HK1120099A - Coupling between two bodies - Google Patents

Description

Coupling between two bodies

Technical Field

The invention relates to a coupling (coupling) between cylindrical end regions of a first body and a second body, the first body having a cylindrical bore with an axis, the cylindrical end region of the second body being intended to be inserted into the first body in an axial insertion direction, a plurality of elastically deformable tongues extending in said bore and/or on the surface of said end region, said tongues being fixedly connected to the respective body and being arranged in an angularly regular manner, for example equidistantly, the free end edges of said tongues each lying substantially on an imaginary, substantially rotationally symmetrical circumferential surface, the diameter of the rotationally symmetrical body being smaller than the outer diameter of the end region of the second body or the diameter of the rotationally symmetrical body being larger than the diameter of the bore, said tongues extending at an angle to the axial direction, such that when said end regions are inserted, the tongues are curved in the insertion direction and scrape over the surface of the end zone by means of their free edges, so that after insertion of the end zone over a certain distance, movement in the backward direction with respect to the insertion direction is prevented.

Background

Such couplings are known from EP-A-0378035, EP-A-0212883, EP-A-0579194, EP-A-0294948, EP-A-0972981 and DE-A-19723594. With respect to the above-mentioned prior art, the object of the present invention is to implement a coupling between two bodies such that it can be released very easily, without requiring specific dismantling operations and without requiring the use of tools specific for the purpose, while in the coupled condition the bodies are still very firmly and even apparently inseparably coupled to each other.

Disclosure of Invention

These and other objects are achieved by a coupling of the type mentioned in the introduction, which has the following features: the end edge of the tongue has an inclined position corresponding to a partial spiral, thus following the shape of the spiral when the second body is rotated about the axis relative to the first body, whereby an axial movement also takes place and the end region of the second body can be removed from the bore of the first body.

The tongue may extend on the inner side of the hole, but alternatively the tongue may also be located on the surface of said end area. It is advisable for safety reasons when the coupling is effected that the tongues are located inside the holes, since otherwise there is a risk that the person effecting the coupling may be injured by the sharp tongues.

The tongue may be constructed of any suitable material. So that plastics of sufficient strength, such as for example ABS, are suitable. A cheaper and very reliable embodiment is one where the tongues consist of metal, in particular steel.

In a preferred embodiment, the coupling according to the invention has the following particular features: the tongue forms part of a unitary unit that also includes a substantially flat ring that is at least partially received in the wall of the bore of the first body. This embodiment is relatively easy to manufacture by stamping and pressing, whereby the product cost will be relatively low.

This latter embodiment may advantageously have the following specific features: the ring has a plurality of projections which, during mutual rotation of the two bodies in the manner described, bear against the material of the body to which the ring is fixedly connected. When the end regions of the second body are moved outwards by rotation, a distribution of forces is then created over the entire circumference of the ring, which in turn helps to distribute these forces over the projections acting as barbs. It will therefore be appreciated that the protrusions are preferably regularly distributed, for example angularly equidistant on the circumference of the ring. They may be located in the same plane as the ring or may also be embodied as additional tongues pressed out of the plane of the ring.

According to a further aspect of the invention, the coupling according to the invention has the following particular features: each tongue has a main direction in axial projection, which is different from the radial direction and in a direction opposite to the direction of rotation when the end region of the second body moves outwards. Whereby during rotation of the cylindrical end region of the second body a more or less radially directed additional force is applied to each tongue, whereby the ring has a slight tendency to expand, which to some extent facilitates the helical rotation.

In a particular embodiment, the coupling according to the invention has the following particular features: the bore has an axial stop so as to define a distance through which the end region of the second body can be inserted into the bore. With this embodiment, the coupling can be achieved in a very simple manner by inserting the cylindrical end region of the second body into the cylindrical hole in the first body with a certain axial force, wherein the axial insertion distance is determined by said axial stop. The axial stop can be embodied, for example, as an annular shoulder against which the front edge of the second body end region is positioned.

