US1593761A - Buffer device for draft gears and the like - Google Patents

Description

July 27 1926. 1,593,761

| E. ENDSLEY BUFFER DEVICE FOR DRAFT GEARS AND THE LIKE Fi1 ed March 24 1925 PATENT OFFICE.

, Louis E. nnnsnnr, or rrr'rsianrtsir, PENNSYLVANIA.

BUFFER DEVICE roa DRAFT onansnnn THELIKEL Application filed Marcl1 24, 1325. Serial N-o.. 1f?,958..

My invention relates to buffer devices for draft gears and the like, and is particularly.

applicable to those structures wherein spring steel plates are employedas shockabsorbing elements.

One object of my invention is to provide meanswhereby a spring steel plate or plurality of plates are stressed substantially uniformly at all ponits throughout their length WllGIl deflected, as compared to those structures wherein the stress on a plate at the central portion only is maximumand the stresses at points removed from said central portion are reduced ifrom the maximum stress to zero. 1

Another object of my invention isvto increase and improve generally the absorbing capacity of a given number of spring plates.

One mannerin which my. invention may be. practiced is shown in the accompanying drawing wherein Fig. -1 is a sectional view showing a 'general arrangement of draft gear rigging for railway cars in which my invention. is incorporated, and Fig.v 2-is. a view. onan enlar ed scale, of a portion of theapparatus of Fig. 1 and illustrating my invention diagrammatically.

I-Ieretofore it has been customary, in employing spring steel plates as shock absor ing members, to cause deflection thereof upon a surface that is uniformly curved or that has a single radius. The objection to this arrangement arises .fromthe fact that the spring plates are subjected to very great stresses atthe point where deflection begins, and to. comparatively little stress at points removed therefrom. For,v instance, if. a spring plate 012a plurality of plates are placed upon .a. surface having uniform. curvature and the ends of the plates deflected until they Contact with such. surfaces throughout their length, the plates .at their mid portions may be under a'stress of-120,- 000 lbs. atv given points on either side of said first-named point the stresses may be but 115,000 lhs. at points still farther removed, the stresses may be 90,000 lbs; still farther away the plates may be under a stress of but 7 0,000 lhs., while at the extreme ends of the curved plates their stresses will be zero.

By providing, for the spring plates, a seating surface having an, initial curvature of a given radius and changing the curvature of said surface at points removed from the initial point so that a plurality of curves of progressively smaller radii are provided,

I am enabled to effect a substantially uniform stress on the spring plates at all points throughout their length. Thus, by thisarrangement, the plates in the first zone of deflection may be under a stress of 114,000 lbs, in the second zone .(at. each side of the first zone) they may be under a stress of 114,000 lbs, and also under stresses, of 114,000 lbs. in the third and fourth zones, as compared. to the stresses enumerated above in connection with theformer types of buffers. Thus there is a uniform stress to sub stantially the end of the. plates. i

In the drawingl have shown a draft sill or beam 3 provided with follower stops 4 and 5. A yoke 6 of the usual form may be employed. A plurality of sets of spring steel plates 7 are also provided; The plates 7 are mounted. between a rear follower 8 and a front follower 9, and spacers 10 and 11 are interposed between the groups of plates 7.

Thespacing plates 10 are concave so that only their end portions Willengage .with the spring plates 7, even during deflection there. of. The end group of platesare-deflected about the curved surfaces of the follower plates 8 and 9, and the two intermediate groups of..platesare deflected about the cur-vedfaces of the convex spacer block 11.

