DESC:FIELD OF THE INVENTION:
This invention relates to the field of mechatronics engineering.

Particularly, this invention relates to a system for measuring length of paper of a paper roll.

BACKGROUND OF THE INVENTION:
Nowadays, printed bills have almost completely replaced handwritten bills. Use of such printed bills, and rolls of paper which printing of such bills, can be seen at ATM machines, in shops, at POS mechanisms, at petrol pumps, at restaurants, and the like. All such mechanisms use thermal papers. Thermal papers are made into thermal paper rolls which are cut into different sizes according to their length and width suitable for different applications.

A Thermal paper is coated with a material formulated to change color when exposed to heat. It is used in thermal printers, particularly in inexpensive or lightweight devices such as cash registers, and credit card terminals. The surface of such a paper is coated with a solid-state mixture of dye and a suitable matrix. The quality of paper is such that it does not get affected by heat.

When such a roll of paper is used, there is no mechanism, currently, to measure the length of paper roll in a POS bill printing mechanism; only when a roll of paper finishes, a notification is sent in order to refill such roll of paper.

According to prior art, there are big, and complex, machines available to cut a proper length of paper but no certain machines are available to measure the length of wounded roll.

Vendors expect precise lengths of paper rolls to meet their requirements. Therefore, there is an unmet need of a mechanism which, automatically, measures rolls of paper before dispensing them for use at POS mechanisms.

PRIOR ART:
According to the prior art, a variety of methods are used to measure rolls of paper, these methods being:
- direct weight measurement of the roll;
- manual length measurement;
- empirical method (based on previous experience or calibration);
- measurement using laser.

However, none of these methods and / or systems are reliable, none of them is accurate, and none of them is easy to provide in conjunction with a POS mechanism.

OBJECTS OF THE INVENTION:
An object of the invention is to provide a mechanism which, automatically, measures rolls of paper before dispensing them for use at POS mechanisms.

Another object of the invention is to mechanism which, automatically, measures rolls of paper and is such that it makes loading and unloading the roll easy.

Yet another object of the invention is to mechanism which, automatically, measures rolls of paper and is such that it makes loading and unloading the roll in relatively less time.

SUMMARY OF THE INVENTION:
According to this invention, there is provided a system for measuring length of paper of a paper roll, said system comprises:
- an enclosure with an angularly displaceable shaft configured to hold a roll of paper about its angular displacing axis;
- a motor configured to angularly displace said angularly displaceable shaft and the roll of paper about it;
- a first idler roller spaced apart from said angularly displaceable shaft and being configured to angularly displace in consonance with angular displacement of said roll of paper about said angularly displaceable shaft, said roll of paper extending from said angularly displaceable shaft to said first idler roller;
- said first idler roller comprising a driving shaft and a driven roller shaft with said roll of paper, received from said angularly displaceable shaft, gripped therebetween; and
- a revolution counter configured to measures number of rotations of said first idler roller through a coupled proximity sensor which, in turn, being calibrated into a length of paper roll, used.

In at least an embodiment, said driving shaft and said driven roller shaft are attached to a hinged plate.

In at least an embodiment, said enclosure comprises a cylindrical bellow shaped assembly consisting of:
- a lower firm plate acting as a base and carrying a first set of three dead centres to locate said rolls;
- a top cover acting as a top and carrying corresponding second set of three dead centres co-axial to said first set of three dead centres; and
- a proximity sensor connected on said lower firm plate and being connected to an output display;
o said roll of paper being mounted in between said two sets of dead centres in a driving roller, said roll of paper being wrapped from said driving shaft to driven shaft by passing it across said idler roller.

In at least an embodiment, said enclosure comprises:
- an operative lower support plate, a co-axial operative central plate, and a co-axial operative support plate; all ensconced in a cylindrical cover;
- one or more paper rollers;
said operative top support plate carrying a set of roll dead centres and a paper roller mounted on said set of roll dead centres; and
said operative lower support plate carrying a set of roll dead centres configured to receive other ends of said mounted paper rollers.

In at least an embodiment, said roll dead centres and said paper rollers are each four in number on said operative lower support plate and are each four in number on said co-axial operative central plate, in that, at least one roller being a paper roller, at least two rollers being idler intermittent rollers, and at least one rolled being an end roller carrying a gripper to hold said paper.

