U.S. patent application number 09/760227 was filed with the patent office on 2001-08-30 for vehicle running board construction.
Invention is credited to Bernard, Edward Helmut.
Application Number | 20010017452 09/760227 |
Document ID | / |
Family ID | 23171307 |
Filed Date | 2001-08-30 |
United States Patent
Application |
20010017452 |
Kind Code |
A1 |
Bernard, Edward Helmut |
August 30, 2001 |
Vehicle running board construction
Abstract
An improved vehicle running board construction and method of
making same comprising a hollow metal support pipe with an
elongated mid-section step portion adapted in vehicle-mounted
orientation to extend generally parallel to and adjacent a sill of
a vehicle door that provides access to a passenger or freight
compartment of the vehicle. An elongate mounting opening is formed
in an upwardly facing exterior surface area of the pipe
mid-section. A support plate has a plurality of transverse trusses
arranged in spaced apart relation in a longitudinally extending row
and straddling the opening side edges and resting thereon for
support. A plurality of spacer webs are individually interposed
between and joined to longitudinally adjacent pairs of the trusses
and support at each of their longitudinally opposite ends, a
resilient spring finger catch oriented to underlie an associated
one of the pipe opening side edges. Each finger catch has a free
end resiliently engaging an interior surface of the pipe for
holding said step plate against upward release from the pipe. A
step plate is mounted on and covers the support plate as well as
the mounting opening of the pipe. The step plate has a generally
flat planar central step tread portion with an undersurface bearing
upon the support plate trusses. The step plate also has downwardly
extending side flanges respectively extending outwardly of and
downwardly past the pipe opening side edges and terminating at free
end edges that preferably resiliently engage the exterior surface
of the pipe. A plurality of retaining barbs extend downwardly from
the step plate undersurface into snap lock tang engagement with
associated receiving slot anchor tabs provided in the trusses for
holding the step plate on the support plate, and vice versa.
Inventors: |
Bernard, Edward Helmut;
(Tecumseh, CA) |
Correspondence
Address: |
William J. Waugaman
Reising, Ethington, Barnes, Kisselle,
Learman & McCulloch, PC
P.O. Box 4390
Troy
MI
48099-4390
US
|
Family ID: |
23171307 |
Appl. No.: |
09/760227 |
Filed: |
January 12, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09760227 |
Jan 12, 2001 |
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09303274 |
Apr 30, 1999 |
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6173979 |
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Current U.S.
Class: |
280/163 ;
280/169; 296/75 |
Current CPC
Class: |
B60R 3/002 20130101 |
Class at
Publication: |
280/163 ;
280/169; 296/75 |
International
Class: |
B60R 003/00 |
Claims
1. A vehicle running board construction comprising in combination a
hollow support step pipe adapted to be secured to a vehicle
exterior at first and second longitudinally opposite ends of said
pipe, said pipe having an elongated mid-section step portion
adapted in vehicle-mounted orientation to extend generally parallel
to and adjacent a sill of a vehicle door that provides access to a
passenger or freight compartment of the vehicle, said pipe
mid-section having an elongate mounting opening formed in an
upwardly facing exterior surface area thereof and defined by first
and second laterally opposite and longitudinally extending opening
side edges both lying in a plane chordally intersecting an upper
radial cross sectional segment of said pipe, said opening being
defined at opposite longitudinal ends thereof by first and second
end edges each extending from said opening side edges to a junction
with an uppermost apex area of said upwardly facing exterior
surface area of said pipe, a support plate having a plurality of
truss means straddling said opening side edges and resting thereon
for support, a plurality of spacer web means individually
interposed between and joined to longitudinally adjacent pairs of
said truss means, each of said web means having at each
longitudinally opposite end thereof a resilient spring finger catch
underlying an associated one of said pipe opening side edges and
having a free end resiliently engaging an interior surface of said
pipe for holding said step plate against upward release from said
pipe, and a step plate mounted on and covering said support plate
and said mounting opening of said pipe, said step plate having a
generally flat planar central step tread portion having an
undersurface bearing upon said support plate truss means, said step
plate also having first and second downwardly extending side
flanges respectively extending outwardly of and downwardly past
said first and second pipe opening side edges and each terminating
at a free end edge resiliently engaging the exterior surface of
said pipe, and fastening means securing said step plate onto said
support plate.
2. The combination of claim 1 wherein said fastening means
comprises a plurality of retaining barbs extending downwardly from
said step plate undersurface into snap lock tang engagement with
associated receiving slot anchor tabs provided in said truss means
for holding said step plate on said support plate.
3. The combination of claim 1 wherein each of said support plate
truss means has a planar top wall extending lengthwise
perpendicular to the longitudinal dimension of said pipe, said
truss means top walls being co-planar with one another, and wherein
each of said truss means has a pair of sidewalls, one dependent
from the leading and one from the trailing edges of said truss
means top wall, and wherein each said web means comprises a planar
member extending in a plane parallel to said truss means top walls
and spaced therebelow, the opposite forward and trailing edges of
each said web wall being joined to the lower edges of the mutually
adjacent sidewalls of a mutually longitudinally adjacent pair of
said truss means.
4. The combination set forth in claim 3 wherein each said spring
finger catch comprises a V-shaped member lying in a plane
perpendicular to the longitudinal axis of said pipe and having a
first leg integrally joined at its upper end to the end edge of an
associated one of said web walls, said first leg extending
downwardly to a vertex of said V of said spring leg catch, said
V-shaped spring finger catch having a second leg extending from a
junction at said vertex with said first leg upwardly and outwardly
at an acute angle to said first leg and terminating in a free end
edge defining said free end of said spring finger catch.
