GB2216949A

GB2216949A - Journal bearing for a sun visor

Info

Publication number: GB2216949A
Application number: GB8904916A
Authority: GB
Inventors: Jean-Christophe Canadas
Original assignee: Rockwell-CIM
Current assignee: Rockwell-CIM
Priority date: 1988-03-17
Filing date: 1989-03-03
Publication date: 1989-10-18
Anticipated expiration: 2009-03-03
Also published as: IT1233566B; FR2628800B1; SE8900933D0; DE3900829C2; DE3900829A1; SE467957B; FR2628800A1; SE8900933L; IT8904811A0; GB8904916D0; GB2216949B

Description

I JOURNAL BEARING FOR A SUN VISOR r1 r') 2,2 16949 The invention relates

to a journal bearing for a sun visor.

In order that sun visors can be pivoted into the viewing area a journal bearing is provided, which is normally anchored by means of a wire frame to sun visor body. The journal bearing should on the one hand allow an easy pivoting of the sun visor and should on the other hand provide adequate holding or retaining forces to fix the sun visor body reliably in a desired position. The holding forces should be sufficient to ensure that no undesired pivoting of the sun visor results from vehicle is vibrations.

Therefore a round bearing sleeve can be provided in a journal bearing for a sun visor, which sleeve loops in a substantially curved manner the journal of a bearing spindle. Thus, for the journal, the bearing sleeve forms a bearing box. A curved leaf spring extending along the axial direction is provided between the journal and the inner wall of the bearing sleeve. Thus, the leaf spring presses the journal into the curved bearing box of the bearing sleeve and as a result of the frictional force produced brings about a considerable holding force for the sun visor. In order that the sun visor is also fixed in the non-use position, the round journal is provided in the axial direction with a planar flattened portion. which forms a stop face. Thus, it is necessary to overcome a limit force if the leaf spring bears on the planar flattened portion and subsequently by pivoting the sun visor is to be engaged with the circular area of the journal.

However, it has been found that it is difficult to manufacture the bearing box adapted to the curvature of the round journal and that subsequently problems are frequently encountered in use. In order that the journal does not have a large clearance in the bearing box, the latter which forms the bearing sleeve must closely engage with the journal. Due to the relatively large looping or contact angle, the bearing sleeve can be locked on the journal as a result of the manufacturing tolerances. It is then only possible with difficulty to rotate the sun visor body about the journal. In addition, manufacturing problems are encountered if the bearing sleeve engages in large-area manner on the journal. These problems are increased if the journal diameter is to be reduced. It is therefore scarcely possible with the known construction to use thinner journals and therefore arrive at flatter sun visors, because the diameter of the journal bearing determines the thickness of the sun visor. Besides the described disadvantages in connection with the manufacture of the known journal bearing construction, a further disadvantage is caused by increased abrasion wear if, for example, following prolonged use foreign matter passes between the journal and the closely engaging bearing sleeve.

DE-OS 32 35 997 and German Patent 33 45 764 disclose journal bearings. comprising a bearing sleeve, a bearing spindle and a leaf spring. The bearing spindle journal has two diametrically facing planar flattened portions, 4- which once again form stop faces and permit the positioning of the sun visor in two preferred locking positions. However, in the case of these known journal bearings the leaf springs engage on the outside via recesses in the bearing sleeves on the planar flattened portions on the journal. This journal bearing construction permits a rotation of the sun visor body about the bearing spindle and also a longitudinal displacement on the journal. However. these journal bearing constructions are extremely complicated and in particular do not permit the application of adequate holding forces in order to position the sun visor body in reliably a desired position.

The problem of the invention is consequently to provide a journal bearing for a sun visor, which can be more simply manufactured and which allows the use of a journal with a smaller external diameter.

According to the present invention, there is provided a journal bearing for a sun visor, comprising a bearing sleeve which has a substantially rectangular cross-section in its. axial direction with planar walls, and which is for anchoring in a sun visor body, a journal of a bearing spindle provided in the bearing sleeve, the journal having a planar flattened portion extending in the axial directiont and a leaf spring extending along the axial direction and located so as to act resiliently between the inner wall of the bearing sleeve and the journal. and the leaf spring facing a said planar wall.

