Drawer pull-out guide

A drawer pull-out guide includes a carcass rail to be fixed to a furniture carcass, an extension rail displaceable relative to the carcass rail between a closed position and an open position, and a rolling body and a supporting body movable along a running limb of the carcass rail and a running surface of the extension rail upon a movement of the extension rail. A clearance is formed on the running limb of the carcass rail and/or on the running surface of the extension rail. The rolling body is accommodated within the clearance in the closed position of the extension rail and is thereby relieved from the load of the extension rail so that, in the closed position of the extension rail, the load of the extension rail is carried by the supporting body. Furthermore, rolling body and the supporting body are arranged in a common running carriage.

BACKGROUND OF THE INVENTION

The present invention relates to a drawer pull-out guide, including a carcass rail to be fixed to a furniture carcass, at least one extension rail which is displaceable relative to the carcass rail between a closed position and an open position, and at least one rolling body and at least one supporting body which are movable along a running limb of the carcass rail and a running surface of the extension rail upon a movement of the extension rail. A clearance is arranged on the running limb of the carcass rail and/or on the running surface of the extension rail, and the at least one rolling body is accomodated within the clearance in the closed position of the extension rail. The at least one rolling body is thereby relieved from the load of the extension rail such that, in the closed position of the extension rail, the load of the extension rail is carried by the at least one supporting body.

The invention further concerns an arrangement with a drawer pull-out guide of the kind to be described and with a drawer which is movable relative to a furniture carcass by way of the drawer pull-out guide in the mounting position.

With such drawer pull-out guides, the load of the drawer is transmitted by rolling bodies which are subjected to different loading conditions. After a longer standstill of the drawer in the closed position, the foremost rolling bodies—particularly because of the considerable weight of a drawer front panel—bear the greatest load which leads in the course of time to a peripheral deformation, flattening, or even to a breakage of the rolling bodies. Due to this mechanical stress exerted on the rolling bodies, the running behaviour and thus the functionality of the drawer pull-out guide can adversely be affected which results in a shorter lifetime.

A measure for avoiding such a flattening of rolling bodies is described in EP 2 079 342 B1 to the applicant. Here, a running carriage having a group of rolling bodies is displaceable between the rails, and at least one further load-transmitting element is supported on a front cantilever of the running carriage—with a spacing to the group of rolling bodies. In the closed position of the extension rail, the load of the drawer is carried by the load-transmitting element so that the group of rolling bodies, in the closed position, are substantially relieved and thus protected from deformation. In an open position of the extension rail, the load-transmitting element is moved over the front end of a rail of the drawer pull-out guide, and the load of the extension rail is carried by the group of rolling bodies. However, also in the closed position of the extension rail, the group of rolling bodies is partly subjected to a load which can lead to a deformation of the rolling bodies. Also, the construction of the shown running carriage is a special form which is relatively voluminous and causes extra manufacturing costs.

DE 197 51 384 A1 and GB 515,899 A each show pull-out devices for drawers, in which several rollers which are spaced from each other in the longitudinal direction of the extension rail are rotatably arranged on the extension rail. In the closed position, the rollers can run into dents of the stationary rail so that the rollers are relieved from the weight of the drawer and an undesired opening movement of the pull-out devices is prevented. A disadvantage is the fact that a relatively great force is required in order to open the pull-out device, because the rollers each need to be moved out of their associated dents. This leads to abrupt transitions when opening and closing the extension guides which adversely affect the running behaviour of the extension guide. Moreover, the diameters of the rollers are to be dimensioned relatively large for reasons of stability, whereby the installation space is significantly enlarged.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a drawer pull-out guide of the kind generally referred to above, but without the above drawbacks.

According to the invention, the at least one rolling body and the at least one supporting body are arranged in a common running carriage.

By way of the arrangement in a common running carriage, the rolling resistance of the drawer pull-out guide can be reduced, because the diameter of the rolling bodies and of the supporting bodies in comparison with stationary rollers can be significantly smaller. The transitions between the closed position and the open position result practically without stoppage, wherein the distribution of load of the drawer pull-out guide is effected more uniformly.

