Title of Invention

A METHOD AND MACHINE FOR THERMOFORMING AND IN–LINE CUTTING OF THERMOFORMED ARTICLES

Abstract

A method for thermoforming and inline cutting of thermoformed articles comprising the steps of [i] drawing a synthetic polymeric sheet from a roll into an indexing station; [ii] indexing the drawn sheet into a forming station having a forming top platen fitted with a male tool, a forming bottom platen fitted with a female die and a motor with a spline, a crankshaft and a connecting rod assembly for driving the forming bottom platen; [iii] forming the articles by driving the forming bottom platen into the first of the two operative positions i.e forming position in which the forming bottom platen reaches the forming top platen, clamping the sheet in between the male tool and the female die; deforming the sheet in the female die by descending the male tool towards and into the cavity of the female die and supplying forming air into the female die to enable forming of articles in the deformed sheet; [iv] displacing the formed article sheet by descending the bottom platen into the second operative position i.e. mould open formed article displacing position; [v] indexing the formed article sheet to a cutting station said cutting station provided with a cutting top platen and a cutting bottom platen, a cutting blade assembly fitted to the cutting top and bottom platens, and a motor with a crankshaft and a connecting rod assembly, for driving the cutting bottom platen; , [iv] cutting the formed articles by driving the cutting bottom platen of the cutting station into a first operative position i.e. cutting position in which the cutting bottom platen travels operatively upwards to reach the cutting top platen, cutting the webs between the formed articles by operating the cutting blade assembly; and [vii] extricating the formed and cut articles by descending the cutting bottom platen for opening the cutting blade assembly.

