SK285634B6 - Ball-and-socket joint - Google Patents

Abstract

The invention relates to a ball-and-socket joint provided in the form of an insertion detent connection, consist of a first fixed joint part (1) which forms a joint cup (3), and comprises a second joint part (2) which has a spherical surface (4) and which is mounted in the joint cup (3) such that it can slide, whereby on the one part (1,2) of the ball-and-socket joint is on the neck (6) that projects from the centre of the cup (3) in full with this joint cup (3) is placed ball which goes through a opening whose inner width (W) is smaller than the ball di-ameter (D). The ball is placed on the first part (1) of the ball-and-socket joint on which is created joint cup and is created like detent ball (12) and the opening which created in second part (2) is created like detent opening (7) which its a widened surface wall (8) created expanding surface for expanding the detent opening (7) to a diameter which snaps the detent ball (12), whereby a detent sliding surface (10) adjoins the wall (8) on the inside of the opening and is located at a distance from the spherical surface (4), said spherical surface extending concentrically thereto, which is equal to at least the length (L) of the neck (6).

Description

Technical field

BACKGROUND OF THE INVENTION The invention relates to a ball joint formed as a snap joint and comprising a first part forming an articulated housing, in which a sliding surface of a second ball joint part is disposed, wherein one of the ball joint portions is on the neck extending from the center of the articulated housing. located a ball which passes through a snap hole whose clear width is less than the diameter of the ball.

BACKGROUND OF THE INVENTION

Such ball joints are known in the art. The first part of the ball joint, which forms the articulated sleeve, is pulled inwards at the edge of the articulated sleeve, thereby forming an undercut holding the second part of the ball joint which is provided with a spherical surface. This spherical surface is locked in the articulated sleeve by means of said undercut and is slidably received in the articulated sleeve. The second part of the ball joint then sits firmly on the first part of the ball joint due to the rim of the hinge sleeve which forms the undercut and extends beyond the spherical surface equator.

The object of the invention is to improve this known ball joint in terms of its performance and manufacture.

SUMMARY OF THE INVENTION

The problem is solved and the drawbacks of known solutions of this kind are largely eliminated by a ball joint made as a snap joint and consisting of a first part forming an articulated housing in which the sliding surface of the second ball joint part is supported, extending from the center of the articulated sleeve integral with the articulated sleeve is a ball which extends through a latch opening whose clear width is smaller than the diameter of the ball according to the invention, the principle being that the ball is located on the first part of the ball joint an articulated sleeve, and is formed as a snap ball, and the aperture is formed as a spherical aperture formed in the spherical surface of the second portion of the ball joint, with its outwardly expanding funnel walls forming a spacing surface for expanding the snap aperture up to the snap fit diameter The funnel-shaped walls on the inside of the snap-in opening are adjoined by a sliding surface whose distance from the concentrically spherical surface extending thereto is at least equal to the length of the neck.

Due to this embodiment, the ball joint is easy to mount. Between the snap ball and the articulated sleeve there is an annular gap whose walls are formed by surfaces having a common center of curvature. An annular undercut body extends into this annular gap, one wall of which slides in the articulated sleeve and its opposite wall slides over the snap ball.

The funnel-shaped walls preferably extend at an angle which corresponds to the deflection angle of the ball joint defined by the diameter of the neck.

The end angular position is reached when these funnel-shaped walls engage a neck which preferably has a circular cross-section. The opening angle of the funnel-shaped walls is selected such that in the end angular position of the ball joint there is a line contact between the funnel-shaped walls and the neck. The dimensions, in particular the length, of the neck are chosen such that the snap ball permanently attracts the spherical surface to the articulated sleeve. Thus, a thrust is permanently applied in the neck between its heel in the center of the articulated sleeve and its transition into the snap ball.

Furthermore, a ball joint is known from the prior art, which consists of a first part and a second part, the first part of the ball joint forming a hinged sleeve and the second part of the ball joint forming a spherical surface. In the center of the articulated sleeve there is an opening into which a riveted pin extends, which extends into the opening in the second part of the ball joint. This opening extends inwards up to the sliding surfaces. A leaf spring is mounted on these sliding surfaces on the back of the riveted pin, which holds the two ball joint parts together. The assembly of this as a whole four-part ball joint is lengthy. At the same time, it is not possible to mount it simply by snapping.

