sealing ring

Abstract

Sealing ring (1) with a central axis (X) for a pipe press connection, which in a section orthogonal to the central axis (X) has a circular outer edge (2) and an inner edge (3), wherein in the sealing ring (1) - at least four neutral zones (N) are formed in which the inner edge (3) of the sealing ring (1) is section by section circular arc, which circular arc sections of the inner edge (3) define an inner circle (4), - at least two leakage zones (L) are formed in which the inner edge (3) of the sealing ring (1) is radially offset from the inner circle (4), - at least two retaining zones (H) are formed in which the inner edge (3) of the sealing ring (1) protrudes radially relative to the inner circle (4), and wherein, with reference to one revolution around the central axis (X), - the leakage zones (L) and the holding zones (H) are formed alternately, and - a neutral zone (N) is formed between each leakage zone (L) and the nearest adjacent holding zones (H).

Description

[0001] The present invention relates to a sealing ring for a pipe press connection and a press fitting for water pipes with the sealing ring.

[0002] Pipe press fittings are used in building installations for the permanent connection of pipe sections or segments. Typically, a socket with an integrated sealing ring is pushed over the respective pipe end, and the socket is then permanently pressed to the pipe using a pressing tool, creating a positive and force-fit connection. The present invention aims to provide an improved sealing ring for a pipe press fitting.

[0003] According to the invention, this problem is solved by a sealing ring according to claim 1. This ring comprises an annular base body with a central axis. In a section orthogonal to the central axis, which divides the sealing ring into two identical ring halves or discs, the sealing ring has a circular outer edge and an inner edge that is at least partially arcuate. The sealing ring has at least four neutral zones, preferably at least six, in which the inner edge of the sealing ring is partially arcuate. The arcuate sections of the inner edge together define a common inner circle with a constant radius, i.e., a single circle. In addition to the neutral zones, the sealing ring has at least two leakage zones and at least two retention zones, preferably at least three of each.In the respective leakage zones, the inner edge of the sealing ring is set back radially outwards relative to the inner circle; thus, in the respective leakage zone, the inner edge is located radially further outwards (relative to the central axis) than the inner circle. In the respective retention zones, on the other hand, the inner edge of the sealing ring projects radially inwards relative to the inner circle; it lies radially closer to the central axis than the inner circle defined by the neutral zones. Put simply, an inner radius measured locally in the leakage zone (especially in its central section, see below) is larger than the inner circle radius. Conversely, an inner radius measured locally in the retention zones (especially in its central section, see below) is smaller than the inner circle radius of the sealing ring.

[0004] With respect to one revolution around the central axis of the annular base of the sealing ring, the leakage zones and retention zones of the sealing ring are arranged alternately, and exactly one neutral zone is formed between each leakage zone and the two retention zones nearest to it. In this context, "nearest" refers to the retention zones that follow the leakage zones in the direction of revolution without any further retention zones in between; that is, the retention zones closest to each other. Put simply, the sealing ring has a repeating sequence: neutral zone - leakage zone - neutral zone - retention zone. A neutral zone is formed between each leakage zone and a retention zone; the leakage and retention zones do not follow each other directly (in the direction of revolution).The neutral zones have a constant inner radius, while the radius in the leakage zones is larger and in the retention zones smaller. In this context, the neutral zones could also be described as "arc-shaped inner contour sections"; the sealing ring has its nominal inner diameter in these sections.

[0005] The inventors recognized that the special design of the zones and their sequence according to the invention result in an advantageous sealing ring. In the leakage zones, the inner edge is radially offset and enlarged relative to the inner circle defined by the neutral zones, such that a desired leak point is created if the sealing ring is insufficiently or completely not compressed. If the sealing ring is inserted into a socket and then pushed over a pipe end, but the cold forming of the pipe press connection by forming the socket is omitted or inadequately performed, this faulty connection will be detected during a pressure test (often referred to as "pressure testing" by those skilled in the art) of the assembled pipe section or at the latest during initial commissioning.The leakage zone thus creates a reliably leaky area in the unpressed state of the sealing ring, allowing assembly errors to be detected immediately. The sealing ring is "leaking unpressed" in the leakage zone, indicating, for example, insufficient compression by leakage of the medium in the pipe at a reference pressure of 3 bar. However, significantly lower or higher pressure values ​​can also be defined as the reference pressure, depending, for example, on the medium used. Water or air can be used as the medium for the pressure test. In the case of water, typical pressures for the pressure test are at least 1 bar and at most 6 bar; in the case of air, at least 0.15 bar and at most 6 bar.

[0006] In addition to the leakage zones, the sealing ring also features retention zones where the inner edge of the sealing ring projects radially inwards relative to the inner circle. In the area of ​​the retention zones, the inner radius of the sealing ring is smaller than the inner circle radius defined by the arc-shaped inner contour sections or neutral zones. This radial projection causes a certain degree of expansion when the ring is slid onto a pipe due to the inherent elasticity of the material used. This expansion, in turn, results in a certain clamping force on the sealing ring (in the area of ​​the retention zone). This clamping force prevents the sleeve with the sealing ring inside from slipping, thus making cold forming of the sleeve relatively easy. The installer only needs to hold the tool required for cold forming; the sleeve is held in place by the clamping force without any further action from the installer.