Full Text

FORM-2 THE PATENTS ACT, 1970 (39 of 1970) COMPLETE Specification (Section 10; rule 13) A METHOD AND MACHINE FOR THERMOFORMING AND IN-LINE CUTTING OF THERMOFORMED ARTICLES WONDERPACK INDUSTRIES PVT. LTD. of Plot No. 12, Bombay Agra Road, Talegaon, Igatpuri, Pin: 422 403, Dist.Nashik, Maharashtra, India, an Indian Company THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED:- This invention relates to a method and machine for thermoforming and in-line cutting of thermoformed articles. In the prior art the usual method of thermoforming is to operate the mould platform with the help of cams. These gives limited production cycles because the machine has to continuously follow the cam surfaces. Pneumatically operated machines are also known but these consume high levels of energy and are also limited in speed. They are also quite expensive. In the prior art cams or heavy-duty power presses are used to trim and cut the finished thermoformed articles. Alternatively, a manual roller cutting system is used. The prior art systems and devices are very cumbersome to use and difficult to synchronize. Further the conventional die punch system is very expensive and time consuming. An object of this invention is to provide an in line cutting mechanism on a thermoforming machine so that the thermoformed article can be trimmed and cut easily inexpensively and fast. The principal feature of the machine of this invention is that a crankshaft and a connecting rod assembly, forming drive mechanism is used for achieving the inline cutting as desired and envisaged in accordance with this invention. According to this invention, there is provided a method for thermoforming and inline cutting of thermoformed articles comprising the steps of [i] drawing a synthetic polymeric sheet from a roll into an indexing station; [ii] indexing the drawn sheet into a forming station having a forming top platen fitted with a male tool, a forming bottom platen fitted with a female die and a motor with a spline, a crankshaft and a connecting rod assembly for driving the forming bottom platen; [iii] forming the articles by driving the forming bottom platen into the first of the two operative positions i.e forming position in which the forming bottom platen reaches the forming top platen, clamping the sheet in between the male tool and the female die; deforming the sheet in the female die by descending the male tool towards and into the cavity of the female die and suppl3dng forming air into the female die to enable forming of articles in the deformed sheet; [iv] displacing the formed article sheet by descending the bottom platen into the second operative position i.e. mould open formed article displacing position; [v] indexing the formed article sheet to a cutting station said cutting station provided with a cutting top platen and a cutting bottom platen, a cutting blade assembly fitted to the cutting top and bottom platens, and a motor with a crankshaft and a connecting rod assembly, for driving the cutting bottom platen; [vi] cutting the formed articles by driving the cutting bottom platen of the cutting station into a first operative position i.e. cutting position in which the cutting bottom platen travels operatively upwards to reach the cutting top platen, cutting the webs between the formed articles by operating the cutting blade assembly; and [vii] extricating the formed and cut articles by descending the cutting bottom platen for opening the cutting blade assembly. According to another aspect of this invention, there is provided a machine for thermoforming and in-line cutting of thermoformed articles consisting of three discreet stations [i] an indexing station adapted to draw a synthetic polymeric sheet from a roll; and [ii] a forming station adapted to receive the sheet for thermoforming from the indexing station, said forming station comprising a forming top platen, fitted with a mail tool, a forming bottom platen fitted with a female die and a motor with a spline, a crankshaft and a connecting rod assembly, for driving the forming bottom platen into two operative positions: a first forming position where the forming bottom platen reaches the forming top platen, and clamping the said sheet in between the male tool and the female die, and the male tool descending towards and into the cavity of female die to deform the sheet in the female die, a means for supplying forming air into the female die for forming the deformed sheet into formed articles, a second mould open, formed article displacing position, in which the forming bottom platen moves downwards for displacing the formed articles sheet; [iii] a cutting station adapted to receive the formed article sheet, for cutting, from the forming station, said cutting station comprising a cutting top platen and a cutting bottom platen, a cutting blade assembly fitted to the said cutting top and bottom platens, and a motor with a crankshaft and connecting rod assembly to drive the cutting bottom platen into two operative positions: a first cutting position where the cutting bottom platen with its cutting blade is urged towards the cutting blade of the cutting top platen, to cut the webs between the formed articles; and a second operative position in which the cutting bottom platen descends to open the cutting blade assembly extricating the formed and cut article. An object of this invention is to provide a thermoforming machine in which the mould platform is connecting rod driven and in which a cutting mechanism is provide in-line. Another object of this invention is to provide a mechanism that is designed to get higher cycle speed in an in-line