EP2086720A1

EP2086720A1 - Electric hand-held machine tool for carrying out grinding work, in particular an orbital sander

Info

Publication number: EP2086720A1
Application number: EP06841266A
Authority: EP
Inventors: Joerg Dehde; Juergen Hesse; Eike U. Von Specht
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2006-10-24
Filing date: 2006-10-24
Publication date: 2009-08-12
Anticipated expiration: 2026-10-24
Also published as: EP2086720B1; US8007346B2; CN101511534A; US20100197209A1; CN101511534B; WO2008049458A1; DE502006006018D1; ATE455622T1

Abstract

An electric hand-held power tool for performing sanding work, in particular a finishing sander, is provided, that includes a drive plate (16)—which is drivable in a sanding motion using an electric motor—and a sanding plate (21′) attached thereto such that it is removable without the use of a tool, with means for attaching a sanding pad (22′). To create a multifunctional device with which various types of sanding work may be performed in an optimal manner, a tub-like recess (23) with a flat tub bottom (231) for receiving the drive plate (16) in a form-fit manner is formed in the top side of the sanding plate (21′) facing the drive plate (16); the sanding plate (21′) is attached in a manner such that it is removable without the use of tools, preferably via a Velcro attachment between the tub bottom (231) and the surface of the drive plate (16). The easy method of replacing the sanding plate makes it possible to quickly replace sanding plates (21) having different configurations for different requirements on sanding work (FIG. 4).

Description

Electric hand tool for carrying out grinding work, in particular Schwinqschleifer

State of the art

The invention relates to an electric hand tool for performing grinding work, in particular orbital sander, according to the preamble of claim 1.

In a known trained as an eccentric grinder

Electric hand tool (DE 101 48 339 A1), the circular drive plate is mounted by means of a rolling bearing on an eccentric pin which is driven by the output shaft of an electric motor. The likewise circular grinding plate carries upwardly projecting spring tongues, at the free ends of each latching hook is formed. When attached to the drive plate

Grinding plate engage over the spring tongues the outer edge of the drive plate and engage with their locking hooks formed in the drive plate locking openings. The means for securing the sanding sheet to the sanding pad include a hook and loop fastener secured to the underside of the sanding pad and a sanding pad having a velor backing for adhering to the hook and loop fastener and having a hook and loop coating on its underside facing away from the sanding pad Adhesive absorption of a sanding sheet. If the Velcro pad worn on the sanding plate, ie, no longer able to hold the sanding pad with sufficient security when grinding, the catch hooks can be dug out of the detent openings by manually pivoting the spring tongues, and the sanding plate can from the worktop and thus of the

Hand tool removed and replaced with a new, provided with a sanding pad grinding plate.

In a likewise known, executed as a sander electric hand tool (DE 198 00 025 A1), the drive plate is rotatably mounted on a sleeve which sits eccentrically on the output shaft of an electric motor rotatably. The rectangular drive plate is fixed elastically movable with respect to the machine housing and performs on rotation of the electric motor, its drive shaft and the eccentric sleeve a reciprocating oscillatory motion with superimposed orbital oscillation. The also rectangular grinding plate is releasably secured by screws to the drive plate and is composed of a rigid, upper-side plate and a lower-side plate made of soft material. The means for fixing the sanding sheet to the sanding plate have a hooked on the underside of the underside plate Velcro strip, which together with the

Velorrücken a sanding sheet makes a Velcro bond with the sanding sheet.

Advantages of the invention

The electric hand tool according to the invention with the features of claim 1 has the advantage that the same hand tool used to perform different grinding and can be adjusted by tool-free changing the grinding plate optimally to each carried out grinding work. In particular for a power tool designed as an orbital sander, a multifunction device is produced, since the orbital sander can only be used by sanding plate change as a surface grinder, corner grinder or edge grinder with good corner and edge accessibility. The grinding plate used in each case has a rectangular or square shape for surface grinding, a pentagonal or triangular shape for corner and edge grinding, and a grinding tongue in the form of a projecting loop plate section with greatly reduced plate thickness for lamella grinding. All replaceable abrasive plate variants are attached to the drive plate of the orbital sander, wherein the polygonal drive plate form-fitting encompassing, trough-like depression in the grinding plate all parallel to the plane to be machined

Workpiece surface acting forces are transmitted reliably and largely wear-free. Forces perpendicular to the drive plate, e.g. by pressing the grinding plate to the workpiece are easily transmitted through the resting on the trough bottom drive plate on the grinding plate, so that made on the bottom of the tub fastening the sanding plate on the lower plate surfaces of the drive plate, which is preferably effected by Velcro, only the whereabouts of Grinding plate on the hand tool when removing the hand grinder from the workpiece surface or other handling of the machine outside the grinding process ensures.

