US3536012A - Dampened railway bogie bolster - Google Patents

Description

United States Patent Inventor Frederick William Sinclair Qlwsss Engl n 721 ,371 Filed April 15, 1968 Patented Oct. 27, 1970 Assignee Gloucester Railway Carriage & Wagon Company Limited Gloucester, England Priority April 15, 1967 Great Britain 17,3 87/67 DAMPENED RAILWAY BOGIE BOLSTER 12 Claims, 10 Drawing Fig.

US. Cl 105/197, 105/202, 105/206 Int. Cl. B6lf3/08, B6 lf 5/ l 2 Field of Search 105/ 1 97D,

[56] References Cited UNITED STATES PATENTS 1,894,386 1/1933 Webb ..l05/l97(D)UX 2,190,643 2/1940 Hobson... ..105/197(D)UX 3,245,357 4/1966 Sinclair ..l05/l97(D)UX Primary ExaminerArthur L. La Point Assistant Examiner-Howard Beltran Attorney-Young & Thompson ABSTRACT: A railway bogie including two side frames each of which has two spaced hollow guide columns defining between them a bolster guide within which the corresponding end of a bolster slides vertically during normal suspension movement. One column of each side frame houses damping means operative, through the intermediary of a member connected to the bolster, to apply a greater damping force to the bolster when the bogie is in a loaded condition as compared with the damping force applied to the bolster when the bogie is in an unloaded or tare condition.

Patented Oct. 27, 1970 Shae t INVENTOR Razz/c4 Wu 4 mam/aw Patented Oct. 2 7, 1970 Sheet w R w 3 1 Q e m ww p 4 m? k Q ,N, llll W m wv .fi J. g \Wmm m A WWW. mm, R MM m R 25 F R Q Q m v uww r /A BY ATTORNEYS Patented Oct 27, 1970 Sheet INVENTOR feepse/c/zwu/nmJ/mcznw ATTORNEYS Mama 0a. 27, 1910 3,536,012

Sheet 5 016 W7 r Jw w ATTORNEYS DAMPENED RAILWAY BOGIE BOISIER This invention relates to railway bogies of the type in which a lateral bolster for supporting a vehicle superstructure is vertically movable in bolster guides in two side frames. The bolster is supported by the bogie suspension and damping means are provided to prevent undue vertical oscillation of the bolster.

According to the invention a railway bogie includes two side frames each of which has two spaced guide columns defining between them a bolster guide within which the corresponding end of a bolster slides vertically during normal suspension movement, with at least one column of each side frame supporting, and preferably housing, damping means operative, through the intermediary of a member which follows vertical movement of the bolster within the corresponding guide, to apply a greater damping force to the bolster when the bogie is in a loaded condition as compared with the damping force applied to the bolster when the bogie is in an unloaded or tare condition. This provides load sensitive damping as the arrangement is such that a light damping force is applied when the vehicle is running light and the damping force is materially increased when the vehicle is loaded with consequent downward movement of the bolster to a new suspension equilibrium position.

In assembling bogies of the foregoing type, each end of the bolster must be inserted between the two corresponding guide columns but below the guide and then raised into the guide, after which suspension springs are fitted between the underside of the bolster and a lower web or crossmember of the side frame which interconnects the guide columns below the guide. If load sensitive damping is required, damper springs are commonly mounted between the bolster and the web of the side frame, but lack of space due to the presence of the bolster complicates the fitting of the damper springs and also means that the latter must be compact. However. in the present invention, the damping means need not be particularly compact and can be fitted in the appropriate guide column before the bolster is fitted in the side frame.

Preferably friction damping means are employed with a damper shoe which projects from the corresponding guide column into the bolster guide for frictional engagement under the action of a damper spring which is housed within the guide column and the compression of which is varied by movement of said member to vary the damping force. Practicable alter native arrangements may employ any form of telescopic damper of either the hydraulic or rubber energy absorption type in which case the telescopic damper is connected to the bolster through said member which applies the damping force to the bolster. Yet another alternative may employ rubber energy absorbing damping means of the type in which a plunger having a corrugated profile is forced into a conical bore of decreasing diameter. As used with the invention, the plunger is connected to said member through which the damping force is applied to the bolster.

