US2030681A - Spring means for car truck bolsters - Google Patents

Description

Feb. 11, 1936. Q R, BUSCH SPRING MEANS FOR CAR TRUCK BOLSTERS Filed July 14, 1934 Patented Feb. l1, 1936 UNITED STATES PATENT OFFICE SPRING MEANS FOR CAR TRUCK BOLSTERS Charles R. Busch, Orange, N. J., asslgnor to Buffalo Brake Beam Company, New York, N. Y., a

6 Claims.

This invention relates to spring means for car truck bolsters which includes a special spring in addition to the usual spring nests for supporting the bolster. The coil springs of a car truck usually grouped in nests have a destructive point of vibration which at certain speeds of a train create a harmonic action which causes excessive damage to the ladings and to the equipment, and various means have been resorted to to break up this harmonic action.

It is an object of the present invention to provide springs of different form from the usual coil springs with elements bearing on the spring plank, but used as auxiliary special springs to the coil springs so as to break up such harmonic action at increased speeds.

Other objects of the invention are to provide spring means for car truck holsters including such as equalizing springs, and which are simple and durable, besides being of relatively low cost.

'I'hese being among the objects of the present invention the same consists of certain features of construction and combinations of parts to be hereinafter described and then claimed with reference to the accompanying drawing showing preferred embodiments of the invention and wherein Fig. 1 is a cross-section of truck side frames, together with a spring plank and bolster in elevation as well as comcomitant parts, the spring plank being partly broken away for the sake of cleamess of illustration;

Fig. 2 is a broken plan view of the same parts shown in Fig. 1;

Fig. 3 is an edge elevation of an equalizing spring of modied shape with respect to the equalizingr spring in Figs. 1 and 2;

Fig. 4 is a broken elevation of one half of the spring plank and bolster showing amodiflcation of the springs, and

Fig. 5 is a top plan View of Fig. 4 omitting the bolster.

Referring to Figs. 1 and 2, the side frames 6, 1 of a car truck are connected together by a tie 8 usually known as a spring plank. 'I'his is usually a channel member and rigidly connects together the two side frames in a well known manner. The parallel side anges 9, 9 of the spring plank extend upwardly towards the bolster I which is adapted to move in the space between such flanges. The ends of the bolster I0 extend in the usual manner into openings or windows II in the side frames and are supported upon the coil springs of spring nests I2, I3 which parts shown in may be of any desirable construction, and which rest upon the ends of the spring plank.

Under the present invention there is associated with the coil springs I2, I3 a half substantially elliptic spring I4 composed of one or more leaves of spring metal. Between the ends of the spring I4 there is formed a middle deflection I 5 or minor bow which is reversed to the bow of spring I4 as a Whole. Transverse flanges or lugs I6 are bent outwardly from the extremities of spring I4 so that they are directed in opposite direction to that in which the general bow shape of spring I4 is directed. 'Ihese lugs I6 and the ends of the spring I4 contact with friction shoes I'I, Il which are provided with slots I9 in which the lugs I 6 are entered. Friction shoes I'I, I8 are preferably in the form of at plates of considerable area as compared with the cross-section of the lugs I6, they being preferably of oblong rectangular shape.

In use the spring I4 constitutes an equalizing spring located between the coil springsY I2, I3 located at each end of the spring plank 8, between its flanges 9. 'I'he space between the bolster and the bottom of thespring plank being rather restricted in car trucks, fastening means are preferably not used to mount the equalizing spring I4 upon the bolster. The spring I4 is merely confined in position by the bolster and the spring plank, and as a bolster is usually bellied out between its ends, it is preferred to so curve the middle portion I of spring I4, so as to conform with the curvature of the belly of the bolster and to provide means for compelling the spring I4 to move with the bolster. In such way the end portions of spring I4 just beyond the deflected portion I5 are enabled to have suiiicient vertical depth to obtain advantage of the elasticity of the somewhat stiiT spring I4. As the ends of the equalizing spring I4 carry the friction shoes I1, I8 upon which the ends of the spring bear, these friction shoes are caused to move outwardly or inwardly in response to the depressive, tilting or end-wise movements of the bolster. The equalizing spring I4 is preferably of such. length as that when in use the friction shoes, I'I, I8 may move on the spring plank at points close to the coil springs I2, I3.

Equalizing spring I4 acts as a vibration reducing spring or snubber, and as it is of considerable length and its shape is such as to take advantage of the reduced space in which it is confined, it iseffective in breaking up the harmonic action caused when coil springs, such as I2, I3, are employed merely for supporting the bolster, the

friction shoes having considerable area and producing a maximum amount of friction as they move back and forth on the spring plank. It will be noted that as the equalizing spring I4 has a more or less definite ratio in contrast with the truck springs I2, I3, the period of vibration is broken up, as the springs I2, I3 and the equalizing spring I4 are working under the same load, and have different periods of vibration.

