Compression knit fabric component

Abstract

A compression knit fabric, in particular a flat-knit fabric, composed of at least one knitted yarn and an incorporated elastic weft yarn, with a first knit fabric section having a compressive first base weave, to which is attached a second knit fabric section having a second weave different from the base weave which imparts to the second knit fabric section greater elasticity in the longitudinal and/or transverse direction of the knit fabric section than in the first knit fabric section, to which is attached a third knit fabric section having a third weave different from the first base weave and second base weave which imparts to the third knit fabric section greater elasticity in the longitudinal and/or transverse direction of the knit fabric section than in the second knit fabric section.

Claims

1. A compression knit fabric, in particular a flat-knit fabric, composed of at least one knitted yarn and an incorporated elastic weft yarn, with a first knit fabric section having a compressive first base mesh structure, to which, within separate stitch rows of the first knit fabric section between two areas of the first knit fabric section, is knitted a second knit fabric section having a second mesh structure different from the base mesh structure which imparts to the second knit fabric section greater elasticity in a longitudinal or a transverse direction of the knit fabric section than in the first knit fabric section, to which is knitted a third knit fabric section having a third mesh structure different from the first base mesh structure and second base mesh structure which imparts to the third knit fabric section greater elasticity in the longitudinal or the transverse direction of the knit fabric section than in the second knit fabric section.

2. The knit fabric component according to claim 1, wherein all of the knit fabric sections are knitted with a right-right (RR) knitted yarn, a right-left (RL) knitted yarn that is more elastic, and the weft yarn.

3. The knit fabric component according to claim 2, wherein the first base weave is a half-tube weave of the RR knitted yarn, which is knitted with an RR weave, the RL knitted yarn, which is knitted with an RL weave, and the incorporated weft yarn.

4. The knit fabric component according to claim 3, wherein in the second weave, the RR knitted yarn is a tuck stitch and the RL knitted yarn is knitted with an RR weave, or the RL knitted yarn is a tuck stitch and the RR knitted yarn is knitted with an RL weave.

5. The knit fabric component according to claim 3, wherein in the third weave, the RR knitted yarn is knitted with an RR weave and the RL knitted yarn is knitted with an RR weave, with at least a part of the stitches knitted with the RR knitted yarn being transferred.

6. The knit fabric component according to claim 5, wherein every second, third, or fourth stitch knitted with the RR knitted yarn is transferred.

7. The knit fabric component according to claim 5, wherein the transferred stitches of a stitch row knitted with the RR knitted yarn are staggered with respect to the transferred stitches of the stitch row previously knitted with the RR knitted yarn.

8. The knit fabric component according to claim 1, wherein all of the knit fabric sections are knitted with an RR knitted yarn and the weft yarn.

9. The knit fabric component according to claim 8, wherein the first base weave comprises an RR weave knitted with the RR knitted yarn and the incorporated weft yarn.

10. The knit fabric component according to claim 9, wherein in the second weave, the RR knitted yarn is tuck-knitted.

11. The knit fabric component according to claim 9, wherein in the third weave, the RR knitted yarn is knitted with an RR weave, with at least some of the stitches knitted with the RR knitted yarn being transferred.

12. The knit fabric component according to claim 11, wherein every second, third, or fourth stitch knitted with the RR knitted yarn is transferred.

13. The knit fabric component according to claim 11, wherein the transferred stitches of a stitch row knitted with the RR knitted yarn are staggered with respect to the transferred stitches of the stitch row previously knitted with the RR knitted yarn.

14. The knit fabric component according to claim 1, wherein the first knit fabric section partially or completely surrounds the second knit fabric section or the second knit fabric section partially or completely surrounds the third knit fabric section.

15. The knit fabric component according to claim 1, comprising being a stocking, a sock, a leg stocking, an arm stocking, a body stocking, or a bandage.

16. The knit fabric component according to claim 15 configured as a stocking or sock, wherein a fourth knit fabric section is provided, to which is connected at least the first knit fabric section.

17. The knit fabric component according to claim 16, wherein all three knit fabric sections are attached to the fourth knit fabric section.

