AU2004202040A1

AU2004202040A1 - Pneumatic Tire

Info

Publication number: AU2004202040A1
Application number: AU2004202040A
Authority: AU
Inventors: Toshiharu Tanikawa
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2003-05-16
Filing date: 2004-05-13
Publication date: 2004-12-02
Anticipated expiration: 2024-05-13
Also published as: JP2004338628A; JP4098668B2; GB2401588B; AU2004202040B2; GB0410555D0; DE102004024162A1; GB2401588A

Description

S&F Ref: 676535

AUSTRALIA

PATENTS ACT 1990 COMPLETE

SPECIFICATION

FOR A STANDARD

PATENT

Name and Address of Applicant: Actual Inventor(s): Address for Service: Invention Title: Sumitomo Rubber Industries, Ltd., of 6-9, Wakinohamacho 3-chome Chuo-ku, Kobe-shi, Hyogo-ken, Japan Toshiharu Tanikawa Spruson Ferguson St Martins Tower Level 31 Market Street Sydney NSW 2000 (CCN 3710000177) Pneumatic Tire The following statement is a full description of this invention, including the best method of performing it known to me/us:- 5845c PNEUMATIC TIRE BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a pneumatic tire capable of exhibiting high dry grip performance and wear resistance when racing such as circuit race and gymkhana race while sufficiently securing excellent wet grip performance (hydroplaning resistance) when running on a general road.

Prior Art As a tread pattern for a high performance tire produced for not only running on a general road but also for racing such as circuit race and gymkhana race, an S-shape pattern produced mainly for the sake of enhancing the dry grip performance as shown in Fig. 7 and a V-shaped pattern produced mainly for the sake of enhancing both wet grip performance and dry grip performance as shown in Fig. 7(B) are widely used (see Figs.

2 and 8 of Japanese Patent Application Laid-open No. 2000- 127715).

In the S-shaped pattern, since pattern rigidity with respect to the lateral acceleration (lateral G) is high, although the dry grip performance (especially lateral grip performance) is excellent, there is a tendency to proceed wear fast in a portion P1 where an angle 0 between a tread groove a and a circumferential direction of the tire becomes small.

Most portion of the tread groove a is largely increased as large as the angle 0 of 350 or more, and the hydroplaning resistance is inferior.

In the V-shaped pattern, the wet grip performance is excellent, but when a vehicle races on a road having high friction coefficient 9, such as a race course at high lateral acceleration (lateral lateral rigidity in an outer tread half to which is located outer side of the vehicle is not high, and it is difficult to shorten the running time even if composition of tread rubber and a structure of the tire are changed. There is a problem that in the tread groove a disposed in the outer tread half to, aportion P2 where the angle 0 becomes 350 or smaller is worn fast.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a pneumatic tire capable of appropriately enhancing the pattern rigidity while securing excellent dewatering effect, and capable of further enhance dry grip performance, wet grip performance and wear resistance To achieve the above object, claim 1 of the present application provides a pneumatic tire having an asymmetric pattern in which tread patterns on opposite sides of the tire with respect to a tire equator are different from each other, wherein a tread surface is divided in a virtual manner from the tire equator into an inner tread half located at inner side of a vehicle when the tire is mounted to the vehicle and an outer tread half located outer side of the vehicle, a groove area ratio Li of the tread pattern in the inner tread half is set greater than a groove area ratio Lo of the tread pattern in the outer tread half by 0.05 or greater (Li-Lo S0.05), and a groove area ratio L of the tread pattern of the entire tread surface is in a range of 0.15 to 0.35, the inner tread half includes a straight circumferential main groove which continuously extends in a circumferential direction of the tire and which is disposed in a region Y away from the tire equator by a distance corresponding to 20 to of a tread half width from the tire equator to the tread end, an inclination angle X of the groove wall surface of the circumferential main groove with respect to a normal toward the tread surface is 30 to 500, the outer tread half is not provided with a circumferential groove which continuously extends in the circumferential direction of the tire, but is provided with an outwardly inclined lateral main groove having a lateral groove main portion which extends from an inner end on the tire equator toward the tread end and having an inclination angle P of 350 or greater formed between the lateral groove main portion and the circumferential direction of the tire, and the outwardly inclined lateral main groove includes an inner communication portion which is connected to an inner end of the lateral groove main portion and which is in communication with the circumferential main groove beyond the tire equator and/or an outer communication portion which is connected to an outer end of the lateral groove main portion and which is in communication with the tread end, the inclination angle P at the communication position of the communication portion is to 900.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a sectional view of an embodiment of.a pneumatic tire of the present invention; Fig. 2 is a development of a tread pattern of the tire; Fig. 3 is a lateral sectional view of a circumferential main groove; Figs. 4(A) and are diagrams for explaining an inclination angle of a groove wall surface of the circumferential main groove; Fig. 5 is a diagram showing one example of a circumferential groove which is to be eliminated from an outer tread half; Fig. 6 is a development showing another embodiment of a tread pattern used in the invention; and Figs. 7 and are developments showing one example of a tread pattern of a conventional tire.

DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be explained with reference to the drawings. Fig. 1 shows ameridional cross section of a pneumatic tire according to the present invention.

Fig. 2 shows a tread pattern of the pneumatic tire.

In Fig. 1, the pneumatic tire 1 is a high performance tire produced for both running on a general road and running on a race road such as circuit race and gymkhana race. The pneumatic tire 1 includes a carcass 6 of a radial structure. The carcass 6 extends from a tread portion 2 to a bead core 5 of a bead portion 4 through a sidewall portion 3.

A belt layer 7 is provided radially outward of the carcass 6 and radially inward of the tread portion 2. A tire aspect ratio H/W which is a ratio of a tire cross section height H and a tire width W is set to 50% or lower 40%) by hoop effect.

With this configuration, tire rigidity is enhanced, a tread width TW is increased, and high speed performance and steering stability are enhanced.

Here, the "tread width TW" is a distance of the tire in its axial direction between tread ends E and E. Here, a point of intersection of a phantom line which is obtained by extending an outline of the tread surface 2S outwardly in the axial direction of the tire and a phantom line obtained by extending an outline of a buttress surface 3S outwardly in a radial direction of the tire is defined as The "tread end E" is a point where a line in the radial direction of the tire passing through this intersection point J intersects with a tire surface.

In the pneumatic tire 1 of this invention, when the tread surface 2S is divided in a virtual manner from a tire equator C into an inner tread half Si located at inner side of a vehicle (0 when the tire is mounted to the vehicle and an outer tread half So located outer side of the vehicle, a tread pattern of the inner tread half Si and a tread pattern of the outer tread half So are different from each other and are asymmetric with each other.

'1 More specifically, as shown in Fig. 2, the inner tread half Si includes one circumferential main groove 10 which straightly extends continuously in a circumferential direction of the tire. The circumferential main groove 10 is formed in a region Y separated from the tire equator C by a distance corresponding to 20 to 55% of a tread half width TW/2 (1/2 of the tread width TW).

The circumferential main groove 10 is a straight groove having high dewatering effect, and its groove width GWO is 14 mm or wider, and preferably 18 mm. The groove width GWO is preferably 25mm or less. A center line of the groove is located in the region Y. That is, a distance LO between the groove center line and the tire equator C is 20 to 55% of the tread half width TW/2.

If the circumferential main groove 10 is disposed outer side of the vehicle from the region Y, pattern rigidity in the outer tread half So can not sufficiently be secured, and it becomes difficult to satisfy high dry grip performance and wear resistance at high level which are required in the case of racing.

If the circumferential main groove 10 is disposed inner side of the vehicle than the region Y on the contrary, wet grip performance required when running on a general road can not sufficiently be secured.

For securing the dry grip performance and wear resistance, in a groove cross section which is perpendicular to the groove center line of the circumferential main groove 10, as shown in Fig. 3, it is necessary that the groove wall surfaceg is inclined at an inclination angle x as great as 30 to 500 with respect to a normal of the groove side edge with respect to the tread surface 2S. A large lateral force is applied to the outer side of the vehicle as compared with the inner side of the vehicle especially when the vehicle turns. Therefore, it is preferable that an inclination angle xo of a groove wall surface go located at outer side of the vehicle is greater (Oco xi) than an inclination angle ai of a groove wall surface gi located inner side of the vehicle within the above-described angle range. If the inclination angle c is less than 300, the rigidity in the vicinity of the groove side edge is insufficient, deviated wear such as orbit wear is caused and the wear resistance is deteriorated. If the inclination angle X exceeds 50', the groove volume is reduced and the dewatering effect is deteriorated.

