EP2112285A2 - Linear guide for drainage fitting of a cistern - Google Patents

Abstract

The guide has a fixed guide element (1) including a defined bearing surface (11), and movable guide element (2) including another defined bearing surface (21), which is larger than the former defined bearing surface of the fixed guide element. The latter bearing surface of the movable guide element includes interruptions (3) with periodic movement of the guide, such that the contact area and the surface of tangential stuff region of the guide elements are smaller than the bearing surface of the fixed guide element. The fixed and movable guide elements are made up of plastic material.

Description

The present invention relates to linear guides for drain fittings and actuators according to the preamble of claim 1.

Drain fittings are usually made of plastic. These are located in a cistern filled with water. A drain fitting comprises a drain valve, an overflow pipe and a Spülkastenverschlussglied and an actuator. For rinsing off partial or total scavenging quantities, the rinsing box closure member is moved away from the valve seat by a lifting device in a linear guide. Often, the Spülkastenverschlussglied is connected to the overflow pipe. About the actuator, the drain valve can be controlled so that it comes either to Teilspülungsvorgang or to Vollspülungsvorgang. To close the lower Spülkastenöffnung the Spülkastenverschlussglied must be returned exactly to its starting point, so that not constantly flushing water escapes. By pressing the actuating device, the lifting device is activated, so that the Spülkastenverschlussglied is optionally moved together with the overflow pipe in a linear guide.

Linear guides consist of at least two guide elements whose surfaces interact during the relative movement of the guide elements, so that friction and wear play a major role. friction and wear depend on a wealth of factors: among other things, the types of movement and the movement of the guide elements. Overall, the frictional forces counteract the relative movement of the guide elements.
Since no lubrication is possible in drain fittings due to the upcoming water, it is not possible to completely separate the guide body from each other (fluid friction). Caused by the contact and the relative movement of the guide body to each other occurs wear, which is noticeable by progressive loss of material on the surface of the guide body. Scoring on the surfaces worsens the properties of the linear guide over its lifetime.

The force for actuating the lifting device and thus the linear guide is limited to international standards. Usually attempts are made to minimize frictional forces due to large guide lengths and large guide diameters. Friction and wear in plastic guides are composed of deformative and adhesive components. The deformative frictional force changes depending on the modulus of elasticity of the plastic degressive or progressive with increasing surface roughness. The adhesion is based on the van der Waals interaction of the sliding partners involved. Since these forces, depending on the material and guide surface cause large frictional forces and mass transfer, these obstacles must be overcome by the actuator or the lifting device in particular at the beginning of movement.

Due to the high proportion of adhesion in the friction linear guides on Spülkastenverschlussgliedern or overflow tubes long guide lengths required to keep the normal forces in guides below the wear limit small. From this, the size of the valve and thus the use of material is increased.

From the DE 10 2005 020 747 A1 a drain fitting for a cistern is disclosed. In the bottom of the cistern, a drain valve with an overflow pipe and a trained at the end of the overflow pipe Spülkastenverschlussglied is arranged over an opening. The overflow pipe is guided in a drain valve housing. The force for lifting the Spülkastenverschlussglieds is transmitted from an actuator via the lifting device on the overflow pipe. The overflow pipe is guided as a movable guide element in the drain valve housing, in which in turn the counter-guide elements are arranged.

The invention is based on the object to improve linear guides in drain fittings.

This object is achieved by a linear guide with the features of the independent claim 1. Advantageous developments are the subject of dependent claims and included in the description.

Accordingly, in a linear guide for sanitary drain fittings with a fixed guide member having a first defined guide surface and with a movable guide member having a second guide surface which is larger than the guide surface of the fixed guide member, wherein in the relative movement of the guide elements, the fabric areas touching the fixed guide member and the movable guide member, provided that the guide surface of the movable guide member has interruptions at regular intervals in the direction of movement of the linear guide, such that the contact surface of the contacting fabric portions of the guide elements is smaller than the guide surface of the fixed guide member.
The fixed guide element -or also referred to as the base body-is a solid body on which the movable guide element -or else called the counter body-slides along. There, where the material areas of the two solids Touch, it comes to friction, which counteracts the relative movement. In the present invention, the movable guide element on its guide surface interruptions, through which the contact of the contacting material areas of the two guide elements is separated again and again in the relative movement. Furthermore, the contact surface, within which it can come to the interaction between contacting material areas of the two guide elements, reduced.