In the closed position, the at least one rolling body is accomodated within the clearance (expanded space) of a rail and is thus relieved from the load of the extension rail, while the at least one supporting body is located outside of the clearance and thereby carries the load of the extension rail. The at least one rolling body which is located within the clearance in the closed position of the extension rail is not subjected to any weight force and therefore not subjected to premature wear.

It is thereby irrelevant whether the supporting body located outside of the clearance is subjected to the weight force of the drawer in the closed position and will therefore be deformed or not, because the supporting body, in an open position of the extension rail, does not act as a rolling body rolling along a running limb and therefore does not have any influence on the running behaviour of the drawer pull-out guide.

The advantage of this construction firstly lies in a clear functional separation of the dynamic rolling bodies (i.e. the ones which roll along a running limb of the rails upon a movement of the extension rail) and the static rolling bodies (i.e. the ones which carry the load of the drawer in the closed position of the extension rail). Furthermore, in comparison with the construction according to EP 2 079 342 B1, running carriages with a shorter length and with a cheaper construction are also applicable. In particular, running carriages with a standard design can be easily used which need not to be equipped with additional components.

Preferably, the at least one rolling body and the at least one supporting body are made of a plastic material. If required, for example when there is a considerable load due to a heavy drawer front panel, the at least one supporting body may be also made of steel.

According to an embodiment of the invention, two or more rolling bodies can be provided which, in the closed position of the extension rail, are accommodated within the clearance. Thereby, preferably at least two of the two or more rolling bodies have different diameters. As a result, a stepped configuration of the diameters of the rolling bodies can be provided, namely such that the diameters of the rolling bodies decrease in a direction towards the front end of the extension rail, preferably monotonously (continuously). This has the particular advantage that the weight forces with an extension rail extracted and being under load (namely when the front end of the extension rail flexes downwardly) are distributed more evenly onto the rolling bodies having different diameters.

With a two-part rail system, the extension rail can be configured as a drawer rail to be connected to the drawer. With a three-part rail system, which enables a full extension of a drawer relative to the front face of the furniture carcass, the extension rail can be configured as a drawer rail and/or as a central rail.

According to an embodiment, the at least one supporting body can also be in the form of a rolling body. It is, however, not mandatory that the supporting body rolls off along a running limb of a rail upon a movement of the extension rail.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows a perspective view of an item of furniture1with drawers3which are displaceable relative to a furniture carcass2by way of drawer pull-out guides4. The drawer pull-out guide4, in the shown embodiment, is configured as a full-extension pull-out guide having a three-part rail system, in which a carcass rail5is to be fixed to the furniture carcass2, a drawer rail7is to be fixed to the drawer3, and a central rail6is displaceable between the carcass rail5and the drawer rail6. For movably supporting the rails5,6,7to each other, rolling bodies (not visible here) are provided (reference numbers18a-18eand20inFIG. 4a) which are arranged in or on a running carriage27(FIG. 4b) displaceable between the rails5,6,7. The drawer pull-out guide4, in the shown Figure, is in the fully open position, and those rolling bodies18a,18bwhich are located adjacent to the front end9of the drawer rail7are considerably subjected to the load of the drawer front panel8in a direction of the shown arrow10, in particular when the drawer3remains in the fully closed position over a longer period of time. This loading, with the time, can lead to deformations or also to a breakage of the, in particular foremost, rolling bodies18a,18bso that the functionality of the drawer pull-out guide4can no longer be ensured.