4 The invention also extends to a sun visor incorporating a journal bearing essentially as defined in the preceding paragraph. The bearing sleeve is no longer constructed as a bearing box engaging in large-area manner on the journal. There is advantageously a linear contact along the axial direction between the journal and the inner wall of the bearing sleeve. The linear contact or narrow contacting surface, compared with the large- area contact in conjunction with the leaf spring offers the advantage that it is more easily possible to compensate manufacturing tolerances of the bearing sleeve and the journal.' It is also to.manufacture the bearing sleeve through the linear contact. A bearing sleeve which must be exactly adapted to the curvature of the journal is much more difficult and more expensive to manufacture. if, following prolonged use of the present journal bearing, foreign matter or dirt particles should appear -he linear within the bearing sleeve, as a result of 1. contact between the journal and the inner wall of the bearing sleeve, a scraping action occurs, i.e. the foreign matter is no longer fixed in the bearing surfaces and is instead transported in accordance with the journal rotation direction to one or other side of the bearing sleeve wall. The corners of the bearing sleeve also offer a free space for receiving such foreign matter or, as a reservoir, can receive lubricants. Additional advantage results from the planar wall of the bearing sleeve, which faces the leaf spring. in that two locking positions of the journal can be reached with a planar flattened portion. one locking position is obtained if the flattened portion of the journal engages on the bearing sleeve wallr whilst a second locking position is h I-, - 5 obtained if the flattened portion engages with the leaf spring.

The holding or frictional force between the journal and bearing sleeve results from the contact pressure applied by the leaf spring and by which the leaf spring is biassed in the fitted position. In the out-of-use position of the sun visor. the planar flattened portion of the journal engages for example on the planar wall or on the leaf spring. Therefore the contact pressure is additionally increased if the journal is turned out of the locking position counter to the tension of the leaf spring. This additional contact pressure is determined by the spring displacement and the spring constant of the leaf spring. The spring displacement is in turn determined by the extent to which the tangential flattened portion is offset with respect to the rounded surface of the journal or its diameter in the direction of the axial centre. Thus, outside the locking position, the complete diameter of the journal determines the holding force and on passing from the locking position into the use position of the sun visor, it is necessary to overcome one of the abutting edges between the flattened portion and the journal surface. The holding force of the sun visor is not determined by the surface of the bearing sleeve or the journal.

It would basically be possible in the case of known journals to provide a spindle with a smaller external diameter. However. as described hereinbefore. this is not possible due to the manufacturing problems encountered in producing the bearing box curvature. It is also not possible to dimension the holding force exactly because, as a result of the looping angle of the bearing box, there is a clamping action similar to a drum brake. Variations to the holding force can occur with even minor manufacturing tolerances of the bearing box or the journal. However, the present journal bearing with the linear contact surface does not suffer from this disadvantage and it is therefore possible to use journals with a smaller diameter and exactly predeterminable holding forces and, in addition, imprecise clamping forces due to the looping or contact angle do not occur. Thus, the present journal bearing with the linear contacting surface between the journal and the bearing sleeve makes it possible to produce flatter sun visors.

It is also not necessary for the individual walls of the bearing box to be exactly at right angles to one another, because it is exclusively a question of the linear contact between the journal and one or more walls or the leaf spring. In conjunction with the planar wall of the bearing sleeve, it is possible to increase the holding force through the provision of a second flattened portion, which diametrically faces the first flattened portion of the journal and simultaneously accompanied by a smaller external diameter of the journal. In this case the spring displacement of the leaf spring is increased by the amount by which the second flattened portion is offset with respect to the journal surface. Due to the linear contact between the journal and the bearing sleever the -journal must not in cross-section have a circular shape and can e.g. be polygonal. The linear contacting surface provides the additional advantage that a clearance fit can exist between the bearing sleeve and the journal. which considerably facilitates manufacture of the two parts. The clearance fit is compensated by the leaf spring in conjunction with the planar wall.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example. to the accompanying drawing, in which:- Figure 1 is a perspective view of a journal bearing, Figure 2 is a section through the journal bearing of Figure 1 taken along line A-A, and Figure 3 is a section along the journal bearing showing means to prevent removal.

