US2552145A - Cushioning device - Google Patents

Description

May 8, 1951 E. H. BLATTNER CUSHIONING DEVICE Filed Nov. 50, 1944 Patented May 8, 1951 UNITED STATES PATENT OFFICE The Symington-Gould Corporation, Depew,

N. Y., a corporation of Maryland Application November 30, 1944, Serial No. 565,853

9 Claims.

The invention pertains to a cushioning device or snubbing unit adapted to be associated with resilient means of different character with the association being particularly adaptable for use in a railway truck as a bolster supporting medium.

An object of the present invention is to provide a cushioning device or snubbing unit cap able of disturbing harmonic or synchronous vibrations of other resilient means with which it will be associated in service.

A further object of the invention is to provide a cushioning device or snubbing unit arranged and constructed to materially increase its capacity after a predetermined compressive movement thereof.

An added object of the invention is the provision of shoes in a cushioning device having inclined surfaces or faces intermediate their height with the surfaces so disposed that after a predetermined compressive movement of the device the surfaces or faces will be positioned within the horizontal limits of an associated housing. I

A still further object of the invention is to provide a cushioning unit with shoes having stems projecting within a housing and being cylindrically formed; the stems. having spaced inclined surfaces directed inwardly of the unit with frusto-conical means engaging the inclined faces and spring means interposed between and urging the frusto-conical means apart resulting in the shoe stems being urged outwardly and radially into engagement with the housing.

A still further object of the invention is the provision in a snubbing unit of one of the frustoconical means within the unit being arranged to be displaced from normal position after a certain compressive movement of the unit to additionally compress an associated spring means.

The above as well as numerous other objects will become apparent from the succeeding description considered together with the accompanying drawing, the latter of which discloses an exemplified form of the invention and where- 1n:

Figure l is a vertical sectional view of a cushioning device or snubbing unit embodying the present invention and illustrated in normal or expanded position.

Figure 2 is a view similar to Figure 1 excepting that herein the cushioning device or snubbing unit is illustrated in fully compressed position.

Figure 3 is a horizontal sectional view taken along the lines 33 of Figure 1, looking in the direction of the arrows.

Figure 4 is a horizontal sectional view taken along the lines 44 of Figure 1, looking in the direction of the arrows.

Referring now in detail to the drawing, wherein like reference characters indicate lilze parts, the numeral I designates, in a general manner, a cushioning device or a snubbing unit of a selfcontained type, capable of being associated with spring means, notably coil or helical springs, to form a nest of springs non-harmonic in character for resiliently supporting a bolster or loadcarrying member of a railway truck. The device or unit comprises a housing 2 formed by a cap or top plate 3 which presents a radial or annular flange 4 adapted to bear against a truck bolster (not shown) and an inner recessed, convoluted or dish-like portion 5. By thus forming the cap a cavity 6 opening outwardly of the device is arranged to receive an embossment or any desired structure (not shown) for maintain ing the upper extremity of the unit in a predetermined or operable position and having a shoulder 1 extending away from the cap flange axially of the unit. Completing the housing is a tubular or cylindrical casing or barrel 8 desirably of lesser extent than the height of the unit and having its upper or one extremity outwardly scarfed as at 9. The scarfed extremity of the casing is in telescoping relation with and neatly accommodates the cap shoulder to be joined integrally with the cap through the medium of the weld IO. It has been found commercially expedient in actual practice to form the cap as a cast or forged member and employ a section or nipple of commercial pipe or tubing as the casing or barrel but it will be clearly understood that this particular designation is not to be construed as a definition of the limits of the present invention since it may at times be equally advantageous to make the cap and casing as a single element.

Associated with the housing and arranged to move axially of the device relative to the housing are a plurality of shoes I l each having a stem portion l2 extending into the barrel and arcu-' ately or cylindrically disposed considered in horizontal cross section to present a surface bearing relationship between the casing and shoes. The shoes are desirably three in number for the purpose to be hereinafter apparent. Each shoe has a foot or base in the shape of an outwardly directed radially disposed rib or narrow flange l3 constituting the lower extremity of the shoe.

Interlocked with the shoe bases is a ring or annular member Hi having a downwardly and inwardly facing recess 15 accommodating the shoe flanges. As will be apparent, the multipart formation of the lower extremity of the device or unit will present a somewhat flexible construction at this location tending to allow for an equalization of the shoes and ring as a unit is,

rocked or moved about its vertical axis in response to service forces. Extending about the housing casing in spaced relation thereto is a resilient element characterized by a coil or helical spring l6 having end convolutions thereof in intimate contact with the cap flange and ring. The coil spring is arranged to react axially of the unit and thereby resiliently resists a compressive movement of the device as well as urge the shoes and housing in opposite directions during an expansive movement of the unit.

