Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02334562 2001-02-08
A SMOOTH, NAILABLE FLOOR FOR A RAILROAD CAR
BACKGROUND OF THE INVENTION
Nailable metal steel floors have been used in railroad cars for many years.
These floors
utilize relatively narrow rectangular panels that extend side to side across
the width of a
railroad car with the longitudinal ends of the panels resting on and fastened
to the side sills of
the railroad cars. The longitudinal edges of the adjacent panels of such a
nailable floor are
deformed with nesting projections and recesses which interflt to form a
tortuous channel
between panels to bend and hold nails that are driven through wood chucks and
blocks to
secure cargo against movement during transit. A typical nailable steel floor
is shown in U.S.
Patent No. 2,783,718.
The seams formed between the longitudinal edges of the adjacent narrow floor
panels of
a nailable steel floor into which :nails are driven result in irregular
projections which interfere
with the sliding of palletized loads across the floor especially when the
palletized loads are
pushed by forklift trucks.
SUMMARY OF THE INVENTION
This invention is directed. to a smooth, nailable metal floor for a railroad
car which
provides the ability to secure loads against undesired movement while also
providing a smooth
surface which allows lift vehicles to travel across the floor without
excessive flexing of the
floor and to slide heavy loads across the surface of the car floor without
hangups due to
projecting ridges and ragged edges at the joints between the floor panels
which constitute the
floor.
An object of this invention is a railroad car floor formed of panels which are
prefabricated and installed in a railroad car to provide a smooth strong floor
with nailable joints
which panels are lightweight to facilitate final assembly of the floor.
Another object of this invention is a railroad car floor panel which is both
strengthened
and lightened by a continuous corrugated reinforcing member that is resistant
welded to the
metal top plate of the panel.
Yet another object of the invention is a railroad car floor panel having a
continuous
corrugated reinforcing member with channels and flanges in which the pattern
and number of
resistant welds which connect the flanges to the top plate of the floor are
arranged to provide
maximum strength while using material of minimum thickness and tensile
strength.
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BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a partial top plan view of the smooth, nailable floor for a railroad
car
embodying the novel features of this invention with a portion of the top floor
surface broken
away and with structural features hidden under the floor surface only
selectively shown for
clarity of illustration;
Fig. 2 is a vertically exaggerated view taken along line 2-2 of Fig. 1;
Fig. 3 is an enlarged top plan view of a typical panel comprising the smooth,
nailable
floor of Fig. l;
Fig. 4 is an enlarged, partial cross section view taken along line 4-4 of Fig.
3 showing
a spot resistant weld connecting the top floor plate to the corrugated metal
reinforcing member;
Fig. 5 is a partial, orthographic view of side by side floor panels showing
the smooth,
nailable floor joint of the invention;
Fig. 6 is an enlarged, partial cross sectional view taken along line 6-6 of
Fig. 1 showing
one embodiment of a bolster top cover plate;
Fig. 7 is an enlarged, partial cross sectional view taken along line 7-7 of
Fig. l;
Fig. 8 is a partial view taken along line 8-8 of Fig. l;
Fig. 9 a partial, cross sectional view taken line 9-9 of Fig. 1 and showing a
smooth,
nailable joint between floor panels;
Fig. 10 is a partial, cross sectional view similar to the view of Fig. 9 and
showing a nail
driven into a smooth, nailable joint between floor panels; and
Fig. 11 is an enlarged, partial cross sectional view similar to the view of
Fig. 6 and
showing another embodiment of a bolster top cover plate.
Description of the Preferred Embodiment
Fig. 1 is a partial, top plan view of a railroad car floor 11 embodying the
novel aspects
of this invention. As is typical, the floor 11 is formed of panels which are
supported on the
side sills 13 (Fig. 8), end sills 15 (Fig. 7) and longitudinally extending
stringers 17 (Fig. 8) of
a conventional railroad car frame. For clarity of illustration, only the
portions of the frame
which are necessary for an understanding of the invention are depicted in the
drawings.
