Tyre building plant and method for supplying an elongated element to a forming drum in a tyre building plant

Abstract

A tyre building plant includes a forming drum and a supply device for supplying an elongated element toward the forming drum. The supply device includes at least one conveyor belt which extends in a supply direction between a loading region, in which the elongated element is loaded on the conveyor belt and an unloading region, a control unit for controlling the loading of the elongated element on the conveyor belt, at least a first detection element which is fixed with a first portion of the conveyor belt, a sensor which is fixed and independent with respect to the conveyor belt and which detects the position of the first portion with respect to the supply device. The loading of the elongated element on the conveyor belt is performed when the first portion is at a predefined reference distance from the loading region.

Claims

1. A method for supplying an elongated element by a supply device with at least one conveyor belt to a forming drum in a tyre building plant, comprising: fixedly associating at least one first detection element with a first portion of said at least one conveyor belt, wherein said at least one conveyor belt moves in a supply direction and said at least one first detection element comprises a through-opening which has a closed contour and which is formed in said at least one conveyor belt in said supply direction; positioning, at a loading region of said supply device, a front end of said elongated element at a predefined reference distance from said first portion; detecting a position of said first portion with respect to said supply device at a detection zone through a mutual interaction between said at least one first detection element and a sensor, which is positioned on said supply device fixedly and independently with respect to said conveyor belt; calculating, in accordance with the detected position of said first portion, the movement of said at least one conveyor belt which is necessary to bring said first portion to said reference distance from said loading region; advancing said at least one conveyor belt toward an unloading region of said supply device until said elongated element is deposited at said forming drum; bringing, in accordance with the calculated movement, said first portion of said at least one conveyor belt to said reference distance from said loading region; and positioning a front end of a successive elongated element on said conveyor belt.

2. The method according to claim 1, wherein detection of the position of said first portion with respect to said supply device comprises: recording, by said sensor, a signal corresponding to an arrival of said at least one first detection element at said detection zone which is controlled by said sensor; and attributing to the recording of said signal the position of said first portion in said detection zone.

3. The method according to claim 2, wherein duration of the detection of said signal is compared with a minimum duration value and the position of said first portion is attributed to recording of said signal if said duration is greater than said minimum value.

4. The method according to claim 1, wherein said first portion is brought at said loading region and said elongated element is loaded on said at least one conveyor belt, positioning said front end on said first portion.

5. The method according to claim 4, further comprising detecting the position of said front end of said elongated element on said first portion with respect to said supply device.

6. The method according to claim 5, wherein the position of said front end of said elongated element is detected through a mutual interaction between said at least one first detection element and said sensor.

7. The method according to claim 6, wherein the detection of the position of said front end of said elongated element on said first portion with respect to said supply device comprises: recording the start of the detection by said sensor of a signal corresponding to arrival of said at least one first detection element at said detection zone controlled by said sensor; recording an end of the detection by said sensor of said signal; and comparing duration of the detection of said signal with a maximum duration value and, if said duration is less than said maximum value, attributing to said end of the detection of said signal the position of said front end of said elongated element in said detection zone.

8. The method according to claim 7, wherein the position of said front end of the elongated element is attributed to said end of the detection of said signal if said duration is less than said maximum value and greater than a minimum value.

9. The method according to claim 1, wherein said elongated element is cut to a predefined measurement before being deposited on said forming drum.

10. The method according to claim 9, wherein said elongated element is cut to said predefined measurement by a cutting member which is provided at said loading region, and said at least one conveyor belt is moved in said supply direction in order to move said front end of said elongated element away from said cutting member.

11. The method according to claim 10, wherein the position of said front end of said elongated element on said first portion is detected by said sensor at a distance from said cutting member less than said predefined measurement, to which said elongated element has to be cut.

12. The method according to claim 11, wherein, once said position of said front end is detected, said at least one conveyor belt is moved in said supply direction by a length equal to a difference between said predefined measurement and said distance, and said elongated element is cut by said cutting member so as to obtain an elongated element which is cut precisely.

13. The method according to claim 1, wherein said at least one first detection element has an extent, in said supply direction, less than 10% of an extent, in said supply direction, of said at least one conveyor belt.

