DE10154208A1 - Drum lock for domestic device, especially washing machines and dryers, has locking piston for belt drive pulley mechanically coupled to force storage device loaded by external force source - Google Patents

Abstract

The device (9) has a locking device that engages a drive belt pulley (6) in the form of an axially movable locking piston that engages an aperture in the pulley. The locking piston is mechanically coupled to a force storage device loaded by an external force source. The force storage device can be a second spring-loaded piston.

Description

The invention relates to a drum lock for a household appliance after Preamble of claim 1.

Well-known top loading washing / drying machines for the Household appliance industries have some positioning and devices Lock the laundry drum. The drum lock is for relief laundry loading and unloading. With today's Locking units become a guided tappet (later also called pistons) through a release unit in a recess or groove of the drive Pulley inserted. This plunger locks the drum in a form-fitting manner when loading and unloading laundry or during transport.

However, the present invention is not limited to the locking of Drums limited, but generally refers to the lock all rotatably driven drums, especially in washing and Drying machines, but also in commercial machines  rotary drums that are loaded and unloaded from case to case have to.

In the known drum locks is in a known manner in a recess on the pulley non-rotatably connected to the drum a plunger (piston) is engaged when the drum is to be locked. This Tappet is arranged on a locking device and in the radial direction movable with respect to the rotary driven pulley.

In a known drum lock, the locking plunger consists of Plastic, which is also made of plastic in a housing is arranged displaceable. The mechanics are extremely sensitive, because the plastic plunger is only in the circumferential direction effective, high locking forces must absorb. So he's on break loaded. Furthermore, the longitudinal guides of this plunger in the housing Locking device made of plastic, which is the whole Locking device granted only a short life.

The displacement drive of the locking piston takes place in the Locking device built-in electric motor that acts on a gearbox which in turn acts on a spindle, which is connected to the locking piston in Is related.

By switching on the electric motor, the gearbox becomes accordingly driven and the spindle screwed into the locking piston, the so is moved in the direction of its longitudinal axis. This drive principle is susceptible to failure and has a short lifespan.

In the case of strong ones acting on the locking piston in the locked state Clamping forces are very difficult for such small motors, the fixed Locking piston again from its clamping position into the retracted  Bring to rest. Either the locking piston is damaged or the drive (spindle and gear) or the Electric motor itself.

Another locking device has become known, which is also associated with a locking piston and an associated auxiliary rotary drive for the Pulley works.

As soon as the reset button is pressed, for example in the case of a top loader Opening the swing lid will activate the auxiliary drive for the pulley set by a separate motor that can be coupled to the pulley Rotation is offset until the associated with the locking device Locking piston engages in the pulley and fixes it. disadvantage this known arrangement is the relatively long response time from pressing the Reset button until the pulley is locked. Furthermore it is a very complex and complex mechanical Construction because a separate auxiliary rotary drive for the pulley is required becomes.

The invention is therefore based on the object of a drum lock propose machines equipped with rotatably driven drums the locking of the drum in much easier, more reliable and done in a cost-effective manner.

To achieve the object, the invention is achieved by the technical solution of claim 1.

An essential feature of the invention is that at least one radially movable Locking piston is present, which is mechanical with an energy accumulator connected, which is charged by an external power source.  

With the given technical teaching there is the main advantage that now a much simpler drive is used for the locking piston can be because this according to the invention with a mechanical Energy store is coupled, which is necessary for locking and unlocking Provides strength. The displacement drive of the locking piston is therefore from an energy store charged by an external power source.

This energy accumulator is preferably implemented by one or more springs.

In the invention, the required locking and unlocking force by a Provided energy storage, which is loaded during the drive of the drum becomes. This charging is done by mechanical pretensioning or by permanent magnetic bias during the relative movement of the moving parts to the fixed parts.

Biasing of the energy store is also possible by appropriate Use of centripetal forces possible. With the energy storage systems this energy storage through the drive unit of the washing or Drying machines loaded indirectly. The advantage of such systems is that Unlocking low forces with correspondingly small actuators are required. Thus, they are inexpensive, small and responsive Drum locks can be carried out.

The present invention describes several preferred exemplary embodiments, all in combination with each other, but also in isolation should enjoy.