18. A method for producing a knit fabric component using a flat knitting machine having a front and a rear needle bed, in which a first knit fabric section having a compressive first base mesh structure is knitted, to which, within separate stitch rows of the first knit fabric section between two areas of the first knit fabric section, is knitted a second knit fabric section having a second mesh structure different from the base mesh structure which imparts to the second knit fabric section greater elasticity in a longitudinal or a transverse direction of the knit fabric section than in the first knit fabric section, to which is knitted a third knit fabric section having a third mesh structure different from the first base mesh structure and second base mesh structure which imparts to the third knit fabric section greater elasticity in the longitudinal or the transverse direction of the knit fabric section than in the second knit fabric section.

19. The method according to claim 18, wherein all of the knit fabric sections are knitted with a right-right (RR) knitted yarn, a right-left (RL) knitted yarn, and the weft yarn.

20. The method according to claim 19, wherein a first base weave is composed of a half-tube weave from an RR knitted yarn which is knitted with an RR weave, an RL knitted yarn which is knitted in an RL weave, and the incorporated weft yarn.

21. The method according to claim 20, wherein in the second weave, the RR knitted yarn is tuck-knitted and the RL knitted yarn is knitted with an RR weave, or the RL knitted yarn is tuck-knitted and the RR knitted yarn is knitted with an RL weave.

22. The method according to claim 20, wherein in the third weave, the RR knitted yarn is knitted with an RR weave, and the RL knitted yarn is knitted with an RR weave, with at least some of the stitches knitted with the RR knitted yarn being transferred from one needle bed to the other.

23. The method according to claim 22, wherein every second, third, or fourth stitch knitted with the RR knitted yarn is transferred.

24. The method according to claim 23, wherein the transferred stitches of a stitch row knitted with the RR knitted yarn are staggered with respect to the transferred stitches of the stitch row previously knitted with the RR knitted yarn.

25. The method according to claim 18, wherein all of the knit fabric sections are knitted with an RR knitted yarn and the weft yarn.

26. The method according to claim 25, wherein the first base weave is knitted using RR weave knitted from the RR knitted yarn and the incorporated weft yarn.

27. The method according to claim 26, wherein in the second weave, the RR knitted yarn is knitted by tuck stitching.

28. The method according to claim 26, wherein in the third weave, the RR knitted yarn is knitted with an RR weave, with at least a part of the stitches knitted with the RR knitted yarn being transferred.

29. The method according to claim 28, wherein every second, third, or fourth stitch knitted with the RR knitted yarn is transferred.

30. The method according to claim 28, wherein the transferred stitches of a stitch row knitted with the RR knitted yarn are staggered with respect to the transferred stitches of the stitch row previously knitted with the RR knitted yarn.

31. The method according to claim 18, wherein the first knit fabric section is knitted so as to partially or completely surround the second knit fabric section or the second knit fabric section is knitted so as to partially or completely surround the third knit fabric section.

32. The method according to claim 18, wherein the knit fabric component is a stocking, a sock, a leg stocking, an arm stocking, a body stocking, or a bandage.

33. The method according to claim 32, wherein a fourth knit fabric section is attached at least to the first knit fabric section.

34. The method according to claim 33, wherein all three knit fabric sections are attached to the fourth knit fabric section, wherein the first knit fabric section only partially surrounds the second knit fabric section and the second knit fabric section only partially surrounds the third knit fabric section.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) In the drawing:

(2) FIG. 1 is a schematic diagram of a compression knit fabric component according to the invention in the form of a stocking,

(3) FIG. 2 is an enlarged partial sectional view of the first, second, and third knit fabric section,

(4) FIG. 3 is a diagram of the course of the yarn over several stitch rows for producing the first, second, and third knit fabric section using two knitted yarns and a weft yarn,

(5) FIG. 4 is a schematic diagram of the mesh structure of the first, second, and third knit fabric section, produced according to the course of the yarn shown in FIG. 3,

(6) FIG. 5 is a sectional view of the mesh structure of the first knit fabric section of FIG. 4,

(7) FIG. 6 is a sectional view of the mesh structure of the second knit fabric section of FIG. 4,

(8) FIG. 7 is a sectional view of the mesh structure of the third knit fabric section of FIG. 4,

(9) FIG. 8 is a diagram of the course of the yarn over several stitch rows for producing the first, second, and third knit fabric section using only a knitted yarn and a weft yarn,

(10) FIG. 9 is a schematic diagram of the mesh structure of the first, second, and third knit fabric section, produced according to the course of the yarn shown in FIG. 8,

(11) FIG. 10 is a sectional view of the mesh structure of the first knit fabric section of FIG. 9,

(12) FIG. 11 is a sectional view of the mesh structure of the second knit fabric section of FIG. 9, and

(13) FIG. 12 is a sectional view of the mesh structure of the third knit fabric section of FIG. 9.

