Drawer guide and household appliance

Abstract

Drawer guide (1), in particular for a household appliance or a piece of furniture, with a guide rail (2) and a running rail (4) movably mounted on the guide rail (2), wherein a damping device (6, 6') with a one-sided acting damper is provided on the guide rail (2), the damper having a damper housing (9) and a piston rod (10) that can be inserted into and removed from the damper housing (9), wherein, during a closing movement of the running rail (4), a first activator (5, 5') acts on the damping device (6, 6') shortly before reaching a closed position in order to decelerate the movement of the running rail (4), wherein, during an opening movement of the running rail (4), a second activator (8) acts on the damping device (6, 6') shortly before reaching the maximum opening position in order to decelerate the movement of the running rail (4), characterized in that the second activator (8) is arranged on a central rail (3),which is provided between the guide rail (2) and the running rail (4).

Description

The present invention relates to a drawer slide, in particular for a dishwasher, another household appliance or a piece of furniture, with a stationary guide rail and a running rail mounted movably on the guide rail, wherein a damping device with a single-acting linear damper is provided on the guide rail, the damper having a damper housing and a piston rod that can be inserted into and removed from the damper housing, wherein, during a closing movement of the running rail, shortly before reaching a closed position, a first activator acts on the damping device to decelerate the movement of the running rail, wherein, during an opening movement of the running rail, shortly before reaching the maximum opening position, a second activator acts on the damping device to decelerate the movement of the running rail, and a dishwasher or another household appliance with a rail-guided sliding element. EP 2 422 682 B1 discloses a dishwasher with a damping device for damping the movement of a dish basket, wherein the damping device comprises a cylindrical housing and a piston that divides the housing. The piston can be moved in a first direction when the dish basket is pulled out over a first plate and in the opposite direction when the dish basket is pushed in over a second plate, in order to provide damping forces. The damper housing is open on opposite sides, which makes sealing the damper housing problematic, especially when larger damping forces are to be provided by pressure differences. Furthermore, the damper is only effective when the dish basket has been moved to its maximum opening position to displace the piston rod relative to the housing. Furthermore, DE 10 2013 114 309 A1 discloses a retraction and damping unit that can be mounted on a center rail of a drawer slide. For damping in the maximum opening position as well as in the closing position, a first activator is provided on the running rail and a second activator on the stationary guide rail. Due to the movement of the retraction and damping unit together with the center rail, a comparatively large installation space is required. Furthermore, DE 10 2013 222 576 A1 discloses a drawer guide for a household appliance, in which a retraction mechanism is provided by which a dishware holder can be moved into a closed position. The retraction mechanism has a spring element and a damping element to decelerate the dishware holder and hold it in the closed position. Damping in the opening direction is not provided, so that an opening movement of the dishware holder results in an abrupt stop accompanied by a banging noise against the dishes. DE 10 2013 101 358 A1 discloses a drawer guide for a movable furniture component, comprising a cabinet rail, a center rail, and a running rail. An end-position damping unit is arranged on the center rail, which can be actuated either by a first activator on the cabinet rail or by a second activator on the running rail. It is therefore an object of the present invention to create a drawer guide, in particular for a dishwasher, which is compact in design and ensures that the guide rail is decelerated before reaching an end position in both the closing and opening directions. This problem is solved by an extract guide with the features of claim 1. The drawer slide according to the invention features a single-acting linear damper that is fixed to the guide rail, i.e., stationary. A first activator activates the damping device shortly before the guide rail reaches a closed position during a closing movement, while a second activator acts on the damping device shortly before the guide rail reaches its maximum opening position during an opening movement to decelerate the movement of the guide rail. This allows the damping device with the single-acting linear damper to be effective in both the opening and closing directions. Preferably, a deflection mechanism is provided to convert the movement of the second activator in the opening direction into a movement of a stop acting on the linear damper in the closing direction. The terms "opening direction" and "closing direction" refer to the movement of the drawer slide's guide rail, which is moved from its respective end positions in the opening or closing direction. Since the linear damper acts in one direction only, the deflection mechanism can cause the second activator to move in the opposite direction. For this purpose, a rotatably mounted deflection lever is preferably provided. The rotatably mounted deflection lever can have a first arm that