GB2033955A

GB2033955A - Flexible Support with Ball and Socket Joint

Info

Publication number: GB2033955A
Application number: GB7911452A
Authority: GB
Original assignee: Societa Applicazioni Gomma Antivibranti SAGA SpA
Current assignee: Societa Applicazioni Gomma Antivibranti SAGA SpA
Priority date: 1978-07-03
Filing date: 1979-04-02
Publication date: 1980-05-29
Also published as: GB2033955B; DE2916186A1; FR2430538A1; ES479011A1; IT7825265A0; IT1096896B; FR2430538B3

Abstract

A flexible support (1) has a ball and socket joint formed by part- spherical surfaces formed on an internal sleeve (2) and an external sleeve (5). The internal sleeve has an annular layer (3) of elastomer material provided with a rigid internal annular element (4) which defines a part- spherical convex surface. The external sleeve has a plurality of parts (15) which together define the co- operating concave part-spherical surface and which are held together by an external bush (7). <IMAGE>

Description

SPECIFICATION Flexible Support with Ball and Socket Joint The invention relates to flexible supports having a ball and socket joint, and in particuiar to supports of the type comprising an internal sleeve provided with a bearing seat having a partspherical and convex shape, an external sleeve which is coaxial with the internal sleeve and is provided with a bearing seat having a partspherical and concave shape, which cooperates with the bearing seat of the internal sleeve, and elastic means for damping down the transmission of vibrations between the two sleeves.

This type of support allows rotation of the external sleeve with respect to the internal sleeve which is greater than that which is normally admissible when there is simple torsional deformation of the elastic element. This rotation is in fact made possible by relative sliding between the two part-spherical bearing seats.

Such sliding does however lead to localised wear of the bearing seats. There is consequently the problem of finding a way of preventing such wear which would otherwise lead to excessive play between the support sleeves which can give rise, under operating conditions, to sharp localised jolts which may lead to breakage of the support.

The aim of the invention is to provide a flexible support of the type specified above which, apart from being of a particularly simple construction and economic in manufacture, ensures correct and uniform operation even when wear, which always occurs under normal operating conditions, is present.

According to the present invention in a flexible support of the type described above the internal sleeve comprises a cylindrical support body on the radially external surface of which is disposed a layer of elastomer material provided with a rigid internal annular element on which the partspherical convex bearing seat is formed, the external sleeve comprising a rigid external annular element formed by a plurality of separate parts forming the concave spherical bearing seat, the support including an external cylindrical bush having means for clamping together the separate parts of the rigid external annular element.

One example of a support according to the invention will now be described with reference to the attached drawings in which: Figure 1 is a cross-sectional view along a middle plane of the support; Figure 2 is an elevational view, partly in crosssection, of some parts shown in Figure 1; and, Figure 3 shows one particuiar part of Figure 1.

The flexible support 1 comprises an internal cylindrical sleeve 2, the outer surface of which has an annular layer of rubber 3 attached to it by vulcanisation. The layer 3 has a central partspherical portion 3a which is bounded at each of its extremities by an annular collar 3b which has the shape, in cross-section, of a lip. The spherical surface 3a has a plurality of projecting parts 13 in its lateral regions which are adjacent to the two collars 3b.

The convex-shaped partspherical surface 3 has an internal rigid annular element 4 mounted on it which is made up by three separate segments 44 which are identical to each other and each extend over an arc of circle which is substantially equal to 1200. Each segment 44 is constituted by a part in the form of a part-spherical shell which mates up with the external surface 3 and has a plurality of openings 14 on its lateral faces into which the projections 1 3 of the layer of rubber 3 engage. In this way the segments 44 are prevented from rotating over the layer of rubber 3 and constitute the internal annular rigid element 3.

The annular element 4 cooperates with an external rigid annular element 5. The internal surface of element 5 has a part-spherical bearing seat 5a which is concave and cooperates with a corresponding convex bearing seat, 4a of annular element 4. Annular element 5 is sub-divided into at least two separate parts in the form of rings 1 5 which are arranged axiaily facing each other. A cylindrical bush 7 with its outer edges 7a and 7b folded radially inwards is arranged coaxially with respect to annular element 5 and externally of it.

By this arrangement the two rings 1 5 are clamped together so as to form the annular element 5.

The annular collars 3b which border the axial ends of the layer of elastomer material 3 are arranged so as to be in positions which align with the folded-over edges 7a, 7b of bush 7. The radially outer part of each collar 7b abuts against the end face 1 5a of the external annular element 5. This arrangement makes it possible for the collar 3b to perform both a sealing and a protective function against dust and impurities in general for the bearing seats 4a and 5a which are in contact in the elastic support.

