FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention: AUTOMATED MATERIAL CASSETTE HANDLING SYSTEM
2. Applicant(s)
NAME NATIONALITY ADDRESS
CEAT LIMITED Indian RPG HOUSE, 463, Dr. Annie
Besant Road, Worli, Mumbai,
Maharashtra- 400 030, India
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.
TECHNICAL FIELD
[0001] The present subject matter relates, in general, to tire building machines
and, particularly but not exclusively, to let-off station in the tire building machines.
BACKGROUND
[0002] In tire manufacturing process, different tire building *# materials are applied
on a tire building drum, for producing a green tire (uncured tire). Layers of tire
building materials are wrapped around the tire building drum around the
circumferential margins of the drum. The tire building materials are usually kept in a
servicer rack and while applying the tire building materials on the tire building drum,
the tire building materials are first taken out from the servicer rack, and then tips of
the tire building materials are located. The located tip of the tire building material is
placed and affixed to a predetermined position on the building drum. After winding
of the tire building materials on the tire building drum, the tire building materials, at
finishing end, is slashed, and the tire building materials are folded back to the service
rack. After wrapping all the required tire building materials, layer by layer, on the
tire building drum, the green tire is disintegrated from the tire building drum and is
sent for further processing.
BRIEF DESCRIPTION OF DRAWINGS
[0003] The detailed description is described with reference to the accompanying
figures. In the figures, the left-most digit(s) of a reference number identifies the
figure in which the reference number first appears. The same numbers are used
throughout the drawings to reference like features and components.
[0004] Figure. 1 illustrates an automated material cassette handling system
comprising a let-off station and a material cassette, in accordance with an
implementation of the present subject matter.

[0005] Figure. 2 illustrates detailed view of the material cassette, in accordance
with an implementation of the present subject matter.
[0006] Figure. 3 illustrates detailed view of the let-off station, in accordance with
an implementation of the present subject matter.
[0007] Figure. 4 illustrates a block diagram of drive mechanism and its
components, in accordance with an implementation of the present subject matter.
DETAILED DESCRIPTION
[0008] The present subject matter relates to an automatic system for loading and
unloading of a material cassette in a let-off station of a tire building machine.
[0009] During the manufacturing process of a tire, building materials, such as
inner liner, ply 1, ply 2, etc., are assembled on a tire building drum to make a green
tire. The building materials and their composition may vary, depending on the type
and size of the tire. To meet this diversity, many production steps are required.
Technique through which these tire building materials are rolled onto the tire
building drum is very important, at least for giving the tire its required strength and
shape. Therefore, to supply a tire building material onto the tire building drum, a
material drum with the tire building material wound on it, is used. This material
drum may be secured on a material cassette, wherein the material cassette is then
loaded onto a let-off station. Once the material cassette securing the cassette drum,
reaches up to a predetermined position on the let-off station, the tire building
material wound on the material drum, is unrolled through a feeding mechanism and
is applied on the tire building drum, either centrally or eccentrically.
[0010] Conventionally, loading and unloading of the material cassette onto the
let-off station is done manually. In the tire building machine, there may be separate
let-off stations for each type of building materials, such as inner liner, ply 1, ply 2,
etc., and each one of the let-off station may have a separate material cassette, loaded
with the material drum of one type. The material cassette, carrying on it a fully
loaded material drum, sometimes, may weigh more than four hundred kilograms.
[0011] Conventionally, the loading and unloading of the material cassette onto
the let-off station is performed by an operator manually, approximately twenty to
twenty-five times in a single working shift, wherein one working shift may be eight
hours long. This may affect overall working capacity of the operator resulting in loss
in productivity. Further, the manual loading and unloading of the material cassette on
the let-off station by the operator, may cause damages to the material cassette and the
let-off station. In addition, down time increases due to improper loading of the
material cassette on the let-off station.
[0012] Thus, the present subject matter provides an automated material cassette
handling system (hereinafter referred to as system) for automatic loading of a
material cassette onto a let-off station and automatic unloading of the material
cassette, after consumption of the tire building material wound on the material
cassette, from the let-off station of a tire building machine.