A further advantageous embodiment of the ball joint according to the invention consists in that the second ball joint part is designed as a plug-in part, the end of which at least partially overlaps the snap ball in the snap hole.

In this way, a precisely shaped fit of the snap ball in the snap hole is ensured. The two parts of the ball joint are preferably made of plastic. Despite the complicated shape of the first part of the ball joint, it is preferred to manufacture it by the injection molding method. A pipe, for example of steel, slid onto the other part of the ball joint, if it extends beyond the region of the latch ball, forms a safety catch, since the latch hole is thereby secured against expansion by pulling off its circumference.

In a further preferred embodiment of the ball joint according to the invention, the first part of the ball joint which forms the articulated sleeve, on the side facing away from the neck, is provided with an open opening on the outside.

This recess is primarily used to accommodate the plug-in part which forms the base surface. This embodiment is particularly advantageous if the ball joint is designed as a base joint for the chair leg.

Said recess formed on the side of the first part of the ball joint facing away from the neck is preferably provided with a radially inwardly directed flange with an undercut edge.

As a result of this undercutting, the first part of the ball joint must be removed from the mold with a certain force after it has been produced by the injection molding method. However, this is not a significant disadvantage since some force is also required to separate the injection mold parts from the snap ball. During this forced removal from the mold, the die-cast part can be retained by its removal on the underside of the mold, so that it is ensured that the two mold parts which extend into the annular space can reliably move away from the die-cast part.

In a preferred alternative embodiment of the ball joint according to the invention, the first ball joint part is provided on the side facing away from the neck with a flat, rounded base surface, so that said plug-in part is omitted.

Another alternative embodiment of the ball joint according to the invention consists in that the flat base surface of the first ball joint part is provided with a radially outwardly directed flange for snapping the steel cap.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS The invention is further elucidated with reference to the accompanying drawings, in which:

FIG. 1 shows a first embodiment of the invention in cross-section, wherein the first part of the ball joint is latched in the second part of the ball joint,

-naobr. 2 is a view corresponding to FIG. 1, wherein the parts of the ball joint are deflected relative to one another,

FIG. 3 shows the illustration according to FIG. 2, wherein the part of the ball joint which forms the spherical surface is fitted with a tube, for example of steel,

FIG. 4 shows a second embodiment of the invention in FIG. 1 with the tube on,

FIG. 5 is a view corresponding to FIG. 4, wherein the parts of the ball joint are deflected relative to one another,

FIG. 6 shows the part of the ball joint forming the spherical surface,

FIG. 7 shows the part of the ball joint forming the articulated sleeve; and

FIG. 8 shows a section along line VIII-VIII in FIG. 4th

DETAILED DESCRIPTION OF THE INVENTION

In the case of the first embodiment of the ball joint shown in FIG. 1 to 3, the spherical joint consists of a first part 1 and a second part 2. The first part 1 consists of an articulated sleeve 3. A neck 6, which has a cylindrical cross-section with a length L, protrudes from the center of the articulated sleeve 3. the engagement ball 12, wherein the engagement 12 'of the engagement ball 12 to the neck 6 is located above the level of the edge 3' of the articulated housing 3. The center 5 of the articulation ball 12 simultaneously represents the center of curvature of the articulated housing 3.

A recess 13 is formed on the side of the first ball joint part 1 away from the neck 6. This recess 13 is circular in shape and serves to accommodate the plug-in part 15 which forms the base surface 14. The plug-in part 15 is snapped into the recess 13 for radial direction an inwardly directed flange 16 of a first ball joint portion 1 that forms an undercut edge of the recess 13.

A bore 18 can be formed in the neck 6, which opens into the recess 13. The bottom of the bore 18 is approximately at the level of the connection 12 'of the snap ball 12 to the neck 6.

At the end of the second ball joint part 2, a spherical surface 4 is formed. This spherical surface 4 is annular and in its axial center there is a snap hole 7 with funnel-shaped walls 8 with an angle and an opening. The clear width W of the latch hole 7 is smaller than the diameter D of the latch ball 12. The funnel-shaped walls 8 of the latch hole 7 are followed by a sliding surface 10 behind its narrowest point. The radial distance A between the sliding surface 10 and the spherical surface 4 is slightly greater than L .

