Differential pull-out guide with self-retracting device

Abstract

The invention relates to a differential pull-out guide (1) having a damped self-retracting device (2), wherein the central rail (4) has a limiting roller (8) that is always in contact with both the pull-out rail (5) and the carcass rail (3), and wherein the self-retracting device has a remedial device for rectifying faulty operation.

Description

[0001] Differential extension with self-closing device

[0002] The present invention relates to a differential extension for extendable furniture parts with a self-closing device.

[0003] Such differential extension slides have at least one cabinet rail attachable to a furniture carcass and one extension rail attachable to the extendable furniture section, and typically, in addition to the at least two rails, a central rail arranged between them, so that these three rails are essentially staggered. Each of these rails has a front end, a rear end, a main surface 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 cabinet rail and the extension rail each have one or more tracks on which rollers roll during use, preferably all of which are arranged on the central rail as upper and lower rollers.The rollers have one or both upper and lower contact points with corresponding raceways on the other rails, where a contact point is defined as the area of ​​the roller that contacts a raceway. Therefore, when a roller rotates, all areas of a roller's circumference become contact points as soon as and as long as they contact the corresponding raceway.

[0004] The cabinet rail has a main surface with mounting points for a furniture carcass, an upper secondary surface arranged at an angle to this main surface with an upper, downward-facing track, and a lower secondary surface arranged at an angle to this main surface with a lower, upward-facing track, so that both tracks essentially face each other. The upper rollers of the center rail run on the upper track with their upper contact points, and the lower rollers of the center rail run on the lower track with their lower contact points.

[0005] The rollers serve to move the differential slide from a closed position to an open position along an extension path in one direction and back again. The closed position is when the three rails of the differential slide are fully retracted, the open position when they are fully extended. The open position is predominantly found in the standard extension, meaning that in the end position of the extension rail, its end is still located between a differential roller and one of its associated rollers. In the extended extension, which is possible in some models, this end is no longer located between the aforementioned rollers, but rather, viewed in the extension direction, beyond them.

[0006] The relative positions of the rails can be changed by means of the rollers that act between them and roll on their respective tracks. Typically, all the rollers, including the differential roller, are rotatably mounted on the center rail. This differential roller, due to its larger circumference, creates a 2:1 ratio between the distances traveled by the extension rail and the center rail. In other words, the center rail travels half the distance of the extension rail when both extending and retracting.

[0007] The center rail is typically shorter than both the cabinet rail and the extension rail. When the differential extension guide is retracted, the rear end of the center rail is offset forward relative to both the rear end of the cabinet rail and the rear end of the extension rail. A closing mechanism, which may also act as a damping device, is optionally located in the resulting space. This mechanism automatically pulls the extension rail, along with the attached furniture component (drawer), into the closed position, with this movement being dampened.

[0008] Drawer slides with self-closing mechanisms are known, in which the drawer slide is automatically retracted over the final section of its extension path. These self-closing mechanisms are often integrated into the drawer slide, as disclosed, for example, in EP 4 164 450 A1. In the differential drawer slide with self-closing mechanism and damping element described therein (damped self-closing mechanism), the damping element is attached to the rear end of the cabinet slide. This known damped self-closing mechanism has a base body with a slide slidably guided in grooves, on which a tilting element is rotatably arranged. This tilting element is connected to a spring lever so that its position can be adjusted relative to the lever, and a retraction spring is attached to the lever, the other end of which is fixed to the housing.The extension rail engages in the tilting element with a driver and is automatically retracted by the spring force transmitted to it via these components. This retraction is damped by a damper unit consisting of a piston-cylinder unit and an extendable arm connected to it, against which the center rail abuts. The components of the self-retraction mechanism and those of the damping mechanism interact in a coordinated manner, particularly through position-adjustable connecting elements, and are locked or released in their respective end positions by the positive locking of projections and stop surfaces, particularly in corresponding grooves of the housing. For details of this damped self-retraction unit, reference is made to this EP publication, and the relevant disclosure is explicitly incorporated into the present application.

[0009] A disadvantage of the differential extension with self-closing device disclosed there is the fact that safe guidance and retraction of the extension rail are not always guaranteed.

[0010] The present invention therefore aims to avoid these disadvantages.