The measures listed in the further claims advantageous refinements and improvements of claim 1 electric hand tool are possible.

drawing

The invention is explained in more detail with reference to embodiments illustrated in the drawings in the following description. Show it: - A -

Fig. 1 is a perspective view of a

Electric hand tool with dust collector,

2 shows a detail of a longitudinal section along the line II - II of the electric power tool in Fig. 1 without

Dust collector, shown enlarged,

Fig. 3 is an exploded view of a grinding plate of

Electric hand tool in Figs. 1 and 2,

Fig. 4 is a perspective view of

Electric hand tool in Fig. 1 when applying a grinding plate according to another embodiment,

5 is an exploded view of the grinding plate in Fig. 4,

6 is an exploded view of a grinding plate according to another embodiment for attachment to the electric power tool in Fig. 1 or 4.

Description of the embodiments

The illustrated in Fig. 1 in perspective view and in Fig. 2 fragmentary sectional vibratory grinder as an exemplary embodiment of an electric hand tool for performing grinding operations, a housing 11, the housing head is formed into a hand knob 12 for the purpose of gripping and guiding the orbital sander. To the housing 11 a detachable dust collecting container 13 is attached by hand. The dust collecting container 13 is thereby pushed over a dust outlet pipe 14 (FIG. 2), via which suction is taken off from the workpiece surface by means of a suction blower

Grinding dust is transported into the dust collecting container 13. On the bottom of the housing 11 projects a rectangular, preferably square drive plate 16, which is mounted on an eccentric pin 18 by means of a roller bearing 17 accommodated in the housing 11. The eccentric pin 18 is rotatably mounted on an output shaft 19 of a housing 11 arranged in the electric motor 20, which also drives an impeller 15 of the suction fan. The drive plate 16 is fixed elastically movable with respect to the housing 11, so that upon rotation of the eccentric pin 18, the drive plate 16 performs a reciprocating oscillatory motion with superimposed, orbital oscillation.

On the drive plate 16, a grinding plate 21 is fixed so that it is releasable without tools. The grinding plate 21 is provided on its side facing away from the output shaft 19 bottom with means for fixing a sanding sheet 22. The grinding plate 21 with its means for fixing the abrasive sheet 22 is sketched in Fig. 3 in an exploded view.

The grinding plate 21 has, in its upper side facing the drive plate 16, a rectangular, preferably square, trough-like depression 23 with a flat trough bottom 231. The inner dimensions of the recess 23 and the outer dimensions of the drive plate 16 are coordinated so that the drive plate 16 is positively received in the recess 23. The tool-less releasable attachment of the grinding plate 21 to the drive plate 16 is realized between the tub bottom 231 and this facing plate surface of the grinding plate 21 by a Velcro. By the Velcro adhesion, a reliable holding of the grinding plate 21 on the drive plate 16 and a slight release of the grinding plate 21 is made possible by the drive plate 16. The trough-like depression 23 with positive reception of the drive plate 16 ensures reliable, largely wear-free transmission of all lateral forces between the drive plate 16 and the grinding plate 21, which are directed parallel to the tool surface to be ground during the grinding process. To produce the Velcro adhesion between the drive plate 16 and the grinding plate 21, a Veloureinlage 24 is fixed to the tub bottom 231 of the recess 23, which is preferably glued to the tub bottom 231, and the grinding plate 21 facing plate surface of the drive plate 16 with a hook and loop fastener 25 (FIG ) Mistake. For dust extraction, the drive plate 16 is provided with concentric apertures 26 (FIG. 2), similar apertures 28 (FIG Breakthroughs 28 in the Veloureinlage 24 and the apertures 26 in the drive plate 16 congruent, concentric grooves 27 and radially extending grooves 29 incorporated, which together with the Veloureinlage covering them 24 dust transport channels form (Fig. 3). The grooves 29 open into the troughs 27, so that there is a dust transport connection to the impeller 15 of the suction fan via the openings 28 in the Veloureinlage 24 and the apertures 26 in the drive plate 16.