Whether friction or telescopic damping means are employed, said member may be in the form of a bellcrank lever one limb of which engages beneath the bolster so as to be displaced thereby as a result of vertical bolster movement and the other limb of which is connected to the damping means; with a telescopic damper it is necessary to attach the bellcrank lever both to the damper and underneath the bolster as the lever has to be double-acting, whereas with the spring friction damper arrangement no lever attachments are necessary and the lever can merely engage a suitable abutment-beneath the bolster. In either case the bellcrank lever translates vertical bolster movement into a horizontal movement operative at the damping means so that a progressive and continuously variable damping action is obtained. However, in the case of friction damping by a helical compression spring the bellcrank lever maybe dispensed with and the change of damping force with vertical bolster movement may follow any desired characteristic by means of a cam and cam follower arrangement which preferably transmits movement of the member into appropriate movement of an actuating lever which is pivotally movable to vary the damping force. v

Said member may take the form of a yoke the two side limbs of which are pivotally mounted on the guide column on a transverse pivot axis, Le. an axis extending parallel to the bolster between the side frames. Preferably, the free ends of the limbs are respectively located in pockets in the bolster and the inner surface of the intermediate limbcooperates-with a cam formation on the actuating lever one end of which is pivotally mounted about a transverse pivot axis 'below the damping means and the other end of which effects horizontal movement of an outer spring abutmentof the spring. If desired, the arrangement may be such that the dampiiigriieans applies a constant damping force over a light load range and a constant but increased damping force over a more heavily loaded load range. To achieve this, said member may carry a cam which cooperates with a cam follower carried by the actuating lever. In order to provide the aforesaid damping characteristics, the cam will normally have upper and' lower vertical surfaces which the follower respectively engages when the bogie is in the lightly loaded and heavily loaded conditions and which are interconnected by an inclined transition surface along which the cam follower rides when the load on the bogie changes between the lightly loaded and heavily loaded conditions.

It will be appreciated that a bolster of a bogie incorporating the cam and follower arrangement previously described in the immediately preceding paragraph may undergo small vibrational movement in either an unloaded (or very lightly loaded) or a heavily loaded condition without the prevailing damping force on the bolster changing. In certain circumstances it is desirable to provide an increasing damping force during the upward movement of each bolster vibration within the guides and a decreasing damping force during the downward movement of each bolster vibration and this is preferably achieved by suitable inclination of the upper and lower surfaces of the cam so that the small vibrational movement of the bolster is accompanied by pivotal oscillations of the lever. In one'arrangement, the cam profile is formed on the actuating lever and the profile is engaged by a block carried by said member.

The invention will now be further described with reference to the accompanying drawings which show, by way of example, four forms of railway vehicle bogie in accordance with the invention. In the drawings:

FIG. '1 is a perspective view of the first bogie with parts cut away and one side frame detached for clarity.

FIG. 2 is a fragmentary sectional view. to a larger scale. of one side frame of the bogie of FIG. 1, taken on a fore-and-aft vertical plane,

FIG. 3 is a fragmentary sectional view on the line III-III of FIG. 2,

FIG. 4 is a fragmentary end view on the line IV-IV of FIG FIG. 5 is a view generally similar to FIG. 3, but showing the second form of bogie,

FIG. 6 is a fragmentary and diagrammatic side view of the bogie of FIG. 5,

FIG. 7 is a diagrammatic fragmentary plan view showing the third form of bogie,

FIG. 8 is an explanatory fragmentary side view of the bogie shown in FIG. 7,

FIG. 9 is a fragmentary side view of the fourth form of bogie, and

FIG. 10 is a fragmentary plan view of the bogie shown in FIG. 9.

Referring to FIG. 1, the bogie has a pair of side frames 1 provided with axle boxes 2 for the usual wheel axle sets 3, and a transverse bolster 4 extends centrally between the side frames 1 each of which has a guide defined by two hollow guide columns 5 between which the corresponding one of two ends 6 of the bolster 4 slides vertically. Suspension springs 7 are mounted between each end 6 of the bolster 4 and a central web 8 of the corresponding side frame 1, and the bolster 4 has the usual load bearing centre pivot 9 and side bearers 10 for the vehicle body (not shown) which is mounted on two spaced bogies in the usual manner.