Spreading means has been incorporated into the snubber to urge the shoe stems horizontally, outwardly or radially so as to ensure a surface bearing relationship between theshoesandhousing for the creation of frictional forces on contiguous surfaces thereof during an expansive and compressive movement of the unit. As exemplary of such arsprea'ding means there is formed on the :upper or free extremityof each shoe stem an .upwardly and inwardly inclined-or angularly disposed face or surface ll, frusto-conical in configurationsoas'to face inwardly and downwardly of the unit. Each shoe stem also has an inwardly extending ledge or shoulder 18 intermediate the height'thereof with each ledge or shoulder carrying an inclined face or surface l9 angularly disposed relative to the shoe stem and facing inwardly or upwardly or'directed upwardly and outwardly of the unit. Like the complementary and vertically removed surfaces H the intermediate faces I9 are also of frusto-conical formation. Within the confines of the shoe stems are vertically spaced counterpart wedges, discs or upper and lower spreader means 26 and 20a, respectively, each of which has a shoe engaging .portion 2! of frusto-conical configuration so as to present an outer or side surface 22 thereof disposed at the same inclination as the faces or surfaces J] and 19.

Since the wedge surfaces 22 are in intimate contact with the shoe faces Hand IQ for urging the shoe radially outwardly of the unit, consideration has been given to avoiding a binding action :between the shoes and wedges. Towards the elimination of such a contingency reference is directed particularly to Figure 4 of the drawing wherein it will be noted that the radii of the surfaces i9 is different, preferably greater than the radius of the adjacent wedge surface 22. Accordingly, only a line contact as contra-distinguished from a surface bearing relationship will exist between the shoes and spreader means. This flexible or adjustable construction and arrangement of par-ts will ensure an equal distribution of forces through the spreader means into theshoe stems to result in the creation or development of the same frictional forces upon successive compressive and expansive movement of the unit or device. A coil or helical spring 23 is positioned within the shoes to react vertically or axially of the unit against the spreader means 20 and 20a to urge them in opposite directions and because of the particular disposition of the related surfaces urge the shoe stems radially of the unit into intimate contact with the housing casing. Spuds 23a are formed integrally with the wedges to present centering means and maintain the coil spring 23 in a fixed position axially of the unit. While Figure 4 is taken through the unit to illustrate the relationship of the spreader means 20a and the surfaces I9 it will be clearly understood that the surface 22 of the wedge 29 is related to the inclined surfaces I! in like manher.

The wedges 2i] and 20a are provided with an :axiallydirected stalk, shank or projection 24 and while the shank of thespreader means 20a serves .no useful purpose in the unit it is deemed advisable to form the wedges as counterparts of one another to simplify manufacture thereof and. eliminate the necessity of making two separate types of spreader means. However, the projection 25 of the wedge 20 extends through or between the shoe stems therebeyond to terminate short of the cap dish-like portion 5. By reason of this arrangement and upon a predetermined compressive movement of the unit, the cap adjacent projection will be contacted or engaged by the'cap to urge it into the confines of the shoe to additionally compress or energize the spring 23 resulting in an increase of the component forces adjacent the area of the wedge 20a urging the shoes radially against the barrel of the sleeve to intensify the frictional forces in the area of the lower wedge 20a towards the end of the compressive stroke of the unit. As will be noted by referring particularly to Figure 2 of the drawing, at the .end of the compressive movement of the device, an upwardly facing plane surface '25 forming the upper limits of each shoe stem will come to rest against a correspondingly disposed sur face 26 of the cap to permit the unit to thereafter function as a solid or rigid column preventing or arresting a further compressive action of the accompanying springs which would, if permitted, be detrimental thereto.

Before the projection of the wedge 20 is engaged by the sleeve cap the center or center line of the radial forces urging the shoe stems against the sleeve barrel, indicated by the horizontal diagrammatic line marked X, is substantially midway between the two spaced wedges. However, as the sleeve is lowered to a position where the wedge '25! is forced or urged away from normal position so that the surface 22 thereof will move away from the faces I1, the center line of the component forces is then shifted, altered or lowered to a position substantially within the horizontal plane or vertical limits of the wedge surface 22 and shoe surfaces I!) as indicated by the horizontal diagrammatical line marked Y.

From the illustration and above description it will be noted that various changes and alterations may be made thereto without departing from the spirit of the invention and scope of the appended claims.

I claim:

1. In a cushioning device, the combination of, a housing, a plurality of shoes within said housing, resilient means reacting against said shoes and housing, spaced inclined faces adjacent an inner end of said shoes and substantially midway between the ends thereof, spaced wedge means within said shoes and engaging said inclined faces, and spring means interposed between said wedge means for urging them apart and the shoes radially of said device; one of said wedge means having means outstanding therefrom in a direction away from said spring means and arranged to be moved axially of said shoes after only a predetermined compressiv movement of said device to transmit forces to said shoes. only through the other of said wedge means.

