US 3631810 A
A railway vehicle comprises a bolster supported by each wheel-set through a lateral suspension. The bolster is connected to the vehicle body to constrain it to move laterally with the bolster under centrifugal force by an amount related to the stiffness of said lateral suspension, but permitting lateral tilting of the body relatively to the bolster. Actuating means are provided to tilt the vehicle body relatively to said bolster through an angle related to the centrifugal force acting on the vehicle body, simultaneously with the lateral displacement of the body to counteract the effects of centrifugal force.
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Description (OCR text may contain errors)
 References Cited UNITED STATES PATENTS Alan John Bing London, England Appl. No. 827,555  Filed United States Patent  Inventor X XXX 7 999 M HM 515551 0 000 l 111 951 Lynn et 937 Schoepfet al.
950 Soloview 968 Bingham 969 Love May 26, 1969  Patented Jan. 4,1972
 Assignee British Railway Board London, England  Priority May 29, 1968 Primary Examiner-Arthur L. La Point Assistant ExaminerHoward Beltran AttorneySommers & Young Great Britain 25,847/68 w w mflma tr. t a t S t mm hm qn Wm 5 ub m n m m n e S v iia c TC t 3 0 3 am LT m U0 .m. a a e n l m b o m P e m $.W. e l w e mm mom SD i eu u wn y ABSTRACT: A railway vehicle com by each wheel-set through a lateral connected to the vehicle body to constrain it to move lateral] with the bolster under centrifugal force 105/171, t0 the stiffness of said lateral suspension,
tilting of the body relatively to the bol B61f 3/00, are provided to tilt the vehicle bod B6 1f 5/24, B6lf 5/44 through an angle related to the cen l05/l97, vehicle body, simultaneously with the 190 R, 210 the body to counteract the effects of centrifugal force.
m H m M w R H .9. E m w W? v mm m H m Mn M W4 R M B F m m m m m Mm w m m m M m Y D m m mA .L 7 L m m m9 m n S1 .1 In h ECm C G o TUC M AR s m .w 4 U U W r i 5 U PATENTEUJAN 4m SHEET 1 BF 4 Alan 70 m 71h Trader/ Mom ys PATENTEDJAN 4:972 3.631.810
SHEET 3 BF 4 FIG.7
PATENTEDJAN 41912 3.631.810
SHEET 0F 4 I nurln w LATERALLY MOVABLE RAILWAY VEHICLE TRUCK This invention relates to railway vehicles, and more particularly, but not exclusively, to railway coaches for use in highspeed passenger trains capable of speeds of upwards of 100 mph.
In designing a railway coach for use in highspeed passenger trains running on existing tracks not designed for such high speeds, the effect of centrifugal force on the comfort of passengers arising from deficiencies in the cant of the track at curves when the train negotiates these curves at the designed high speeds, has to be counteracted and one way of doing this is to tilt the coach body laterally relatively to the wheelsets. For the comfort of passengers, it is desirable to tilt the coach body so that the resultant force on a passenger is perpendicular or nearly perpendicular to the coach floor. Ideally the coach body is therefore tilted so that the coach floor is at an angle to the plane of the track (hereafter tenned 0,,) equal to the cant deficiency; as will be appreciated the cant deficiency 0,, is a function of the vehicle speed and the radius of the curve being negotiated by the vehicle. For optimum use of the space available within the loading gauge of the track, the tilt center about which the coach will in effect be rotated will normally fall relatively high up within the coach body. To physically pivot the coach body on this tilt center would therefore require structure which intrudes into the passenger space and this is very undesirable.
It is the object of this invention to provide a mechanism which will effectively tilt the body about the aforementioned tilt center but which is contained generally beneath the coach floor.
