EP1075905B1 - Hand-held electrical hammer - Google Patents

Abstract

The combi-hammer has an actuating element (17) for an electrical on/off switch in its handle operated against a bias force, a changeover device (4) for changing between drilling and chiselling mode and a locking arrangement (5-22) for the actuating element in its on position activated by the changeover device when chiselling mode is selected. A locking switch (15) fixes the actuating element in its on position in one switch position when chiselling mode is selected and deactivates the locking device in another switch position in which the actuating element springs back into the off position under the bias force when released by the user.

Description

The invention relates to a hand-held electric combination hammer for user switchable, optional use as a drill or chisel, with an actuated in the housing handle against a biasing force actuatable actuator for an electrical ON / OFF switch, a switching device for switching from drilling to chisel operation and vice versa, as well as with an activatable by the switching device locking device for the actuating element in its ON-switching position when selecting the chisel operation.

Rotary hammers of this type generally have an actuating element articulated on one side in the housing handle for an electrical ON / OFF switch which frequently serves as an adjusting element, for example for a potentiometer, for the steplessly variable change of the engine speed or is coupled to such an actuating element is. If the device user presses the actuating element lying on the inside of the device handle, the motor drive of the hammer drill is switched ON and OFF again when it is released.

It is known in electric hand tools, such as drilling and impact drills, orbital sanders and jigsaws to lock the switch actuator by a lock button in the ON position of the actuator. By this locking button the electric hand tool is kept in continuous operation, so that the actuating element does not have to be kept pressed constantly. With a further increased pressure on the actuator, the locking button is unlocked again when the device is to be turned OFF.

In contrast to electric hand tools of the type mentioned, it is necessary or at least desirable for rotary hammers for safety reasons that locking of the actuating element in the ON-switching position may only be possible with chisel operation, but not during drilling operation. This problem is at a in the publication DE 197 20 947 A1 Elektrokombihammer described encountered in that a rotatable toggle button for manually switching from drilling to chisel operation existing cam rotates a spring-loaded in the direction of the cam pivot lever, so that an integrally formed detent recess in the Bewegüngsbahn a holding element passes, which is formed at the free end of a fixed to the latch for the ON / OFF switching leaf spring. With this proposed solution, the pawl, so the actuator for the ON / OFF switch at chisel operation in the ON-shift position can forcibly fix, while rotated by 180 ° switch button, ie drilling operation, the cam-operated pivot lever from the path of the holding element is pushed out on the pawl, so that a locking of the pawl by the user is no longer possible.

The known from the aforementioned DE document proposal is associated with practical problems and difficulties: Firstly, the locking the chisel operation causing elements, namely the detent recess on the pivot lever and the form-fitting molded spring, different degrees of wear by pressure-supported abrasion and fatigue conditions of detent spring. In addition, when selecting the chisel operation after pressing the pawl of the continuous operation forcibly and always set. The user must trigger the pawl below its fulcrum, so usually by moving a working hand, only when he wants to interrupt the chisel operation. However, there are a number of bit machining operations where continuous operation of the bit is undesirable. As an example may be called the so-called Abspitzen, so briefly consecutive chisel machining operations in which, for example, edge overhangs are removed on concrete structures after removing the casing with an electric chisel. For such processing operations, the device user usually does not want continuous operation.

The invention is therefore an object of the invention to improve combined drill / chisel hammers so that a locking of the switch operating element excluded during drilling operation, but with chisel operation optional and with high long-term functionality is possible.

The invention is in a hand-held electric combination hammer of the type mentioned inventively by a locking switch, which causes the locking device for fixing the actuating element in the ON-switching position and in a different switching position ineffective switches in the switching position when selecting the chisel operation, in which the actuating element when released by the user under the effect a biasing force in the OFF-switching position springs back.

Advantageous embodiments and further developments of the inventive concept are explained in more detail in the following description or defined in the dependent claims.

• Bei Bohrbetrieb ist keine Arretierung des Betätigungselements für den EIN-/AUS-Schalter möglich. Eine gegebenenfalls zuvor gewählte Arretierung wird zwangsweise aufgehoben, sobald auf Bohrbetrieb umgeschaltet wird.
• Bei Meißelbetrieb ist bei einer bevorzugten Ausführungsform der Erfindung eine Arretierung des Betätigungselements für den EIN-/AUS-Schalter möglich. Diese Arretierung ist durch den Benutzer vorwählbar und kann auch während des Betriebs der Maschine gewählt oder abgeschaltet werden.