Each guide column 5 of each side frame 1 supports a damper housing 12 from which a damper shoe 13 with a friction facing 14 projects into the guide for frictional engagement with the adjacent side face 15 of the corresponding end 6 of the bolster 4. As shown in FIG. 3, the frictional facings 14 on the damper shoes 13 are convex in plan view and-each shoe 13 is located for self-aligning movement between upper and lower collets 16 and 17 respectively which are horizontally slidable between upper and lower guides 18 and 19 respectively. The guides 18 and 19 are constituted by U-shaped webs which are integrally cast with the remainder of the side frame, and in particular with side and end walls 20 and 21 respectively of the corresponding guide column 5. Each upper guide adjoins a tubular cross member 22 which is shown in F 1G. I and the lower wall 22a of which is shown in FIG. 2.

Each damper shoe 13 has upper and lower convex arcuate faces 23 and 24 respectively against which are urged, by an associated damper spring 25, planar surfaces 26 and 27 formed on the corresponding upper and lower collets: 16 and 17 respectively. The collets 16 and 17 are recessed so that they cooperate to form a circular aperture 28 through which the spring passes and an internal space 29 which, in the side view of FIG. 2, appears generally semicircular. The spring 25 is disposed between an inner abutment plate 30, which engages shoulders 31 and 32 on the collets l6 and 17 respectively, and an outer abutment plate 33. The spring is located transversely by tubular guide stems 34 and 35 welded to the abutment plates and 33 respectively.

Each spring 25 thus acts on the corresponding pair of collets 16 and 17 and urges them towards the bolster 4 to provide the damper force. and this arrangement not only allows self-aligning movement of the associated shoe 13, which in effect tends to be squeezed out from between the collets l6 and 17, but also urges the collets l6 and 17 themselves apart so that wear in the housing 12 is automatically taken up.

A bellcrank lever 36 is mounted on the shank of a bolt 37 supported between the side walls 20 of each guide column 5 and pivots about an axis A-A. The lever 36 has a generally horizontal lower arm 38 with an upturned end 39 which projects into the guide for engagement with anabutment pad 40 welded to the under surface 42 of the bolster 4. The other arm 43 of the lever 36 is upwardly and generally vertically directed and it engages a yoke 44 welded to the abutment plate 33. Thus as the bolster 4 rises and/or falls due to dynamic fluctuations when the vehicle is running, or due to changing loading of the vehicle, the lever 36 is displaced to vary the compression of the damper spring 25 and hence the frictional damping force applied to the bolster 4. It will be appreciated that when the vehicle is unloaded less damping force is exerted as the bolster 4 will stand higher from rail level in relation to the side frame 1 than is the case when loaded, with correspondingly less compression of the damper spring 25 this condition being shown in full lines in FIG. 2. When the vehicle is loaded the bolster 4 moves down as the suspension springs are compressed, thus increasing the damping force as a result of the attendant pivotal movement of the lever 25 as shown in broken lines in FIG. 2.

The lever 36 is of fabricated form with two cranked side plates 36a and 36b which at the upper ends are joined bya crosspin 45 which is located between the limbs 46, of the yoke 44 and at the lower ends are joined by a crossmember 47 with a convex upper surface 48 which engages the abutment pad 40 with a generally rolling action during bolster movement. The lower arm 38 of each bellcrank lever 36 passes through apertures 49 in the end walls 21 of the corresponding guide column 5, and the outer end wall 21 of each column 5 terminates at its upper end in two aligned bearing bosses 50 responding bellcrank lever 36, and a thrust washer 54 is positioned between each boss 50 and the adjacent radial face of the sleeve 53. A retaining nut 55 is screwed on to the end of each bolt 37. It will be appreciated that sirnilar'opposed damping arrangements are provided at each end of the bolster 4.

In FIGS. 5 to 10 parts corresponding'to those in'FIGS. l to 4 have been given the same reference numerals; in each of the three constructions shown in FIGS. '5 to 10 the-damping means are generally as has previously been described in that the means comprise a damper sh'o'e 13 engaged by two collets 16 and 17 with a helical compression spring 25 prosgding the damping force. The constructions of FIGS. -5 to 10 digits from the arrangement of FIGS. 1 to 4 only in the manner Err-which vertical bolster movement is translated into horizontal movement at the damping means, and hence FIGS. 5 to -10show mainly those parts of the second to fourth forms of bogie in so far as they differ from the first form shown in FIGSJI to 4.