14. The method according to claim 1, wherein when said opening is at said detection zone said sensor detects a light radiation which passes from one side to another of said conveyor belt.

15. The method according to claim 1, wherein a terminal end of said elongated element is positioned on a second portion of said at least one conveyor belt, which second portion is distinct and separate from said first portion, with which there is fixedly associated at least a second detection element.

16. The method according to claim 15, comprising detecting the position of said terminal end of said elongated element on said second portion with respect to said supply device through the mutual interaction between said at least one second detection element and said sensor.

17. The method according to claim 15, comprising detecting the position of said terminal end of said elongated element on said second portion with respect to said supply device through a mutual interaction between said at least one second detection element and an auxiliary sensor which is positioned at said loading region in a fixed and independent manner from said conveyor belt.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The features and advantages of the invention will be better appreciated from the detailed description of a preferred embodiment thereof, which is illustrated by way of non-limiting example with reference to the appended drawings, in which:

(2) FIG. 1 is a schematic side view of a tyre building plant which is produced in accordance with the present invention;

(3) FIG. 2 is a schematic front view of a supply device of the building plant of FIG. 1;

(4) FIG. 3 is a view, drawn to an enlarged scale, of a portion of the supply device of FIG. 2,

(5) FIG. 4 is a view of a construction variant of the supply device of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

(6) With reference to the appended Figures, there is generally designated 1 a tyre building plant which is produced in accordance with the present invention.

(7) The plant 1 comprises at least one building station in which an elongate element 3 is distributed on the radially external surface of a forming drum 4, or a component of the tyre which is provided thereon.

(8) Preferably, the plant 1 comprises a plurality of building stations, which are arranged in a position adjacent to each other so that the forming drum can be readily moved therebetween in accordance with a predefined order, which is defined by the succession of the elongated elements which have to be deposited thereon in order to form the tyre to be built.

(9) The forming drum 4 has a generally cylindrical formation and is advantageously mounted on a motorized support unit (not illustrated in the appended Figures) which provides for it to be rotated about its own axis Z and to be moved between one building station and another.

(10) Each building station further comprises a supply device 10 which is provided to supply the elongated element 3 towards the forming drum 4 and to deposit it on the radially external surface presented thereby.

(11) The elongated element 3 extends in a prevailing longitudinal direction between a front end 5 and a terminal end 6 and can be constituted by any tyre component in accordance with the type of tyre to be built in the plant 1. For example, it may be formed by a ply of the carcass, by a belt strip, by a layer of liner or complex (a multi-layered structure comprising a liner, sub-liner, anti-abrasive) or by a sidewall insert or a sidewall (the sidewalls generally being supplied in pairs).

(12) The elongated element 3 can therefore be formed by a continuous strip of elastomer material which is provided with reinforcement cords or only by elastomer material and/or any other reinforcement element which is advantageous for building a tyre, as known in the relevant technical field.

(13) The supply device 10 comprises at least one conveyor belt 11 which is mounted on a frame 11a and which extends in a supply direction X between a loading region 12, in which the elongated element 3 is loaded on the conveyor belt 11, and an unloading region 13, in which the elongated element 3 is unloaded from the conveyor belt 11.

(14) In the preferred embodiment described here with reference to FIGS. 1 to 3, the supply device 10 is configured to supply to the forming drum 4 a pair of elongated elements which are intended to formed the sidewall inserts of a tyre and therefore comprises a pair of conveyor belts 11, which are substantially identical to each other and which are arranged in a parallel manner.

(15) There will be described in detail below a single conveyor belt, but it is to be understood that the same characteristics are also intended to be referred to the other conveyor belt of the pair, and may be referred to supply devices which provide for a single conveyor belt.

(16) Preferably, the loading region 12 and the unloading region 13 correspond to the longitudinal ends of the conveyor belt 11. Furthermore, the unloading region 13 is positioned in the vicinity of the surface of the forming drum 4, at a predefined distance, so as to promote the depositing of the elongated element 3 thereon.

(17) The conveyor belt 11 is closed in a ring-like manner about rollers 14 which are rotatably supported on the frame 11a, so that there remains identified on the conveyor belt 11 a support surface 15 which is directed upwards, and on which the elongated element 3 is positioned.