5. The combination set forth in claim 4 wherein said support plate
plurality of truss means, said support plate spacer web means and
said resilient spring finger catches are all integrally joined
together by being molded with said support plate as a one-piece
part.
6. The combination set forth in claim 5 wherein said support plate
is injection molded from plastic material comprising a high
strength, high melting point polycarbonate.
7. The combination set forth in claim 6 wherein said step plate
side flanges and said step plate retaining barbs are all integrally
joined together by being molded with said step plate as a one-piece
part.
8. The combination set forth in claim 7 wherein said step plate is
formed by being injection molded from plastic material comprising a
high strength, high melting point thermoplast polyosalene
material..
9. The combination set forth in claim 1 wherein said first and
second end edges of said opening in said support pipe are
respectively defined by cut planes inclined at a shallow angle
upwardly relative to the longitudinal axis of said pipe and extend
in oppositely divergent directions at the respectively axially
opposite ends of said opening, and wherein said step plate has
bullet-nose shaped end platforms at each of the axially opposite
longitudinal ends thereof inclined to conform to the cut plane of
the end edges of said pipe opening and covering the same in
assembly.
10. The combination set forth in claim 9 wherein said step plate is
formed with a longitudinally extending and laterally alternating
row of grooves and ridges to form a tread pattern thereon.
11. The combination set forth in claim 9 wherein said side flanges
of said step plate comprise a portion of and are integrally joined
to a single flange of said plate encircling the entire periphery
thereof and resiliently sealably engaging the exterior surface of
said pipe in surrounding relation to the entirety of said edges of
said pipe opening.
12. The combination set forth in claim 3 wherein said support plate
has leading and trailing tab portions having snap-tang engagement
with the underside of said step plate and being disposed in
assembly below the apex of said end edges of the associated end of
said pipe opening, said step plate having first and second stop
abutments protruding from the underside thereof adapted to
abuttingly engage the apex of the adjacent said first and second
end edges of said opening to limit movement of the sub-assembly of
said step plate and said support pipe longitudinally relative to
said pipe.
13. The combination set forth in claim 4 wherein each of said
spring finger catches has a protrusion extending downwardly from
said vertex and oriented to provide an extension thereof to thereby
assist lead-in entry assembly of said support plate into and past
the side edges of said pipe opening during assembly thereinto.
14. The combination set forth in claim 13 wherein said support
plate has fore and aft stiffening ribs integrally joined thereto
and protruding downwardly from the underside thereof and extending
upwardly to a flush relationship with the upper surface of said top
walls of said truss means, each said rib extending with its major
plane parallel to the axis of said pipe and perpendicular to the
plane of said top walls of said support pipe, each said rib also
extending beneath an associated one of said end tabs and toward the
longitudinal center of said step plate so as to span at least two
of said truss means.
15. A method of constructing a vehicle running board construction
comprising the steps of: (1) providing a hollow support step pipe
adapted to be secured to a vehicle exterior at first and second
longitudinally opposite ends of said pipe, said pipe having an
elongated mid-section step portion adapted in vehicle-mounted
orientation to extend generally parallel to and adjacent a sill of
a vehicle door that provides access to a passenger or freight
compartment of the vehicle, (2) forming in said pipe mid-section an
elongate mounting opening in an upwardly facing exterior surface
area thereof and defined by first and second laterally opposite and
longitudinally extending opening side edges both lying in a plane
chordally intersecting an upper radial cross sectional segment of
said pipe, said opening being defined at opposite longitudinal ends
thereof by first and second end edges each extending from said
opening side edges to a junction with an uppermost apex area of
said upwardly facing exterior surface area of said pipe, (3)
providing a support plate having a plurality of truss means
dimensioned for straddling said opening side edges and resting
thereon for support, and also having a plurality of spacer web
means individually interposed between and joined to longitudinally
adjacent pairs of said truss means, each of said web means having
at each longitudinally opposite end thereof a resilient spring
finger catch adapted for underlying an associated one of said pipe
opening side edges when in assembly therewith and having a free end
adapted for resiliently engaging an interior surface of said pipe
for holding said step plate against upward release from said pipe
when in assembly therewith, (4) providing a step plate adapted to
be mounted on and cover said support plate and said mounting
opening of said pipe when in assembly therewith, said step plate
having a generally flat planar central step tread portion having an
undersurface adapted to bear upon said support plate truss means
when in assembly therewith, said step plate also having first and
second downwardly extending side flanges adapted to respectively
extend outwardly of and downwardly past said first and second pipe
opening side edges when in assembly therewith, and each said side
flange terminating at a free end edge adapted to resiliently engage
the exterior surface of said pipe when in assembly therewith, (5)
providing fastening means for securing said step plate onto said
support plate, comprising a plurality of retaining barbs extending
downwardly from said step plate undersurface adapted for snap lock
tang engagement with associated receiving slot anchor tabs provided
in said truss means for holding said step plate sub-assembly on
said support plate, (6) forming a sub-assembly of said plates by
assembling said step plate onto said support plate by relatively
moving said plates bodily toward one another while maintaining
their respective longitudinal axes generally parallel until said
retaining barbs have fully snap lock engaged said truss means
anchor tabs, and (7) forming an assembly of said support pipe with
said sub-assembly by relatively moving said sub-assembly and said
pipe bodily toward one another with the leading and trailing ends
of said sub-assembly and said pipe opening aligned and while
maintaining their respective longitudinal axes generally parallel
until said free ends of said second legs of said spring catches
have been slid past said first and second pipe opening edges and
into the interior of said pipe and said step plate side flanges
resiliently engage the exterior surface of said pipe.