can engage with the second activator and a second arm located on the opposite side of the axis of rotation, which acts directly or indirectly on the linear damper via a stop.To return the deflection lever to its starting position after the linear damper has been actuated, it can be coupled to the stop. For example, the deflection lever's second arm can engage with a receptacle of a linearly guided stop that acts on the linear damper, so that when the stop moves, the deflection lever pivots in one direction or the opposite direction. In another embodiment, the linear damper is designed as a pressure damper, in which damping forces are generated only when the piston rod is inserted into the damper housing. Alternatively, the linear damper can also be designed as a tension damper, in which damping forces are generated only when the piston rod is withdrawn from the damper housing. With a unidirectional linear damper, a damping force is provided in one direction of movement of the piston rod, while in the opposite direction, the piston rod can move freely relative to the damper housing. If the linear damper is designed as a pressure damper, the damper housing can be cup-shaped, i.e., closed on the side opposite the piston rod, so that no sealing problems arise, especially when high pressures are present in the area of ​​the cup-shaped housing when the piston rod is inserted.Then only the area around the piston needs to be sealed, which is easier due to the protected arrangement of the piston inside the damper housing. The damping device preferably includes a spring to pull or push the piston rod out of the damper housing when unloaded. The spring can be located either inside or outside the damper housing to move the linear damper to its starting position when unloaded. The linear damper can be designed, for example, as a fluid, air or gas damper, in which the respective medium flows through narrowed overflow channels when the piston rod moves in the damping direction, thereby exerting a damping or braking effect, and in which the overflow channels are widened when the piston rod moves against the damping direction, thus eliminating or reducing the damping or braking effect. In a further embodiment, the first activator is fixed to the guide rail. This activator then provides damping in the closing direction. According to the invention, a second activator is arranged on a central rail that is provided between the guide rail and the running rail of the drawer slide. The second activator then becomes effective in the opening direction shortly before the guide rail reaches its maximum opening position. The damping device is preferably fixed to the guide rail via a housing, for example a plastic housing to which the damper housing is snapped. Conversely, the piston rod can also be fixed to the guide rail via the housing, so that the first or second activator acts on the damper housing and causes its movement relative to the guide rail. In a further embodiment, a self-closing mechanism is provided, by means of which the guide rail can be moved in the closing direction shortly before reaching the closed position. The self-closing mechanism can have a driver movable along a housing, which is biased in the closing direction by a force storage device. The self-closing mechanism is preferably only effective in the range of motion shortly before the closed position, but not before reaching the maximum opening position. To ensure that the self-closing mechanism is only effective in the closing position, the driver of the self-closing mechanism can act on a movable stop, by means of which the linear damper can be actuated. This stop can also be actuated in the opening direction by the second activator, while the driver of the self-closing mechanism remains inactive when the guide rail moves in the opening direction. The drawer slide according to the invention is preferably used in a household appliance, particularly preferably in a dishwasher. In particular, two drawer slides are fixed to opposite sides of an interior space. Slide elements, which in dishwashers can be designed as dish racks, can then be mounted so that they can move along the drawer slide. Use in furniture or other household appliances with rail-guided cooking trays or containers is also possible. It is also possible to attach the drawer slides not directly to the side walls of a dishwasher or furniture carcass, but to position-adjustable lever mechanisms, which in turn are hinged to the side walls. Such a lever mechanism is shown, for example, in DE202009004771 U1. In this way, the functionality of this invention can also be transferred to dish racks or movable furniture parts that can change not only their horizontal position but also their vertical position relative to the dishwasher housing or furniture carcass. The invention is explained in more detail below with reference to two exemplary embodiments and the accompanying drawings. The drawings show: Fig. 1 a perspective view of a drawer slide with a damping device in a closed position; Fig. 2 a view of the drawer slide of Fig. 1 without a cover; Fig. 3 a view of the drawer slide of Fig. 1 in a slightly open position; Fig. 4 a view of the drawer slide of Fig. 1 shortly before reaching the maximum opening position; Fig. 5 a view of the drawer slide of Fig. 1 in the maximum opening position; Figs. 6A to 6C several views of the damping device of the drawer slide of Fig. 1; Figs. 7A and 7B two views of a drawer slide with a modified damping device in a closed position; Figs. 8A and 8B two views of the drawer slide