Title of Invention

AN IMPROVED DEVICE FOR PRODUCING DIFFERENT VARIETIED OF DOSA AND A METHOD OF PREPARING THE SAID PRODUCTS USING THE DEVICE

Abstract

An improved device as shown in fig. 2 for producing different varieties of dosa which comprises a machine base (1), a cover plate (2), a hot plate (3) being connected to a motor (4), the burner (21) and pilot burner (22) being installed under the hotplate (3) and capable of being connected to a cooking gas cylinder (28) kept aside the machine base (1), a resistance temperature detector (RTD) (17) being fixed below the hot plate (3) and connected to a programmable logic controller ( PLC) (16)The PLC (16) as shown in fig .3 comprising of a Central Processing Unit CPU (23), one input of the CPU being connected to a memory block (25), second input being connected to a Display cum keyboard unit (24), third input being connected to RTD (17), fourth input being connected to a thickness controlling unit (9), fifth input being connected to the digital I/O unit (26), the digital I/O unit capable of driving the solenoid valve ( SOV ) (18), Motors(4, 6, 8) and pumps (11,13,15) through isolating relay board (27), the PLC(16) maintains the hot plate temperature, Water pump (15) being connected to a water tank (14) for spraying water on the hot plate (3), a scrapper unit (5) provided with a motor (6) being fixed to the machine base (1) for cleaning the hot plate (3) , a proximity sensor (19) being fixed on the side of the scrapper unit capable of cutting off the movement of the motor ( 6) , a spreader assembly (7) being connected to another motor (8) fixed on the side of the hot plate (3) capable of moving around 45 degree from its home position to the center of the hot plate (3), a proximate sensor (20) being fixed on side of the spreader unit (7) capable of cutting off the movement of the motor ( 8 ) , a batter pump (11) being fixed to the machine base(l) for dispensing the required quantity of dosa batter from the batter tank (10) to the hot plate(3), the spreader unit (7) being connected to a thickness control unit (9) connected with a stepper motor driven by the PLC unit (16) to maintain the required thickness of the dosa, an oil pump(13) being connected to an oil tank (12) being fixed on to the machine base(l) capable of spraying oil on the pre cooked dosa and the motors ( 4 ,6,8,9) and pumps(11,13,15) being powered and controlled by the PLC (16)..

