Coupling for coupling to a lubricating nipple

Abstract

The invention relates to a coupling (1) for coupling to a lubricating nipple (2), in particular to a conical lubricating nipple, comprising a tubular main body (3) which has a wall (5) comprising recesses (6), clamping elements (4) which are arranged in the recesses (6) and are designed for coupling the main body (3) to the lubricating nipple (2) in a form-fitting manner, and an actuating element (7). The coupling (1) is designed for transmitting media through the coupling (1) and through the lubricating nipple (2). In the state in which the coupling (1) is coupled to the lubricating nipple (2), the clamping elements (4) bear in each case against the actuating element (7) in a contact region (21a) and against the lubricating nipple (2) in a contact region (21b). According to the invention, the recesses (6) of the main body (3), in which the clamping elements (4) are arranged, are each designed as an elongated hole (16) having a longitudinal extension in the axial direction (L) and / or are formed in the circumferential direction (U) of the tubular main body (3), and webs (17) are arranged between the elongate holes (16), wherein the main body (3) has a hardness of 50-65 HRC in the respective contact region with the clamping elements (4).

Description

[0001] MEISSNER BOLTE

[0002] Meissner Bolte

[0003] Applicant: Patent Attorneys, Lawyers, Partnership mbB

[0004] Dipl.-Ing. Rudolf Schlenker, Plathnerstraße 3a, Rigistrasse 137, 30175 Hannover | Germany, 6353 Weggis, Tel.: +49-511 2613478-0

[0005] Switzerland Fax: +49-511 2613478-10 hannover@meissnerbolte.de www.meissnerbolte.de

[0006] Our reference: V / PSG-0001-WO

[0007] Date: October 14, 2025 / 1616

[0008] Coupling for connection to a grease nipple

[0009] Description

[0010] Technical field of the invention

[0011] The invention relates to a coupling for connection to a grease nipple, in particular to a conical grease nipple, with

[0012] • a tubular base body with a wall that has recesses,

[0013] • Clamping elements arranged in the recesses and designed for positive-locking coupling of the base body to the grease nipple, and

[0014] • an actuating element, for example in the form of a tubular actuating sleeve.

[0015] The coupling is designed for the transmission of media through the coupling and through the grease nipple. When the coupling is connected to the grease nipple, the clamping element is in contact with the actuating element in one area and with the grease nipple in another.

[0016] Such couplings are frequently used to transfer gaseous and liquid media, especially lubricants such as greases, at separation and connection points of lubrication lines.

[0017] Commercially available couplings can usually be opened and closed with one hand and without tools. One component of the connection is often a grease nipple, which has an undercut on its outer surface in a clamping area. Suitable grease nipples are known, for example, as conical grease nipples, which are standardized according to DIN 71412. Another component of the connection is a coupling that positively engages the clamping area of ​​the grease nipple.

[0018] The coupling incorporates clamping elements that make contact with the undercut of the grease nipple. Depending on the pressure of the transmitted medium, a force is exerted on the connection, which is absorbed by the undercut in the clamping area and the clamping elements. The clamping elements are often spherical and are arranged circumferentially in recesses in the wall of a tubular base. The base transmits the force from the spheres to the coupling. The coupling also frequently includes a sealing element that prevents the pressurized medium from escaping the connection.

[0019] State of the art

[0020] From GB 197436 A, couplings are known in which the clamping elements are designed as balls. An actuating sleeve, by means of the force of a spring, moves the balls radially inwards towards the undercut of a grease nipple. In a locked state of the coupling, the actuating sleeve prevents the balls from moving radially outwards by means of a positive locking mechanism.

[0021] German patents GB 574 983 A and GB 677 164 A disclose a coupling for grease guns with balls as clamping elements. There is no actuating sleeve; instead, the balls are pressed inwards into the clamping area by a spring. When the medium, in this case grease, is pressurized, it exerts a force on the balls in addition to the spring force. This also exerts a greater force on a sealing element, resulting in a tighter seal. In the locked position, the force of the spring and the pressure prevent the balls from moving radially outwards through frictional engagement.

[0022] WO 2013 177 696 A1 and US 2018 0313495 A1 disclose a coupling in which the sealing element is moved toward the coupling when connected to the grease nipple. An actuating sleeve is moved toward the grease nipple and, in the locked state, prevents the balls from moving radially outward by means of a positive locking mechanism. US 2019 0120 413 A1 discloses a coupling in which the actuating sleeve is moved by means of a hand lever. In its initial state, the hand lever runs along the coupling. When the hand lever is pushed transversely toward the coupling, the actuating sleeve moves forward toward the grease nipple against the force of a spring. This allows clamping elements to move radially outward to engage the clamping area of ​​the grease nipple in the coupling. The clamping elements are either balls or three-dimensionally shaped segmented gripping or holding jaws that press against the undercut of the clamping area.

[0023] Further couplings with segment-shaped gripping or holding jaws as clamping elements are disclosed in EP 2 531 766 B1 , EP 3 293 436 B1 , EP 3 559 539 B1 and EP 3 388 726 B1.

[0024] EP 3 825 596 B1 discloses a coupling for a grease nipple comprising a coupling body, an inner sleeve connected to the coupling body and having at least one bore that is inclined with respect to a longitudinal axis of the coupling, and a fastening element that is movably arranged in the at least one bore of the inner sleeve. The fastening element is designed to fix the grease nipple in a predetermined position relative to the inner sleeve.

[0025] Object of the invention

[0026] The invention is based on the objective of creating an improved coupling for transmitting media, which is designed for secure coupling to a variety of grease nipples of different types and degrees of wear and is sufficiently stable against forces acting on the coupling.

[0027] Solution to the task

[0028] The problem is solved by the coupling with the features of the independent claims. Advantageous embodiments are described in the dependent claims.

[0029] It is proposed that the recesses of the base body in which the clamping elements are arranged are each designed as an elongated hole with a longitudinal extent in the axial direction and / or in the circumferential direction of the tubular base body, and that webs are arranged between the elongated holes, wherein the base body has a hardness of 50-65 HRC in the respective contact area with the clamping elements.

[0030] By designing the recesses of the base body, in which the clamping elements are arranged, as elongated holes with a longitudinal extension in the axial direction or in the circumferential direction of the tubular base body of the coupling, the maximum transmissible pressure of the medium can be increased, the installation space of the coupling reduced and / or the wear of the coupling and the grease nipple reduced.

[0031] The couplings according to the invention increase the number of contact points between the coupling components, such as clamping elements, the base body, and the grease nipple, through a specific coupling design. The proposed designs of the clamping elements and recesses, as well as the connecting webs in the base body, increase the number of contact points, thereby improving force transmission to the grease nipple and reducing wear. This solves the technical problem of increasing the efficiency and durability of the coupling.

[0032] Due to the small diameter of grease nipples, the diameter of the base body is very small compared to other coupling types, such as pneumatic couplings. Furthermore, the insertion depth of the coupling onto the grease nipple is severely limited, so that when coupled, the free end of the coupling can only be inserted a few millimeters behind the lubricant retention contour. The proposed use of elongated holes for grease nipple couplings then leads to the problem that the front webs, which are necessarily very narrow due to the limited insertion depth and which define the elongated holes, cannot adequately withstand the forces occurring during operation.It has surprisingly been shown that the use of elongated holes is still possible and results in a reliable coupling if the base body is hardened, at least in the contact area with the clamping elements, i.e., in the area of ​​the front webs and the intermediate webs between the elongated holes, and has a hardness in the range of 50 to 65 HRC (HRC = Rockwell hardness on the C scale). A hardness in the range of 52.5 ± 2 HRC is advantageous. This achieves sufficient surface hardness with maximum toughness (fracture strength). This can be advantageously achieved by hardening the base body through and subsequently tempering it several times, preferably twice. The hardness ensures that the front webs in the base body no longer bend or even break, thus preventing the clamping elements from losing their grip.This makes it possible to design grease nipple couplings with elongated holes, which, thanks to very narrow front webs preferably in the range of 0.5 to 1 mm and extremely short insertion depth, ensure a secure coupling to grease nipples of various types and degrees of wear.

[0033] The proposed coupling offers the possibility of achieving the following advantages in particular: a reduction of the coupling's tip diameter for improved accessibility to a grease nipple, an increase in load-bearing capacity at higher operating pressures, ergonomic operation with reduced actuation forces, and increased service life and wear resistance.

[0034] The longitudinal extension direction of the slot refers to the longer extension of the slot compared to its narrower width.

[0035] It is noted that the article "a" or "an" throughout the text simultaneously means "several." This means that the article "a" or "an" includes a plurality, and that what is mentioned in the plural throughout the text may simultaneously mean "individuals thereof." The reference numerals, position numbers, and figures placed in parentheses in the claims are not to be understood as limiting the claim and are not exhaustive. References or citations are generally not to be understood as limiting. It is noted that the described embodiments represent only some preferred embodiments of the present invention. All equivalent structures disclosed in this description and the appended claims fall within the scope of the present invention.