[0011] This problem is solved by the features of claim 1. These features advantageously prevent the undesired upward deflection of the rear end of the extension rail in a vertical direction, thus ensuring that the retraction mechanism functions even under non-standard operating conditions of the extension guide. The previously described components, the slide and the tilting element of the self-closing device, can no longer unintentionally return to the retracted position without engaging the extension rail, since the diameter-sized limiting roller provided according to the invention always rests on a respective running surface on both the cabinet rail and the extension rail, and thus acts as a lock against an unintentional upward vertical pivoting of the extension rail, particularly caused by incorrect operation. As described, this upward pivoting, due to the failure of the extension rail's drive element to engage, leads to the self-closing device not being activated.The limiting roller according to the invention further ensures purely horizontal guidance of the extension rail, since it is now guided at two axially spaced points by pairs of rollers, each pair of which guides the extension rail between the rollers of the pair. In other words, the idea of ​​the invention is to provide the previously known, axially rearmost upper guide roller of the center rail, designed solely for guiding the center rail on the body rail, with an additional function, namely that of a limiting roller. This is achieved according to the invention by increasing the diameter and, in particular, also by relocating the axis of rotation of the limiting roller both axially rearward and vertically toward the extension rail.Advantageously, one of the previously provided lower guide rollers of the center rail at its rear end can be omitted. This roller was intended to provide a longer axial guide path for the extension rail and, due to the trough-shaped design of the lower track of the cabinet rail, vertically lifted the drive element of the extension rail as it passed over it and lowered it into the recess of the tilting element for positive engagement. Therefore, according to the invention, the retraction device further provides for a tilting element that can be vertically compressed or moved with greater vertical freedom.

[0012] In an embodiment of the invention, a release is provided in the base body - the housing - of the self-retracting device, by means of which the spring lever and thus the tilting part connected to it can be pressed downwards in the operating position "waiting position" during the first actuation of the self-retracting device and thus be pushed over by the extension rail.

[0013] In a further development of the invention, the self-retracting device is provided with a means to manually tilt a tilting part that has not been tilted from the waiting position to the return position, particularly due to incorrect operation, in particular by providing a recess in a tilting part-related sliding surface of the base body. Finally, in an embodiment of the invention, the limiting roller is positioned upstream of the self-retracting device in the extension direction.

[0014] Finally, it is also stipulated that the limiting roller has a diameter of 32 mm and / or is made of a plastic or plastic mixture.

[0015] The invention is explained in more detail below with reference to the figures of the drawing of an embodiment, where identical parts are designated by the same reference numerals. Specifically, the figures show...

[0016] Fig. 1: a perspective view of an embodiment in the closed position,

[0017] Fig. 2: a perspective view in open position,

[0018] Fig. 3: a cutaway side view in the operating state of the initial activation of the self-retracting device,

[0019] Fig. 4: a cutaway side view in the operating state at the end of the actuation of the self-closing device, i.e. in the closed position;

[0020] Fig. 5: a cutaway side view in the operating state shortly before the end of the actuation of the self-retracting device in case of incorrect actuation and

[0021] Fig. 6: Three partial figures 6a to 6c show a perspective view of a self-closing device according to the invention. Fig. 1 shows an embodiment of a differential extension guide 1 with a self-closing device 2 according to the invention in a perspective view in the closed position.

[0022] A center rail 4 is guided in the cabinet rail 3, which in turn guides an extension rail 5. A differential roller 6 and the limiting roller 7 according to the invention are visible. The inventive insertion device 2, attached to the cabinet rail 3, is visible on the right; in its installed position, this is the furthest or innermost position in a furniture cabinet from any extendable furniture part or drawer attached to the extension rail 5. From this closed position, the center rail and extension rail are moved in the direction of arrow A along an extension direction into the open position, with the extension rail 5 traveling twice the distance of the center rail 4 due to the differential roller 6. The cabinet rail and extension rail have fastening points 9 for attachment to a cabinet or drawer – or more generally – to an extendable furniture part. A locking bar 10 prevents, orThis allows the extension and center rails to be separated, thus enabling the removal of the extendable furniture section. The limiting roller 7 according to the invention contacts an upwardly pointing upper track 11 of the extension rail 5 and a downwardly pointing upper track 11 of the cabinet rail 3. A more detailed description of the three rails can be found with reference to Fig. 2. The limiting roller 7 preferably has a large roller diameter of 32 mm, which advantageously means that it requires only a few revolutions for both the extension and retraction strokes, thus increasing its durability and ensuring smooth operation.

[0023] Fig. 2 shows a perspective view of the invention.

[0024] Embodiment of the differential extension guide 1 with self-closing device 2 in the open position. From this open position, the center and extension rails are moved in the direction of arrow B along a retraction direction into the closed position, whereby the extension rail 5 travels twice the distance of the center rail 3 again due to the differential roller 6.

[0025] 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, the opposing surfaces of these secondary surfaces 12, 13 each forming a track 11 for rollers 14 of the central rail 4. The free ends of the secondary surfaces 12, 13 are bent at least partially towards each other along the length of the cabinet rail 3, so that, viewed from the end face, an approximately box-like profile cross-section with one open side is obtained.

