Tyre forming drum provided with a telescopic central body

Abstract

The present invention relates to a tyre forming drum (1) comprising: a central shaft (3), which is mounted so as to rotate around a first rotation axis (2); two cylindrical half-drums (4), which are mounted so as to slide on the central shaft (3); an actuator system (5) to move the two half-drums (4) in opposite directions along the central shaft (3); and a telescopic and cylindrical central body (6), which is coaxial to the two half-drums (4), connects the two half-drums (4) to one another and comprises a central tubular element (7), which is integral to an intermediate point of the central shaft (3), and two lateral tubular elements (8), which have a telescopic coupling to the central tubular element (7) and are carried by the central tubular element (7) so that they can axially slide relative to the central tubular element (7).

Description

[0001] "TYRE FORMING DRUM PROVIDED WITH A TELESCOPIC CENTRAL BODY"

[0002] Cross-Reference to Related Applications

[0003] This Patent Appl ication claims priority from Italian Patent Application No . 102024000018496 filed on August 6 , 2024 , the entire disclosure of which is incorporated herein by reference .

[0004] Technical Field

[0005] This invention relates to a tyre forming drum equipped with a telescopic central body .

[0006] Prior Art

[0007] A tyre forming drum comprising a central shaft , two coaxial cylindrical hal f-drums mounted so they slide on the central shaft , actuators for moving the two hal f-drums in opposite directions along the central shaft, and a substantially telescopic central body, coaxial to the two hal f-drums , and connecting the two hal f-drums to each other, is known from patent US4402783A1 . The telescopic central body comprises a central tubular element integral with an intermediate point of the central shaft , two lateral tubular elements integral with their respective hal f-drums , and two intermediate tubular segments , each of which is placed between the central tubular element and a lateral tubular element .

[0008] In the known forming drum described above , the intermediate segments only assume a precise position in relation to the hal f-drums and the telescopic central tubular element when the telescopic central body is fully extended or fully contracted, but are in no way controlled in position when the telescopic central body assumes an intermediate configuration, that is , during the forming of the frame and during the return of the hal f-drums to their cycle start position . In other words , in the known drum described above , there is no unique correspondence between the length of the telescopic central body and the position of the intermediate segments . Such a situation can lead to serious drawbacks , especially when it comes to forming the frame . During this step, the hal f-drums actually move quickly towards each other, causing the intermediate segments to enter each other with a good chance of more or less serious j amming i f all the intermediate segments move together .

[0009] To solve the above-mentioned drawback and to ensure that a certain length of the telescopic central body uniquely corresponds to a certain position of the intermediate segments in relation to the central tubular element , the tyre forming drum described in patent EP0780220B1 was proposed .

[0010] Speci fically, in the forming drum described in patent EP0780220B1 , the two cylindrical half-drums are mounted so that they slide on the central tubular shaft to be moved in opposite directions and along the central shaft itsel f by a central screw . In addition, each lateral tubular element is supported, sliding, by the central tubular element and can be moved towards the central tubular element against the thrust of multiple springs .

[0011] The forming drum described in patent EP0780220B1 solves the drawback described above , as in this forming drum a certain length of the telescopic central body uniquely corresponds to a certain position of the intermediate segments with respect to the central tubular element .

[0012] In the known embodiments described above , to be able to adapt the forming drum to tyres of di f ferent widths , it is necessary to replace certain parts of the telescopic central body with similar parts of a di f ferent width ( that is , a di f ferent axial dimension) . In particular, the two lateral tubular elements integral with the respective hal f-drums , and the two intermediate segments , each of which is placed between the central tubular element and a lateral tubular element , must be replaced .

[0013] In the known forming drums described above , in order to replace the two lateral tubular elements and the two intermediate segments , it is necessary to disassemble and remove one of the two hal f-drums to be able to disassemble and remove a lateral tubular element and the corresponding intermediate segment ; then it is necessary to disassemble and remove the central tubular element in order to disassemble and remove the other lateral tubular element and the corresponding intermediate segment . Once the old parts have been disassembled, the new parts are assembled in reverse order : a new lateral tubular element , a new intermediate segment , the central tubular element , another new intermediate segment , another new lateral tubular element , and the hal f-drum are assembled .

[0014] The above-described replacement of the two end elements and the two intermediate segments is particularly timeconsuming and complex as it requires the disassembly and removal of a hal f-drum and the central tubular element . It is important to note that both the hal f-drum and the central tubular element have a considerable mass ( approximately at least 50- 60 kg) that cannot be handled manual ly by an operator and therefore their disassembly / assembly requires the use of an external li fting device ( a hoist or crane ) . In addition, the disassembly / assembly of a hal f-drum and central tubular element subj ects the threaded parts of these components to signi ficant mechanical wear .

