and high friction region in the warp-fabric-produced sliding sheet.

[0020] According to another variant of this second embodiment, the first thread bond, i.e., the thread bond in the high friction region, is a pre-set Fringe-bond while the other thread bond, i.e. the thread bond in the low friction region, is an Atlas-bond. This choice gives a distinct difference in friction between high friction region and low friction region while creating a relatively stable fabric.

[0021] According to another embodiment, the sliding sheet is made in one and the same manufacturing process in a weaving or warp knitting machine. This becomes possible due to the fact that the first set of threads extends across both regions. Therefore, it becomes easiest and best to have the same manufacturing process for the entire sliding sheet, which, in turn, gives faster production than having several separate steps.

Brief description of drawings

[0022] The invention will now be described, by way of example, with reference to the accompanying drawings in which:

Fig. 1 is a schematic top view of a bed in which a prior art sliding sheet is bedded.

Fig. 2 shows a perspective view of a sliding sheet according to an embodiment of the invention.

Fig. 3a shows a perspective view from the side of a sliding sheet according to the embodiment in fig. 2.

Fig. 3b shows a schematic top view of a bed in which a sliding sheet according to an embodiment of the invention is bedded.

Fig. 4a shows a schematic top view of a report of a high friction region according to an embodiment.

Fig. 4b shows a schematic top view of a report of a low friction region according to an embodiment.

Fig. 5 shows a schematic top view of a sliding sheet according to another embodiment of the invention.

Description of embodiments

[0023] Briefly, a sliding sheet which is woven or crocheted in one piece is described, and which lacks joints between high friction region and low friction region. There are therefore no seams or other elevations that can cause chafe or pressure damage to the user. This sliding sheet is achieved by letting the same first set of threads extend over both the high friction region and the low friction region. The wanted different friction numbers between high friction region and low friction region is achieved by having a first thread bond in the high friction region, which gives high friction to the region, and another type of thread bond in the low friction region, which gives the region lower friction than the high friction region. By utilizing the same first set of threads in both the low friction region and the high friction region, the regions will be bonded so that the sliding sheet holds together in one piece, and at the same time achieving the different friction regions through different types of thread bonds in the different friction regions.

[0024] Fig. 1 shows a bed 1 provided with a sliding sheet 2 according to prior art. This sliding sheet has joints 4 between the high friction regions 5, 6 and the low friction region 7.

[0025] Fig. 2, on the other side, shows a close-up of an upper side 12 of a sliding sheet 11, which is woven according to an embodiment of the invention. In this example, two different thread bonds are combined in the same piece of cloth. The sliding sheet 11 has a low friction region 17 located between two high friction regions 15 and 16. Typically, a low friction region is placed between two high friction regions on a sliding sheet, but one can also think of other locations, such that there is only one high friction region or that there are several low friction regions and several high friction regions on a sliding sheet. The sliding sheet according to the embodiment shown in Fig. 2 further has a first set of threads 21, where the individual threads extend over both the high friction regions 15, 16 and the low friction region 17. The first set of threads extends in a first direction X which also may be called the weft direction. Therefore, in the following, the first set of threads 21 is called weft threads. The first set of threads is woven into a second set of threads 22 extending in a Y-direction, which is substantially perpendicular to the X-direction. The Y-direction can also be called the warp direction. Therefore, in the following, the second set of threads 22 is called warp threads. However, one can also imagine a reverse terminology. The individual warp threads 22 in the sliding sheet of Fig. 2 extend either over one of the high friction regions 15, 16 or over the low friction region 17. By that the weft threads 21 are woven into the warp threads 22 means that the weft threads and warp threads are bonded to each other. In order to provide the high friction regions 15, 16, the weft threads 21 are bonded to the warp threads 22 with a first thread bond that provides relatively high friction to skin. In order to provide the low friction region 17, the weft threads 21 are bonded to the warp threads 22 with a second thread bond that provides relatively low friction to skin, at least lower friction than in the high friction region.

[0026] According to a non-shown example, the low friction region is completely surrounded by the high friction region. In this case, there is a high friction region on all sides of the low friction region. The low friction region can be positioned anywhere on the bed sheet and the bed sheet can be made as big as one wishes. In this way, the sliding sheet can have a length so that it covers an entire bed, regardless of the size of the low friction region, which means that a bed will not have to be bedded with a bottom sheet under the sliding sheet, even though the low friction region of the sliding sheet is relatively small in the Y-direction.

