Abstract:
The invention relates to a portable power tool for a rotating, preferably disk-shaped tool ( 12 ). Said portable power tool comprises a machine housing ( 14 ), having a flange ( 16, 160 ) or a machine neck, and a protective hood ( 18 ) that can be detachably tensioned on the machine neck to cover the tool ( 12 ) or that has a protective hood neck ( 20 ) or protective hood collar that annularly carries a tightening strap ( 22 ). Said strap can be tightened by tensioning means ( 24 ). An anti-rotation lock effective between the machine neck and the protective hood ( 18 ) is interposed between the protective hood ( 18 ) and the machine neck in the form of a profiled structure ( 26 ). The invention is characterized in that the tensioning means ( 24 ), in its tensioned position, can be connected several times in a form fit to the machine neck and in its detached positioned is no longer connected in a form fit to the machine neck.

Description:
CROSS-REFERENCE TO A RELATED APPLICATION 
     The invention described and claimed hereinbelow is also described in German Patent Applications DE 10 2006 053 304.6 filed on Nov. 13, 2008 and DE 10 2007 041 840.1 filed on Sep. 3, 2007. These German Patent Applications, whose subject matter is incorporated here by reference, provide the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d). 
     BACKGROUND OF THE INVENTION 
     The present application is related to a hand-held power tool with a guard. 
     An angle grinder with an adjustable guard is made known in EP 0 812 657 A1. In that case, the guard is adjustable in a rotating manner on a connection piece of a flange of the angle grinder, and is supported such that it may be detachably attached using a single form-fit locking means. The spindle of the angle grinder passes through the center of the flange. A cutting and/or grinding disk is installed on the free end of the spindle in a clampable, rotationally drivable manner for cutting and machining work pieces, which are partially enclosed by the guard. The guard must be positioned in a rotationally adjustable manner on the hand-held power tool such that the region of the grinding disk that faces the user is enclosed by the guard. At the same time, a region of the grinding disk that points away from the user extends past the flange, radially relative to the work piece engagement. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a hand-held power tool for a rotating, preferably disk-shaped tool, with a machine housing that includes a flange and/or a machine neck, and with a guard that is detachably clampable to the machine neck, for covering the tool, and that includes a guard neck and/or a guard collar with an annular clamping band that may be tightened using a clamping means, and with an anti-rotation lock being located between the guard and the machine neck that is designed as a profiled structure and acts between the machine neck and the guard. 
     It is provided that the clamping means, in its clamping position, may be connected repeatedly and in a form-fit manner with the machine neck and, in its release position, is disengaged from the form-fit connection with the machine neck. The result is to advantageously ensure a secure connection between the guard and the machine neck of the machine housing that may withstand strong loads that occur during a working process. The guard is preferably prevented from rotating via the profiled structure during operation of the hand-held power tool, thereby ensuring that the guard safely protects the operator, in particular if the tool—a grinding disk, in particular—should burst. The guard may be used in general with hand-held power tools that include a rotating, preferably disk-shaped tool, such as a grinding disk, a cutting disk, and/or a polishing disk, and is usable—particularly advantageously—with an angle grinder. 
     In this context, a “flange and/or a machine neck” refers to a region of the hand-held power tool that serves to accommodate and/or attach the guard to the hand-held power tool, and that encloses the tool at least partially. This flange and/or machine neck may be designed as a single piece with the hand-held power tool, or it may be designed as a separate component. A “guard connection piece and/or guard collar” located on or integrally formed with the guard preferably refers, in this context, to a region that preferably extends perpendicularly to a main extension plane of the guard, which is provided for attachment with the hand-held power tool and/or for placement on a subregion of the hand-held power tool, in particular on a flange and/or machine neck of the hand-held power tool. This guard connection piece and/or guard collar is advantageously designed as a single piece with a body of the guard. In this context, a “clamping band” refers to a band, and particularly advantageously to a metal band, that bears around a subregion of the guard, e.g., a guard connection piece, in particular in order to attach the guard to the hand-held power tool, and that encloses the subregion in a non-positive and/or form-fit manner with a clamping force in particular. A “clamping means” refers, in particular, to a means that reduces a circumference, in particular of the clamping band, using a clamping process, e.g., the folding down of a lever, the tightening of a screw, or by using another process that appears suitable to one skilled in the technical art. A “profiled structure” refers, in particular, to a shape, e.g., a perforated structure, an edge, and/or an internal pressed-out region, that includes a profile and/or a contour whose geometry depends on a function of the anti-rotation lock. Another type of anti-rotation lock that appears reasonable to one skilled in the art is also feasible, however. In this context, a “clamping position” refers to a position of the clamping band in which the clamping band enters into a connection with a further component that is under mechanical tension, in particular, e.g., a connection based on a form fit, e.g., with the flange and/or the machine neck of the hand-held power tool in particular. A released position therefore refers to a position of the clamping band in which a clamped connection between the clamping band and the further component has been released. 