Full Text

FORM 2 THE PATENTS ACT 70 (Act 39 of 70) COMPLETE SPECIFICATION (Section 10) AN IMPROVED DEVICE FOR PRODUCING DIFFERENT VARIETIES OF DOSA AND A METHOD OF PREPARING THE SAID PRODUCTS USING THE DEVICE PIDILITE INDUSTRIES LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT 1956 HAVING ITS REGISTERED OFFICE LOCATED AT REGENT CHAMBERS, NARIMAN POINT, MUMBAI - 400021, MAHARASHTRA, INDIA. THE FOLLOWING DESCRIPTION PARTICULARLY DESCRD3ES THE NATURE OF THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED 16-1-2006 GRANTED ORIGINAL Field of Invention The invention relates to an improved device for manufacturing dosa and other allied traditional ethnic Indian food products and a method of manufacturing said products using the device. The device of the present invention is particularly useful for the preparation of traditional ethnic Indian food products such as Dosa, Uttapa, and allied food products, The device of the present invention can more particularly manufacture large quantities of dosa allied food products with different shapes, sizes & thickness under hygienic conditions on continuous basis. The dosa and other allied food products manufactured using the device of the present invention, has standardized uniform tastes, improved product characteristics . In other words, the device of the present invention is useful for manufacture of all types of dosas, and other allied food products using various ingredients with combination of different parameters such as size, thickness, taste, mouth feel and crispiness. Background of Invention Dosa, uttapa & allied products are traditional Indian style pancakes made from ured dal black gram splits) and rice ( plain or pre boiled ) other legumes such as moong dal ( green gram split ) etc. are also used. Rice or dal in requisite proportion is soaked in water and grinded either in a mixer grinder or a stone grinder The grind batter of requisite consistency is allowed to ferment over a period of time and small quantity of a fermented batter is spread on a hot plate to form a circular or oval shaped thin sheet. It is allowed to roast for few minutes to get a soft a crisp dose which is then removed from griddle and eaten with chutney /samba or with different filling. As the above whole operation lacks hygiene & do not follow GMP. In order to provide a hygienically processed dosa untouched by hand, a fully automated device is being developed so as to prepare plain or filled dosa and allied products with requisite size, shape, thickness, color and mouth feel under very hygiene condition and untouched by hand. Prior art: Central Food Technological Research Institute ( CFTRI) , Mysore , a constituent laboratory of CSIR has developed a semi automatic dosa machine shown as shown in Figure 1 of the drawing accompanying this specification . This machine operates by the use of cooking gas for heating, which comprises of a main housing (113) , a hot plate (100) connected to motor (104) and a variable frequency drive (115) The temperature of the hot plate (100) being controlled by a temperature controller installed inside the control panel (112). Initially the pilot burner(101) is ignited manually after opening the cooking gas regulator (114) and based on the temperature sensed by the Resistance Temperature Detector (105) the controller out put opens the SOV (103) and the main burner (102) starts. The dosa thickness is adjusted manually by thickness control unit (109) by rotating thumb wheels mounted above the hotplate(100). The dosa batter is fed from the batter tank (110) through SOV (111) on the hot plate(100) under gravity. The oil is spread on the dosa from the oil tank(107) through SOV (108). The SOV(l 11) and (108) timings are set manfully through the timers kept inside the control panel (112).Water from tank (106) flows continuously on the hot plate (100). The CFTRI device lacks proper hygiene. If a hygienically, untouched by hand and a fully automated device to prepare plain or filled dosa and allied products with requisite size, shape, thickness, color and mouth feel is provided it would be beneficial for their commercial and large scale preparation It is therefore, the main objective of the present invention to provide an improved device to prepare plain or filled dosa and allied products Another objective of the present invention to provide an improved device prepare plain or filled dosa and allied products with requisite size, shape, thickness, color and mouth feel Yet another objective of the present invention to provide an improved device prepare plain or filled dosa and allied products with requisite size, shape, thickness, color and mouth feel in large volumes and having uniform qualities such as consistent tastes and uniform appearance Still another objective of the present invention is to provide an improved device for the manufacture of dosa and other allied food products that can be carried out with Good Manufacturing Practices (GMP) and untouched by hands so that the products manufactured are hygienic to eat. Recognizing the importance of making available such a device for achieving the above objectives, we initiated R&D towards that direction. It should be noted that in this application, the invention is described with reference to dosa but it should not be construed to limit the scope of the invention as the invention can be applied to similar allied food products also. This