CN107856333B

CN107856333B - Tyre building drum

Info

Publication number: CN107856333B
Application number: CN201711037369.XA
Authority: CN
Inventors: 李志军
Original assignee: Suzhou Sachi Huachen Machinery Co Ltd
Current assignee: Safe Run Intelligent Equipment Co Ltd
Priority date: 2017-10-30
Filing date: 2017-10-30
Publication date: 2020-04-17
Anticipated expiration: 2037-10-30
Also published as: WO2019085886A1; KR20200067865A; KR102135730B1; CN107856333A

Abstract

The invention discloses a tire building drum, comprising: the drum shaft and install the shaping subassembly on the drum shaft, but the shaping subassembly includes two side drums and is located the well drum between two side drums, but well drum includes but two half drums of axial mutual embedding cooperation and connect two respectively half drum's synchronization unit, each half drum includes the first tile and the second tile and the drive of a plurality of circumference distributions first tile with second tile radial movement's drive assembly, the synchronization unit is used for controlling two half drum's tile radial synchronization radial movement.

Description

Tyre building drum

Technical Field

The invention relates to the technical field of tire building machines, in particular to a tire building drum applied to a tire building machine.

Background

In the step of installing the tire bead in the existing tire molding process, the transfer ring carrying the tire bead sleeves the tire bead at a designated position on the tire body material on the tire molding drum, and the tire bead supporting unit of the tire molding drum needs to circumferentially fix the tire bead so that the turn-up unit of the tire molding drum further wraps the tire bead in the tire body material. In order to avoid a shift in the position of the bead during the turn-up step, a certain abutment force can be imparted to the end faces of the bead by the drum shoe expansion of the mid-drum. At present, the expansion of the drum tiles of the medium drum depends on a cylinder to drive a connecting rod mechanism so as to drive the drum tiles to lift in the radial direction. Because the initial angle of each link is consistent, and in order to ensure that the drum tiles form a seamless circumferential surface for coiling in the contracted state, gaps are necessary between the drum tiles in the expanded state of the drum tiles, especially at the end positions of the drum tiles close to the tire bead. In the process of molding a green tire, the extrusion force of the gap of the middle drum close to the end part of the tire bead and the extrusion force of the drum tile on rubber are different, so that the risk of air bubbles or indentation on the inner side of the tire bead is caused, and the quality accident of the tire is caused. In addition, the drum tile lifting mechanism can be divided into a left part and a right part which are driven by a cylinder driving mode, so that the left drum tile and the right drum tile can independently act. Because gas is led in from one side and the left and right side drum tiles can be independently controlled by the cylinder to lift, and meanwhile, the gas has certain compressibility, so that the phenomenon of inconsistent speed can occur in the lifting process of the left and right side drum tiles. The side drum tile rising fast can bias the rubber material to cause rubber material asymmetry, resulting in tire quality accidents.

Disclosure of Invention

The invention aims to provide a tire building drum without gaps on the circumferential direction and the end surface under the condition that drum tiles are extended, and the drum tiles on the left side and the right side of the tire building drum can be synchronously lifted.

In order to achieve the purpose, the invention adopts the following technical scheme:

a tyre building drum comprising:

the drum comprises a drum shaft and a forming assembly arranged on the drum shaft, wherein the forming assembly comprises two side drums and a middle drum positioned between the two side drums, the middle drum comprises two half drums which can be embedded and matched with each other in the axial direction and a synchronizing unit connected with the two half drums, each side drum can be driven to be away from the corresponding half drum, each half drum comprises a plurality of first tiles and second tiles which are distributed in the circumferential direction, and a driving assembly for driving the first tiles and the second tiles to expand or contract in the radial direction, the synchronizing unit controls the tiles of the two half drums to move synchronously in the radial direction, each first tile and each second tile comprises a body part, and the body parts of the first tiles and the second tiles are arranged at intervals and can form a closed circular ring together. .

Further, the synchronizing unit comprises racks oppositely arranged on the two half drums and gears respectively meshed with the two racks, and the gears are fixedly connected with the drum shafts in the radial direction.

Furthermore, one end of each rack is fixed on one of the half drums, and the other end of each rack is a free end.

