Patent Publication Number: US-2022235579-A1

Title: Locking device

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application is based upon and claims the benefit to EP 21 152 964.9 filed on Jan. 22, 2021, the entire contents of each of which are incorporated herein by reference. 
     BACKGROUND 
     Field 
     The present disclosure relates to a locking device and more particularly to a locking device for electrical appliances, such as washing machines, having a linearly movable locking pin and a linearly movable tappet for the locking pin, wherein the tappet is connected to the locking pin by a clamping device. 
     The present disclosure further relates to an electrical appliance, such as a washing machine, as well as a use of a locking device. 
     Prior Art 
     Locking devices are known in the prior art, wherein locking devices are used where machine parts or system parts, for example doors or flaps, are locked in a specific position. 
     For example, locking devices are also used in washing machines. 
     A prelocking mechanism for a locking system actuated by motor and a locking system are disclosed in DE 10 2012 204 490 B4. 
     DE 603 16 237 T2 also discloses a device for locking the door of a washing machine. 
     Moreover, a lock for the door of a device having a rotary drum is disclosed in EP 1 826 309 B1. Moreover, EP 0 439 849 B1 discloses a door locking device with rapid locking and delayed unlocking, such as for a washing machine. 
     A generic locking device with a linearly movable locking pin and a linearly movable tappet for the locking pin is disclosed in DE 10 2017 128 301 B1, wherein the tappet is connected to the locking pin by a clamping device. In this case, the clamping device has two springs arranged in series one behind the other. 
     SUMMARY 
     An object is to provide an alternative locking device, for example for washing machines, wherein the locking device is compact and permits a reliable locking, for example for a door or flap. 
     Such object can be achieved by a locking device, for use in devices such as electrical appliances, such as washing machines, where the locking device having a linearly movable locking pin and a linearly movable tappet for the locking pin, wherein the tappet is connected to the locking pin by a clamping device, wherein the clamping device has two coaxially arranged springs, a first inner spring of the clamping device is at least partially surrounded by a second outer spring of the clamping device. 
     In the disclosed embodiments, the locking device has a clamping device having two springs which are arranged inside one another and coaxially to one another, whereby a compact arrangement of the inner (first) spring and the outer (second) spring is produced. Thus, a compact locking device is permitted. As the locking device requires little installation space, it is advantageously possible to install the locking device in multiple and optionally different appliances, such as washing machines. It is also possible to equip or, respectively, retrofit different appliances or machines with locking devices for doors or the like, by the compact locking device. 
     By the use of the clamping device, a linearly movable tappet and a linearly movable locking pin can be used and can be mechanically coupled together. The direction of movement of the pin-shaped or cylindrical tappet and the direction of movement of the locking pin can be collinear, such that the locking pin is linearly moved or movable, for example, by a linear movement of the tappet. 
     Moreover, the clamping device can be pretensioned between the tappet and the locking pin. The tappet can be configured to be pin-shaped or, respectively, cylindrical and with a circular cross section. 
     In the locked state of the locking device, the locking pin engages in a locking body to be locked, such as of a door lock. 
     One end of the tappet can be arranged, with the clamping device having the coaxially arranged springs, in a receiving chamber of the locking pin. As a result, one end of the tappet and the clamping device are positioned in the locking pin. 
     The first inner spring of the clamping device and the second outer spring of the clamping device can be mechanically decoupled from one another. 
     The first inner spring and the second outer spring can be arranged concentrically to the tappet and/or to the axis of motion of the tappet, wherein the first inner spring and the second outer spring can surround the tappet. 
     A sleeve-like coupling body can be arranged between the first inner spring and the second outer spring. 
     The first inner spring can be arranged between the tappet and the coupling body and/or the second outer spring can be arranged between the coupling body and the locking pin surrounding the tappet. A spatial separation of the first inner spring and the second outer spring can be permitted by the coupling body. 
     A stop can be provided in each case for the first inner spring on the tappet and on the coupling body and/or a stop can be provided in each case for the second outer spring on the coupling body and on the locking pin. 
     The first inner spring of the clamping device and/or the second outer spring of the clamping device can be configured in each case as a compression spring, such as a helical compression spring or a clamping spring. 
     The first inner spring, which can be configured as a compression spring, of the clamping device and/or the second outer spring, which can be configured as a second compression spring, of the clamping device, can be arranged on the tappet such that the spring or the springs are passed through by the tappet. 
     One end of the tappet for the locking pin can be at least partially received in a cavity of the locking pin. 
     Moreover, in one embodiment of the locking device, a drive, such as a lifting drive, can be provided for a linear movement of the tappet, wherein the drive, such as the lifting drive, can be configured as a bistable lifting magnet, such as a reversible lifting magnet. 
     The tappet can be (linearly) guided in the locking pin. The tappet and the locking pin can be (linearly) movable relative to one another. 
     Moreover, a locking body, such as a rotatable locking body can be provided, wherein the locking pin engages in the locking body in a locked position of the locking pin. The locking body can have a recess in which the locking pin engages in the locked position of the locking body. As a result, the locking body can be impeded or, respectively, fixed in terms of its movement. In the open state, the locking pin does not engage in the locking body or, respectively, in the recess of the locking body, whereby the locking body is released. 
     Moreover, such object can be achieved by an electrical appliance, such as a washing machine, having a closable door and having an above-described locking device for the door. In order to avoid repetition, reference is expressly made to the above embodiments. 
     Moreover, such object can be achieved by a use of a locking device as described above, in an electrical appliance, such as a washing machine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further features of the embodiments will become apparent from the description of embodiments, together with the claims and the accompanying drawings. Embodiments may fulfil individual features or a combination of a plurality of features. 
       The embodiments are described hereinafter without limiting the general inventive idea by exemplary embodiments with reference to the drawings, wherein relative to all of the details, which are not described in more detail in the text, reference is expressly made to the drawings. In the drawings: 
         FIG. 1  illustrates schematically a perspective view of a locking device; and 
         FIG. 2  illustrates schematically a cross-sectional view of a locking device in the open state. 
     