(18) The conveyor belt 11 is caused to rotate about the rollers 14 by a drive member 16 so that the support surface 15 thereof is moved from the loading region 12 to the unloading region 13 in the supply direction X.

(19) Additional tension rollers 14a are further mounted on the frame 11a in order to abut the conveyor belt 11 and to tension it in an adjustable manner to the degree of tension which is most suitable.

(20) In the preferred embodiment described here, the supply device 10 further comprises an additional conveyor belt 17 which is positioned upstream of the conveyor belt 11 and which is provided to take the elongated element 3, for example, from a reel where the elongated element is stored in a continuous manner, and to bring it towards the loading region 12 of the conveyor belt 11.

(21) The supply device 10 further comprises a cutting member 18 which is positioned at the loading region 12 of the conveyor belt 11, preferably between a terminal end of the additional conveyor belt 17 and the conveyor belt 11, and which is provided to cut the elongated element 3 at a predefined measurement. Each cutting operation carried out by the cutting member 18 defines the terminal end 6 of an elongated element 3 which is already substantially loaded on the conveyor belt 11 and the front end 5 of the successive elongated element 3.

(22) The supply device 10 further comprises a control unit 19 which is provided inter alia to control the movement of the conveyor belt 11, the movement of the additional conveyor belt 17 and the cutting member 18.

(23) In particular, the control unit 19 is provided to move the conveyor belts 11 and 17 so as to load the elongated element 3 on the conveyor belt 11 when a specific first portion 20 of the conveyor belt 11 is located at a predefined reference distance from the loading region 12.

(24) In the preferred embodiment described here, the elongated element 3 is loaded on the conveyor belt 11 when the first portion 20 is located at the loading region 12, that is to say, when the above-mentioned reference distance is substantially zero, so that the front end 5 of the elongated element 3 is precisely positioned on the first portion 20.

(25) The first portion 20 of the conveyor belt 11 is defined by a first detection element which is fixedly associated therewith.

(26) There is further mounted on the frame 11a, in a fixed position independent with respect to the conveyor belt 11, a sensor 22 which is provided to detect, by means of an interaction with the first detection element, the position of the first portion 20 and/or the position of the front end 5 of the elongated element 3 which may be positioned on the first portion 20 with respect to the supply device 10.

(27) In the preferred embodiment described here, the first detection element is formed by a through-opening 21 which has a closed contour and which is formed in the conveyor belt 11 and which extends in the supply direction X.

(28) The opening 21 is positioned in the region of a longitudinal axis Y of the conveyor belt 11 and has an extent in the supply direction X which is limited with respect to the extent of the conveyor belt 11, having, for example, a length between 50 mm and 300 mm, preferably of 100 mm, and a width measured in a direction perpendicular to the supply direction X of between 5 mm and 30 mm, preferably of 10 mm.

(29) Preferably, the opening 21 has an extent in the supply direction X which is less than 10% and preferably less than 5%, of the extent of the conveyor belt 11, which, in the embodiment illustrated here, has an extent in the supply direction of approximately 2.5 m.

(30) The sensor 22 is of the optical type and comprises a light radiation detector 23 and a light radiation emitter 24 which are arranged at the same side with respect to the conveyor belt 11 in a direction substantially perpendicular to the support surface 15 and in the region of the longitudinal axis thereof. In particular, the light radiation detector 23 and the light radiation emitter 24 are positioned at the side of the support surface 15, above the conveyor belt 11, while at the opposite side to the support surface 15, under the conveyor belt 11, there is positioned a reflection element 26.

(31) The mutual positioning of the light radiation emitter 24 and the light radiation detector 23, on the one hand, and the reflection element 26, on the other hand, defines a detection zone 25 which is involved in the control of the sensor 22 and through which the conveyor belt 11 is driven during its advance in the supply direction X. In particular, during the passage of the first portion 20 in the region of the detection zone 25, the radiation emitted by the light radiation emitter 24 passes through the opening 21 and is reflected by the reflection element 26 so that, by again passing through the opening 21, it can be detected by the light radiation detector 23. The passage of the light radiation is instead prevented when the conveyor belt 11 or the elongated element 3 is interposed between the light radiation emitter 24 and the reflection element 26.