[0036] The force exerted by the medium on the connection between the coupling and the grease nipple results in a high contact stress in the contact area between the clamping elements and the undercut of the grease nipple, depending on their geometry. The magnitude of this contact stress, or Hertzian contact pressure, limits the maximum transmissible pressure of the medium and can impair the load-bearing capacity, service life, and operability of the coupling.

[0037] Depending on the country-specific standard, the grease nipples have an undercut that is conical or circumferentially concave or convex. In combination with clamping elements designed as balls, this results in a point contact for a single clamping element. Couplings known from the prior art have up to seven balls as clamping elements.

[0038] Accordingly, the average Hertzian pressure per contact in this case is one seventh of the total contact pressure.

[0039] If more balls are used, additional recesses for the balls are necessary. Between these recesses, webs remain in the base body, which are subjected to tensile stress due to the force on the balls. Furthermore, during manual coupling and uncoupling of the coupling from the grease nipple, the webs can be subjected to uneven loading and bending stress in addition to tensile stress. Intensified by the notch effect, the mechanical stress on individual webs can thus significantly exceed the average tensile stress. Therefore, with a large number of recesses, the remaining cross-section of the webs limits the maximum transmissible pressure of the medium.

[0040] Using more balls with a smaller diameter increases the contact stress due to the smaller radius of curvature of the balls. Additionally, the wall thickness of the base body must be reduced so that the balls can protrude beyond the base body on the inside when pressed inwards by the actuating element on the outside.

[0041] Against this background, the invention proposes a coupling with the known features of a tubular base body with a wall having recesses with a clamping element in each recess, and an actuating element in the form of, for example, a tubular actuating sleeve. When the coupling is connected to the grease nipple, the clamping element rests in one contact area on the actuating element and in another contact area on the grease nipple.

[0042] Tubular in the sense of the present invention means that a body has a longitudinal extension and a continuous cavity along its longitudinal extension, leaving a wall surrounding the cavity. A ring-shaped body is thus suitable for conveying media or materials and / or fulfilling a structural function. The cross-section of the basic body is not predetermined by the term "tubular" and can have any geometric shape, including, but not limited to, circular, oval, rectangular, or polygonal. In particular, it can be a round tube that is cylindrical and has a cylindrical, concentric cavity. However, it is also conceivable that the tubular basic body is designed as a polygonal tube, such as a square tube, a pentagonal tube, a hexagonal tube, a heptagonal tube, an octagonal tube, etc. The tubular basic body is preferably rotationally symmetrical, e.g.,It is designed as a circular tube or a square tube in cross-section. The structure of a tubular body can be flexible or rigid and can vary in length, width, or thickness.

[0043] It is advantageous if the actuating element also has a hardness of 50-65 HRC in the respective contact area with the clamping elements. For this purpose, the actuating element can, for example, be made of a hard material produced by hardening or tempering. Hardening can be achieved by through-hardening followed by a single tempering. Multiple tempering cycles, unlike those of the base body, offer no relevant advantages in terms of bending and fracture strength. Alternatively, the actuating element can be treated, for example, by nitriding to ensure a hardness greater than 50 HRC.

[0044] The clamping elements can also have a hardness of 50-65 HRC.

[0045] In one embodiment, the actuating element can be an actuating sleeve.

[0046] Because the recesses are designed as elongated holes with a longitudinal extension in the axial or circumferential direction, the contact area between the grease nipple and the clamping elements can be increased, particularly through a higher number of contact points. Furthermore, the webs of the base body can be dimensioned sufficiently strong even with a higher number of clamping elements arranged in the recesses compared to conventional couplings.

[0047] The elongated hole can extend longitudinally in the circumferential direction of the base body. One or more clamping elements are arranged side by side in a common elongated hole in the circumferential direction of the base body. Preferably, the clamping elements are arranged abutting each other. However, it is also possible that the clamping elements do not touch each other in the recess. The elongated hole can extend longitudinally in the circumferential direction of the base body. The leading edge, which delimits the elongated hole towards the free end of the base body, can have a front edge width that tapers radially inwards between the inner end face of the leading edge, which faces the clamping elements inserted into the elongated hole, and the outer end face, which forms the free end of the base body.This allows the clamping elements to move even further forward towards the free end, resulting in an even more secure hold when the coupling is inserted into the grease nipple with a limited depth. While this does disadvantageously lead to a further narrowing of the front webs that define the elongated holes towards the free end, it has been shown that, with sufficient hardness, the wider radial outer area of ​​the front webs and the transition to the intermediate webs between the elongated holes can reliably absorb the force transmission from the clamping elements, even when external forces are acting on the coupling.

[0048] It is conceivable that the elongated hole on the end face of the base body, which borders the front web, tapers radially inwards towards the front web. This would simplify the manufacturing of the elongated holes. Alternatively, the end face could also be a plane perpendicular to the longitudinal direction or axis of the base body, i.e., a straight plane not inclined to the longitudinal direction.

[0049] At least one of the end faces that defines the elongated hole, i.e., the inner end face of the leading edge and / or the opposite end face of the base body, can have an angle of inclination of 55° to 85°, preferably 60° to 80°, to the longitudinal direction of the base body. This angle of inclination ensures that the clamping elements move far enough forward for secure coupling to various grease nipples without excessively weakening the leading edges of the elongated holes.

[0050] The surfaces of the clamping elements can be rounded, allowing them to slide along the functional surfaces of the actuating element. Alternatively, the clamping elements can be designed as rotationally symmetrical rolling bodies with a single axis of rotation. This allows the clamping elements to roll out of the grease nipple recess instead of simply sliding out, as would be the case with a rotationally asymmetrical sliding body. The actuating element can be slidably mounted on the outer circumference of the base body. When the coupling is clamped onto the grease nipple, the clamping elements rest against the side of the actuating element facing the base body, ensuring a positive clamping contact with the grease nipple.

[0051] The elongated hole can have a longitudinal extension in the axial direction, and at least one clamping element can have an axis of rotation. The thickness of the clamping element in the radial direction of the axis of rotation can be greater than the width of the clamping element in the axial direction of the axis of rotation. One or more clamping elements can be arranged circumferentially in the elongated hole of the base body.

[0052] The clamping elements inserted into such an axially oriented elongated hole can, for example, be rotationally symmetrical, with the radial dimension of a clamping element being greater than its axial dimension. The shape of such laterally narrower, and in particular laterally flattened, clamping elements allows one or more clamping elements to be arranged circumferentially within an elongated hole.

[0053] The clamping elements can be in the form of a sphere, a cylinder, a sphere with two parallel, opposing flats, a barrel roller, a revolution ellipsoid, and / or a cylindrical or conical bolt or a prismatic body with a polygonal or non-circular cross-section and rounded circumferential edges. Advantageously, the clamping elements are designed in the form of cylinders, cylindrical rollers, or as cylindrical or conical bolts with rounded circumferential edges, which can form a line contact with the base body.

[0054] It is also possible for a clamping element to only partially exhibit the shape of one of the aforementioned forms. It is advantageous if the clamping elements have parallel, opposing surfaces. The clamping elements can then be arranged side by side, with the parallel surfaces of different clamping elements either in contact with each other or spaced apart.

[0055] At least one of the clamping elements may have a concave indentation. If several clamping elements are arranged side by side, it is possible that part of one clamping element protrudes into the concave indentation of another clamping element. At least one of the clamping elements may have a concave profile. Depending on the geometry of the clamping element and its concave shape, a clamping element, when coupled to the grease nipple, may bear against the grease nipple at two or more contact points in the contact area of ​​the grease nipple, and / or, when coupled to the grease nipple, bear against the actuator at two or more contact points in the contact area of ​​the actuator.

[0056] However, it is also possible that the geometry of the clamping body and the concave shape are designed in such a way that a clamping body forms a linear contact with the grease nipple.

[0057] Regardless of whether the recesses are designed as elongated holes, it is also advantageous for embodiments with bores, which may also have an inclined limiting wall, if the contact areas of the base body and / or the actuating element with the clamping elements have a hardness of 50 to 65 HRC.

[0058] The distances between adjacent recesses, whether as elongated holes or as bores, can differ in the circumferential direction of the base body, so that the web width between at least two adjacent recesses is greater than the web widths between the other adjacent recesses, resulting in one or more webs with an enlarged load-bearing cross-section and increased load-bearing capacity compared to the other webs with a narrower web width.

[0059] Regardless of whether the recesses are elongated, at least one of the clamping elements can have a concave profile. In the contact area of ​​the grease nipple, the clamping element can bear against the grease nipple at two or more points, and / or in the contact area of ​​the actuating element, the clamping element can bear against the actuating element at two or more points. The clamping element with a concave shape can have a linear contact area with the grease nipple over a partial circumference.