When the groove wall surface g is curved into a convex circular shape as shown in Fig. an inclination angle a of a tangent at each position of the curved surface is in a range of 30 to 500. When the groove wall surface g is a bent surface having a plurality of surfaces as shown in Fig. an inclination angle a of each surface is in a range of 30 to 500.

When the inclination angle xi and the inclination angle Xo are compared with each other, if the groove wall surface g is the curved surface, the comparison is made using an average value of a maximum value and a minimum value of the inclination angle x of the tangent, and if the groove wall surface g is the bent surface, the comparison is made using an average value of the inclination angles X of the surfaces.

The inner tread half Si can be provided with an inner inclined lateral main groove 11 between the circumferential main groove 10 and the inner tread end Ei. The inner inclined lateral main groove 11 of this example includes a first inner inclined lateral main groove 11A whose inner end is in communication with the circumferential main groove 10 and outer end is away from the inner tread end Ei by a distance L1 in the axial direction of the tire.

Especially in this example, the inner inclined lateral main groove 11 includes, in addition to the first inner inclined lateral main groove 11A, a second inner inclined lateral main groove liB whose outer end is in communication with the inner tread end Ei and inner end is away from the circumferential main groove 10 by a distance L2 in the axial direction of the tire.

It is preferable that the first and second inner inclined lateral main grooves 11A and 11B are disposed alternately in the circumferential direction in terms of uniformity.

The distances L1 and L2 are preferably 7% to 14% of the tread width TW. If the distances are less than the rigidity is lowered and there is a tendency to deteriorate the dry grip performance and the wear resistance. If the distances exceed 14%, there is a tendency to reduce the wet grip performance.

To secure the wet grip performance, it is preferable that the first and second inner inclined lateral main grooves 11A and liB are superposed on each other in the circumferential direction of the tire to form a superposed portion 12.

It is preferable that the inclination angle y formed between the inner inclined lateral main groove 11 and the circumferential direction is 350 or greater. It is especially preferable that an inclination angle yl formed between the circumferential main groove 10 and the inner tread end Ei at their communication position is 75 to 900. With this configuration, it is possible to suppress the excessive reduction in rigidity and deterioration of wear resistance at the communication position.

Since greater lateral force is applied to the outer tread half So when the vehicle turns, higher lateral rigidity is required. For this purpose, as shown inFig. 2, the outer tread half So is not provided with a circumferential groove continuously extending in the circumferential direction of the tire, and is formed with an outwardly inclined lateral main groove 20 inclining with respect to the circumferential direction of the tire.

The above expression that "the outer tread half So is not provided with a circumferential groove continuously extending in the circumferential direction of the tire" means that all circumferential grooves which may reduce the pattern lateral rigidity are eliminated. For example, grooves which should be eliminated are a main groove having a width of 3 mm or wider provided mainly for the sake of dewatering, a thin groove having a width of 1.0 to 3 mm providedmainly for the sake of optimizing the dewatering and pattern rigidity, and a sipinghavinga width of less than 1.0 mm provided mainly for the sake of optimizing the patter rigidity and securing the edge effect. As briefly shown in Fig. 5, connection grooves 30A which sequentially connect the outwardly inclined lateral main grooves 20 and to each other which are adjacent to each other in the circumferential direction of the tire can also be regarded as one zigzag circumferential grooves 30, and these grooves should also be eliminated.

The outwardly inclined lateral main groove 20 includes at least a lateral groove main portion 21 which has an inclination angle P of 350 or greater with respect to the circumferential direction of the tire and which extends from an inner end 21Ei on the tire equator C toward an outer tread end Eo. The lateral groove main portion 21 is continuously provided with an inner communication portion 22i which is connected to the inner end 21Ei and which is in communication with the circumferential main groove 10 beyond the tire equator C, and an outer communication portion 22o which is connected to an outer end 21Eo of the lateral groove main portion 21 and which is in communication with the outer tread end Eo.

