EP2149315B1

EP2149315B1 - Guide for overhang extractable drawers

Info

Publication number: EP2149315B1
Application number: EP08425514A
Authority: EP
Inventors: Antonio Cabini
Original assignee: ICAS Srl
Current assignee: ICAS Srl
Priority date: 2008-07-28
Filing date: 2008-07-28
Publication date: 2010-09-15
Anticipated expiration: 2028-07-28
Also published as: EP2149315A1; ES2353042T3; ATE481014T1; DE602008002585D1

Abstract

Three stage (100, 200, 300) telescopic guide (10, 11), in particular for extractable drawers of pharmacy furniture, wherein the second stage (200) is guided by the first stage (100) by means of roller bearings, which comprise at least an alignment and clearance recovery bearing (231, 232); preferably there are provided guide bearings (230) having a horizontal axis, a rear bearing (231) for vertical clearance recovery and further bearings (232) for alignment and transversal adjustment.

Description

Field of the invention

The present invention relates to the field of guides for overhang extractable drawers, and more in particular to a telescopic guide of the three-stage full extraction type. The invention is used in particular in the field of pharmacy furniture.

Known art

Various types of guides are known, which are used for overhang extractable drawers. In particular, a so called three stage telescopic guide substantially comprises a first stage, which is fixed to a piece of furniture or a supporting structure; a second intermediate stage, which slides with respect to the first stage, and a third stage, which in turn is slidable with respect to the second stage, and which is integral with the side of the extractable drawer, or which is composed of the same side of drawer. Each of the three guiding stages is substantially represented by an essentially longitudinal profile, usually made of metal.
There are various known systems for ensuring telescopic sliding, depending on type of application. For example, telescopic guides with ball fillings are known, which have the advantage of a reduced size, although they can withstand small loads, they allow a certain torsion and have a relatively high clearance; for these reasons they are used for example in kitchen furniture, but are less convenient in the field of pharmacy furniture, which typically have a considerable overhang (up to 1,20 meters in normal production) and generate relevant loads on the guides.
In the field of drawers for pharmacy furniture, the guides usually slide over roller bearings, positioned with a horizontal rotation axis, and therefore a vertical rotation plane parallel to the sliding direction. More in detail, in a conventional three stage telescopic guide for pharmacy furniture, the first stage is represented by a profile having a substantially C-shaped section, wherein the second stage is housed and guided by a pair of roller bearings, both having a vertical axis and being mutually aligned along the telescopic sliding direction. The second stage, in turn, supports at its front end at least another bearing with a horizontal axis, over which the third stage, which is integral with the drawer, slides. A three-stage guide according to the preamble of claim 1 is known from EP-A-1 360 914 .
Telescopic guides are appreciated for various reasons, as they do not take away room in the rear portion of the furniture or supporting structure, and therefore do not reduce the useful volume of the drawer. A drawback of these guides is however the clearance in the vertical direction between the bearings and the guides (i.e. in direction perpendicular to extraction direction of drawer) as well as in the transversal direction.
This problem is particularly felt in the coupling between the first and the second stage. In fact, in the known art, the height of the C-section of the first stage is greater by at least some millimeters than the diameter of the second-stage bearings, for easy coupling and assembly, but the resulting clearance between the guide and the bearings may have negative consequences, such as a less accuracy of movement, less sliding characteristic, guide locking, misaligned stages, torsion forces on the structure, increasing load of the bearings and corresponding rotation pins, with the risk of compromising the reliability.
The clearance cannot be eliminated with a more accurate assembly of the bearings, since costs would be too high, and because of possible installation difficulties or hard sliding of tube drawer. A smooth sliding is important, in particular in the case of drawers for pharmacy furniture, which are required to close automatically due to assembly with a slight inclination (one and a half degree). This automatic re-entry function, as is evident, requires very smooth guides.
With reference to pharmacy furniture, the features of considerable overhang, weight and intensive use have to be taken into account, which require a strong mechanical resistance. Moreover, the guides have to be as simple as possible, and have to be adapted to the different standards of the field.

