Abstract:
A power tool has a drive motor with an actuating element. The power tool has a power tool housing with a first subassembly and a second subassembly that is connected with the first subassembly. An operating element is supported on the first subassembly. A Bowden cable is disposed within the power tool housing and has a Bowden cable housing and a Bowden cable inner wire arranged in the Bowden cable housing. The actuating element is a part of the second subassembly. The Bowden cable inner wire has a first end connected to the operating element and a second end connected to the actuating element, wherein the operating element acts on the actuating element through the Bowden cable. The Bowden cable housing has a first end and a second end and the first and second ends are secured on the same one of the first and second subassemblies.

Description:
BACKGROUND OF THE INVENTION 
     The invention concerns a power tool with a Bowden cable. The power tool has a drive motor for driving a tool member and comprises a power tool housing that is at least partially formed by a first subassembly and a second subassembly connected with the first subassembly. An operating element is supported on the first subassembly and actuates by means of a Bowden cable guided within the power tool housing an actuating element of the drive motor. The actuating element is part of the second subassembly. The Bowden cable comprises a Bowden cable inner wire and a Bowden cable housing, wherein the Bowden cable inner wire is secured with a first end on the operating element and with a second end on the actuating element. 
     U.S. Pat. No. 5,142,934 discloses a power tool, namely a motor chainsaw, where the throttle trigger actuates the carburetor by means of a Bowden cable. The throttle trigger is secured on a grip housing and the carburetor on a motor housing. The two housing parts are connected to each other by elastic elements. One end of the Bowden cable housing is secured on the motor housing and the other end of the Bowden cable housing on the grip housing. One end of the inner wire of the Bowden cable is hooked to the throttle lever and the other end to the throttle trigger. When mounting this Bowden cable, one end can be secured first on the throttle lever and on the motor housing. Subsequently, the motor housing can be arranged on the grip housing and the free end of the Bowden cable can be hooked on the grip housing or on the throttle trigger. This type of assembly is possible only when the Bowden cable can still be accessed after the two housing parts have been attached to each other. 
     The invention has the object to create a power tool of the aforementioned kind in which installation of the Bowden cable is possible in a simple way even at mounting locations that are difficult to access. 
     SUMMARY OF THE INVENTION 
     This object is solved by a power tool where the two ends of the Bowden cable housing are secured on the same one of the two subassemblies. 
     Since both ends of the Bowden cable housing are secured on the same subassembly, both ends of the Bowden cable housing can be mounted on said subassembly before the second subassembly is connected to said subassembly. After connecting the two subassemblies to each other, it is only necessary to hook the Bowden cable inner wire onto the second subassembly. This is possible easily because the position of the Bowden cable inner wire is substantially predetermined as a result of the Bowden cable housing being positionally fixed at this end. Accordingly, a Bowden cable installation is possible very well even in very tight spatial conditions. After having connected the subassemblies to each other, only the free end of the Bowden cable inner wire must be accessible. 
     A Bowden cable is to be understood as any flexible transmission element that comprises a housing secured at two spaced-apart regions and an element that is movable relative to this housing. The regions where the housing is secured are referred to as ends. The ends of the Bowden cable inner wire are the areas where the Bowden cable inner wire is secured on the actuating element and on the operating element. The ends of the Bowden cable housing are preferably arranged spatially adjacent to the ends of the Bowden cable inner wire. 
     Advantageously, the power tool has a mounting aid with a receptacle for a first end of the Bowden cable housing. This mounting aid is arranged at a first one of the two subassemblies and projects toward the second one of the two subassemblies. The receptacle is advantageously arranged adjacent to the second one of the two subassemblies. In this way, the Bowden cable housing can be arranged proximal to the correlated end of the Bowden cable inner wire. Advantageously, the position of the receptacle is defined by the second one of the two subassemblies. In this way, a defined position of the end of the Bowden cable inner wire to the end of the Bowden cable housing is realized. Manufacturing tolerances that occur between the receptacle of the mounting aid and the subassembly where the actuating element is supported can be minimized in this way. Advantageously, the mounting aid is elastically deformed by the second one of the two subassemblies. In this way, it is ensured that the mounting aid is resting against the second subassembly so that a defined position results. 