Claims

1. A flexible support having a ball-and-socket joint comprising an internal sleeve, an external sleeve which is coaxial with the internal sleeve and which cooperates with the internal sleeve, and means for damping the transmission of vibration between the two sleeves, the internal sleeve comprising a cylindrical support body on the radially external surface of which is disposed an annular layer of elastomer material provided with a rigid internal annular element on which a part-spherical convex bearing seat is formed, the external sleeve comprising a rigid external annular element formed by a plurality of separate parts and forming a concave part-spherical bearing seat and an external cylindrical bush having means for clamping together the separate parts of the rigid external annular element.

2. A support according to claim 1, in which the layer of elastomer material has a central portion which has a part-spherical external surface having a plurality of projecting parts which engage in corresponding slots formed on the internal annular element.

3. A support according to claim 1 or claim 2, in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Flexible Support with Ball and Socket Joint The invention relates to flexible supports having a ball and socket joint, and in particuiar to supports of the type comprising an internal sleeve provided with a bearing seat having a partspherical and convex shape, an external sleeve which is coaxial with the internal sleeve and is provided with a bearing seat having a partspherical and concave shape, which cooperates with the bearing seat of the internal sleeve, and elastic means for damping down the transmission of vibrations between the two sleeves. This type of support allows rotation of the external sleeve with respect to the internal sleeve which is greater than that which is normally admissible when there is simple torsional deformation of the elastic element. This rotation is in fact made possible by relative sliding between the two part-spherical bearing seats. Such sliding does however lead to localised wear of the bearing seats. There is consequently the problem of finding a way of preventing such wear which would otherwise lead to excessive play between the support sleeves which can give rise, under operating conditions, to sharp localised jolts which may lead to breakage of the support. The aim of the invention is to provide a flexible support of the type specified above which, apart from being of a particularly simple construction and economic in manufacture, ensures correct and uniform operation even when wear, which always occurs under normal operating conditions, is present. According to the present invention in a flexible support of the type described above the internal sleeve comprises a cylindrical support body on the radially external surface of which is disposed a layer of elastomer material provided with a rigid internal annular element on which the partspherical convex bearing seat is formed, the external sleeve comprising a rigid external annular element formed by a plurality of separate parts forming the concave spherical bearing seat, the support including an external cylindrical bush having means for clamping together the separate parts of the rigid external annular element. One example of a support according to the invention will now be described with reference to the attached drawings in which: Figure 1 is a cross-sectional view along a middle plane of the support; Figure 2 is an elevational view, partly in crosssection, of some parts shown in Figure 1; and, Figure 3 shows one particuiar part of Figure 1. The flexible support 1 comprises an internal cylindrical sleeve 2, the outer surface of which has an annular layer of rubber 3 attached to it by vulcanisation. The layer 3 has a central partspherical portion 3a which is bounded at each of its extremities by an annular collar 3b which has the shape, in cross-section, of a lip. The spherical surface 3a has a plurality of projecting parts 13 in its lateral regions which are adjacent to the two collars 3b. The convex-shaped partspherical surface 3 has an internal rigid annular element 4 mounted on it which is made up by three separate segments 44 which are identical to each other and each extend over an arc of circle which is substantially equal to 1200. Each segment 44 is constituted by a part in the form of a part-spherical shell which mates up with the external surface 3 and has a plurality of openings 14 on its lateral faces into which the projections 1 3 of the layer of rubber 3 engage. In this way the segments 44 are prevented from rotating over the layer of rubber 3 and constitute the internal annular rigid element 3. The annular element 4 cooperates with an external rigid annular element 5. The internal surface of element 5 has a part-spherical bearing seat 5a which is concave and cooperates with a corresponding convex bearing seat, 4a of annular element 4. Annular element 5 is sub-divided into at least two separate parts in the form of rings 1 5 which are arranged axiaily facing each other. A cylindrical bush 7 with its outer edges 7a and 7b folded radially inwards is arranged coaxially with respect to annular element 5 and externally of it. By this arrangement the two rings 1 5 are clamped together so as to form the annular element 5. The annular collars 3b which border the axial ends of the layer of elastomer material 3 are arranged so as to be in positions which align with the folded-over edges 7a, 7b of bush 7. The radially outer part of each collar 7b abuts against the end face 1 5a of the external annular element 5. This arrangement makes it possible for the collar 3b to perform both a sealing and a protective function against dust and impurities in general for the bearing seats 4a and 5a which are in contact in the elastic support. Claims

3. A support according to claim 1 or claim 2, in which the internal annular element comprises a plurality of separate parts.

4. A support according to any one of claims 1 to 3, in which the layer of elastomer material has, at each end, an annular collar having a lip-shaped cross-section, the radially outermost part of the collar being arranged to abut a corresponding end of the external sleeve in order to provide a seal.

5. A support according to any one of claims 1 to 4, in which the rigid external annular element is subdivided into separate annular parts along at least one plane which is perpendicular to the axis of the sleeves.

6. A support according to claim 5, in which the means on the cylindrical bush for clamping together the separate parts of the external rigid element comprises radially inwardly directed edges at the ends of the bush.

7. A support according to claim 1, substantially as described with reference to the accompanying drawings.