Patent Publication Number: US-10780562-B2

Title: Hand tool device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of U.S. patent application Ser. No. 14/273,176, filed May 8, 2014, now U.S. Pat. No. 10,046,449, which claims priority to German Patent Application No. 10 2013 208 882.5, filed May 14, 2013, both of which are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a hand tool device which has a tool spindle and a hammer mechanism. 
     2. Description of the Related Art 
     A hand tool device has already been proposed which has a tool spindle and a hammer mechanism including a hammer and at least one curve guide which drives the hammer at least during a hammer drilling operation. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to a hand tool device which has a tool spindle and a hammer mechanism including a hammer and at least one curve guide which drives the hammer at least during a hammer drilling operation. 
     It is proposed that the tool spindle has at least one bearing surface on which the hammer is, in particular, at least movably supported at least during one operating state. A “tool spindle” is, in particular, to be understood to mean a shaft which transfers a rotational movement from a transmission of the hand tool device to an insert tool holding fixture of the hand tool device. The bearing surface preferably subjects the hammer to a bearing force which is oriented in a radial direction. During the hammer drilling operation in the impact direction, the hammer is preferably moved in an essentially translatory manner in the impact direction, while the tool spindle is rotatably driven during the hammer drilling operation. The tool spindle is preferably designed as a solid shaft. Alternatively, the tool spindle might be designed as a hollow shaft. A “hammer mechanism” is, in particular, to be understood to mean a device which is provided to generate an impact momentum and to output it, in particular, in the direction of an insert tool. Preferably, the hammer mechanism advantageously relays the impact momentum to the insert tool via the tool spindle and/or in particular via the insert tool holding fixture of the hand tool device at least during a hammer drilling operation. The hammer mechanism is preferably provided to convert a rotational movement into a translatory impact movement, in particular. In particular, the hammer mechanism is not designed as a ratchet-controlled hammer mechanism. The term “provided” is, in particular, to be understood to mean specially programmed, designed and/or equipped. In particular, the term “hammer” is to be understood to mean a means which is, in particular, at least essentially accelerated in a translatory manner at least during the hammer drilling operation and which outputs a momentum, which it acquired during the acceleration, as an impact momentum in the direction of the insert tool. The hammer is preferably designed as one piece. Alternatively, the hammer may also have a multi-part design. In particular, a “curve guide” is to be understood to mean a device which converts a kinetic energy of rotation for an impact generation into a linear kinetic energy of the hammer at least with the aid of a specially formed guiding area along which a connecting means runs at least during a hammer drilling operation. The hammer mechanism preferably has a hammer mechanism spring which stores the linear kinetic energy of the hammer for impact generation. The specially formed area is preferably an area which delimits a guiding curve of the curve guide. The curve guide is preferably provided to induce the hammer once to an impact during one rotation of a hammer mechanism spindle of the hand tool device. Alternatively, the curve guide may also be provided to induce the hammer to at least two or advantageously three impacts during one rotation of the hammer mechanism spindle. In this case, a hammer mechanism transmission stage might be dispensed with. The curve guide preferably subjects the hammer to a force which points away from the insert tool holding fixture. A “connecting means” is, in particular, to be understood to mean a means which establishes a mechanical coupling between at least one part of the hammer mechanism, in particular a hammer mechanism spindle which moves rotatingly during a hammer drilling operation, and the hammer which moves linearly, in particular. The connecting means is preferably designed as a sphere. Alternatively, the connecting means may also have a different shape which appears to be reasonable to those skilled in the art. The connecting means preferably has a diameter which is greater than 4 mm, advantageously greater than 5 mm, and particularly advantageously greater than 6 mm. The connecting means preferably has a diameter which is smaller than 14 mm, advantageously smaller than 10 mm, and particularly advantageously smaller than 8 mm. A “hammer drilling operation” is, in particular, to be understood to mean an operation of the hand tool device during which the insert tool is rotatably and percussively driven, while work is being done on a workpiece. In particular, a “bearing surface” is to be understood to mean a surface which subjects the hammer during an operation to a bearing force vertically to the surface and allows the hammer to move in parallel to the surface. The bearing surface is preferably provided so that the hammer slides on the surface during the hammer drilling operation. The surface has preferably little roughness. Preferably, the bearing surface is, in particular, oriented completely in parallel to an impact direction of the hammer. The bearing surface is advantageously designed in the shape of a cylinder jacket. The bearing surface is preferably in contact with the hammer at least in one operating state. With the aid of the embodiment according to the present invention of the hand tool device, a bearing may be achieved which is particularly low in friction as well as wear and tear. 
     In another embodiment, it is proposed that the hammer encloses the tool spindle at least essentially on at least one plane, thus achieving large hammer dimensions, while having a small overall size. In particular, the phrase “enclosing at least essentially on at least one plane” is to be understood to mean that beams which originate from an axis of the tool spindle and which are situated on the plane intersect with the hammer over an angular range of at least 180 degrees, advantageously at least 270 degrees. Particularly advantageously, the hammer encloses the hammer mechanism spindle by 360 degrees. The plane is preferably oriented vertically to an axis of rotation of the tool spindle. 
     Furthermore, it is proposed that the hammer mechanism includes a hammer mechanism spindle having a bearing surface on which the hammer is movably supported in at least one operating state, thus making a particularly small overall size possible. A “hammer mechanism spindle” is, in particular, to be understood to mean a shaft which transfers a rotational movement directly to the curve guide. The hammer mechanism spindle advantageously transfers the rotational movement to the curve guide separately from a rotational movement which drives the insert tool holding fixture. In particular, the hammer mechanism spindle is implemented separately from the tool spindle. The hammer mechanism spindle is preferably designed as a hollow shaft. 
