Abstract:
The invention relates to a work leg protector, having at least one first protector region, and at least one second protector region, and at least one retaining means for fastening the work protector to a leg. The first protector region is configured at least for the arrangement in the region of a knee, and the second protector region is configured at least for the arrangement in the region of the shin. At least the first protector region and the second protector region are configured in one piece and form a substantially rigid shield, wherein the retaining means is disposed only on the second protector region.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of international patent application PCT/EP2009/003105 filed Apr. 29, 2009, which claims priority of German Patent Application 10 2008 021 755.7 filed Apr. 30, 2008, both of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention concerns a “work leg protector” [hereinafter, “occupational leg guard” or “leg guard”], in particular for protecting the knee and shin of the leg. 
       BACKGROUND OF THE INVENTION 
       [0003]    Knee guards for working in a kneeling position are generally known. There are knee guards currently on the market that are held onto the leg by means of rubber straps above and below the knee or the hollow of the knee. As the knee guard is subjected to stresses and strains during use, the rubber straps regularly slip, which results in the knee guard being poorly positioned and causing discomfort. In particular, there are knee guards on the market that lie firmly against the knee, leading to perspiration in the area of the knee, which can result in chafing of the skin. This impedes wearing the knee guard over a longer period of time or makes wearing it over a longer period of time nearly impossible. One consequence is the need for continuous correction of the position of the knee guard. 
         [0004]    The task of the invention is to make available an improved occupational leg guard. 
       SUMMARY OF THE INVENTION 
       [0005]    This task is solved in accordance with the invention by means of a leg guard, the use of a leg guard, a method for protecting a leg, and a method for producing a leg guard. 
         [0006]    Proposed is a leg guard with at least one first guard region and at least one second guard region and at least one retaining means for affixing the leg guard to the leg. The first guard region is designed at least for arrangement in the region of the knee and the second guard region is designed at least for arrangement in the area of the shin. At least the first guard region and the second guard region are made in one piece and essentially form a solid shield, and the retaining means is arranged only on the second guard region. 
         [0007]    In what follows the term leg guard or occupational leg guard is used for leg guards that are used mainly for activities of craftsmen. In particular, the leg guard is an occupational apparatus for tile setters, screed layers, parquet and laminate floor layers, roofers or masons, for example. The term occupational leg guard can also include guards that protect at least parts of the foot and/or the thigh. 
         [0008]    “One piece” is understood to mean that the first guard region and the second guard region are made as material composites and especially are made in one piece. 
         [0009]    The proposed invention has the advantage that, besides the knee, the shin is also protected by means of the leg guard. In particular, protection of the shin is advantageous when working, for example, on stairs or in situations in which kneeling on an edge is unavoidable. In addition, it is advantageous that wetting of the pant leg can be avoided when working on a wet or damp floor. The largely solid composition of the individual guard regions has the advantage that it is easy to correct the position of the entire leg guard, for example by pulling or pushing on one part of the leg guard in order to bring the complete leg guard into the correct position. 
         [0010]    In another variation, the first guard region and the second guard region are designed to be offset from each other. In one embodiment the first and the second leg guards are arranged at an angle to each other. In one embodiment the angle is about 5° to 30°, in particular 10° to 20°, preferably 10° to 15°, especially preferably 13° to 14°. In particular, the angle, or the offset, is arranged above the uppermost retaining means, preferably about 0.5 cm to about 10 cm, additionally preferably about 2 cm to about 5 cm. In addition, the angle is preferably arranged largely centrally with respect to the lengthwise axis of the leg guard. Especially preferably, the first guard region, when the leg guard is affixed to the leg, bends somewhat away from the leg. Additionally preferably, the first guard region in at least one segment curves toward the leg, so that in a lengthwise section it describes a curve around the leg. In addition, envisioned in one embodiment is that the first guard region, in a lengthwise section, runs straight in at least one section, in particular parallel to a section of the second guard region. In particular, in one embodiment an offset is a step or a curved transition between the first and second leg guard. The inside of the first guard region in a lengthwise section at the upper edge has a spacing from a straight line, on which at least one segment of the inner side of the second guard region is arranged, of about 10 mm to about 50 mm, preferably of about 20 mm to 35 mm, additionally preferably about 25 mm to about 30 mm. The spacing of the first guard region from the leg brings about improved wearing comfort, since, especially when standing, air can flow behind the leg guard. In addition, the spacing of the second guard region prevents rubbing of the leg guard against the knee when standing and walking. The leg guard is preferably designed so that, for a knee circumference of, for example, about 42 cm to about 45 cm and projection of the knee cap beyond the head of the tibia of about 0.5 cm to about 2 cm when standing, i.e., with the knee pushed through, it does not bump into the knee. In particular, it is provided that even during walking, in particular when the shin is at an angle up to 100°, contact with the leg guard does not occur. 