[0013] The system comprises a material cassette, wherein, a material drum is
loaded onto the material cassette. The material drum comprises a tire building
material, which is wound on the material drum, to be applied on a tire building drum.
The system further comprises a let-off station, wherein, the let-off station acts as a
carriage for the material cassette and the material cassette acts as a carriage for the
material drum. The let-off station is provided with an entrance position at a first end
and a lock position at a second end, wherein the second end and lock position both
are located opposite to the first end and the entrance position respectively.
[0014] In an example implementation of the present subject matter, after placing
the material cassette at the entrance position of the let-off station, a drive mechanism
provided at the let-off station, may operate to automatically move the material
cassette from the entrance position of the let-off station to the lock position of the let5
off station, so as to properly position the material cassette onto the let-off station
without any manual interference.
[0015] The let-off station further comprises a locking mechanism to lock the
material cassette onto the let-off station. The locking mechanism has a pair of
extendable and retractable arms, located at the lock position of the let-off station,
wherein the locking mechanism extends to a latching position to lock the material
cassette at the lock position of the let-off station, in order to retain the material
cassette therein. Once, the material cassette is locked onto the let-off station, then
from the let-off station, the tire building material is transferred onto the tire building
drum, by unwinding the tire building material from the material drum.
[0016] For automatic unloading of the material cassette from the let-off station,
after consumption of the tire building material, the locking mechanism retract to an
initial position and the drive mechanism moves the material cassette towards the
entrance position from the lock position.
[0017] The present invention provides techniques to automatically load the
material cassette onto the let-off station. Also, the present invention facilitates the
automatic unloading of the material cassette from the let-off station after
consumption of the tire building material wound on the material cassette. Technique
of the present invention overcomes the limitations associated with the conventional
techniques of loading and unloading of the material cassette, and eliminates the
damages caused to the material cassette and the let-off station, during the manual
loading and unloading of the material cassette. Furthermore, system for automatic
loading and unloading of the material cassette onto a let-off station described herein
requires substantially low attention of the operator and may be operated with
minimum manual intervention, which reduces production time of a green tire, thus
increasing efficiency.
[0018] The above-mentioned implementations are further described herein with
reference to the accompanying figures. It should be noted that the description and
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figures relate to exemplary implementations and should not be construed as a
limitation to the present subject matter. It is also to be understood that various
arrangements may be devised that, although not explicitly described or shown herein,
embody the principles of the present subject matter. Moreover, all statements herein
reciting principles, aspects, and embodiments of the present subject matter, as well as
specific examples, are intended to encompass equivalents thereof.
[0019] Figure 1 illustrates a system 100 comprising a material cassette 102 and a
let-off station 106, in accordance with an implementation of the present subject
matter. In an example implementation, a pair of material drum 104-1, 104-2 is placed
on the material cassette 102 as shown in figure 1. First material drum 104-1 is for
winding the tire building material along with liner and second material drum 104-2 is
for winding the liner, after conveying the tire building material on the tire building
drum for tire building.
[0020] Further, the let-off station 106 as shown in figure 1, has an entrance
position 108 towards a first end 110 and a lock position 112 which is opposite to the
entrance position 108 and located towards a second end 114 of the let-off station
106. The let-off station 106 receives the material cassette 102 at the entrance position
108 and carries the material cassette 102 up to the lock position 112 of the let-off
station 106.
[0021] As already explained in above paragraphs, the let-off station 106
comprises a drive mechanism (shown in figure 4) to move the material cassette 102
from the entrance position 108 to the lock position 112. The let-off station 106
further comprises a locking mechanism (shown in figure 3), to lock the material
cassette 102 at a predetermined position onto the let-off station 106, wherein the
same locking mechanism may be used to unlock the material cassette 102 from the
let-off station 106.
