BACKGROUND OF THE INVENTION In modern automotive vehicle plants, automated equipment is used to assemble and inflate tires on wheels in preparation for mounting on a vehicle. Prior to inflation, the tire is mounted on the wheel, usually at a separate mounting station, and in some instances the tire is then angularly aligned relative to the wheel to minimize the overall runout of the tire/wheel assembly. See, for example, U. S. Patent No. 5,826,319 to Colwell et al. At a typical tire inflation station, the uninflated wheel-mounted tire is conveyed onto a stationary tire platen beneath an overhead tire inflation bell. Centering arms then engage the tire and center it into alignment with the overhead inflation bell.

The inflation bell is then moved downwardly into engagement with the wheel-mounted tire and inflation air is delivered into the interior of the tire around its inner peripheral bead. The head is then retracted allowing the bead of the tire to seat and seal against the outer peripheral rim of the wheel.

As described in U. S. Patent No. 6,148,892, issued November 21,2000 to A.

Koerner and hereby incorporated herein by reference, a conveyor belt delivers the wheel- mounted tire to the tire platen (bed) of the tire inflation station. To assist in the alignment of the tire relative to the vertical axis of the inflation bell, the bed may be floated on a cushion of air for near-frictionless centering of the tire.

Although the bed of the typical tire inflation station is capable of handling tires of varying outer diameters, the bell housing is typically limited to tires having a specific inner bead diameter, or rim diameter. In addition, a typical station may be capable of

only inflating tires of a single width, with manual adjustment or tool changes being necessary when switching to tires of differing diameter or width. Some approaches for providing automated handling of different sized tires have been proposed. In U. S. Patent No. 5,509,456 to Bonko et al., a segmented manifold is used to supply the inflation air.

The manifold can be expanded radially to accommodate different sizes of tires. U. S.

Patent No. 5,072,765 discloses an auxiliary tire bead depressor for use with an inflation machine to permit a single inflation bell to be used in conjunction with different sized tires. The tire bead depressor comprises a shaft that depresses the tire sidewall at a location between the inflation bell's outer seal ring and the wheel (rim) to prevent premature seating of the bead when the machine is used with a tire and wheel having a relatively small diameter when compared to that of the inflation bell's outer seal ring.

SUMMARY OF THE INVENTION In accordance with the invention there is provided a tire inflation apparatus for use in sequentially inflating a plurality of wheel-mounted tires that can have differing diameters and/or widths. The apparatus includes a base having a tire platen or other support surface upon which the tire being inflated is first loaded. A first bell housing is supported by the base for movement toward and away from the tire support surface, with the first bell housing moving along an axis between a retracted position and an extended position. A second bell housing is also supported by the base for movement along the axis toward and away from the tire support surface between retracted and extended positions. The first bell housing is used in conjunction with larger-sized wheel-mounted tires and the second bell housing is used with smaller-sized tires. The first bell housing is constructed such that, when in its extended position, it will mate with a larger-sized wheel-mounted tire to thereby define a first air chamber between the tire and first bell housing. The second bell housing is constructed such that, when in its extended position, it will mate with a smaller-sized wheel-mounted tire to thereby define a second air chamber between the tire and second bell housing. The second bell housing is located within the first air chamber when the second bell housing is in its retracted position and the first bell housing is in its extended position. This permits a single compressed air

supply tap located within the second bell housing to be used for inflation of both the larger and smaller-sized tires.

Preferably, the first and second bell housings are nested and can extend telescopically, with the first bell housing comprising an outer bell housing the substantially encloses the second, inner bell housing. This can be accomplished using a bell assembly that includes the first and second bell housings along with one or more actuators for telescoping the inner bell housing in and out of the outer bell housing. The bell assembly is supported by the base and is movable as a unit using one or more bell housing actuators. By moving the entire bell assembly with the inner bell housing in its retracted position, the outer bell housing can be moved between from its retracted position into its extended position while the inner bell housing is maintained in its retracted position inside the outer bell housing, and this arrangement permits use of the outer bell housing for inflation of larger-sized tires. Then, for smaller-sized tires, the inner bell housing can be telescoped out of the outer bell housing.

Preferably, a programmable electrical controller controls actuation of the inner bell housing and bell assembly actuators which is dictated by the size or diameter of the tires. Also, the controller establishes the distance between the assembly's extended and retracted positions by taking reference from an elongated linear measurement sensor engaged vertically to the bell assembly. The distance between assembly positions is dictated by the thickness of the tire, or distance between sidewalls. Control of the length of travel of the bell assembly can then be accomplished using one or more hydraulic stops.