According to this invention there is provided a railway vehicle comprising at least one wheelset disposed at each end thereof, a bolster supported by said wheelset through a lateral suspension permitting the bolster to move laterally of the wheelset against a predetermined stiffness of the lateral suspension, connecting means between said bolster and the vehicle body constraining the vehicle body to move laterally with the bolster whereby the body and bolster will be displaced laterally together under centrifugal force by an amount related to the stifiness of said lateral suspension, but permitting lateral tilting of said body relatively to said bolster, and servocontrolled actuating means arranged to tilt said vehicle body relatively to said bolster through an angle related to the centrifugal force simultaneously with the lateral displacement thereof, whereby the effective tilt center of said body lies in the vertical central longitudinal plane of the vehicle and above the floor of the vehicle.
By the term bolster it is intended to include any appropriate form of beam or frame.
Thus it will be seen that the tilting arrangement of a railway vehicle according to the invention is advantageously combined with the lateral suspension for the vehicle in a way permitting a soft lateral suspension and low lateral unsprung mass.
In the case of a simple fourwheeled vehicle a bolster and tilting actuating means will be provided at each wheelset. Similarly in the case of a bogietype vehicle each bogie having two or three wheel-sets, a said bolster and tilting actuating means will be provided at each bogie of the vehicle.
In the case where a pair of railway vehicles are interconnected by a beam articulated at its ends to the two vehicle bodies at a distance from the ends of said bodies the connecting means may be between said beam and a bolster on a single wheelset, or respective bolsters on a pair of wheelsets each said wheel-set having tilting actuating means for a respective one of the vehicle bodies.
Advantageously said connecting means are arranged to effective tilt center of said body is spaced a distance d from said pivot given substantially by the expression d=Mg/Kk,, (where M is the mass of the body and bolster and g is gravitational acceleration).
The invention will now be further explained with the air of the accompanying diagrammatic drawings in which:
FIG. I shows diagrammatically one example of tilting system in the untilted position,
FIG. 2 shows the system of FIG. I in a tilted position,
FIG. 3 shows diagrammatically a second example of tilting system in the untilted position,
FIG. 4 shows the system of FIG. 3 in a tilted position,
FIG. 5 shows a diagrammatic plan view of one vehicle connected to another vehicle in a train by a steering beam and in their relative position when negotiating a curve,
FIG. 6 is a perspective view of one example of construction of wheelset and associated bolster frame, and
FIG. 7 is a diagrammatic view of the servocontrolled tilting actuator.
Referring now to FIGS. 1 and 2 these show the arrangement at one wheelset of a fourwheeled vehicle, the arrangement at the other wheelset being similar. Chaindotted line 1 indicates the centerline of the wheelset axle on which the pair of wheels are mounted and which is rotatably supported in axle boxes. The vehicle has a bolster 2 extending transversely of the vehicle and pivotally mounted at its ends to the lower ends of swing links 3. The swing links 3 at their upper ends are pivotally mounted to a frame 4 mounted directly on the axle boxes of the wheelset. This provides a soft passive lateral suspension. The system will however work with any form of lateral suspension, whether employing potential energy like swing links, or strain energy like simple springs. Thus the bolster 2 can swing relatively freely laterally of the vehicle and relatively to the wheelset under centrifugal force, but has no freedom in roll. The vehicle body 5 is pivoted at P to a structural member 6 solidly mounted on the swinging bolster 2 and, by a similar pivot on a swinging bolster at the other wheelset but constraining it to move laterally with the bolster 2. Tilting actuating means, in this example comprising hydraulic jacks 7 and 8, is provided for tilting the vehicle body about the pivot P by an amount related to the centrifugal force acting as determined by an accelerometer mounted on the vehicle body. The control of the tilting actuating system is described later with reference to FIG. 7.
The vertical central longitudinal plane of the vehicle is indicated by chain-dotted line 9 and the medial plane of the coach body by chaindotted line 10. The point 0 indicates the desired tilt center of the vehicle body in the vertical central longitudinal plane 9 and G the center of gravity of the vehicle body.