invention has been developed based on our sustained R&D work and the observations that if a device is fabricated and provided with a control mechanism which will, (i) measure and control the temperature of hot plate (ii) adjust the thickness of dosa (iii) control the dosa batter quantity dispensing and (iv) oil spreading time, the resulting final products will satisfy all the above desired requirements. Accordingly, we have developed an improved device for the production of dosa and other allied food products, the device when used for the manufacture of the said products meets all the above mentioned objectives. The improved device of the present invention is shown in Figure 2 having one hopper for holding batters, common hot plate, scrapper, spreader, oil & water dispensing unit, temperature & thickness control unit. Accordingly, the present invention provides an improved device for producing different varieties of dosa which comprises a machine base (1), a cover plate (2), a hot plate (3) being connected to a motor (4), the burner (21) and pilot burner (22) being installed under the hotplate (3) and capable of being connected to a cooking gas cylinder (28) kept aside the machine base (1), a resistance temperature detector (RTD) ( 17) being fixed below the hot plate (3) and connected to a programmable logic controller ( PLC) (16), the programmable logic controller, PLC (16) as shown in figure 3 comprising of a Central Processing Unit CPU (23), one input of the CPU being connected to a memory block (25), second input being connected to a Display cum keyboard unit (24), third input being connected to RTD (17), fourth input being connected to a thickness controlling unit (9), fifth input being connected to the digital I/O unit (26), the digital I/O unit capable of driving the solenoid valve ( SOV ) (18), Motors(4, 6, 8) and pumps (11,13,15) through isolating relay board (27), the PLC(16) as shown in figure 2 maintains the hot plate temperature, water pump (15) being connected to a water tank (14) for spraying water on the hot plate (3), a scrapper unit (5) provided with a motor (6) being fixed to the machine base (1) for cleaning the hot plate (3), a proximity sensor (19) being fixed on the side of the scrapper unit capable of cutting off the movement of the motor ( 6) , a spreader assembly (7) being connected to another motor (8) fixed on the side of the hot plate (3) capable of moving around 45 degree from its home position to the center of the hot plate (3), a proximate sensor (20) being fixed on side of the spreader unit (7) capable of cutting off the movement of the motor ( 8 ) , a batter pump (11) being fixed to the machine base(l) for dispensing the required quantity of dosa batter from the batter tank (10) to the hot plate(3), the spreader unit (7) being connected to a thickness control unit (9) connected with a stepper motor driven by the PLC unit (16) to maintain the required thickness of the dosa , an oil pump(13) being connected to an oil tank (12) being fixed on to the machine base(l) capable of spraying oil on the pre cooked dosa and the motors ( 4 ,6,8,9) and pumps(l 1,13,15) being powered and controlled by the PLC (16). In a preferred embodiment of the present invention, the machine base (1) may be connected with two or more batter tanks to make different variety of dosas such as Uttapa, Rava,Paper dosa etc. The batter pump(ll) may be provided with a batter volume adjusting system for making different size of dosas. The gap between the hot plate (3) and spreader(7) may be adjusted automatically using PLC (16) to make dosa of required thickness. Masala is added on dosa at the end of drying time automatically for masala dosa. In another preferred embodiment of the present invention the various components used in the fabrication of the device may be as follows : 4. Hot plate (3) : The batter used to make dosa being spread over hot plate(3) which is made of mild steel being connected to a motor (4). After switching on the panel, the hot plate(3) rotates continuously. The heating is effected by LPG which may be replaced by electrical heating. One electric heater can be installed below the hot plate with on off control from the same PLC (16). The burner has two gas connections , one is pilot and other is main. The Hot plate(3) is placed above the burner provided with resistance temperature detector (17) , Solenoid valve (18) & controlled by PLC (16). The pilot flame is ignited manually and can be made atomically by connecting with a ignition transformer in the panel. Hot plate motor Details : Make: Emtech Speed:16RPM Voltage:240V AC,50 HZ 2. Machine Cover (2): Machine Cover (2) is made of SS-316 material and grooved with transparent glasses. The transparency is to view the process of dosa making. It also serves the purpose of keeping the machine clean during operation as well as during idle time. 3. Scrapper (5): The scrapper (5) cleans the hot plate (3) before dispensing of batter on the hot plate & takes out the dosa after being prepared. After spraying of water on the hot plate the scrapper assembly moves on the hot plate all most in touch condition there by takes away any foreign particle deposited on the hot plate surface. The scrapper is rotated by the motor(6),being controlled by PLC(16). The Proximity sensor-cuts off the scrapper motor movement at set position. The preferred specifications of this motor & proximity