[0060] It is also possible for positioning elements to be arranged in a slotted hole. These positioning elements keep the clamping elements in the slot, ensuring they remain in their designated positions. This allows, for example, the clamping elements to be guided during coupling and uncoupling, preventing unintended contact with other clamping elements. In particular, if a clamping element is damaged or lost, or if the slot is not equipped with the intended number of clamping elements for other reasons, this prevents the remaining clamping elements from moving unintentionally within the slot or from being located in undesirable positions.

[0061] As one embodiment, the positioning elements can be formed from the end face of the elongated hole and have the shape of a wedge or a triangle with straight and / or rounded legs and / or rounded corners. In particular, the shape of the positioning elements in an elongated hole can be different and / or adapted to the respective shape of the clamping elements.

[0062] Furthermore, positioning elements can extend from one end face of the elongated hole to the opposite end face. In any case, the positioning elements have a very low or limited load-bearing capacity compared to the webs. This is achieved, for example, by making the continuous positioning elements considerably narrower than the webs.

[0063] The positioning elements can also be independent bodies that are inserted into the elongated hole together with the clamping elements. This embodiment is comparable to the cage of a rolling bearing, which positions the rolling elements.

[0064] Regardless of the design of the recesses, for example as elongated holes, the stability of the webs between the recesses can be improved by altering the arrangement of the clamping elements around the circumference of the base body. The distances between the corresponding recesses are varied so that they differ in size. This increases the web width between at least two adjacent recesses in the circumferential direction of the base body compared to the web widths between the other adjacent recesses. This results in the formation of one or more webs with increased load-bearing capacity.

[0065] The load-bearing cross-section, and thus the load-bearing capacity, of the webs can be increased by radially thickening the webs towards the actuating element, regardless of the design of the recesses for the clamping elements and the arrangement of the clamping elements on the circumference of the base body. The resulting reinforcing elements extend radially along the base body, with one reinforcing element located in a corresponding recess on the side of the actuating element facing the grease nipple. The webs are thus reinforced by protrusions that project from the adjacent outer plane of the base body on their radial outer surface. The recesses in the actuating element can be designed either as slots or as grooves, such as concave depressions, on the inner surface of the actuating element facing the base body. This results in increased stability and load-bearing capacity of the coupling.

[0066] Additionally, the actuating element can have a support element on its outer surface facing the grease nipple, which prevents or reduces radial expansion of the actuating element. The support element can be circumferentially closed. It can be annular or tubular. The support element can be integral with the actuating element. However, it is also possible for the support element to be a separate part, which, for example, is pressed onto the free end of the actuating element. This can be done either as a longitudinal press fit or a transverse press fit. It is also conceivable that the support element, which bridges the recesses in the actuating element, is designed as a separate part or as several separate parts and connected to the actuating element. The connection can be friction-fit, positive-fit, and / or material-fit.

[0067] Between the recess in the base body and the end of the base body that points towards the grease nipple, the base body has a front wall. This front wall forms a front web that defines the elongated hole and is held in place by the intermediate webs between the recesses on the remaining part of the base body. During operation, the force transmitted by the clamping elements to the undercut of the grease nipple also acts directly on the front wall (i.e., the front webs). The front wall must therefore be dimensioned to be correspondingly robust.

[0068] Furthermore, the thickness of the front wall determines how far the coupling can be pushed onto the grease nipple. The front wall must be thin enough, or at most wide enough, to allow the clamping elements to make contact with the undercut of the grease nipple. The thickness of the front wall can range from approximately 1.1 to 1.8 mm for various clamping element designs. The elongated hole can extend circumferentially around the base body. The front web, which defines the elongated hole at the free end of the base body, forms a front wall. This front web width, measured between the inner end face of the front web (facing the clamping elements inserted into the elongated hole) and the outer end face (forming the free end of the base body), can range from 0.5 to 1.0 mm.These very narrow front ribs allow for a very shallow insertion depth while ensuring good grip of the clamping elements, and surprisingly, the stability is still guaranteed by the hardness of the base body.

[0069] Furthermore, a coupling may have a flow regulating element. This element serves to prevent the medium from splashing, leaking, oozing out, or overflowing from the coupling when it is not connected to a grease nipple. At high internal pressures, a supply line carrying the medium to the coupling can deform elastically, increasing its volume. After the transmission process is complete, when the coupling is disconnected from the grease nipple, the volume of the supply line decreases again, forcing the medium into the coupling, potentially causing it to splash out. The flow regulating element may be located at the rear end of the coupling, where the medium flows into it. However, it is also possible for the flow regulating element to be located in the middle of the coupling or in the front area where the coupling is connected to the grease nipple.The flow control element can be designed as a separate part or integrated into a component of the coupling.

[0070] The flow control element can be designed as a shut-off element. In this case, it can assume a closed state in which no medium can flow through the coupling, or in which no medium can flow from the rear end of the coupling forward toward the clamping elements. If the shut-off element is in a closed state before the coupling is disconnected, no medium, or only a small portion of the medium, will escape from the coupling. The shut-off element can be a manually or automatically operated valve attached to the rear end of the body. For example, it could be a standard ball valve. Alternatively, the shut-off element can be opened by an attached grease nipple and closed again when disconnected from the grease nipple.In this case, the stroke for opening and closing must be less than the distance the coupling travels when connecting and disconnecting from the grease nipple in order to ensure proper function.

[0071] Another embodiment of the flow regulating element can be a constriction in the area through which the medium flows. This constriction acts like a hydraulic throttle or orifice. It reduces the cross-section, thus increasing the flow velocity in this area and causing the fluid to experience greater friction. The friction dissipates energy from the medium, making it less prone to splashing out of the coupling. Such a flow regulating element can be designed as a disc or sealing disc with a central orifice that is smaller than the cross-section of the passage in the base body. In one embodiment, the diameter of the orifice is 0.3–0.9 mm.

[0072] The central passage opening or sealing disc can be flexible, allowing it to expand under the pressure of the medium. During the pressure reduction initiated when disconnecting the coupling, a flexible passage opening partially or completely contracts, thus reducing the flow of medium back into the grease nipple when the coupling is disconnected.

[0073] Combinations of a lockable flow control element and a friction-generating flow control element are also possible.

[0074] The coupling can have a closing element, which is designed as a spring-loaded closing element located in the coupling's lubrication channel. Such a spring-loaded closing element acts as a valve and, depending on the lubricant pressure, also as a flow regulating element. The closing element, for example, designed as a ball, together with the spring, functions as a valve that reduces the amount of lubricant that escapes as a result of the shrinkage of the supply hose after disconnection from the grease nipple and pressure release. At the same time, the closing element prevents the lubricant from freely leaking out of the coupling due to gravity.

[0075] The base body can have an opening, and the coupling can have a bypass cavity and a sealing element. The sealing element is positioned so that it can slide relative to the bypass cavity. When the grease nipple is disconnected, the opening is connected to the bypass cavity, and when the grease nipple is connected, it is separated from the bypass cavity. This reduces or even completely prevents lubricant from flowing out of the coupling after the grease nipple is disconnected. When connected to the grease nipple, the receiving element is pushed into the base body, forcing the lubricant ahead of it. Due to the decreasing volume, the lubricant from the interior of the base body escapes through the openings in the base body, then through the bypass cavity, and finally out of the coupling through the space between the base body and the actuating element.The bypass can be formed by an enlarged bore diameter of the actuating element, creating a bypass cavity, and by the sealing element. The bypass allows a coupling equipped with a valve to be fitted onto a grease nipple by allowing the lubricant, compressed during the fitting process and prevented from flowing back by the valve, to escape into the bypass cavity. After the coupling is fully fitted onto the grease nipple, the actuating element is moved forward, sealing the space between the base body and the actuating element with the sealing element. During lubrication, the lubricant can no longer escape through the bypass but flows exclusively into the grease nipple via the conventional route.

[0076] The coupling can also have a rotary compensation element. This element allows the coupling, or a part of it, to be rotated relative to the supply line or the other part of the coupling. The angle of rotation can be limited, for example, from a starting position of 90° (or 120° or 180°) in one direction and 90° (or 120° or 180°) in the opposite direction. Alternatively, the angle of rotation can be unlimited, allowing rotation of more than 360° in both directions. The rotation can also be performed in detented steps, for example, in 15° (or 10°, 30°, or 90°) increments.

[0077] The swivel joint has the advantage that the coupling, or part of the coupling, can be rotated without twisting the supply line. If a grease nipple is installed in such a way that access to the coupling is only possible with a specific rotational position, the coupling can simply be turned into the required position. For example, if the supply line has become twisted due to unwinding, the swivel joint can correct the twist without having to remove the coupling from the grease nipple. In one embodiment, the supply line can be connected to the coupling at an angle, i.e., at an angle that is not 180° relative to the longitudinal extent of the coupling. If a swivel joint is present in this case, it can prevent the supply line from kinking and / or twisting.

