EP1070331A1

EP1070331A1 - Electric switch

Info

Publication number: EP1070331A1
Application number: EP99944139A
Authority: EP
Inventors: Peter Broghammer; Uwe Stratmann
Original assignee: Marquardt GmbH
Current assignee: Marquardt GmbH
Priority date: 1998-04-04
Filing date: 1999-03-31
Publication date: 2001-01-24
Anticipated expiration: 2019-03-31
Also published as: WO1999052118A1; DE59901506D1; US6555773B1; EP1070331B1; DE19913712A1

Abstract

Two blocking means (5, 6) are assigned to the switch (1), shifting from a blocked position which blocks the movement of actuator (3) and a release position which releases the movement of the actuator (3). The first blocking means is located in the vicinity of the actuator (3) and acts upon said actuator in an initial position. The second blocking means is located in the vicinity of the tappet and acts upon the actuator (3) in a first actuating position. An actuating element (7) with three switching positions is assigned to the switch (1) for the shifting of both blocking means (5, 6).

Description

- 1 -

Electrical switch

The invention relates to an electrical switch according to the preamble of claim 1.

Such electrical switches are used in particular in electrical devices, such as in electrical hand tools or the like. used. For example, the electric hand tool can be an electric drill. The switch is used to switch on and off and, if necessary, further to set the speed of an electric motor of the electric hand tool. In order to prevent the electrical hand tool from being switched on unintentionally, the electrical switch can be provided with a switch-on lock.

Electrical switches with a switch-on lock are known for example from DE-OS 24 10 871. This switch has a housing, an actuating member which is arranged movably on the housing and a plunger which transmits the movement of the actuating member into the housing and acts on the switch. The actuating member can be moved from an initial position into actuating positions, in each of which a function of the switch can be triggered. The switch is assigned a blocking means which can be switched between a blocking state for blocking the movement of the actuating member and a release state for releasing the movement of the actuating member. The locking device in this switch acts as a switch-on lock. After the actuating means has been switched from the locked state to the released state in the starting position, the actuating member can be moved into the actuating position. In the actuation position, however, no further effect of a locking means is provided, so that the locking means on this switch only has a single functionality.

The invention has for its object to provide a switch of the type mentioned with locking means of extended functionality.

This object is achieved in a generic electrical switch by the characterizing features of claim 1.

In the switch according to the invention, first locking means act on the actuating member in its initial position and second locking means in a first actuating position of the actuating member. The switch has an actuating element with three switch positions for switching the two locking means. In the first switching position of the actuating element, the first locking means is in the locked state. In the second switch position, the first locking device is in the release state and the second locking device is in the locked state. Finally, in the third switch position, both locking devices are in the release state. Further embodiments of the invention are the subject of the dependent claims.

The arrangement of the first locking means in the vicinity of the actuating member and the second locking means in the vicinity of the tappet is preferred. A backdrop on the top of the actuator for guidance for part of the serve first blocking means. Part of the second locking means can be arranged centrally on the tappet.

The first locking means can be designed in the manner of a switch-on lock and the second locking means in the form of a lock-out lock for the actuating member. The actuating element is expediently only switchable in the initial position of the actuating member.

In a special embodiment, the first locking means consists of an attachment which is operatively connected to the actuating element and a corresponding stop arranged on the actuating member. In the initial position, the attachment comes into contact with the stop in the locked state and can be moved sideways past the stop in the released state. The second locking means is designed as a stroke limiter for the actuating member in such a way that the movement path of the actuating member is limited to the first actuating position in the locked state and is released for further movement into the second actuated position in the released state.

The stroke limitation can in turn consist of a movable cam ring which surrounds the tappet centrally and a corresponding stop attached to the actuating member. In the first actuation position in the locked state, the stop comes into contact with a cam of the cam ring and can be moved past the cam in the release state. A pin on the actuator that engages a fork attached to the cam ring can be used to move the cam ring between the locked and unlocked states.

In order to ensure good operability by the user, the actuating element can be used as a slide, swivel lever, adjusting wheel or the like. with three rest positions - 4 -

be trained. An attachment on the actuating element interacts with a detent spring to determine the detent positions. The first switching position for the actuating element is preferably formed by the middle and the second and third switching positions each by a lateral latching position. Function symbols can be attached to the actuating element, the function symbol that characterizes this switching position being visible to the user in the respective switching position.

A simple assembly of the switch in the electrical device is further provided if the actuating element forms a preassembled structural unit with the switch. For this purpose, for example, a carrier part can be connected to the housing of the switch, the actuating element being movably mounted in the carrier part.