Referring now to FIG. 2, this shows the geometry of the system under steady curving conditions with a considerable cant deficiency 0 and therefore with the vehicle body tilted through an angle 0,, about the desired tilt center 0 by the tilting actuating means 7 and 8. Under the centrifugal force MgO the bolster 2 will move laterally a distance PQ==Mg0 /k,, relative to the wheelset axle, where k, is the lateral suspension stiffness. For correct tilting geometry, the point 0 must be where the medial plane of the tilted body 5 intersects the vertical centerline of the axle, i.e. intersects the vertical central longitudinal plane of the vehicle, thus;
0P=PQlsin0 as 0,, is small, and substituting for PQ This applies to any form of lateral suspension with linear stifi ness k, between the bolster 2 and wheelset axle. With the cause said vehicle body to pivot on said connecting means, the swinglink form of lateral suspension shown in FIG. 2 lateral lateral suspension means has a constant stiffness k, and said actuating means tilt the body on said pivot and through an angle to the vertical k0 directly proportional to the centrifugal force acting (where K is the constant of proportionality which may be greater than, equal to or less than unity) whereby the If the vertical and roll suspension is situated between the body and bolster 2 as shown diagrammatically in FIGS. 3 and 4 where the vertical and roll suspensions are represented by way of example as coils springs 12 in series with the hydraulic jacks 7 and 8 between the coach body and the bolster, there is relative vertical movement between the body and swinging bolster. The pivot P is then replaced by tie bar ll connected to the body 5 and member 6 at R and S. The bar 11 pennits this vertical roll movement but restrains lateral movement between the swinging bolster and body.
One practical construction of the arrangement shown in FIGS. 3 and 4 is shown in FIGS. 6 and 7.
Referring now to FIG. 6 the wheelset axle is rotatably mounted in axle boxes provided in axle casing 4 and caries the pair of wheels 17. The axle casing 4 thus corresponds to frame 4 of FIGS. 3 and 4. The bolster 2 is in the form of a rigid frame surrounding the wheelset and is suspended by the swing links 3 pivoted at their upper ends to yokes 4a on the axle casing 4. The hydraulic jacks 7 and 8 are duplicated and for convenience have been given the suffix letters a and b. The body 5, represented by a longitudinal frame member (corresponding to steering beam 13 of FIG. 5, to be described), is connected to the bolster 2 by the bar 11. The jacks 7a, 7b, 8a and 8b are combined with a hydropneumatic or hydromechanical system to provide vertical and roll suspensions in the manner shown in FIG. 7. Obviously a wheel set arrangement as shown in FIG. 6 is provided at each end of the body 5.
Referring now to FIG. 7, this shows one simple form of tilting actuating means adapted for use in the present invention, and corresponding in structure and operation to the accelerometer controlled fluid pumping and jacking system shown and described in FIG. 5a of Bingham U.S. Pat. No. 3,376,830, issued Aug. 9, 1968, for Railway Vehicle Suspension System." The hydraulic jacks 7 and 8, in FIG. 7 are double acting, i.e. they have working spaces l8, 19, 20 and 21 above and below their pistons 22, the working space above each piston being connected to the working space below the other by connections 19 and 20'. The two connections 19' and 20' are themselves interconnected through hydraulic pump 21' which is controlled by accelerometer 221. Thus in response to a tilting signal from the accelerometer 221 hydraulic fluid will be pumped from one pair of working spaces 18 and 21 into the other pair 19 and 20 and vice versa depending upon the direction of tilt required. This will cause the pistons to become disposed somewhat as shown in FIGS. 2 and 4.
Accumulators 23 may be pneumatic or mechanical spring devices and will thus provide vertical and roll suspensions equivalent to the springs 12 shown in FIG. 4.
It may be desired that the vehicle body tilts to less than the cant deficiency 0,,. If the required tilt angle is K6, and since the lateral movement of the bolster is unchanged at Mga lky n u fl/K for the swinglink suspension OP is thus increased by the factor l/K.
