Differential extension with self-closing device

Abstract

The present invention relates to a differential pull-out guide (1) with a damped self-closing device (2), in which the central rail (4) has a limiting roller (8) which always contacts both the pull-out rail (5) and the carcass rail (3) and in which the self-closing device has a recovery device for incorrect operation.

Description

[0001] The present invention relates to a differential extension for extendable furniture parts with self-closing device.

[0002] Such differential pull-outs have at least one carcass rail that can be attached to a furniture carcass and a pull-out rail that can be attached to the pull-out furniture part. As well as the at least two rails, they usually have a middle rail arranged between the two, so that these three rails are essentially staggered. Each of these rails has a front end, a rear end, a main surface that is oriented vertically in the installed position, and one or more secondary surfaces arranged thereon. The latter are each arranged at an angle to the respective main surface. The carcass rail and the pull-out rail each have one or more tracks on which rollers roll when in use, all of which are preferably arranged on the middle rail as upper and lower rollers.The rollers have one or both upper and lower contact points with associated raceways of the other rails, with a contact point being defined as the area of ​​the roller that contacts a raceway. Thus, when a roller rotates, all areas of the roller's circumference become contact points as soon as and as long as they contact the associated raceway.

[0003] The cabinet rail has a main surface with attachment options to a furniture carcass, as well as an upper secondary surface angled to this surface with an upper, downward-facing track, and a lower secondary surface angled to this main surface with a lower, upward-facing track, so that the two tracks essentially point towards each other. The upper rollers of the center rail run along the upper track with their upper contact points, and the lower rollers of the center rail run along the lower track with their lower contact points.

[0004] The rollers are used to move the differential extension from a closed position to an open position along an extension path in one extension direction and back again. The closed position occurs when the three rails of the differential extension are fully pushed together, and the open position when they are fully pushed apart. The open position is predominantly in the normal extension position, i.e. such that in the end position of the extension rail its end is still located between a differential roller and a roller assigned to it. In the over-extension position, which is possible in some designs, this end is no longer located between the aforementioned rollers, but after them as seen in the extension direction.

[0005] The relative positions of the rails can be adjusted by means of the rollers acting between the rails and rolling on the respective track(s). Typically, all of the rollers are rotatably mounted on the center rail, including the aforementioned differential roller. Due to its larger circumference, this differential roller creates a 2:1 ratio between the distances traveled by the extension and center rails. In other words, the center rail travels half the distance of the extension rail when extended and half the distance of the extension rail when retracted.

[0006] The center rail is usually shorter than the cabinet rail and shorter than the extension rail. When the differential extension guide is retracted, the rear end of the center rail is offset forward relative to the rear end of the cabinet rail and relative to the rear end of the extension rail. A retraction device, which can also be configured as a damping device, is optionally arranged in the space thus created. This device automatically retracts the extension rail with the attached furniture part (drawer) into the closed position, with this movement being dampened.

[0007] Pull-out guides with self-closing devices are known, in which the pull-out rail is automatically retracted over the final section of the insertion path. These self-closing devices are often integrated into the pull-out guide, as disclosed, for example, in EP 4 164 450 A1. In the differential pull-out with self-closing device and damping element (damped self-closing device) described therein, the damping element is attached to the rear end of the cabinet rail. This known damped self-closing device has a base body with a slide guided in grooves, on which a tilting part is rotatably arranged. This tilting part, in turn, is connected to a spring lever so that its position can be adjusted relative to one another. To which a retracting spring is attached, the other end of which is fixed to the housing.The pull-out rail engages in the tilting part with a driver and is automatically retracted by the spring force transmitted to it via these components. This retraction is dampened by a damper unit consisting of a piston-cylinder unit and a connected, extendable and retractable arm, against which the center rail runs. The components of the self-retracting mechanism and those of the damping interact in a coordinated manner, particularly through position-adjustable connecting elements, and are locked or released in their respective end positions by the positive engagement of projections and stop surfaces, particularly in corresponding groove tracks in the housing.

[0008] With regard to the details of this damped self-closing unit, reference is made to this EP document and the relevant disclosure is explicitly included in the present application.