2. In a cushioning device, the combination of, a plurality of shoes having stems cylindrically formed, a housing surrounding said shoe stems, means interlocked with said shoes, a coil spring reacting against said housing and means for urging said shoes and housing apart, frusto-conically formed surfaces on said shoe stems adjacent one end thereof, frusto-conically formed faces on said shoe stems intermediate the height thereof, frusto-conical means within the confines of said shoes and normally in bearing relation with said surfaces and faces, spring means in bearing relation with said frusto-conical means, and vertically directed shank means outstanding from one of said frusto-conical means for moving that associated frusto-conical means away from the associated surfaces after a predetermined compressive movement of said device, the forces on said shoes being centered within the horizontal limits of said housing after one of said frustoconical means is displaced from normal position.

3. In a cushioning device, the combination of, a housing, three shoes within and arranged to frictionally engage said housing, spring means reacting against said housing and shoes for urging them apart axially of said device, each shoe having an inclined surface adjacent an inner end thereof and an inclined surface adjacent the center thereof, spaced wedge means engaging said inclined surfaces, and resilient means interposed between said wedge means for urging them apart; one of said wedge means having a projection outstanding therefrom in a direction away from said resilient means and adapted to be engaged and urge the associated wedge inwardly of said device away from its contact with said shoes after a predetermined compressive movement thereof to further energize said resilient means.

4. In a cushioning device; the combination of, a housing, three shoes having portions within and arranged to frictionally engage said housing, spaced inclined surfaces on said shoes, spaced frusto-conical means in bearing relation with said inclined surfaces, spring means reacting axially of said device for urging said frustoconical means apart and said shoes into engagement with said housing, and a shank outstanding from one of said frusto-conical means in a direction away from said spring means and extending beyond the limits of said shoes and normally spaced from said housing, said outstanding shank being arranged to be engaged by said housing only after a predetermined compressive movement of said device.

5. In a cushioning device, the combination of, a housing, three shoes having portions within and arranged to frictionally engage said housing,

6 a plurality of shoes having stem portions cylindrically formed, a housing surrounding said shoe stems, frusto-conically formed surfaces on said shoe stems adjacent one end thereof, frustoconically formed faces on said shoe stems spaced inwardly from another end thereof, frusto-conical means within the'confines of said shoes and normally in bearing relation with said surfaces and faces, spring means in bearing relation with said frusto-conical means, and an integral shank outstanding from one of said frusto-conical means in a direction away from said spring means for moving that frusto-conical means away from the associated surfaces only after a predetermined compressive movement of said device; said surfaces and faces being of a given curvature and said frusto-conical means of a shank means outstanding from one of said frusto- 6. In a cushioning device, the combination of,

different curvature; said faces on said shoes being disposed Within the horizontal limits of said housing when one of said frusto-conical means is displaced from normal position.

7. In a cushioning device, the combination of, a plurality of shoes having stem portions cylindrically formed, a housing normally surrounding only parts of said shoe stems, frusto-conically formed faces on said shoe stems spaced inwardly from one end thereof, frusto-com'cal surfaces adjacent another end of said shoe stems, frustoconical means within the confines of said shoes and in bearing relation with said surfaces and faces, and spring means interposed between said frusto-conical means and reacting axially of said device against said frusto-conical means; said surfaces and faces being of a given curvature, and said frusto-conical means being of a different curvature to thereby cause only line contacts between said surfaces and faces and said frustoconical means.

8. In a snubbing unit, the combination of, a housing, shoes having stems within and arranged to frictionally engage said housing, spaced inclined surfaces on each shoe stem, spaced wedges positioned between said shoe stems and having portions thereof engaging and disposed to correspond with the inclination of said surfaces, and spring means reacting against said wedges for urging said wedges apart and said shoe stems radially of said unit, said wedges having a projection extending toward and spaced from said housing, said projection being arranged so as to be engaged by said housing so that the center of radial forces urging the shoe stems against the housing is shifted towards the center of the shoe stems only after a predetermined compressive movement of the unit.

9. In a snubbing unit, the combination of, a housing, shoes having stems within and arranged to frictionally engage said housing, coil resilient means acting axially of said unit against said housing and shoes for urging them in opposite directions, spaced inclined surfaces on each shoe stem, wedges positioned between said shoe stems and having portions thereof engaging and disposed to correspond with the inclination of said surfaces, spring means reacting against said wedges for urging said wedges apart and said shoe stems radially of said unit, said wedges having a projection extending axially of said unit toward but normally spaced from said housing, said projection being arranged so that the center of radial forces urging the shoe stems against the housing is shifted towards the center of the shoe stems after a predetermined compressive movement of the unit, and said housing being 7 8 adapted to engage said shoe stems to "efiect a solid UNITED 1ST ATES PATENTS height of said unit whereby 'said coil resilient v means .is guarded against solid blows. Number Name D 7 1,169,862 Pecyke Feb. 1, 1916 5 1,876,908 Geiger Sept. 13, 1932 BLATTNER' 1,985,369 Fuchs Dec. 25, 1934 REFERENCE [TED 2,059,503 Webb NOV. 3, 1936 s C v 2,097,523 Hedgcock et a1. Nov. 2, 1937 The following references are of record in the 2,220074 Blattner 5 1940 file this Patent: 10 2,229,442 Clark Jan. 21, 1941

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