US2341452A

US2341452A - Car truck

Info

Publication number: US2341452A
Application number: US387938A
Authority: US
Inventors: Leppla Rudolph
Original assignee: McConway and Torley LLC
Current assignee: McConway and Torley LLC
Priority date: 1941-04-10
Filing date: 1941-04-10
Publication date: 1944-02-08
Anticipated expiration: 1961-02-08

Description

R. LEPPLA Feb. 8, 1944.

CAR'TRUGK Filed April 1o, 1941 l lll Patented Feb. 8, 1944 CAR TRUCK Rudolph Leppla, Davenport, Iowa, assignor, by mesne assignments, to McConway & Torley Corporation, Pittsburgh, Pa., a corporation of l Pennsylvania Application April 10, 1941, Serial No. 387,938

4 Claims.

This invention relates to car trucks of the type in which both the transom and the bolster are supported upon cushioning springs, and more particularly to trucks in which the transom is movable downwardly into engagement with xed seats on the side frames of the truck, and in which the transom is normally supported by its springs above the seat. A truck of the type referred to is shown in my U. S. Patent No. 2,317,391, granted April 27, 1943, on application Serial No. 386,702, filed April 3, 1941.

Th present invention has for its object to provide an improved car body cushion comprising bolster and transom cushioning springs of different harmonic characteristics which by their combined action materially lessen the transmission of vibrations from the truck to the car body.

., A further object of the invention is to provide a transom cushion in the form of a single semielliptic spring which is centrally disposed with respect to the transom and which engages the bottom chord at points spaced a considerable distance from the center thereof, so that the stresses are advantageously distributed in the side frames.

With the above and other objects in View the invention may be said to comprise the car truck as illustrated in the accompanying drawing hereinafter described and particularly set forth in the appended claims, together with such variations and modifications thereof as would be apparent to one skilled in the art to which the invention pertains.

Reference should be had to the accompanying drawing forming a part of this specication, in which:

Figure 1 is a side elevation of the truck embodying the invention;

Fig. 2 is a fragmentary side elevation on an enlarged scale showing the central portion of the truck, portions of the side frame and transom being shown in section;

Fig. 3 is a section taken on the line indicated at 3-3 in Fig. 2; and

Fig. 4 is a section taken on the line indicated at 4-4 in Fig. 2.

Since the side frames of the truck and the supports for the opposite ends of the transom, spring planks, and bolster are identical, the accompanying drawing shows the construction at one side of the truck only, it being understood that this construction is duplicated at the opposite side of the truck, as is the usual practice in car truck construction.

Referring to the accompanying drawing, the

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(arios-190) truck of the present invention has a bolster A upon which the car body is supported, a spring plank B which carries the cushioning springs upon which the ends of the bolster A rest, a transom C from which the spring plank is pivotally suspended, and side frames D in which the ends of the transom C are slidably mounted.

Each side frame D has an upper compression chord l and a lower tension chord 2 which connect journal boxes 3 located at opposite ends of the frame. The bottom chord 2 may be in the form of an upwardly facing channel and has a horizontal central portion 4 provided with deep side flanges 5. Adjacent opposite ends of the horizontal portion 4 of the bottom chord each side frame is provided with vertical guide columns l which connect the top and bottom chords and provide a substantially rectangular opening midway between the ends of the side frame in which an end of the transom C is guided for vertical movement. At their upper ends the columns 6 are provided with laterally offset portions 1 which widen the side frame opening immediately beneath the top chord l.

The transom C has a pair of cross beams 8 which extend across the space between the side frames at right angles to the side frames and which are spaced apart a suicient distance to receive the bolster A between them. The cross beams are rigidly connected at each end of the transom by a rectangular guide frame 9 which is slidable in the opening of the side frame between the guide columns 6. Each transom guide frame 9 has laterally projecting lugs I0 adjacent the top thereof which overlie opposite sides of each of the guide columns 6. The height and width 'of the lugs l0 is such that when the guide frame 9 is elevated to a position adjacent the top chord l, the lugs ll) may pass through the enlarged upper portion of the side frame opening. The bottom of the guide frame 9 has depending flanges il disposed centrally thereof and these anges overlie the opposite sides of the bottom chord 2. The height of the flanges l l is such that when the transom guide frame 9 is elevated to its uppermost position in the side frame opening, the flanges ll will be cleary of the bottom chord so that the side frame may be readily removed. The lugs il) and flanges i I serve to guide the frame 9 vertically and to hold the side frames against tilting or other angular movements with respect to the transom C. The spring plank B is suspended from the cross beams B by means of links l2 which are connected at their upper ends to the cross beams by pivots I3 and at their lowf er ends to the spring plank B by pivots Ill. The bolster A is supported at each end above the spring plank by means of suitable springs interposed between the spring plank and bolster, such as the nest of coil springs I5.

