EP0868256B1 - Electrical tool machine - Google Patents

Description

State of the art

The invention relates to an electric hand machine tool designed as a scraper.

DE-OS 42 35 278 is a hand tool known whose file-like insert tool by an eccentric output shaft via a Driver is driven back and forth. The output shaft is driven by an electric motor through an angular gear Movement set, the approximately 90 ° relative to the motor shaft angled output shaft no adjustment means for Setting the angular gear play, i.e. the play of the output shaft compared to the motor shaft or the axial play the output shaft opposite the housing. The top The end of the output shaft is in the upper area of the gearbox from an axial and radial force absorbing Rolling bearings and the lower shaft end in the lower area of the Gearbox housed by a needle bearing. There are no means to adjust / readjust the axial play of the Output shaft provided, which can be adjusted from outside without dismantling are. If the axial clearance has become too large, is a considerable measurement, adjustment and assembly effort for Restoration of the original minimal axial play necessary. To keep the minimal game as low as possible or To secure long, the housing, the gear parts and the output shaft very dimensionally accurate and therefore proportionate are expensive to produce.

In addition, the division level of the housing runs as before usual for hand-held power tools, vertical in the working position and even, with at least one bearing point of the output shaft is in the area of the division level, i.e. that the Camp seat is also shared. This allows the insert tool forces transmitted to the housing to a Deformation of the housing edges in the area of the division level to lead. This in turn can affect the bearing seats of the output shaft deform and thus interfere with the transmission function.

The clamping means for the tool, in particular the insert tool, are in the clamping and releasing position from the outside using controls movable, but must also the movement of the driver and can follow the tool. That’s why Clamping device for coupling the insert tool with the driver designed relatively complex.

From EP 0548 717 A1 a handheld power tool is included Angular gear known a housing, a motor and an output shaft with angular gear and at least two bearings contains and where a bearing of the output shaft in operative connection with at least one opposite the output shaft the housing for adjusting the angular gear play axially adjustable adjusting means. The number game of Angular gear can be removed without dismantling the housing to adjust.

Advantages of the invention

The electric hand machine tool according to the invention with the Features of claim 1 has the advantage that the output shaft with respect to the input shaft and opposite the housing can be optimally adjusted. In order to is an effective tolerance compensation created by the use roughly tolerated, inexpensive to manufacture parts for the housing and the gearbox.

Further advantages of the invention result, for example by the features of the dependent claims, e.g. thereby, that a simple actuating means is created which, as, in particular with a steep thread, axially adjustable in the housing Bearing bush is designed and that the bearing bush on the underside of an upper radial collar at least one Ring wedge, which a housing-side counter-ring wedge is assigned as a support surface.

The positioning device is against unwanted adjustment with a Secure against rotation relative to the housing, whereby the anti-rotation lock in a particularly simple version an externally toothed clamping ring, the inside with a Double an opposite double on the lower outside the bearing bush from the one facing the collar or the ring wedge Reaches over here.

The fact that a compression spring on the as an adjusting ring trained anti-rotation supports and this against holds the bearing bush or the housing, is the actuating means particularly wear-resistant. Also, the push button reliably returned to their starting position when it is released or when the tool is clamped.

The detachable arrangement of the anti-rotation device on one, in particular tool-facing side accessible from the outside enables adjustment of the axial play of the output shaft without dismantling the hand tool.

The fact that the side of the output shaft remote from the tool axially resilient against the housing is their axial play Can be elastically compensated over a wide tolerance range.

The support is simple and inexpensive in that the output shaft via a spring-loaded, axially displaceable Ball against the housing supports and that a compression spring is arranged in the upper housing shell, the one on the housing side mandrel and the other one engages around a support disk-bearing pin and over the support disc supports against the ball, which in a front recess in the upper end of the output shaft sits and protrudes beyond the edge of the recess.

