Abstract:
The invention relates to a guiding cart for a manually guided tool, for example an abrasive cut-off machine, which comprises a movable frame on which a first and a second locating recess for inserting the abrasive cut-off machine are provided. A locking device is assigned to the first recess by means of which forces can be applied to the abrasive cut-off machine in the direction of the first locating recess and the second locating recess. In this way the abrasive cut-off machine can be reliably and rapidly fixed to the guiding cart after it has been inserted into the locating recesses. The insertion of the abrasive cut-off machine is facilitated by inclined inserting elements situated in the locating recesses.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a guide carriage for a cutting implement which can be guided by hand such as a parting-off grinder. 
     2. Description of the Related Art 
     Guide carriages of this kind are suitable, in particular, for carrying and guiding parting off grinders. Parting-off grinders or “cutting implements” which can be guided by hand, especially diamond parting-off grinders, are generally used when cutting pipes, stone slabs etc. and are suitable for carrying out work rapidly at different locations, even in spatially restricted conditions, by virtue of their low weight and ease of handling. The range of applications of a parting-off grinder of this kind is extended by the fact that it is secured on a guide carriage. This opens up the possibility of making precise cuts of defined depth in asphalt or concrete. 
     For this purpose, the parting-off grinder is generally secured on the guide carriage with the aid of lugs and bolts, this being very time-consuming and sometimes completely impossible because of the lack of suitable tools on site. 
     U.S. Pat. No. 4,938,201 has disclosed a guide carriage for a parting-off grinder which can be guided by hand, having a mobile frame and a holding device, mounted on the frame, for holding the parting-off grinder. 
     DE 30 00 390 has disclosed a guide carriage which comprises a mobile frame which rises on one side in the form of a pushing bar to a height at which it can be gripped by the operator. An implement designed as a parting-off grinder is arranged on the guide carriage. 
     DE 70 40 737 U has disclosed a guide carriage for a parting-off grinder having a mobile frame and a guide bar which rises from the frame to a handle, and having a holding device, mounted on the frame, for holding the implement. The holding device has a first holder on the guide bar and a second holder for supporting the implement on the frame. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The object underlying the invention is to specify a guide carriage in the case of which the implement can be secured quickly and reliably and in a simple manner. 
     According to the invention, the object is achieved by means of a guide carriage having a guide carriage for a cutting implement. The guide carriage includes a mobile flame and a holding device which is mounted on the frame and which has a first holder and a second holder for supporting the implement on the frame. The first and second holders include first and second receptacles, respectively, for insertion of the implement therein. The first receptacle is assigned a locking device, with a stop which has at least one stop surface which can be moved relative to the frame and aligned to strike the implement, such that a perpendicular vector associated with the orientation of the stop surface has a directional component extending in a direction of extension of at least one of the first and second receptacles. 
     A guide carriage configured in this way therefore has at least one stop surface by means of which forces in the direction of the first and the second receptacle can be produced in the case of an implement used, by virtue of the corresponding alignment. In general, this is made possible by appropriate sloping of the stop surface. As an alternative, the stop can also have a plurality, e.g. two, stop surfaces, the first stop surface being oriented in the direction of the first receptacle and the second stop surface being oriented in the direction of the second receptacle. In this case too, a combination of the two perpendicular vectors perpendicular to the stop surfaces has directional components in the direction of the first and the second receptacle. However, it is advantageous if each of the receiving surfaces assumes a fixing and clamping function assigned to it. 
     This makes it possible to fix the implement reliably in the holding device with the aid of just one locking device. 
     To ensure reliable fixing in the first receptacle, it is particularly advantageous if the first stop surface is arranged opposite a bottom surface of the first receptacle. It is furthermore very expedient if the second receptacle has supporting surfaces which are arranged in such a way that the second receptacle allows only a relative movement of the implement in the direction of the first receptacle. It is namely possible, by restricting the degrees of freedom in the second receptacle in this way, to hold the implement reliably in the second receptacle by means of the force produced in the direction of the second receptacle by the second stop surface. 
     A very advantageous development of the invention consists in a guide surface being provided on the second receptacle, opposite a bottom surface, thereby making it particularly easy to restrict the degrees of freedom. 
     In a particularly advantageous embodiment of the invention, the first and the second receptacle have guide surfaces which slope counter to a direction of insertion of the implement. The insertion slopes thereby formed make it easier to insert the implement into the holding device and ensure definite and play-free seating. 