[0026] The central rail 4 has a main surface 8' to which rollers 14 of different functions are rotatably attached. Of particular importance to the invention is the limiting roller 7, whose attachment to the central rail 4, compared to the other rollers in the upper region of the central rail 4, is positioned axially rearward and vertically downward so that it can exert the described vertical limiting effect for the extension rail 5 by simultaneously contacting it and the cabinet rail 3. A lateral guide roller 15 establishes lateral contact with the extension rail 5. The lower track 12 has a trough-like recessed axial section 16, the function of which is explained below.

[0027] The extension rail 5 also has a main surface 8", to which an upper secondary surface 13' is arranged at an angle. This secondary surface has a raceway 11 on both its upper and lower surfaces for the rollers 14 of the center rail 4. At its rear end, which points towards the self-retracting device 2, the extension rail 5 has a driver 17 (see Fig. 4) in the form of a projection for contacting and actuating the self-retracting device 2. This is shown in Fig. 2 in the "standby" operating position, i.e., it is configured to perform the self-retraction after contact by the extension rail 5.

[0028] Fig. 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 row of rollers. In the lower row of rollers, the rollers 14 run in the lower track 11 of the cabinet rail 3 and contact it with their lower contact points, and in the lower track 11 of the extension rail 5, which they contact with their upper contact points. For rails longer than those shown, additional upper and lower rollers 14 may be provided, particularly upper ones.

[0029] In enlarged view A, Fig. 3 shows a cutaway side view of the embodiment in the operating state shortly before the self-closing device 2 is activated. As can be seen from the upper part of Fig. 3, the extension guide 1 has already moved far towards the closed position on the retraction path.

[0030] 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 extension rail 5 and with its upper contact point on the upper track 11 of the cabinet rail 3. This effectively prevents unintentional upward pivoting of the extension rail 5 due to incorrect operation and ensures that the self-closing device 2 is correctly engaged. The image shows the operating state shortly before the self-closing device 2 is triggered. A driver 17, here formed by a projection or bend in the extension rail 5 arranged at an angle to the running surface 11, is just making contact with the tilting element 18, or rather its receiving pocket 23. The tilting element 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-closing device 2.The tilting element 18 is mounted in a tilting position in a slide 19 and is moved along a self-retracting path on the base body 20. A piston-cylinder unit 24 is also visible, to which an extendable and retractable arm 25 is attached. This arm is contacted by the central rail 4 and subsequently dampens its movement.

[0031] During further retraction of the center and extension rails, the tilting element 18 folds to the right and rests against the carriage 19 with a surface that is, in particular, rubberized or elastic. The tilting movement releases the locking mechanisms, so that the self-closing device 2 moves from the operating position “standby” to the operating state “damped retraction”.

[0032] Fig. 4 shows a cutaway 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 engaged in the receiving pocket 23, the carriage 19 has retracted, the tilting element 18 has pivoted as described, and the return spring 21 is relaxed. The arm 25 is retracted, as is the piston-cylinder unit 24 – and thus pre-tensioned – and the self-closing device 2 is in the "rest position" operating state, with the moving parts correspondingly locked in a positive position. Fig. 5 shows the same cutaway side view as Fig. 4, but in the operating state of a malfunction, in which, for example, due to vertical pivoting of the extension rail 4, the driver 17 was not engaged in the receiving pocket 23 and the tilting element 18 was not pivoted.This occurs particularly with heavy extendable furniture parts with large drawer fronts, which exert a correspondingly high vertical force on the extension rail 5 and thus raise their end vertically with the driver 17.

[0033] 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 extension rail 5 still protrudes beyond the front edges of the body and middle rail.

[0034] In this operating state, the self-retracting device 2 cannot be moved back into the waiting position by pulling out the center and extension rails.

[0035] The invention therefore advantageously provides a remedy for this operating condition, which is described below and in which the self-closing device 2 is returned to its rest position by manually inserting the extension rail 5 in the retraction direction until it is in the closed position.

[0036] Fig. 6 shows the self-closing device 2 according to the invention in three partial figures a) to c) in perspective view. Partial figure a) shows it in the operating position “standby position” with the return spring 21 tensioned, the tilting part 18 tilted, ready to receive the driver 17, and the slide 19 in its foremost position, this position being positively locked at least by the stop 30. For corresponding details of further projections of the corresponding components of the self-closing guide that abut against stops, reference is made to the aforementioned EP 4 164450 B1 and its related disclosure, which is explicitly included in this application and is implemented in the described embodiment. In a cam 26, the spatial position of the spring lever 22 relative to the tilting part 18 and the slide 19 is determined by means of the guide body 27 of the spring lever 22.In this operating position, the extension guide has partially or completely displaced rails.