     Furthermore, it is proposed that the hammer encloses the hammer mechanism spindle at least essentially on at least one plane, thus achieving large hammer dimensions, while having a small overall size. 
     It is additionally proposed that the hammer delimits an inner space of the hammer in the impact direction in an inwardly constricting manner, whereby small tool spindle dimensions may be achieved constructively simply. In particular, an “inner space” is to be understood to mean a space which is situated on a straight line between at least two points in which the straight line intersects with the hammer. The hammer preferably encloses the inner space completely on at least one plane. An “impact direction” is, in particular, to be understood to mean a direction which runs in parallel to an axis of rotation of the tool chuck and which points from the hammer in the direction of the tool chuck. In particular, the phrase “delimit in an inwardly constricting manner” is to be understood to mean that a diameter of the inner space decreases vertically to the impact direction in the impact direction. The hammer preferably has an at least essentially U-shaped section in parallel to the impact direction. 
     Furthermore, it is proposed that the tool spindle has at least one impact surface which the hammer impacts at least during a hammer drilling operation, whereby a particularly simple construction may be achieved. An “impact surface” is, in particular, to be understood to mean a surface of the tool spindle through which the hammer transfers the impact momentum to the tool spindle in at least one operating state. The hammer preferably impacts the tool spindle directly. Alternatively, the hammer might impact the tool spindle via a snap die. 
     In one advantageous embodiment of the present invention, it is proposed that the hammer has at least one part of the curve guide, thus making available a particularly small, lightweight, but still powerful hammer mechanism. The phrase that “the hammer has at least one part of the curve guide” is, in particular, to be understood to mean that the hammer has an area onto which a connecting means of the curve guide directly transfers the energy in order to generate the percussion movement. Preferably, the part of the curve guide, which the hammer has, is designed as an area which fixes the connecting means in place in relation to the hammer. Advantageously, the part of the curve guide, which the hammer has, includes a fastening recess which is delimited by the area which fixes the connecting means in place in relation to the hammer. Advantageously, the hammer is provided to hold a connecting means which connects during operation that part of the curve guide and another part of the curve guide, in particular the guiding curve. The connecting means and the hammer are preferably connected without the use of a spring. This means, in particular, that a spring is not operatively situated between the connecting means and the hammer. Alternatively, the connecting means might be designed, at least partially, in one piece with the hammer. Furthermore, the part of the curve guide, which the hammer has, might alternatively be designed as a guiding curve. “Fixed in place” is, in particular, to be understood to mean that an axis of symmetry and/or a central point of the connecting means is essentially immovable in relation to the hammer during a percussive operation. 
     In another embodiment, it is proposed that the hammer mechanism has at least one hammer mechanism spring which stores at least a part of an impact energy in at least one operating state, thus making available a powerful hammer mechanism constructively simply. A “hammer mechanism spring” is, in particular, to be understood to mean a spring which subjects the hammer to a force in the impact direction in at least one operating state. In particular, an “impact energy” is to be understood to mean an energy which accelerates the hammer in the impact direction prior to an impact. In this context, “storing” is, in particular, to be understood to mean that the hammer mechanism spring absorbs the impact energy at a point in time and releases it to the hammer, in particular by accelerating the hammer, at a later point in time. The curve guide preferably tensions the hammer mechanism spring. 
     Furthermore, it is proposed that the hammer mechanism spring holds the hammer in at least one operating state in the peripheral direction, thus achieving a particularly cost-effective, lightweight, and space-saving construction. In particular, a separate fastening of the hammer may be dispensed with. In particular, the phrase “held in the peripheral direction” is to be understood to mean that the hammer mechanism spring subjects the hammer in at least one operating state to a force which counteracts a force which acts on the hammer in the peripheral direction and which, in particular, causes the curve guide. The fastening of the hammer with the aid of the hammer mechanism spring preferably prevents the hammer from moving about an axis of rotation of the hammer mechanism spindle by more than 360 degrees, advantageously from moving by more than 180 degrees, and particularly advantageously from moving by more than 90 degrees. “A force acting in the peripheral direction” is, in particular, to be understood to mean a force which has at least one component which is oriented vertically in relation to an axis of rotation of a hammer mechanism spindle of the hammer mechanism and which effectuates a torque relative to the peripheral direction of the hammer mechanism spindle. 
     The hand tool device according to the present invention is not to be limited to the application and specific embodiment described above. In particular, the hand tool device according to the present invention may have a number of individual elements, components, and units which deviate from the number mentioned herein for the purpose of fulfilling a functionality described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a section of a hand tool having a hand tool device according to the present invention. 
         FIG. 2  shows a partially exposed section through a hammer mechanism and a planetary gear of the hand tool device from  FIG. 1 . 
         FIG. 3  shows a first side view of a hammer of the hammer mechanism of the hand tool device from  FIG. 1 . 
         FIG. 4  shows a second side view of the hammer from  FIG. 3  from an opposite side. 
         FIG. 5  shows a first section area A of the hammer mechanism of the hand tool device from  FIG. 1 . 
         FIG. 6  shows the hammer from  FIG. 3  viewed in the impact direction. 
         FIG. 7  shows the hammer from  FIG. 3  in a perspective view. 
         FIG. 8  shows the hammer from  FIG. 3  viewed in the impact direction. 
         FIG. 9  shows a section area B through a first planetary gear stage of the hand tool device from  FIG. 1 . 
         FIG. 10  shows a partially exposed side view of a part of the hand tool device from  FIG. 1 . 
         FIG. 11  shows a section area C through a control element of an impact deactivation device of the hand tool device from  FIG. 1 . 
         FIG. 12  shows a section area D through a spindle blocking device of the hand tool device from  FIG. 1 . 
