AU624743B2

AU624743B2 - Method for joining a tread in an apparatus for making a tire

Info

Publication number: AU624743B2
Application number: AU64929/90A
Authority: AU
Inventors: Jiro Agawa; Yoshinori Miyamoto; Hidemasa Sato
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1989-11-13
Filing date: 1990-10-23
Publication date: 1992-06-18
Anticipated expiration: 2010-10-23
Also published as: AU6492990A; DE4035708A1; NL9002382A; NL195053C

Description

'V A 4 624743 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 Form COMPLETE SPECIFICATION FOR OFFICE USE Short Title: Int. Cl: Application Number: Lodged: t0t 0 0 0 0, 0 Complete Specification-Lodged: so Accepted: oo000 0 o Lapsed: Published: 0000 000 o Priority: Related Art: a000 o000 00 TO BE COMPLETED BY APPLICANT 0 0 0*0 Name of Applicant: MITSUBISHI JUKOGYO KABUSHIKI Kh-SHA 00000 O o Address of Applicant: 5-1 Marunouchi 2-chome, Chiyoda-ku, TOKYO, JAPAN Actual Inventor: Yoshinori Miyamoto; Jiro Agawa and 0 *0 Hidemasa Sato Address for Service: GRIFFITH HACK CO 71 YORK STPEET SYDNEY NSW 2000 Complete Specification for the invention entitled: METHOD FOR JOINING A TREAD IN AN APPARATUS FOR MAKING A TIRE The following statement is a full description of this invention, including the best method of performing it known to us:- 9991-EC:DJH:RK 7188A:rk F f.* 2.:

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METHOD FOR JOINING A TREAD-IN AN APPARATUS FOR MAKING A TIRE BACKGROUND OF THE INVENTION: 1. Field of the Invention The present invention relates to a method for joining opposite ends of a strip of tread in an app. tus for making a tire.

2. Description of the Prior Art Treads are cut to a length each corresponding to the circumferences of a tire. The length of such treads may vary depending not only on how accurately they are cut, but also on mixing conditions, the period between an extrusion process and a molding process, and tempemature or other conditions. A -tolerance for a part in which opposite ends of each tread is joined is quite small for 0 better performance of the tire.

A conventional apparatus for joining a tread includes no such effective means for altering or adjusting the length of a tread. To thio end, an operator must manually adjust it by himself in the process of joining the tread.

There has been proposed a method for Joining opposite ends of a tread by adjusting the speed of each of a conveyor and a tread drum to roll the tread, as cut 'o a length equal to the circumference of a tire, 1Aaround the drum.

As earlier stated, the treads as cut may vary depending not only on how accurately they are cut, but also on mixing conditions, the period between an extrusion process and a molding process, and temperature or other conditions. A tolerance for a part in which opposite ends of each tread is joined is however quite small. Manual adjustment of the length of each tread by 0 o0 the operator suffers from the following problems: a) Considerable skill is required; b) It is a heavy work; and c) It is not efficiently operated, and the opposite ends of the tread are not always joined in an accurate fashion.

A disadvantage with the method for joining opposite ends of a tread by adjusting the speed of each of a conveyor and a tread drum so as to roll the tread around the drum is as follows.

As shown in Fig. 15, the speed of a conveyor and a tread drum is adjusted to roll a tread 57 around the drum in such a manner as to bring the centers E of the front and rear ends of the tread 57 into alignment with each other. In such a case, any portions of the tread 57 other than the center E are likely to leave spaces X 1 and X 2 To this end, an operator must manually -2

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S- 3i J -3alter or adjust the rear end of the tread.

SUMMARY OF THE INVENTION: The present invention aims to ameliorate at least some of the problems of the prior art.