The means for fixing the sanding sheet 22 have in the square-shaped sanding plate 21 shown in FIG. 1 to 3 a square Velcro disk 30 with the same dimensions as the sanding plate 21, with the sanding plate 21 to form a foam layer 31 between Velcro 30 and underside of Sanding plate 21 is foamed. As shown in Fig. 2, the Velcro disk 30, the abrasive sheet 22 is pressed with its Velourrücken and is held reliably during the grinding process. When foaming at the same time balancing weights 32 which are used in not shown recesses in the bottom of the grinding plate 21, with integrated. In the sketched in Fig. 3 in exploded view, foamed module of Velcro 30, foam layer 31 and grinding plate 21 now through holes 33 are punched for the dust transport, which open into the grooves 29 in the tub bottom 231 of the recess 23 in the grinding plate 21, preferably at the remote from the trough mouths mouths ends. In the embodiment of FIG. 3, a total of eight through holes 33 are present. Of course, the grinding plate 21 can also be made rectangular. Velcro disk 30 and foam layer 31 are then also rectangular. The contours of the recess 23 remain unchanged.

In Fig. 4 is the same orbital sander as shown in Fig. 1, in which the square grinding plate 21 has been removed from the drive plate 16 and by a pentagonal grinding plate 21 ', a so-called. Pentaplatte replaced. The sanding plate 21 'has a quadrangular plate portion which integrally merges into a triangular plate portion. The triangular plate section is executed in the embodiment on the same side with convex curved side edges. The in Fig. 5 in exploded view together with its means for fixing the sanding sheet 22 'sketched abrasive plate 21' has in its square plate portion the same recess 23 with the flat tray bottom 231 for positive reception of the drive plate 16 as the grinding plate 21 in Fig. 1st to 3. For releasably securing the sanding plate 21 'to the drive plate 16, which in turn takes place between the tub bottom 231 and this facing plate surfaces of the drive plate 16 by Velcro, the Veloureinlage 24 is glued to the tub bottom 231, with the on the unchanged drive plate 16th existing Velcro 25 cooperates. The Veloureinlage 24 has, as in Fig. 1 to 3 with the openings 26 in the

Drive plate 16 congruent openings 28, while the grinding plate 21 'is provided with similar, concentrically arranged apertures 34 which are congruent with the openings 28 in the Veloureinlage 24 and the openings 26 in the drive plate 16. In the side facing away from the drive plate 16 underside of the grinding plate 21 'not shown grooves are introduced here, which open into the concentric openings 34 and extend radially. The grooves are covered by an attached to the underside of the grinding plate 21 'intermediate layer 35 and thus form Staubabsaugkanäle. The intermediate layer 35 realizes the means for fixing the sanding sheet 22 'to the sanding plate 21' and for this purpose is provided with a Velcro covering 39 on the underside facing away from the sanding plate 21 '. The intermediate layer 35 is from a working direction rear quadrangular ply portion 352 and a flush-fitting front triangular ply portion 351, the front triangular ply portion 351 being in conformity with the front triangle portion of the sanding plate 21 'in the same direction with convexly curved side edges. The intermediate layer 35 also consists of a composite in the same way, at the bottom of the sanding plate 21 'bonded upper layer 36 and a similarly assembled, the Velcro 39-bearing, attached to the upper layer 36 lower layer 37. The front, triangular layer portion 371 of the lower layer 37 is releasably secured to the front triangular layer portion 361 of the topsheet 36 and the rear quadrangular layer portion 372 of the backsheet 37 undetachably secured to the rear quadrangular layer portion 362 of the topsheet 36. The releasable attachment is effected by a trained on the front layer portion 361 of the upper layer 36 Velcro 38 and a velor back of the front layer portion 371 of the lower layer 37. The permanent connection of the two rear layer portions 362 and 372 by gluing. The intermediate layer 35 is provided with dust holes serving through holes 40, wherein in each case a through hole 40 terminates in one of the openings 34 in the openings grooves, preferably at the mouth distal end of the grooves. In addition, the abrasive sheet 22 'as well as the abrasive sheet 22 in Figs. 1 and 2 with

Staubdurchtrittslöchern 42 provided, which are congruent with the through holes 35 attached to the intermediate layer 35 Abrasive sheet 22 '.