[0037] Part b) shows the operating position “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 cocked and locked, the carriage 19 is moved to its rearward position, and the tilting part 18 is tilted into its vertical rest position.

[0038] In contrast to the self-closing device described in the EP publication, the present device 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 / passed by the driver 17. This modification is necessary because, due to the elimination of the rear guide roller 14 known from the prior art and the limiting roller 7 according to the invention, the extension rail 5 no longer changes its vertical position via the trough-shaped axial sections 16 of the lower raceway 11 of the cabinet rail 3 and can no longer be lifted into the receiving pocket 23 as known.

[0039] The self-healing function according to the invention can be seen in particular in the third part of Figure c). This is characterized by a passage recess 31 on the sliding track 29 of the carriage 19. This passage recess 31, which can also be described as a constriction of the sliding track 29, allows the wing-like stops 30 of the tilting part 18, clearly visible in Figure 6a), to pass through upwards, so that the tilting part 18 can be manually

[0040] The extension rail 5 can be inserted into its rest position. This passage recess 31 is not shown in partial figure a) - but is present and covered in partial figure b).

[0041] The invention offers a significant advantage: by increasing the diameter and changing the position of a roller, it provides a stop function for the extension rail, thus ensuring more secure vertical guidance and eliminating the need for another component. The damped self-closing device according to the invention is designed to retain its functionality in the event of incorrect operation, or to allow for easy restoration of functionality without having to remove the extension rail.

[0042] REFERENCE MARK LIST

[0043] 1 Extraction guide

[0044] 2 Self-closing device

[0045] 3 cabinet rails

[0046] 4 Center rail

[0047] 5 extension rail

[0048] 6 Differential roller

[0049] 7 Limiting roller

[0050] 8 Main area

[0051] 9 Mounting options

[0052] 10 locking levers

[0053] 11 Career

[0054] 12 Lower secondary surface

[0055] 13 Upper secondary surface

[0056] 14 Roller

[0057] 15 Side guide roller

[0058] 16 Axial section

[0059] 17 drivers

[0060] 18 Tilting part

[0061] 19 sleds

[0062] 20 basic bodies

[0063] 21 Return spring

[0064] 22 spring levers

[0065] 23 Recording bag

[0066] 24 piston-cylinder unit

[0067] 25 Arm

[0068] 26 Scenery

[0069] 27 guide bodies

[0070] 28 In-depth study

[0071] 29 Slide

[0072] 30 Stop / Lock Waiting Position

[0073] 31 Passage trough

Claims

PATENT CLAIMS 1. Differential extension guide (1) for extendable furniture parts with self-closing device (2), comprising a cabinet rail (3) attachable to a furniture carcass, an extension rail (5) attachable to an extendable furniture part, and a central rail (4) arranged between the two, wherein the self-closing device (2) is arranged on the cabinet rail (3), and wherein the cabinet rail (3) and the extension rail (5) each have an upper and a lower track (11), wherein the central rail (4) is shorter than the cabinet rail (3) and the extension rail (5) and has rollers (14) and a differential roller (6), wherein the rollers (14) of the central rail (5) run in the upper track (11) of the cabinet rail (3) and in the lower and upper tracks (11) of the extension rail (5), wherein the differential extension guide (1) extends along an extension path (A) in an extension direction from a Closed position, in which the rails (3, 4,5) are maximally retracted, can be moved into an open position in which the rails (3, 4, 5) are maximally extended, characterized in that the middle rail (5) has a limiting roller (7) which always bears against both a raceway (11) of the body rail (3) and a raceway (11) of the extension rail (5) and thus prevents the extension rail (5) from pivoting vertically upwards relative to the middle rail (4).

2. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to claim 1 , characterized in that the limiting roller (7) has a diameter between 25 and 35 mm, in particular 32 mm.

3. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to claim 1 or 2, characterized in that an axis of the limiting roller (7) is not in a horizontal line with the axes of the other running rollers (14) of the center rail (3), in particular is vertically offset to them.

4. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to claim 1 , 2 or 3, characterized in that the self-closing device (2) has a slide track (29) for a carriage (19) which has a passage recess (31 ).

5. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to one of the preceding claims, characterized in that the self-closing device (2) has a base body (20) with a cam (26) and a recess (28) by means of which a tilting part (18) can be displaced downwards relative to the base body.

6. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to one of the previous claims, characterized in that the tilting part (18) can be actuated by a driver (17) of the extension rail (5), in particular displaceable.

7. Differential extension guide (1 ) for extendable furniture parts with self-closing device (2) according to one of the previous claims, characterized in that the limiting roller (7) is positioned in front of the self-closing device (2) in the extension direction.

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