Abstract:
The invention is based on a machine tool receptacle with a slaving device ( 12, 14, 16, 300 ), by way of which an insert tool can be operatively connected to a drive shaft ( 54 ), wherein the insert tool is operatively connectable to the slaving device ( 14, 16, 300 ) via at least one detent element ( 24, 26, 302 ), supported movably counter to a spring element ( 20, 22 ), which detent element snaps into place in an operating position of the insert tool and fixes the insert tool by positive engagement. 
     It is proposed that the insert tool is a circular saw blade ( 18, 32 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention is based on a machine tool receptacle. 
     From European Patent Disclosure EP 0 904 896 A2, a grinding machine tool receptacle for a hand-held angle grinding machine is also known. The angle grinding machine has a drive shaft that has a thread on the side toward the tool. 
     The grinding machine tool receptacle has a slaving means and a lock nut. For mounting a grinding wheel, the slaving means is slipped with a mounting opening onto a collar of the drive shaft and braced against a bearing face of the drive shaft in the circumferential direction by nonpositive engagement via the lock nut. The slaving means has a collar, extending axially on the side toward the tool, that on two radially opposed sides on its outer circumference has recesses that extend axially as far as a bottom of the collar. From each of the recesses, a respective groove extends on the outer circumference of the collar, counter to a driving direction of the drive shaft. The grooves are closed counter to the driving direction of the drive shaft and taper axially, beginning at the recesses, counter to the drive direction of the drive shaft. 
     The grinding wheel has a tool hub with a mounting opening, in which two opposed tongues are disposed, pointing radially inward. The tongues can be introduced axially into the recesses and then in the circumferential direction, counter to the driving direction, into the grooves. The grinding wheel is fixed by positive engagement in the grooves in the axial direction via the tongues and by nonpositive engagement by means of the tapering contour of the grooves. During operation, the nonpositive engagement increases as a consequence of reaction forces exerted on the grinding wheel, which act counter to the driving direction. 
     To prevent the grinding wheel from running off center when the drive shaft is braked by the slaving means, a stopper, which is movably supported in the axial direction in an opening, is disposed in the region of a recess on the circumference of the collar. In a working position where the grinding wheel points downward, the stopper is deflected axially by gravity in the direction of the grinding wheel and closes the groove in the direction of the recess and blocks a motion of the tongue, located in the groove, in the driving direction of the drive shaft. 
     SUMMARY OF THE INVENTION 
     The invention is based on a machine tool receptacle, having a slaving device by way of which an insert tool can be operatively connected to a drive shaft; wherein the insert tool is operatively connectable to the slaving device via at least one detent element, supported movably counter to a spring element, which detent element snaps into place in an operating position of the insert tool and fixes the insert tool by positive engagement. 
     It is proposed that the insert tool is a circular saw blade. By means of the positive engagement, a high degree of safety can be attained, and a simple, economical, tool-less fast-clamping system for a circular saw, especially a circular power saw can be created. The circular saw blade can be securely prevented from running off center, even in the event of braked drive shafts, in which major braking moments can occur. 
     Because of the movably supported detent element, major deflection of the detent element can be made possible in the assembly of the circular saw blade, and as a result on the one hand a major overlap between two corresponding detent elements, and an especially secure positive engagement, can be realized, and on the other, a readily audible snap-in noise can be achieved, which advantageously tells the user that the snap-in operation has been completed as desired and that the tool is ready for operation. 
     The detent element can fix the circular saw blade by positive engagement directly or indirectly via an additional component, for instance via a rotatably and/or axially displaceably supported detent lever or tappet and the like coupled to the detent element. The detent element can fix the circular saw blade by positive engagement directly and/or indirectly in various directions, such as the radial direction, axial direction, and/or especially advantageously the circumferential direction. It is also possible that by the positive-engagement fixation of the circular saw blade to the detent element in a first direction, such as the radial direction, the circular saw blade is fixed by positive engagement in a second direction, for instance the circumferential direction, by means of a component separate from the detent element. 
     The movably supported detent element can be embodied in various forms that appear useful to one skilled in the art, for instance in the form of an opening, protrusion, peg, bolt, and so forth, and can be disposed on the circular saw blade or on the slaving device. The detent element can itself be supported movably in a component at a bearing point, for instance in a flange of the slaving device or in a tool hub of the circular saw blade. Moreover, by means of the positive engagement, an advantageous coding can be attained, so that only intended circular saw blades can be fastened in the machine tool receptacle. The slaving device can be embodied at least in part as a separable adapter part, or it can be joined inseparably to the drive shaft by nonpositive engagement, positive engagement, and/or material engagement. 
