Patent Description:
The green tire is built on a tire building drum and is removed from said tire building drum once the tire building has been completed with the use of a tire unloading unit. The known tire unloading unit is provided with two lower arms and one upper arm which are insertable in the space between a transfer ring and the tire building drum such that the green tire may already be transferred to the tire unloading unit prior to or during retraction of the tire building drum. The upper arm is movable towards the two lower arms to stabilize the green tire in the tire unloading unit. Subsequently, the upper arm is moved away from the two lower arms to allow for weighing of the green tire and/or removal of the green tire from the tire unloading unit by a robot.

<CIT> discloses a method for manufacturing a green tire using a building drum and a transfer device.

<CIT> discloses a tire support device comprising a support member having an inner surface and an outer surface and a support flange mounted to the support member.

A disadvantage of the aforementioned removal of the green tire from the tire building drum and transfer to the tire unloading unit is that the steps are performed relatively quickly to reduce the cycle time of the tire building. The transfer ring, the tire building drum may unintentionally exert forces onto the green tire that may destabilize said green tire. The upper arm has to be pressed down relatively hard onto the green tire to prevent that the green tire falls over within the tire unloading unit. The forceful application of the upper arm on the green tire may cause imprints. It may even deform the general shape of the green tire.

Moreover, after the initial pressing down of the upper arm, the green tire may collapse slightly to a level below the reach of the upper arm, causing it to fall over despite the earlier attempts to stabilize it.

It is an object of the present invention to provide a tire unloading unit for unloading a green tire, wherein the green tire can be reliably stabilized.

The invention provides a tire unloading unit for unloading a green tire, wherein the green tire has an externally facing circumferential tread surface extending around a tire axis, wherein the tire unloading unit comprises a base and a support member for supporting the green tire relative to the base at the externally facing circumferential tread surface from below and an upper arm projecting from the base for stabilizing the green tire at the externally facing circumferential tread surface from above, , wherein the upper arm comprises an arm body projecting in the lateral direction from the base and movable relative to the base in a clamping direction between a standby position and a hold position closer to the support member in the clamping direction than the standby position, wherein the upper arm comprises a first lateral boundary member and a second lateral boundary member, supported by said arm body, which are positionable on opposite sides of the green tire in a lateral direction at least partially alongside said green tire, wherein the upper arm comprises a plurality of intermediate boundary members located side-by-side in the lateral direction on the arm body between the first lateral boundary member and the second lateral boundary member, wherein the first lateral boundary member, the second lateral boundary member and the plurality of intermediate boundary members are individually movable in the clamping direction relative to the arm body and relative to each other.

In the standby position, the upper arm can be moved over the green tire in the lateral direction to correctly align the lateral boundary members at the respective sides of the green tire, before moving said upper arm down into the hold position in which the lateral boundary members extend alongside the green tire at said respective sides.

In particular, when used in combination with a transfer ring, the upper arm, in the standby position, is positioned relative to the transfer ring and the tire building drum such that the upper arm, including the lateral boundary members, fits in the space between said transfer ring and the tire building drum.

The intermediate boundary members can be used to contact the green tire in the area between the lateral boundary members, to more securely hold the green tire. Moreover, the intermediate boundary members can closely follow or adapt to the contour of the green tire and remain in contact with said contour even when the green tire collapses slightly over time.

Because the intermediate boundary members are independently movable, the set of the lateral boundary members and the intermediate boundary members can be used to reliably stabilize green tires of different shapes and sizes. In particular, if the width of the green tire is smaller than the distance between the lateral boundary members, the intermediate boundary members closest to the respective sides of the green tire can take over the functionality of lateral boundary member from the outermost lateral boundary members. Hence, any width of green tire can be reliably stabilized.

Moreover, the lateral boundary members and the intermediate boundary members can be individually positioned to follow the cross-sectional contour of the externally facing circumferential tread surface of the green tire as close and/or as accurately as possible. In particular, the lateral boundary members and the group of intermediate boundary members that are located at the transition from the externally facing circumferential tread surface to the sidewall, also known as the 'shoulder', can be positioned progressively in the clamping direction to closely follow the curvature of said shoulder. In this way, the green tire is not only stopped from falling over, its position on the support member can be secured more reliably, for example by also preventing minimal movements of the green tire relative to the support member.

