Slank holder and method for operating a slank holder

Abstract

The present invention relates to a slab clamp and a method for operating the slab clamp wherein the slab clamp comprises a base, a clamping arm and a holder for holding the clamping arm relative to the base wherein the clamping arm defines a clamping surface for applying a clamping force to a zig-zag stack in a clamping direction, the slab clamp further includes a clamping drive for urging the clamping surface onto the zig-zag stack with a clamping force in a clamping direction, where the clamping force is urged against the zig-zag stack in response to contact of the clamping surface with the stack in the clamping direction, and the clamping force is urged against the zig-zag stack in response to contact of the clamping surface with the zig-zag stack in the clamping direction. The clamping arm can be at least partially lifted relative to the holder in a braking activation direction opposite to the clamping direction, and wherein the slab clamp further comprises a braking mechanism which activates to brake a displacement of the clamping arm when the clamping arm is at least partially lifted relative to the holder in the braking activation direction.

Description

BACKGROUND OF THE INVENTION

[0001] The present invention relates to a slab gripper for holding a pre-cut elastomeric slab in place as strip segments are pulled from the pre-cut elastomeric slab. The present invention also relates to a method for operating the above slab gripper.

[0002] In tire manufacturing, slabs of elastomeric material are stored in a zigzag stack or a zigzag pile of superimposed layers extending in alternating directions. The slabs of elastomeric material are pre-cut to include parallel strip segments extending throughout the zigzag stack, thereby forming a plurality of parallel vertical columns in the zigzag stack. Each column holds a continuous length of elastomeric strip, and for each vertical column, the elastomeric strip can be pulled in by a feed unit that serves as the feed section of an extruder. When one of the strip segments is pulled from the pre-cut elastomeric slab, the feed unit can pull along an adjacent strip segment of the pre-cut elastomeric slab together with the one strip segment.

[0003] To prevent the above situation, it is known to use a slab gripper to hold the zigzag stack in place at a selected vertical column that is adjacent to or directly adjacent (immediately adjacent) to the vertical column from which the continuous elastomeric strip is pulled.

[0004] Known slab grippers include a base and a clamping arm that can be manually rotated relative to the base about a vertical axis of rotation into a position above the zigzag stack. The height of the clamping arm relative to the base is adjustable until it is just positioned above or resting on the selected vertical column. Subsequently, the clamping arm is pressed against the zigzag stack to hold the zigzag stack at the selected vertical column while pulling the continuous elastomeric strip from an adjacent vertical column. SUMMARY OF THE INVENTION

[0005] A disadvantage of known slab grippers is that the clamping arm is not fixed against rotation about the axis of rotation. When the zigzag stack becomes unstable, for example, when the zigzag stack or its vertical columns are pulled by the feed unit, the downward pressure of the clamping arm on the stack may unpredictably turn into a swinging motion and rotate uncontrollably away from the zigzag stack, which may cause damage to its surrounding environment and / or injury to the operator.

[0006] Another disadvantage of known slab grippers is that the height fixing of the clamping arm along the base is manually controlled by a locking mechanism that is close to the moving parts of the slab gripper. When the fixing is released, the clamping force is suddenly released, and parts of the slab gripper may suddenly jump up or down, again possibly causing damage to its surrounding environment and / or injury to the operator.

[0007] The object of the present invention is to provide a slab gripper device and a method for operating a slab gripper, wherein the operating safety of the slab gripper can be improved.

[0008] According to a first aspect, the present invention provides a slab gripper for holding a pre-cut elastomeric slab stored in a zigzag stack in place as a strip section is pulled out from the pre-cut elastomeric slab, wherein the slab gripper comprises a base, a clamping arm and a retainer for holding the clamping arm relative to the base, wherein the clamping arm defines a clamping surface for applying a clamping force to the zigzag stack in a clamping direction, wherein the slab gripper further comprises a clamping drive for pressing the clamping surface onto the zigzag stack with the clamping force in the clamping direction, wherein the clamping arm is capable of being positioned along a positioning path in a positioning plane transverse or perpendicular to the clamping direction above the zigzag stack into a clamping position, wherein in response to contact of the clamping surface with the zigzag stack in the clamping direction, the clamping arm is capable of being at least partially lifted relative to the retainer in a braking activation direction opposite to the clamping direction, and wherein the slab gripper further comprises a braking mechanism that is activated to brake the displacement of the clamping arm along the positioning path when the clamping arm is at least partially lifted relative to the retainer in the braking activation direction.

[0009] Once the clamping surface has been pressed onto the zigzag stack by the clamping force, the zigzag stack can be held more firmly in place by preventing, slowing down, stopping or braking the displacement of the clamping arm along the positioning path, thereby reducing the risk of the zigzag stack becoming unstable and the clamping arm moving away uncontrollably. Thereby, damage to the surrounding environment can be prevented and the safety of the operator can be increased. Since the braking mechanism is activated passively or automatically in response to the relative movement between the clamping arm and the retainer, the operator does not have to approach the clamping arm to activate the braking mechanism, which can further increase the safety of the operator.

[0010] More specifically, once any clamping force is applied to the zigzag stack, the braking mechanism can ensure that a corresponding braking force is generated as an automatic reaction to the clamping force. In this way, there will never be a clamping force without an immediate braking force to automatically hold the clamping arm.

[0011] In a preferred embodiment, the braking mechanism is configured to passively, automatically and / or mechanically convert the clamping force generated by the clamping drive in the clamping direction (C) into a braking force to brake the displacement of the clamping arm along the positioning path. As described above, for example, through the mechanical conversion of the relative movement between the clamping arm and the retainer, this automatic activation can further improve the safety of the operator because the operator does not have to intervene to activate the braking mechanism. In addition, when the clamping force is mechanically converted into a braking force, no separate or active actuator or drive is required to activate the braking mechanism.

[0012] In another embodiment, the clamping arm is rotatable relative to the base about a rotational axis, wherein the positioning path is circular or includes a circular section. Thus, the braking mechanism can automatically slow down, stop, or brake the rotation of the clamping arm, thereby preventing the clamping arm from swinging unpredictably or uncontrollably away from the zigzag stack.

[0013] Preferably, the rotational axis is parallel to the clamping direction. In other words, the clamping arm can move along the base parallel to the rotational axis, and / or the clamping force can be applied to the zigzag stack in a direction parallel to the rotational axis.