In a first embodiment of the invention, a so-called Alternating piston principle proposed. It is a simple and robust construction, which has short access times and only a small one Actuator is necessary because the energy of the lid movement for the charge of the Lift mechanism is used. The pretensioning takes place via the lid movement,  which directly or via a Bowden cable via a power transmission improving lever arm on a pre-centering piston.

So there are two alternately engaged with the pulley in the Locked state proposed pistons. Either is provisional locking position of the pre-centering piston or in the final Locking position of the fixing piston in locking engagement with the Pulley, which is non-rotatably connected to the drum to be locked.

The advantage of this measure is that the previous intervention of the Pre-centering piston in an associated recess in the pulley therefor it is ensured that the drum always remains in a fixed position when the cover is opened. So there is a "running away" of the drum with the lid open avoided by first placing a pre-centering piston in an associated Recess in the pulley is engaged.

As soon as at the end of the program or when the program is interrupted If the opening command for the swivel lid is given, the Pre-centering piston spring-loaded in the radial direction outwards in the direction of the pulley is pushed and gropes the inner circumference of the pulley from until it is under spring load in the assigned snap-in opening of the Pulley engages. After this pre-centering, the drum is already already provisionally in their correct rotational position towards the swivel cover locked. When opening the swivel cover, the opening movement of the Transfer the swivel cover to the pre-centering piston using a Bowden cable, which then mechanically controls a fixing piston in engagement with the Pulley brings and - as soon as this intervention is made - out of engagement brought with the drum.

So there is a positive guidance between two pistons, namely the Pre-centering piston and the fixing piston, being in the preliminary  Locking position only the pre-centering piston in engagement with the pulley stands. Located in a transitional area that adjoins this both pistons in locking engagement with the pulley and at final locking is then only the fixing piston in Locking engagement with the pulley.

These technical measures ensure that the relatively high Displacement forces when loading and unloading the drum only from that stable built, heavy-duty fixing piston can be included. It will be with the invention a separation of the functions "biasing" and "centering" one Locking piston separated. So it is a structure that this mechanically separates both functions, with the aim of opening of the swivel cover both a mechanical pretension and a To achieve locking of the fixing piston.

The said pre-centering piston is therefore only intended to temporarily fix the rotational position the drum. By transmitting the swiveling movement of the Swiveling cover on the fixing piston is then in its final Brought locking position and the precentering piston out of engagement with the Brought pulley and at the same time mechanically preloaded.

Generally it is noted that the type of described here Lift mechanism is to be understood in general. If only compression springs are described here are not to be understood as limiting. All known, mechanical, hydraulic and pneumatic energy accumulators, including the elastomeric energy store, claimed as essential to the invention.

According to the Bowden cable, which is the pivoting movement of the Transmits swivel cover, via a connecting lever directly with the Fixing piston coupled. This has the advantage of an absolutely safe, inevitable locking of the pulley.  

The advantage of the invention is that because of the rigid connection between the Fixing piston and the Bowden cable is now always at hand high clamping forces that act on the fixing piston, this securely out of engagement can be brought up with the pulley when the lock is released shall be.

It is a very inexpensive, mechanical structure because only mechanical connections via a corresponding connecting lever must be present between the pre-centering piston and the fixing piston. On the arrangement of expensive geared motors with the corresponding vulnerability to be dispensed with.

Superior response rates are also achieved because of the Movement of the swivel lid immediately locks the Pulley leads while in the prior art arrangements either an auxiliary rotary drive was used to keep the pulley still in to turn the locking position or a geared motor accordingly had to be driven to move the locking piston what was also associated with a relatively long response time.

Another advantage of using a Bowden cable to control the Locking device is that the Bowden cable can also be used for this can, the opening flaps on the drum also simultaneously with to open or close.

The Bowden cable is therefore used for a dual purpose, namely once Manufacture of locking and unlocking and secondly as additional opening and closing drive for the loading flaps in the Drum.  

Due to the mechanical preload of the pre-centering piston Bowden cable therefore also manages relatively small and inexpensive actuators to be used, which are necessary to trigger the pre-centering.

In a second embodiment of the present invention, a Similar locking principle shown, but with a single fixing piston is used.

However, the invention is not limited to this. This second Embodiment can also according to the alternating piston principle of the first Embodiment work.

It is important in the second embodiment that an energy store It is proposed that its potential energy (mechanical charge) from derives the kinetic energy of the rotating drum. Such a Energy storage can of course also with the alternating piston principle of first embodiment or with the others described below Working examples together.