In a preferred embodiment one or more intermediate boundary members of the plurality of intermediate boundary members are pivotable with respect to a normal plane perpendicular to the lateral direction from a first state parallel to said normal plane to a second state at an oblique angle to said normal plane. Preferably, the normal plane extends vertically or substantially vertically. When a relative movement is generated between the alternative tire unloading unit and the tire building drum in the removal direction to remove the green tire from said tire building drum, there may be a delay in the release of the green tire from the tire building drum or the green tire may not detach from the tire building drum at all. The pivoting of the boundary members may absorb an initial delay in the removal of the green tire without damaging said green tire. It may also provide some time to stop the removal process before the green tire is seriously damaged.

In another embodiment the tire unloading unit further comprises a first axial fixation member and a second axial fixation member immovably arranged on the upper arm in the lateral direction on opposite sides of a group comprising the first lateral boundary member, the second lateral boundary member and the intermediate boundary members.

Alternatively, the tire unloading unit further comprises a first axial fixation member and a second axial fixation member arranged on the upper arm in the lateral direction on opposite sides of a group comprising the first lateral boundary member, the second lateral boundary member and the intermediate boundary members, wherein at least one of the first axial fixation member and the second axial fixation member is movable in the lateral direction away from the other of the first axial fixation member and the second axial fixation member. This may provide some freedom of movement to the group of boundary members in the lateral direction in response to unexpected errors during the removal of the green tire from the tire building drum.

In a preferred embodiment thereof the at least one of the first axial fixation member and the second axial fixation member is biased to move towards the other of the first axial fixation member and the second axial fixation member. Hence, the group of boundary members can be kept in position on the arm body as if the at least one axial fixation member is fixed, until a force exerted onto said at least one axial fixation member exceeds a biasing force.

In a further embodiment thereof each boundary member of the group is pivotable with respect to a normal plane perpendicular to the lateral direction from a first state parallel to said normal plane to a second state at an oblique angle to said normal plane. This has the same technical advantages as mentioned in relation to an earlier embodiment introducing this feature.

Preferably, the first axial fixation member and the second axial fixation member are provided with a first chamfered surface and a second chamfered surface, respectively, facing the group to provide the first lateral boundary member and the second lateral boundary member, respectively, freedom to move from the first state into the second state. Hence, despite the presence of the axial fixation members, the boundary members are allowed to pivot.

More preferably, the first chamfered surface and the second chamfered surface extend point-symmetrically with respect to each other. In this manner, the chamfered surfaces provide the space for the boundary members to pivot.

In another embodiment, the first lateral boundary member, the second lateral boundary member and the plurality of intermediate boundary members each comprise a boundary body with a through opening in the lateral direction for receiving the arm body, wherein the arm body has an arm body height in the clamping direction and wherein the through opening has an opening height in the clamping direction that is greater than the arm body height, wherein the boundary body is slidable over the arm body in the clamping direction within a range defined by the difference between the arm body height and the opening height. The boundary body can thus be slid up and down in the clamping direction around the arm body in response to a contact of the respective boundary member with the green tire.

More preferably, the arm body is provided with two oppositely facing guide surfaces extending parallel to the clamping direction, wherein the through opening has two mutually facing sliding surfaces extending parallel to the clamping direction for sliding along the respective guide surfaces of the arm body. The interaction between guide surfaces and the slide surfaces can prevent that the boundary body moves relative to the arm body in any other direction other than the clamping direction. In particular, rotation of the boundary body about the arm body can be prevented. Hence, the orientation of the boundary body with respect to the arm body can be maintained.

Most preferably, the arm body has a rectangular cross section perpendicular to the lateral direction. The boundary body can slide along the parallel sides of said rectangular cross section.

