DE4004463C2 - - Google Patents

Description

The invention is based on a switching device the preamble of claim 1.

A well-known electric hand tool with one Switching device for electrical switching from Power tools (DE-OS 37 31 079) has an elec motor with right and left rotation, in which the Collector from a carrier ring with contacts and thus electrically connected to each other diametrically arranged is surrounded by brush holders. This carrier ring is around the collector axis by a certain angle swiveling, its contacts with frame-fixed  Counter-contacts cooperate, which in turn with the Field winding and the electrical connections ver are bound, so that in the two pivot positions of the Carrier rings the field winding and the armature winding un poled differently and at the same time by this twist also the carbon brushes the respective directions of rotation are electrically optimized in their function. Are there which are electrically connected to one of the brush holders which contact springs in the carrier ring in the circumferential direction arranged. So when using the respective Ge councils, preferably a hand drill, the Drehrich can be activated, has the same carrier ring sitting inside the device housing laterally projecting actuating wings, which in radia direction through longitudinal slots in the device protruding housing outwards. These form throughs but there are free access openings in the device housing so that it is the device when working in a dirty or dust-filled environment tightness especially in the sensitive collector / office area may be lacking.

With a lot of electric hand tools, it is a matter of turning reversal of direction also common, for example at Screwdrivers, the reversal of direction only by a simple electrical switch in the power supply guide to the stator and / or brushes to reali sieren without a mechanical / geo metric brush adjustment is carried out.

It is common practice to use power tools, specifically Electric hand tools, for example with the help of  Toggle switches, for example with a rocker-like structure or by slide switch or throttle switch on and turn off, these switches in appropriate Are attached to the outside of the housing or only whose actuating parts, as already explained, protrude through housing openings and ver can be put.

With many handheld electrical devices, for example with Bohr machines, rotary hammers and. Like. It is also common in Connection with switching on and off at the same time to adjust the speed by operating the pisto Slide gripped by a finger switch.

To a well-known cordless hammer drill in to switch the percussion drilling function, it is also be knows (Metabo leaflet "The Metabo battery family - wireless and powerful ", note 32835.00 / 0487), on the outside of a drill neck adjacent to the chuck to turn a collar, creating a corresponding Gear adjustment is achieved, or it can by means of such an outer collar for realization other purpose, namely a fine-grained Change in torque, an externally adjustable Affect ball pressure clutch.

After all, it's a reversible electrical Motor known (GB-Note 21 67 909), for the direction of rotation Presetting a reverser during assembly to provide switches and by means of locking markings for them to ensure that regardless of the number of vorese  gears always have the desired default Direction of rotation is realized by a corresponding Positioning the direction switch.

One way to reverse the direction of rotation from the outside, So after acquiring the appropriately equipped hand tool is not provided, therefore one is missing Actuators enabling external adjustment.

The invention has for its object a switching device for electrical switching for switching on / off Switch off or to reverse the direction of rotation at Elek Train power tools in such a way that such functions yourself without much effort and without the need Allow open through slots in the device housing to have to be realized in a simple way.

Advantages of the invention

The power tool according to the invention resolves this sabe with the characterizing features of claim 1 and has the advantage that a clearly operable external adjusting device for at least one of the elec trical switching options with an electric hand is provided with which, for example, the Switching on / off and / or a change of direction can be realized by turning from the outside mechanically immediately and without additional electrical Wire connections directly into a control area on the Electric hand tool driving electric motor takes hold.  

Therefore, an Er for the realization points finding suitable electric motor internal switching or Control elements, preferably an inner switching ring on, by its limited rotational movement such elec trical switchovers in the area of the drive motor can be made. For this purpose, the Switch ring in a suitable manner with directly on the electrical motor-mounted conduits, preferably in one suitable lead frame, together, so that in the each prepared form of the lead frame example wise through the inner switching ring movement of the electro motor can be switched on and off or the opti Male reversal of direction of rotation with simultaneous brush ver position can be made.

The present invention only appears to take one putative disadvantage in buying that consists of that in this case the heart of every electric hand tool, namely the electric drive motor completely self-contained, all necessary the bearings for the rotor shaft and their one wall-free centering as well as for the other motors drive unit with corresponding parts encapsulation including the mentioned switching ring is.

For a better understanding it is pointed out that advantageously used an electric universal motor can be, as in the German utility model 89 08 646 is described.

It is also advantageous in the present invention that  by arranging an outer or inner position all around at an axial height to the inner switching ring is that for the mechanical interlocking opening of the two rings required slot openings are covered in the device housing, the rest of the externally accessible collar also can be stored on the inside of the housing so that it can a housing opening is accessible.