of Fig. 7 in a slightly open position. Fig. 9A and Fig. 9B show two views of the extension guide of Fig.7 shortly before reaching the maximum opening position; Figs. 10 and 10B two views of the drawer slide of Fig. 7 in the maximum opening position; Figs. 11A to 11C several views of the damping device of the drawer slide of Fig. 7; Figs. 12A to 12C several views of the damping device of Fig. 11 in different positions; Figs. 13A and 13B two views of a drawer slide mounted on a dishwasher in an open position, and Figs. 14A and 14B two views of the drawer slide of Fig. 13 in the closed position. An extension guide 1 comprises a stationary guide rail 2 on which a central rail 3 is movably mounted via rolling elements. A running rail 4 is movably mounted on the central rail 3 via further rolling elements. A web-shaped activator 5 is fixed to one end face of the running rail 4 and can be brought into engagement with a damping device 6, which is arranged behind a cover 7 in Fig. 1. In Fig. 2, the cover 7 has been omitted, and it can be seen that the damping device 6 has a housing 12 which is fixed to the stationary guide rail 2. A damper housing 9 of a linear damper, designed as a fluid damper, in particular as a liquid damper, is fixed to the housing 12. A cylindrical interior is formed in the damper housing 9 in which a piston is slidably mounted and coupled to a piston rod 10. The damping device 6 can thus decelerate the movement of the guide rail 4 both shortly before reaching the maximum opening position and shortly before reaching the closed position. In Fig. 3, the guide rail 4 was moved slightly in the opening direction, and it can be seen that the web-shaped activator 5 is now arranged spaced apart from a plunger 16 of the damping device 6. The guide rail 4 can be moved, as shown in Fig. 4, until just before reaching its maximum opening position, before the damping device 6 becomes effective. A second activator 8, fixed to the center rail 3, can engage with a deflection lever 20 shortly before reaching the maximum opening position. This lever acts on the damping device 6 to provide damping forces for decelerating the movement of the guide rail 4 in the opening direction. Advantageously, the second activator 8 is designed as a section of the center rail 3 that projects from the plane of the center rail 3. In Fig. 5, the guide rail 4 has reached its maximum opening position, and the deflection lever 20 has been pivoted counterclockwise about an axis of rotation. Figures 6A to 6C show the damping device 6 in detail. Two web-shaped holders with a receptacle 18 are formed on the housing 12 to receive an axis 22 of the deflection lever 20. The deflection lever 20 comprises a first arm 21, which can be engaged with the second activator 8 on the central rail 3. Furthermore, the deflection lever 20 comprises a second arm 23 on the opposite side of the axis 22, which acts on the linear damper. For this purpose, the second arm 23 engages in a recess 17 on the plunger 16, which is guided linearly on the housing 12. The plunger 16 has a connecting section 15, which is connected to a connecting element 11 on the piston rod 10. The plunger 16 can thus be moved together with the piston rod 10. The damper housing 9 is fixed to a sleeve-shaped projection 13 of the housing 12, in particular by locking it in place. To move the linear damper into a starting position in which the piston rod 10 protrudes from the damper housing 9, a spring 14 is provided which is supported on one side against the housing 12 and on the opposite side against a stop 19 of the plunger 16. To dampen the movement of the guide rail 4 in the closing direction, the first activator 5 presses against the plunger 16, which acts via the connecting section 15 on the piston rod 10 and pushes it into the damper housing 9. This slows down the movement of the guide rail 4 in the closing direction to prevent loud impact noises. When the guide rail 4 is moved in the opening direction, the intermediate rail 3 also moves at approximately half the speed relative to the guide rail 4, so that the second activator 8 abuts the deflection lever 20 shortly before reaching the maximum opening position. This rotates the arm 21 of the deflection lever 20 about the axis 22, and the second arm 23 pushes the plunger 16 back in the closing direction, so that the piston rod 10 is retracted back into the damper housing 9. It can happen that the deflection lever 20 comes into contact with the second activator 8 not just shortly before reaching its maximum opening position, but even before. This occurs, for example, when the center rail 3 and the guide rail 4 extend together until the center rail 3 reaches its maximum extension position. In this case, too, the arm 21 of the deflection lever 20 is only rotated and the damping activated when the guide rail 4 is also just before reaching its maximum extension position. Regardless of whether the first activator 5 or the second activator 8 has caused a damping process, the piston rod 10 moves out of the damper housing 9 again due to the force of the spring 14 as soon as the guide rail 4 leaves the closed position or the maximum open position. In the embodiment shown in Figs. 1, 2, 3, 4, 5 to 6, the damping device 6 serves only to decelerate the movement of the guide rail 4 before it reaches an end position. Figs. 7, 8, 9, 10, 11 to 12 show a further embodiment of a drawer slide 1 with a damping device 6' which additionally features a self-closing mechanism. The extension guide 1 with the running rail 4, the intermediate rail 3 and the