In this example, the outwardly inclined lateral main groove 20 includes first outwardly inclined lateral main grooves 20A whose outer communication portions 22o are connected to the lateral groove main portions 21, and second outwardly inclined lateral main grooves 20B whose inner communication portions 22i are connected to the lateral groove main portions 21. At that time, it is preferable that the first and second outwardly inclined lateral main grooves 20A and are alternately disposed in terms of uniformity. If necessary, an edge-projecting portion 24 (shown with a chain line) which extends from the inner end 21Ei of the lateral groove main portion 21 beyond the tire equator C and which separated from the circumferential main groove 10 by a distance L3 in the axial direction of the tire may be provided as the first outwardly inclined lateral main groove Here, in the outwardly inclined lateral main groove it is necessary that the inclination angle P is 350 or greater.

If the angle is less than 350, the pattern lateral rigidity with respect to the lateral force at the time of turning of the vehicle is insufficient. As a result, the dry grip performance (especially lateral grip performance) during racing becomes insufficient, running time can not be enhanced, and the wear resistance in the vicinity of the groove side edge of the outwardly inclined lateral main groove 20 is deteriorated.

There is a tendency that in the outwardly inclined lateral main groove 20, the rigidity of the communication position between the outer tread end Eo and the circumferential main groove 10 is reduced, and the wear resistance is deteriorated.

Thus, it is important that the inclination angle P1 at the communication position of the communication portions 22i and 22o is set in a range of 75 to 900 and the reduction in rigidity is suppressed.

When the outwardly inclined lateral main grooves 11 and are curved, the inclination angles P andy are indicated with inclination angle of the tangent.

In the second outwardly inclined lateral main groove it is preferable that a distance L4 between its outer end and outer tread end Eo is 10 to 20% of the tread width TW. If the distance L4 is less than 10%, the rigidity is reduced and there is a tendency to reduce the dry grip performance and wear resistance. If the distance L4 exceeds 20% on the contrary, there is a tendency to reduce the wet grip performance. If the first outwardly inclined lateral main groove 20A is provided with the edge-projecting portion 24, it is preferable that the distance L3 between the edge-projecting portion 24 and the circumferential main groove 10 is 12% or more of the tread width TW in order to secure the dry grip performance and wear resistance.

Next, in the pneumatic tire 1 of the present invention, a groove area ratio L of the tread pattern in the entire tread surface 2S is in a range of 0.15 to 0.35. A groove area ratio Lo of the tread pattern in the outer tread half So is set smaller than a groove area ratio Li of the tread pattern in the inner tread half Si by 0.05 or smaller (Li-Lo 0.05) so that the pattern rigidity is enhanced and greater lateral grip can be obtained in the outer tread half So. The groove area ratio means a ratio of an opening area of the tread groove which occupies the tread surface.

If the groove area ratio L is less than 0.15, it is difficult to secure the necessary wet grip performance. If the groove area ratio L is greater than 0.35 and if a difference Li-Lo of the groove area ratios is less than 0.05, it becomes difficult to satisfy high dry grip performance and wear resistance required by racing. It is preferable that the difference Li-Lo of the groove area ratios is 0.12 or less in terms of the wet grip performance.

The inner and outwardly inclined lateral main grooves 11 and 20 are dewatering main grooves having widths GW1 and GW2 of 3 mm or more. The upper limit values of the groove widths GWO, GW1 and GW", and forming pitches of the inner and outwardly inclined lateral main grooves 11 and 20 are appropriately set in accordance with the groove area ratio L, and the difference Li-Lo of the groove area ratios.

Next, in order to largely enhance the turning performance while sufficiently utilizing the excellent lateral grip performance, a ratio Hi-Ho of a radial distance Hi of the inner tread end Ei from the tire equator point CO and a radial distance Ho of the outer tread end Eo from the tire equator point CO is 1.02 to 1.20, and the pneumatic tire 1 of the present invention has asymmetric tread outline shape.

When a vehicle turns, in a tire thereof closer to the turning center, a ground-contact center of the tire is on the side of the inner tread half Si, and in a tire of the vehicle on the opposite side from the former tire closer to the turning center, a ground-contact center of the tire is on the side of the outer tread half So. At that time, if the ratio Hi/Ho is 1.02 to 1.20, an actually rotating radius of the tire closer to the turning center, an actually rotating radius on the side of the inner tread half Si can be smaller than an actually rotating radius of the tire opposite from the turning center, an actually rotating radius of the outer tread half So, and the vehicle can turn smoothly. If the ratio Hi/Ho is less than 1.02, the above effect can not be exhibited, and if the ratio exceeds 1.20, there are tendencies that the straight running performance is deteriorated, a ground-contact pressure distribution becomes uneven, and the wear resistance is deteriorated.