Three different types of floor panels are installed in the railroad car floor
11 of this
invention. They include a bolster top cover plate panel 21, a smooth, nailable
panel 23 and a
wheel bay panel 25. The bolster top cover plate panel 21, shown in location in
Fig. 1 and in
detail in two embodiments in Fig. 6 and 11, is provided to span the bolster of
the railroad car
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truck. While a conventional panel, it has been modified to include some of the
novel aspects
of this invention to permit its incorporation in the smooth, nailable floor of
this invention. The
bolster top cover panel 21 which is shown in one embodiment in Fig. 6 includes
a heavy metal
base plate 31 to which cross supports 33 are attached to the underside of the
plate 31. Three
narrow floor panel sections 34, each eight inches wide, are mounted on the
plate 31. A U-
shaped channel 35 is welded to the under side of the top plate 37 of each
panel. Each top plate
37 is formed with downturned edges 39 which interfit with similar edges of
other panel
sections 34 to form a nailable groove as shown in U.S. Patent No. 2,783,718,
which is
incorporated herein by reference. One edge 39 is formed with a concave portion
41 while the
opposite edge of the panel is foamed with a convex portion 43. The concave
edge of a panel
section 34 interfits with a convex edge of an adjacent panel section 34 to
form a nailable joint
45. The downwardly turned edges 39 also include reversely bent inwardly
directed flanges 47
which in this construction rest on the upper surface of the metal base plate
31. The provision
of the downturned edges 39 on the top plate 37 of the bolster cover top plate
21 provides
nailable joints 45 which enable it to be incorporated into the smooth,
nailable floor of the
invention. The panel sections 34 are placed, one at a time, on the heavy metal
base plate 31
when the plate is positioned as shown in Fig. 6. Customarily, a panel section
34 is placed on
the plate 31 at the left as viewed in Fig. 6 where its downwardly turned edge
39 is adjacent the
downwardly turned edge 39 of tithe panel 23. The panel 34 is welded at its top
plate 37 to the
top plate of the floor panel 23 at four spaced locations along the length of
the joint 45. The
downturned edge 39 on the opposite side of the panel 34 is welded to the plate
31. The second
of the panels 34 is positioned on the plate 31 and is welded in place in the
same manner. The
third and final panel is placed in position between the second panel 34 and
the floor panel 23 on
the right as viewed in Fig. 6. The third panel 34 is welded to the adjacent
panel 34 and the
floor panel 23 only at its top plate 37 because its downturned edges are not
accessible. The
aforementioned welds are not shown in the drawings for clarity of
illustration.
Another embodiment of a bolster top cover plate panel is shown in Fig. 11 of
the
drawings in which the top cover plate panel 121 includes a single floor panel
section 123 which
is as wide as the three panel sections 34 of the embodiment of Fig. 6 or
twenty four inches
wide so that this embodiment and the embodiment of Fig. 6 are interchangeable.
The floor panel section :L23 includes four inverted U-shaped channels 125
which are
first welded to the metal base plate 31. A slotted top plate 127 is welded to
the bases 129 of
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the inverted channels by fusion welds 129 applied through the slots in the top
plate 127. The
top plate 127 is formed with downturned edges 39 at its sides with one edge
formed with a
concave portion 41 and the other with a convex portion 43 to form nailable
joints 45 as
described for the embodiment oi' Fig. 6.
The smooth, nailable floor panel 23 shown in detail in Figs. 3, 4, 5, 7, 8, 9
and 10 and
the floor panel 123 shown in Fig. 1 I of the drawings are each rectangular in
shape with their
longer dimension as shown in Fig. 3 for panel 23 extending across the width of
a railroad car.
For purposes of description, the longer sides of a panels 23 and 123 will be
referred to as the
longitudinal sides 51 and the shorter sides of the panels will be referenced
as the transverse
sides 53. The panels will be installed in a railroad car with their sides
having opposite
alignment to the longitudinal and transverse dimensions of the railroad car.
The panel 23 includes a top plate 55 having downturned edges 39 along its
longitudinal
sides 51 as shown in Fig. 9 of the drawings. These downturned edges interfit
with similar
edges of other panels to form a nailable groove as shown in U.S. Patent No.
2,783,718. One
edge 39 is formed with a concave portion 41 while the opposite downturned edge
of the panel
is formed with a convex portion 43. The concave edge of a panel interfits with
a convex edge
of an adjacent panel to form a nailable joint 45. The downward turned edges 39
also include
reversely bent inwardly directed flanges 47 which are welded to the
undersurface of the top
plate 55.
