The present invention relates to a primary type suspension for railway vehicles as per the preamble of claim 1, the evident object of which is to constitute a device providing an independent two-wheel and short shaft bogie with a primary suspension for railway vehicles, allowing vertical displacements of the suspension independently of each wheel, maintaining, as a consequence, a parallelism and a separation between same.

This invention applies to the industry devoted to manufacture railway vehicles and accessories.

It is well known how difficult is for the railway vehicles to keep a parallelism of wheels, as well as a separation between them on an independent wheel and short shaft bogie when it is fitted - with a primary suspension, and that, on the other side, it is imperative this condition for a safe running.

The inventor is, at present, aware of the existence of different primary suspension systems, but none of them has, in fact, an efficient performance of its elements composing it, which results in a deterioration of the carried wheels.

An evident solution to this problem would be to provide a device or primary suspension for railway vehicles fitted with an articulated dual connecting rod and, at the same time, obtaining a vertical suspension by distorting the spring or - springs mounted between the bearing boxes and the bogie structure, and, at the same time, a side suspension by distortion of resilient bushings.

Nevertheless, nothing is known, up to now, about the existence of a primary type suspension for railway vehicles obviating this present problem.

The primary type suspension for railway vehicles proposed by the invention constitutes, a solution to the current problem in this field.

In a more specific manner, the envisaged primary type suspension for railway vehicles is constituted starting from an articulated dual connection rod having two horizontal shafts, which, by means of two bushings coupled to the bogie structure, and other two bushings coupled to a part common to a bearing box, acts as a guide for the suspension spring or springs.

The suspension has two bars articulated at its ends joining the bearing boxes with the bogie structure, so allowing the wheel and short shaft assembly to carry out a vertical and parallel displacement, as well as the bearing boxes, and, furthermore, by means of a strip joining the inner bearing boxes, independent vertical displacements of each of the two bearing - sets are possible, so maintaining a full and absolute separation between them .

The vertical suspension is obtained by distortion of the spring or springs mounted between the bearing boxes and the bogie frame.

The side suspension is obtained by distortion of the resilient bushings, the axial characteristic of which is relatively soft in relation to its radial one which is harder, allowing some millimeters of separation simultaneously shown at the two wheels - since both bearing sets are joined through a strip.

The main features of the invention are set forth in the characterizing portion of claim 1 while preferred embodiments of same are described in dependent claims 2 to 4.

In order to supplement the present description and to aid to a better understanding of the features of the invention, the accompanying drawing, which forms part of this description, shows a perspective view of the invention relative to a primary type suspension for railway vehicles.

From this Figure, it can be seen that the envisaged primary type suspension for railway vehicles is constituted starting - from an articulated dual connecting rod 1 pivoting at two horizontal shafts A and B, which, through two bushings 2, joined with the bogie structure 3 and other two bushings 4 joined with a part 5 common to the bearing box 6, 7, acts as a guide for the suspension spring or springs 11.

The invention contemplates two bars 12 mounted on supports 14 , articulated at their ends and joining the bearing boxes with the bogie structure 3, allowing the wheel set 8 and the short shaft 9 and bearing boxes 6, 7 to vertically and parallel displace.

Furthermore, by means of a strip 10 joining the inner bearing boxes 6, 7, they make possible independent vertical displacements of each of two bearing sets, maintaining a separation - between them in a constant way.

Solidly connected with the bogie frame 3 is a plate 13 by means of which the bogie rests on the springs 11, slides along the parts 5 and is thus resiliently and vertically movable, the bogie being accompanied in its vertical movement by the bushings 2 attached to it. This allows a movement of the connecting rod 1 about the two axes A and B formed by said bushings 2 and 4.

The vertical suspension is obtained by distortion of the spring or springs 11 which are mounted between the bearing boxes and the bogie structure, while the side suspension is obtained by distortion of resilient bushings 2, 4, the axial - characteristic of which is relatively soft in relation to the radial one which is harder, so allowing some millimeters of displacement simultaneously shown at the two wheels, since - the bearing sets are joined through said strip 10.

In synthesis, it can be said that this primary suspension between an independent wheel bogie frame 3 and a wheel-shaft assembly 9, mounted between two bearing boxes 6, 7, per each wheel 8, of course, disposes of a bearing box, which is fited with a vertical extension 5 acting as a guide for the suspension springs 11 and which is articulated through bushings 4, horizontally turning, at a dual connecting rod 1, which in turn is articulated by means of other horizontally rotating bushings 2, at the bogie frame, so allowing vertical displacements of each of independent wheels.

Also, the bearing boxes 7 are united to the bogie structure 3 by means of a bar 12, which is articulated at its ends, which, together with the connecting rod 1, allows each of the bearing sets to carry out independent vertical and parallel displacements .

Likewise, the primary suspension has resilient bushings 2, 4 which permit transverse displacements which are caused by side efforts transmitted to the wheel through the track and that, - due to the resilient characteristics of the bushing, act as a side primary suspension.

Lastly, the primary suspension stands out against the union of the inner bearing boxes through a strip 10 maintaining a separation between both wheels, but meaning, at the same time, that it allows independent vertical and parallel displacements at each of the wheels.

The springs 11 can be substituted by rubber sandwiches of appropiate dimensions.

It is not considered necessary to extend more this description for an expert in the art to understand the scope of the invention and the advantages derived from it.

The materials, size, shape and arrangement of the components are open to variation, provided that it does not imply any alteration to the essence of the invention.