[0009] DE 10 2023 112 548 B3 discloses a differential pull-out guide that can be moved from a closed position to an open position along an extension path, comprising a furniture rail that can be attached to a furniture carcass, a pull-out rail that can be attached to an extendable furniture part, and a center rail arranged between the carcass rail and the pull-out rail. The pull-out rail and the carcass rail each have an upper and lower track, with upper and lower rollers of the center rail running in these tracks such that the upper rollers of the center rail run in the upper track of the carcass rail and the lower rollers of the center rail run in the lower track of the carcass rail. Furthermore, the upper rollers of the center rail run in the upper track of the pull-out rail and the lower rollers run in the lower track of the pull-out rail. The center rail further has a differential roller.In the closed position of the differential extension guide, the cabinet rail, the center rail, and the extension rail are pushed together as far as they can, with the center rail being shorter than the other two. In the open position of the differential extension guide, the rails are pulled apart as far as they can, with stop devices for limiting travel and self-retracting devices arranged on the cabinet rail.

[0010] A disadvantage of the differential drawers with self-retracting device disclosed in the prior art is that safe guidance and retraction of the drawer rail are not always guaranteed.

[0011] The present invention therefore aims to avoid these disadvantages.

[0012] This object is achieved by the features of claim 1. These advantageously prevent the undesired deflection of the rear end of the pull-out rail in a vertical direction upwards and thus ensure that the retraction is effective even when the pull-out guide is in non-standard operating conditions. The previously described components, carriage and tilting part of the self-retracting device can advantageously no longer inadvertently return to the retracted position without taking the pull-out rail with them, since the large-diameter limiting roller provided according to the invention always rests on a respective running surface both on the body rail and on the pull-out rail and thus serves as a barrier against undesired vertical pivoting of the pull-out rail upwards, particularly caused by incorrect operation, which, as described, leads to a non-activation of the self-retracting device due to a failure of the pull-out rail driver to engage.The limiting roller according to the invention further provides a purely horizontal guidance of the pull-out rail, since it is now guided at two axially spaced points by pairs of rollers, each pair of which guides the pull-out rail between the rollers of the pair.

[0013] In other words, the idea of ​​the invention is to provide the axially rearmost upper roller of the middle rail, which was previously intended solely for guiding the middle rail on the carcass rail, with an additional function, namely that of a limiting roller. This is achieved according to the invention by an increase in diameter and in particular by relocating the axis of rotation of the limiting roller both axially backwards and vertically in the direction of the pull-out rail. Advantageously, one of the previously provided lower rollers of the middle rail at its rear end can be omitted. This roller was intended to achieve an axially longer guide path for the pull-out rail and, due to a trough-shaped design of the lower track of the carcass rail, raised the driver of the pull-out rail vertically when passing through this roller and lowered it into the recess of the tilting part for positive locking.It is therefore further provided according to the invention that the retraction device has a tilting part that can be pushed over vertically or is more vertically movable.

[0014] In an embodiment of the invention, a release is provided in the base body - the housing - of the self-closing device, by means of which the spring lever and thus the tilting part connected to it can be pressed downwards in the "waiting position" operating position when the self-closing device is first actuated and can thus be pushed over by the pull-out rail.

[0015] In a further development of the invention, it is provided that the self-retracting device has the possibility of manually tilting a tilting part which has not been tilted from the waiting position into the return position, in particular due to incorrect operation, in particular by providing a recess in a sliding surface of the base body related to the tilting part.

[0016] Finally, in an embodiment of the invention, it is also provided that the limiting roller is positioned upstream of the self-closing device in the pull-out direction.

[0017] Finally, it is also intended that the limiting roller has a diameter of 32 mm and / or is made of a plastic or plastic mixture.

[0018] The invention will be explained in more detail below with reference to the figures of the drawing of an embodiment, wherein like parts are designated by the same reference numerals. In detail, Fig. 1: a perspective view of an embodiment in closed position, Fig. 2: a perspective view in open position, Fig. 3: a sectional side view in the operating state of the initial actuation of the self-retracting device, Fig. 4: a sectional side view in the operating state at the end of the actuation of the self-closing device, thus in the closed position; Fig. 5: a sectional side view in the operating state shortly before the end of the operation of the self-closing device in case of incorrect operation and Fig. 6: in three Fig. 6a to 6c a perspective view of a self-retracting device according to the invention.

