US2291621A - Rail car - Google Patents

Description

F. M. GUNN RAIL CAR I Aug. 4, 1942.

Filed Dec. 1, 1959 5 Sheets-Sheet l.

F. M. GUNN Aug. 4, 1942.

RAIL CAR 5 Sheets-Sheet 2 Filed Dec. 1, 1939 m NN m m mm R NMX mm v we] um w @N Y I F. M. GUNN Aug. 4, 1942.

RAIL" CAR Filed Dec. 1, 1939 5 Sheets-Sheet 3 Aug. 4,1942. F. M. GUNN 2,291,621

RAIL'CAR Filed D66. 1, 1939 I 5 Sheets-Sheet 4 4, 4 F. M. GUNN 2,291,621

RAIL CAR Filed Dec. 1, 1939 5 Sheets-Sheet 5 Patented Aug. 4,1942

UNITED STATES PATENT OFFICE I mm. on Francis M. Gunn, Chicago, 111., assignor to Pullman-Standard Car Manufacturing Company, V Chicago, 111., a corporation of Delaware Application December 1, 1939, Serial No. 307,143

4 Claims.

This application is a continuation in part of a copending application of Francis M. Gunn, Serial No. 297,558, filed October 2, 1939.

Due to the extremelyhigh speeds attained bypassenger trains today, it; is of considerable importance to reduce the wind resistance of the train to a minimum. Indentations, projections, and sharp comers extending outwardly on the surface of the car sides are very objectionable; and, as a result of considerable wind tunnel testin: conducted in 1932 and 1933 and prior to that time on streamlined trains, it was definitely concluded that even the presence of rivet heads on the side of a car produces a substantial dragging eifect due to the resistance of turbulent air.

Because of the desirability of reducing all irregularities along the car sides and in an effort to produce a smooth contour along the sides of the car to satisfy the ever increasing public demand for modern appearing equipment, the present invention is particularly valuable as it relates to the railway passenger car industry.

Some years ago, riveting wasused almost exclusively in the construction of steel passenger cars,-but today the use of welding is becoming more and more common, and on modern equipment the presence of rivet heads on the sides of the cars is rapidly becoming a thing of the past. Even though welding has been used for a number of years, the car sides still are marredby ripples and buckles in the side sheathing and welding impressions left after the welding operation has been completed. Many attempts have been made to hide these disfigurations by painting and other means, but their presence still can be detected.

It is one of the principal objects of this invention, then, to eliminate the buckles and welding scars on the outer surface or. the car side, thereby greatly improving the 'outside appearance and making it possible to produce a greater streamlined effect.

In a girder type construction of the side frame of a car, the sheathing plays an important part in carrying the stresses. Because of this, it is extremely diillcult to eliminate the ripples and buckles occurring in the side sheathing due to the presence of stresses. The present invention successfully eliminates these buckles and yet retains the plain streamlined appearance of the car.

Heretoiore, in performing the welding operation on the outside of the car side, when attaching the sheathing to the framing members, it has been necessary to use a special jig for each individual car design in order to locate the framing members for the welder. Electric eyes and other equipment have been employed for this purpose and this necessitated building a new jig each time a newly designed car was being constructed. The present invention eliminates this objection and is a definite step towards simpliiication and reduction in construction costs.

In prior methods of constructing car sides, the expansion and contraction occurring in the sheathing during the welding operation have been resisted by the framing, resulting in the setting up of internal stresses in the side sheets, producing buckles.

It is intended by the present invention to prevent the setting up of these initial stresses, thus completely eliminating the buckles.

The above constitute some of the principal objects and advantages of the present invention and other objects will become apparent from the drawings and the following description, in

which Fig. l is an elevation showing two small side sheet panels to be used in fabricating the side sheathing, with the window opening cut in the letter-board panel;

Fig. 2 is a plan view of the panel shownin Fig. 1 showing the stifleners applied to the inner face of each panel:

Fig. 3 is the plan view of the panel shown in Figs. 1 and 2 welded together by a horizontal seam and a dotted line showing of a second adjoining panel unit welded to the first by a vertical seam.