With the invention, the following functions are performed for combi hammers of the type mentioned to solve the task:

• In drilling operation , no locking of the actuator for the ON / OFF switch is possible. A possibly previously selected lock is forcibly canceled when switching to drilling operation.
• When chisel operation is in a preferred embodiment of the invention, a locking of the actuating element for the ON / OFF switch possible. This lock is pre-selectable by the user and can also be selected or disabled during operation of the machine.

Fig. 1

die perspektivische Außenansicht eines Gehäuses eines elektrischen Kombihammes mit den erfindungsgemäßen Merkmalen;

Fig. 2

die schematische Perspektivdarstellung einer Umschalteinrichtung für einen Kombihammer mit wahlfreier Fixiermöglichkeit für ein Schalterbetätigungselement bei Wahl des Meißelbetrieb;

Fig. 3A

eine schematische Draufsicht-Teilschnittdarstellung der Umschaltvorrichtung bei Wahl des Bohrbetriebs;

Fig. 3B

die schematische Seitenansicht der Umschaltvorrichtung ebenfalls bei gewähltem Bohrbetrieb;

Fig. 4A

eine der Fig. 3A entsprechende Draufsicht- und Teilschnittdarstellung der Umschaltvorrichtung bei Wahl des Meißelbetriebs; und

Fig. 4B

eine der Fig. 3B entsprechende Seitendarstellung der Umschalteinrichtung wiederum bei Wahl des Meißelbetriebs und gewählter Arretierung des Schalterbetätigungselements.

The invention and an advantageous and proven embodiment thereof are explained in more detail below with reference to the drawing with reference to an embodiment. Show it:

Fig. 1

the perspective external view of a housing of an electric Kombihammes with the features of the invention;

Fig. 2

the schematic perspective view of a switching device for a combination hammer with optional fixing possibility for a switch operating element when selecting the chisel operation;

Fig. 3A

a schematic plan view partial sectional view of the switching device in the selection of the drilling operation;

Fig. 3B

the schematic side view of the switching device also with selected drilling operation;

Fig. 4A

one of Figure 3A corresponding plan view and partial sectional view of the switching device when selecting the chisel operation. and

Fig. 4B

one of the Fig. 3B corresponding side view of the switching device again when selecting the chisel operation and selected locking of the switch actuator.

Corresponding parts and components are marked in all figures with the same reference in each case.

Fig. 1 shows the composite of essentially two parts housing a hand-held combi hammer. One part forms the housing shell 1 and the other the rear-side handle shell, referred to as handle 2 for short. On the left side of the housing shell 1, an opening for receiving and rotatable mounting of a rotatable by 180 ° switch 3 for selecting the drilling operation on the one hand and the chisel operation on the other hand provided. In handle 2, a locking device 15 which can be moved back and forth transversely to the longitudinal axis of the device is provided in the rear part above an actuating element 17 for an ON / OFF switch (not shown).

Fig. 2 illustrates the perspective view of the switching device according to the invention with locking possibility for the switch actuator 17 at the choice of chisel operation. On the inside of the mounted in the housing shell 1 switch 3, an eccentric 4 is provided, which upon rotation of the switch 3 for selecting the switch position shown in Fig. 2 and in Figs. 4A, 4B "chisel" a shift rod 5 relative to the longitudinal axis of the Kombihammers against the force of a pair of springs 13a, 13b to the rear, ie in the direction of the actuator 17, shifts. The switching rod 5 has on the upper side an integrally formed guide plate 8 and laterally downwardly standing arms 6, on the underside of which a likewise with the shift rod 5 longitudinally displaceable magnetic holder 7 is formed. The shift rod 5 with guide plate 8, 6 arms and magnetic holder 7 is preferably made as a one-piece injection molded from synthetic resin component. The guide plate 8 of the shift rod 5 acts on a frame-like slide 9, which at its the guide plate 8 facing cross member has a dome-shaped or as a half-round web protruding molding 11 in a V-shaped vertical groove 10 engages the slider 9 facing the end of the guide plate 8. The slider 9 is thus pivotable about a fixed by the shape of the groove 10 and molding 11 pivot point perpendicular to the vertical axis of the combihammer. The pivot angle is a few degrees and is usually between 1 ° and 6 °; it is in a preferred embodiment of the invention 2.7 ° for reasons explained in more detail below. The pivoting angle for the slide 9 is limited by projections 20 formed on the underside which delimit the angular range of the pivoting angle of the slide 9 in both pivoting directions by abutment against the guide plate 8 rounded at the front. In the perspective view of Fig. 2 can be seen beyond that the two the slider 9 and the shift rod 5 in the direction of the eccentric 4 under bias holding compression springs 13 a, 13 b are supported against a detent plate 14 which also under the action of the springs 13 a , 13b exerts a certain pressure on the transverse to the longitudinal axis and the vertical axis of the combihammer displaceable locking switch 15 and limited by stop pin 16, the switching path of the locking switch 15 in one or the opposite direction of switching. The stop pins 16 act against two upwardly projecting side walls of a sweeping under the locking switch 15 extension 19 on the actuator 17th

