Technical Domain

The present invention is directed to an assembly drum and a building system incorporating such a drum for effecting processes for turning up rubber products in the field of tire manufacturing.

Background

A tire type device is intended to equip any type of vehicle, including, without limitation, passenger vehicles, heavy-duty vehicles, two-wheeled vehicles, agricultural vehicles, engineering vehicles and aircraft. It is understood that a tire in this sense includes a crown with a tread designed to contact the ground via a tread surface. In a known manner, the tread of a tire is provided with a tread pattern having notably tread elements or elementary blocks delimited by various main, longitudinal or circumferential, transverse or even oblique grooves, the elementary blocks being able to additionally include various incisions or finer sipes. The grooves constitute channels intended to evacuate water when driving on wet ground.

In the field of tire manufacturing, there are assemblies (or "closed objects") that include an elastic structure and a load-bearing structure for which the manufacture requires a special use of internal reinforcements (see, for example, the assemblies disclosed in the Applicant’s publications WO2016/116490 and WO2018/130782). The characteristics of these assemblies can be easily described but are much less obvious to master during their realization because of the absence of a beadwire. One of the main difficulties encountered during the manufacture of these objects is the control of the different lengths of material during the turn-up of the chamber closure (or "turn-up"), as well as the centering of this chamber under the top block. A poor control of the lengths of the flank sheet leads to problems of molding, top centering or folds, depending on whether there is overlength or underlength.

In order to control the manufacture of a closed tire (without taking into account the installation of the internal reinforcement), it is necessary to control the length of the sidewalls with headless turn-up. It is also necessary to control the centering of the blank when the crown is set. In order to effect the pose of products, the disclosed invention combines a "fictitious retractable beadwire" with a mechanical turn-up system, thus presenting a turn-up architecture to include a superimposition in the center of one end of a product. The disclosed invention also anticipates embodiments that combine these elements to maintain constant control over the products, even during an overlap operation (or “overlap” in English).

Summary of the invention

The invention is directed to an assembly drum for a building system that effects turn up of rubber products, the drum including a shaft rotating relative to a building frame on which the drum is mounted so as to rotate around a central axis, the drum being in two halves separable from a ferrule to create two sides of the drum in an assembly that includes a reference and an anti-reference, the drum further including a cylindrical laying generatrix having a circumferential surface on which the rubber products are assembled during posing of the rubber products, characterized in that the drum includes:

- a turn-up subassembly disposed at each end of a corresponding drum and being radially expandable with respect to the circumferential surface of the drum, each turn-up subassembly having corresponding turn-up arms that are distributed in a series (RET _A ) closest to a ferrule center plane, and in a series (RET _B ), each arm of a series having a predetermined length with a corresponding free end;

- a mobile sleeve on which are arranged a first annular actuator and a second annular actuator, with the series (RET _A ) being directly pivoted on the mobile sleeve and the series (RET _B ) being pivoted on the first annular actuator on the mobile sleeve; and

- a lifting ring in communication with the second annular actuator of the mobile sleeve and in communication also with the two series (RET _A , RET _B ) of arms to allow the lifting of the two series of arms by the actuation of the second annular actuator.

In certain embodiments, the drum also includes a mobile clutch arranged on each side of the drum, each mobile clutch engaging the mobile sleeve during a turn-up process.

In certain embodiments, the drum also includes a central screw with opposite pitches that allows a symmetrical displacement of the mobile clutches with respect to the central axis.

In certain embodiments, the drum also includes a spring(s) or roller(s) at each corresponding free end to engage rubber products posed on the circumferential surface of the drum during a turn-up process.

In certain embodiments, the drum also includes a stop bar(s) that is slidably mounted in the lifting ring and maintained in a standby position by a spring between turn-up cycles.

The invention is also directed to a building system that effects the turn-up of rubber products, wherein the building system includes:

- the disclosed drum; and - at least one mobile pallet serving as a fictitious beadwire of the building system.

