Method for force correction

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a known tire uniformity machine having two grinding wheels, wherein said grinding wheels are positioned to grind one or more shoulder ribs or opposing center ribs of the tread surface of the tire;
• (b) employing said uniformity machine to grind the tire whereby at least one of the grinding wheels is engaging the tire in an up-grinding manner and at least one of the grinding wheels is engaging the tire in a down-grinding manner;
• and
• (c) applying an unequal grinding pressure to the tire, wherein a grinding pressure applied to the tire by the grinding wheel engaging the tire in a down-grinding manner is greater than a grinding pressure applied to the tire by the grinding wheel engaging the tire in an up-grinding manner.

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a known tire uniformity machine having three grinding wheels;
• and
• (b) employing said uniformity machine to grind the tire whereby at least one of the grinding wheels is engaging the tire in an up-grinding manner and at least one of the grinding wheels is engaging the tire in a down-grinding manner;
• (c) wherein the tread surface of the tire has a center and two shoulders, and two of said grinding wheels are positioned to grind the two shoulders, both of said grinding wheels being driven in the same rotational direction relative to each other;
• and
• (c) the third of said grinding wheels is positioned to grind the center of the tread surface of the tire, said grinding wheel being driven in the opposite rotational direction relative to the grinding wheels positioned on the two shoulders of the tire.

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a known tire uniformity machine having at least two grinding wheels;
• and
• (b) employing said uniformity machine to grind the tire whereby at least one of the grinding wheels is engaging the tire in an up-grinding manner and at least one of the grinding wheels is engaging the tire in a down-grinding manner;
• wherein unequal grinding pressures are applied to the tire, so that a grinding pressure applied by the grinding wheel(s) engaging the tire in a down-grinding manner is greater than a grinding pressure applied by the grinding wheel(s) engaging the tire in an up-grinding manner.

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a known tire uniformity machine having at least two grinding wheels;
• and
• (b) employing said uniformity machine to grind the tire whereby at least one of the grinding wheels is engaging the tire in an up-grinding manner and at least one of the grinding wheels is engaging the tire in a down-grinding manner;
• wherein a grinding pressure applied by the grinding wheel(s) engaging the tire in a up-grinding manner corresponds to a load on the grinding wheel motor of about 30 to 80% of the load on the grinding wheel motor of the down-grinding wheel(s).

An improved method for simultaneously correcting radial and tangential force variation exerted by a pneumatic tire rotating against a load, regardless of the tire's rotational direction, including the reduction of the tangential force variation component that is resultant from the uniformly sloped tread-blocks of conventional radial force correction, the improvement comprising:

• (a) mounting a tire, having two shoulders, on a tire uniformity machine having two grinding wheels, wherein one grinding wheel is positioned on each shoulder of the tire;
• (b) employing said uniformity machine to grind the tire whereby one of the grinding wheels is engaging the tire in an up-grinding manner and the other grinding wheel is engaging the tire in a down-grinding manner;
• and
• (c) applying unequal grinding pressures to the tire, wherein a grinding pressure applied by the grinding wheel engaging the tire in a down-grinding manner is greater than the grinding pressure applied by the grinding wheel engaging the tire in an up-grinding manner.

An improved method for simultaneously correcting radial and tangential force variation exerted by a pneumatic tire rotating against a load, regardless of the tire's rotational direction, including the reduction of the tangential force variation component that is resultant from the uniformly sloped tread-blocks of conventional radial force correction, the improvement comprising:

• (a) mounting a tire, having a tread with two shoulders and a center, on a tire uniformity machine having three grinding wheels, wherein a grinding wheel is positioned on each shoulder of the tire, and the remaining grinding wheel is positioned in the center of the tread surface;
• (b) employing said uniformity machine to grind the tire whereby at least one of the grinding wheels is engaging the tire in an up-grinding manner and at least one of the grinding wheels is engaging the tire in a down-grinding manner;
• (c) driving the grinding wheels positioned on the shoulders of the tire in the same rotational direction relative to each other, and driving the grinding wheel positioned in the center of the tread surface in the opposite rotational direction relative to that of the other grinding wheels;
• and
• (d) applying unequal grinding pressures to the tire, wherein a grinding pressure applied by the center grinding wheels is greater that a grinding pressure applied by the shoulder grinding wheels.

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a on a known tire uniformity machine having two grinding wheels;
• (b) grinding one or more shoulder ribs of said tire whereby the grinding wheels are rotating in the same direction relative to each other, creating a similarly sloped heel-to-toe profile across the tread surface of the tire;
• (c) determining the rotational direction of the tire which corresponds to the tread blocks rotating heel-to-toe;
• (d) determining on which side of a vehicle said tire should be mounted so that it rotates heel-to-toe when the vehicle moves in the forward direction;
• and
• (e) identifying the tire so that it is to be mounted the specific side of the vehicle, as determined above.

An improved method for reducing tangential force variation exerted by a pneumatic tire rotating against a load, the improvement comprising:

• (a) mounting a tire on a on a known tire uniformity machine having two grinding wheels;
• (b) grinding one or more shoulder ribs of said tire whereby the grinding wheels are rotating in the same direction relative to each other, creating a similarly sloped heel-to-toe profile across the tread surface of the tire;
• (c) determining the rotational direction of the tire which corresponds to the tread blacks rotating heel-to-toe;
• and
• (d) determining on which side of a vehicle said tire should be mounted so that it rotates heel-to-toe when the vehicle moves in the forward direction.