sensor can be Scraper motor:- Make : Emtech Speed :2RPM Voltage: 12V DC Proximity sensor:- 1 No Make : Omron,5mm ,24Volt DC , 500mA 4. Spreader assembly (7) : Spreader assembly consists of a metallic plate fitted with a Teflon blade. It rests vertically parallel to the Hotplate (3).The spreader rotates to an angle of 45 degree by using the motor (8) and spreader assembly maintains the required gap between the hot plate & Teflon blade equal to thickness of dosa. After dispensing of dosa batter the Teflon blade spreads the batter in a circular shape due to rotation of hot plate(3). The Proximity sensors cutoff the spreader motor movement at set position The preferred specifications of this motor & proximity sensor can be Spreader motor:- Make: Emtec Speed: 2 RPM Voltage:240V AC,50 HZ Proximity sensor:-1 No Make : Omron,5mm ,24Volt DC, 500mA 5. Water dispensing pump (15) The water pump(15) dispenses water over the hot plate(3) at the start up of the machine. It is for cleaning the hot plate. The preferred specification of this pump can be Water Pump : Make : Prabha Voltage: 12 V DC, 1 AMP 6. Batter Dispensing Pump (11) The Batter pump (11) dispenses dosa batter of required quantity on the hot plate(3). The batter quantity can be adjusted by positioning reed switch on the suction cylinder. The preferred specifications of this batter dispensing pump can be Batter pump:- Magnetic Type Speed: 10mm/sec Torque: 1000N Power: 150Watt,230V. Reed switch:- Make: Rotex Voltage: 3-24V DC max. Current: 50 mA 7. Oil dispensing (13) The Oil pump (13) sprays oil over the pre cooked dosa after spreading of batter on hotplate (3). The preferred specifications of this oil dispensing unit can be Oil Pump : Make : Prabha Voltage: 12 V DC, 1 AMP 8. Thickness Adjusting Unit (9) The thickness control motor (9) is a stepper motor which carries the spreader assembly. The spreader assembly has a Teflon blade , held perpendicular to hot plate maintains the gap between the hotplate(3) & the assembly equal to required Dosa thickness. Dosa thickness can be maintained automatically at pre set value using PLC( 16). The preferred specifications of the thickness adjusting unit can be Motor Details : Make : Strategi Motor : 24 Volt, DC. 2 Amp, Stepper. 9. Resistance Temperature Detector, RTD( 17) The RTD (17) senses the hotplate(3) temperature and the PLC display unit indicate it. Based on hot plate temperature setting the PLC controller control the hot plate temperature using solenoid valve, SOV (18). The preferred specifications of this Temperature sensor is follows. Temperature Sensor : PT 100 Calibration : 0 to 300 Deg C . Accuracy :+/- 2 Deg C. lO.Machine Controlling Unit, ( Programmable logic controller, PLC) (16) : The machine utilizes a programmable logic controller , PLC based controlling unit. The PLC is composed of electronic circuits with a micro computer in center. It is regarded as an integrated body of relay, timer, & counters etc. It is operated by the instruction input from push button switch, selector switch provided on panel or sensor input from limit switch, proximity switch etc used to detect the operation condition of the equipment. It serves to control the driving load such as SOV, motor, indication lamps, digital indicator etc. The out put signal against input signal is determined by the content of the program configured in the PLC. The PLC based controlling system is as shown in Fig 3. The PLC (16) controls entire process operation of the machine. The movements of spreader, scrapper assembly, and thickness controlling units are controlled by the PLC for preprogrammed time & distance. The batter, oil & water pump are controlled by PLC to dispense required quintiles of fluids. Using the integrated display unit, the machine hot plate temperature, dosa thickness, motor timings & nos. of dosa required could be pre programmed before starting of the machine. (a) Central processing Unit, CPU (23): It process the instruction data - entered though the key board with preset program & memory unit & delivers the out put to drive the loads. It has 2 KB memory. (b) Display cum Keyboard Interface unit (24) This display unit is the controller-operating panel. It interfaces between the operator and the controller. It has 16 characters LCD Display screen. Display screen shows operator messages, variable information from the program and system information. The keyboard used is a dust and water-resistant with Membrane keypad. The panel comprises a 15 key numeric keypad. The keypad is used to input data into the application, such as Timer values.User interacts with the machine using this keyboard. (c) Memory (25) The system will have 2 types of memory. First will be flash memory to store programmes and data that does not need to be secured. There will be also RAM (random access memory) to store dynamic data that will be needed during programme execution. (d) Digital Input /Out put unit (26) The central processing unit interacts with sprader motor, scrapper motor, hot plate motors, solenoid valves and water, oil and batter pumps through digital I/O. The motors, batter pumps operate from 230 V AC supply where as solenoid valve on 24VDC and oil and water pumps operate on 12VDC. This I/Os are isolated from PLC using relay card. (e) Relays cards (27) Relays are provided for isolation between I/O and the field components like motor & SOV to avoid accidental high voltage short