     In particular, the mounting aid has at least one arm that spans the distance formed between the two subassemblies. The arm can be of a delicate configuration because it must hardly transmit forces in operation. Advantageously, the arm has a thin-walled, in particular rectangular, cross-section. A thin-walled cross-section is to be understood as a cross-section in which the ratio of maximum width to maximum thickness is at least 2, in particular at least 3. For a rectangular cross-section of the arm that has advantageously rounded corners, a simple configuration results. The arm can however also have a different, for example, a T-shaped or L-shaped, cross-section. 
     A simple configuration results when the mounting aid is configured as a separate component and is secured on a housing part of the first subassembly. Advantageously, the mounting aid has means for positioning the second subassembly. The means for positioning the second subassembly are advantageously arranged adjacent to the receptacle. In this way, a correct positioning of the subassemblies on each other and a correct positioning of the mounting aid on the second subassembly can be ensured in a simple way. 
     Water may collect in the power tool in operation. This is particularly the case when the power tool has a tool member that is cooled with water, for example, a cut-off machine. In order to drain this water in a targeted fashion, it is provided that the mounting aid has at least one drain element for draining the collected liquid. The drain element is advantageously arranged adjacent to the receptacle. In this way, it can be avoided that liquid, in particular water, can be guided via the mounting aid from the second subassembly to the first subassembly. 
     Advantageously, the mounting aid has a partition that separates at least partially different areas of the power tool from each other. By integration of the partition into the mounting aid, an additional component for the partition can be avoided. For example, the partition can serve for separating from each other different cooling areas of the power tool. 
     Advantageously, both ends of the Bowden cable housing are secured on the second subassembly. The actuating element is advantageously connected fixedly with the drive motor and connected by means of at least one anti-vibration element with a subassembly component of the second subassembly. The Bowden cable therefore must span the vibration gap that is formed between the first subassembly and the drive motor. In order to prevent that the mounting aid in operation must compensate relative movements between the drive motor and the first subassembly, it is provided that the mounting aid is secured on the subassembly component of the second subassembly. Accordingly, the mounting aid must not span the vibration gap. 
     A simple configuration results when the mounting aid is attached with at least one locking element on the subassembly component. The locking element has advantageously an opening for engagement of a tool so that the locking element can be released easily. The tool, because of the opening, can engage from below the locking hook and release it. This is in particular advantageous when the locking hook is not accessible from all sides. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One embodiment of the invention will be explained in the following with the aid of the drawing. 
         FIG. 1  shows a schematic side view of a cut-off machine. 
         FIG. 2  is a schematic illustration of the arrangement of the subassemblies of the cut-off machine. 
         FIG. 3  is a perspective detail illustration of the second subassembly of the cut-off machine with mounting aid arranged thereat. 
         FIGS. 4 and 5  each show a perspective illustration of the mounting aid. 
         FIG. 6  is a section view of the power tool housing of the cut-off machine in the area of the mounting aid. 
         FIG. 7  is a section along the section line VII-VII in  FIG. 6 . 
         FIG. 8  is a side view of the mounting aid. 
         FIG. 9  is a top view of the mounting aid. 
         FIG. 10  is a bottom view of the mounting aid. 
         FIG. 11  is a side view of the mounting aid in the direction of arrow XI in  FIG. 9 . 
         FIG. 12  is a side view of the mounting aid in the direction of arrow XII in  FIG. 9 . 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  shows a hand-held power tool, namely a cut-off machine  1 , as an embodiment of a power tool. The mounting aid to be described in the following can also be advantageous in connection with other power tools such as motor chainsaws, hand-held blowers or the like. The cut-off machine  1  has a power tool housing  2  on which a top handle  6  and a handle bar  7  are secured. The power tool housing  2  has legs  48  with which the cut-off machine  1  is resting on the ground or another flat surface in the usual rest position  49 , shown in  FIG. 1 .  FIG. 1  shows also the direction of action  50  of gravity in the rest position  49 . 
     On the power tool housing  2  a cantilever arm is secured having at its free end a cutter wheel  4 . The cutter wheel  4  is driven in rotation by a drive motor  14  that is at least partially arranged within the power tool housing  2 . The cutter wheel  4  is covered across more than half of its circumference by a protective cover  5 . 
