Abstract:
A coarse separator ( 10 ) for a power tool ( 2 ) is used for separating, at least partially, from an air flow (L), material particles (M) produced during operation of the power tool ( 2 ) and aspirated by a suction device ( 8 ), and includes an inlet opening ( 48 ) connectable with the suction head ( 6 ) of a suction device ( 8 ) that aspirates the particles, an outlet opening ( 40 ) for letting a purified air flow (L) out, and a lamella separator arranged between the inlet opening ( 48 ) and the outlet opening ( 40 ).

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a coarse separator for a power tool for separating, at least partially, from an air flow, material particles produced during operation of the power tool and aspirated by a suction device including a suction head. The coarse separator includes an inlet opening connectable with the suction head, an outlet opening for letting a purified air flow out, and separation means arranged between the inlet opening and the outlet opening. 
     2. Description of the Prior Art 
     Coarse separators of the types described above are primarily used for separating particles with a diameter of at least 10 μm and can be permanently or releasably secured on a power tool or be connected by a suction conduit with a suction head attached to the power tool. 
     German Publication DE 198 27 173 discloses a separator for a hand-held power tool and which is formed as a cyclone separator. The separator is formed essentially of a feeding tube that opens in a cylindrical forechamber. The forechamber is located within a collecting container in which separated material particles are collected. For removal of the partially purified air, there is provided an immersion pipe that projects into the forechamber from above. 
     A drawback of the known separator consists in that it requires a relatively large constructional space in order to insure a satisfactory filtration efficiency. In addition, the separator has a relatively bulky geometry. This leads, in particular with integration of the separator in the power tool, to a poor handling of the separator. 
     Accordingly, an object of the present invention is to provide a coarse separator in which the drawbacks of the known separator are eliminated. 
     Another object of the present invention is to provide a coarse separator as compact as possible. 
     SUMMARY OF THE INVENTION 
     These and other objects of the present invention, which will become apparent hereinafter, are achieved by providing a coarse separator that includes a lamella separator. With use of a lamella separator, the shape of a coarse separator can be relatively arbitrary determined. In addition, a lamella separator provides for a very compact shape of a coarse separator. The compact shape of a coarse separator according to the present invention permits to better integrate it in the suction device or it can so be mounted on a power tool so that its handling during an operation is not negatively affected. 
     According to an advantageous embodiment of the present invention, there is provided, at a side of the lamella separator remote from the inlet opening, an opening region or simply an opening of a catch chamber. The catch chamber insures that a reliable and a satisfactory dimensioned receptacle is provided for receiving material particles separated at the lamella separator. 
     In effect, the catch chamber is open only at this opening. With the opening provided only at one side, the air, which is entered into the catch chamber with an air flow flowing through the inlet opening, bottles up in the catch chamber. The bottling-up of air provides for at least partial short-circuiting of the air flow from the inlet region about the lamellas of the lamella separator toward the outlet opening. The material particles, in particular the heavy ones, are separated from the air flow due to their inertia and are accumulated in the catch chamber. With such separation of material particles, the separator requires a particularly little constructional space and can be economically produced. 
     Advantageously trap means is provided in the catch chamber for blocking displacement of material particles collected in the catch chamber from displacement in a direction of the opening of the catch chamber. The trap means prevents the particles, which are accumulated in the catch chamber, from leaving the catch chamber as a result of rotation of the power tool or of the separator, or as a result of blows or vibrations produced during operation of the power tool. 
     Advantageously, the trap means is formed by catch walls projecting into the catch chamber and tilting away from the catch chamber opening toward their free ends. The formation of the trap means as catch walls provides for simply produced trap means that provides for an easy entry of the particles into the catch chamber while simultaneously blocking their reemergence from the catch chamber. 
     Preferably, the lamella separator has a plurality of lamellas arranged parallel to each other and one after another in an entry direction of the air flow and which partially sidewise limit an inlet path which extends between the inlet opening and the opening of the catch chamber in a direction of the outlet opening. The lamellas form, at their ends adjacent to the inlet path, an acute angle with the inlet path. 