     Further advantages result from the description of the drawing, below. Exemplary embodiments of the present invention are shown in the drawing. The drawing, the description, and the claims contain numerous features in combination. One skilled in the art will also advantageously consider the features individually and combine them to form further reasonable combinations. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an inventive hand-held power tool with a guard, in a schematic depiction, 
         FIGS. 2   a ,  2   b  show a subregion of the hand-held power tool with a machine housing and a machine neck, in two different perspective views, 
         FIGS. 3   a  and  3   b  show the flange with an orientation spring, in two different views, 
         FIG. 4  shows the orientation spring in a perspective view, 
         FIGS. 5   a ,  5   b  show the subregion of the hand-held power tool with the machine housing and the installed guard ( FIG. 5   a ), and a detailed view of a fastening region ( FIG. 5   b ), in perspective views, 
         FIG. 6  shows the clamping band in a perspective view, 
         FIGS. 7   a ,  7   b ,  7   c  show the guard with a clamping band and a toggle joint system in a clamping position ( FIGS. 7   a ,  7   c ) and in a release position ( FIG. 7   b ), both in perspective views, 
         FIG. 8  shows the guard with the orientation spring, in a perspective view, 
         FIGS. 9   a ,  9   b  show an alternative design of the orientation spring in a perspective view ( FIG. 9   a ) and in a top view ( FIG. 9   b ), 
         FIGS. 10   a ,  10   b  show the orientation spring in  FIGS. 9   a  and  9   b  located inside a flange, in a perspective view ( FIG. 10   a ), and in a top view ( FIG. 10   b ), 
         FIGS. 11   a ,  11   b  show a subregion of the hand-held power tool with an installed guard, with an alternative closing element, in a perspective view, 
         FIGS. 12   a ,  12   b  show the guard in  FIGS. 9   a  and  9   b  with the alternative closing element, in a perspective view and in a side view, 
         FIG. 13  shows an alternative design of a rocker, in a perspective view, and 
         FIG. 14  shows a further design of the rocker, in a perspective view. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A hand-held power tool  10  designed as an angle grinder is shown in  FIG. 1 , in a top view. The angle grinder includes a machine housing  14  and a main handle  66 , which is integrated in machine housing  14 . Main handle  66  extends on a side  68 —that faces away from tool  12  designed as a cutting disk—in a longitudinal direction  70  of the angle grinder. An auxiliary handle  74  is located in a front region  72  of the angle grinder that is close to the tool, and it extends transversely to longitudinal direction  70  of the angle grinder. To protect an operator, hand-held power tool  10  includes a guard  18 , which encloses tool  12  at least partially in a circumferential direction  76  of tool  12 . 
       FIGS. 2   a  and  2   b  show a subregion of hand-held power tool  10  and/or machine housing  14  facing tool  12 , with a spindle  82 , which is rotatable around spindle axis  78 . During operation of hand-held power tool  10 , spindle  82  transfers a drive torque from a not-shown motor of hand-held power tool  10  to tool  12 . To this end, the subregion includes a flange  16 , which is designed as a machine neck, and which is fixedly connected with machine housing  14 . Flange  16  includes a circular recess  80  in the center, in the region of spindle  82 , through which spindle  82  is guided when flange  16  is installed in machine housing  14 . Spindle  82  extends in an axial direction  84 —which extends perpendicularly to longitudinal direction  70  of hand-held power tool  10 —and beyond flange  16 . Flange  16  has a toothed profile, which extends outwardly in a radial direction  86 , and which includes teeth  58 —which extend outwardly in radial direction  86 —and recesses  38  and/or tooth gaps, which extend inwardly in radial direction  86 . The teeth are also designed in the manner of puzzle pieces, and/or such that they are undercut inwardly in radial direction  86  (refer also to  FIGS. 2   a  through  3   b ). The toothed profile is provided as a counter-toothed profile  36  for coupling with a matching toothed profile  34  of guard  18  (see  FIGS. 5   a ,  5   b , and  5   c ). Counter-toothed profile  36  extends in circumferential direction  76  around a range of approximately 270° ( FIGS. 2 ,  2   b ,  3   a , and  3   b ). 