[0027] Preferably, two different thread bonds with clearly different friction but also the same k-value are used. Using thread bonds with the same k-value can reduce the risk that the different regions of the sliding sheet shrink differently, which can create folds. Fig. 2 shows a preferred embodiment where a 4*4 Panama-bond is used for the thread bond in the high friction region. High friction is achieved by passing four warp threads and four weft threads alternately over and under each other. Here the threads follow the same binding pattern in pieces of four and four, both in weft and warp. This design creates small elevations in the fabric that gives a braking effect to a person lying on the fabric. Another example of a preferred design is a 2*2 Panama-bond, that is where two warp threads and two weft threads alternately cross over and underneath each other. Here the threads follow the same binding pattern in pieces of two and two, both in weft and warp. For the low friction region 17, in the example in Fig. 2, a Satin-bond 7/1 has been used, where a weft thread 21 runs over seven warp threads 22 to then run under a warp thread 22 before the weft thread 21 passes up to the upper side again and then again run over seven warp threads. In order to distinguish the threads in the figure, the weft threads are white while the warp threads are black. Through this thread bond, a sliding surface is created, especially in the weft direction because the weft threads are mostly on top of the warp threads. Another example of a suitable thread bond in the sliding region is Satin 10/1. This fabric has even less friction than Satin 7/1 but on the other hand it is more fragile than Satin 7/1.

[0028] I fig. 3a, a three-dimensional view is shown substantially from the side of the sliding sheet 11 according to the embodiment of Fig. 2. In Fig. 3a, the difference in the thread orientation between the upper side 12 and the underside 13 is clearly shown. In Fig. 3b, a schematic view is instead shown from above of the sliding sheet 11 when it is placed on a bed 1 with a person 9 placed on top. In order to illustrate in Fig. 3b that the boundaries 24 between the respective high friction region 15, 16 and the low friction region 17 are lacking and thus appear more indefinite than in the prior art of Fig. 1, these boundaries 24 are marked with thinner lines in Fig. 3b than the marking of the lines of the joints 4 in Fig. 1. The long arrows that extends between Fig. 3a and 3b show where the corresponding region in the schematic view from above is in the three-dimensional view of the sliding sheet. Therefore, the corresponding region has the same reference number.

[0029] Fig. 4a shows a report of a Panama 4*4-bond, thus a suitable bond for the high friction region. Fig. 4b shows a report for a Satin 7/1-bond, thus a suitable bond for the low friction region. The black squares show at which crossings the warp threads are at the top and the white squares show at which crossings the weft threads are at the top. When choosing which thread bonds to have in the low friction region and in the high friction region, one should also consider the k-value of the two thread bonds (also known as the weaving methods). The k-value is a measure of the thread bond capacity, that is, its ability to contain threads. The k-value is calculated by the formula: k-value = R/g, where R is the report number of the bond and g is the number of passage points for a warp thread in a report. Thus, in the case of Panama 4*4 and Satin 7/1, both bonds have a report of 8, each warp thread makes two passages per report, and the k-value accordingly becomes 4 for both bonds. Furthermore, the Satin-bond 7/1 shown in Fig. 4b has an increase of 5, which means that between two black squares that are adjacent to the weft direction, there are five squares in the warp direction to get an irregular pattern.

[0030] According to one embodiment, a glossy thread, i.e. a thread with a low friction value is used as a weft thread (X-direction), and a matte thread, i.e. a thread with a relatively higher friction value than the glossy thread, is used as the warp thread (Y-direction). Because the weft thread is mostly on the upper side of the sliding sheet in the low friction region, while in the high friction region, weft and warp threads will proportionately be on the upper side as often, at least in the example shown in Fig. 3a, the low friction region will have an even lower friction relative to high friction region, than when threads with the same friction number are used in warp and weft direction. An additional greater difference between the high friction and low friction region can be obtained if the warp threads in the low friction region also have a low friction value, while the warp threads in the high friction region have a high friction value.

[0031] Fig. 5 shows another embodiment of a sliding sheet 11 according to the invention. In this case the sliding sheet is of warp fabric. That is, the sliding sheet is made on a hosiery machine. The technique of warp fabric is based on a single set of separate threads that fit on one or more bars, also called yarn guide bar, similar to those of a weaving machine. Normally, two to three yarn guide bars are used to achieve a thickening of the warp fabric, but it is also possible to use only a yarn guide bar or more than three yarn guide bars. Unlike the weaving, no weft in the warp fabric is required, i.e. no other set of threads, but instead, stitches running in x- and y-direction are formed by crocheting/binding these separate threads to each other. The advantage of the warp fabric is that it becomes slightly extensible, which improves the sliding sheet and further prevents creasing. Also in this embodiment different bonding types are used in the low friction regions and in the high friction regions, respectively, to provide the different frictions.