-Fig. 4 is a vertical transverse sectional view through the side frame and vertical jig showing the relationship of the various elements making up the side frame when mounted on the vertical j Fig. 5 is a full assembly view of the sheathing for the entire car side welded into an integral sheet showing the stiifeners on the inner face. A portion oi the sheathing is broken away at the center; a

Fig. 6 is a side elevational view of the car side framing members welded together to form the entire car side, a portion of the frame being broken away at the center;

Fig. 7 is an enlarged fragmentary side elevational view of the car side showing the relative positions of the framing members, stiflfeners, and welded joints in the completed side;

Fig. 8 is a side elevational view of the side sheathing viewed from the outside;

Fig. 9 is a side elevational view of the completed car side viewed from the inside of the car;

Fig. 11 is a horizontal sectional view of a portion of the car side taken on the line Il-il of Fig. 9;

.Fig. 12 is a fragmentary plan view of a small side sheet segment placed on the spot welding 1 s:

Fig. 13 is an enlarged fragmentary longitudinal sectional view taken through the Jig working surface and side sheet segment showing the side sheet with a stiffener in place and the positions of the electrodes prior to the application of electrode pressure and Fig. 14 is an enlarged sectional view corresponding to Fig. 13 but showing the upper electrode exerting force on the stiffener and sheet in position for welding. The bowing of the sheet downwardly is exaggerated to more clearly bring out the process. When constructing the car side, the sheathing and side frame are fabricated separately and are assembled when both have been cooled to atmospheric temperature and properly straightened.

The sheathing is made up of a plurality of relatively small sheet panels I and I5 (Fig. 1) reenforced and welded together to form a unitary sheet extending the full length and height of the car side frame. Panel l5 may be referred to as a segment of the letter board panel and sheet Ii as a segment of the usual girder sheet.

The first operation in constructing the side sheathing is to cut window openings I! in the of the individual sheets, a plurality of stiffening,

units ll (Fig. 2) are welded to the inner face of both the letter board panel sheets and the small segments of the girder sheets. These stiffeners comprise a series of corrugations l9 pressed into a sheet, and they are cut in the required size before being welded to the sheet.

' Referring to Fig. 12, a spot welding jig 50 is shown, having its bench top divided into two segments II and 52, spaced apart to provide a gap 58. For the purpose of illustration, 9. girder bottom electrode is slightly lower than the upper surfaces of the work bench areas 5| and 52; and, when the side sheet l5 and the corrugated stiflener sheet I! are straddling the opening 53 prior to the application of electrode pressure, they are substantially straight and are spaced from the lower electrode 55 with upper electrode 51 directly above the lower electrode.

As shown in Fig. 14, the-upper electrode 51 is moved downwardly onto the inner surface of stiffener sheet II, and then pressure is exerted,

the side sheet being concave.

against the lower electrode 55 to place the welding electrodes in position for performing the welding operation and bowing sheet I! downwardly to place its outer surface in tension. With the parts in this position, the welding current is turned on and a spot weld made between the stiffener and side sheet; and then, upon raising electrode 51, the inherent resiliency in the corrugated stifl'eners l5 aids in restoring the side sheet ii to its normal fiat position.

If during the welding operation the side sheet and stifleners were held flat, on completion of the operation. the tendency would be for the stiffeners to be bowed with their faces engaging This is caused by the greater heat on this contacting face of the stiifeners due to the concentration of welding heat between the side sheet and the stiifeners. Because of the greater thickness of material in the stifl'eners as compared with the side sheet, this warpage in the stiffeners causes buckling in the side sheet to place in the outer surface undesirable concavities. In order to overcome this objectionable bowing. the sheets and stiffeners are initially bowed to place the outer surface of the sheet in tension, as previously described, so that, upon cooling of these members, they will be substantially flat or only slightly convex on the outer surface of the sheet. The amount of bowing required during the spot welding operation depends upon the material used as well as its thickness. It is important that the side sheet be held on the welding jig in such a manner that, during the welding operation and upon subsequent cooling. the sheet and stiifeners are as nearly flat as practicable; and, in order to insure against the presence of concavities in the outer surface of the sheet, it may be desirable to be somewhat liberal in determining the initial bow.