Manufacturing tolerances and production-related deformations in guide elements, which are noticeable in both differences in material thickness and shrinkage, must be taken into account in the design of linear guides. Furthermore, the linear guide should work well over its entire life, even if wear has occurred. Therefore, it is advantageous if the guide elements are arranged with a certain clearance or distance from each other. This distance can be in the microscopic or measurable millimeter range. This means that when interrupting the contact of the guide elements at the same time comes to a lifting perpendicular to the direction of movement. As a result, the movable guide member rattles or bumps over the guide surface with interruptions, whereby frictional forces are also reduced.
Preferably, the interruptions in the guide surface are arranged such that a continuous contact of the substance regions of the two guide elements is ensured. This means that when one edge of the defined guide surface reaches or passes over an interruption, another part of this edge is nevertheless guided in an area where contact is ensured in the material region of the guide elements. This prevents that the guide is interrupted altogether or tilt the guide elements. In advantageous embodiment variants, the interruptions are provided as notches or as concave depressions. Preferably, the interruptions are provided as grooves which extend linearly over the guide surface of a guide element.

In this case, the interruptions are arranged at intervals relative to one another in the direction of the relative movement, which are matched to the size or length of the defined guide surface.
Preferably, the interruptions run at an angle α relative to the direction of the relative movement.
Further embodiments of the linear guide according to the invention have interruptions that are oval, elliptical or circular.

According to a preferred embodiment of the invention, the guide elements are made of plastic.
In this case, the relative movement of the guide elements takes place both in a gaseous and liquid surrounding medium, in particular in water.

According to a preferred embodiment, a use of the linear guide according to the invention is provided in a sanitary drain fitting, wherein the fixed guide element is provided an extension to a drain valve housing and the movable guide element in the form of an overflow pipe or Spülkastenverschlussglieds.
Preferably, the overflow pipe is guided by a plurality of over the circumference of the overflow pipe distributed extensions of the lifting device.

The further development variants described above are particularly advantageous both individually and in combination. All training variants can be combined with each other. Some possible combinations are explained in the description of the embodiments of the figures. However, these possibilities of combinations of further development variants presented there are not exhaustive.

Fig. 1

eine explosionsartige Ansicht einer sanitären Ablaufarmatur mit einer erfindungsgemäßen Linearführung

Fig. 2

einen Schnitt durch eine erfindungemäße Führungsbahn im Detail

Fig. 3

einen Schnitt entlang der Linie III-III in Fig.2

In the following the invention will be explained in more detail by exemplary embodiments with reference to drawings. Show

Fig. 1

an explosive view of a sanitary drain fitting with a linear guide according to the invention

Fig. 2

a section through a erfindungemäße guideway in detail

Fig. 3

a section along the line III-III in Fig.2

The invention is not limited to the illustrated embodiments of the FIGS. 1 to 3 limited.

FIG. 1 shows a part of a drain fitting 4 made of plastic, which is in a cistern (not shown), which is filled with water, is used. The items are shown exploded. The drain fitting 4 comprises an overflow pipe 5 with a Spülkastenverschlussglied 51 and an actuator (not shown) and a lifting device 6, 61, which serves to open the drain valve. The cistern usually has at its lower end a drain opening which is closed by the Spülkastenverschlussglied 51, which cooperates with a valve seat provided there.
For rinsing certain amounts of water, the overflow pipe 5 is moved with the Spülkastenverschlussglied 51 by a piston 61 which is guided in the drain valve housing 6, by means of a linear guide from the valve seat. The linear guide comprises a plurality of fixed guide elements 1 and a movable guide element 2, wherein the movable guide element corresponds to the overflow pipe 5.
The fixed guide elements 1 are formed on the one hand by a plastic half-shell 7, which is firmly connected in use with the drain valve housing 6, and on the other hand by the drain valve housing 6 itself. Overall, four guide surfaces 11 are provided on the fixed guide elements 1, which are arranged in the circumferential direction at different distances from the movable guide element 2. The movable guide element 2 in turn has in the circumferential direction at several points raised guide surfaces 21, which correspond to the guide surfaces 11 of the fixed guide elements 1.

In the cistern, the relative movement of the two guide elements 1, 2 usually takes place in the water. Since thus no lubricant is present, which separates the two sliding partners, there is an interaction between the two substance areas of the guide elements 1, 2, which counteracts the relative movement. In addition, due to atomic bonds additional adhesive forces between the guide elements 1 and 2 act.
Due to the inventive design of the guide surface 21 of the overflow pipe 5 and the associated interruptions 3, the contact surface, within which it can lead to interactions between the fabric regions of the guide elements 1, 2, initially reduced. Furthermore, the guide elements 1, 2 move away from one another in the region of the interruptions 3, with the result that adhesive forces which occur at the atomic level between the guide elements 1, 2 also decrease disproportionately with the distance.

