Abstract:
A manual machine tool ( 10 ) includes a vacuum device for dust removal ( 19 ) situated in its housing ( 12 ) and a blow-out connection ( 20 ) installed after this. A dust collection box ( 21 ), particulaily self-contained, can be attached in detachable fashion to the blow-out connection ( 20 ) via its blow-in connection ( 22 ). The dust collection box ( 21 ) is airtight on all but two sides and has air-exit holes ( 40 ) on the top side ( 36 ) and a dustproof filter element ( 48 )—especially a fluted filter—on the inside. The dust collection box is particularly secure against the unintentional escape of dust after the dust collection box is detached from the associated manual machine tool because a pair of sealing lips ( 500 ) arranged as a separate part is provided inside the blow-in connection ( 22 ), which pair of sealing lips ( 500 ) is connected as a single part with closing flaps ( 520, 520 ) projecting into the interior of the dust collection box ( 210 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention is based on a manual machine tool with a vacuum device for dust removal. 
     A hammer drill is made known in U.S. Pat. No. 4,192,390 that includes its own vacuum device for dust removal, with which the boring dust produced can be suctioned—according to the vacuum cleaner principle using suction air—into a dust collection box mounted on the hammer drill in relatively complicated fashion, with the suction air passing through a lamellar dust filter onto which the boring dust is deposited and collects in the dust collection box. The dust collection box is intended to remain attached to the hammer drill and has a base that can be swung open to empty the boring dust. 
     Another hammer drill is made known in U.S. Pat. No. 5,467,835 that comprises a vacuum device for dust removal with which boring dust that is produced can be suctioned—also according to the vacuum cleaner principle using suction air—into a separate dust collection box installed in a housing in removeable fashion. A fluted filter is situated in front of the suction port of the dust collection box facing the suction fan, onto which the dust is deposited when suction air passes through and collects in the dust collection box, so that pure air is transported toward the suction fan. The dust collection box can be detached from the housing to empty the boring dust, and the boring dust can be emptied through the entrance port. 
     The dust collection boxes of the two known hammer drills can be emptied only by way of a relatively complicated procedure, whereby replacement of the lamellar or fluted filter is a complicated procedure. Moreover, these dust collection boxes are unsuited for self-contained attachment to manual machine tools with integrated vacuum devices for blowing in the dust. 
     Manual machine tools are also known that are provided with plastic cassettes serving as dust collection boxes that are either provided with a multitude of air vents and are lined with filter material—similar to a grass catcher used with lawn mowers—or that consist of porous, only slightly dimensionally stable, air-permeable plastic that cleans the air blowing in the dust released from the container and is intended to retain the dust inside it. Both plastic cassettes tend to become plugged, and they are difficult to empty and clean. 
     In the known dust collection box, a specially-formed sealing lip made of the same material as the housing is produced during injection-molding. This can be achieved only if relatively soft material such as polypropylene (PP) is used as the housing material. When materials such as PA6 (polyamide, quality class  6 ) or light-metal die casting, for example, are used to make the housing for dust collection boxes, separate rubber-elastic seals must be installed instead. 
     In the known dust collection box, a specially-formed sealing lip made of the same material as the housing is produced during injection-molding. This can be achieved only if relatively soft material such as PP is used as the housing material. When materials such as PA6 or light-metal die casting, for example, are used to make the housing for dust collection boxes, separate rubber-elastic seals must be installed instead. 
     SUMMARY OF THE INVENTION 
     The manual machine tool according to the invention with vacuum device for dust removal has the advantage, in contrast, that a particularly lightweight and compact dust collection box was created than can accommodate a large volume of blown-in dust without losing its inherent stability, whereby the removal by suction of the grinding dust from the tool takes place with a consistently high level of effectiveness and a long usable filter life with improved fine-dust filtration practically until the maximum fill level is reached. 
     Due to the fact that the dust collection box is held tightly against the manual machine tool—except at the dust blow-out connection of the manual machine tool—by way of a projection on its top cover, the forces of deformation produced when the dust collection box becomes full of dust are reduced to the extent that the cross-sections of the walls of the dust collection box can be minimal and, as a result, the dust collection box is particularly lightweight but stable, i.e., not 
     Due to the fact that the dust collection box, as a case open on the top, is provided with a removeable cover that closes the opening from above, only a minimal loss of pressure occurs during dust removal, whereby the dust can be disposed of particularly conveniently by opening the cover, without creating a dust cloud and polluting the environment. 