Referring to the construction of FIGS. 5 and 6,.two cranked actuating levers are pivoted at their respective upper ends about a transverse axis B (FIG. 6) and are pivotally movable to alter the damping force. The levers 60 are mounted externally of the guide column 5 and are pivotally connected at an intermediate point by a yoke 62, an intermediate portion 63 of which provides an outer end movable abutment for the spring 25 of the damping means. The lower ends of the levers 60 carry between them a roller forming a cam follower 64 which cooperates with a cam member 65 supported on two spaced brackets 66 secured to and depending from the bolster 4.

The cam member 65 is movable in a vertical direction with the bolster 4 and has upper and lower vertical cam surfaces 67 and 68 respectively interconnected by an inclined surface 69, the profile of the cam 65 thus being generally stepped as shown in FIG. 6. When the bogie is unloaded the cam member 65 is arranged so that the cam follower 64 engages the lower vertical surface 68, this condition being shown in FIG. 6 from which it can be seen that as the bogie is loaded and accompanying downward movement of the bolster 4 occurs, the cam follower 64 rides along the inclined surface 69 causing pivotal movement of the levers 60 and corresponding compression of the spring 25, with the result that a progressively increasing damping force is applied to the bolster 4 until the cam follower 64 engages the upper vertical surface 67. As the surfaces 67 and 68 are vertical, the bolster can undergo small vibrational movement in either of the loaded or unloaded conditions without altering the magnitude of the prevailing damping force.

The cam member 65 is mounted on the bracket 66 with a small degree of horizontal play so that the lateral thrust exerted by the cam follower 64 on the cam member 65 as a result of the action of the spring 25 is' resisted by an adjacent end face 70 of the guide column 5. This ensures that no horizontal thrust is applied to the bolster 4, which enables damping means to be fitted to one column 5 only of each side frame rather than two which would otherwise be necessary for balancing the lateral forces on the bolster 4.

The construction of FIGS. 7 to 8 employs two levers 72 and 73 which are secured to a common transverse shaft 74 and which together translate vertical movement of the bolster 4 into horizontal movement at an outer abutment 75 of the spring 25. As shown in FIG. 8, the lever 72 has an upper end through which the corresponding bolt 37 passes. The shank of nose portion 76 which engages the abutment 75 centrally between two side flanges 77 of the latter. and the lower end of the lever 72 is secured to the shaft 74 which extends between and is pivotally mounted in the two side walls 20 of the column 5 below the damping means.

The shaft 74 has a projecting'inner end on which is mounted the lever 73 which, as shown in FIG. 8, has an upper end 79 with a cam profile which cooperates with a convex surface of a block 80 supported by a rod 82 carried by the bolster 4. The block 80 engages an upper surface 83 of the cam profile when the bogie is in the unloaded condition (as shown in FIG. 8), the block 80 riding along an intermediate surface 84 and finally a lower surface 85 as the loading, on the bogie in-- creases.

It will be seen from FIG. 8 that the surfaces 83 and 85 are suitably inclined so that small vibrational movement of the bolster 4 in either the loaded or unloaded conditions causes corresponding fluctuation in the damping force provided by the spring 25. The surfaces 83 and 85 are inclined in a direction such that, in either the loaded or unloaded conditions, the damping force increases during the upward movement of each vibration of the bolster 4 within the guides, and a decreasing damping force during downward movement of the bolster. Such a construction gives smoother running characteristics with less bounce.

The block 80 has a horizontally elongated slot 86 to receive the rod 82, the small amount of horizontal play ensuring that the lateral thrust exerted by the lever 73 on the block 80 is resisted by a projecting side flange 87.

The fourth form of bogie shown in FIGS. 9 and employs a yoke 90 the side limbs 92 of which embrace the guide column and are pivotally mounted thereon about a transverse axis CC by means of bolts 93 screwed into the side walls of the column 5. The two extreme ends 94 of the yoke 90 respectively engage pockets 95 formed in the bolster 4 so that vertical movement of the latter within the guides causes corresponding pivotal movement of the yoke 90. The intermediate limb 96 of the yoke 90 is formed with a convex edge surface 97 which cooperates with a cam formation 98 on an upper outer edge of an actuating lever 99 the lower end of which is pivotally mounted, about a transverse axis D, between two lugs 100 of the guide column 5.