Further, the intermediate drum has a contracted state and an expanded state, the first tile is located on the radial outer side of the second tile in the contracted state of the intermediate drum, and the first tile and the second tile are on the same circumferential surface in the expanded state of the intermediate drum.

Furthermore, the driving assembly comprises a first supporting piece and a second supporting piece which are fixedly connected with the side drum respectively, and a first sliding piece and a plurality of second sliding pieces which are slidably connected with the first supporting piece and the second supporting piece respectively, the driving assembly further comprises a plurality of connecting rods which are pivoted with the first sliding piece and the second sliding pieces, and the second sliding pieces are connected with the body part.

Furthermore, a plurality of fixed blocks used for being pivoted with the connecting rods are fixed on the first sliding piece along the circumferential direction at equal intervals.

Further, the connecting rods comprise first connecting rods and second connecting rods, the first connecting rods are connected with the first drum tiles through the corresponding first sliding pieces, and the second connecting rods are connected with the second drum tiles through the corresponding first sliding pieces.

Furthermore, the included angle between the first connecting rod and the axial direction is smaller than the included angle between the second connecting rod and the axial direction.

Further, the first drum tile is a large drum tile, the second drum tile is a small drum tile, and the radial stroke of the first drum tile is smaller than that of the second drum tile.

Further, the first and second drum tiles further comprise a plug portion extending from one side of the body portion, the plug portion comprises at least one elongated finger portion, and the finger portions of the two half drums are in staggered fit with each other so that the two middle drums are in axial embedded fit with each other.

Furthermore, the outer side surface and the outer circumferential surface of the circular ring surrounded by the plurality of body parts are seamless.

The invention has the beneficial effects that: the first drum tile and the second drum tile are driven to stretch radially through the contraction assembly, when the drum tiles are expanded to the limit position, the middle drum is close to two end faces of the side drum, no gap exists in the circumferential direction, the gap is prevented from impressing rubber materials when the middle drum is abutted against the tire bead, and meanwhile, the two half drum tiles are controlled to synchronously lift through the synchronization unit, so that a tire body material belt cannot be deviated, the asymmetry of the tire body material is avoided, and the quality of the tire is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic view of a tire building drum in a first perspective configuration.

FIG. 2 is a second perspective structural view of the tire building drum.

FIG. 3 is a third perspective structural view of the tire building drum.

FIG. 4 is a cross-sectional view of a tire building drum.

Fig. 5 is a schematic structural view of a mid-drum of the tire building drum.

Fig. 6 is a partial enlarged view of the cross-sectional view of fig. 5.

Fig. 7 is a schematic diagram of a first view of the synchronization unit.

FIG. 8 is a partial schematic view of a tire building drum.

Figure 9 is a perspective view of a first drum tile of the tire building drum.

Fig. 10 is a side view of the expanded state of the head of the mid-drum.

Fig. 11 is a side view of the mid-drum with the tiles in a contracted condition.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings.

As shown in fig. 1 to 4, the present invention discloses a tire building drum 100, the tire building drum 100 comprising a drum shaft 1, a building assembly 2 arranged on the drum shaft 1 and a driving device 3.

As shown in fig. 3 to 4, the forming assembly 2 comprises two side drums 20 arranged symmetrically and a middle drum 21 located between the two side drums 20. Wherein, the middle drum 21 comprises two half drums 210 which can be embedded and matched with each other along the axial direction, and the two half drums 210 are symmetrically arranged. Each side drum 20 is connected to the corresponding side half drum 210, and a part of each side drum 20 can be driven away from the corresponding half drum 210. The two side drums 20 are each fixedly connected to the drive device 3, so that the side drum 20 together with the respectively connected half drum 210 can be driven by the drive device 3 to move axially along the drum shaft 1. Specifically, the side drum 20 and the half drum 210 on one side of the drum shaft 1 and the side drum 20 and the half drum 210 on the other side can be moved synchronously toward or away from each other. Because the two half-drums 210 in the molding assembly 2 can be mutually embedded and matched, the molding assembly 2 can realize a wider range of molding width sizes, and tires with more size specifications can be molded.

