US3150780A - Cushioning device for underframes - Google Patents

Description

Sept. 29, 1964 J. B. CUNNINGHAM 3,150,780 f CUSHIONING DEVICE F 0R UNDERFRAMES Filed June 25, 1962 2 Sheets-Sheet 1 5. fm n ma N N W m t W- N .NN ma A Q al w IIIIII II Illhh. lll lll rr- Illll l "nl {Iii} Il .,mwu..." l ||l M nu 1 1111111 111 I f HWNIHHM mw .||.|Ir|. n 1. ilflli ....TI... fn? 4 .IIII v cercata EL@ l" N RMN. RN- k.. MN \\QN N\ N n N N .N .NSN n, J Q l 1 IL dauw .tif HHH l L Ad. u.. l M .KI MII m a Sept. 29, 1964 J. B. CUNNINGHAM cusHIoNING DEVICE FOR UNDERFRAMES 2 Sheets-Sheet 2 Filed June 25, 1962 mmf United States Patent O 3,156,780 CUSHINING DEVCE FR UNDERFRAMES lames B. Cunningham, 6927 Forest vHill Drive, Si. Louis 20, Mo. Filed .fune 25, 1962, Ser. N0. 204,784 ia claims. (ci. zia-s2) This invention relates to a combined spring and friction snubbing device for railway cars with floating draft sills.

An object of the invention is to provide a snubbing device in which the energy absorption is effected by means of spring and wedge actuated friction shoes and a single pair of springs act in parallel to resist movement of the lloating sill away from neutral position and to restore it to neutral position whereby both the resistive and restorative force is equal to the sum of both spring loads.

It is an additional object of the invention to provide such a device in which movements of the sill in either direction away from or toward neutral position are snubbed by the friction shoes.

It is a further object to provide a friction centering device in which the element which transmits energy from the springs .to the friction shoes is constantly in tension and hence never in compression when the sill is in olfcenter positions.

An additional object is to provide a relatively simple, inexpensive, and easily maintained device of this character.

The foregoing and additional objects and advantages will be apparent from the following description of the u accompanying drawings, in which:

FIG. 1 is a horizontal sectional view, taken on line 1-1 of FIG. 2 of the central portion of the center sill of a railway freight car underframe embodying the invention.

FIG. 2 is a longitudinal vertical sectional view along line 2-2 of FIG. 1.

FIG. 3 is a transverse vertical sectional view along line 3-3 of FIG. 1.

FIG. 4 is a transverse vertical sectional view along line 4-4 of FIG. 1.

FIG. 5 is a transverse vertical sectional view along line 5--5 of FIG. l.

FIG. 6 is a horizontal section along line 1-1 of FIG. 2 showing the floating sill in an olf-center position after being struck on its left hand end.

Throughout the following specification and claims, the terms innen outer, inward, outward, inwardly, outwardly and the like shall be used to denote relative proximity to the longitudinal center of the underframe.

Referring now to the drawings, FIG. l shows the center sill portion of a car underframe, which comprises an outer iixed center sill 1 extending the full length of the car and forming the usual backbone of the car underframe. Sill 1 is built up of outwardly open channels 3 and a top cover plate 5 secured by welding to the upper ilanges of the channels. An inner floating sill 9, of the usual AAR hat-section, formed by welding two Zs together along the adjacent edges of their upper flanges, is slidably received within sill 1. The ends of lloating sill 9 may be formed in the usual way as draft gear pockets to mount conventional draft gear and couplers.