The. curvatures ofthe plate contacting surfaces of the blocksS, 9 and llare preferably thesame, so that adescription of the curvature'of the follower block 8 will suflice alsofor blocks 9 and 11. y

In .Fig. 2 I-have shown only one-half of the follower 8, since the curvature at each side of its central portion is the same. The radius of curvature.ofthe follower 8 in the zone marked a is such that when the plates are. bent into contact with the follower throughout the distance a, they are under maximum stress, Within the zone I) the follower 8 has a curve of less radius than that of zone a. Therefore, further deflection of the plates 7 is-required inorder to bring them into engagement with that portion of the follower 8 lying withinzone b. That portion of the plates overlying zone bis likewise under maximum stress (114,000 lbs, for example). The follower 8 has a curvature of still shorter radius within the zone 0, and likewise with respect to zone d. The dotted line 12 indicates a true arc struck from the radius of the mid-portion .ofthe follower 8.

faces on blocks 8, 9 and ll, respectively, which have curvatures of successively shorter radii, and thereby utilize the yielding capacity of the spring plates to their fullest extent, as compared to the older structures, wherein a single curved surface of uniform arcuate shape is employed. and wherein the plates are under maximum stress at their inidportions. The seating surface could obviously be of elliptical form, if desired.

Below is a table of actual tests made, under similar conditions, with a follower block of the usual uniform radius and my special form of block having non-uniform radii. The readings were obtained by a strain gage of a, well li'i'iown type, and show that as deflection of the spring plates increased against the surface of the standard type of follower there was a very rapid de crease in stress, as compared to the almost uniform stress in the case of my follower, up until the three-inch mark.

illrr'rimim: ell-cases in plates.

Follower having radii decreasing from 29 to 17 27% radius Location on plate Std follower Stress.

Center 1% ofi cent 3" off center" 4% oiT center" under stresses greater than would be the case when employed against a surface having uniform curvature, and that I do not limit myself to certain degrees of curvature nor to he number of zones of deflection.

- in as my invention: a draft gear structures, a pair of spaced follower blocks having seating sur- "aees sprin steel plates disposed between said surfaces, and a double concave spacer between said plates, each of said surfac r having a curvature of a given radius at 1., normal point of contact with one of said and having a curvature of shorter at points removed from said normal point. 'i

it: draft gear structures, a pair of spaced follower blocks having seating surfaces, spring steel plates disposed between said surfaces, and a double concave spacer between said plates, each of said surfaces having a curvature of a given radius at its normal point of. contact with one of fsaid plat plates, and having curvatures of progressively shorter radii at points successively removed from said normal point.

3. In draft gear structures, a pair of spaced follower blocks having seating surfaces, spring steel plates disposed between said surfaces, and a double concave spacer between said plates, each of said surfaces having a. curvature of a given radius at its normal point of contact with one of said plates, and having curvatures of progressively shorter radii to either side of said normal point, at points successively removed therefrom.

t. Buffer structure comprising a seating block, a spring steel plate normally engaging said block at one portion of its surface, and impact receiving means for deflecting said plate into engagement with another portion of said surface, the first named portion being formed to cause that part of the spring adjacent thereto to assume one ourvature, and the second named portion being formed to cause that part of the spring engaging therewith to assume a curvaturehaving a different radius than the curvature of the first-named portion.

5. Buffer structure comprising a curved seating block, a. spring plate normallyengaging said block at its mid-portion, and impact receiving means for deflecting said plate into engagement with portions of said block to either side of said mid-portion, the last-named portions of said block being curved about radii of different length than the radius of said mid-portion.

6. Buffer structure comprising a curved seating block, a spring plate normally .engaging said block at its mid portion, and impact receiving means for deflecting said plate into engagement with a plurality of portions at each side of said mid-portion, the engaging surfaces of said plurality of portions having curvatures of progressively shorter radii at points successively removed from said mid-portions.

7. The combination with a spring metal plate, of a seat therefor having a curvature of generally arcuate form but of varying radii, and an impact receiving member for deflecting said plate against said seat.

8. The combination with a. spring metal plate and a support therefor, of a forcetransmitting member having engagement with said plate at a point removed from the said support, and means limiting the bending movement of said plate but permitting increased bending movements thereof at points successively removed from said support.

In testimony whereof I, the said LoUIs E. EivnsLnrg'have hereunto set my hand.

LOUIS E. ENDSLEY.

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