DESC:FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and rule 13)
Title: SYSTEM AND METHOD FOR DETERMINING CONTOUR OF ARTICLES
APPLICANT DETAILS:
(a) NAME: Asahi India Glass Ltd
(b) NATIONALITY: IN
(c) ADDRESS: 94.4Kms, NH-8, Village-Jaliawas, Tehsil-Bawal, Distt-Rewari, Haryana,
India – 123501.
PREAMBLE TO THE DESCRIPTION:
The following specification particularly describes the nature of this invention and the manner
in which it is to be performed

SYSTEM AND METHOD FOR DETERMINING CONTOUR OF ARTICLES
Field of Invention:
[001] The invention relates generally to a system and method of inspecting the
contour of articles, and more particularly, to a system and method for determining
cross-curvature of a bent glass sheet, e.g. an automotive glass.
Background of the Invention:
[002] The following background discussion includes information that may be useful
in understanding the present invention. It is not an admission that any of the
information provided herein is prior art or relevant to the presently claimed invention,
or that any publication specifically or implicitly referenced is prior art.
[003] In case of automotive laminated glass, cross curvature (CC) is very critical
dimension parameter of the glass. The cross curvature of the glass has to be measured
at multiple points, for example nine different position, as per customer requirement
and these points generally lies at different location for different models.
[004] Glass sheets which are employed for vehicles, e.g. automobiles, must be bent
to precisely defined curvatures or contours in order to ensure proper fit of a given
sheet within a vehicular fixture adapted to receive and retain the sheet. More
particularly, the gap or deviation between the contoured marginal edge periphery of
the sheet and the contoured supporting surface of the vehicular fixture should be
within prescribed tolerances in order to facilitate proper installation of the glass sheet
and to ensure adequate performance of thereafter. Therefore, it is desirable to inspect
the glass sheets in the production facility for quality control purposes, and to provide
process feedback information to detect glass sheets which are without the allowable
tolerances, and therefore unacceptable.
[005] In this regard, it has been common practice to employ a checking fixture
which has a glass sheet supporting surface. In general, a bent glass sheet to be
inspected is placed upon with/without the contoured sheet supporting surface of the
checking fixture and, and cross curvature of the glass sheet is measured with respect
to fixed points taking glass edge as a reference through a measuring tool provided on
device arm. However, in the conventional setup the points are fixed, and the
measuring system will capture same point irrespective of glass size and shape. The
measurement device arm is not parallel to the glass edge and measuring tool is also
not perpendicular to the glass. Further, the conventional setup has only 2 - Degree of
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freedom i.e. up down and tilt in x-direction, which is not capable to measure what an
operator can do as per standard for different shape and size. So there is a difference
between the measured value of equipment and manual measurement. Therefore the
measurement is not accurate and non-reliable.
[006] Robots are known for similar functions but using Robot becomes unviable due
to high temperature of 150~180 deg C at measurement area. Robots would require
very sophisticated cooling arrangement, making the process not efficient.
[007] Some other available systems that measure the actual cross curvature of glass
employ Non-Contact type sensors, for example vision sensors (Camera) for
measurement. However, it is very costly procedure as it captures all points, instead of
specific multiple points, which is not required.
[008] United States Patent publication US4221053A provides an inspection
apparatus for determining the contours of sheet material, particularly glass sheets,
comprising a checking fixture having a plurality of probe assemblies for determining
the exact position of points along the sheet and the deviation, if any, of such measured
points from reference points constituting the ideal contour. The probe assemblies
generate linear signals transmitted to a controller which, in turn, converts such signals
into data displayed on a video screen in selectively different forms.
[009] United States Patent publication US4473953A provides an apparatus for
checking the profile of a sheet and comparing measured data with that data from
measurement of a standard. The apparatus includes a frame, a plurality of studs on the
frame providing three support locations for the sheet, a plurality of reference stops
spaced along two adjacent sides of the frame and structure along opposite sides for
moving a sheet into a centered position at the stops and measuring structure for
measuring the profile of the sheet at a centered position. The sheet may be held at the
centered position to immobilize it during measurement and the apparatus may be
located along a production line including structure for moving a sheet to the frame
and removing the sheet from the frame.