         FIG. 13  shows a section area E through a limiting and guiding means of the spindle blocking device of the hand tool device from  FIG. 1 . 
         FIG. 14  shows a section area F through a second planetary gear stage of the hand tool device from  FIG. 1 . 
         FIG. 15  shows a section area G through a planet carrier of a third planetary gear stage of the hand tool device from  FIG. 1 . 
         FIG. 16  shows a section area H through planetary wheels of the third planetary gear stage of the hand tool device from  FIG. 15 . 
         FIG. 17  shows a section area I through a planet carrier of a fourth planetary gear stage of the hand tool device from  FIG. 1 . 
         FIG. 18  shows a section area J through planetary wheels of the fourth planetary gear stage of the hand tool device from  FIG. 17 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows a hand tool  10 . Hand tool  10  is designed as a cordless hammer combi drill. Hand tool  10  has a hand tool device  12  according to the present invention, a hand tool housing  14 , and a battery interface  16 . Battery interface  16  is provided to supply hand tool device  12  with electrical energy from a hand tool battery which is not illustrated here in greater detail. Hand tool housing  14  is essentially designed in the shape of a pistol. It includes a handle  18  with the aid of which an operator holds hand tool  10  during operation. Hand tool device  12  includes a tool guiding unit  20 , a hammer mechanism  22 , an impact deactivation device  24 , a transmission  26 , a hammer mechanism transmission  28 , a drive unit  30 , an operating device  32 , a torque limiting unit  34 , and a spindle blocking device  36 . Drive unit  30  is designed as an electric motor. Transmission  26  is provided to reduce a speed of drive unit  30 . In addition, transmission  26  is provided to make available at least two different gear ratios. 
     A gripping surface of handle  18  is essentially designed vertically in relation to an axis of rotation of tool guiding unit  20 . Hand tool housing  14  has an overhang with respect to handle  18  on a side facing away from tool guiding unit  20 . This means that a basic shape of hand tool housing  14  is a T shape. 
     Tool guiding unit  20  includes an insert tool holding fixture  38  and a tool spindle  40 . Insert tool holding fixture  38  and tool spindle  40  are screwed to one another. Alternatively, insert tool holding fixture  38  and tool spindle  40  might be detachably connected without the use of tools in a manner which appears reasonable to those skilled in the art. Insert tool holding fixture  38  holds during operation an insert tool, e.g., a drill bit or a screwdriver bit, which is not illustrated here. Insert tool holding fixture  38  holds the insert tool in a force-fitted manner. Alternatively or additionally, an insert tool holding fixture might hold the insert tool in a form-locked manner, for example, with the aid of an SDS tool chuck or a hexagonal receptacle. Insert tool holding fixture  38  has three chuck jaws which are held in such a way that they may be moved by an operator and which hold the insert tool during operation. In addition, insert tool holding fixture  38  holds the insert tool during operation axially immovably with respect to insert tool holding fixture  38  and, in particular, with respect to tool spindle  40 . A part of insert tool holding fixture  38  and tool spindle  40  are immovably connected in relation to one another. In this case, insert tool holding fixture  38  and tool spindle  40  are screwed to one another. 
     Hand tool device  12  has a bearing means  42  on which tool spindle  40  is supported on a side facing insert tool holding fixture  38 . Tool spindle  40  is axially displaceably supported on bearing means  42 . Bearing means  42  is axially fixedly connected to tool spindle  40 . Bearing means  42  is axially movably supported in hand tool housing  14 . Hand tool device  12  has a further bearing means  44  on which tool spindle  40  is supported on a side facing transmission  26 . Bearing means  44  is designed as a friction bearing. Tool spindle  40  is axially displaceably supported on bearing means  44 . Tool spindle  40  includes an impact surface  46  which hammer mechanism  22  impacts during an illustrated hammer drilling operation. 
     Hand tool housing  14  has a multi-part design. Hand tool housing  14  includes a two-shell handle and drive housing  48 , a two-shell outer housing  50 , a transmission housing  52 , a hammer mechanism transmission housing  54 , and a hammer mechanism housing  56 . These parts of hand tool housing  14  are produced separately from one another. Handle and drive housing  48  forms handle  18  and encloses drive unit  30 . Outer housing  50  encloses transmission housing  52  and hammer mechanism transmission housing  54 . In addition, outer housing  50  holds transmission housing  52 , hammer mechanism transmission housing  54 , and hammer mechanism housing  56  to handle and drive housing  48  in a form-locked manner. Transmission housing  52  encloses transmission  26 . It has a tubular design. Hammer mechanism transmission housing  54  encloses hammer mechanism transmission  28 . Hammer mechanism housing  56  encloses hammer mechanism  22 . It also has a tubular design. 
       FIG. 2  shows hammer mechanism  22  and transmission  26 , hammer mechanism transmission  28 , torque limiting unit  34 , and spindle blocking device  36  in greater detail. Hammer mechanism  22  is switchable into an activated and a deactivated operating state. Hammer mechanism  22  has a hammer  58 , a hammer mechanism spindle  60 , a hammer mechanism spring  62 , and a hammer driving device  64 . Hammer mechanism spindle  60  encloses bearing means  44  on which tool spindle  40  is supported on a side facing transmission  26 . Bearing means  44  is operatively situated between tool spindle  40  and hammer mechanism spindle  60 . Hammer  58  is translatorily movably supported in an impact direction  66 . Impact direction  66  is oriented in parallel to an axial direction of hammer mechanism spindle  60 . 