At the center of the car, within and axially aligned lengthwise of floating sill 9, is positioned a casting comprising a short tube 11 and an integral base plate 13, which is secured to the bottom flanges of fixed sill channels 3. Tube 11 is formed with outwardly facing fiat pads 12 at its opposite sides, slidably engageable with the inner upright surfaces of sliding sill 9, for guiding the latter in its longitudinal movement. Within tube 11, intermediate its ends, is positioned an expansible shoe device comprising sectoral friction shoes 19 of quadrant form having convex outer segmental cylindrical surfaces 20 fric- Patented Sept. 29, 1964 ice tionally engageable with the inner surface 1S of tube 11, and central concave cylindrical surfaces 20a with outwardly flared ends 2012, which cooperate -to form a central aperture through the shoe device. A rod 15, formed intermediate its ends with spaced apart opposing conical Wedges 17, passes through the central aperture formed by concave cylindrical surfaces 20a and is normally positioned therein with the wedges 17 slightly spaced from the ilared end surfaces of :the aperture so that when rod 15 moves axially, it will cause expansion of the shoe device into frictional engagement with the inner surface of tube 11 and will also cause the shoe structure to move lengthwise of the tube. For transmitting movement from the draft sill to friction shoes 19, at each end of the friction shoes an outwardly open cup-shaped inner spring seat 23 is received within the ends of tube 11. To permit slight initial movements of the sill from neutral position each spring seat 23 has, on its inner end which is spaced a short distance outwardly from the flat outer face of adjacent wedge 17, an annular flange 26 normally seated against the ends of the friction shoes 19 coil springs 25, the opposite ends of which are seated against outer seats 27, also mounted on rod 15. The outer rims of inner seats 23 are formed with outwardly extending flanges 24, which are normally spaced a slightly greater distance outwardly from the ends of tube 11 than are the inner ends of spring seats 23 from wedges 17, and are adapted for engagement with the rim of tube 11 upon slight movement of the floating sill from its centered position. Seats 27 are normally positioned equidistantly from the center of the car by abutments 29 which are secured to center sill 1, and normally abut adjacent ends of spacer tubes 3l which are mounted on rod 15 and are welded at their outer ends to collars 33. The latter are adjustably positioned on the threaded ends 35 of rod 15 by a nut 37. For transmitting movements of iloating sill 9 to spring seats 27 and to rod 15, through collar 33, iloating sill 9 rigidly mounts lug bars 39 on its inner walls, with their inner ends normally engaging outer spring seats 27 and their outer ends spaced the same distance inwardly from collar 33 as inner spring cap outer anges 24 are from the rim of tube 11.

With this arrangement it will be evident that initial movement of the floating sill will be transmitted directly to struck end outer spring seat 27 by struck end lugs 39, and through struck end spring 2S, struck end inner spring seat 23 and its inner ilange 24, whereby shoes 19 are moved in the same direction, but without expansion, into frictional engagement with tube 11, compressing opposite end spring 25 against opposite end outer spring seat 27, which is held immobile by opposite end abutments 29. When the predetermined initial movement is exceeded struck end inner spring seat 23 is held against further inward movement by engagement of its outer llange 24 with tube 11, and opposite end lugs 39 engage opposi-te end collar 33, pulling rod 15 toward the opposite end. This causes struck end wedges 17 to engage shoes 19, thereby expanding them into engagement with the internal surface of tube 11 and moving them lengthwise of the tube, thus snubbing Ithe movement of the floating sill. At the same time struck end lugs 39, acting through struck end outer spring seat 2'7, are further compressing struck end spring against the immobilized struck end inner spring seat 23 and moving shoes 19 which are moving opposite end inner spring seat 23 to compress opposite end spring 25 against opposite end outer spring seat 27, which is immobilized by engagement with opposite end fixed abutments 29. Thus springs 25, though axially aligned with each other, act in parallel to oppose movement of the floating sill from its normal neutral or centered position.

Operation of the device is as follows: When an impact is received, for example, by the left hand end of sill 9, left hand lugs 39 on the inside of sill 9 urge left hand also,

spring outer seat 27 to the right, compressing left hand spring 25 against left hand inner spring seat 23 and causing the latter to move toward the right, its inner annular liange 26 engaging shoes i9, and through the latter, right hand inner spring seat Z3, compressing right hand spring ZS against right hand outer spring seat 27, which is prevented from moving to the right by abutment 29. When outer flange 24 of left hand inner spring seat 23 engages the adjacent end of tube il, further movement of fioating sill 9 toward the right will cause right hand lugs 39 to engage right hand collar 33, which, acting through right hand nut 3'7, will urge rod l5 to the right, thus pulling the wedges 17 to the right and thereby expanding friction shoes 19 into frictional engagement with the inner surface of tube il, such frictional engagement effectively snubbing movements of the sill in the right hand direction. This movement of friction shoes 19 to the right also compresses right hand spring 25 against right hand outer spring seat 27. Movement of rod l to the right also causes left hand coilar 33, acting through left hand spacer 3i and left hand outer spring seat 27, to compress left hand spring against its immobilized inner seat 23. Floating sill Si continues moving to the right until all excess kinetic energy is dissipated or the end stops (not shown) on the left hand end of the floating sill strikes the striker casting (not shown) on the ends of fixed sill l. When this occurs, left hand spring 25 will expand, and being restrained against further movement to the right by the engagement of inner spring seat flanges 24 with the left hand end of tube 1l, will urge left hand outer spring seat 27 toward the left. Acting through left hand spacer 3i, left hand collar 33 will be similarly urged to the left, and acting against left hand nut 37, will place operating rod l5 in tension, tending to move wedges f7' and with them shoes l@ toward the left, to centered position. Similarly right hand spring 2S will expand against its immobilized ou'ter seat 27, urging its inner seat 23 against the flat outer face of right hand wedge E7 and thus urging rod l5 to the left. Movement of rod l5 to the left, acting through right hand collar 33 and right hand lugs 39, causes corresponding movement of draft siii 9 leftward toward centered position, complete return to centered position being effected by the expansion of left hand spring 2S against left hand outer spring seat 27 and the engagement of the latter with left hand lugs 39, whereby left hand lugs 39 are returned to their normal position, with their right hand ends aligned with left hand abutments Z9. When the sill has returned to centered, or neutral position, any remaining kinetic energy tending to produce ovcrtravcl is immediately resisted by reverse action of the parts.