[0032] In the example of warp fabric shown in Fig. 5 there are two high friction regions 15, 16 and one low friction region 17. The warp fabric consists of a first set of threads bonded in the form of a first yarn guide bar to form a first type of stitches 32, which provides the first thread bond in the high friction regions 15, 16. Furthermore, the first set of thread are bonded together in the low friction region 17 in the form of a second yarn guide bar so that a second type of stiches 33 are formed, which provides the second thread bond. According to the example shown in Fig. 5, the first yarn guide bar which provides the first thread bond in the high friction regions is a pre-set Fringe-bond which may consist of textured polyester 90/2. An alternative to this pre-set Fringe-bond may be to have a straight Fringe-bond. Further, according to the example, the second yarn guide bar which gives the second thread bond in the low friction region is a 4-row Atlas-bond, which may consist of modal 80/2 alternatively cotton. An alternative to this 4-row Atlas-bond may be to have a 2-row Atlas-bond. In addition, the warp fabric may have a standing lining 34, which gives the fabric stability. The standing lining is advantageously inserted so that it does not appear on the upper side of the fabric. The standing lining is shown on the side of the high friction region and the low friction region in the crochet description in Fig. 5, but the lining is normally over the entire fabric and is located on the underside of the fabric. Furthermore, the warp fabric can be supplemented with an non-shown weft insert, i.e. another set of threads where one may use an absorbent fiber to create stability and above all create comfort for the user. This weft insert is advantageously inserted to not be visible from the upper side of the bed sheet.

[0033] The appropriate thickness of the threads used in both the fabric and the warp may be 50-300 dtex. The sliding sheet is advantageously made of textile fabric. In order for a user to easily see the difference between the high and low friction regions for these new sliding sheets without joints, the high friction region and low friction region can be marked differently, for example, different colors may be given, or one region or both can be marked with a thread rim in a color that differs from the fabric.

[0034] Although the description above shows various specific embodiments, they should not be construed as limiting the scope of the invention, but are essentially there to illustrate various possible ways of practicing the invention falling within its scope. References to an element in singular are not meant to mean "one and only one" unless it is specifically expressed, but rather "one or more". It is an intention that elements mentioned in the described embodiments cover all structural and functional equivalents to the elements known to those skilled in the art.

Claims

1. Sliding sheet (11) comprising of at least one first set of threads (21, 31), wherein the sliding sheet having an upper side (12) and an underside (13), of which the upper side (12) comprising:

a high friction region (15, 16) which has a first friction coefficient to human skin, and

a low friction region (17) which has a second friction coefficient to human skin, wherein the second friction coefficient is lower than the first friction coefficient, characterized in that the high friction region (15, 16) having a first thread bond giving the first friction coefficient and the low friction region (17) having a second thread bond giving the second friction coefficient, and by that the individual threads in the first set of threads (21, 31), extending over both the high friction region (15, 16) and the low friction region (17).

2. Sliding sheet (11) according to claim 1, wherein the first thread bond giving the first friction coefficient in a first direction (X) and the second thread bond giving the second friction coefficient in a first direction (X).

3. Sliding sheet (11) according to claim 1 or 2, wherein the sliding sheet having two high friction regions (15, 16), and the low friction region (17) is positioned between the two high friction regions.

4. Sliding sheet (11) according to claim 1 or 2, wherein the low friction region (17) is completely surrounded by the high friction region (15, 16).

5. Sliding sheet (11) according to any of the previous claims, wherein the second thread bond has fewer thread passages from the upper side (12) to the underside (13), or from the underside (13) to the upper side (12), per surface area than the first thread bond.

6. Sliding sheet (11) according to any of the previous claims, wherein the sliding sheet is a woven sliding sheet comprising the first set of threads (21) which substantially extending in the first direction (X) and a second set of threads (22) substantially extending in a second direction (Y) perpendicular to the first direction, and wherein the first set of threads and the second set of threads is accomplished by bonding the first set of threads (21) to the second set of threads (22).

7. Sliding sheet (11) according to claim 6, wherein the first set of threads (21) is at a relatively greater extent positioned on top of the second set of threads (22) when included in the second thread bond, than when they are included in the first thread bond.

8. Sliding sheet (11) according to claim 7, wherein the first thread bond and the second thread bond has the same k-value.

9. Sliding sheet (11) according to claim 8, wherein the first thread bond and the second thread bond also has the same report number and the same number of passages in one report for the first set of threads (21).

10. Sliding sheet (11) according to claim 9, wherein the first thread bond is a Panama 4*4-bond and the second thread bond is a Satin 7/1-bond.

11. Sliding sheet (11) according to any of claims 6-10, wherein the threads in the first set of threads (21) have a third, relatively low friction coefficient, while at least the threads of the second set of threads (22) extending over the high friction region (15, 16) have a friction coefficient greater than the third friction coefficient.

12. Sliding sheet (11) according to any of claims 1-5, wherein the sliding sheet is a warp-fabric-produced sliding sheet, made of the first set of threads (31) forming a first type of stitches (32) providing the first thread bond in the high friction region (15, 16), and a second type of stitches (33) providing the second thread bond in the low friction region (17).

13. Sliding sheet (11) according to claim 12, wherein when a single thread in the first set of threads is in the low friction region (17), it is lying as longest on top of more second threads in one sweep, than the same single thread makes as longest in the high friction region (15, 16).

14. Sliding sheet (11) according to claim 12 or 13, wherein the second thread bond is a Fringe-bond while the second thread bond is an Atlas-bond.

15. Sliding sheet (11) according to any of the previous claims, characterized in that the sliding sheet is manufactured in one and the same manufacturing process in a weaving or warp knitting machine.

Drawing