The bearing point in the upper housing shell can be skewed compensate the output shaft in that a ring-like Plain bearings to support the upper end of the output shaft is arranged, the tread is conical. The plain bearing is particularly similar to the misalignment of the output shaft effective from the fact that the tread of the plain bearing in its upper area over a length of about 2 to 3 mm cylindrical and adjoins it downwards in an opening at an angle of about 5 ° conical area, about 7 mm long. The conical Opening facilitates when assembling the hand machine tool the insertion of the output shaft into the slide bearing.

Because the driver is disengaged by moving can be brought to the tool, which is thereby separated from the drive and is easily removable, the operation can be done with simple Means, namely via a push button with which the Driver can be moved by hand.

The tool is in the area of its clamping end in one Longitudinal guide with little play and friction and thus the drive and the housing of work-related transverse forces as well changing frictional effects relieved by the longitudinal guide the flat area on the clamping side of the tool and when working against twisting guaranteed.

A sealing cap covers the opening of the front area of the Housing through which the shank of the tool passes. It serves as a sliding guide and vibration damping for the tool.

Because the tool is a cross to its direction of movement cutting edge, it is particularly hasty can be used as a chisel, spatula or the like.

The longitudinal guide is securely locked in the housing shell through a comprehensive, box-like profile with one Open at the back and front to allow the tool to pass through Recording tunnel.

The housing is particularly resistant to deformation in that it from two with a horizontal division level in the working position composite housing shells is formed, the output shaft in both housing shells in one Bearing is rotatably mounted. The stability of the case will increased by the shells and those formed by dividing edges Split level in the neck area - in working position considered - bent down and run the kink serves as a handle. The stiffening of the Housing increases by attacking the operator's hand and as a result of the operators while working, which makes the Housing shells virtually intertwined and firmly against each other be tense.

Another advantage is that the clamping means for Attach the tool from just a few, inexpensive Individual parts exist with which the tool is convenient to use in a few simple operations with the driver can be connected and is therefore also quickly exchangeable. The danger, that the operator is on the cutting edge of the tools injured, is reduced by the ease of use. The simplified tool change thus contributes to improvement occupational safety.

The fact that the driver itself with a head start in the Recess of the clamping end of the tool engages releasably, is a particularly simple design, easy to use Clamping system for scraping tools designed as tools created.

Characterized in that the push button in the release position for the insert tool held in place with respect to the housing and the locking means by the tool when it is inserted can be released again, the push button does not have to held down while inserting the tool become. So one hand of the operator stands alone for that Hold the hand machine tool and the other hand Tool removal available. This makes the change easier of the tool.

Characterized in that the driver is designed as a connecting rod with a head that has a projection becomes its unwanted one Avoid turning inside the housing and a special one quiet, low-wear running of the hand tool achieved, with the head in the notch of the longitudinal guide is guided to dampen vibrations. The axially parallel limits Arrangement of the driving projection for the eccentric pin with a radial distance to the recess, the rotatability of the driver opposite the eccentric pin and thus reduces friction and wear between the eccentric pin, the driver and the tool. It is advantageous that the recess of the clamping end of the tool is circular and essentially the same diameter how the lead has the lead.

Instead of being circular, this can also be viewed in the direction of movement of the Tool elongated, slot-like recess of the clamping end, the length of which is greater than the stroke of the eccentric. This is how the movement is transmitted from the drive via the driver to the tool only if, for example, when touching down on the Workpiece, pushed back as far as the projection of the driver is that the projection on the edge of the slot support and a back and forth motion on the tool can pass on. So it is idle Tool when turning the motor and the driver silently, see above that the wear on the motion-transmitting parts is reduced.

The longitudinal guide is immovable as a separate body Arranged inside the case once the case shells are screwed together. The longitudinal guide is supported in the direction of movement of the inserted tool against a front wall from one of the housing shells and is thereby captive and free of play but also easy to replace, held because the longitudinal guide after easy Lift off the housing shells in the front area can be removed from the housing.