Since the pending water penetrates into the interruptions 3 and notches, the substance areas in which it interacts, cooled and wetted with water, so that it comes to reducing the adhesion by changing the interfacial tension of the participating friction partners.
Overall, friction and wear can be minimized thereby, so that the life cycle of the linear guide can be considerably extended.

FIGS. 2 and 3 show details of the linear guide. The fixed guide element 1 is part of the plastic half-shell 7. An extension on the plastic half-shell 7 defines a specific guide surface 11. The movable guide element 2 is part of the overflow tube 5. In the surface 21 of the guide element 2 interruptions 3 are arranged, which have a notch shape. Out FIG. 3 it becomes clear that the interruptions 3 not perpendicular to the direction of movement, but inclined at an angle α to the direction of movement. The dimensions of the contact surface, the interruptions 3 and the distances between the interruptions 3 are chosen so that it can not come to the hooking of the guide surface 11 at the interruptions 3. For this purpose, the dimensions h and b of the guide surface 11 are selected so that the largest part of the guide surface 11 is guided during the movement process on the surface 21 of the movable guide element 2, while only portions of an edge of the guide surface 11 in the region of another interruption. 3 reach. Thus, the contact surface of the guide elements 1, 2 is basically smaller than the smallest guide surface 11, 21 of the guide elements. Through the interruptions 3 takes place in the movement process, a slight rattling, which reduces the surface contact of the guide elements 1, 2 temporarily and thus the adhesion. Overall, the frictional forces and the wear can be reduced by the selected construction of the guide elements 1, 2 so that predetermined Aushebekräfte can be maintained throughout the life and long life cycles are achieved despite interaction of surfaces and materials.

LIST OF REFERENCE NUMBERS

1

Fixed guide element

11

guide surface

2

Movable guide element

21

guide surface

3

interruption

4

drain unit

5

Overflow pipe

51

Spülkastenverschlussglied

6

Drain valve housing

61

Piston, lifting device

7

Plastic half-shell

Claims (15)

Linear guide for sanitary drain fittings, with a fixed guide element (1), - - Having a first defined guide surface (11), and a movable guide element (2), - - Having a second guide surface (21) which is larger than the guide surface (11) of the fixed guide element (1),
characterized in that the guide surface (21) of the movable guide element (2) has interruptions (3) at regular intervals in the direction of movement of the linear guide, such that the contact surface and thus the surface of contacting material areas of the guide elements (1,2) is smaller than the guide surface (11) of the fixed guide element (1). Linear guide for sanitary drain fittings, with a movable guide element, - - Having a first defined guide surface, and a fixed guide element, having a second guide surface which is larger than the guide surface of the movable guide element, characterized in that the guide surface of the fixed guide member having interruptions (3) at regular intervals in the direction of movement of the linear guide, such that the surface of the contacting material portions of the guide elements is smaller than the guide surface of the movable guide member. Linear guide according to claim 1 or 2, characterized in that the guide elements (1,2) are arranged at a distance from each other. Linear guide according to one of the preceding claims, characterized in that the interruptions (3) are arranged such that a continuous contact and / or a continuous contact of the substance regions of the two guide elements (1,2) is ensured. Linear guide according to one of the preceding claims, characterized in that the interruptions (3) are provided as notches. Linear guide according to one of claims 1 to 4, characterized in that the interruptions (3) are provided as concave depressions. Linear guide according to one of claims 1 to 4, characterized in that the interruptions (3) are provided as grooves. Linear guide according to one of the preceding claims, characterized in that the interruptions (3) extend at an angle α relative to the direction of movement of the linear guide. Linear guide according to one of the preceding claims, characterized in that the interruptions are provided oval, elliptical or circular. Linear guide according to one of the preceding claims, characterized in that the guide elements (1, 2) are made of plastic. Linear guide according to one of the preceding claims, characterized in that the relative movement of the guide elements (1, 2) takes place both in a gaseous and liquid surrounding medium. Linear guide according to claim 11, characterized in that the liquid surrounding medium is water. Linear guide according to one of the preceding claims, characterized in that the guide surface (21) of the movable guide element (2) is raised with respect to its remaining surface. Linear guide according to one of the preceding claims, characterized in that the fixed guide element (1) is provided as an extension on a lifting device (6, 61) and the movable guide element (2) in the form of an overflow tube (5). Linear guide according to one of the preceding claims, characterized in that the movable guide element (2) in the form of the overflow tube (5) by a plurality of solid over the circumference of the overflow pipe (5) distributed guide elements (1) in the form of extensions of the lifting device (6, 61 , 7) is guided.

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