In at least an embodiment, said proximity sensor is connected on an operative lower side of one of the rollers.

In at least an embodiment, said system is communicably coupled to a controller is programmed in order to convert one or more signals received from said proximity sensor reading to a required output means in terms of meters of paper; these readings are shown on an output display unit.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
The invention will now be described in relation to the accompanying drawings, in which:
FIGURE 1 illustrates various typical examples of paper rolls in common use, today;
FIGURE 2 illustrates a schematic drawing of this first embodiment;
FIGURE 3 illustrates a schematic drawing of this second embodiment;
FIGURE 4 and FIGURE 5 illustrate schematic drawings of this third embodiment.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
According to this invention, there is provided a system for measuring length of paper of a paper roll.

FIGURE 1 illustrates various typical examples of paper rolls in common use, today.

In at least an embodiment, there is a first embodiment, configured, to overcome the aforementioned challenges.

FIGURE 2 illustrates a schematic drawing of this first embodiment.

In at least an embodiment, this first embodiment comprises a main body with an outer cover. This body comprises an angularly displaceable shaft (16) configured to hold a roll of paper (14) about its angular displacing axis. A motor (12) (which may be battery driven) is configured to angularly displace the angularly displaceable shaft and the roll of paper about it. This first embodiment, further, has a first idler roller (18) which is spaced apart from the angularly displaceable shaft (16) and is configured to angularly displace in consonance with angular displacement of roll of paper about angularly displaceable shaft. Furthermore, this first embodiment comprises a driving shaft and a driven roller shaft which are fixed to a hinged plate. A roll of paper needs to be manually wrapped all around the first idler roller onto the driven side and, then, rap it on the driven roller shaft which acts as a grip for the roll of paper and helps to move it easily.

As the motor starts angularly displacing the angularly displaceable shaft, it causes the roll of paper to, also, angularly displace; which, in turn, raps the paper on to the driven side. During this operation a revolution counter measures the number of rotations of roll through a proximity sensor which, in turn, calibrates into a length of paper roll. Reference numeral 18a refers to roll idler.

Reference numeral 11 refers to battery.
Reference numeral 13 refers to controller.
Reference numeral 15a refers to hinged plates.
Reference numeral 15b refers to fixed plate.
Reference numeral 19 refers to dead centres and shaft.

The primary advantage with such an assembly is that it is sturdy and increase life of product.

In at least an embodiment, there is a second embodiment, configured, to overcome the aforementioned challenges.

FIGURE 3 illustrates a schematic drawing of this second embodiment.

In at least an embodiment, this second embodiment comprises a cylindrical bellow shaped assembly. This bellow shaped assembly has an advantage of occupying very low space. Typically, this cylindrical bellow shaped assembly is a corrugated cylindrical bellow shaped assembly (22). This second embodiment comprises a main body (which is the cylindrical bellow shaped assembly). Its casing consists of a lower firm plate (21) which acts as a base and carries three dead centres (22a) to locate the rolls. The casing comprises a top cover (23) which also carries three dead centres (22b). A proximity sensor (25) is connected on the lower firm plate which, in turn, is connected to an output display.

During operation, the paper roll is first mounted in between the two dead centres in a driving roller (27). After mounting paper roll, paper is wrapped from driving roller to driven roller by passing it across an idler roller. Idler roller helps to increase the contact angle of paper with roll thus increasing friction which is necessary for avoiding any slip of paper. As the motor starts, paper roll starts rotating, thereby, causing paper to get rolled on to driven roller from driving roller. During this wrapping the proximity sensor measures the angular displacement of idler roller and, then, calibrates the roller’s angular displacement on length of paper roll. In unloading condition, the casing is totally flat and in loading condition it is expanded to load the roller in it.

In at least an embodiment, there is a third embodiment, configured, to overcome the aforementioned challenges.

FIGURE 4 and FIGURE 5 illustrate schematic drawings of this third embodiment.

In at least an embodiment, this third embodiment comprises a cylindrical casing comprising four rollers, a sensor a controller, and a battery. End locators of this system are adjustable to accommodate various length of roll.

In some embodiments, a main body of this system consists of a cylindrical cover (31).