thermoforming and cutting stations using a connecting rod mechanism which avoids the use of cams and allows the machine to run at a much higher speed of up to 40% more as compared to the prior art cam driven or pneumatically operated machines. The principal feature of the machine of this invention is that a connecting rod mechanism is used for achieving both the thermoforming and in line cutting as desired and envisaged in accordance with this invention. A unique feature of this invention is that the thermoforming and cutting mechanisms is able to achieve desired trim dimensions for male and female thermoformed articles irrespective of the type of material used for thermoforming having varied shrinkages. A particular feature of this invention is the applicability of the device and improvement as envisaged in accordance with this invention for steel rule cutting. In accordance with a preferred embodiment of this invention the cutting mechanism is integral with the thermoforming mechanism and cutting is achieved using cheaper tools. According to another preferred embodiment of this invention the cutting device also further permits stacking of the thermoformed articles after cutting. According to yet another preferred embodiment of this invention the cutting mechanism is robust and provides for economic steel rule cutting. The invention will not be described with reference to the accompanying drawings, which illustrates one preferred embodiment of this invention, in which Figure 1 shows the schematic drawing of the machine in accordance with this invention showing the three-stage machine having an indexing station, a thermoforming station and a cutting station; Figures 2 and 2a show details of the thermoforming station shown in figure 1; Figures 3 and 3 a show details of the in-line cutting station as envisaged in accordance with this invention; Figures 4 and 4a show details of the cutting mechanism in the cutting station shown in Figures 3 and 3 a. Referring to the drawings, a method and a machine of in-line cutting of a plurality of thermoformed articles is illustrated by way of an example of a machine shown in the figures, which in no way limits the scope and extent of the concept disclosed in this invention. As shown in Figure 1 the machine consists of a three discreet stations the indexing station I, the forming station F and the cutting station C. Sheet S for thermoforming is drawn from a roll MALT by the indexing station I and led to the forming station F. The forming station illustrated in Figure 2 and 2a of the drawings consists of a forming top platen FTP having a male tool MT and a forming bottom platen FBP having a female die FD, typically having a plurality of cavities in which the thermoformed article is created by thermoforming. The forming top platen FTB and forming bottom platen FBP together are termed as mould, In the process of thermoforming a heated sheet element is led to the forming station F between the two forming platens FTP and FBP. A motor Ml drives the forming bottom platen FBP via a alpine SU, a crankshaft CS and a connecting rod CR, towards the forming top platen FTP until the two forming platens clamp the sheet in between and achieve a position shown in figure 2 a. In this position the male tool MT is made to descent downwards and stretch the heated film into the cavities of the female tool/die FD so that the film takes the desired shape. Forming air through the aperture FA is then led into the female die FD to enable the articles A to be formed. These thermoformed articles in the forming station F are connected to each other by the remaining of the film which is referred now to the 'web' between the articles and this web is required to be cut away to obtain a discreet thermoformed article. Cutting of this web is achieved in line in the cutting station C more particularly illustrated in Figures 3 and 3 a of the drawings and the method is particularly shown in figures 4 and 4a. The cutting station C has a cutting bottom platen CBP and a cutting top platen CTP with the cutting blade assembly CBA mounted on both cutting platens. This cutting blade assembly may be a knife-edge cutter or a shear cutter or a blunt edge cutter. A motor M2 through a connecting rod and crankshaft assembly CRCS drives the urges the cutting bottom platen CBP up to the cutting top platen CTP for cutting the web between the thermoformed articles A. After cutting, the cutting bottom platen CBP, moves downwards by the stroke of the connecting rod and crankshaft assembly CRCS which opens the cutting blade assembly CBA and discreet thermoformed articles are now obtained as typically seen in figures 4 and 4a, which can be extricated for stacking. The mechanism of connecting rod and crankshaft assembly CRCS make for ease of cutting and opening of the cutting assembly at a relatively low cost and high speed. The motors (Ml & M2) of the forming station and the cutting station may be synchronized for smoother operations and at least one of the motor can be servo controlled. ADVANTAGES : 1. SMOOTH RUNNING AND LESS VIBRATIONS 2. WEAR & TEAR OF CAM USED IN EXISTING MACHINES IS AVOIDED 3. HIGH SPEED IS ACHEIVED VARIABLE CLAMP POSITIONING ALLOWS ADJUSTMENTS FOR DIFFERENT SHEET THICKNESS. It will be appreciated that numerous variations of the basic concept can be envisaged without departing from the basic nature and the scope of the invention. While considerable emphasis has been placed herein on the structures and structural interrelationships between the component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principals of the invention. These and other changes in the preferred