DE3329668A1 - Device for switching an electric power tool equipped with a two-speed transmission from the first to the second transmission stage and vice versa - Google Patents

Abstract

Devices for switching an electric power tool equipped with a two-speed transmission from the first to the second transmission stage are known which contain a final control element actuable by way of a switch knob. This final control element is either a sliding linkage with a switch lever or an eccentric. It is the object of the invention to provide a switching device which takes up less space and is cheaper. This is achieved according to the invention by virtue of the fact that the final control element is designed as a rocker arm (28) which is arranged on a journal (27) positioned eccentrically with respect to the axis (26) of rotation of the switch knob (25), and that one end of the rocker arm is supported movably in the interior of the housing and its other end engages in a circumferential groove (22) of the gear wheel (20) arranged in axially displaceable fashion on the output shaft of the transmission. <IMAGE>

Description

-L?. * C- e R; * t *; i * · β *: .. ": Patent ^: " - ^: Ueruraltrrngs - · - GmbH TheodDr-Stern-Kai 1, -6DGD Frankfurt 3379668

ES 83/13 Frankfurt, August -15th, 1989:

. ^: Dr.Uf / Set

Device for switching one with a two-speed transmission equipped electric works van der first , on the second. Gear stage and vice versa

The invention relates to a device for switching a power tool equipped with a two-speed transmission from the first to the second gear stage and vice versa, the contains an actuator that can be actuated via a toggle handle, that on a non-rotatable, but axially displaceable on the Gear drive source attached gear of the second gear stage acts and either keeps this gear in direct engagement with a countershaft gear (overdrive) or by axial displacement with a rotatable on the gearbox output shaft brings the seated drive gear of the second gear stage (slow gear) into a force-fit connection, the van another gear attached to the new countershaft is set in rotation.

In known switching devices of this type, the actuator is realized either by a [ sliding linkage with shift fork vein by an eccentric. The object of the invention is to create a switchover device which requires comparatively less space and is more cost-effective.

This object is achieved according to the invention in that the actuator alsSchsltschwinge is designed on an eccentric to the axis of rotation of the switch handle pin is arranged, and that one end of the rocker arm in the housing interior is movably mounted and the other end in a Engages circumferential groove of the axially displaceable gear arranged on the transmission drive shaft.

ES a3 / 13

An embodiment of the switching device according to the invention is explained below using the. Drawing explained.

Show it: .' "Fig. 1 is a longitudinal section through the transmission .. '" . '"-". . housing of a hammer drill,. .

..: ·· '.., .. .Fig. 2 'is a view along section A-A .by Fig. 1,. '

'. · · -' Fig. 3 ″ is a partial view in direction B of FIG.

As can be seen from FIG. 1, the pinion 1 is the armature source 4 "of the drive motor (not shown) with" a gear "6 attached to the gear shaft 5, which is ^{rotatably mounted in the bearing web 3 1 of the gear housing 3 by means of a roller bearing 2} The gear shafts 5, which are rotatably mounted at their drive-side end by means of a bearing 7, also in the bearing web 3 'and in their output-side area in a roller bearing 8, carry an additional gear 9 in front of this bearing, followed by a gear 10 '. the gear 10 meshes with a rotatably arranged on the Getriebeabtriebsuelle 11 Zahnrad.12, the' on a radius arranged distributed bolts or pins · 13 carries, for example two by 180 ° or by 120 ° to each other staggered ^·:. '

At its end on the mator side, the transmission output source 11 is mounted in the form of a roller bearing 14 in the bearing web 3 and also in a roller bearing 15 in the transmission neck. In its end region located on the motor side, the gear output shaft contains a detent disk 16 to which a ^{counter-detent disk 17 fixedly arranged in the bearing web 3 1} is assigned. An eccentric 18 engages on the rear face of the gear output socket 11, which is rotatable by means of the actuating member 19 and keeps the detent disc 16 of the gear output socket out of engagement with the counter detent disc 17 or enables this engagement. The "latter case is held in the lower position of the gearbox output source." ■. ·