[0078] Furthermore, the flow control element can be integrated into the rotary compensation element or vice versa.

[0079] For couplings, it is advantageous if they are made of a hard material or at least have a hard surface. High contact stresses between the clamping elements and the other components of the coupling can otherwise lead to damage to these components. In the contact area between the components and the clamping elements, the components preferably have a hardness of 50–65 HRC. This can be achieved through common processes for modifying material properties, such as hardening or tempering. Surface coating or the incorporation of materials into the outer surface layer, for example, through hardfacing, coating with titanium nitride using PVD or CVD processes, nitriding, or electroless nickel plating, can also be used to harden the contact area. Surface hardening offers significant advantages in terms of wear resistance, load-bearing capacity, and friction reduction.This extends the service life of the components in a friction pair, improves efficiency, and reduces the risk of damage due to deformation, wear, or fatigue. These processes also reduce sliding friction between the clamping elements and between the clamping elements and the clutch components in contact with them. Surface hardening can also be advantageously used in other friction pairs within the clutch, such as in the contact area between the hand lever and the actuating element, or in the hand lever's bearing within the base body.

[0080] A further improvement to a coupling involves providing a hand lever that makes disassembly of the coupling or individual components difficult or impossible. Unintentional disassembly of the coupling can lead to the loss or destruction of components, thus compromising optimal and safe operation. To address this, the invention proposes mounting the hand lever last during coupling assembly, thereby preventing the (non-destructive) disassembly of the other components. The hand lever is pivotally mounted to the coupling's base body by means of two pivot bearings. The hand lever also features a coupling element that connects it to an actuating element. This coupling results in the actuating element being guided by the hand lever. In this state, the actuating element can no longer be removed from the coupling.

[0081] To mount the hand lever, it is first coupled to the actuating element using the coupling element and then mounted in the pivot bearings. The pivot bearing is designed to allow not only pivoting of the hand lever but also permanent fixation of the hand lever on the pivot bearings. In one embodiment, the pivot bearing can be achieved by two pins that protrude from the base body on opposite sides and are at least partially enclosed by corresponding, open-edged recesses in the handle. Locking can be accomplished by bending tabs on the hand lever so that the recesses are closed at their open edges.

[0082] However, it is also conceivable that the pivot bearings are formed by a bolt that extends through the hand lever and at least partially through the base body. After assembly, the bolt is widened at one or both ends, similar to the head of a rivet, so that non-destructive disassembly is no longer possible.

[0083] Brief description of the characters

[0084] The invention will be explained in more detail below with reference to exemplary embodiments and the accompanying drawings. These show:

[0085] Fig. 1a - a coupling in a cutaway side view in a ready-to-couple state and a grease nipple in a cutaway side view;

[0086] Fig. 1b - a coupling in a cutaway side view, which is coupled to a grease nipple;

[0087] Fig. 2 - a basic body of a coupling in a three-dimensional view from the front and from the side;

[0088] Fig. 3 - a basic body in a cutaway view from the front;

[0089] Fig. 4 - another basic body in a cutaway view from the front;

[0090] Fig. 5 - another basic body in a cutaway view from the front;

[0091] Fig. 6 - another basic body in a cutaway view from the front;

[0092] Fig. 7 - another basic body in a partially cutaway view from the front;

[0093] Fig. 8 - another basic body in a partially cutaway view from the front;

[0094] Fig. 9 - a clamping element in a side view;

[0095] Fig. 10 - a basic body in a partially cut-away front view; Fig. 11 - a clamping element in a side view, arranged individually and between two other clamping elements;

[0096] Fig. 12 - another clamping element in a side view, arranged individually and to the left and right of another clamping element;

[0097] Fig. 13 - a basic body in a three-dimensional view from the front and from the side;

[0098] Fig. 14 - a basic body in a partially cut-away view from the front;

[0099] Fig. 15 - in a cutaway view a part of a base body in which a clamping element is arranged;

[0100] Fig. 16 - a three-dimensional view of a single clamping element arranged in a base body;

[0101] Fig. 17 - a section of a basic body with an elongated hole that has positioning elements;

[0102] Fig. 18 - a front part of a base body having elongated holes with through-hole positioning elements;

[0103] Fig. 19a - a clamping element in the form of a cylindrical bolt with a bolt length greater than the bolt diameter or bolt cross-sectional area in a recess in the base body in a side view;

[0104] Fig. 19b - a clamping element in the form of a conical bolt with rounded or chamfered bolt ends in a recess in the base body in a side view;

[0105] Fig. 20 - a coupling in a cutaway side view with a flow regulating element integrated into the pipe connection.

[0106] Fig. 21 - shows in a three-dimensional view a part of the base body with a bolt attached to the side surfaces of the base body as well as a section of the hand lever, which is pivotably mounted on the bolt with its tabs.

[0107] Fig. 22a - the front face of the base body with reinforcing elements on the webs arranged in the recesses of the actuating element, in a three-dimensional view from the front and from the side.

[0108] Fig. 22b - the front face of the base body with the reinforced webs between the recesses, shown in a three-dimensional view from the front and from the side.

[0109] Fig. 23 - a base body with reinforced webs arranged in the actuating element, in a partially cutaway view from the front;

[0110] Fig. 24 - Base body and actuating element from Figure 23 with the support element on the actuating element in a partially cutaway front view; Fig. 25a - Perspective view of an actuating element with the support element, wherein the support element is integrally formed with the actuating element;

[0111] Fig. 25b - perspective view of an actuating element with separate support element;

[0112] Fig. 26 - a coupling in a cutaway side view in a ready-to-couple state with inclined surface in the recesses;

[0113] Fig. 27 - Detail view of the coupling from Figure 26 with the grease nipple inserted;

[0114] Fig. 28 - Partial sectional view of the base body for the coupling from Figures 26 and 27;

[0115] Fig. 29 - Sectional view of the coupling in a cut side view with a front web width that tapers radially inwards;

[0116] Fig. 30 - Detail view of the coupling from Figure 29 with grease nipple inserted;

[0117] Fig. 31 - a coupling in a ready-to-couple state with spring-loaded locking body and with bypass for lubricant and a grease nipple in a cutaway side view;

[0118] Fig. 32 - View of the section of the coupling from Figure 31 in the decoupled state; Fig. 33 - Coupling from Figure 31 in the coupled state with grease nipple inserted, spring-loaded locking element, and bypass for lubricant;

[0119] Fig. 34 - View of the section of the coupled coupling from Figure 33.

[0120] Character description

[0121] Figure 1a shows a coupling 1 in a sectional side view and a grease nipple 2 in a sectional side view. The coupling 1 has a tubular base body 3 with a wall 5 that has recesses 6. Clamping elements 4 are arranged in the recesses 6. The front part of the base body 3 is located within an actuating element in the form of an actuating sleeve 7, which is slidably mounted on the base body 3 by means of a hand lever 8. In the illustrated state, the hand lever 8 is actuated, which moves the actuating element 7 rearward on the base body toward the coupling input and compresses a compression spring 9. The rearward displacement of the actuating element 7 allows the clamping elements 4 to assume a radially outer position in the recesses 6.Inside the base body 3 is a receiving element 10, which is slidably displaceable forwards and backwards in the longitudinal direction of the base body 3. A compression spring 11, supported on the base body, exerts a spring preload on the receiving element 10 and presses the receiving element 10 against a stop 12 in a disengaged position. In this position, the receiving element 10 displaces the clamping elements 4 from a radially inner position to a disengaged, radially outer position. The clamping elements 4, supported on the receiving element 10, form a stop for the actuating element 7 in their radially outer position and prevent the actuating element 7 from moving further forward in the axial longitudinal direction of the base body 3 towards the clutch output due to the force of the compression spring 9.The base body 3 and the receiving element 10 each have a through bore extending from the front end face at the coupling outlet to the rear end face at the coupling inlet (i.e., from front to back). A seal 13 is located on the outside of the receiving element 10, sealing the bores in the base body 3 to the bore in the receiving element 10. The front end of the receiving element 10 has a seal 14, which seals the receiving element 10 to the grease nipple 2. The grease nipple 2 has a through bore extending from its front end face to its rear end face. Part of its outer surface features a mounting area with an undercut 15.

[0122] The hand lever 8 can be pivotally mounted on the base body 3 by means of a pin or bolt 26. The pin can be integrally formed with the base body 3. A pin can protrude from both diametrically opposite sides. Alternatively, the base body 3 may have a bore through which a bolt 26 is installed, projecting from both sides of the base body 3 to pivot the hand lever 8.