embodiment as well as other embodiments of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illusfrative of the invention and not as a limitation. We Claim: 1. A method for thermoforming and inline cutting of thermoformed articles comprising the steps of [i] drawing a synthetic polymeric sheet from a roll into an indexing station; [ii] indexing the drawn sheet into a forming station having a forming top platen fitted with a male tool, a forming bottom platen fitted with a female die and a motor with a spline, a crankshaft and a connecting rod assembly for driving the forming bottom platen; [iii] forming the articles by driving the forming bottom platen into the first of the two operative positions i.e forming position in which the forming bottom platen reaches the forming top platen, clamping the sheet in between the male tool and the female die; deforming the sheet in the female die by descending the male tool towards and into the cavity of the female die and supplying forming air into the female die to enable forming of articles in the deformed sheet; [iv] displacing the formed article sheet by descending the bottom platen into the second operative position i.e. mould open formed article displacing position; [v] indexing the formed article sheet to a cutting station said cutting station provided with a cutting top platen and a cutting bottom platen, a cutting blade assembly fitted to the cutting top and bottom platens, and a motor with a crankshaft and a connecting rod assembly, for driving the cutting bottom platen; , [iv] cutting the formed articles by driving the cutting bottom platen of the cutting station into a first operative position i.e. cutting position in which the cutting bottom platen travels operatively upwards to reach the cutting top platen, cutting the webs between the formed articles by operating the cutting blade assembly; and [vii] extricating the formed and cut articles by descending the cutting bottom platen for opening the cutting blade assembly. 2, A machine for carrying out the method as claimed in Claim 1, consisting of three discreet stations [i] an indexing station adapted to draw a synthetic polymeric sheet from a roll; and [ii] a forming station adapted to receive the sheet for thermoforming from the indexing station, said forming station comprising a forming top platen, fitted with a mail tool, a forming bottom platen fitted with a female die and a motor with a spline, a crankshaft and a connecting rod assembly, for driving the forming bottom platen into two operative positions: a first forming position where the forming bottom platen reaches the forming top platen, and clamping the said sheet in between the male tool and the female die, and the male tool descending towards and into the cavity of female die to deform the sheet in the female die, a means for supplying forming air into the female die for forming the deformed sheet into formed articles, a second mould open, formed article displacing position, in which the forming bottom platen moves downwards for displacing the formed articles sheet; [iii] a cutting station adapted to receive the formed article sheet, for cutting, from the forming station, said cutting station comprising a cutting top platen and a cutting bottom platen, a cutting blade assembly fitted to the said cutting top and bottom platens, and a motor with a crankshaft and connecting rod assembly to drive the cutting bottom platen into two operative positions: a first cutting position where the cutting bottom platen with its cutting blade is urged towards the cutting blade of the cutting top platen, to cut the webs between the formed articles; and a second operative position in which the cutting bottom platen descends to open the cutting blade assembly extricating the formed and cut article. 3. A machine for thermoforming and in-line cutting of thermoformed articles as claimed in claim 2, in which the female die has a plurality of cavities. 4. A machine for thermoforming and in-line cutting of thermoformed articles as claimed in claim 2 or 3, in which the cutting blade is a knife-edge cutter. 5. A machine for thermoforming and in-line cutting of thermoformed articles as claimed in claim 2 or 3, in which the cutting blade is a shear cutter. 6. A machine for thermoforming and in-line cutting of thermoformed articles as claimed in claim 2 or 3, in which the cutting blade is a blunt edge cutter. 7. A machine for thermoforming and in-line cutting of thermoformed articles as claimed in any one of the preceding claims in which at least one of the two motors is servo controlled. 8. A machine for thermoforming and in-line cutting of the thermoformed articles as described herein with reference to the accompanying drawings. 9. A method for thermoforming and in-line cutting of the thermoformed articles as described herein with reference to the accompanying drawings.

Documents:

567-mum-2001-cancelled page(05-08-2004).pdf

567-mum-2001-claim(granted)-(05-08-2004).pdf

567-mum-2001-claims(granted)-(05-08-2004).doc

567-mum-2001-correspondence(05-08-2004).pdf

567-MUM-2001-CORRESPONDENCE(23-9-2011).pdf

567-mum-2001-correspondence(ipo)-(08-12-2006).pdf

567-mum-2001-drawing(26-04-2002).pdf

567-mum-2001-form 1(19-06-2001).pdf

567-mum-2001-form 1(26-04-2002).pdf

567-MUM-2001-FORM 16(24-6-2011).pdf

567-mum-2001-form 2(granted)-(05-08-2004).doc

567-mum-2001-form 2(granted)-(05-08-2004).pdf

567-MUM-2001-FORM 26(23-9-2011).pdf

567-mum-2001-form 3(26-04-2002).pdf

567-mum-2001-form 5(05-08-2004).pdf

567-mum-2001-form 5(26-04-2002).pdf

567-mum-2001-power of attorney(19-06-2001).pdf

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