US2606505A - Articulated railway vehicle - Google Patents

Description

Aug. 12, 1952 J MaQVEIGH 2,606,505

' ARTICULATED RAILWAY VEHICLE Filed 001 4, 1949 I 2 SHEETS SHEET 1 "INVENTOR. v

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I www f Patented Aug. 12, 1952 ARTICULATED RAILWAY VEHICLE James 'MacVeigh, Madrid, Spain, assignor to Patentes Talgo, S. A., Madrid, Spain, a corporation of Spain Application October 4, 1949, Serial No. 119,471

4 Claims. 1

This invention relates to articulated railway vehicles and aims to improve the riding qualities of such vehicles.

In an articulated railway vehicle consisting of short sections or a train of very short cars, satisfactory riding comfort cannot be secured unless the individual sections or cars are integrated into a unit. U. S. Patent 2,462,666, issued February 22, 1949, describes connecting means for the sections of an articulated vehicle which restrain any relative movement of translation between adjacent section ends in any direction and also restrain any relative rotation of the ends of adjacent sections. The connecting means do not hold the end walls of adjacent sections parallel but permit the horizontal fanning of the section ends required to enable the vehicle to follow curves in the track and the slight vertical fanning of the section ends required by the slight vertical bending of the vehicle occurring in entering or leaving grades in the track. While the use of connections which permit such vertical fanning movements is essential to the operation of the vehicle, they have been found in practice to permit certain objectionable parasitic fanning movements which have not been easy to eliminate.

, -It has been found that slight humps or irregularities in the surface of the track cause slight vertical fanning movements of the section ends which load the springs of the vehicle unevenly and persist as vibrations having a frequency of 'two or three cycles per second.

In accordance with my invention, these difliculties are eliminated by longitudinal connections between the vertical ends of adjacent sections which make use of hydraulic friction to prevent rapid approaching or separating movements between the points which they connect while at the same time to permit slow approaching and separating movements. The eiTect of these motion-retarding connections is to leave the sections free to make the slow articulation movements required to follow the track, and at the same time to make the entire vehicle, when eithercurved or straight, substantially rigid in its resistance to rapid relative turning movements between the sections.

Each motion-retarding connection contains a hydraulic device arranged to resist movement by means of the friction developed in forcing a fluid through a restricted orifice. Such hydraulic devices are commonly used as dash pots and as shock absorbers.

While the physical construction of the motionretarding connections may be similar to those Iii used as shock absorbers, their operation and adjustment are entirely different from those of shock absorbers. A shock absorber used in connection with a spring suspension must be adjusted to permit rapid movement necessary to the normal yielding of the spring suspension. The motion-retarding connections of my invention, on the other hand, permit only the slow fanning movements required to enable the vehicle to follow the track and effectively prevent the occurrence of all fanning movements which could result from yielding of the spring suspensions of the vehicle.

My invention will be further described in connection with the accompanying drawings, in which:

Fig. 1 is a diagram illustrating the effect of a hump in the track on an articulated vehicle of the type shown in Patent 2,462,666, and Fig. 2 is a similar diagram illustrating a vehicle embodying my invention under similar circumstances. In both these diagrams, the height of the hump in the track and the vertical curvature of the track are greatly exaggerated for the sake of clearness.

Fig. 3 is an enlarged side view of the connected ends of two sections of an articulated vehicle shown in Fig. 2.

Fig. 4 is a rear end elevation perspective view of one of the sections of a modified construction embodying my invention.

Fig. 5 is a sectional detail of retarding connections. v

The articulated vehicle shown in the drawings consists of a number of rigid body sections a each supported by a pair of wheels o at its rear end through a spring suspension 5. The adjacent ends of adjacent sections are connected and kept in alignment by a central pivotal traction connection c and lateral sliding connections 11 each consisting of a slide element all and a guide element d2 pivotably mounted on the section ends.

Both the central and lateral connections are one of the motionformed to permit sufficient vertical articulation of the sections to permit the vehicle to follow vertical curves (i. e. changes of grade) in the track. For this purpose, the traction connection 0 contains a universal joint which may take the form of separate horizontal and vertical pivotal connections as shown in Patent 2,462,666. The very slight bending required in the lateral sliding connections (1 may be obtained by the use of yielding material such as rubber in the mountings of these connections as shown in Patent 2,462,666. In accordance with my present invention, however, I find it desirable to avoid even a slight yield in the lateral connections and provide for vertical flexing of the vehicle body by mounting either the slide element or guide element of each connection 01 on a ball joint d3.