Because the longitudinal guide is a separate body, she takes the cassette-like over the shaft of the tool bending forces transmitted to the housing and conducts them large area on the housing so that this is only slight Is subjected to bending and twisting forces and in Lightweight construction can be carried out, with rolling elements on both ends of the guide slot of the longitudinal guide wear or, the friction between the longitudinal guide and the Reduce the tool by using only rolling instead of is permitted by sliding friction.

The tool can be a chisel, scraper, spatula or the like. made of metal, e.g. Tungsten carbide or HSS steel. It is versatile, e.g. to carve, to remove Paint, wallpaper, carpet adhesive, foam backing, needle felt, PVC, also for cleaning work, e.g. Removing dirt, Adhesive and glue, plaster, plaster, filler, putty, Paint and silicone residues as well as mortar and concrete residues Lath. Finally, it can also be used to prepare substrates be carried out, e.g. Screed and concrete preparation, Smoothing caterpillars and noses, making cracks, Removing tile adhesive.

The tool has a flat, especially in the area of the shaft rectangular, cross section, in a longitudinal guide, in particular in a flat slot, is feasible and elastic, leaf spring-like, absorbs bending forces when scraping. This prevents the tool from twisting around its Longitudinal axis secured and springs when operating the scraper between the workpiece and the operator.

Since the tool is a wearing part, its quick Interchangeability is a major advantage. This advantage results from the interaction of the locking means of the insert tool with those of the hand machine tool.

drawings

The invention is based on exemplary embodiments shown in the drawing in the description below explained.

Show it

Figure 1 is an exploded view of an embodiment the electric hand machine tool according to the invention,

Figure 2 assembled the area labeled II in Figure 1 in longitudinal section,

Figure 3 shows the front bearing of the drive shaft Figure 2 as a detail,

Figure 4, the designated III, related parts shown enlarged in Figure 1,

Figure 5 shows part of a further embodiment of the Electric hand machine tool according to the invention in longitudinal section,

Figure 6 shows the detail of the end bearing of the drive shaft according to FIG. 5,

FIG. 7 shows an exploded view of FIG. 4 analogously to FIG Parts of the machine tool according to FIG. 5,

FIG. 8 shows an electric hand machine tool according to FIG. 1 up to 7 belonging tool with an associated longitudinal guide for the intervention of the driver in a spatial view,

Figure 9 shows an exploded view of the longitudinal guide rolling elements,

Figure 10 is an exploded view of the top and bottom Housing shells only with the plain bearing and the bearing bush according to FIG. 1

and FIG. 11 shows an exploded view of the lower housing shell with the bearing bush.

Description of the embodiments

FIG. 1 shows an exploded view and FIG. 2 a partial longitudinal section of an electric hand machine tool for scraping machining of workpieces, briefly as scrapers Designated 10. Whose cylindrical housing 11 is made of two Housing shells 12, 14 formed from plastic, the edges of which each form a dividing edge 15, which is a horizontal dividing plane define. The housing 11 has in its rear Area a thickening 30 and in its front area a neck 32 inclined with respect to the housing axis. The housing is between the neck 32 and the thickening 30 designed as a handle 28. The housing shells 12, 14 are connected to each other by screws 26.

An electrical cable (not shown) can be attached to the housing 11 secured by a further screw 24 secured with a clamp become. A motor 16 is located inside the housing 11 arranged with a fan wheel 18, the drive shaft 19th stored in a ball bearing 20 and with a tapered pinion 22 is rotatably connected. The pinion 22 meshes with one by an output shaft 50 rotatably supported conical Ring gear 48, whose axis of rotation 36 is perpendicular to the drive shaft 19 runs.

The bearing point of the output shaft 50 remote from the tool exists from a ring-shaped into a cylindrical bearing seat 38 the housing shell 12 insertable plain bearing 40, in particular made of sintered material, a compression spring 42, a support disc 44 and a ball 46 which is in a central Recess 43 in the upper end face of the output shaft 50 is stored.

