This invention relates to rail vehicles.
According to the present invention there is provided a rail vehicle comprising a base frame supporting the vehicle body, a bogie frame on which wheels of the vehicle are mounted, bearing structures between the base frame and bogie frame and forming the means which support the base frame on the bogie frame, the bearing structures being spaced horizontally from the vertical axis about which the frames can perform relative pivoting motion, and means for limiting pivoting motion of said frames relatively to one another about said axis.
In a preferred form, the bogie frame is of U-shape in plan and comprises two spaced side members joined by a transverse member, there being a bearing structure between each side member and said base frame, and a further bearing structure between said transverse member and said base frame. The base frame can be of elongated, rectangular form and there can be a bogie frame beneath each end of the base frame. Each bearing structure can comprise a downwardly facing pressure plate on said base frame, and an upwardly facing pressure plate on said bogie frame with suitable lubrication provision as necessary. However, it is preferred that each bearing structure comprise a plurality of rolling elements. In a specific form each bearing structure comprises a downwardly open arcuate groove and an upwardly open arcuate groove, said grooves registering with one another, and said rolling elements being located in the registering grooves.
To provide positive relative location of the frames with respect to one another, one of said frames can have an arcuate slot therein, and the other of said frames can include a pin which projects into said slot, said slot being concentric with said axis and the pin and slot constituting the means for limiting pivoting motion of said frames relatively to one another about said axis. Preferably, said slot is provided in the bogie frame and said pin projects downwardly into said slot from the base frame. In this form, said pin can project downwardly through said slot and means can be provided on the lower end of said pin for preventing upward withdrawal of the pin from the slot. Desirably, a plurality of arcuate slots and pins are provided, each slot being concentric with said axis.
The number of arcuate slots can equal the number of pairs of registering grooves, and each slot can be positioned radially with respect to a pair of registering grooves. In one constructional form, some of said slots are positioned radially inwardly of the pairs of registering grooves, and others are positioned radially outwardly of said pairs of registering grooves. In another form, each slot lies radially outwardly of an associated pair of registering grooves.
For a better understanding of the present invention, reference will now be made to the accompanying drawings which illustrate the invention by way of example and in which:
FIG. 1 is a side elevation of one end of a rail vehicle according to the invention;
FIG. 2 is an end view taken in the direction of the arrow II in FIG. 1;
FIG. 3 is a plan view of one of the bogies of the rail car of FIGS. 1 and 2;
FIG. 4 is a section on the line IV--IV of FIG. 3, drawn to a larger scale;
FIG. 5 is a view similar to that of FIG. 3 and shows a modified arrangement;
FIG. 6 is a view similar to that of FIGS. 3 and 5 shows a further modified form;
FIG. 7 is a plan view of a ball retainer; and
FIG. 8 is a side elevation similar to FIG. 1, showing the entire rail vehicle.
In FIGS. 1 and 2 reference numeral 10 denotes the base frame of a hopper rail vehicle 12 and on which is mounted a bottom discharge hopper 14 which extends substantially the full length of the frame 10. The hopper 14 is arranged to discharge gravitationally through the frame 10 which provides an unobstructed opening extending the full length of the frame. Rail vehicles of this type are used to transport ore, coal, etc.
Each end portion of the frame 10 is supported on a bogie 16. Each bogie 16 comprises a rigid bogie frame which is of substantially U-shape in plan (see for example FIG. 3) and comprises two parallel, spaced side members 18 and a transverse member 20. Each bogie 16 presents a planar upper face.
A plate 22 is mounted on the upper face of the center portion of each side member 18. Each plate 22 has an arcuate groove 24 therein and is secured to the underlying member 18 by means such as bolts and nuts. A further grooved plate 22 is provided on an inwardly projecting portion 26 of the transverse member 20. Adjacent each grooved plate 22 an arcuate slot 28 is provided in the members 18 and 20. The grooves 24 of the plates 22 and the slots 28 formed in the bogie frame members are all centered on a center point 30 which coincides with the required vertical pivoting axis of the bogie 16.
The side members 18 mount bearings for wheel axles 32 which in turn carry flanged wheels 34.
At positions on the end portion of the base frame 10 corresponding to the positions of the plates 22, similar, but inverted, grooved plates 36 (see FIG. 4) are provided for location over the plates 22 of the bogie 16. In the grooves 24 of the plates 22 on the bogie, hard metallic balls 38 are received. These balls 38 enter the grooves of the base frame plates 36 when the frame 10 is placed over the bogie 16 thereby to support the base frame 10 on the bogie 16. The balls 38 permit relative pivoting movement of the bogie and base frame about the vertical axis passing through the center point 30. While balls 38 are preferred, rollers can be used.
The slots 28 of the bogie frame members are entered from above by pins 40 (see FIG. 4) fixed to and extending downwardly from the base frame 10. The pins 40 each project downwardly through the associated slot 28 and receive a nut and washer arrangement 42 on the lower end thereof to prevent unintentional upward retraction of the pins from the slots. Rotatable sleeves (not shown) or other means for reducing wear can be provided on the pins 40.
The three grooves 24, and consequently also the balls 38, are arranged, in the embodiment of FIG. 3, on a common pitch circle 44, while the slots 28 are all arranged on a common, larger diameter pitch circle 46. According to the modified arrangement of FIG. 5, the grooves 24 and the balls 38 of the plates 22 on the side members 18 are located on an inner pitch circle 48. The groove 24 and balls 38 on the transverse member 20 of the bogie are on a larger radius pitch circle 50. All the slots 28 in this form are on a common pitch circle 52 which lies between the circles 48 and 50.
According to the modification of FIG. 6, the grooves 24 and the balls 38 are all on a common pitch circle 54. The slots 28 in the side members 18 of the bogie 16 are on a common pitch circle 56 whereas the slot 28 in the transverse member of the bogie is on an outer pitch circle 58.
It will be understood that the plates 36 and the pins 40 of the base frame 10 are arrangd on corresponding pitch diameters.
In FIG. 6 pneumatic cylinders 60 for operating the brakes of the wheels 34 are shown.
To assure that the balls 38 are maintained at the desired spacing, a retainer or cage, as shown in FIG. 7, is employed in conjunction with each set of balls.
The retainer comprises a thin metallic plate 62 (FIG. 7) having closely spaced holes 64 in each of which a ball 38 is located. In one side of the plate a wide notch 66 is provided which receives a stub pin (not shown) protruding upwardly from the bottom plate 22. The stub pin permits only limited movement of such retainer. The retainer is located with small clearance between a co-acting pair of grooved plates 22 and 36. By limiting the freedom of movement of the retainer, the balls can be retained in the central region of the slots in which they roll.
In operation, on swivelling of the bogie relative to the base frame, the base frame rides on the balls 38. The extent of swivelling is limited by the effective length of the slots 28.
If desired, the thickness of the pin 40 engaging the slot 28 in the transverse member 20 of the bogie may be larger than the other pins, as this pin can be subjected to greater forces during running of the vehicle.
The only obstruction to discharge of the hopper load is the axle of the innermost pair of wheels of each bogie, i.e., the right-hand pair in each of FIGS. 3, 5 and 6. The said pairs of wheels are fixed to the respective axles in order that a live axle is presented which, due to its rotary movement, prevents material from packing thereon.