         [0011]    The leg guard preferably features a material from a group comprising at least ethylene vinyl acetate (EVA), polyurethane, polyamides and/or aramids. In particular, the leg guard has a foamed polyurethane or thermoformed ethylene vinyl acetate. Other materials that have a similar Shore hardness can also be used. The leg guard has, at least in one region, a Shore hardness from 15 A to 35 A, preferably about 20 A to 25 A, additionally preferably about 23 A. In particular, a Shore hardness between 15 A and 35 A in the region of the transition between the first guard region and the second guard region is provided. 
         [0012]    The flexible material of the leg guard is especially comfortable, especially with regard to the embodiment with an offset between the first guard region and the second guard region. If a user kneels on the leg guard, the leg guard deforms so that the first guard region fits closely to the knee of the user and protects it. 
         [0013]    In one embodiment it is also provided that the leg guard includes one layer of a puncture-resistant material. Preferably, the puncture-resistant material consists of at least 80-100% polyamides and 0-20% polyurethane adhesive, more preferably at least approximately 95% polyamides and approximately 5% polyurethane adhesive. In particular, puncture protection comprising a puncture-resistant material is provided. In one embodiment the puncture protection is a thermoplastic material, in particular a polyolefin, for example a weakly branched polyethylene (HDPE) or polypropylene (HDPP). It is also provided in one embodiment that the puncture-resistant material is an aramid, preferably aramid fibers or glass fibers. The puncture-resistant material has a puncture resistance of type 1 or type 2 in accordance with EN 863. Preferably, the leg guard is a protector in accordance with DIN 14404. Additionally preferably, the leg guard, at least in the region of the layer of puncture-resistant material, has a puncture resistance of at least 95 Newtons, preferably at least 105 Newtons, additionally preferably at least 240 Newtons, especially preferably at least 260 Newtons, further especially preferably at least 445 Newtons, in accordance with EN 863. 
         [0014]    In one embodiment the puncture resistant material, or the puncture protection, is produced by foaming or foaming in place. Additionally preferably, the puncture-resistant material is glued on. In another embodiment the puncture-resistant material is arranged between two layers of EVA or PU. 
         [0015]    The leg guard has at least one retaining means for affixing the leg guard to the leg. It is provided in one embodiment that there is more than one retaining means or member, for example two, three, or more retaining means or members. The retaining means is designed in particular as a strap, which in an especially preferred embodiment has a closure device. The closure device comprises, for example, a Velcro strip, a clamping closure, a button closure or a lace closure. It is especially provided that the retaining means consists of a stretch material. In particular, the holding of the retaining means is at least supported by the stretch material. It is provided in one embodiment that the retaining means consists of a nonstretch material. In another embodiment it is provided that the retaining means comprises a tubular element into which the leg can be inserted. In particular, a retaining means can also be combined with pants, for example by making the retention means in at least two parts and assigning at least part of the retaining means to the pants. For example, a Velcro closure is provided, where one closure part of the Velcro closure is arranged on the pants. It is also provided that the leg guard can be inserted into a pant leg, in particular into a holding device provided on the pant leg for this purpose, or can be incorporated into the pant leg. Especially preferably, the retaining means comprises at least one strap, preferably with a width of 4 cm to 15 cm, especially preferably 6 cm to 10 cm. The retaining means can be arranged on the leg guard separably or permanently. For example, the retaining means can be drawn through openings in the leg guard. In addition, in one embodiment it is provided that the retaining means is foamed in place, glued on, and/or clamped in place. 