In an alternative embodiment the first lateral boundary member, the second lateral boundary member and the plurality of intermediate boundary members each comprise a boundary body that is slidably received in a corresponding through hole in the arm body to be movable in the clamping direction relative to said arm body. The boundary body can thus be slid up and down in the clamping direction through the arm body in response to a contact of the respective boundary member with the green tire. There is no need to fixate the boundary members in the lateral direction because they are already restricted in said lateral direction by the respective through hole in the arm body.

In a further embodiment the first lateral boundary member, the second lateral boundary member and the plurality of intermediate boundary members are movable in the clamping direction relative to the arm body under the influence of gravity. In other words, the boundary members are free to move downwards in the clamping direction when the distance between the shaft and the green tire at the location of the respective boundary member allows for said downward movement. Consequently, no separate drive is required to actively push the boundary members down.

In a further embodiment the support member comprises a first lower arm projecting from the base in the lateral direction for supporting the green tire at the externally facing circumferential tread surface from below. The first lower arm can project from the base and extend underneath the green tire to support said green tire from below in at least one support position. A single lower arm can be sufficiently lean to fit into tight spaces, i.e. in the space left between the drum and the transfer ring.

More preferably the support member further comprises a second lower arm projecting from the base in the lateral direction for together with the first lower arm supporting the green tire at the externally facing circumferential tread surface from below in two circumferentially spaced apart support positions. The two lower arms can provide a more stable two-point support for the green tire.

<FIG> show a tire unloading unit <NUM> for unloading a green or unvulcanized tire <NUM> according to a first exemplary embodiment of the invention. The green tire <NUM> is built on a tire building drum and is removed from said tire building drum by the tire unloading unit <NUM> once the tire building has been completed. The tire unloading unit <NUM> may already be moved into position around the tire building drum when the tire building process is still operational or being completed, e.g. when a transfer ring for transferring one or more tire components to the tire building drum is still in a position around the drum. When the green tire <NUM> has been engaged by the tire unloading unit <NUM>, the tire building drum and/or the transfer ring can subsequently be retracted and/or moved away. Alternatively, the tire building drum may remain in place and the tire unloading unit <NUM> can be retracted and/or moved away. The movements of the tire building drum and/or the tire unloading unit <NUM> are preferably controlled by a linear drive, for example a servo motor. The green tire <NUM> - once stabilized - can be analyzed, inspected, measured, weighed and/or tagged in said tire unloading unit <NUM>, prior to final unloading.

The green tire <NUM> has an externally facing circumferential tread surface <NUM>, i.e. the circumferential surface that faces radially outwards. The tread surface <NUM> extends circumferentially and/or concentrically about a tire axis X. The tire unloading unit <NUM> is arranged for holding the green tire <NUM> in an upright orientation, i.e. with the tire axis X extending horizontally or substantially horizontally. The green tire <NUM> further has a first side S1 and a second side S2, opposite to the first side S1, in a lateral direction L parallel to said tire axis X.

As shown in <FIG>, the tire unloading unit <NUM> comprises a frame or a base <NUM> that represents the fixed world. The base <NUM> may be placed on the ground, i.e. the factory floor. The tire unloading unit <NUM> further comprises a support member <NUM>, <NUM> comprising a first lower arm <NUM> and a second lower arm <NUM> that project from the base <NUM> in the lateral direction L for supporting the green tire <NUM> at the externally facing circumferential tread surface <NUM> from below in two circumferentially spaced apart support positions.

Alternatively, the tire unloading unit <NUM> may be provided with a single lower arm, table, platform or another suitable supporting element that has a width or geometry suitable to reliably support the green tire <NUM> from below.

The support member <NUM>, <NUM> may be arranged so as to be movable along the base <NUM> into contact with the green tire <NUM> at the tire building drum.

The tire unloading unit <NUM> further comprises an upper arm <NUM> projecting from the base <NUM> for stabilizing the green tire <NUM> at the externally facing circumferential tread surface <NUM> from above. The upper arm <NUM> comprises an arm body <NUM> projecting in the lateral direction L from the base to stabilize the green tire <NUM> at the tread surface <NUM> from above. The arm body <NUM> is shaped like a shaft, rod or beam. The arm body <NUM> is movable along or relative to the base <NUM> in a clamping direction C between a standby position, as shown in <FIG>, and a hold position, as shown in <FIG>, closer to the first lower arm <NUM> in the clamping direction C than the standby position. In this example, the clamping direction C is vertical or substantially vertical. The upper arm <NUM> may cooperate with the support member <NUM>, <NUM> to clamp the green tire <NUM> from opposite sides along the base <NUM> when the green tire <NUM> is still on the tire building drum.