(32) The sensor 22 is positioned in the vicinity of the conveyor belt 11 in such a manner that the detection zone 25 is at a distance D (measured parallel with the supply direction X) from the cutting ember 18, which is advantageously selected so as to be slightly less (for example, from 100 to 200 mm) than the minimum length at which the elongated element 3 can be cut.

(33) In construction variants which are not illustrated, the light radiation emitter 24 and the light radiation detector 23 are independently arranged at opposite sides with respect to the conveyor belt 11 in a direction which is substantially perpendicular to the support surface 15 and in the region of the longitudinal axis thereof. For example, the light radiation detector 23 can be positioned at the side of the support surface 15, above the conveyor belt 11, while the light radiation emitter 24 can be positioned at the side opposite the support surface 15, under the conveyor belt 11. In this case, it is not necessary to provide a reflection element.

(34) In another construction variant which is not illustrated, the reflection element can be positioned directly on the support surface 15 or, more preferably, at the bottom of a groove which is formed in the conveyor belt and which has a closed contour and a lowered profile with respect to the support surface 15.

(35) In a further construction variant which is not illustrated, the light radiation emitter can be incorporated in the first detection element which is positioned, for example, at the bottom of a groove having a closed contour and a lowered profile with respect to the support surface formed in the conveyor belt.

(36) In the cases set out above, the groove could have dimensions of length and width similar to those set out above for the opening 21.

(37) The building plant 1 operates in accordance with the following.

(38) The elongated element 3 is moved by the additional conveyor belt 17 towards the conveyor belt 11 so as to bring the front end 5 in the region of the loading region 12.

(39) When the control unit 19 establishes, as explained in detail above, that the first portion 20 of the conveyor belt 11 is in the region of the loading region 12, the additional conveyor belt 17 is moved so as to transfer the elongated element 3 onto the support surface 15 of the conveyor belt 11. The additional conveyor belt 17 and the conveyor belt 11 are moved at the same speed, so as not to bring about undesirable sliding actions of the elongated element 3 with respect to the conveyor belt 11.

(40) In this manner, the front end 5 becomes located on the first portion 20, partially covering the opening 21.

(41) Following the advance movement of the conveyor belt 11 in the supply direction X, the first portion 20 arrives in the region of the detection zone 25 which is defined by the sensor 22, where the light radiation emitted by the emitter 24 can pass through the opening 21, be reflected by the reflection element 26 and then be detected by the detector 23, generating a corresponding signal.

(42) The sensor 22 and/or the control unit 19 to which it is connected records that signal so as to establish the start and the end (and consequently the duration) of the detection of the light radiation carried out by the detector 23.

(43) The end of the detection of the light radiation can be established by the discharge of the opening 21 from the detection zone 25 or, if an elongated element 3 is positioned on the opening 21, by the arrival in the detection zone 25 of the front end 5 of that elongated element 3.

(44) The start of the detection of the signal is attributed by the control unit 19 to the arrival of the opening 21 (and therefore of the first portion 20) in the region of the detection zone 25. In this manner, the control unit 19 is capable of establishing with precision the position of the first portion 20 with respect to a fixed reference of the supply device 10 and, by knowing the length of the conveyor belt and the distance of the sensor 22 from the loading region 12, it is capable of calculating the movement of the conveyor belt 11 necessary to bring the first portion 20 into the region of the loading region 12 or, in the more general case, to bring the first portion 20 to any predefined reference distance from the loading region 12.

(45) Preferably, the position of the first portion 20 is attributed, as described above, after the control unit 19 has subsequently compared the duration of the detection of the signal with a minimum duration value, so as to prevent possible false detections of signals which can be attributed to the presence in the detection zone of an optional zip type closure of the conveyor belt 11.

(46) The end of the detection of the signal is attributed by the control unit 19 to the arrival in the detection zone 25 of the front end 5 of the elongated element 3. In this manner, the control unit 19 is capable of establishing with precision the position of the front end 5 of the elongated element 3 with respect to a fixed reference of the supply device 10.