     Due to the fact that only the cover carries a filter, in particular a fluted filter, and it is the only part of the dust collection box provided with air vents, the filter surface can be designed to be particularly large in size. As a result, the air carrying the dust becomes blocked only to a minimal extent, and the vacuum device for dust removal is highly effective. Additionally, the dust can come loose from the fluted filter automatically when it reaches a certain layer thickness and fall into the dust collection box under the influence of gravity. 
     Due to the fact that the surface of the dust collection box with the cover is tilted in comparison with the direction of flow of the blow-out air in such a fashion that the dust collection box tapers toward the machine in the shape of a wedge, dust-preventing flow conditions are created for the blow-out air that optimize the removal of dust. 
     Due to the fact that the cover is held tightly against the dust collection box in elastic and impermeable fashion, it is particularly easy to open and close. The indentations on the sides of the dust collection box provided for opening purposes make it easier for the operator to establish a hold with his fingers and handle the dust collection box using one hand without the use of tools when removing, emptying, and reattaching the dust collection box. 
     Due to the fact that sealing lips are arranged in the blow-in connection of the dust collection box that encompass the dust blow-out connections of the manual machine tool and act as a seal, the dust collection box is reliably dust-proof during operation of the manual machine tool. 
     Due to the fact that the fluted filter is situated only in the cover of the dust collection box, it is particularly easy to replace in that a new one is either attached using adhesive, or the entire cover is replaced along with the filter. 
     Due to the fact that the dust collection box can be attached to the manual machine tool using locking levers designed in the shape of a rocker, it can be removed, emptied, and reattached in particularly convenient and time-saving fashion. 
     Due to the fact that the blow-in connection of the dust collection box can be closed using a valve, dust can be effectively prevented from escaping unintentionally when the dust collection box is removed from the manual machine tool. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is explained in greater detail below using a design example with associated drawings. 
     FIG. 1 shows a longitudinal view of a manual machine tool with a dust collection box according to the invention, 
     FIG. 2 shows a top view of the manual machine tool according to FIG. 1, 
     FIG. 3 shows a spacial view of the dust collection box with the cover removed, as viewed diagonally from the front, 
     FIG. 4 shows a longitudinal view of the dust collection box with the cover removed, 
     FIG. 5 shows a view of the dust collection box from below, 
     FIG. 6 shows a spacial top view of the dust collection box, 
     FIG. 7 shows a spacial bottom view of the dust collection box, 
     FIG. 8 shows a cross-section of the dust collection box, 
     FIG. 9 shows a cross-section of the fluted filter of the dust collection box, 
     FIG. 10 shows an enlarged cross-section of a single lamina of the fluted filter, 
     FIG. 11 shows a longitudinal view of a design example of a blow-in connector of the dust collection box with sealing flaps connected to the sealing lips, 
     FIG. 12 shows the longitudinal view according to FIG. 11 with a a sealing lip that has been acted upon, 
     FIG. 13 shows a further embodiment of sealing flaps with short sealing lips, and 
     FIGS. 14 and 15 show a final embodiment of sealing flaps with short sealing lips. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The longitudinal view in FIG. 1 showed a manual machine tool  10  designed as an orbital sander with a housing  12  that has a handle  14  with switch  15 , to which a tool  16  designed as a rubbing plate is attached in a fashion that allows it to move. The manual machine tool  10  comprises an electric connecting cable  18  on the back end of the handle  14  and a fan wheel  19  inside the housing  12 . The fan wheel  19  creates a vacuum over the rubbing plate when the manual machine tool is operated. Grinding dust is thereby removed at and below the rubbing plate  16  and blown through a blow-out connection  20  of the housing  12 . 
     The blow-out connection  20  comprises a blow-in connection  22  form-fit above it that belongs to a dimensionally stable dust collection box  21  arranged in self-contained fashion. Except for the blow-in port  27  of the blow-in connection  22  and its top side, the dust collection box  21  is airtight. The top side of the dust collection box  21  is formed by a cover  23 , out of the top side  36  of which a hook  24  extends to grip in a retention opening  25  in the rear section of the handle  14 . The dust collection box  21  is also held tightly against the housing  12  of the manual machine tool by way of the hook  24 , which allows the housing structure of the dust collection box  21  to be constructed with particularly thin wall cross-sections, making it extremely lightweight. 
     The cover  23  of the dust collection box  21  is held particularly tightly in spring-elastic, latching fashion at the upper edge  32  of the dust collection box  21 —which forms a circumferential bead  33 —by way of its snap-in edge  42  in an interlocking, adherence-actuated fashion. 
