COUPLING

Abstract: In a Hookes joint, particularly for steering columns, the intermediate element (24) pivotally receives outward projections (25',26',27',28') of the coupling parts (33,34). The inner part of the ring (24) and the bearings for the projections, are preferably of re-inforced plastics.

Description: The invention concerns a coupling for coupling two generally shaft-shaped elements in such manner that a rotational force can be transferred from one element to the other whereby the center-lines of these elements can form different angles with each other, including an intermediate element to which two swivelling coupling elements are connected each of which is, or can be, connected to a shaft and each of which has two opposing parts located on both sides of the center-line of the coupling element which are connected to, and can rotate around, the intermediate element, so that the one coupling element can swivel in one plane and the other coupling element can swivel in a plane perpendicular to the first, with regard to the intermediate element, which is generally an endless section or annular part and whereby the opposing parts of each coupling element are constituted by two pivot pins located inside the annular intermediate element and projecting radially outward with regard to the centre-line of the coupling element, each being capable of rotating around its centre-line and being carried on bearings in said element. Couplings of this kinds are particularly suitable for application in the steering column of a vehicle. A similar coupling is generally known from DE-C-901739 In the known coupling the intermediate element is formed by a cruciform component and each coupling is formed by a bracket- type component with two cheeks running parallel at a distance from one another, each equipped with an opening encircling an arm of the cruciform intermediate element so it can rotate, with the intervention of a needle bearing. The known coupling is relatively expensive, mainly because special tools are needed for its assembly and because, once assembled, the coupling cannot, or only with great difficulty, be disassembled. In addition, the construction of this coupling allows only a limited angle of rotation. Moreover, the coupling elements must be connected to the shafts by means of bolts, so that when they are applied to the steering column of a vehicle - which usually requires two of these couplings - especially adapted steering columns must be designed for each type of vehicle, because the steering columns of different types of vehicles differ in length. The objective of the invention is to provide a coupling of the type mentioned which allows a greater angle of rotation, is cheaper than the known coupling and easy to disassembly, while satisfying, at the same time, safety and operation regulations when applied in steering columns, especially with regard to a flexible and easy transmission of the rotational force, the need to be free of vibrations and the need to break when the car is involved in a collision. This objective is met on account of the fact that in the coupling according to the invention the pivot pins are constituted by the ends - bent at right angles - of two rods running parallel to one another and contained in a generally rod-shaped holder. In an advantageous execution the outer surface of the holder has at least two diametrically opposed recesses in which said rods are held while sliding lengthwise whereby, in applications on steering columns, the distance between two couplings, and/or the distance between a coupling and the steering-wheel mechanism, and/or the distance between a coupling and the steering-box mechanism can be changed in a simple manner at the wheels to be steered, so that a single complete steering wheel can be used for different types of vehicles. The holder may also be formed by a sleeve which has two diametrically opposed indentations forming two containment spaces inside the sleeve for holding the rods. In an advantageous manner, between each rod and the side-walls, formed by indentations, of the rod-containing space in the holder, elements of a flexible material are inserted to dampen the vibrations in the steering box. The invention is further explained with reference to the drawing in which Figure 1 shows a steering column for a vehicle containing two couplings according to the invention. Figure 2 shows the coupling applied to the steering column according to Figure 1, Figure 3 represents a cross-section of the coupling according to Figure 2, Figure 4 is a cross-section according to the line IV-IV in Figure 3, Figure 5 is a cross-section according to the line V-V in Figure 3, Figures 6 and 7 are cross-sections of holder of a different form, As shown in Figure 1 the steering column involves a part 2 connected to the steering wheel 1 with an energy-absorbing part 2′, an intermediate shaft 3 and a shaft 5 connected to the steering box 4. Part 2 is connected via the coupling 6 with the intermediate shaft 3 and the intermediate shaft 3 is connected via the coupling 7 with the steering box shaft 5. As shown in Figures 2 and 3, the couplings 6 and 7 each include an annular intermediate element 8 and two coupling elements 9 and 10, each of which are constituted by a holder 11 or 12 and two parallel rods 13, 14 or 15, 16, whose ends 13′, 14′ or 15′. 16′ are bent at right angles to form pivot pins carried in openings in the intermediate element 8. In this design, the pivot pins 13′ and 14' are oriented according to a center line of the annular intermediate element 8, and the pivot pins 15′ and 16′ according to a center line of the annular intermediate element 8 perpendicular to the first. Each pivot pin 13′, 14′, 15′, 16′ is carried by means of a sleeve bushing 17 in an opening in the annular intermediate element 8, with the addition of sealing rings 18. As shown in Figure 2, each holder 11, 12 consists of an essentially solid shaft in which two parallel guide ways have been drilled at a distance to one another for receiving the rods 13, 14 or 15, 16, and a central guide way 19 to which a shaft, in particular part of a steering column, is attached. Figure 3 shows another form of execution of the holders 11′ and 12′. As appears in particular from Figure 5, the holder consists of a sleeve on whose outer surface recesses 12″ and 12> are formed diametrically opposed to one another, which recesses serve to receive the rods 13, 14 or 15, 16. These rods are placed in the recesses up to the shoulders 13″, 14″ formed on the latter. As shown in Figure 6, a sleeve 19 with a square cross-section may be inserted in the holder 12′ for reinforcement. The holder shown in Figure 7 in cross-section consists of a cylindrical sleeve in which indentations 20′ have been formed extending over a certain length of the sleeve from its end facing the annular intermediate element. The inwardly indented wall sections 20″ create containment spaces inside the sleeve 20 in which the rods 21, 22 are placed with the intervention of elements 23 made of a flexible material.

Claims: Coupling for two generally shaftshaped elements (3,5) in such manner that a rotational force can be transferred from one element to the other whereby the centre-lines of these elements can form different angles with each other, including an intermediate element (8) to which two swivelling coupling elements (9,10) are connected each of which is, or can be, connected to a shaft (3,5) and each of which has two opposing parts located on both sides of the centre-line of the coupling element (9,10) which are connected to, and can rotate around, the intermediate element (8), so that the one coupling element can swivel in one plane and the other coupling element can swivel in a plane perpendicular to the first, with regard to the intermediate element (8) which is generally an endless section or an annular part and whereby the opposing parts of each coupling element (9,10) are formed by two pivot pins located inside the annular intermediate element (8) and projecting radially outward with regard to the centre-line of the coupling element (9,10), each being capable of rotating around its centre-line and being carried on bearings in the said annular intermediate element (8),characterized in that the pivot pins are formed by the ends (13', 14', 15', 16') bent at right angles of two rods (13, 14, 15, 16, 21, 22) running parallel to one another in a rod-shaped holder (11, 12', 20). Coupling according to claim 1, characterized in that the outer surface of the holder (12') has at least two diametrically opposed recesses (12'', 12''') in which said rods (13, 14) are held while sliding lengthwise. Coupling according to claim 1 or 2, characterized in that the holder is formed by a sleeve (20) which has two diametrically opposed indentations (20') which form two containment spaces inside the sleeve for inserting the rods (21, 22). Coupling according to claim 3, characterized in that between each rod (21, 22) and the side-walls, formed by indentations (20'), of the rod-containing recess in the holder, elements (23) of a flexible material have been inserted.

Inventors: KAPAAN, HENDRIKUS JAN
Applicants: SKF INDUSTRIAL TRADING & DEVELOPMENT CO, B.V.
Application year: 1987
Main classification: F16D3
IPC codes: B62D1, F16D3