[0007] According to the invention, the three zones alternate as explained above, with a neutral zone (i.e., an arc-shaped inner contour section) following each leak zone or retaining zone. The neutral zone is positioned between two adjacent leak zones and retaining zones; thus, when the sealing ring rotates around its central axis, it lies between each leak zone and its nearest retaining zone (or vice versa). The neutral zone acts as a kind of "buffer" between the leak zone with the larger inner radius and the retaining zone with the smaller inner radius. Compared to alternative approaches in which the leak and retaining zones follow each other directly (i.e., without intervening neutral zones), this arrangement has the advantage that any geometric and / or dimensional deviations (e.g., due to manufacturing) in the respective zones do not interact with each other. For example, if...If, due to manufacturing processes, the inner radius of the retaining zone is in the lower tolerance range (meaning the ring is particularly "tight" in this area) and the inner radius of the leakage zone is in the upper tolerance range (meaning the ring is particularly "wide" in this area), then sliding the sealing ring onto the pipe could result in a comparatively large expansion. This can lead to the leakage zone being bent too far, even when correctly crimped, due to the retaining zone's inner radius being at the upper end of the tolerance range, and consequently exhibiting a certain degree of leakage; thus, an unwanted escape of air or water occurs.In contrast, providing a neutral zone between these extreme points prevents interaction between the two zones; in the case described above, the tolerance deviations due to the spacing of the leakage and retention zones around the circumference of the sealing ring would not cause any adverse interaction through the neutral zone.

[0008] According to the invention, the sealing ring, as already explained, has a circular outer contour. This circular outer contour is relatively easy to manufacture and has the advantage that, when inserting the sealing ring into the socket, it is not necessary to pay attention to the orientation of the sealing ring relative to the socket (in the direction of rotation). Compared to alternative designs, e.g., a corrugated outer contour of the sealing ring, the circular outer contour also ensures a uniform, radially inward clamping force on the sealing ring during cold pressing of the socket; the pipe press connection can therefore be produced simply and reliably.

[0009] In the context of this application, a "pipe press connection" is understood to be a pressure-tight connection between pipe sections when fully pressed; see also the following explanations. The pipe sections are water pipes, in particular those for supplying a building with cold drinking water, hot domestic water, and / or heating energy (i.e., heating supply and return lines). The pipe sections are joined together, for example, by means of the aforementioned socket, into which at least one sealing ring is inserted. This sealing ring is pressed onto the respective pipe section by cold forming the socket, thereby sealing the connection. In the context of this invention, the term "pressure-tight" means a tightness for media, in particular air and water, of at least 1 bar and at most 10 bar; pressures of approximately 1.5 bar to 6 bar are typically present in such pipe networks.

[0010] Various embodiments of the invention are conceivable. Generally speaking, for example, the number of leakage and retention zones can differ, but preferably they are the same. The number of neutral zones corresponds to the sum of the leakage and retention zones. According to a preferred embodiment, the sealing ring described above has at least three leakage zones and at least three retention zones, each separated from the other by a neutral zone (in this case, a total of six neutral zones would be distributed around the circumference of the sealing ring, namely arranged between each of the leakage and retention zones).A larger number of neutral, leakage, and retention zones particularly benefits the centering of the sealing ring on the pipe; in the inventors' experiments, sealing rings with at least six neutral zones, at least three leakage zones, and at least three retention zones have proven especially advantageous for this design. More preferably, the sealing ring has at least four or at least five leakage and retention zones, and particularly preferably at least six (each with neutral zones in between). Regardless of this, possible upper limits are at most twelve, ten, eight, or seven leakage and retention zones (each spaced apart by neutral zones).

[0011] Further preferred embodiments are specified in the dependent claims and are explained in more detail below together with the basic idea of ​​the invention. No further distinction is made between the individual claim categories.

[0012] Preferably, the respective neutral zone of the sealing ring extends over an opening angle of at least 2° relative to the central axis, particularly preferably at least 11° (where possible upper limits, e.g., depending on the number and angular extent of the other zones, may be at most 61° or 59°). In this context, the term "opening angle" refers to the angular range that the respective zone (here: the neutral zone) sweeps out circumferentially relative to the central axis of the sealing ring. A certain minimum extent of the neutral zone relative to the circumference of the sealing ring promotes the desired "buffering effect" between the zones nearest to the respective neutral zone, as already explained above, so that the undesirable interaction between the zones nearest to the neutral zone can be significantly reduced or even largely avoided (see also the preceding explanations).