[0123] At the rear of the coupling 1, a line connection 27 is coupled to the base body 3. This connection has an internal thread for receiving a line connection coupling and an inlet channel leading into the through-channel of the base body 3. The inlet channel can taper in a funnel shape and have a smaller cross-section than the through-channel of the base body 3.

[0124] The line connection 27 is rotatably mounted on a locking element 28, which engages in circumferential grooves of the line connection 27 and base body 3, secured axially to the base body and yet rotatable about the longitudinal axis of the base body 3.

[0125] Between the outlet area of ​​the line connection 27, which is immersed in the base body 3, and the inner wall of the channel of the base body 3, an elastic seal 29 for sealing and a flow regulating element 30 with a central opening are arranged.

[0126] It can be seen that the flow control element 30 is connected to the base body 3 in the rear area of ​​the coupling 1, which is in an open state, so that media can flow from the rear area of ​​the flow control element 30 through the flow control element 30 and into the rear part of the base body 3.

[0127] Figure 1b shows a coupling 1 coupled to a grease nipple 2, each in a sectional side view. In this state, the clamping elements 4 are displaced in the recesses 6 in the wall 5 of the base body 3 into their radially inner locking position. Part of the grease nipple 2 is located in the bore of the base body 3, with the clamping elements 4 bearing against the grease nipple 2 in the area of ​​the undercut 15. The actuating element 7 is displaced forward on the base body 3. Part of the inner surface of the actuating element 7, which is held in position by the force of the compression spring 9, is located in the radially outer area of ​​the clamping elements 4 and displaces the clamping elements 4 from their radially outer position. The hand lever 8 is not actuated in this case.

[0128] While the grease nipple 2 is held in the bore of the base body 3 by the clamping elements 4, the receiving element 10 with its seal 14 rests against the grease nipple 2. The compression spring 11 generates a compressive force on the seal 14, thus ensuring a sealing effect. If a pressurized medium is present in the through-bore of the base body 3, it exerts an additional force on the seal 14 of the receiving element 10, in addition to the force exerted by the compression spring 11.

[0129] Figures 2 to 18, as well as 19a and 19b, show advantageous embodiments of the coupling 1 with the recesses 6, 16 in the base body 3 and the clamping elements 4 in the form of a sphere 4a, a disc 4b with parallel lateral flattening, a disc with a recess on the circumferential surface 4c, 4d, a disc 4da with rounded, concave recesses on the circumference with flattening of the curve that is symmetrical to an axis of symmetry, a spherical cap 4e, a crescent-shaped disc 4f, a disc with a convex circumference 4g, a sphere with two opposing parallel flattening 4h, 4i, a cylindrical bolt 4j, and a conical bolt 4k. These embodiments are characterized by having an increased number of contact points between the clamping elements 4 and the base body 3, as well as between the clamping elements 4 and the grease nipple 2. The webs 17 between the recesses 6, 16 in the base body 3 have a sufficiently large load-bearing cross-section.This achieves both the desired increase in the load-bearing capacity of the coupling and the solution of other sub-problems of the invention.

[0130] Figure 2 shows the front part of the base body 3, which has a recess 6 in its wall 5 in the form of an elongated slot 16, the longitudinal extent of which runs in the circumferential direction U of the base body 3. Three clamping elements 4 in the form of a sphere 4a are located side by side in the circumferential direction U within the elongated slot 16. The clamping elements 4 can be moved between the radially inner engaged position and the radially outer disengaged position. In the radially inner engaged position, the clamping elements 4 are held by the actuating element 7 (not shown in Figure 2) and contact the grease nipple 2 (not shown) at its undercut 15. At least one further recess 6, also in the form of an elongated slot extending in the circumferential direction U of the base body 3, can be located on the same circular path, offset in the circumferential direction U of the base body 3.This at least one further elongated hole 16 can also be fitted with clamping elements 4. The base body 3 has webs 17 between the elongated holes 16, which have a sufficiently large load-bearing cross-section.

[0131] The elongated holes 16 are bounded at the free end of the base body 3 by a front wall or front web 32. The free end of the base body 3 forms an outer end face 40.

[0132] Figure 3 shows the front view of a cut base body 3a with three recesses 6 in the form of elongated slots 16 extending circumferentially around the base body 3a. The elongated slots 16 are evenly distributed around the circumference of the base body 3a. Between the recesses 6, the base body 3a has webs 17, which are spaced according to the circumferential distribution of the elongated slots 16. Three clamping elements 4 in the form of balls 4a are located in each of the elongated slots 16 in their radially inner locking position. Each clamping element 4 is in contact with the undercut 15 of the grease nipple 2.

[0133] Figure 4 shows the front view of a cutaway base body 3b, which has four recesses 6 in the form of an elongated hole 16 evenly distributed along a common circular path in its circumferential direction, the longitudinal extent of which runs in the circumferential direction of the base body 3b. The webs 17 of the base body 3b are located between the recesses 6. Two clamping elements 4a are located in each of the elongated holes 16 in their radially inner locking position. The clamping elements 4 are in contact with the undercut 15 of the grease nipple 2.

[0134] Figure 5 shows the front view of a sectioned base body 3c, the wall 5 of which has four recesses 6 in the form of elongated slots 16 extending circumferentially around the base body 3c on a common circular path. Each elongated slot 16 contains three clamping elements 4 in the form of a sphere 4a and two disks 4b. The disk-shaped clamping elements 4b have two opposing, parallel flattened surfaces 18. Due to these flattened surfaces 18, the disk-shaped clamping elements 4b are narrower than the clamping elements 4a, allowing two disk-shaped clamping elements 4b and one spherical clamping element 4a to fit side by side in one elongated slot 16.

[0135] It can be seen that the clamping elements 4a and 4b, each arranged in an elongated hole 16, have different contours. The middle clamping element 4a is spherical, while the adjacent outer clamping elements 4b are disc-shaped with flattened sides.

[0136] Figure 6 shows the front view of a cut basic body 3d with four elongated holes 16 in the circumferential direction, wherein two opposite elongated holes 16a extend so far that three disc-shaped clamping elements 4b can be placed side by side in them and two opposite elongated holes 16b extend so far that four disc-shaped clamping elements 4b can be placed side by side.

[0137] The disc-shaped clamping elements 4b arranged in an elongated hole 16 can have the same contour as shown and be narrower than spheres due to flattened sides, i.e., disc-shaped. This allows a larger number of disc-shaped clamping elements 4b to be accommodated in an elongated hole 16, thereby increasing the number of contact points and distributing the load across a larger number of contact points. This reduces the contact stresses at each contact point.

[0138] Figure 7 shows the front view of a partially cut base body 3e, which exemplarily has six recesses 6 in the form of elongated slots 16 extending axially along the base body 3e. Due to the axial extension of the elongated slots, two adjacent webs 17 each have a long end face 25 that runs parallel to each other. A disc-shaped clamping element 4c is located in each of the elongated slots 16. The clamping element 4c has two opposing, parallel flats 18 as well as an outer 19a and an inner indentation 19b. The areas between the flats 18 and the outer and inner indentations 19a, 19b are convexly rounded.

[0139] As a variation to the variant in Figure 7, it is conceivable that the elongated holes 16 extend in the circumferential direction.

[0140] Figure 7 further shows the actuating element 7, which is arranged around the base body 3e, and the area of ​​the undercut 15 of the grease nipple 2, which is arranged inside the base body 3e. Between the actuating element 7 and a disc-shaped clamping element 4c, two contact points 20a are formed by the indentations 19a. Between the area of ​​the undercut 15 of the grease nipple 2 and the clamping elements 4c, two contact points 20b are formed by the indentations 19b.

[0141] Figure 8 shows a front view of a partially cut base body 3f with an elongated hole 16 in the axial direction of the base body 3f. The elongated hole 16 represents further elongated holes 16 distributed circumferentially. A disk-shaped clamping element 4d is located in each of the elongated holes 16, representing further clamping elements 4d. Each clamping element 4d has two opposing, parallel flats 18 and is rotationally symmetrical about an axis of rotation 22. The axis of rotation 22 is perpendicular to the flats 18. Circumferentially around the axis of rotation 22, each clamping element 4d has a rounded, concave indentation 19 with a radius of curvature that transitions into a convex curve in the direction of the flats 18. The concave indentation 19a and the convex curves create two contact points 20a between the clamping elements 4d and the actuating element 7.According to the radius of curvature of the grease nipple 2 and the curvature of the concave indentation 19b, the following is created between the clamping element 4d and the grease nipple 2:.

[0142] - a point-like contact 20b if the radius of curvature of the concave indentation 19b is greater than the radius of curvature of the grease nipple 2,

[0143] - a linear contact area 21b if the radius of curvature of the concave indentation 19b and the grease nipple 2 are equal or approximately equal, or

[0144] - two contact points 20b if the radius of curvature of the concave indentation 19 is smaller than the radius of curvature of the grease nipple 2.