     The bottom side  34  of the dust collection box  21  is tilted in comparison to the longitudinal axis of the blow-in connection  22 , so that, in the longitudinal view, the dust collection box  21  forms a wedge shape in comparison to the axis  35  and tapers toward the manual machine tool  10 . 
     The top side  36  of the cover  23  comprises spherical air-exit holes  40  with a filter element  48  made of special paper and designed as a fluted filter installed before them, so that its top side  49  (FIG. 9) faces the underside of the cover  23 . Additionally, the top side  36  of the cover  23  is provided with an indentation  38  having a u-shaped profile in the area of the hook  24  which is directed toward the interior of the dust collection box  21  that stiffens the structure of the cover  23  and provides space to accommodate the passage of larger, further overhanging housing shapes of other manual machine tools. 
     Two side indentations  44  are provided on opposite sides of the front section of the dust collection box  21  near the blow-in connection  22  that make it easier for the operator to reach under the cover  23  with his fingers and therefore conveniently open the cover  23 . 
     The cover  23  comprises two side panels  46  that extend as single parts parallel to the side edges  58  of the dust collection box  21  and project into the interior of the dust collection box  21  in keel-like fashion and form a lateral delineation and mechanical protection for the filter element  48  if the cover is removed from the dust collection box  21  and set aside, and if dust is knocked out of the filter element  48 . 
     The blow-in connection  22  of the dust collection box  21  includes a circumferential sealing lip  50  in the interior that encloses the blow-out connection  20  of the manual machine tool in airtight fashion. Moreover, the blow-in connection  22  of the dust collection box  21  comprises ribs on the top and bottom that improve the stiffness of the dust collection box  21  when the wall cross-section is thin. 
     FIG. 2 shows the details of the manual machine tool  10  with the dust collection box  21  mentioned previously, with the following being particularly easier to see than in FIG.  1 : the indentation  38  of the cover  23 , the holes  40  for blow-out air cleaned of dust to pass to the outside, and a rocker  26  for attachment of the dust collection box  21  to the manual machine tool  10  by way of latching. The rocker  26  of the dust collection box  21  is designed as a dual-arm lever, one of the arms of which is designed as the push-button arm  28  and the other arm of which is designed as the latch arm  29 . The rocker  26  is attached to the blow-in connection  22  of the dust collection box in pivoting fashion by means of a film hinge  30 . The latch arm  29  is held tightly by a lateral projection—not shown—of the housing  12  of the manual machine tool  10  in the area of its blow-out connection  20  in an elastic, preloaded fashion. 
     It is also made clear that the base of the manual machine tool  10  is formed by the rectangular rubbing plate  16 , and that the back edge  56  of the dust collection box  21  and the cover  23  arches toward the outside. 
     The detail of the dust collection box  21  without the cover  23  shown in FIG. 3 shows its details mentioned in the descriptions of FIGS. 1 and 2 once more. Additionally, the bead  23  becomes obvious, which extends around the circumference enclosed by the upper edge  32  and, together with the snap-in edge  42  (FIGS. 1,  7 ) forms a tighly closing connection between the cover  23  and the dust collection box  21  that is convenient to open. The indentations  44  that make it easier to establish a hold on the side underneath the cover  23  and open it using the fingers are also obvious. FIG. 3 also clearly shows the blow-in connection  22  with the circumferential sealing lip  50 , the rockers  26  situated on opposite sides, and their one push-button arm  28  and one latch arm  29  each with internal snap-in edge  31  for latching in a recess of the blow-out connection  20  to hold the dust collection box  21  tightly against the manual machine tool  10  in positive fashion. 
     FIG. 4 shows the longitudinal view of the dust collection box  21  with the circumferential bead  33  on the upper edge  32  of the dust collection box  21 , whereby the position of the sealing lip  50  inside the blow-in connection  22  of the dust collection box  21  is particularly obvious. 
     FIG. 5 shows the top view of the open dust collection box  21  with the upper edge  32 , the indentations  44 , the dust blow-in connection  22 , and the rocker  26 . Particularly obvious are the push-button arm  28  of the rocker  26  with nubs—not shown in greater detail—the latch arm  29 , and the snap-in edge  21  situated on the inside of the latch arm  29  for latching into a recess—not shown in greater detail—of the manual machine tool  10 . 
