Title of Invention	"AN IMPROVED WRAPPING MACHINE FOR WRAPPING PAPER"
Abstract	This invention relates to an improved wrapping machine for wrapping paper comprising of wrapper unwound from spool over rollers, spring loaded pull rollers to pull wrapper and a rotary knife over stationary knife characterized in that said pull roller is driven by a servomotor and said rotary knife is connected to a servomotor for cutting the wrapper, which is gripped between belts near two edges of wrapper driven by said first servomotor to convey the wrapper to be gripped between two flat vacuum belts driven by individual servomotor wherein the said servomotors are controlled by a programmable logic controller.

Title of Invention

"AN IMPROVED WRAPPING MACHINE FOR WRAPPING PAPER"

Abstract

This invention relates to an improved wrapping machine for wrapping paper comprising of wrapper unwound from spool over rollers, spring loaded pull rollers to pull wrapper and a rotary knife over stationary knife characterized in that said pull roller is driven by a servomotor and said rotary knife is connected to a servomotor for cutting the wrapper, which is gripped between belts near two edges of wrapper driven by said first servomotor to convey the wrapper to be gripped between two flat vacuum belts driven by individual servomotor wherein the said servomotors are controlled by a programmable logic controller.

Full Text	FIELD OF INVENTION This invention relates to an improved wrapping machine for wrapping paper. PRIOR ART In a typical wrapping machine for wrapping ream of cut sheets, wrapper (1 Fig. 1) is drawn from spool (2 Fig. 1) and pulled over rollers (3 Fig. 1) and roller mounted on a dancing lever (4 Fig. 1) that applies brake on the wrapper spool in case tension in the wrapper lessens. Wrapper is pulled by means of a pair of rollers (5 & 6 Fig. 1). Roller (5 Fig. 1) is spring loaded against roller (5 Fig. 1) which is driven through a calculated gear drive to pull length equal to the required cut length of wrapper per cycle of the machine. Wrapper thus pulled moves over the interacting point of rotary knife (7 Fig. 1) and fixed knife (8 Fig. 1). Rotary knife rotates the RPM of the machine, thus cutting one wrapper every cycle of the machine. Since wrapper is pulled by requisitic length it can be positioned in such a way that knife cuts at the required position every time. Any drift in the position is noticed by print mark scanner that gives a signal to the speed correcting mechanism, typically a differential drive unit consisting of star and planet gears which is rotated by a small motor (18 Fig. 1) in the require direction to slightly increment or decrement the output speed of the unit according to the requirement. Detail of this mechanism is two well known to be explained here. Wrapper after being cut by the rotary knife clinges to the under side of belt (9 Fig .1) that has holes at regular intervals that passes over slots in chamber (12 Fig .1) that is connected to a vacuum unit thus conveying suction to the holes in the belt. Cut wrapper sheet held by suction is conveyed forward till it meets the vertically rising ream (13 Fig .1) by means of elevator (14 Fig . 1) to carry the wrapper with it to position (19 Fig .1) for further wrapping operation. This instant of contact between wrapper and ream is so timed as to give symmetrical side folds. This scheme has following disadvantages: 1. Any size change in wrapper requires cumbersome change in drive ratio to get the right cut length. 2. Instant of contact between rising ream and cut wrapper sheet is a sensitive setting and affects the symmetry of side folds. 3. Any difference in the pull action of vacuum belts (5 & 6 Fig .1) top view) causes the wrapper to skew a little causing skewing of folds. In yet another known mechanism of wrapper feeding drive to the pull rollers is from a servo motor. Vacuum belts are also driven by a common shaft taking drive from another servomotor. Feed roller servomotor pulls wrapper equal to the cut length of wrapper and beings it to a stop at the right position and waits for knife to cut. After the cut wrapper sheet is held by suction belts and brought to the station where it meets the rising ream on elevator. At this station cut wrapper sheet stops and waits for ream to rise vertically and take the wrapper alongwith it. This above said prior art has following disadvantages: 1. Wrapper is pulled and stopper every cycle of the machine. Unwinding mechanism of wrapper, therefore, requires a complex taking mechanism so that the spool does not unwind because of inertia and cause slackness in the wrapper. 2. Vacuum belts are driven by a single servo on the common shaft wherein any shift on two sides of wrapper because of slippage during the conveyance by means of vacuum belts on two sides cannot be corrected. OBJECTS OF THE INVENTION The primary object of the present invention is to propose an improved wrapping machine for wrapping ream of cut paper which overcomes the disadvantages of the prior art. Another object of the present invention is to propose an improved wrapping machine for wrapping ream of cut paper which is efficient. STATEMENT OF INVENTION According to this invention there is provided an improved wrapping machine for wrapping paper comprising of wrapper unwound from spool over rollers, spring loaded pull rollers to pull wrapper and a rotary knife over stationary knife characterized in that said pull roller is driven by a servomotor and said rotary knife is connected to a servomotor for cutting the wrapper, which is gripped between belts near two edges of wrapper driven by said first servomotor to convey the wrapper to be gripped between two flat vacuum belts driven by individual servomotor wherein the said servomotors are controlled by a programmable logic controller. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein: Fig. 1 shows front elevation of conventional wrapping machine. Fig. 2 shows top view of the machine shown in fig. 1. Fig. 3 shows front elevation of wrapping machine of the present invention. DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS; This invention provides an improved wrapping machine as indicated in Fig. 3. Wrapper is unwound from spool (1 Fig. 3) over rollers (3 Fig. 3). Action of dancing roller (4. Fig. 3) offers a simple mechanism to vary the braking force on the wrapper spool to maintain a uniform tension in the wrapper. Spring loaded pull roller (5 and 6 Fig .3) pull the wrapper. Drive to pull roller (6 Fig. 3) is provided by a servomotor (7 Fig .3). Wrapper is cut by interaction of rotary knife (9 Fig. 3) over stationery knife (10 Fig. 3). Drive to rotary knife is provided by servo motor (11 Fig. 3). After the cutting station wrapper is gripped between belts (15 8s 16 Fig .3). Drive to these belts is provided from shaft (17 Fig .3) which is driven by servomotor (7 Fig. 3). These belts pairs which are arranged near the two edges of wrapper, convey the cut wrapper sheet to be gripped by suction through series of holes in the middle of flat belts passing over suction chamber (19 Fig. 3). These vacuum belts (18 Fig. 3) and (ISA Fig. 3) are located near right hand edge and left-hand edge of the wrapper as seen from top, respectively. Drive to these vacuum belts is given by servo motors (20 and 21) individually driving respective pulleys (23 85 24) for right and left hand belts. Servo motors (7,11, 20 & 21 Fig. 3) are controlled by a programmable logic controller that receives a signal from shaft encoder mounted on the main drive shaft of the machine and serves as "Master" to the slave servos for timing purposes. PLC is also linked to the Man-Machine- Interface to read the output signals as well as provided means for changing parameters for different size settings. Servo motor (7 Fig. 3) is programmed to give right speed to pull roller (6 Fig .3) to pull right length of wrapper per machine cycle. Any cumulative deviation in pull length is sensed by print mark sensor (25 Fig .3) to slightly increment or decrement the speed according to the deviation with respect to the master encoder time signal. Meanwhile, rotary knife driven by servo motor (11 Fig. 3) is timed to cut at a prefixed encoder time and at a speed equal to or greater than the speed of wrapper fed through the cutting zone by pull rollers, to give cut at the right position. Gripper belt pairs (14 & 15 Fig. 3) convey the wrapper after cut to vacuum belt pairs (18, ISA Fig. 3) which bring it to the right position with respect to the vertically rising ream over which it has to wrap. Photo electric sensors (26 Fig 3) and (27 Fig. 3) are positioned close to the right hand and left hand edge of the wrapper, respectively. Sensor (26 Fig. 3) gives signal to stop right hand drive servo motor (20 Fig 3) and sensor (27 Fig. 3) gives signal to stop left hand drive servo motor (21 Fig. 3) if required. Thus, if there is any skew in the wrapper because of slippage during transfer it gets corrected. Thus motors are programmed to stop the vacuum conveyor belts at the right instant and position to meet the vertically rising ream for symmetrical side folding. In case of missing product, feed rollers and knife stop at the right position to stop wrapper feed for that cycle. In the present invention separate motor is attached to pull roller and rotary knife unlike prior art. Therefore, the roller and knife are not stopped rather their speed is controlled according to the requirement with the help of PLC so as to avoid jerk due to sudden stoppage of wrapper. Further, pull roller, rotary knife and belts run simultaneously. However, if required pull roller and rotary knife can be stopped due to non-availability of ream etc. It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:- I CLAIM: 1. An improved wrapping machine for wrapping paper comprising of wrapper unwound from spool over rollers, spring loaded pull rollers to pull wrapper and a rotary knife over stationary knife characterized in that said pull roller is driven by a servomotor and said rotary knife is connected to a servomotor for cutting the wrapper, which is gripped between belts near two edges of wrapper driven by said first servomotor to convey the wrapper to be gripped between two flat vacuum belts driven by individual servomotor wherein the said servomotors are controlled by a programmable logic controller. 2. An improved wrapping machine as claimed in claim 1 wherein the programmable logic controller receives control signals from detectors for sensing printing mark and position of the front edge of the cut wrapper. 3. An improved wrapping machine as claimed in any one of the preceding claims wherein the PLC receives a signal from shaft encoder mounted on main drive shaft of the machine and serves as master to the servo drives for timing purposes. 4. An improved wrapping machine as claimed in claim 3 wherein the PLC is also linked to a man-machine-interface to read the output signals as well as provide means for changing parameters for different size settings. 5. An improved wrapping machine as claimed in claim 1 wherein each motor for the vacuum belt stops individually when leading edge is sensed by respective photoelectric sensor located close to corners, thus correcting any skew in the wrapper generated during transfer of the wrapper after cutting. 6. An improved wrapping machine as claimed in any of the preceding claims wherein the first servomotor is programmed such as herein described for right speed of pull roller to pull right length of wrapper per machine cycle in which the rotary knife is timed to cut at a prelinked encoder time and at a speed greater than or equal to the speed of wrapper feed through the cutting zone by pull rollers to give cut at the right position. 7. An improved wrapping machine as claimed in any of the preceding claims comprising of atleast two photo electric sensors positioned close to the right hand and left hand edge of the wrapper. 8. An improved wrapping machine for wrapping paper substantially as herein described with reference to the accompanying drawings.