[0013] As explained above, there is a numerical relationship between the number of leakage, holding, and neutral zones. The minimum angular extent of the neutral zone described above depends on the number of neutral zones. In the preferred case of at least four neutral zones (and correspondingly two holding and two leakage zones), the opening angle of each neutral zone, relative to the central axis, is preferably at least 32° and at most 61°, more preferably at least 41° and at most 59°, further preferably at least 42.5° and at most 56°, and most preferably at least 45° and at most 49°.In the case of six neutral zones (i.e., three holding zones and three leakage zones, each with a neutral zone between them), the opening angle of the neutral zone relative to the central axis is at least 2° and at most 31°, preferably at least 11° and at most 29°, more preferably at least 12.5° and at most 26°, and further preferably at least 15° and at most 19°. In the case of eight neutral zones, possible opening angles for the neutral zone can be at least 4° and at most 16°, preferably at least 11° and at most 14°.

[0014] According to a preferred embodiment, the sealing ring has a circular cross-section in the area of ​​the neutral zones or the arc-shaped inner contour sections. In a cross-sectional plane through the circular cross-section that includes the central axis of the sealing ring, its shape is accordingly circular, particularly preferably circular. Possible diameters of the circular cross-section are at least 1 mm and at most 10 mm, preferably between 2 mm and 8 mm, and particularly preferably between 2 mm and 4 mm. The circular cross-section of the neutral zones is constant over their circumference.

[0015] Alternatively, the sealing ring in the neutral zone area may have a D-shaped cross-section (sometimes referred to as "delta-shaped" in technical circles), meaning its cross-section resembles the capital letter "D". In this case, the nearly straight back side of the D forms the inner edge, while the convex, arc-shaped bulge of the capital letter D points away from the central axis of the ring-shaped sealing ring. Of course, the term "D-shaped" should only be understood as approximating the shape of the capital letter D; for example, the sealing ring does not have any sharp edges in cross-section, but rather certain rounded edges at the transitions (e.g., at least an edge radius of 0.5 mm). Compared to round cross-sections, the D-shape has increased torsional resistance, so that twisting of the D-shaped sealing ring can be largely avoided when it is slid on.In addition, the (approximately flat) rear wall surface of the D (i.e., the vertical leg in relation to the capital letter D) rests on the pipe contained within it over a comparatively large area, thus enabling a reliable seal in the neutral zone.

[0016] Preferably, the respective leakage zone extends over an opening angle of at least 10°, particularly at least 12°, and at most 60°, relative to the central axis. More preferably, the opening angle is at least 12° and at most 45°, more preferably at least 14° and at most 40°, further preferably at least 16° and at most 26°, and most preferably at least 18° and at most 26°. The opening angle refers to the entire circumferential extent of a respective leakage zone; this is measured between the two nearest adjacent neutral zones (or arc-shaped inner contour sections).

[0017] According to a preferred embodiment, the inner edge of the sealing ring has a circular arc-shaped central section in the leak zone and a transition zone on either side of it. Preferably, each transition zone merges tangentially into the central section of the leak zone and tangentially into the next adjacent neutral zone; the inner edge has a change in curvature between these two sections. In other words, the leak zone is formed from three parts: the circular arc-shaped central section located centrally with respect to the leak zone, and the two transition zones on either side of it.Starting from the circular arc-shaped central section, the inner edge of the sealing ring transitions first tangentially and then arcuately into the transition zone, with a change in curvature occurring approximately in the middle of this zone. The inner edge then transitions, first arcuately and then tangentially, into the next adjacent neutral zone. In the context of this invention, the term "change in curvature" refers to a transition of the inner edge where the curvature of the curve changes sign, so that the curve shape changes from concave to convex or from convex to concave; the transition point forms an inflection point (turning point). On both sides of the central section, the inner edge thus has a slight "S-shape," namely, it has two arc segments with a change in curvature between them. Preferably, the inner edge in the leakage zone is mirror-symmetrical with respect to the central section.The leakage zone designed in this way acts like a "bridge" for forces occurring in the radial direction, so that a defined leakage path is kept open in the unpressed state of the sealing ring.

[0018] According to a preferred embodiment, the inner edge of the sealing ring is concentric with the inner circle of the sealing ring in the region of the circular arc-shaped central section of the leak zone. In other words, the inner edge lies on concentric circles in the region of the circular central section of the leak zone and the neutral zones. Such geometries can be manufactured relatively easily, for example, by injection molding with a suitably milled tool.

[0019] Preferably, the respective transition area of ​​the leak zone extends over an opening angle of at least 5.5° and at most 20° relative to the central axis, more preferably at least 8.5° and at most 19°, and particularly preferably at least 10° and at most 17.5°. In this context, the opening angle refers to the circumferential extent of the respective transition area, measured from the point of tangential transition to the nearest adjacent area. By extending the transition area over a certain opening angle, the adjacent central section is stabilized, particularly in conjunction with the change in curvature formed in the transition area, ensuring that the sealing ring is reliably leak-proof in the uncompressed state.