Accordingly, the present invention provides a method for joining opposite ends of a tread in an apparatus for making a tire, the tread incorporating at skive at its ends and the method comprising the steps of: 0 a) measuring an actual length of a tread; b) attaching a front end of said tread to a drum C C t and fixing a rear end of said tread to a conveyor; c) adjusting the speed of rotation of said conveyor and said drum as follow: e* v= Vx

L

where L (mm) is the circumference of the drum, el 15 (mm) is the actual length of the tread, e2 (mm) is the Slength of the skive, V (mm/sec) is the speed of rotation of the drum, and v (mm/sec) is the speed of the conveyor; and d) joining the front and rear ends of said tread 20 together.

Preferably, the front and rear ends of the tread are gripped after the actual length of the tread has been measured. A machine is used to stretch the rear end of the tread so as to joint it to the front end of the tread.

S9991-EC/426/27.02.92 9991-EC/426/27.02.92 T 4 In a preferred embodiment, the operation is as follows: The actual length of the tread is first measured. The front end of the tread is bonded to the drum, and the rear end of the tread is secured to the conveyor. The speed of rotation of the drum and the speed of the conveyor are adjusted in a manner as explained t above. The tread is then rolled around the drum while it S is being stretch to the extent as necessary. As a result, the opposite ends of the tread can be joined together with Z t no space left therebetween.

While the tread is being rolled in a manner as set forth in the previous paragraph the front and r, rear ends of the tread are gripped, and the rear end of the tread is so stretched as to eliminate the spaces X 1 and X 2 By altering the end of the tread in consideration of materials of the tread, mixing conditions and shapes, the front and rear ends of the tread can be joined together 44 without any space therebetween.

BRIEF DESCRIPTION OF THE DRAWINGS: A better understanding of the present invention may be had by reference to the following description of preferred embodiments when taken in conjunction with the accompanying drawings, in which: Fig. 1 is side view of an apparatus for joining tre;d ends, according to a first embodiment of the present invention; Fig. 2 is a top plan view of the apparatus shown in Fig. 1; Fig. 3 is a sectional view taken along the line B-B of Fig. 2; Fig. 4 is a side view of the apparatus, but looking in the opposite direction from Fig. 1; Fig. 5 is a sectional view taken along the line A-A of Fig. 1; i Fig. 6 is a schematic view showing the manner in which a tread is positioned and measured; Fig. 7 is a schematic view showing the manner in which the tread is aligned; f'o Fig. 8 is a view of the tread immediately before aoaa °a t5 it is rolled to commence joining; I Fig. 9 is a view of the tread immediately before opposite ends of the tread are joined together; S:Fig. 10 is a side view showing the shape of the tread; ?ig. i1 is a sectional view of an apparatus according to a second embodiment of the present invention; Fig. 12 is a sectional view taken along the line C-C of Fig. 11; Fig. 13 is a view showing the manner in which the rear portion of the tread is locally deformed; F i g i A Fig. 14 is a sectional view taken along the line D-D of Fig. 13; and Fig. 15 is a view showing the manner in which front and rear ends of the tread are joined together.

DESCRIPTION OF THE PREFERRED EMBODIMENTS: In Figs. 1 to 10, the reference numeral 1 is a conveyor frame. 2 and 3 are brackets provided at opposite ends of the conveyor frame 1. 4 is a plate slidable along the bracket 3. 5 is a pull screw threaded into the plate 4. 6 is a press roller. 7 is a pneumatic cylinder. 8 is a drive roller. 9, 10 and 12 are idler rollers. 11 is a tension roller. 13 is a pivot pin about which the press roller 6 is rotated. 14 is a slide bearing. 15 are rails placed on a support frame 53. 16 are bearings provided on the upper ends of vertical members. 17 are brackets °provided at one end of the support frame 53. 18 is a o S" motor for taking up a wire. 16 is a conveyor drive motor.

o 20 is a screw adapted to push up the other end of the support frame 53. 21 is a bracket extending from the upper portion of another vertical member 23. 22 is a base on which the vertical members 23 and 24 are supported.

and 28 are reflection type optical switches. 26 is an arm extending upright on the conveyor frame 1. 27 is an arm extending upright on a carrier 50. 29 are fingers extending from the upper ends of spline shafts 33. 30 are 6- -i j_ blocks in which bearings 31 are arranged. 32 are pneumatic cylinders by which the blocks 30 are moved up and down.