Description
FIELD OF THE INVENTION
[0001] This invention relates to automotive vehicle running board
constructions, and more particularly to heavy duty tubular or
bent-pipe type running boards or similar exterior mounted steps
currently in use on various sport utility and pick-up truck type
automotive vehicles.
BACKGROUND OF THE INVENTION
[0002] The wide spread popularity in recent years of pick-up trucks
and sport utility vehicles for both on-road and off-road use in
business, recreational as well as everyday travel has popularized
the "rugged" styling of such vehicles, as well as their
accessories, from both the practical as well as aesthetic
standpoint. Thus the exterior running board construction provided
for such vehicles, both as original equipment and after-market
accessory type products, has seen the advent of a simple large
tubular support, typically in the form of a two or three inch
diameter steel pipe bent-formed at its opposite axial ends for
connection to the undercarriage of the vehicle. A straight run
central portion of the pipe is typically positioned outboard of and
below the door sill of the cab of the pick-up truck or the front
and/or rear doors of a sport utility vehicle (SUV). Such pipe
running boards provide both the rugged strength and structural
support required for such use, and are also resistant to damage
from traveling through underbrush as well as from various other
types of misuse encountered in the typical service life of such
vehicles. Also, since the pipe is spaced outboard of the vehicle
body metal it is easy to clean off, as by a hose-down, mud clinging
to the surface of the pipe and to the step carried by the pipe.
[0003] Although the use of a simple pipe in and of itself has been
proposed and marketed with some success, safety considerations
require that a step plate of some type be mounted on top of the
pipe and provided with a ribbed, corrugated or other contoured
gripping pattern on its upper face. This insures safe and secure
footing by users of the running board both during entry and
departure from the vehicle passenger space, as well as when riding
in a standing position on the running board. Hitherto, such a pipe
and step plate running board construction has been provided by
mounting a step plate, made as a plastic extrusion, onto the
opposed edges of an upper cut-off section of a metal support pipe.
The step plate was supported along its longitudinal center line by
support a support beam in the form of a piece of untreated pine
wood board inserted into the metal pipe. The board rested along its
bottom longitudinal edge on the bottom interior of the pipe and was
dimensioned so that its upper longitudinal edge abutted the
underside of the plastic extrusion step plate. However, this
arrangement tended to become loose and disassembled from use and
abuse under normal wear and tear conditions, as well as from
swelling of the wood support from water collecting in the pipe.
Thus, this prior commercial construction did not provide a fully
secure mounting of the step plate on the pipe and hence could be
pried off during running through heavy brush or similar extreme but
not unusual conditions encountered during the off-road use of such
vehicles. Accordingly, it has been previously proposed (but not
produced or reduced to practice) to provide a step plate/pipe
running board construction in which the wood interior brace is
replaced by an injection molded plastic member spanning the length
and width of the interior of the pipe beneath the slotted portion
of the pipe to serve as an insert support structure for a
separately manufactured step plate to be mounted thereon. However,
this proposed design presented problems as to its mounting assembly
into a straight pipe section in order to capture the support member
within the pipe, and involved an expensive and impractical
procedure for assembly. Hence, this design was abandoned as being
not satisfactory at least from the standpoint of secure mounting,
ruggedness and/or economy of manufacture and assembly.
OBJECTS OF THE INVENTION
[0004] Accordingly, among the objects of the present invention are
to provide an improved running board construction for installation
and use on automotive vehicles such as pick-up trucks, SUVs and
similar type vehicles wherein the aforementioned tubular pipe-type
running board is employed in combination with an improved support
plate member and an improved step plate member, and wherein the
latter two members may be molded each as a one-piece member from
plastic materials, wherein the step plate may be mounted to the
support plate as a sub-assembly without use of separate fastening
members and yet securely and reliably thereafter retained as a
unitary sub-assembly, and wherein the step plate/support plate
sub-assembly may be easily and securely mounted on the support pipe
in a rapid and reliable manner, again without the use of separate
fastening members.
[0005] Another object is to provide an improved running board
construction of the aforementioned character that, once mounted on
the running board pipe, provides a rugged and secure mount thereto
that is able to withstand abuse, damage and resist pry-off removal
from striking under brush and other similar forces, that is easily
cleaned, that is mass producible by conventional injection molding
processes and can be made in recyclable materials that are weather
and moisture resistant and able to withstand the extremes of
outdoor temperature conditions from dessert to arctic temperatures,
that provides a safe, rattle-free, and squeak-proof standing
platform mounted on the tubular pipe support and that has a long
and useful service life, that is easily repairable and that is
economical in construction and reliable in operation.
SUMMARY OF THE INVENTION
[0006] In general, by way of summary description and not by way of
limitation, the invention accomplishes the foregoing and other
objects by providing an improved vehicle running board construction
comprising the aforementioned hollow metal support pipe adapted to
be secured to a vehicle exterior at first and second longitudinally
opposite ends of the pipe. The elongated mid-section step portion
of the pipe is adapted in vehicle-mounted orientation to extend
generally parallel to and adjacent a sill of a vehicle door that
provides access to a passenger or freight compartment of the
vehicle. An elongate mounting opening is formed in an upwardly
facing exterior surface area of the pipe mid-section as defined by
first and second laterally opposite and longitudinally extending
opening side edges both lying in a plane chordally intersecting an
upper radial cross sectional segment of the pipe. This opening is
defined at opposite longitudinal ends thereof by first and second
divergently inclined end edges each extending from the opening side
edges to a junction with an uppermost apex area of the upwardly
facing exterior surface area of said pipe.
[0007] The running board construction also includes a support plate
having a plurality of transverse trusses arranged in spaced apart
relation in a longitudinally extending row and straddling said
opening side edges and resting thereon for support.