     An orientation spring  62  is located in a region  88  of flange  16  that has a smooth contour and does not have a toothed profile in circumferential direction  76 . Orientation spring  62  serves to establish an exactly defined insertion position of guard  18  relative to flange  16  when guard  18  is installed. To this end, orientation spring  62  is designed as a bent spring-steel lamella. To support orientation spring  62  on flange  16 , orientation spring  62  includes two bearing elements  92  in end regions  90 . Bearing elements  92  are located in end regions  90  of orientation spring  62  such that they extend outwardly in radial direction  86  (see  FIGS. 3   a  and  4 ). For placement inside flange  16 , flange  16  includes a recess  94  that extends in circumferential direction  76  and has a length that corresponds to a length of orientation spring  62  ( FIG. 3   a ). Via bearing elements  92 , orientation spring  62  bears inside recess  94  of flange  16 . Bearing elements  92  extend through recesses  138  on an underside  142  and a top side  144  of flange  16 , thereby ensuring that orientation spring  62  will not drop out of flange  16  ( FIGS. 2   a ,  2   b , and  3   b ). Orientation spring  62  has a U shape in a central subregion  96 . U-shaped subregion  96  extends radially outwardly ( FIGS. 2   b ,  3   a , and  4 ). When orientation spring  62  is installed, U-shaped subregion  96  extends radially outwardly beyond a smooth, profile-free region  88  of flange  16  ( FIGS. 2   b  and  3   a ). 
       FIGS. 5   a  and  5   b  show hand-held power tool  10  with a guard  18  installed on flange  16 . Guard  18  is located on flange  16  such that it may be detached easily without the use of auxiliary tools and such that it is adjustable in a rotating manner. Guard  18  includes a disk-shaped body  146 , which extends around a partial circle of approximately 180° of tool  12  in circumferential direction  76 , and which is centered around spindle  82 . Guard  18  includes a guard connection part  20 , which is designed as a guard collar. A clamping band  22  is located around guard connection part  20 . Clamping band  22  may be tightened using clamping means  24 , thereby forming an anti-rotation lock between flange  16  and guard  18  via a profiled structure  26 . To attach guard  18  to flange  16 , end regions  98 ,  100  of clamping band  22  are bend outwardly in circumferential direction  76  and forms tabs  102 ,  104 , which are rotation point eyelets, and which are provided for positioning clamping means  24  relative to clamping band  22  ( FIG. 6 ). An inwardly bent design of tabs  102 ,  104 , i.e., bent from the outside toward the inside, reduces and/or prevents tabs  102 ,  104  from being bent upward when loads are applied ( FIGS. 5   a ,  5   b  and  6 ). By attaching (e.g., via welding, riveting, etc.) ends  106  of tabs  102 ,  104  with clamping band  22 , they are prevented from accidentally becoming expanded. It is also basically feasible for ends  106  of tabs  102 ,  104  to be unattached. Combined with clamping band  22 , unattached ends  106  of tabs  102 ,  104  provide clamping band  22  with spring action. Tabs  102 ,  104  of clamping band  22  may also be designed merely as bent, as bent and secured against expansion, or as bent from the outside toward the inside. 
     Clamping means  24 —when in a clamped position—may be connected repeatedly and in a form-fit manner with flange  16 , which is designed as the machine neck ( FIGS. 5   a  and  5   b ). In a release position, clamping means  24  are not in a form-fit connection with flange  16 . Clamping means  24  are composed of clamping levers  28 ,  30 , which form a toggle joint system  44 . Clamping levers  28 ,  30  are designed as a rocker  40  and a latch  42 . Rocker  40  is supported in circumferential direction  76  with an end region  108 —which faces away from latch  42 —via a bearing bolt  110  in tab  102  of clamping band  22  such that it is movable around a rotation axis, which extends parallel with and/or coaxial with bearing bolt  110 . Latch  42  is supported in tab  104  using a further bearing bolt  112  via an end region  114 , which faces rocker  40 , such that it is rotatable around an axis of bearing bolt  112 . Via a bearing element  116 , rocker  40  and/or an end region  118 —which faces latch  42 —of rocker  40  and a region  120  of latch  42  are supported such that they are rotatable relative to each other. Region  120  of latch  42  is located after end region  114 , which serves as support in tab  104  of clamping band  22 , along latch  42  in a direction facing away from rocker  40 . Three rotation points of toggle joint system  44  are formed by bearing bolts  110 ,  112  and/or bearing element  116 . When latch  42  is closed, the rotation point of the connection of rocker  40  with latch  42  is moved from latch  42  in the direction of rocker  40  in front of the rotation point of latch  42  with tab  104  of clamping band  22 , thereby overcoming a dead point of toggle joint system  44 , and latch  42  automatically returns to its clamping position. This takes place in a snap-in manner that is audible to the operator. An additional type of detent action, e.g., between tab  102  and rocker  40 , is also feasible, of course, to provide additional security. Forces of expansion and/or strain that occur, or motions that occur on clamping band  22  during operation of the hand-held power tool amplify the closing forces on rocker  40  and latch  42  that aim to further tighten toggle joint system  44 . A closing force increases with the forces of expansion and/or strain ( FIGS. 5   a  and  5   b ). 