Summary of the invention

The technical problem solved by the invention is to improve the guiding and alignment precision among stages of a three stage telescopic guide, of the considered type, in particular with reference to vertical and/or transversal clearance, with respect to sliding of same guide, between the first fixed stage and the second intermediate stage.
The idea underlying the invention is to provide alignment and recovery of clearance by means of appropriate positioning of bearings.
The problem is solved with a three stage telescopic guide for extractable drawers, comprising a first fixed stage, a second stage, which is slidable with respect to said first fixed stage, and a third stage, which is slidable with respect to said second stage, wherein the second stage comprises at least a roller bearing with a horizontal axis, which contacts a first guiding surface of the first stage, and at least a further roller bearing disposed to cooperate with at least a second and different contact surface of said first stage, for alignment and clearance recovery between said second stage and said first stage, characterized in that:

said second stage is provided with at least one transversal adjusting bearing, said bearing having a substantially vertical rotation axis and rotation plane which is parallel to the telescopic sliding direction of the same guide, and
said first stage has a C-shaped section, comprising a flange having a peripheral L-bent edge defining a guiding rail for said at least one transversal adjusting bearing.

According to an aspect of the invention, the second stage is provided with a plurality of lateral guide bearings, with a horizontal axis, among which there are provided at least a first guide bearing and a second adjusting bearing, which is positioned at a different height with respect to the first bearing, having a clearance recovery function along a vertical direction, between the bearings of the second stage and guiding surfaces of the first stage.
In substance, the axis of rotation of the transversal adjusting bearing is perpendicular to the axis of rotation or the guide bearings.
In a preferred embodiment, the first stage has a substantially C-shaped cross section, comprising a web or rib and two opposed flanges; said second stage comprises guide bearings with a horizontal axis, which are aligned along the sliding direction and is in contact with one of the flanges of said first stage, and comprises at least a further adjusting bearing with a horizontal axis, which contacts the opposed wing of the same first stage.
Preferably, said vertical adjusting bearing is mounted on the rear of the second stage. More preferably, according to an aspect of the invention, only one vertical adjusting bearing is provided, which is supported on the rear end of second stage; on the other hand, the number of guide bearings is appropriate to the extension of the guide, and is generally at least two.
The first stage having a C section with a flange having a peripheral L-shaped bent edge, defines a guiding rail for a bearing or a plurality of bearings with a substantially vertical axis, and provide transverse adjusting function.
Advantageously, guide and adjusting bearings are mounted on an external side of said second stage.
It is to be noted that the terms of horizontal or vertical axis or plane are used in this description and attached claims referring to the assembled ready-to-use guide, and are to be ,understood, as is evident to the person skilled in the art, regardless of usual tolerances of the field, as well as the possible rearward inclination (as usual for pharmacy furniture installation) to allow automatic re-entry of the drawer under its own weight. The term vertical direction, in particular, refers to the direction which is perpendicular to the telescopic sliding direction of the guides, which normally is equivalent to horizontal direction, except for the above-said inclination.
In a further aspect of the invention, the second stage is also provided with a front bearing acting as a support and guide for the third stage, and said front bearing is aligned to the web of the profile of the second stage. To this end, the bearing is for example installed in a drawing of the side of the profile, advantageously on the external side.
The invention allows an improvement of alignment and guiding precision in a simple and economic way.
The provision of guide bearings and adjusting bearings, mounted at different heights on a side of the second stage, allows a substantial cancellation of vertical clearances between the first and second stage, and ensures a perfect coupling with an easy and smooth mounting. In particular, in the preferred embodiment with a C-shaped first stage and a second stage sliding inside, the invention allows to use bearings with a diameter smaller than the height of the guide, recovering the vertical clearance with the bearings being positioned at different heights, or in a staggered arrangement, on lateral side of the second stage.
The provision of transversal adjusting bearings moreover maintains alignment of guides and reduces torsional stress. A further advantage is due to the drawing of the second stage in the mounting area of the front supporting bearing for the third stage: in fact, by keeping this bearing aligned with the web of the second stage, the weight of the drawer causes a less severe load on the second stage, substantially comprising only bending and no torsion stress.
Another aspect of the invention is the fact that the first stage is provided at the rear end and on the external side of two differentiated bayonets to be inserted into a frame structure, opposed to one single bayonet as in the known art: in particular, according to the invention, the first stage has a larger bottom bayonet, and a smaller upper bayonet, which are sized for their insertion in a supporting structure with a 25 mm pitch as well as 35 mm, these being standard sizes in pharmacy furniture. The supporting structure preferably comprises corresponding differentiated slots for bayonets of the first stage.
The invention relates also to a pharmacy furniture provided with at least a drawer, and typically a plurality of drawers, which slide on telescopic guides as previously defined.
These and further advantages will be readily understood by means of the following description of a preferred and not limiting embodiment of the same, and with reference to appended drawings.