The energy of the drive motor and, accordingly, the swing energy the pulley is used for the mechanical preload of this piston used.

The idea of the invention is now that the piston of the energy accumulator a relatively strong spring is biased and via a two-armed lever acting connecting lever acts on the locking piston by a relatively weaker spring is applied.

The locking piston is preloaded due to the large size Lever ratio of the connecting lever between the piston of the Lift mechanism and the locking piston.  

A cam is arranged on the rotating pulley, which during the rotation strikes the piston of the mechanical energy accumulator, this radially inward presses and thus biases the spring of this energy accumulator. After this Both pistons (locking piston and piston of the mechanical energy accumulator) in a tensioned idle state. For triggering the lock is now the locking piston by means of an actuator unlocked and is now radial due to the relatively large stored force moved outward.

In a development of this embodiment, it is provided that the Piston of the mechanical energy storage after charging except Contact with the circumferential inner circumference of the pulley - especially with the cam - is brought. This is a permanent magnetic repulsion provided. For this purpose, in one Recess of the piston of the mechanical energy storage Permanent magnet arranged, the opposite on the rotating Another pulley arranged in repulsion polarity Permanent magnet is assigned.

As soon as these two permanent magnets are in a first circulation facing each other, the repulsive force leads between the two Permanent magnets for a radially inward displacement of the Piston of the mechanical energy accumulator. This turns this piston into a Locked position brought and locked with an associated Locking lever. Thanks to this contactless repulsion between the permanent magnets, it is therefore out of contact brought with the rotating pulley.

In a third embodiment of the present invention it is provided that a locking piston is combined with a brake piston.  

This arrangement is also characterized by a simple, robust construction, a low noise level and relatively short access times. It only a small actuator is necessary, as pressure translation is used. The Pressure translation in this embodiment consists of a Bellow, which either hydraulically or pneumatically the appropriate Brake piston moves in the radial direction.

Instead of such a pneumatic or hydraulic movement drive can of course also other motion drives, such as. B. Solenoids or spindle drives can be used.

It is important in this exemplary embodiment that a prestressed Pre-centering piston ensures precise positioning of the drum. In a fourth embodiment, a radially outwardly movable Mass, which is pressed outwards by the centripetal force, on the Drive pulley applied. Due to the rotational speed, this becomes The mass is pushed outwards and at the corresponding speed, one elastic spring biased so far that it goes into storage position. to In this case, unlocking again uses a relatively small actuator.

The subject matter of the present invention does not only result from the subject of the individual claims, but also from the Combination of the individual claims.

All disclosed in the documentation, including the summary Information and features, especially those shown in the drawings spatial training, are claimed as essential to the invention, insofar as they individually or in combination are new compared to the prior art.  

In the following, the invention is explained on the basis of a number of design options illustrative drawings explained in more detail. Here go from the drawings and its description further features and advantages of the invention Invention.

Show it:

Fig. 1 schematically a side view of a household appliance with swing cover and rotatably driven drum,

Fig. 2 shows a first embodiment of a locking device in the unlocked and prestressed state,

Fig. 3, the locking device according to Fig. 2 in the pre-centered condition,

Fig. 4 shows the locking device according to Figs. 2 and 3 in the final locked state,

Fig. 5 shows a second embodiment of a locking device shortly after starting the program,

Fig. 6 shows the locking device according to Fig. 5 in the prestressed state,

Fig. 7 shows the locking device according to Figs. 5 and 6 in the final locked state,

Fig. 8 shows a third embodiment of a locking device in the unlocked state,

Fig. 9 shows the locking device according to Fig. 8 in the pre-centered condition,

Fig. 10 shows the locking device according to Figs. 8 and 9 in the final locked state,

Fig. 11 shows a fourth embodiment of a locking device with centrifugal bias.

In Fig. 1, a household appliance 1 is generally shown in side view. This can be a top loader of a washing machine, but it can also be a dryer or a machine that can be used for commercial or industrial purposes and has a corresponding, rotary-driven drum. It is important that the household appliance 1 has a housing 2 which defines an upper opening 3 . The opening 3 is closed by a swivel cover 4 which is mounted on the housing 2 about a specific, horizontal swivel axis.

A stationary tub 5 is arranged in the housing in a manner known per se, in which a drum (not shown in more detail) is rotatably mounted. The drum is rotatably connected to a pulley 6 , which is to work together with the locking devices described below.