Reinforcing for the top prate 55 of the panel 23 is provided by a corrugated
metal
member 65 formed with continuous and integral channels 67 and flanges 69 which
extend from
one transverse side 53 of the panel to the other transverse side of the panel
as shown in Figs. 3,
5 and 7. The flanges 69 which connect the channels are welded to the top plate
55 by a row of
spot resistant welds 71 as shown in Figs. 3, 4 and 5 of the drawings. By spot
resistant welds,
it is meant welding by using the application of mechanical forces to forge the
heated parts
together. The use of spot resistant welds 71 eliminates the introduction of
extraneous
materials, such as fluxes, filler rods, etc. into the metallography of the
weld. It utilizes the
application of mechanical forces to forge the heated parts together thereby
reducing the heat
input compared to fusion welding. The heat is also generated rapidly so that a
minimum
amount of heat will be dissipated to cooler adjacent metal. The use of
resistant spot welding
with its lower generation of heat and less dissipation of heat results in less
distortion. It is
particularly advantageous in fastening the top plate 55 to the flanges 69 of
the corrugated
CA 02334562 2001-02-08
member 65 because. as shown most clearly in Fig. 4 of the drawings, it
provides a smooth
surface 72 for the top plate 55 ~rith the indentation 73 formed by the welding
tool to be located
on the underside of the assembly. Narrower flanges 75 are provided at the
longitudinal sides
of the panel 23 and these flange~~ are resistant welded to the top plate 55
each by a single row
5 of resistant welds 71. The panels installed at the front and rear ends of
the railroad car (the
longitudinal ends of the car) have one of the downturned edges 57 omitted with
the top plate 55
extended, as shown in Fig. 7 to rest on a spacer plate 81 which is supported
on an end sill 15
of the railroad car underframe.
At the sides of the railroad car as shown in Fig. 8, the ends of the channels
67 of the
corrugated metal member 65 are supported on car side sills 13 with the
channels 67 extending
to the edges of the top plate 55. The open ends of channels of the corrugated
member 65 are
closed by end plates 85 which are welded to the open ends of the channels and
flanges as
shown in Figs. 5 and 8. The end plates 85 are flush with the top surface of
top plate 55 and
terminate short of engaging the car sill 13. The car builder may install a
plate (not shown) to
close the gap between the floor -panel 23 and the side wall 95 of the railroad
car.
The wheel bay panels 25 are shown in detail and most clearly in Fig. 6 of the
drawings
where they are shown located on opposite sides of the bolster plate cover
plate 21. Their
construction is similar to that of the smooth, nailable panel 25 but the wheel
bay panels also
include a bottom plate 100 welded to the bottoms of the channels 67 of the
corrugated
reinforcing 65. The wheel bay ;panels eliminate the need for a wheel bay cover
which was
previously used in railroad car construction and also continues the smooth,
nailable floor
provided by the panels 23 and bolster top cover plate 21 and 121 because each
of these floor
components have downturned edges which form nailable joints 45.
The smoothness of the nailable joints 45 is improved by filling the joints
with an
elastomer compound 101 as shown in Figs. 5, 9 and 10 to a level flush with the
upper surface
of the top plate 55. Nails 103 can be driven into and removed from the
elastomer compound.
The elastomer compound supports forklift tires without excessive flexing. The
elastomer
compound can be readily replaced to maintain the smoothness of the car floor.
Unexpected strength of the smooth, nailable floor panel 23 and ease of
manufacture,
and therefore reduced cost, has been obtained in the smooth floor panel of
this invention for the
following reasons. The top plates 37 and 55 may be formed of 10 gauge steel
having a 50,000
or 60,000 lb. tensile yield stren~;th. The steel is available in coils of
sufficient width to be
CA 02334562 2001-02-08
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formed into a top plate with downturned edges and inwardly turned flanges. The
corrugated
reinforcing member 65 is also formed of the same steel in nine gauge . The
attachment of the
top plate 55 to the corrugated reinforcing member is accomplished by spot
resistance welding.
Spot resistance welding creates less heat, thereby minimizing distortion, and
permits faster
welding speeds. It also provides a smooth upper surface for the top plate 55
that does not
require grinding.
It has been found through experiment and testing that there is an advantageous
sizing of
the channels 67 and flanges 69 of the reinforcing member 65 and the spacing
and location of
spot resistant welds 71 which provides maximum strength at minimum cost. The
channels 67
should be formed with a width n.ot greater than 1 17/32 inches and the flanges
69 should be
formed with a width not exceeding 1 3/4 inches. The selection of this width
for the flanges
permits the use of a single row of spot resistant welds. The spacing of the
spot resistant welds
along with length of the flanges may be varied, but will be approximately 6
inches.