     The locking device can be operated comfortably if the first receptacle is arranged close to a handle for guiding the guide carriage. 
     In another particularly advantageous embodiment of the invention, the locking device has a pivoting interlock element which bears the first and the second stop surface, it being very expedient if the first stop surface is formed by a hold-down element formed on the pivoting interlock element and the second stop surface is formed by an eccentric which is arranged about a pivot axis of the pivoting interlock element. By pivoting the pivoting interlock element after inserting the implement, the stop surfaces can be moved equally quickly and precisely up to or over the implement, the stop surfaces thereby ultimately pressing the implement into the receptacles. By means of the eccentric, in particular, the implement is pressed over its entire length into the second receptacle. 
     In another embodiment, the locking device provided is one in which the pivoting interlock element has just one single stop surface, which produces a force with components in the direction of the first and the second receptacle. The pivoting interlock element can be pivoted up laterally over the handle of the implement, thereby giving a compact construction. It is advantageous if a throttle actuator is also provided on the pivoting interlock element, with the aid of which actuator the implement can be remote-controlled via the throttle lever. 
     In a particularly advantageous development of the invention, a safety button provided on the implement can be actuated by means of the first stop surface. To operate the implement, e.g. a parting-off grinder, safety buttons of this kind must be operated in addition to an on/off switch in order to avoid the implement being switched on accidentally. However, this problem is not encountered when the implement is clamped in the guide carriage, and it is thus possible for the safety button to be permanently pressed by being acted upon by the first stop surface. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other features and advantages of the invention will be explained in greater detail below using the accompanying figures, in which: 
     FIG. 1 shows a schematic side view of a guide carriage according to the invention; 
     FIG. 2 shows a detail looking in direction Z in FIG. 1; 
     FIG. 3 shows a side view of the guide carriage according to the invention from FIG. 1 with a parting-off grinder inserted; 
     FIG. 4 shows an enlarged detail looking in direction X in FIG. 3; 
     FIG. 5 shows a second embodiment of the guide carriage according to the invention with the parting-off grinder inserted; 
     FIG. 6 shows an enlarged detail looking in direction X in FIG. 5; 
     FIG. 7 shows a three-dimensional view of a third embodiment of the guide carriage; 
     FIG. 8 shows a side view of the guide carriage from FIG. 7; 
     FIG. 9 shows a front view of the guide carriage in FIG. 7; 
     FIG. 10 shows a locking device used in the third embodiment, in three-dimensional view; 
     FIG. 11 shows an enlarged representation of the locking device from FIG. 10; 
     FIG. 12 shows a schematic representation of a fourth embodiment; and 
     FIG. 13 shows a schematic representation of a fifth embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 shows a schematic side view of the guide carriage according to the invention. 
     The guide carriage essentially comprises a frame  1 , which is welded together from tubes or metal sheets and can be moved on rollers  2 . Secured on the frame  1  is a pivotable handle  3 , using which the guide carriage can be moved over concrete or asphalt, for example, and on which a throttle lever  4  for controlling the parting-off grinder (not shown) to be inserted into the guide carriage is provided. 
     Also mounted on the frame  1  is a holder  5  with a water tank  6 , from which water is fed to the parting-off location in a customary manner via hoses or tubes (not shown). 
     A holding device for holding the parting-off grinder is furthermore mounted on the frame  1 , said holding device comprising a first receptacle  7  and a second receptacle  8 . The first receptacle  7  is assigned a locking device  9 , the operation of which will be described below. 
     The first receptacle  7  essentially comprises two sheet-metal tabs which project from the frame  1  and into which part of the handle of the parting-off grinder can be inserted. 
     In FIG. 2, the second receptacle  8  is illustrated in the form of an enlarged plan view looking in direction Z in FIG.  1 . It comprises sheet-metal pieces  10  which taper obliquely downward relative to one another and thereby forms a shell shape. An extension  11 , the operation of which will be explained below, is formed on one of the sheet-metal pieces  10 . The second receptacle  8  is illustrated in FIG. 1 in the form of a partial section. However, as can be seen from FIG. 2, it has sheet-metal pieces  10  on all four sides. 
     FIG. 3 shows the guide carriage from FIG. 1 with a parting-off grinder  12  inserted. 
     The commercially available parting-off grinder  12  with a frame or casing, an internal combustion engine  13 , a handle  14 , a throttle-actuating means  15 , a guiding and supporting bar  16  and a diamond parting-off or cutting wheel  18  arranged underneath a protective hood  17  is inserted into the first receptacle  7  and the second receptacle  8 . 