The reenforced small sheets are next placed with a letter-board panel sheet l5 above and a girder sheet segment i5 below, as shown in Fig. 3, on a welding jig and butt welded together, as indicated at 23. This operation is performed by the use of arc welding, and is continued until all like units of letter-board panel sheets and girder sheet segments l5 and i6 respectively for one entire car side are completely welded together.

These units are then placed on a large jig adapted to accommodate the sheathing for an entire car side and complementary units are placed side by side and welded together by means of a vertical butt weld 24. also accomplished by the use of arc welding. Thus the entire sheathing for the car side is integrally welded together into a single'reenforced sheet extending the full length and height of the car side.

This sheet is then carried to a vertical Jig, generally indicated at 25 in Fig. 4.

While the side sheathing is being fabricated as described, the side frame, generally indicated at 25 in Fig. 6, is being assembled on a framing jig. This frame comprises the usual side plate 21, window header 25, belt rail 29, and side sill 35, with a plurality of vertical side posts 3| suitably spaced throughout the length of the side frame. These various members are welded together,

- preferably by arc welding, as indicated at 22, and

forcing the stiffener and side sheet downwardly additional horizontal and vertical braces (not shown) may be employed if needed. When the frame has been completely welded together and cooled, it is straightened on a straightening jig and put into shape for receiving the side sheathing.

Before the sheathing indicated at 33 in Figs.

4 and 5 is mounted on the jig 25 (Fig. 4), the welding bead, formed by welding together the small side sheets as previously described, is ground flush with the sheets on the inside surface of the sheathing, and then it is placed in the vertical jig 25 with its outside face flush against a flat copper plate 34 forming part of the vertical jig. While the sheathing is being held in place against this copper plate, the car frame 26 is properly positioned against the inner face of the sheathing with the framing members fitting between the stiffeners in the proper manner, and a plurality of upper and lower clamps 35 and 35', respectively, are drawn tight to securely hold the sheathing and frame on the jig. These clamps may be of any suitable design or construction, but, for the purpose of illustration, a. U-shaped clamping member 36 is employed with one leg 3i resting against a backing plate 38 of the jig and the other leg 39 resting against some part of the side frame, as, for example, the side sill 38, as in the case of the lower clamp shown in Fig. 4. Some suitable means, such as a bolt fill with a nut 40, is used to tighten the clamp against the jig and the car frame.

The jig itself comprises a plurality of H beams ll, anchored to the ground, as indicated at 42, to which is rigidly secured a steel backing plate 38. The copper plate 34 previously described is bolted or otherwise aflixed to the backing plate 38, and serves as a conductor for the welding current.

The side sheathing and frame are now mounted on the vertical jig and ready for the applicaspaced to attain the required strength and rigidity in the fastening. The spot welds are also applied to the horizontal framing members, and their spacing also is suitable for obtaining the required strength.

The finished product gives a smooth, plain appearance on the outside of thelcar, as shown in Fig. 8, with the car side entirely free from buckles or electrode impressions caused during the welding operation. The fact that the electrode pressure is applied from the inside on the car framing members in the spot welding operation and the outside surface is flush against the relatively smooth copper plate 34, (Fig. 4) makes it possible to entirely eliminate the welding scars on the outer face of the side sheathing.

By welding the stiffeners to the back of the small side panels, it is possible to obtain a very flat reenforced sheet highly resistant to buckling before any expansion and contraction are allowed to occur in the sheet itself, so that, when these sheets are are welded together in the manner described, these stiffeners resist any tendency to buckle-which may be present. Also, by fabrieating the .side sheathing and framing separately and then welding them together after they have cooled to atmospheric conditions and have been properly straightened, one of the greatest causes for buckling in the side sheathing has been eliminated.

Previously'it was the practice to weld the individual side sheets directly to the frame, and'during cooling of these sheets, after the welding had been completed, the resulting contraction was resisted by the framing members, thus setting up internal stresses and causing ripples and buckles to form.

