Note: Descriptions are shown in the official language in which they were submitted.
I ~ 1.3~S
The present invention relates to the inflation of
vehicular tires, more particularly to the inflation of tires that
can cause considerable damage when something goes wrong.
Among the objects of the present invention is the
provision of novel apparatus for relatively safe inflation of
tires.
According to the present invention there is provided an
apparatus for relatively safely inflating pneumatic tireS on
vehicular wheel rims, the apparatus comprising a box -that
receives a tire-carrying truck wheel rim, the walls being
sufficiently strong and securely held to contain all tire and
wheel parts in the even~ the tire or rim explodes, one wall of
the box being a door openable to permit the introduction and the
removal of the tire-carrying wheel rim) a flexible air conduit
within the box and having an outlet connector that can be clamped
to a tire valve stem, the air conduit having linking means
penetrating through a wall of the box to a valved supply line
outside the box, a pressure indicator visible from outside the
box and connected to the tlexible air conduit to indicate the
pressure in the tire, and precautionary interlock means coacting
with the door and the air conduit to prevent the flow of air from
the valved supply line to the valve stem when the door is not
closed bwt permitting such flow when the door is closed.
The foregoing and further objects of the present inven-
tion will be more fully explained in the following description of
several of its exemplifications, reference being made to the
accompanying drawings, wherein:
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A
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Figure I is an isometric v;ew of an inflating apparatus
represcntative of the present invention;
Figures 2 and 3 are similar views of modified con-
structions typical of the present invention;
Figure 4 is a schematic representation of an air-supply
circuit particularly suited for the present invention;
Figure 5 is a detail view, partly in section, of a
further modified construction of the present invention;
Figure 6 is a sectional v;ew of an inflation actuating
control desirable :Eor use with the present invention; and
Figure 7 is a view like Figure 3 of a still further
modified con-
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3 1~133.S
struction of the present invention.
The illustrated apparatus for relatively safely inflating pneumatic
tires on vehicular wheel rims comprises a box that receives a tire-carrying
wheel rim, the box having walls surrounding all sides, top and bottom of the
tire-carrying wheel rim, the walls being sufficiently strong and securely held
to contain all tire and wheel parts in the event the tire explodes, one wall
of the box being openable to permit the introduction and the removal of the
tire-carrying wheel rim, a flexible air conduit within the box having an outlet
connector that can be clamped to a tire valve stem, the air conduit having
linking means penetrating through a wall of the box to a valved supply line
outside the box, and a pressure indicator visible from outside the box and
connected to the flexibleair conduit to indicate the pressure in the tire.
The box is conveniently made of l/4 inch thick steel plates welded
together, although thicker plates can also be used. It is also helpful for the
box not to be airtight but to contain leak gaps that permit the harmless escape
of air from the box, in the event a tire in the box explodes ~ total leakage
through at least about 20 square inches effective leak cross-section is
preferred.
Turning JIOW to the drawings, ~igure 1 shows a box 10 made of steel
plates 11, 12, 13, 14, 15 and 16, each about 1/~ lnch thick. Side plates 11,
12 are welded to top and bottom plates 13, l~, and to a rear plate 15 to form
an open box large enough to receive a wheel-rim-mounted truck tire. The inter-
ior of this box can be ~ feet high, 4 feet deep and about 1~ inches wide, so
that most truck tires can easily be rolled in through its open mouth 20. Truck
tires are the type of tire most likely to explode, Eor example because oF an
unnoticed crack or failure of the wheel rim on which they are being inElated.
Itnproper mounting of the tire on the rim can also lead to such explosions.
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3 1 .3 ~ ~
~ louth 20 can then be closed by door plate 16, ~hich is shown pivot-
ally mounted on hinges 22, 23securely fitted to plate 16 and ~o side plate 12.