The locking device 9 according to the first embodiment is arranged in the interior of the housing 2, however, outside of the tub 5 . It is preferably connected to the tub 5 . This is done, for example, by a holding plate 8 which is firmly connected to the tub 5 .

In the first exemplary embodiment according to FIGS. 2 to 4, an alternating piston device is described which serves as a locking device 9 . Two pistons 12 , 13 are provided, which are positively controlled and displaced radially outwards and inwards with a connecting lever 22 connecting them.

In the unlocked position shown in FIG. 2, the pulley 6 runs freely rotatable over the fixed holding plate 8 . The pre-centering piston 13 is in its tensioned and locked position. Here, it works against a fixedly mounted compression spring 25 and is locked in its inwardly displaced locking position by the fact that the cam 18 is in locking engagement with an associated cam 17 on the piston 13 on a locking lever 15 which is pivotally mounted on one side in a pivot axis 16 .

The free pivotable end of this locking lever 15 is seated on an actuating armature 27 of an actuator 23 .

In this biased position shown in FIG. 2, the free end acts on a Bowden cable 20 at the free, pivotable end of the connecting lever 22 at position 40. At the same time, a driver pin 26 is moved to the upper stop in the region of a longitudinal guide 14 of the piston 13 .

The connecting lever 22 is pivotally mounted in a pivot axis 24 fixed to the housing and the other free pivotable end of the connecting lever 22 engages the piston 12 via a pivot bolt 30 , which is used for locking with the pulley 6 . The pulley rotates in the arrow directions 19 .

At the end of the program, the locking process according to FIGS. 3 and 4 is triggered. First of all, the program acts on the actuator 23 so that it moves its actuating anchor 27 in the direction of the arrow 28 . Characterized the locking lever 15 is pivoted about its pivot axis 16 and the two cams 17 , 18 come out of engagement. The locking lever 15 actuates a microswitch 29 at the same time. This thus determines the unlocking of the pre-centering piston 13 . The pre-centering piston 13 is thus displaced radially outwards under the force of the spring 25 and scans the inner surface of the pulley 6 until it comes into engagement with an associated recess 11 on the pulley 6 . Pre-centering and pre-locking of the pulley 6 is thus ensured. This has the advantage that this pre-centering ensures that the opening flaps in the drum are now opposite the opening 3 in the housing 2 .

The arrangement of a driving pin 26 , which is firmly connected to the connecting lever 22 in a longitudinal guide 14 in the pre-centering piston 13 , ensures that it is in its position according to FIG. 3 in engagement with the recess 11 and the fixing piston 12 is not yet engaged with the associated recess 10 .

If the swivel cover 4 is now opened and thus the opening 3 in the housing 2 is exposed, this swivel movement is transmitted via the Bowden cable 20 at position 40 to the connecting lever 22 and this swings about its swivel bearing 24 into its swivel position according to FIG. 4.

Thus, the pre-centering piston 13 is simultaneously brought out of locking engagement with the recess 11 and ensures that the fixing piston 12 is already in locking engagement with the recess 10 . This is the function of the longitudinal guide 14 , which ensures that in this short transition state it is always ensured that either the piston 11 is in locking engagement with the recess 10 or the piston 13 is in locking engagement with the recess 11 .

The return spring 21 for the Bowden cable 20 is thus tensioned at the same time.

With the establishment of this locking engagement the final locking of the drum is achieved. The fixing piston 12 can now absorb high locking forces and transverse displacement forces of the drum without being subjected to breakage or shearing. It therefore consists of a high-quality plastic material and is moved radially in the direction of arrow 39 by pivoting the connecting lever 22 when the Bowden cable 20 is actuated.

Another type of mechanical energy accumulator is described in the locking device 31 according to FIGS. 5 to 7. It is expressly pointed out that the mechanical energy accumulator according to FIGS. 5 to 7 can also be exchanged for the energy accumulator according to FIGS. 2 to 4 and that, moreover, the locking device according to FIGS. 2 to 4 against the locking device according to FIGS can be interchanged Fig. 5 to 7.

The possibilities of interchanging between the locking devices and the energy stores also apply to all others described here Embodiments.

It is essential in the mechanical energy accumulator according to FIGS. 5 to 7 that it consists of a piston 33 which is spring-loaded in the radial direction in the holding plate 8 by the force of the compression spring 25 .