[0022] Once, the material cassette 102 is locked onto the let-off station 106, then
from the let-off station 106, the tire building material is transferred onto a tire
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building drum (not illustrated), by unwinding the tire building material from the
material drums 104-1, 104-2 with the help of separate drive. The drive mechanism
provided on the let-off station 106 further operates to move the material cassette 102
towards the entrance position 108 from the lock position 112, in order to unload the
material cassette 102 from the let-off station 106. Detailed structure and working of
the material cassette 102 and the let-off station 106 is explained with respect to
figures 2-4 below.
[0023] Figure 2 depicts the material cassette 102 of the system 100, in greater
detail, according to an implementation of the present subject matter. As stated
earlier, in the material cassette 102, the material drum 104-1, 104-2 is used to wind
and unwind the material/liner. The material cassette 102 may contain the tire
building materials such as inner liner, ply 1, ply 2, etc. The tire building material
may be wound in a form of layers on the material drum 104-1, 104-2. The material
drum 104-1, 104-2 may comprise a cylindrical housing 200-1, 200-2 for facilitating
the winding of the layers of the tire building material onto surface of the material
drum 104-1, 104-2.
[0024] The material cassette 102 may comprise a pair of frame structure 202-1,
202-2, to support the first material drum 104-1 onto the material cassette 102,
wherein the first frame structure 202-1 is located at first side 204-1 and the second
frame structure 202-2 is located at second side 204-2 of the material cassette 102.
Similarly, the material cassette 102 may also comprise another pair of frame
structure 206-1, 206-2, to support the second material drum 104-2 onto the material
cassette 102, wherein the first frame structure 206-1 is located at the first side 204-1
and the second frame structure 206-2 is located at the second side 204-2 of the
material cassette 102.
[0025] The first material drum 104-1 and the second material drum 104-2 may
further comprise, means for unwinding the tire building material from the first
material drum 104-1 and the second material drum 104-2, and means for relaxing the
tire building material on the cylindrical housing 200-1, 200-2 of the material drums
104-1, 104-2, so that, the tire building material which leaves the housing through the
outlet to enter on a surface of the tire building drum is free from any tensional
stresses.
[0026] In another example embodiment, the material drums 104-1, 104-2 may
further comprise a pair of holding member 208-1, 208-2 passing through the center
of the material drums 104-1, 104-2 to support the material drums 104-1, 104-2 on the
material cassette 102 or any device or plate on which the material drums 104-1, 104-
2 may be placed for dispensing of a selected length of the tire building material for
applying on the tire building drum. The holding member 208-1 and 208-2 may be
provided, at both the ends of the material drum 104-1, 104-2. The material drum
104-1, 104-2 is connected to a drive, which is to rotate the material drum 104-1, 104-
2, wherein during this rotation the liner and the tire building material separates. In
one of the example embodiment, the purpose of the liner is to avoid the sticking of
the tire building material, during winding. As may be apparent, the pair of holding
member 208-1, 208-2 may rest on the pair of frame structure 202-1, 202-2, with one
holding member-frame structure engagement on either side of the material cassette
102.
[0027] In an example implementation, of the present subject matter, the material
drum 104-1, 104-2 may rotate in a clockwise or in an anticlockwise direction, about
the holding members 208-1, 208-2 for winding and unwinding of the tire building
material from the material drums 104-1, 104-2 with the help of drive. The rotation of
the material drum 104-1, 104-2 in the clockwise direction ensures unwinding of a
length of the tire building material, which may suffice the need of applying the tire
building material on the tire building drum. In another example, the material drums
104-1, 104-2 may be provided with a separating layer to prevent sticking of the tire
building material layers.
[0028] Although, in the present subject matter, the material drum 104-1, 104-2 is
exemplified in circular shape, but the material drum 104-1, 104-2 may be of any
shape and size such as oval or elliptical etc. The material cassette 102 may be
provided with means such as a wheel 210, to enable the easy movement of the
material cassette 102 over the ground. Though only one wheel 210 is indicated in the
figure 2, it is to be understood that the material cassette 102 may comprise more than
one wheels on all the corners of the material cassette 102.