     In the plan view in FIG. 4, the locking device  9 , which is illustrated in the closed condition in FIG. 3, is illustrated on an enlarged scale looking in direction X. It comprises a handle  19 , which can be pivoted about an axis of rotation  20  and is coupled to a pivoting interlock element  21  acting as a stop. The pivoting interlock element  21  is hook-shaped and bears a hold-down element  22  acting as a first stop surface and an eccentric  23  acting as a second stop surface. 
     As can be seen in FIGS. 3 and 4, the pivoting interlock element  21  can be turned in such a way by actuating the handle  19  that the parting-off grinder  12  can be inserted into the two freely accessible receptacles  7 ,  8 . This is made easier by the fact that both receptacles  7 ,  8  have insertion slopes in the form of obliquely angled metal sheets. In this case, a front part of the parting-off grinder housing enters the second receptacle  8 , the extension  11  being able to enter a corresponding recess in the parting-off grinder  12 . As a result, the parting-off grinder  12  can be pulled or pivoted out of the second receptacle  8  only in the direction of the first receptacle  7 . To make the illustration clearer, the sheet-metal piece  10  of the second receptacle  8 , said sheet-metal piece being at the top in relation to the plane of the drawing, has been omitted. 
     During insertion, the handle  14  of the parting-off grinder  12  moves between the two sheet-metal pieces of the first receptacle  7 . The sheet-metal pieces of the first receptacle  7 , said pieces being visible in FIG. 4, are joined by a bottom surface, which is obscured by the handle  14  and is therefore not visible. The hold-down element  22  is arranged essentially opposite the bottom surface. 
     Once the parting-off grinder  12  has been inserted into the two receptacles  7 ,  8 , the parting-off grinder  12  is positioned without play and in a precise manner relative to the frame  1 . In this state, it is only possible for it to be lifted upward out of the first receptacle  7  and thus pulled or pivoted out of the second receptacle  8 . 
     To finally secure the parting-off grinder  12 , the pivoting interlock element  21  is pivoted into the position shown in FIGS. 3 and 4 by actuating the handle  19 . The hold-down element  22  thereby moves over the handle  14  of the parting-off grinder and presses the latter into the first receptacle  7  against the two lateral sheet-metal pieces by virtue of a beveled slope on the hold-down element  22 . During this process, there should be no contact between the handle  14  and the bottom surface connecting the two sheet-metal pieces, so as to achieve adequate preloading. If the handle  14  does touch the bottom surface, however, the preloading must be achieved by means of corresponding elasticity of the hold-down element  22 . 
     As the pivoting interlock element  21  is pivoted, the eccentric  23  also makes contact with a rear end  24  of the handle  14  and, as the pivoting interlock element  21  is pivoted further, presses the handle  14  and thus the parting-off grinder  12  into the second receptacle  8 . By virtue of the preloading in the direction of the first and the second receptacle  7 ,  8 , the parting-off grinder  12  is held with the highest possible accuracy on the frame  1 . The preloading ensures that lifting of the parting-off grinder  12  out of one of the receptacles  7 ,  8  can be avoided even in operation and with cutting forces acting via the parting-off wheel  18 . 
     The locking device  9  can be supplemented by a latching device (not shown), by means of which the pivoting interlock element  21  can be fixed at least in the locking position, thus making it possible to avoid unintentional release of the pivoting interlock element  21 . Other embodiments of the locking device  9 , in which the two stop surfaces  22 ,  23  can be moved relative to the frame  1 , are also conceivable instead of the pivoting interlock element  21  shown. Thus, for example, each of the surfaces can be coupled to a screw thread, thus allowing the stop surfaces to be adjusted toward the parting-off grinder  12  by turning corresponding handles or wing nuts or the like. It is likewise readily possible for the person skilled in the art to replace the pivoting interlock element by a wedging means. 
     Conventional parting-off grinders have, in the region of the handle  14 , a safety button  25  which the operator must keep pressed simultaneously with the throttle-actuating means  15 . Only then can the parting-off wheel  18  be set in motion by the internal combustion engine  13 . However, this safety aspect is only significant when the parting-off grinder  12  is guided by hand, whereas operation of the safety button  25  is more of a hindrance when it is used in the guide carriage. For this reason, the pivoting interlock element  21  is designed in such a way that it not only presses the handle  14  into the first receptacle  7  by means of the hold-down element  22  but also simultaneously operates the safety button  25 . 