The operating position shown in Fig. 5 is the operating position between the pulley 6 and the holding plate 8 shortly after starting the program. The radially inward cam 36 on the pulley 6 has not yet passed the piston 33 . The piston 33 assigned to the mechanical energy store is in the untensioned position. Here, the compression spring 25 is relatively relaxed and the locking lever 15 is in the unlocked position.

A mechanical connecting lever 22 is also arranged between the piston 33 of the mechanical energy accumulator and a piston 32 , which is used for locking.

The pivot axis 24 shown there is arranged in a stationary manner on the holding plate 8 and not in the piston 33 .

The locking piston 32 is in its unlocked position and is locked here by a locking lever 15 a, which interacts with assigned cams 17 a, 18 a.

As soon as the cam 36 according to FIG. 6 overflows the piston 33 , the latter is displaced radially inward and thus prestresses the compression spring 25 as an energy store. At the same time, the locking lever 15 pivots into its locked position and holds the piston 33 in the position shown in FIG. 6. The spring necessary for pivoting the locking lever 15 is not shown for reasons of drawing.

The cams 17 , 18 which come into mutual engagement thus hold the piston 33 in the position shown in FIG. 6.

With this radially inward movement of the piston 33 , however, the connecting lever 22 was simultaneously pivoted about its fixed pivot axis 24 , as the transition from FIG. 5 to FIG. 6 shows. The driver pin 30 was thus moved in the longitudinal guide 14 of the piston 32 , as was the driver pin 26 in the longitudinal guide 14 a of the piston 33 .

The two pivot pins 30 , 26 are each in the radially outward stop position in the respective longitudinal guides 14 and 14 a.

The actuator 23 is now controlled by a corresponding program command and moves its actuating armature 27 in the direction of the arrow 28 ', as a result of which it acts on the free pivotable end of the locking lever 15 a, which thus disengages the interlocking cams 17 a, 18 a. Thus, the locking piston 32 is brought into locking engagement with the recess 10 by the force of the compression spring 25 a. The pulley 6 is now finally locked.

The actuator 23 can work in both arrow directions, namely in the arrow directions 28 and 28 '.

The operation of the actuator 23 in the direction of arrow 28 is also effected by a program instruction and thus unlocks the piston 33 located beforehand in a radially inwardly displaced locking position according to FIG. 5 and the compression spring 25 the piston displaces 33 in the in Fig. Shift position shown 5.

Overall, it can be determined in this embodiment that a relatively large dimensioned energy store (compression spring 25 ) can be pretensioned on the piston 33 by the inwardly directed cam 36 due to the kinematic force of the drum rotation.

The connecting lever 22 and the large transmission ratio of the lever arms (short lever arm between the driving pin 26 and the pivot axis 24 , and long lever arm between the pivot axis 24 and the driving pin 30 ) achieve a relatively large displacement path for the piston 32 over the large pivoting path of the connecting lever 22 , Also, the balance of power is optimally interpret because the displacement force of the relatively large-scale energy storage mechanism of the compression spring is a with transferred 25 to the relatively small force store the compression spring 25th

In the following, it is described as a further exemplary embodiment that it is advantageous if the piston 33 is not in contact engagement on the inner circumference of the pulley 6 . For this purpose, a permanent magnetic force bias and a resulting displacement force on the locking piston 33 are described.

According to the invention, a permanent magnet 35 is connected to the cam 36 and rotates with the pulley 6 .

On the other hand, a recess is arranged in the piston 33 , in which a permanent magnet 34 is arranged.

The two permanent magnets 34 , 35 which can be brought into comparison are designed for repulsive force. That means the poles of the same name face each other.

In order to avoid the contact (touch contact) of the outer circumference of the piston 33 on the inner circumference of the pulley 6 , it is provided in FIG. 6 that the two permanent magnets 34 , 35 briefly face each other when the pulley 6 runs past, and thereby a repulsive impulse on the piston 33 is generated due to the opposing permanent magnets 34 , 35 , which moves the piston 33 in the direction of arrow 37 and ensures that the cams 17 , 18 assigned to one another snap into place. It is only through this additional force that the piston 33 is locked with the locking lever 15 and secured against radial outward displacement. It is therefore always ensured that a certain radial play 38 remains between the inner circumference of the radially inward standing cam and the outer circumference of the piston 33 . A frictional intervention is avoided.