The door plate also carries a forked pair of rings 25 that become aligned with
a pintle ring 27 welded to plate 11, when the door is closed. The door can
then be locked in closed position by inserting a pintle pin 30 downwardly
through the aligned rings. Pln 30 is sho~Yn as carried by a chain 32 anchored
to plate 11, so that it does not get lost.
Within box 10 is a flexible compressed air conduit 40 of the type
used to i~lflate tires. This conduit leads ~o a pressure gauge 42 mounted again-
st the inner surface of plate 15 but having its face exposed through an opening
44 cut in plate 13. The pressure gauge leads in turn to a control valve 46, by
means of a short length of pipe, not shown, that penetrates through a hole in
plate 12. A compressed air supply line runs from valve 46 to a compressor or
other source of compressed air, and a control button 48 is shown on control valve
46 to turn on and off the flow of compressed air to conduit 40. That conduit
can be fitted with a clamp-on fitting 50 ~hat removably clamps onto a tire valve
stem to make an air-tight connection to the interior of the tire.
Box 10 is also shown as having a lifting strap 52 welded to the top
of plate 13 so that the box can be conveniently lifted and lowered to move it
to any desired location. Also an open container 54 can be secured to plate 13
or any of the adjoitling l~lates 11, 12 or 15, to ho]d tire lubricant, or spare
~ittings or the lik~, that may be helpful for use when mounting or inflating
a tire.
Air conduLt 40 can desirably be made relatively short in length,
so that it does not have a long projection that must be stuE-~ed into the box
with a tire and wheel assembly, and there is accordingly less danger of the con-
duit becoming pinched or kinked. Also a short conduit projection makes it
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I ~31'3~
easier to first roll a wheel and tire assembly part way into the box, then
clamp the conduit to the tire valve stem, and finally roll the wheel and tire
assembly with the conduit attached, all the way into the box. The door panel
can then be closed, pinned, and the tire inflated.
In addition it becomes difficult or impossible to mount a short con-
duit 40 Dnto a tire valve stem unless the tire is partly rolled into the box.
Door panel 16 need not be closely -fitted with respect to the mouth
of the box. A gap of 1/16 inch all around that panel is actually helpful in
that it permits the harmless escape of compressed air in the event a tire bursts
while in the box. One or more openings 56 can also or alternatively be pro-
vided in the cover panel to permit further air escape, if desired.
Some tire explosions have been reported as taking place several
minutes after completing inflation. It is accordingly desirable to wait five
to ten minutes after completing an inflation, before opening the door panel and
removing the inflated tire. To assure such a delay, ~he box can be equipped
with an automatic lock that prevents premature opening.
In ~igure 1 a precautionary interlock assembly 60 is welded onto
the exterior of side plate 11 and holds an interlock nose 6Z above pintle ring
27 and in the path of pin 30 as it is inserted in or removed from pinning
engagement with the rings 25 of the door panel. Nose 62 is carried by the
piston of an air cylinder that extends through the interior of the interlock
asseMbly to the rear panel 15 where it is connected to receive air from the
coMpressed air supply when valve ~6 is activated. Upon such activation the air
cylinder will Eorce nose 62 into the blocking position shown, and thus keep a
previously inserted pin from being withdrawn.
Yalve ~6 can be of the type that when it shuts o~f the delivery of
compressed air it automatically bleeds out to the atmosphere the air downstream
~ ~ c~ I '3 .s ~
of the valve. In the Figure 1 const-ruction valve 46 has two branched down-
stream linesl one to conduit ~0 and the other to precautionary interlock 60.
The branch -to conduit 40 is fitted with a check valve to prevent the automatic
bleeding, but the line to the interlock assembly is permitted to bleed. The
bleeding rate is fixed at a value that requires 5 to 10 or more minutes before
the interlock cylinder air pressure is low enough to allow nose 62 to be with-
drawn or pushed away from pin-blocking position. The pin 30 can then be removed,
the door panel opened, and the inflated tire rolled out of the box.