[0145] Figure 9 shows the clamping element 4d from Figure 8. The clamping element 4d has two opposing, parallel flats 18, through each of which a rotation axis 22 runs perpendicularly. The clamping element 4d is rotationally symmetrical about the rotation axis 22 and has a rounded, concave indentation 19 on its circumference with a radius of curvature that transitions into a concave curve towards the flats 18. For one embodiment of the clamping element 4d, the course of the flats of the concave and convex curves is symmetrical about a mirror axis 23 that runs perpendicular to the rotation axis 22.

[0146] As a variation of the variant shown in Figure 9, it is conceivable that the clamping elements 4d, 4da have concave or convex end faces instead of the flattened end faces 18.

[0147] Figure 10 shows an elongated hole in the wall 5 of a base body 3g, representing further elongated holes (not shown) distributed around the circumference of the base body 3g and separated from each other by webs 17 of the base body 3g. Three clamping elements 4a and 4e are located in the elongated hole 16 shown as a representation. Clamping element 4e is rotationally symmetrical and has an axis of rotation 22. Clamping element 4e has two opposing (concave) indentations 24 perpendicular to the axis of rotation 22, each in the form of a spherical cap. The radius of the spherical cap indentation 24 is larger than the radius of the clamping elements 4a. This allows the spherical clamping elements 4a and 4e to rest on the curved circumference of the grease nipple 2 in the radially inner engagement position.Figure 11 shows a clamping element 4e with an axis of rotation 22 and two indentations 24, similar to the one used in Figure 10. Figure 11 also shows how a clamping element 4e can be arranged between two clamping elements 4a. The radius of curvature of the indentations 24 corresponds exactly or approximately to the radius of the clamping elements 4a.

[0148] Figure 12 shows a rotationally symmetrical clamping element 4f with an axis of rotation 22 and a recess 24 perpendicular to the axis of rotation 22. Figure 12 further shows how two crescent-shaped clamping elements 4f, each with concave recesses 24 on its side, can be arranged on one side of a clamping element 4a.

[0149] Figure 13 shows a base body 3h with a wall 5 into which recesses 6 in the form of elongated holes 16 are formed. The elongated holes 16 extend in the axial direction L of the base body 3h and are evenly distributed around the circumference of the base body 3h. Between each of the elongated holes 16, there is a web 17 in the wall 5 of the base body 3h.

[0150] Figure 14 shows a front view of a cutaway base body 3h from Figure 13, which has recesses 6 in its wall 5 in the form of elongated holes 16 extending in the axial direction of the base body 3. In each elongated hole is a clamping element 4g, which has two opposing, parallel flats 18 extending parallel to long end faces 25 of the elongated hole 16.

[0151] Figure 15 shows a sectional longitudinal view of a portion of a base body 3 with an elongated hole 16 extending axially along the base body 3. A rotationally symmetrical clamping element 4h with an axis of rotation 22 is located in the elongated hole 16. This clamping element has two opposing, parallel flats 18, although only one flat 18 is shown in this view. The long end faces 25 of the elongated hole 16 run parallel to the flats 18, although one end face 25 is not visible in the section.

[0152] Figure 16 shows a rotationally symmetrical clamping element 4i, which has the shape of a sphere with an axis of rotation 22 and two opposing, parallel flats 18. Figure 16 further shows how the clamping element 4i is arranged in an elongated hole 16 in a cutout of a wall 5 of a base body 3. The flats 18 run parallel to the long end faces 25 of the elongated hole 16. Above the clamping element 4i, a cutout of an actuating element 7 is visible. The clamping element 4i is in contact with the undercut 15 of a cutout of a grease nipple 2.

[0153] Figure 17 shows a section of a base body 3i, which has an elongated slot 16 in its wall 5. Four positioning elements 31 are located in the elongated slot 16, each extending from opposite long end faces 25 of the elongated slot 16. The positioning elements 31 have the shape of a wedge with rounded corners and prevent clamping elements 4 (not shown) from being displaced in the longitudinal direction of the elongated slot 16.

[0154] Figure 18 shows the front part of a base body 3j, which has two elongated slots 16 in its wall 5, the longitudinal extent of which runs in the circumferential direction U of the base body 3j. Two positioning elements 31 are located side by side in the circumferential direction U of the elongated slot 16, each extending from one long end face 25 to the opposite long end face 25 of the elongated slot 16. The positioning elements 31 each have the form of two wedges that touch or are connected at their tips. The positioning elements 31 prevent clamping elements 4 (not shown) from touching each other and / or being displaced in the circumferential direction U of the elongated slot 16. The minimum width P of a positioning element 31 is considerably smaller than the web width S of the web 17.

[0155] The thickness of the front wall 32 determines how far the coupling 1 is pushed onto the grease nipple 2. To ensure sufficient stability of the front wall 32 and at the same time enable secure coupling of the coupling 1 onto a standard grease nipple 2, the thickness of the front wall 32 can preferably be between 1.1 and 1.80 mm, depending on the design of the clamping elements.

[0156] Figure 19a shows a clamping element 4j in the form of a cylindrical bolt whose length is greater than its diameter or cross-sectional dimension. The clamping element 4j is arranged in a recess 6 of the base body 3 and is in contact with the undercut 15 of a cutout of the grease nipple 2. One clamping element 4j is shown to represent further clamping elements 4j and / or other clamping elements 4 (not shown) in the respective recesses 6 along the circumference of the base body 3. Figure 19b shows a clamping element 4k in the form of a conical bolt or cone with rounded or chamfered bolt ends. The clamping element 4k is arranged in a recess 6 of the base body 3 and is in contact with the undercut 15 of a cutout of the grease nipple 2. One clamping element 4k is shown to represent further clamping elements 4k and / or other clamping elements 4 not shown in the respective recesses 6 along the circumference of the base body 3.

[0157] As a variation of the variants shown in Figures 19a and 19b, it is conceivable that the clamping elements 4j and 4k have a non-circular cross-section.

[0158] Figure 20 shows an exemplary coupling in the disconnected state in a cut side view, wherein a flow regulating element 30 in the form of a central bore regulating the flow is shown in the line connection 27.

[0159] Figure 21 shows a three-dimensional view of a portion of the base body 3 with a pin or bolt 26 attached to the side faces of the base body 3, which is designed to receive the hand lever 8. The hand lever is pivotally mounted on the pin or bolt 26 by means of its tabs 8. The tabs of the hand lever 8 enclose the pin or bolt 26 from both sides, thus preventing non-destructive disassembly. The pin 8 can be integrally formed with the base body 3 and protrude from both diametrically opposite sides. Alternatively, the base body 3 may have a bore through which a bolt 26 is inserted, projecting from both sides of the base body 3 to pivotally mount the hand lever 8.

[0160] The hand lever (8) has a coupling element (33) that is coupled to the actuating element (7) to cause a linear displacement of the actuating element (7) when the hand lever (8) is pivoted. Since the hand lever (8) limits the movement of the actuating element (7) along the base body (3), once the tabs of the hand lever (8) have engaged in the base body (3), it is no longer possible to move the actuating element (7) into a position where the clamping elements can be removed from the base body (3) or fall out. This ensures that the clamping elements are securely and captively arranged in the coupling. Figure 22a shows the end face of the base body (3), with the reinforcing elements 34 on the webs 17, which are arranged in the recesses 35 of the actuating element 7, in a three-dimensional view from the front and from the side. This increases the load-bearing cross-section and the load-bearing capacity of the webs.It can be seen that the reinforcing elements 34 are designed as a projection extending from the outside of the base body 3, i.e., as a bead extending radially outwards and in the longitudinal direction of the respective web 17. The reinforcing elements 34 are integrally formed with the webs 17. The recesses 35 in the actuating element 7 can, for example, be designed as slots in the actuating element 7 or as concave depressions on the inside of the actuating element 7 facing the base body 3.

[0161] Figure 22b shows the front face of a base body 3 with webs 17, which are provided with reinforcing elements 34 between the recesses 6, 16, shown in a three-dimensional oblique view from the front looking at the front and the side.

[0162] Figure 23 shows the front view of a partially cut-away base body 3, which has, by way of example, eight recesses 6 with the clamping elements 4, 4a. These are in contact with the grease nipple 2 and the actuating element 7. The reinforcing elements 34 on the webs 17 extend in the radial direction of the base body 3 and are arranged in the recesses 35 of the actuating element 7.

[0163] Figure 24 shows the front view of a partially cut-away base body 3 and actuating element 7 from Figure 23, wherein a support element 36 bridges the groove-shaped recesses 35 of the actuating element 7. The support element 36 can also be formed integrally with the actuating element 7. For this purpose, for example, the recesses 35 can be formed as grooves from the inside of the actuating element 7 into the inner wall. The groove bases bridge the recesses 35 and form the circumferential support element 36.

