FR2844737A1 - MOTORIZED HAND TOOL WITH DUST SUCTION - Google Patents

Abstract

Motorized hand tool (10) with a housing (12) to which a dust box (30, 300, 3000, 130) can be removably attached. The dust box (30, 300, 3000, 130) can be fitted with a filter (44, 440, 4400, 144) in the form of a tube, in particular of revolution, in particular a pleated filter, in particular exchangeable.

Description

State of the art

  The invention relates to a motorized hand tool with a housing to which a dust box can be removably attached.

  Document WO 00/73016 discloses a motorized hand tool with a dust box, carrying in a replaceable, air permeable cover, a pleated filter which effectively retains dust, in particular fine dust and contributes greatly to improve occupational hygiene and safety. This box-shaped dust box is relatively expensive to manufacture. In addition, with regard to its capacity

  limits and suction power, the limits are reached.

  Advantages of the invention To overcome these drawbacks, in the motorized hand tool with dust extraction according to the invention, the dust box 15 can be fitted with a tube-shaped filter, in particular of revolution, in particular a pleated filter, in particular exchangeable, so it has the advantage of having an even lighter and more stable dust box, having a filter surface, permeability and filtration power never reached until so. In addition, the corresponding cor20 filter, in the form of a cylindrical tube, is economical to manufacture,

  convenient, and can be emptied ecologically and exchanged easily.

  Since the dust box has the shape of a truncated cone or a cylinder and its rear surface is constituted by a removable cover, it is simple to manufacture, to open and to close, it can be closed. with safety, it is therefore easy to handle.

  Because the dust box has in the center a dust collecting chamber which the cover closes with airtightness, the external annular wall, that is to say the cylindrical envelope of the box can serve as a permeable surface air and be packed with a large adjoining filter tube or a cylindrical or conical filter cartridge.

  Because the dust box has a central collecting chamber, the cover has one or more air outlet openings and internally carries a dust filter, the filtration capacity of the dust box is improved.

  Because the dust box has an eccentric dust collecting chamber and the cover has an air outlet opening, in particular centered, the air holes can be placed on the internal annular wall of the annular chamber instead of to be placed on the outer annular wall which thus has a rigidity of form

higher.

  Because the outer annular wall as the inner annular wall of the dust box, which define the eccentric dust collecting chamber have air holes and that these walls are each sealed by a shaped pleat filter tubular, the filtration capacity, already high, of a dust box having a single annular wall pierced with holes, is roughly doubled.

  Due to the fact that it is a stepped cylinder whose smaller diameter area constitutes the inlet pipe for the aspirated dust, the

  dust can be conveniently coupled to the power hand tool.

  Because in the internal annular wall there is mounted centered a flow cone, the point of which is directed opposite to the direction of the incoming air and deflects it radially outwards, in particular in the annular chamber, pressure losses when air is drawn inside

  from the dust box, are weak.

  Since the filter is a rolled pleated paper filter, a particularly large filtration area can be achieved in a simple manner.

  Because the filter is composed of two concentric pleated filter tubes, which form an annular chamber between them which can pass through the dust-laden air and which have their relative position as25 secured by a stiffened plastic corset, a filter particularly efficient is created.

  The fact that the air flow is conducted without the possibility of leakage through the particularly tight filter at the level of the cover and

  from the inlet area, the dust level of the filtered air is minimized.

  Because it has a plastic corset, the filter has a resistance such that it can be dusted off conveniently

without risking damaging it.

  Drawing The invention is described in detail below with the aid of the accompanying drawings in which: - Figure 1 shows with partial longitudinal section, the motorized hand tool equipped with a dust box, - Figure 2 is a longitudinal sectional view of the single dust box, - Figure 3 is a median cross-sectional view of the dustbox, - Figure 4 is a median cross-sectional view in the inlet area, of the dust box, - Figure 5 shows another embodiment of the dust box, having an outlet zone arranged radially outwards, - Figure 6 shows another embodiment of the dust box having zones outlet arranged both radially inward and outward, - Figure 7 is a side view of the dust box of Figures 5 and 6, S5 - Figure 8 is a cross-sectional view of the box at dust of FIG. 6, FIG. 9 is a view in longitudinal section of another embodiment of a dust box,

  - Figure 10 is a cross-sectional view of the box of Figure 9. Description of the exemplary embodiments Figure 1 shows, in side view, a motorized hand tool 10 in the form of a vibrating sander, with a housing 12 having a handle 14 and a contact button 16. Under the housing 12 is a sanding sole 18 pierced with suction holes 24 with, fixed to it, a sanding sheet 20, this sole being able to be driven in rotation

  around an axis 22, for sanding. A suction air stream, not shown in detail, follows the direction of the flow arrow 26 and transports the particles and the sanding dust produced, from the work surface through the housing 12, to the rear end of the latter which has a blowing pipe 28 on which is mounted by its connecting pipe 34, a dust box 30, fixed by a captive link or another locking method The motorized hand tool 10 carries an electrical connection conductor 17 at the rear end of its handle 14 and inside the housing 12, a fan wheel not shown which produces, when the tool is in use, a depression under the sole of sanding 18 that is to say the sanding sheet 20. Thus, when the motorized hand tool 10 is in use, sanding dust is sucked through the openings

  passage 24 of the sole 18 and returned through the blowing pipe 28 into the connection pipe 34 of the dust box 30.

