|Title of Invention||
"A CARDAN JOINT FOR STEERING COLUMNS"
|Abstract||A cardan joint for steering columns comprising a tubular element (12), one end of which is partially introduced into the interior of an incorporated yoke (15), the ends or wings (15a) of which are formed with circular recesses (20) for coupling the universal joint, the resilient joint and bearings (16, 17, 18) for articulating it to the yoke (19), characterised in that an absorber (14) is inserted between the tubular element (12) and the body (13) of the yoke (15) so as to prevent vibration, the absorber being of injected rubber and partially covering longitudinally the entire lateral surface of tubular element (12) and the body (13), changes of cross-section being disposed in the longitudinal direction of tubular element (12) and the body (13) and on its side surface as means for coupling the end of tubular element (12) in the interior of the body (13) in a single position and for compensating axial forces.|
|Full Text||The present application for a patent of invention, as indicated in the title, comprises a "Cardan joint for steering columns", whose novel constructional, shape and design features fulfil the purpose for which it has been specifically designed, with maximum safety and efficiency.
The proposed invention is in the mechanical sector, more particularly in the motor vehicle sector, with special application to steering columns where motion cannot be transmitted via a longitudinal shaft in one piece, but as a result of the mechanical characteristics of modern motor vehicles, where maximum space is provided for the occupants, it is necessary among other objects that transmission of motion, e.g. steering and the like, must change direction so that both the driver's position and the steering casing are coupled relative to the engine, in a place which is usually disposed in the front part of the vehicle. The Cardan joint can also be applied to other kinds of vehicles, whenever the transmitted motion must follow various directions until it arrives at the desired point, starting from a point at the other end of the shaft as required by the user.
Known technical solutions, with the aforementioned objects regarding safety and space, start from the steering shaft, in that one end of the shaft, which we have called the male part, is inserted into the interior of the other end of the shaft of the female part, optionally with interposed anti-vibration means such as resilient joints or the like, preventing relative motion between the two parts, via a bolt which secures the two provided they are formed with holes for inserting the bolt.
The bolt also compensates torsional force between the ends of the divided shaft, and also prevents axial motion between the aforementioned ends, being optionally actuatable in dependence on its greater or lesser resistance, as a safety element in the event of a collision.
Another technical aspect which has also to be taken into account is the ease of assembly and dismantling of the divided steering shaft, which cannot adversely affect the reliability and safety, since the Cardan joint, before suffering a collapse, is capable of withstanding axial forces without some components disengaging from the others, i.e. the inner male part disengaging from the female part which surrounds it, the most frequent solution nowadays.
Other objects must also be fulfilled, e.g. the transmission shaft with its Cardan joint must not convey or amplify, acting as a conducting support of, vibrations generated by components or devices disposed at one end of the shaft and transfer them to the user of the vehicle, and consequently the transmission shafts must incorporate anti-vibration elements capable of absorbing a number of vibrations and movements which affect the shaft, thus avoiding noise, vibration and shaking of the user, and also other components with which the shaft is in contact, resulting in a manifold annoyance of the occupants inside the vehicle passenger compartment.
The advantage of the proposed novel Cardan joint is basically the elimination of the bolt and providing the male and female ends with means for preventing axial motion and means for coupling the parts so as to facilitate assembly of the shaft under any conditions, i.e. both at the factory and when the shaft is repaired.
The means provided for preventing axial motion basically consist in a spatial design of the outer surface of the male part and of the inner surface of the female part, the former being provided with some projections at one end, with an appreciably warped configuration substantially similar to the female part, so that the male part can be force-fitted into the interior of the female part and cannot come out unless the force reaches a level which is abnormal under the usual operating conditions. All the above is supplemented by action
of the previously-mentioned projections, formed by flanges which are doubled towards the interior, preventing the male part from projecting in front of the interior of the female part.
The coupling means are obtained via a change in the cross-section of the male part corresponding to a change in the section of the female part which facilitates insertion of the former into the interior of the latter in a single position, i.e. the correct position.
Accordingly, the present invention provides a cardan joint for steering columns comprising a tubular element, one end of which is partially introduced into the * interior of an incorporated yoke, the ends or wings of which are formed with circular recesses for coupling the universal joint, the resilient joint and bearings for articulating it to the yoke, characterised in that an absorber is inserted between the tubular element and the body of the yoke so as to prevent vibration, the absorber being of injected rubber and partially covering longitudinally the entire lateral surface of tubular element and the body, changes of cross-section being disposed in the longitudinal direction of tubular element and the body and on its side surface as means for coupling the end of tubular element in the interior of the body in a single position and for compensating axial forces.
Other details and features of the patent of invention will be clear from the following description with reference to the drawings accompanying this specification, which diagrammatically show preferred details. These details are given by way of example with reference to a possible embodiment, but are not limited to the details set out. Accordingly the description should be considered as an illustration and without limitation of any kind.