In certain embodiments, the building system also includes:

- at least one building frame on which the drum is rotatably mounted; and

- a top transfer ring.

In some embodiments of the building system, the moving pallet includes a shoe with a body having means for mounting on the top transfer ring, the body of the shoe extending between two opposite ends and having an upper surface on which at least one rubber product is posed, and an opposite lower surface with a curvature that engages the circumferential surface of the drum, the body of the shoe having a predetermined length and a predetermined width.

In some embodiments, the building system further includes a retraction system for retracting the moving pallets acting as a fictitious beadwire, the retraction system having a pre-loaded tension spring for retracting the moving pallet.

The invention furthermore is directed to a retraction process effected by the disclosed building system during a retraction cycle, the process including the following steps:

- a step of raising the respective turn-up up arms of the series (RET _A , RET _B ), this step including a step of lowering the mobile pallets in contact with the rubber products previously placed on the circumferential surface of the drum;

- a step of advancing the respective turn-up arms of the series (RET _A , RET _B ) that, by radial return, come and ride on the moving pallet;

- a step of retraction of the mobile pallet to leave blank the turn-up of the rubber products; and

- a turn-up step during which the series (RET _B ) of turn-up arms are moved backwards until they close the turn-up by bonding the rubber products.

In certain embodiments of the turn-up process, the process is effected in an iterative manner.

Other aspects of the invention will become evident from the following detailed description.

Brief description of the drawings

The nature and the various advantages of the invention will become more obvious when reading the following detailed description, together with the attached drawings, in which the same reference numbers designate identical parts everywhere, and in which: Figure 1 represents a cross-sectional view of an embodiment of an assembly drum that is part of a building system for effecting the turn-up of rubber products.

Figure 2 represents an enlarged view of turn-up subassemblies of the assembly drum of Figure 1.

Figure 3 represents a perspective view of an embodiment of a mobile pallet to serve as a fictitious beadwire of the building system incorporating the drum of Figure 1.

Figures 4 to 8 represent steps of an embodiment of a turn-up process of the invention.

Detailed description

Referring now to the figures, in which the same numbers identify identical elements, Figure 1 represents an embodiment of an assembly drum (also called "building drum" or "drum") 100 that effects a process of turning up rubber products (called "product" or "products"). These products include fabrics and plies (including reinforcing plies sandwiched between rubber layers) that are prepared flat on a cylindrical support. The invention facilitates the manufacture of a variety of tire types incorporating multiple products without changing the drum.

The drum 100 is mounted on a known building frame (not shown) that also includes mechanical means capable of rotating the drum around a central axis X-X' (e.g., driven by a drum flange coupled thereto). In order to maintain a symmetrical design, the drum 100 is designed in two separable halves 100', 100" with respect to a support ring (or "ferrule") 102. This separation is achieved via an expandable hub (or "hub") 112 attached to the end of the top form. The hub faces the drum 100 and can pass through a top transfer ring ("ATS") known to effect separation. The two sides 100', 100" the of drum 100 are differentiated by the position of a barcode, called the reference (R) side when assembled. The opposite side is called the anti-reference (AR) side.

The drum 100 includes a cylindrical laying generatrix (or "generatrix") with a circumferential receiving surface (or "surface") 100a upon which products are assembled (e.g., during a building cycle). The generatrix is cylindrical, allowing total coverage of the product posing area by two known placement and centering subassemblies 104, 106. The almost continuous cylindrical geometry of the generatrix allows an easy posing of the products (winding on a cylinder), as well as a better workability of the different bonds to be turned-up.

The drum 100 also includes a central screw 108 with opposite pitches that allow the symmetrical movement of the two mobile clutches ER and EAR. The central screw 108, being with opposite pitches, allows the symmetrical displacement of the two mobile clutches E _R and EAR, SO that a shaft 110 serves as a tool holder. The choice is made to clutch either on a turn up subassembly 114, 116, or on a placement and centering subassembly 104, 106. This has the main advantage of allowing precise control of the speed and position of the different subassemblies by using only one motorized motion input. Independent or combined movements can thus be realized.