  FIG. 2 shows the unit constituted by the dust box 30 in the form of a stepped cylinder. This box has an outer annu5 wall 32 defining its outline and, with the exception of its inlet opening, that is to say the opening 31 of its connection pipe 34 and its inner annular wall 38 in the form of cylindrical tube, it is airtight. This internal wall 38 is pierced with several air holes 39, round and regularly distributed, and carries, on its radially ex10 dull side, a pleated filter 44, made of special paper. This filter has its external face turned towards the annular wall 38 and its internal face turned towards the inside of

the annular chamber 33.

  The dust box 30 carries at its free front end a cover 42 and, at the opposite end its external front wall 29, curved inward, continues with a smaller cylinder which forms the connection pipe 34 to be coupled to the tool 10, that is to say to the outlet pipe 28 thereof which sends the blowing air into the opening

input 31.

  The annular-shaped cover 42 encloses with airtightness 20 by its external edge 48 the external annular wall 32, in the form of a tube, of the dust box 30 and is firmly held thereon in a captive manner, in particular by external snap-in. By its internal edge 46, the cover 42 is removably engaged and with airtightness inwards, with the internal annular wall 38 in the form of a tube, so that the central opening 43 of the annular cover 42 serves as an outlet for the air freed from dust having previously passed through the filter 44 and the air holes 39. In the central opening 43, it is possible, for example, to also fit the end of the hose of a vacuum cleaner and thus increase,

  in a simple way, vacuuming the dust.

  Inside the dust box 30, that is to say of the internal annular wall 38, is mounted frontally and in leaktight manner with its external contour continuing with an internal front face 40 of the dust box 30, an air director body 36 in the form of a central truncated cone which directs the air charged with dust coming from the blowing pipe 28, with the minimum pressure drop, radially outwards in the annular chamber 33 between the external 32 and internal 38 annular walls. For this, the blown air passes through recesses 41 drilled, forming a sort of network, in the internal front wall 40 of the dust box 30 and enters the annular chamber 33 passing then through a pleated filter 44 sealingly pressing on the front annular wall 32, to gain through the air holes 39 drilled in the internal annular wall 32 the internal tubular chamber 5 delimited by the inner annular wall 38 and leave the

  dust box 30 axially towards the rear, that is to say towards the outside.

  To maintain the spacing of the annular walls 32, 38 and stabilize them, these are connected radially by a rear internal front wall 47 pierced with numerous holes through which, after the cover 42 has been removed, can be evacuated. collected dust that has accumulated in

upstream of filter 44.

  Figure 3 shows the dust box 30 of Figure 2, cut transversely to about the middle of its length, as indicated by the cutting arrows B-B. We can clearly see the central con15 arrangement of the outer 32 and inner 38 annular walls, the air holes 39

  in the internal wall 38 and the arrangement of the pleated filter 44 in the annular chamber 32 located between the walls 32 and 38. This filter is meandered and encloses by its radially internal zone, in a sealed manner, the external surface of the wall internal annular ring 38. Thus the dust-laden air is forced to pass through the filter 44 before it can leave, through the air holes, the dust box 30.

  FIG. 4 represents the dust box 30, cut transversely in front of the internal front wall 40, as indicated by the cutting arrows AA in FIG. 2. The ray structure of the internal front wall 40 is seen through which air can penetrate inside the annular chamber 33. We also see the plan section of the air director body 36 so that the air arriving frontally is directed radially outwards in a favorable flow. bringing in

the annular chamber 33.

  Figure 5 shows in longitudinal section another dust box 300, the construction principle of which is similar to that shown in Figure 2, but with air holes 390 drilled not in the internal annular wall 380 friends in the wall external annular 320. This wall is sealed internally by the flat application 35 of a pleated filter 440, so that the dust-laden air is purified after passing through the filter. The dust-laden air, after passing through the connection tube 340, meets the air director body 360 which makes it favorably flow radially outward to pass into the annular chamber 330. From there, it comes out radially outward

  through the air holes 390, and leaves purified the dust box 300.

  The dust box 300 is closed, with airtightness, by a cover 420 mounted frontally at its rear end. On the opposite side, of which at the front end, the annular chamber 330 is delimited by an internal front wall 400, which radially fixes the internal annular wall 380 relative to the external annular wall 320, this wall 400 being permeable to air so the dust-laden air enters

the annular chamber 330.

  The cover 420 with its central opening 430 ensures the centering of the internal annular wall 380 relative to the annular wall

external 320.

  FIG. 6 shows another embodiment of a dust box 3000, which differs from that shown in FIG. 5 by the fact that the internal annular wall 3800 is, like the external annular wall 3200, also pierced with holes d 'air 3900. The rest of the construction corresponds to the representation of Figure 5, so that the references thereof are preserved, with simply the addition of a

" WE.