The compression spring 42 engages around the top, i.e. one end, one fixed to the housing Mandrel 41 and below, i.e. elsewhere, a one Support disc 44 bearing pin 44 'and is supported the support disc 44 opposite the ball 42, which in the Central recess 43 of the output shaft 50 is seated, wherein it projects beyond the edge of the recess 43. The plain bearing 40 has a tapered or crowned inner tread 47 for receiving the upper bearing end of the output shaft 50. and also by the axial support on the ball 46 the output shaft 50 can be inclined by a certain amount out of play with respect to the central axis of the plain bearing 40 are destroyed without the plain bearing 40 being destroyed becomes. This enables the use of roughly tolerated individual parts for the scraper 10, its function being high Quality is assured.

The bearing near the tool of the output shaft 50 exists from a sleeve-like bearing bush 56, an annular disc 54 and a roller bearing or needle bearing 58.

One carried by the end of the output shaft 50 near the tool Eccentric pin 52 with an eccentric axis 53 passes through Bearing bush 56, with its free end from above into one Bore 72 of a connecting rod-like driver 68 engages is supported axially downward on a pushbutton 76. It can also other eccentric drives known per se be used.

The distance between the eccentric axis 53 and the axis of rotation 36 determines the eccentricity, being double eccentricity determines the stroke of the eccentric pin or driver 69.

Between the driver 68 and the bearing bush 56 are one Anti-rotation device 62 and a disk 66 arranged between which a spacing spring means 64 is supported. The anti-rotation lock designed as an adjusting washer or clamping ring 62 is for positive engagement around the bearing bush 56 educated. The push button 76 closes a dust-tight Opening 60 in the lower housing shell 14 and ends there flush with the housing contour.

In Figure 2 it is shown that the edge of the collar 71 'as a stop serves for the clamping end 77, being in the stop position the recess 90 in the clamping end 77 exactly aligned is positioned to the projection 70 of the driver 68. This facilitates the insertion of the insert tool 88, 288 because when touching the insert tool 88, 288 on the collar 71 'the projection 70 snaps into the recess 90 is secure so that the exact clamping position is reached and the push button 76 can be released.

Behind a frontal opening 34 of the housing 11, which is proportional through appropriate shapes of the housing shells 12, 14 is formed, is inside the housing 11 Longitudinal guide 82 for a tool, in particular an insert tool 88 arranged in a fixed position. A transverse wall 13 is in the area the opening 34 in the upper plastic shell 12 and engages over the outer end face 82 'of the longitudinal guide 82 partially and thus secures them against unwanted emergence out of the opening 34 or against loss. In the longitudinal guide 82, the shank 89 of the tool 88 is straight, forward and guided to move back. The driver 68 engages a projection 70 designed as a pin can be rotated from above in a circular recess 90 of the clamping end 77 of the shaft 89 of the tool 88. As soon as the output shaft 50 rotates, the eccentric pin 52 circles around the axis of rotation 36, the driver 68 following him. As a result of the articulated Coupling between the projection 70 of the driver 68 in the Recess 90 of the shaft 89 is only the back and forth Share of movement of the eccentric pin 52 on the tool 88 transferred, which is why the recess 90 be circular can or why a backdrop-like elongated hole as shown in the figure 4, 5 is unnecessary.

Figures 2 and 4 show that for low-friction, better Bearing of the eccentric pin 52 of the driver 68 in its Bore 72 for the passage of the eccentric pin 52 a roller bearing 73, in particular needle bearings. The one with the recess 90 cooperating pin 70 is at a distance arranged axially parallel to the recess 72 or the roller bearing 73.

Figures 1 to 4 show that the driver 68th guided along the eccentric pin 52 and axially displaceable is mounted and that the projection 70 of the driver 68 out of engagement with its axial displacement the recess 90 of the tool 88 can be brought, so that the drive can be separated from the tool 88. is if this is the case, the tool 88 can then be easily moved by hand removed and replaced.

The driver 68 is on the fingers of the operating hand sliding pushbutton 76 moved to the release position. The push button 76 is in the housing 11 in the opening 60 - like an engine piston in the cylinder - slidable in the Housing shell 14 mounted, the push button 76 in the same direction as the carrier 68 on which it is supported, movable is.