Referring again to Figure 1 and also to Figure 2, as well as to Figures 4 to 8, the drum 100 also includes turn-up subassemblies 114, 116 that effect turn-up cycles of the products deposited on the surface 100a of the drum 100. Each turn-up subassembly 114, 116 is located at one end of a corresponding drum 100, and each is radially expandable with respect to the axis X-X'. It is understood that the turn-up subassemblies 114, 116 all have the same components and function in the same manner.

Each turn-up subassembly 114, 116 includes a mobile sleeve 118 in which the mobile clutch ER engages. The mobile sleeve 118 is slidably mounted on the shaft 110 along a path 110a defined between a first stop 110a' and a second stop 110a" (see Figure 4). The mobile sleeve 118 is set in sliding motion during product turn-up processes.

Each turn-up subassembly 114, 116 includes a corresponding set of turn-up arms. The turn-up arms of a subassembly are divided into two series RET _A and RET _B as shown in Figure 2 (the two series RET _A and RET _B are also shown during operation of the turn-up process of the invention in Figures 4 to 8). Each arm A, B has a predetermined length with a corresponding free end Aio, Bio (see Figure 2 and Figures 4 to 8). Each free end Aio, Bio can carry a corresponding engagement means that engages one or more products posed on the circumferential surface 100a of the drum 100. As shown in Figures 4 to 8, the engagement means includes one or more springs or rollers 50, 50' corresponding to each respective free end Aio, Bio. It is understood that the springs or rollers 50, 50' may be replaced by equivalent tool(s) (e.g., membrane(s), fmger(s), articulated device(s) and/or known equivalent device(s)). In the description, reference is made to spring(s) 50, 50' and this includes springs and their equivalents.

The series RET _A including arms A is closest to the mid-plane of the ferrule 102, and it pivots directly on the mobile sleeve 118. The series RET _B with arms B pivots on a first annular actuator 120 mounted on the mobile sleeve 118, allowing the arms B to be moved backwards for product closure (for example, the closure of a ply of a sheet as shown in Figure 8 by the closed ply P400 of sheet 400). A second annular actuator 122 is mounted on the mobile sleeve 118 together with a lifting ring 124, allowing a sliding movement of the lifting ring. The lifting ring 124 is not directly attached to the turn-up arms, but it allows the turn-up arms to be lifted by contact. Thus, when the series RET _B is retracted to close the fold, the arms are able to press at a smaller radius than the one reached during lifting, since they will have lost contact with the lifting ring 124 upon retraction.

On the outside of the actuators 120, 122, one or more stop bars 126 are slid into the lifting ring 124 (see Figures 4 to 8). A spring return (not shown) maintains the stop bar 126 in a standby position between turn-up cycles.

The drum 100 is part of a positive building system. A "positive" system is one in which there is no loss of reference between the start and the end of an operation (e.g., a process or a turn-up cycle), and the combination of a series of actions of a given system ensures that an accurate and repeatable result is achieved. During product turn-up cycles, the product must be precisely posed and bonded in order to have at least one set of peripheral contacts at all times (and thus prevent any risk of uncontrolled slipping). The drum 100 therefore includes two series of turn-up arms in order to remain positive during retraction of a fictitious beadwire in the form of a moving pallet. In the manufacture of tires where no beadwire is available (for example, the manufacture of closed objects), the product must be turned up in relation to another object to determine the turned-up length. Once this length is known (and since the final ply must be empty), the area must be cleared without losing reference, hence the retractable aspect of the fictitious beadwire.

The building system including the drum 100 includes one or more movable pallets that replace pallets attached to the ATS (not shown). It is these moving pallets that act as the fictitious beadwire.