Figure 2 shows a modified construction in which the interlock also
helps assure that the door panel must be closed before inflation can be effected.
Here an auxiliary control valve 70 has an activating button 72 deeply recessed
in the interior of guide passageway 74, and located on the door panel so that
closing of that panel brings passageway 74 into alignment with a pin-receiving
aperture 76 in side panel 11.
Valve 70 has two air lines 81, 82, one going to a main control
valve 1~6 and the other to valve stem clamp 50. When the door panel is closed,
interlock nose 62 can be pushed in and pin 130 then inserted through aperture
76 and guide passageway 74. Control button 72 can be strongly spring loaded so
that considerable force is needed to cause pin 130 to activate the valve. Nose
62 can then be pulled out to hold pin 130 in activating position. Inflation can
now be effected, after which the nose 62 can again be pushed out of the way once
the kime-delcLyed bleeding is completed.
The air cylincler in interlock 60 c~n be replaced by a rubber bladder
that is inPlated by the comprossed air ancl presses against a loosely fitted
vcrtically positionecl internal plate on which nose 62 is mounted. The bleed
opening necd only be abc~ut a 5 m:il wide hole, when the total volume of air to
be bled is about 2 litres. Preferably a wire is inserted through the bleed
-- 5 --
~ ~1'3~5
hole and loosely hel~ there so that it can jLggle and keep the hole frorn becom-
ing clogged with dust or the like.
Holes 56 can be cut through the bottom plate 14, instead of the
door plate, in which event it is helpful to have the box f]oor a little above
the ground, as by welding skid strips or short feet to the outside of the box.
Such holes can be covered with heavy wire mesh to keep conduit 40 from getting
trapped in them.
In ~igure 2 the main control valve 146 has its actuating button
positioned on a vertical face, so that the button is pushed in a horizontal
di-rection to trigger the inflation. This makes it difficult to defeat the need
to manually operate the valve, an undesirable technique that could be effected
as by placing a weight on .~s actuating button to hold it down. If desired,
that button can be located on the under surface of the control valve.
The precautionary interlock can be provided in other ways. Thus,
electrical micro-switches can be mounted on the door panel of the construction
of ~igure 2, one to be actuated when the door panel is closed and another when
the pin 130 is moved into door-locking position. These switches can be wired
in series with each other and in series with a main electrical switch that starts
a compressor which furnishes the compressed air to flexible llne 40. That main
switch can be located at 146 and can also be separately connected to a solenoid
that brings interlock nose G2 into locking position and latches it in that
position. A timer is also started when the main switch is disengaged and the
timing out of the timer unlatches the solenoid.
Alternatively, the flexible air conduit 40 can include a make-and-
break push-pull connector consisting of two separable parts one of which is
mounted on the door panel and tne other of which is mounted on ~he outside of
panel 11, When the door panel i5 closed it carries its part of the connector
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into engagement with the part on ~anel ll, ancl in this way establishes the
compressed air path to a portion of air conduit 40 that extends through an
opening in the door panel and into the interior of the box.
Opening the door panel then opens the make-and-break connection so
that no compressed air can reach the tire valve. The parts of the make-and-
break connector can also be arranged to lock together when their interiors are
subjected to superatmospheric pressure, to thus lock the door in closed posi-
tion. This can be effected by making the make-and-break connection bet~een a
rubber male connector that expands when its interior is under pressure, and a
relatively rigid female connector that receives the male connector and has a
tapered internal bore that holds the male connector in place when the male
connector is expanded.
A bleed hole can be used to bleed ~he pressurized air out of the
make-and-break connector over the desired time period. A check valve do~nstream
of the make-and-break connector prevents bleeding of the air -from the inflated
tire.
The boxes of the present invention can be larger or smaller than
indicated in the dimensions given above, and can be made to fit any tire.
To prevent misoperation, filters can be ins~alled in the air lines,
particularly just upstream of an air cylinder, or upstream of the main valve,
to trap dust and other particles and thus keep them from getting into critical
places.