[0020] Preferably, the central section of the leak zone extends over an opening angle of at least 1° and at most 20° relative to the central axis, more preferably at least 2° and at most 10°, and particularly preferably at most 8°. In this context, the opening angle refers to the circumferential extent of the central section of the leak zone; this is measured between the two adjacent transition areas. Extending the central section over a certain opening angle ensures, on the one hand, the reliable function of the leak zone in the event of an incorrectly crimped sleeve, and on the other hand, a reliably closing connection when crimped.

[0021] It is advantageous for the cross-sectional area of ​​the sealing ring in the central section of the leak zone, in a section plane containing the central axis of the sealing ring, to be smaller than in the adjacent transition areas. Put simply, the cross-section is tapered in the central section; this forms the "thinnest" point of the sealing ring.

[0022] According to a preferred embodiment, the respective retaining zone extends over an opening angle of at least 36° and at most 56°, preferably at least 50° and at most 56°, relative to the central axis. The opening angle refers to the entire circumferential extent of a respective retaining zone; this is measured between the two nearest adjacent neutral zones (or arc-shaped inner contour sections). A retaining zone dimensioned accordingly can ensure or at least promote reliable retention of the sealing ring in the uncompressed state.

[0023] Preferably, the sealing ring has a circular arc-shaped central section in the area of ​​the retaining zone and a transition area on either side of it, wherein each transition area merges tangentially into the central section of the retaining zone and the nearest neutral zone, with a change in curvature in between. Preferably, the inner edge in the retaining zone is mirror-symmetrical with respect to the central section. In the case of the retaining zone, the circular arc-shaped central section acts as the actual "clamping section" of the sealing ring, while the transition areas on either side are provided to form a buffer to the neutral zones and to introduce the radial forces evenly (without local stress peaks) into the neutral zone.

[0024] According to a preferred embodiment, the inner edge of the sealing ring is concentric with the inner circle of the sealing ring in the region of the circular arc-shaped central section of the retaining zone. In other words, the inner edges of the sealing ring lie on concentric circles in the region of the circular central section of the retaining zone and in the region of the nearest adjacent neutral zones. This improves the manufacturability of the sealing ring and ensures a geometrically defined fit of the sealing ring on the pipe.

[0025] Preferably, the central section of the holding zone extends over an opening angle of at least 10° and at most 30° relative to the central axis, more preferably at least 12° and at most 25°, and more preferably at least 14° and at most 20°. The appropriately dimensioned central section of the holding zone ensures uniform clamping of the tube while also being relatively easy to manufacture. According to the inventors, the opening angle of the central section of the holding zone is particularly relevant for the holding force and significantly influences it.

[0026] According to a preferred embodiment, the respective transition area of ​​the holding zone extends over an opening angle of at least 13° and at most 20°, particularly preferably at most 18°, relative to the central axis. This can be advantageous with regard to a uniform force transmission from the holding zone to the neutral zone.

[0027] It is advantageous for the cross-sectional area of ​​the sealing ring to be larger in the central section of the retaining zone, in a section plane containing the central axis of the sealing ring, than in the adjacent transition areas. Put simply, the cross-section in the central section of the retaining zone is enlarged or thickened; this forms the "thickest" part of the sealing ring.

[0028] According to a preferred embodiment, the inner circle diameter of the inner circle defined by the arc-shaped inner contour sections is at least 12 mm and at most 56 mm, and in the case of a D-shaped cross-section, in particular at least 28 mm and at most 56 mm. Providing the D-shaped cross-section for (in this context) larger diameters results in improved torsional stiffness (compared to the round cross-section), so that twisting of the sealing ring when sliding it onto the pipe can be avoided or, ideally, largely prevented.

[0029] In principle, depending on the number of neutral, leakage, and retention zones, any configuration of the sealing ring with respect to its symmetry is conceivable. According to a preferred embodiment, however, the sealing ring is point-symmetric with respect to the central axis, and particularly preferably rotationally symmetric with respect to multiple zones. Possible values ​​for the number of zones are at least two and at most 20, preferably between four and twelve. Particularly preferably, the sealing ring is mirror-symmetric with respect to at least one plane containing the central axis, and further preferably with respect to at least two planes (e.g., orthogonally oriented to each other).

[0030] Preferably, the two ring halves or discs of the sealing ring are mirror-symmetrical with respect to a dividing plane that divides it into two equal discs. In other words, the sealing ring is divided into two equal ring discs by a dividing plane perpendicular to the ring axis. This dividing plane preferably forms a mirror plane; the ring discs are mirror-symmetrical to each other. A design of the sealing ring that is symmetrical with respect to the mirror plane simplifies its manufacture and, in particular, its handling, since it is not necessary to ensure the alignment / orientation of the zones with respect to the socket or pipe axis during assembly of the sealing ring.

[0031] Preferably, the neutral, leakage, and retention zones distributed around the circumference of the sealing ring are identically designed as zones of the same type, possessing the same geometry. In other words, with respect to one revolution around the central axis of the sealing ring, preferably all neutral zones, all leakage zones, and (if present) all retention zones are identical. A sealing ring designed in this way is both easy to manufacture and relatively easy to handle, since no consideration needs to be given to any asymmetries during assembly.