Brief description of drawings

Fig. 1 shows a perspective view of a drawer for pharmacy furniture, which is provided with guides according to the invention,
Fig. 2 shows a simplified transversal section of one of guides of drawer of fig. 1,
Fig. 3 and 4 show views of first stage of guide of drawer according to fig. 1,
Fig. 5 and 6 show views of second stage of guide of drawer of fig. 1, from both sides,
Fig. 7 shows a perspective view of third stage of guide,
Fig. 8 shows a schematic view of guide, in its entirety,
Fig. 9 shows a further view of first stage, from opposite side with respect to fig. 3 and 4,
Fig. 10 shows a mounting detail of first stage in a suitable supporting structure,
Fig. 11 shows mounting of drawer of fig. 1 on a suitable supporting structure.

Detailed description of a preferred embodiment

Fig. 1 shows an extractable drawer 1 for a pharmacy piece of furniture, comprising a front panel 2, sides 3 and rear panel 4, which define spaces 5 for containing pharmaceuticals. The drawer 1 is extractable from a piece of furniture or structure (not shown) over three-stage telescopic guides 10, 11. The sliding direction of the guides 10, 11 and therefore the direction of extraction of the drawer is indicated by A.
Each guide 10, 11 substantially comprises three stages, which are made of respective, telescopically slidable profile elements. More in particular, each guide comprises a first stage fixed to the piece of furniture, a second stage slidingly guided in the first stage, and a third stage guided in the second stage and integral with the side 3 of the drawer 1. The figure shows the first stage 100, second stage 200 and third stage 300 of guide 11.
The second stage 200 (fig. 2) is housed in the first stage 100 and is supported by a front bearing 110, which is mounted on the first stage and is guided by two bearings 230 and by a further rear bearing 231.
Bearings 230 and 231 are mounted on the external side of the stage 200; guide bearings 230 have a horizontal rotation axis x1-x1 and are aligned to each other along direction A of telescopic sliding; the further adjusting bearing 231 is rotatable about an axis x2-x2, which is also horizontal, and is mounted on the external side of stage 200, at a different height, i.e. staggered by a distance "d", with respect to the guide bearings 230. Therefore, bearings 230 roll over a contact surface 150 of first stage 100, whereas the adjusting bearing 231 rolls in contact with a different surface 151, thereby achieving cancellation of vertical clearance, i.e. a perfect coupling between stages 100 and 200. Preferably, the bearing 231 has the same diameter as bearing 230.
Moreover, the second stage 200 is also guided by two transversal adjusting bearings 232, which have a vertical rotation axis indicated as y-y. Said bearings 232 roll in contact with further opposed surfaces 152 and 153, recovering the transversal clearance and maintaining a constant alignment among the same stages 100 and 200.
The stages of the guides 10, 11 are individually shown with greater detail in Figs. 3 to 7.
The first stage 100 (Figs. 3 and 4) is substantially formed of a C-shaped metal profile, having a web 101 and flanges 102, 103 which define a housing space 104 for the second stage 200 and bearings 230 and 231. In the front, the first stage 100 carries a bearing 110 acting as support and adjusting bearing for the second stage.
In self-supporting guides, as shown, the first stage 100 is further provided with a bolt 117, which is inserted during assembly, exerting a supporting action, inside an upright of a metal frame of the furniture (not shown), and with a pin 112 with return spring 113, to prevent unintentional separation of stage 100, by engaging a corresponding hole or slot of the frame.
The lower flange 103 is centrally provided with a substantially V-shaped groove 114, where the guiding bearings 230 of the second stage roll, and essentially defining the respective contact surface 150. The adjusting bearing 231 rolls by contacting internal surface 151 of the upper flange 102, as shown in Fig. 2.
The upper flange 102 has a substantially L-shaped section with a bent edge 115 defining a space 116 for housing and guiding the transversal adjusting bearings 232, which in use contact the internal surfaces 152 and 153 of the web 101 and said bent edge 115, thereby aligning the stages 100 and 200. It is evident from the above detailed description, that a torsion of stage 200 inside stage 100 is prevented by said bearings 232.
Moreover, the first stage 100 is provided with suitable inserts of elastic material, for instance small gum knobs, for softening the contact with the second, moving stage 200: in particular it is provided on the rear side with an insert of soft material or small gum knob 120 with a hook-shaped front portion 121, defining a space 122 for housing one of the bearings of the second stage 200, in order to obtain a slight mechanical retaining action of said second stage, to ensure a sequential opening of the stages of the telescopic guide.