As shown in fig. 4, each side drum 20 is provided with a turn-up unit 22 and a bead support unit 23. The tire building drum 100 is used for building a carcass assembly (not shown), when a carcass material advances and is attached to the building assembly 2, the drum shaft 1 rotates to drive the building assembly 2 to rotate, so that the carcass material is connected end to form a ring, and then the bead material is packed into the carcass material through the turn-up unit 22 and the bead support unit 23. Each side drum 20 further includes a shaft sleeve 24 fitted over the drum shaft 1 and a side drum cylinder block assembly 25 fitted over an outer circumferential surface of the shaft sleeve 24. Wherein the turn-up unit 22 and the bead support unit 23 are both disposed at one end of the side drum cylinder assembly 25 near the middle drum 21.

As shown in fig. 4, the driving device 3 is a screw rod which can rotate under the control of an external control device (not shown). The driving device 3 is connected to the shaft sleeve 24 and the side drum cylinder assembly 25 through a connecting member (not shown), and one end of the connecting member is in threaded connection with the driving device 3, so that the driving device 3 can drive the connecting member to axially move in a self-rotating state, and further drive the shaft sleeve 24 to axially move along the drum shaft 1.

As shown in fig. 4, the side drum cylinder assembly 25 operates in a similar manner to a cylinder, and includes a side drum outer cylinder 251, a side drum inner cylinder 252, and a side drum piston 253 interposed between the side drum inner cylinder 252 and the side drum outer cylinder 251. An inner cavity (not labeled) is formed between the side drum inner cylinder 252 and the side drum outer cylinder 251, and one end of the side drum piston 253 extends into the inner cavity. In addition, the side drum piston 253 is fixedly connected with the shaft sleeve 24 and the connecting piece, the side drum inner cylinder 252 is tightly abutted against the shaft sleeve 24 and is fixedly connected to the side drum outer cylinder 251, and the side drum inner cylinder 252 and the side drum inner cylinder 251 can slide relative to the side drum piston 253 and the shaft sleeve 24. Further, as shown in fig. 4, the side drum inner cylinder 252 has a substantially T-shaped axial cross section, and includes a first portion 252a and a second portion 252b that are fixedly connected to each other and perpendicular to each other. The first portion 252a extends axially and is sleeved outside the shaft sleeve 25, the second portion 252b extends radially and is perpendicular to the shaft sleeve 25, and the second portion 252b is fixedly connected to the side drum outer cylinder 251 through a bolt (not shown). Therefore, when the air is supplied to the inner cavity of the side drum cylinder assembly 25, the side drum inner cylinder 252 and the side drum outer cylinder 251 can move reciprocally together along the drum shaft 1 on the sleeve 24 with respect to the side drum piston 253, while bringing the turn-up unit 22 and the bead support unit 23 together to move axially. Therefore, a part of the side drum 20, i.e., the side drum inner cylinder 252 and the side drum outer cylinder 251, is movable away from the corresponding half drum 210 with respect to the sleeve 24 and the side drum piston 253 of the side drum 20. When a portion of the side drum 20 is separated from the half drum 210, a space is formed therebetween so that other station devices can move into the space for the process step of carcass material positive wrapping, whereby sidewalls can be compounded onto the carcass material to form the carcass assembly. After the carcass material is positively wrapped, a portion of the side drum 20 is moved close to the half drum 210, and then the two half drums 210 are driven by the driving device 3 to close and fit each other to complete the inflation shaping step of the carcass assembly.

As shown in fig. 2 to 6, the intermediate drum 21 further includes a synchronizing unit 211 connecting the two half drums 210, and the synchronizing unit 211 can control the tiles (reference numerals) of the two half drums 210 to move synchronously in the radial direction. The two half drums 210 of the middle drum 21 are respectively connected to the bushings 24 of the two side drums 20, so that each side drum 20 can be connected to the half drum 210 of the corresponding side.

As shown in fig. 5 to 6, each half drum 210 is in a contracted state, i.e., an initial state, at the time of winding, when the intermediate drum 21 has the first outer diameter dimension. When the bead turn-up is performed, the half-drum 210 is expanded outward and finally in an expanded state, in which the intermediate drum 21 has a second outer diameter dimension. Wherein the second outer diameter dimension is greater than the first outer diameter dimension. Each drum half 210 comprises a plurality of first and second drum shoes 212, 213 arranged circumferentially and a drive assembly 214 fixedly connected to the sleeve 24 of the side drum 20. Wherein the driving assembly 214 can drive the first and second drum shoes 212, 213 to move radially (away from or close to the drum shaft 1) to realize the drum 21 with two different outer diameter sizes.