stationary guide rail 2 corresponds to the preceding embodiment, wherein a modified damping device 6' is fixed to the guide rail 2. To actuate the damping device 6', a first web-shaped activator 5' is provided on the running rail 4, and a second activator 8 is fixed to the intermediate rail 3. Figures 7A and 7B show the extension guide 1 in a closed position. If the guide rail 4 is moved slightly in the opening direction, as shown in Figs. 8A and 8B, a spring pushes a piston rod 10 out of the damper housing 9, thus pivoting the deflection lever 20' clockwise. If the guide rail 4 is moved further in the opening direction, the second activator 8 engages the deflection lever 20', as shown in Figs. 9A and 9B. The movement of the guide rail 4 in the opening direction is now slowed, since the rotation of the deflection lever 20' retracts the piston rod 10 into the damper housing 9 until the position shown in Figs. 10A and 10B is reached.From this end position, the guide rail 4 can now be moved again in the closing direction, whereby by moving the second activator 8 in the closing direction and by the force of the spring 14 the deflection lever 20' is turned clockwise again, and the linear damper is ready to brake the guide rail 4, regardless of whether it is moved to an end position in the opening or closing direction. The modified damping device 6' with self-retraction is shown in detail in Figures 11A to 11C. A sleeve-shaped projection 13 is provided on the housing 12', against which the damper housing 9 is latched. The deflecting lever 20' is rotatably mounted on the damper housing 12' at a receptacle 18' and has an axis 22' from which a first arm 21' and a second arm 23' extend radially. The first arm 21' can engage with the second activator 8, while the second arm 23' engages with a block-shaped stop 50, which is guided linearly in the housing 12'. The block-shaped stop 50 is coupled to the connecting element 11 on the piston rod 10. Additionally, a spring 14 acts on the block-shaped stop 50 to pre-tension the stop 50, and thus also the piston rod 10, into an extended position. Furthermore, a driver 40 is movable along a guide track 60 on the housing 12', which has an angled end section 61. The driver 40 is guided in the guide track 60 by means of pins 42, with two side walls of the housing 12' surrounding the driver 40. A receptacle 41 is provided on the driver 40, which can engage with a section of the first activator 5'. The activator 5' can be inserted into a slot-shaped receptacle 62 of the housing 12' to engage with the driver 40. The follower 40 is pre-tensioned in the closing direction by a spring 30, the spring 30 being fixed at one end 31 to the damper housing 9 and at the other end 32 to the follower 40. Alternatively, the spring can also be fixed to another component, to the inner wall of a household appliance, or to the body of a piece of furniture. When the follower 40 is in a parked position with a pin 42 on the angled end section 61, it is in a parked position. By inserting the activator 5' into the receptacle 41 on the follower 40, it can be released or unlocked from the parked position and then moved in the closing direction by the force of the spring 30 along the guide track 60. As the follower 40 moves in the closing direction, it runs against the linearly guided stop 50, which is guided in the guide track 63, so that the movement of the follower 40 is braked by the linear damper. The movable stop 50 is located between the driver 40 and the connecting element 11 on the piston rod 10. This allows the movable stop 50 to be activated both during a closing movement of the guide rail 4 and during an opening movement of the guide rail 4, while the driver 40 of the self-closing mechanism is only actuated via the activator 5' during a closing movement of the guide rail 4. Fig. 12A shows the damping device 6' when the guide rail 4 is in the closed position. Both the driver 40 and the movable stop 50 are in the rear position 12' and have ensured that the piston rod 10 is retracted into the damper housing 9. Figure 12B shows the position when the guide rail 4 is in its maximum opening position. The follower 40 of the self-closing mechanism is in the parked position, while the movable stop 50 has been moved along a guide track 63 inside the housing 12' to retract the piston rod 10 into the damper housing 9. In the opening direction, only the linear damper is active, not the self-closing mechanism. Figure 12C shows the position of the damping device 6' when the guide rail 4 is neither in the closed nor in the fully open position. Due to the force of the spring 14, the movable stop 50 has moved into a position where the piston rod 10 is extended. The spring force of the spring 14 is significantly less than the spring force of the spring 30, so that the self-closing mechanism can reliably move the guide rail 4 into its retracted end position. In Figures 13A, 13B, 14A, and 14B, the drawer guide shown in Figures 7, 8, 9, 10 to 11 is mounted on an inner wall 70 of a dishwasher. Two brackets 71 are located on the inner wall 70, to which the guide rail 2 is fixed, for example, by means of locking or clamping devices. A sliding element, for example, a dish basket 73, is held on the guide rail 4. Before reaching the maximum opening position and before reaching the closed position, the sliding element is decelerated by braking the guide rail 4. A corresponding drawer guide can be provided on opposite sides of the dishwasher's interior. In Fig. 14A, the pull-out guide 1 is shown in the closed position in the dishwasher