In at least an embodiment, there is provided an operative lower support plate (32), a co-axial operative central plate (34), and a co-axial operative top cap (36); all ensconced in the cylindrical cover (31). The operative lower support plate (32) carries a set of dead centres (33) and a paper roller (35) which is mounted on the set of dead centres. In a preferred embodiment, the dead centres and the paper rollers are each four in number on the operative lower support plate (32) and similarly on the co-axial operative central plate (34). The cylindrical cover (31) encloses all the components of instrument and the co-axial operative top cap (36) is screwed to isolate this system, completely. The co-axial operative central plate (34) carries a battery, a motor assembly, and controller dashboard is provided on outer periphery of the cylindrical cover (31). In at least an embodiment, the controller, the motor, and the battery are separated from roller assembly to in order to ensure that there should not be any problem with quality of paper.

Reference numeral 31 refers to roll dead centre on an operative lower support plate (32).
Reference numeral 39 refers to driving centre and shaft on the co-axial operative central plate (34).
Reference numeral 41 refers to motor on the co-axial operative central plate (34).
Reference numeral 43 refers to battery on the co-axial operative central plate (34).

In at least an embodiment, the paper roll centres are mounted on the operative lower support plate (32) and the co-axial operative central plate (34), they are four in numbers. Main function of the roll centres is to carry paper rollers and to enable its angular displacement.

In at least a working embodiment of this invention, the operative lower support plate (32), the co-axial operative central plate (34), and the co-axial operative top cap (36); are all disassembled, manually

Then, a paper roll (whose length is to be measured) is put on a first roller and, gently, the paper is tightened over and across two intermittent rollers (idlers) (37a, 37b). Lastly, an end roller (37c), is fixed, which carries a small gripper to hold the paper.

Then, the operative lower support plate (32), the co-axial operative central plate (34), are assembled; thereby, insuring that the other ends of all rollers are engaged with centres in the co-axial operative central plate (34) so that paper rollers are firmly mounted in between the centres. Now, the co-axial operative top cap (36) is assembled to complete the assembly.

In at least an embodiment, a proximity sensor (38) is connected on an operative lower side of one of the rollers. A proximity type of sensor is use for measuring the rotation of idler roller. A Proximity Sensor is a sensor in a position to detect the presence of nearby objects without any physical get in touch with. Proximity sensor is used to measure rotation of roller which in turn calibrated into length of paper in paper roll.

In at least an embodiment, a controller is programmed in order to convert one or more signals received from the proximity sensor in terms of number of revolutions and then is used to multiply it with circumference of idler roller. A stepper kind of pre-programmed controller is used to control the motor and convert the rotation into length

In at least an embodiment, a battery supplies power to a motor which angularly displaces the end roller which, in turn, rotates the first roller. Paper roll is mounted on first roller which starts angularly displacing. Paper gets unwound from the first roller and wounds on the last roller through idler rollers. Thus, while the paper passed through the idler roller, the proximity sensor measures the angular displacement of one of the idler rollers and, then, multiplies it with the circumference of the roller; this, gives as an output, the measurement of in paper length.

A controller is configured to converts signals from the proximity sensor reading to a required output means in terms of meters of paper; these readings are shown on an output display unit.

CALCULATIONS
Let,
T1=Tension in tight side
T2=Tension in slack side
?= Angle of contact …assume 210 degree
Tensile strength of thermal paper=2.5 KN/m
Voltage rating of motor = 3
FIGURE 6A illustrates a schematic arrangement
Current rating of motor = 0.2 amp N= 100 rpm
µ = coefficient of friction for thermal paper is 0.17

Motor Power = v × I
=3 × 0.2
=0.6 watts
P = (T1-T2) × V …(1) T1/T2 = eµ? …(2).

FIGURE 6b illustrates a free body diagram

Now,
pulley 2
?= 2pN/60
=2p×100/60
=10.4 rad/s V= r × ?
= 0.15 × 10.4
=0.157 m/s
T1 =T2 × eµ? …(3) P =( T2 × eµ?-T2) × V
0.6=( T2 × e0.17×210×p/180-T2) × 0.157
T2=4.41 N
From eq…(3)
T1 =4.41× e0.17×210×p/180 T1=10 N

Now, torque required for rotor
T=T1×r
T =10 × 8 ×10-3 ….(8 mm radius of rotor) T=80 N-mm
Torque obtained, P=2pNT/60
0.6= 2p×100×T
T= 57.29 N-mm

Therefore torque given by motor is less than the required torque to roll
So, switch to next standard rated motor.