circuit damage to the control system. It should be noted that though the device has been shown having one dosa batter tank (10) in the Fig 2, it should be kept in mind that this is an illustration only and other variations are also envisaged within the scope of the present invention. Also it should be noted that though the device has been shown using cooking gas cylinder (28)for heating of the hot plate in the Fig 2 , it should be kept in mind that this is an illustration only and other system using electrical heating can be envisaged within the scope of the present invention. Also it should be noted that though the device has been shown having PLC based control system(16) in the Fig 3 , it should be kept in mind that this is an illustration only and other variations like use of embedded control system can be envisaged within the scope of the present invention. Description of the operating software of Dosa Machine: - The description of the software for operating of the Dosa Machine is shown by way of the flowchart fig: 4A & 4B. This consists of following components, (A) Security Component, (B) Parameter setting, (C) System Operation. (A) Security Component: The Login "Security Component" of software performs authorization using login numeric Password. The user has to enter a pin code via keypad (Fig. 3, #24). The security component validates the pin code. Upon successful authorization "Parameter Setting" Block ( B) allows the user to choose proper parameter. (B) Parameter setting: This section of software has facility to select process parameter for making dosa in this automatic machine. The user can select the type of dosa of his/her choice using following parameters. • The user has to select number of dosa required. The total number of dosa can be entered using keypad (Fig. 3, #24). • Baking Timer (T1): - This is total time require to bake dosa. Time can be set in "minute" using keypad (Fig. 3, #24). • Dosa Thickness in "mm" resolution is feed in machine via keypad (Fig. 3, #24). Thickness motor adjusts the thickness before dispensing the Batter on Hot Plate. • Oil spraying Timer (T2): - The time duration can be set in "mili second" resolution using keypad (Fig. 3, #24). • Spreader Timer (T3): - The spreader spreads batter on hot plate uniformly. This time duration can be set in "second" resolution using keypad (Fig. 3, #24). • Scraper Timer (T4): - It takes away dosa from the hot plate after set time. This time duration can be set in "second" resolution using keypad (Fig. 3, #24). • Water Spraying Timer (T5): - Before spreading batter on hot-plate, water is spread on hot plate for cleaning. This time duration can be set in "second" resolution using keypad (Fig. 3, #24). • Hot plate Temperature: - Dosa is baked at set temperature. The temperature can be set using keypad (Fig. 3, #24) in 0.1 degree resolution. • After selection of all above parameter, the display queries whether to modify the data or not? If yes, then enter. The PLC will register the new data in system memory & it will proceed to System Operation Block (Fig. B). If no then the system will proceed with previously stored data. If the user wants to modify further parameter, systems links to D (Fig. 4A). During sequential operation PLC (Fig. 1, #16) will fetch data from memory (Fig. 3, #25) & will execute the program. (C) System Operation: The PLC (Fig. 2, #16) scans all input/outputs for actual process parameter interpretation. If the parameter matches with set values then it proceeds with sequential steps. The RTD (Fig. 3, #17) senses the hot plate temperature. Till the temperature display shows below set value, the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to keep gas solenoid (Fig. 2, #18) on. Once require temperature of hot plate (Fig. 2, #3) reaches, the system checks for home position of Spreader (Fig. 2, #7). Then system digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) & start the hot-plate motor (Fig. 2, #4). Then the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start water pump (Fig. 2, #15) to spray water on hot plate for set duration (T5). After completion of spraying time (T5), the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start the scraper motor (Fig. 2, #6), which moves the scraper unit (Fig. 2, #5) forward & reverts back to home position after cleaning the hot plate. Then the digital I/O (Fig. 3, #26) energizes relex board (Fig. 3, #27) to start batter pump (Fig. 2, #11) and batter suction cylinder completely fills with batter. Then the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start spreader motor (Fig. 2, #8), which moves the spreader assembly by 45 deg. angle from its home position above the hot plate. Then the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start thickness control unit (Fig. 2, #9). This adjusts spreader vertical position above the hot plate that subsequently set dosa thickness in "mm". Then the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start batter pump (Fig. 2, #11) to dispense batter on hot plate. Then the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start oil pump (Fig. 2, #13) to spray oil on dosa for set duration (T2). At the end of spreader time (T3), the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start spreader motor (Fig. 2, #8) to lift spreader assembly upward & moves back to its home position. After completion of baking time (Tl), the digital I/O (Fig. 