     The detent element can be embodied as movable in various directions counter to a spring element, for instance in the circumferential direction or especially advantageously in the axial direction, as a result of which a structurally simple embodiment is attainable. 
     In a further feature of the invention, it is proposed that a drive moment can be transmitted via a positive-engagement connection between the circular saw blade and the slaving device. A high drive moment can be securely transmitted, and moreover, a drive moment can be prevented from acting on a nonpositive connection. 
     If the detent element can be released from its detent position by an unlocking button, then independent separation of the detent connection, for instance by a braking moment, can be securely avoided, and safety can thus be enhanced. Operation of the circular saw blade in two circumferential directions can be made fundamentally possible, and the convenience upon mounting and unmounting of the circular saw blade can be increased. 
     It is also proposed that the circular saw blade is connectable to the slaving device via a tongue-and-groove connection, which is secured by positive engagement via at least one detent element in an operating position of the circular saw blade. With a tongue-and-groove connection, an especially space-saving, lightweight construction can be attained, in which individual components are used for multiple functions; for instance, the detent element and/or spring elements that engage grooves can be used for radial centering, fixation in the axial direction, and/or fixation in the circumferential direction. 
     If the circular saw blade is connected to the slaving device in the circumferential direction via at least a first element and in the axial direction via at least a second element, however, then simple and economical tool hubs can be attained, which can advantageously be embodied as flat. The tool hubs can be prevented from catching in production and storage, and good manipulation of the circular saw blade with its tool hubs can be made possible. The components can furthermore be designed advantageously for their function, that is, for either the fixation in the circumferential direction or the fixation in the axial direction. The elements can be formed by a single component or advantageously by separate components. The tool hubs can advantageously be embodied simply, with a closed centering bore, and low-vibration running of the circular saw blade can be made possible. Also, given a suitable choice of the diameter of the centering bore, it can be attained that circular saw blades intended for the machine tool receptacle of the invention can be secured to conventional circular saw blades via already-known fastening devices known, specifically via fastening devices in which the circular saw blade can be fixed by positive engagement in the axial direction and by nonpositive engagement in the circumferential direction on the drive shaft against a bearing face, using a tightening screw or tightening nut. 
     In a further feature, it is proposed that at least one detent element, extending in the axial direction, snaps into a recess, corresponding to the detent element, of a tool hub of the circular saw blade in an operating position of the circular saw blade and fixes the circular saw blade in the circumferential direction by positive engagement. With a structurally simple embodiment, an advantageous positive engagement in one circumferential direction and preferably in both circumferential directions can be attained. The axially extending detent element can be formed by a separate bolt or by a formed-on peg, the latter made for instance by a deep-drawing operation, and so forth. 
     Advantageously, at least one detent element extending in the axial direction is secured in a component supported displaceably on the drive shaft counter to the spring element. One and especially advantageously a plurality of detent elements can be well guided on the drive shaft via a large bearing area. Tilting of the detent elements and motion of the detent elements relative to one another can be avoided reliably, and with a spring element that can advantageously be disposed centrally and rotationally symmetrically, a desired spring force for a detent operation can be achieved. However, it is also possible for one or more detent elements to be embodied as displaceable, each in respective bearing points, counter to at least one spring element each, or counter to a common spring element. 
     It is also proposed that the slaving device has at least one fastening element, extending in the axial direction, which can be passed through at least one region of an elongated slot of the circular saw blade and in the elongated slot is displaceable in a narrower region of the elongated slot, and by way of which the circular saw blade is axially fixable in the elongated slot via a contact face disposed on the fastening element. The tool hub can advantageously be embodied economically and essentially flat and can be used as a spring element, for instance elastically deforming the tool hub upon displacement of the component in the elongated slot. The tool hub can furthermore be used to deflect a component counter to a spring element in the axial direction. Additional components and installation effort and expense can be saved as a result. 