[0032] The sealing ring, as is customary in this technical field, is made of an elastically deformable material. According to a preferred embodiment, the sealing ring has a hardness of at least 40 IRHD (International Rubber Hardness Degree) and at most 80 IRHD, measured according to DIN ISO 48-2:2021-02. Particularly preferably, the hardness is at least 65 IRHD and at most 75 IRHD, and even more preferably approximately 70 IRHD. The material of the sealing ring thus possesses a certain inherent elasticity, allowing it to expand radially (to a certain extent) to be pushed onto the pipe and, at the same time, to be sufficiently compressible to achieve a reliable seal over the entire inner circumference when compressed.

[0033] Preferably, the sealing ring is manufactured in one piece from the same material, i.e., without any intervening material boundaries. Furthermore, preferably, the sealing ring is made of a material comprising ethylene propylene diene monomer (EPDM) rubber, silicone rubber, or thermoplastic elastomers, in particular ethylene propylene diene monomer (EPDM) rubber, ethylene propylene ethylidene norbornene rubber, hydrogenated nitrile butadiene rubber (HNBR), butyl rubber (IIR), chlorinated butyl rubber (CIIR), brominated butyl rubber (BIIR), fluororubber (FKM), or a mixture thereof.

[0034] The invention further relates to a press fitting for water pipes, in particular drinking water pipes, with - a socket comprising an insertion space for a pipe end to be inserted therein, wherein the insertion space has a pressing area which is bounded by a pressing wall part; - an annular groove-shaped space that is present in or bounded by the pressed wall section; and - a sealing ring according to one of the above embodiments, which is placed or arranged in the annular groove-shaped space, wherein the pressing area can be plastically transformed or deformed from an unpressed state to a pressed state as a result of a radially inward pressing action applied by a pressing tool, wherein the pressing tool causes a radial compression of the pressing wall part, in particular of the annular groove-shaped space, and the sealing ring simultaneously seals against an inserted pipe end over its entire circumference.

[0035] Furthermore, the use of a sealing ring according to one of the aforementioned aspects for pressure-tight connection of two pipe sections, in particular in a press fitting for a water pipe, especially for pressure-tight connection of several water pipe segments or for obtaining a pressure-tight water pipe, is to be disclosed. In this context, "pressure-tight" means a pressure resistance for fluids, in particular air and water, of at least 1 bar, preferably at least 2 bar, 3 bar or 4 bar (with possible upper limits, irrespective of this, of no more than 16 bar, 12 bar, 10 bar, 8 bar, 6 bar or 5 bar).

[0036] Furthermore, a method for manufacturing a sealing ring according to one of the above aspects shall be disclosed, wherein: - a ring-shaped starting body with a central axis is provided, which in a section orthogonal to the central axis has a circular outer edge and a circular inner edge, wherein in the ring-shaped starting body, preferably due to a suitably designed injection mold, - at least four neutral zones are formed in which the inner edge of the sealing ring is section by section circular arc, which circular arc sections of the inner edge define an inner circle, - at least two leakage zones are formed in which the inner edge of the sealing ring is radially offset from the inner circle, - at least two retaining zones are formed in which the inner edge of the sealing ring protrudes radially from the inner circle, and wherein, with reference to one revolution around the central axis, - the leakage zones and the holding zones are formed alternately, and - a neutral zone is formed between each leakage zone and the nearest adjacent holding zones.

[0037] Furthermore, a sealing ring, which is not part of the claimed subject matter, is to be disclosed. This alternative sealing ring has at least five leakage zones, each connected to the others via arcuate inner contour sections (neutral zones). This sealing ring has only leakage and neutral zones, but no retention zones. This sealing ring can be advantageous if no special requirements are placed on the retention or clamping force (especially for larger pipe diameters, see below). According to a preferred embodiment, the sealing ring described above has at least six leakage zones, each spaced apart from the others by a neutral zone (in this case, a total of six retention zones would be distributed around the circumference of the sealing ring).This sealing ring particularly preferably has at least seven, eight, nine, ten or twelve leak zones (whereby possible upper limits, irrespective of this, are at most 18, 16 or 14 leak zones).

[0038] To simplify the presentation of the invention, aspects of the apparatus, method, and use have been explained separately, with explanations and preferred embodiments relating equally to the apparatus, method, and use. If preferred features are described in connection with the apparatus, it follows that the method or use is also preferably designed and suitable accordingly. Conversely, if preferred features are described in connection with, for example, the method and / or the use, it follows that the apparatus is also preferably implemented accordingly.

[0039] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention.

[0040] Generally, “ein” and “eine” within this revelation are to be read as indefinite articles and therefore, unless explicitly stated otherwise, always as “at least one” or “at least one”.