         [0016]    The retaining means is assigned to the second guard region. This has the advantage that the retaining means is affixed only to the calf of the leg. In particular, when the leg guard is positioned on the leg, the retaining means has a distance down from the hollow of the knee such that the retaining means cannot slip into the hollow of the knee. In particular, it is provided that at least two retaining means below the knee fasten the leg guard to the leg. The retaining means are arranged so that at least one retaining means can be arranged on an upper region of the calf and at least one second retaining means can be arranged on a lower region of the calf. The advantage of this embodiment is that knee movement is possible without affecting the position of the leg guard. Moreover, the first guard region stands off from the knee when it is bent, which contributes to improved wearing comfort. 
         [0017]    In a preferred embodiment the leg guard has guide channels in which the retaining means can be arranged. In particular, the guide channels are arranged as depressions on the surface of the leg guard. Additionally preferably, the guide channels have increasing depth toward the edge of the leg guard. Preferably, the guide channels have a depth of about 0 mm to about 3 mm, preferably 2 mm, at the point the retaining means emerges from the surface of the leg guard. Additionally preferably, the guide channels have a depth of about 3 mm to about 7 mm, preferably 5 mm, at the edge of the leg guard. 
         [0018]    In another embodiment the retaining means is arranged at an angle to the transverse axis of the leg guard. In particular, it is provided that the retaining means is arranged at an angle of about 5° to about 10° to the transverse axis of the leg guard. In particular, an angle of about 8° to about 9° is provided. In another embodiment at an angle of about 8.4° and/or about 9° is provided. A tolerance of up to about 10% should be specified for these data. Preferably, the retaining means is guided at an angle through the transverse axis by means of the guide channels. In one variation it is provided that a first retaining means is arranged on the leg guard so that the first retaining means can be arranged on an upper region of the calf. In addition, a second retaining means can be arranged on a lower region of the calf. In one embodiment, in particular with at least two retaining means, it is additionally provided that one retaining means, which can be arranged on an upper region of the calf, is angled in the direction of the first guard region. In addition, it is especially provided that at least one retaining means, which can be arranged on a lower region of the calf, is angled away from the first guard region. In particular, at least two retaining means have different angles, in particular, different values of the angle to the transverse axis. The fact that the retaining means lies against the calf so that upward slippage is prevented is an advantage of an arrangement of a retaining means in the lower half, preferably the lower third, of the second guard region. Preferably, a retaining means is arranged in the upper third of the second guard region and a retaining means is arranged in the lower third of the second guard region. In this way slipping of the leg guard downward is prevented by the upper retaining means and upward by the lower retaining means. The distance of the upper retaining means to the hollow of the knee thus remains more or less the same even when the leg moves. 
         [0019]    In another embodiment of the leg guard, it has at least one cushioning element. The cushioning element can be bonded to the leg guard as one part or two parts. In particular, the cushioning element is made of the same material as the leg guard. It is also provided in one embodiment that the cushioning element consists of at least one material that is different from the material of the leg guard. An embodiment is also provided where the cushioning element can be removed from the leg guard and replaced without damage. In particular, by making it exchangeable, the cushioning element can be matched to the weight of the user. The cushioning element is preferably arranged on the first and/or the second guard region. 
         [0020]    Another embodiment calls for the cushioning element to have different cushioning constants over its surface. In particular, a continuous transition of the cushioning constants from a first side to a second side is provided. Also, it is possible to provide an iterative transition, i.e., a transition over a plurality of discrete zones, each with its own cushioning constant. In particular, in one embodiment the cushioning element consists of different materials in order to ensure different cushionings. It is also provided that the cushioning element has different cushionings over its surface due to a shaping. Thus, in one embodiment it is provided that the cushioning element has at least one notch or one groove. In a further embodiment the notch has a varying width over its course. A preferred embodiment calls for the notch to extend in particular in the direction of the second guard region. In particular, the notch is wider toward the second guard region. Also, the notch can have a varying depth over its course. In a further embodiment the notch is made wedge-shaped. In particular, the notch is arranged in the lengthwise direction of the leg guard. However, an embodiment is also provided, in which at least one notch extends at an angle to the lengthwise axis. In particular, an angle of 30°, 45° or 90° is provided. Also, a plurality of notches can be provided, which are arranged, for example, at varying distances from and/or varying angles to the lengthwise axis. In particular, the notches are arranged so that they enable different cushioning properties over the area of the cushioning element. In particular, it is provided that firmer cushioning is provided on an upper region of the cushioning element in order to be able to better cushion the greater weight of larger users of the leg guard. Also, when the user bends forward there is a greater surface load on the upper part of the cushioning element, so that a firmer cushioning is provided there in order to offer the greatest possible comfort. 