[0029] In an operation, the material cassette 102 is first carried till the let-off
station 106 manually by an operator with the help of the wheels and is placed in a
direction Z1 as shown in the figure 2, facing the entrance position 108 of the let-off
station 106. From the entrance position 108, the material cassette 102 is further
carried onto the let-off station 106 automatically, without any manual interference,
by the drive mechanism provided on the let-off station 106. The working of the drive
mechanism is explained in detail with respect to the FIGS. 3 and 4 below.
[0030] Figure 3 depicts the let-off station 106 of the system 100, in greater detail,
according to an implementation of the present subject matter. The let-off station 106
is for holding the material cassette 102 and supplying the tire building material, by
pulling it from the material drum 104-1, 104-2, to the surface of the tire building
drum.
[0031] The let-off station 106 comprises a pair of positioning rollers 300-1, 300-
2 on either side of the let-off station 106 as shown in the figure 3. The positioning
rollers 300-1, 300-2 are fitted on entry area of the let-off station 106 towards the
entrance position 108. The positioning rollers 300-1, 300-2 are used for aligning the
material cassette 102 during loading, towards the lock position 112. The let-off
station 106 further comprises the drive mechanism to move the material cassette 102
from the entrance position 108 to the lock position 112. The drive mechanism
comprises a drive unit 302 located at the second end 114 of the let-off station 106,
which may be used to automatically pull the material cassette 102 up to the lock

position 112 of the let-off station 106. The drive unit 302 may be combination of an
electric motor (not illustrated) with gear box, wherein an output shaft (not illustrated)
of the gear box is connected to a drive pulley (not illustrated).
[0032] The drive mechanism further comprises a drive shaft 304 located towards
the second end 114 of the let-off station 106, wherein the drive shaft 304 is rotatably
coupled to the drive unit 302 about a horizontal axis passing through the center of the
drive unit 302. The drive unit 302 is energized to cause a clockwise or an anticlockwise
circular motion to the drive shaft 304. Drive shaft 304 may be in a shape
of solid rod, with necessary provisions for coupling with drive unit 302. The drive
shaft 304, as shown in figure 3 may be supported onto the let-off station 106 through
a pair supporting structures 310-1, 310-2 located at the second end of the let-off
station 106.
[0033] In the same implementation of the present subject matter, the drive
mechanism also comprises a pair of primary sprockets 306-1, 306-2 rotatably
coupled to the drive shaft 304. The primary sprockets 306-1, 306-2 are located,
opposite to each other, equidistant from a central axis parallel to a length L1 of the
let-off station 106 and towards the second end 114 of the let-off station 106. Further
the drive mechanism comprises a pair of chains 308-1, 308-2 rotatably coupled to the
primary sprockets 306-1, 306-2 located equidistant from the central axis parallel to
the length L1 of the let-off station 106 and towards the second end of the let-off
station 106). In an operation, when the drive unit 302 is energized to rotate the drive
shaft 304, which is rotatably coupled to the drive unit 302, then a whole length of the
drive shaft 304 rotates either in the clockwise direction or in the anti-clockwise
direction depending upon the instruction given by the operator to the drive unit 302.
[0034] The primary sprockets 306-1, 306-2 may include plurality of curved
toothed profile for guiding the chains 308-1, 308-2 away from the primary sprockets
306-1, 306-2 when engaged by the curved toothed profile. The chains 308-1, 308-2
may have multiple grooves (not illustrated), wherein the grooves buildup on the
11
primary sprockets 306-1, 306-2 and become embedded in the curved toothed profile
of the primary sprockets 306-1, 306-2 as the chains articulates over the sprockets.
[0035] As described earlier, the chains 308-1, 308-2 are rotatably coupled to the
primary sprockets 306-1, 306-2, therefore, the rotation of the drive shaft 304 in the
clockwise direction or in the anti-clockwise direction also causes *# the rotation of the
chains 308-1, 308-2. Direction of rotation of the chains 308-1, 308-2 is in
synchronization with that of the primary sprockets 306-1, 306-2.