In this exemplary embodiment, the tire unloading unit <NUM> comprises a tilt member <NUM> between the base <NUM> and the arm body <NUM> to position the arm body <NUM> relative to the base <NUM>. In particular, the tilt member <NUM> is hingably connected to the base <NUM> in order to tilt about a tilt axis T parallel to the tire axis X. Consequently, the arm body <NUM> has some freedom of movement about the tilt axis T to move into towards the green tire <NUM> from above under the influence of gravity G.

As best seen in <FIG>, the upper arm <NUM> comprises a set of boundary members <NUM>-<NUM>, including a first lateral boundary member <NUM>, a second lateral boundary member <NUM> and a plurality of intermediate boundary members <NUM>. The lateral boundary members <NUM>, <NUM> are positionable alongside said green tire <NUM> on the opposite sides S1, S2 of the green tire <NUM> in the lateral direction L. The plurality of intermediate boundary members <NUM> are located or arranged side-by-side in the lateral direction L on the arm body <NUM> between the first lateral boundary member <NUM> and the second lateral boundary member <NUM>. In this exemplary embodiment, the lateral boundary members <NUM>, <NUM> and the intermediate boundary members <NUM> are supported by said arm body <NUM>, projecting downwards from said arm body <NUM> in the clamping direction C. In particular, the lateral boundary members <NUM>, <NUM> and the intermediate boundary members <NUM> are movable, preferably individually and/or independently, in the clamping direction C relative to the arm body <NUM>. In other words, each boundary member <NUM>-<NUM> of the group comprising the lateral boundary members <NUM>, <NUM> and the intermediate boundary members <NUM> is individually and/or independently movable in the clamping direction C relative to the other boundary members <NUM>-<NUM> of the group, and with respect to the arm body <NUM>.

In this example, the tire unloading unit <NUM> is provided with a first axial fixation member <NUM> and a second axial fixation member <NUM> which are immovably arranged on the upper arm <NUM> in the lateral direction L. The fixation members <NUM>, <NUM> are located on opposite sides of a group formed by the boundary members <NUM>-<NUM>, to fix said group in place on the upper arm <NUM> relative to the lateral direction L.

As shown in <FIG>, each boundary member <NUM>-<NUM> comprises a boundary body <NUM> with a through opening <NUM> in the lateral direction for receiving the arm body <NUM>. In this exemplary embodiment, the boundary body <NUM> is planar or platelike and preferably has a rectangular or substantially rectangular cross section, as shown in <FIG>. Alternatively, the boundary body <NUM> may have a different cross-sectional shape, i.e. a round or disc-shape.

As shown in <FIG>, the arm body <NUM> has an arm body height H1 in the clamping direction C. The through opening <NUM> has an opening height H2 in the clamping direction C that is greater than the arm body height H1. The boundary body <NUM> is slidable over the arm body <NUM> in the clamping direction C within a stroke or a range R defined by the difference between the arm body height H1 and the opening height H2. In particular, the arm body <NUM> is provided with two oppositely facing guide surfaces <NUM>, <NUM> extending parallel to the clamping direction C. The through opening <NUM> has two mutually facing sliding surfaces <NUM>, <NUM> complimentary to the guide surfaces <NUM>, <NUM> and extending parallel to the clamping direction C for sliding along said respective guide surfaces <NUM>, <NUM> of the arm body <NUM>. In this example, the arm body <NUM> has a rectangular or square cross section, or a substantially rectangular or square cross section. Preferably, the through opening <NUM> has a rectangular inner contour.