     As shown in  FIG. 1 , the power tool housing  2  has an air filter cover  12  as well as a hood  8 . On the hood  8  the handle  6  is formed. On the handle  6  a throttle trigger  10  and a throttle trigger lock  11  are pivotably supported. The top area of the top handle  6  is covered by a separate cover  9 . As also shown in  FIG. 1 , the power tool housing  2  comprises a motor housing  56  on which the hood  8  is secured (e.g. by screws). 
       FIG. 2  shows the configuration of the cut-off machine  1  in detail. The cut-off machine  1  comprises a first subassembly  61  that comprises the hood  8 , the top handle  6 , the cover  9 , the throttle trigger  10 , and the throttle trigger lock  11 , not shown in  FIG. 2 . A second subassembly  62  comprises the motor housing  56  and an air filter housing  13  that is fixedly arranged on the motor housing  56 . The air filter housing  13  can also be integrated partially into the motor housing  56 . On the motor housing  56 , the drive motor  14  is supported with antivibration elements  15  so as to be vibration-isolated. The drive motor  14  is also part of the second subassembly  62 . On the drive motor  14 , a throttle housing  16  is secured that is also a part of the second subassembly  62  and in which a throttle element, not shown in  FIG. 2 , for example, a throttle flap or a throttle barrel, is pivotably supported. On the exterior side of the throttle housing  16 , a throttle lever  23  is secured that has a groove  57  for receiving the Bowden cable inner wire  20  of a Bowden cable  18 . The Bowden cable inner wire  20  is secured with a first end  21  on the throttle trigger  10 , in particular hooked. A second end  22  of the Bowden cable inner wire  20  is secured at the end of the groove  57  on the throttle lever  23 . The Bowden cable  18  has also a Bowden cable housing  19  that is secured with a first end  54  in a receptacle  26  and with a second end  55  in a second receptacle  41 . The first subassembly  61  is fixedly connected to the motor housing  56  and is vibration-decoupled from the drive motor  14 . The Bowden cable  18  spans thus the vibration gap  58  that is formed between the drive motor  14  and the first subassembly  61 . The drive motor  14  is connected by means of a flexible intake socket  17  that is secured on the throttle housing  16  with the air filter housing  13 . The intake socket  17  is comprised of an elastic material, for example, rubber, and spans also the vibration gap  58 . 
     As shown in  FIG. 2 , the first receptacle  26  is formed on a mounting aid  24  which is secured on the second subassembly  62  adjacent to the intake socket  17 . The mounting aid  24  spans the distance between the two subassembly  61  and  62  and projects from the second subassembly  62  up to the first subassembly  61 . The receptacle  26  is arranged adjacent to the throttle trigger  10 , in particular proximal to the area of the throttle trigger  10  where the first end  21  of the Bowden cable inner wire is secured on the throttle trigger  10 . When mounting the Bowden cable  18 , the Bowden cable housing  19  is mounted on the second subassembly  62 . When doing this, the two ends  54  and  55  of the Bowden cable housing  19  are fixed. Also, the second end  22  of the Bowden cable inner wire  20  is hooked. Subsequently, the cover  8  is attached. Only after the hood  8  has been attached, the access to the Bowden cable  18  is limited. Through the still open opening that is to be closed by the cover  9  after mounting of the first subassembly  61  on the second subassembly  62 , the first end  21  of the Bowden cable inner wire  20  can be hooked on the throttle trigger  10 . This is easily possible because the first end  21  is positioned by the mounting aid  24  as a result of the fixation of the first end  54  of the Bowden cable housing  19  adjacent to the throttle trigger  10 . Subsequently, the cover  9  can be mounted on the hood  8 . For mounting the first end of the Bowden cable inner wire, only very little space and only a very small access opening are required due to securing the first end  54  of the Bowden cable housing  19  on the second subassembly  62 . In this way, the power tool housing  2  of the cut-off machine  1  can be designed to be substantially closed and the opening that is to be dosed by the cover  9  can be designed to be very small. 