Fig. 6 shows another embodiment of the tread pattern. In Fig. 6, an inner inclined lateral main groove 11 comprising only the first inner inclined lateral main groove 11A is disposed in the inner tread half Si, and an outwardly inclined lateral main groove 20 comprising only the first outwardly inclined lateral main groove 20A is disposed in the outer tread half So.

Although the preferred embodiment has been described in detail, the tire of the present invention can be employed as a tire for a general passenger car, and the invention is not limited to the illustrated embodiment, and the invention can be variously modified and carried out.

Examples Pneumatic tires (255/40ZR17) having the structure shown in Fig. 1 and having tread patterns shown in Figs. 2, 6 and 7 were prototyped in accordance with specifications shown in Table 1, the wet grip performance and running time in a gymkhana race of the prototyped tires were measured, and results thereof are shown in Table i. Specifications not shown in Table 1 are substantially the same.

Wet grip performance (straight hydroplaning resistance): The prototyped tires were mounted to all wheels of a passenger car (2600 cc) having rims (9Jx17) and internal pressure (230 kPa), the vehicle was allowed to accelerate on a straight road (depth of water was 10 mm) and the acceleration limit speed was measured. Results of the measurement are shown with indices in which a comparative example 1 is 100. The higher numeric value, the more excellent the result is.

Wet grip performance (lateral hydroplaning resistance): The same vehicle was allowed to run on an asphalt road surface having a puddle (depth of water was 5 mm and length was the speed was increased in stages, the lateral acceleration (lateral G) was measured, and average lateral G of a front wheel at the speed of 50 to 80 km/h was calculated.

The average lateral G is indicated with indices in which the comparative example 1 is 100. The higher numeric value, the more excellent the result is.

Table 1 Comparative Example 1 Example 2 Example 1 Tread pattern Groove area ratio L Groove area ratio Li Groove area ratio Lo Circumferential main groove Groove width GWO (mm) Distance LO (mm) Inclination angle of groove wall surface (0) (ai, ao) Inner inclined lateral main groove Groove width GW1 (mm) Inclination angle y (minimum value) (0) Inclination angle yl (0) Distance L1 (mm) Distance L2 (mm) Outer inclined lateral main groove Groove width GW2 (mm) Inclination angle 3 (minimum value) (0) Inclination angle 3i (0) Distance L3 (mm) Distance L4 (mm) Straight hydroplaning resistance Lateral hydroplaning resistance Running time Fig. 7 0.22 0.22 0.22 No groove groove Fig. 6 0.22 0.24 0.20 Straight 18 45 (45, 45) Groove 14 55 55 34 Groove 13 50 90 36 102 103 1'01"05 Fig. 2 0.22 0.26 0.18 Straight 18 (45, Groove 14 34 19 Groove 13 36 36 105 105 1'00"84 No groove 100 100 1'01"42 It can be confirmed that in the present example tire, both the wet grip performance and dry grip performance can be enhanced.

Effect of the Invention Since the present invention has the above-described structure, it is possible to appropriately enhance the pattern rigidity while securing excellent dewatering effect, and the dry grip performance, hydroplaning resistance, and wear resistance can be enhanced.

