US2189208A - Nonharmonic load supporting spring unit - Google Patents

Description

Feb. 6, 1940. c. J. HoLLAND NONHARMONIC LOAD SUPPORTING SPRING UNIT Filed May 2, 1938 EINE Il III." .III

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@has JO//Q/zd Patented Feb. 6, 1940 UNITE;

STATES NONHARMONIC LOD SUPPORTING SP-RING'UNIT Cyrus J.. Holland, Chicago, lll., assignor` -to Holland Company, a corporation .of Illinois Application May 2, 1938,` Serial No. 205,503

- 6 Claims.

This invention relates to spring units 4foruse in spring assemblies for railway cars.

One of the objects of the invention is the provision Aof a new and improved-spring unit having 5 novel means for frictionally resisting the free movement of the unit during use.

A ffurther object of the invention is the provi- Sion of a new and improved friction device for frictionally engaging the coils or turns of a helical springduring its movement under compression or release. f

A ffurther object of the invention is the provision of a new and improved friction device for use in connection with helical springs for dampenl ing the vertical vibration of the same.

A still further vobject of the invention is the provisionof a new and improved device foruse on one 'or Imore helical springs of a spring assembly for railway cars that is simple in construction, inexpensive to construct, easily installed and that is effective in'operation. j

Other and 'further objects and advantages lof the invention will appear from the following description taken in connection wit-h the 'accom- 25 panying drawing in which- Fig. 1 is'a'side-elevation of a truck frame showing the invention in position thereon;

Fig. 2 is a vertical sectionthrough one ofthe units;

Fig. 3 is a perspective view of one of the friction devices;

Fig. 4 shows a modied form of construction;

Fig. 5 is a vertical section through vone of the units showing a further modified form f con- 35 struction;

Fig. 6 shows a perspective view of a modified form ofthe friction device; and

Fig. 7'is a view similar to Fig. 5 but showing a modified form of unit.

In load supporting spring assemblies for railway cars, wherein the conventional free acting helical springs are employed, 'it is not uncommon in use for these springs to develop harmonic action. There are various causes 'for such action. Flat wheels, low places in the track occurring at regular intervals, rail joints, and the like, combined with critical speeds of the car, are some of these causes. For instance, if the conditions are such that the causes or sources of vertical vibration of the car synchronize with'the natural vibration of the springs., `the vibrations may build up to such 'a Vpoint that ran accident may result as where the springs go solid and cause their breakage or breakage of the car truck parts.

The present invention seeks to dampen or cushion this free movement by providing means for frictionally engaging the turns of the helical springs.

Referring now to-the drawing, the reference character I0 vdesignatesaside frame of a 'railway l -truck 4having the bolster opening `lII therein for receiving the end I2 of the bolster. The bolster is supported by a spring assembly I3 which comprises a plurality of helical springs `II and one or more spring units I5. The spring unit I comprises a helical spring 'I6 similar to the conventional helical spring I'4 and interchangeable therewithand a rictiondevice I8. v Suitable means are provided for frictionally engaging the intermediate turns II of the helical spring I6. In the form of the construction shown, which is vby way Aofexample only, -a friction'device I8 is employed l-for this purpose. This device comprises a plate or base I9 having `upstanding spring arms 2'I integral with, or rigidly 20 secured to, the plate member I9. rThe inner or attaching portion 22 of the arms is bowed out- Wardly to give added lresilience to the arms 2|.

Any suitable number of arms 2| may be em- 25 ployed. In the form of the construction shown, threefarms 120 apart are provided. These'arms are of `resilient material andhave their outer ends bent outwardly as at 23 `in order to function as guides when the spring It is inserted in position. The a'rms are soconstructed that when the device is removed from the'spring, they converge slightly toward their outer ends so that when they are in position on the spring I4, these arms will be parallel and will grip the `turns of the spring for frictionally resisting the oscillation of the spring. p j

It will thus be seen that when the spring is compressed, the arms will frictionally engage the outer surfaces of the coils andsince these coils, as the spring is compressed, tend to increase in 40 diameter, these arms will more firmly .grip the spring and consequently the frictional resistance to the compression of the spring by the arms 2l will increase as the unit is compressed.v Likewise, there will be frictional resistancealso to' the expansion Vof the spring but since the helical spring contracts somewhat in diameter, this friction on release will lbe somewhat less than' on compression. The arms are of such material andare so constructedthat the frictional resistance will at no Y time be excessive so that when thespring is released, `it will readily and promptly expand or assume its normal unexpanded position.