     Tool spindle  40  and hammer mechanism spindle  60  each have a bearing surface  68  and  70 , respectively, on which hammer  58  is movably supported. Bearing surfaces  68 ,  70  act directly on hammer  58 . Bearing surfaces  68 ,  70  are lateral surfaces of tool spindle  40  and hammer mechanism spindle  60 , respectively. Alternatively, hammer  58  might also be supported only on tool spindle  40  or on hammer mechanism spindle  60  and on an outer surface of hammer  58 , if necessary. An inner surface of hammer  58  delimits an inner space which is inwardly constricting in impact direction  66 . Bearing surface  68  of tool spindle  40  acts on a constricted area of the inner surface of hammer  58 . Bearing surface  70  of hammer mechanism spindle  60  acts on an unconstricted area of the inner surface of hammer  58  which faces transmission  26 . 
     Hammer  58  has a pot-shaped basic shape, a recess, through which tool spindle  40  runs, being situated in the bottom of the pot-shaped basic shape. Hammer  58  impacts tool spindle  40  with a bottom outer surface of the pot-shaped basic shape during operation. Hammer  58  encloses tool spindle  40  and hammer mechanism spindle  60  on at least one plane which is oriented vertically to impact direction  66  by 360 degrees. 
     Alternatively, a hammer mechanism might have a hammer and a hammer mechanism spindle, the hammer mechanism spindle enclosing the hammer. In this case, a curve guide of the hammer mechanism would be situated on an outer surface of the hammer. Here, either the hammer or the hammer mechanism spindle might have a guiding curve of the curve guide. Due to a larger radius of the curve guide, it would be advantageous in this case if the curve guide were provided to induce the hammer to multiple impacts during one rotation. 
       FIGS. 3 and 4  show hammer mechanism spindle  60  in two side views which differ by 180 degrees.  FIG. 5  shows a section area A of hammer driving device  64 . Hammer driving device  64  has exactly one curve guide  72 . Curve guide  72  includes a guiding curve  76 , a connecting means  78 , and a fastening means  80 . Curve guide  72  is situated on hammer mechanism spindle  60 . Alternatively, at least one curve guide might be situated on a hammer. Fastening means  80  is situated on hammer  58 . Hammer  58  thus has a part of curve guide  72 . Alternatively, at least one fastening means might be situated on a hammer mechanism spindle. 
     Fastening means  80  is designed as a fastening recess for connecting means  78 . Fastening means  80  is situated on an inner surface of hammer  58 . Fastening means  80  is introduced into the inner surface of hammer  58  with the aid of a bore through a side of hammer  58  which faces away from the fastening means. Connecting means  78  is designed as a sphere. Connecting means  78  has a diameter of 7 mm. Fastening means  80  fixedly supports connecting means  78  in relation to hammer  58 . Connecting means  78  slides in guiding curve  76  during the hammer drilling operation. Hammer mechanism spindle  60  delimits a space in which connecting means  78  moves during the hammer drilling operation. 
     Hammer mechanism spindle  60  is designed as a hollow shaft. Hammer mechanism spindle  60  is rotatably supported in hand tool housing  14  on a side which faces away from insert tool holding fixture  38 . Hammer mechanism transmission  28  drives hammer mechanism spindle  60 . For this purpose, hammer mechanism spindle  60  has a toothing  82  on a side which faces away from insert tool holding fixture  38 . Guiding curve  76  has an impact free-wheel area  84 , an impact elevator area  86 , and an assembly recess  88 . During an assembly, connecting means  78  is introduced through assembly recess  88  into fastening means  80  of hammer  58 . Hammer mechanism spindle  60  rotates clockwise, viewed in impact direction  66 , during the hammer drilling operation. Impact elevator area  86  has a spiral-shaped design. It extends by approximately 180 degrees about an axis of rotation  90  of hammer mechanism spindle  60 . Impact elevator area  86  moves connecting means  78  and thus hammer  58  against impact direction  66  during the hammer drilling operation. 
     Impact free-wheel area  84  connects two ends  92 ,  94  of impact elevator area  86 . Impact free-wheel area  84  extends by approximately 180 degrees about an axis of rotation  90  of hammer mechanism spindle  60 . Impact free-wheel area  84  has an impact edge  96  which runs approximately in parallel to impact direction  66  starting from end  92  of impact elevator area  86 , which faces transmission  26 . As soon as connecting means  78  enters impact free-wheel area  84 , hammer mechanism spring  62  accelerates hammer  58  and connecting means  78  in impact direction  66 . In this case, connecting means  78  moves through impact free-wheel area  84 , without being acted on by an axial force, until hammer  58  impacts impact surface  46 . Therefore, hammer mechanism spring  62  stores in at least one operating state at least a part of an impact energy which hammer  58  transfers to tool spindle  40  during an impact. 
       FIGS. 6 and 7  show hammer  58 . Hammer mechanism spring  62  accelerates hammer  58  in impact direction  66  prior to an impact. For this purpose, hand tool housing  14  supports hammer mechanism spring  62  on a side which faces away from hammer  58 . Hammer mechanism spring  62  presses against hammer  58 . An essentially circular or spiral-shaped surface  100  of a circular molding  98  with the basic shape of hammer  58  supports hammer mechanism spring  62 . Hammer mechanism spring  62  encloses a part of hammer  58 . Hammer mechanism spring  62  holds hammer  58  during the hammer drilling operation in the peripheral direction. 
     Hammer  58  has a catching means  102  which is acted on by hammer mechanism spring  62  in the case of a clockwise rotation of insert tool holding fixture  38  during a hammer drilling operation in the peripheral direction. In the case of a clockwise rotation of insert tool holding fixture  38 , hammer mechanism spindle  60  also rotates clockwise, viewed in impact direction  66 , in this exemplary embodiment. It is apparent to those skilled in the art to adjust catching means  102  to a hammer mechanism spindle  60  which rotates counterclockwise. 