FIG. 2shows the drawer pull-out guide4in a perspective view. The carcass rail5is to be fixed to the furniture carcass2by a fastening section11, while the drawer rail7is to be connected to the drawer3. A displaceable central rail6is arranged between the stationary carcass rail5and the drawer rail7, whereby a full extension of the drawer3relative to the furniture carcass2is possible. The drawer rail7is provided with a fastening device12having an adjustable peg13, wherein by an adjustment of the peg13(which is to be arranged within a bore of the drawer rear wall), the rear end region of the drawer3can be raised and lowered. In this way, the inclination of the front panel8(FIG. 1) relative to the furniture carcass2can be adjusted. An adjusting device14with a height-adjustable stop15allows the height of the front panel8to be adjusted in the mounting position. The drawer pull-out guide4further includes a spring-assisted retraction device16so that the drawer rail7(and therewith the drawer3), at the end of the closing movement, can be pulled with spring force into the fully closed end position.

Visible is a clearance (expanded space)17aarranged on the drawer rail7, the clearance17ais in the form of an embossing protruding upwardly in the mounting position and which can be haptically recognized, the clearance17ais provided for accommodating the rolling bodies18awhich are arranged between the rails5,6,7so as to relieve pressure on the rolling bodies18awhen the drawer is closed. The clearance17ahas a substantially flat base25, wherein the rolling bodies18aare movable into the clearance17avia at least one inclined surface portion26a,26b. In this way, the rolling bodies18acan be moved into and out of the clearance17awithout abutting an edge. The drawer rail7has a horizontal limb7awith a width (D), wherein the width (d) of the clearance17ais smaller than the width (D) of the horizontal limb7aof the drawer rail7. In this way, the drawer rail7will not be locally weakened by the arrangement of the clearance17a. The clearance17a, in the shown embodiment, is located in the foremost third of the length of the drawer rail7.

FIG. 3shows a perspective cross-section of the drawer pull-out guide4according toFIG. 2in the fully closed position. Arranged between the central rail6and the drawer rail7is at least one rolling body18a(in the present case four rolling bodies18a) which can be rolled along a running surface23aof the drawer rail7which extends in a longitudinal direction of the drawer rail7. In the closed position, the rolling bodies18aare accommodated within the clearance17aof the drawer rail7and are thereby relieved from the load of the drawer rail7. Moreover, there is arranged at least one supporting body19a(in the present case, two supporting bodies19a) between the central rail6and the drawer rail7, the supporting body19abearing the load of the drawer3in the closed position of the drawer rail7. In the shown embodiment, both supporting bodies19aare also configured as rolling bodies. The rolling bodies18aarranged within the clearance17aare thus spaced by the formation of a gap from the running surface23aof the drawer rail7and are thus not subjected to vertical forces which could cause deformation or breakage of the rolling bodies18a. In the closed position of the drawer rail7, the weight force is carried by the supporting bodies19aand19cwhich are located to the left and to the right of the rolling bodies18a.

Moreover, in the shown embodiment, the running limb22of the carcass rail5is also provided with a clearance (expanded space)17b. The clearance17b, as well as the clearance17a, can be formed as a depression or recess in the carcass rail5which accommodates the rolling bodies18b(which are arranged between the carcass rail5and the central rail6) in the closed position. In this way, the rolling bodies18b, in the closed position, are relieved from the load of the drawer3and protected from deformation, and the load in that case is carried by the supporting bodies19b. Arranged below the rolling bodies18bthere are at least two rolling bodies18cwhich bear against the underside of the running limb22of the carcass rail5. The rolling bodies18cresting against the underside of the running limb22, together with the running bodies18band the rolling bodies18dand18cspaced therefrom, are arranged in a common running carriage27(seeFIG. 7). In the rear end region, a separate running carriage is provided for accommodating the rolling bodies20. The rolling bodies20are arranged between the central rail6and the drawer rail7.

FIG. 4ashows the drawer pull-out guide4in a cross-section. The carcass rail5has the running limb22, the central rail6has a running surface23b, and the drawer rail7has a running surface23aalong which the various rolling bodies18a-18ecan roll off. The rolling bodies18aand18b, in the closed position of the drawer pull-out guide4, are each relieved by the arrangement of a clearance17a,17b. The weight force, in the closed position, is carried by the supporting bodies19a,19b,19c.