     To make a long spring travel of the hub possible, advantageously a component forming a bearing face for the circular saw blade, in the fastened state of the circular saw blade, has a recess in the region of the elongated slot, into which recess part of the circular saw blade is pressed elastically, in an operating position of the circular saw blade. 
     If the fastening element extending in the axial direction is supported elastically displaceably in the axial direction counter to a spring element, for axially fixing the circular saw blade, on the one hand an advantageously long spring travel can be attained independently of the tool hub, and on the other, the component and the spring element can be designed in a targeted way for their separate functions. However, the fastening element can also be embodied at least in part integrally with a spring element. If a plurality of axially extending components are provided for the axial fixation, then they can each be loaded via a respective spring element or advantageously via one common spring element, so that additional components, installation effort, weight and expense can all be saved. 
     To achieve an advantageous centering and low-vibration running of the circular saw blade, a collar, by way of which the circular saw blade can be radially centered, is preferably formed onto a component of the slaving device that forms a bearing face for the circular saw blade. A self-contained centering face can simply be formed. Forces on the circular saw blade in the radial direction can advantageously be absorbed by positive engagement, an example being forces in the radial direction when some item is severed. Forces can be prevented from acting radially on components that are axially displaceable, thus preventing consequent damage or wear to these components. In addition, a radial play of the insert tool is reliably avoided, so that better concentricity is attainable. Instead of a collar, an indentation which the tool hub in the secured state engages with a protrusion is also fundamentally conceivable. 
     The circular saw blade and its tool hub can be produced by various methods that appear useful to one skilled in the art. Especially advantageously, however, in one production operation, especially a laser-cutting process, for producing an outer contour of the circular saw blade, at least one recess for the machine tool receptacle can be made in the circular saw blade or the tool hub, making economy of production time and expense possible. Furthermore, it is possible to produce the circular saw blade with its tool hub in a stamping operation. 
     If at least one detent element is integrally formed onto a disklike component and/or if at least two elements for fixing the circular saw blade in the axial direction are integrally formed onto a disklike component, then additional components, assembly effort and expense can be saved. Moreover, pressed connections between individual components and the resultant leak points can be avoided. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1, a circular power saw obliquely from above; 
     FIG. 2, a schematic cross section taken along the line II—II of FIG. 1 through a machine tool receptacle of the invention; 
     FIG. 3, a tool hub seen from a side remote from the circular power saw; 
     FIG. 4, a variant of FIG. 2; 
     FIG. 5, an exploded view of a variant of FIG. 4; 
     FIG. 6, a tool hub of FIG. 5 from a side remote from the circular power saw; 
     FIG. 7, a section taken along the line VII—VII of FIG. 6; 
     FIG. 8, an unlocking button of FIG. 5 from a side remote from the circular power saw; 
     FIG. 9, a section taken along the line IX—IX of FIG. 8; 
     FIG. 10, a slaving element of FIG. 5 from a side remote from the circular power saw; 
     FIG. 11, the slaving element of FIG. 10 from the side; 
     FIG. 12, a section taken along the line XII—XII of FIG. 10; 
     FIG. 13, an exploded view of a variant of FIG. 4; 
     FIG. 14, a section through a slaving disk of FIG. 13 with a bolt formed onto it; 
     FIG. 15, a side view of a sheet-metal plate of FIG. 13; and 
     FIG. 16, a slaving flange from FIG. 13, seen from below. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a circular saw  10  obliquely from above, with an electric motor, not shown, supported in a housing  96 . The circular power saw  10  can be guided via a first handle  98 , integrated with the housing  96 , and a second handle  102 , secured to a guard baffle  100 . 
     With the electric motor, via a gear not shown, a drive shaft  54  can be driven, on whose end pointing toward the circular saw blade  18  a slaving device  12  is disposed (FIG.  2 ). The slaving device  12 , on a side toward the circular saw blade  18 , has a slaving flange  82  pressed firmly onto the drive shaft  54 , and on a side remote from the circular saw blade  18 , it has a slaving disk  56  that is supported dlsplaceably on the drive shaft  54  axially counter to a centrally disposed helical spring  20 . 
     In the slaving flange  82 , three pins  40  disposed at uniform intervals one after the other in the circumferential direction  34 ,  36  and extending in the axial direction  38  to the circular saw blade  18  past the slaving flange  82  are press-fitted into the slaving flange  82 . On their end pointing toward the circular saw blade  18 , the pins  40  each have one head, which has a larger diameter than a remainder of the pin  40 , and on a side toward the slaving flange  82 , this head has a transmission face  76  that narrows in the axial direction  44 . The slaving flange  82  forms an axial bearing face  80  for the circular saw blade  18 , which face defines an axial position of the circular saw blade  18 ; recesses  84  are made in this face in the region of the pins  40 . Three axial through bores  104  are also made in the slaving flange  82  one after the other in the circumferential direction  34 ,  36 ; specifically, one through bore  104  is disposed between each two pins  40  in the circumferential direction  34 ,  36 . 