[0036] Another component of the drive mechanism is secondary sprocket
members 312-1, 312-2, 312-3, 312-4 located at both ends, parallel to the length L1 of
the let -off station 106. The function of the secondary sprocket members 312-1, 312-
2, 312-3, 312-4 is to support the rotation of the chains 308-1, 308-2 onto the let-off
station 106. As explained for the primary sprockets 306-1, 306-2, the secondary
sprocket members 312-1, 312-2, 312-3, 312-4 may also include plurality of tiny
curved toothed profile for guiding the chains 308-1, 308-2 away from the secondary
sprocket members 312-1, 312-2, 312-3, 312-4 when engaged by the curved toothed
profile to keep the chains 308-1, 308-2 circulating.
[0037] It is to be understood that unlike the primary sprockets 306-1, 306-2 the
secondary sprocket members 312-1, 312-2, 312-3, 312-4 are independent of the
movement of the drive shaft 304. Rotation of the drive shaft 304 causes the rotation
of the primary sprockets 306-1, 306-2 and the rotation of the primary sprockets 306-
1, 306-2 causes the rotation of the secondary sprocket members 312-1, 312-2, 312-3,
312-4. The secondary sprocket members 312-1, 312-2, 312-3, 312-4 may rotate
independently without effecting the actual rotation of the other components of the
drive mechanism. The chains 308-1, 308-2 are connected between the primary
sprockets 306-1, 306-2 and the secondary sprocket members 312-1, 312-2, 312-3,
312-4, 312-3, 312-4 wherein, on the top of on the chains 308-1, 308-2, the material
cassette 102 sits and performs loading and unloading operation.
12
[0038] Although, in figure 3, only four secondary sprocket members 312-1, 312-
2, 312-3, 312-4 are indicated, this is to be noted that less or more than four secondary
sprocket members may also be provided on the let-off station 106. For the sake of
brevity, additional secondary sprocket members are not shown therein.
[0039] As explained earlier with respect to figure 1, the let off station 106 further
comprises a locking mechanism, wherein the locking mechanism comprises a pair of
extendable and retractable arms 314-1, 314-2 which are located at the lock position
112 of the let-off station 106. The locking mechanism extends to a latching position
to retain the material cassette 102 at a predetermined position onto the let-off station
106 and the locking mechanism retract to an initial position to unlock the material
cassette 102 from the let-off station 106.
[0040] In an example, the locking mechanism is fixedly connected to upper
plane of the let-off station 106, parallel to each other, wherein the extendable and
retractable arms 314-1, 314-2 of locking mechanism may move up and down
(*# pneumatically. In an example implementation, the retractable arms 314-1, 314-2 may
be triggered by a single triggering unit (not illustrated) which is controlled by the
drive unit 302. In another example implementation of the present subject matter, the
retractable arms 314-1, 314-2 may also be triggered by more than one triggering unit,
which is controlled by the drive unit 302.
[0041] In an example, supporting rollers 316-1, 316-2, 316-3, 316-4, 316-5, 316-
6, 316-7, 316-8 may be mounted on both sides and equidistant from the central axis
of the let-off station 106, to support the movement of the material cassette 102 onto
the let-off station 106 and to control the deflection of the material cassette 102 from
the let-off station 106. The supporting rollers 316-1, 316-2, 316-3, 316-4, 316-5,
316-6, 316-7, 316-8 rotates by coming in contact with the material cassette 102, in a
clockwise or anti-clockwise fashion in synchronization with the movement of the
material cassette 102. The supporting rollers 316-1, 316-2, 316-3, 316-4, 316-5, 316-
13
6, 316-7, 316-8 are metallic rollers, however it is to be understood that other rollers
such as fiber rollers, plastic rollers, ceramic rollers etc., may also be used.
[0042] In one of the embodiments of the present subject matter, the let-off station
106 comprises a sensing mechanism operable to sense arrival of the material cassette
102 at the locking position 112, so that, the locking mechanism may lock the
material cassette 102 at the lock position 112.