     Catching means  102  has a ratchet surface  104  which is oriented at least essentially vertically to surface  100  of molding  98  and on which hammer mechanism spring  62  presses to accelerate hammer  58 . Surface  100  on which hammer mechanism spring  62  presses to accelerate hammer  58  is designed in the shape of a ramp and tilted in relation to impact direction  66 . In the case of the clockwise rotation of insert tool holding fixture  38 , hammer mechanism spring  62  acts on ratchet surface  104  and connects hammer  58  and hammer mechanism spring  62  in a form-locked manner in the peripheral direction. In the case of the counterclockwise rotation of insert tool holding fixture  38 , hammer mechanism spring  62  slides over ratchet surface  104 . In this way, hammer  58  and hammer mechanism spring  62  have a free wheel in the peripheral direction with respect to one another during the counterclockwise rotation of insert tool holding fixture  38 . Alternatively, hammer mechanism spring  62  might always be rotatably fixedly connected to hammer  58 , and hammer mechanism spring  62  might have a free wheel with respect to hand tool housing  14  during the counterclockwise rotation. 
     As  FIG. 8  shows, a component of hand tool  10  which is rotatably fixedly connected to hand tool housing  14  and which has an annulus gear  122  in this case, as an example, has an essentially circular or spiral-shaped surface  106  which supports hammer mechanism spring  62  in a direction which is oriented against impact direction  66 . Surface  106  is interrupted by a ratchet surface  107  which is oriented essentially vertically to surface  106  of the component. Ratchet surface  107  is provided for the purpose of applying a force in the peripheral direction to hammer mechanism spring  62 , which counteracts a movement of hammer  58 , in the case of the clockwise rotation of insert tool holding fixture  38 . In this way, ratchet surface  107  connects hand tool housing  14  and hammer mechanism spring  62  in the peripheral direction in a form-locked manner in the case of the clockwise rotation of insert tool holding fixture  38 . Alternatively, hammer mechanism spring  62  might also be rotatably fixedly connected to hand tool housing  14  on a side facing away from hammer  58 , for example in that one end of a wire which forms hammer mechanism spring  62  is bent in such a way that it sticks out in the direction of drive unit  30 . Furthermore, as an alternative to the above-described component having an annulus gear  122 , another component, which appears reasonable to those skilled in the art, might have ratchet surface  107 , e.g., a housing part of hand tool housing  14 . 
     Hammer  58  has a ventilation opening  108  through which air may escape from a space which is delimited by tool spindle  40 , hammer mechanism spindle  60 , and hammer  58  and/or flow into this space during a movement of hammer  58 . 
     Hammer mechanism transmission  28  is situated between transmission  26  and hammer mechanism  22 . Hammer mechanism transmission  28  has a first planetary gear stage  110 . Transmission  26  has a second planetary gear stage  112 , a third planetary gear stage  114 , and a fourth planetary gear stage  116 . 
       FIG. 9  shows a section area B of first planetary gear stage  110 . First planetary gear stage  110  increases a first rotational speed of second planetary gear stage  112  for driving hammer mechanism  22 . Second planetary gear stage  114  drives tool spindle  40  at this first rotational speed. Toothing  82  of hammer mechanism spindle  60  forms a sunwheel of first planetary gear stage  110 . Toothing  82  meshes with planetary wheels  118  of first planetary gear stage  110  which are guided by a planet carrier  120  of first planetary gear stage  110 . Annulus gear  122  of first planetary gear stage  110  meshes with planetary wheels  118  of first planetary gear stage  110 . Annulus gear  122  is rotatably fixedly connected to hand tool housing  14 . 
     Impact deactivation device  24  is provided to deactivate hammer mechanism  22  during a screw-driving operation, a drilling operation, and in a hammer drilling mode, if the insert tool is unloaded. Impact deactivation device  24  has three transfer means  128 , a control element  130 , and an impact deactivation clutch  132 . 
       FIG. 10  shows an exposed side view of impact deactivation device  24 .  FIG. 11  shows a section area C through control element  130  of impact deactivation device  24 . Furthermore,  FIG. 11  shows a connecting means  124  which rotatably fixedly connects tool spindle  40  and a planet carrier  126  of second planetary gear stage  112 . Connecting means  124  connects tool spindle  40  and planet carrier  126  of second planetary gear stage  112  axially displaceably. Impact deactivation clutch  132  is situated between first planetary gear stage  110  and second planetary gear stage  112 . Impact deactivation clutch  132  has a first clutch element  134  which is always rotatably coupled to a part of hammer mechanism  22 . First clutch element  134  is rotatably fixedly connected to planet carrier  120  of first planetary gear stage  110 . First clutch element  134  is designed in one piece with planet carrier  120  of first planetary gear stage  110 . Impact deactivation clutch  132  has a second clutch element  136  which is always rotatably coupled to a part of transmission  26 . Second clutch element  136  is rotatably fixedly connected to connecting means  124 . Second clutch element  136  is designed in one piece with connecting means  124 . Planet carrier  126  of second planetary gear stage  112  is rotatably fixedly connected to second clutch element  136 . In the illustrated hammer drilling operation, impact deactivation clutch  132  is engaged. During the hammer drilling operation, tool spindle  40  transfers an axial clutch force to impact deactivation clutch  132  when the operator pushes the insert tool against a workpiece. The clutch force engages impact deactivation clutch  132 . When the operator removes the insert tool from the workpiece, an impact activation spring  140  of impact deactivation device  24  disengages impact deactivation clutch  132 . 