An advantage of the present invention is the ability to inflate either a large or small wheel-mounted tire without requiring a manual hardware alteration of the tire inflation apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS A preferred exemplary embodiment of the present invention will now be described in conjunction with the appended drawings, wherein like numerals denote like elements, and wherein:

Figure 1 is a side view, with portions removed to show detail, of a tire inflation apparatus of the present invention; Figure 2 is a partial side view of the tire inflation apparatus of Figure 1 rotated 90° about a centerline; Figure 3 is a cross section view of the tire inflation apparatus taken along line 3-3 of Figure 2; Figure 4 is a cross section view of the bell assembly of the tire inflation apparatus taken along line 4-4 of Figure 3, wherein the bell assembly is shown in the extended position and the inner bell housing is shown in an extended position; Figure 5 is a cross section view of a bell assembly of the tire inflation apparatus taken along line 5-5 of Figure 3, wherein the bell assembly is shown in an extended position and an inner bell housing of the bell assembly is shown in a retracted position; Figure 6 is a cross section view of the bell assembly taken along line 6-6 of Figure 2; and Figure 7 is a partial side view of the tire inflation apparatus showing a linear measurement transducer.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to Figures 1 to 5 of the illustrated embodiment, a high volume tire inflation apparatus 10 is shown as it would be constructed for use in automatically inflating wheel-mounted tires varying in size from a small tire 12 to a large tire 14, without requiring any manual hardware changes. As is common in such machines, inflation air is not blown in through the supplied air valve; instead, a much larger air gap is created by apparatus 10 between the outer peripheral rim 16 of the wheel and an inner peripheral bead 18 of the tire. Pressurized air flows through this gap in the direction indicated by the arrows shown in Figures 4 and 5, thereby inflating the tire to a desired pressure. The apparatus 10 has a stationary frame or base 20 which secures and/or levels to a floor on either side of a conveyer belt and centering apparatus 22 that is used to deliver and position the small or large wheel-mounted tire 12,14 while it is lying substantially flat or horizontally on a tire platen (or other tire support surface) 23.

The tire inflation apparatus 10 includes a bell assembly 24 that extends telescopically downward along a centerline 26 of the centered small or large wheel- mounted tire 12,14 to engage and inflate the tire. Disposed above the small or large tire 12,14 is a substantially planar stationary member 28 secured rigidly to the stationary frame 20 and transversing the centerline 26. The bell assembly 24 is suspended beneath the stationary member 28 and above the small or large tire 12,14. The bell assembly 24 moves axially along the centerline 26 between a tire transfer or retracted position 30 to an extended position 32 (as best shown in Figure 1) via a pair of diametrically opposing bell assembly actuators 34 (as best shown in Figures 2 and 3) engaged between the stationary member 28 and an outer bell housing 36 of the bell assembly 24. The inner bell housing 38 extends to an extended position 40 and retracts to a retracted position 42 with respect to the outer bell housing 36 via a pair of diametrically opposing inner actuators 44, which are offset circumferentially from the bell assembly actuators 34 by ninety degrees, as best shown in Figures 4,5 and 6. Referring to Figure 1, when the wheel-mounted tires are being transferred to or from the tire inflation apparatus 10, the bell assembly 24 and bell assembly actuators 34 are in the retracted position 30 and the inner bell housing 38 and inner actuators 44 are normally in the extended state 40. As best shown in Figures 1 and 4, when the small wheel-mounted tire 12 is being inflated, the bell assembly 24 and bell assembly actuators 34 are in the extended position 32 and the inner bell housing 38 and inner actuators 44 are in the extended state 40. As best shown in Figures 1 and 5, when the large wheel-mounted tire 14 is being inflated, the bell assembly 24 and bell assembly actuators 34 are substantially in the extended position 32 and the inner bell housing 38 and inner actuators 44 are in the retracted state 42.

Referring to Figure 3, the outer bell housing 36 of the bell assembly 24 has a substantially planar square plate 48 which transverses the centerline 26. Engaged rigidly between, and projecting downward from the plate 48 to an outer annular seal ring 50 is a substantially cylindrical skirt 52. The plate 48, skirt 52 and ring 50 define an outer air chamber 54 large enough to envelop the inner bell housing 38. As best shown in Figure 5, when the bell assembly 24 is in the extended position 32 and the inner bell housing 38 is in the retracted state 42, the outer annular seal ring 50 has pushed down upon an upward facing side wall 56 of the large wheel-mounted tire 14 forcing the tires peripheral bead 18 away from the rim 16 of the wheel, creating the air gap through which

compressed air flows enveloping the wheel and tire. The downward force of the air and ring 50 causes the downward facing sidewall 57 of the tire to seal against the bed or centering apparatus 22 thereby allowing the tire to inflate.