[0014] In another embodiment, the braking mechanism includes one or more first braking members and one or more second braking members. The one or more first braking members are configured to move along the positioning path together with the clamping arm, and the one or more second braking members are configured to remain in a fixed position along the positioning path relative to the base. Wherein, a first braking member of at least a first pair of braking members including a first braking member of the one or more first braking members and a second braking member of the one or more second braking members and the second braking member are arranged to interact with each other when the clamping arm is at least partially lifted relative to the holder in the braking start direction. Since the respective braking members are associated with different parts of the slab gripper, the passive and / or automatic application of the clamping force to the zigzag stack via the clamping arm causes relative movement between the corresponding braking members, which can conveniently result in the interaction and / or engagement between the braking members without the need for a separate or active actuator to activate the braking mechanism.

[0015] Preferably, the clamping arm is at least partially liftable relative to the holder from a release position to a braking position in the braking start direction. Wherein, when the clamping arm is at least partially lifted to the braking position, the first braking member and the second braking member of the first pair of braking members are pressed into physical contact with each other. When in physical contact, the friction generated between the braking members can effectively slow down or brake the displacement of the clamping arm along the positioning path.

[0016] In another embodiment, the clamping arm is rotatable relative to the base about a rotational axis, wherein the positioning path is circular or includes a circular section, wherein a first braking member of the first pair of braking members and a second braking member physically extend beyond the rotational range about the rotational axis, and wherein the first braking member and the second braking member of the first pair of braking members are arranged to interact with each other when the other of the first braking member and the second braking member is in any overlapping angular position within the rotational range. In other words, it doesn't matter how the clamping arm is positioned about the rotational axis as long as the corresponding braking members overlap.

[0017] Preferably, the swivel range is at least ninety degrees, preferably at least one hundred and twenty degrees, more preferably at least one hundred and sixty degrees, and most preferably at least two hundred and fifty degrees. The larger the swivel range, the greater the freedom of the operator to swivel the clamping arm to any angular position within the swivel range, while the slab gripper maintains the function of braking the swivel of the clamping arm in any such angular position.

[0018] In yet another embodiment, one of the first braking member and the second braking member of the first pair of braking members includes a braking finger that projects radially with respect to the swivel axis. In this way, the braking finger can effectively reach a radial distance from the swivel axis at which the other of the first braking member and the second braking member is located. By increasing the radial distance at which the braking members interact with each other, a moment can be created that requires a smaller braking force to slow down or brake the swivel of the clamping arm.

[0019] In yet another embodiment, one of the first braking member and the second braking member of the first pair of braking members includes a braking plate that at least spans an annular section that extends concentrically around the swivel axis. Due to the concentric positioning around the swivel axis, the braking plate can apply a consistent and / or constant braking force on the other of the first braking member and the second braking member at any angular position around the swivel axis.

[0020] In yet another embodiment, one or more of the first braking members include a set of first braking members, and wherein one or more of the second braking members include a set of second braking members that alternate with a first braking member of the set of first braking members in a braking start direction to form a first pair of braking members and additional pair or pairs of braking members having a first braking member of the set of first braking members and a second braking member of the set of second braking members, wherein the first braking member and the second braking member of each pair of braking members are arranged to interact with each other when the clamping arm is at least partially lifted relative to the holder in the braking start direction. By providing multiple pairs of corresponding braking members that interact with each other, the braking force can be effectively increased.

[0021] Preferably, the first pair of braking members and the additional pair or pairs of braking members are stacked in the clamping direction to form a stack of braking members, wherein the slab gripper further includes a first clamping member below the stack of braking members and a second clamping member above the stack of braking members to clamp the braking members together when the clamping arm is at least partially lifted relative to the holder in the braking activation direction. When the corresponding pairs of braking members can be stacked one on top of the other in the braking activation direction, the footprint of the braking mechanism can remain relatively small and / or compact. Additionally, by clamping the braking members together, each braking member can contact two other braking members on its opposite sides, thereby increasing the amount of friction and thus the effective braking force.

[0022] In another embodiment, the clamping arm includes an arm body and a clamping member that is rotatable relative to the arm body about an alignment axis for aligning the clamping member with a Z-shaped stack, wherein the clamping member defines a clamping surface. Thus, when the stack is misaligned with the arm body, the clamping member can be rotated to correct the misalignment between the stack and the arm body without repositioning the stack.

[0023] In another embodiment, the holder is configured to adjust the height position of the clamping arm relative to the base. Thus, the height position of the clamping arm can be adjusted to accommodate Z-shaped stacks of different heights. Additionally, the clamping arm can be lowered to a position directly above or on the Z-shaped stack such that the driving range of the clamping actuator can remain relatively small and be dedicated solely to clamping.

[0024] In another embodiment, the clamping actuator is configured to indirectly apply a clamping force to the clamping arm via the holder, and the slab gripper further includes a height lock that is configured to fix the clamping actuator in a drive position relative to the base in the clamping direction and release the clamping actuator from the drive position relative to the base in the clamping direction. By fixing and releasing the clamping actuator, the drive position can be varied along the base for adjustment to accommodate the varying height of the stack. When fixed, the clamping actuator can apply a clamping force to the holder from the fixed drive position.

[0025] More preferably, in an embodiment that can also be applied independently of the braking mechanism, the slab gripper is configured to allow release of the fixation of the clamping actuator from the drive position only when the clamping force generated by the clamping actuator in the clamping direction is below a predetermined threshold or is zero. In this way, it is possible to prevent the uncontrolled jumping of the clamping actuator, the holder, and / or the clamping arm that may injure the operator due to a large clamping force applied to the Z-shaped stack when terminating the fixation of the clamping actuator.

[0026] Optionally, the height lock is remotely controllable. By allowing remote control of the height lock, the operator can be prevented from being in the vicinity of the height lock, the retainer, and / or the clamping arm when terminating the fixation of the clamping drive.

[0027] According to a second aspect, the present invention provides a method for operating a slab gripper according to any one of the embodiments of the first aspect of the present invention, wherein the method comprises the following steps:

[0028] - Positioning the clamping arm along a positioning path to a clamping position above the zigzag stack in the clamping direction;

[0029] - Clamping the clamping surface onto the zigzag stack with a clamping force in the clamping direction; and

[0030] - Activating a braking mechanism to brake the displacement of the clamping arm along the positioning path when the clamping arm is at least partially lifted relative to the retainer in the braking activation direction.