     Transfer means  128  are designed as bars. Control element  130  supports tool guiding unit  20  in a direction against impact direction  66  during a screw-driving and drilling mode. A force which is applied to tool guiding unit  20  acts via bearing means  44 , another transfer means  142  of impact deactivation device  24 , and transfer means  128 , which are designed as bars, on supporting surfaces  144  of control element  130 . This prevents clutch elements  134 ,  136  from engaging during screw-driving and drilling mode. The other transfer means  142  is essentially star-shaped and has a ring-disk-shaped central area. Control element  130  has three recesses  146 . In the illustrated hammer drilling operation, transfer means  128  are inserted in recesses  146 , whereby tool guiding unit  20  is axially movable in the hammer drilling mode. 
     Connecting means  128  is operatively situated between planetary carrier  126  of second planetary gear stage  112  and tool spindle  40 . In addition, connecting means  128  has second clutch element  136  of impact deactivation clutch  132 . 
     Connecting means  128  is axially displaceably supported against impact activation spring  140 . By axially displacing connecting means  128  in the direction of insert tool holding fixture  38 , impact deactivation clutch  132  is disengaged. Connecting means  128  is always rotatably fixedly and axially displaceably connected to tool spindle  40 . In this way, planet carrier  126  of second planetary gear stage  112  remains rotatably coupled even in the case of an impact with tool spindle  40 . Planet carrier  126  of second planetary gear stage  112  is rotatably fixedly connected to connecting means  128 . Planet carrier  126  of second planetary gear stage  112  and connecting means  128  are axially displaceably connected in relation to one another. 
       FIG. 12  shows a section area D of spindle blocking device  36 . Spindle blocking device  36  is provided for rotatably fixedly connecting tool spindle  40  with hand tool housing  14  when a tool torque is applied to insert tool holding fixture  38 , e.g., when clamping an insert tool into insert tool holding fixture  38 . Spindle blocking device  36  is designed partially in one piece with connecting means  128  and planet carrier  126  of second planetary gear stage  112 . Spindle blocking device  36  has blocking means  150 , first clamping areas  152 , a second clamping area  154 , and free-wheel areas  156 . Blocking means  150  have a cylindrical design. First clamping areas  152  are designed as areas of a surface of connecting means  128 . First clamping areas  152  are designed to be planar. Second clamping area  154  is designed as an inner surface of a clamping means  158  of spindle blocking device  36 . 
     Clamping means  158  is designed as a clamping ring. Clamping means  158  is rotatably fixedly connected to hand tool housing  14 , namely to hammer mechanism housing  56  of hand tool housing  14 , via a component of spindle blocking device  36 . Here, clamping means  158  is rotatably fixedly connected to hand tool housing  14  via a stop means  160  of spindle blocking device  36 . Free-wheel areas  156  are designed as areas of a surface of planet carrier  126  of second planetary gear stage  112 . When a tool torque is applied to insert tool holding fixture  38 , blocking means  150  clamp between first clamping areas  152  and second clamping area  154 . When drive unit  30  drives, free-wheel areas  156  guide blocking means  150  to a circular trajectory and prevent them from clamping. Planet carrier  126  of second planetary gear stage  112  and connecting means  128  are meshed with one another having clearance. Spindle blocking device  36  is situated outside of transmission housing  52 . Spindle blocking device  36  is situated inside of hammer mechanism housing  56 . 
     Torque limiting unit  34  is provided to limit in a screw-driving mode a tool torque which is output maximally by insert tool holding fixture  38 . Torque limiting unit  34  includes stop means  160 , an operating element  162 , adjusting elements  164 , limiting springs  166 , a transfer means  168 , first stop areas  170 , a second stop area  172 , and limiting means  174 . Transfer means  168 , first stop areas  170 , and second stop area  172  form a clutch of torque limiting unit  34 . With the aid of operating element  162 , a torque which is maximally transferable to insert tool holding fixture  38  may be limited. Operating element  162  has a circular design. Operating element  162  has a two-shell design. It joins insert tool holding fixture  38  in the direction of transmission  26 . Operating element  162  has kinked setting areas  176  which act on adjusting elements  164  in the axial direction. Adjusting elements  164  are supported rotatably fixedly and axially displaceably by operating element  162 . A rotation of operating element  162  displaces adjusting elements  164  in the axial direction. 
     Limiting springs  166  are supported on one side on adjusting element  164 . Limiting springs  166  are supported on the other side at stop means  160  of torque limiting unit  34  via transfer means  168 . Transfer means  168  are displaceably supported in the axial direction. A surface of stop means  160  has first stop areas  170 . In the screw-driving mode, top means  160  is supported movably in the axial direction against limiting springs  166 . 
     Second stop area  172  is designed as an area of a surface of an annulus gear  178  of second planetary gear stage  112 . Second stop area  172  delimits trough-shaped recesses  180 . Limiting means  174  have a spherical design. Torque limiting unit  34  has a limiting and guiding means  182  which is provided to axially displaceably support limiting means  174 .  FIG. 13  shows a section area E of limiting and guiding means  182 . Limiting and guiding means  182  delimits recesses  184  in which limiting means  174  are supported displaceably in impact direction  66 . Recesses  184  have a tubular design. Hammer mechanism transmission housing  54  rotatably fixedly holds limiting and guiding means  182 . During a screw-driving operation limiting means  174  are situated in trough-shaped recesses  180 . Here, limiting means  174  hold annulus gear  178  of second planetary gear stage  112 . Upon reaching the set maximum tool torque, limiting means  174  press stop means  160  away against limiting springs  166 . Subsequently, limiting means  174  each jump into a next of trough-shaped recesses  180 . Annulus gear  178  of second planetary gear stage  112  rotates in the process, thus interrupting the screw-driving operation. 
