Sealing device

The invention relates to a sealing device for sealing two parts with essentially flat surfaces, at least one part having a sealing groove for receiving an elastic seal, the sealing groove having a groove cross-section which is larger than the cross-section inside the sealing groove that is in the sealing groove inserted seal in unloaded condition.

Sealing devices of the type mentioned are known. In addition to the general requirement that the seal must be as insensitive as possible to the sealing medium and produce a reliable and permanent seal between the parts, there is also the requirement for simple manufacture. In many applications there is the additional objective that the sealing surfaces of the parts to be sealed have the smallest possible spacing from one another or are even in direct body contact with one another. In addition, it should be possible to manufacture seals with a complex geometrical plan in the simplest possible manner.

It is known to bring dimensionally elastic seals, for example made of polyurethane, into the desired shape by water jet cutting. Seals of this type are usually placed in a sealing groove of one of the two parts to be sealed which is adapted in cross section to the seal, the seal being designed to protrude with respect to the flat surface of the part. Sealing takes place by pressing the second part against the seal, the surfaces of the parts to be sealed being slightly spaced from one another. Due to the incompressibility of the sealing material of the seal filling the groove, a minimum gap is unavoidable to ensure a good seal. In many cases, however, direct contact between the two surfaces to be sealed is desirable.

From US Pat. No. 5,722,667 A, a sealing device for sealing two essentially flat surfaces is known, the seal being arranged in grooves in the parts. The seal itself consists of O-rings, which are encased in a stiffer material. The sealing sleeve is pressed against the groove flanks by the flexible O-rings, creating a secure seal. Due to the complicated structure of the seal, however, production is relatively expensive. This seal is particularly unsuitable for sealing surfaces with a complicated floor plan. This seal can only be used as a sealing cord. One or more closed contours on a seal cannot be realized. This seal cannot vary in width either.

The publications US 4,776,600 A and US 5,482,297 A disclose sealing devices for sealing two parts of the type mentioned at the beginning. However, particularly in the case of more complex geometrical floor plans, such sealing elements can very easily fall out of the groove or move out of the predetermined position during assembly and disassembly work. so that a secure seal is no longer guaranteed.

The object of the invention is to avoid these disadvantages and to achieve reliable sealing of two parts in the simplest possible way. In particular, a sealing gap between the two parts should be avoided.

According to the invention, this is achieved in that the seal has lateral retaining claws formed by material projections. The retaining claws reliably prevent the seal from accidentally falling out or shifting during assembly or disassembly.

Elastic seals, which for example consist of polyurethane, are essentially incompressible. This means that when there is a pressure load, there is only a change in shape, but practically no change in volume. The fact that the groove cross-section is designed to be larger than the cross-sectional area of ​​the part of the seal lying within the seal groove in the unloaded state ensures that the material of the seal can fill the previously unfilled areas of the seal groove under load and the seal can thus completely be relieved of the load Sealing groove is added. This is possible if the groove cross-section of the sealing groove corresponds at least to the cross-sectional area of ​​the seal. In order to keep the manufacturing effort as low as possible, the sealing groove is only molded in part. Alternatively, however, it can be provided that each part has a sealing groove for receiving the seal, the sum of the groove cross-sections of the sealing grooves being greater than the cross-sectional area of ​​the seal and the sum of the groove depths being less than the seal height.

In a particularly preferred embodiment of the invention it is provided that the sealing groove is designed as a dovetail groove. The dovetail groove enables

AT 411 289 B on the one hand a good fit of the sealing groove, which preferably has a rectangular cross-sectional area, and on the other hand provides sufficient free space for the parts of the sealing material that migrate under load. It can be provided that the dovetail groove has an opening angle between two opposite groove flanks of approximately 15 ° to 45 °, preferably approximately 30 °.

In order to guarantee a secure seal, it is advantageous if the depth of the sealing groove is smaller than the height of the seal.

In principle, the seal can have any possible geometric outline. Simple and inexpensive shaping is possible if the seal, which is preferably designed as a molded seal, is formed by water jet cutting.

The seal is loosely guided in the area of ​​the collar of the dovetail groove to facilitate assembly and disassembly.

The invention is explained in more detail below with reference to the figures. 1 shows a sealing device according to the invention in the unloaded state in a cross section, FIG. 2 shows the sealing device in a loaded state, and FIG. 3 shows a plan view of a seal of the sealing device according to the invention.

1 shows a part 1 of two parts 1, 2 to be sealed with a molded-in sealing groove 3 which is designed as a dovetail groove 4. A seal 5 made of polyurethane and having a rectangular cross-section is inserted into the sealing groove 3. In the unloaded state, the seal 5 has a width B which corresponds at most to the width of the collar 6 of the dovetail groove 4. The height H of the seal 5 is slightly greater than the depth T of the seal groove 3.

The lateral groove flanks 7, 8 of the dovetail groove 4 have an opening angle α which is between 15 ° and 45 °, preferably around 30 °. The collar 6 can be flattened over an area a in order to facilitate the insertion of the seal 5 and to avoid damage to the seal 5 due to sharp edges. In the one shown in Fig. 1 In the unloaded state shown, the seal 5 fills only part of the dovetail groove 4 and protrudes slightly over the flat surface 9 of the part 1.

FIG. 2 shows the assembled parts 1 and 2, which are sealed against one another by the seal 5. The flat surface 10 of the second part 2 rests on the flat surface 9 of the first part 1. As a result, the seal 5 is pressed into the sealing groove 3, so that the material of the seal 5 fills the dovetail groove 4. As a result of this elastic deformation of the seal 5, it rests in a force-locking manner on part 2 and causes both parts 1 and 2 to be reliably sealed.

In order to enable simple assembly and disassembly, the seal 5 is inserted loosely over the collar 6 of the seal groove 3 into the dovetail groove 4. The seal 5 can be prevented from falling out of the sealing groove 3 if the seal 5 - viewed in plan - has retaining claws 12 formed by lateral projections 11, which rest on the collar 6 of the sealing groove 3 and slightly tension the seal 5 laterally. The lateral retaining claws 12 are shown in Fig. 3 evident. The seal 5 can be designed with any desired layout. The shape of the floor plan is expediently done by a water jet cutting machine, a particularly good cutting result can be achieved if the raw material of the seal 5, for example polyurethane sheets, is glued to a thin plastic sheet before cutting.