FIG. 5 shows, in plan view, a train configuration in which a pair of adjacent vehicles have their bodies 50 and Sb connected to each other through a steering beam 13 which is articulatedly connected at its ends on the centerlines of the two vehicle bodies 5 through vertical and roll pivots 14. The adjacent ends of the bodies 5 are jointed at in an manner permitting them to adopt the configuration when curving. The steering beam 13 is mounted to two wheelsets in substantially the same manner as the vehicle body is mounted to the wheelset in FIG. 3, i.e., through a tie bar, bolster and swinglinks. Thus the appropriate constructional arrangement for the wheelset is shown in FIG. 6.
The hydraulic jacks 7a, 7b, 8a and 8b of one wheelset arrangement are connected at their upper ends to the coach bodies, say 5a. The second wheelset arrangement shown in FIG. 5 has its hydraulic jacks connected at their upper ends to the coach body 5b. It will be appreciated that the two wheelsets shown in FlG. 5 could be replaced by a single wheelset arrangement in which case the hydraulic acks of this single wheelset would connect with both coach bodies 50 and 5!).
For correct tilting the pivots R and S on the tie bar ll must be disposed a distance Mg/K below the tilt center which, for the swing link suspension shown, equates to [the length of the swinglinks. Therefore the lateral connections from the bolster 2 to steering beam 13 to body 5 should be a distance I below the tilt center.
In a modification of the systems described above, the simple pivoting arrangements between the bolster and body could be replaced by a linkage designed to produce a substantially rotational movement about the desired pivot point which will in this case be an imaginary pivot point. This would be useful where the desired pivot point i.e., the actual center of rotation of the body movement, falls within the passenger carrying space of the vehicle body, because the linkage could be disposed completely below the floor of the body.
1. In combination, a railway vehicle comprising a vehicle body, at least one wheelset, a vehicle suspension supporting said vehicle body on said wheelset, said vehicle suspension including a lateral suspension of substantially constant stiffness mounted on said wheelset for normally positioning said body at a predetermined location relative to said wheelset, a bolster connected to said lateral suspension for movement laterally of the vehicle against the stiffness of said lateral suspension, connecting means between said bolster and the vehicle body for constraining the vehicle body and bolster to move together, in lateral directions away from said predetermined location, under the influence of centrifugal force acting on the vehicle body, a pivot incorporated in said connecting means to permit tilting of said body relative to said bolster, means for providing a signal proportional to the centrifugal force acting on the vehicle body, and actuating means connected between said body and said bolster, and responsive to said signal, for tilting said body relative to said bolster about said pivot through an angle directly proportional to the cen trifugalforce acting on the vehicle body.
2. The combination of claim 1 wherein said pivot comprises a simple pivot between said body and said connecting means.
3. The combination of claim 1 wherein said lateral suspension comprises swinglinks.
4. The combination of claim I wherein the vehicle body is arranged for vertical and roll displacement relative to said bolster through vertical springing positioned between the bolster and body, the tilting of the vehicle body being efiected through a tie bar pivotally connected at its ends to the vehicle body and bolster.
5. The combination of claim 1 wherein said connecting means comprises a linkage constraining the tilting of said vehicle body about an imaginary pivot point.
6. The combination of claim 1 wherein said actuating means comprises hydraulic jacks.
7. The combination of claim 1 wherein said actuating means comprises hydraulic jacks mounted in series with vertical springing between said body and said bolster.
8. The combination of claim 1 wherein a pair of said railway vehicles are interconnected by a beam articulated at its ends to the two vehicle bodies at a distance from the ends of said vehicle bodies, said connecting means for each vehicle body being located between said beam and a bolster.
9. The combination of claim 8 wherein a single wheelset is provided on said beam.
10. The combination of claim 8 wherein a pair of said wheelsets are connected to said beam through a pair of respective bolsters, the respective actuating means associated with each of said bolsters acting on a respective one of the bodies of said pair of railway vehicles.