[0031] This method relates to the actual implementation of the slab gripper according to the first aspect of the present invention and thus has the same technical advantages, which will not be repeated hereinafter.

[0032] In a preferred embodiment of the method, the braking mechanism passively, automatically, and / or mechanically converts the clamping force applied by the clamping surface onto the zigzag stack in the clamping direction into a braking force to brake the displacement of the clamping arm along the positioning path.

[0033] In another embodiment, the displacement of the clamping arm along the positioning path is a rotary movement around a rotary axis along a circular section of the positioning path.

[0034] In another embodiment, the braking force is proportional to the clamping force applied by the clamping surface onto the zigzag stack. Since the braking force is actually frictional force, according to Amontons' first law, the frictional force is proportional to the applied load, which corresponds to the clamping force.

[0035] In another embodiment of the method, which can also be applied independently of the braking mechanism, the slab gripper comprises a clamping drive for generating a clamping force in the clamping direction and a height lock for fixing the clamping drive relative to the base in the clamping direction to a drive position, wherein the method further comprises the following steps:

[0036] - Fixing the clamping drive in the drive position using the height lock;

[0037] - Generating a clamping force using the clamping drive; and

[0038] - Release the fixation of the clamping drive from the drive position only when the clamping force applied to the clamping arm by the clamping drive in the clamping direction is lower than a predetermined threshold value or zero.

[0039] Optionally, the height lock is remotely controlled.

[0040] The various aspects and features described and shown in this specification can be applied separately whenever possible. These individual aspects, particularly those described in the appended claims, can be the subject of divisional patent applications. Brief Description of the Drawings

[0041] The present invention will be described based on the exemplary embodiments shown in the attached schematic drawings, in which:

[0042] Figure 1 An isometric view of a pre-cut elastomeric slab stored in a zigzag stack and a slab gripper according to the present invention is shown, the slab gripper being for holding the zigzag stack in place as strip segments are pulled from the pre-cut elastomeric slab;

[0043] Figure 2 Shows according to Figure 1 A top view of the slab gripper;

[0044] Figure 3 Shows according to Figure 1 Details of the slab gripper according to circle III in

[0045] Figure 4 Shows according to Figure 1 A side view of the slab gripper, in which the height lock is in the unlocked state; and

[0046] Figure 5 And Figure 6 Shows according to Figure 1 A side view of the slab gripper, in which the clamping arms of the slab gripper are in the release position and the braking position, respectively. Detailed Description of the Invention

[0047] Figure 1 A slab gripper 1 according to an exemplary embodiment of the present invention is shown. In the field of tire building or tire manufacturing, the slab gripper 1 is used to manipulate elastomeric raw materials, particularly rubber, which are used as feed materials for an extruder (not shown). The extruder converts the elastomeric raw materials into continuous strips, which can be used to form tire components of a green tire or an unvulcanized tire.

[0048] As Figure 1As shown, the elastomeric raw material is provided in the form of an elastomeric sheet, strip or slab 90, which is stored or stacked in a continuous length on a carrier, such as a pallet or rack. In particular, the continuous length of the elastomeric slab is folded onto itself into a plurality of superimposed layers, which extend in alternating directions from each subsequent fold. In this way, the elastomeric slab 90 is stored or stacked into a so-called Z-shaped (zigzag) stack or Z-shaped stack 9.

[0049] The elastomeric slab 90 is pre-cut and may hereinafter be referred to as the "pre-cut elastomeric slab" 90. In particular, the pre-cut elastomeric slab 90 includes a plurality of longitudinally extending incisions that form, define or include a plurality of parallel strip sections 91-94. The incisions extend along the length of the pre-cut elastomeric slab 90. In this way, they extend through the Z-shaped stack 9 and divide the Z-shaped stack 9 into a plurality of parallel vertical columns K1-K4. Each column K1-K4 holds a continuous length of elastomeric strip 95.

[0050] As Figure 1 shown, the elastomeric strip 95 originating from the first vertical column K1 of the plurality of vertical columns K1-K4 has been partially pulled out from the Z-shaped stack 9 in the feed direction F by a feed unit (not shown), which serves as the feed section of an extruder. In this example, the feed direction F is perpendicular or transverse to the longitudinally extending incisions in the Z-shaped stack 9. In other words, the elastomeric strip 95 is pulled out from the respective vertical columns K1-K4 in a lateral or side direction. Once the vertical columns K1-K4 have been depleted, the feed unit can be connected to the elastomeric strip 95 of the subsequent vertical columns K1-K4. This process can be repeated until the entire Z-shaped stack 9 is depleted.

[0051] As Figure 1 best shown in, the slab gripper 1 includes a base 2 and a pivoting or clamping arm 3 that can be moved relative to the base 2 along a positioning path D into a clamping position above the Z-shaped stack 9.

[0052] In this exemplary embodiment, the clamping arm 3 can rotate or pivot relative to the base 2 about a pivot axis S. Accordingly, the positioning path D is at least partially circular or includes a circular section.

[0053] In an alternative embodiment of the slab gripper (not shown), the clamping arm can be laterally displaced into and out of a clamping position above the Z-shaped stack 9, i.e., displaced into or out of a clamping position above the Z-shaped stack 9 along a linear guide or linear track provided at the base.

[0054] The slab gripper 1 further comprises a carrier, guide shoe, slide or retainer 4 for holding the gripper arm 3 relative to the base 2. In this example, the retainer 4 is configured to adjust the height position of the gripper arm 3 relative to the base 2. In particular, the retainer 4 is slidable relative to the base 2 in the gripping direction C and / or contributes to the lowering of the gripper arm 3 in the gripping direction C onto the zigzag stack 9. In this example, the gripping direction C is vertical or substantially vertical.

[0055] Alternatively, instead of lowering the gripper arm 3 onto the zigzag stack 9, the factory may provide a lifting mechanism to lift the zigzag stack 9 relative to the base 2. In this case, it may not be necessary to lower the retainer 4.

[0056] In the embodiment as Figure 1 shown, the positioning path D extends in a positioning plane E that is transverse or perpendicular to the gripping direction C.

