Patent Description:
The present disclosure relates to a robotic wheel gripper. More specifically, the present disclosure relates to a robotic wheel gripper that is configured to orient/rotate the wheel to position a tire pressure monitor sensor ("TPMS") valve stem in a predetermined position to prevent damage to the TPMS valve stem during an assembly operation where the tire is mounted to the wheel.

In one exemplary automated tire/wheel assembly system, wheels are transported via a first conveyor system, while the tires are delivered via a second conveyor system. An assembly conveyor is positioned between the first and second conveyor systems. A wheel load robot is configured to grip a wheel and move it to an assembly conveyor, while a tire load robot grips a tire and moves it to the assembly conveyor, so as to partially position the tire on the wheel at an angle to create a tire/wheel subassembly. The tire/wheel subassembly is then transported by the assembly conveyor to a mounting robot. The tire is then mounted on the wheel by the mounting robot so as to fully seat the tire on the wheel, prior to inflation of the tire.

However, one issue that remains problematic in such an automated assembly is that current wheels include valve stem TPM sensors that need to be positioned at a certain angle to properly mate with the tire, without damage the TPM sensors during the assembly operation. Indeed, the degree of precision required in locating the TPM valve stem sensor during assembly of the wheel/tire assembly is problematic because threads of the TPM valve stem can be irreparably damaged during assembly. Accordingly, what is needed is a system that can locate the TPM valve stem and position the wheel on the assembly conveyor so as to properly place the wheel on the tire before the wheel is fully seated so as to prevent damage to the TPM valve stem.

Document <CIT> discloses a dual mode end effector for handling vehicle wheels.

Document <CIT> discloses a tire changing machine.

Document <CIT> discloses an inflation station for inflating tire-wheel assemblies.

Document <CIT> discloses an apparatus for mounting tires.

The invention is set forth in the independent claims. Embodiments result from the dependent claims and the below description.

A robotic wheel gripper unit that is configured for gripping and transporting a wheel to a predetermined position during an assembly operation with a tire is disclosed. In one exemplary arrangement, the robotic wheel gripper unit comprises a selectively moveable arm that includes a gripper tool connected thereto. The gripper tool further includes a plurality of gripper fingers and at least one sensor. The gripper fingers are configured for selectively engaging a portion of a wheel. The sensor is configured to detect a predetermined element on the wheel, such as a TPMS valve stem, to assist in placement of the wheel at a predetermined position during an assembly operation to prevent damage of the wheel element during an assembly operation of mounting a tire to the wheel.

According to the invention, a robotic wheel gripper unit configured for gripping and transporting a wheel to a predetermined position, comprises:.

According to a preferred embodiment, the gripper fingers are selectively moveable from a releasing position to a gripping position, wherein in the releasing position, the gripper fingers are moved laterally away from the wheel.

In one exemplary arrangement, the gripper fingers are carried on platforms that are selectively moveable from a releasing position to a gripping position. When the gripper fingers are in the releasing position, the gripper fingers are moved laterally away from the wheel.

The gripper fingers may include or comprise gripper grooves that are configured to engage with the portion of the wheel when the gripper fingers are in the gripping position.

In one exemplary arrangement, the gripper tool includes two pairs of gripper fingers, with each pair being carried on a common platform. The sensor may be mounted to one of the platforms. For example, in one arrangement, the sensor is mounted to a sensor plate that extends from one of the platforms that carry the gripper fingers.

In one exemplary arrangement the sensor is an optical sensor.

In one exemplary embodiment, the sensor is configured to locate a tire pressure monitor system valve stem on the wheel.

In one exemplary embodiment, the sensor is operatively connected to a controller that records the position of the tire pressure monitor system valve stem with respect to a fixed position such that the gripper tool may position the wheel on an assembly conveyor in a predetermined position to locate the tire pressure monitor system valve stem at a predetermined orientation during an assembly operation with a tire.

According to another preferred embodiment, the moveable arm is operatively connected at a second end thereof to a body portion, wherein the body portion is rotatably-connected to a base portion such that the base portion may be pivoted relative to the base portion.

The invention further relates to a robotic wheel gripper unit configured for gripping and transporting a wheel to a predetermined position, comprising:.