[0043] In an example embodiment, the sensing mechanism may comprise a
proximity sensor 318, wherein the proximity sensor 318, may be suitably calibrated
to sense the presence of the material cassette 102 once the material cassette 102 is
placed in the proximity of the proximity sensor 318. In another embodiment, it is to
be understood that the sensing mechanism may also comprise sensors other than the
proximity sensor, such as a capacitive transducer, capacitive displacement sensor,
Eddy-current sensor, ultrasonic sensor, grating sensor etc., that will be readily
understood by one skilled in the art have not been discussed herein.
[0044] In one of the embodiments of the present subject matter, the proximity
sensor 318 and a reflector 320, are placed opposite to each other on the let-off station
106, in line with the lock position 112 and at axis parallel to a length L1 of the let-off
station 106. In operation, the proximity sensor 318 produces a light beam. The light
beam travels up to the reflector 320. The reflector 320, reflects the beam to the
proximity sensor 318. Any interruptions between the proximity sensor 318 and the
reflector 320 may give an output signal. The reflector 320 is placed in front of the
proximity sensor 318 in axially straight line.
[0045] It is to be understood that the proximity sensor 318 may comprise means
to receive power for its operation, for example, the proximity sensor 318 may
comprise a positive pin and a negative pin for receiving power supply and a ground
pin. For the sake of brevity, such pins of the proximity sensor 318 and other similar
components that will be readily understood by one skilled in the art have not been
discussed herein.
14
[0046] In an implementation of the present subject matter, for automatic loading,
the material cassette 102, on which the material drum 104-1, 104-2 is rotatably
placed, is brought near the let-off station 106 and placed at the entrance position 108.
Then, the drive mechanism is switched on by the operator which leads to the
energization of the drive unit 302. The drive unit 302 thentransmits power to the
drive shaft 304, which starts rotating in clockwise direction, causing the primary
sprockets 306-1, 306-2 to rotate in the clockwise direction. Since, the chains 308-1,
308-2 are rotatably engaged with the primary sprockets 306-1, 306-2, the chains 308-
1, 308-2 also rotate in a clockwise fashion.
[0047] As discussed earlier, the chains 308-1, 308-2 are supported onto the
secondary sprocket members 312-1, 312-2, 312-3, 312-4, therefore, the rotation of
the chains 308-1, 308-2 causes the rotation of the secondary sprocket members 312-
1, 312-2, 312-3, 312-4 as well, in the clockwise direction. In this manner, the whole
drive mechanism starts its operation. Then the operator aligns the material cassette
102 at rotation point of the chains 308-1, 308-2. The drive mechanism moves the
material cassette 102 up to the lock position 112 on the let-off station 106. The
sensing mechanism senses the presence of the material cassette 102 at the lock
position 112 of the let-off station 106. The extendable and retractable arms 314-1,
314-2 extends to a latching position to lock the material cassette 102 at a
predetermined position onto the let-off station 106. Once locked, the tire building
material wound on the material drum 104-1, 104-2 is unrolled through a feeding
mechanism and is applied on the tire building drum, either centrally or eccentrically.
[0048] For automatic unloading of the material cassette 102 from the let-off
station 106, after consumption of the tire building material which is wound on the
material drum 104-1, 104-2 the extendable and retractable arms 314-1, 314-2 retract
to the initial position and the drive mechanism starts rotating in reverse direction, to
move the material cassette 102 towards the entrance position 108 from the lock
position 112. Once, the material cassette 102 reaches to the entrance position 108,
15
the operator may manually move the material cassette 102 to any appropriate
location.
[0049] Figure 4 illustrates a block diagram of drive mechanism and its
components, in accordance with yet another implementation of the present subject
matter. The drive mechanism 400 is similar to the drive mechanism explained above
with respect to FIGS. 1-3. The drive mechanism comprises a drive unit 402 similar
to the drive unit 302, a drive shaft 404 similar to the drive shaft 304, primary
sprocket(s) 406 similar to the primary sprockets 306-1, 306-2. The drive mechanism
400, further comprises chain 408 similar to the chains 308-1, 308-2 and secondary
sprocket member(s) 410 similar to the secondary sprocket members 312-1, 312-2,
312-3, 312-4.