[0057] The slab gripper 1 further comprises a braking mechanism 5 for preventing, slowing down, stopping or braking the movement, displacement or rotation of the gripper arm 3 relative to the base 2 along the positioning path D, in the positioning plane E and / or about the axis of rotation S. The slab gripper 1 is further provided with a gripping drive 6, a height drive 7 and a height lock 8, the gripping drive 6 for applying a gripping force F1 to the gripper arm 3 in the gripping direction C, the height drive 7 for adjusting the drive position of the gripping drive 6 along the base 2 in the gripping direction C, and the height lock 8 for fixing the gripping drive 6 relative to the base 2 in the gripping direction C in the said drive position and for releasing the gripping drive 6 relative to the base 2 from the said drive position in the gripping direction C.

[0058] In this particular example, the gripping drive 6 indirectly applies the gripping force F1 to the gripper arm 3 via the retainer 4. However, it will be understood that when each zigzag stack 9 has the same or substantially the same height, or when the zigzag stack 9 is lifted by an external lifting mechanism rather than lowering the gripper arm 3 onto the zigzag stack 9, the gripping drive 6 may contribute to the movement of the gripper arm 3 relative to the base 2 towards and away from the zigzag stack 9 over a small gripping stroke, in which case the retainer may be fixed relative to the base 2 and the gripping drive 6 may be directly engaged to the gripper arm 3 or a part thereof.

[0059] As Figure 1As shown, the base 2 includes a base body 20 in the form of a housing, a frame, a column or a beam. In this example, the base body 20 extends parallel to or substantially parallel to the clamping direction C. More specifically, in this particular embodiment, the base body 20 extends vertically or substantially vertically. The base body 20 can be directly mounted to the factory floor, or it can be part of a tire building machine. Alternatively, the base body 20 can be placed on a mobile platform (not shown). The base 2 also includes a base guide 21 for guiding the movement of the clamping arm 3 relative to the base 2 in the clamping direction C. The base guide 21 can be formed by one or more guide rails or guide profile members.

[0060] As Figure 4 Best shown in, the clamping arm 3 includes an arm body 30 that projects radially relative to the base 2 and / or projects radially away from the base 2. In this example, the clamping arm 3 also includes a product holding carriage or clamping member 31 that is rotatable relative to the arm body 30 about an alignment axis A for aligning the clamping member 31 with the zigzag stack 9. The alignment axis A is spaced from the rotational axis S but is parallel or substantially parallel to the rotational axis S. The clamping arm 3 is provided with a clamping surface 32 for physically contacting, resting on and / or pressing down on the zigzag stack 9 in the clamping direction C. In this example, the clamping surface 32 is formed at or defined by the clamping member 31, specifically by the bottom side of the clamping member 31 facing the clamping direction C.

[0061] In this example, the clamping member 31 is also configured to be slidable along the longitudinal direction of the arm body 30, thereby changing the position of the alignment axis A and thus increasing the reach of the clamping arm 3.

[0062] Optionally, a braking mechanism similar to the braking mechanism 5 between the clamping arm 3 and the retainer 4 can be provided between the arm body 30 and the clamping member 31 to slow down, stop or brake the rotation about the alignment axis A and / or the sliding along the arm body 30.

[0063] In this example, the arm body 30 is coupled or connected to the retainer 4 in a rotatable manner, which will be described in more detail below. Optionally, the arm body 30 is provided with one or more rotary pins 33 configured to engage the retainer 4 in a manner to be described below to facilitate the rotation of the clamping arm 3 about the rotational axis S relative to the base 2 and / or the retainer 4.

[0064] As Figure 4As further shown, the retainer 4 includes a retainer body 40 for holding, carrying or supporting the clamping arm 3 relative to the base 2. The retainer 4 further includes a retainer guide 41 that is fitted to and / or engages with the base guide 21 to facilitate sliding of the retainer 4 along the base 2 in the clamping direction C. The clamping arm 3 is configured to move with the retainer 4 in the clamping direction C at least until the clamping surface 32 contacts the zigzag stack 9.

[0065] The clamping arm 3 may be pivotally connected to the retainer body 40 so as to be rotatable or swivellable relative to the retainer 4 and / or the base 2 about a swivel axis S. In particular, the retainer body 40 is formed as a fork that pivotally holds the clamping arm 3 at the swivel axis S. Specifically, the retainer body 40 is provided with one or more swivel sockets 42 at the swivel axis S for receiving each of one or more swivel pins 33 of the clamping arm 3. It is obvious that the clamping arm 3 may alternatively be provided with swivel sockets and the retainer 4 may alternatively be provided with swivel pins. In addition, alternative hinge mechanisms can be envisaged that have the same effect of facilitating swivelling of the clamping arm 3 relative to the retainer 4 and / or the base 2 about the swivel axis S.

[0066] One or more swivel pins 33 may slide in their respective swivel sockets 42 in the clamping direction C and the braking start direction B, thereby providing the clamping arm 3 with degrees of freedom of movement to slide relative to the retainer 4 in the clamping direction C and the braking start direction B (i.e., parallel to the swivel axis S).

[0067] When comparing Figure 5 and Figure 6 it will be understood that the clamping arm 3 can move with the retainer 4 in the clamping direction C towards the zigzag stack 9. When the clamping arm 3 reaches the zigzag stack 9, at least a part of the clamping arm 3 may move, retract or lift relative to the retainer 4 in the braking start direction B opposite to the clamping direction C in response to contact of the clamping surface 32 with the zigzag stack 9 in the clamping direction C. In this example, the clamping arm 3 as a whole may lift relative to the retainer 4.

[0068] Alternatively, when the clamping actuator 6 is placed between parts of the clamping arm 3, only the part of the clamping arm 3 that is not pressed against the zigzag stack 9 by the clamping actuator 6 may lift relative to the retainer 4. For example, the clamping actuator 6 may be placed between the arm body 30 and the clamping member 31, in which case only the arm body 30 is lifted relative to the retainer 4.

[0069] More specifically, as Figure 5As shown, when the clamping surface 32 is not supported on the Z-shaped stack 9, the clamping arm 3 will automatically drop relative to the holder 4 under the influence of gravity into the release position P1. The clamping arm 3 then moves from the release position P1 as shown in Figure 5 to the braking position P2 as shown in Figure 6 . When the clamping arm 3 is lifted from the release position P1 towards and / or into the braking position P2, the relative movement between the clamping arm 3 and the holder 4 is passively and / or automatically converted by the braking mechanism 5 into a braking force F2, in particular a tangential braking force F2. In other words, the relative movement between the clamping arm 3 and the holder 4 passively and / or automatically activates (and deactivates) the braking mechanism 5.