Referring again to Figures 1 and 2 and 4 to 8, and also to Figure 3, in Figures 3 and 4, an embodiment of a moving pallet of the building system includes a shoe 200 with a body 202 that facilitates standard mounting on the ATS (these modifications to the ATS do not disturb its normal operation). The body 202 of the shoe 200, which extends between two opposite ends, has an upper surface 202' on which one or more products are posed, and an opposite lower surface 202" with a curvature that engages the surface 100a of the drum 100 (see Figures 4 to 8). The body 202 of the shoe 200 has a known size, including a known length (represented by the opposite ends of the body 202) and a known width (represented by a predetermined width of the body 202).

In order to limit the effect on the ATS, a passive retraction system is provided for the retraction of the moving pallets acting as a fictitious beadwire. The retraction system uses the potential energy of a pre-loaded return spring 210 to retract the moving pallet (in this case, the shoe 200). Thus, the moving pallets are armed by pulling them, then a trigger 211 maintains them in the extended position. The trigger 211 includes an actuation point 211a and a stop notch 211b that engages the body of shoe 202 between cycles of turning up products deposited on the surface 100a of the drum 100. This engagement is ensured by a return spring 21 lc of the trigger 211. The arrival of the series RET _A of turn-up arms on this trigger causes the retraction of the shoe 200 (i.e., the fictitious beadwire). For re-arming, a re-arming notch 212 is provided on the lower surface 202" of each shoe 200, in which pins provided on the surface 100a of the drum 100 can be engaged. The combination of a radial lowering of the shoes 200 of the ATS with a translational movement of the drum 100 thus allows the springs to be tensioned.

Referring again to Figures 1 to 8, a detailed description is given of an exemplary product turn-up process of the invention (it represents only the right side). Such a turn-up process is realized during a turn-up cycle and/or a manufacturing cycle effected by the building system of which the drum 100 is a part. It is understood that the process can be easily adapted for all embodiments of a building system incorporating one or more drums 100

Referring to Figure 4, upon starting a product turn-up process from a starting position, the stop bar 126 is held in the standby position. In this starting position, the moving pallets are positioned in contact with the products 400 previously posed on the drum surface (represented by the shoes 200). This starting position is taken by all turn-up assemblies 114, 116 between turn-up processes.

Referring to Fig. 5, the process includes a step of raising the turn-up arms A, B of the respective series RET _A , RET _B (see arrow I in Fig. 5). This step includes a step of setting the annular actuator 122 in sliding motion with respect to the mobile sleeve 118 (see arrow II of Figure 5). The step of setting the annular actuator 122 in sliding motion causes the lifting ring 124 to move. As a result, the two series RET _A , RET _B are pivoted to effect the elevation of the turn-up arms A, B. During this step, an adjustment of the relative position between the drum and the ATS is possible to adjust the turn-up length of the product.

Referring to Figure 6, the process further includes a step of advancing the turn-up arms A, B which, by radial (spring) return, turn over the fictitious beadwire (the shoe 200) to control the length of a tire part (for example, the length of the shoe 200 that corresponds to the length of a sidewall of the tire being produced)(see arrow III of Figure 6). This fictitious shape will have to "disappear" during the turn-up to leave it empty. The combination of the movement and the radial advance of the springs 50, 50' controls the length of the turned-up product.

This step includes a step of moving the mobile sleeve 118 along the path 110a in the direction of the first stop 110a' (see arrow IV of Figure 6). This step is realized by the action of the central screw 108 on a nut of the mobile clutch E _R (it is understood that the movement of the mobile clutch EAR is performed in the same manner). Thus, the turn-up arms A, B are advanced to effect the termination of the winding of the products 400 around the shoe 200 during this step.

Referring to Fig. 7, the process also includes a step of retracting the fictitious beadwire (the shoe 200) to leave the turn-up of the product 400 empty (see arrow V in Fig. 7). It is noted that the two series RET _A , RET _B of arms A, B are in contact with a non-moving part 500 during the retraction of the shoe 200 acting as a fictitious beadwire, so that the products 400 are maintained.