As shown in fig. 5 and 6, the driving assembly 214 includes a first supporting member 2142 and a second supporting member 2145 fixedly connected to the sleeve 24 of the side drum 20, a first sliding member 2143 and a plurality of second sliding members 2144 slidably connected to the first supporting member 2142 and the second supporting member 2145, respectively, and a plurality of connecting rods 2146 having two ends pivotally connected to the first sliding member 2413 and the plurality of second sliding members 2144, respectively. The first supporting member 2142 extends horizontally and annularly, and is sleeved outside the drum shaft 1 and axially connected to the shaft sleeve 24. The second supporting element 2145 is annular and is disposed around the end of the shaft sleeve 24 and radially connected to the shaft sleeve 24. Since two ends of each connecting rod 2146 are pivotally connected to the first sliding member 2413 and the second sliding member 2144, respectively, the axial movement of the first sliding member 2143 can drive the radial movement of the second sliding member 2144, and thus, the radial movement of the first drum shoe 212 and the second drum shoe 213 can be further driven.

Since the first support 2142 and the second support 2145 are both fixedly connected to the sleeve 24, when the axial position of the sleeve 24 relative to the drum shaft 1 is unchanged, the positions of the first support 2142 and the second support 2145 relative to the drum shaft 1 are also unchanged, and the second sliding member 2144, which is slidably disposed on the second support 2145 in the radial direction, will not be axially displaced relative to the drum shaft 1.

As shown in fig. 5 and fig. 6 in combination with fig. 4 and fig. 10 to fig. 11, the first sliding member 2143 moves axially inward, which drives one end of the plurality of connecting rods 2146 pivoted to the first sliding member 2143 to move axially inward, and drives the other end of the plurality of connecting rods 2146 pivoted to the second sliding member 2144 to move radially inward, so that the plurality of second sliding members 2144 also move radially to approach the drum shaft 1, and the plurality of first drum shoes 212 and the plurality of second drum shoes 213 connected to the plurality of second sliding members 2144 move radially to approach the drum shaft 1, so that the diameters of the plurality of first drum shoes 212 and the plurality of second drum shoes 213 become smaller, thereby completing the contraction of the drum 21.

In the disclosed embodiment of the invention, a number of first and second drum shoes 212, 213 are each connected to a respective second slide 2144. It should be noted here that the first drum tile 212 is a large drum tile, the second drum tile 213 is a small drum tile, and the stroke of the first drum tile 212 in the radial direction is smaller than the stroke of the second drum tile 213 in the radial direction.

As shown in FIGS. 5 and 6, the first sliding member 2143 has a plurality of fixing blocks 2147 fixed thereon at equal intervals in a circumferential direction for pivotally connecting to the plurality of connecting rods 2146. the connecting rods 2146 include first connecting rods 2146a and second connecting rods 2146b, the first connecting rods 2146a are pivotally connected to the first tiles 212 by the corresponding first sliding member 2143, the second connecting rods 2146b are pivotally connected to the second tiles 213 by the corresponding first sliding member 2143. C is a line parallel to the drum axis as shown in FIG. 6. the first connecting rods 2146a and the second connecting rods 2146b are respectively at angles α and β with respect to the line C. in order to achieve different radial strokes of the first tiles 212 and the second tiles 213. α is smaller than β. therefore, when the first tiles 212 and the second tiles 213 move radially to a limit position (outermost), the first tiles 212 and the second tiles 213 are located on the same circumferential surface, i.e., the expanded limit position is the same as the radial stroke of the first tiles 213, the second tiles 213 are still retracted from the limit position to the first tile position, the second tile 213 is still retracted position, and the first tile 213 is still retracted from the first tile position, the first tile position is still retracted to the second tile position, the second tile 213, which is still retracted position, which is still extended, and the second tile 213, the second tile is located on the first tile is still being located on the same radial stroke, the first tile 213, and the first tile is still being located on the same radial stroke, the same size is still being smaller than the same.