     Three bolts  24  are press-fitted one after the other in the circumferential direction  34 ,  36  into the slaving disk  56  that is supported axially displaceably on the drive shaft  54 ; these bolts extend in the axial direction  38  to the circular saw blade  18  via the slaving disk  56 . The slaving disk  56  is pressed by the helical spring  20  in the direction  38  toward the circular saw blade  18  against the slaving flange  82 . The bolts  24  protrude through the through bores  104  and extend in the axial direction  38  past the slaving flange  82 . 
     The slaving device  12  also has a cup-shaped unlocking button  28 , disposed centrally on the side toward the circular saw blade  18 . The unlocking button  28  has three segments  106 , distributed uniformly in the circumferential direction  34 ,  36  and extending in the axial direction  44  to the axially movably supported slaving disk  56 , which segments reach through corresponding recesses  108  in the slaving flange  82  and are secured against falling out in the axial direction  38  via a snap ring  110  with the slaving disk  56 . The unlocking button  28  is guided displaceably in the axial direction  38 ,  44  in an annular recess  112  in the slaving flange  82 . 
     The circular saw blade  18  has a tool hub  52 , which is embodied integrally with the circular saw blade  18 . In principle, a tool hub that is connected to the circular saw blade via a nonpositive, positive and/or material engagement would also be conceivable. The tool hubs can then be made from some material, independent of the circular saw blade itself, that seems useful to one skilled in the art, such as a special plastic. The tool hub  52 , in the circumferential direction  34 ,  36 , has three uniformly distributed bores  46 , 48 ,  50 , whose diameter is slightly greater than the diameter of the bolts  24 . The tool hub  52  also has three elongated slots  64 ,  66 ,  68 , extending in the circumferential direction  34 ,  36  and distributed uniformly in the circumferential direction  34 ,  36 , each having a respective narrow region  70 ,  72 ,  74  and a respective wide region  58 ,  60 ,  62  that is produced by means of a bore, and whose diameter is slightly greater than the diameter of the heads of the pins  40 . 
     The tool hub  52  has a centering bore  116 , whose diameter is advantageously selected such that the circular saw blade  18  can be clamped on a conventional circular power saw with a conventional chucking system that has one or two chucking flanges and a clamping screw or tightening nut. This assures so-called downward compatibility. 
     Upon installation of the circular saw blade  18 , the circular saw blade  18  is slipped with its centering born  116  onto the unlocking button  28  and centered radially. Next, the circular saw blade  18  is rotated, until the pins  40  engage the wide regions  58 ,  60 ,  62 , intended for them, in the elongated slots  64 ,  66 ,  68  of the tool hub  52 . Pressing the tool hub  52  against the bearing face  80  of the slaving flange  82  has the effect that the bolts  24  in the through bores  104  and also the slaving disk  56  are displaced counter to a spring force of the helical spring  20  axially on the drive shaft  54  in the direction  44  remote from the circular saw blade. 
     Further rotation of the tool hub  52  counter to the drive direction  34  has the effect that the pins  40  are displaced into the curved, narrow regions  70 ,  72 ,  74  of the elongated slots  64 ,  66 ,  68 . In the process, with their conical contact faces  76 , the pins  40  press against the edges of the elongated slots  64 ,  66 ,  68  and press them elastically into the recesses  84  of the slaving flange  82 . As a result, the tool hub  52  is pressed against the bearing face  80  and is fixed in the axial direction  38 ,  44 . 
     In a terminal position, or in an operating position of the circular saw blade  18  that is attained, the bores  46 ,  48 ,  50  in the tool hub  52  come to rest above the through bores  104  of the slaving flange  82 . By the spring force of the helical spring  20 , the bolts  24  are axially displaced in the direction  38  of the circular saw blade  18  and snap into the bores  46 ,  48 ,  50  of the tool hub  52  and fix the tool hub by positive engagement in both circumferential directions  34 ,  36 . Upon snapping into place, a snapping noise that is audible to a user occurs, indicating operating readiness to the user. 
     A driving moment of the electric motor of the circular power saw  10  can be transmitted by the drive shaft  54  to the slaving flange  82  by nonpositive engagement and by the slaving flange  82  to the circular saw blade  18  via the bolts  24  by positive engagement. The drive moment is transmitted solely via the bolts  24 , since the elongated slots  64 ,  66 ,  68  are designed such that when the bolts  24  have snapped into place, the pins  40  do not come to rest on the end of the narrow regions  70 ,  72 ,  74  of the elongated slots  64 ,  66 ,  68 . In addition, a braking moment that occurs when the electric motor is switched off and thereafter and which is oriented counter to the driving moment can be transmitted by positive engagement from the slaving flange  82  to the circular saw blade  18  via the bolts  24 . Unintended loosening of the circular saw blade  18  is reliably avoided. By means of the three bolts  24  uniformly distributed in the circumferential direction  34 ,  36 , an advantageous uniform distribution of both force and mass is attained. 