[0008] The support plate also has a plurality of spacer webs
individually interposed between and joined to longitudinally
adjacent pairs of the trusses. Each of these webs has, at each of
the longitudinally opposite ends thereof, a resilient spring finger
catch oriented to underlie an associated one of the pipe opening
side edges. Each finger catch has a free end resiliently engaging
an interior surface of the pipe for holding said step plate against
upward release from the pipe.
[0009] The running board construction further includes a step plate
mounted on and covering the support plate as well as the mounting
opening of the pipe. The step plate has a generally flat planar
central step tread portion with an undersurface bearing upon the
support plate trusses. The step plate also has first and second
downwardly extending side flanges respectively extending outwardly
of and downwardly past the first and second pipe opening side
edges. These flanges each terminate at a free end edge that
preferably resiliently engages the exterior surface of the pipe. A
plurality of retaining barbs extend downwardly from the step plate
undersurface into snap lock tang engagement with associated
receiving slot anchor tabs provided in the trusses for holding the
step plate on the support plate, and vice versa.
[0010] Preferably each support plate truss has a planar top wall
extending lengthwise perpendicular to the longitudinal dimension of
the pipe, the truss top walls being co-planar with one another.
Each of the trusses has a pair of sidewalls, one dependent from the
leading and one from the trailing edges of each truss top wall. The
spacer webs preferably each comprise a planar member extending in a
plane parallel to the truss top walls and spaced therebelow. The
opposite forward and trailing edges of each web wall are joined to
the lower edges of the mutually adjacent truss sidewalls of a
mutually longitudinally adjacent pair of the trusses.
[0011] Preferably each spring finger catch comprises a V-shaped
member lying in a plane perpendicular to the longitudinal axis of
the pipe. Each catch has a first leg that is integrally joined at
its upper end to the end edge of an associated one of the spacer
web walls and extends downwardly to a vertex of the V of the spring
leg catch. Each catch also has a second leg extending upwardly and
outwardly at an acute angle to the first leg from a junction at
such vertex with the first leg, and terminates in a free end edge
that forms the free end of the spring finger catch.
[0012] Preferably the support plate trusses, spacer webs and
resilient spring finger catches are all integrally joined together
by being injection molded with the support plate as a one-piece
part, preferably from recyclable high strength thermoplastic
material such as a polycarbonate.
[0013] Likewise, preferably the step plate side flanges and step
plate retaining barbs are all integrally joined together by being
injection molded with the step plate as a one-piece part, again
perferably from a high strength recyclable plastic material such as
thermoplast polyosalene containing some synthetic rubber
material.
[0014] The invention also includes a method of constructing the
vehicle running board construction that includes the steps of
forming a sub-assembly of the plates by assembling the step plate
onto the support plate by relatively moving said plates bodily
toward one another while maintaining their respective longitudinal
axes generally parallel until the retaining barbs have fully snap
lock engaged the truss anchor tabs. Then an assembly of the support
pipe with the sub-assembly is formed by relatively moving the
sub-assembly and pipe bodily toward one another with the leading
and trailing ends of the sub-assembly and pipe opening aligned and
while maintaining their respective longitudinal axes generally
parallel until the free ends of the catch second legs have been
slid past the pipe opening edges and into the interior of the pipe
and the step plate side flanges resiliently engage the exterior
surface of the pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The foregoing as well as other objects, features and
advantages of the present invention will become apparent from the
following detailed description of the best mode presently known to
the inventor of making and using the invention, from the appended
claims, and from the accompanying drawings (which are to
engineering scale unless otherwise indicated) wherein:
[0016] FIG. 1 is a perspective view of a current model pick-up
truck illustrating one preferred embodiment of a running board
construction of the invention mounted to the underside of the
vehicle and extending outboard of and adjacent the sill edge of the
driver-side door of the truck cab.
[0017] FIG. 2 is a fragmentary perspective view illustrating the
mid-section straight-length portion of the support pipe of the
running board construction of the invention embodiment of FIG. 1
with a step plate/support plate sub-assembly mounted thereon.
[0018] FIG. 3 is an exploded perspective view of the components
shown in FIG. 2 illustrating the step plate disposed above the
underlying support plate which in turn is shown disposed above the
elongated mounting opening provided in the upper surface of the
pipe mid-section.
[0019] FIG. 4 is a fragmentary top plan view of the step plate of
the assembly of FIGS. 1, 2 and 3.
[0020] FIG. 5 is a fragmentary side elevational view of the step
plate of FIG. 4.
[0021] FIG. 6 is a fragmentary bottom plan view of the step plate
of FIGS. 4 and 5.
[0022] FIG. 7 is an end elevational view of the trailing end of the
step plate, i.e., the right hand end as viewed in FIG. 5.
[0023] FIGS. 8 and 9 are cross-sectional views taken respectively
on the lines 8-8 and 9-9 of FIG. 4.
[0024] FIG. 10 is a fragmentary top plan view of the support plate
component shown by itself.
[0025] FIG. 11 is a fragmentary side elevational view of the
support plate of FIG. 10 shown by itself.
[0026] FIG. 12 is an end elevational view of the trailing end of
the support plate, i.e., the right hand end as viewed in FIGS. 10
and 11.
[0027] FIG. 13 is a fragmentary bottom plan view of the support
plate of FIGS. 10-12.
[0028] FIGS. 14 and 15 are cross-sectional views taken respectively
on the lines 14-14 and 15-15 of FIG. 11.
[0029] FIG. 16 is a fragmentary side elevational view of a portion
of the mid-section of the support pipe of the running board
construction shown in FIGS. 1-3, but shown by itself.