Full Text

FIELD OF INVENTION
This invention relates to an improved wrapping machine for wrapping paper.
PRIOR ART
In a typical wrapping machine for wrapping ream of cut sheets, wrapper (1 Fig. 1) is drawn from spool (2 Fig. 1) and pulled over rollers (3 Fig. 1) and roller mounted on a dancing lever (4 Fig. 1) that applies brake on the wrapper spool in case tension in the wrapper lessens. Wrapper is pulled by means of a pair of rollers (5 & 6 Fig. 1). Roller (5 Fig. 1) is spring loaded against roller (5 Fig. 1) which is driven through a calculated gear drive to pull length equal to the required cut length of wrapper per cycle of the machine. Wrapper thus pulled moves over the interacting point of rotary knife (7 Fig. 1) and fixed knife (8 Fig. 1). Rotary knife rotates the RPM of the machine, thus cutting one wrapper every cycle of the machine. Since wrapper is pulled by requisitic length it can be positioned in such a way that knife cuts at the required position every time. Any drift in the position is noticed by print mark scanner that gives a signal
to the speed correcting mechanism, typically a differential drive unit consisting of star and planet gears which is rotated by a small motor (18 Fig. 1) in the require direction to slightly increment or decrement the output speed of the unit according to the requirement. Detail of this mechanism is two well known to be explained here. Wrapper after being cut by the rotary knife clinges to the under side of belt (9 Fig .1) that has holes at regular intervals that passes over slots in chamber (12 Fig .1) that is connected to a vacuum unit thus conveying suction to the holes in the belt. Cut wrapper sheet held by suction is conveyed forward till it meets the vertically rising ream (13 Fig .1) by means of elevator (14 Fig . 1) to carry the wrapper with it to position (19 Fig .1) for further wrapping operation. This instant of contact between wrapper and ream is so timed as to give symmetrical side folds.
This scheme has following disadvantages:
1. Any size change in wrapper requires cumbersome change in drive ratio to get the right cut length.
2. Instant of contact between rising ream and cut wrapper sheet is
a sensitive setting and affects the symmetry of side folds.
3. Any difference in the pull action of vacuum belts (5 & 6 Fig .1)
top view) causes the wrapper to skew a little causing skewing of
folds.
In yet another known mechanism of wrapper feeding drive to the pull rollers is from a servo motor. Vacuum belts are also driven by a common shaft taking drive from another servomotor. Feed roller servomotor pulls wrapper equal to the cut length of wrapper and beings it to a stop at the right position and waits for knife to cut.
After the cut wrapper sheet is held by suction belts and brought to the station where it meets the rising ream on elevator. At this station cut wrapper sheet stops and waits for ream to rise vertically and take the wrapper alongwith it.
This above said prior art has following disadvantages:
1. Wrapper is pulled and stopper every cycle of the machine.
Unwinding mechanism of wrapper, therefore, requires a
complex taking mechanism so that the spool does not unwind
because of inertia and cause slackness in the wrapper.
2. Vacuum belts are driven by a single servo on the common shaft
wherein any shift on two sides of wrapper because of slippage
during the conveyance by means of vacuum belts on two sides
cannot be corrected.
OBJECTS OF THE INVENTION
The primary object of the present invention is to propose an improved wrapping machine for wrapping ream of cut paper which overcomes the disadvantages of the prior art.
Another object of the present invention is to propose an improved wrapping machine for wrapping ream of cut paper which is efficient.
STATEMENT OF INVENTION
According to this invention there is provided an improved wrapping machine for wrapping paper comprising of wrapper unwound from spool over rollers, spring loaded pull rollers to pull wrapper and a rotary knife over stationary knife characterized in that said pull roller is driven by a servomotor and said rotary knife is connected to a servomotor for cutting the wrapper, which is gripped between belts near two edges of wrapper driven by said first servomotor to convey the wrapper to be gripped between two flat vacuum belts driven by individual servomotor wherein the said servomotors are controlled by a programmable logic controller.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with the accompanying drawings and wherein:
Fig. 1 shows front elevation of conventional wrapping machine.
Fig. 2 shows top view of the machine shown in fig. 1.
Fig. 3 shows front elevation of wrapping machine of the present
invention.
DETAIL DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS;
This invention provides an improved wrapping machine as indicated in Fig. 3. Wrapper is unwound from spool (1 Fig. 3) over rollers (3 Fig. 3). Action of dancing roller (4. Fig. 3) offers a simple mechanism to vary the braking force on the wrapper spool to maintain a uniform tension in the wrapper. Spring loaded pull roller (5 and 6 Fig .3) pull the wrapper. Drive to pull roller (6 Fig. 3) is provided by a servomotor (7 Fig .3). Wrapper is cut by interaction of rotary knife (9 Fig. 3) over stationery knife (10 Fig. 3). Drive to rotary knife is provided by servo motor (11 Fig. 3). After the cutting station wrapper is gripped between belts (15 8s 16 Fig .3).
Drive to these belts is provided from shaft (17 Fig .3) which is driven by servomotor (7 Fig. 3). These belts pairs which are arranged near the two edges of wrapper, convey the cut wrapper sheet to be gripped by suction through series of holes in the middle of flat belts passing over suction chamber (19 Fig. 3).
These vacuum belts (18 Fig. 3) and (ISA Fig. 3) are located near right hand edge and left-hand edge of the wrapper as seen from top, respectively.
Drive to these vacuum belts is given by servo motors (20 and 21) individually driving respective pulleys (23 85 24) for right and left hand belts.
Servo motors (7,11, 20 & 21 Fig. 3) are controlled by a programmable logic controller that receives a signal from shaft encoder mounted on the main drive shaft of the machine and serves as "Master" to the slave servos for timing purposes. PLC is also linked to the Man-Machine-
Interface to read the output signals as well as provided means for changing parameters for different size settings.
Servo motor (7 Fig. 3) is programmed to give right speed to pull roller (6 Fig .3) to pull right length of wrapper per machine cycle. Any cumulative deviation in pull length is sensed by print mark sensor (25 Fig .3) to slightly increment or decrement the speed according to the deviation with respect to the master encoder time signal. Meanwhile, rotary knife driven by servo motor (11 Fig. 3) is timed to cut at a prefixed encoder time and at a speed equal to or greater than the speed of wrapper fed through the cutting zone by pull rollers, to give cut at the right position. Gripper belt pairs (14 & 15 Fig. 3) convey the wrapper after cut to vacuum belt pairs (18, ISA Fig. 3) which bring it to the right position with respect to the vertically rising ream over which it has to wrap. Photo electric sensors (26 Fig 3) and (27 Fig. 3) are positioned close to the right hand and left hand edge of the wrapper, respectively. Sensor (26 Fig. 3) gives signal to stop right hand drive servo motor (20 Fig 3) and sensor (27 Fig. 3) gives signal to stop left hand drive servo motor (21 Fig. 3) if required. Thus, if there is any skew in the wrapper because of slippage during transfer it gets corrected. Thus motors are programmed to stop the vacuum
conveyor belts at the right instant and position to meet the vertically rising ream for symmetrical side folding.
In case of missing product, feed rollers and knife stop at the right position to stop wrapper feed for that cycle.
In the present invention separate motor is attached to pull roller and rotary knife unlike prior art. Therefore, the roller and knife are not stopped rather their speed is controlled according to the requirement with the help of PLC so as to avoid jerk due to sudden stoppage of wrapper. Further, pull roller, rotary knife and belts run simultaneously. However, if required pull roller and rotary knife can be stopped due to non-availability of ream etc.
It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