DETAILED DESCRIPTION OF THE INVENTION

(14) FIG. 1 shows a compression knit fabric component according to the invention as a flat-knit fabric component 1 in the form of a stocking. The flat-knit fabric component 1 consists in the example shown of four knit fabric sections, and specifically has a first knit fabric section 2 knitted with a compressive first base weave. This first knit fabric section forms the compressive base knit fabric. A second knit fabric section 3, which is knitted with a second weave differing from the first base weave, is knitted to the first knit fabric section 2. This second weave is selected so as to provide the second knit fabric section with greater elasticity in the longitudinal and/or transverse direction, preferably in both directions, than that of the first knit fabric section 2. Finally, a third knit fabric section 4 with a third weave differing from the first two weaves is knitted to the second knit fabric section 3 and is selected so as to again provide the third knit fabric section 4 with greater elasticity in the longitudinal and/or transverse direction, preferably in both directions, than that of the second knit fabric section 3. There is therefore an increasing elasticity gradient from the first knit fabric section 2 over the second knit fabric section 3 to the third knit fabric section 4, so that an area of greater elasticity and therefore lower compressive pressure compared to the first knit fabric section 2 is formed over the knit fabric sections 3 and 4.

(15) All of the knit fabric sections 2, 3, and 4 may be knitted with only one knitted yarn and one elastic weft yarn incorporated into the knitted stitches. Alternatively, two knitted yarns into whose stitches the elastic weft yarn is incorporated may also be used. Of the two knitted yarns used, one knitted yarn may be largely inelastic and the other elastic, both knitted yarns may be inelastic, or both knitted yarns may be elastic. Preferably, one largely inelastic and one elastic knitted yarn are used. The yarns used may be optionally entwined.

(16) In the embodiment of a stocking shown, a fourth knit fabric section 5 is also provided which forms the toe section. This section is knitted only with the knitted yarn(s), and not with the weft yarn. In the example shown, this fourth knit fabric section 5 is connected to all three knit fabric sections 2, 3, and 4. This means that in this embodiment, the first knit fabric section 2 only partially surrounds the second knit fabric section 3, and the second knit fabric section 3 only partially surrounds the third knit fabric section 4. In this case, the relief zone is therefore formed over the second and third knit fabric sections 3, 4 in the area of the hallux valgus, in order not to excessively compress said hallux valgus area. However, if such a relief zone is provided, for example, in the area of the ankle joint, indicated by the dotted lines in FIG. 1, the second and third knit fabric sections 3, 4 will be knitted in the shape of a circle, an ellipse, etc., but in this case the respective knit fabric sections completely enclose one another. The second knit fabric section 3, which is only intended to act as a soft elastic transition, may be relatively narrow, i.e. only a few stitches wide, compared to the third knit fabric section 4, which is the most elastic section, provides the essential pressure relief, and is therefore much larger. This combination is only an example, and other variants or geometries are also possible.

(17) FIG. 2 shows an enlarged schematic diagram of a sectional view III of FIG. 1 showing the first knit fabric section 2, the second knit fabric section 3, and the third knit fabric section 4, each in a partial view. The different weaves and stitches are indicated by the different symbols in the individual fields of the respective knit fabric sections 2, 3, and 4. In the embodiment shown, the first knit fabric section 2 is knitted with a compressive base weave, for example a half-tube weave or a pure right/right weave. This is indicated by the longitudinal symbols. In contrast, the second knit fabric section 3 is knitted with a softer, more elastic tuck weave, and it forms a kind of transitional zone between the first knit fabric section 2 and the third knit fabric section 4. The tuck weave is indicated by the transverse symbols. The third knit fabric section 4 is knitted for example with an elastic right/right weave having partially transferred stitches, which provides even greater elasticity of the knit fabric. In the following, two embodiments are described in greater detail which show how the individual knit fabric sections could be produced using differing yarns. The right/right weave is indicated by the circular symbols, and the transferred stitches by the cross symbols.