[0030] FIG. 17 is a fragmentary top plan view taken on the line
17-17 of FIG. 16.
[0031] FIG. 18 is a cross-sectional view taken on the line 18-18 of
FIG. 16, and
[0032] FIG. 19 is a cross-sectional view taken on the line 19-19 of
the exploded view of FIG. 3 but showing the parts non-exploded in
assembled relation as in FIG. 2.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0033] Referring generally to FIG. 1, a current model pick-up truck
20 is shown with a preferred but exemplary embodiment of a
pipe-type running board construction 22 of the invention mounted to
the underframe of the vehicle and positioned for use as a running
board for the driver-side door 24 of the truck cab 26. The running
board construction 22 comprises a hollow support pipe 28 having
bent-formed opposite longitudinal ends 30 and 32 respectively that
extend beneath the vehicle and are mounted in a conventional manner
to the vehicle frame. Pipe 28 has a generally straight mid-section
portion 34 extending between ends 30 and 32 that supports a step
plate/support plate sub-assembly 36 provided in accordance with the
invention.
[0034] As best seen in FIG. 3, the step plate/support plate
sub-assembly 36 is made up of two one-piece molded plastic
components, namely a step plate 38 that is snap-tang-lock mounted
on a support plate 40 that in turn is snap-spring-finger-catch
installed in an elongated mounting opening 42 (FIGS. 3 and 16-18)
provided in the upwardly facing approximately 90.degree.
circumferential surface area of pipe mid-section 34.
[0035] Support pipe 28, by way of preferred example, may be a
hollow stainless steel pipe section having an outside diameter of
about three inches and a wall thickness of one sixteenth inch.
Alternatively, the pipe may be made of a suitably aluminum alloy
material. In a typical installation the axial or longitudinal
dimension of the mid-section 34 of pipe 28 may run from six to
sixty inches, depending upon the vehicle application. The mounting
opening 42 in pipe mid-section 34 is defined by pair of parallel,
longitudinally extending and laterally opposite side edges 44 and
46 (FIGS. 3 and 16-18) that lie in an imaginary horizontal (in-use
orientation) cut plane P (perpendicular to the plane of the drawing
in FIG. 18) disposed approximately half way between the horizontal
center line C/L of tube section 34 (FIG. 18) and the apex A of the
uppermost surface area of the complete circular section of pipe
section 34 (FIGS. 16 and 17). The opposite ends of mounting opening
42 are defined by cut planes E.sub.1 and E.sub.2 (FIG. 16) that
extend perpendicular to the plane of the drawing in FIG. 16. The
end cut planes E.sub.1 and E.sub.2 thus respectively form the
elliptical curved end edges 50 and 52 (FIGS. 3 and 17)
characteristic of the intersection of a plane intersecting a
cylinder at an acute angle to the cylinder axis.
[0036] Step plate 38 is preferably made as a one-piece injection
molded part from a suitable recyclable high strength, high melting
point thermoplastic material, such as thermoplast polyosalene, and
preferably containing some suitable synthetic rubber material.
Plate 38 has an appropriate lengthwise dimension parallel to its
longitudinal axis so that when mounted to pipe mid-section 34 the
opposite longitudinal ends 60 and 62 of plate 38 axially overlap
and cover the end edges 50 and 52 respectively of opening 42 (FIG.
2). As best seen in FIG. 19, plate 38 has an inverted U-shape in
transverse cross section as defined by a tread platform or deck
portion 64 provided with a peripherally encircling dependent side
edge flange 80. Deck 64 has a smooth undersurface 66 bearing on the
upper surface of support plate 40. Deck 64 has a suitable tread
configuration on its upper surface made up of parallel
longitudinally extending ribs 68 that alternate with grooves 70 to
provide good footing or traction to a person standing on step plate
38. Preferably the friction grip of the deck upper surface is
further enhanced by providing a conventional acid etched stipple
grain finish on this surface. The ribs 68 and grooves 70 terminate
at their opposite longitudinal ends at the bases slightly inclined
smooth forward and aft (i.e., leading and trailing) deck areas 72
and 74 that are each inclined upwardly from the major plane of
platform at a slight angle, say 10.degree., as best seen in FIG. 8.
As best seen in FIGS. 4 and 6, these inclined end deck areas 72 and
74 in plan view are generally bullet-nose shaped so that the
overall configuration of plate 38 is generally canoe-shaped in plan
view.
[0037] The downwardly dependent flange 80 integral with platform 64
and end deck portions 72 and 74 surrounds substantially the entire
outer periphery of these portions of plate 38. Flange 80 thus has
an outboard portion 82 integral with the outboard edge of platform
64, and an inboard (closest to vehicle) flange 84 integral with the
inboard edge of platform 64. As best seen in FIG. 19, the lower
free end edges 86 and 88 of flange portions 82 and 84 are
preferably designed such that, when step plate 38 is in assembly
with pipe 28 and support plate 40, these edges yieldably and
resiliently engage the outer surface of pipe section 34 at
approximately the horizontal mid-plane thereof. Thus, the molded
free-state condition of flange portions 82 and 84 has a span
distance slightly less than the chordal dimension of pipe 34 at the
engagement points of tips 86 and 88 so that the flanges 82 and 84
are resiliently cammed apart during installation and retain a tight
embracing and generally water tight fit with the outer surface of
pipe section 34.
[0038] Flange 80 in the portions 90 and 92 thereof contiguous with
the inclined end platform portions 72 and 74 respectively terminate
in a lower edge 94 and 96 (FIGS. 5, 6 and 8) that is inclined
upwardly from the junction with lower edges 86 and 88 at oppositely
inclined angles generally matching the angles of inclination of cut
planes E.sub.1 and E.sub.2 that define the end edges 50 and 52 of
opening 42.