In the exemplary embodiment according to FIGS. 8 to 10, a further locking device is described, which also works according to the two-piston principle.

In the case of this locking device, a radially displaceable friction piston 43 is arranged in the region of a recess of the support plate 8 and receives a piston 42 which serves for pre-centering in an associated, radially outwardly directed recess. This piston 42 is spring-loaded by a compression spring 45 .

The friction piston 43 is carried by a stationary prestressing bellows 46 , which is supported on a stationary support surface and which, with appropriate expansion, displaces the friction piston 43 in a radially outward direction and, if appropriate, moves it radially inward again.

The preload bellows 46 can be filled with a liquid or with a pressure medium. In the exemplary embodiment shown, it is filled with a hydraulic fluid. For this purpose, there is a pump 48 which draws in the pressure fluid and which compresses the pressure fluid in the direction of the arrow 50 via a line 49 . This is pressed into a line 52 , corresponding to the position of an overflow valve 51 , and the prestressing bellows 46 is thus expanded. In this operating position, the overflow valve 51 is closed.

In the position shown in FIG. 8, the prestressing bellows 46 is depressurized and the entire device is unlocked. The piston 42 is not in contact with the pulley 6 .

The pump 48 is acted upon by a corresponding program command in the position according to FIG. 9 and directs the pressure fluid via lines 49 , 52 into the prestressing bellows 46 , which is thus expanded. First of all, the friction piston 43 is displaced radially outward without it coming into contact with the pulley 6 . Instead, the free, radially outward end of the piston 42 comes into the region of a recess 11 on the pulley 6 and thus temporarily fixes it. This pulley 6 is thus pre-positioned.

With further expansion of the preload bellows 46 , the friction surface of the friction piston 43 then frictionally engages the inner circumference of the pulley 6 and fixes it with high holding force. The shift therefore takes place in the direction of arrow 47 .

The operation of the prestressing bellows described here with a hydraulic fluid is particularly favorable in the case of water-supplied household machines. It is very easy to additionally install a small oscillating piston pump as pump 48 and the water required for operation is available from the household network anyway.

Instead of the prestressing bellows 46 shown here, other displacement drives can also be used for such a friction piston 43 . Such displacement drives can, for example, also be a heat drive, ie a wax filling in the prestressing bellows 46 , the expansion of which is generated by a corresponding heat source. Likewise, others, e.g. B. electromechanical or electromagnetic, drives for the friction piston 43 are used.

The expansion of the Vorspannbalges 46 is otherwise carried out as long as the associated cam 53 actuated until, according to Fig. 8 for further radial outward displacement of the Reibkolbens 43 on the piston 42 a microswitch 29, which allow the pump 48 is still, and also the rotary drive for the pulley 6.

For graphic reasons, the microswitch 29 is shown in a cutout 44 in the friction piston 43 . This is intended to make it clear that the microswitch is arranged in a stationary manner and outside the friction piston 43 at another location on the holding plate 8 .

Otherwise, this embodiment is characterized by relatively good and large-sized holding forces. With an inexpensive oscillating piston pump (pump 48 ) it is possible to generate relatively high pressures in the preload bellows 46 in a small space, which in turn transmits a large holding force to the pulley 6 via the radially outward displacement of the friction piston 43 .

In the exemplary embodiment according to FIG. 11, the centrifugal force of a mass 55 is used for the energy store.

Here, the entire locking device 59 is rotatably arranged in the pulley 6 .

In a radially outwardly directed guide receptacle 56 of the pulley 6 , the mass 55 is arranged to be displaceable in both directions. In the tensioned position shown in FIG. 8, the mass 55 is displaced outwards in the guide receptacle 56 by the centrifugal force when the pulley 6 rotates and compresses the compression spring 41 . At the same time, the mass 55 locks in this clamping position with the locking lever 15 by engagement of the mutually assigned cams 17 , 18 .

The shorter free end of the connecting lever 22 engages the mass 55 via a pivot pin 60 . The connecting lever 22 can in turn be pivoted in the direction of the arrow 39 and the longer end of the connecting lever 22 engages, for example, the piston 12 according to the exemplary embodiment according to FIGS. 2 to 4 and the piston 32 according to the exemplary embodiment from FIGS. 5 to 8. A large displacement path and a relatively large force on the locking pistons 12 , 32 are thus achieved over a relatively small pivoting path of the mass 55 .