Between the driver 68 and the lower housing shell 14 is aligned and concentric with the output shaft 50 a Compression spring 64 arranged at one end over an annular disc 66 supported on the driver 68 or the push button 76 and return it to its starting position. The compression spring 64 is supported against the driver 68. The Washer 66 prevents the reciprocating movement of the driver 68 transferred to the compression spring 64 becomes.

It can also be seen that the push button 76 means inside the housing shell 12 snap hooks 75, 79 is secured against falling out. To support against the rod-like driver 68 carries the push button 76 radial Ribs 8 and 9.

The tool 88 is in a range between its one Cutting load-bearing working end 92 and its clamping end 77 guided in the longitudinal guide 82. The longitudinal guide 82 is like this formed, see also Fig. 9 that the flat shaft 89 of the tool 88 engages like a cassette and thereby the absorbs bending forces occurring when working, so that none local voltages can occur, leading to destruction the housing shells 12, 14 would lead

The longitudinal guide 82 can be inserted into the housing 12, 14 Cubes or cuboids with a continuous guide slot 67, see Figures 6 and 8, for the passage of the Shaft 89 of the tool 88 designed. The longitudinal guide 82 has one on its side facing the driver 68 Notch 83 on which the in the recess 90 of the clamping end 77 of the tool 88 gripping head 65 of the driver 68 centered in the clamping end 77 of the tool 88 engaging and this engaging projection 70 carries.

According to Figure 5, the longitudinal guide 87 there by a Push through the transverse recess 81. Escapes to this in the lower one Housing shell 14 has a recess 81 'through which unused tool 88 Lubricant introduced or through which the screwdriver is used Connection between the two plastic shells 12, 14 made or can be solved.

The longitudinal guide 82 does not have to be rectangular, but rather can also have a different exterior depending on your needs Have design.

FIG. 6, like FIG. 3, shows the upper bearing of the output shaft 50 in the housing 12, 14 as a detail, the Compression spring 42, the central recess 43, the disc 44, the ball 46 and the upper region of the output shaft 50 are clearly recognizable.

Figures 1 to 7 show that the tool facing Bearing point of the output shaft 50 through the roller bearing 58 bearing bushing 56 is formed, which has a like a helical wedge acting on a Mating ring wedge 63 (Fig. 10) of the housing shell 14 after Releasing the anti-rotation device 62 is axially adjustable and the - after removing the key 76 and the driver 68 -, from outside e.g. for a wrench or the like for turning is accessible.

The bearing bush 56 could instead of the ring wedge 57 Wear steep external threads that fit into a suitable housing Counter thread should be screwable.

The anti-rotation device of the bearing bush 56 is externally toothed Clamping ring 62 designed with two on his Internally arranged teeth 61 in two opposite Grooves 59 on the lower outside of the bearing bush 56 attacks. The clamping ring 62 holds with its external teeth on projections of the housing 11, in particular the housing shell 12, snapping securely by the teeth grip between cams 67 (FIG. 10) at the bottom of the opening 60. He thus secures the bearing bush 56 against twisting the housing 11.

The compression spring 64 is supported on the clamping ring 62, with which it is this axially relative to the bearing bush 56 or relative to the Biased housing 11 and thus in particular on the cams holds. The clamping ring 62 has an external toothing the housing shell 14 rotatably connected.

According to FIGS. 1 to 7, the tool 88 or 188 exits the opening 34 of the front covered by a sealing cap 86 Area of the housing 11. Over the cutting edge or the working end 92 of the tool 88 or 188 is a knife guard 94 can be placed, which secures the cutting edge against damage and the operators especially when transporting the Hand machine tool 10 against cutting edge injury protects.

According to Figures 5 and 7 is a driver 69 as a perforated disc trained - in contrast to that according to the figures 1 to 3 connecting rod-shaped driver 68. In a Central bore 72 'of the driver 69 engages an eccentric pin 51 of the output shaft 50, which is significantly shorter as the eccentric pin 52 according to Figures 1 to 3. This a shorter dimension is necessary because the eccentric pin 51 even out of engagement with the recess 91 of the clamping end of the insert tool 188, thereby the insert tool 188 across the eccentric pin 51 - over the latter free end can be pushed past - can be removed.