The advantages achieved by the invention are, in particular, that certain functions of the switch can be selected in the starting position of the actuating member and further functions can be blocked. This effectively prevents accidental activation of undesired functions by the user, which also reduces the risk of accidents for the user. For example, the electric hand tool can be used in a first

The actuating position of the actuating member can be operated at a variable and optionally regulated speed, which is lower than the maximum speed, while in a second actuating position the electric hand tool can be operated at the maximum, but unregulated, speed. Depending on the material to be processed, the user can selectively lock the second actuation position, which results in an optimal work result.

The functionality mentioned is additionally combined with a switch-on lock that has already been used. - 5 -

Advantageously, only a single actuating element is used for both locking means, so that on the one hand the operation is simplified and on the other hand costs are also saved.

The switch according to the invention achieves yet another safety gain for the user of the electric hand tool. The formation of the locking means prevents the occurrence of a tilting moment on the actuating member even when the actuating member is subjected to excessive stress when the locking member is in the locked state. This effectively prevents accidental or improper switching on of the electric hand tool.

Embodiments of the invention with various developments are shown in the drawings and are described in more detail below. Show it

1 is an electrical switch in side view,

2 shows the electrical switch from FIG. 1 in plan view,

3 shows a section along the line 3-3 from FIG. 1, the actuating element for the locking means being in the second switching position,

Fig. 4 shows a section as in Fig. 3, wherein the

Actuating element for the locking means is in the first switching position,

Fig. 5 shows a section as in Fig. 3, wherein the

Actuating element for the locking means is in the third switching position,

6 the electrical switch arranged in an electric drilling machine, - 6 -

7 shows a section through the switch along the line 7-7 from FIG. 1,

Fig. 8 is an electrical switch in side view according to another embodiment and

9 is a plan view of the actuating element according to FIG. 8.

An electric hand tool 20 is shown in FIG. 6. The electric hand tool 20 has an electrical switch 1 arranged in the handle 21, which is used to switch on and off and to set the speed of the electric motor (not shown further) in the electric hand tool 20. The electric hand tool 20 can be, for example, a mains-operated electric drill, a cordless drill or the like. act.

The switch 1 shown in more detail in Fig. 1 has a housing 2 on which an actuator 3 is movably arranged. The actuator 3 has, for example, the shape of a linearly movable trigger that the user moves manually. In accordance with the respective actuation path of the actuating member 3, the speed of the electric motor is then set by means of a phase control, pulse width modulation or the like and, if necessary, regulated, i.e. kept largely constant even under load on the electric hand tool 20. When the actuator 3 is fully switched on, the electric motor then runs at maximum speed.

The switch 1 also has a plunger 4, which transmits the movement of the actuating member 3 into the housing 2. In the case of an actuating element 3 designed as a pusher, the tappet 4 can be located approximately in the middle or somewhat outside - 7 -

the middle, for example facing the underside of the handle, be attached to the handle. In the housing 2, the plunger 4 acts on at least one electrical component located in the housing 2, such as on a contact system 22, 23, on a potentiometer 25 or the like assigned to a printed circuit board 24, as can be seen in more detail from FIG. 7. The actuating member 3 can be moved from a starting position, which is shown in FIG. 1, by manual action of the user in the direction 26 into a first actuating position and from there into a further second actuating position. In these two actuation positions, a function of the switch 1 can be triggered by the action of the plunger 4, namely in the first actuation position a control of the electric motor for a speed corresponding to the actuation path covered by the actuation member 3 and in the second actuation position the setting of the maximum speed by the full voltage is applied to the electric motor.

The switch 1 is assigned two locking means 5, 6, which can be switched between a locked state for blocking the movement of the actuating member 3 and a release state for releasing the movement of the actuating member 3. The first locking means 5 is located in the vicinity of the actuator 3 and acts on the actuator 3 in its initial position. The second locking means 6 is located in the vicinity of the plunger 4 and acts on the actuating member 3 in the first actuating position. The second locking means 6 is preferably arranged centrally on the tappet 4. It is also essential that a single, three switching positions actuating element 7 for switching the two locking means 5, 6 is assigned to the switch 1. In the first switching position of the actuating element 7, the first locking means 5 is in the locked state. In the second switching position of the actuating element 7, the first locking means 5 is in the - 8th -

Release state and the second locking means 6 is in the locked state. Finally, in the third switching position of the actuating element 7, both locking means 5, 6 are in the release state.