Now the motor voltage = 6 V
Motor Power = v × I
= 6 × 0.2
= 1.2 watts
And torque gives,

P=2pNT/60

1.2= 2p×100×T
T=114.2 N-mm
Therefore this torque is able to counter the load apply by the weight of roller and friction and force between paper and roll.

The TECHNICAL ADVANCEMENT of this invention lies in providing a new compact, portable, efficient, easy to operate and smart mechanism in respect of an automatic paper roll length measuring machine. This invention reduces effort required to open a roll and measure it by scale and also reduces wastage of rolls as it rewound on another core in the mechanism. Additionally, this system can measure length of a paper roll, accurately

While this detailed description has disclosed certain specific embodiments for illustrative purposes, various modifications will be apparent to those skilled in the art which do not constitute departures from the spirit and scope of the invention as defined in the following claims, and it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.
,CLAIMS:WE CLAIM,

1. A system for measuring length of paper of a paper roll, said system comprising:
- an enclosure with an angularly displaceable shaft (16) configured to hold a roll of paper (14) about its angular displacing axis;
- a motor (12) configured to angularly displace said angularly displaceable shaft and the roll of paper about it;
- a first idler roller (18) spaced apart from said angularly displaceable shaft (16) and being configured to angularly displace in consonance with angular displacement of said roll of paper (14) about said angularly displaceable shaft (16), said roll of paper extending from said angularly displaceable shaft (16) to said first idler roller (18);
- said first idler roller (18) comprising a driving shaft and a driven roller shaft with said roll of paper, received from said angularly displaceable shaft (16), gripped therebetween; and
- a revolution counter configured to measures number of rotations of said first idler roller (18) through a coupled proximity sensor which, in turn, being calibrated into a length of paper roll, used.

2. The system as claimed in claim 1 wherein, said driving shaft and said driven roller shaft being attached to a hinged plate.

3. The system as claimed in claim 1 wherein, said enclosure comprising a cylindrical bellow shaped assembly (22) consisting of:
- a lower firm plate (21) acting as a base and carrying a first set of three dead centres (22a) to locate said rolls;
- a top cover (23) acting as a top and carrying corresponding second set of three dead centres (22b) co-axial to said first set of three dead centres (22a); and
- a proximity sensor (25) connected on said lower firm plate (21) and being connected to an output display;
o said roll of paper being mounted in between said two sets of dead centres (22a, 22b) in a driving roller (27), said roll of paper being wrapped from said driving shaft to driven shaft by passing it across said idler roller.

4. The system as claimed in claim 1 wherein, said enclosure comprising:
- an operative lower support plate (32), a co-axial operative central plate (34), and a co-axial operative support plate (36); all ensconced in a cylindrical cover (31);
- one or more paper rollers;
said operative top support plate (34) carrying a set of roll dead centres (31) and a paper roller (35) mounted on said set of roll dead centres; and
said operative lower support plate (32) carrying a set of roll dead centres (33) configured to receive other ends of said mounted paper rollers (35).

5. The system as claimed in claim 1 wherein, said roll dead centres and said paper rollers are each four in number on said operative lower support plate (32) and are each four in number on said co-axial operative central plate (34), in that, at least one roller (37a) being a paper roller, at least two rollers being idler intermittent rollers (37b, 37c), and at least one rolled being an end roller (37c) carrying a gripper to hold said paper.

6. The system as claimed in claim 1 wherein, said proximity sensor (38) being connected on an operative lower side of one of the rollers.

7. The system as claimed in claim 1 wherein, said system being communicably coupled to a controller is programmed in order to convert one or more signals received from said proximity sensor reading to a required output means in terms of meters of paper; these readings are shown on an output display unit.

Dated this 02nd day of August, 2022

CHIRAG TANNA
of INK IDÉE
APPLICANT’S PATENT AGENT
REGN. NO. IN/PA – 1785