As shown in <FIG>, the boundary members <NUM>-<NUM> are movable in the clamping direction C relative to the arm body <NUM> under the influence of gravity G. The boundary members <NUM>-<NUM> start out in the standby position of <FIG> being lowered into their lowermost position on the arm body <NUM>, i.e. at the end of the range R. The arm body <NUM> is then lowered towards the green tire <NUM> and, upon contact with the green tire <NUM>, the boundary members <NUM>-<NUM> that come into contact with the green tire <NUM> are pushed upwards in an upward direction D opposite to the clamping direction C. In the hold position, as shown in <FIG>, each boundary member <NUM>-<NUM> either contacts the tread surface <NUM> of the green tire <NUM> or remains at the end of the range R relative to the arm body <NUM> alongside the green tire <NUM> in the lateral direction L. As such, the group of boundary members <NUM>-<NUM> is able to closely and/or accurately follow the contour or cross-sectional shape of the green tire <NUM>, in particular the contour of the tread surface <NUM>, thereby limiting the freedom of movement of the green tire <NUM> in the tire unloading unit <NUM> and thus effectively stabilizing the green tire <NUM>. More specifically, the boundary members <NUM>-<NUM> extending at, near, around and/or alongside the shoulders of the green tire <NUM>, i.e. at the transition from the tread surface <NUM> to the sides S1, S2, can stop the green tire <NUM> from falling over in the tire unloading unit <NUM>.

<FIG> shows an alternative tire unloading unit <NUM> according to a second exemplary embodiment of the invention, that differs from the further alternative tire unloading unit <NUM> according to the first exemplary embodiment of the invention in that the first lateral boundary member <NUM>, the second lateral boundary member <NUM> and the intermediate boundary members <NUM> are pivotable with respect to a normal plane V perpendicular to the lateral direction L from a first state parallel to said normal plane V (similar to <FIG>) to a second state at an oblique angle F to said normal plane V. In this example, the normal plane V extends vertically or substantially vertically. When a relative movement is generated between the alternative tire unloading unit <NUM> and the tire building drum <NUM> in the removal direction W to remove the green tire <NUM> from said tire building drum <NUM>, there may be a delay in the release of the green tire <NUM> from the tire building drum <NUM> or the green tire <NUM> may not detach from the tire building drum <NUM> at all. The pivoting of the boundary members <NUM>-<NUM> may absorb an initial delay in the removal of the green tire <NUM> without damaging said green tire <NUM>. It may also provide some time to stop the removal process before the green tire <NUM> is seriously damaged.

As shown in <FIG>, the alternative tire unloading unit <NUM> further comprises a first axial fixation member <NUM> and a second axial fixation member <NUM> arranged on the upper arm <NUM> in the lateral direction L on opposite sides of a group comprising the first lateral boundary member <NUM>, the second lateral boundary member <NUM> and the intermediate boundary members <NUM>. The axial fixation members <NUM>, <NUM> differ from the aforementioned axial fixation members <NUM>, <NUM> in that the second axial fixation member <NUM> is movable in the lateral direction L away from the first axial fixation member <NUM>. As such, the second axial fixation member <NUM> may provide some freedom of movement to the group of boundary members <NUM>-<NUM> in the lateral direction L, for example to allow for the aforementioned pivoting of the boundary members <NUM>-<NUM> in response to a delay in the release of the green tire <NUM> from the tire building drum <NUM>.

In this example, the alternative tire unloading unit <NUM> comprises a biasing element <NUM>, for example a spring, for biasing the second axial fixation member <NUM> towards the first axial fixation member <NUM>. Hence, the group of boundary members <NUM>-<NUM> can be kept in position on the arm body <NUM> as if the second axial fixation member <NUM> is fixed, until a force exerted onto said second axial fixation member <NUM> exceeds a biasing force exerted by the biasing element <NUM> onto said second axial fixation member <NUM>.

Moreover, in this example, the first axial fixation member <NUM> and the second axial fixation member <NUM> are provided with a first chamfered surface <NUM> and a second chamfered surface <NUM>, respectively, facing the group of boundary members <NUM>-<NUM> to provide the first lateral boundary member <NUM> and the second lateral boundary member <NUM>, respectively, freedom to move from the first state into the second state. The chamfered surfaces <NUM>, <NUM> are located on opposite sides of a horizontal midplane E extending through the heart of the arm body <NUM>. In this exemplary embodiment, the first chamfered surface <NUM> and the second chamfered surface <NUM> extend point-symmetrically with respect to each other, in particular on opposite sides of said horizontal midplane E. More in particular, the chamfered surfaces <NUM>, <NUM> extend parallel or mutually parallel, or at inclined in the same direction.