[0015] Description of the Invention

[0016] The purpose of this invention is to provide a tyre forming drum provided with a telescopic central body that is free of the drawbacks described above ( that is , it is easily adaptable to making tyres of di f ferent widths ) and, at the same time , is easy and inexpensive to manufacture .

[0017] According to this invention, a tyre forming drum provided with a telescopic central body is provided according to what is set forth in the appended claims .

[0018] The claims describe preferred embodiments of this invention forming an integral part of this description .

[0019] Brief Description of the Drawings

[0020] This invention will now be described with reference to the accompanying drawings , which illustrate a non-limiting embodiment thereof , wherein :

[0021] • Figure 1 is schematic view of a tyre forming drum;

[0022] • Figure 2 is a perspective view of a telescopic central body of the forming drum in Figure 1 ;

[0023] • Figure 3 is an exploded perspective view of the telescopic central body in Figure 2 ;

[0024] • Figure 4 is a perspective view of support devices and elastic components of the telescopic central body in Figure 2; and

[0025] • Figure 5 is an enlarged view of two support devices in Figure 4.

[0026] Preferred Embodiments of the Invention

[0027] In Figure 1, the reference number 1 denotes, as a whole, a tyre forming drum.

[0028] The forming drum 1 is mounted so as to rotate about a horizontal rotation axis 2 and comprises a central tubular shaft 3 coaxial to the rotation axis 2, two cylindrical halfdrums 4 mounted so as to slide on the shaft 3 coaxial to each other and to the rotation axis 2, and an actuator system 5 configured to axially translate the two half-drums 4 along the rotation axis 2, that is, the actuator system 5 is configured to move the two half-drums 4 symmetrically away from each other or to move the two half-drums 4 symmetrically towards each other. The forming drum 1 also comprises a substantially cylindrical telescopic central body 6, which is coaxial to and connects the half-drums 4.

[0029] As illustrated in Figures 2 and 3, the telescopic central body 6 comprises a central tubular element 7 (that is, a central ring) and two lateral tubular elements 8 (that is, lateral rings) that are coaxial to the rotation axis 2, are arranged on opposite sides of the central tubular element 7, and are axially movable with respect to the central tubular element 7 to form a telescopic coupling with the central tubular element 7.

[0030] That is, an outer diameter of the lateral tubular elements 8 is (slightly) different from an outer diameter of the central tubular element 7 so that the central tubular element 7 overlaps the lateral tubular elements 8 and the extent of the overlap can be modi fied ( increased or decreased) by moving the lateral tubular elements 8 away from or closer to the central tubular element 7 by means of an axial movement . According to the preferred embodiment illustrated in the attached figures , the outer diameter of the lateral tubular elements 8 i s ( slightly) smaller than the outer diameter of the central tubular element 7 and, thus , the central tubular element 7 is radially further out than the lateral tubular elements 8 ; according to a di f ferent embodiment not il lustrated, the outer diameter of the lateral tubular elements 8 is ( slightly) larger than the outer diameter of the central tubular element 7 .

[0031] In other words , the telescopic and cylindrical central body 6 is coaxial to the two hal f-drums 4 , connects the two hal f-drums 4 to one another and comprises the central tubular element 7 , which is integral with an intermediate point of the central shaft 3 , and the two lateral tubular elements 8 , which have a telescopic coupling to the central tubular element 7 and are carried by the central tubular element 7 so that they can axially slide relative to the central tubular element 7 .

[0032] The central tubular element 7 comprises an inner disc 9 that is oriented radially with respect to the rotation axis 2 and is fitted on ( integral with) the shaft 3 at the centre of the shaft 3 , and a ring-shaped outer shell 10 ( that is , an outer ring ) integral with the inner disc 9 ( that is , supported by the inner disc 9 and then fixed to an edge of the inner disc 9 ) . The inner disc 9 is arranged in the centre of the outer shell 10 and thus the outer shell 10 extends axially symmetrically on both sides of the inner disc 9 . In other words , the shell 10 is integral with ( fixed, mounted on) the inner disc 9 and is arranged symmetrically around the inner disc 9 ; in contrast , the inner disc 9 is screwed to a median portion of the shaft 3 .

[0033] Similarly, each lateral tubular element 8 comprises an inner disc 11 that is oriented radially with respect to the rotation axis 2 and a ring-shaped outer shell 12 ( that is , an outer ring) integral with the inner disc 11 ( that is , supported by the inner disc 11 and thus fixed to an edge of the inner disc 11 ) . In each lateral tubular element 8 , the inner disc 11 is arranged on one s ide of the outer shell 12 and, thus , the outer shell 12 extends axially asymmetrically in relation to the inner disc 11 . The telescopic coupling takes place between the outer shel l 10 of the central tubular element 7 and the outer shells 12 of the lateral tubular elements 8 .