The absorption of the impact force is accomplished by the cushioning effect of the springs and the snubbing effeet of the friction between the shoes and the tube. This friction force is produced by the action of the spring on the friction shoe wedges, which forces the shoes against the inner surface of the tube. This friction force also reacts on the friction sh e wedges in the same manner as the spring force, thereby creating additional friction for snubbing. Because of this combination of forces which produces cushioning and snubbing, the great-e' the impact force, the greater the cushioning and snubbing forces are, until the full travel of the sill reached. The sill travel is iimitcd by the engagement of strikers at the ends of the car, which occurs just prior to the springs going solid, thus protecting the device against extreme loads.

The details of the levice be varied substantially without departing from the spirit of invention, and the exclusive use of those Iications come within tbn scope of the appended claims is contemplate What is claimed is:

. In combination with underframing and a draft member longitudinally movable relative thereto, an element fixed. to said underframing and having a surface extending lengthwise thereof, a shoe device normally positioned intermediate the ends of said fixed element and adapted for sliding frictional engagement with said surface, said shoe device being formed with oppositely tapered end surfaces, an elongated member having a pair of tapered surfaces engageable with the tapered end surfaces of said shoe device for moving said shoe device lengthwise of said fixed element and into frictional engagement with said surface extending lengthwise thereof, rst spring seats normally abutting the ends of said shoe device and adapted alternately to seat against the ends of said fixed element and to abuttingly engage portions of said elongated member upon predetermined movement of said draft member, second spring seats spaced outwardly from said first seats and held against outward movement only relative to said underframing, springs extending between and seated on adjacent first and second seats, means on said draft member normally in engagement with said second spring seats and adapted to urge the same toward said first seats and adapted also to urge the adjacent ends of said elongated member outwardly when said predeermined movement of said draft member is exceeded, and means carried by said elongated member and normally engaging said second spring seats for transmitting the opposing spring forces to said elongated member whereby to center the latter lengthwise of the car.

2. Structure according to claim l in which said fixed element is an open ended tubular member and the transverse dimension of said shoe device is smaller than that of said tubular member, said shoe device being cxpansible into frictional engagement with the inner surface of said tubular member.

3. Structure according to claim 2 in which said shoe structure is formed with a central aperture and said oppositely tapered end surfaces of said shoe structure are flared ends of the central aperture, said elongated member passing through said central aperture, said tapered surfaces of said elongated member being similar in contour to said flared ends and normally being in spaced mating relation thereto.

4. ln combination with car underframing and a draft member longitudinally movable relative thereto, an openended tubular member fixed to said underframing and extending lengthwise thereof, an expansible shoe device normally positioned intermediate the ends of said member and adapted for sliding frictional engagement with the inner surface of said tubular member when expanded, said expansible shoe structure being formed with a central aperture with outwardly flared ends, an elongated member extending lengthwise of said sills and passing through the aperture in said expansible shoe device and having a pair of tapered surfaces received within the flared ends of said shoe device aperture and engageable therewith for expanding said shoe device, first spring seats surrounding said elongated member outwardly of its tapered surfaces and having their inner ends normally in engagement with the opposite ends of said shoe device and their outer ends normally spaced from but engageable with the opposite ends of said tubular member, springs seated in said first seats and extending lengthwise of said elongated member, second spring seats surrounding said elongated member and abutting the outer ends of said springs, abutments fixed to said underframng and engaging said second seats for preventing outward movements of said second seats lengthwise of said first sill, collars on said clongated member outwardly of said second seats, means maintaining said second seats a predetermined minimum distance inwardly from said collars, and stop elements on said draft member normally in engagement with outer surfaces of said second spring seats and normally spaced from but engageable with inner surfaces of said collars.

5. Structure according to claim 4 in which said underframing comprises a hollow center sill and said draft member is received therein.

6. Structure according to claim 5 in which said draft member is a hollow sill and said tubular member, said elongated member, said springV seats, spring abutments,

and collars are positioned therein, said stop elements being mounted on internal surfaces of said draft sill.