    
    
     In the drawings, in each case the same or similar elements and/or parts are provided with the same reference numbers, so that in each case a repeated introduction is omitted. 
     DETAILED DESCRIPTION 
     A perspective view of a locking device  10  is shown schematically in  FIG. 1 .  FIG. 2  shows schematically a cross section through the locking device  10  which is used, for example, for washing machines, such as for industrial washing machines. 
     The locking device can also be used for closing doors, flaps or the like in further electrical appliances. 
     The locking device  10  is arranged, for example, in a housing (not shown here). The locking device  10  has a bistable lifting magnet  12  which is used as a drive or, respectively, lifting drive for a linearly movable tappet  16 . An armature  14  is arranged on the tappet  16  in the interior of the lifting magnet  12 . The tappet  16  passes through the bistable lifting magnet  12 , wherein when the respective end-side coils of the bistable lifting magnet  12  are energized, the tappet  16  is moved with reciprocal motion between the end positions by the armatures  14  which are movable in the lifting magnet  12 . In the position of the tappet  16  or, respectively, the armature  14  shown in  FIG. 2 , this tappet or, respectively, armature is arranged in the upper end position thereof. The lifting magnet  12  can be configured as a reversible lifting magnet. 
     Outside the bistable lifting magnet  12  one end of the tappet  16  is arranged in the interior of a locking pin  18 , wherein the tappet  16  is partially received in the locking pin  18 . The tappet  16  is provided in this case for actuating the locking pin  18 . 
     The locking pin  18  is configured at the end opposite the bistable lifting magnet  12  with a front-side locking stud  20  which engages in a locking groove  22  of a rotatable rotary segment  24  for locking a door hook  26  (see  FIG. 1 ). In this case, the door hook  26  of a door (not shown here) is rotatably mounted and is introduced into a door hook receiver  28  of the rotary segment  24 . 
     In  FIG. 1  the rotary segment  24  is arranged in an unlocked position. In  FIG. 2  the rotary segment  24  is arranged in a locked position. 
     In the interior of the locking pin  18 , the end of the tappet  16  received therein is surrounded by a first compression spring  30  and a second compression spring  32 , wherein the first compression spring  30  and the second compression spring  32  are coaxially arranged and the first inner compression spring  30  is surrounded by the second outer compression spring  32 . 
     A sleeve-like coupling body  34  is arranged between the first compression spring  30  and the second compression spring  32 , whereby the first compression spring  30  and the second compression spring  32  are separated from one another. The coupling body  34  is arranged between the compression springs  30  and  32 , wherein the springs  30 ,  32  in contact with the coupling body  34 , and the coupling body  34 , are arranged to be linearly movable relative to the locking pin  18 . 
     For the inner compression spring  30 , an upper end-side locking ring  36  which faces the lifting magnet  12  is configured on the tappet  16  as a stop for the inner spring  30 , such that the inner compression spring  30  pushes the coupling body  34  against a second locking ring  38 , which is opposite the lifting magnet  12 , on the tappet  16 . In this case, the locking ring  38  serves as a stop for the coupling body  34 . The locking pin  18  is pushed upwardly or, respectively, in the direction of the bistable lifting magnet  12  by the second compression spring  32  which is arranged between the coupling body  34  and the locking pin  18 . The first compression spring  30  and the second compression spring  32  are pretensioned in each case. 