[0010] United States Patent publication US4679331A provides an inspection
apparatus includes a checking fixture having an article supporting surface having a
contour representative of the desired/ideal peripheral marginal edge contour of a
contoured article to be inspected, such as a bent glass sheet, e.g. an automotive lite.
The article is supported by the article supporting surface of the fixture. The apparatus
further includes position-sensing facilities, e.g. a linear potentiometer, and facilitates,
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e.g. a robot, for moving the potentiometer about the periphery of the article to be
inspected, to generate a plurality of signals indicative of the gap between a plurality of
predetermined points around the marginal edge periphery of the article supporting
surface and a corresponding plurality of points around the marginal edge periphery of
the article. The apparatus further preferably includes a computer or the like for
processing the generated signals to provide information about the contour
characteristics of the article, e.g. bend, sag, kink, or the like. Also disclosed herein is a
method for using the apparatus of this invention.
[0011] WIPO Patent publication WO2020120294A1 relates to the field of the
checking of the reliefs of the curved surfaces of materials, particularly curved surfaces
of window glazing designed for means of transport, notably in the automotive
industry. The subjects of the invention are a method and system for measuring the
geometric discrepancies between the curved surfaces of a plurality of materials that
are to be evaluated and a curved surface of a reference material.
[0012] None of the prior arts addresses the problem solution approach highlighted in
the present disclosure.
Objective of the Invention:
[0013] Primary object of the present invention is to overcome the drawback
associated with the prior systems and methods.
[0014] The object of the present invention is to provide a system and method of
inspecting the contour of articles.
[0015] Yet another object of the present invention is to provide a system and method
for determining cross-curvature of a bent glass sheet, e.g. an automotive glass.
[0016] Yet another object of the present invention is to provide a multiple point cross
curvature measurement system and method for measuring cross curvature of glass.
[0017] Yet another object of the present invention is to provide a probe assembly
having a plurality of adjustable measuring probes configured to measure cross
curvature of glass.
[0018] Yet another object of the present invention is to provide a probe assembly
having a plurality of adjustable measuring probes that can be oriented perpendicular
to glass for measuring cross curvature.
[0019] Yet another object of the present invention is to provide a probe assembly
having a measuring gauge unit substantially parallel to the glass.
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[0020] Yet another object of the present invention is to provide a drive assembly for
movement of the measuring gauge unit and the plurality of measuring probes about
multiple degrees of freedoms.
[0021] Yet another object of the present invention is to provide the probes that
include contact type Linear Variable Differential Transformer (LVDT) technology.
Detailed Description of Drawing:
[0022] The foregoing detailed description of preferred embodiments, are better
understood when read in conjunction with the appended drawings. For the purpose of
illustrating the invention, there is shown in the drawings exemplary constructions of
the invention; however, the invention is not limited to the specific methods and
system disclosed. In the drawings:
[0023] Figures 1a-1c illustrates different schematic views of a multiple point cross
curvature measurement system (100) for measuring cross curvature of an object (102)
in accordance with an embodiment of the present disclosure.
[0024] Figure 2 illustrates a schematic view illustrating positioning of the multiple
point cross curvature measurement system (100) with respect to the object in
accordance with an exemplary embodiment of the present disclosure.
Detailed Description of Invention:
[0025] Some embodiments of this invention, illustrating all its features, will now be
discussed in detail.
[0026] The words "comprising," "having," "containing," and "including," and other
forms thereof, are intended to be equivalent in meaning and be open ended in that an
item or items following any one of these words is not meant to be an exhaustive
listing of such item or items, or meant to be limited to only the listed item or items.
[0027] It must also be noted that as used herein and in the appended claims, the
singular forms "a," "an," and "the" include plural references unless the context clearly
dictates otherwise. Although any systems and methods similar or equivalent to those
described herein can be used in the practice or testing of embodiments of the present
invention, the preferred, systems and methods are now described.