The construction of ~igure 3 has a box 210 similar to those of
~igures 1 and 2, but with a viewing window 230 in each of the box's side panels
211, 212. each window is cut out of its panel and covered with a transparent
sheet 253 of a thick, tough plastic such as polycarbonate. The sheet is illus~
trated as mounted against the inner face o~ its panel, and held by flat head
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3 1 ~s S S
screws 255 recessecl in the shee-t ancl threadeclclirectly into threaded openings
in the panel. If desired one or both plastic sheets can be fitted to the exter-
ior faces of their panels, in which eventthe sheets can be made thicker and
can be fastened with more fasteners. These sheets are thick enough to withstand
the force of a tire explosion that takes place inside the box, and a thickness
of about 1/2 inch or a little more is suitable for this purpose.
Box 210 has vent openings 256 in its floor panel, but they can
alternatively or additionally be in the top panel 213. These ven* openings are
spanned by spaced metal straps welded in place to make sure anything escaping
through a vent is quite small in size, and also to prevent passing through the
vent the air line used for inflating. This makes it more difficult to use that
line for inflating a tire without fitting the tire inside the box.
The inflating line is not shown in Figure 3, but is connected to
one branch of a junction block 270 having another branch connected to the input
line 272 of an air cylinder. ~ third branch of the junction block is connected
by pipe or flexible tubing to an interlock valve 281 mounted in the mouth
of the box for activation by a post or plunger 282 carried b~ door 216. Valve
281 is normally closed, but is opened when door 216 is closed, so that the air
will not reach the junction block unless that door is closed.
The construction of Pigure 3 is also fitted with two more valves,
one a normally closed main inflating valve connected between the intake of the
interlock valve 281 and the compressed air supply, and the other connected to
act as a discharge for dePlating the tire. The inflating vaLve is placed as in
rligures 1 or 2, suPficiently far rom the interlock valve to make it impossible
for one person to manually open both of these valves simultaneously.
'Ihe discharge valve is opened when a tire under inflation is to be
deflated, such as when it is noticed through a window 230 that the tire and/or
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wheel rim has not been properly ~ounted or thcre is some defect or failure that
renders the in-flation unsafe. To help examine for such problems one or more
electric lights 278 can be fitted above or around the outer face of each window,
or inside the corners of the box.
The inflating, deflating and interlock valves can be of identical
construction, such as Schrader poppet valve 7796SP5 shown in Schrader Pluid
Power Division Catalog VAL-l ~Rev. 10/76).
Air cylinder 280 is secured to the outer face of panel 211 to hold
a piston rod 284 up against the bottom of one end of a latch lever 286. That
lever is pivoted on a pin 287 secured to panel 211, so that the opposite end 288
of the latch lever projects forwardly beyond the open mouth of the box. That
projecting end has a locking notch 289 in its lower portion, and also has a
latching nose cam 290. These coact with a latch bar 291 welded to the door 216.
When that door is being closed with the air cylinder not inflated, the bar 291
first engages the nose cam 290 to thus tilt up the latch lever end 288. Further
closing movement beings ba~ 291 under locXing notch 289 permitting the latch
lever end 288 to drop over the bar and lock the door in a closed position.
The closing of the door automatically opens interlock valve 281,
and the actuation of the inflating valve then in~lates the t:ire and wheel pre-
viously inserted into the box as described in connection with Figure 1. Such
inflation also in~lates air cylinder 280, forcing rod 284 up against the rear of
latch lever 286, securely holding it in door-locking posi~:ion. ~ rest or stop
bar 202 can be provided to keep the latch lever 286 from tilting down below
latching position.