The central bore 72 'can of course, like the bore 72 2 and 4, a needle bearing 73 included to the movement of the eccentric pin 51 with little friction on the driver 69 and the tool 188 to transfer.

A protrudes beyond the free end of the eccentric pin 51 concentric to the recess 91, ring-like Projection 71 of the driver 69. This engages in the as Elongated recess 91 of the clamping end 77 of tool 188. The slot-like recess 91 is arranged near the free end of the clamping end 77, wherein their longitudinal extent transverse to the direction of movement of the tool 188 runs and at least around the stroke h or around the double eccentricity of the eccentric pin 51 is longer than the diameter of the eccentric pin 51. The width of the elongated hole 91 is dimensioned so that the projection 71 essentially can intervene without play.

Means that an unwanted rotation of the driver 69 with the eccentric pin 51 due to the bearing friction between the Eccentric pin 51 and the driver 69 in the bore 72 'prevent are not shown.

The position of the front working end 92 or the cutting edge of insert tools 88, 188 opposite the frontal opening 34 of the housing 11 is intended in accordance with all exemplary embodiments Figures 1, 2, 4, 5 and 7 are the same. For this reason the shaft 89 of the insert tool 188 according to FIGS. 5, 7 opposite that according to Figures 2, 4 longer because of the point of engagement between the shaft 89 and the driver 69 according to FIGS. 5, 7 lies further inside the housing 11.

FIG. 8 shows an insert tool 288 that is used for the scraper 10 according to Figures 1 to 4 is suitable. The difference to the insert tool 88 according to FIGS. 1 to 4 Insert tool 288 has a recess 93 in the clamping end 77 on that as extending longitudinally to the direction of movement Elongated hole is designed, the width of the outer diameter of the pin 70, which is circular in cross section is. Its longitudinal extent is around the stroke h or around the double eccentricity of the eccentric pin 52 larger than that Outer diameter of the eccentric pin 52 Motor only then back and forth the tool 288 moved or driven when it is from a frontal Opposing force is applied so that the projection 70th Drivingly supported on the front edge 193 of the recess 90 can. As a result, when the engine 16 is switched on and at Workpiece lifted insert tool 288 this still, so that energy consumption, noise and the Wear on the longitudinal guide 82 and on all motion transmitters Parts of the scraper 10, e.g. between the driver 68 and the clamping end 77 of the insert tool 288, is kept low.

A comparison of the clamping ends 77 of the insert tools 88, 188, 288 according to Figures 1 to 8 shows that the recess 90 of the insert tool 88 further from the free end of the clamping end 77 removed as the recess 91 of the insert tool 188 and as the recess 93 of the insert tool 288 according to FIGS. 5 and 7.

FIG. 9 shows the longitudinal guide 82 according to the enlargement Figure 1. The longitudinal guide 82 carries designed as needles Rolling elements 78 and 84, which are in front of and behind the rectangular, flat guide slot 67 are arranged and on which can support the tool 88, 188, 288 on a rolling basis. The rolling elements 78 and 84 are in corresponding slots 85 of the Longitudinal guide 82 stored. This arrangement of the rolling elements 78, 84 becomes sliding friction in the longitudinal guide 82 significantly reduced, their resilience increases as well as heat development and wear on the scraper 10 is reduced and Bending forces of the insert tool 88, 188 and 288 from the housing 11 kept away.

The cooperation between the longitudinal guide 82 and the Connecting rod-like carriers 68 are shown in FIGS. 1, 2 and 4. The driver 68 has the projection 70 carrying Head part 65, in the notch serving as a guide slot 83 of the longitudinal guide 82 snaps into place. Thereby it is ensured that the head 65 and thus the driver 68 also secured against rotation within the housing 11 is guided when the scraper 10 is not with a tool 88, 288 and if the motor is in this state 16 is started.