33 are spline shafts extending vertically from brackets 34 which are, in turn, attached to a carrier 55. 35 are fingers extending from the blocks 30. 36 is a conveyor belt. 37 are guide rollers for guiding the conveyor belt 36. 38 are plates of the conveyor frame 1. 39 is a rectangular pipe of the conveyor frame 1. 40 are slide bearings for the carrier 55. 41 is a pneumatic cylinder ,,I0 mounted to the support frame 53. 42 are rails placed on *a table 56. 43 is a nut fixed to the carrier 50. 44 is t i a screw for threaded engagement with the nut 43. 45 is a motor by which the screw 43 is driven for rotation.

0' 'o 46 is a bearing for the screw 44. 47 is a bracket extendo v15 ing from the carrier 50. 48 is a forming drum. 49 is a stopper attached to the carrier 55. 50 and 55 are the carriers. 51 is a wire connected to the carrier 55. 52 are pins for supporting the guide rollers 37. 54 is an arm of the press roller 6. 56 is a table which is an D a extension of the support frame 53. 57 is a tread. 58 are rails placed on the conveyor frame 1. 59 is a slide bearing for the carrier The conveyor belt 36 shown in Fig. 3 as taken along the center line Y-Y of the apparatus, is trained around the idler, rollers 11, 12, 10 and 9 and the drive 7i '1 r roller 8. The drive roller 8 is connected to the motor 19 such as a servo motor, the speed of rotation of which is controllable. The idler roller 11 is moveable in a to-and-fro direction relative to the conveyor to adjust the tension of the conveyor belt 36. The forming drum 48 is located forwardly of the conveyor and is driven for rotation by a servo motor (not shown). At the front o portion of the conveyor, the press roller 6 is rotatably supported by the arm 54 which is, in turn, pivotably a°i_0 supported by the conveyor frame 1 through the pivot pin 13. The arm 54 is also supported by the pneumatic cylinder 7 which is, in turn, mounted to the conveyor frame 1.

Below the conveyor belt 1 are the slide bearings 400o t 14 slidably supported on the rails 15 and 15 which are "a 15 fixedly mounted on the support frame 53. The pneumatic Di°>o cylinder 41 is mounted to the support frame 53 and connected to the conveyor frame 1 so as to move the conveyor in a to-and-fro direction. The support frame 53 has a Si a. o rear end rotatably supported by the bearing 16 and a front end vertically adjustable by the screw 20. The bearing 16 is mounted to the carrier 24 which is, in turn, fixed to the base 22. The screw 20 is mounted through the bracket 21 to the vertical member 23 which is, in turn, fixed to the base 22.

Placed on the conveyor frame 1 are the rails 58 8 along which the carrier 55 is moveable through the slide bearings 40. The brackets 34 are fixed to opposite sides of the carrier 55. The spline shafts 33 extends from the respective brackets 34. The fingers 29 are mounted to the upper ends of the spline shafts 33. Also, the blocks are slidable along the spline shafts 33 through the bearings 31, and the fingers 35 extend from the respective 2 blocks 30. The pneumatic cylinders 32 are fixedly mounted oo to the brackets 34 and have rods connected to the blocks 1"'10 30. The motor 18 is mounted to the conveyor frame 1 and o0, has a shaft to which a cylindrical take up drum (not shown) is mounted to take up a wire 51. One end of the wire 51 is attached to the carrier °ooo The table 56 extends from the support fram- 53 on o15 and forms part thereof. Placed on the table 56 are the 00 rails 42 along which the carrier 50 is moveable through the bearings 59. The carrier 50 includes the arm 27, a forward end of which is provided with the reflection type Se optical switch 28. The stopper 49 is mounted to the carrier 55 and when the carrier 55 is returned, brought int., contact with the arm 27 so as to stop the carrier The bracket 47 is attached to the carrier and the nut 43 is fixed to the bracket 47. The nut 43 is fit around the screw 44 which is, in turn, connected to the motor 45 such as a servo motor for positioning purposes.

