Mobile headstock for bi-modal rail/road wagon

Abstract

 The mobile headstock (1) for a bimodal rail and road vehicle, equipped with rail type draw (4) and buffing (3) gears and with guide slides (5), permitting it to slide on a horizontal level inside the vehicle frame (7), make it possible for the vehicle to use, in the rail position, the above-mentioned draw and buffing gears. It is also possible to retract them inside the underframe (7), in the road position. In order to be locked, in the relative road and rail positions, the mobile headstock (1) is equipped with two rear bars (6) which, through the action of two locking devices (10), make it an integral part with the frame (7) of the bimodal vehicle.

Description

[0001] The invention consists of the headstock of a bimodal rail and road vehicle, provided with a rail type draw and buffing gears, which can retract in the vehicle's underframe, and with a device locking the headstock to the vehicle's underframe.

[0002] Nowadays intermodal systems are used for transport of goods by rail and road.

[0003] These systems, by means of standard units of load (containers), ensure efficient performances of the rail and road vehicles expressly designed for this special purpose. Research and experiments have been carried out for some years in order to develop new techniques with the aim of integrating the railway wagon and the road vehicle into a single vehicle, so that the transfer of goods would not be necessary.

[0004] These new techniques are well-known as bimodal techniques or systems and the respective vehicles are generally defined as bimodal vehicles.

[0005] At present there are two bimodal techniques:

1.the ROAD-RAILER system (called after the name of the firm which developed it in the United States);

2.the attached system which is still in the course of being developed and for which a patent was applied for in Italy - application No. RM93 A 000615 September 13 1993.

[0006] The ROAD-RAILER system consists of special semi-trailers (derived from the standard road semi-trailers) whose ends are put on special railway bogies in order to run on the rails.

[0007] To understand the present situation of this technique, see figures No. 1, a) to e), which illustrate the sequence of position changes of the ROAD-RAILER system, that is, from the road position to the rail position.

[0008] The particular configuration in the railway position of the ROAD-RAILER system, however, creates an extremely stiff convoy, both in relation to the capacity to adapt to dynamic stress, while the train is moving, and in relation to ordinary shunting works which the railway vehicles are subjected to.

[0009] These reasons, together with others of a technical and handling nature, are still obstructing the ROAD-RAILER system from being accepted according to the opinion of the COMMISSION OF THE EUROPEAN COMMUNITIES - Directorate General for Transport in DOC.EURET-410-94 DG VII-A-4 - September 1994 on pages 22 - 26.

[0010] The other bimodal system, previously mentioned, consists of a vehicle which can be used either with railway bogies or with road bogies.

[0011] Also in this case, for a better understanding of this system, see figure No. 2, f) to m), which explain the sequence of position changes from the rail position to the road position. Note that, unlike the ROAD-RAILER system, the position of the railway bogies, in comparison with the underframe, is the typical position of ordinary rolling stocks. This leaves the vehicle ends free. In this way each of these ends can be equipped with conventional railway draw and buffing gears, in the same way as an ordinary headstock (which in railway terminology is the end of the underframe of rolling stocks). This vehicle then assumes a form of an ordinary rolling stock.

[0012] The above-mentioned draw and buffing gears must be retractable so that they do not interfere with manoeuvrability and the good working order of the vehicle in the road position.

[0013] The present invention, a mobile headstock, fulfills this necessity. The mobile headstock, provided with draw end buffing gears, can slide in a horizontal plane, in the vehicle's frame along its longitudinal axle, by means of special guide bars. In this way the mobile headstock can assume two different positions:

• the forward position
• the backward position.

[0014] When the headstock is in the forward position (in the railway position) the draw and buffing gears are functional. In the same way when the headstock is in the backward position (in the road position) the draw and buffing gears will be kept within the maximum length allowed for semi-trailers and they will not obstruct the regular use of the semi-trailer.

[0015] In both positions, the mobile headstock will be locked to the vehicle frame by means of two identical locking devices which will act on the two bars fixed to the headstock.

[0016] Each of these locking devices is composed of a rotary bushing permanently screwed on the inside of a coupling sleeve, by means of threads. The coupling sleeve is fixed on the inside of the main cross bearer of the vehicle frame.

[0017] On the inside, the rotary bushing is drilled and threaded lengthwise. The threads, however, are not on the overall circumference of the bushing's hole, but only on some land longitudinal sectors which alternate, in number, with some void longitudinal sectors. The land longitudinal sectors have the same angular measure as the void longitudinal sectors.