In Figure 10, the upper and lower housing shell 12, 14 shown pulled apart parallel to the axis, wherein the inclined course of the dividing edge 15, which is bent at the front is clear with both housing shells. The upper case shell shows particularly clearly the mandrel 41 and the associated concentric bore 45 for receiving the not shown here, but shown in Figures 1 to 3, 5, 6 Compression spring 42, which in turn pin 44 'with the washer 44 contributes to the axial support on the ball 46 or on the Output shaft 50. A circular, clearly serving as a bearing receptacle 38, the concentric is arranged to the mandrel 41 and in which the annular slide bearing 40 can be used. In addition, the front bulkhead 13 near the opening 34 for the passage of what is not shown here Tool 88 particularly clearly visible.

It is also clear that the inner tread 47 of the plain bearing 40 conical, down towards the housing shell 14 expanded. For this, it has proven to be particularly advantageous proved to be an approximately 7 mm long area of the tread itself open downwards at an angle of 5 ° leave, with a straight up about 2 to 3 mm long cylindrical area of the tread connects. In order to become out of balance of the output shaft within certain limits 50 allowed without affecting the function of the scraper is, or without damaging the plain bearing 40 or would be destroyed.

The lower housing shell 14 clearly shows the counter ring wedge surface 63, on which the ring wedge 57 on the collar 55 of the Bearing bush 56 supports, so that when the bearing bushing rotates 56 counterclockwise this moves axially. There the output shaft 50 according to Figures 1, 2 and 5 axially is supported on the bearing bush, it turns when the bearing bush is turned 56 axially entrained, so that the setting the axial play of the output shaft 50 relative to the upper housing shell 12 or opposite the ball 46, the Washer 44 and the mandrel 41 is possible.

There is also a on the housing shell 14 near the opening 34 Annular groove 25 for holding the sealing cap 86 (FIG. 1) can be seen and a receiving tunnel 33 with an insert opening 35 to insert and hold the not shown here Longitudinal guide 82, which is located on the ribs 37 39 Clamping 60 is also recognizable Management and recording of the push button 76 (Fig. 1).

The adjusting means in the form of the bearing bush 56 could also instead of in the lower housing shell 14 in the upper housing shell 12 may be arranged, then instead of the needle bearing 73 the plain bearing 40 is seated in the bearing bush 56 could.

Claims (18)