       FIG. 3  shows the arrangement of the mounting aid  24  and of the Bowden cable  18  in detail. The mounting aid  24  is designed as a separate component and is attached to the motor housing  56 . A partition  25  is integrated with the mounting aid  24  and separates the area of the air filter housing  13  from the area of the throttle housing  16 . In this way, different cooling zones can be achieved in a simple way for the cut-off machine  1 .  FIG. 3  shows also the constructive configuration of one of the antivibration elements  15  that comprises a coil spring as a damping element in this embodiment. As illustrated also in  FIG. 3 , in the throttle housing  16  a throttle shaft  43  is supported that carries a throttle flap, not illustrated. In the throttle housing  16  an intake passage  42  is formed that can be released or substantially closed by the throttle element. The drive motor  14  is embodied as an internal combustion engine, in particular as a two-stroke engine or as a four-stroke engine that is lubricated by a fuel-oil mixture. As illustrated also in  FIG. 3 , the mounting aid  24  is secured on a housing wall  33  of the motor housing  56  by means of a locking hook  31  that is integrally formed on the mounting aid  24 . In the illustrated embodiment, the mounting aid  24  is comprised of plastic material. The mounting aid  24  is advantageously produced as a monolithic component, in particular by an injection molding process. 
       FIGS. 4 and 5  show the configuration of the mounting aid  24  in detail. The mounting aid  24  has in the area of the partition  25  several guide pins  32  with which it is positioned on the motor housing  56  and pre-fixed on the motor housing  56 . An additional fixation by the locking hook  31  is provided. For a good separation of cooling zones of the cut-off machine  1 , a separation plate  44  is provided that extends in the illustrated embodiment approximately perpendicular to the partition  25  and approximately horizontal in the rest position  49 . On the topside of the separation plate  44  that is facing away from the partition  25 , separation plate sections  45  are arranged that project in upward direction perpendicularly from the separation plate  44 . By means of the separation plate  44 , a high stability is also imparted to the mounting aid  24 . The partition  25 , the separation plate  44  and the separation plate sections  45  serve for separating the cooling zones of the cut-off machine  1 . 
     The mounting aid  24  has two arms  28  that each have an approximately rectangular cross-section and that project from the separation plate  44  to the vicinity of the receptacle  26 . The receptacle  26  is approximately cylindrical and has a slot  27  that extends in longitudinal direction of the cylinder and through which the Bowden cable inner wire can be guided. The Bowden cable housing is secured frictionally, i.e. is clamped, in the receptacle  26 . Two ribs  59  extend outwardly away from the receptacle  26 . The ribs  59  each have a stop surface  29  on the end facing the hood  8 . The ribs  59  pass into the arms  28 . Adjacent to the receptacle  26 , the mounting aid  24  has a wall  39  that extends transversely to the arms  28  and that has a central opening  35 . In the rest position  49  of the cut-off machine  1  illustrated in  FIG. 1 , the wall  39  extends at an incline toward a drain edge  60 . Guide walls  42  are arranged on the sides of the wall  39  laterally adjacent to the drain edge  60 . In this way, liquid that collects on the wall  39  is drained across the drain edge  60 . Accordingly, it is prevented that the liquid can flow along the arms  28  of the mounting aid  24  into the area of the cut-off machine  1  where the intake air is sucked in by the drive motor  14 . In the illustrated cut-off machine  1 , the combustion air is sucked in from the area that is positioned at the side of the partition  25  that is facing away from the throttle housing  16 . 
     The opening  35  of the wall  39  has a rounded portion  52  at its periphery that ensures that the centering pin  36  illustrated in  FIG. 6  can engage easily the opening  35 . On one of the arms  28  reinforcement webs  46  are arranged that are located in the area of the connection of the arms  28  with the separation plate  44 . The other one of the two arms  28  is formed on a projecting section of the separation plate  44  so that high elasticity of the arrangement results. This arm  28  has adjacent to its connection to the separation plate  44  a drain element  63  that is formed as a downwardly projecting pin. The drain element  63  serves for draining liquid and avoids that liquid can flow into the area of intake of the combustion air by means of the mounting aid  24 . As shown in  FIG. 5 , the partition  25  has a cutout  38  for the intake passage  42 . 