     To release the circular saw blade  18  from the circular power saw  10 , the unlocking button  28  is pressed. The slaving disk  56  is displaced with the bolts  24  via the unlocking button  28 , counter to the helical spring  20 , in the axial direction  44  remote from the circular saw blade  18 , and as a result the bolts  24  move in the axial direction  44  out of their detent position, that is, out of the bores  46 ,  48 ,  50  of the tool hub  52 . Next, the circular saw blade  18  is rotated in the driving direction  34 , specifically until the pins  40  come to rest in the wide regions  58 ,  60 ,  62  of the elongated slots  64 ,  66 ,  68 , and the circular saw blade  18  can be removed from the slaving flange  82  in the axial direction  38 . Once the unlocking button  28  is let go, the slaving disk  56 , bolts  24  and unlocking button  28  are displaced backward into their outset positions by the helical spring  20 . 
     In FIG. 4, an alternative exemplary embodiment to the exemplary embodiment of FIG. 2 is shown, with a slaving device  14 . Components that remain essentially the same are identified by the same reference numerals in the exemplary embodiments shown. Also, the description of the exemplary embodiment in FIGS. 2 and 3 can be referred to for characteristics and functions that remain the same. 
     The slaving device  14  has a slaving flange  90  pressed onto the drive shaft  54 . A collar  92  is formed onto the slaving flange  90 , which forms a bearing face  88  for the circular saw blade  18 ; by way of this collar, the circular saw blade  18  is radially centered in the state in which it is mounted with its centering bore  116 . Radial forces can advantageously be absorbed by the slaving flange  90  without puffing a load on the unlocking button  28 . 
     Also in the slaving flange  90 , three pins  42  distributed uniformly in the circumferential direction  34 ,  36  and extending in the axial direction  38  past the bearing face  88  are supported displaceably in the axial direction  38 , each against a respective cup spring  86 , for the sake of axial fixation of the circular saw blade  18 . Each of the pins  42 , on its end pointing toward the circular saw blade  18 , has a head, which has a larger diameter than a remaining portion of the pin  42 , and on a side toward the slaving flange  90 , the pins have a conical contact face  78 , which tapers in the axial direction  44 , and a contact face  78   a  extending parallel to the bearing face  78 . If the heads of the pins  42  are guided by the wide regions  58 ,  60 ,  52  of the elongated slots  64 ,  66 ,  68 , then a rotation of the tool hub  52  counter to the driving direction  34  causes the pins  42  to be displaced into the curved narrow regions  70 ,  72 ,  74  of the elongated slots  64 ,  66 ,  68 . In the process, the pins  42  are displaced axially in the direction  38 , counter to the pressure of the cup springs  86 , via the conical contact faces  78  until the contact faces  78   a  of the pins  40  cover the edges of the elongated slots  64 ,  66 ,  68  in the curved narrow regions  70 ,  72 ,  74 . 
     In the installed state, the cup springs  86 , via the contact faces  78  of the pins  42 , press the circular saw blade  18  against the bearing face  78   a . Instead of being loaded with a plurality of cup springs  86 , the pins can also be loaded via other spring elements that appear useful to one skilled in the art, such as one cup spring, not shown, with its centering bore is radially centered in the installed state. Radial forces can advantageously be absorbed by the slaving flange  90 , without putting a load on an unlocking button  28 . 
     In FIGS. 5-12, one further exemplary embodiment with a slaving device  16  is shown. The slaving device  16  has a slaving flange  118  (FIG. 5; FIGS. 10,  11  and  12 ) secured via a thread  120  to a drive shaft not identified by reference numeral. The slaving flange could also be joined to the drive shaft via an inseparable connection or integrally embodied with it. 
     The slaving flange  118  has three segments  122 ,  124 ,  126 , distributed uniformly in the circumferential direction  34 ,  36  and extending in the axial direction  38  toward a circular saw blade  32 , and between the segments it has interstices  128 ,  130 ,  132  (FIG.  10 ). Each of these segments  122 ,  124 ,  126  has a groove  134 ,  136 ,  138  on its circumference; these grooves are closed counter to the drive direction  34 , each via a respective rotation stop  140 ,  142 ,  144 , and are open in the drive direction  34 . The slaving flange  118  furthermore has a bearing face  114 , which defines an axial position of the circular saw blade  32 . The segments  122 ,  124 ,  126  furthermore form a centering collar for the circular saw blade  32 , by way of which the circular saw blade  32  can be centered. 
     In the installed state, a detent element  26  is connected to the slaving flange  118  via three detent pegs  146 ,  148 ,  150  distributed in the circumferential direction  34 ,  36 , which reach through corresponding recesses  158 ,  160 ,  162  of the slaving flange  118  and radially outward engage the slaving flange  118  from behind (FIGS. 5,  8  and  9 ). On the detent element  26 , which at the same time forms an unlocking button  30 , three radially outward-extending blocking segments  152 ,  154 ,  156  are formed on, distributed uniformly in the circumferential direction  34 ,  36 . Between the slaving flange  118  and the detent element  26  is a helical compression spring  22 , against which the detent element  26  is displaceable, in the axial direction  44  remote from the circular saw blade  32 , relative to the slaving flange  118 . Via radially outward-pointing bearing faces  164 ,  166 ,  168  between the blocking segments  152 ,  154 ,  156 , the detent element  26  is guided in radially inward-pointing faces of the segments  122 ,  124 ,  126  of the slaving flange  118 . To prevent canting of the detent element  26  and to attain small bearing faces  164 ,  166 ,  168 , the bearing faces  164 ,  166 ,  168  are formed by radially outward-extending protrusions  170  (FIG.  8 ). 