(47) Therefore, by knowing the predefined measurement at which the elongated element 3 has to be cut and the distance D between the detection zone 25 and the cutting member 18, the control unit 19 is capable of calculating (by subtracting the distance D from the predefined measurement) the movement of the conveyor belt 11 necessary for bringing the front end 5 to a distance from the cutting member 18 corresponding to that predefined measurement.

(48) Preferably, the position of the front end 5 is attributed, as described above, after the control unit 19 has subsequently also compared the duration of the detection of the signal, in addition to a comparison with a minimum value as explained above, with a maximum duration value, so that the end of the opening 21 is not incorrectly mistaken for the arrival of the front end 5.

(49) The conveyor belt 11 is then moved in the supply direction X away from the cutting member 18, by a length equal to the difference between that predefined measurement and the distance D and, at that location, the elongated element 3 is cut by the cutting member 18 at the instruction of the control unit 19.

(50) The conveyor belt 11 is then further moved in order to advance the elongated element 3 which is now cut to the predefined measurement in the supply direction X as far as the loading region 13 where it is deposited in the region of the forming drum 4.

(51) The conveyor belt 11 is then further caused to rotate about the rollers 14 until the first portion 20 is brought into the region of the loading region 12, on the basis of the movement calculated previously by the control unit 19.

(52) At this point, there may be positioned on the first portion 20 the front end of a successive elongated element.

(53) In FIG. 4, there is generally designated 100 a second embodiment of the building plant according to the invention wherein similar elements with respect to the building plant 1 are indicated using the same reference numeral.

(54) The building plant 100 differs from the building plant of the preceding example as a result of a different configuration of the conveyor belt and the first detection element.

(55) In particular, the building plant 100 comprises a pair of conveyor belts 101, which are configured identically and each of which comprises a protruding projection at the opposite side to the support surface 15 over a predefined measurement and extends along the longitudinal axis Y over the entire extent of the conveyor belt 101.

(56) The projection is engaged in a sliding manner in suitable guides which are formed on the frame 11a so as to allow a more coherent advance in the supply direction X, limiting any lateral deviations of the conveyor belt.

(57) In order not to interrupt the continuity of the projection, on the conveyor belt 101 there is provided a pair of first detection elements which are formed by respective openings 102, which are provided in a staggered position with respect to the longitudinal axis Y.

(58) Preferably, the openings 102 have similar dimensions with respect to the opening 21 of the plant 1, and are arranged in a symmetrical position with respect to the longitudinal axis Y, parallel therewith.

(59) Naturally, in this embodiment there is provision for the sensor 22 to comprise a pair of elements for detecting light radiation, a corresponding pair of light radiation emitters and a corresponding pair of reflection elements.

(60) There is further defined on each conveyor belt 101 a second portion 103 which is separate and distinct from the first portion 20 and which is identified by a second detection element which is fixedly associated with the second portion 103 and provided to cooperate with an auxiliary sensor 105, which is mounted in the region of the loading region 12 in order to detect the presence of the terminal end 6 of the elongated element 3.

(61) The second detection element has an extent in the supply direction which is generally greater than the first detection element because it has to be able to detect the position of the terminal end 6 of elongated elements which can generally have measurements which are different from each other in accordance with the tyre to be built on the forming drum 4.

(62) Preferably, the second detection element has an extent in the supply direction X of from 300 to 700 mm.

(63) The second detection element is advantageously constructed in a manner similar to the first detection element, also in accordance with the configuration of the sensor 22, so that, on the conveyor belt 101, there is provided a pair of openings 104 which are arranged symmetrically with respect to the longitudinal axis Y in alignment with the openings 102.

(64) The functionality of the plant 100 is similar to that of the plant 1, with the additional characteristic, afforded by the provision of the second detection element, of being able to control the position of the terminal end 6 and consequently being able to establish the length of the elongated element 3 which is cut by the cutting member 18.

(65) Naturally, a person skilled in the art could apply additional modifications and variants to the invention described above for the purpose of complying with specific and contingent application requirements, variants and modifications in any case being included within the scope of protection as defined by the appended claims.