(18) FIG. 3 shows a first example of a course of the yarn for producing the three knit fabric sections 2, 3, and 4 or the three different weaves respectively. In this embodiment, two knitted yarns and a weft yarn are used to form the knit fabric. As knitted yarn, an RR knitted yarn (right/right knitted yarn), indicated in the following figures by RR, and an RL knitted yarn (right/left knitted yarn), indicated in the following figures by RL, are used. While the RR knitted yarn is largely inelastic, the RL knitted yarn, in contrast, is significantly more elastic. The weft yarn is elastic and is indicated in the figures by S.

(19) FIG. 3 shows as an example six stitch rows a-f, with the respective course of the yarn being shown for each stitch row. As the weft yarn S in only incorporated into the stitches, it is always shown as a simple line, while the RR and RL knitted yarns are indicated according to the yarn or stitch course.

(20) It is also indicated in the respective stitch row, for each individual needle through which the respective RR or RL course of the yarns runs, whether the knitting is carried out in the first knit fabric section 2, the second knit fabric section 3, or the third knit fabric section 4, specifically by the corresponding numbers shown below the yarns, 2, 3, or 4. Finally, the first knit fabric section 2 is knitted in stitch row a. It is a half-tube weave of the RR knitted yarn and the RL knitted yarn. For this purpose, the RR knitted yarn is knitted with an RR weave on both needle beds of the flat knitting machine, i.e. a right/right weave. The knitted yarn RL, which is knitted only on the front needle bed, in contrast, is knitted with an RL weave, i.e. a right/left weave. The weft yarn S is incorporated into the forming stitches.

(21) All three knit fabric sections or all three different weaves respectively are knitted in stitch row b. In the areas indicated by 2, the RR and the RL knitted yarn are knitted in order to form the compressive half-tube base knit fabric as described above for stitch row a.

(22) The second fabric section 3 is formed in the areas indicated by 3. For this purpose, a tuck weave is knitted in which the RR knitted yarn is knitted by tuck stitching so that tuck stitches 6 form, as can be seen in the course of the yarn. The RL knitted yarn in this area 3 is no longer knitted with an RL weave (as in area 2), but on both needle beds with an RR weave, i.e. a right/right weave. The above-described tuck weave, resulting from knitting of the RR yarn by tucking and knitting of the RL yarn with an RR weave, leads to increased elasticity in area 3, i.e. in the second knit fabric area 3, compared to the strongly compressive first knit fabric area 2, which has a half-tube base knit fabric weave.

(23) The second knit fabric area is attached to the third knit fabric section 4 as shown in stitch row b. The individual needles of this area are indicated here by 4. In this area 4, the RR yarn is again knitted with an RR weave, as can be seen from the course of the yarn. However, individual stitches, in this case every other stitch, are transferred from the front to the rear needle bed. This causes the RL yarn, which is still knitted with an RR weave, to form tuck stitches 7, specifically on the needles on which the transferred RR stitches of the RR yarn previously lay. Because of this transfer, and the fact that the RL yarn is knitted with an RR weave and is consequently knitted on the front and rear needle bed, the result is an open knit fabric that is highly elastic in the longitudinal and transverse directions which forms the core of the relief zone. The transfer, i.e. the stitch transfer, is indicated in the respective stitch rows by the arrows.

(24) Attached to the knit fabric section 4, cf. stitch row b, is the area 3, i.e. the knit fabric section 3 which forms the transition area. Here, the RR yarn is again tuck-stitched, and it forms stitches 6, while the RL yarn, again on both needle beds, is knitted with an RR weave. In the area connected thereto, indicated by 2, which forms the first knit fabric section 2, the RR yarn is again knitted with an RR weave, while the RL yarn is again knitted only on the front needle bed with an RL weave.

(25) This pattern continues in stitch rows c and d shown in FIG. 3. Only the number or position of the stitches varies within the respective knitting areas 2, 3, 4, as can be seen by comparing stitch rows c and d with stitch row b, for example. As an example, the number of transferred RR stitches also decreases in the area 4, after whichalso see FIG. 2the third knit fabric section 4 elliptically tapers and therefore becomes increasingly narrow. However, the basic knitting pattern within the respective areas remains unchanged, which means that the respective first knit fabric section 2 is always knitted as a half-tube weave, while the second knit fabric section 3 is knitted as a tuck weave and the third knit fabric section 4 is always knitted with a stitch transfer of the RR stitches of the RR yarn and an RR-knitted RL yarn. The transferred stitches of a row are preferably staggered around a needle with respect to the transferred stitches of the previous row, resulting in a staggered hole pattern in the third knit fabric area 4.