[0034] In use , each inner disc 11 of each lateral tubular element 8 is in contact with a respective hal f-drum 4 .

[0035] The telescopic central body 6 comprises multiple support devices 13 (better illustrated in Figures 4 and 5 ) , each connecting a lateral tubular element 8 to the central tubular element 7 , thus allowing the lateral tubular element 8 to axially slide relative to the central tubular element 7 . In other words , the central tubular element 7 supports a respective lateral tubular element 8 by means of corresponding support devices 13 that have one end integral with the central tubular element 7 and an opposite end integral with the lateral tubular element 8 ; that is , each lateral tubular element 8 is supported by corresponding support devices 13 connecting it to the central tubular element 7 .

[0036] According to one possible embodiment illustrated in the attached figures , the telescopic central body 6 comprises , for each lateral tubular element 8 , three support devices 13 symmetrically distributed around the rotation axis 2 ; according to other embodiments , for each lateral tubular element 8 a di f ferent number of support devices 13 is provided, for example two , four, five , six, seven or eight support devices 13 .

[0037] According to what is better illustrated in Figure 5 , each support device 13 comprises a central plate 14 integral with ( screwed on to ) the central tubular element 7 ( in particular integral with the inner disc 9 of the central tubular element 7 ) and a lateral plate 15 integral with ( screwed on to ) the respective lateral tubular element 8 ( in particular integral with the inner disc 11 of the lateral tubular element 8 ) . In addition, each support device 13 comprises multiple connectors 16 , each comprising a central arm 17 hinged, at one end, to the central plate 14 and a lateral arm 18 hinged, at one end, to the lateral plate 15 and, at the other end, to the central arm 17 . According to one possible embodiment illustrated in the attached figures , each support device 13 comprises four symmetrically distributed connectors 16 ; according to other embodiments , each support device 13 comprises a di f ferent number of connectors 16 , for example two , three , five , six, seven or eight connectors 16 .

[0038] In each support device 13 , each arm 17 or 18 is hinged to rotate about respective rotation axes 19 perpendicular to the rotation axis 2 . In addition, in each connector 16 , the two arms 17 and 18 form a "V" ( of variable width) with the vertex facing outwards ; the axial sliding of each lateral tubular element 8 varies the angle formed between the arms

[0039] 17 and 18 of each support device 13 : by decreasing the angle between the arms 17 and 18 of each support device 13 ( that is , by tightening the "V" ) the lateral tubular element 8 moves closer to the central tubular element 7 , while by increasing the angle between the arms 17 and 18 of each support device 13 ( that is , by widening the "V" ) the lateral tubular element 8 moves away from the central tubular element 7 .

[0040] In the preferred embodiment illustrated in the attached figures , each support device 13 comprises two arms 17 and 18 ; according to a di f ferent embodiment not illustrated, each support device 13 comprises more than two arms 17 and

[0041] 18 .

[0042] According to a preferred embodiment illustrated in the attached figures , each support device 13 of a lateral tubular element 8 is axially aligned with a respective support device 13 of the other lateral tubular element 8 .

[0043] In other words , each support device 13 creates an articulated parallelogram that only allows an axial movement parallel to the rotation axis 2 ; that is , each support device 13 prevents any rotation of the corresponding lateral tubular element 8 with respect to the central tubular element 7 and prevents any radial translation of the corresponding lateral tubular element 8 with respect to the central tubular element

[0044] 7 and, therefore , each support device 13 only allows an axial translation of the corresponding lateral tubular element 8 with respect to the central tubular element 7 .

[0045] According to what is illustrated in Figures 3 and 4 , the telescopic central body 6 comprises multiple elastic components 20 configured to axially push the lateral tubular elements 8 away from the central tubular element 7 ( and away from each other ) ; that is , the elastic components 20 generate an elastic force that axially pushes the lateral tubular elements 8 away from the central tubular element 7 ( and away from each other ) . Accordingly, the elastic components 20 must be compressed by overcoming their elastic force to bring the lateral tubular elements 8 closer to the central tubular element 7 ( that is , to bring the tubular elements 8 closer to each other ) and tend to move the lateral tubular elements

[0046] 8 away from the central tubular element 7 ( that is , to move the lateral tubular elements 8 away from each other ) . According to a preferred embodiment illustrated in the attached figures , each elastic component 20 is a helical spring .