The transom is yieldably supported upon each side frame by means of a semi-elliptic spring I6 which is mounted in the deep horizontal channel of the bottom chord 2. The spring I 6 has opposite end portions I'I which are slidable upon the bottom wall of the bottom chord adjacent the ends of the horizontal portion and substantially beneath the vertical guide columns E. The spring I6 is provided with a central band I3 which engages the bottom of the rectangular transom guide frame 9 centrally thereof. The spring I6 is held against longitudinal movements by means of lugs I9 on the bottom of the frame 9 which engage opposite ends of the band, and against lateral movements by a lug 20 on the band engaging in an aperture or recess in the bottom of the frame 9. The spring I6 normally projects above the'side flanges 5 of the bottom chord and supports the transom above the bottom chord. The spring I6, however, is compressible into the channel of the bottom chord, and, when a predetermined downward pressure is exerted thereon, permits the frame 9 to seat upon the bottom chord.

The seat for the transom guide frame is provided by the upper edges of the side flanges and cross webs 2l flush with the upper edges of the flanges and connecting the flanges adjacent the lower ends of columns 6. The capacity of the spring I6 may be such that when the car body supported by the trucks is empty or lightly loaded, the transom is supported above its seats and the car body is cushioned by both the bolster and transom springs. When the car is heavily loaded, the spring I6 is compressed by the load sufficiently to permit the transom to rest upon its seat and the cushioning of the car body is then effected by the bolster cushioning springs I5. The springs I5 may be designed to effectively cushion a heavily loaded car and the spring It to provide an effective cushion'for an empty or lightly loaded car. In order for the bolster springs I5 to effectively cushion heavy loads, they must be very stiff, and for this reason they provide a poor cushion for an empty or lightly loaded car. The lighter spring i6, together with the springs I5, however, provide a soft cushion for a lightly loaded or empty car. The spring I6 also serves when the car is heavily loaded to cushion movements of the side frames with respect to the car body such as are due to passage of loose rail joints or to eccentric or at wheels.

The combined action of the semi-elliptic springs I6 and the coil springs I5 is such as to materially lessen the vibrations transmitted to the car body when the transom is supported above its seat by the spring i6 by reason of the different harmonic characteristics of the coil and semielliptic springs` The spring I also serves to advantageously distribute the stresses imposed upon the side frames by reason of the fact that the load is transmitted to the side frames at points spaced a considerable distance from the center of the side frame and to points substantially beneath the vertical guide columns rigidly connecting the top and bottom chords of the side frame.

The spring supports of the present invention may also be used to advantage for cars which are not designed for carrying heavy loads, in which case the car body is cushioned at all times by both the transom and bolster supporting springs, and the transom engages its seat only when excessive pressure is exerted upon the springs due to impact, in which case the transom cushioning springs serve to provide a softer cushion and reduce vibrations and have a snubbing action when the car or truck is subjected to heavy impacts.

It is to be understood that variations and modications of the specic devices herein shown and described for purposes of illustration, may be made without departing from the spirit of the invention.

What I claim is:

1. In a car truck having side frames with top and bottom chords and columns spaced apart to provide central openings, the portion of the bottom chord of each side frame beneath the opening thereof being in the form of an open top channel, a transom having end portions guided for vertical movement in said openings, and having portions engaging said columns to hold the side frames against tilting movements with respect to the transom, a bolster yieldably supported by said transom, and a semi-elliptic transom supporting spring mounted in said channel having a central portion projecting above the bottom chord centrally of `said opening, and end portions slidably engaging the bottom ofl the channel beneath said columns.

2. In a car truck having side frames with top and bottom chords and columns spaced apart to provide central openings, the portion of the bottom chord of each side frame beneath the lopenings thereof being in the form of an open top channel, a transom having end portions guided for vertical movement in said openings and hav-. ing portions engaging said columns to hold the side frames against angular movements with respect to the transom, a bolster, supporting springs interposedbetween said transom and said bolster, said springs having a capacity and range of dev flection sufcient to cushion maximum loads, and a semi-elliptic transom supporting spring mounted in said channel having a central portion projecting above the bottom chord centrally of said opening, and end portions slidably engaging the bottom of the channel adjacent Sad columns, said spring being compressible into said channel under a predetermined pressure greater than that'imposed by a lightly loaded car but within the cushioning capacity of the bolster springs to permit the transom to seat upon said bottom chord. A

3. In a car truck, a side frame having a top chord, a bottom chord in the form of a channel with upwardly extending side nanges and spaced columns connecting said chords and forming a central opening, said columns having webs extending across the bottom chord channel adjacent the top edges of the bottom chord flanges and terminating above the bottom of said chan-,- nel, a transom having an end portion slidable in the side frame opening, a bolster yieldably mounted on the transom, and a semi-elliptic spring mounted in the bottom chord channel with its center arched upwardly and supporting the end portion of the transom above the bottom chord flanges and with its ends extending beneath the lower ends of the webs of the guide columns and slidably engaging the bottom of the bottom chord channel.

4. In a car truck, a side frame having a top chord, a bottom chord in the form of a channel with upwardly extending side flanges, spaced columns connecting said chords and forming a central side frame opening and stop webs connecting the bottom chord flanges at their uppr edges adjacent the columns, said webs being integral with the columns and bottom chord anges, a transom having end portions guided between said columns and engageable with said said stop webs.

stop Webs, and a semi-elliptic spring having end portions engaging the bottom of the bottom chord channel and a central portion extending above the bottom chord anges to normally support the transom above and .out of contact with RUDOLPH LEPPLA.