Finally, it is also advantageous that the collar spring-loaded is held in a preferred position.

This can be done, for example, when the adjusting ring as a means for switching the electric motor on and off is used, the automatic feedback arranged in a suitable manner and on the collar have gripping springs and is then in the out steered, i.e. the switch-on state of the electric motor locking position locked. For this, a outer rocker on the adjusting ring with a hook like projection in a recess of the main housing engage the wall so that when the rocker is pushed back or only when the electrical appliance is put down in suitable position the rocker is automatically triggered and the switching ring with its own spring preload in the starting position is returned.

The invention can then be used with particular advantage use if the housing itself from several, each but in the general axial direction of the electric hand tool-divided areas, with a Main body part is a cylindrical, closed tube  has a shaped structure, as is the case with specially trained professional tools for themselves is known, in which the drive unit then le diglich to be pushed up to a seat stop that needs. Such a main body of cylindrical Basic structure offers a particularly suitable fit for the arrangement of an inner collar or someone who may not be completely self-contained ring structure that best forms on the inside of the housing conclusively and is only partially visible, or an outer collar, which is also circular can be shaped and the housing tube shape as closed ring surrounds and being both collar shape with radial projections on the inside reach for the switching ring and this with their own manual Take adjustment with you.

By dividing the housing into the main housing seteil and an axially attachable cover you also create in the transition between these two Housing parts an area where the outer collar easily applied and against moving through the rear cover can be held.

The construction of such an electric hand tool can then be taken so that the self-contained rigid, self-supporting unit of the electric drive motor tors on the output side, i.e. where the engine shaft end piece, either trained as a gear det or carrying a pinion, the drive side A bearing plate protrudes, the gearbox of each because electrical hand tool, for example the  Angle head for an angle grinder or gearbox head of a hand drill is flanged; on the electric drive motor then closes into the tube shaped main housing inserted; the connection with this is done through holes from the gear head, so that the construction is done from behind, so to speak and the electric motor only on the gearbox opposite side, preferably cushioning compliant with a protrusion in a housing recess on this page for safe mounting takes hold.

Then you can on the back open Slide on the collar until it stops ben who the electrical connections with the Engine produces. The structure is then completed through a rear housing cover, which with its front annular edge into this edge engaging annular groove in the collar and engages itself on a rear-facing, tapering Protrusion of the main housing strikes and there too screwed or otherwise attached. On In this way, the collar can be easily in place and hold the spot because he is through the back engaging ring edge of the rear housing cover secured and forward can be secured against axial displacement take place in that adjusting ring and main housing at this point with stepped, aligned ring grooves on the stop gene.

The collar then sits on the outside of the tubular,  closed housing body and reaches with Inside directed through housing openings jump on the shift ring in the area of the B bearing shield of the drive motor on which it is out is aimed so that a shift ring adjustment to Re Versions of the direction of rotation or for switching on and off device is possible.

drawing

Embodiments of the invention are in the drawing and are shown in the following Description explained in more detail. Show it:

Fig. 1 as a partial section of a partial view of an electric drive motor accommodated in a tubular main housing (an angle grinder) with arrangement of the outer adjusting ring and its passage through the electric motor switching ring;

Figure 2 shows the tubular main housing of an electric hand tool, especially for an angle grinder, with a set collar.

Fig. 3 shows the representation of Fig. 2 in a view from the right, with the adjusting ring in its deflected position while the

Fig. 4 shows the same view with the collar in the rest position; the

Fig. 5 and 6 show detail views inner half of the dotted outline of Figures 3 and 4 of the Arretierwippe for the adjusting ring in the engaged position and in the rest position (Fig. 6). (Fig. 5);

Fig. 7 shows a better understanding of the overall construction of the electric hand tool (angle grinder as a possible embodiment) a top view of the representation of Fig. 1 from the right, from which the inner switching ring of the electric motor can be seen and the

Fig. 8 shows a possible embodiment of an electric hand tool with an outer adjusting ring.

Description of the embodiments

The basic idea is outside or inside the housing of a power tool, specifically an electric hand tool, at the level of the B-end shield of the electric motor that drives this electric hand tool to arrange a rotatable collar, the Verdre in one direction or the other given angular positions and with projections inside, e.g. B. by suitably cut out housing Openings up to the inner switching ring of the electromo tors engages so that it is possible to operate of the collar electrical switching in the area of the electric drive motor immediately before increase.  

The following detail Explanation relates specifically to the structure and the on / off switch mechanism in an angle grinder; but it goes without saying that the offered electrical intervention options especially in the operation of the drive motor suitable and usable for such electric hand tools are in which a via the collar adjustment Reversal of the direction of rotation is made possible with the Angle grinders described here, however, are not necessary is.