     In the installed state, the blocking segments  152 ,  154 ,  156  are located in the interstices  128 ,  130 ,  132  of the slaving flange  118  and protrude radially past a groove bottom of the grooves  134 ,  136 ,  138 . In an outset position, before the circular saw blade  32  is installed, the blocking segments  152 ,  154 ,  156  of the detent element  26  are located in front of the grooves  134 ,  136 ,  138 , and specifically are loaded by the prestressed helical compression spring  22 . 
     A tool hub  94  is integrally formed onto the circular saw blade  32 ; on its inner diameter it has radially inward-pointing tongues or spring elements  172 ,  174 ,  176  for a tongue-and-groove connection (FIGS. 5,  6  and  7 ). In conjunction with the slaving flange  118  and the unlocking button  30 , the spring elements  172 ,  174 ,  176  serve to transmit the drive moment, to position the circular saw blade  32  axially, and to secure the circular saw blade  32  against running off center when the electric motor is turned off or the drive shaft is braked. In addition, along with the segments  122 ,  124 ,  126 , the spring elements can be used for centering the circular saw blade  32  relative to the drive shaft. 
     In the installation of the circular saw blade  32 , the circular saw blade is aligned with the slaving flange  118 , so that the spring elements  172 ,  174 ,  176  on the inner diameter of the tool hub  94  point into the interstices  128 ,  130 ,  132  between the segments  122 ,  124 ,  126  of the slaving flange  118 . The spring elements  172 ,  174 ,  176  of the circular saw blade  32  rest on the blocking segments  152 ,  154 ,  156  of the unlocking button  30 . Next, the circular saw blade  32  is pressed in the axial direction  44  until it reaches the bearing face  114  of the slaving flange  118 . The spring elements  172 ,  174 ,  176  displace the unlocking button  30 , with its blocking segments  152 ,  154 ,  156 , in the direction  44  axially remote from the circular saw blade  32 , counter to the spring force of the helical compression spring  22 . The blocking segments  152 ,  154 ,  156  are pressed into recesses  178  of the slaving flange  118  (FIG.  12 ), so that the spring elements  172 ,  174 ,  176  come to rest in front of the grooves  134 ,  136 ,  138 . 
     In the process, the circular saw blade  32  is radially centered via the centering collar formed by the segments  122 ,  124 ,  126 . By rotation of the circular saw blade  32  counter to the drive direction  34 , the spring elements  172 ,  174 ,  176  engage the grooves  134 ,  136 ,  138  of the slaving flange  118 . A tongue-and-groove connection is made. The spring elements  172 ,  174 ,  176  have the same length in the circumferential direction  36  as the grooves  134 ,  136 ,  138 . Once the spring elements  172 ,  174 ,  176  have been thrust all the way into the grooves  134 ,  136 ,  138 , that is, once an operating position of the circular saw blade  32  is reached, the detent element  26  with its blocking segments  152 ,  154 ,  156  snaps into place, and the helical compression spring  22  presses the detent element  26  with its blocking segments  152 ,  154 ,  156  into its outset position, so that once again the blocking segments  152 ,  154 ,  156  come to rest in front of the grooves  134 ,  136 ,  138 . With its blocking segments  152 ,  154 ,  156 , the detent element  26  fixes the circular saw blade  32  by positive engagement counter to the drive direction  34 . The process of snapping into place creates a snap-in noise that is audible to a user and indicates to the user that the snap-in process has been completed as desired, and the system is ready for operation. 
     The transmission of the drive moment to the spring elements  172 ,  174 ,  176  of the tool hub  94  or circular saw blade  32  is done by positive engagement via the rotation stops  140 ,  142 ,  144  of the slaving flange  118 . The circular saw blade  32  is centered via the centering collar formed by the segments  122 ,  124 ,  126  of the slaving flange  118  and is held in its axial position by the bearing face  114  and the grooves  134 ,  136 ,  138 . In addition, a braking moment, oriented counter to the drive moment and occurring upon and after the shutoff of the electric motor, is transmitted by positive engagement from the blocking segments  152 ,  154 ,  156  and the slaving flange  118  to the spring elements  172 ,  174 ,  176  of the circular saw blade  32 . 
     An equalization of play is achieved in the axial direction by means of a spring element, not identified by reference numeral but formed by a tool strip, in the grooves  134 ,  136 ,  138 . An equalization of play could also be attained via other spring elements appearing useful to one skilled in the art, such as spring-loaded balls that are placed at suitable points of the slaving flange and that fix the tool hub of the circular saw blade without play, and/or with a slight oversize of the spring elements of the tool hub, by means of a slightly wedgelike shape of the grooves and the spring elements of the tool hub, and so forth. 