According to a certain aspect of the invention, the coupling has the following particular features: the first body is a tube or pipe joint.

According to a further aspect of the invention, the coupling may have the following specific features: at least the end region of the second body is composed of plastic, concrete, wood or a metal such as iron, copper or aluminium. It is important that the material of the tongues is chosen such that they can effectively interact with the material of the second body in the manner described above.

An embodiment that is easy to assemble has the following specific features: the ring has an interruption and is clampingly received in an annular groove in the respective wall of the respective body while being elastically deformed. In order to prevent unintended rotation of the rings in the case where the bodies have to be separated from each other by relative rotation, means for preventing such rotation may be used. The coupling described above may have the following specific features for this purpose: the ring has a plurality of projections which, during mutual rotation of the two bodies in the manner described, bear against the material of the body to which the ring is fixedly connected. Alternatively, the annular groove may have a local interruption in the form of a stop wall, with which the end of the ring at the location of the interruption can interact during said rotation. The unintended rotation of the ring can be effectively prevented by two variants.

A particular embodiment of the coupling according to the invention has the following particular features: the ring is fixed against rotation in both directions.

Such a coupling is adapted to perform a method of establishing said coupling, said method comprising the steps of:

(a) moving the surface of the associated body in the axial direction over a distance along the end edge; and

(b) the end region of the second body is moved further axially into the bore by relative rotation of the two bodies.

According to another aspect of the invention, the coupling has the following particular features: a seal ring is provided on the first or second body upstream with respect to the insertion direction. Due to the sealing ring in the upstream position, incomplete sealing caused by scraping caused by the tongue end edge in the associated body surface with which it is engaged is prevented.

According to a final aspect of the invention, the coupling has the following specific features: the sealing ring is received in an annular groove widening in the insertion direction, such that after insertion of the cylindrical end region of the second body into the bore and subsequent displacement of the cylindrical end region of the second body in the opposite direction, the ring is brought into engagement in a clamping and sealing manner with the bottom of the annular groove and with the facing surface of the associated body.

During the establishment of this type of coupling, a circumferential wedge-shaped space is formed between the widened annular groove and the cylindrical surface of the associated body. Initially the elastic sealing ring will move together with the surface of the associated body until it is prevented from moving further, in particular due to the presence of a tongue which may form part of a ring, for example. During the further axial movement, the sealing ring is displaced in the axial direction over the relevant surface until the operator has judged that the insertion movement is sufficient or until the further movement is prevented by the presence of the stop means. The latter is then caused by a suitable relative rotation of the two bodies to move axially backwards, causing the sealing ring to be secured by a wedging operation in clamping manner against the bottom of the groove which tapers in the backward direction. In the case of a coupling as described, which is loaded by a medium under pressure, the sealing ring will be pushed into the wedge-shaped space, which further enhances the sealing operation.

The coupling according to the invention can be used, for example, for the coupling of two pipes. In this way, for example, a double-sided coupling sleeve can be coupled at its two ends to the respective tubes by means of two respective couplings according to the invention. Such a sleeve may optionally be an outer sleeve or an inner sleeve. In the case of an outer sleeve, a connection between the tubes coupled to one another can be achieved such that the free end edges of the tubes rest against one another. A completely media-tight seal can further be ensured by using suitable sealing means, such as a sealing ring present on the inner surface of the outer sleeve.

The invention is not only applicable to coupling pipes but is generally applicable to coupling a body provided with a hole and another body having at least a cylindrical end region, for example a solid rod. Thus the coupling according to the invention can function to place an external mail box on, for example, a wooden post. The legs may also be connected to a table top provided with holes using a coupling according to the invention. A hammer head provided with a suitable hole can also be connected to the handle with a coupling according to the invention.