[0047] Each elastic component 20 has one end integral with a lateral tubular element 8 ( in particular with the inner disc 11 of the lateral tubular element 8 ) and an opposite end integral with the other lateral tubular element 8 ( in particular with the inner disc 11 of the lateral tubular element 8 ) . That is , each elastic component 20 is only attached to the two lateral tubular elements 8 without having any point of contact with the central tubular element 7 . The central tubular element 7 ( in particular, the inner disc 9 of the central tubular element 7 ) preferably has , for each elastic component 20 , a through hole 21 , through which the elastic component 20 is arranged, which has no contact with the central tubular element 7 .

[0048] According to a preferred embodiment illustrated in the attached figures , the telescopic central body 6 is indivisible and, therefore , to be assembled or disassembled, it must be axially removed from the shaft 3 after having removed a hal f-drum 4 from one side ; according to an alternative embodiment not illustrated, the telescopic central body 6 is divisible into two semi-cylindrical halves and, therefore , to be assembled or disassembled, it can be separated into the two halves to be radially removed .

[0049] In use , the two hal f-drums 4 are arranged at a desired distance from each other to achieve the nominal width of the tyre to be formed . The elastic components 20 push the two lateral tubular elements 8 outwards , bringing them into contact with their respective hal f-drums 4 . That is , the hal f-drums 4 establish the axial position of the lateral tubular elements 8 as they limit the axial movement of the lateral tubular elements 8 under the thrust of the elastic components 20 .

[0050] To reduce the distance of the two hal f-drums 4 ( and thus form a narrower tyre ) , the actuator system 5 is activated, bringing the two hal f-drums 4 closer together ; in this movement , the two hal f-drums 4 push the two lateral tubular elements 8 towards each other (that is, towards the central tubular element 7) compressing the elastic components 20. To increase the distance of the two halfdrums 4 (and thus form a wider tyre) , the actuator system 5 is activated, moving the two half-drums 4 further apart; in this movement, the two half-drums 4 allow the two lateral tubular elements 8 to move away from each other (that is, away from the central tubular element 7) under the thrust of the elastic components 20 that expand.

[0051] The embodiments described here can be combined.

[0052] The forming drum 1 described above has numerous advantages .

[0053] The forming drum 1 described above makes it possible to adapt the width of the tyres to be formed very simply (that is, without replacing any components or adjusting any components) , as it is sufficient to bring the two half-drums 4 closer together or move them further apart for the telescopic central body 6 to adapt autonomously and automatically to the size set by the two half-drums 4.

[0054] In addition, the forming drum 1 described above allows the width of the tyres to be formed to be adapted within a very wide range, guaranteeing great flexibility of use. Thus, to cover all possible widths (for example between approx. 30 cm and approx. 70 cm) of the forming drum 1 required to produce one tyre size (diameter) , it is sufficient to have a small number (generally three or four) of telescopic central bodies 6 of different sizes; on the other hand, to cover all possible widths of the forming drum 1 required to produce one tyre size (diameter) , it is necessary to have more than thirty known telescopic central bodies of di f ferent si zes . In this way, the forming drum 1 described above substantially reduces the replacement frequency of the telescopic central body 6 , the overall cost of the series of telescopic central bodies 6 of di f ferent si zes , and the complexity of storing the series of telescopic central bodies 6 of di f ferent si zes .

[0055] The telescopic central body 6 of the forming drum 1 described above is particularly compact and space-saving, especially in the outer part of the lateral tubular elements 8 ; therefore , the telescopic central body 6 can be coupled to any type of hal f-drum 4 .

[0056] The telescopic central body 6 of the forming drum 1 described above is also particularly light , as it consists of a small number of parts ; thus , handling of the telescopic central body 6 is particularly quick and easy .

[0057] Finally, the forming drum 1 described above is simple and inexpensive to manufacture .