3, #26) energizes relay board (Fig. 3, #27) to start the scraper motor (Fig. 2, #6), which moves scraper on hot plate to pick up ready dosa. The digital display (Fig. 3, #24) indicates number of dosa produced. If less then the set quantity, the system links to step F (Fig. 4 B) for continuing production of remaining number of dosas. If the set numbers of dosa are produced then the system goes to stop mode & hot plate stops rotating. Then system displays process completion indication. Method of Manufacturing As a first step the basic materials such as Rice ,urad dal (black gram splits) required for producing different varieties of dosa are mixed in the requisite proportions, soaked in water , ground in grinder & put in a vessel for fermentation for requisite time. The fermented batter is put inside the batter tank (10) for preparation of dosa . Switch on the machine. The programmable logic controller, PLC (16) will be on. Then set all the process parameters like hotplate temperature, dosa baking time, dosa thickness, nos. of dosa required, oil pump on time, spreader on time, scrapper on time and water pump on time in the PLC (16). Open the machine hot plate cover (2). Open the cooking gas valve to ignite the pilot flame burner (21) manually. If the hot temperature is below the set temperature, the SOV (18) opens and the main flame burner (22) ignites automatically. Then PLC display unit (24) shows the hot plate temperature. Once the hot plate temperature is reached to the set temperature, press the push button to start the sequential operation of the machine. The hotplate (3) starts rotating through motor (4) with the commands from PLC (16), a Water pump (15) connected to a water tank (14) sprays water on the hot plate(3), a scrapper unit(5) used for cleaning of hot plate(3) fitted with motor(6) moves from its home position towards center of the hot plate all most in touch condition there by takes away any foreign particle deposited on the hot plate surface, the proximity sensor (19) fixed on the side of scrapper assembly cuts off the motor ( 6) movement, and scrapper ( 5) returns back to its home position after the set time interval in PLC(16), a spreader assembly (7) fixed on the side of the hot plate ,moves around 45 degree from its home position to the center of the hot plate (3), connected to a motor (8), the proximate sensor (20) fixed on side of spreader assembly (7) cuts off the motor ( 8 ) , a batter pump (11) fixed to machine base(l) dispenses required quantity of dosa batter from batter tank(10) to the hot plate(3) , the spreader (7) spreads the batter in form of a circular thin disk, the thickness of which can be controlled by maintaining the gap (thickness) between the hot plate(3) and the spreader assembly(7) and the dosa diameter can be varied by varying the quantity of the batter addition and above gap (thickness), the spreader assembly (7) being connected to a thickness control unit (9) uses a stepper motor driven by PLC (16) to maintain the required thickness, an oil pump(13) connected to oil tank (12) fixed on machine base(l) sprays oil on pre cooked dosa or on allied products, the spreader assembly(7) moves up and goes back to its home position and the dosa baking time starts, the hot plate rotation stops during dosa backing period as per time set in the PLC(16),after the baking time the hot plate starts rotating and scrapper(5) moves from its home position towards the hot plate(3) to take out the dosa from the hot plate(3) and then goes back to its home position. The motors ( 4 ,6,8,9) and pumps(l 1,13,15) are being powered and controlled by PLC (16). The above process repeats sequentially until the number of dosa entered in the PLC system being prepared. Masala, chutney any other filling is dispensed on dosa before it is rolled in requisite shape and size, removed and served. The following table demonstrates the difference between the locally available semi automatic machine and fully automatic machine developed by us. NOVEL FEATURES CFTRI DESIGNED DOSA M/C (Prior art) M/C DEVELOPED BY Pidilite 1. Control System It is a Semi automatic machine Based on local controller and timers. It is a fully automatic PLC based control system. 2. Cleaning System. No CIP (Clean In Place)system. Needs manual cleaning every time. Efficient CIP(Clean In Place) system. Machine cleans the hot plate automatically after production of individual dosa. 3. Thickness. Manual control. Hence lack of uniformity in thickness of dosa. Automatic control of thickness using stepper motor. Thickness of dosa can be adjusted at 0,1mm steps . Hence very useful to make thin and crispy dosa. 4. Dosa shape. Dosa Shape are irregular. Always round in shape. 5. Capacity. Huge capacity Machine (400 dosa /hour), requires 3 phase electric power supply. Hence can not be used for small establishment. Small capacity machine ( 20 dosa / hr ), requires single phase electric power supply, 1 can be used in both house hold & commercial establishment. 6. Variation in batter dispensing quantity. Dispensed batter quantity always varies due to change of liquid level in batter storage tank. No variation in dispensed batter quantity since it operates by piston pump. 7. Better control of wastage. Always chances of spillage due to gravity feeding as batter tank is housed above the hot plate level. No dropping of batter from feeding nozzle as batter tank is housed below the hot plate level. 