(26) In stitch row e, only the first and the second knit fabric sections 2, 3 are knitted, as indicated by the areas 2 and 3. Therefore in area 2, the RR yarn is knitted with an RR weave on both needle beds, and the RL yarn is knitted with an RL weave only on the front needle bed. In section 3, the RR yarn is knitted to form the tuck stitches 6 by tucking, while the RL yarn is knitted on both needle beds with an RR weave.

(27) In the last stitch row f, corresponding to stitch row a, the base knit fabric weave is again knitted to form the knit fabric section 2.

(28) FIGS. 4-7 show as an example a mesh structure or sectional views thereof respectively showing how said structure is formed with the course of the yarn according to FIG. 3. FIG. 4 shows the three knit fabric sections 2, 3, and 4. The RR yarn RR and the RL yarn RL which form the respective stitches are also shown. Only on the right edge according to FIG. 4 is the weft yarn S also shown, and it was omitted in the remainder of the figure and in FIGS. 5-7 for reasons of clarity.

(29) FIG. 5 shows an enlarged view of the mesh structure of the compressive first knit fabric section 2. As described above, the first base weave is a half-tube weave, and the RR knitted yarn is knitted on both needle beds with an RR weave. The RL knitted yarn is knitted only on the front needle bed with an RL weave, as shown in FIG. 5.

(30) FIG. 6 shows an enlarged sectional view of the second knit fabric section 3. As described above, the RR knitted yarn here is tuck-knitted so that it forms the tuck stitch 6 shown in FIG. 6. For its part, the RL knitted yarn is knitted on both needle beds here with an RR weave.

(31) Finally, FIG. 7 shows a sectional view of the third knit fabric section 4. In this third weave, the RR knitted yarn is again knitted with an RR weave, but every second stitch is transferred from the front to the rear needle bed. Two examples of such transferred stitches 8 are shown in FIG. 7. They can also be clearly seen in FIG. 4.

(32) The transfer of the RR stitches of the RR knitted yarn produces small holes 9 in the mesh structure, as FIGS. 4 and 9 clearly show. This makes this knit fabric section 4 more open and therefore even more elastic in the longitudinal and transverse directions. The fact that the RL yarn must form tuck stitches on the empty needles resulting from the stitch transfers also contributes toward greater elasticity.

(33) FIG. 8 shows as an example the course of the yarn in production of all knit fabric sections 2, 3, and 4 from only one knitted yarn, specifically an RR yarn and a weft yarn S. Seven stitch rows a-g are shown here. For the individual stitch rows, the needle-specific area numbers 2, 3, and 4 are indicated, specifying the needles on which the respective knit fabric sections 2, 3, or 4 are knitted.

(34) Loop row a is a stitch row of the first knit fabric section 2, i.e. of the base knit fabric area. The RR yarn is knitted with a pure RR weave on both needle beds. The weft yarn S is incorporated into the stitches formed.

(35) Stitch row b shows the course of the yarn of a row of stitches in which all three fabric sections 2, 3, and 4 are knitted. In the area indicated by 2, the RR knitted yarn is again knitted with an RR weave, because it forms the first knit fabric section 2.

(36) In the area indicated by 3, the RR knitted yarn is knitted with a tuck weave, and the corresponding tuck stitches 6 also form here. By means of these tuck stitches, greater elasticity is achieved in area 3, i.e. in the knit fabric section 3.

(37) In area 4, the RR yarn is again knitted with an RR weave. However, every other stitch, as indicated by the arrows, is transferred from the front to the rear needle bed, and reverse transfer is also possible in this case. By means of the transfer of these stitches, i.e. the stitch transfer, the third knit fabric section 4 is provided with even greater elasticity than that of the second knit fabric section 3, which is knitted with a pure tuck weave.