Preferably, there are two contact systems 22, 23 in the housing 2 of the switch 1, as can be seen in more detail in FIG. 7. Optionally, a potentiometer 25 and electronics for speed adjustment or speed control of the electric motor can be arranged on the circuit board 24 in the housing 2. In the starting position of the

Actuator 3 is now no action of the plunger 4 on the two contact systems 22, 23, whereby the electric motor is switched off. The first locking means 5 is designed in the manner of a switch-on lock for the actuating member 3, so that the actuating member 3 cannot be moved in the first switching position of the actuating element 7, which prevents the electric motor from being switched on. The electric motor can only be switched on after the actuating element 7 has been switched to the second or third switching position.

If the actuating element 7 is in the second switching position, the actuating member 3 can be moved into the first actuating position. In the first actuation position, the plunger 4 has a switching action on the first contact system 22, whereby the voltage for the electronics is switched on. If necessary, there is also an action on the potentiometer 25 in accordance with the movement path of the actuating member 3 in the direction 26 (see FIG. 1), so that a setting of a variable and preferably regulated speed of the electric motor corresponding to the moving position of the actuating member 3 is carried out via the electronics. The second locking means 6 is designed in the manner of a switch-through lock for the actuating member 3, which means that the - 9 -

Actuator 3 in the second actuation position is prevented because the second locking means 6 is in the locked state.

If the actuating element 7 is finally in the third switching position, the actuating member 3 can be moved into both the first and the second actuating position, since both locking means 5, 6 are in the release state. In the second actuation position, the plunger 4 then has a switching action on the second contact system 23, as a result of which the electronics are bridged. As a result, the full voltage is applied to the electric motor and the electric motor moves at maximum, unregulated speed.

The actuating element 7 is expediently only switchable in the initial position of the actuating member 3. In the starting position, a switch-on lock for the electric motor is present in the first switching position, which is used to protect the user against unwanted operation of the electric hand tool 20. For operation, the user must consciously switch the actuating element 7. The user can choose between the second and third switching position. In the second switching position, the electric motor is to be operated at an adjustable and regulated speed, which is, however, less than the maximum speed. This mode of operation is suitable for processing hard materials, for example for drilling in metal. In the third switch position, the electric motor can be operated at an adjustable speed up to the maximum speed, but the operation at maximum speed is unregulated. This mode of operation can be useful when processing soft materials, for example when drilling in wood. - 10 -

A preferred closer embodiment of the two locking means 5, 6 will be described in more detail below.

As can be seen from FIG. 1, the first locking means 5 consists of an attachment 8 which is operatively connected to the actuating element 7 and a corresponding stop 9 arranged on the actuating member 3. The attachment 8 can be formed in one piece with the actuating element 7. The approach 8 comes in the starting position of the actuator 3 in the locked state, ie when the actuating element 7 is in the first switching position, in contact with the stop 9, as can be seen in more detail in FIGS. 2 and 4. The release state corresponding to the second switching position of the actuating element 7 can be seen in FIG. 3 and the release state corresponding to the third switching position of the actuating element 7 can be seen in FIG. 5. As can be seen from FIG. 2 in connection with FIG. 3 or 5, in the released state the attachment 8 and the stop 9 can be moved laterally past one another. For this purpose there is a link 10 in the actuating member 3. In particular in the case of an actuating member 3 designed as a pusher, it is advisable to guide the link 10 for part of the first locking means 5, specifically for the attachment 8, on the upper side of the actuating member 3 to arrange.

The second locking means 6 is designed as a stroke limitation for the actuating member 3. As a result, the movement path of the actuating member 3 in the locked state, that is to say when the actuating element 7 is in the second switching position, is limited to the first actuated position. The stroke limitation consists of a cam element 11 movably arranged on the housing 2 with at least one cam 12 and at least one corresponding stop 13 attached to the actuating member 3, as can be seen in more detail in FIG. 2. The stop 13 comes in the first operating position of the actuator 3 in the locked state - 11 -

in contact with the cam 12, as can be seen in FIG. 3, whereby the movement path or the stroke of the actuating member 3 is limited to the first actuating position. In the release state for the second locking means 6 according to the third switching position of the actuating element 7 shown in FIG. 5, the stop 13 can be moved laterally past the cam 12, so that the actuating member 3 can be moved into the second actuating position.