The largest width of the latch opening 7, which is delimited by the funnel walls 8, is greater than the diameter D of the latch ball 12. When the second ball joint portion 2 is mounted on the latch ball 12 and applied in the axial direction, the free half of the latch ball 12 slides The sliding surface 10 engages below the half of the snapping ball 12 on the side of the neck 6 and the spherical surface 4 with the pressure bears against the articulated sleeve 3. Due to the ratio of the length L of the neck 6 and the radial distance A presses the snap ball 12 onto the sliding surface 10 so that the two ball joint parts 1, 2 can be held together at different angular positions with respect to one another.

A cylindrical section 19 is formed on the second part 2 of the ball joint, which is defined by an annular shoulder 17. This annular shoulder 17 in this embodiment is in the direct relative position of the ball joint portions 1, 2 at the neck level 6. a section 19 of a pipe 11, for example of steel, with its end 11 'extends over the funnel-shaped wall 8 at the location of their smallest diameter. This makes it impossible to expand the catch opening 7.

In the second embodiment shown in FIG. 4 to 7, the connection 12 'of the snap ball 12 to the neck 6 is located below the edge 3' of the articulated sleeve 3. The length L of the neck 6 is here smaller than in the first embodiment. Correspondingly, the radial distance A between the sliding surface 10 and the spherical surface 4c is also smaller than in the first embodiment. The snap-fit connection in other aspects corresponds to the first exemplary embodiment, and the corresponding parts of the description of the first exemplary embodiment may be referred to herein.

Also in the second embodiment, the second ball joint part 2 is provided with a cylindrical section 19, which is defined in the axial direction by an annular shoulder 17 and onto which a pipe 11, for example a chair leg, can be slid. In the second embodiment, however, the annular shoulder 17 is located in the region of the free half of the snapping ball 12, i.e. above the equator 9.

The material of the sliding surface 10 may be weakened in the axial direction by running notches or slots. This facilitates the engagement of the latch opening 7 over the equator 9 of the latch ball 12.

According to a further variant (not shown), the device may also be provided in that the first ball joint part 1 is not provided with a plug-in part 15 and is integrally formed with the underside of plastic, optionally rounded at the edge.

Similarly, it is also possible to provide a steel part which is hinged on the outside of the first ball-joint part 1 instead of the plug-in part 15. Instead of a radially inwardly facing flange 16, a radially outwardly facing flange can then be used, onto which the stainless steel cap engages.

Claims (8)

A ball joint made as a snap joint and comprising a first part (1) forming an articulated sleeve (3), in which a sliding surface (4) of a second ball joint part (2) is supported, wherein one of the parts (1, 2) ) a ball is provided on the neck (6) extending from the center of the articulated sleeve (3) integrally with the articulated sleeve (3) through a snap hole whose clear width (W) is smaller than the diameter (D) of the ball, in that the ball is located on the first ball joint part (1) on which the articulated sleeve (3) is formed and is designed as a snap ball (12) and the opening is made in the ball surface (4) of the second part (2) a spherical hinge (7) formed by its spherical walls (8) extending outwardly to form a spacing surface for expanding the spherical hole (7) up to the diameter of the spherical ball (12), with the funnel-shaped walls (8) on the inner a sliding surface (10) adjoins the side of the opening (7), the distance from which the spherical surface (4) extending concentrically thereto is at least equal to the length (L) of the neck (6). Ball joint according to claim 1, characterized in that the funnel-like walls (8) extend at an angle (α) which corresponds to the deflection angle of the ball joint defined by the diameter of the neck (6). Ball joint according to one of the preceding claims, characterized in that the second ball joint part (2) is designed as a plug-in part into a pipe (11) whose end (11 ') extends at least partially over the snap ball (12) in the snap hole. (7). Ball joint according to one of the preceding claims, characterized in that the first ball joint part (1) on which the articulated sleeve (3) is formed is provided on the side facing away from the neck (6) with an open recess (13). Ball joint according to claim 4, characterized in that a recess (15) is provided in the recess (13), which forms the base surface (14). Ball joint according to one of Claims 4 and 5, characterized in that the recess (13) formed on the side of the first ball joint part (1) facing away from the neck (6) is provided with a radially inwardly directed flange (16) with undercut edge. Ball joint according to one of the preceding claims, characterized in that the first ball joint part (I) is provided on a side facing away from the neck (6) with a flat, rounded base surface (14). Ball joint according to claim 7, characterized in that the flat base surface (14) of the first ball joint part (I) is provided with a radially outwardly directed flange for snapping the steel cap.