Of course, in other alternative embodiments, in order to ensure that the radial strokes of the first and

second drum shoes

212 and 213 are different, the lengths of the first and second connecting

rods

2146a and 2146b may be changed, or the positions of the pivot points of the two ends of the first connecting rod 2146a in the radial direction and the axial direction, or the positions of the pivot points of the two ends of the second connecting rod 2146b in the radial direction and the axial direction, respectively, and the detailed structure thereof will not be described herein again.

Referring to fig. 4 to 9, the first and

second drum tiles

212 and 213 are similar in structure and each include a body portion 2120 fixedly connected to the second sliding member 2233 and an insertion portion 2121 extending from one side of the body portion 2120. The body portions 2120 of the first and second plurality of

tiles

212, 213 are spaced apart from each other in the expanded state of the tiles and form a closed ring. Specifically, the side end surface and the outer circumferential surface of the ring are seamless, i.e., the body portions 2120 of the adjacent first and

second tiles

212, 213 are tightly joined, as shown at a and B of the tiles in fig. 6. Therefore, in the turn-up process, the body 2120 of the first and

second drum tiles

212 and 213 of the two half drums 210 can provide an abutting force to the end surface of the bead in the expanded state, and the circumferential surface of the ring formed by the body 2120 is seamless, so that the body 2120 of the two half drums 210 can be prevented from generating indentation to the tire material in the turn-up process, and the risk of air bubbles or indentation inside the tire blank opening can be avoided.

Further, as shown in FIGS. 8 and 9, each of the mating parts 2121 of the first and

second tiles

212, 213 includes at least one elongated finger portion 2105, wherein the finger portion 2105 of the first tile 212 is greater than the finger portion 2105 of the second tile 213. The two drum halves 210 are axially fitted into each other by the design of the oppositely disposed fingers 2105 that are staggered with respect to each other.

Since the inserting parts 2121 of the first and

second drum tiles

212 and 213 are indirectly fixed to the driving assembly 214, and the driving assembly is fixed to the sleeve 24, the inserting parts 2121 can move axially through the sleeve 24 to be engaged with each other, so that the width of the drum shoulder between the two half drums 210 can be changed by using the inserting parts 2121, and the inflation shaping step of the carcass assembly can be completed.

As shown in fig. 4 and 7, the synchronizing unit 211 includes racks 2111 having both ends connected to the two half drums 210, respectively, and gears 2112 located between the two racks 211 and engaged with the two racks 2111, respectively. Each rack 2111 is fixed at one end to the first slide 2143 of one of the half drums 210 and at the other end extends freely in the axial direction. The gear 2112 is located at the axial center of the two drum halves 210 and is radially fixed to the drum shaft 1. When the driving assemblies 214 of the two drum halves 210 control the corresponding first sliders 2143 to axially move, the rack 2111 fixed to the first sliders 2143 of the two drum halves 210 also axially moves. Since the gears 2112 are engaged with the two racks 2111, respectively, the moving speeds of the two racks should be the same. Therefore, even if the first slide 2143 of one of the drum halves 210 moves too slowly or cannot move due to a gas path failure or the like, the first slide 2143 of the other drum half 210 moves slowly or not correspondingly due to the presence of the gear 2112. Therefore, the connecting rod 2146 pivotally connected to the first sliding member 2143 does not move, and further the second sliding member 2144, the first drum tiles 212 and the second drum tiles 213 do not move radially any more, so that the synchronization unit 211 of the present invention can control a plurality of drum tiles of the two half drums 210 to move radially and synchronously, thereby avoiding the inconsistency of the expansion and contraction speeds of the drum tiles at the two sides, and further avoiding the asymmetry of the tire body material caused by the deviation of the rubber material driven by the drum tile at the side where the drum tile rises quickly.

The invention has the beneficial effects that: the contraction assembly 214 drives the first drum tile 212 and the second drum tile 213 to radially extend and retract, and the radial strokes of the first drum tile 212 and the second drum tile 213 are set to be different, so that the first drum tile 212 and the second drum tile 213 are located on the same circumferential surface at the expansion limit position, and the second drum tile 213 can be contracted into a circular ring surrounded by the first drum tile 212 at the contraction limit position; when the first and

second drum tiles

212, 213 are expanded to the extreme positions, the middle drum 21 is close to the two end faces of the side drum 20 and has no gap in the circumferential direction, so that the gap is prevented from impressing the rubber material when abutting against the bead, and the synchronous lifting of the two half drum 210 drum tiles is controlled by the synchronization unit 211, so that the carcass material band is prevented from deviating, the asymmetry of the carcass material is avoided, and the quality of the tire is improved.