[0070] The relative movement from the release position P1 to the braking position P2 can be over a stroke equal to or less than one centimeter, preferably five millimeters or less, and more preferably one millimeter or less.

[0071] In particular, as shown in more detail in Figure 3 , the braking mechanism 5 includes a set of first braking members 51 and a set of second braking members 52, the set of first braking members 51 being configured to move along a positioning path D together with the clamping arm 3, and the set of second braking members 52 being configured to remain in a fixed position along the positioning path D relative to the base 2.

[0072] In this exemplary embodiment, the set of first braking members 51 is associated with and / or connected to the clamping arm 3, while the set of second braking members 52 is associated with and / or connected to the holder 4.

[0073] The set of second braking members 52 alternates with a first braking member 51 of the set of first braking members 51 in the braking activation direction B to form a first pair of braking members 50 having one first braking member 51 of the set of first braking members 51 and one second braking member 52 of the set of second braking members 52, and one or more additional pairs of braking members 50'. In other words, in the braking activation direction B, the braking mechanism 5 is then provided with a first braking member 51, a second braking member 52, a first braking member 51, a second braking member 52, and so on. The paired braking members 50, 50' having the braking members 51, 52 together form a stack or stack group of alternating braking members 51, 52, which are stacked one on top of the other in the braking activation direction B.

[0074] The clamping arm 3 is further provided with a first clamping member 34 which is connected to the arm body 30 so as to move together with or in unison with the arm body 30 in the clamping direction C and the braking start direction B when the clamping arm 3 is lowered and / or lifted. In particular, the first clamping member 34 can be fixed to the arm body 30 or formed as an integral part of the arm body 30. The first clamping member 34 is located below the lowermost braking members 51, 52 in the stack of braking members 51, 52 to support the lowermost braking members 51, 52 from below.

[0075] Similarly, the retainer 4 is further provided with a second clamping member 44 which is connected to the retainer body 40 so as to move together with or in unison with the retainer body 40 in the clamping direction C when the clamping actuator 6 forces the retainer 4 downward. In particular, the second clamping member 44 can be fixed to the retainer body 40 or formed as an integral part of the retainer body 40. The second clamping member 44 is located above the uppermost braking members 51, 52 in the stack of braking members 51, 52 to stop the uppermost braking members 51, 52 from moving in the braking start direction B beyond the second clamping member 44.

[0076] The clamping members 34, 44 are configured together to move towards each other when the clamping arm 3 is lifted relative to the retainer 4, thereby clamping or sandwiching together the stack of braking members 51, 52.

[0077] It will be understood that the braking mechanism 5 according to the present invention may further be characterized in having a single pair of braking members 51, 52 (e.g., the first pair of braking members 50). In the case of the single pair of braking members having braking members 51, 52, the first braking member 51 can be fixed to the arm body 30 and the second braking member 52 can be fixed to the retainer body 40 so as to move towards and away from each other in the clamping direction C and the braking start direction B in unison with the respective bodies 30, 40. In this case, the above-mentioned clamping members will not be required to clamp or sandwich the single pair of braking members having braking members 51, 52.

[0078] However, by having more pairs of braking members having braking members 51, 52, the amount of friction, and thus the amount of braking force F2, can be significantly increased. In addition, these pairs of braking members can be stacked one on top of the other in the braking start direction B without increasing the footprint of the braking mechanism 5, resulting in a relatively compact braking mechanism 5.

[0079] When the swing arm 3 is in the release position P1, the braking members 51, 52 can rest on one another with little force, i.e., in a relatively weak contact. Alternatively, the braking members 51, 52 can be slightly spaced apart to avoid contact.

[0080] When the swing arm 3 is lifted from the release position P1 to the braking position P2, the first braking members 51 and the second braking members 52 in each pair of braking members 50, 50' are pressed into contact with each other. In particular, a decrease in the distance or spacing between the clamping members 34, 44 on opposite sides of the stack of braking members 51, 52 causes the stack of braking members 51, 52 to be pressed together.

[0081] In this example, each first braking member 51 in the group of first braking members 51 includes a braking finger 53 that projects radially away from the axis of rotation S and / or projects radially with respect to the axis of rotation S. The braking finger 53 is connected to the arm body 30 of the clamping arm 3. In particular, the braking finger 53 is coupled to the arm body 30 so as to rotate together with or in unison with the arm body 30 as the clamping arm 3 rotates about the axis of rotation S. At the same time, each braking finger 53 is free to slide relative to the arm body 30 in the clamping direction C and the braking activation direction B.

[0082] In addition, in this example, each second braking member 52 in the group of second braking members 52 includes a braking plate 54 for engaging the braking fingers 53 of the corresponding pair of braking members. The braking plate 54 is connected to the retainer 4. In particular, the braking plate 54 is coupled to the retainer body 40 so as to remain in a fixed orientation relative to the retainer 4 about the axis of rotation S. At the same time, each braking plate 54 is free to slide relative to the retainer body 40 in the clamping direction C and the braking activation direction B, for example, along a sliding pin 45 protruding from the second clamping member 44.

[0083] As Figure 2 best shown, the braking plate 54 physically extends along an arc or circular arc concentric with the axis of rotation S.

[0084] In particular, the braking plate 54 at least spans an annular section concentric with the axis of rotation S.

[0085] Specifically, the braking plate 54 is shaped as an annular section.

[0086] In this exemplary embodiment, the braking plate 54 physically extends about the axis of rotation S beyond the rotation range R. Preferably, the rotation range R is at least ninety degrees, at least one hundred and eighty degrees, or at least two hundred and seventy degrees. The rotation range R may alternatively extend through a full circle, i.e., three hundred and sixty degrees. The braking fingers 53 are arranged to engage, contact, and / or interact with the braking plate 54 at any overlapping angular position of the braking fingers 53 and the braking plate 54 within the rotation range R. In other words, as long as the braking finger 53 is within an angular position within the rotation range, it can interact with the braking plate 54 to slow down, stop, or brake the rotation of the clamping arm 3.

[0087] Alternatively, the brake plate 54 may have a different shape, such as a circular section, semi-circular or rectangular, as long as it includes an area in which the brake plate 54 at least partially overlaps with the first brake member 51 of the corresponding pair of brake members.