without the dish basket 73. In Fig. 14B, the dish basket 73 is retracted into the interior of the dishwasher, and the guide rail 4 is in the closed position. In the exemplary embodiment, the drawer slide 1 is installed in a dishwasher. The drawer slide according to the invention can be used in furniture or in other household appliances, such as refrigerators, freezers, ovens, microwaves or warming drawers. The extension guide 1 in the exemplary embodiment consists of a guide rail 2, a center rail 3 and a running rail 4. It is also possible to use the damping device 6 in a so-called partial extension without a center rail, in which case the second activator 8 would also be arranged on the running rail 4. In another variant not shown, the driver 40 and the stop 50 are moved in a common guide track. In the illustrated embodiment, the deflection mechanism comprises a rotatably mounted deflection lever. It is also possible to use a slidably mounted deflection element instead of a deflection lever, which can be moved, for example, along a curved path. The damper can be actuated by a tension spring instead of a compression spring. The tension spring can, for example, be fixed to the housing on one side and to the movable stop on the other, in order to return the damper to its starting position. Reference symbol list 1 Drawer guide 2 Guide rail 3 Center rail 4 Running rail 5, 5' Activator 6, 6' Damping device 7 Cover 8 Activator 9 Damper housing 10 Piston rod 11 Connecting element 12, 12' Housing 13 Projection 14 Spring 15 Connecting section 16 Plunger 17 Recess 18, 18' Receptacle 19 Stop 20, 20' Deflection lever 21, 21' Arm 22, 22' Axle 23, 23' Arm 30 Spring 31 End 32 End 40 Driver 41 Receptacle 42 Pin 50 Stop 60 Guide track 61 End section 62 Receptacle 63 Guide track 70 Inner wall 71 Holder 73 Dish basket

Claims

Drawer guide (1), in particular for a household appliance or a piece of furniture, with a guide rail (2) and a running rail (4) movably mounted on the guide rail (2), wherein a damping device (6, 6') with a one-sided acting damper is provided on the guide rail (2), the damper having a damper housing (9) and a piston rod (10) that can be inserted into and removed from the damper housing (9), wherein, during a closing movement of the running rail (4), a first activator (5, 5') acts on the damping device (6, 6') shortly before reaching a closed position in order to decelerate the movement of the running rail (4), wherein, during an opening movement of the running rail (4), a second activator (8) acts on the damping device (6, 6') shortly before reaching the maximum opening position in order to decelerate the movement of the running rail (4), characterized in that the second activator (8) is arranged on a central rail (3),which is provided between the guide rail (2) and the running rail (4). Drawer guide according to claim 1, characterized in that a deflection mechanism is provided to effect a movement of a stop (15, 50) acting on the damper in the closing direction by means of a movement of the second activator (8) in the opening direction. Extraction guide according to claim 2, characterized in that the deflection mechanism has a rotatably mounted deflection lever (20, 20'). Extension guide according to claim 3, characterized in that the rotatably mounted deflection lever (20, 20') has a first arm (21, 21') which can be brought into engagement with the second activator (8), and a second arm (23, 23') arranged on the opposite side of a pivot axis (22, 22') which acts on the damper via a stop (15, 50). Extension guide according to claim 4, characterized in that the deflection lever (20, 20') engages with the second arm (23, 23') in a receptacle of a linearly guided stop (15, 50) which acts on the damper. Extraction guide according to one of the preceding claims, characterized in that the damper is designed as a pressure damper in which damping forces are generated when the piston rod (10) is inserted into the damper housing (9). Extraction guide according to claim 6, characterized in that the damping device (6, 6') has a spring (14) to pull the piston rod (10) out of the damper housing (9) in the unloaded state. Extraction guide according to one of the preceding claims, characterized in that the first activator (5, 5') is fixed to the guide rail (4). Drawer guide according to one of the preceding claims, characterized in that the damping device (6, 6') has a housing (12, 12') which is fixed to the guide rail (2). Drawer guide according to one of the preceding claims, characterized in that a self-closing mechanism is provided by means of which the guide rail (4) can be moved in the closing direction shortly before reaching the closing position. Extension guide according to claim 10, characterized in that the self-closing mechanism has a driver (40) movable along a housing (12') which is biased in the closing direction by a power storage device (30). Extraction guide according to claim 11, characterized in that the driver (40) acts on a movable stop (50) by means of which the damper can be actuated. Household appliance with at least one pull-out guide (1) according to one of the preceding claims. Household appliance according to claim 13, characterized in that the household appliance is designed as a dishwasher. Household appliance according to claim 13 or 14, characterized in that the extension guide (1) is fixed directly or indirectly to an inner wall (70) of the household appliance and a sliding element (73) is mounted movably by means of the extension guide.

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