1. Electrical handheld machine tool, which is designed as a scraper (10), having a housing (11), which contains a motor (16) and an output shaft (50), with an angular gear connected between them, and at least two bearing points (38, 58), and having an eccentric pin (51, 52) which is positioned at the end of the output shaft, which tool can be fitted with an insert tool (88, 188, 288), which moves in a reciprocating manner, can be coupled to the eccentric pin (51, 52) via a driver (68, 69) and has a clamping end (77) which is held in the housing (11), the driver (68, 69) having a bore (72, 72') into which the eccentric pin (51, 52) engages in a rotatable manner, the housing (11) comprising two housing shells (12, 14) and a bearing point (58) of the output shaft (50) being operatively connected to at least one adjustment means (56), which can adjust the output shaft (50) in the axial direction with respect to the housing (11) in order to set the angular gear clearance and which is arranged in an opening (60), which can be closed off with respect to the outside, on one of the housing shells (12, 14), a push-button (76) for releasing the insert tool (88, 188, 288) being used to close off the opening (60) and being removable for the purpose of actuation of the adjustment means (56) - and also of the drivers (68, 69) - without having to dismantle the handheld machine tool.
2. Machine tool according to Claim 1, characterized in that the bearing bush (56), instead of a steep thread on the underside of an upper, radial collar (55), bears at least one annular wedge (57), which is assigned a mating annular wedge (63) on the housing as a supporting surface.
3. Machine tool according to Claim 2, characterized in that the rotation-locking means is designed as an externally toothed clamping ring (62) which engages non-rotatably, in particular internally by means of at least one inner tooth (61), in at least one groove (59) on the lower outer side of the bearing bush (56) and engages over the bearing bush (56), in particular from the side which faces the annular wedge (57).
4. Machine tool according to Claim 3, characterized in that the clamping ring (62) is held latched, by means of its external toothing, on projections on the housing (11), in particular on lugs (67) at the bottom of an opening (60) in the housing shell (12).
5. Machine tool according to Claim 4, characterized in that a compression spring (64) is supported on the clamping ring (62) and holds the latter in place with respect to the bearing bush (56) or the housing (11).
6. Machine tool according to Claim 3, 4 or 5, characterized in that a push-button (76) for releasing the tool (88) is supported on the compression spring (64), so that the latter simultaneously serves as a restoring spring for the driver (68) and the push-button (76), the push-button (76) being prevented from falling out of the machine tool (10).
7. Machine tool according to Claim 6, characterized in that the driver (68, 69) can be disengaged from the tool (88, 188, 288) by displacement of the push-button (76, 176), with the result that the tool (88, 188, 288) is separated from the drive and as a result can easily be removed.
8. Machine tool according to one of Claims 1 to 7, characterized in that the output shaft (50), on the side which is remote from the tool, is supported in an axially resilient manner with respect to the housing (11).
9. Machine tool according to Claim 8, characterized in that the output shaft (50) is supported with respect to the housing (11) by means of a resiliently mounted, axially displaceable ball (46).
10. Machine tool according to one of the preceding claims, characterized in that the two housing shells (12, 14) can be assembled to form the housing (11) at a parting plane which runs horizontally in the working position, the output shaft (50) being mounted rotatably, in each case in a bearing (40), in both housing shells (12, 14).
11. Machine tool according to Claim 10, characterized in that the housing (11), comprising the two housing shells (12, 14) and the parting plane formed by parting edges (15), in particular in the region of the neck (32), is bent off downwards in an s-shape in the working position.
12. Machine tool according to one of the preceding claims, characterized in that a compression spring (42) is arranged in the upper housing shell (12), which compression spring at one end engages around a housing-side mandrel (41) and at the other end engages around a pin (44') which bears a support disc (44), and which compression spring is supported with respect to the ball (46) via the support disc (44), this ball being seated in an end-side recess (43) in the upper end, which is remote from the tool, of the output shaft (50) and projecting above the edge of the recess (43).
13. Machine tool according to Claim 12, characterized in that an annular sliding-contact bearing (40) for bearing the upper end of the output shaft (50) is arranged in the upper housing shell (12), the running surface (47) of which bearing is designed conically, at least in regions, so that skew positions of the output shaft (50) with respect to the centre axis of the sliding-contact bearing (40) are compensated for.
14. Machine tool according to Claim 13, characterized in that the running surface (47) of the sliding-contact bearing (40) runs cylindrically in its upper region (47''), preferably over a length of approximately 2 to 3 mm, and this cylindrical section merges at the bottom into a conical region (47') which opens out at an angle of approximately 5° and is preferably approximately 7 mm long.
15. Machine tool according to one of the preceding claims, characterized in that the tool (88, 188, 288) can be guided in an axially displaceable manner in a longitudinal guide (82) in the housing (11), its flat clamping end (77) being surrounded, with little clearance, by guide elements (82).
16. Machine tool according to one of the preceding claims, characterized in that the tool (88, 188, 288) projects out of an opening (34), which is covered by a sealing cap (86), in the front region of the housing (11), the sealing cap (86) being supported, in particular in a sealed manner, on the tool (88, 188, 288).
17. Machine tool according to one of the preceding claims, characterized in that tool (88, 188, 288) bears a cutting edge running transversely with respect to its direction of movement and serves as chisel, spatula or the like.
18. Machine tool according to one of the preceding claims, characterized in that one of the housing shells (12, 14) contains a box-like profiled section which engages around a longitudinal guide (82) and has a receiving tunnel (33) which is open at the back and the front for the tool (88, 188, 288) to pass through.

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