- 5th

- · ΐ ■

ES 83/13 ■ '■''·. ·

'. On. A gear 20 cannot rotate on the transmission output shaft 11. .. · however - arranged to be axially displaceable. This is due to a 'longitudinal toothing of the gear 20 with the transmission output shaft'. {■. '. realized. Trained or serving as a ratchet .Zahn- _; '. wheel 20 contains, on its end face facing the pins of the gear 1.2, a number of axial bores 21 corresponding to the number of pins or twice the number of pins, which lie on a radius corresponding to the pins 13 and enable the pins to be received. Own diameter. On its side located on the motor side, the gear 20 has a circumferential groove 22; in 'which the in Figures 2 and. 3 .with- 28 designated switchgear intervenes. In the upper half of Fig; 1 'held position, the gear 20 is in.Eingriff with the on the l / orge. legewel.le located gear 9. This is the second gear- '

• The level is effective and the hammer drill runs at high speed. When the gear 20 is moved against the gear 12, the pins 13 engage with the bores 21 of the gear 20, . Which is facilitated by the relative rotation of the two gears 20 and 12 ■ to each other. As a result, the gear 12 is on the Gear 20 is coupled to the transmission output shaft 11 and the machine runs in slow gear (1st gear stage). '· ·

• As. Figures 2 and 3 show is in a recess 23 of the .Housing or the housing half 2 {f a switch handle 25 for the ' Switching on one or the other gear stage arranged, the is rotatable about the axis 26. Eccentric to the axis of rotation "25 lies a pin 27 on which a rocker arm 28 is rotatably arranged .and by means of a locking ring 29 on an axial displacement is prevented. The rocker arm is at its lower end 30 between two ribs attached to the inner wall of the housing 31,32 stored and engages in its upper end region using the corresponding lever ratio in the circumferential groove 22 of the tooth and switch gear 20 a.

ES 83/13

The switching handle is located in the position indicated by 2 in FIG Position, the gear 20 is in engagement with the on the Countershaft 5 arranged gear 9 (Fig. 1), and the transmission output shaft runs at high speed. When the switch handle is moved into the position marked 1, the gear wheel 20, As already stated., axially, shifted to the gear 12 towards and finally comes into a positive connection with it Gear.

The gear 12 then transmits a rotational movement via the non-rotatable gear 20 connected to the gear output shaft 11 and now disengaged from gear wheel 9 to the gear output source. This thus rotates at the low speed. The rocker arm 28 is preferably made of sheet metal, whereby saving space on the one hand and hosting on the other.

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Claims (1)

Ll c * e. Q -Γ-a - "- Patent ~ ^; -Verwal ⁱ biJn'g-s - -Gmb-H Theodor-Stern-Kai 1, 6D00 Frankfurt 83/13 'Frankfurt, 15.B.1983 Dr. LJf / Sch Claims . Device for switching a power tool equipped with a two-speed gearbox from the first to the second gear stage and vice versa, which contains an actuator which can be operated via a switch handle and which acts on a non-rotatable but axially displaceable gear of the second gear stage and this gear wheel either in direct engagement with a primary shaft gear (overdrive) or through axial shifting with a drive gear of the second gear stage (slow gear) that is rotatably seated on the transmission drive shaft, which is set in rotation by a further gear mounted on the primary shaft, characterized in that the actuator is designed as a rocker switch (28) which is arranged on a pin (27) eccentric to the axis of rotation (2S) of the switch handle (25), and that one end of the rocker switch is movable inside the housing gelager.t and the other end of which engages in a circumferential groove (22) of the gearwheel (20) which is axially displaceable on the gear output source. '- ■ · 2. Device according to claim 1, characterized in that the axially displaceable gearwheel (20) has bores (21) provided on a radius, into which after actuation the rocker arm (28) in the sense of the connection of the longitudinal samgang Corresponding gearwheel (12) accommodated in the gearwheel (12) rotatably seated on the transmission drive shaft (11) Engage the bolt (13) ". ΕΞ 83/13 3 * device according to claims 1 and 2, characterized in that that the UmschaltgrifF within the outer contour of the housing of the electric tool is arranged and dsß the axis of rotation of the Shift handle transversely to the longitudinal axis of the transmission output shaft runs. k. Device according to Claims 1 to 3, characterized in that the shift slips can be pivoted in a plane running parallel to the longitudinal dividing plane of the electric tool. is. 5. Device according to claims 1 to 5, characterized in that that the shift shoes are made of sheet metal. S. Device according to claims 1 to 5, characterized in that that one end of the. Shift shoes in rib-shaped approaches stored in one half of the shell of an additional machine is.