~ ~re~erred air line system is shown in ~igure 4. The compressed
air supply runs Prom intake 241 of inflating valve 2~2 through that valve~ then
through connector 243, through interlock valve 281 and connector 24~ to air
_ 9 _
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cylinder 280. A check ValVe 292 branches from connector 2~4 and in turn connects
to tire connector 250 Deflating valve 283 has its intake 293 opening into tire
connector 250. A bleed 294 opens into connector 244 to gradually bleed out
compressed air from cylinder 280 when inflation is completed. Check valve 292
is polarized to confine such bleeding to its air cylinder side, and the bleeding
is adjusted~ as pointed out above, to keep the latch lever in door-locking
position for 5 to 10 minutes or more, beore the pressure in the air cylinder
drops to a level that permits unlocking of the latch lever. As little as 1/4
minute or even 3 to 4 minutes delay is helpful in reducing the possibility of
injury from delayed tire bursting.
It will be noted that when deflating valve 283 is actuated to deflate
an inflated or partially inflated tire, the air cylinder is also deflated so
that the deflated tire can be immediately removed from the box without waiting
the length of time required for the slow bleeding. A restriction can be in-
serted in the line through which the cylinder thus deflates, or can be built
into check valve 292, to help assure that the cylinder deflation is not com-
pleted much before the tire deflation.
If desîred a normally open manually-operated shut-off valve can be
inserted in the connection between bleed 294 and junction boY~ 270, and its
operator can be ganged with the operator of inflating valve 242, so that when
the inflating valve is opened to inflate a tire, the bleed passageway is closed
and no bleeding takes place. This speeds the tire inflation step.
Valves 242 and 2~3 can be solenoid-operated if desired, in which
event valve 2~1 can be replaced by an electrlc circuit i~terlock switch, and
connecting lines 243, 244 permanently open to each other. Such an interlock
.switch can be normally open but connected to switch to circuit-closing position
and thu.s automatically actuate the inflating valve when door 216 is closed, and
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can be so heavily spring-blased toward open-circuit position that it takes the
mechanical leveragc provided by door 216 to switch it to circuit-closing posi-
tion. ~hen valve 281 is used it can similarly be heavily biased to closed
position.
The use of electrical valve operation requires an electric power
supply line in addition to an air supply line3 but so does ~he use of lights 278.
In addi~ion an electric supply circuit can be readily fitted with a relay-
operated warning light or alarm located at a supervisor's station, to show that
the inspection lights 278 are not operating or that no electric power is being
consumed. This will help guard against misoperating the apparatus, and will
also show the unit is in use.
To prevent an operator from using the unit without elec~rical power
a normally closed electric solenoid can be placed in the air supply line.
The construction of Figure 3 also has feet 220 holding the bottom
panel 214 of the box a little above the floor on which the box stands. Uear
foot 220 can merely be an extension of the rear panel of the box, and front
foot 220 can be a narrow length of plate welded to the bottom panel 214.
Figure S is a view from below of a box similar to those of Figures
1, 2 and 3, partly sectioned to show a modified construction for inspection
windows 350. This window construction has a plate 353 of transparent plastic
fitted across an opening 351 in box 310 as in the construction of Figure 3. ~low-
ever, in Pigure 5 the plastic plate is reinforced by a series of spaced bars
360 cxtending across the opening 351 and welded to the box, or to a metal frame
354, at both ends. In addition the bars 360 have their ends notched out so as
to provide a longitudinal face 361 that engages the outer face of the plastic
plate
ears 360 have horizontal widths that can be as much as an inch so as
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to provide rugged stiffening of the box as well as a tremenclous support or
the plate. The vertical depth of bar 360 can be as little as 1/4 to 3/8 inch,
and they can be spaced from each other by 1 1/2 to 3 inches, so as not to
interfere too much with visual inspection through the window. The reinforcing
bars 360 can be aligned so that they point toward any light or lights mo~mted
on the exterior of the box and thus obstruct such lighting as little as possible.