[0050] In an example implementation, the system 100 may be controlled by a
programmable logic control (PLC) 412, to enable the movement of components of
the system 100. One such implementation of the PLC 412 is shown in figure 4,
wherein the drive unit 402 is controlled by the PLC 412. The PLC 412 comprises a
control panel 414. On the control panel 414, a load selector switch 416 is provided,
wherein an operator by selecting the load selector switch 416 gives commands to the
drive unit 402 to start the operation of loading the material cassette 102 onto the letoff
station 106. The control panel 414 further comprises an unload selector switch
418, wherein by using the unload selector switch 418, the operator gives command to
the drive unit 402 to rotate in reverse direction to unload the material cassette 102
from the let-off station 106.
[0051] In an embodiment of the present subject matter, for automatic loading of
the material cassette 102 onto the let-off station 106, the load selector switch 416 is
selected, which is provided on the control panel 414 of the PLC 412. The material
cassette 102 is then positioned at the entrance position 108 of the let-off station 106
by the operator. Once the material cassette 102 is placed at the entrance position 108,
the drive mechanism 400 automatically pulls the material cassette 102 up to the lock
16
position 112 of the let-off station 106. The proximity sensor 318 senses the presence
of the material cassette 102 at the lock position 112 of the let-off station 106 and the
PLC 412 sends command to locking mechanism to lock the material cassette 102 on
the let-off station 106, based on the input of the proximity senor 318. Thereafter, the
material cassette 102 may be loaded onto the let-off station by the techniques as
described above.
[0052] For automatic unloading of the material cassette 102 from the let-off
station 106, after consumption of the tire building material wound on the material
drum 104-1, 104-2 the unload selector switch 418 is selected, which is provided on
the control panel 414 of the PLC 412. The extendable and retractable arms 314-1,
314-2 of the locking mechanism retracts to its initial position, to unlock the material
cassette 102 from the let-off station 106. From there, the drive unit 402 starts to
rotate in reverse direction to unload the material cassette 102 from the let-off station
106, without any manual intervention.
[0053] In an example embodiment, the control panel 414, may also have a
display screen, wherein the display screen may be further provided with a control
keyboard for providing input to the PLC 412 for controlling the drive unit 402. The
control panel 414 may further comprise switches that may control the movement of
the components of the let-off station 106. For the sake of brevity, switches of the
control panel 414, and other similar components that will be readily understood by
one skilled in the art have not been discussed herein.
[0054] Therefore, the present subject matter, provides for an automatic loading
of the material cassette, rotatably placed there on a fully wound material drum, on
the let-off station and automatic unloading of the material cassette after the
consumption of the tire building material, wound on the material drum, overcoming
the above-mentioned limitations associated with the conventional techniques of
loading and unloading of the material cassette, and eliminates the damages caused to
the material cassette and the let-off station, during the manual loading and unloading
17
of the material cassette. Furthermore, automatic loading and unloading system of the
material cassette described herein requires substantially low attention of the operator
and may be operated with minimum manual intervention. This reduces preparation
time of a green tire, cost towards spare replacement, and operator fatigue is also
reduced, which further enhances the working efficiency and *# life time of the material
cassette.
[0055] Although the subject matter has been described in considerable detail
with reference to certain examples and implementations thereof, other
implementations are possible. As such, the present disclosure should not be limited
to the description of the preferred examples and implementations contained therein.