The pentagonal abrasive sheet 22 'attached to the velcro backing 39 on the backsheet 37 has a rear quadrangular blade portion 222 congruent with the rear quadrangular ply portion 352 of the liner 35 and a congruent with the front triangular ply portion 351 of the liner 35 between the front and rear blade sections 221 and 222, respectively, is a perforation 41 through which the two blade sections 221 and 222 can be easily separated. By dividing the intermediate layer 35 in the front, Triangular ply portion 351 and the rear quadrangular ply portion 352 and in upper layer 36 and lower layer 37 can wear the tip portion of the intermediate layer 35, the front layer portion 371 of the lower layer 37 of the front layer portion 361 of the top layer 36 subtracted, rotated by 120 ° and back to the front layer portion 361 of the topsheet 36 are attached. In this case, when worn, the front layer part 371 of the lower layer 37 can be pivoted a total of twice by 120 °. Similarly, when only the tip portion of the sanding sheet 22 'is worn, the front sanding sheet portion 221 may be torn off the back sanding sheet portion 222 via the perforation 41 and rotated 120 ° back against the hook and loop surface 39 at the front sheet portion 351. In the grinding plate 21 'is still a balance weight 32 is added, which is inserted into a introduced into the tub bottom 231 sink 43 and set in the sink 43 of the bonded to the tub bottom 231 Veloureinlage 24.

With the grinding plate 21 "sketched in an exploded view in Fig. 6, the orbital sander in Fig. 1 and 4 can be converted into a sipe grinder for grinding louver doors, louvred gratings and the like in the same way as described with their recess 23 to the drive plate 16 positively attachable and by Velcro adhering to the drive plate 16 'fastened

The sanding plate 22 "has a looping tongue 44 projecting in one piece from the plate part accommodating the recess 23 and rectangular in the embodiment, which is provided with a hook and loop on the bottom and top 44. The required balancing weight 32 is inserted in a depression 43 in the trough bottom 231 of the recess 23 and secured against falling out by means of the Veloureinlage 24 glued to the trough bottom 231. The Veloureinlage 24 and the hook-and-loop cover 25 on the plate surface of the drive plate 16 (FIG. 2) again provide the hook-and-loop connection between the grinding plate 21 "and the drive plate 16. In all the described embodiments, the sanding plate 21, 21 'and 21 "is made of plastic and is preferably made of a glass fiber reinforced polyamide.

In all the described embodiments, the balancing weights 32 can be omitted if a suitable center of gravity is generated by a suitable shaping of the sanding plate 21, 21 'and 21 "as by the balancing weights 32.

Claims

claims

1. Electric hand tool for performing grinding, in particular orbital sander, with an electric motor for grinding movement driven drive plate (16) and with a on the drive plate (16) tool-less releasably attached grinding plate (21, 21 ', 21 "), the means for fixing a sanding sheet (22; 22 ', 22 ") carries, characterized in that the grinding plate (21; 21', 21") in its the drive plate (16) facing the top of a trough-like depression (23) with a flat trough bottom (231) for the positive Receiving the drive plate (16) and that the releasable attachment of the sanding plate (21, 21 ', 21 ") to the drive plate (16) between the trough bottom (231) and facing this

Plate surface of the drive plate (16) is made.

2. Electric hand tool according to claim 1, characterized in that the tool-less releasable attachment between the tub bottom (231) and plate surface of the drive plate (16)

Velcro liability is realized.

3. Electric hand tool according to claim 2, characterized in that on the trough bottom (231) in the grinding plate (21, 21 ', 21 ") formed recess (23) has a

Veloureinlage (24) attached, preferably glued, and the Plate surface of the drive plate (16) with a Velcro pad (25) is provided.

4. Electric hand tool according to one of claims 1 to 3, characterized in that the grinding plate (21, 21 ', 21 ") receives at least one balance weight (32).

5. Electric hand tool according to claim 3 or 4, characterized in that the drive plate (16) and the Veloureinlage (24) concentrically arranged, congruent openings (26, 28) for

Have dust extraction.

6. Electric hand tool according to one of claims 1 to 5, characterized in that the grinding plate (21) is rectangular, preferably square, is formed.

7. Electric hand tool according to claim 6, characterized in that the means for fixing a sanding sheet (22) having a hook and loop (30) with the grinding plate (21) to form a foam layer (31) between the hook and loop (30)

Bottom of the sanding plate (21) is foamed.