1 and 2, a pin 14 is arranged on the actuating element 7, which engages in a fork 15 attached to the cam element 11. By means of the pin 14, when the actuating element 7 is switched between the second and third switching positions, the cam element 11 can be moved between the locked state and the released state, as can be seen in more detail in FIGS. 3 to 5. In Fig. 3 the second switching position of the actuating element 7 is shown, in which the cam 12 is in such a position that the second locking means 6 is in the locked state. 4 shows an intermediate position of the cam 12, which corresponds to the first switching position of the actuating element 7. In the first switching position, however, as already explained above, the first locking means 5 is in the locked state, so that the second locking means 6 is no longer effective here. 5 finally shows the third switching position of the actuating element 7, in which the cam 12 is in such a position that the second locking means 6 is in the release state.

The design of the second locking means 6 as a stroke limitation arranged in the vicinity of the tappet 4 prevents the occurrence of a tilting moment on the actuating member 3 in the event of improper or violent action by the user on the actuating member 3. In particular if the actuating element 7 is in the second switching position according to FIG. - 12 -

3 is located, with which the second locking means 6 assumes its locked state, a tilting of the actuating member 3 is excluded, since the actuating member 3 bears firmly on the cam 12, which is located on the lower part of the housing 2. Overcoming the locked state and an unwanted switching of the actuator 3 into the second actuation position is thus effectively prevented. This mode of operation can be further improved by designing the cam element 11 as a cam ring which centrally surrounds the tappet 4, which can be seen in particular from FIGS. 3 to 5. Moreover, in the first switching position of the actuating element 7 according to FIG. 4, tilting of the actuating member 3 is effectively prevented by the cam 12 additionally resting there on a web 19 which is integrally formed in the actuating member 3.

As shown in FIG. 1, the actuating element 7 can be movably mounted in a carrier part 16 connected to the housing 2. Of course, the actuating element 7 can also be mounted as a separately assembled part only in the handle 21 of the electric hand tool 20.

The actuating element 7 is designed as a slide 17 with three locking positions. As can be seen in particular from FIG. 2, where the second switching position of the actuating element 7 is shown in dashed lines and the further switching positions of the actuating element 7 are shown in dashed lines, the first switching position for the actuating element 7 is from the middle detent position and the second and third switching position from formed two lateral locking positions. A detent spring, not shown here, interacts with a projection 18 visible in FIG. 2 on the actuating element 7 for the fixing of the detent positions. - 13 -

Of course, the actuating element 7 can also be designed as a swivel lever or the like. 8 and 9, a setting wheel 27 is shown as an actuating element for switching the two locking means 5, 6 as a further embodiment. The adjusting wheel 27 is rotatably mounted in the handle 21 of the electric hand tool 20. The adjusting wheel 27 has three locking positions, which are defined by the interaction of a locking spring 28 visible in FIG. 9 with an extension 18 of the adjusting wheel 27. These locking positions are in turn the three switching positions of the adjusting wheel 27. Function symbols 29 are attached to the adjusting wheel 27, which characterize the respective switching position. In the handle 21 there is a window 30 so that the function symbol 30 assigned to the switch position assumed is visible to the user.

The invention is not restricted to the exemplary embodiment described and illustrated. Rather, it also includes all professional training within the scope of the inventive concept. Thus, an electrical switch which is equipped with two blocking means which interact according to the invention can not only be used on electric hand tools, but can also advantageously be used in household appliances, gardening appliances or other electrical appliances.

- 14 -

Reference symbol list:

1: electrical switch

2: housing

3: actuator

4: pestle

5: first blocking agent

6: second blocking means

7: actuator

8: Approach (from the first blocking agent)

9: stop (from the first locking device)

10: backdrop (in the actuator)

11: cam element (from the second locking means)

12: cams (on the cam element)

13: stop (from the second locking means)

14: pin (on the actuating element)

15: fork (on the cam element)

16: support part (for actuating element)

17: slide (actuating element)

18: shoulder (on the actuator)

19: bridge

20: electric hand tool

21: handle

22.23: contact system

24: printed circuit board

25: potentiometer

26: directional arrow

27: adjusting wheel

28: detent spring

29: Function symbol

30: window

Claims

- 15 -patent claims:

1. Electrical switch, in particular for the speed setting of an electric motor in an electrical device, such as in an electric hand tool (20) or the like, with a movable actuating member (3), the actuating member (3) from a starting position in actuating positions, in particular in a first and a second actuating position can be moved, in each of which a function of the switch (1) can be triggered, and locking means are assigned to the switch (1), which between a blocking state for blocking the movement of the actuating member (3) and a release state for Release of the movement of the actuating member (3) can be switched over, characterized in that a first locking means (5) acts on the actuating member (3) in the starting position, that a second locking means (6) acts on the actuating member (3) in the first actuating position , and that a three-position actuator (7) for switching the two locks r means (5, 6) is assigned to the switch (1), the first locking means (5) being in the locked state in the first switching position, the first locking means (5) in the unlocked state and the second locking means (6) in the second switching position are in the locked state, and in the third switching position both locking means (5, 6) are in the unlocked state.