[0039] The underside of step plate 38 is provided with a plurality
of locking tangs preferably arranged, as best seen in FIGS. 6, 7, 8
and 9, in a longitudinally extending inboard row of tangs 100, 102,
104, 106, 108, 110 and a longitudinally extending outboard row of
tangs 112, 114, 116, 118, 120 and 122 that protrude integrally
downwardly from the platform 64 of plate 38. Each locking tang
100-122, as best seen in FIGS. 7, 9 and 19, is provided with a
leading end having an inclined camming surface 124 extending
divergently back toward platform surface 66 and terminating in a
locking ledge or shoulder 126 (FIG. 19), and functions as described
in more detail hereinafter. Similar but slightly longer centrally
located forward and aft locking tangs 130 and 132 depend from the
fore and aft end platforms 72 and 74 and are likewise configured
with an inclined leading camming surface terminating in a locking
shoulder surface that is generally parallel to the undersurface 64
of plate 38.
[0040] The construction and details of support plate 40 are best
seen in FIGS. 3 and 10-15 as well as in FIG. 19. Support plate 40
is preferably made as a one-piece molded part, preferably injection
molded from a suitable recyclable plastic material such as a high
strength, high melting point polycarbonate material, and includes a
plurality of weight-load bearing truss means that in the disclosed
example total ten in number. These truss means are individually
identified by truss reference numerals 140, 142, 144, 146, 148,
150, 152, 154, 156 and 158 in FIG. 3, are arranged in a
longitudinal;y extending row and are equally longitudinally spaced
from one another. Each of these trusses 140-158 is identical in
construction and configuration and hence the forward-most or
leading truss 140 will only be described in detail. Truss 140
comprises a planar top wall 160 of rectangular configuration in
plan view (FIG. 10) and having a smooth, flat planar upper surface
162 (FIGS. 10-12 and 19), and longitudinally opposite ends 164 and
166 that are spaced apart a suitable distance so as to extend in
assembly with pipe 28 beyond pipe opening edges 44 and 46 as shown
in FIG. 19. Each truss section 140-158 also has a pair of laterally
spaced downwardly divergent sidewalls 170 and 172 (FIGS. 10, 11 and
14) that provide vertical load bearing and bending-stress-resistant
supports for top wall 160. The bottom surface of wall 160 is a
stepped configuration symmetrical about the longitudinal center
line of plate 40 (FIGS. 11, 13, 15 and 19) made up of ledge
supporting surfaces 174 and 176 that bear upon pipe opening edges
44 and 46 respectively (FIG. 19). Ledge surfaces 174 and 176 are
inwardly bounded by shoulder portions 178 and 180 that help
restrain sliding motion of plate 40 on edges 44 and 46 in a
direction perpendicular to the pipe axis. Reinforcing gussets 182
and 184 are also provided between shoulder 178 and the adjacent
side surfaces of the truss bottom wall that extend downwardly to
the plane of the major flat bottom wall surface 186 of truss
section 140 (FIGS. 13 and 19). Corresponding gussets 188 and 190
are provided at the opposite longitudinal end of truss section 140.
These gussets help brace support ledges 164/176 and 166/174 since
the truss sidewalls 170 and 172 do not underlie these ledges but
rather terminate flush with the outer edges of the major bottom
surface 186.
[0041] Each truss section 140 also has a pair of tang-receiving
through openings 192 and 194 of rectangular cross section (FIG.
10), each inboard side of which has a locking lug 196 and 198
respectively protruding into the opening and configured in vertical
cross section, as best seen in FIG. 19, to cooperate with the
associated tang 100-122 of step plate 38 to form a one-way catch
construction for holding step plate 38 on support plate 40 in
assembled relation. The undersurface of each truss is also provided
with four rectangular pockets 200, 202, 204 and 206 (FIG. 13) to
reduce weight and material in each truss section, leaving an
intervening cruciform rib pattern for increasing the
strength-to-weight ratio of the truss section. Likewise, the upper
surface 162 of each truss is provided with a pair of
weight-reducing rectangular pockets 208 and 210 adjacent each of
the tang through openings 192 and 194 respectively, and also
leaving a rib therebetween.
[0042] Each of the truss sections 140-158 that laterally span pipe
opening 42 in assembly therewith is spaced from its longitudinally
adjacent truss section(s) and integrally connected thereto by the
associated one of a plurality of web walls 220, 222, 224, 226, 228,
230, 232, 234 and 236 (FIG. 3). Each of these web walls 220-236 is
integrally joined along its side edges to the bottom of the
flanking sidewalls 170 and 172 of the mutually adjacent pair of
truss sections 140-158. In addition to serving as a longitudinal
spacer between truss sections, each web wall 220-236 adds further
lateral stiffness and structural modulus to the support plate 40,
by imparting a corrugated overall configuration to the support
plate in vertical cross section along the longitudinal axis of the
same. In addition, each web wall 220 provides support for a pair of
V-shaped spring catches 240 and 242 integrally joined one to each
of the opposite longitudinal ends of each web wall 220-236.
[0043] The construction of spring catches 240, 242 is shown in
FIGS. 10-15 and 19. It will be seen that the inboard leg 244 of
catch 240, and the corresponding mirror image inboard leg 246 of
catch 242 (FIG. 14), is integrally joined at its upper edge to the
respective end edge of the associated web wall 220, 222, etc. so
that the catches are cantilever supported therefrom. ("Integral" as
used herein means joined together or united by being molded in one
piece). The free end edges 248 and 250 of the outboard legs 252 and
254 of catches 240 and 242 respectively (FIG. 14) are spaced apart
from one another in their free-state condition a distance slightly
greater than the span between the end edges 164 and 166 of top wall
160 of each truss section. The vertex of each spring catch 240, 242
is provided with a downwardly pointing V-shaped entrance protrusion
256, 258 respectively (FIGS. 15 and 19) to provide a "lead-in"
extension of the tapering entrance surface to facilitate downward
insertion assembly of support plate 40 into opening 42 of pipe
section 34.