     Rocker  40  and latch  42  include undercut-engagement means  32 ,  60  that are formed by a toothed profile  34 , which, together with counter-toothed profile  36  of flange  16 , forms profiled structure  26 . Toothed profile  34  is provided for engagement in counter-toothed profile  36  and/or in recesses  38  of flange  16  to establish a non-rotatable, form-fit connection between guard  18  and flange  16 . Undercut-engagement means  32 ,  60  and/or toothed profile  34  are/is located on a side  122  of latch  42  and/or rocker  40  facing flange  16 . Rocker  40  includes three undercut-engagement means  32 , and latch  42  includes two undercut-engagement means  60  ( FIG. 7   c ). Undercut-engagement means  32  of rocker  40 —which face latch  42 —engage, in a clamping position, in the same recess  38  of counter-toothed profile  36  as do undercut-engagement means  60  of latch  42 , which face rocker  40 . Any other distribution of undercut-engagement means  32 ,  60  that appears reasonable to one skilled in the technical art is also feasible, however. In addition, clamping band  22  includes a recess  124  in the region of latch  42  ( FIG. 7   b ) that extends in circumferential direction  76  on clamping band  22 . 
     Undercut-engagement means  60  of latch  42  extend through recess  124  and form, together with counter-toothed profile  36  of flange  16 , a form-fit connection when in a clamping position ( FIGS. 5   a  and  5   b ). Instead of one recess  124 , it is also possible to provide several recesses in clamping band  22 , each of which is provided for only one tooth  126  of toothed profile  34  of latch  42 . To establish a form-fit connection, a width of teeth  126  of toothed profile  34  is matched to a width of recesses  38  of counter-toothed profile  36 . Rocker  40  and latch  42  are also provided with holes  50 , to reduce weight. One or more of the undercut-engagement means  32 ,  60  may also be designed to move sooner than do the other undercut-engagement means  32 ,  60  when a load is applied, so that they contact flange  16  sooner. An angle of contact surfaces of undercut-engagement means  32 ,  60  and recesses  38  in faster-moving undercut-engagement means  32 ,  60  is designed such that, if tool  12 —in particular a grinding or cutting disk—should burst, faster-moving undercut-engagement means  32 ,  60  act in a tightening manner, thereby providing an operator with maximum protection during operation of hand-held power tool  10 . 
     Guard  18  may be locked in a fixed position on flange  16  via toothed profile  34 , which engages in counter-toothed profile  36  of flange  16  when guard  18  is installed. In addition, an operator may select an installation position in circumferential direction  76  that provides him with maximum protection. Given that counter-toothed profile  36  of flange  16  is limited in circumferential direction  76  to a range of approximately 270°, counter-toothed profile  36  serves as a coding means, thereby ensuring that guard  18  is not installed on flange  16  in a non-permitted position and preventing toggle joint system  44  from closing in region  88  that does not have a counter-toothed profile  36 . 
     If tool  12  should burst, airborne tool particles act forcefully on a guard edge  148  and guard  18 . Pulling and rotational forces therefore act on guard  18 , but guard  18  is prevented from rotating due to the form-fit connection between clamping means  24  and flange  16 . In addition, the pulling forces on guard  18  and clamping band  22  act radially outwardly, thereby causing latch  42  and rocker  40  and/or toothed profile  34  to engage more tightly in recesses  38  and/or counter-toothed profile  36  of flange  16 , thereby creating a lock that acts dynamically with increasing strength and serves as a highly effective anti-rotation lock. 