Prame 354 can be used to support a plastic plate so that the inner
surface 355 of the plate is flush with~ or recessed outwardly with respect to,
the inner face of the box panel in which the window is fitted. This reduces the
scratching of plastic face 355 by the tire or wheel rim, or tire connector,
and thus prolongs the life of a plastic plate. It is preferred to use tire
connectors that project as little as possible toward the windows. Connectors
numbered 5449K61 or 5449K62 described on page 1692 of McMaster-Carr Supply
Company (New Brunswick, New Jersey) catalog 87 copyrighted 1981, are of this
preferred type.
The inspection windows can be made circular or oval or of any other
outline. Rectangular openings are simpler to fit with reinforcing bars 360
inasmuch as all such bars ~or one window can then be made identical to each
other.
~igure 5 also shows an inflating valve 242 and a deflating valve 283
mounted on the box panel opposite door 216 and having their control bwttons 302,
303 projecting downwardly so that they have to be pushed upwardly to be actuated.
A pressure gauge 342 is also shown in ~igure 5 as connected in such a way that
only a small per~oration is needed in the box panel to receive the shank 343 of
the pressure gauge. The entire ace portion of the gauge is accordingly outside
the box.
Pigure 6 illustrates a modified valve 380 built into a metal block
1 l~l13;:~S
381 having a recess 382 in its lower tace. The valve mechanism 383 is fitted
to one end of the block and has an actuating button 384 in a bore 385 that opensin~o recess 382. Button 384 can be actuated by inserting one's finger into
recess 382 and then bending the finger so that the fingertip engages button 384,after which the fingertip can be pushed against the button to move the button
deeper in its bore. ~he wall 387 of recess 382 flares outwardly in a downward
direction so as to make it difficult to wedge any member inside the recess for
the purpose of attempting to hold the button 384 actuated without the use of
one's hands.
The construction of Figure 6 is particularly desirable if it is
important to avoid tempting an operator to misuse the apparatus.
The apparatus of the presen* invention is also desirably fitted with
a warning or record that contains instructions for its use. Thus a plate 299
can be mounted on its top panel for example as shown in Figure 3, to carry a
warning as to the maximum air pressure to be used, and also a place in which canbe inscribed the number of tire explosions that the box can be expected to safe-ly withstand. Space can be provided for scratching into the plate 299 a smaller
number after each explosion it lives through, so that the bo,c can be withdrawn
from service after its safe life has been exhausted.
All fittings for the box are best protected against tampering; thus
air cylinder 280 and its intake line 272 can be covered by a rugged metal shieldwelded to the outside of the panel 211. A similar shield can be eitted around
and over pressure gauge 342 to help assure that it is not removed for the pur-
pose o~ using its connection as a source of compressed air.
In~lating and de~'lating valves 242, 243 can be combined into a
single three-position valve. In one position the combined valve can then inflateboth the tire and the air cylincler, while i.n another position both can be
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I 1~ 13~S
deflated. In a third position there is neither inflation no-r deflation. As
noted above, a restrictor can be inserted in the deflation line from the air
cylinder to make sure it does not become fully defla~ed much before the tire
does. Alternatively a ballast tank can be connected to the air cylinder supply
line to effectively increase the volume of air that must be deflated before the
air cylinder permits unlatching of the door.
Such a three-way valve can be spring-biased toward the position in
which there is no inflation or deflation, or it can be completely unbiased so as
to remain in any position into which it is manually actuated.
The inflating and deflating control can be modif:ied to use a stand-
ard quick-connect air supply connector as a control means. Such quick-connect
connector is easily slipped into connecting engagement, and just as easily
removed from connecting engagement. By having such engagement with a line that
runs through a check valve to the air cylinder, and also witn a branched line
that runs through an on-off valve and through the door-interlock valve to the
tire, no further mechanism is needed. Inflation is accomplished by attaching
the air-suppl~ connector which causes the air cylinder to become inflated, and
actuating the on-of~ valve to on position to cause the tire also to be inflated.