FIG. 4bshows the framed region ofFIG. 4ain an enlarged view. The running limb22of the carcass rail5has a trough-shaped clearance (expanded space)17bin which the rolling bodies18bare accommodated in the closed position of the drawer pull-out guide4and are thus relieved from the occurring weight force. In the lower plane, the load is carried by the front supporting bodies19b. The clearance17ais formed in the running surface23aof the drawer rail7. In the upper plane, the load is carried by the supporting bodies19a,19c. It is also possible to provide a clearance (expanded space)17a,17bin the upper and lower running surface23bof the central rail6for relieving the rolling bodies18a,18b, whereby these can be relieved in the closed position of the drawer pull-out guide4. According to an embodiment, at least two of the two or more rolling bodies18a,18b, which are arranged within the common running carriage27have different diameters. Thereby, it is advantageous when the diameters of the rolling bodies18a18b, in a direction towards the front end9of the extension rails6,7, decrease continuously, whereby the weight force, in an open position of the drawer pull-out guide4, is distributed more uniformly onto the rolling bodies18a,18b. In this sense, it is also beneficial when the diameters of the supporting bodies19a,19b,19care smaller than the diameters of the rolling bodies18a,18b. In the shown Figure, two or more supporting bodies19a,19b,19care provided which, in the closed position of the drawer pull-out guide4, are located outside the clearances (expanded spaces)17a,17band thereby carry the load of the drawer3. The supporting bodies19a,19b,19ceach can have the same diameter. According to an alternative embodiment, the diameters of the supporting bodies19a,19b, in a direction towards the front end9of the drawer pull-out guide4, can also decrease continuously so that each foremost supporting body19a,19bis smaller than the other supporting bodies19a,19c.

FIG. 5a-5cshow (highly schematized) the sequence of the opening process of the drawer pull-out guide4. In the fully closed position according toFIG. 5a, both the upper rolling bodies18aand the lower rolling bodies18bare each arranged within a common clearance (common expanded space)17aand17b, wherein the upper half expanded space17ais formed in the running surface23aof the drawer rail7and the lower half expanded space17bis formed in the running limb22of the carcass rail5. In this way, the rolling bodies18aand18bare relieved from the load of the drawer3. In the closed position, the load rests on the lower and upper supporting bodies19a,19b,19cwhich are located outside the clearances (expanded spaces)17a,17b. When now the drawer rail7is being moved in the extension direction24by a person, the rolling bodies18aand the rolling bodies18bare moved, one after the other, out of their associated clearances17a,17b(FIG. 5b) and are loaded by the drawer rail7. Instead of the supporting bodies19a,19b,19c, the rolling bodies18a,18binteract with the running limb22of the carcass rail5and with the running surface23aof the drawer rail7, respectively, as shown inFIG. 5c. InFIG. 5c, it can also be seen that the drawer rail7, by way of the choice of diameter of the rolling bodies, is arranged in a slight inclined position, wherein the front side end9of the drawer rail7faces upwards. The inclined position is, however, compensated for by the load of the drawer3so that the drawer3eventually can be moved in a (ideal) horizontal plane. Moreover, the inclined position of the drawer rail7improves the engagement of the rolling bodies18a,18bwhen closing the drawer3. The diameter of the rolling bodies18a,18band the diameter of the supporting bodies19a,19bcan reduce in a direction towards the front end9of the drawer rail7. The clearances (expanded spaces)17a,17beach have a substantially flat base surface portion25and inclined surface portions26a,26b(FIG. 5c), whereby the rolling bodies18a,18bcan be moved into the clearances17a,17bwithout abutting an edge and with little effort.