[0041] The invention will be explained in more detail below using exemplary embodiments, whereby the individual features within the scope of the dependent claims may also be essential to the invention in other combinations, and no distinction will be made in detail between the different claim categories.

[0042] In detail, it shows Fig. 1 a side view of a sealing ring according to a first embodiment, Fig. 2 a side view of a sealing ring according to a second embodiment, Fig. 3a a greatly enlarged side view of the sealing ring in the holding zone, Fig. 3b a greatly enlarged side view of the sealing ring in the leakage zone, Fig. 4 a side view of a sealing ring according to an alternative design.

[0043] Fig. Figure 1 shows a side view of a sealing ring 1 for a pipe press connection (not shown). The sealing ring 1 has a central axis X (in the illustration shown, orthogonal to the drawing plane). As in Fig. As can be seen in Figure 1, the sealing ring 1 has a circular outer edge 2 or outer contour and a segmentally arcuate inner edge or inner contour. These arcuate segments of the inner edge are referred to as "arcuate inner contour segments" or "neutral zones" and are marked with reference numeral "N" in the figures. In addition to the neutral zones N, the sealing ring 1 also has several leakage zones L and several retention zones H. In the example shown, the sealing ring 1 has three leakage zones L and three retention zones H, which are arranged alternately with respect to one revolution around the central axis X. A neutral zone N is formed between each leakage zone L and the nearest adjacent retention zones H; thus, the leakage and retention zones L and H are each separated from each other by a neutral zone N. In total, the sealing ring in the example shown has six neutral zones N.

[0044] As in Fig. As can be seen from the comparison of the sections through the neutral zone N (left), the holding zone H (top right) and the leakage zone L (right), the sealing ring 1 has cross-sectional geometries that vary depending on the zone in the three zones N, H, L. In this configuration, the sealing ring 1 has a round cross-section in the neutral zone N, with a diameter of, for example, 6 mm.

[0045] The inner edges 3 of the neutral zones N define an inner circle 4. Within the neutral zones N, an inner edge 3 of the sealing ring 1 coincides with the inner circle 4; they are congruent. In contrast, within the respective leakage zone L, the inner edge 3 of the sealing ring 1 is radially offset relative to the inner circle 4; accordingly, the inner radius of the sealing ring 1 measured locally within the leakage zone L is larger than the inner circle radius of the inner circle 4. Conversely, in the retaining zones H, the inner edge 3 of the sealing ring 1 projects radially inward relative to the inner circle 4; the inner radius measured locally within the retaining zones is smaller than the inner circle radius of the inner circle 4.

[0046] The leakage zone L and the retention zone H each have a circular arc-shaped central section and a transition zone on either side of it. Each transition zone merges tangentially at one end into the circular arc-shaped central section (of the respective zone) and at the opposite end into the nearest neutral zone N. Between these two points, the transition zone exhibits a change in curvature. The inner edge 3 of the sealing ring 1 is concentric with the inner circle 4 defined by the neutral zones N in the area of ​​the respective circular arc-shaped central section of the leakage zone L or the retention zone H.

[0047] In the example shown, the sealing ring 1 has three retaining zones H, three leakage zones L, and six neutral zones N. The retaining zones H each extend over an opening angle of approximately 50° relative to the central axis X, the leakage zones L each over an opening angle of approximately 45°, and the six neutral zones N each over an opening angle of approximately 12.5°.

[0048] Fig. Figure 2 shows an alternative design of the sealing ring 1; compared to the one in Fig. As shown in Figure 1, this ring has a D-shaped cross-section. The figure at the top right shows a cross-section through the sealing ring 1 in the area of ​​the neutral zone N; the D-shape is clearly visible here. Furthermore, the sealing ring 1 corresponds to the following: Fig. 1 essentially the same as the one from Fig. 1.

[0049] An overview of possible dimensions of the sealing ring 1 is given below. For dimension d12, the inner circle diameter can be in the range of 12 mm to 13 mm, e.g., 12.48 mm, 12.51 mm, or 12.53 mm. The cross-sectional shape can be round, with an exemplary cross-sectional diameter of 2.0 mm to 3.4 mm. For dimension d15, the inner circle diameter can be approximately 15 mm to 16 mm (e.g., 15.22 mm, 15.36 mm, or 15.38 mm), also with a round cross-sectional shape and a possible cross-sectional diameter of 2.0 mm to 3.4 mm. For dimension d18, an inner circle diameter in the range of 18 mm to 19 mm can be provided (e.g., 18.31 mm, 18.36 mm, or 18.74 mm), again with a round cross-sectional shape and a cross-sectional diameter of 2.0 mm to 3.4 mm. For dimension d22, the inner circle diameter can be approximately 22 mm to 23 mm, e.g., 22.10 mm, 22.50 mm, or 22.85 mm.Here too, the cross-sectional shape can be round, with a cross-sectional diameter of 2.0 mm to 3.4 mm. From dimension d28 onwards, the sealing ring 1 can have a D-shaped cross-section. With this dimension, the inner circle diameter can be approximately 28 mm to 29 mm (e.g., 28.12 mm, 28.50 mm, or 28.80 mm), while the cross-section can, for example, have a height of 3.0 mm to 3.4 mm and a width of 3.2 mm to 3.6 mm.