The radially outward displacement of the mass 55 is limited in the guide receptacle 56 by a radially outward stop 57 .

The spring preload F1 generated by the relatively large dimensioned compression spring 41 is the actual energy store which applies the force for the displacement of the piston 12 , 32 .

A relatively small-sized actuator 23 also only has to apply a correspondingly small-sized pushing force F2 in order to unlock the mass 55 and to release the energy accumulator of the compression spring 41 .

Drawing Legend

1

household appliance

2

casing

3

opening

4

hinged cover

5

vat

6

Pulley (drum)

7

Interior (vat

5

)

8th

Retaining plate

9

locking device

10

recess

11

recess

12

Piston

13

Pre-centering piston

14

longitudinal guide

14

a

15

locking lever

15

a

16

swivel axis

17

Cam

18

Cam (

15

)

19

arrow

20

Bowden

21

Return spring

22

connecting lever

23

actuator

24

swivel axis

25

compression spring

25

a

27

operation lever

28

arrow

28

'

29

microswitch

30

pivot pin

31

locking device

32

Piston (locking)

33

Piston (mechanical energy storage)

34

permanent magnet

35

"

36

cam

37

arrow

38

game

39

arrow

40

position

41

compression spring

42

Piston (pre-centering)

42

Reibkolben

44

outbreak

45

compression spring

46

bias bladder

47

arrow

48

pump

49

management

50

arrow

51

overflow

52

management

53

cam

54

distance

55

Dimensions

56

guide seat

57

attack

58

locking device

59

"

60

pivot pin

Claims (12)

1. drum lock for household appliances, in particular washing machines and dryers, with a rotary drum arranged in a fixed tub ( 5 ), which is connected in a rotationally fixed manner to a pulley ( 6 ) on which a locking device ( 9 , 31 , 58 , 59 ) engages, which consists of at least one axially displaceable locking piston ( 12 ) which engages in a recess in the pulley ( 6 ), characterized in that the locking piston ( 12 ) is mechanically connected to an energy accumulator which is charged by an external power source. 2. Drum lock according to claim 1, characterized in that the energy accumulator consists of a spring-loaded displaceable second piston ( 13 ) which is connected to the first piston ( 12 ) via a lever transmission (connecting lever 22 ) ( Fig. 2-4). 3. Drum lock according to claim 2, characterized in that the two pistons ( 12 , 13 ) are mutually in engagement with associated recesses ( 10 , 11 ) of the pulley ( 6 ). 4. Drum lock according to one of claims 1 to 3, characterized in that the charging of the mechanical energy accumulator is derived from the pivoting movement of the pivoting cover ( 4 ) of the machine ( Fig. 2-4). 5. Drum lock according to one of claims 1 to 3, characterized in that the mechanical energy accumulator is charged by the kinetic energy of the rotating drum ( Fig. 5-7). 6. Drum lock according to claim 5, characterized in that the piston ( 33 ) of the energy accumulator is biased via a spring ( 25 ) and acts via a connecting lever ( 22 ) acting as a two-armed lever on the locking piston ( 12 ), which is operated by a spring ( 25 a) is applied. 7. Drum lock according to claim 5 or 6, characterized in that on the pulley ( 6 ) a cam ( 36 ) is arranged, which moves the one piston ( 13 ) directed radially inwards. 8. drum lock according to claim 7, characterized in that the acted upon by the cam (36) piston (13) is brought by a permanently magnetically acting force out of contact engagement with the cam (36). 9. Drum lock according to one of claims 1 to 8, characterized in that the mechanical energy accumulator is charged by an expansible preload bellows ( 46 ) ( Fig. 8-10). 10. Drum lock according to claim 9, characterized in that the prestressing bellows ( 46 ) acts on a radially displaceable friction piston ( 43 ) which accommodates a piston ( 42 ) serving for pre-centering in an associated, radially outward-directed recess, which piston ( 42 ) 45 ) is biased. 11. Drum lock according to one of claims 1 to 10, characterized in that the charging of the mechanical energy store, the centrifugal force of a movable mass ( 55 ) is used ( Fig. 11). 12. Drum lock according to claim 11, characterized in that in a radially outwardly directed guide receptacle ( 56 ) of the pulley ( 6 ), the mass ( 55 ) is arranged displaceably in both directions and acts at least in one direction against a spring ( 41 ).