The partial representation of FIG. 1 shows an electric universal motor 10 as a suitable drive source, which is located within a tubular main housing 11 and is of generally cylindrical shape. The B-end shield 12 is designed such that it forms a hub 13 for the B-bearing of the rotor shaft on this side, which is held in one piece by ribbed both-sided carriers 14 a, 14 b. On an outward-facing outer ring surface (not visible) of the B-end shield, there is rotatably a switching ring which also carries the brushes 15 in quivers 16 and which is visible in the top view of FIG. 7 and designated 23 there. Against axial falling, the switching ring 23 is held by a locking ring 17 which is anchored on the B-end shield 12 with locking lugs 18 projecting inwards.

So that one can carry out the rotary movement of the switching ring, axial projections 19 a, 19 b can be provided on the switching ring, which thereby lie with the outer or inner, guided on the housing adjusting ring 20 come into active connection that this bilaterally inwardly directed projections 21 a, 21 b, which comprise the projections 19 a, 19 b of the switching ring, so that it rotates when the outer adjusting ring 20 is rotated. As a result, not only can the brushes be oriented in a new win cell position for the respective direction of rotation, but also, if desired, can produce further electrical switches. Is the collar z. B. inside a hand drill and is then only partially visible bar, then housing openings serve to manually actuate the collar from the outside, for. B. if an adjusting handle or sliding piece on the adjusting ring protrudes through the opening or is accessible through it.

Here are in any position per se, in the illustrated embodiment within the two-sided carrier 14 a, 14 b of the B-end shield 12 , only two connecting plug contacts (in Fig. 4 at 22 a, 22 b recognizable), the two power supplies represent for the drive motor and are to be connected to an external power supply, for example by plug connection with an electrical plug-in module, which is designed so that further electrical switching operations can be carried out with this, if necessary for the specific electrical hand tool, such as the "gas function "on a hand drill or switching the electrical hand tool on and off when the influence of the outer collar is reserved for reversing the direction of rotation. This depends, as it goes without saying, on the type of power tool and, of course, on the electrical wiring within the electric motor specified by the lead frame shape, with which the switching ring of the electric motor is in appropriate contact connection or can be brought depending on the rotation.

Here, 1 is a better understanding in Fig., The tubular main body not shown led beyond the outer collar 20 in the plane of the drawing to the left for reasons. This can be seen in more detail in FIG. 2, while in FIG. 1 the B-side motor details can be better recognized. In the following, the circumstances of an angle grinder will be dealt with specifically, so that here, always, but not by limitation, there is talk of an outer adjusting ring.

The sectional view of FIG. 1 shows how an annular shoulder 24 of the adjusting ring 20 formed by internal steps sits on the facing outer end face or edge surface 25 of the main housing. Opposite the adjusting ring has an axially opening ring recess 26 , into which the front edge of a rear cover part housing 27 then engages to secure the adjusting ring ( FIG. 8), which is pushed onto an inner projection 28 of the main housing 11 as far as it will go. Before jump 28 is forked and includes an upper leg 28 a and a lower leg 28 b ( Fig. 2), the electrical switching module can be inserted into the space between these two legs, which is not the subject of the invention; a luster terminal 29 serves to relieve the strain on the supplied electrical line. For example, the lower leg 28 b of the main housing extension 28 can then serve to hold the rear housing cover 27 by means of a screw or pin 30 a ( FIG. 8) against axial pulling, which at the same time also secures the adjusting ring 20 .

If the outer collar 20 for switching the device on and off, as is the case with the described angle grinder, then the switching ring also has an additional locking device with automatic reset, as shown in FIGS . 3, 4 and 2 . In this case, return springs 31 a, 31 b are initially provided which engage additional fastening pins 30 on the inwardly directed projections 21 a, 21 b of the adjusting ring 20 . The return springs are attached to the rear of the housing-fixed webs 32 which, tapering conically, carry the rear bifurcated inner housing projection 28 of the main housing 11 .