In the description of the embodiments, discussion of the phrases "in this embodiment," "in one embodiment," "in a particular embodiment," and the like, is intended to mean that a particular feature or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. And in particular embodiments, the schematic representations of the terms used above do not necessarily refer to the same embodiment. Furthermore, the particular features or points described may be combined in any suitable manner in any one or more embodiments.

It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A tyre building drum, characterized in that it comprises: a drum shaft (1) and a forming assembly (2) mounted on the drum shaft (1), wherein the forming assembly (2) comprises two side drums (20) and a middle drum (21) positioned between the two side drums (20), the middle drum (21) comprises two half drums (210) capable of being embedded and matched with each other in the axial direction and a synchronizing unit (211) respectively connecting the two half drums (210), each side drum (20) can be driven to be away from the corresponding half drum (210), each half drum (210) comprises a plurality of first tiles (212) and second tiles (213) distributed in the circumferential direction and a driving assembly (214) for driving the first tiles (212) and the second tiles (213) to move in the radial direction, the synchronizing unit (211) is used for controlling the tiles of the two half drums (210) to move in the radial direction synchronously and in the radial direction, and each of the first tiles (212) and the second tiles (213) comprises a body part (2120), the body parts (2120) of the first drum tiles (212) and the second drum tiles (213) are arranged at intervals and can form a closed circular ring together, the synchronizing unit (211) comprises racks (2111) which are oppositely arranged on the two half drums (210) and gears (2112) which are respectively meshed with the two racks (2111), and the gears (2112) are fixedly connected with the drum shaft (1) in the radial direction.

2. Tyre building drum according to claim 1, in which each rack (2111) is fixedly connected at one end to one of the drum halves (210) and at the other end is a free end.

3. Tyre building drum according to claim 1, characterized in that the intermediate drum (21) has a contracted state and an expanded state, the first tiles (212) being located radially outside the second tiles (213) in the contracted state of the intermediate drum (21), the first tiles (212) and the second tiles (213) being on the same circumferential surface in the expanded state of the intermediate drum (21).

4. Tyre building drum according to claim 3, wherein the drive assembly (214) comprises a first support (2142) and a second support (2145) fixedly connected to the side drum (20), respectively, a first slider (2143) and a number of second sliders (2144) slidably connected to the first support (2142) and the second support (2145), respectively, and a number of connecting rods (2146) pivotally connected at both ends to the first slider (2143) and the number of second sliders (2144), respectively, the number of second sliders (2144) being connected to the body portion (2120).

5. Tyre building drum according to claim 4, in which a number of fixing blocks (2147) are fixed to the first slide (2143) at circumferentially equidistant intervals for pivotal connection to the connecting rod (2146).

6. Tyre building drum according to claim 5, wherein the number of connecting rods (2146) comprises a number of first connecting rods (2146a) and a number of second connecting rods (2146b), the first connecting rods (2146a) being connected to the first drum tiles (212) by corresponding first slides (2143), the second connecting rods (2146b) being connected to the second drum tiles (213) by corresponding first slides (2143).

7. Tyre building drum according to claim 6, in which the first link (2146a) has a smaller angle to the axial direction than the second link (2146 b).

8. Tyre building drum according to claim 1, characterised in that the first drum tile (212) is a big drum tile and the second drum tile (213) is a small drum tile, the first drum tile (212) having a smaller radial stroke than the second drum tile (213).

9. Tyre building drum according to claim 1, characterised in that the first (212) and the second (213) tiles further comprise an insert part (2121) extending from one side of the body part (2120), the insert part (2121) comprising at least one elongated finger part (2105), the finger parts (2105) of the two half-drums (210) being interfitted with each other so that the two mid-drums (21) are axially interfitted with each other.

10. Tyre building drum according to claim 1, in which the body parts (2120) enclose the outer and outer circumferential surfaces of the ring without seams.