Referring to Figures 4 and 6, the inner bell housing 38 of the bell assembly 24 has a substantially circular plate 58 which traverses the centerline 26 and has a diameter less than an inner diameter of the outer annular ring 50. An inner annular seal ring 60 projects substantially perpendicular to, and downward from, the peripheral edge of the circular plate 58, thereby defining an inner air chamber 62. When the inner bell housing 38 is in the extended state 40, a substantial portion of the inner annular seal ring 60 projects axially below the outer bell housing 36. When the bell assembly 24 is in the extended position 32 and the inner bell housing 38 is in the extended state 40, the inner annular seal ring 60 has pushed down upon the upward facing side wall 56 of the small wheel-mounted tire 12 forcing the tires peripheral bead 18 away from the rim 16 of the wheel, creating the air gap through which compressed air flows and the small tire inflates as the downward facing sidewall 57 seals against the bed 22.

Feeding compressed air to the inner air chamber 62 are four compressed air supply taps 64 mounted to the plate 66 and spaced circumferentially so that the air flow is quickly and evenly distributed within the tire. Air flows through the taps 64 when the outer or inner bell housings 36,38 are engaged to the respective large or small tires 14, 12.

Referring to Figures 2 and 3, projecting upward from the square plate 48 at each corner is a base sleeve 68 which receives a base rod 70 of a bell assembly linear guide 72. All four of the bell assembly linear guides 72 are parallel to the centerline 26. The guides assure that the bell assembly 24 remains concentric about the centerline 26 and extends and retracts above the wheel-mounted tires 12,14 squarely and without skewing.

Projecting rigidly above the stationary member 28 are four bell assembly guide sleeves 74 each having bores which receive the respective base rod 70 for linear translation there through. The base rods 70 do not penetrate or communicate with the outer or inner air chambers 54,62.

Each one of the diametrically opposed bell assembly actuators 34 of the bell assembly 24 extend parallel to the centerline 26 and are equally spaced between two adjacent bell assembly linear guides 72. The bell assembly actuator 34 is preferably

pneumatic having an encasement mounted to and projecting above the stationary member 28. A cylinder 76 of the bell assembly actuator 34 translates through the stationary member 28 and is engaged at a distal end to the square plate 48 of the bell assembly 24.

The cylinder 76 moves downward out of the encasement of the bell assembly actuator 34 to engage the small or large tires 12,14 and retracts into the encasement of the bell assembly actuator 34 to move the bell assembly 24 back to a tire transfer or retracted position 30 wherein the next wheel-mounted tire 12,14 is aligned and placed, via the conveyer belt and positioning apparatus 22, for inflation.

Projecting rigidly upward from circular plate 58 of the inner bell housing 38 are four circumferentially spaced inner linear guides 78 which assure that the inner bell housing 38 moves squarely along the centerline 26. Each guide 78 has an inner base sleeve 86 which projects rigidly upward from the circular plate 58. Each inner base sleeve receives an inner rod 88 of the inner linear guide 78 which extends upward through the square plate 48. Projecting rigidly upward from the square plate 48 are four inner guide sleeves 90 disposed concentrically about each respective inner rod 88. The inner guide sleeves 90 are disposed at the four corners of the square plate 48 but radially inward from the base sleeves 68, as best shown in Figure 3. A plate or reinforcement web 92 interconnects longitudinally the base sleeve 68 to the inner guide sleeve 90 respectively, thereby reinforcing the sleeves and assuring the bell assembly remains aligned and unskewed to the centerline 26 of the wheel-mounted tire 12,14. To prevent the escape of air from the outer air chamber 54, two circular seals 94 are longitudinally spaced from one-another between the inner guide sleeve 74 and the inner rod 88. The inner rods 88 are preferably hollow thereby forming or defining air passages 96 which communicate through the respective air supply taps 64 creating an evenly distributed and high rate of compressed air to the inner air chamber 62.

Each one of the diametrically opposed inner actuators 44 of the bell assembly 34 extend parallel to the centerline 26 and are equally spaced between two adjacent inner linear guides 78. The inner actuator 44 is preferably pneumatic having an encasement mounted to and projecting above the square plate 48. An inner cylinder 100 of the inner actuator 44 translates through the square plate 48 and is engaged at a distal end to the round plate 58 of the inner bell housing 38 from above. The inner actuators 44 are positioned ninety degrees out of phase from the bell assembly actuators 34, about the

centerline 26. The inner cylinder 100 moves downward out of the encasement of the inner actuator 44 to extend the inner bell housing 38 for engagement of the small wheel- mounted tire 12 and retracts into the encasement of the inner actuator 44 to clear the outer bell housing 36 for engagement of the large wheel-mounted tire 14 for inflation.