The traction and lateral connections are the only connections between the ends of the sections in the articuated vehicle shown in Patent 2,462,666 and in Fig. 1 of this application. When one of the wheels of such a vehicle strikes a hump in the track as shown in Fig. 1, one wheel or one pair of wheels is thrown upwardly causing an extra strain on the spring suspension s associated with this wheel which raises the ends of two adja cent sections and causes their end walls to fan out vertically as shown in Fig. 1. In practice, this vertical movement, while slight in extent, may tend to set up a vibration which causes slight pitching movements of the individual sections and interferes with comfortable riding.

The articulated vehicle shown in Fig. 2 embodies my invention and has an additional connection i between the ends of the sections. This is a motion-retarding connection which extends lengthwise of the vehicle between points A, B located at a considerable vertical distance from the pivotal traction connection c. Th connection It includes a hydraulic device ll (hereinafter described in detail) which strongly resists rapid relative approaching and separating movements of the points A and B and offers practically no resistance to slow approaching and separating movements of these points.

The operation of the vehicle provided with the connections I0 is shown in Fig. 2. Each hydraulic motion-retarding connection permits the slow vertical fanning of the vehicle ends required in entering or leaving a grade in the track, but, whether the vehicle is straight or slightly curved vertically as shown in Fig. 2, it is substantially rigid with respect to rapid relative vertical fanning movement between its sections. When one of its wheels strikes a hump in the track as shown in Fig. 2, the wheel which strikes the hump is thrown upwardly compressing the spring suspensions associated with it, but, as the entire vehicle is substantially rigid in respect to rapid movements, the compression of this spring suspension is resisted by the entire Weight of the vehicle. In theory, the entire vehicle is moved upward by the one spring suspension subjected to the force of the hump on the track, but, in practice, this upward movement of the entire vehicle is so slight as to be imperceptible.

As' shown in Fig. 5, the connection [0 includes a double acting hydraulic device H of the type used on airplane struts. The passages controlling the flow of oil are adjusted so that the connection offers slight resistance to the fanning movements required to follow vertical curves in the track andhigh resistance to the rapid vertical fanning movements which would, in the absence of the connection It, be caused by irregularities or humps in the track. This adjustment may easily be made as the approaching and separating movements of the points A and B required in entering and leaving grades on the track occur at a rate of only a few hundredths of an inch per second,

while the movements caused by track irregularities, in the absence of the connection II], have a maximum speed of four inches per second.

What I claim is:

1. An articulated railway vehicle, comprising an articulated body including two rigid sections, a central traction connection between the sections including a universal joint, lateral aligning connections between the sections, a single pair of wheels and a spring suspension associated with it supporting the adjacent ends of the two sections, and a longitudinal double-action hydraulic, motion-retarding connection between the adjacent ends of the sections located a substantial distance above the central traction connection.

2. In a railway train, the combination with two rigid body sections and integrating connections between the sections formed to positively hold their adjacent ends in alignment while permitting relative turning of the sections in horizontal and vertical planes and a single pair of wheels and a spring suspension associated with it supporting the adjacent ends of the two sections, of an additional connection extending between points on the adjacent ends of the two sections located at a substantial distance above the integrating connections and formed to frictionally resist both approaching and separating movements of the points which it connects.

3. In a railway train, the combination with two car bodies having their adjacent ends spring supported on a single pair of wheels and connected by a traction pivot for relative turning in horizontal and vertical planes, of a two-way frictional retarding device so connected to the two bodies as to retard relative turning movements of the sections in a vertical plane.

4. An articulated railway vehicle comprising an articulated body including two rigid sections, a central traction connection between the sections including a universal joint, lateral connections between the sections each including a horizontal slide element and a horizontal guide element, one of which is pivotably mounted on one section to turn about a vertical axis, a ball joint mounting the other element on the adjacent section end, a single pair of wheels and a spring suspension associated with it supporting the adjacent ends of the two sections, and a longitudinal double-actin hydraulic motion-retarding connection between the ends of the sections located a substantial distance above the central traction connection.

JAMES MACvEIGH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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