[0019] Fig. 1 shows an embodiment of a differential pull-out guide 1 with self-closing device 2 according to the invention in a perspective view in the closed position.

[0020] A central rail 4 is guided in the carcass rail 3, which in turn guides a pull-out rail 5. A differential roller 6 and the limiting roller 7 according to the invention can be seen. The retraction device 2 according to the invention, which is fastened to the carcass rail 3, can be seen on the right; in the installed position, this is the furthest or innermost position in a furniture carcass from a pull-out furniture part or drawer fastened to the pull-out rail 5. From this closed position, the central and pull-out rails are moved in the direction of arrow A along a pull-out direction into the open position, with the pull-out rail 5 traveling twice the distance of the central rail 4 due to the differential roller 6. The carcass and pull-out rails have fastening options 9 for fastening to a carcass or to a drawer - or more generally - to a pull-out furniture part. A locking bolt 10 prevents orAllows the separation of the pull-out and middle rails, thus allowing the removal of the pull-out furniture part. The limiting roller 7 according to the invention contacts an upwardly facing upper track 11 of the pull-out rail 5 and a downwardly facing upper track 11 of the carcass rail 3. A more detailed description of the three rails can be found in . Fig. 2. The limiting roller 7 preferably has a large roller diameter of 32 mm, which advantageously means that it only requires a few revolutions for the extension and retraction paths, which in turn makes it durable and ensures smooth running.

[0021] Fig. Figure 2 shows a perspective view of the inventive embodiment of the differential pull-out guide 1 with self-retracting device 2 in the open position. From this open position, the center and pull-out rails are moved in the direction of arrow B along a retraction direction into the closed position, with the pull-out rail 5 again traveling twice the distance of the center rail 3 due to the differential roller 6.

[0022] The cabinet rail 3 has a main surface 8, on which a lower secondary surface 12 and an upper secondary surface 13 are arranged at an angle, wherein the mutually facing surfaces of these secondary surfaces 12, 13 each form a track 11 for rollers 14 of the center rail 4. The free ends of the secondary surfaces 12, 13 are at least partially bent towards each other over the length of the cabinet rail 3, so that, viewed from the front, an approximately box-like profile cross-section with one open side is produced.

[0023] The center rail 4 has a main surface 8' to which rollers 14 with different functions are rotatably mounted. Of particular importance for the invention is the limiting roller 7, whose attachment to the center rail 4 has been relocated axially backward and vertically downward compared to the other rollers in the upper region of the center rail 4 so that it can exert the described vertical limiting effect on the pull-out rail 5 through simultaneous contact with the latter and the body rail 3. A lateral guide roller 15 establishes lateral contact with the pull-out rail 5. The lower track 12 has a trough-like, recessed axial section 16, the function of which is explained further below.

[0024] The pull-out rail 5 also has a main surface 8'', to which an upper secondary surface 13' is arranged at an angle, which has a track 11 on both its upper and lower sides for the rollers 14 of the middle rail 4. At its rear end, facing the self-closing device 2, the pull-out rail 5 has a driver 17 (see Fig. 4) in the form of a molding for contacting and actuating the self-retracting device 2. This is in Fig. 2 is shown in the operating position “waiting position”, ie it is configured to carry out the self-retraction after contact by the pull-out rail 5.

[0025] Fig. Figure 3 shows the arrangement of the rollers 14, which also include the differential roller 6 and the limit roller 7, in an upper and a lower roller row. In the lower roller row, the rollers 14 run in the lower track 11 of the cabinet rail 3, contacting it with their lower contact points, and in the lower track 11 of the extension rail 5, contacting it with their upper contact points. For rails longer than those shown, additional upper and lower rollers 14 can be provided, especially upper ones.

[0026] In magnification A shows Fig. 3 a sectional side view of the embodiment in the operating state shortly before the actuation of the self-closing device 2. As can be seen from the upper part of the Fig. 3, the drawer guide 1 has already moved far towards the closed position on the retraction path.