9 The rectangular pipe 39 extends centrally of the conveyor. The plates 38 are of a L-shape and secured to opposite sides of the pipe 39. The upper side of each plate 38 are configured to support near center of the conveyor belt 36. The pins 52 extend along and between the plates 38 so as to rotatably support the guide rollers 37. Each guide roller 37 has a V-shaped projection at its center as shown in Fig. The arm 26 is fixed to the front portion of the 10 support frame 53 and has a free end to which the reflection 0 0 o, type optical switch 25 is attached.

An operator places a tread 57 on the conveyor to effect lateral positioning of a central groove of the 'tread 57 relative to the projections of the guide rollers o o15 57, or to bring the central groove of the tread 57 into 0 0o alignment with the projections of the guide rollers 57.

0 The conveyor is then moved back and forth and stopped when 0 o the forward end of the tread 57 is brought into alignment S" with the front switch 25. The rear switch 28 is driven by the motor 45 to detect the rear end of the tread 57.

At this time, the actual length of the tread is simultane- S";ously measured.

After the tread has been positioned, and the actual length of thi, tread has been measured, the pneumatic cylinders 32 are.operative to drive the fingers 35. The 10 t

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Stiia fingers 35 then cooperate with the fingers 29 to grip the 'read 57. The optical switch 28 and the fingers 29 and are held in position since the fingers are in contact with the arm 27 of the stopper 49 mounted to the carrier LI I II I

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5000 0I 0490 00 0* 0 0 200 o 0 S 0 o «0 4 00 00 The pneumatic cylinder 41 is then operative to move the conveyor in a forward direction and stop the same when the press roller 6 is located right below the drum 48.

The press roller 6 thereafter presses and sticks the tread 57 against the drum 43. At this time, the drum 48 and the conveyor 36 are rotated at such a speed as to bring the front and rear ends of the tread 57 into alignment with one another. Such speed of the conveyor 46 is represented by the following equation.

1 -l v Vx

L

where L (mm) is the circumference of the drum, 1 (mm) is the actual length of the tread, Z 2 (mm) is the length of a skive, V (mm/sec) is the speed of rotation of the drum, and v (mm/sec) is the speed of conveyor.

As shown in Fig. 9, the fingers 29 and release the tread 57 immediately before the tread 57 is turned once and is then retreated while the wire 51 is being taken up by the motor 18.

.In the illustrated embodiment, the belt conveyor ia 11 i::i i i i-1 i r_ I.E i i. L.

is used. Alternatively, a circulating type roller conveyor may be used. In such a case, a conveyor roller, rather than the guide rollers, includes a guide projection.

Also, the carrier with the fingers, rather than the roller 9 conveyor, may be driven by a ball screw or the like, and the roller conveyor follows.

(Second Embodiment) In Figs. 11 to 14, the numeral 1 is a conveyor frame. 29 are fingers. 36 is a conveyor belt. 37 are guide rollers. 38 is a plate of the conveyor frame 1.

39 is a rectangular pipe of the conveyor frame 1. 40 are slide bearings for a carrier 55. 57 is a tread. 58 are rails placed on the conveyor frame 1. The foregoing components are the same as those shown in the first «15 embodiment.

101 are brackets mounted to the carrier :102 are rails placed on the brackets 101. 114 are stopper bolts mounted to the brackets 101. 103 are slide bearings *00 4 for corresponding carriers 104. 105 are rails placed on the carriers 104. 106 are slide bearings mounted to carriers 107. 108 are pneumatic cylinders mounted to the carriers 107. 115 are stopper bolts mounted to the carriers 104. 113 are pneumatic cylinders mounted to the brackets 101. 112 are pneumatic cylinders mounted to the carriers 104. 109 are clamps mounted'to the carriers 107.