A gum knob 130 (Fig. 3), approximately positioned at half the length of the stage 100, acts like an exit end stop; by removing this gum knob 130, it is possible to extract the second stage from the first stage.
The shaped gum knob 120 has also the function to close the rear of the first stage 100 and avoid separation of the second stage 200.
The second stage 200 (Figs. 5 and 6) is essentially made of a profile 201, suitably shaped, therefore forming a further space 204 for housing and guiding the third stage 300.
In particular, stage has a side or rib 202 which supports the guide bearings 230 and the rear adjusting bearing 231 on the external side 206; moreover, it has an upper flange 205 supporting a pair of bearings 232 with vertical axis. Figures refer to a particularly preferred embodiment, wherein the second stage 200 comprises two guide bearings 230 and a single vertical adjusting bearing 231, which is positioned on the rear side.
Said bearings 232 generally have a diameter less than bearings 230 and are guided inside the rail 116 of the first stage, in order to maintain transversal alignment between stages 100 and 200 and reduce torsional stress on the second stage 200.
The second stage 200 is further provided with a front bearing 210, which is set in a cupping 211 of the rib 202, bringing it in alignment with the upper edge 203 of the rib 202, and allowing that the weight of the drawer is transmitted to said rib. It is to be noted that cupping 211 advantageously allows that the bearing 210 is mounted on the external side of the profile 201 (at front in fig. 6), contrary to the internal side, as in the known art.
On the front side, the stage 200 is provided with a gum knob 220 which acts like a stop for the third stage 300 and, moreover, drags the second stage during exit and guides it during closing operation.
Third stage 300 (Fig. 7) in the example shown is represented by a Z-shaped profile 301, essentially comprising its own supporting bearing 302 and pin 303 abutting against the knob 220 of the second stage. Said third stage may for example be a metallic element, to be screwed on a wood drawer, or it may be integral with the side of drawer, made of aluminum or steel.
A further characteristic of the first stage 100, according to the invention, is shown in Figs. 9 to 11, consisting in two differentiated supporting bayonets 160, 161, in particular a larger bottom bayonet 160, and a smaller upper bayonet 161, sized for the insertion into supporting structure having a pitch of 25 mm or 35 mm, which are the most frequently used standards in the field of pharmacy furniture.
A structure having a pitch of 35 mm is preferably formed with first-stage insertion slots also differentiated and corresponding to above said bayonets 160, 161. Fig. 10 shows a metallic frame structure 400, of a drawer for a pharmacy, with differentiated slots 401, of greater height, and 402, of lesser height, for first- stage bayonets 160 and 161, respectively. In a structure with 25 mm pitch (shown in Fig. 11), bayonets 160 and 161 are inserted in respective mounting slots of same height.
The operation, in essential terms, is as follows.
At the opening of the drawer, the third stage 300 slides with respect to second stage 200, supported by front bearing 210 and retained on the back side by supporting bearing 302. In this step, the second stage 200 remains fixed with respect to the first stage, due to rear knob 120 retaining rear bearing 231 of same second stage. When the third stage 300 reaches the end-stop position, the second stage 200 is dragged and guide opens telescopically up to complete extraction; in particular, end stop position is defined by abutment of front bearing 232 against knob 130. Above said bearings 231 and 232, during opening, maintain their alignment with respect to stage 100, limiting torsion strains on the guide.
The guide comprised of stages 100, 200 and 300, in a partially extracted position, is shown in Fig. 8, wherein the positions of the bearings are indicated. It is to be noted that bearings are known per se, and widely used in this field, and therefore they are not described in detail.
Assembly is accomplished for example by coaxially coupling the stages and fixing the guide, i.e. the first stage 100, to a supporting structure such as the frame 400 in Fig. 11, by means of bayonets 160, 161 and on the front by means of the bolt 117 and retaining pin 112, which is received in a corresponding hole of the same frame.
The guides 10, 11 according to the invention are fully interchangeable with conventional guides and ensure the above said advantages, regarding better alignment among stages and cancellation of clearance between bearings and respective guides.