     FIG. 6 shows the spacial top view of the cover  23  of the dust collection box  21  with the round air-exit holes  40  that penetrate the cover  23 , the arched back edge  56 , the straight side edges  58 , as well as the straight front edge  54 . The hook  24  is also obvious, which projects upward and forward tangent-bent from the indentation  38  impressed in the cover. Moreover, the side panels  46  that form a single part with the cover  23  and project downward in keel-like fashion are obvious. They provide mechanical protection against damage to the fluted filter  48  designed in the shape of ribs and which projects downward. 
     FIG. 7 shows a spacial view of the underside of the cover  23 , whereby the snap-in edge  42 , the keel-like side panels  46 , and the filter element  48  provided with rib-like lamina  47  extending in the longitudinal direction of the dust collection box  21  and designed as a fluted filter are obvious. Moreover, the back edge  56  arched toward the outside, the straight front edge  54  and the straight side edges  58  are obvious. 
     The cross-section of the cover  23  shown in FIG. 8 clearly depicts the arrangement of the keel-like side panels  46 , the circumferential snap-in edge  42 , the indentation  38  with the hook  24  projecting upward, and the slightly-arched upper side  36  that extends upward and outward with the air-exit holes  40 . 
     FIG. 9 shows a detained view of the filter element  48  designed as a laminar filter for non-removeable insertion in the cover  23 . Its filter lamina  47  extend parallel with the side panels  46  of the cover  23  and in the longitudinal direction of the dust collection box  21  like ribs. It also becomes clear in FIG. 9 that the filter lamina  47  were made to form a flat filter plate with increased surface area using a process of meandering folds and stamped-out sections, and that the filter element  48  is attached via adhesion, in particular, or welded to it with its top side  49  facing the underside of the cover  23 . 
     The enlargement of a single filter lamina  47  shown in FIG. 10 reveals its meandering design and stamped out-sections on the sides. As a result of this design, when a certain critical amount of dust is collected, it comes loose from the filter lamina  47  under the influence of gravity, falls downward toward the dust collection box  21 , and clears the filter element  48  for optimal passage of air. 
     FIG. 11 shows a longitudinal view of a section of the dust collection box  210  in the region of the blow-in connection  220 . Sealing lips  500  are situated there that encompass the dust blow-out connection  200  of a manual machine tool in sealing fashion and prevent dust from escaping and outside air from entering. The sealing lips  500  arch in convex fashion inward and toward the middle of the aspiration connection and form a type of bead diagonal to the longitudinal axis. The elastic, thin walls of the sealing lips  500  continue toward the interior of the dust collection box and are held tightly there on rib-like projections of the dust collection box. Each of the regions of the sealing lips  500  that extend further toward the inside of the dust collection box is designed as a sealing flap  520 . They effectively retain the dust inside the dust collection box  210  after the machine is turned off. The functions of sealing off the blow-in connection  220  and providing protection against the escape of dust are thereby effectively combined. 
     The sealing and dust-retention element comprises a rubber-elastic material such as an elastomer or NBR (acrylnitryl-butadien-rubber). This formed part is distinguished by its favorable price and can be used in boxes of different sizes. 
     When the dust collection box is slid onto the dust blow-out connection of associated manual machine tools, the sealing lips  500  are elastically deformed in such a way that the wall in front of it acts as a seal. 
     To secure its position, the formed part is provided with a circumferential collar  60  on the front of the blow-in connection  59  and a circumferential latch nose  62  on a circumferential rib  63  of the back side of the blow-in connection. Instead of the circumferential collar in the front section, latch noses or pegs can be applied to prevent a drawing-in into the blow-in connections  220 . The proper function of the closing flaps  520  is ensured by way of the conical or bent shape of the individual flaps as well as by the selection of a suitable elastic material, so that the sealing slit  540  between the front sides of the flaps  520  is always sealed off securely when an airstream from the machine side does not try to open it. 
     FIG. 12 shows the lower section of the sealing lip  500  when seated on the dust blow-out connection  200  of an associated manual machine tool. The remaining details are the same as described for FIG.  11 . 
     FIG. 13 shows a variant of sealing lips  560  designed as a bellows. 
     In the top part of the drawing, FIG. 14 shows a short sealing lip  510  that is held tightly on a circumferential rib  63  of the back side of the blow-in connection only by way of a latching groove  62 . The sealing lips  510  press against the inside of the blow-in connection  220  with prestress, so that, when it is slid onto the dust blowout connection of a manual machine tool, the sealing lip comes between them and a corresponding sealing effect can take place. 
     FIG. 15 a  shows the two sealing lips  520  designed as a bead rolled toward the inside, and, in FIG. 15 b,  as a bead rolled toward the outside.