Referring to Fig. 8, the process includes a final turn-up step during which the turn-up arms B (furthest from the center of the ferrule 102) are retracted until they close the turn-up of the products by bonding (see arrow VI of Fig. 8). At the end of a retraction stroke of the arms B of the series RET _B , the stop bar 126 allows the second actuator to execute an additional displacement of the lifting ring 124, still in contact with the series RET _A arms that slightly rise at the end of the stroke (see arrow VII of Figure 8). Thus, a set of stops is used to keep the arms A in contact while the arms B move backwards, then once the bonding starts, the contact of the arms A is relieved to completely remove the ficitious beadwire system. The system is therefore positive because the products 400 are never "released".

At the end of the turn-up process, the stop bar 126 returns to the standby position by means of a spring return when the second actuator 122 has returned to a starting position (as shown in Figure 4). Thus, the series RET _A , RET _B are at the initial lift height for a complete removal of the turn-up arms A, B without crushing the freshly executed closed fold P400.

At the end of the process, the moving pallets (i.e., the shoes 200) are re-set and the process can be restarted.

In some embodiments of the turn-up process of the invention, the process is carried out iteratively. In these embodiments of the process, the turn-up can be performed successively in a synchronized or non-synchronized manner (regardless of the presence or absence of an overlap in the architecture). By using mobile pallets (the shoes 200), one can thus choose to set in motion the two opposite turning subassemblies 114, 116 with a symmetrical displacement with respect to the center of the ferrule 102. The mobile pallets that allow use of a continuous cylindrical generator during the building phase also have a centering function. It is by combining the position of the turn-up subassemblies 114, 116 with the synchronized and symmetrical feed of the subassemblies 104, 106 that a surface is obtained on both sides of the uncured product on which the blank is placed during its inflation.

At the end of a turn-up cycle including a turn-up process realized by the system incorporating the drum 100, one or more turned-up products are produced that have the desired qualities for tires incorporating these turned-up products. These qualities are ensured while also preserving other performance qualities of the tires incorporating the turn-up products emanating from the disclosed system and the drum 100.

A turn-up process (and/or a turn-up cycle including a turn-up process of the invention) performed by the system including the drum 100 can be done by PLC control and can include pre-programmed management information. For example, a process setting can be associated with the parameters of the drum 100 and also with the properties of the products posed on the surface 100a of the drum 100.

For all embodiments, a monitoring system could be set up. At least part of the monitoring system can be provided in a portable device such as a mobile network device (e.g., cell phone, laptop, network connected portable device(s) (including "augmented reality" and/or "virtual reality" devices, network connected wearable clothing and/or any combination and/or equivalent)). In some embodiments of the invention, the drum 100 (and/or a system that incorporates the drum 100) may receive voice commands or other audio data representing, for example, a request for the current status of a turn-up process. A generated response may be represented in an audible, visual, tactile (e.g., using a haptic interface) and/or virtual or augmented manner.

The drum 100 can facilitate its training (or the training of a system that incorporates the drum 100) to recognize representative values of the turn-up products (for example, parameters of a length of a shoe 200) and to make a comparison with target values. This step may include the step of training the system to recognize non-equivalences between the compared values. Each training step includes a classification generated by means of machine learning. This classification may include, but is not limited to, the parameters of the rubber mixtures incorporated into the products, the duration of the turn-up cycles and the values expected at the end of a turn-up cycle in progress.

The terms "at least one" and "one or more" are used interchangeably. Ranges that are presented as "between a and b" include the values "a" and "b". While specific embodiments of the disclosed device have been illustrated and described, it is understood that various changes, additions and modifications may be made without deviating from the spirit and scope of this disclosure. Consequently, no limitations should be imposed on the scope of the invention described except those set forth in the claims annexed hereto.