     In this way, on one side, lamellas prevent a sidewise exit of at least heavy particles carried by the air flow from the inlet path extending toward the catch chamber. On the other hand, the air flow that flows around the entry side ends of the lamellas, can flow between the lamellas, without encountering any large flow resistance, toward the outlet opening. Simultaneously, a relatively high filtration or separation efficiency regarding the material particles carried by the air flow, is achieved. Thus, a high purification efficiency at a small flow loss is achieved. 
     It is advantageous, the lamellas are bent in the entry direction of the air flow at their ends adjacent to the inlet path. This increases the flow path about the lamellas, which increases the separation efficiency. 
     Advantageously, the entry direction extends in a direction a gravity force acts, in a horizontal position of the power tool, and which corresponds to a main direction of the coarse separator. 
     As a result, not only the air flow carries the material particles in the direction of the catch chamber but they are also displaced by a gravity force. 
     Advantageously, the inlet opening is formed by a nozzle, in particular, a slotted nozzle. This provides for an optimal flow velocity independent on the power of the suction generator, which permits to achieve a maximal efficiency. 
     It is further advantageous, when a removable cover that limits the catch chamber from one side, also abuts, in its mounted position, end surfaces of the lamellas. 
     With a common cover for both the catch chamber and the lamellas, the removal of the cover for emptying the catch chamber simultaneously makes the lamellas accessible for cleaning. 
     Advantageously, the coarse separator housing is securable to the power tool housing. Thereby the separator is moved together with the power tool during operation, which permits to effect a rapid and easy exchange at different sites the power tool is used at. 
     Advantageously, the outlet opening is connected with a fine separator. This permits to combine a coarse separator with a fine separator, e.g., a filter, which provides for a high separation efficiency, without a need to use a complicated fine separator. 
     This permits to increase the operational period within which the fine separator is added and to achieve an improved separation of the material particles from the air flow. 
     The novel features of the present invention, which are considered as characteristic for the invention, are set forth in the appended claims. The invention itself, however, both as to its construction and its mode of operation, together with additional advantages and objects thereof, will be best understood from the following detailed description of preferred embodiment, when read with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawing show: 
         FIG. 1  a side elevational view of a power tool with a suction device that includes a coarse separator according to the present invention; 
         FIG. 2  a front elevational view of the coarse separator shown in  FIG. 1 ; 
         FIG. 3  a side view of the coarse separator shown in  FIGS. 2 and 4  in a direction III of an outlet opening; and 
         FIG. 4  a cross-sectional view of the coarse separator along line IV-IV in  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  shows a power tool  2  that is formed as a hand-held hammer drill or chisel hammer. The power tool  2  is equipped with a working tool  4  in form of a drill or chisel, respectively. A suction head  6  of a suction device, which is generally designated with a reference numeral  8 , is held adjacent to the working tool  4 . The suction device  8  includes a coarse separator  10  which is connected with the suction head  6  by a connection conduit  12 . Instead of a hammer drill or chisel hammer, the coarse separator  10  can be conveniently used with hand-held saw, cutting or grinding tool. 
     The coarse separator  10  is connected with a fine separator  16  which is provided with a filter  14  located in a housing  16 ′ of the fine separator  16 . The fine separator  16  is connected at its side remote from the coarse separator  10  with ventilation slots  20  formed in the housing  22  of the power tool  2 . A ventilation conduit  18  connects the fine separator  16  with the ventilation slots  20 . In the tool housing  22 , there is arranged a ventilator  26  driven by a motor  24 . Upon actuation of the motor  24 , the ventilator  26  generates an air flow shown with arrow L. The air flow L enters the suction device  8  at the suction head  6  and flows to the ventilator  26  through the connection conduit  12 , coarse separator  10 , fine separator  16 , and the ventilation slots  20 . The ventilator  26  then directs the air flow L past the motor  24  and to outlet recesses  28  formed in the housing  22 . 
     On one hand, the air flow L provides for suction of material particles M which are released upon operation of the working tool  4  from a treated material. On the other hand, the air flow L serves for cooling of the motor  24 . 