It is furthermore clear that the location of the equalizing spring I4 enables it to act so as to cradle the bolster on its center line, which will also tend to absorb all side thrusts and end thrusts which are in themselves damaging to the lading and the car equipment.

A slight modiiication is illustrated in Fig. 3 Where the equalizing spring is shown as bowed or curved in such way as to provide a middle bow 20 reversed to the end bows 2l, 22 of the spring, which have friction shoe engaging lugs 23 at their extremities. In this modification the middle bow 20 is considerably elongated so as to have an area of greater frictional contact with the bellied out bottom of the bolster, and thereby also increasing the vertical depth ci the effective resilience of the spring at points between the middle of the bolster and the coil springs of the truck. The lugs 23 are entered into the slots of friction plates as in the preferred construction, and it is apparent that the connection between the equalizing spring and the friction shoes is not a tight ilt, as a little play between the parts is desirable, as the lugs at the end of the spring have a slight tilting motion due to the compression and expansion oi.' the equalizing spring.

In the modification shown in Figs. 4 and 5 p only portions of the spring plank 24 and the bolster 25 are illustrated, as the construction is the same at both ends of these parts. In some car trucks the supporting coil springs 28, 21

' are separated suiiiciently so as to provide a considerable transverse space between them, and in such cases the ends of the spring plank are formed with enlargements 28 to acccommodate the greater distance between the axes of the respective groups 26, 21 of coil springs. Under the present invention advantage is taken of this condition and arrangement inherent in such types of coil spring supports by providing an equalizing spring 29 which is obviously longer than the equalizing springs shown in Figs. 1 and 3, it being long enough so that a friction shoe 30 at each end of the equalizing spring 29 may have its sliding frictional movement in the space provided between the coil springs 26, 21.

It will be obvious to those skilled in the art that the constructions shown and described may be more or less modified without departing from the scopeof the appended claims. For example, the middle portions of the equalizing spring may be positively secured in some suitable way to the bolster.

What I claim as new is- 1. Spring means for car-truck bolsters, including, in combination, side frames, a spring plank rigidly attached to the frames, a bolster, supporting springs between the ends of the bolster and spring plank, and an equalizing leaf spring bearing upwardly at its middle portion upon the bolster and having means at its ends to provide sliding contacts with the spring plank, the supporting springs being so arranged as to provide longitudinal spaces between them, and the sliding contacts being in the spaces.

2. Spring means for car truck bolsters, including, in combination, side frames having openings or windows, a bolster extending at both ends into such openings and guided on the side walls of the openings, supporting springs between the ends of the bolster and side frames. and an equalizing leaf spring bearing upwardly at its middle portion upon the bolster and having means at its ends to provide sliding frictional contacts with the bottoms of the openings, such frictional contacts including friction shoes carried within the openings by the ends of the leaf spring.

3. Spring means for car truck bolsters, including, in combination, side frames having openings or windows, a bolster extending at both ends into such openings and guided on the side walls of the openings, supporting springs between the ends of the bolster and side frames, such supporting springs being coil springs located within the openings of the side frames and including two sets of springs spaced apart, and an equalizing leaf spring bearing upwardly at its middle portion upon the bolster and having means at its ends to provide sliding frictional contacts with the bottoms of the openings, such frictional contacts including friction shoes carried within the openings by the ends of the leaf spring, and slidable in the spaces between the coiled springs.

4. Spring means for car-truck bolsters, including, in combination, side frames having window openings, a spring plank attached to and rigidly connecting the frames, a bolster having a central belly portion, supporting springs for the bolster located in the window openings, between the ends cf the bolster and spring plank, an equalizing leaf-spring located between the supporting springs and conformed to and bearing upwardly at its middle portion upon the belly of the bolster, and means at the ends of the leaf-spring to provide sliding contacts with the spring plank.

5. Spring means for car-truck bolsters, including, in combination, side frames having window openings, a spring plank attached to and rigidly connecting the frames, a bolster having a central belly portion, supporting springs for the bolster located in the window openings, between the ends of the bolster and spring plank, an equalizing leaf-spring located between the supporting springs and conformed to and bearing upwardly at its middle portion upon the belly of the bol'- ster, and means at the ends of the leaf-spring to provide sliding contacts with the spring plank, the equalizing spring being bowed downwardly, reversely to the upward bowingl thereof, along the area where it bears on the bolster so as to conform to the belly portion of the bolster.

6. Spring means for car-truck bolsters, includ.- ing, in combination, side frames having window openings, a spring plank attached to and rigidly connecting the frames, a bolster having a central belly portion, supporting springs for the bolster located in the window openings, between the ends of the bolster and spring plank, an equalizing leaf-spring located between the supporting springs and conformed to and bearing upwardly at its middle portion upon the belly of the bolster, and means at the ends of the leaf-spring to provide sliding contacts with the spring plank, the leaf spring being substantially of semi-elliptic shape and having slight upward bows adjacent to its mid-length and bearing on the belly portion of the bolster to provide a maximum resiliency between the bolster and spring plank.

CHARLES R. BUSCH.

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