The examples given are not limiting but merely indicative of possible applications of the invention. It is important that the established coupling cannot be released by applying only an axial tension to the two bodies. The connection formed by the coupling according to the invention can only be released by mutually rotating the bodies in the manner described above.

Drawings

The present invention will now be described based on the accompanying drawings. In the drawings:

figure 1a shows a partially sectioned perspective view of a coupling between two pipes according to the invention, in a stage in which the pipes to be coupled to each other are still at a distance;

FIG. 1b shows a cross-section corresponding to the state of FIG. 1 a;

FIG. 2a is a perspective view of a unit comprising a ring with tongues extending inwardly and a plurality of barbs on the outside;

FIG. 2b shows a bottom view of the ring of FIG. 2 a;

FIG. 2c shows a cross-section A-A of FIG. 2 b;

fig. 3a shows a view corresponding to fig. 1a in a first phase, in which a pipe coupling has been effected;

FIG. 3b shows a view corresponding to FIG. 1b of the state of FIG. 3 a;

FIG. 4a shows a view corresponding to FIGS. 1a and 3a in a state in which the two tubes start to be disassembled by mutual rotation;

FIG. 4b shows a view corresponding to FIGS. 1b and 3b of the state of FIG. 4 a;

fig. 5a shows a view corresponding to fig. 1a, 3a and 4a in the final stage, with the disassembly being completely effected and the tube disassembled to the state shown in fig. 1 a;

FIG. 5b is a view corresponding to FIGS. 1b, 3b and 4b in the disassembled state shown in FIG. 5 a;

6a, 6b and 6c show respective exploded views in alternative forms, in side view, in longitudinal section and in perspective, respectively;

FIG. 7 illustrates an exploded view of a coupling sleeve according to yet another embodiment of the present invention;

FIG. 8 shows a cross-section through a sleeve in another embodiment; and

fig. 9 shows a view of the final embodiment corresponding to fig. 8.

Detailed Description

Fig. 1a shows a first tube 1 and a second tube 2. The inner diameter of the first tube corresponds to the outer diameter of the second tube 2, so that this second tube 2 can be inserted into the first tube 1 up to the annular axial stop 3. The axial insertion direction is indicated by arrow 4. Located on the annular shoulder 5 is a steel ring 6, which ring 6 is provided with twelve inwardly projecting tongues 7, and which ring and tongues form an integral unit. Reference is also made in this connection to fig. 2a, 2b and 2 c. As is clearly shown in fig. 1a and 1b, the tongue 7 has a slightly downwardly bent position with respect to the insertion direction 4.

In this embodiment, the ring 6 is fixed relative to the tube 1 by a cylindrical fixing ring 8, the fixing ring 8 being fixedly connected to the tube 1 by screwing, gluing, welding or any other suitable method after the ring 6 is inserted. It should be noted that the ring 6 may also be embedded in the first tube 1, for example if the ring 6 is made of plastic.

According to the invention, it is essential that the end edge 9 of the tongue 7 has an inclined position corresponding to a partial spiral. This aspect can also be seen in particular in fig. 1b and 2 c. Due to this inclined position, the direction 13 of the spiral (see fig. 4a) is formed during mutual rotation of the tube 1 and the tube 2 about the axis 10 of the hole 11, i.e. the lumen of the tube 1, whereby an axial movement 14 takes place and the end region 15 of the second tube 2 can be removed from the hole 11 of the first tube.

Fig. 1a and 1b show an initial stage before the coupling is achieved.

Fig. 2a, 2b and 2c show a possible construction of a one-piece single steel ring with tongues 7 and barb-like projections 16 extending on the outside of the ring.

Fig. 3a and 3b show that by axial displacement of the second tube 2 relative to the first tube 1 by means of a force, as indicated by the arrow 4, the tongues 7 are bent further downwards by the tubes 2, so that the front edge 17 of the second tube 2 is finally placed on the upper surface 18, the upper surface 18 serving as an axial stop for the annular axial stop 3. The above is the coupled state according to fig. 3a and 3 b. Due to the presence of the tongues 7, the backward movement of the second tube 2 with respect to the arrow 4 is prevented, whereby the coupling between the tube 1 and the tube 2 in this way is very strong.