Figure 1 shows a perspective view of a journal bearing comprising a bearing spindle 1, a bearing sleeve 2 and a leaf spring 14. The bearing spindle 1 is provided at its free end with a journal 18, which is inserted in the bearing sleeve 2. At its front end the journal 18 has a point 7 (shown in dot-dash form), which abuts against 6 closure 12 of the bearing sleeve 2 in the inserted state. In the embodiment shown in Figure 1 the bearing sleeve 2 in cross-section at right angles to the axial direction has a rectangular shape. Therefore the walls of the bearing sleeve 2 form planar surfaces. On the journal 18 are provided two flattened portions 8. 9 and in te present representation the upper flattened portion 8 engages on the upper wall 19 of the bearing sleeve 2 and the lower flattened portion 9 engages with the curved leaf spring 14. The free ends of the leaf spring 14 are supported on the lower wall of the bearing sleeve 2 and, as a result of its curved shape. presses the journal 18 against the inside of the planar wall 19. For clarity, the fastening of the leaf spring 14 is not shown. In addition, on the upper wall 19 of the bearing sleeve 2 corrugations 10 are provided which form sliding faces for the journal 18, so that it does not completely engage on the inner wall portion of the upper wall 19 of the bearing sleeve 2. During assembly, the journal 18 is inserted in the bearing opening 11 with the point or tip 7 to the front and consequently comes into contact with the leaf spring 14 and the corrugations 10. As a function of the holding force to be applied, the leaf spring 14 fixed in the bearing sleeve 12 can be correspondingly curved.

The bearing sleeve 2 is preferably bent from a piece of sheet metal, so that the bearing sleeve 2 forms a box-shaped tube with the bearing opening 11 and closure 12. As a result of the manufacture of the bearing sleeve 2 as a part bent from a sheet metal portion, through corresponding cutting, punching and bending, support plates 3 and stops 4 can be shaped in one piece on the bearing sleeve 2. The support plates 3 and stops 4 serve to receive a wire frame 5. which is arranged in the interior of the sun visor body (not shown). The sun visor body completely surrounds the parts shown in Figure 1 and exclusively in known manner a lateral opening is provided for the insertion of the journal 18, which in its extension over the curved bearing spindle 1 is for J i 9 example connected to a pivot bearing. The support frame 5 is for example joined by a welded joint or by bent parts (not shown) to the support plates 3 or stops 4. For the better supporting of the support frame 51 supports 6 can be provided on the plates 3, as shown in Figure 1. In order that the box-shaped bearing sleeve 2 is not bent upwards through the contact pressure emanating from the leaf spring 14, the ends of the bent part overlap in the vicinity of the support plates 3 and are firmly interconnected, e.g. by flanged portions 13. The bearing sleeve 2 together with the support plates 3 consequently forms a stable, one-piece component, which is produced following the insertion and locking of the leaf spring 14. A torsionally stiff bearing sleeve 2 results from the box- shaped profile. As a function of the intended use, the bearing sieeve 2 can also be made from plastics material.

Figure 2 shows a cross-section through the journal bearing of Figure 1 along line A-A. The opening cross-section of the bearing opening 11 is laterally bounded by side walls 21, which are spaced from one another by the same as or at least the diameter of journal 18. Thust the side walls 21 form a lateral guide for the journal 18 during insertion and during its rotary movements. In the position shown in Figures 1 and 2 the bearing sleeve 2 is in a locking position and can only be pivoted into another position by overcoming a certain limit force.

Due to the flattened portions 8# 9. leaf spring 14 and upper wall 19 of the bearing sleeve 2, the journal 18 can lo - assume two locking positions. The journal 18 can also assume two locking positions if there is only one flattened portion 8 or 9. The advantage of the diametrically facing flattened portions 8, 9 is that a significantly larger displacement path for the leaf spring 14 is obtained if the journal 18 is turned out of the locking position by clearing the abutting edge 22 (Figure 1) with its rounded portion on the leaf spring 14 or the inner wall portion of the wall 19. The displacement or travel of the leaf spring 14 is obtained from the diameter minus the spacing of the flattened portions 8, 9.

Therefore the holding force in the locking positions is lower than in the pivoting positions. The holding force in the locking positions is determined by the bias of the is leaf spring 14.

Besides the limit force which must be expended in order to rotate the journal 18 over the abutting edges 22 on the leaf spring 14, the width or lowering of the flattened portions 8, 9 determines the adjustment angle by which the sun visor can be continuously adjusted. If the bearing sleeve 2 is in a locking position, then the rounded surface. of the journal 18 engag.es linearly on the insides of the inner walls 21. apart from a small clearance. At the same time the flattened portions 8, 9 engage in large-area manner on the leaf spring 14 and wall 19 or corrugations 10. By pivoting the bearing sleeve 2 over and beyond the abutting edge 22, the wall 19 and leaf spring 14 linearly engage with the journal 18. If the bearing sleeve 2 in Figure ' 2 is e.g. rotated by 900f due to the flattened portions 8. 9. the maximum possible clearance with respect to the side walls is obtained.

1 il However, this is not a particularly great disadvantage and can be compensated by a relatively long journal bearing. This also corresponds to a sun visor use position, which is rarely used.