[0164] Figure 25a shows a perspective view of an actuating element 7 with a one-piece support element 36. It can be seen that the recesses 35 are formed as grooves in the actuating element 7, such that the base of each groove forms a section of the support element 36 bridging the recess 35. Figure 25b shows a perspective view of an actuating element 7 with a separate support element 36. This support element can, for example, be shrunk onto the circumference of the actuating element 7 and thus frictionally connected.

[0165] The actuating element 7 can optionally have a smaller outer diameter in the area of ​​the separate support element 36. The support element 36 can have approximately the same outer diameter as the remaining part of the actuating element 7.

[0166] Figure 26 shows a modified coupling 1 in a cutaway side view in a ready-to-couple state. The base body 3 is connected to a base body connection part 3a. For this purpose, the base body 3 can be pushed onto a connecting stub of the base body connection part 3a and sealed by an O-ring seal 37. The base body 3 is tubular and forms a ball cage made of hard material. It can be made, for example, of manganese-chromium-containing metal, such as 16MnCr5, which, through hardening and multiple (e.g., two) tempering cycles, achieves a hardness in the range of 52.5 ± 2 HRC and a microstructure toughness that provides the required deformation and fracture resistance. This ensures a secure coupling even when sudden loads act on the coupling 1 or the lever 8.

[0167] The elongated holes 16 can have a radially inwardly tapered front web 32 towards the free end.

[0168] Figure 27 shows an enlarged detail view with the grease nipple 2 inserted. It can be seen that the clamping elements 4 can move slightly further forward due to the inclination of the inner end face 38 of the front web 32. The end face 39 of the base body 3 opposite the inner end face 38, which defines the elongated hole 16, can also taper radially inwards towards the front web 32 or the outer end face 40. This allows the end face 39 to run parallel to the inner end face. However, it is also conceivable that the end face 39, as shown in Figure 27, spans a plane perpendicular to the longitudinal extent or axial direction L.

[0169] Figure 28 shows a partial sectional view of the base body 3, in which the elongated holes 16 have an inner end face 38 and an opposing end face 39 that are not perpendicular to the axial direction L. The angle α to the plane of the outer end face 40 is in the range of 5° to 35°, in this example approximately 15° ± 5°. Thus, at least the inner end face 38 is at an obtuse angle to the axial direction L in the range of 85° to 55°, preferably 75° ± 5°. The thickness D of the leading edge 32 is very small. It can be in the range of 0.5 to 1 mm. This takes into account the smallest thickness in the radially inner region of the leading edge 32 and the largest thickness in the radially outer region of the leading edge 32 in the case of a radially inwardly tapered leading edge 32.

[0170] The width B of the elongated holes 16 is adapted to the size of the clamping elements 4. It can, for example, be in the range of 2.5 mm to ensure good coupling to many types of grease nipples 2.

[0171] Figure 29 shows a partial sectional view of the base body 3, in which the elongated holes 16 have an inclined inner end face 38 due to conically radially inwardly tapering front webs 32. The opposite end face 39, however, is not inclined.

[0172] Figure 30 shows a partial sectional view of the base body 3 from Figure 29 with the grease nipple 2 inserted. It can be seen that the clamping elements 4 positively lock the grease nipple 2 onto its concave clamping surface. The base body 3 is pushed onto the grease nipple 2 as far as possible without abutting the threaded collar 41.

[0173] Figure 31 shows a coupling 1 in a ready-to-couple state with a spring-loaded locking element 44 in the form of, for example, a ball. Figure 32 shows a view of the section of the coupling from Figure 31 in the uncoupled state.

[0174] The closing element 44 is pressed against a nozzle opening 48 in a lubricant channel 47 of the coupling 1 by a compression spring 45 to close it. The lubricant pressure acting against the compression spring 45 pushes the closing element 44 away from the nozzle opening 48, thus allowing the lubricant to flow. When the coupling 1 is disconnected from the grease nipple 15, the lubricant pressure is typically reduced before disconnection, so that the closing element 44 closes the lubricant channel 47.

[0175] The ball-shaped closing element 44, together with the spring 45, functions as a valve that reduces the amount of lubricant that escapes as a result of the hose shrinking after disconnection from the grease nipple 15 and pressure release. At the same time, the sealing element 46 formed by the closing element 44 and the spring 45 prevents the lubricant from freely leaking out of the coupling 1 due to gravity.

[0176] The coupling 1 can have a lubricant bypass, as shown. This bypass is formed by a bypass cavity 42 and a sealing element 43, such as an O-ring, between the base body 3 and the actuating element 7. Furthermore, an opening 41 is provided in the base body 3 leading to the lubricant channel 47. This opening 41 opens into the space between the base body 3 and the actuating element 7. Looking in the direction of extension of the base body 3, seals 43 in the form of O-rings are inserted into circumferential grooves on both sides of the opening 41 and on opposite pairs of openings 41. The actuating element 7 has a circumferential bypass cavity 42 on its inner surface, which, in the decoupled state shown, is connected to the opening 41. For this purpose, the seal 43 is positioned in the bypass cavity 42 when no grease nipple 15 is connected.This allows lubricant to escape from the lubricant channel 47 through the opening 41 into the bypass cavity 42.

[0177] Fig. 33 shows the coupling 1 from Figure 31 in the coupled state with the grease nipple 15 inserted. Fig. 34 shows the view of the section of the coupled coupling from Figure 33.

[0178] The coupling in turn has a valve or closing element 46, which is formed by the compression spring 45 and the closing element 44, which is spring-loaded by the compression spring 45. In the coupled state, the bypass for the lubricant is now decoupled from the lubricant channel 47. It can be seen that the seal 43, i.e., the O-ring, is now positioned between the opening 41 and the bypass cavity 42. Thus, no lubricant can enter the bypass cavity 42.

[0179] When the grease nipple 15 is connected to the coupling 1, the receiving element 10 is pushed into the base body 3, pushing and compressing the lubricant. The lubricant channel 47, sealed by the closing element 46, prevents further backflow into the flexible supply hose. Due to the decreasing volume of the base body 3, the lubricant can now escape from the outside through the openings 41, then through the bypass cavity 42, and finally through the space between the base body 3 and the actuating element 7, exiting the coupling 1. The bypass is formed by an enlarged bore diameter in the actuating element 7, creating the bypass cavity 42, and by the sealing element 43. The bypass allows the coupling 1, equipped with a valve, to be attached to the grease nipple 15.

[0180] After the coupling 1 is fully inserted onto the grease nipple 15, the actuating element 7 is moved forward, thereby closing the space between the base body 3 and the actuating element 7 by means of the sealing element 43. During lubrication, the lubricant can therefore no longer escape through the bypass, but flows exclusively into the grease nipple 15 via the conventional route.

[0181] Reference symbol list

[0182] 1 coupling 35 recess in

[0183] 2 grease nipples actuating element

[0184] 3 base bodies 36 support elements

[0185] 4 clamping element 37 O-ring seal

[0186] 5 wall 38 inner end face

[0187] 6 recess 39 opposite end face

[0188] 7 Actuating element 40 outer end face

[0189] 8 hand levers 41 threaded ring

[0190] 9 compression spring 42 bypass cavity

[0191] 10 Receiving element 43 Sealing element

[0192] 11 Compression spring 44 Locking element

[0193] 12 Stop 45 Spring

[0194] 13 Seal 46 Locking element

[0195] 14 Seal 47 Lubricant channel

[0196] 15 Undercut at grease nipple 48 Nozzle opening

[0197] 16 elongated holes

[0198] 17 Bridge D Front bridge width

[0199] 18 Flattening L axial direction

[0200] 19 Indentation U Circumferential direction

[0201] 20a / b Contact point P Width of the positioning element

[0202] 21a / b Contact line S Bridge width

[0203] 22 Rotation axis

[0204] 23 Mirror axis

[0205] 24 indentations

[0206] 25 Front surface

[0207] 26 bolts

[0208] 27 Line connection

[0209] 28 locking element

[0210] 29 Seal

[0211] 30 Flow regulating element

[0212] 31 Positioning element

[0213] 32 Front wall / front web

[0214] 33 Coupling element

[0215] 34 Reinforcing element

Claims

MEISSNER BOLTE Meissner Bolte Patent Attorneys Lawyers Applicant: Partnership mbB Plathnerstrasse 3a 30175 Hanover | Germany Dipl.-Ing. Rudolf Schlenker Rigistrasse 137 Tel.: +49-511 2613478-0 Fax: +49-511 2613478-10 6353 Weggis Switzerland hannover@meissnerbolte.de www.meissnerbolte.de Our reference: V / PSG-0001-WO Date: October 14, 2025 / 1616 Patent claims:

1. Coupling (1) for coupling to a grease nipple (2), in particular to a conical grease nipple, with - a tubular base body (3) with a wall (5) which has recesses (6), - clamping elements (4) which are arranged in the recesses (6) and are designed for positive locking coupling of the base body (3) to the grease nipple (2), and - an actuating element (7), wherein the coupling (1) is designed for the transmission of media through the coupling (1) and through the grease nipple (2), and wherein the clamping elements (4) in the coupled state of the coupling (1) to the grease nipple (2) each bear in a contact area (21a) on the actuating element (7) and in a contact area (21b) on the grease nipple (2), characterized in that the recesses (6) of the base body (3) in which the clamping elements (4) are arranged are each designed as an elongated hole (16) with a longitudinal extent in the axial direction (L) and / or in the circumferential direction (U) of the tubular base body (3), and webs (17) are arranged between the elongated holes (16), wherein the base body (3) has a hardness of 50-65 HRC in the respective contact area with the clamping elements (4). [Duplicate] Application Documents_Claims PCT Late Application DRAFT 2025-10-08 [2025051955] DOCX 2. Coupling (1) according to claim 1 , characterized in that the actuating element (7) has a hardness of 50-65 HRC in the respective contact area with the clamping elements (4).