[0088] It will be understood that the first brake member 51 may alternatively be formed to be similar to the brake plate 54 described above, and the second brake member 52 may alternatively be formed to be similar to the brake finger 53 described above.

[0089] In another alternative embodiment, as described above, the clamping arm may be laterally displaced instead of being rotatable. In such an embodiment, the aforementioned brake plate linearly extends along at least a portion of the linear section of the positioning path.

[0090] Returning to the embodiment as Figure 5 shown, each first brake member 51 includes a first brake surface 55 and an oppositely facing second brake surface 56. Each second brake member 52 includes a third brake surface 57 and an oppositely facing fourth brake surface 58. When the clamping arm 3 is lifted to the braking position P2, the brake surfaces 55 - 58 are in frictional contact with each other, as Figure 6 shown.

[0091] The materials and / or surface finishes of the brake members 51, 52 and their corresponding brake surfaces 55 - 58 are selected to provide the amount of friction required to slow down, stop or brake the rotation of the clamping arm 3. Optionally, the brake members 51, 52 may be provided with a high friction coating or texture.

[0092] In an alternative embodiment, the brake members 51, 52 may be provided with grooves, teeth or corrugations that are configured to mesh when the brake members 51, 52 move towards each other.

[0093] It will be understood that the clamping arm 3 may include one or more hinged arm body sections that may rotate about additional axes of rotation to provide the clamping arm 3 with a greater degree of freedom of movement. Between each pair of arm body sections, additional brake mechanisms similar in function and / or characteristics to the aforementioned brake mechanism 5 may be applied to brake the rotation of one of the arm body sections relative to the other of the arm body sections about a corresponding additional axis of rotation.

[0094] As in Figure 5 and Figure 6Best seen in, the clamping driver 6 includes a linear actuator 60, which in this example is a pneumatic cylinder that can be controlled to extend in the clamping direction C. In this example, the linear actuator 60 is coupled or fixed to the holder body 40 such that any extension or retraction of the linear actuator 60 is directly applied to and / or converted into a corresponding movement of the holder body 40. Alternatively, the linear actuator 60 can only abut the holder body 40 in the clamping direction C to push it downward. In this case, a biasing member (not shown) can be used to bias the holder body 40 to move upward with the retraction of the linear actuator 60.

[0095] As Figure 4 and Figure 5 Further shown, the height adjustment mechanism 7 includes a support body 70 that can move and / or slide along the base body 20 in the clamping direction C. The support body 70 holds or supports the clamping driver 6 along the base body 20 in the driver position. The height adjustment mechanism 7 is configured to control, allow, or assist in adjusting the driver position of the support body 70 and indirectly the clamping driver 6 along the base body 20 in the clamping direction C. In this example, the height adjustment mechanism 7 includes a support cable 71 that extends around a pulley 72 between a counterweight 73 (or a reel) and the support body 70. The weight of the counterweight 73 is selected to be equal to or substantially equal to the combined weight of the clamping driver 6, the holder 4, and the clamping arm 3. In this way, a human operator can manually adjust the driver position of the clamping driver 6 by pushing or pulling on any one of the support body 70, the clamping driver 6, the holder 4, or the clamping arm 3.

[0096] Alternatively, the height adjustment mechanism 7 can be provided with an active drive component, such as a linear actuator, to adjust the driver position.

[0097] Finally, as Figure 4 and Figure 5 shown, the height lock 8 includes a locking member 81 that is used to fix or lock the clamping driver 6 in the driver position along the base body 20. In this particular embodiment, the locking member 81 is disposed between the support body 70 and the base body 20 to lock the position of the support body 70 relative to the base body 20 in the clamping direction C. In this example, the locking member 81 is formed by a pneumatically controlled brake pad that frictionally engages with the base guide 21. Alternatively, other mechanical solutions, such as pin-hole engagement or the use of (electro)magnets, can be envisioned.

[0098] The height lock 8 is provided with a control unit 82 that is functionally or operatively connected to the height lock 8 for placing the locking member 81 in the unlocked state as Figure 4 shown and the locked state as Figure 5switch between the shown locked states. In this example, the control unit 82 is a lever-operated pneumatic manifold or valve that pneumatically controls the locking member 81. The control unit 82 is provided with a lever 83 for manual operation, but alternatively can be controlled remotely, for example in response to a received control signal from a remote station.

[0099] In this embodiment, the control unit 82 is also functionally or operationally connected to the clamping actuator 6 such that the switching of the locking member 81 between the locked state and the unlocked state depends on or is conditional upon the state of the clamping actuator 6. In particular, the control unit 82 can conveniently be configured to always first switch the locking member 81 to the locked state before allowing the clamping actuator 6 to apply the clamping force F to the holder 4. Vice versa, the control unit 82 can be configured to allow the locking member to switch from the locked state to the unlocked state only when the clamping force F first decreases below a predetermined threshold or to zero. The predetermined threshold can be selected to be equal to or lower than the gravity acting on the clamping arm 3 and / or the holder 4.

[0100] In this particular example, where the control unit 82 is a pneumatic manifold or valve, the control unit 82 can have different valve sections that operate sequentially in response to the operation of the lever 83.

[0101] Alternatively, the clamping actuator 6 and the height lock 8 can be independently controlled sequentially, for example in response to control signals received from a remote station. The operation of the height lock 8 can also be conditionally controlled based on sensor input, for example based on sensor signals received from a pressure sensor at the clamping actuator 6.

[0102] Now reference will be made to Figure 1 - Figure 6 briefly describe a method for operating the above slab gripper 1.

[0103] Figure 1 The following situation is shown, where the clamping arm 3 has moved or rotated into the clamping position above the Z-shaped stack 9 and has lowered its clamping surface 32 onto the strip section 92 at the second vertical post K2. The strip section 91 at the first vertical post K1 is pulled in the feed direction F. In particular, the strip section 91 at the first vertical post K1 has been partially depleted.

[0104] Figure 2 The rotation of the clamping arm 3 between the initial position shown by the dashed or broken line and the clamping position shown by the solid line is schematically shown.