Claims

1. A pneumatic tire having an asymmetric pattern in which tread patterns on opposite sides of the tire with respect to a tire equator are different from each other, wherein a tread surface is divided in a virtual manner from the tire equator into an inner tread half located at inner side of a vehicle when the tire is mounted to the vehicle and an outer tread half located outer side of the vehicle, a groove area ratio Li of the tread pattern in the inner tread half is set greater than a groove area ratio Lo of the tread pattern in the outer tread half by 0.05 or greater (Li-Lo S0.05), and a groove area ratio L of the tread pattern of the entire tread surface is in a range of 0.15 to 0.35, the inner tread half includes a straight circumferential main groove which continuously extends in a circumferential direction of the tire and which is disposed in a region Y away from the tire equator by a distance corresponding to 20 to of a tread half width from the tire equator to the tread end, an inclination angle a of the groove wall surface of the circumferential main groove with respect to a normal toward the tread surface is 30 to the outer tread half is not provided with a circumferential groove which continuously extends in the circumferential direction of the tire, but is provided with an outwardly inclined lateral main groove having a lateral groove main portion which extends from an inner end on the tire equator toward the tread end and having an inclination angle of 350 or greater formed between the lateral groove main portion and the circumferential direction of the tire, and the outwardly inclined lateral main groove includes an inner communication portion which is connected to an inner end of the lateral groove main portion and which is in communication with the circumferential main groove beyond the tire equator and/or an outer communication portion which is connected to an outer end of the lateral groove main portion and which is in communication with the tread end, the inclination angle 5 at the communication position of the communication portion is to

2. The pneumatic tire according to claim 1, wherein the outwardly inclined lateral main groove comprises only a first outwardly inclined lateral main groove in which an outer communication portion is connected to the lateral groove main portion.

3. The pneumatic tire according to claim 1, wherein the outwardly inclined lateral main groove includes a first outwardly inclined lateral main groove in which an outer communication portion is connected to the lateral groove main portion, and a second outwardly inclined lateral main groove in which an inner communication portion is connected to the lateral groove main portion.

4. The pneumatic tire according to claim 3, wherein the outwardly inclined lateral main groove comprises alternately disposed first outwardly inclined lateral main grooves and second outwardly inclined lateral main grooves.

The pneumatic tire according to any one of claims 1 to 4, wherein said inner tread half includes first inner laterally extending grooves communicating with said main circumferential groove and second inner laterally extending grooves extending from said inner tread end towards said equatorial plane.

6. A pneumatic tire having a tread extending from an outer tire shoulder across an equatorial plane of the tire to an inner tire shoulder, said tread having a first pattern between said inner tire shoulder and said equatorial plane and a second pattern between said equatorial plane and said outer tire shoulder, said first pattern including a substantially straight circumferential main groove spaced from said equatorial plane and said inner tire shoulder, said second pattern not having a circumferential groove but a plurality of laterally extending main grooves, each having a main portion extending generally between said equatorial plane and a position spaced inwardly of said outer tire shoulder and inclined at an angle 0 above 35* to a local circumferential direction of the tire, at least some of said main portions being extended by further main groove sections communicating with said circumferential groove and/or being extended by other main groove sections to said outer tire shoulder and being axially outwardly open there.

7. The pneumatic tire according to claim 6, wherein said main circumferential groove has groove wall surfaces inclined at an angle o within the range 30° to 50° with respect to a normal to the tire surface.

8. The pneumatic tire according to claim 6, wherein a groove area ratio Li of the tread pattern in the inner tread half is set greater than a groove area ratio Lo of the tread pattern in the outer tread half by 0.05 or greater (Li-Lo 0.05), and a groove area ratio L of the tread pattern of the entire tread surface is in a range of 0.15 to 0.35.

9. The pneumatic tire according to claim 6, wherein said main circumferential groove is disposed in a region spaced from said equatorial plane by a distance lying in the range of 20-55 of a width corresponding to the distance between said inner tire shoulder and said equatorial plane.

The pneumatic tire according to any one of claims 6 to 9, wherein said first tread pattern includes first inner laterally extending grooves communicating with said main circumferential groove and second inner laterally extending grooves extending from said inner tire shoulder towards said equatorial plane.

11. The pneumatic tire according to any one of the preceding claims, wherein in the tread surface, a ratio Hi/Ho of a radial distance Hi from the inner tread end to the tire equator and a radial distance Ho from the outer tread end to the tire equator is 1.02 to 1.20.

12. The pneumatic tire according to any one of the preceding claims, wherein said main circumferential groove has a width in the range from 14 mm to mm.

13. A pneumatic tire substantially as hereinbefore described with reference to figures 1 to 6.

14. A pneumatic tire substantially as hereinbefore described with reference to any one of the examples. Dated 11 May, 2004 Sumitomo Rubber Industries, Ltd. Patent Attorneys for the Applicant/Nominated Person SPRUSON FERGUSON [R:\LIBLL] I 5629.doc:gxt