-12 1 1 1 111 are pins secured to the clamps 109. 110 are fingers rotatable about the pins 111. The members 101 to 115 are symmetrically arranged with respect to the center of the conveyor frame 1.

Operation of the apparatus will now be described.

The actual length of the tread 57 is first measured. The tread 57 is then gripped by the fingers 29.

Thereafter, th' pneumatic cylinders 112 are operative to move the clamps 109 and the fingers 110 toward the center of the conveyor. The pneumatic cylinde'.s 108 are then operative to rotate the fingers 110 about the pins 111 to thereby grip opposite ends of the tread 57. The movement of the clamps 109 and the fingers 110 are adjusted or o limited by the stoppers 115. The pneumatic cylinders 113 "o 015 are now operative to move the clamps 109'and the fingers a° 1 110 so as to stretch the tread between the fingers 29 and 110. The stopper bolts 114 are used to limit movement of 4 0 0 o the carriers 104 so as to adjust the amount of which the O tread is stretched. The clamps 109 and the fingers 110, like the fingers 29 and 35, release the tread 57 immediately before the tread is turned once. The front and rear ends of the tread 57 can accurately be joined together by adjusting the ends of the tread depending on materials, mixing conditions, and shapes.

Advantages of the present invention are as follows: 13 In accordance with the present invention, a method for joining opposite ends of a tread in an apparatus for making a tire, comprising the steps of: measuring an actual length of a tread; attaching a front end of the tread to a drum and fixing a rear end of the tread to a conveyor; adjusting the speed of rotation of the conveyor S and the drum as follows: V V x I

I,

10 where L (mm) is the circumference of the drum, (mm) is the actual length of the tread, Z2 (mm) is the length of a skive, V (mm/sec) is the speed of rotation of the drum, and v (mm/sec) is the speed of the conveyor; and joining the front and rear ends of the tread' °1 5 together. By this method, the opposite ends of the tread can automatically and evenly or accurately be joined by the drum.

Also, the operator is no longer required to manually stretch and join the ends of the tread.

'0 After the actual length of the tread has been measured, the opposite ends of the tread are gripped.

A machine is used to stretch the rear end of the tread so as to join the opposite ends of the tread together. In this way, the ends of the tread can be adjusted. in conformity with materials of the tread, mixing conditions, 14 <Ai i 0 a T1 y 1 and shapes before it is rolled.

Accordingly, the amount of work by the operator can be reduced or completely avoided.

Although there have been described what are at present considered to be the preferred embodiments of the invention, it will be obvious to those skilled in the art that changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes-and 10 modifications as fall within the spirit and scope of the invention.

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Claims

9991-EC/426/27.02.92 -A 1 16 THE CLAIMS DEFINING THE INVEA"TCN ARE AS FOLLOWS: 1. A method for joining opposite ends of a tread in an apparatus for making a tire, the tread incorporating at skive at its ends and the method comprising the steps of: a) measuring an actual length of a tread; b) attaching a front end of said tread to a drum and fixing a rear end of said tread to a conveyor; c) adjusting the speed of rotation of said conveyor and said drum as collow: v= Vx k2 L where L (mm) is the circumference of the drum, R, (mm) is the actual length of the tread, e 2 (mm) is the length of the skive, V (mm/sec) i's the speed of rotation of the drum, and v (m/sec) is the speed of the conveyor; and Es I ri t c~ Es Es,. t is C C c I .I 20 P1, d) together. joining the front and rear ends of said tread
2. The method of claim 1, wherein the front and rear ends of said tread are gripped after the actual length of the tread has been measured, and a machine is used to stretch the rear end of the tread so as to join it to the front end of the tread.
3. A method of joining opposite ends of a tread in an apparatus for making a tire substantially as herein described with reference to figures 1 to 14 of the accompanying drawings. DATED this 27th day of February 1992 MITSUBISHI JUKOGYO KABUSHIKI KAISHA By their Patent Attorneys GRIFFITH HACK CO -EC/426127.02.92