Fig. 1 is a longitudinal section in elevation of a Cardan joint with the device;
Fig. 2 is a section via two-two in Fig. 1;
Fig. 3 is a section via three-three in Fig. 1;
Fig. 4 is a section via four-four in Fig. 1 and
Fig 5 is a longitudinal section 6-6 in Fig. 1.
We shall now list the various components numbered in the drawings accompanying the present description: Cardan joint 11, tubular element 12, cylindrical part 12a, rectangular section 12b, yoke body 13, flat bases 13a, curved sides 13b, shock-absorber 14, incorporated yoke 15, wings 15a of the yoke
whereas the sides have a substantially circumferential curvature 13b, the absorber 14 being inserted between the cylindrical part 12a of the tubular element 12 and the bases 13a and sides 13b.
In Fig. 4, which is a view or section via four-four in Fig. 1, we see that at this point the body 13a of the yoke 15 has the same shape whereas the tubular element 12 in the interior of 13 has a rectangular cross-section 12b secured at its ends in projections 22 at the end of the intermediate piece 12 and permitting relative motion of 13 on 14 under normal conditions and avoiding undesired relative motion of the two components. Accordingly at the ends of 13 and 14 there is a constriction or curve or curved zone 21 which serves as a mechanical catch between the element 13 and 12 when necessary, without vibration via 12 reaching 19 since the absorber 14 is between 13 and 12, as can be seen in Figs. 3 and 4.
The changes in cross-section of 12 and 13 in the direction of its longitudinal axis as shown in Figs. 4 and 5 are designed so that, starting from a given axial force, a mechanical catch is provided between 12 and 13 and, under these special conditions, reliable transmission of rotation is guaranteed. A specially important case is when, owing to damage of 14, a discontinuity could occur in the material and 12 could rotate relative to 13.
The special shape of the curved zone 21 in co-operation with the projections 22 in the form of flanges which are doubled in the front of one end of the element 12 ensures axial retention both towards the exterior (dismantling) of 12 with respect to 13 and towards the interior (collapse), the energy in this case being absorbed with additional effect.
As shown by the drawings and our explanation of them, the patent application as described in the present specification provides a simple and effective construction which can be
applied with great ease, undoubtedly constituting a novel industrial result.
Since the present patent has been sufficiently described in conjunction with the accompanying drawings, it can be understood that any modifications in detail which are considered appropriate may be introduced into the same, provided the proposed variations do not substantially alter the patent, which is summarised in the following CLAIMS.
1. A cardan joint for steering columns comprising a tubular element (12)", one
end of which is partially introduced into the interior of an incorporated
yoke (15), the ends or wings (15a) of which are formed with circular
recesses (20) for coupling the universal joint, the resilient joint and
bearings (16,17,18) for articulating it to the yoke (19), characterised in that
an absorber (14) is inserted between the tubular element (12) and the body
(13) of the yoke (15) so as to prevent vibration, the absorber being of
injected rubber and partially covering longitudinally the entire lateral
surface of tubular element (12) and the body (13), changes of cross-section
being disposed in the longitudinal direction of tubular element (12) and
the-body (13) and on its side surface as means for coupiing-the-end of tubular element (12) in the interior of the body (13) in a single position and for compensating axial forces.
2. A cardan joint for steering columns as claimed in claim 1~ wherein the tubular element (12) has a circular cross-section (12a) in a first zone which changes in a second zone near the wings (15a) into a substantially rectangular corss-section (12b) with rounded corners.
3. A cardan joint for steering columns as claimed in any preceding claims wherein the means for coupling (12) to (13) are formed by the ends (13b) of body (13) and (12b) of element (12), and finish in a curved zone (21) which in collaboration with the projections (22) in the form of flanges bent
at 90° relative to (12b) serve as a mechanical catch between body (13) and element (12) and for compensating axial forces.
4. A cardan joint for steering columns as claimed in claim 1 wherein the
incorporated yoke (15) has in its body (13) a first cross-sectional zone (13a)
formed by flat bases and substantially circular sides (13b) and in a second
zone near the wings (15a) the aforementioned sides (13) are circular but of
5. A cardan joint for a steering columns substantially as hereinbefore
described with reference to and as illustrated in the accompanying drawings.
|Indian Patent Application Number||672/DEL/1996|
|PG Journal Number||17/2004|
|Date of Filing||27-Mar-1996|
|Name of Patentee||MELCHOR DAUMAL CASTELLON|
|Applicant Address||DIPUTACION 455, 08013 BARCELONA, SPAIN|
|PCT International Classification Number||F16D 3/22|
|PCT International Application Number||N/A|
|PCT International Filing date|