[0058] LIST OF REFERENCE NUMBERS IN THE FIGURES

[0059] 1 forming drum

[0060] 2 rotation axis

[0061] 3 shaft

[0062] 4 hal f-drums

[0063] 5 actuator system

[0064] 6 telescopic central body

[0065] 7 central tubular element

[0066] 8 lateral tubular elements

[0067] 9 inner disc

[0068] 10 outer shell 11 inner disc

[0069] 12 outer shell

[0070] 13 support devices

[0071] 14 central plate 15 lateral plate

[0072] 16 connectors

[0073] 17 central arm

[0074] 18 lateral arm

[0075] 19 rotation axis 20 elastic components

[0076] 21 through-hole

Claims

C L A I M S1) A tyre forming drum (1) comprising: a central shaft (3) , which is mounted so as to rotate around a first rotation axis (2) ; two cylindrical half-drums (4) , which are coaxial to one another and are mounted so as to slide on the central shaft ( 3 ) ; an actuator system (5) to move the two half-drums (4) in opposite directions along the central shaft (3) ; and a telescopic and cylindrical central body (6) , which is coaxial to the two half-drums (4) , connects the two halfdrums (4) to one another and comprises a central tubular element (7) , which is integral to an intermediate point of the central shaft (3) , and two lateral tubular elements (8) , which have a telescopic coupling to the central tubular element (7) and are carried by the central tubular element (7) so that they can axially slide relative to the central tubular element (7) ; wherein the telescopic central body (6) comprises a plurality of support devices (13) , each connecting a lateral tubular element (8) to the central tubular element (7) , thus allowing the lateral tubular element (8) to axially slide relative to the central tubular element (7) ; and wherein the telescopic central body (6) comprises a plurality of elastic components (20) configured to axially push the lateral tubular elements (8) away from the central tubular element (7) ; the forming drum (1) is characterized in that each support device (13) comprises:a central plate (14) integral to the central tubular element ( 7 ) ; a lateral plate (15) integral to the respective lateral tubular element (8) ; and at least two connectors (16) , each comprising a central arm (17) hinged, at one end, to the central plate (14) and a lateral arm (18) hinged, at one end, to the lateral plate(15) and, at the other end, to the central arm (17) .2) The forming drum (1) according to claim 1, wherein each arm (17, 18) is hinged so as to rotate around respective second rotation axes (19) , which are perpendicular to the first rotation axis (2) .3) The forming drum (1) according to claim 1 or 2, wherein, in each connector (16) , the two arms (17, 18) form a "V" with the vertex facing outwards.4) The forming drum (1) according to claim 1, 2 or 3, wherein each support device (13) comprises at least three, and preferably four, symmetrically distributed connectors(16) .5) The forming drum (1) according to one of the claims from 1 to 4, wherein each support device (13) of a lateral tubular element (8) is axially aligned with a respective support device (13) of the other lateral tubular element (8) .6) The forming drum (1) according to one of the claims from 1 to 5, wherein each support device (13) creates an articulated parallelogram, which only enables an axial movement parallel to the first rotation axis (2) .7) The forming drum (1) according to one of the claimsfrom 1 to 6, wherein, for each lateral tubular element (8) , the telescopic central body (6) comprises at least three support devices (13) symmetrically distributed around the first rotation axis (2) .8) The forming drum (1) according to one of the claims from 1 to 7, wherein each elastic component (20) has one end integral to a lateral tubular element (8) and an opposite end integral to the other lateral tubular element (8) .9) The forming drum (1) according to claim 8, wherein the central tubular element (7) has, for each elastic component (20) , a through hole (21) , through which the elastic component (20) is arranged, which has no contact with the central tubular element (7) .10) The forming drum (1) according to claim 8 or 9, wherein each elastic component (20) is a helical spring.11) The forming drum (1) according to one of the claims from 1 to 10, wherein the central tubular element (7) comprises : a first inner disc (9) , which is radially oriented relative to the first rotation axis (2) , is rigidly fixed to the central shaft (3) and is connected to the support devices (13) ; and a first outer shell (10) with an annular shape, integral to the first inner disc (9) .12) The forming drum (1) according to one of the claims from 1 to 11, wherein each lateral tubular element (8) comprises : a second inner disc (11) , which is radially oriented relative to the first rotation axis (2) and is connected tothe support devices (13) ; and a second outer shell (12) with an annular shape, integral to the second inner disc (11) .13) A telescopic central body (6) for a tyre forming drum (1) comprising: a central tubular element (7) , which can be fixed to a central shaft (3) ; two lateral tubular elements (8) , which have a telescopic coupling to the central tubular element (7) and are carried by the central tubular element (7) so that they can axially slide relative to the central tubular element (7) ; a plurality of support devices (13) , each connecting a lateral tubular element (8) to the central tubular element (7) , thus allowing the lateral tubular element (8) to axially slide relative to the central tubular element (7) ; and a plurality of elastic components (20) configured to axially push the lateral tubular elements (8) away from the central tubular element (7) ; the telescopic central body (6) is characterized in that each support device (13) comprises: a central plate (14) integral to the central tubular element ( 7 ) ; a lateral plate (15) integral to the respective lateral tubular element (8) ; and at least two connectors (16) , each comprising a central arm (17) hinged, at one end, to the central plate (14) and a lateral arm (18) hinged, at one end, to the lateral plate (15) and, at the other end, to the central arm (17) .

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