7. Structure according'to claim 6 in which the bottoms of said sill and said draft member are open, said tubular member being formed with a horizontal laterally extending base secured underlying said sill and said draft member and secured at its ends to said center sill and slidably supporting said draft sill.

8. Structure according to claim 7 in which said abutments are carried by a horizontal base plate underlying both said sills and secured at its ends to said center sill.

9. Structure according toV claim 4 in which the bore of said tubular member is cylindrical and said shoe device comprises a plurality of sectoral shoes the outer surfaces of which are convex cylindrical segments and the inner surfaces of which are opposinf7 concave conical segments connected by smaller diameter concave cylindrical segments, said tapered surfaces of said elongated member being opposing conical surfaces.

10. A device for cushioning relative movements of two structures lengthwise of the evice, comprising longitudinally extending surface means fixed to one of the structures, a shoe normally positioned intermediate the ends of said surface means and adapted for sliding frictional engagement with said surface means, said shoe being formed with oppositely tapered end surfaces, an elongated member having a pair of tapered'surfaces engageable with the tapered end surfaces of said shoe for moving said shoe lengthwise of and into frictional engagement with said surface means, springs extending in both directions longitudinally of the device from said shoe and both held at their inner ends against movement longitudinally inwardly from the normal position thereof relative to said one structure and to said elongated member and at their outer ends against outward movement relative to both said structures, said elongated means being held against substantial movement relative to said other structure whereby relative movements of said structures away from their normal positions will move said shoe into frictional engagement with and longitudinally of said surface means and will compress both said springs separately.

References Cited in the le of this patent UNITED STATES PATENTS 773,387 Gallagher Oct. 25, 1904 1,998,388 Scharfenberg Apr. 16, 1935 2,425,364 Dath Aug. 12, 1947 2,752,048 Fillion lune 26, i956 FOREIGN PATENTS 672,562 France Sept. 17, 1928 772,194 France Apr. 21, 1934 321,677 Italy Oct. 12, 1934

Claims (1)

1. IN COMBINATION WITH CAR UNDERFRAMING AND A DRAFT MEMBER LONGITUDINALLY MOVABLE RELATIVE THERETO, AN ELEMENT FIXED TO SAID UNDERFRAMING AND HAVING A SURFACE EXTENDING LENGTHWISE THEREOF, A SHOE DEVICE NORMALLY POSITIONED INTERMEDIATE THE ENDS OF SAID FIXED ELEMENT AND ADAPTED FOR SLIDING FRICTIONAL ENGAGEMENT WITH SAID SURFACE, SAID SHOE DEVICE BEING FORMED WITH OPPOSITELY TAPERED END SURFACES, AN ELONGATED MEMBER HAVING A PAIR OF TAPERED SURFACES ENGAGEABLE WITH THE TAPERED END SURFACES OF SAID SHOE DEVICE FOR MOVING SAID SHOE DEVICE LENGTHWISE OF SAID FIXED ELEMENT AND INTO FRICTIONAL ENGAGEMENT WITH SAID SURFACE EXTENDING LENGTHWISE THEREOF, FIRST SPRING SEATS NORMALLY ABUTTING THE ENDS OF SAID SHOE DEVICE AND ADAPTED ALTERNATELY TO SEAT AGAINST THE ENDS OF SAID FIXED ELEMENT AND TO ABUTTINGLY ENGAGE PORTIONS OF SAID ELONGATED MEMBER UPON PREDETERMINED MOVEMENT OF SAID DRAFT MEMBER, SECOND SPRING SEATS SPACED OUTWARDLY FROM SAID FIRST SEATS AND HELD AGAINST OUTWARD MOVEMENT ONLY RELATIVE TO SAID UNDERFRAMING, SPRINGS EXTENDING BETWEEN AND SEATED ON ADJACENT FIRST AND SECOND SEATS, MEANS ON SAID DRAFT MEMBER NORMALLY IN ENGAGEMENT WITH SAID SECOND SPRING SEATS AND ADAPTED TO URGE THE SAME TOWARD SAID FIRST SEATS AND ADAPTED ALSO TO URGE THE ADJACENT ENDS OF SAID ELONGATED MEMBER OUTWARDLY WHEN SAID PREDETERMINED MOVEMENT OF SAID DRAFT MEMBER IS EXCEEDED, AND MEANS CARRIED BY SAID ELONGATED MEMBER AND NORMALLY ENGAGING SAID SECOND SPRING SEATS FOR TRANSMITTING THE OPPOSING SPRING FORCES TO SAID ELONGATED MEMBER WHEREBY TO CENTER THE LATTER LENGTHWISE OF THE CAR.

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