8. Variation in Oil dispensing quantity. Quantity varies due to change of oil level head in tank. Oil is dispensed by pump for stipulated time set in the PLC. 9. Better control of baking time. Dosa baking time depends on hot plate speed and temperature. Time is set after hit and trial method. Dosa baking time is pre-programmed in the PLC and easy to change. From the above given comparative description it can be observed very clearly that the device of the present invention is totally different from that known in the prior art. Therefore the devise satisfies the novelty requirement of patent law Advantages of the device of the present invention: • Good quality of different varieties of dosa , such as sada dosa, masala dosa , rava dosa etc with uniform consistency, taste, size, volume and desired appearance can be produced employing the device. • The device facilitates producing different varieties of dosa without physically handling, in a completely mechanized operation and in large quantities under hygienic conditions employing good manufacturing practices • The device and method of using the device to manufacture different varieties of dosa is simple to operate and no trained and / or skilled personnel are required. • The device and the method can be employed for manufacturing variety of dosa on a bulk quantities economically We Claim 1. An improved device as shown in fig. 2 for producing different varieties of dosa which comprises a machine base (1), a cover plate (2), a hot plate (3) being connected to a motor (4), the burner (21) and pilot burner (22) being installed under the hotplate (3) and capable of being connected to a cooking gas cylinder (28) kept aside the machine base (1), a resistance temperature detector (RTD) (17) being fixed below the hot plate (3) and connected to a programmable logic controller ( PLC) (16)The PLC (16) as shown in fig .3 comprising of a Central Processing Unit CPU (23), one input of the CPU being connected to a memory block (25), second input being connected to a Display cum keyboard unit (24), third input being connected to RTD (17), fourth input being connected to a thickness controlling unit (9), fifth input being connected to the digital I/O unit (26), the digital I/O unit capable of driving the solenoid valve ( SOV ) (18), Motors(4, 6, 8) and pumps (11,13,15) through isolating relay board (27), the PLC(16) maintains the hot plate temperature, Water pump (15) being connected to a water tank (14) for spraying water on the hot plate (3), a scrapper unit (5) provided with a motor (6) being fixed to the machine base (1) for cleaning the hot plate (3) , a proximity sensor (19) being fixed on the side of the scrapper unit capable of cutting off the movement of the motor ( 6) , a spreader assembly (7) being connected to another motor (8) fixed on the side of the hot plate (3) capable of moving around 45 degree from its home position to the center of the hot plate (3), a proximate sensor (20) being fixed on side of the spreader unit (7) capable of cutting off the movement of the motor ( 8 ) , a batter pump (11) being fixed to the machine base(l) for dispensing the required quantity of dosa batter from the batter tank (10) to the hot plate(3), the spreader unit (7) being connected to a thickness control unit (9) connected with a stepper motor driven by the PLC unit (16) to maintain the required thickness of the dosa, an oil pump(13) being connected to an oil tank (12) being fixed on to the machine base(l) capable of spraying oil on the pre cooked dosa and the motors ( 4 ,6,8,9) and pumps(11,13,15) being powered and controlled by the PLC (16).. 2. An improved device as claimed in claim 1 wherein a batter tank (10) is provided inside the main base (1) 3. An improved device as claimed in claims 1 & 2 wherein the thickness adjusting stepper motor (9) used is of 24V DC. 4. An improved device as claimed in claims 1 to 3 wherein the motors (4), (6), (8) & (9) are controlled by the PLC( 16). 5. An improved device as claimed in claims 1 to 4 wherein the hot plate (3) and the scrapper (5) and the spreader (7) are made of mild Steel 6. An improved device as claimed in claims 1 to 5 wherein the motors (4), (6), (8) & pump (11) used are of 230 VAC single phase motor and the pumps (13) & (15)used are of 12 VDC motor. 7. An improved device for producing dosa and other traditional ethnic Indian foods products substantially as herein described with reference to the Fig 2 of the drawings accompanying this specification. Dated this day of, 2008 (MADHUKAR BALVANTRAY PAREKH) Managing Director Pidilite Industries Ltd

Documents:

62-mum-2006-abstract.doc

62-mum-2006-abstract.pdf

62-mum-2006-cancelled page(16-1-2006).pdf

62-mum-2006-claim(granted)-(16-1-2006).doc

62-mum-2006-claim(granted)-(16-1-2006).pdf

62-mum-2006-claims.doc

62-mum-2006-claims.pdf

62-mum-2006-correspondence(29-6-2007).pdf

62-mum-2006-correspondence(ipo)-(22-3-2007).pdf

62-mum-2006-description (complete).pdf

62-mum-2006-drawing(16-1-2006).pdf

62-mum-2006-drawings.pdf

62-mum-2006-form 1(16-1-2006).pdf

62-mum-2006-form 18(20-9-2006).pdf

62-mum-2006-form 2(granted)-(16-1-2006).doc

62-mum-2006-form 2(granted)-(16-1-2006).pdf

62-mum-2006-form 9(27-1-2006).pdf

62-mum-2006-form-1.pdf

62-mum-2006-form-18.pdf

62-mum-2006-form-2.doc

62-mum-2006-form-2.pdf

62-mum-2006-form-9.pdf

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