[0028] The disclosed embodiments are merely exemplary of the invention, which
may be embodied in various forms.
[0029] The elements illustrated in the Figures inter-operate as explained in more
detail below. Before setting forth the detailed explanation, however, it is noted that all
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of the discussion below, regardless of the particular implementation being described,
is exemplary in nature, rather than limiting.
[0030] The invention relates generally to a system and method of inspecting the
contour of articles, and more particularly, to a system and method for determining
cross-curvature of a bent glass sheet, e.g. an automotive glass.
[0031] In an embodiment, the multiple point cross curvature measurement system
(100) for measuring cross curvature of an object (102), comprises following
components:
o a platform (104) for placing the object (102);
o a probe assembly (106) provided above the platform (104), the probe assembly
(106) and the platform (104) defining a space there between for receiving the
object (102), the probe assembly (106) having:
? a measuring gauge unit (108), and
? a plurality of adjustable measuring probes (110) operatively coupled to
the measuring gauge unit (108), the measuring probes (110) being
configured to measure at least one parameter associated with the object
(102);
? a drive assembly (112) operatively coupled to the measuring gauge
unit (108) and the plurality of measuring probes (110); and
? a computing system (114) communicably coupled to the plurality of
measuring probes (110) for receiving and analysing the least one
parameter associated with the object (102).
[0032] In an embodiment, the measuring gauge unit (108) is substantially parallel to
the object (102).
[0033] In an embodiment, the drive assembly (112) is configured for movement of
the measuring gauge unit (108) and the plurality of measuring probes (110) about
multiple degrees of freedoms.
[0034] In an embodiment, the drive assembly (112) is configured to move each of the
plurality of measuring probes (110) independently, such that the probes (110) are
oriented perpendicular to a surface (102a) of the object (102).
[0035] In an embodiment, the movement of the measuring gauge unit (108) and the
plurality of measuring probes (110) about multiple degree of freedoms includes:
linear movement along x-y-z direction; and
rotational movement about x-y-z direction.
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[0036] In an embodiment, the the drive assembly (112) includes:
? servo motor driven ball screw mechanisms for the linear movement along x-yz
direction; and
? planetary gear box for the rotational movement about x-y-z direction.
[0037] Figures 1a-1c illustrates different schematic views of a multiple point cross
curvature measurement system (100) for measuring cross curvature of an object (102)
in accordance with an embodiment of the present disclosure.
[0038] Figure 2 illustrates a schematic view illustrating positioning of the multiple
point cross curvature measurement system (100) with respect to the object (102) in
accordance with an exemplary embodiment of the present disclosure.
[0039] In an embodiment, the multiple points cross curvature measurement system
(100) is placed at the end of glass bending furnace, where temperature is around
150-180 deg. Celsius, which includes a platform (104) for placing the object (102).
The platform (104) provides a supporting surface to the object (102). In an example,
the object (102) is a glass panel. The supporting surface is conveniently formed from
metal or plaster to the bent contour desired in the object (102) to be inspected. the
supporting surface can/can’t be conforms precisely to the ideal contour desired or the
exact contour intended to be imparted to the object (102) to be inspected.
[0040] In an embodiment the Invention uses Jet coolers of Vortex cooling principle to
overcome the problem of high temperature for temperature affected parts like
servomotors.
[0041] In an embodiment, the multiple point cross curvature measurement system
(100) further includes a probe assembly (106) provided above the platform (104). In
an embodiment, the probe assembly (106) and the platform (104) defines a space
there between for receiving the object (102). In an embodiment, the probe assembly
(106) includes a measuring gauge unit (108), and a plurality of adjustable measuring
probes (110) operatively coupled to the measuring gauge unit (108). In an
embodiment, the measuring gauge unit (108) is substantially parallel to the object
(102). In an embodiment, the measuring probes (110) are configured to measure at
least one parameter associated with the object (102).