As shown in fig. 4a and 4b, when tube 2 is rotated according to arrow 12 relative to tube 1, a helical movement according to vector 13 occurs, which is accompanied by an axial movement 14, whereby tube 2 is gradually moved out of tube 1. The sharp steel tongues 7 are formed to damage the outer surface of the tube 2 in the form of grooves 19 engraved therein. These grooves are clearly visible, in particular in the case of relatively soft plastics such as PVC. But this does not make it impossible to couple the tube 2 to the tube 1 again as shown in figures 1 and 3.

Fig. 5a and 5b show the final state, in which the tube 2 is completely separated from the tube 1 by the continuous rotation 12. The groove 19 then extends over a larger axial area.

Fig. 6 shows a pipe coupling according to the invention in an exploded view. Said coupling being adapted to the mutual coupling of the two tubes 30 and 31. A coupling sleeve 32 is used for this purpose. The tube 31 is pushed into this coupling sleeve 32 until it is positioned against an annular stop shoulder 33. The coupling between the sleeve 32 and the tube 31 is fixed, for example by a glued connection.

The sleeve 32 has an annular groove 34 in which a rubber-elastic sealing ring 35 is received. This acts as a seal against the outer surface of the tube 30.

A resilient steel ring 37 with tongues 38 arranged in a helical position is arranged clamped under resilient tension in the annular groove 36. This ring is shown in particular clearly in fig. 6 c.

The tube 30 is inserted with force into the sleeve 32 and passes through the flexible, at least partially elastically deformed tongue 38 and the sealing ring 35 until it is placed against the stop shoulder 33.

Thereby completing the coupling. It will be appreciated that the tube 31 is sealingly fixed relative to the sleeve 32 and that the tube 30 is sealed relative to the sleeve 32 by a sealing ring 35 and can be removed from fixation relative to the sleeve 32 by suitable rotation only.

Fig. 7 shows the coupling sleeve 41 in an exploded view. The rotationally symmetrical sleeve 42 co-acts with a clamping ring 43 for clamping a stainless steel or spring steel clamping ring 44 having tongues 7 thereon. The ring has four grooves on its outer edge, all marked with reference numeral 45. These grooves 45 interact with elongate protrusions 46 arranged on the inside of the sleeve 42 such that rotation of the ring 44 relative to the sleeve 42 in both directions is prevented. The clamping ring 43 is provided with a correspondingly formed recess 47.

An O-ring 48 made of rubber elastic material serving as a sealing member is placed on the inner surface of the clamping ring 43. For this purpose, present on the inner surface of the ring 43 is an annular groove into which the O-ring 48 partially fits, as will become clear with reference to the variant according to fig. 8.

The rotational locking of the ring 44 relative to the sleeve 42 in both directions is important, because for example when a tube is inserted into the sleeve 41 over a defined distance such that it contacts the end edges 9 of the tongues 7 of the ring 44, said tube can be continuously moved inwards relative to the coupling sleeve 41 by appropriately rotating the inserted tube due to the helical position of the edges 9. This is important in the case of tubes having a relatively large diameter, because of tolerance variations and the inability to automatically move the tube inwardly by axial pressure. Once the tube has reached its desired end position, an outward movement is obtained according to the invention by rotation in the opposite direction.

It should be noted that a sealing ring 48 interacting with the outer surface of the inserted pipe is placed upstream of the tongue 7. The outer wall of the inserted pipe is thus not damaged by scraping by the edge 9, which could lead to an incomplete sealing action of the O-ring 48 during the upstream movement.