     As a supplement to the description, it may be stated that the throttle lever  4  on the handle  3  of the guide carriage is coupled by a Bowden cable (not shown) to a lever  26  which is in contact with the throttle-actuating means  15  of the parting-off grinder  12 . This makes it possible to control the internal combustion engine  13  remotely from the handle  3 . 
     FIGS. 5 and 6 show a guide carriage corresponding to FIGS. 3 and 4 but with a modification. Here, a shorter pivot axis  27  than the pivot axis  20  in FIG. 3 is formed. This allows the hold-down element  22  of the pivoting interlock element  21  to make contact with a lower region of the usually bow-shaped handle  14  of the parting off grinder  12 . The parting-off grinder  12  is thereby pressed into the first receptacle  7 , as already described in conjunction with FIG.  3 . Here, the eccentric  23  operates in the same way. 
     As compared with the embodiment described first, this variant has the advantage of a more compact construction. However, an additional clamping device is required to hold down the safety button  26  on the handle  14  of the parting-off grinder  12 . 
     The remaining components correspond to those already described with reference to FIGS. 3 and 4, and a more detailed description is therefore dispensed with. 
     In the embodiments shown, the pivoting interlock element  21  bears two stop surfaces, namely the hold-down element  22  and the eccentric  23 . However, the invention also relates to a solution in which the pivoting interlock element is provided only with a stop surface, which can be designed like the hold-down element  22 , for example. In FIG. 3, it can be seen that the hold-down element  22  is at an angle to an imaginary axis connecting the first receptacle  7  and the second receptacle  8 . By virtue of this angularity, the hold-down element  22  exerts on the parting-off grinder  12  a force with components in the direction of the first and the second receptacle  7 ,  8 . The force components are in a certain ratio depending on the angular position of the hold-down element  22 , making it possible, given appropriate setting, to dispense with the eccentric  23 , with the parting-off grinder  12  nevertheless being pressed reliably into the second receptacle  8 . An angle of 45° has proven to be a suitable angular position in this context. In this case, the force components in the direction of the first receptacle  7  and of the second receptacle  8  are of equal magnitude. However, other angles may also be suitable, depending on requirements. 
     The guide carriage according to the invention is distinguished by the fact that a commercially available parting-off grinder can be secured with great precision and within an extremely short time on the guide carriage without the use of tools and additional fixing elements. By virtue of the preloading produced by the locking device, even the cutting forces which occur during operation can be reliably absorbed without the parting-off grinder moving relative to the frame of the guide carriage. Incorrect mounting is excluded by the simplicity of construction of the holding device. 
     The fixing of the parting-off grinder is suitable both for parting-off wheels arranged centrally and for those arranged noncentrally on the parting-off grinder. 
     FIGS. 7 to  11  show another embodiment of the guide carriage, in which, in particular, the locking device has been modified. 
     FIGS. 7 to  9  show the guide carriage in three-dimensional representation, in side view and in front view respectively. Where the same reference numerals as in the previous embodiments are used, the individual subassemblies are not described again. 
     Essentially, this embodiment differs in having a modified locking device  29 , which is illustrated on an enlarged scale in FIGS. 10 and 11. 
     Welded to the frame  1  is a lug  30 , which carries a pivoting interlock element  32  which can be pivoted about a pin  31 . 
     At an opposite end from the pin  31 , the pivoting interlock element  32  has a stop surface  33  which is bent upward at one end  34  to provide better guidance via the handle of the parting-off grinder. The stop surface  33  corresponds essentially to the stop surface  22  in accordance with FIG.  3 . 
     The pivoting interlock element  32  can be fixed by means of a latching device  35  in at least one end position, in which it presses the parting-off grinder into the holding device. The latching device  35  comprises a spring-loaded pin which can enter a hole (not shown) in the lug  30 , thereby bringing about a form-fitting connection between the pivoting interlock element  32  and the lug  30 . The form-fitting engagement can be canceled again by pulling on the pin, whereupon the pivoting interlock element  32  is released and can be pivoted. 
     The pivoting interlock element  32  furthermore has an angled extension  36  on which a throttle actuator  37  in the form of a pivotable lever is mounted. As can be seen, for example, from FIG. 7, the lever of the throttle actuator  37  is coupled to the throttle lever  4  by a Bowden cable  38 . The throttle actuator  37  is arranged in such a way that, when the pivoting interlock element  32  is pivoted in, an actuating finger  39  comes to rest against the throttle lever of the parting-off grinder. This makes it possible to remote-control the motor of the parting-off grinder by means of the throttle lever  4 . 