         [0021]    In another embodiment the leg guard has at least one means or attachment member for hooking or catching onto a step or an edge. In particular, the means can comprise at least a hook, a claw or a lip. The lip or hook can consist of a material that consists of at least a thermoplastic plastic or a metal. Also, the means for catching can be a material that is also in the first or second guard region. It is advantageous that when working on stairs, for example, slipping from a step can be prevented with the means for hooking or catching. 
         [0022]    In another embodiment the leg guard includes a wear layer which can be made detachable or nondetachable from the leg guard. For example, it can be affixed to the leg guard by hooks, snaps, glue or foam. Also, one embodiment calls for it to be affixed, for example, by means of a Velcro closure. In a preferred embodiment the wear layer comprises a puncture proofing. The wear layer can, in one embodiment, be applied to the first and/or second guard region, in particular to the cushioning element. 
         [0023]    Another idea of the invention calls for a leg guard to be used to protect the knee in a kneeling activity. Preferably, the leg guard is used for work such as floor tiling, screed laying, parquet laying, roofing work, masonry work, and/or other manual work. Even though the leg guard is intended for skilled manual labor, in a further development it can be provided that the above described leg guard will be used for sports activities. In particular, the leg guard can also be used to avoid injuries that can be caused by impacts or cuts, such as can occur, for example, in skilled manual labor or also in contact sports. 
         [0024]    Another idea of the invention envisions a method for protecting the leg, whereby a leg protector is affixed to the leg, so that it protects the leg like a shield and whereby the leg guard is affixed exclusively below the knee by means of at least one retaining means. In a further development the leg guard is affixed to the leg by means of at least two retaining means, where in particular a first retention means is affixed on an upper region of the calf and a second retaining means is affixed in the lower region of the calf. In addition, in one embodiment it is provided that at least retaining means is arranged at an angle to a transverse axis of the leg guard. 
         [0025]    Another idea of the invention calls for a method for producing a leg guard, where the leg guard includes a first guard region and a second guard region, where the first guard region and the second guard region are integrally bonded together. In particular, in a first embodiment it is provided that the first and the second guard regions are produced in a single operation, in particular by injection molding. Another embodiment calls for the first guard region and the second guard region to consist of the same material. In particular, the two guard regions are made of one material. In another development it is provided that the leg guard and at least one cushioning element is made of one material. However, in a further embodiment it is also provided that the leg guard is made of more than one material. In particular, the individual guard regions can be made of different materials. In one embodiment it is provided that the first guard region and the second guard region are made in one piece. In particular, the leg guard is made with the guard regions and the cushioning element in one piece. It is further provided that the leg guard is made of a flexible material. The leg guard can also be made of an inflexible material. For example, it is provided that the leg guard consists of a rubber, polymer foam, ethylene vinyl acetate, polyamides, olefins and/or aramids. 
         [0026]    In one embodiment the leg guard is made by thermoforming, whereby in particular the leg guard is made of an outer shell and an inner shell. Preferably a puncture-resistant material is incorporated between the outer shell and inner shell. 
         [0027]    In another variation the leg guard is made by foaming, in particular a PU foam is injected into a mold. It is provided in a further development that a puncture-resistant material is made by foaming or is foamed in place. In particular, the puncture resistant material is introduced into the mold before the PU foam is injected. 
         [0028]    In another embodiment at least one retaining means is bonded to the leg guard in the manufacturing process, in particular bonded so that it cannot be removed without damage. In particular, the retaining means is clamped on or glued. If PU foam is used, the retaining means can be incorporated by foaming. It is also provided in one embodiment that the retaining means is pressed between the outer shell and the inner shell. 