     A closing force and/or clamping force of clamping band  22  together with clamping means  24  may also be adjusted by an operator. A clamping band length may therefore also be adjusted, e.g., to compensate for production tolerances. To this end, clamping band  22  includes a semi-loop  46 , which is realized in circumferential direction  76  by a contour of clamping band  22  that is bent radially outwardly and then radially inwardly ( FIGS. 6 ,  7   a , and  7   b ). Semi-loop  46  includes a recess  128  through which an adjusting element in the form of a screw  48  extends, and which is tightened with a nut  130 . The more tightly nut  130  is screwed onto screw  48 , the narrower a clamping band diameter becomes and the greater the clamping force becomes. Further designs of clamping band  22  that deviate geometrically from semi-loop  46  are possible, e.g., a two-pieced design of clamping band  22  with two clamping band elements that may be connected with each other using the adjusting element, thereby adjusting a clamping force and/or a clamping band diameter. The adjustability may also be influenced by a number of adjusting elements and/or a design of the adjusting elements and/or a position of the adjusting elements. Clamping band  22  is located such that it is unexpandable on guard connection piece  20  around a range of 180°. It may also be attached via a subregion of only, e.g., 90°, however, which leaves the remaining subregion of clamping band  22  exposed, thereby allowing it to expand. Clamping band  22  may also be fixed in position at only one point. 
       FIGS. 7   a ,  7   b , and  7   c  show guard  18  with clamping band  22  and clamping means  24  in a clamping position ( FIGS. 7   a  and  7   c ) and in a release position ( FIG. 7   b ). Guard connection piece  20  of guard  18 , which is enclosed by clamping band  22  on a radially outwardly directed surface  132 , includes pressed-out regions  52  shaped as a wavy profile or a ring gear that extend perpendicularly to circumferential direction  76 . Accordingly, a region  56  of clamping band  22  adjacent to guard connection piece  20  includes pressed-out regions  52  shaped as a wavy profile or a ring gear ( FIG. 6 ). A simpler geometric design of clamping band  22  is also feasible, however, e.g., a contour in particular that does not include an additional stamped profile. Ring gear-type pressed-out regions  52  of guard connection piece  20  have the main function of snapping into place in a rotational lock manner with orientation spring  62  when guard is intentionally displaced ( FIG. 8 ). When guard  18  is rotated, orientation spring  62  moves out of one pressed-out region  52  and snaps in place in the next pressed-out region  52 . In addition, pressed-out regions  52  correspond with counter-toothed profile  36  of flange  16  and form a positioning aid, in particular a coded positioning aid. A V-shaped indentation  64  at a defined point in clamping band  22  is assigned to orientation spring  62  installed in flange  16  ( FIG. 6 ). Guard  18  may be inserted when installed with flange  16  only when orientation spring  62  engages in indentation  64  in clamping band  22 . To ensure that, when guard  18  is subsequently rotated on flange  16 , orientation spring  62  transitions in a gliding manner from clamping band  22  to guard connection piece  20 , a continually rising lamella indentation  136  is provided on a radially inwardly directed side  134  of clamping band  22  that ensures that orientation spring  62  may deviate radially inwardly in a gentle, over-latching manner. 
     Alternative exemplary embodiments are shown in  FIGS. 9   a  and  14 . Components, features, and functions that are essentially the same are labelled with the same reference numerals. The description below is essentially limited to the differences from the exemplary embodiment in  FIGS. 1 through 8 . With regard for the components, features, and functions that remain the same, reference is made to the description of the exemplary embodiment in  FIGS. 1 through 8 . 