The upper end of the actuating lever 99 has a projecting nose 102 in engagement with the outer spring abutment 75 of the damping means so that pivotal movement of the actuating lever 99 causes movement of the outer spring abutment 75 and attendant variation in the compression of the spring and the magnitude of the damping force applied to the bolster 4. In FIG. 9, the position of the yoke 90 shown in broken lines represents the fully loaded condition of the bogie. it will be appreciated that the profile of the cam formation 98 may be chosen to give any required relationship between the variation in bolster position and the variation in the damping force applied to the bolster 4. As the yoke 90 does not apply any lateral force to the bolster 4, it is not necessary to fit damping means in each guide column 5 of each side frame, one damping means in each side frame being sutficient.

Although the surfaces 67 and 68 on the cam 65 of FIG. 5 are vertical, it will be appreciated that they may, if desired, be inclined to the vertical by a small amount to give, in either the unloaded or fully loaded conditions, an increasing damping force during the upward bolster movement of each bolster vibration and a decreasing damping force during the downward movement of such vibration.

I claim:

1, A railway bogie comprising two spaced side frames, a laterally extending bolster supported between the side frames, each side frame having two spaced columns defining between them a bolster guide within which the corresponding end of the bolster slides vertically during normal suspension movement of the bolster and, at each side of the bogie, damping means supported by one of said columns of the corresponding side frame and operative to apply a damping force to the corresponding end of the bolster during said suspension movement, and a damping control member mounted on the corresponding side frame for movement as a result of said suspension movement of the bolster, said member acting on the corresponding damping means in such manner as to increase the effective damping force as the bolster moves downwardly from a position corresponding to an unloaded tare condition of the bogie to a position corresponding to a loaded condition of the bogie.

2. A railway bogie according to claim 1, wherein said damping control member is a lever which acts on the damping means and is pivotally mounted on the corresponding side frame for pivotal damping control movement as the bolster moves alon the correspondin bolster ui de.

3. A rai way bog e accor mg to calm 2, wherein said member is a bellcrank lever which is pivoted about a transverse axis and one limb of which engages beneath the bolster so as to be displaced thereby as a result of vertical bolster movement, the other limb being operative at the damping means to vary the damping force.

4. A railway bogie according to claim 3, wherein said one limb of the bellcrank lever is generally horizontal and has an upturned end with a convex upper surface which engages an abutment pad welded to the under surface of the bolster.

5. A railway bogie according to claim 1, wherein said one column is hollow and houses the damping means alongside the bolster guide.

6. A railway bogie according to claim 5, wherein the damping means employ friction damping and comprise a damper shoe which projects from the corresponding guide column into the bolster guide for frictional engagement with the side of the bolster at the corresponding end of the latter under the action of a damper spring, with movement of said member in a direction corresponding to downward displacement of the bolster being operative to compress the spring and hence increase the damping friction.

7. A railway bogie according to claim 6, wherein said damping control member is a cranked lever which adjacent its upper end is pivotally mounted on the corresponding side frame and the lower end of which is displaceable by the bolster to produce pivotal damping control movement of the lever, the lever acting on the damper spring at an intermediate point along the length of the lever.

8. A railway bogie according to claim 1, wherein movement of said member is transmitted into movement operative at the damping means through the intermediary of a cam and cam follower arrangement with a cam profile shaped to give the desired characteristic between the variation in bolster position and the variation in the damping force.

9. A railway bogie according to claim 8, wherein the cam profile is formed on an edge surface of an actuating lever which is pivotally movable to alter the compression of the spring and which is engaged by said member which is pivotally mounted with respect to the guide column.

10. A railway bogie according to claim 9, wherein said member takes the form of a yoke the intermediate limb of which engages the cam profile on the actuating lever and the two side limbs of which embrace and are pivotally mounted on the guide column about a transverse axis, with the extreme ends of the side limbs projecting into pockets in the bolster so that vertical movement of the latter causes corresponding pivotal movement of the yoke.

11. A railway bogie according to claim 8, wherein the cam profile is arranged to provide a constant damping force over a light load range and a constant but increased damping force over a more heavily loaded load range.

12. A railway bogie according to claim 8, wherein the cam profile is arranged to provide an increasing damping force during the upward movement of the bolster during vibration of the latter within the guides and a decreasing damping force during the downward movement during such vibration.

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