       FIGS. 6 and 7  show the arrangement of the mounting aid  24  on the hood  8 . In  FIG. 6 , by dashed line  47  the shape of the mounting aid  24  is shown, with the hood  8  not being attached. The mounting aid  24  is designed such it is elastically deformed when the hood  8  is attached; the hood  8  is then resting on the stop surface  29 . As shown in  FIG. 7 , the hood  8  has housing webs  37  that are resting on the stop surfaces  29  of the ribs  59  and thereby elastically deform the mounting aid  24 . The ribs  59  and the housing webs  37  extend transversely relative to each other and cross each other in the contact area. In this way, it is ensured that contact of the housing webs  37  on the contact surfaces  29  is possible also in case of unfavorable tolerances. 
     On the housing webs  37  of the hood  8 , the centering pin  36  illustrated in  FIG. 6  is arranged that has a bevel  51  at its free end; the bevel  51 , in connection with the round portion  52  at the opening  35 , provides a centering action.  FIG. 6  shows also clearly the inclined position of the wall  39  in the illustrated rest position  49 . The housing webs  37  are positioned exclusively at the contact surfaces  29 . In the area of the wall  39  no contact between mounting aid  24  and hood  8  is provided. In this way, it is ensured that only the contact surfaces  29  define the position of the receptacle  26 . The contact surfaces  29  are arranged very dose to the receptacle  26  so that a comparatively exact positioning of the receptacle  26  relative to the hood  8  and to the throttle trigger  10  arranged at the hood  8  results. 
     As shown in  FIGS. 4 and 8 , adjacent to the ribs  59  drain elements  30  are arranged on the arms  28 . The drain elements  30  are formed as pins that extend approximately in vertical direction in the usual rest position  49 . By means of the drain elements  30  liquid that has precipitated on the hood  8  or on the mounting aid  24 , in particular precipitated water, can be drained. In this way, it is prevented that liquid can flow by means of the arms  28  of the mounting aid  24  from the hood  8  to the second subassembly  62  and to the air intake. In order to ensure that liquid does not flow along the topside of the arms  28  in downward direction to the separation plate  44 , on the topside of the arms  28  recesses  64  are provided that interrupt the straight top edge of the arms  28  and interrupt drainage of the liquid in this way. The interruptions  64  ensure that liquid drains by means of the drain elements  30 . Recesses  64  can be provided on the arms  28  on either side of the drain elements  30 . The recesses  64  are also shown in  FIG. 5 . 
     As shown in  FIGS. 9 and 10 , the locking hook  31  has at its topside an opening  53 . A tool, for example, a screwdriver, can engage through the opening  53  and push the locking hook  31  outwardly and release it so that the mounting aid  24  can be demounted easily from the second subassembly  62 .  FIG. 10  shows also the arrangement of the guide pins  32  on the bottom side of the mounting aid  24  facing the second subassembly  62 . 
     As shown in  FIG. 11 , the arms  28  have a width a that is significantly greater than the thickness b. The width a has advantageously at least twice, in particular at least three times, the size of the thickness b. In this way, a minimal weight of the mounting aid  24  with sufficient stability is provided. The arms  28  as a result of the minimal thickness b and their large length are elastically deformable and can be deformed by the hood  8  when attached, as shown in  FIG. 6 . Since after mounting of the first subassembly  61  on the second subassembly  62 , the receptacle  26  is supported on the first subassembly  61 , the forces that are acting in operation at the receptacle  26  are absorbed largely by the first subassembly  61  so that the arms  28  do not need high stability. The cross-section of the arms  28  is selected such that the desired high elasticity results. 
     As shown in  FIG. 4 , on the side of the receptacle  26  that is facing the second subassembly  62  an insertion funnel  34  is formed so that the first end  54  of the Bowden cable housing  19  can be arranged easily in the receptacle  26 . At the opposite side the receptacle  26  is closed with the exception of the slot  27  so that only the Bowden cable inner wire  20  can project through the receptacle  26 . 
     In the illustrated embodiment, the mounting aid  24  is secured on the motor housing  56 . However, it can also be provided that the mounting aid  24  is arranged at the first subassembly  61 , for example, on the hood  8 , and projects toward the second subassembly. A monolithic configuration of the mounting aid with another component of one of the subassembly may be advantageous. 
     The specification incorporates by reference the entire disclosure of German priority document 10 2011 120 469.9 having a filing date of Dec. 7, 2011. 
     While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.