3. Coupling (1) for connection to a grease nipple (2), in particular to a conical grease nipple, with - a tubular base body (3) with a wall (5) having recesses (6) and webs (17) between the recesses (6), - clamping elements (4) which are arranged in the recesses (6) and are designed for positive locking coupling of the base body (3) to the grease nipple (2), and - an actuating element (7), wherein the coupling (1) is designed for the transmission of media through the coupling (1) and through the grease nipple (2), and wherein the clamping elements (4) in the coupled state of the coupling (1) to the grease nipple (2) each bear in a contact area (21a) on the actuating element (7) and in a contact area (21b) on the grease nipple (2), characterized in that a) the distances between adjacent recesses (6) in the circumferential direction (U) of the base body (3) are different, such that the web width (S) between at least two adjacent recesses (6) is greater than the web widths between the other adjacent recesses, whereby one or more webs (17) with an enlarged load-bearing cross-section and increased load-bearing capacity are formed compared to the other webs (17) with a narrower web width (S),and / or b) the contact areas of the base body (3) and / or the actuating element (7) with the clamping elements (4) on the coupling have a hardness of 50 to 65 HRC.

4. Coupling (1) according to one of claims 1 to 3, characterized in that the base body (3) consists of a hard material formed by hardening and that the actuating element (7) consists of a hard material formed by hardening or tempering.

5. Coupling (1) according to one of claims 1 to 4, characterized in that the elongated hole (16) has a longitudinal extension in the circumferential direction (U) of the base body (3) and several clamping elements (4) in the circumferential direction (U) of the The base body (3) is arranged side by side in a common elongated hole (16).

6. Coupling (1) according to one of the preceding claims, characterized in that the elongated hole (16) has a longitudinal extension in the circumferential direction (U) of the base body (3) and the front web (32) limiting the elongated hole (16) to the free end of the base body (3) has a front web width that tapers radially inwards conically between the inner end face (38) of the front web (32), which faces the clamping elements inserted into the elongated hole (16), and the outer end face (40), which forms the free end of the base body (3).

7. Coupling (1) according to claim 6, characterized in that the end face (39) of the base body (3) limiting the elongated hole (16) on the side opposite the front web (32) is radially inclined inwards towards the front web (32).

8. Coupling (1) according to claim 6 or 7, characterized in that at least one of the end faces defining the elongated hole (16) in the form of the inner end face (38) of the front web (32) and / or the opposite end face (39) of the base body (3) has an angle of inclination of 55° to 85°, preferably 60° to 80°, to the longitudinal extension direction of the base body (3).

9. Coupling (1) according to one of the preceding claims, characterized in that a front wall (32) is located between the recess (6, 16) of the base body (3) and the front end face of the base body (3) which points towards the grease nipple (2), the thickness of which is between 1.1 and 1.8 mm.

10. Coupling (1) according to one of the preceding claims, characterized in that the elongated hole (16) has a longitudinal extension in the circumferential direction (U) of the base body (3) and the front web (32) limiting the elongated hole (16) to the free end of the base body (3) has a front web width (D) between the inner end face (38) of the front web (32), which faces the clamping elements inserted into the elongated hole (16), and the outer end face (40), which forms the free end of the base body (3), in the range of 0.5 to 1.0 mm.

11. Coupling (1) according to one of the preceding claims, characterized in that the clamping elements (4) have one or more of the following shapes: - Bullet, - Cylinder or cylinder roller, - Sphere with two parallel, opposite flattens, - Barrel roller, - ellipsoid of revolution, - Cylindrical or conical bolt or prismatic body with a polygonal or non-circular cross-section, the circumferential edges of which may be rounded.

12. Coupling (1) according to one of the preceding claims, characterized in that at least one of the clamping elements (4) has a concave indentation (24) perpendicular to an axis of rotation (22), wherein an adjacent clamping element (4) can project into the concave indentation (24).

13. Coupling (1) according to one of the preceding claims, characterized in that at least one of the clamping elements (4) has a concave indentation (19) and / or two opposing convex bulges, in particular in the form of a cylinder or a truncated cone with rounded circumferential edges.

14. Coupling (1) according to one of the preceding claims, characterized in that at least one of the clamping elements (4) in the coupled state to the grease nipple (2) a) has a contact area with two or more contact points (20a, 20b) with the grease nipple (2) and / or the actuating element (7) over a partial circumference of the actuating element (7) and / or b) has a contact area in the form of a contact line (21a, 21b) with the grease nipple (2) and / or the actuating element (7) over a partial circumference of the actuating element (7).

15. Coupling (1) according to one of the preceding claims, characterized in that at least one section of the base body (3) in the area between the adjacent recesses (6) on the side facing the grease nipple (2) of the base body (3) has a reinforcing element (34) which extends outwards in the radial direction of the base body (3) and is arranged in a corresponding recess (35) of the actuating element (7).

16. Coupling according to one of the preceding claims, characterized in that the base body (3) and / or the actuating element (7) each has a support element (36) on the outer side facing the grease nipple (2), which prevents or reduces radial expansion of the actuating element (7).

17. Coupling (1) according to one of the preceding claims, characterized in that the base body (3) has a line connection (27) at its inlet end diametrically opposite the outlet end with the clamping elements (4), which is rotatably arranged on the base body (3) by means of a rotation compensation element.

18. Coupling (1) according to one of the preceding claims, characterized in that the coupling (1) has a flow regulating element (30) designed to prevent or reduce the splashing, leaking, overflowing or overflowing of the medium from the coupling (1), in particular the outflow of the medium from the outlet end of the base body (3) provided with clamping elements (4) when the coupling (1) is disconnected from the grease nipple (2), wherein the flow regulating element is designed either as a separate part or integrated in a component of the coupling (1).

19. Coupling (1) according to claim 18, characterized in that the flow regulating element (30) is designed as a constriction in the area of ​​the coupling (1) through which the medium flows and is designed either as a hydraulic throttle or hydraulic orifice, wherein the diameter of the constriction forming the passage opening is between 0.3 mm and 0.9 mm.

20. Coupling (1) according to claim 18 or claim 19, characterized in that the flow regulating element (30) is designed as a flexible sealing disc with a central through-hole whose diameter is variable.

21. Coupling (1) according to one of the preceding claims, characterized in that the coupling (1) has a locking element (46) which is in in a closed state completely or partially prevents the flow of a medium or prevents the flow from the rear to the front side in the direction of the clamping elements, wherein the closing element: a) can be opened and closed manually and / or b) is automatically opened by coupling a grease nipple (2) and closed again by disconnecting from the grease nipple (2).

22. Coupling (1) according to claim 21 , characterized in that the closing element (46) is designed as a closing element (44) arranged in the lubricant channel (47) of the coupling (1) and pre-tensioned with a spring (45).

23. Coupling (1) according to one of the preceding claims, characterized in that the base body (3) has an opening (41) and the coupling has a bypass cavity (42) and a sealing element (43), wherein the sealing element (43) is arranged to be displaceable relative to the bypass cavity (42) such that the opening (41) is connected to the bypass cavity (42) when the grease nipple (2) is disconnected and is separated from the bypass cavity (42) when the grease nipple (2) is connected.

24. Coupling (1) according to one of the preceding claims, characterized in that a hand lever (8) is pivotably mounted on the base body (3) by means of two pivot bearings relative to the base body (3), wherein the hand lever (8) has a coupling element (33) which is coupled to the actuating element (7) in order to effect a linear displacement of the actuating element (7) when the hand lever (8) is pivoted, wherein the hand lever (8) is provided with tabs which adjoin the pins or bolts (26) of the pivot bearings and are locked to the coupling (1) in such a way that the hand lever (8) is pivotable but not removable from the coupling (1).

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