[0044] Each of the opposite longitudinal ends of support plate 40
is constructed with a symmetrical mirror image configuration
providing longitudinal leading and tailing end anchoring tabs 260
and 262 extending longitudinally from longitudinally opposite end
truss portions of the support plate (FIG. 3). A top wall 264 (FIG.
10) of each of the tabs 260 and 262 extends from the free end of
the tab toward the body of plate 40 to a junction with a transverse
dependent wall 172 joined to another web wall 266, in the case of
forward tab 264, and in the case of aft or rearward tab 262, to a
sidewall 170 joined to a web wall 268 in turn joined to the
sidewall 172 of truss 158 (FIG. 10). Each of the ends tabs 260, 262
has generally, in transverse cross section, an inverted-U-shape as
defined by sidewalls 270 and 272 (FIGS. 11, 12 and 13) that
continue across associated web wall 266 and 268 to form reinforcing
struts between the associated cross walls 170 and 172 (FIG. 10).
Each end tab 260, 262 is provided with a through slot 274 and 276
respectively that respectively receive the central catch-tang 130
and 132 (dependent from step plate 38 as described previously) when
step plate 38 is assembled to support plate 40 to form the initial
step plate/support plate sub-assembly 36 (FIG. 3).
[0045] The opposite longitudinal ends of support plate 40 are
further reinforced by a pair of stiffening ribs 278 and 280 (FIGS.
10-15 and 19). The forward stiffening rib 278 extends along the
central vertical plane of support plate 40 beneath front tab 260
(FIGS. 11 and 13), and back to the forward sidewall 170 of truss
144. The upper edge of rib 270 is flush with the top surface plane
of support plate 40 throughout the length of the rib, and likewise
protrudes below the plane of the web walls beneath the support
plate 40. The rear stiffening rib 280 is constructed in like manner
and symmetrically to rib 278 and the corresponding associated
structure of the support plate 40.
[0046] Assembly Procedure
[0047] As indicated previously, step plate 38 is injection molded
as a one-piece part separately from the remaining components, and
preferably likewise as to support plate 40. Preferably, step plate
38 is constructed such that flange 80 is semi-resilient and hence
somewhat pliable. Hence when support plate 40 is inserted bodily
into step plate 38, with its then respective axes oriented
longitudinal parallel, to the outboard free end edges 248 and 250
of the spring catches of support plate 40 can be inserted past the
bottom edges 86 and 88 of the side flanges 82 and 84 while these
flanges are suitable fixture-held flexed apart to facilitate
passage of the catch-finger free ends. Preferably this is done on a
suitable assembly jig so that the locking tangs 100-122 are axially
aligned with their associated tang-receiving openings 192, 194 in
support plate 40. Also, this sub-assembly procedure is preferably
performed while step plate 38 is still at an elevated temperature
following de-molding so as to take advantage of the greater
softness and flexibility of the flanges while reaching final cure
and room temperature conditions.
[0048] As the inclined leading surface of each tang 100-122 engages
the inclined surface of the locking tabs 196 and 198 in each of the
associated openings 192 and 194, the respective locking tangs will
be cammed or wedge-forced so as to flex to thereby permit passage
of the barb of the locking tang past the locking barbs or lugs 196,
198 of the associated tang-receiving opening in the support plate.
As the bottom surface 66 of the step plate seats on the upper
surfaces 162 of the support plate, the tangs 100-122 will snap into
catch relationship with lugs 194 and 196 in a one-way
locking-tang-catch relationship. Hence, step plate 38 cannot be
pulled apart from support plate 40 merely by exerting separation
forces on these two parts, short of exerting a destructive force
capable of shearing the locking tangs and/or lugs. After assembly
of the support plate to the step plate to form the sub-assembly 36,
and release from the assembly fixtures, the side flanges 82 and 84
return to their original as-molded free-state condition.
[0049] The step plate/support plate sub-assembly 36 is assembled to
the running board pipe 28 by aligning the front and rear ends 60
and 62 of step plate 38 with the front and rear ends of pipe
opening 42 in axially overlapping relationship therewith. The
registry of the parts for vertical lateral bodily insertion of the
sub-assembly 36 into the opening 42 is done by aligning the forward
edge of an abutment tab 300 (FIGS. 6 and 8), which depends from the
undersurface of forward platform 72 forward of leading edge of tang
130, with the apex of the leading edge 50 of opening 42. Likewise,
the trailing edge of another abutment lug 302, that depends from
platform 74 of step plate 38 adjacent locking tang 132, is aligned
with the apex of the trailing edge 52 of opening 42. Then
sub-assembly 36 is loaded onto and into pipe opening 42 by moving
it bodily, preferably with its longitudinal axis oriented parallel
to that of pipe section 34, in a direction perpendicular to the
longitudinal axes of these components. This relative assembly
motion initially engages the outer surfaces of the spring legs 252
and 254 of spring catches 240 and 242 with the side edges 46 and 44
respectively of opening 42. This will laterally center the
sub-assembly with its axis aligned vertically with the axis of the
pipe section (when oriented as in FIG. 19). When such initial
contact is made, it will be seen from FIG. 19 that the lower free
end edges 86 and 88 of the side flanges 82 and 84 of the step plate
38 are spaced slightly outboard of the exterior surface of pipe
section 34, respectively being disposed radially outwardly and
overlapping the opening edges 44 and 46. Hence, as jig assembly
force is exerted on pipe section 34, opposing the assembly force
being exerted on sub-assembly 36, to move the two major components
toward one another, the spring catches 240 and 242 will flex in the
free legs 252 and 254 in the inboard legs 244 and 246 and also
about the cantilever integral junction with the associated web
wall. This permits the pipe opening edges 44 and 46 to slide along
the surfaces of the outboard legs of the spring catches until the
free ends 248, 250 thereof clear these pipe opening edges 44 and
46. The leg free ends 248, 250 then slidably engage the interior
surface of the pipe section 34.