Furthermore, the collar 20 is still a Arretieran arrangement 33 ; in the illustrated embodiment consisting of an approximately centrally mounted rocker 34 , which ends on one side in a bent locking lug 35 and the other side is biased by its own small preload compression spring 36 ( Fig. 5) so that the locking lug 35 after inside presses. It can be seen from the representation of FIGS. 3 to 6 that when the outer adjusting ring is rotated in the counterclockwise direction according to the arrow A - with corresponding driving of the switching ring inside the motor via the projections 21 a, 21 b, - when a predetermined position is reached the locking lance 35 is incident on a housing-fixed recess 37 and the outer adjustment ring 20 then also remains when released in this position. In the game relating to the angle grinder, the device can be switched on in this way and locked in the switched-on position as described, with the other end of the rocker corresponding to the arrow B in FIG. 3. If one then presses this rocker end to switch off the device, then the locking lug 35 is released again from the holding opening 37 , the outer adjusting ring 20 snaps back into its original position and, due to the correspondingly strong force of the return springs, takes the switching ring in the region of the B- Bearing plate of the drive motor with and switches off the device in this way, if necessary, however, an automatic reset in a preferred direction of rotation can be realized even if the direction of rotation is reversed.

Since the rear edge of the rocker switch 34 protrudes beyond the dimensions of the switching ring or housing in the switched-on position, it is sufficient, if positioned accordingly, that the device is simply put down, as a result of which the device's own weight pushes the rocker switch back and triggers the return movement of the adjusting ring becomes. The device then switches off.

In Fig. 7, finally, the bias springs 38 a, 38 b for the carbon brushes and separate on receiving troughs 39 a, 9 b can be seen, which can serve to accommodate chokes 40 for interference suppression of the drive motor and are also carried by the switching ring.

Claims (10)

1.Switching device for the electrical switchover for switching on / off or for reversing the direction of rotation of power tools, in particular electric hand tools such as hand drills, (angle) grinders, saws, jigsaws, impact drills, hammer drills, polishing devices, by means of a switching ring which can be rotated by a predetermined angle ( 23 ) in the area of the B-end shield of the electric motor driving the tool with simultaneous brush bridge twisting, characterized in that a manually rotatable ring structure is guided as an adjusting ring ( 20 ) on the outside or inside of the housing ( 11 ) of the power tool, that the adjusting ring ( 20 ) is arranged axially at the level of the inner switching ring ( 23 ), and that at least one inwardly directed projection ( 21 a, 21 b) extends from the adjusting ring and engages to adjust the angle on the inner switching ring ( 23 ), the adjusting ring ( 20 ) itself held by spring tension in a starting position and can be traced back into it t. 2. Switching device according to claim 1, characterized in that the adjusting ring with annular shoulders ( 24 ) or ring recesses ( 26 ) on corresponding facing ring projections ( 25 ) or end faces in its axial position on the housing ( 11 ) or a rear cover part housing ( 27 ) of the power tool is held. 3. Switching device according to claim 1 or 2, characterized in that on the adjusting ring ( 20 ) engaging bias springs ( 31 a, 31 b) are attached to the rear of the housing ( 11 ), the restoring force of which is designed such that the adjusting ring ( 20 ) is carried along of the inner switching ring ( 23 ) can be traced back to its starting position. 4. Switching device according to one of claims 1-3, characterized in that the inner switching ring ( 23 ) is in electrical operative connection with an electrically conductive lead frame forming the inner connections of the electric motor. 5. Switching device according to one of claims 1-4, characterized in that a locking device ( 33 ) is provided on the adjusting ring ( 20 ), which locks the adjusting ring in its deflected (activated) end position relative to the starting position. 6. Switching device according to claim 5, characterized in that the locking device ( 33 ) a on the adjusting ring ( 20 ) mounted rocker switch ( 34 ) to the spring-loaded with a nose ( 35 ) in the deflected state of the adjusting ring ( 20 ) in one Wall recess ( 37 ) of the housing ( 11 ) engages. 7. A switching device according to claim 6, characterized in that the switching rocker (34) is approximately centrally supported and in which the locking lug (35) sitting in the activated state in the wall recess (37) solutions with its end facing away from the Außenabmes of the housing towered over in such a way that the locking position of the rocker switch is automatically released when the electric hand tool is put down and the adjusting ring is returned to its starting position. 8. Switching device according to one of claims 1-7, characterized in that the adjusting ring ( 20 ) overlaps the main housing part with an apron-shaped ring projection ( 20 a). 9. Switching device according to one of claims 1-8, characterized in that the inner switching ring-entraining, from the adjusting ring ( 20 ) outgoing projections ( 21 a, 21 b) axially extending receiving openings for axial from the switching ring ( 23 ) of the electric motor Protrusions ( 19 a, 19 b) have such that the driving position between the adjusting ring ( 20 ) and switching ring ( 23 ) by axially pushing on the adjusting ring ( 20 ) on the main housing ( 11 ) comprising the electric motor is reached. 10. Switching device according to claim 1, characterized in that the adjusting ring ( 20 ) held on the inside of the housing and is accessible through at least one housing opening for manual adjustment.