(38) In the next stitch row c, which for example is knitted on stitch row b, the RR yarn in the area 2 is still knitted with an RR weave. In area 3, the yarn is knitted with an RR weave. This is necessary in order to cast off the tuck stitches 6 of the previous stitch row b, as no two tuck stitches should be located on the same needle.

(39) In area 4, where the RR knitted yarn is again RR knitted, tuck stitches 10 on the side of the RR yarn form on the empty needles, on which the previously transferred RR stitches lay. The transferred stitches and the tuck stitches formed, as described above, ensure the high elasticity of this third knit fabric section 4.

(40) In stitch row d, which is knitted following stitch row c, the first knit fabric section 2 is again knitted with an RR weave. In area 3, two tuck stitches 6 are again shown, which means that this stitch row is again knitted with a tuck weave.

(41) Corresponding stitches 10 again form in area 4, after RR stitches are again transferred from the front to the rear needle bed in the stitch row c, as indicated by the transfer arrow. The transferred stitches are staggered with respect to the transferred stitches of the previously knitted stitch row so that in the knitted mesh structure, the stitches of one row are staggered with respect to those of the other.

(42) In stitch row e, next to the knit fabric section 2 with an RR weave, an RR weave is again knitted in knit fabric section 3, as the tuck stitches 6 of stitch row d must again be cast off.

(43) In area 4, only two tuck stitches 10 form after two RR stitches are transferred from the front to the back in stitch row d.

(44) In the course of the yarn according to stitch row f, only the first and second knit fabric sections 2 and 3 are knitted. This can be clearly seen from the RR weave in area 2 and the number of tuck stitches 6 in section 3.

(45) Finally, stitch row g) again shows a pure base knit fabric row, i.e. the knit fabric area 2 with a pure RR weave.

(46) A mesh structure such as that resulting from the course of the yarn according to FIG. 8 is shown in FIG. 9. The RR knitted yarn and the weft yarn S respectively are shown. From the mesh structure, the individual knit fabric sections 2, 3, and 4 can again be clearly seen, said sections being shown in somewhat highlighted form in FIGS. 10, 11 and 12.

(47) FIG. 10 shows a sectional view of the compressive first knit fabric section 2. The RR knitted yarn is knitted with a pure RR weave, and the weft yarn 5 runs through the stitches formed.

(48) FIG. 11 shows a sectional view of the second knit fabric section 3. The figure shows the tuck-knitted yarn RR with a tuck stitch 6 that can also be seen in FIG. 9.

(49) Finally, FIG. 12 shows a sectional view of the third knit fabric section 4 with a transferred RR stitch 11 which can also be clearly seen in FIG. 9. As every second RR stitch 11 is transferred, this produces in each stitch row holes 12 which are positioned at intervals from one another in a mutually staggered pattern from one stitch row to the next, and as clearly shown in FIG. 9, these holes impart to the third knit fabric section 4 a certain openness and thus even greater elasticity.

(50) Both of the variants shown in the FIGS. 3-7 and 8-12 respectively make it possible to produce the three knit fabric sections 2, 3, and 4 with different weaves and different transverse and longitudinal elasticities. In this manner, in the third knit fabric section 4, which is configured to be as elastic as possible, a pressure relief zone that can be configured in any desired size is produced, said zone being connected softly and with a constant pressure transition profile via the second knit fabric section 2, which has a somewhat lower elasticity, to the first, strong compression knit fabric section 2. The knit fabric sections 3 and 4 can have any final shape desired, they may be round, elliptical, square, or rectangular, or have any other shape, and this ultimately depends on the geometry of the pressure relief area.

(51) The use of two knitted yarns, preferably of the above-described RR and RL knitted yarns, makes it possible to achieve significantly higher elasticity gradients, and therefore pressure gradients, between the first knit fabric section 2, the second knit fabric section 3, and the third knit fabric section 4. The use of only one knitted yarn, in the example a RR knitted yarn, also allows the configuration of an elasticity or pressure gradient, but not entirely to the extent allowed by the use of two knitted yarns. The use of two knitted yarns also provides a more optically attractive mesh structure than the use of only one knitted yarn. At the same time, however, the object of the invention is also achieved using only one knitted yarn.

(52) In forming the individual knit fabric sections, it is possible to use knitted yarns of the same or different colors. This would make it possible to optically emphasize the relief area, i.e. the knit fabric sections 3 and 4, by knitting it in a different color.

(53) While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.