According to another preferred embodiment, the gripper fingers engage a top peripheral edge of the wheel.

A method of operating a robotic wheel gripper unit is also disclosed.

Referring to <FIG>, a robotic wheel gripper <NUM> that is configured for gripping a wheel <NUM> so as to properly load the wheel <NUM> on an assembly conveyor is disclosed. The robotic wheel gripper <NUM> is operable such that a TPMS valve stem <NUM> may be oriented at a predetermined position during assembly with a tire during the assembly process. In this manner, the TPMS vavle stem <NUM> will not be damaged when the tire is assembled to the wheel <NUM>. The robotic wheel gripper <NUM> may include at least one articulated joint <NUM> and a wrist <NUM>. An arm <NUM> is positioned between the joint <NUM> and the wrist <NUM>. The robotic wheel gripper <NUM> is capable of movement with at least three degrees of freedom along one of a selectable plurality of programmable predetermined paths. A gripper tool <NUM> is mounted to the wrist <NUM> of the robotic wheel gripper <NUM>.

The joint <NUM> is mounted to a body portion <NUM> that is connected to a base portion <NUM>. In one exemplary arrangement, the body portion <NUM> is rotatably-connected to the base portion <NUM> such that the body portion <NUM> may be pivoted relative to the base portion <NUM>. Further, the body portion <NUM> may be hinged to the base portion such that the body portion <NUM> may be articulated vertically relative to the base portion <NUM>.

In one exemplary embodiment, the arm <NUM> may be connected to the body portion <NUM> such that the arm <NUM> may be articulated in any desirable upward or downward position relative the body portion <NUM>. Similar to the rotatable connection of the base portion <NUM> and body portion <NUM>, the gripper tool <NUM> may be rotatably-connected to the arm <NUM> such that the gripper tool <NUM> may be rotated, pivoted or otherwise spun <NUM>° relative the arm <NUM>; as will be described in further detail below.

The gripper tool <NUM> includes a plurality of gripper fingers <NUM>. Each gripper finger <NUM> further comprises a grip groove <NUM> that is configured for selectively engaging an upper flange <NUM> of the wheel <NUM> (best seen in <FIG>). In one exemplary arrangement, the gripper tool <NUM> includes <NUM> gripper fingers <NUM>, with the gripper fingers <NUM> arranged in opposing pairs. The gripper tool <NUM> also comprises at least one sensor <NUM> that is configured to locate the TPMS valve stem <NUM>. In one exemplary arrangement, the sensor <NUM> is an optical sensor such as an LED sensor. However, other sensors are contemplated.

The gripper fingers <NUM> may be carried on platforms <NUM> that are selectively moveable from a releasing position (i.e., <FIG>) to a gripping position (i.e., <FIG>). In the releasing position, the opposing gripper fingers <NUM> are moved away from one another. In the gripping position, the opposing gripper fingers <NUM> are moved toward one another, to a distance that is approximately the width of the wheel <NUM>. The sensor <NUM> may be mounted on a separate sensor plate <NUM> that is connected to one of the platforms <NUM>, so as to be positioned between one of the pairs of the gripper fingers <NUM>. With this configuration, the sensor <NUM> will move with the gripper fingers <NUM>.

The operation of the robotic wheel gripper <NUM> will not be described in connection with the flow chart in <FIG>, as well as <FIG>. More specifically, in an initial step <NUM>, the wheel <NUM> is initially positioned on wheel conveyor system (not shown) or platform (not shown) in a known, conventional manner. The robotic wheel gripper <NUM> has the arm <NUM> that is carrying the gripper tool <NUM> fully raised such that a bottom surface <NUM> of the gripper fingers <NUM> is positioned above the top flange <NUM> of the wheel <NUM>. The gripper tool <NUM> is positioned, however, directly over the wheel <NUM> so as to be centered over the wheel <NUM>, as shown in <FIG>, for example.