[0042] In an embodiment, the probes (110) include contact type Linear Variable
Differential Transformer (LVDT) technology. A linear displacement transducer, e.g. a
linear encoder (not shown) or a linear potentiometer, is securely mounted to the end
of the probes (110) by any suitable means, e.g. by means of an attachment bracket or
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the like. As will hereinafter to be more fully appreciated, any other convenient
position-sensing facilities may be employed in lieu of a linear displacement
transducer, e.g. a fluid-operated position-sensing device; an optical sensor; a pressure
probe; or any other suitable device.
[0043] In an embodiment, the multiple point cross curvature measurement system
(100) further includes a drive assembly (112) operatively coupled to the measuring
gauge unit (108) and the plurality of measuring probes (110). In an embodiment, the
drive assembly (112) is configured for movement of the measuring gauge unit (108)
and the plurality of measuring probes (110) about multiple degrees of freedoms. In an
example, the drive assembly (112) is configured for movement of the measuring
gauge unit (108) and the plurality of measuring probes (110) about six degree of
freedoms.
[0044] In an embodiment, the movement of the measuring gauge unit (108) and the
plurality of measuring probes (110) about multiple degrees of freedoms include linear
movement along x-y-z direction and/or rotational movement about x-y-z direction. In
an embodiment, the drive assembly (112) includes servo motor driven ball screw
mechanisms for the linear movement along x-y-z direction; and planetary gear box for
the rotational movement about x-y-z direction. In an embodiment, the drive assembly
(112) is configured to move each of the plurality of measuring probes (110)
independently, such that the probes (110) are oriented perpendicular to a surface
(102a) of the object (102).
[0045] In an embodiment, the multiple point cross curvature measurement system
(100) further includes a computing system (114) communicably coupled to the
plurality of measuring probes (110) for receiving and analysing the least one
parameter associated with the object (102). The computing system (114) preferably
further includes a microcomputer, or any other convenient signal processing facility,
functionally connected to both the measuring gauge unit (108) and the plurality of
measuring probes (110), e.g. by means of an input/output (I/O) module or any other
convenient means. The microcomputer is preferably interfaced with an interactive
console or terminal and/or a printer. The terminal includes a keyboard functionally
connected to a CRT visual display device or video monitor. However, it should be
appreciated that a programmable controller or the like may be used in place of the
microcomputer, and/or a histogram-type display device and/or strip-chart recorder or
the like may be employed in lieu of the video monitor and the printer.
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[0046] In an embodiment, a multiple point cross curvature measurement method for
measuring cross curvature of the object (102) is explained as follows. The method
includes placing the object (102) in a space defined in-between the platform (104) and
the probe assembly (106). The method further includes orienting, by the drive
assembly (112), the probe assembly (106) relative to the object (102). The method
further includes measuring, by the measuring probes (110), at least one parameter
associated with the object (102). The method further includes receiving and analysing,
by the computing system (114), the least one parameter associated with the object
(102). In an embodiment, the at least one parameter associated with the object (102) is
indicative of the cross curvature, or bend/bent contour, or radii of the object (102).
[0047] In an embodiment, the drive assembly (112) is configured for movement of
the measuring gauge unit (108) and the plurality of measuring probes (110) about
multiple degree of freedoms, and wherein the drive assembly (112) is configured to
move each of the plurality of measuring probes (110) independently, such that the
probes (110) are oriented perpendicular to a surface (102a) of the object (102). The
perpendicular orientation of the probes (110) with respect to the object (102) allows
for a precise, accurate, and error-free measurement of the parameters associated with
cross curvature of the object (102).
[0048] In an embodiment, the multiple point cross curvature measurement method for
measuring cross curvature of an object (102), comprises following steps:
? placing the object (102) in a space defined in-between a platform (104) and a probe
assembly (106) provided above the platform (104), the probe assembly (110) having:
? a measuring gauge unit (108), and
? a plurality of adjustable measuring probes (110) operatively coupled to
the measuring gauge unit (104);
? orienting, by a drive assembly (112), the probe assembly (106) relative to the
object (102);
? measuring, by the measuring probes (110), at least one parameter associated
with the object (102); and
? receiving and analysing, by a computing system (114), the least one parameter
associated with the object (102).