     An alternative design of orientation spring  150  is shown in  FIGS. 9   a  and  9   b . A central, U-shaped subregion  152  of orientation spring  150  has crimping  156 —which extends in circumferential direction  76  ( FIG. 10   a )—in the form of notches in curves  154 , which reinforce subregion  152 . In addition, a further, U-shaped region  158  is located in circumferential direction  76  to the left and right of subregion  152  to support spring action that occurs when a guard  18  is installed on a flange  160  of a hand-held power tool  10 . Enlarged fastening regions  164  for attachment with flange  160  are located on ends  162  of orientation spring  150 , in circumferential direction  76 . To this end, crimping  166  that is also formed using notches and that extends perpendicularly to circumferential direction  76  is stamped in fastening regions  164 . Fastening regions  164  extend perpendicularly to circumferential direction  76  and perpendicularly to a radial direction  86  ( FIGS. 10   a  and  10   b ). For attachment with flange  160 , orientation spring  150  is inserted into a receiving region  168  of flange  160 , and flange  160  is deformed plastically in regions of attachment regions  164  of orientation spring  150 , and it is pressed onto orientation spring  150 . Via integrally formed crimping  166  in fastening regions  164 , orientation spring  150  is fixedly connected via ends  162  with flange  160 . Receiving region  168  extends in circumferential direction  76  on flange  160  ( FIGS. 10   a  and  10   b ). Additional retaining elements  170  of flange  160 , which are located in circumferential direction  76  to the left and right of central, U-shaped subregion  152  of orientation spring  150 , hold orientation spring  150  in an advantageous starting position that enables guard  18  to be installed on flange  160  and prevents orientation spring  150  from becoming damaged. In addition, retaining elements  170 , together with a radially inwardly directed wall  174  of flange  160 , limit spring travel  176  of orientation spring  150  in a radial direction  86  during installation of guard  18 . 
       FIGS. 11   a  and  12   b  show a clamping system  200  that is an alternative to toggle joint system  44  shown in  FIGS. 2 through 8 . Clamping system  200  includes a clamping band  202 , a rocker  206  formed by a clamping part  204 , and clamping means  210  formed by a screw  208 . An end  212  of clamping band  202  is bent radially outwardly and is provided with a recess  214  for receiving screw  208 . Rocker  206  includes a receiving region  216  with a counter-thread to screw  208 , thereby enabling a guard  18  to be attached to flange  16  in a clamping position using screw  208 , rocker  206 , and clamping band  202 . The thread is formed in pressed-out regions  220  of rocker  206 , which are arched in opposite directions and in a flush manner, and which are formed by subpieces. The subpieces of receiving region  216  are located on opposite sides  224 ,  226  of screw  208  along a longitudinal extension  222  of receiving region  216  in an alternating pattern and in the manner of semi-arches ( FIG. 12   b ). The counter-thread is formed in the center, in a side  228  of rocker  208  that determines the lamella thickness. To prevent screw  208  from accidentally moving out of recess  214  when guard  18  is installed, end  212  includes a screw retention  230 , in that end regions  232  of end  212  are bent in direction  234  of a screw head  236  of screw  208  such that it is fixed in position in radial direction  86  inside recess  214 . Once guard  18  has been installed on flange  16 , it may be removed simply by loosening screw  208  until it—together with rocker  206 —may be folded out of clamping band  202  and/or recess  214  with screw retention  230 . A rotation point and/or support point of rocker  206  is located on an end  238  of rocker  206  that faces away from screw  208 , and/or on end  240  of clamping band  202  that faces rocker  206 . To this end, recess  214  of end  212  of clamping band  202  is designed open to the outside, in radial direction  86 , so that screw  208  may be folded—together with rocker  206 —outwardly, and so that undercut-engagement means  242  of rocker  206  formed by teeth  244  may release a counter-toothed profile  36  of flange  16  formed by recesses  38 . Clamping system  200  is closed by performing the steps described above in the reverse order. 
       FIG. 13  shows a design of rocker  260  that is an alternative to the design shown in  FIGS. 11   a  through  12   b . Rocker  260  includes an end region formed by an end tab  262 , which extends on rocker  260  perpendicularly to a main extension surface  264  of rocker  260 . This end region includes a recess  266  with a thread for a clamping means  210  formed by a screw  208 , thereby enabling a guard  18  to be attached to a flange  16  of a hand-held power tool  10  using rocker  260 , screw  208 , and a clamping band  202 . As an alternative, instead of recess  266  for receiving screw  208 , a nut may be located in the end region. 
       FIG. 14  shows a rocker  282 , which is formed by a clamping part  280 , and which is an alternative to the design shown in  FIGS. 11   a  through  13 . Rocker  280  includes two semi-rockers  284 ,  286 , each of which has half the thickness  288  of rocker  282 . Rocker  282  also includes a receiving region  290  with a thread  292  for a clamping means  210 , which is formed by a screw  208 . Semi-rockers  284 ,  286  in receiving region  290  are designed as semi-arches, to receive screw  208 . Thread  292  is formed in the center, in a side  294  of rocker  282  that determines a lamella thickness. It is also possible to form semi-rockers  284 ,  286  simply by embossing a desired pitch shape and/or bearing that matches that of screw  208  and/or clamping means  210 .