I CLAIM:
1. An improved wrapping machine for wrapping paper comprising
of wrapper unwound from spool over rollers, spring loaded pull
rollers to pull wrapper and a rotary knife over stationary knife
characterized in that said pull roller is driven by a servomotor
and said rotary knife is connected to a servomotor for cutting
the wrapper, which is gripped between belts near two edges of
wrapper driven by said first servomotor to convey the wrapper
to be gripped between two flat vacuum belts driven by
individual servomotor wherein the said servomotors are
controlled by a programmable logic controller.
2. An improved wrapping machine as claimed in claim 1 wherein
the programmable logic controller receives control signals from
detectors for sensing printing mark and position of the front
edge of the cut wrapper.
3. An improved wrapping machine as claimed in any one of the
preceding claims wherein the PLC receives a signal from shaft
encoder mounted on main drive shaft of the machine and serves as master to the servo drives for timing purposes.
4. An improved wrapping machine as claimed in claim 3 wherein
the PLC is also linked to a man-machine-interface to read the
output signals as well as provide means for changing
parameters for different size settings.
5. An improved wrapping machine as claimed in claim 1 wherein
each motor for the vacuum belt stops individually when leading
edge is sensed by respective photoelectric sensor located close
to corners, thus correcting any skew in the wrapper generated
during transfer of the wrapper after cutting.
6. An improved wrapping machine as claimed in any of the
preceding claims wherein the first servomotor is programmed
such as herein described for right speed of pull roller to pull
right length of wrapper per machine cycle in which the rotary
knife is timed to cut at a prelinked encoder time and at a speed greater than or equal to the speed of wrapper feed through the cutting zone by pull rollers to give cut at the right position.
7. An improved wrapping machine as claimed in any of the
preceding claims comprising of atleast two photo electric
sensors positioned close to the right hand and left hand edge of
the wrapper.
8. An improved wrapping machine for wrapping paper
substantially as herein described with reference to the
accompanying drawings.

Documents:

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Patent Number

278392

Indian Patent Application Number

1345/DEL/2007

PG Journal Number

53/2016

Publication Date

23-Dec-2016

Grant Date

21-Dec-2016

Date of Filing

22-Jun-2007

Name of Patentee

RAJESH KHOSLA

Applicant Address

644, SECTOR-16-D, CHANDIGARH,INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAJESH KHOSLA	644, SECTOR-16-D, CHANDIGARH,INDIA.

PCT International Classification Number

B65B11/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA