U.S. patent application number 13/907062 was filed with the patent office on 2014-12-04 for rollover protection structure.
This patent application is currently assigned to Sahil Bhardwaj. The applicant listed for this patent is Sahil BHARDWAJ, Jack R. Smith. Invention is credited to Sahil BHARDWAJ, Jack R. Smith.
Application Number | 20140353955 13/907062 |
Document ID | / |
Family ID | 51948281 |
Filed Date | 2014-12-04 |
United States Patent
Application |
20140353955 |
Kind Code |
A1 |
BHARDWAJ; Sahil ; et
al. |
December 4, 2014 |
ROLLOVER PROTECTION STRUCTURE
Abstract
The ROPS comprises a highly rigid behind-cab-frame, a
mounting-plate of which is bolted to the truck chassis. A
roof-canopy is integrated into the frame. The ROPS includes a brace
which holds the frame upright, and ensures that the roof-canopy
remains in position, protecting the cab, during rollover. The frame
is bolted into the chassis using the same bolts that hold the
cargo-box to the chassis (or longer bolts), whereby installation is
quick and easy. The installed ROPS is held fast to the chassis of
the truck with great strength and rigidity, but there is no
disruption to the structural integrity of the chassis.
Inventors: |
BHARDWAJ; Sahil; (Sudbury,
CA) ; Smith; Jack R.; (Blezard Valley, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BHARDWAJ; Sahil
Smith; Jack R. |
Sudbury
Blezard Valley |
|
CA
CA |
|
|
Assignee: |
Bhardwaj; Sahil
Sudbury
CA
Stanley Appleton Corporation
Val Caron
CA
Smith; Jack R.
Blezard Valley
CA
|
Family ID: |
51948281 |
Appl. No.: |
13/907062 |
Filed: |
May 31, 2013 |
Current U.S.
Class: |
280/756 ;
29/897 |
Current CPC
Class: |
B60R 21/13 20130101;
Y10T 29/49616 20150115 |
Class at
Publication: |
280/756 ;
29/897 |
International
Class: |
B60R 21/13 20060101
B60R021/13; B62D 65/16 20060101 B62D065/16 |
Claims
1. Procedure for mounting an external rollover protection structure
(ROPS) onto a truck, including: providing a truck having a cab, a
cargo-box behind the cab, and a chassis; the chassis being formed
with mounting-structures, to which fasteners can be attached; the
mounting-structures in the chassis are located close behind the
cab; providing a ROPS, the ROPS having an integrated-assembly
comprising a front-mounting-plate, a behind-cab-frame, and a
roof-canopy, integrated rigidly together; providing fasteners, and
engaging the fasteners with the front-mounting-plate and with the
mounting-structures in the chassis; whereby the fasteners, thus
engaged, make the front-mounting-plate fast to the
mounting-structures in the chassis.
2. Procedure as in claim 1, including: where the cargo-box has a
box-floor, having front-floor-bolt-holes; where the chassis of the
truck includes left and right chassis-girders; where the
mounting-structures in the chassis include
front-bolt-receiving-sockets which are integrated into or onto the
chassis-girders; where the front-mounting-plate is formed with
front-plate-bolt-holes; exposing the front-floor-bolt-holes and the
front-bolt-receiving-sockets; placing the integrated-assembly into
the cargo-box; so positioning the integrated-assembly that the
behind-cab-frame lies close behind the cab and the roof-canopy
overlies the roof of the cab; so positioning the
front-mounting-plate of the integrated-assembly on the box-floor
that the front-plate-bolt-holes align with the
front-floor-bolt-holes; passing front-box-bolts through the
front-plate-bolt-holes and the front-floor-bolt-holes; tightening
the front-box-bolts into the front-bolt-receiving-sockets; thereby
making the integrated-assembly fast to the chassis of the
truck.
3. Procedure as in claim 2, including: where the behind-cab-frame
of the integrated-assembly comprises left and right pillars, which
support a bridge of the behind-cab-frame; where the roof-canopy is
integrated rigidly into the behind-cab-frame, at the bridge; where
the behind-cab-frame includes brace-receivers, located on the left
and right pillars at or near the bridge; providing a brace-frame,
which includes a rear-mounting-plate; attaching the brace-frame to
the brace-receivers; making the rear-mounting-plate fast to the
chassis of the truck; whereby the brace-frame braces the
behind-cab-frame in an upright position, with the roof-canopy
overlying the cab.
4. Procedure as in claim 3, wherein: where the box-floor has
rear-floor-bolt-holes; where the mounting-structures in the chassis
include rear-bolt-receiving-sockets which are integrated into or
onto the chassis-girders; where the rear-mounting-plate is formed
with rear-plate-bolt-holes; exposing the rear-floor-bolt-holes and
the rear-bolt-receiving-sockets; so positioning the
rear-mounting-plate of the brace-frame on the box-floor that the
rear-plate-bolt-holes align with the rear-floor-bolt-holes; passing
rear-box-bolts through the rear-plate-bolt-holes and the
rear-floor-bolt-holes; tightening the rear-box-bolts into the
rear-bolt-receiving-sockets; thereby making the brace-frame fast to
the chassis of the truck.
5. Procedure as in claim 2, including exposing the
front-floor-bolt-holes and the front-bolt-receiving-sockets by:
loosening existing front-box-bolts that secure the cargo-box to the
chassis from the bolt-receiving-sockets; and removing the box-bolts
through the floor-bolt-holes.
6. Rollover protection structure (ROPS) for a vehicle, wherein: the
ROPS has the capability, as a physical structure, to be
incorporated into a vehicle, being a vehicle that has the following
characteristics: (a) the vehicle has left and right chassis-girders
having front-bolt-receiving-sockets, and a cab; (b) the vehicle
includes a cargo-box, having a box-floor of sheet metal; (c) the
cargo-box is provided with front-floor-bolt-holes in the
sheet-metal box-floor; the ROPS includes a behind-cab-frame, a
front-mounting-plate, and a roof-canopy; the roof-canopy extends
forwards from the top-end of the behind-cab-frame; the
behind-cab-frame, the front-mounting-plate, and the roof-canopy,
together form an integrated-assembly, in that the behind-cab-frame,
the front-mounting-plate, and the roof-canopy, are integrated
solidly and rigidly together in such manner as to preclude relative
movement therebetween; the front-mounting-plate is so configured
that, when the integrated-assembly is placed in the cargo-box, the
front-mounting-plate: (a) can lie flat against the box-floor; and
(b) can be so positioned that front-plate-bolt-holes in the
front-mounting-plate align with the front-floor-bolt-holes in the
box-floor; thereby enabling: (a) front-box-bolts to pass through
both the front-plate-bolt-holes and the front-floor-bolt-holes; (b)
the front-box-bolts to be tightened into the
front-bolt-receiving-sockets; and (c) securement of the
integrated-assembly to the chassis.
7. As in claim 6, wherein: the behind-cab-frame of the
integrated-assembly comprises left and right pillars, which support
a bridge of the behind-cab-frame; the roof-canopy is integrated
rigidly into the behind-cab-frame, at the bridge; the
behind-cab-frame includes brace-receivers, located on the left and
right pillars at or near the bridge; the ROPS includes a
brace-frame, which includes a rear-mounting-plate; the brace-frame
is attached to the brace-receivers; the rear-mounting-plate is fast
to the chassis; whereby the brace-frame braces the behind-cab-frame
in an upright position, with the roof-canopy overlying the cab.
8. As in claim 7, wherein: the behind-cab-frame and the roof-canopy
of the integrated-assembly are formed of steel tubes, welded
together; and the front-mounting-plate includes a flat-plate, which
is welded to the steel tubes.
9. As in claim 8, wherein: the brace-receivers comprise a stud and
socket engagement between the behind-cab-frame and the brace-frame;
the brace-receivers are located at or near the bridge of the
behind-cab-frame; the rear-mounting-plate being made fast to the
chassis, the brace-frame has the capability, as a physical
structure to brace the behind-cab-frame against tipping or rocking
movement of the behind-cab-frame in a roll-mode about the
front-mounting-plate.
10. Combination of a rollover protection structure (ROPS) and a
pickup-truck, wherein: the truck has left and right chassis-girders
having front-bolt-receiving-sockets; the truck includes a
cargo-box, having a box-floor of sheet metal; the cargo-box is
provided with front-floor-bolt-holes in the sheet-metal box-floor;
the ROPS includes a behind-cab-frame, a front-mounting-plate, and a
roof-canopy; the roof-canopy extends forwards from the top-end of
the behind-cab-frame, over the roof of the cab of the truck; the
behind-cab-frame, the front-mounting-plate, and the roof-canopy,
together form an integrated-assembly, in that the behind-cab-frame,
the front-mounting-plate, and the roof-canopy, are integrated
solidly and rigidly together in such manner as to preclude relative
movement therebetween; the integrated-assembly being placed in the
cargo-box of the truck, with the front-mounting-plate lying flat
against the box-floor of the truck, the front-plate-bolt-holes
align with the front-floor-bolt-holes in the box-floor;
front-box-bolts pass through both the front-plate-bolt-holes and
the front-floor-bolt-holes; the front-box-bolts are tightened into
the front-bolt-receiving-sockets, thereby securing the
integrated-assembly to the chassis.
11. As in claim 10, wherein: the roof-canopy of the ROPS has no
direct attachment to the roof of the cab; the roof-canopy is not
made fast, directly or indirectly, to any part of the chassis of
the truck, except that the roof-canopy is a component of the
integrated assembly, and the front-mounting-plate of the
integrated-assembly is made fast to the chassis of the truck.
12. Procedure as in claim 1, wherein: the truck has box-fasteners
by which the cargo-box is fastened to the mounting-structures of
the chassis; the procedure includes removing the box-fasteners,
prior to engaging the fasteners with the front-mounting-plate and
with the mounting-structures in the chassis.
13. Procedure as in claim 1, wherein: where the cargo-box has a
box-floor, having front-floor-fastener-holes; where the
mounting-structures in the chassis include
front-fastener-receivers; where the front-mounting-plate is formed
with front-plate-fastener-holes; and the procedure includes
exposing the front-floor-fastener-holes and the
front-fastener-receivers, prior to engaging the fasteners with the
front-mounting-plate and with the mounting-structures in the
chassis.
Description
[0001] This technology relates to a rollover protection structure
(ROPS) for use in pickup trucks and similar light-duty commercial
vehicles.
[0002] Rollover events occur when vehicle are driven over ordinary
roads, but such events occur significantly more frequently when the
roads are the roads of open-pit mines, tailing areas, exploration
sites, construction sites, and so on, which often do not have a
metalled surface. At such sites, the risk of running off the road
or track is much greater than on ordinary roads. Rolling over,
often at medium or slow speed, down a sloping embankment, is a
common type of accident at such sites, and is a common cause of
injuries and fatalities. Most of the injuries arise as a result of
the cab being flattened or crushed.
[0003] Many types of vehicle have been fitted with roll-cages or
other ROPSs. In some cases, the ROPS includes a roof-canopy, which
is supported from the chassis of the vehicle at a location that is
forward of the cab. It might be considered preferable, from the
strength and rigidity standpoint, for the roof-canopy to be
supported both by rear-struts to the rear of the canopy, and by
forward-struts which extend from the front of a roof-canopy, over
the cab, and down to left and right attachment points on the
chassis of the vehicle.
[0004] However, providing such forward-struts, located in that
manner, is contra-indicated in the case of a light commercial
vehicle such as a pickup truck, from the standpoint that there is
no convenient location, in such vehicles, at which such a
forward-strut can be robustly attached to the chassis-girders, e.g
in the area of the front bumper. In order to make provision for
such forward-struts, it would be necessary e.g to weld brackets, or
to drill bolt-holes, or the like, in/on the chassis-girders. Such
things can hardly be done without compromising the structural
integrity of the chassis (which would likely negate the truck
insurance).
[0005] In the present technology, the disadvantages of providing
forward-struts being noted, it is recognized that an adequately
strong and rigid protective roof-canopy, over the roof of the cab,
can be furnished even though the framework for supporting the
canopy is attached to the chassis-girders--not at the front through
forward-struts, but--through the floor of the cargo-box.
[0006] It is generally found that installing an internal rollcage,
inside the cab, is not a good solution. An internal rollcage
interferes significantly with access to the cab, and operation of
the truck, and the rollcage itself is compromised by the need to
minimize that inconvenience. Also, installation of an internal
rollcage in a cab is expensive, and requires the services of
specialized trained mechanics. Furthermore, internal rollcages in
the cabs of pickup trucks, despite the expense and inconvenience,
have not been shown to effectively prevent crushing damage to the
cab.
[0007] External rollcages that attach to the chassis underneath the
cab, are even more disruptive and expensive, but can be reasonably
effective.
[0008] The present technology is aimed at providing a rollover
protection structure that is robust enough, and is secured to the
chassis robustly enough, to protect the cab from sustaining
injury-causing damage during a rollover. At the same time, the aim
is that the ROPS should not interfere with the main function of a
pick-up truck, which is to enable persons to load items into, and
unload items from, the cargo-box of the truck, and to transport
those items by road over rough tracks, and should not interfere
with access to the cab, and with normal driving and operation of
the truck.
LIST OF DRAWINGS
[0009] FIG. 1 is a pictorial view of the back of a pickup truck, in
which has been installed a rollover protection structure (ROPS)
that accords with the present technology.
[0010] FIG. 2 is a diagrammatic side elevation of the truck and
ROPS of FIG. 1.
[0011] FIG. 3 is a view of the ROPS of FIG. 1, on its own, from the
back of the truck.
[0012] FIG. 4 is a view of the ROPS of FIG. 1, on its own, from the
front of the truck.
[0013] FIG. 5 is a side-view of the ROPS of FIG. 1.
[0014] FIG. 6 is a top plan view of an integrated assembly of the
ROPS of FIG. 1.
[0015] FIG. 7 is a close-up cross-section of a bolted joint, by
which the ROPS is fixed to the truck.
[0016] FIG. 8 is a pictorial view of another ROPS.
[0017] FIGS. 9A,9B are diagrammatic side and front cross-sectional
views of the cab of a pickup truck having an internal ROPS, showing
the condition of the cab before and after a rollover event.
[0018] The ROPS 20 of FIGS. 1-6 comprises a behind-cab-frame 21, a
brace-frame 25, and a roof-canopy 27. The pickup truck 29 includes
a cab 30 and a cargo-box 32, both of which are bolted to respective
chassis-posts (the chassis-posts to which the cargo-box is bolted
are shown at 34 in FIG. 2) the chassis-posts being integrated into
the chassis-girders 36 of the truck.
[0019] The behind-cab-frame 21 comprises two steel tubes, each bent
basically into an inverted U-shape. The front one 38 of these two
tubes is a little taller than the rear tube 40. Both of the tubes
38,40 are welded at the bottom to a front-mounting-plate 41. The
two tubes 38,40 of the behind-cab-frame 21 have the form of two
left and two right pillars of great sturdiness, which support a
cross-bar or bridge 43 at their top-ends.
[0020] The behind-cab-frame 21 thus serves as an immensely strong
and rigid supporting structure for the bridge 43. Even when the
truck is undergoing a violent rollover, the bridge 43 of the
behind-cab-frame 21 is most unlikely to be able to move closer to
the front-mounting-plate 41.
[0021] Extending forwards from the bridge 43 of the
behind-cab-frame 21 is the roof-canopy 27. This is made from two
steel canopy-tubes, bent to upper and lower U-shapes 45,47. Spacers
49 are welded in, to maintain the positions of the tubes 45,47 with
respect to each other. As will be understood, the roof-canopy 27 is
not only highly rigid in itself, but the joint at the top-end
bridge 43 between the behind-cab-frame and the roof-canopy is also
highly rigid. Left and right gussets 52 reinforce the rigidity of
the joint area.
[0022] Thus, the roof-canopy 27 is highly resistant to being
deflected relative to the behind-cab-frame 21 (and thus is highly
likely to protect the roof of the cab from being crushed) even when
the truck is undergoing violent rollover.
[0023] The behind-cab-frame 21 is braced into its desired upright
position by the brace-frame 25. The brace-frame 25 includes left
and right brace-struts 50, which are secured to a
rear-mounting-plate 49. The rear-mounting plate 49 is--like the
front-mounting-plate 41--bolted, through the box-floor, to
chassis-posts 34.
[0024] It is recognized that the integrated-assembly 53 of the
behind-cab-frame 21, the roof-canopy 27, and the
front-mounting-plate 41, can be the same for many trucks. A number
of pickup trucks vary very little as to the width of the floor of
the cargo-box 32, and the one welded assembly can be used for all
those trucks. In fact, most pickup trucks can be catered for with
just two integrated-assemblies, one with a longer canopy to cater
for the crew-cab option.
[0025] FIG. 8 shows a ROPS with a long roof-canopy 63. The ROPS of
FIG. 8 also is suitable for a truck that has a longer
cargo-box--and such a truck would likely also have a longer
wheelbase.
[0026] The positions of the bolts-holes in the box-floor are more
variable, but these variations can easily be accommodated by simply
providing the mounting-plates with a selection of mounting holes,
again without variation to the integrated-assembly 53.
[0027] However, the distance between the front of the cargo-box and
the wheel-arch in the box-floor varies considerably, as between
makes, models, options, and this variation affects the distance
apart at which the front- and rear-mounting-plates 41,49 are
located. For this reason, it is preferred to keep the components
that make up the brace-frame 25 detachable and separable from the
integrated-assembly 53. Thus, the ROPS for regular-cab trucks can
be sold all with the same integrated assembly, and the only special
component is the brace-frame 25, which is tailored to the
individual length of the cargo-box in the particular truck.
[0028] The special brace-struts 50 for the particular truck engage
studs 54 that are built into the behind-cab-frame, and are locked
in place with cotter-pins 55. Conveniently, the two brace-struts 50
and the rear-mounting-plate 49 are mutually separable, again using
cotter-pins to lock the tubes to studs that are fast to the
rear-mounting-plate.
[0029] The major function of the brace-frame 25 is to hold the
behind-cab-frame upright. If the brace-frame 25 were omitted, the
behind-cab-frame 21 and the roof-canopy 27 could continue to
provide all the required rollover protection for the cab
30--provided the behind-cab-frame remained upright. However, simply
bolting the front-mounting-plate 41 (through the floor of the
cargo-box) to the chassis would not keep the behind-cab-frame
upright, i.e would not secure the behind-cab-frame against rocking
or tipping in the pitch-mode.
[0030] The behind-cab-frame 21 is a highly robust structure, in
itself. When the front-mounting-plate 41 of the behind-cab-frame is
bolted to the chassis, the behind-cab-frame is locked very rigidly
against all modes of movement relative to the chassis, other than
pitch-mode tipping or rocking. Thus, it may be regarded that the
major function of the brace-frame 25 is to prevent the
behind-cab-frame 21 from rocking about the front-mounting-plate 41,
in the pitch-mode.
[0031] Again, the ROPS is highly robust in itself; the ROPS does
not gain its robustness from its interaction with the truck
chassis. The exception to this is that the resistance of the
behind-cab-frame to pitch-mode rocking indeed is derived from the
interaction of the ROPS with the chassis--in that the brace-frame
25 enables the chassis to form a link that triangulates the
behind-cab-frame, and thereby locks the behind-cab-frame against
pitch-mode rocking.
[0032] During rollover, the forces on the ROPS 20 are not limited
to simple compression of the behind-cab-frame 21, but rather the
ROPS is subjected to heavy forces and impacts from all directions.
It will be understood that the key to protecting the roof of the
cab 30 lies in locking the bridge 43 of the behind-cab-frame to the
chassis, not just robustly and rigidly, but substantially
immovably, in the face of these impacts and forces. It will be
understood, also, that the ROPS as described herein is a structure
that is indeed highly effective in holding the bridge 43 in a fixed
position relative to the chassis.
[0033] The brace-frame 25 enables a triangulation that braces the
behind-cab-frame against pitch-mode-tipping. The brace-struts do
not themselves need to be of immense construction. It is the
behind-cab-frame that should be very strong, since that is what
saves the cab from being flattened. But the immense rigidity of the
behind-cab-frame 21 would count for nothing if the behind-cab-frame
were not braced against pitch-mode tipping, relative to the
chassis.
[0034] It will be understood that the ROPS as depicted and
described herein achieves its advantageous safety function without
in any way compromising the structural integrity of the chassis.
Installation is easy and quick, and the installers do not need
special training. Also advantageously, the ROPS for many makes and
models of trucks can use the same
behind-cab-frame/canopy/front-plate integrated-assembly 53. Also
advantageously, as can be seen from FIG. 1, the ROPS hardly
interferes with the use of the cargo-box for its intended purposes;
and the ROPS does not interfere at all with access to the cab and
normal operation of the truck. To be sure, the ROPS adds some
weight to the truck (and its strength is related to its weight),
but any ROPS faces that penalty. An external ROPS has a chunky
visual appearance, but cosmetic considerations generally have
little effect on commercial users of pickup trucks. One
side-benefit of providing the ROPS in the cargo-box and over the
cab-roof is that a convenient framework is provided on which may be
mounted such accessories as a built-in secure toolbox, extra
lighting fittings, and so on.
[0035] The ROPS depicted and described herein have mounting-plates
by which the ROPS is secured to the chassis of the vehicle. As
mentioned, one of the aims of the technology is to provide a ROPS
that can be installed easily and quickly on an existing pickup
truck, by unskilled persons, without disruption to the truck.
[0036] In order to assemble the ROPS, first the installers remove
the box-bolts 56 (FIG. 7) that fasten the box-floor 58 of the
cargo-box 32 to the chassis-posts 34 of the chassis-girders 36.
These box-bolts 56 pass through bolt-holes in the sheet-metal of
the box-floor 58, and then through corresponding bolt-holes in the
box-floor-struts 60 that are part of the cargo-box 32. The
box-bolts 56 continue on down, and are fastened through bolt-holes
provided for the purpose in the chassis-posts 34. The chassis-posts
34 are welded or otherwise integrated into the chassis-girders 36
of the truck, and they provide a convenient and secure attachment
location that enables the cargo-box to be firmly attached to the
chassis. (In some trucks, there are no chassis-posts and the
box-bolts are bolted directly into the chassis-girders.)
[0037] The box-attachment arrangements vary, truck to truck; a ROPS
in accordance with the present technology can be regarded as
suitable when the cargo-box is bolted down to the chassis, and when
the box-bolts can be removed and replaced without affecting the
structural integrity of the chassis. (The technology is not
suitable for use on trucks in which the cargo-box is not fixed but
is able to tip.)
[0038] An aim of the present technology is to make it possible
basically to simply bolt the ROPS to the chassis, using the same
box-bolts, and the same bolts-holes, that were already provided by
the truck manufacturer for the purpose of attaching the cargo-box
to the chassis. (The box-bolts that are required for attaching the
ROPS might need to be slightly longer than the OEM box-bolts that
came with the truck, but that is easily dealt with.)
[0039] If a particular pickup truck is of such construction that
the cargo-bed is not bolted to the chassis, or if the box-bolts
cannot be removed and replaced without disrupting the chassis, the
present technology likely would not be applicable. Some previous
ROPS have required that the truck be substantially dismantled, in
order to provide anchorage for the ROPS. If the users are willing
to resort to taking the truck to pieces, and to resort to
substantially modifying the chassis and/or the cab, then no doubt
they can provide an effective ROPS. But the present technology
recognizes that a highly-effective ROPS can be provided, which only
requires to be simply bolted through the box-floor of the cargo-box
to the chassis in the same manner in which the cargo-box is already
secured to the chassis--and recognizes that, apart from that rather
trivial operation, no disruption to the structure of the truck is
required.
[0040] The box-bolts 56 having been removed, the
integrated-assembly of the behind-cab-frame 21, the roof-canopy 27,
and the front-mounting-plate 41, can be hoisted into position. The
bolt-holes in the front-mounting-plate 41 are aligned with the
bolt-holes in the box-floor 58 and the chassis-posts 34. The
brace-struts 50 are engaged with the studs 54 and locked in place
with the cotter-pins 55. The brace-struts are also assembled to the
rear-mounting-plate 49 in similar manner. The rear-mounting-plate
49 is bolted through the box-floor 58 and made fast to the chassis
as was the case with the front-mounting-plate 41.
[0041] It may be noted that the forces acting on the box-bolts that
secure the rear-mounting-plate 49 are likely to be considerably
smaller than the forces on the box-bolts securing the
front-mounting-plate (which bear the brunt of the impact forces).
Thus, in some cases, it might be adequately sound, structurally,
for the rear-mounting-plate 49 to be secured (e.g bolted) e.g to
the box-floor-struts 60 of the cargo-box, rather than directly to
the chassis-posts 34 or chassis-girders 36. (The box-floor-struts
60 would themselves be firmly secured to the chassis). Thus, the
range of trucks to which the present technology can be applied need
not be limited only to those trucks in which existing box-bolts and
bolt-holes are accessible for use with the rear-mounting-plate
49.
[0042] FIGS. 9A,9B are diagrams that illustrate the results of two
rollover tests performed on similar pickup trucks. In the first
rollover test, the truck was fitted with an internal rollover
protection structure, comprising a cage made of welded steel tubes,
located inside the cab. When the ROPS is internal, compromises have
to be made that affect the efficacy of the ROPS, in that the ROPS
must be so configured as not to interfere with movement of persons
into and out of the cab, nor with normal operations of the
truck.
[0043] Certain dimensions in the cab were measured before and after
the rollover event. The table shows the recorded measurements:
TABLE-US-00001 before after percent roll roll crush front seat
headroom 41.0 30.8 25.0 front seat shoulder room 65.3 61.0 6.5
front seat hip room 61.5 61.5 0 left rear seat headroom 38.5 36.5
5.2 right rear seat headroom 38.5 31.5 18.2 rear seat shoulder room
66.3 61.0 8.0 rear seat hip room 61.5 60.0 2.4 front seat to
windshield 41.0 27.5 32.9
[0044] In FIG. 9A, the plain lines show the internal form of the
sides and roof of the cab in end-elevation, prior to the rollover
test, from the above "before" dimensions. FIG. 9B shows the same
thing in side-elevation.
[0045] The bold lines in the two drawings show the condition of the
cab, following the first test, using the internal ROPS, from the
above "after" dimensions.
[0046] Of course, the "after" dimensions of the cab were measured
after the truck came to rest. Thus, the measured "after" dimensions
represent permanent or set distortions, that are retained after the
structure has come to rest. One may be sure that the magnitude of
the distortions was even greater, actually during the rollover
event. It will be understood from the table that significant
crushing of the cab occurred as a result of the rollover--despite
the presence inside the cab of the internal ROPS.
[0047] In the second test, a similar truck was fitted with an
external ROPS in accordance with the present technology. It
happened that, in the second test, one of the box-bolts holding the
front-mounting-plate to the chassis-girders was torn out. This was
probably due to the corroded state of the chassis-post on the
chassis-girder to which the box-bolt was fastened. Despite this, a
video of the test shows that the roof-canopy of the ROPS was in
place, overlying and protecting the cab-roof, when the
still-rolling truck was upside down.
[0048] Following the second test, it was found that the internal
dimensions of the roof and sides of the cab, as illustrated again
by the plain lines in FIGS. 9A,B, had not changed. That is to say,
when the cab was protected by the external ROPS, as described
herein, the roof and sides of the cab were not compressed to any
measurable degree. (Thus, no diagrams showing the second test are
included--or, in other words, the plain lines in FIGS. 9A,9B
represent the second test cab both "before" and "after" the
rollover test.)
[0049] Thus, in the first test, the occupants could hardly expect
to escape serious crushing injuries; in the second test (assuming
their seat-belts and airbags deployed properly) the occupants could
expect to walk away injury-free. It is mentioned again that, in the
second test, one of the front-mounting-plate box-bolts tore away of
the chassis, and yet still the external ROPS provided full
protection for the cab.
[0050] It is not suggested that the present ROPS should be used
without being bolted firmly to the truck chassis. But the fact
remains that one of the box-bolts tore free during the second test.
This might well have been regarded--if the second test had resulted
in a badly-crushed cab--as a good reason to discount the second
test, in that a truck with such a badly corroded chassis would not
be on the road. But what actually occurred in the second test was
that the external ROPS, as described herein, still did provide
excellent (potentially life-saving) protection for the
cab-roof.
[0051] As shown in FIGS. 1,3,4, the rear-pillar tube 40 of the
behind-cab-frame 21 has been formed with protruding side-ears 61.
These ears can be effective to prevent impacts from reaching the
sides of the cab 30. As will be understood, this extra
side-protection can be procured more or less for nothing in the
external ROPS as described.
[0052] The described technology is highly suitable for the
after-market, i.e for use when the ROPS is to be retro-fitted to an
already manufactured truck. The technology might be less
advantageous when integrating a ROPS into a truck as a feature of
the original design and manufacture of the truck.
[0053] The scope of the patent protection sought herein is defined
by the accompanying claims. The apparatuses and procedures shown in
the accompanying drawings and described herein are examples.
[0054] A reference to a component being "integrated rigidly into"
another component means, herein, that the two components are either
formed from one common piece of material, or, if formed separately,
are fixed together so firmly and rigidly as to be functionally and
operationally equivalent to having been formed from one common
piece of material.
[0055] The numerals used in the drawings are listed as: [0056] 20
rollover protection structure (ROPS) [0057] 21 behind-cab-frame
[0058] 25 brace-frame [0059] 27 roof-canopy [0060] 29 pickup truck
[0061] 30 cab of truck [0062] 32 cargo-box of truck [0063] 34
chassis-post [0064] 36 chassis-girder [0065] 38 front pillar-tube
of behind-cab-frame [0066] 40 rear pillar-tube of behind-cab-frame
[0067] 41 front-mounting-plate [0068] 43 cross-bar or bridge of
behind-cab-frame [0069] 45 upper tube of roof-canopy [0070] 47
lower tube of roof-canopy [0071] 49 rear-mounting-plate [0072] 50
brace-struts [0073] 52 gussets [0074] 53 integrated assembly
(21+27+41) [0075] 54 studs for brace-struts [0076] 55 cotter pins
[0077] 56 box-bolts [0078] 58 box-floor [0079] 60 box-floor-struts
[0080] 61 side-ears of 40 [0081] 63 roof-canopy (FIG. 8).
* * * * *