In Fig. 4 is shown a modified form of a spring unit. This form of construction diiers from that the outer surface thereof as in Figs. 1 to 3. In

this form of construction, the base 24 extends radially outwardly beyond the arms 25 which are integral with, or rigidly attached to, the* base 24. As shown, the base may be slit as at 26 and the tongue formed thereby bent upwardly to form a portion of the arm 25, see Fig. 6. The arms 25, however, may be secured to the base in any suitable manner, as by being integral`v therewith. The arms 25 have their lower or attaching portions 21 bowed inwardly to increase the resiliency of the arms and their outer ends are bent inwardly as at 28 to guide the same intothe spring when the device is applied.

Whenin position within the spring I1, lthe outer coil of the spring l1 rests on, or engages, the base 24, and the arms 25 frictionally engage theinner surfaces of the spring. The arms are so constructed that they normally diverge outwardly when not in position within the spring l1 so that when they are inserted in the spring, they will-be parallel and there will be sufficient pressure to create the necessary friction to prevent harmonic action of the spring and of the spring assembly. t

A modiiied form of the construction is shown inFig. 7. This differs from that shown in Fig. 5 in that one of the interior friction devices vis employed at each endy of the spring. These devicesgare duplicates and further descriptionA is believed to be unnecessary. It will thus be seen that with either form of construction, the resilient arms will frictionally engage either the inner or outer surfaces, or both the inner and outer surfaces, of the intermediate coils or turns of the springs to frictionally resist the compression and expansion of those springs.

While the constructionsA described above are limited. to the device being used on veither the exterior or interior of the helicals, it is understood that where necessary or desirable, as where more sluggish movement of the helicals is required, both inner and an outer friction devices may be employed on the same helical.

It is thought from the foregoing, taken in connection with the accompanying drawing, that the construction and operation of my device will be apparent to those skilled in the art and that changes in size, shape and proportion may be made without departing from the spirit and scope of the appended claims.

I claim as my invention: 1. A spring unit comprising a friction member provided with a circular base plate forming aseat for said spring, said base plate having a solid central portion, a helical spring having one end directly engaging said base plate, a plurality of resilient arms integral with, and 'extending outwardly from, said base plate and frictionally engaging turns of said spring, said arms being provided with curves of short radius adjacent ing a base plate having a solid central portion engaging one end of said spring, three spring arms equi-distant apart integral with said plate frictionally engaging the exterior of a plurality of turns of said spring, the inner portions of said arms being bowed outwardly to avoid engagement with the adjacent turns of the spring, the arms of Asaid friction devices being spaced angularly and lapping past one another.

3. A spring unit comprising a railway bolster supporting helical spring, a friction member as-v sociated with said spring, said member comprising a circular base plate having a solid central portion engaging one end of said spring, a plurality of resilient arms integral with said plate and extending outwardly in planes at right angles to said base plate, and frictionally engaging intermediate turns of said spring, each of said arms having a resilient portion bowed sharply outwardly adjacent to said base.

4. In combination, a spring unit comprising a railway car bolster supporting helical spring, a friction unit having a circular base plate having a s olid central portion on which said spring is seated, said plate being substantially of the same diameter as the external diameter of said spring,

resilient arms integral with, and extending upwardly from, said base plate and frictionally engaging the inner sides of intermediate turns of said spring, said arms normally being non-parallel whereby when in position on said spring a said arms will be resiliently forced into frictional contact with the turns of said spring.

5. A spring unit comprising a railway car bolster supporting helical spring, al plurality of dampener members associated with said spring, v; .one of said members comprising a base plate having a solid central portion, a plurality of resilient arms rigidly connected to said base plate and extending into and frictionally engaging the inner sides of the intermediate turns of said spring, the other member comprising a base plate, a plurality of resilient arms rigidly connected to said base plate and frictionally engaging the outer surfaces of the intermediate turns of said spring.

6. For use with a helical spring, a friction member comprising a base plate of sufficient breadth to form a firm three-point support for an end convolution of the spring, at least three resilient arms rising from the plate for frictionally engaging a plurality vof convolutions of the spring, the outer spring engaging ends of said arms being normally spaced apart a different distance than the inner spring engaging portions thereof whereby when the device is in position on the spring the arms will be substantially parallel and each will frictionally engage a plurality of convolutions of the spring, the inner ends of each of the arms being directly joined to the adjacent arm by a solid portion of the base plate.

CYRUS J. HOLLAND.

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