In step <NUM>, the gripper tool <NUM> is moved downward over the wheel <NUM> into a scanning position. More specifically, as may be seen in <FIG>, the arm <NUM> is pivoted such that the gripper tool <NUM> is lowered. In the scanning position, the gripper fingers <NUM> are positioned to straddle around the wheel <NUM>. In other words, the bottom surface <NUM> of the gripper fingers <NUM> are positioned below the top flange <NUM> of the wheel <NUM>. The sensor <NUM> is also positioned below the top flange <NUM>, but is configured to be located in the plane where the TPMS valve stem <NUM> is positioned on the wheel <NUM>, such that a beam <NUM> from the sensor <NUM> will intersect the TPMS valve stem <NUM> during the scanning operation. In one exemplary configuration, the robot <NUM> can be programed to lower to a certain predetermined height to ensure that the sensor <NUM> intersects with the TPMS valve stem <NUM>. In step <NUM>, the gripper fingers <NUM> are still in a releasing position, such that the gripper fingers <NUM> are not contacting the wheel <NUM>.

Referring to <FIG>, once in the scanning position, in step <NUM>, the gripper tool <NUM> is then operated to rotate around the wheel <NUM>. More specifically, the gripper tool <NUM> rotates around the wheel <NUM> (as illustrated by arrows A in <FIG>) until a beam <NUM> of light from the sensor <NUM> intersects the TPMS valve stem <NUM> so as to locate the TPMS valve stem <NUM>. Once the TPMS valve stem <NUM> is located, the process moves on to step <NUM>.

In step <NUM>, the robotic wheel gripper <NUM> records the angle where the TPMS valve stem <NUM> is located relative to a fixed reference point. The process then proceeds to step <NUM>.

Referring to <FIG>, in step <NUM>, the gripper tool <NUM> is retracted upwardly (with respect to the wheel <NUM>) a predetermined distance so as to align the grip grooves <NUM> of the gripper fingers <NUM> with the upper flange <NUM> of the wheel <NUM>. Once positioned, the gripper fingers <NUM> are moved into an engagement position. More specifically, the gripper fingers <NUM> are moved inwardly and into contact with the upper flange <NUM> of the wheel <NUM>. The process then proceeds to step <NUM>.

In step <NUM>, referring to <FIG>, the robotic wheel gripper <NUM> will rotate the wheel <NUM> and move the wheel <NUM> to orient the TPMS valve stem <NUM> to a predetermined position such that assembly to the tire will not lead to damage. In one exemplary arrangement, the robotic wheel gripper <NUM> rotates the wheel <NUM> while simultaneously moving the wheel <NUM> to the assembly conveyor. The process then proceeds to step <NUM>.

In step <NUM>, and referring specifically to <FIG>, once the wheel <NUM> is positioned on the assembly conveyor (not shown), with the TPMS valve stem <NUM> oriented to a predetermined position, the gripper tool <NUM> moves into the releasing position. More specifically, the gripper fingers <NUM> are moved away from the wheel <NUM>, so as to release the wheel from the gripper tool <NUM>. Next, referring to <FIG>, the arm <NUM> is retracted so as to lift the gripper tool <NUM> upward and away from wheel <NUM>. Once the arm <NUM> is retracted, the robotic wheel gripper <NUM> will return to the wheel conveyor (not shown) and is positioned over another wheel <NUM> to begin the process again.

It is understood that the robotic wheel gripper <NUM> may be automatically operated by a controller (not shown) that is configured to lift and move wheel <NUM> at predetermined time intervals, including coordinating with other robots to producing an automated wheel/tire assembly and inflation system.

Claim 1:
A robotic wheel gripper unit (<NUM>) configured for gripping and transporting a wheel (<NUM>) to a predetermined position, comprising:
a selectively moveable arm (<NUM>); and
a gripper tool (<NUM>) that is connected to a first end of the moveable arm (<NUM>);
wherein the gripper tool (<NUM>) further includes a plurality of gripper fingers (<NUM>) carried on platforms (<NUM>) and configured for selectively engaging a portion of a wheel (<NUM>);
characterized in that
the gripper tool (<NUM>) further comprises at least one sensor (<NUM>) mounted to at least one of the platforms (<NUM>) and configured to detect a location of a predetermined element (<NUM>) on the wheel (<NUM>), the moveable arm (<NUM>) being configured to rotate the gripper tool (<NUM>) about the wheel (<NUM>) until the sensor (<NUM>) detects the location of the predetermined element (<NUM>) on the wheel (<NUM>).