     The first compression spring  30  and the second compression spring  32  are coaxially arranged relative to the longitudinal axis of the tappet  16  or, respectively, the axis of motion of the tappet  16 , wherein the compression springs  30 ,  32  are arranged inside one another. The first compression spring  30  and the second compression spring  32  form a clamping device between the linearly movable tappet  16  and the linearly movable locking pin  18 , so that due to the pretensioning of the compression springs  30 ,  32  the tappet  16  is connected or, respectively, coupled to the locking pin  18 . 
     In normal operation, the rotatable door hook  26  is introduced into the door hook receiver  28  of the rotary segment  24  (see  FIG. 1 ), wherein the rotary segment  24  is subsequently rotated clockwise into a locked position until the locking groove  22  of the rotary segment  24  is arranged below the locking stud  20  of the locking pin  18  (see  FIG. 2 ). The armature  14  is subsequently moved together with the tappet  16  out of an end position (upper position in  FIG. 2 ) into the second end position (lower position), whereby the locking stud  20  is moved in the direction of the locking groove  22  and engages therein. As a result, the rotary segment  24  is blocked together with the door hook  26 . 
     In the event that the rotary segment  24  is not positioned in the locked position for the locking process, as shown in  FIG. 1 , the locking pin  18  may be brought into a waiting position for the locking process, by the lifting magnet  12  being energized, whereby the tappet  16  is moved (downwardly), such that the first compression spring  30  is pretensioned further or, respectively, pretensioned even further. In this position, the locking pin  18  pushes against the rotary segment  24 . In order to lock the rotary segment  24 , said rotary segment is rotated clockwise such that due to the pretensioned first (inner) compression spring  32  the locking stud  20  of the locking pin  18  is brought into the locking groove  22  of the rotary segment  24 . 
     When unlocking or, respectively, locking the rotary segment  24 , when opening or, respectively, closing the locking device  10 , the tappet  16  and the locking pin  18  are moved in the direction or, respectively, counter to the direction of the lifting magnet when the bistable lifting magnet  12  is energized, whereby the locking pin  18  is correspondingly moved due to the compression springs  30 ,  32  simultaneously engaging on the tappet  16 . 
     In a locked position, in which the locking stud  20  of the locking pin  18  engages in the locking groove  22  of the rotary segment  24 , and in the event that the rotary segment  24  is rotated by an external manual force against the engaging locking stud  20  such that a free linear movement of the locking pin  18  is impeded, it is possible for the tappet  16  to be moved in the direction of the lifting magnet  12  by the lifting magnet  14  being energized, whereby the second outer compression spring  32  is pretensioned (even further), wherein the locking pin  18  is held or is to be held in the locked position. If the locking of the locking pin  18  is subsequently released, the blocked locking pin  18  is linearly moved into the unlocked position by the pretensioned compression spring  32 . 
     While there has been shown and described what is considered to be preferred embodiments, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims. 
     LIST OF REFERENCE NUMERALS 
     
         
           10  Locking device 
           12  Lifting magnet 
           14  Armature 
           16  Tappet 
           18  Locking pin 
           20  Locking stud 
           22  Locking groove 
           24  Rotary segment 
           26  Door hook 
           28  Door hook receiver 
           30  Spring 
           32  Spring 
           34  Coupling body 
           36  Locking ring 
           38  Locking ring