[0050] During this assembly motion the free edges 86 and 88 of
flexible flanges 82 and 84 initially strike the exterior surface of
pipe section 34 approximately in the zone thereof aligned with the
spring catch outboard leg free ends 248 and 250 when in final
assembled relationship, as in FIG. 19. Then during the completion
of the assembly motion of the major components together to the
assembled position of these components in FIG. 19 the curvature of
the pipe section cams the free ends 86 and 88 of flanges 82 and 84
mutually apart to thereby resiliently stress the same so that they
tightly resiliently engage the pipe surface as they reach their
final assembled position shown in FIG. 19. In this condition the
fore and aft relative motion of the sub-assembly 36 relative to
pipe section 34 is limited by the abutments 300 and 302
respectively striking the associated apices of the pipe opening end
edges 50 and 52. This longitudinal range of shifting may be on the
order of say one eighth of an inch, whereas the overlap of the ends
60 and 62 of step plate 38 relative to the apices of opening end
edges 50 and 52 is a matter of say one half inch or so.
[0051] The semi-resilient nature of the spring legs 240 and 242
renders them relatively stiff springs which require significant
assembly force even though assembly is facilitated by the camming
angle provided by the V-shape of the spring catches. Retrograde or
removal motion of the sub-assembly 36 from pipe section 34 is
therefore strongly resisted by the geometry and construction of the
spring catches relative to the curvature of the pipe, and the
difference in the radial dimension of the opening edges 44 and 46
from the pipe center line relative to the similar dimension of the
free end edges of the outboard legs of the spring catches, i.e., a
substantial amount of interference for this essentially one-way
interference insertion assembly mode.
[0052] It thus will be seen in the mass production set-up for an
automotive parts manufacturer, suitable assembly jigs (not shown)
can be relatively simple and yet perform the two-step assembly
operation in rapid sequence. The one-way locking tangs integrally
dependent from the underside of step plate 38 provide a very strong
and secure one-way catch with an associated support plate 40 so
that the resultant sub-assembly 36 can be handled as such reliably
without danger of component separation in the manufacturing
process. Likewise, when sub-assembly 36 is drop-in, snap-engaged
assembled with running board pipe 28, there is again a snap-in
one-way type engagement that is readily accomplished rapidly and
reliably and yet provides a rattle-proof, squeak-free and secure
fit and spring-stressed retention of these components one with
another during adverse usage and over an extended service life in
use.
[0053] Due to the one-way locking tangs between step plate 38 and
support plate 40 on the one hand, and the one-way resilient
spring-finger engagement between support plate 40 and the running
board pipe section 34 on the other hand, fitting together in
assembly and retention thereafter of the finished assembly
components is accomplished without the use of extraneous or
separate fastening members such as screws, bolts or the like.
However, if desired, such separate fastening members, whether they
be conventional threaded fasteners, pop rivets, blind rivets, etc.
can be employed to secure step plate 38 onto support plate 40,
either in addition to or in lieu of the locking tangs 100-122 and
130 and 132.
[0054] It will be understood that the lengthwise dimension of step
plate 38 and the corresponding dimension of support plate 40 can be
varied to suit the application requirements and the length of the
straight section 34 of the running board pipe 28. It is also to be
understood that in some applications two or more pairs of locking
tangs 100-122 of the step plate 38 can be omitted from the row of
pairs of locking tabs between the opposite extremes in the row, if
desired to reduce molding and material costs. Also, for larger
length sizes of step plate 38, the support plate 40 alternatively
can be made up of two or more sections molded successively from a
single shorter length mold cavity in order to economize on mold
cost. These sections then are held in longitudinal end-to-end
abutment by their respective snap engagement with associated step
plate tangs 100-122.
[0055] It also will be apparent from the foregoing description to
those skilled in the art that the running board construction as
described hereinabove with reference to the accompanying drawings
fully and amply fulfills the aforestated objects of the invention.
The running board construction of the invention also provides many
advantages over the aforementioned prior art constructions in terms
of stronger more reliable assembly and rattle-proof and squeak-free
operation, extended service life, ease of assembly, economy of
manufacture, weatherproof durability of materials, absence of
extraneous or separate fastening members, pleasing aesthetic and
appearance qualities, and good traction and footing for boarding
and unboarding of the vehicle as well as standing on the running
board while the vehicle is standing still or traveling.
[0056] Indeed, in a test of a working prototype constructed
pursuant to the embodiment described and illustrated hereinabove
the failure mode occurred under a statically applied solitary
weight loading of about 1300-1400 psi, thereby greatly exceeding
the initial design criteria of failure at about 300 psi applied at
any given point on the step plate. The running board construction
of the invention has thus been proven to have a high
strength-to-weight ratio achieved at a very low cost.
[0057] It is also to be understood that support plate 40 can be
first molded as a separate piece and then used as an insert in a
mold cavity designed for overmolding step plate 38 onto support
plate 40 in order to make sub-assembly 36.
* * * * *