Optionally, each axial fixation member <NUM>, <NUM> may be provided with two chamfered surfaces forming a triangular tip portion (not shown) symmetrical to the horizontal midplane E to allow for pivoting of the group of boundary members <NUM>-<NUM> to both sides of the normal plane V.

Each of the aforementioned tire unloading units <NUM>, <NUM> may be used in a method for unloading or removing the green tire <NUM> from a tire building drum, using the respective upper arms <NUM>, <NUM> in the manner as previously described.

It is to be understood that the above description is included to illustrate the operation of the preferred embodiments and is not meant to limit the scope of the invention. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the scope of the present invention.

For example, the spindle-and-nut mechanism as shown in figure <NUM> may be replaced by any other suitable linear drive mechanism, i.e. one or more servo-motors, a gear rack, a timing belt or the like.

Furthermore, embodiments are envisioned in which the lateral boundary members are kept close to or parallel to the arm body during the interaction of the tire unloading unit with the transfer ring and/or the tire building drum to minimize the dimensions of upper arm, given the limited space available between the transfer ring and the tire building drum. Such lateral boundary members may be deployed, extended and/or folded outwards after the tire building drum and/or the transfer ring have cleared and/or moved away from the tire unloading unit.

As shown in <FIG>, a marking device M may be provided at or near the tire unloading unit <NUM> for marking the green tire <NUM> when manufacturing of said green tire has been completed, i.e. just prior to, during or after unloading. In this example, the marking device M produces a sticker <NUM> with information related to the completed green tire <NUM>, e.g. a serial number, a bar code, a QR code or the like. Alternatively, the marking device M may be a printer that prints a marking directly on the green tire <NUM>. In yet a further alternative embodiment, the marking device M may be configured for creating the marking directly on or in the material of the green tire <NUM>, i.e. by engraving.

In the prior art, such a marking is provided prematurely on a part of the green tire or an incomplete green tire, for example to the side wall. With further manufacturing steps still to be performed, there is a risk that the premature marking is lost, for example when it is applied to a part of the green tire that is cut away.

Claim 1:
Tire unloading unit (<NUM>, <NUM>) for unloading a green tire (<NUM>), wherein the green tire (<NUM>) has an externally facing circumferential tread surface (<NUM>) extending around a tire axis (X), wherein the tire unloading unit (<NUM>, <NUM>) comprises a base (<NUM>) and a support member for supporting the green tire (<NUM>) relative to the base (<NUM>) at the externally facing circumferential tread surface (<NUM>) from below and an upper arm (<NUM>, <NUM>) projecting from the base (<NUM>) for stabilizing the green tire (<NUM>) at the externally facing circumferential tread surface (<NUM>) from above, wherein the upper arm (<NUM>, <NUM>) comprises an arm body (<NUM>) projecting in the lateral direction (L) from the base (<NUM>) and movable relative to the base (<NUM>) in a clamping direction (C) between a standby position and a hold position closer to the support member in the clamping direction (C) than the standby position, characterized in that the upper arm (<NUM>, <NUM>) comprises a first lateral boundary member (<NUM>) and a second lateral boundary members (<NUM>), supported by said arm body; (<NUM>), which are positionable on opposite sides of the green tire (<NUM>) in a lateral direction (L) at least partially alongside said green tire (<NUM>), wherein the upper arm (<NUM>, <NUM>) comprises a plurality of intermediate boundary members (<NUM>) located side-by-side in the lateral direction (L) on the arm body (<NUM>) between the first lateral boundary member (<NUM>) and the second lateral boundary member (<NUM>), wherein the first lateral boundary member (<NUM>), the second lateral boundary member (<NUM>) and the plurality of intermediate boundary members (<NUM>) are individually movable in the clamping direction (C) relative to the arm body (<NUM>) and relative to each other.