     Torque limiting unit  34  has deactivation means  186 ,  188  which are provided for deactivating a torque limitation of torque limiting unit  34 , whereby a maximum torque is a function of a maximum torque of drive unit  30 . Adjusting element  164  and transfer means  168  each have a part of deactivation means  186 ,  188 . Deactivation means  186 ,  188  prevent an axial movement of stop means  160  at least during a drilling mode. Deactivation means  186 ,  188  are designed as pillar-shaped moldings for adjusting element  164  and transfer means  168 , respectively. Deactivation means  186 ,  188  extend toward one another. Deactivation means  186 ,  188  are operatively oriented in parallel to limiting springs  166 . In a drilling position of operating element  162  of torque limiting unit  34 , deactivation elements  186 ,  188  prevent an axial displacement of stop means  160 . In this case, adjusting element  164  is displaced in the direction of transfer means  168  far enough for deactivation means  186 ,  188  to make contact. 
       FIG. 14  shows a section area F of second planetary gear stage  112 . Annulus gear  178  of second planetary gear stage  112  is securely supported in a hand tool housing  14  against a complete rotation at least during a drilling operation. Planetary wheels  190  of second planetary gear stage  112  mesh with annulus gear  178  and a sunwheel  192  of second planetary gear stage  112 . 
       FIG. 15  shows a section area G through a planet carrier  194  of third planetary gear stage  114 .  FIG. 16  shows a section area H through planetary wheels  196  of third planetary gear stage  114 . Sunwheel  192  of second planetary gear stage  112  is rotatably fixedly connected to planet carrier  194  of third planetary gear stage  114 . Planetary wheels  196  of third planetary gear stage  114  mesh with a sunwheel  198  and an annulus gear  200  of third planetary gear stage  114 . 
     Annulus gear  200  of third planetary gear stage  114  has a toothing  202  which rotatably fixedly connects annulus gear  200  of third planetary gear stage  114  to hand tool housing  14  in a first gear ratio. Toothing  202  of annulus gear  200  of third planetary gear stage  114  engages in a first gear ratio an internal toothing of a ring  204  which, in turn, is rotatably fixedly connected to hand tool housing  14 . 
     Between second planetary gear stage  112  and third planetary gear stage  114 , a supporting means  206  is situated which is provided for deflecting a force to hand tool housing  14 , this force acting axially on annulus gear  200  of third planetary gear stage  114  and being in particular caused by torque limiting unit  34 . Supporting means  206  is designed in the shape of an annular disk. Supporting means  206  is connected in a form-locked manner to hand tool housing  14  via ring  204  in an axial direction pointing away from insert tool holding fixture  38 . A snap ring  208  holds supporting means  206  in an axial direction pointing toward insert tool holding fixture  38 . 
       FIG. 17  shows a section area I through a planet carrier  210  of fourth planetary gear stage  116 .  FIG. 18  shows a section area J through planetary wheels  212  of fourth planetary gear stage  116 . Sunwheel  198  of third planetary gear stage  114  is rotatably fixedly connected to planet carrier  210  of fourth planetary gear stage  116 . Planetary wheels  212  of fourth planetary gear stage  116  mesh with a sunwheel  214  and an annulus gear  216  of third planetary gear stage  116 . Annulus gear  216  of fourth planetary gear stage  116  is rotatably fixedly connected to hand tool housing  14 . Annulus gear  216  of fourth planetary gear stage  116  is designed in one piece with a transmission housing cover  218  which faces away from insert tool holding fixture  38 . Transmission cover  218  may be designed in one piece with transmission housing  52 , but is implemented separately in this case. Transmission housing cover  218  is connected to transmission housing  52  prior to equipping transmission housing  52  with transmission  26 . Sunwheel  214  of fourth planetary gear stage  116  is rotatably fixedly connected to a rotor  220  of drive unit  30 . 
     Annulus gear  200  of third planetary gear stage  114  is supported displaceably in an axial direction, as shown in  FIG. 2 . In the first gear ratio, annulus gear  200  of third planetary gear stage  114  is rotatably fixedly connected to hand tool housing  14 . In the second gear ratio, annulus gear  200  of third planetary gear stage  114  is rotatably fixedly connected to planet carrier  210  of fourth planetary gear stage  116  and rotatably supported in relation to hand tool housing  14 . For this purpose, planet carrier  210  of fourth planetary gear stage  116  has an external toothing. This results in a reduction gear ratio of the first gear ratio between rotor  220  of drive unit  30  and planet carrier  194  of third planetary gear stage  114  being greater than a reduction gear ratio of the second gear ratio. Thus, insert tool holding fixture  38  rotates at a maximum rotational speed of drive unit  30  more slowly in the case of the first gear ratio than in the second gear ratio. A torque which is maximally achievable by drive unit  30  at insert tool holding fixture  38  is greater in the case of the first gear ratio than in the second gear ratio. A maximally achievable torque by drive unit  30  at insert tool holding fixture  38  is 40 Nm in the first gear ratio. A maximally achievable torque by drive unit  30  at insert tool holding fixture  38  is 14 Nm in the second gear ratio. 
     Transmission housing cover  218  is formed by plastic. 
     Transmission housing cover  218  closes transmission housing  52  on the side facing away from insert tool holding fixture  38 . Torque limiting unit  34  is provided for closing the side of transmission housing  52  which faces insert tool holding fixture  38  in an operationally ready state. Hammer mechanism transmission housing  54  holds at transmission housing  52  the component of torque limiting unit  34  which closes the side of transmission housing  52  which faces insert tool holding fixture  38  in an operationally ready state. Limiting and guiding means  182  of torque limiting unit  34  closes the side of transmission housing  52  which faces insert tool holding fixture  38  in an operationally ready state. Limiting and guiding means  182  is formed from a metallic material. Transmission housing  52  is equipped on a side which faces insert tool holding fixture  38  with at least the second, the third, and the fourth planetary gear stage  112 ,  114 ,  116  of transmission  26 . 