2. Electrical switch according to claim 1, characterized in that by means of a plunger (4) the movement of the actuating member (3) can be transmitted to act on the switch (1), in particular to trigger the functions of the switch (1) in the actuating positions, that preferably the first locking means (5) is in the vicinity of the actuating member (3), and that further - 16 -

preferably the second locking means (6) is located in the vicinity of the plunger (4).

3. Electrical switch according to claim 1 or 2, characterized in that the first locking means (5) in the manner of a switch-on lock for the actuating member (3) and the second locking means (6) in the manner of a switch-off lock for the actuating member (3) are that a link (10) for guiding part of the first locking means (5) is preferably located on the upper side of the actuating member (3), and that the plunger (4) is preferably located approximately in the middle or outside the center, facing the underside of the actuating member (3) is arranged on the actuating member (3), in particular a part of the second locking means (6) being arranged centrally on the tappet (4).

4. An electrical switch according to claim 1, 2 or 3, characterized in that the actuating member (3), for example a linearly movable pusher, is arranged movably on a housing (2) of the switch (1) in that the plunger (4) detects the movement of the actuator (3) in the housing (2), and that preferably the plunger (4) on at least one in the housing (2) electrical component, such as a contact system (22, 23), potentiometer (25) or the like. , acts.

5. Electrical switch according to claim 4, characterized in that in the housing (2) two contact systems (22, 23), optionally a potentiometer (25) and optionally electronics for speed adjustment, in particular for speed control of the electric motor, are located in the starting position of the actuator (3) there is no action of the plunger (4) on the two contact systems (22, 23), that in the first actuation position there is a switching action of the plunger (4) on the first contact system (22), in particular - 17 -

for switching on the voltage for the electronics, as well as possibly an action on the potentiometer (25) for setting a variable, preferably regulated speed of the electric motor according to the movement position of the actuating member (3), and that in the second actuating position there is a switching action of the plunger ( 4) on the second contact system (23), in particular for bridging the electronics for the maximum and possibly uncontrolled speed of the electric motor.

6. Electrical switch according to one of claims 1 to

5, characterized in that the actuating element (7) can only be switched over in the starting position of the actuating member (3), that preferably the first locking means (5) consists of an operative connection with the actuating element (7), in particular in one piece with the actuating element (7 ) formed shoulder (8) and a corresponding stop (9) arranged on the actuating member (3), such that the shoulder (8) comes into contact with the stop (9) in the starting position in the locked state and in the release state laterally on the stop ( 9), in particular in the setting (10) in the actuating member (3), can be moved past, and that further preferably the second locking means (6) is designed as a stroke limitation for the actuating member (3), such that the movement path of the actuating member (3) in Locked state is limited to the first actuation position and is released in the release state for further movement in the second actuation position.

7. Electrical switch according to one of claims 1 to

6, characterized in that the stroke limitation comprises a cam element (11) which is movably arranged on the housing (2) and has at least one cam (12), in particular a cam ring which surrounds the tappet (4) centrally, and at least one on the actuating member (3) corresponding - 18 -

Stop (13) is such that the stop (13) comes into contact with the cams (12) in the first actuation position in the locked state and can be moved past the cam (12) laterally in the release state, the cam element (11) preferably being by means of an Actuating element (7) arranged pin (14), which engages in particular in a fork (15) attached to the cam element (11), can be moved between the locked state and the released state.

8. Electrical switch according to one of claims 1 to

7, characterized in that the actuating element (7) is designed as a slide (17), swivel lever, adjusting wheel (27) or the like with three latching positions, preferably a latching spring (28) with a shoulder (18) on the actuating element (7 ) for the determination of the locking positions, that preferably the first switching position for the actuating element (7) is formed by the central locking position and the second and third switching positions are each formed by one of the two lateral locking positions, and that the actuating element (7) is even more preferably a function symbol (29) which is visible in the respective switching position and characterizes this switching position is attached.

9. Electrical switch according to one of claims 1 to

8, characterized in that the actuating element (7) is movably mounted in a carrier part (16) which is connected to the housing (2).