[0027] The lower part of the image clearly shows the inventive design of the stop wheel 6, which runs with its lower contact point on the upper track 11 of the pull-out rail 5 and with its upper contact point on the upper track 11 of the carcass rail 3. This advantageously prevents the pull-out rail 5 from pivoting upwards unintentionally due to incorrect operation and ensures that the self-closing device 2 is correctly contacted.

[0028] The operating state is shown shortly before the self-retracting device 2 is triggered. A driver 17, here formed by a molded-on portion or bend in the extension rail 5 arranged at an angle to the running surface 11, is just contacting the tilting part 18, or rather its receiving pocket 23. The tilting part 18 is connected to a spring lever 22, which in turn is connected to one end of the return spring 21, the other end of which is fixed to the base body 20 of the self-retracting device 2. The tilting part 18 is tiltably mounted in a carriage 19 and is guided therewith along a self-retracting path on the base body 20. Also visible is a piston-cylinder unit 24, to which a retractable and extendable arm 25 is attached. This arm is contacted by the center rail 4 and further dampens its movement.

[0029] Upon further retraction of the center and extension rails, the tilting part 18 folds to the right and rests against the carriage 19 with a particularly rubberized or elastic surface. The tilting movement releases locking positive locks, so that the self-retracting device 2 moves from the "waiting position" operating position to the "damped retraction" operating state.

[0030] Fig. Figure 4 shows a sectional side view in the operating state at the end of the actuation of the self-closing device 2, i.e., in the closed position. The driver 17 is fully received in the receiving pocket 23, the carriage 19 is retracted, the tilting part 18 is pivoted as described, and the return spring 21 is released. The arm 25 is retracted, the piston-cylinder unit 24 is also retracted—and thus preloaded—the self-closing device 2 is in the "rest position" operating state, and the moving parts are again positively locked.

[0031] Fig. 5 shows the same sectioned side view as Fig. 4, but in the operating state of a faulty operation, in which, for example, due to vertical pivoting of the pull-out rail 4, the driver 17 was not received in the receiving pocket 23 and the tilting part 18 was pivoted. This occurs particularly in the case of heavy pull-out furniture parts with large drawer fronts, which exert a correspondingly high vertical force on the pull-out rail 5 and thus vertically lift its end with the driver 17.

[0032] In this operating state, the middle rail 4 is fully retracted into the closed position and rests against the arm 25, but the front end of the pull-out rail 5 still protrudes beyond the front edges of the body and middle rail.

[0033] In this operating state, the self-retracting device 2 cannot be moved back into the waiting position by pulling out the middle and pull-out rails.

[0034] The invention therefore provides a remedy for this operating condition, which is described below and in which the self-closing device 2 is returned to the rest position by manually pushing the pull-out rail 5 in the retraction direction until it is in the closed position.

[0035] Fig. 6 shows, in three partial figures a) to c), the self-closing device 2 according to the invention in a perspective view. Partial figure a) shows it in the "waiting position" operating position with a tensioned return spring 21, a tilted tilting part 18 ready to receive the driver 17, and the carriage 19 in the frontmost position, wherein this position is positively locked at least by the stop 30. With regard to corresponding details on further projections of the corresponding components of the self-closing guide that bear against stops, reference is made to the aforementioned EP 4 164 450 B1 and its related disclosure, which is also explicitly incorporated into this application and which is implemented in the described embodiment. In a link 26, the guide body 27 of the spring lever 22 determines its spatial position relative to the tilting part 18 and the carriage 19.In this operating position, the drawer guide is positioned with partially or completely displaced rails.

[0036] Partial figure b) shows the "rest position" of the damped self-closing device 2, which is present in the closed position of the extension device 1. Here, the return spring 21 is relaxed, the arm 25 is retracted, the piston-cylinder unit 24 - the damper - is tensioned and locked, the slide 19 is moved to its rearward position, and the tilting part 18 is tilted into its vertical rest position.