The pivotable slide 9, hereinafter also referred to as a pivoting slide, has a at the pivot point 12 opposite web on the underside, preferably integrally formed cam, pin or hook 21 (see Fig. 3A, 4A), which together with and through the slider 9 to the pivot point 12 is pivotable perpendicular to the vertical and longitudinal axis of the combination hammer. This cam, pin or hook, hereinafter referred to only as cam 21, is thus positioned within the vertical side walls of the extension 19. This cam 21 is in drilling operation, ie. In a detent switch 15 under the action of the springs 13 a, 13 b moved away position of slide 9 and shift rod 5, outside a possible displacement of an extension 19 of the actuator 17 integrally formed Arretieransatzes 22 Locking switch 15, for example, in the position shown in Fig. 3A, in which the slide 9 is in its one in the longitudinal direction of the combihammer pivoted to the left end position, wherein the one (in Fig. 3A upper right) lug 20 abuts the guide plate 8 and in addition to the cam 21 a free space of some Millimeters, for example of 4 mm due to the pivoting angle of 2.70 remains free through which the locking lug 22 of the actuating member 17 can slip freely when the actuator 17 is released and about its pivot axis 18 in the OFF-switching position under the action of (not shown) Compression spring is pivoted.

Instead of the joint formed by the Aüsformung 11 and the groove 10 may also be provided to make the arrangement of slide 9 and guide plate 8 in itself so flexible that the required in terms of the necessary displacement for the cam 21 low right / left pivoting of the Slider 9 is guaranteed. The cam 21 may also be made flexible by selection of the material and / or by resilient articulation relative to the slide, so that it easily passes into the area of action of the Arretieransatzes 22 in any case.

When chisel operation on the other hand (see Fig. 4A, 4B) is the slide 9 and thus also the cam 21 in the position shown in Fig. 4A shifted to the left position. If - as shown in Fig. 4A, the locking switch 15 is pressed to "lock", so seen in the longitudinal direction of the combihammer to the right and in Fig. 4A by pivoting the slider 9 is pivoted to its other end position, in which now the other (in FIG 4A lower) stop 20 rests against the guide plate 8, so now is the serving as a locking cam 21 in the backward displacement path of the extension 19 of the control element 17 integrally formed Arretieransatzes 22. The control element 17 for the ON / OFF switch is thus locked and the combi hammer is in continuous operation when chiseling is selected.

It is an essential idea of the invention that the lock on continuous operation on the one hand only when selecting the chisel operation is possible, however, on the other hand, in this chisel mode locking on continuous operation before but also selected only after switching on the chisel drive by pressing the locking switch 15 and canceled can. For example, when chisel operation of the locking switch 15 has not (yet) been pressed into the illustrated in Fig. 4A locking position, the cam 21 remains in a lifted position from the Arretieransatz 22 so that when you release the actuator 17 of the locking projection 22 next to the cam 21st can slip through, and the drive is turned off.

On the other hand, if the user wants to set his combi hammer to continuous operation after starting a chisel work, he shifts the lock switch 15 in the longitudinal direction of the apparatus to the right in the position shown in Fig. 4A. He can now let go of the actuator 17; the repulsion of the actuating element 17 and thus an OFF switching of the device drive is prevented. On the other hand, if the device user either switches from chisel operation to drilling operation, or shifts the locking switch 15 to the left in the device longitudinal direction, that is to say the position shown in FIG. 3A, the displacement path of the locking projection 22 is now free and the actuating element 17 always jumps when released the switching position OFF.