[0105] Figure 4This shows a situation where the locking member 81 of the height lock 8 is in the unlocked state. The drive position of the clamping drive 6 can now be adjusted along the base body 20. This adjustment can be performed manually with or without the assistance of the height adjustment mechanism 7, or it can be controlled (semi)-automatically in response to a control signal. The clamping drive 6 is positioned at a drive position from which the stroke of its linear actuator 60 is sufficient to bring the clamping arm 3 into clamping contact with the zigzag stack 9.

[0106] Between Figure 4 And Figure 5 the control unit 82 of the height lock 8 causes the locking member 81 to switch from the unlocked state to the locked state. This can be in response to the operation of the lever 83, or (semi)-automatically in response to a control signal. By moving the locking member 81 into the locked state, the drive position of the clamping drive 6 is fixed or locked. Now, the clamping drive 6 can be operated to apply a clamping force F to the holder 4, which will also allow the clamping arm 3 to descend into a position directly above the zigzag stack 9 or onto the zigzag stack 9.

[0107] Figure 5 And Figure 6 shows the clamping arm 3 descending onto the zigzag stack 9 in the clamping direction C due to the operation of the clamping drive 6. When the clamping arm 3 is in clamping contact with the zigzag stack 9, any further clamping stroke of the clamping drive 6 will cause the holder 4 to move further downward within the tolerances provided between the braking members 51, 52 and the clamping members 34, 44 of the braking mechanism 5 until the braking members 51, 52 come into contact with each other. It is noted that the further downward movement of the holder 4 relative to the clamping arm 3 already supported on the zigzag stack 9 can also be considered as an upward movement of the clamping arm 3 relative to the holder 4 in the braking start direction B from the release position P1 as shown in Figure 5 Shown towards and / or into the braking position P2 as shown in Figure 6 Shown.

[0108] Therefore, during or shortly after the clamping arm 3 descends onto the zigzag stack 9, the braking mechanism 5 can be automatically activated to slow down, stop, or brake the rotation or displacement of the clamping arm 3 about the rotation axis S.

[0109] More particularly, once the clamping force F1 is applied to the zigzag stack 9, the braking force F2 is generated as an automatic reaction to the clamping force F1. In this way, it is possible to prevent the clamping force F1 from being generated without an immediate braking force F2 to hold the clamping arm 3.

[0110] As described above, the braking mechanism 5 passively, automatically, and / or mechanically converts the relative movement between the clamping arm 3 and the retainer 4 in the braking start direction B into a braking force F2. The braking force F2, which is a frictional force, is proportional to the amount of the clamping force F1 applied by the clamping arm 3 to the zigzag stack 9 in the clamping direction C. In other words, if the clamping force F1 is doubled, the braking force F2 is also approximately doubled.

[0111] When it is necessary to lift the clamping arm 3 from the zigzag stack 9, for example, when repositioning the clamping arm 3 to different vertical posts K1 - K4, the clamping actuator 6 can be controlled to retract or lift the retainer 4 in the braking start direction B, which will reintroduce the spacing between the braking members 51, 52 and terminate the braking force F between the retainer 4 and the clamping arm 3. When the clamping arm 3 has been lowered relative to the retainer 4 into the release position P1, the clamping arm 3 will be lifted from the zigzag stack 9 together with the retainer 4. Then, the clamping arm 3 can freely rotate about the rotation axis S.

[0112] Alternatively, the control unit 82 of the height lock 8 can be operated such that the clamping force F is first reduced before the locking member 81 is switched from the locked state to the unlocked state. Subsequently, the locking member 81 can be switched to the unlocked state. Now, the drive position of the clamping actuator 6 can be freely adjusted along the base body 20 until a position where the retainer 4 and the clamping arm 3 are lifted to a clear position above the zigzag stack 9.

[0113] It is to be understood that the foregoing description is for the purpose of illustrating the operation of the preferred embodiments and is not intended to limit the scope of the invention. From the foregoing discussion, many variations will be apparent to those skilled in the art, and these variations are also included within the scope of the invention.

[0114] List of Reference Numerals

[0115] 1 Slab gripper

[0116] 2 Base

[0117] 20 Base body

[0118] 21 Base guide

[0119] 3 Clamping arm

[0120] 30 Arm body

[0121] 31 Clamping member

[0122] 32 Clamping surface

[0123] 33 Rotary pin

[0124] 34 First clamping member

[0125] 4 Retainer

[0126] 40 Retainer body

[0127] 41 Retainer guide

[0128] 42 Rotary socket

[0129] 44 Second clamping member

[0130] 45 Sliding pin

[0131] 5 Brake mechanism

[0132] 50 First pair of brake members

[0133] 50' Additional pair of brake members

[0134] 51 First brake member

[0135] 52 Second brake member

[0136] 53 Brake finger

[0137] 54 Brake plate

[0138] 55 First brake surface

[0139] 56 Second brake surface

[0140] 57 Third brake surface

[0141] 58 Fourth brake surface

[0142] 6 Clamping driver

[0143] 60 Linear actuator

[0144] 7 Height adjustment mechanism

[0145] 70 Support body

[0146] 71 Support cable

[0147] 72 Pulley

[0148] 73 Counterweight

[0149] 8 Height lock

[0150] 81 Locking member

[0151] 82 Control unit

[0152] 83 Lever

[0153] 9 Zigzag stack

[0154] 90 Pre-cut elastomer slab

[0155] Strip section of 91 - 94

[0156] 95 Continuous elastomeric strip

[0157] A Alignment axis

[0158] B Braking start direction

[0159] C Clamping direction

[0160] D Positioning path

[0161] E Positioning plane

[0162] F Feeding direction

[0163] F1 Clamping force

[0164] F2 Braking force

[0165] K1 - K4 Vertical columns

[0166] P1 Release position

[0167] P2 Braking position

[0168] R Rotation range

[0169] S Axis of rotation

Claims

1. A slab gripper for holding a pre-cut elastomeric slab stored in a zigzag stack in place as a strip section is pulled from the pre-cut elastomeric slab, wherein, The slab gripper includes a base, a gripping arm, and a retainer for holding the gripping arm relative to the base. Wherein, the gripping arm defines a gripping surface for applying a gripping force to the Z-shaped stack in the gripping direction. Wherein, the slab gripper further includes a gripping driver for pressing the gripping surface against the Z-shaped stack in the gripping direction with the gripping force. Wherein, the gripping arm can be positioned relative to the base above the Z-shaped stack in a gripping position in a positioning plane transverse to or perpendicular to the gripping direction along a positioning path. Wherein, in response to contact of the gripping surface with the Z-shaped stack in the gripping direction, the gripping arm can be at least partially lifted relative to the retainer in a braking activation direction opposite to the gripping direction. Wherein, the slab gripper further includes a braking mechanism that activates to brake the displacement of the gripping arm along the positioning path when the gripping arm is at least partially lifted relative to the retainer in the braking activation direction.