When the tire inflation is completed the on-off valve is returned to off posi-
tion and the air-supply connector is removed. Such removal permits the air
cylinder bleed to slowly deflate that cylinder, so that the inflated tire will
not be prematurely removed from the protecting box. Also the tire can be
deflated at any time a~ter the air-supply connector is removed, by simply
actuating the on-off valve to on position.
I~ desired the air-cylinder bleed can in the last-men-tioned embodi-
ment be built into the check valve, as by using a speed control valve of the
type described on page 28 of the above-cited Schrader catalog. Such a valve has
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3 ~ tj
no actucltor, perlnits ~ low in one clirection llke an ordinary check valve,
but only very limitecl flow in the opposite direction.
To reduce the danger of having one's finger caught under latch lever
end 288 and abruptly pinched against latch bar 291, the air cylinder can be
arranged to close the latch gradually. One simple way to accomplish this is
to use a cylinder that has an exhaust outlet through which air is pushed out
when the cylinder is being inflated, and sharply restricting the exhaust through
that outlet.
A box as illustrated in Figure 3 has withstood a number of test
explosions induced by inflating large truck tires that had their side walls cut
to induce blow-outs, or were mounted on multi-part rims incorrectly assembled.
Some of the explosions took place at inflation pressures as high as 125 psig.
Although the explosions generally caused a rim part to explode against a plastic
window, the window did not break. On one occasion a small piece of the plastic
was chipped off the edge of the window.
With unreinforced panel walls as thin as 1/~ inch or less, an
explosion at high pressure causes the side walls to bow out a little, particular-
ly at the door opening. A little bowing of this nature does not disable the box,
particularly where as in ~igure 3, the latch conti-nues to operate even after the
mouth of panel 211 bows enough to shift latch lever end 288 an inch or more to-
ward the free end of latch bar 291. The thus-bowed hox can generally be immedi-
ately re-used without the need for repairs. It is accordingly helpful to have
the free end of latch bar 291 extend an extra inch or two beyond the latch
lever. Other latches that tolerate such bowing can also be used. A bulged
box can be readily straightened a number o~ times without seriously weaken;ng
it. 'rO cf~ect the straightening it is only necessary to appl~ a squeezing force
to the opposing side panels o the box, to squeeze them towarcl each other. A
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1 3 .~ ~
heavy pipe clamp can be used for thc squcezing.
Some explosions have caused the wheel rim to cut right through the
air hose where that hose crosses past the edge of the wheel rim to reach the
tire valve. This cutting is not necessarily undesirable, inasmuch as it auto-
matically starts the deflation of the expanded tire tube. That tube does not
necessarily burst when a wheel rim fails. Instead, separation of the rim
causes the tube to expand under the influence of its internal pressure and fill
the available space in the box. However, cutting of the hose can be prevented
by providing it with a sturdy shield. Thus a reinforcing bar one to two inches
deep can be welded to the interior of panel 211 from near the top to near the
bottom of that panel and a slot or passageway cut through the bar ~o carry the
inflating hose past it. An exploding rim will then strike the reinforcing bar
instead of the hose.
Additional reinforcing bars can be welded to panel 211 as well as to
opposing panel 212 to reduce the bulging effect of an explosion, and can
similarly further protect the air hose from being pinched against the inside
wall of the adjacent panel by an expanded tire. The reinforcing bars can be
welded to the exterior of these panels instead of or in addition to their in-
teriors. Thuâ a set o~ four spaced 1 inch by 2 inch reinforcing s~eel bars
welded to the outside sur-~ace of panel 211 over its entire height will reduce
to insigificance the bulging of that panel, and corresponding reinforcement
can also be welded to the outside o-~ opposite panel 212. Such reinforcement can
also be applied across the width of the top panel. A box that has its sides
heavil~ reinforced can have its metal walls somewhat reduced in thickness, to
3/16 inch for example.