     Operating device  32  has a first operating element  222  and a second operating element  224 . First operating element  222  is situated on a side of hand tool housing  14  which faces away from handle  18 . It is movably supported in parallel to the axial direction of transmission  26 . First operating element  222  is connected to annulus gear  200  of third planetary gear stage  114  via an adjusting means  226  of operating device  32  in the axial direction. Annulus gear  200  of third planetary gear stage  114  has a groove  228  which engages adjusting means  226 . In this way, annulus gear  200  of third planetary gear stage  114  is connected in an axial direction to adjusting means  226  in such a way that it is axially rotatable relative to adjusting means  226 . Adjusting means  226  has an elastic design, whereby the gear ratio of a rotational position of annulus gear  200  of third planetary gear stage  114  may be independently adjusted. When first operating element  222  is shifted in the direction of insert tool holding fixture  38 , the first gear ratio is set. When first operating element  222  is shifted away from insert tool holding fixture  38 , the second gear ratio is set. 
     Second operating element  224  is situated on a side of hand tool housing  14  which faces away from handle  18 . Second operating element  224  is situated in such a way that it is displaceable about an axis which is oriented in parallel to the axial direction of transmission  26 . Second operating element  224  mechanically activates or deactivates the hammer drilling mode upon operation. Second operating element  224  is rotatably fixedly connected to control element  130  of hand tool device  12 . The screw-driving and drilling mode as well as the hammer drilling mode are settable with the aid of second operating element  224 . When second operating element  224  is shifted to the left, viewed in impact direction  66 , the hammer drilling mode is set. When second operating element  224  is shifted to the right, viewed in impact direction  66 , the screw-driving and drilling mode is set. 
     Impact activation spring  140  of hand tool device  12  disengages impact deactivation clutch  132  during a hammer drilling operation, when the operator removes the insert tool from the workpiece. Impact activation spring  140  is situated coaxially to planetary gear stages  110 ,  112 ,  114 ,  116  of transmission  26 . Second planetary gear stage  112  and third planetary gear stage each  114  enclose impact activation spring  140  at least on one plane which is oriented vertically to the axial direction of transmission  26 . Connecting means  128  supports impact activation spring  140  on a side which faces insert tool holding fixture  38 . A bearing means  230  supports impact activation spring  140  on a side which faces away from insert tool holding fixture  38 . Bearing means  230  is designed as a sphere. Bearing means  230  is situated between impact activation spring  140  and rotor  220  of drive unit  30 . 
     Hand tool device  12  has a first detection unit  232  and a second detection unit  234 . First detection unit  232  is provided for electrically outputting a characteristic which is a function of whether hammer mechanism  22  is activated, i.e., in the hammer drilling mode, or deactivated, i.e., in the drilling and screw-driving mode. First detection unit  232  is designed as a switch which detects a movement of second operating element  224  in relation to hand tool housing  14 . Alternatively, detection unit  232  might also detect a movement of another part of hammer mechanism  22  which appears reasonable to those skilled in the art. 
     Second detection unit  234  is provided for electrically outputting a second characteristic which is a function of which one of the gear ratios of transmission  26  is set with the aid of first operating element  222 . First detection unit  234  is designed as a switch which detects a movement of first operating element  222  in relation to hand tool housing  14 . Alternatively, detection unit  232  might also detect a movement of another part of transmission  26  which appears reasonable to those skilled in the art. 
     Hand tool device  12  has a control unit  236  which is provided for controlling drive unit  30  during an operation. Control unit  236  includes a microcontroller and a power electronic device. The power electronic device is provided for energizing drive unit  30  for different rotational speeds and/or differing torques. The microcontroller is provided for controlling drive unit  30  via the power electronic device as a function of the first characteristic and the second characteristic. Control unit  236  includes a protective function which is provided for delimiting a torque which is maximally output by drive unit  30  during the operating mode, when the hammer drilling mode is activated and the first gear ratio is set, i.e., a low maximum rotational speed and a high maximum torque. In this case, control unit  236  delimits an electric current which is maximally output to drive unit  30 . 
     Hand tool device  12  has a hammer mechanism spindle bearing means  238  on which hammer mechanism spindle  60  is rotatably supported on the side which faces away from insert tool holding fixture  38 . Hammer mechanism spindle bearing means  238  is fixedly connected in the axial direction to hammer mechanism spindle  60 , in particular hammer mechanism spindle bearing means  238  is press-molded with hammer mechanism spindle  60 . Additionally or advantageously alternatively, hammer mechanism spindle bearing means  238  might be fixedly connected in the axial direction to hand tool housing  14 . 
     Hand tool device  12  has a hammer mechanism spindle fastening means  242  which is provided for fastening hammer mechanism spindle  60  in the axial direction. Hammer mechanism spindle fastening means  242  is designed as a snap ring. Hammer mechanism spindle fastening means  242  engages a groove  240  of hammer mechanism spindle  60 . Groove  240  of hammer mechanism spindle  60  is situated on the side of hammer mechanism spindle  60  which faces away from insert tool holding fixture  38 . 
     In an operationally ready state, hammer mechanism spindle fastening means  242  is situated in the axial direction between hammer mechanism spindle bearing means  238  and first planetary gear stage  110 . Hammer mechanism spindle fastening means  242  holds hammer mechanism spindle  31  in the axial direction in a form-locked manner. Alternatively, hammer mechanism spindle  60  may be fastened in the axial direction in a different way which appears reasonable to those skilled in the art. For example, hammer mechanism spindle bearing means  238  may be connected in the axial direction to hammer mechanism spindle  60  integrally or in a force-fitted manner.