  Figure 7 is a side view of the dust box 300 of Figure 5, showing the round air holes 390 drilled in the outer wall 320, but it is obvious that these holes may have another

  shape and another distribution, they can be slots for example.

  FIG. 8 represents a median cross section of the dust box 3000 showing, in correspondence with FIG. 6, the arrangement of the external pleat filter 44 disposed radially outward in association with the external annular wall 3200, and the arrangement an internal pleat filter 444 disposed inwardly in association with the internal annular wall 3900. The two filters 44, 444 of tubular shape, obstruct the air entering the annular chamber 3300 to pass through their surfaces, so that the dust-free air can leave the dust box 3000 through the air holes 3900 drilled in the two annular walls. FIG. 9 shows another example of embodiment of a dust box 130, of simplified configuration, in which only the outer annular wall 132 is pierced with air holes 139 covered in leaktight manner by the pleated filter 144. In this box 130, the central inlet area is directly accessible via the connection pipe 134 and the incoming air a can pass through the pleat filter 144 only radially outwards, so that the dust is retained inside of the dust box 130. The latter also carries at its end a cover 142, made axially tight with respect to the pleat filter 144 by a seal. There can therefore be no vanishing points between the filter 144 and the external annular wall 132. The air holes 139 are elongated slots and are therefore distinguished from the round holes of the other exemplary embodiments. The front and rear front walls, which are necessary in the other embodiments, have disappeared, because the pleated filter, due to the central air inlet, can extend up to the external front wall of the stepped cylinder 130 located between the external front wall 139 and the connection pipe 134 and there, a non-illustrated seal avoids any point

  leakage leading to air holes 139.

  FIG. 10 represents a cross section of the dust box 130 of FIG. 9, the pleat filter 144 having its meanders applied to the internal face of the external annular wall 132.

  As the service life of such a filter system mounted in the dust boxes according to the exemplary embodiments presented is several times that of the motorized hand tool, it is possible for the examples figu20 res to dispense with an exchange of the filter.

  For special cases, there is provision for dust boxes, filter cartridges which can be mounted and exchanged in a corresponding dust box.

Claims (3)

CLAIMS) Motorized hand tool (10) with a housing (12) to which a dust box (30, 300, 3000, 130) can be removably attached, characterized in that the dust box (30, 300, 3000, 130) can be fitted with a filter (44, 440, 4400, 144) in the form of a tube, in particular of revolution, in particular a pleated filter, in particular exchangeable. ) Motorized hand tool according to claim 1, 10 characterized in that the dust box (30, 300, 3000, 130) has an external contour adapted to the filter (44, 440, 4400, 144). ) Motorized hand tool according to claim 1, characterized in that the dust box (30, 300, 3000, 130) is a truncated cone or a cylinder, in particular of oval section, closed by a removable cover (42, 420, 4200, 142).   40) Motorized hand tool according to any one of claims 1, 2 or 3, characterized in that   the dust box (130) has a central collecting chamber (133) the cover (142) constitutes an airtight wall and the outer annular wall (132) is pierced with air holes.   ) Motorized hand tool according to claim 2, characterized in that   the dust box (30, 300, 3000, 130) has a central collecting chamber (132) and its cover is pierced with air holes.   ) Motorized hand tool according to claim 2, characterized in that the dust box (30, 300, 3000) has a central collecting chamber ex35 (33, 330, 3300) and the cover (42, 420, 4200) is pierced at   minus an air hole (43), in particular central.   ) Motorized hand tool according to claim 5, characterized in that the eccentric collecting chamber (33, 330, 3300) is an external annular chamber and the cover (42) is pierced with a central air outlet hole (43 ). 8) Motorized hand tool according to claim 2, characterized in that   an internal tubular wall, that is to say an internal annular wall (38, 380, 3800) of the external annular chamber (33, 330, 3300) carries a pleated filter (44, 440, 4400) and is pierced air holes (39).   ) Motorized hand tool according to claim 2, characterized in that the external annular wall (32, 320, 3200) like the internal annular wall (38, 380, 3800) of the dust box (30, 300, 3000, 130 ) are pierced with air holes (39) and carry a pleated filter (44, 440, 4400) of tubular shape.   ) Motorized hand tool according to any one of the preceding claims 20,   characterized in that the dust box (30, 300, 3000, 130) is a stepped cylinder whose smaller diameter area forms the inlet manifold (32, 320, 3200) of the dust sucked.   11) Motorized hand tool according to claim 5, characterized in that on the internal annular wall (38, 380, 3800) is mounted centered a flow cone (26, 260, 2600) whose tip is directed in the direction oppo30 se to the flow of incoming air and which deflects it radially towards   outside, by sending it into the annular chamber (33, 330, 3300).   12) Motorized hand tool according to claim 8, characterized in that two concentric tubes made of pleated filter paper are equipped   a plastic corset (50) which keeps them spaced by centering them so that they together form the filtration unit of the dust box (30, 300, 3000).