18
I/We claim:
1. An automated material cassette handling system (100) comprising:
a material cassette (102), wherein the material cassette (102) comprises
material drum (104-1, 104-2) carrying a tire building material; and
a let-off station (106) having an entrance position (108) at a first end (110)
and a lock position (112), opposite to the entrance position (108), at a second end
(114) wherein the let-off station (106) is to receive the material cassette (102) at the
entrance position (108), the let-off station (106) comprising:

a drive mechanism to:
move the material cassette (102) from the entrance
position (108) to the lock position (112); and
move the material cassette (102) towards the entrance position
(108) from the lock position (112) to unload the material cassette
(102) from the let-off station (106);
a locking mechanism having a pair of extendable and retractable
arms (314-1, 314-2) located at the lock position (112) of the let-off station
(106), wherein
the locking mechanism extends to a latching position to lock
the material cassette (102) at the locking position (112) of the let-off
station (106); and
the locking mechanism retracts to an initial position to unlock
the material cassette (102) from the locking position (112) the let-off
station (106).

2. The automated material cassette handling system (100) as claimed in claim 1,
wherein the let-off station (106) further comprises a sensing mechanism operable to
sense arrival of the material cassette (102) at the locking position (112) of the let-off
station (106) to lock the material cassette (102) at the lock position (112).
3. The automated material cassette handling system 100) as claimed in claim 2,
wherein the sensing mechanism comprises:
a proximity sensor (318) located in line with the lock position (112) and
along an axis parallel to a length (L1) of the let-off station (106); and
a reflector (320) positioned on an opposite side of the proximity sensor (318)
and at the axis parallel to the length (L1) of the let-off station (106), wherein the
reflector (320) is to:
receive a light beam from the proximity sensor (318); and
reflect the light beam to the proximity sensor (318) to ascertain the
presence of the material cassette (102);
wherein the locking mechanism is to lock the material cassette (102), based
on the feedback of the proximity sensor (318).
4. The automated material cassette handling system (100) as claimed in claim 1,
wherein the let-off station (106) further comprises:
a pair of positioning rollers (300-1, 300-2) located at either side of the
entrance position (108) of the let-off station (106), to align the material cassette
(102) towards the lock position (112) onto the let off station.
5. The automated material cassette handling system (100) as claimed in claim 1,
wherein the let-off station (106) further comprises:

supporting roller(s) (316) located equidistant from a central axis of the let-off
station (106), to support the movement of the material cassette (102) onto the let-off
station (106) and to control the deflection of the material cassette (102) from the letoff
station (106).
6. The automated material cassette handling system (100) as claimed in claim 1,
wherein the drive mechanism comprises:
a drive unit (302) located at the second end (114) of the let-off station (106);
a drive shaft (304) located towards the second end (114) of the let-off station
(106), wherein the drive shaft (304) is rotatably coupled to the drive unit (302) about
a horizontal axis passing through the center of the drive unit (302);
a pair of primary sprockets (306-1, 306-2) rotatably coupled to the drive shaft
(304), located towards the second end (114), either sprocket in the pair of primary
sprockets (306-1, 306-2) being equidistant from the central axis parallel to the length
(L1) of the let-off station (106);
a pair of chain (308-1, 308-2) rotatably coupled to the pair of primary
sprockets (306-1, 306-2), either chain in the pair of chain (308-1, 308-2) located
equidistant from the central axis parallel to the length (L1) and towards the second
end (114) of the let-off station (106);
secondary sprocket members (312-1, 312-2, 312-3, 312-4) located at both
ends of the let-off station (106), parallel to the length (L1) of the let-off station (106)
and to accommodate the chain (308-1, 308-2); and
the drive shaft (304) is to transmit power to rotate the primary sprockets
(306-1, 306-2), wherein the primary sprockets (306-1, 306-2) transmit power to the
chain (308-1, 308-2) and the secondary sprocket members (312-1, 312-2, 312-3, 312-
4) is to drive the material cassette (102).
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7. The automated material cassette handling system (100) as claimed in claim 6,
wherein the drive unit (302) is controlled by a programmable logic control (PLC)
(412).
8. The automated material cassette handling system (100) as claimed in claim 7,
wherein the PLC (412) comprises:
a control panel (414), comprising:
a load selector switch (416) to load the material cassette (102) onto
the let-off station (106); and
an unload selector switch (418) to unload the material cassette
(102) from the let-off station (106).