The door of the box can also be arranged to help resist the bulging
of the side panels. Thus the door can have about half-way up lts height an
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1 ~13;~
extension such as the rings of Figure 1, that engages the outside face of the
side panel when the door is closed. Supplying the door with a sturdy hinge
fixed to the opposite panel half-way up its height further improved the bulge
resistance.
Block 270 of Figures 3 and 4 should be located where it is not
damaged by an explosion. Thus it can be mounted as far as practicable from the
wheel rim and can even be moved to the outer surface of panel 211.
F~gure 7 illustrates a tire inflating box or charnber 410 along the
lines of the last mentioned modification. Box 410 is built very much like box
210~ with transparent panels 453 secured to the inner faces of side walls 411,
412. In Figure 7 the windows 430 cut out of the metal side panels 411, 412
have rounded corners 431 and each is spanned by one of ~our reinforcing bars
401, 402, 403 and 404 welded to the external faces of those panels.
Side panel 411 carrying the latching mechanism has that mechanism
enclosed by a removable cover 441, and has its reinforcing bar 401 notched out
at 406 to make room ~or that mechanism. Air conduit 472 running to the latching
mechanism is a metal pipe mounted on the outer face of panel 411 and penetrating
through an opening 473 near the panel's top, to connect to interlock valve 481.
The conduit from valYe 481 to the-main valve is also preferably metal pipe.
A pipe tee 470 connects pipe 472 to the latching mechanism as well
as to inflation pipe 479 which runs to near the center of window panel 453. An
opening 469 in reinforcing bar 402 permits pipe 479 to run straight to ano~her
opening 468, this one in that window panel. At opening 468 pipe 479 enters the
interior o~ the box, and within the box is fitted with a self-coiling, resilient,
flexible conduit 466, The end of conduit 466 carries a tire-valve-clamping
fitting 464.
The self~coiling conduit 466 is easily stretched out when it is to
- 17 -
be clamped to a valve on a tire brought near the open box mouth. Then, when
the conduit-carrying tire is rolled into the box, the conduit coils itself and
keeps itself generally out of the way so that it is not likely to be damaged
by inflation explosions. Transparent windows 453 of 1/2 inch thick polycarbon-
ate resin are not damaged by such explosions, notwithstanding ~he weakening
effect of the opening 468.
A check valve 483 is preferably fitted between pipes 472 and 479 to
permit air to flow to the tire, but preventing its flow in the reverse direc-
tion. Also a manually-operated vent valve 485 can be inserted in pipe 479 to
permit the discharge of air from an inflated tire, if it is noted that there is
an inflation problem. A pressure gauge 487 downstream of the vent valve enables
the direct reading of the pressure in the tire, when operating the main valve
at the rear of the box.
Box 410 has three hinges 491, 492, 493 for its door 41~, and the
door needs no further reinforcement. Reinforci.ng bars 401, 402, 403, 404 are
shown as extending over top panel 413 of the box, but need not be nor need they
be welded to that top panel, although welding there provides an extra measure
of safety. These reinforcements can also be similarly extended around the box
floor 414 if desired, and welded to that floor.
The transparent panels 453 can be further strengthened as by filling
in the space between their ~uter faces and the nearby inner f'aces of the rein-
forcing bars. Alternatively, those bars can 'have offset central portions that
rest against the outer faces of those panels.
Reinf'orcing bar 401 or 404 can be omitted. Bars 402 can be welded
to side panels 411, 412 directly over side edges of' the window cutouts 430.
Where bars 404 are wsed, they too can be welded directly over the window cutout
edges.
- 18 -
. .3 '~ ~
Latch bar 488 can be notched as at 489, to receive the nose 490 of
the latching lever when the door is closed, with the unlatched latching lever
arranged to tilt upwardly by an amount that only clears the bottom of notch 489
by about 1/8 inch or less. This leaves no significant room for insertion of a
person's finger where it might be injured by a forceful latch closing.
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