In an embodiment, the drive assembly (112) is configured for movement of the measuring
gauge unit (108) and the plurality of measuring probes (110) about multiple degree of
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freedoms, and wherein the drive assembly (112) is configured to move each of the
plurality of measuring probes (110) independently, such that the probes (110) are oriented
perpendicular to a surface (102a) of the object (102).
[0049] The system and method of the present invention provides that the measuring
Arm/Gauge should be parallel to glass side edge and measuring probe should be
perpendicular to the glass surface while measurement of glass points. The present
invention also uses Linear Variable Differential Transformer (LVDT) to measure the
cross curvature of the glass. The proposed system is also able to capture all the nine
points’ measurement irrespective of size and shape of glass. The present invention
provides 6 Degree of freedom to capture the desire points irrespective of size and
shape which an operator can do. The present invention eliminates the error which
exists between the manual and equipment readings. This error is eliminated by
providing X-Y, rotation and tiling motion in Y-direction to the measuring probes.

CLAIMS:We Claim:
1. A multiple point cross curvature measurement system (100) for measuring cross curvature
of an object (102), the system (100) comprising:
a platform (104) for placing the object (102);
a probe assembly (106) provided above the platform (104), the probe assembly (106)
and the platform (104) defining a space there between for receiving the object (102), the
probe assembly (106) having:
a measuring gauge unit (108), and
a plurality of adjustable measuring probes (110) operatively coupled to the
measuring gauge unit (108), the measuring probes (110) being configured to measure at least
one parameter associated with the object (102);
a drive assembly (112) operatively coupled to the measuring gauge unit (108) and the
plurality of measuring probes (110); and
a computing system (114) communicably coupled to the plurality of measuring probes
(110) for receiving and analysing the least one parameter associated with the object (102).
2. The system as claimed in claim 1, wherein the object (102) is a glass panel.
3. The system as claimed in claim 1, wherein the measuring gauge unit (108) is substantially
parallel to the object (102).
4. The system as claimed in claim 1, wherein the drive assembly (112) is configured for
movement of the measuring gauge unit (108) and the plurality of measuring probes (110)
about multiple degrees of freedoms.
5. The system as claimed in claim 1, wherein the drive assembly (112) is configured to move
each of the plurality of measuring probes (110) independently, such that the probes (110) are
oriented perpendicular to a surface (102a) of the object (102).
6. The system as claimed in claim 1, wherein the movement of the measuring gauge unit
(108) and the plurality of measuring probes (110) about multiple degree of freedoms
includes:
linear movement along x-y-z direction; and
rotational movement about x-y-z direction.
7. The system as claimed in claim 1, wherein the drive assembly (112) includes:
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servo motor driven ball screw mechanisms for the linear movement along x-y-z
direction; and
planetary gear box for the rotational movement about x-y-z direction.
8. The system as claimed in claim 1, wherein the probes (110) includes contact type Linear
Variable Differential Transformer (LVDT) technology.
9. A multiple point cross curvature measurement method for measuring cross curvature of an
object (102), the method comprising:
placing the object (102) in a space defined in-between a platform (104) and a probe
assembly (106) provided above the platform (104), the probe assembly (110) having:
a measuring gauge unit (108), and
a plurality of adjustable measuring probes (110) operatively coupled to the
measuring gauge unit (104);
orienting, by a drive assembly (112), the probe assembly (106) relative to the object
(102);
measuring, by the measuring probes (110), at least one parameter associated with the
object (102); and
receiving and analysing, by a computing system (114), the least one parameter
associated with the object (102).
10. The method as claimed in claim 9, wherein the drive assembly (112) is configured for
movement of the measuring gauge unit (108) and the plurality of measuring probes (110)
about multiple degree of freedoms, and wherein the drive assembly (112) is configured to
move each of the plurality of measuring probes (110) independently, such that the probes
(110) are oriented perpendicular to a surface (102a) of the object (102).