[0018] The bar runs through the hole of the bushing. Along part of its length, congruous with the position ranges of the mobile headstock, it has a twin thread compared to the one thread of the bushing's hole.

[0019] A fraction of a turn of the rotary bushing, equal to the angular measure of the void and land sectors, will bring the land sectors of the bushing's hole in front of the land sectors of the bar, thus screwing the respective threads. In this case the bar will not slide inside the bushing's hole. This will prevent the mobile headstock from moving away from the vehicle's underframe and will therefore lock it. On the other hand, when the land sectors are in front of the void sectors, the bar will be free to slide inside the bushing's hole. Now the headstock will be free to slide into the vehicle's underframe.

[0020] The necessary force for the sliding of the bars, and consequently of the headstock, is produced by two hydraulic rams, one for each bar. The hydraulic ram acts on the bar by means of a fork which transmitts both a thrust and draw action on the bar. Moreover, this fork controls the rotation of the bushing and its safety catch, by means of poppet balls, in order to prevent accidental rotations. This fork is provided with an ordinary escapement system, which acts on two fixed points of the vehicle's underframe, and which predisposes the fork's thrust or draw action on the bar.

[0021] Figure 3 represents the mobile headstock seen in perspective. The mobile headstock (1) consists of a parallelepiped frame (2) made of the most appropriate materials and with the most appropriate manufacturing processes, so that they can take the stress prescribed by homologation regulations which rolling stocks are subjected to. On the fore part of the headstock (1) the buffers (3) and the coupling hook (4) are placed. On the sides it is equipped with special guide bars (5) which are interface the grooves (8) on the inner part, of the side sills of the frame (7). These allow the headstock to slide lengthwise. On the rear part two bars (6) are fixed, which permitt the locking of the headstock, either in the forward position or the backward position. The locking occurs by means of the locking devices which are inside the main cross bearer (9) of the frame (7).

[0022] Figure 4 represents in perspective the mobile headstock (1) in the forward position, in the vehicle's frame (7). This is the railway position.

[0023] Figure 5 represents in perspective the mobile headstock (1) in the backward position, in the vehicle's frame (7). This is the road position.

[0024] Figure 6 represents, in the railway position, the mobile headstock (1), part of the vehicle frame (7), the hydraulic rams (16), seen in the plane level, the locking devices in longitudinal section.

[0025] Figure 7 represents the same elements as figure 6 in the road position.

[0026] Figure 8 represents in longitudinal section the locking device (10) which is composed of:

• the coupling sleeve (11) integral with the frame,which has a longitudinal threaded hole for screwing; the body of the coupling sleeve which has two transversal holes for the passage and movement of the balls (22); and two slots from which the cylindrical pins (13) of the rotary bushing (12) come out. The angular measure of these slots in congruous with the angular measure of the land threaded sectors of the rotary bushing (12).
• The rotary bushing (12) which is threaded on the outside and screwed to the coupling sleeve (11). On the inside the bushing is drilled lengthwise and has longitudinal threaded sectors, so that on the inner circumference of the bushing's hole,land threaded sectors alternate with void sectors. The land and void sectors have the same angular measure. On the outer part of the rotary bushing there are two opposite cylindrical pins (13) which come out of the coupling sleeve (11), by means of the two slots machined in the body of the coupling sleeve. Moreover, on the outer body of the rotary bushing there are two hemispheric notches which can hold part of the balls (22) locking the rotary bushing to the coupling sleeve (11).
• The end of the bar (6) of the mobile headstock (1). This end of the bar is threaded on the outside, in the same way as the inner hole of the rotary bushing (12), for a length congruous with the position ranges of the mobile headstock. It is splined in this hole. The final part of the bar is smooth; on the inside there is a cylindrical axial blind hole which contains the clamping and unclamping block (18), the spring (19), the spring (20) and two cylindrical transversal holes holding the balls (21) which lock the fork (14) to the bar. The axial hole is closed with a plug (17).
• The clamping and unclamping block (18) which is provided with an appendix. The appendix comes out at the side of the bar (6) by means of a slot machined in it, and can temporarily buck two juts (one for each direction of the action) fixed on the vehicle's frame (7). An ordinary escapement mechanism annulls the bucking action between the appendix and the jut when this bucking action finishes.

[0027] In order to avoid an excessive complication in the drawing, the details relative to the appendix of the block and to the escapement mechanism have been omitted.