     The coarse separator  10  has a substantially cuboid-shaped housing  30  secured on the housing  22  of the power tool  2 . Alternatively, the coarse separator  10  can be formed as a part of a suction device that is formed separately from the power tool  2  and is connected with the suction head  6  by a hose. 
     As shown in  FIG. 2 , the separator housing  30  has an inner chamber  32  that is completely closed at one of its sides with a removable cover  34  of the housing  30 . A nozzle  36 , which is formed as a slotted nozzle and is connected to the connection conduit  12 , opens into the inner chamber  32 . 
     The nozzle  36  faces in a direction of an inlet path  38  which is partially limited in the inner chamber  32  in a direction of an outlet opening  40  by a lamella separator generally designated with a reference numeral  42 . The fine separator  16  is arranged at the outlet opening  40  in communication therewith, as shown in  FIG. 1 . 
     The lamella separator  42  has a plurality of extending parallel to each other lamellas  44  which are held one behind the other on a center web  46  in a direction E of entry of the air flow L, as particularly shown in  FIG. 2 . The lamellas  44 , as also shown in  FIG. 2 , extend with their ends adjacent to the outlet opening  40  in a direction of the outlet opening  40  and substantially transverse to the entry direction E. The lamellas  44  bend toward their ends adjacent to the inlet path  38  in the entry direction E. 
     As shown in  FIG. 4 , the nozzle  36  forms an inlet opening  48  that defines a first end of the inlet path  38 . At a second end of the inlet path  38  remote from the first end, there is located an opening  50  of a catch chamber  52 . The catch chamber  52  is open, with the cover  34  being attached, at the opening  50 . 
     Trap means in form of catch walls  54 , which project from the housing  30 , extend into the catch chamber  52 . The catch walls  54  tilt away from the opening  50  toward their free end. 
     The coarse separator  10  is so held on the power tool  2  that the entry direction E somewhat coincides with the direction S of the gravity force when the power tool  2  extends in a horizontal direction which forms a main direction of the power tool, and with a wall-to-wall mounting, of the coarse separator  10 . 
     During an operation, the working tool  4  is driven by the motor  24  in a manner not shown in detail. Simultaneously, the motor  24  drives the ventilator  26  that produces, as it has been described above, the air flow L from the suction head  6  toward the outlet recesses  28 . With the air flow L, the material particles M are aspirated at the suction head  6  and are transmitted by the connection conduit  12  and through the nozzle  36  to the coarse separator  10 . 
     In the coarse separator  10 , the material particles M enter through the inlet opening  48  and move along the inlet path  38  in the entry direction E, as particularly shown in  FIGS. 2 and 4 . The air flow L meanwhile bottles up in the catch chamber  52  which is open only at one side, so that a following air flow L or at least a major portion of it is deflected in the inlet path  38  and flows past the ends of lamellas  44  adjacent to the inlet path  38  in a direction of the outlet opening  40 . 
     The material particles M, which are carried by the air flow L, are displace due to their inertia and, at the main direction of the power tool  2 , due to the gravity force S, further in the direction of opening  50  through which they enter the catch chamber  52 . In this way, the material particles M, which are separated by the lamella separator  42  form the air flow L, accumulate in the catch chamber  52 . The catch walls  54  block an undesired reemergence of the material particles M from the catch chamber  52 . 
     In order to empty the catch chamber  52 , the cover  34  is taken off the coarse separator housing  30 . In the mounted condition of the cover  34 , the cover  34  lies, as shown in  FIG. 3 , with its inner surface  56  on the cover-side end surfaces  58  of the lamellas  44  and on the cover-side inner end surface  60  of the coarse separator housing  30 . Thus, with the cover  34  being removed, both the catch chamber  52  and the lamella separator  42  are accessible for cleaning. 
     Though the present invention was shown and described with references to the preferred embodiment, such is merely illustrative of the present invention and is not to be construed as a limitation thereof and various modifications of the present invention will be apparent to those skilled in the art. It is therefore not intended that the present invention be limited to the disclosed embodiment or details thereof, and the present invention includes all variations and/or alternative embodiments within the spirit and scope of the present invention as defined by the appended claims.