- sheathing to conduct the welding current.

large surface of contact with the sheathing I As shown in Fig. 6, the horizontal and vertical seams in the side sheathing are located as closely as practicable to the two framing members in the car side. This is the preferable location for these seams, although obviously, if it is found desirable, the individual sheets may be cut to sizes different from those shown so that these seams will fall some place else in the car side.

When welding the stiffeners to the sheets, the welding electrode is applied to the stiffener itself so that any scars due to electrode pressure which may result are on the inner face of the stiifeners instead of being on the outer surface of the sheathing. These spots are located as near as possible to the bent edges of the stiffeners so as to minimize as much as possible any tendency to have the stiffeners pull away from the sheets. Thestifieners are placed with the corrugations extending lengthwise of the car because of the needed additional strength in that direction due to the cumulative contractioncaused by the welding heat. This contraction may be as much as three-eighths to five-eighths of an inch.

,The large copper plate 34 in the welding jig serves as an electrical conductor behind the The spreads over a large area the pressure due to the welding electrode pressure. This distribution of force prevents depressions from appearing in the outer face, thus preserving the smooth contour of the sheathing.

Whenbuilding cars, it is customary to place an initial camber in the underframe and as the construction progresses and weight is loaded onto the underframe, this camber straightens out. Befofe welding the side frame onto the sheathing in the present process, an initial camber placed in the sheathing and the side frame which also straightens out as the car shell is loaded. This may be done by filing the opposite edges of the units made up of letter board panel sheets and girder sheet segments l5 and I6 transversely of the car side, so as to taper these units slightly toward their lower edges, so that, when units are welded together side by side, the initial camber is present.

A specific embodiment of the present invention has been .selected for the purpose of disclosure as required by Section 4888 of the Revised Statutes; but, obviously, many changes and modifications may be made, some of which have been suggested, without departing from the spirit of the invention. No attempt has been made to accurately show the location of the spot welding throughout the car side. The spacings between the spots will vary according to individual requirements.

I claim:

1. The method of fabricating a portion of a vehicle side comprising placing aflat side sheet panel on a working surface with the inner face of the panel disposed upwardly, placing relatively fiat stiffeners on the upper face of the panel, applying pressure to the upper face of the working surface with the sheet straddling an' opening between two portions of the working surface, positioning welding electrodes above and below the sheet in the opening between the two spaced portions of the working surface with the lower electrodespaced slightly below the plane of the working surface, placing the stiffener on the upper face of the sheet so that the stiffener extends crosswise to the opening in the working surface, lowering the upper electrode against the stiffener and applying a force to how the sheet and the stiil'ener downwardly within their elastic limits into engagement with the lower electrode, welding the stifl'ener to the sheet while they are in this bowed position, and then allowing the panel and stifleners to return to a substantially flat condition.

3. The method of fabricating a reinforced, straight, thin, metallic sheet having an ultimately smooth, flat side comprising applying a cormgated stiffener sheet to one face of a flat sheet, bowing the stiffener and the flat sheet within their elastic limits to place the other smooth face of the metallic sheet in tension and maintaining the stiffener and the metallic sheet in engagement throughout the, ex-

tent of their overlapping areas. then while so maintaining this bowed condition welding the two members together, the welds being made over a substantial portion of their common areas, and then allowing the inherent resiliency of the assembled members to return them to their original, flat condition.

4. The method of fabricating a reinforced. straight. thin, metallic sheet having an ultimately smooth, flat side comprising applying to one face of a metallic sheet a corrugated stiffener sheet of sumcient size to overlap the major area of the metallic sheet, bowing the stiffener and the metallic sheet together within their elastic limits to place in tension the other face of the metallic sheet and maintaining the stiffener and the metallic sheet in engagement throughout the extent of their overlapping areas, while so malntainlng this bowed condition welding the two members together, the welds being made over a substantial portion of their common areas, and than allowing the inherent resiliency of the assembled members to return them to their original, flat condition.

FRANCIS M. GUNN.

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