[0050] For dimension d35, the inner circle diameter can be approximately 35.5 mm to 36.5 mm (e.g., 35.55 mm, 35.70 mm, or 36.11 mm), with a D-shaped cross-section and a possible cross-section of 3.0 mm to 3.4 mm (height) and 3.2 mm to 3.6 mm (width). For dimension d42, an inner circle diameter in the range of 43.5 mm to 44.5 mm is possible, e.g., 43.50 mm, 43.70 mm, or 44.21 mm. The cross-section can again be D-shaped, with an exemplary height of 3.6 mm to 4.2 mm and a width of 4.0 mm to 4.6 mm. Finally, with dimension d54, an inner circle diameter in the range of 55 mm to 56 mm can be present (e.g. 55.08 mm, 55.32 mm or 55.74 mm), also with a D-shaped cross-section and a possible cross-section of 3.6 mm to 4.2 mm in height and 4.0 mm to 4.6 mm in width.

[0051] Fig. Figure 3a shows a highly magnified section of the sealing ring 1 in the area of ​​the retaining zone H. In the example shown, the angular extent of the respective retaining zone H is labeled "y", the angular extent of the central section of the respective retaining zone H with "α", and the angular extent of the transition areas adjoining it on both sides with "β". The change in curvature on both sides of the central section in the respective curvature profile can also be seen in the figure. Possible numerical values ​​for the respective angular extent are given below as examples, depending on the dimensions of the sealing ring 1. The values ​​given may deviate, for example, within normal manufacturing tolerances, by approximately ±10° relative to the respective angular value.For a sealing ring 1 of dimension d12, the central section can have an angular extent of α = 10°, while the transition areas each extend over β = 20°, and the entire retaining zone has an exemplary angular extent of γ = 50°. For a dimension d15, the values ​​can be α = 30°, β = 13°, and γ = 56°. For dimension d18, a combination of α = 10°, β = 20°, and γ = 50° is again possible. For a ring dimension d22, the angular values ​​can be α = 30°, β = 13°, and γ = 56°; the same values ​​can apply to dimension d28. For dimension d35, the central section can have an angle of α = 10°, while the transition zones each measure β = 13° and the holding zone can comprise a total angle of γ = 36°. For larger ring dimensions such as d42 and d54, exemplary values ​​of α = 10°, β = 20° and γ = 50° can be provided.

[0052] Fig. Figure 3b, in contrast, shows a greatly enlarged section of the sealing ring 1 in the leakage zone L. Again, the angular extent of the leakage zone L is denoted by "γ", the angular extent of the central section of the leakage zone L by "α", and the angular extent of the transition areas formed on either side of it by "β". Possible numerical values ​​for the respective angular extents are given below as examples, depending on the dimension of the sealing ring 1, whereby the tolerances already mentioned may again apply. For a sealing ring of dimension d12, the central section can have an angular extent of α = 2°, while the transition areas each extend over β = 19°, and the entire leakage zone has an exemplary angular extent of γ = 40°. For a dimension of d15, the corresponding values ​​can be α = 20°, β = 20°, and γ = 60°. For a dimension of d18, a combination of α = 10°, β = 17.5°, and γ = 45° is possible.For a ring dimension d22, the angle values ​​can be α = 2°, β = 20°, and γ = 42°. For dimension d28, the central section can have an angle of α = 2°, while the transition areas can each have β = 12°, and the leakage zone can have a total angle of γ = 26°. For dimension d35, α = 2°, β = 10°, and γ = 22° are possible. For larger ring dimensions such as d42, exemplary values ​​of α = 1°, β = 8.5°, and γ = 18° are possible, while for dimension d54, values ​​of α = 1°, β = 5.5°, and γ = 12° are possible.

[0053] Fig.Figure 4 shows a further alternative embodiment of the sealing ring 1, which is not part of the claimed subject matter but is nevertheless to be disclosed. In this variant, the sealing ring 1 has at least four leakage zones L, which are evenly distributed around the circumference and each spaced apart from one another by the intervening neutral zones N. The figure shows a variant of a sealing ring 1 with six leakage zones L, which are evenly distributed around the circumference of the sealing ring 1 and each spaced apart from one another by neutral zones N. Possible (exemplary) dimensions and embodiments of such sealing rings 1 are given below. For example, a sealing ring of dimension d76.1 can have an inner circle diameter in the range of 77 mm to 78 mm, e.g., 77.10 mm, 77.38 mm, or 77.50 mm. The cross-sectional shape can be round, with the cross-sectional diameter being approximately 7 mm to 10 mm.For dimension d88.9, the inner circle diameter can be, for example, 90 mm to 91 mm, e.g., 90.20 mm, 90.49 mm, or 90.76 mm. Here, too, a round cross-sectional shape is possible, with a potential cross-sectional diameter of 8 mm to 10 mm. For dimension d108, the inner circle diameter can be approximately 109 mm to 110 mm, e.g., 109.30 mm, 109.85 mm, or 110.00 mm. The cross-sectional shape can again be round, and the cross-sectional diameter can, for example, range from 10 mm to 11 mm. Reference symbol list 1 sealing ring 2 4 Outer edge (of the sealing ring 1) 3 Inner edge (of sealing ring 1) Inner circle (of sealing ring 1) N Neutral zone (of sealing ring 1) L Leakage zone (of sealing ring 1) H Retaining zone (of sealing ring 1) X Central axis (of sealing ring 1) α Angular extent of the respective mid-segment β Angular extent of the respective transition region γ Angular extent of the respective zone