Claims

Three stage telescopic guide (10, 11) for extractable drawers, comprising a first fixed stage (100), a second stage (200), which is slidable with respect to said first fixed stage, and a third stage (300), which is slidable with respect to said second stage, wherein the second stage (200) comprises at least a roller bearing (230) with a horizontal axis, which contacts a first guiding surface (150) of the first stage (100), and at least a further roller bearing (231, 232) disposed to cooperate with at least a second and different contact surface (151, 152, 153) of said first stage (100), for alignment and clearance recovery between said second stage (200) and said first stage (100), characterized in that:
- said second stage (200) is provided with at least one transversal adjusting bearing (232), said bearing having a substantially vertical rotation axis (y-y) and rotation plane which is parallel to the telescopic sliding direction (A) of the same guide, and

- said first stage (100) has a C-shaped section, comprising a flange (102) having a peripheral L-bent edge (115) defining a guiding rail (116) for said at least one transversal adjusting bearing (232).
Guide according to claim 1, characterized in that said second stage (200) is provided with a plurality of lateral guide bearings, with a horizontal axis, and said plurality comprises at least a first guide bearing (230) and a second adjusting bearing (231), which is positioned at a different height with respect to the first bearing, with effect of clearance recovery in a vertical direction between the bearings (230, 231) of the second stage (200) and the guiding surfaces (150, 151) of the first stage (100).
Guide according to claim 1 or 2, characterized in that the first stage (100) has a C-shaped section with a web (101) and opposed flanges (102, 103); said second stage (200) comprises guide bearings (230) having a horizontal axis (x1), which are aligned along the sliding direction (A) and in contact with a flange (103) of said first stage, and comprises at least a further vertical adjusting bearing (231), in contact with the opposed flange (102) of said first stage.
Guide according to claim 1, characterized in that the C-shaped first stage (100) comprises a lower flange (103) provided with a V-shaped groove (114), which houses said guide bearings (230) of the second stage (200).
Guide according to claim 3, characterized in that said vertical adjusting bearing (231) is mounted in the rear portion of the second stage (200).
Guide according to claim 3, characterized in that said guide bearings (230) and vertical adjusting bearings (231) are associated to an external side (206) of said second stage (200).
Guide according to any of preceding claims, characterized in that second stage (200) is provided with a front bearing (210) supporting said third stage (300), said front bearing being mounted on the external side and at a cupping (211) of second stage, aligning said front bearing with respect to the web of said profile.
Guide according to any of preceding claims, characterized in that the first stage (100) is provided with a bolt, which during the assembly is inserted into an upright of the metal frame of the furniture, providing supporting function, and a pin (112) having a return spring (113) to prevent unintentional unlatching.
Guide according to any of preceding claims, characterized in that first stage (100) is provided with inserts of elastic material, for softening the contact with the second stage (200).
Guide according to claim 9, characterized in that the first stage (100) is provided on the back with an insert of soft material or gum knob (120), with a hook-shaped front portion (121) defining a space (122) for receiving one of the bearings of the second stage (200), therefore achieving a slight mechanical retaining of said second stage, in order to ensure a sequential slide opening of the stages of the telescopic guide.
Guide according to any of preceding claims, characterized in that first stage 100 comprises two differentiated supporting bayonets (160, 161), which are sized in order to allow insertion into a supporting structure (400), having pitch equal to 25 mm as well as 35 mm.
Extractable drawer, in particular for pharmacy furniture, comprising a guide (10, 11) according to any of preceding claims.
Pharmacy furniture, comprising at least an extractable drawer, by means of guides (10, 11), according to any of claims 1 to 11.