FIG. 6a-6cshow schematically a further embodiment of the drawer pull-out guide4, wherein a clearance (expanded space)17cin the form of an opening or recess is arranged in the running surface23bof the central rail6. In the closed position according toFIG. 6a, the rolling bodies18aare located within the clearance17cof the central rail6and are thus relieved from the load of the drawer rail7. In the closed position, the load of the drawer rail7is carried by the supporting bodies19a,19c. By way of the clearance17c, also the lower rolling bodies18bare relieved, while the load in this plane is carried by the lower supporting bodies19b. Upon a movement of the drawer rail7in extension direction24, the central rail6is initially elevated by the interaction of the rolling body18awith the central rail6, wherein the lower supporting bodies19aare relieved. Upon a further movement of the drawer rail7in extension direction24(FIG. 6c), the supporting bodies19aand19care relieved because the drawer rail7now rests on the rear rolling bodies20and on the rolling bodies18ahaving a larger diameter. Thus, the drawer rail7is slightly in an inclined position, wherein the front end of the drawer rail7faces upward. The inclined position is however compensated for by the loading so that the drawer rail7is substantially horizontally displaceable over the entire movement path.

FIG. 7show a possible embodiment of a drawer pull-out guide4in a highly schematized view. The carcass rail5has upper and lower running limbs22, the central rail6has upper and lower running surfaces23b, and the drawer rail7has a running surface23aalong which rolling bodies18a,18b,18c,18d,20can be rolled off. A first clearance (expanded space)17ais arranged in the running surface23aof the drawer rail7, and a second clearance (expanded space)17bis arranged in the upper running limb22of the carcass rail5. The clearances17a,17bare each configured so as to jointly accommodate at least two, preferably three or more, rolling bodies18a,18bof the running carriage27(FIG. 4b) therein. The rolling bodies18a,18b,18c, together with the supporting bodies19a,19b,19c, are arranged in a common running carriage27, while the rolling bodies20,18d,18eare accommodated in a (schematically shown) running carriage28which is separate therefrom.

According to an embodiment, the rolling bodies18aare those rolling bodies having the greatest diameter in the upper plane (i.e. between the central rail6and the drawer rail7), wherein the rolling bodies18ahave an equal diameter. The diameter of the smaller rollers of the rolling bodies19a,19ceach have a diameter less than 95% of the diameter of rolling bodies18a, the diameter of the greater rollers of the rolling bodies19aand19ceach have a diameter less than 96% of the diameter of the rolling bodies18a. The rolling bodies18blocated in the lower plane (i.e. between the carcass rail5and the central rail6) are preferably the ones having the largest diameters of the entire drawer pull-out guide4, so that the largest occurring diameter of the lower rolling bodies18bis larger than the largest occurring diameter of the upper rolling bodies18a. In the shown Figure, the diameter of the lower rolling bodies18barranged in a common running carriage27reduces, preferably continuously, in a direction towards the front end9of the drawer pull-out guide4, whereby the weight forces, with the drawer pull-out guide4in an extended condition and under load, are distributed more evenly onto the rolling bodies18bhaving a different diameter. The smallest diameter of the lower rolling bodies18bhas a diameter which is approximately 98% of the diameter of the largest rolling body18b. Also, at least three supporting bodies19bcan be provided within a common running carriage27, and the diameter of the supporting bodies19bin the common running carriage27reduces, preferably monotonously (continuously), in a direction toward the front end9of the drawer pull-out guide4. The rolling bodies20,18d,18eare arranged within a running carriage28which is separate from the first running carriage27and each have a different diameter, and the rolling bodies20are smaller than the rolling bodies18eand the rolling bodies18eare smaller than the rolling bodies18d.

The applied rolling bodies18a,18b,18c(as well as the rolling bodies18d,18eand20) are each arranged within a common running carriage27and28, respectively, in which they are held with a predetermined spacing relative to each other. The rolling bodies18a,18b,18c,18d,18e,20also can have different shapes, for example in the form of balls, cylindrical rollers, discs, pins, tapered rollers or tons. According to an embodiment, at least two, preferably three or more, rolling bodies18a,18bcan jointly be accommodated within a common clearance17a,17b,17c.