2. The slab gripper according to claim 1, characterized in that, The braking mechanism is configured to passively, automatically, and / or mechanically convert the gripping force generated by the gripping driver in the gripping direction into a braking force to brake the displacement of the gripping arm along the positioning path.

3. The slab gripper according to claim 1 or 2, characterized in that, The gripping arm can rotate relative to the base about a rotation axis, wherein the positioning path is circular or includes a circular section.

4. The slab clamping member according to claim 3, wherein The rotation axis is parallel to the gripping direction.

5. The slab gripper according to any one of the preceding claims, characterized in that, The braking mechanism includes one or more first braking members and one or more second braking members. The one or more first braking members are configured to move along the positioning path together with the gripping arm, and the one or more second braking members are configured to remain in a fixed position along the positioning path relative to the base. Wherein, a first braking member and a second braking member of at least a first pair of braking members including one of the one or more first braking members and one of the one or more second braking members are arranged to interact with each other when the gripping arm is at least partially lifted relative to the retainer in the braking activation direction.

6. The slab clamping member according to claim 5, characterized in that, The gripping arm can be at least partially lifted from a release position to a braking position relative to the retainer in the braking activation direction. Wherein, when the gripping arm is at least partially lifted to the braking position, the first braking member and the second braking member of the first pair of braking members are pressed into physical contact with each other.

7. The slab clamping member according to claim 5 or 6, characterized in that, The gripping arm can rotate relative to the base about a rotation axis, wherein the positioning path is circular or includes a circular section. Wherein, one of the first braking member and the second braking member of the first pair of braking members physically extends beyond a rotation range about the rotation axis. Wherein, the first braking member and the second braking member of the first pair of braking members are arranged to interact with each other at any overlapping angular position where the other of the first braking member and the second braking member is within the rotation range.

8. The slab gripper according to claim 7, wherein The rotation range is at least ninety degrees, preferably at least one hundred and twenty degrees, more preferably at least one hundred and sixty degrees, and most preferably at least two hundred and fifty degrees.

9. The slab gripper according to any one of claims 5 to 8, characterized in that, One of the first braking member and the second braking member in the first pair of braking members includes a braking finger protruding radially with respect to the rotation axis.

10. The slab gripper according to any one of claims 5 to 9, characterized in that, One of the first braking member and the second braking member in the first pair of braking members includes a braking plate that at least spans an annular section extending concentrically around the rotation axis.

11. The slab gripper according to any one of claims 5 to 10, characterized in that, The one or more first braking members include a set of first braking members, and wherein, the one or more second braking members include a set of second braking members, the set of second braking members alternating with the first braking member in the set of first braking members in the braking start direction to form additional pair or pairs of braking members having one first braking member in the set of first braking members and one second braking member in the set of second braking members and the first pair of braking members, wherein the first braking member and the second braking member in each pair of braking members are arranged to interact with each other when the clamping arm is at least partially lifted relative to the holder in the braking start direction.

12. The slab clamping member according to claim 11, wherein, The first pair of braking members and the additional pair or pairs of braking members are stacked in the clamping direction to form a stack of braking members, wherein the slab gripper further includes a first clamping member below the stack of braking members and a second clamping member above the stack of braking members to clamp the braking members together when the clamping arm is at least partially lifted relative to the holder in the braking start direction.

13. The slab gripper according to any one of the preceding claims, characterized in that, The clamping arm includes an arm body and a clamping member that can rotate relative to the arm body around an alignment axis for aligning the clamping member with the Z-shaped stack, wherein the clamping member defines the clamping surface.

14. The slab gripper according to any one of the preceding claims, characterized in that, The holder is configured to adjust the height position of the clamping arm relative to the base.

15. The slab clamping member according to any one of the preceding claims, characterized in that, The clamping actuator is configured to indirectly apply the clamping force to the clamping arm via the holder, wherein the slab gripper further includes a height lock for fixing the clamping actuator in a drive position relative to the base in the clamping direction and releasing the clamping actuator from the drive position relative to the base in the clamping direction.

16. The slab gripper according to claim 15, wherein, The slab gripper is configured to only allow release of the fixing of the clamping actuator from the drive position when the clamping force generated by the clamping actuator in the clamping direction is below a predetermined threshold or zero.

17. The slab gripper according to claim 15 or 16, characterized in that, The height lock can be remotely controlled.

18. A method for operating a slab gripper according to any one of the preceding claims, characterized in that, The method includes the following steps: - Positioning the clamping arm along the positioning path to a clamping position above the Z-shaped stack in the clamping direction; - Clamping the clamping surface to the Z-shaped stack in the clamping direction using the clamping force; and - When the clamping arm is at least partially lifted relative to the holder in the braking start direction, the braking mechanism is activated to brake the displacement of the clamping arm along the positioning path.

19. The method according to claim 18, wherein The braking mechanism passively, automatically, and / or mechanically converts the clamping force applied by the clamping surface to the Z-shaped stack in the clamping direction into a braking force to brake the displacement of the clamping arm along the positioning path.

20. The method according to claim 18 or 19, characterized in that, The displacement of the clamping arm along the positioning path is a rotational movement around a rotational axis along a circular section of the positioning path.

21. The method according to any one of claims 18 to 20, characterized in that, The braking force is proportional to the clamping force applied by the clamping surface to the Z-shaped stack.

22. The method according to any one of claims 18 to 21, characterized in that, The slab gripper includes a clamping drive and a height lock. The clamping drive is used to generate the clamping force in the clamping direction, and the height lock is used to fix the clamping drive relative to the base in the clamping direction at a drive position. Wherein, the method further includes the following steps: - Fixing the clamping drive at the drive position using the height lock; - Generating the clamping force using the clamping drive; and - Releasing the fixing of the clamping drive from the drive position only when the clamping force applied by the clamping drive to the clamping arm in the clamping direction is lower than a predetermined threshold or zero.

23. The method according to claim 22, wherein The height lock is remotely controlled.

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