• the control fork (14) which is splined on the final smooth part of the bar (6). The two tines (15) of the fork have a longitudinal spline suitably shaped lengthwise. These splines receive the ends of the cylindrical pins (13). In the rear part of the fork the end of a hydraulic ram (16) is splined in a fixed position. The other end of the hydraulic ram is fixed to the frame (7) of the vehicle. Moreover, on the inside of the fork, in the part which slips on the bar (6), there are two hemispheric notches which can hold part of the balls (21) locking the fork to the bar (6).

[0028] Figure 9 represents the cross section (W-W), indicated in figure 8, concerning the locking device (10). In this section one can see the land threaded sectors of the rotary bushing (12) which screw to the land threaded sectors of the bar (6). In this case the bar is locked. Moreover, in this section it can be seen that the cylindrical pins (13) of the rotary bushing (12) are intercepted by the shaped splines on the tines (15) of the control fork.

[0029] From figure 10 to figure 17 the sequence of the action of the locking device (10) is illustrated.

[0030] Figure 10;

• The headstock (1) is in the forward position. The bar is integral with the coupling sleeve (11) by means of the roary bushing (12) whose land threaded sectors are screwed to the respective land threaded sectors of the bar. The rotating motion of the bushing is prevented by the balls (22) which are held inside the hemispheric notches machined in the bushing, by the tines (15) of the fork (14).

[0031] Figure 11;

• Operating the hydraulic ram (16) the fork (14) moves backwards thus freeing the balls (22). Now the bushing can rotate.

[0032] Figure 12;

• Still moving backwards, the flow of the shaping of the splines placed on the tines (15) of the fork (14) will allow the bushing to rotate by means of the cylindrical pins. Moreover the hemispheric notches placed in the fork (14) will be in front of the balls (21), which, when pushed by the inclined planes of the block (18), which is pushed by the spring (19), will go into the hemispheric notches. Now the land threaded sectors of the bushing (12) will not be screwed any longer to the land threaded sectors of the bar. The bar will no longer be clamped to the coupling sleeve (11), but it will be clamped to the fork by means of the balls (21).

[0033] Figure 13;

• Still moving backwards, the fork (14) will draw the bar (6) and consequently the headstock (1).

[0034] Figure 14 and 15;

• Still moving backwards, the bar (6), the fork (14), and the outer appendix of the block (18) will buck a jut of the frame (7). Then the block will stop its stroke. Its minor section will be in front of the balls (21) which will be pushed inward by the edges of the hemispheric notches of the fork (14). The fork will be unclamped from the bar (6) which will then stop its stroke. Now the headstock (1) is in the backward position.

[0035] Figure 16;

• Still moving backwards, the fork (14) by means of the shaped splines of its tines (15), (which act on the cylindrical pins of the bushing (12)), will provoke the rotation of the bushing. This will again lock the bar (6) to the coupling sleeve (11). Then the headstock (1) will be locked to the frame (7) of the vehicle.

[0036] Figure 17;

• Moving the fork a little further backwards, the balls (22) will be pushed by the tines (15), into the hemispheric notches of the bushing (12) thus locking the fork to the coupling sleeve (11). At this point the hydraulic ram (16) has finished its action. The outer appendix of the block (18), under the action of the escapement mechanism, will no longer buck the jut of the frame (7). The block pushed by the spring (20) will be capable of pushing the balls (21) again. The balls, then, will be able to connect the fork (14) to the bar (6), this time moving the headstock (1) forward.

[0037] Figures 18-19-20 illustrate in cross-section, the locking device (10) during the rotation of the bushing (12). The rotation is provoked by the action of the splines of the tines (15), on the cylindrical pins (13) of the bushing.

Claims

1. The mobile headstock (1) for a bimodal rail and road vehicle, is composed of a parallelepiped body (2), equipped with rail type draw (4) and buffing (3) gears, in the fore part. The parallelepiped body (2) is provided with two guide bars (5) at the side, which allow it to slide along two guide splines (8) which are inside the side sills of the vehicle frame (7). The sliding occurs in a horizontal plane along the longitudinal axle of the vehicle. The mobile headstock (1) is equipped, in the rear part, with two bars in order to lock the headstock to the vehicle frame (7) by means of two locking devices (10).

2. The locking device (10) of the mobile headstock (1) to the vehicle frame (7). The locking device (10) is composed of a coupling sleeve (11) threaded inside, which is fixed to the vehicle frame (7); of a rotary bushing (12) threaded both on the inside and the outside, coaxial on the inside of the coupling sleeve (11); of the bar (6) of the headstock (1), threaded at the end on the outside; of a control fork (14) with tines (15) splined on the inside lengthwise; of a clamping and unclamping block (18); of balls (21) - (22) and springs (19)-(20).

Drawing