Claims

[1] Sealing ring (1) with a central axis (X) for a pipe press connection, which in a section orthogonal to the central axis (X) has a circular outer edge (2) and an inner edge (3), wherein in the sealing ring (1) - at least four neutral zones (N) are formed in which the inner edge (3) of the sealing ring (1) is section by section circular arc, which circular arc sections of the inner edge (3) define an inner circle (4), - at least two leakage zones (L) are formed in which the inner edge (3) of the sealing ring (1) is radially offset from the inner circle (4), - at least two retaining zones (H) are formed in which the inner edge (3) of the sealing ring (1) protrudes radially relative to the inner circle (4), and wherein, with reference to one revolution around the central axis (X), - the leakage zones (L) and the holding zones (H) are formed alternately, and - a neutral zone (N) is formed between each leakage zone (L) and the nearest adjacent holding zones (H). [2] Sealing ring (1) according to claim 1, in which the respective neutral zone (N) extends over an opening angle of at least 2°, preferably at least 11°, with reference to the central axis (X). [3] Sealing ring (1) according to claim 1 or 2, wherein the respective leakage zone (L) extends over an opening angle of at least 10° and at most 60° with respect to the central axis (X). [4] Sealing ring (1) according to one of the preceding claims, wherein the inner edge (3) in the area of ​​the leak zone (L) has a circular arc-shaped central section and on both sides of it a transition area, wherein the respective transition area transitions tangentially into the central section of the leak zone (L) and the nearest neutral zone (N) and the inner edge (3) has a change in curvature in between. [5] Sealing ring (1) according to claim 4, wherein the inner edge (3) in the area of ​​the arc-shaped central section of the leak zone (L) is concentric to the inner circle (4) of the sealing ring (1). [6] Sealing ring (1) according to claim 4 or 5, wherein the respective central section of the leakage zone (L) extends over an opening angle of at least 1° and at most 20° with respect to the central axis (X). [7] Sealing ring (1) according to one of claims 4 to 6, wherein the respective transition area of ​​the leakage zone (L) extends over an opening angle of at least 5.5° and at most 20° with respect to the central axis (X). [8] Sealing ring (1) according to one of the preceding claims, wherein the respective retaining zone (H) extends over an opening angle of at least 36° and at most 56° with respect to the central axis (X). [9] Sealing ring (1) according to one of the preceding claims, wherein the inner edge (3) in the area of ​​the retaining zone (H) has a circular arc-shaped central section and on both sides of it a transition area, wherein the respective transition area transitions tangentially into the central section of the retaining zone (H) and the nearest neutral zone (N) and the inner edge (3) has a change in curvature in between. [10] Sealing ring (1) according to claim 9, wherein the inner edge (3) in the area of ​​the arc-shaped central section of the retaining zone (H) is concentric to the inner circle (4) of the sealing ring (1). [11] Sealing ring (1) according to claim 9 or 10, wherein the respective central section of the retaining zone (H) extends over an opening angle of at least 10° and at most 30° with respect to the central axis (X). [12] Sealing ring (1) according to one of claims 9 to 11, wherein the respective transition area of ​​the retaining zone (H) extends over an opening angle of at least 13° and at most 20° with respect to the central axis (X). [13] Sealing ring (1) according to one of the preceding claims, wherein an inner circle diameter of the inner circle (4) in the neutral zone (N) - in the case of a circular cross-section, at least 12 mm and at most 56 mm; or - in the case of a D-shaped cross-section, at least 28 mm and at most 56 mm. [14] Press fitting for a water pipe, in particular a drinking water pipe, with - a socket comprising an insertion space for a pipe end to be inserted therein, wherein the insertion space has a pressing area which is bounded by a pressing wall part; - an annular groove-shaped space that is present in or bounded by the pressed wall section; and - a sealing ring (1) according to one of claims 1 to 13, which is arranged in the annular groove-shaped space, wherein the pressing area is plastically deformable from an unpressed state to a pressed state during a radially inward pressing action applied by a pressing tool, which causes the pressing wall part to compress radially while the sealing ring (1) seals against an inserted pipe end around its entire circumference.

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