8. Electric hand tool according to claim 7, characterized in that the at least one balancing weight (32) in at least one recess (46) in the underside of the grinding plate

(21) used and is foamed.

9. Electric hand tool according to one of claims 6 to 8, characterized in that the trough bottom (231) with the openings (28) in the Veloureinlage (24) congruent troughs (27) and in these opening grooves is provided by the Veloureinlage (24) form covered dust transport channels and preferably run radially.

10. Electric hand tool according to claim 9, characterized in that in the foamed module of Velcro

(30), foam layer (31) and sanding plate (21) through holes (33) introduced for the transport of dust, preferably punched, each of which opens into a groove in the grinding plate (21).

11. Electric hand tool according to one of claims 1 to 4, characterized in that the grinding plate (21 ') is pentagonal and having a front in the working direction tip, and preferably that the front tip portion of the grinding plate (21') an equilateral triangle with convex Side edges is.

12. Electric hand tool according to claim 11, characterized in that the means for fixing the sanding sheet (22 ') on the underside of the sanding plate (21') attached, with a Velcro (39) provided intermediate layer (35) and that the intermediate layer ( 35) from a rear, quadrangular in the working direction

Layer part (352) and a flush, front, triangular bearing part (351) is composed, and preferably that the triangular bearing part (351) is executed on the same side with convex curved side edges.

13. Electric hand tool according to claim 12, characterized in that the intermediate layer (35) attached to the underside of the sanding plate (21 '), preferably glued upper layer (36) and a Velcro (39) carrying, attached to the upper layer (36) Lower layer (37) has that the front, triangular

Layer part (371) of the lower layer (37) at the front, triangular Layer part (361) of the upper layer (36) releasably, preferably by Velcro, and the rear, square layer portion (372) of the lower layer (37) on the rear, square layer portion (362) of the upper layer (36) undetachably, preferably by gluing, fixed is.

14. Electric hand tool according to claim 13, characterized in that on the side facing away from the sanding plate (21 ') underside of the front, triangular layer portion (361) of the upper layer (36) a Velcro (38) is arranged and the front, triangular layer portion (371 ) of the lower layer (37) has a Velourrücken.

15. Electric hand tool according to one of claims 11 to 14, characterized in that the trough bottom (231) formed in the grinding plate (21 ') recess (23) with the openings (28) in the Veloureinlage (24) congruent breakthroughs

(34) is provided and that in the side facing away from the worktop (16) underside of the grinding plate (21 ') in the concentric openings (34) opening grooves are introduced, which form from the top layer (36) of the intermediate layer (35) covered dust transport channels and preferably radiating.

16. Electric hand tool according to claim 15, characterized in that in the intermediate layer (35) the dust transport serving through holes (40) are formed and that in each case a through hole (40) in one of the grooves, preferably at the mündungsfernem end expires.

17. Electric hand tool according to one of claims 11 to 16, characterized by a to the sanding plate (21 ') attachable, pentagonal sanding sheet (22'), one with the rear, quadrangular

Layer part (352) of the intermediate layer (35) congruent, rear, a square blade portion (222) and a front, triangular blade portion (221) congruent with the front triangular ply portion (351) of the intermediate ply (35), and that the two blade portions (221, 222) are perforated in the one-piece abrasive sheet (22 '; ) are separable.

18. Electric hand tool according to one of claims 1 to 3, characterized in that the grinding plate (21 ") is rectangular and has an integrally projecting in the direction of work, preferably rectangular grinding tongue (44).

19. Electric hand tool according to claim 18, characterized in that at least the underside of the grinding tongue (44) and the top of the grinding tongue (44) are provided with a hook and loop cover.

20. electric hand tool according to claim 19, characterized in that the Velcro covering of a flexible Velcro strip (45) is formed, which covers the front edge of the grinding tongue (44) and at least on the underside of the grinding tongue (44) and on the

Top of the sanding tongue (44) attached, preferably glued, is.

21. Electric hand tool according to one of claims 11 to 20, characterized in that in the tub bottom (231) in the grinding plate (21 ', 21 ") formed recess (23) at least one

Sink (43) for receiving the at least one balance weight (32) is formed.

22. Electric hand tool according to one of claims 1 to 21, characterized in that the grinding plate (21, 21 ', 21 ") from Plastic is made and preferably made of glass fiber reinforced polyamide.