US1868191A - Car roof - Google Patents

Description

y 19, 1932- c. D. BONSALL 1,868,191

CAR ROOF Filed Feb. 27, 1951 H 7- TO em: K54

seam caps secured Patented July 19, 1932 V UNITED STATES PATENT FF CHARLES DAVID BONSALL, OF PITTSBURGH, PENNSYLVANIA;.ASSIGNOR T01; H. 1mm;

LPI-IY COMPANY, on NEW KENSINGTON, PENNSYLVANIA,

SYLVANIA Application filed February 27, 1931.

level, the side panels being provided with.

upstanding flanges, and the upstanding flanges of adjacent sheets being straddled by thereto by horizontally disposed rivets.

In the accompanying drawing which forms part of this specification and wherein like numerals refer to like parts wherever they occur,

Fig. 1 is a plan view of a roof embodying my invention; I

Fig. 2 is a cross-section of a part "of the car roof on the line 2-2 of ig. 1;

Fig. 3 is a longitudinal sectional View on the line 3-3 of Fig. 1;

Fig. 4 is an enlarged cross-sectional detail at the eaves of the car; and g Fig. 5 is an enlarged section through the seam construction.

part of a car The present roof comprises metal sheets 1 I that extend from side plate to side plate 2 of the car and have their ends bent down and riveted to the side plates. The individual roof sheets are offset vertically along longitudinal lines to form a wide middle panel 3 at one elevation and narrower side panels 4 at a higher elevation, the upper and lower panels being connected continuously by web members 5 which preferably decrease in height from a maximum at the ridge to a minimum at each eaves end. Along the side margins of the upper panels are upstanding flanges 6, and the upstanding flanges of adjacent sheets abut against each other. Such abutting flanges are straddled by a rebent seam cap 7 whose sides are firmly clamped against the upstanding flanges by horizontal rivets 8 that extend through said seam cap and said flanges. Preferably the seam caps than would otherwise A ooaroan rro v or PENN- CAR. noon 7 Serial No. 518.705.

are thicker than the sheets and have lateral I" flanges 9 at their lower edges that rest on the marginal portions of the roof sheets. V

It is noted that the present roof is'designed to function as a beam supported on the side plates, in which case the middle panels of.

the roof sheets are under tensile stress and i the upperpanels are under compression. In designing such a roof, the capacities of the web membersan'd of. the compression memher for taking care of the stressesthat tend to buckle them are the principal limiting factors; and in turn, the strengthof the web' against buckling is. dependent. upon its height, and the strength of a compression panel against buckling is dependent upon its width. In the present construction, .the'compression strengthof the roof is greatly augmented by the seam construction due not only to its consisting of the upstanding flanges and the thick rebent seam cap rigidly clamped together but due also to its location above the upper level of the roof sheets and consequently at the greatest distance above the neutral axis. seam cap is further increased by making it thicker than the sheets and lar section, that is, with lateral flanges'.- Not only does the seam construction itself very the roof considered as a beam,'but s'uch compressive strength is'also increased by making the upper panels of the individualsheets relatively narrow, such a panel being stiffened on one side by the continuous web which joins it to the lower panel and on the other side by the seam construction. Theseseveral factors may be varied individually and permit the webs to be made narrower and consequently more resistant to buckling. As the roof is thus greatly strengthened against compression and buckling stresses, it becomes feasible to make the lowerpanels wider be practicable I for proper beam action; and likewise it becomes feasible to use sheets of lighter gage than would otherwise be practicable. v

In practice, it is convenient and desirable to make the side panels of a sheet equal to The compression strength of the I of greater depth mldway of the 'car and by making it'of anguso greatly increase the compressive strength of the compressive each other and together equal to the middle panel; but-when the sheets are quite wide or thin, it is preferable to make narrower and rely on the seam cap to make strength'of the roof commensurate with the tensile strength of the lower panels.

1 r What-I claimis:

: side portions at a carroof comprising roof sheets rig idly securedftogether at 7 between sucl levelsjbeing such that the roof of theupper portions including the seam coni a structions.

middle portions are I sheets having abutting upstanding flanges 7' along their side margins and seam caps that v i straddle said flanges and are rigidly secured will act as a beam and the'tensile strength ofthe lower portions being substantially commensurate with the compressive strength 2 A car roof comprising a side portions are at one level and whose at a lower level, said thereto, the distance between suchlevels being such that the roof will act asa beam and said seam 1 caps being thicker than said sheets and having .base are adapted to strengthen the roof against buckling and eompressionstresses.

3. A car roof comprising roof sheets whose longitudinal middle portions are at one level and whose side portions are at a higher level, the distance between such levels beingsuch that the roof will act as a beam and the cross- 7 sectional area of the middle portion of a sheet I being substantially equal the middle portion being at a to the cross-sectional area of the two side portions thereof, adjacent sheets being rigidly secured together by upstandingseams.

' 4. Acar roof-comprising-roofsheets whose 7 side vmargins have upstandlng flanges that are rigidly secured together flatwise, the side portions ofeach sheet being at lowerflevel, the distance between such levels being such that theroof will act as a tions being substantiallyequal 1n width and their aggreg; equal to the width of the middle portion.

Signed atNew Kensington,

this 23rd day of Feb, 1931.

V GHARLE S 'DAVID BONSALL. s

the side panels i V their-side edgesby upstandlng' seams, eachsheet having its-lon 3 i i gitudinal middle portion at one level and its 1 higher level, the distance roof sheets whose flanges whereby they one level and beam and said side porr te width being a substantially- Pennsylvania,

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