     Thanks to the possibility of pivoting the pivoting interlock element  32  with the throttle actuator  37  toward the parting-off grinder and—on completion of the work—of pivoting it away again from the parting-off grinder to allow the latter to be removed, the parting-off grinder can be installed and removed within the shortest possible time. 
     By appropriate configuration of the pivoting interlock element  32 , it is possible to ensure that the pivoting interlock element  32  with the throttle actuator  37  can only be pivoted in when both the throttle lever  4  and the throttle-actuating means  15  of the parting-off grinder  12  are in the idling position. This ensures that pivoting of the pivoting interlock element  32  is excluded if the parting-off grinder  12  has accidentally already been set operating by pressing the throttle-actuating means  15  and the diamond parting-off wheel  18  is rotating. It is thereby possible to avoid severe accidents. Conversely, the pivoting interlock element  32  can only be pivoted down from the parting-off grinder  12  if all the throttle actuation elements  4 ,  15 ,  37  are likewise in the idling position. This prevents the parting-off grinder  12  from being removable during operation with the parting-off wheel  18  rotating. 
     FIG. 12 shows schematically the second receptacle  8  of a fourth embodiment. The second receptacle  8  essentially comprises a receiving plate  40 , which is secured on the frame  1  of the guide carriage in a manner not shown. An elongate aperture  41 , into which a likewise elongate extension  42  of the parting-off grinder  12  (not shown in FIG. 12) can be inserted is formed in the receiving plate  40 . The extension  42  is provided on a baseplate  43  of the parting-off grinder  12  and has conical insertion slopes  44  which allow the extension  42  to be inserted easily into the aperture  41  together with the baseplate  43  and the parting-off grinder  12  secured on it. This gives rise to a form-fitting connection between the parting-off grinder  12  and the second receptacle  8 . 
     FIG. 13 shows a schematic representation, similar to FIG. 12, of a fifth embodiment of the invention, in which the second receptacle  8  has likewise been modified. Two holes  46  have been formed in a receiving plate  45  secured on the frame  1  of the guide carriage. Two conical extensions  47  secured on a baseplate  48  of a parting-off grinder  12  (not shown) can be inserted into the holes  46 . This likewise gives rise to a positive-fitting connection between the parting-off grinder  12  and the second receptacle  8 . 
     The second receptacles  8  shown in FIGS. 12 and 13 make it possible to produce positive-fitting engagement between the parting-off grinder  12  and the second receptacle  8  in a particularly simple and reliable manner. The positive-fitting engagement can be released only by pulling the parting-off grinder out in the direction of the first receptacle  7 , movement in the direction of the first receptacle  7  being prevented by the stop  21 ,  32  when the parting-off grinder  12  is inserted and locked. 
     Other variants of the configuration of the receptacles  7 ,  8  are, of course, possible. It may be expedient, for example, to provide at least one of the receptacles  7 ,  8  with a spring device with which a receiving plate is resiliently supported in order, if appropriate, to compensate for any play which occurs and to press the parting-off grinder  12  reliably against the stop  21  or  32 . The spring device can be formed by rubber elements, steel-spring straps or other spring elements. However, a spring device of this kind can also be integrated into the baseplate of the parting-off grinder. 
     Depending on the intended application of the guide carriage, it may furthermore be expedient to provide the stop  21 ,  32  of the locking device  9 ,  29  with a spring device in order to compensate for harmful play during the operation of the apparatus. It should be noted that, by virtue of their configuration, the stops  21 ,  32  described above already have spring properties and are thus capable of compensating for at least a slight play. 
     In practice, the baseplates  43 ,  48  shown in FIGS. 12 and 13 can have the disadvantage that the extensions  42 ,  47  secured on them may be bent or be damaged in some other way if the parting-off grinder  12  is set down roughly on the base, making it more difficult to insert the parting-off grinder  12  into the second receptacle  8 . For this purpose, it is advisable to produce corresponding apertures in the baseplates  43 ,  48  of the parting-off grinder  12 , into which apertures extensions formed on the receptacle  8  of the guide carriage then engage. In this case, the apertures in the baseplate  43 ,  48  can also, for example, take the form of ribs, in the gaps between which corresponding extensions of the second receptacle  8  engage.