Fig. 8 shows a coupling sleeve 51 in which coupling sleeve 51 an elastic steel ring 52 is integrally formed with a plastic sleeve 53 of sleeve 51 during the injection molding process. This achieves a good rotational locking in both directions. To the extent necessary above, the edge portion of the ring 52, which is encapsulated by the plastic, may also be provided with a predetermined profiling (profiling) in order to reinforce the anchorage in the plastic if necessary.

Fig. 9 shows a coupling sleeve 61 with a steel ring 44 clamped between a sleeve 62 and a clamping ring 63 according to the embodiment of fig. 7. In this embodiment the clamping ring 63 has a frustoconical portion 64 on its inner surface with which the O-ring 48 interacts.

The coupling between the two tubes is shown in the drawings by way of example only. The invention is not limited to this application.

It should be understood that many variations are possible within the scope of the invention.

Claims (14)

1. Coupling between a first body having a bore, for example a cylindrical bore with an axis, and a cylindrical end region of a second body to be inserted into the first body in an axial insertion direction, a plurality of elastically deformable tongues extending in the bore and/or on the surface of the end region, which tongues are fixedly connected to the respective body and are arranged in an angular regular manner, for example equidistantly, the free end edges of the tongues lying respectively substantially on an imaginary, substantially rotationally symmetrical circumferential surface of the body, the diameter of the rotationally symmetrical body being smaller than the outer diameter of the end region of the second body or larger than the diameter of the bore, the tongues extending at an angle with respect to the axial direction, such that when the end region is inserted, the tongues are curved in the insertion direction and scrape over the surface of the end zone by means of their free edges, such that after insertion of the end zone over a certain distance, movement in the backward direction with respect to the insertion direction is prevented,

the method is characterized in that: the end edge of the tongue has an inclined position corresponding to a partial helix, so that when the second body is rotated about the axis relative to the first body, it follows the shape of the helix, so that relative axial movement also occurs and the end region of the second body can be removed from the bore of the first body.

2. Coupling as claimed in claim 1, wherein the tongues consist of metal, in particular steel.

3. Coupling as claimed in any of the foregoing claims, wherein the tongue forms part of a one-piece unit, which further comprises a substantially flat ring which is at least partially received in the wall of the bore of the first body.

4. Coupling as claimed in claim 3, wherein the ring has a plurality of projections which, during mutual rotation of the two bodies in the manner described, bear against the material of the body to which the ring is fixedly connected.

5. Coupling as claimed in any of the foregoing claims, wherein each tongue has a main direction in axial projection which is different from the radial direction and in a direction opposite to the direction of rotation when the end region of the second body moves outwards.

6. Coupling as claimed in claim 5, wherein the projections are embodied as barbs.

7. The coupling as claimed in claim 1 wherein the bore includes an axial stop to define a distance through which the end region of the second body can be inserted into the bore.

8. The coupling of claim 1, wherein the first body is a pipe or pipe fitting.

9. Coupling as claimed in any of the foregoing claims, wherein at least the end region of the second body consists of plastic, concrete, wood or a metal such as iron, copper or aluminium.

10. Coupling as claimed in claim 3, wherein the ring has an interruption and is clampingly accommodated in an annular groove in the respective wall of the respective body while being elastically deformed.

11. A coupling as claimed in any preceding claim, wherein the ring is fixed against rotation in both directions.

12. Coupling as claimed in any of the foregoing claims, wherein a sealing ring is provided on the first or second body upstream with respect to the insertion direction.

13. Coupling as claimed in claim 12, wherein the sealing ring is accommodated in an annular groove widening in the insertion direction in such a way that, after insertion of the cylindrical end region of the second body into the bore and subsequent displacement of the cylindrical end region of the second body in the opposite direction, the ring is brought into engagement in a clamping and sealing manner with the bottom of the annular groove and the facing surface of the associated body.

14. A method for establishing a coupling according to claim 11, the method comprising the steps of:

(a) moving the surface of the associated body in the axial direction over a distance along the end edge; and

(b) the end region of the second body is moved further axially into the bore by relative rotation of the two bodies.