     For releasing the circular saw blade  32 , the unlocking button  30  is pressed in the axial direction  44  remote from the circular saw blade  32 . The blocking segments  152 ,  154 ,  156  of the unlocking button  30  and of the detent element  26  are displaced into the recesses  178  of the slaving flange  118 . Next, with its spring elements  172 ,  174 ,  176 , the circular saw blade  32  can be rotated in the drive direction  34  out of the grooves  134 ,  136 ,  138  of the slaving flange  118  and pulled off in the axial direction  38 . As the circular saw blade  32  is pulled off, the unlocking button  30  is compressed into its outset position by the helical compression spring  22 . 
     In FIG. 13, an alternative exemplary embodiment to the exemplary embodiment of FIG. 4 is shown, with a slaving device  300 . The slaving device  300  has a slaving flange  90 , which forms a bearing face  88  for a circular saw blade, not identified by reference numeral here. On the side toward the circular saw blade, a collar  92  is formed onto the slaving flange  90 , and by way of this collar the circular saw blade with its centering bore is radially centered in the installed state. Radial forces can advantageously be absorbed by the slaving flange  90 , without putting a load on an unlocking button  28 . 
     On a side of the slaving flange  90  remote from the circular saw blade, a tool plate  308  for axial fixation of the circular saw blade is disposed, having three circumferentially uniformly distributed, integrally formed-on fastening elements  306  that extend in the axial direction  38 . The fastening elements  306  are formed onto the tool plate  308  in a bending operation. 
     Upon installation, the slaving flange  90 , a wave washer  312  and the tool plate  308  are pre-installed. In the process, the wave washer  312  is slipped onto a collar  322 , pointing in the direction away from the circular saw blade, of the slaving flange  90 . Next, the fastening elements  306  of the tool plate  308 , which on their free end have a hook-shaped extension with an oblique face  310  pointing in the circumferential direction (FIGS.  13  and  15 ), are guided in the axial direction  38  by recesses  314  of the slaving flange  90 , specifically by widened regions  316  of the recesses  314  (FIGS.  13  and  15 ). By compression and rotation of the tool plate  308  and slaving flange  90  against one another, the wave washer  312  is pre-stressed, and the tool plate  308  and the slaving flange  90  are connected by positive engagement in the axial direction  38 ,  44 , specifically in that the hook-shaped extensions are rotated into narrow regions  318  of the recesses  314  (FIGS. 13,  15  and  16 ). Next, loaded by the wave washer  312 , the tool plate  308  is braced on the bearing face  88  of the slaving flange  90  via edges  310   a  of the hook-shaped extensions, which point axially in the direction away from the circular saw blade. 
     Once the tool plate  308  with the formed-on fastening elements  306 , the wave washer  312  and the slaving flange  90  have been pre-installed, a compression spring  20  and a slaving disk  304 , with three circumferentially uniformly distributed, integrally formed-on bolts  302  extending in the axial direction  38 , are slipped onto a drive shaft  54 . The bolts  302  are formed onto a tool plate forming the slaving disk  304  in a deep-drawing operation (FIG.  14 ). 
     Next, the pre-installed group of components, comprising the tool plate  308 , wave washer  312  and slaving flange  90 , are mounted on the drive shaft  54 . In this operation, the bolts  302  are guided by recesses  320  formed onto the circumference of the tool plate  308  and by through bores  104  in the slaving flange  90 , and in the installed state they reach through the through bores  104 . The sheet-metal plate  308  and the slaving flange  90  are secured against rotating relative to one another via the bolts  302 . 
     The slaving flange  90  is pressed onto the drive shaft  54  and then secured with a securing ring, not shown in detail. Instead of a press-fitted connection, however, other connections that appear useful to one skilled in the art are also conceivable, such as a threaded connection, and so forth. 
     Once in the installation of a circular saw blade  18  (see FIGS. 3 and 4) the hook-shaped extensions of the fastening elements  306  are guided through the wide regions  58 ,  60 ,  62  of the elongated slots  64 ,  66 ,  68  of the tool hub  52  (FIG.  13 ), rotating the sheet-metal hub  52  counter to the driving direction  34  has the effect of displacing the hook-shaped extensions into the curved, narrow regions  70 ,  72 ,  74  of the elongated slots  64 ,  66 ,  68  of the tool hub  52 . In the process, the tool plate  308  with the fastening elements  306  is displaced axially in the direction  38  via the oblique faces  310  counter to the pressure of the wave washer  312 , until the edges  310   a  of the hook-shaped extensions come to rest in curved, narrow regions  70 ,  72 ,  74  laterally next to the elongated slots  64 ,  66 ,  68  of the tool hub  53 . In the installed state, the wave washer  312 , via the edges  310   a  of the hook-shaped extensions, presses the circular saw blade  18  against the bearing face  88 . 
     Alternatively, the fastening elements and elongated slots in the tool hub could be embodied as rotated by 180°, reversing the direction of installation, and the sheet-metal hubs would be rotated in the driving direction upon assembly. If the fastening elements are embodied as rotated by 180°, then in operation an oblique face of a lower face-end edge of the fastening element is in the lead, so that injuries from the face-end edge can be prevented. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 List of Reference Numerals 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10  
                 Circular power saw 
               