[0037] In contrast to the self-closing device described in the EP document, the present one is modified in that it has a recess 28 into which, as shown in partial figure a), the guide body 27 is moved, so that the tilting part 18 can move further downwards and thus be pushed over / overrun by the driver 17. This modification is necessary because, due to the omission of the rear roller 14 known from the prior art and the limiting roller 7 according to the invention, the pull-out rail 5 can no longer change its vertical position due to the trough-shaped axial sections 16 of the lower track 11 of the body rail 3 and can no longer be lifted into the receiving pocket 23 as is known.

[0038] The self-healing function according to the invention is particularly the third Fig. c) can be found.

[0039] This is characterized by a passage recess 31 on the slideway 29 of the carriage 19. This passage recess 31, which can also be referred to as a constriction of the slideway 29, allows the passage of the Fig. 6a) wing-like stops 30 of the tilting part 18 are clearly visible, so that the tilting part 18 can be moved into its rest position by manually inserting the extension rail 5. This passage recess 31 is not shown in part a) - but is present and covered in part b).

[0040] The invention advantageously assigns a roller a stop function for the pull-out rail by increasing its diameter and changing its position, thus providing more secure vertical guidance and advantageously eliminating the need for another component. The damped self-closing mechanism according to the invention is designed so that it retains its functionality in the event of incorrect operation, or can be easily restored without having to disassemble the pull-out guide. LIST OF REFERENCE SYMBOLS 1 drawer guide 2 self-retracting device 3 Carcass rail 4 middle rail 5 pull-out rail 6 Differential roller 7 Limit roller 8 Main area 9 Mounting options 10 locking levers 11 Career 12 Lower secondary surface 13 Upper secondary surface 14 roller 15 Side guide roller 16 Axial section 17 drivers 18 Tilting part 19 sleds 20 base bodies 21 Return spring 22 spring levers 23 Recording pocket 24 piston-cylinder unit 25 arms 26 backdrop 27 guide bodies 28 Deepening 29 Slideway 30 Stop / lock waiting position 31 passage trough

Claims

[1] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2), comprising a carcass rail (3) attachable to a furniture carcass, a pull-out rail (5) attachable to a pull-out furniture part and a middle rail (4) arranged between the two, wherein the self-closing device (2) is arranged on the carcass rail (3) and wherein the carcass rail (3) and the pull-out rail (5) each have an upper and a lower track (11), wherein the middle rail (4) is shorter than the carcass rail (3) and the pull-out rail (5) and has rollers (14) and a differential roller (6), wherein the rollers (14) of the middle rail (5) run in the upper track (11) of the carcass rail (3) and in the lower and upper track (11) of the pull-out rail (5), wherein the differential pull-out guide (1) can be moved along a pull-out path (A) in a pull-out direction from a closed position, in which the rails (3, 4, 5) are pushed together to the maximum, into an open position, in which the rails (3, 4, 5) are pulled apart to the maximum, characterized by that the middle rail (5) has a limiting roller (7) which always rests against both a track (11) of the carcass rail (3) and a track (11) of the pull-out rail (5) and thus prevents the pull-out rail (5) from pivoting vertically upwards relative to the middle rail (4). [2] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to claim 1, characterized by that the limiting roller (7) has a diameter between 25 and 35 mm, in particular 32 mm. [3] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to claim 1 or 2, characterized bythat an axis of the limiting roller (7) is not in a horizontal line with the axes of the other rollers (14) of the central rail (3), in particular is vertically offset from them. [4] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to claim 1, 2 or 3, characterized by that the self-retracting device (2) has a slideway (29) for a carriage (19) which has a passage recess (31). [5] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to one of the preceding claims, characterized by that the self-closing device (2) has a base body (20) with a link (26) and a recess (28) by means of which a tilting part (18) can be displaced downwards relative to the base body. [6] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to one of the preceding claims, characterized bythat the tilting part (18) can be actuated, in particular displaced, by a driver (17) of the pull-out rail (5). [7] Differential pull-out guide (1) for pull-out furniture parts with self-closing device (2) according to one of the preceding claims, characterized by that the limiting roller (7) is positioned in front of the self-closing device (2) in the pull-out direction.

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