It is apparent from the journal bearing described up to now, that the holding force can be varied in a wide use range and is only influenced to a limited extent by manufacturing tolerances. due to the linear contact in the pivoted sun visor use position. It is also not necessary for the side walls to be parallel to one another or to be perpendicular to the wall. It is also possible to use a small diameter journal 18, because the boxshaped bearing sleeve 2 can also be easily manufactured with a small opening cross-section. This advantage results from the orientation of the journal bearing for a linear contact along the journal 18 if the sun visor is pivoted out of the locking position. The linear contact is achieved in that the leaf spring 14 faces the planar wall 19 and the journal 18 is fixed between the wall 19 and leaf spring 14. In addition, the corner areas of the bearing sleeve forms three spaces 23F which can be used for receiving lubricants or abraded dust, which can form following prolonged use of the sun visor.

According to a further embodiment not shown, it is possible to provide two leaf springs 14t so that one leaf spring engages on each flattened portion 8, 9. As a result of the box-shape of the bearing sleeve 2. these two leaf springs can easily be housed and fixed on the inside of the planar wall 19. The provision of two leaf springs is particularly appropriate if the bearing sleeve 2 is to is be moved axially to the journal 18 in the locking position. The bias of the two leaf springs in this case is adjusted in such a way that there is an easy sliding guidance and, by means of a pivot bearing (not shown)r the sun visor is pivoted on the bearing spindle 1 on the side window of a vehicle. Due to the large variation possibilities and the exact determinability of the holding force in the locking position, as well as the pivoting position of the sun visor, it is also possible to achieve the aforementioned axial displacement movement with one leaf spring 14.

Figure 3 shows a longitudinal section through part of the journal bearing of Figure 1 with two means to prevent the journal 18 from being removed from the bearing sleeve 2. The first removal barrier is obtained through the free end 16 of the leaf spring 14, which engages in a groove 15. As described hereinbefore, the leaf spring 14 is fixed in the interior of the bearing sleeve 2. The free end 16 of the leaf spring 14 can be dimensioned in such a way that it only engages in the groove 15 when the journal 18 has been pivoted out of the locking position. However. the length of the free end of the leaf spring 14 directed onto the groove 15 can also be dimensioned in such a way that on inserting the journal 18, as a result of the deflection of the leaf springr the free end 16 engages in the groove 15. which in this case passes round the complete journal.

Another way to prevent removal can be formed in that. as shown in Figure 3, the corrugations 10 engage in an associated annular groove 17 in the journal 18. It is also possible to provide a removal barrier in the form of a thickened portion on the tip 7 of the journal 18 if, in addition to the.rotary movement. the journal bearing is to allow the previously-described axial longitudinal displacement of the sun visor. If the closure 12 (Figure 1) is not providedr the journal.bearing can be constructed in such a way that it can be used for sun visors both on the driver's side and on the passenger's side.

A 14 -

Claims

CLAIMS:

A journal bearing for a sun visor, comprising a bearing sleeve which has a substantially rectangular cross-section in its axial direction with planar walls, and which is for anchoring in a sun visor body, a journal of a bearing spindle provided in the bearing sleeve, the journal having a planar flattened portion extending in the axial direction, and a leaf spring extending along the axial direction and located so as to act resiliently between the inner wall of the bearing sleeve and the journalt and the leaf spring facing a said planar wall.
2. A journal bearing according to claim 1, wherein the bearing sleeve has been formed by being bent from one piece of metal sheeting.
3. A journal bearing according to claim 1 or 2, wherein a closure is provided on a free end of the bearing sleeve.
4. A journal bearing according to claim 1, 2 or 3, wherein said planar wall has depressions or corrugations.
5. A journal bearing according to claim 4, wherein the depressions or corrugationsr together with an annular groove in the journalr form a barrier to prevent removal of said journal from the bearing sleeve.
6. A journal bearing according to any one of the preceding claims, wherein there are two of said leaf springs.

-
7. A journal bearing according to any one of the preceding claims, wherein the journal has two of said planar flattened portions, which preferably diametrically face one another.
8. A journal bearing according to any one of the preceding claims, wherein a free end of the or one said leaf spring, together with a groove in the journal, form a barrier to prevent removal of said journal from the bearing sleeve.
9.

A journal bearing for a sun visor. substantially as hereinbefore described with reference to the accompanying drawings.
10. A sun visor incorporating a journal bearing according to any one of the preceding claims.

v Published IM9 atThePatentOffloe.State House, 66,171 High Holborn, London W01R 4TP. Further copies maybe obtainedfrom The Patent0face.

Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD. Printed by Multiplex techniques ltd, St Mary Cray, Kent, Com 1/87