During inflation of the small or large wheel-mounted tires 12.14, the influx of compressed air creates an upward force that can exceed ten tons of force. To maintain the positioning of the bell housings in the presence of this force, a bell assembly hydraulic stop 104 is incorporated, which projects rigidly upward from the stationary member 28 and is centered about the centerline 26. The bell assembly hydraulic stop 104 preferably utilizes oil as a fluid and has a cylinder 106 which extends and retracts in unison with the cylinders 76 of the bell assembly actuators 34. When fully extended or retracted, a control valve (not shown) closes, via an electrical signal from a controller 108, to prevent flow of the oil thereby securing the bell assembly 24 in the extended or retracted positions 40,42. Consequently, the bell assembly hydraulic stop 104 prevents premature upward movement of the bell assembly 24 during inflation of the small or large wheel-mounted tire 12,14, and assures that the bell assembly 24 remains in the retracted position during transfer of tires to and from the apparatus 10.

An inner hydraulic stop 110 has an encasement 112 which rigidly projects upward from the square plate 48 along the centerline 26. Engaged concentrically to the top of the encasement 112 is the distal end of the cylinder 106 of the bell assembly hydraulic stop 104. Retracting and extending through the square plate 48 is a cylinder 114 of the inner hydraulic stop 110. The distal end of the cylinder 114 is engaged centrally to the circular plate 58 of the inner bell housing 38. The cylinder 114 extends and retracts in unison with the inner cylinder 100 of the inner actuator 44. The inner hydraulic stop 110 engages when the cylinder 100 is in the extended position 32 and the inner bell housing 38 is in the extended position 40 for inflating the small wheel-mounted tire 12. The inner hydraulic stop 110 thereby protects the inner actuator 44 from the upward forces produced by the compressed air during the inflation process.

Operation of the tire inflation apparatus 10 is conducted via the controller 108 which can be a suitable PLC or microprocessor-based computer. For inflating small wheel mounted tires 12, the inner bell housing 38 of the bell assembly 24 is pre-set to the extended position 40 while the bell assembly 24 is in the tire transfer or retracted position

30. The known tire thickness (width), which is dependent upon the vertical distance between sidewalls 56,57 of the tire, is also provided to the controller. Where the apparatus 10 is used on a production line handling a single size of tire, this information can be pre-set by the operator. Where production involves multiple tire sizes to be run on a single line at one time, the diameter and width data can be supplied to the controller by a separate, upstream controller so that the apparatus knows the relative dimensions for each tire entering the station.

This tire size information will establish which of the bells should be used for inflation as well as the appropriate linear travel of the bell assembly 24 between the retracted and extended positions for the particular tire entering the station. For the smaller-sized tires, the inner bell housing 38 is extended, and this position is maintained by the controller 108 which electrically closes a control valve of the inner hydraulic stop 110 to lock the inner bell housing 38 in the extended position 40. When the centering apparatus 22 positions the tire 12 beneath the bell assembly 24, the controller 108 electrically opens the control valve of the bell assembly hydraulic stop 104. The bell assembly actuators 34 then extend the bell assembly 24 to the extended position 32 established based on the supplied tire width data. For this purpose, position feedback data is provided to the controller 108 from an elongated linear measurement sensor 116 engaged vertically to the bell assembly 24. This feedback data can be compared against a pre-established value related to the width data so that the hydraulic stop 104 is locked once the proper extended position 32 is reached. The hydraulic stop 104 is locked by closing its control valve via the controller 108. Compressed air is then released into the inner bell housing 38, pressurizing the inner air chamber 62 and the small tire 12. Once pressurized, the controller valve of the hydraulic stop 104 opens, and the bell assembly lifts or retracts to the retracted position 30, via the controller 108 and the cycle repeats.

The same process occurs for inflation of large wheel-mounted tires 14, except that the inner bell housing 38 is pre-set to the retracted position 42.

Accordingly, it should thus be apparent that there has been provided in accordance with the present invention a tire inflation apparatus that achieves the aims and advantages specified herein. It will of course be understood that the foregoing description is of a preferred exemplary embodiment and that the invention is not limited to the specific embodiment shown. Various changes and modifications will become

apparent to those skilled in the art. For example, the hydraulic stops could be eliminated by using actuators capable of withstanding the upward forces produced during the inflation process. In such an embodiment, the actuators could be positioned concentrically to the centerline 26. As another example, the actuators themselves need not be pneumatic, they could be hydraulic or they could be a motored pinion gear or screw rod arrangement. All such changes and modifications are intended to come within the scope of the appended claims.