               
                 12  
                 Slaving device 
               
               
                 14  
                 Slaving device 
               
               
                 16  
                 Slaving device 
               
               
                 18  
                 Circular saw blade 
               
               
                 20  
                 Spring element 
               
               
                 22  
                 Spring element 
               
               
                 24  
                 Detent element 
               
               
                 26  
                 Detent element 
               
               
                 28  
                 Unlocking button 
               
               
                 30  
                 Unlocking button 
               
               
                 32  
                 Circular saw blade 
               
               
                 34  
                 Circumferential direction 
               
               
                 36  
                 Circumferential direction 
               
               
                 38  
                 Direction 
               
               
                 40  
                 Fastening element 
               
               
                 42  
                 Fastening element 
               
               
                 44  
                 Direction 
               
               
                 46  
                 Recess 
               
               
                 48  
                 Recess 
               
               
                 50  
                 Recess 
               
               
                 52  
                 Tool hub 
               
               
                 54  
                 Drive shaft 
               
               
                 56  
                 Component 
               
               
                 58  
                 Region 
               
               
                 60  
                 Region 
               
               
                 62  
                 Region 
               
               
                 64  
                 Elongated slot 
               
               
                 66  
                 Elongated slot 
               
               
                 68  
                 Elongated slot 
               
               
                 70  
                 Region 
               
               
                 72  
                 Region 
               
               
                 74  
                 Region 
               
               
                 76  
                 Contact face 
               
               
                 78  
                 Contact face 
               
               
                 80  
                 Bearing face 
               
               
                 82  
                 Component 
               
               
                 84  
                 Recess 
               
               
                 86  
                 Spring element 
               
               
                 88  
                 Bearing face 
               
               
                 90  
                 component 
               
               
                 92  
                 Collar 
               
               
                 94  
                 Tool hub 
               
               
                 96  
                 Housing 
               
               
                 98  
                 Handle 
               
               
                 100  
                 Guard baffle 
               
               
                 102  
                 Handle 
               
               
                 104  
                 Through bore 
               
               
                 106  
                 Segment 
               
               
                 108  
                 Recess 
               
               
                 110  
                 Snap ring 
               
               
                 112  
                 Recess 
               
               
                 114  
                 Bearing face 
               
               
                 116  
                 Centering bore 
               
               
                 118  
                 Slaving flange 
               
               
                 120  
                 Thread 
               
               
                 122  
                 Segment 
               
               
                 124  
                 Segment 
               
               
                 126  
                 Segment 
               
               
                 128  
                 Interstice 
               
               
                 130  
                 Interstice 
               
               
                 132  
                 Interstice 
               
               
                 134  
                 Groove 
               
               
                 136  
                 Groove 
               
               
                 138  
                 Groove 
               
               
                 140  
                 Rotation stop 
               
               
                 142  
                 Rotation stop 
               
               
                 144  
                 Rotation stop 
               
               
                 146  
                 Detent peg 
               
               
                 148  
                 Detent peg 
               
               
                 150  
                 Detent peg 
               
               
                 152  
                 Blocking segment 
               
               
                 154  
                 Blocking segment 
               
               
                 156  
                 Blocking segment 
               
               
                 158  
                 Recess 
               
               
                 160  
                 Recess 
               
               
                 162  
                 Recess 
               
               
                 164  
                 Bearing face 
               
               
                 166  
                 Bearing face 
               
               
                 168  
                 Bearing face 
               
               
                 170  
                 Protrusion 
               
               
                 172  
                 Spring elements 
               
               
                 174  
                 Spring elements 
               
               
                 176  
                 Spring elements 
               
               
                 178  
                 Recess 
               
               
                 300  
                 Slaving device 
               
               
                 302  
                 Detent element 
               
               
                 304  
                 component 
               
               
                 306  
                 Element 
               
               
                 308  
                 Component 
               
               
                 310  
                 Oblique face 
               
               
                 310a 
                 Edge 
               
               
                 312  
                 Spring element 
               
               
                 314  
                 Recess 
               
               
                 316  
                 Region 
               
               
                 318  
                 Region 
               
               
                 320  
                 Recess 
               
               
                 322  
                 Collar