The magnetic holder 7 integrally connected to the switching rod 5 via the arms 6 serves to hold and guide a switching magnet used at its free end (FIG. 2), in particular permanent magnets or another element suitable for switching the device drive electronics from a drilling operation to a chisel operation, for example one optical or electromagnetic switching element, which triggers a switching function by relative displacement of two functionally cooperating components. In the case of a magnetic switch held by the magnet holder 7, in the longitudinal axis of the combihammer relatively displaceable magnet usually with a Hall sensor (not shown) cooperate to switch the drive electronics of chiseling on Schlagbohrbetrieb and vice versa.

With the invention, a switchover and locking device ensuring stable and long service lives, which is well suited for the "rough" use of combi hammers, is provided which, when the drilling operation is selected, ensures immediate device shutdown upon release of the switch operating element, while selecting the chiseling mode depending on the selectable before or during operation position of the locking switch 15 a continuous operation of the electric bit when releasing the actuator is possible.

Claims (9)

1. Hand-held electric combination hammer which can be switched over by the user for use optionally as a drill hammer or a chisel hammer, comprising an actuating element (17) mounted in the housing hand-grip (2) for actuating against a pre-tensioning force for an electric ON/OFF switch, a switching-over device (3, 4) for switching from drilling operation to chisel operation and vice versa, and a locking device (5-22) for the actuating element (17) in its ON switching position, which locking device can be activated by the switching-over device on selection of chisel operation, characterised by a locking switch (15) which, on selection of chisel operation serves, in one switching position, to fix the actuating element (17) in its ON switching position by means of the locking device and, in another switching position, in which the actuating element (17) springs back into the OFF switching position when released by the user under the effect of the pre-tensioning force, switches the locking device inactive.
2. Combination hammer according to claim 1, characterised in that the locking device comprises a switching bar (5) which can be actuated by the switching-over device (3, 4), said switching bar acting on a pusher (9) which is pivotably linked to said switching bar and is displaceable by a longitudinal displacement of the switching bar (5) relative to the housing hand-grip (2), said pusher being provided on a side opposing the switching bar (5) with a locking element (21) which, on actuation of the locking switch (15) in the "Chisel operation" position of the switching-over device (3, 4), finds its way by pivoting the pusher (9) into the displacement path of a locking shoulder (22) provided on the spring pre-loaded actuating element (17) for the ON/OFF switch and in this switching position prevents pushing of the actuating element (17) back into the OFF switching position.
3. Combination hammer according to claim 2, characterised in that a joint (10, 11, 12) is present between the switching bar (5) and the pusher (9).
4. Combination hammer according to claim 2, characterised in that the locking element (21) is configured as a cam, peg or hook connected to the pusher (9), said locking element, on selection of chisel operation and with the locking switch (15) actuated to "fixing of the actuating element" (17), passes into the pushing-back path of the locking shoulder (22) formed on the actuating element (17).
5. Combination hammer according to claim 3 or 4, characterised by a latching plate (14) assigned to the locking switch (15), said latching plate limiting the back and forth movement of the locking switch (15), which can be actuated from two sides in, respectively, one of two switching positions.
6. Combination hammer according to claim 4, characterised in that, on the switching-over device (3, 4) for switching from drilling operation to chisel operation, an eccentric cam (4) is present which, on selection of chisel operation, displaces the pusher (9) via the switching bar (5) relative to the device housing (1, 2) in the direction nearer to the actuating element (17) against the pushing-back force of a spring (13a, 13b) acting on the pusher (9).
7. Combination hammer according to claim 6, characterised in that the pushing-back force acting on the pusher (9) is exerted by two parallel compression springs (13a, 13b) arranged parallel and in the same plane of action.
8. Combination hammer according to claim 7 in conjunction with claim 5, characterised in that the two compression springs (13a, 13b) act on a surface of the pusher (9) facing away from the pivot point (12) of the pusher (9) and are supported against the latching plate (14) of the locking switch (15).
9. Combination hammer according to one of the preceding claims, characterised in that a magnet holder (7) which is guided within the device housing (1, 2) is connected to the switching bar (5), said magnet holder providing a logical YES/NO switching signal to the control electronics of the combination hammer depending on the switching position of the switching-over device (3, 4).

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