         [0029]    In another variation it is provided that a cushioning element is arranged, in particular integrally, on the first guard region. One embodiment calls for the cushioning element to be arranged on the second guard region after making the first and/or second guard region. The cushioning element can be glued, vulcanized, welded, bolted, riveted, pinned and/or clamped. In particular, the cushioning element in one embodiment can be arranged on the leg guard in a detachable way. In another embodiment the cushioning element is made of at least one material other than that of the first and/or second guard region. In addition, in one embodiment it is provided that a wear layer is arranged on the leg guard, in particular on the first guard region, additionally preferably on the cushioning element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]    Other advantageous embodiments follow from the following drawings. The further developments shown there are, however, not to be interpreted as limiting; rather the elements described there can be combined with each other and with the elements described above to make further embodiments. In addition, it should be noted that the reference numbers given in the description of the figures do not limit the range of protection of the present invention, but only refer to the embodiment examples shown in the figures. Like parts or parts with like function have the same reference numbers in what follows. Here: 
           [0031]      FIG. 1  shows an occupational leg guard in a front view; 
           [0032]      FIG. 2  shows an occupational leg guard in a view from below; 
           [0033]      FIG. 3  shows an occupational leg guard in a perspective view; 
           [0034]      FIG. 4  shows a leg guard being worn; 
           [0035]      FIG. 5  shows another embodiment of a leg guard; 
           [0036]      FIG. 6  shows another embodiment of a leg guard; 
           [0037]      FIG. 7  shows sectional view VII-VII of  FIG. 6 ; 
           [0038]      FIG. 8  shows sectional view VIII-VIII of  FIG. 6 ; 
           [0039]      FIG. 9  shows a leg guard with a wear protection means; 
           [0040]      FIG. 10  shows a mold; 
           [0041]      FIG. 11  shows sectional view XI-XI of  FIG. 10 ; 
           [0042]      FIG. 12  shows another embodiment of a leg guard; and 
           [0043]      FIG. 13  shows sectional view XIII-XIII of  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0044]      FIG. 1  shows a leg guard  1  in a front view. The leg guard  1  has a first guard region  2  and a second guard region  3 , which are largely solid and joined together in one piece. The first guard region  2  includes a cushioning element  4 , which has a notch  5 . The notch  5  is made conical, so that the cushioning element  4  is firmer in the upper region  6  than in the lower region  7 . The leg guard has a length  8  of about 200 cm and a width  9  of about 70 cm. The cushioning element  4  in one embodiment has an anti-slip surface, for example a structured surface, which reduces sliding on a smooth and/or wet substrate. 
         [0045]    Further, the leg guard includes guides  10 ,  11 ,  12 ,  13 ,  14  and  15  in the second guard region  3 , in which retaining means can be inserted. The guides  10 ,  12 ,  13  and  15  are arranged at an angle to a transverse axis  16  or  17 . Guides  10  and  12  have, for instance, an angle α of 5° to 10°, preferably about 8.38°, and guides  13  and  15  have, for instance, an angle β of 5° to 10°, preferably about 8.95°. 
         [0046]      FIG. 2  shows the leg guard in a view from below. One can see that it has a curvature  18 , which can lie against the leg. In particular, this curvature, in one embodiment, is provided with a cushion, not shown here. The cushioning element  4  is made by foaming, for example, so that it has bulges  19  and  20  toward the sides, which are arranged on each side of notch  5 . 
         [0047]      FIG. 3  shows leg guard  1  in a perspective view. One can see that the retaining members or means  21  and  22  are pulled into the guides. In particular, it is provided that the retaining means are made as straps, which have a Velcro closure, not shown here. If the leg guard  1  is affixed to the leg by means of retaining means  21  and  22 , the guides  10 ,  12 ,  13 ,  15 , which are at an angle to transverse axes  16  and  17 , favor ergonomic positioning of retaining means  21  and  22  on the leg. 
         [0048]      FIG. 4  shows a leg guard  1  being worn on a leg  23 . The leg guard is affixed to the calf  24  of the leg  23  by means of retaining means  21  and  22 . Retaining means  21  and  22  are directed so that they lie approximately on the curvature of the calf  24 . This is achieved by the angles α and β that the retaining means  21  and  22  have to transverse axes  16  and  17 . Thus, it is also ensured that the leg guard remains in its preferred position when the user moves. One can also see that there is no retaining means affixed above the hollow of the knee  25 . Thus, the leg guard  1  sits in shield-like fashion in front of the knee. The leg guard  1  remains in position when the knee bends, and thus does not restrict the user. Also, reduced blood flow in the knee is avoided, since constriction in the region of the hollow of the knee  25  by a retaining means does not occur. 
         [0049]      FIG. 5  shows another embodiment of a leg guard  1 . The leg guard  1  has guide channels  26 , which run from an exit point  27  for the retaining means, not shown here, toward the edge  28  of the leg guard  1 . The guide channels  26  become deeper toward edge  28 , so that the channel has a depth  29  of about 2 mm at exit point  27  and a depth  30  of about 5 mm at edge  28 . 
         [0050]    In addition, stiffening elements  31  can be seen, which prevent creasing of leg guard  1  in the region of the transition between the first guard region  2  and the second guard region  3 , for example when kneeling on the leg guard, that is, they increase the bending moment. 
         [0051]    In addition, the leg guard  1  in  FIG. 5  has an anti-slip surface  32 , which is preferably embossed about 1 mm to 2 mm. In particular, the anti-slip surface  32  has a structure. In addition, it is provided in one embodiment that the anti-slip surface  32  has an anti-slip material. Also, the anti-slip surface  32  can serve as an additional cushioning element or stiffening element. In one embodiment the anti-slip surface  32  has a thermoplastic plastic. 
         [0052]      FIG. 6  shows the leg guard  1  from  FIG. 5  with retaining means  21  and  22  indicated. The retaining means  21  and  22  are nondetachable, or are connected to leg guard  1  in a manner that is not detachable without damage. In addition, the retaining means  21  and  22  each have only two exits  27  on an outer side of the leg guard  1 —indicated in  FIG. 6  [sic]. In particular, the exits  27  have a spacing of less than 10 cm, preferably less than 5 cm, from each other. 
         [0053]      FIG. 7  shows section VII-VII in  FIG. 6 . The retaining means  21  can be foamed in place or, if the leg guard base material is thermoformed, especially if it is thermoformed of ethylene vinyl acetate, can be pressed in. Also, the retaining means  21  can be threaded through the leg guard  1  in a detachable way. 
         [0054]      FIG. 8  shows a sectional view through VIII-VIII in  FIG. 6 . One can see that the first guard region  2  is bent away from the second guard region  3 . In particular it is provided that the first guard region  2  is bent by an angle  33  of about 14°. One can also see that the first guard region  2  in the sectional view VIII-VIII describes at least in part a curved course. The distance  34  of the upper edge  35  from a straight line  37  on the inner side  36  of the second guard region  3  in this sectional view is about 10 mm to about 40 mm, additionally preferably about 25 mm to about 30 mm. 
         [0055]      FIG. 9  shows an embodiment of a leg guard  1  with a foamed-on or glued-on wear part  44  in an exploded view. The wear part  44  is mounted on the cushioning element  4 . The wear part  44  in particular, is detachably mounted on the cushioning element  4  in order to enable replacement of the wear element  44 . Preferably, the wear element  44  is made of a puncture-resistant material. In addition, the wear part  44  is preferably puncture protection. 
         [0056]      FIG. 10  shows an embodiment of a puncture protection  38 , which is inserted into a mold  39 . The mold is closed in a subsequent step, not shown here, and filled with PU foam. Spacers  40  hold the puncture protection  38  largely in the middle, so that it becomes nearly completely surrounded by foam. Foaming around it does not occur in the region of spacer  40 . In this way the puncture protection  38  can be seen in the end product, so that a pleasant appearance of the leg guard  1  is achieved. It is also provided in one embodiment that the part of the puncture protection around which there is no foam is faced. 
         [0057]      FIG. 11  shows section XI-XI of a leg guard  1  that was made in the mold from  FIG. 10 . One can see that the puncture protection  38  is surrounded by PU foam  41 . In another embodiment it is provided that the second guard region  3  also has a puncture protection  38 . 
         [0058]      FIG. 12  shows another embodiment of a leg guard  1 . The leg guard  1  has claws  42  in the second guard region, which for example can prevent slipping when a user kneels on an edge or a step. 
         [0059]      FIG. 13  shows a sectional view of section XIII-XIII in  FIG. 12 . One can see that the first guard region  2  is offset from the second guard region  3 . In addition, a step  45  is provided, which represents a transition from the first guard region  2  to the second guard region  3 . The first guard region  2  is offset by a distance  43  of about 20 mm to about 1 cm, preferably about 20 mm to about 40 mm, especially preferably about 30 mm. 
         [0060]    In addition, the claws  42  can be seen in  FIG. 13 , which in this embodiment are joined in one piece to the second guard region.