Abrading – Precision device or process - or with condition responsive... – Computer controlled
Reexamination Certificate
1998-03-11
2001-06-05
Butler, Rodney A. (Department: 3725)
Abrading
Precision device or process - or with condition responsive...
Computer controlled
Reexamination Certificate
active
06241577
ABSTRACT:
BACKGROUND OF THE INVENTION
This invention relates to a lens grinding apparatus and lens grinding method for grinding a lens to conform it to the shape of an eyeglass frame, as well as components in connection with the apparatus and the method.
In a lens grinding apparatus for grinding an eyeglass lens to conform it to the shape of an eyeglass frame, a lens is worked on as it is chucked between two lens rotating shafts. To chuck the lens, a fixing (securing) cup is first set on the front surface of the lens in the desired position determined with a centering device. The base of the fixing (securing) cup is fitted in a cup receptacle mounted on one of the two lens rotating shafts and the lens is chucked with its rear surface being held in position with a lens retainer mounted on the other lens rotating shaft.
The lens being ground is under the stress of the reaction and rotating forces provided by the lens grinding wheel. If the chucking force is smaller than the stress, the axial misalignment of the lens may occur. To avoid this problem and secure the necessary chucking force, a lens having a sufficient diameter to work on is ground using a circular fixing (securing) cup with a large diameter across the mounting surface and a circular lens retainer also having a large diameter.
However, if a lens for “granny's glasses” which has a small distance between the upper and lower edges is processed using a fixing (securing) cup, a cup receptacle and a lens retainer which are of the same sizes as in the case of processing lenses having a sufficient diameter to work on, these components will interfere with the lens grinding wheel. To avoid this problem, they must be replaced by components of smaller diameters which are specially intended for use in the processing of lenses for “granny's glasses”.
However, replacing the cup receptacle and the lens retainer according to the lens diameter to be worked on is not only more time-consuming than one will usually expect but also cumbersome. Frequent replacing operations will reduce the efficiency of the lens processing operation at a processing center where a large number of lenses are collectively worked at the request of optician's shops.
SUMMARY OF THE INVENTION
The present invention has been accomplished under these circumstances and has as an object providing a lens grinding apparatus which is capable of processing different types of lens efficiently without the need for replacing the cup receptacle and the lens retainer and yet with a reduced possibility of misalignment in the axis of the lens during processing.
The present invention provides the followings:
(1) A lens grinding apparatus for grinding an eyeglass lens to conform it to the shape of an eyeglass frame, said lens grinding apparatus comprising:
a first lens rotating shaft having mounted thereon a cup receptacle member that is so shaped as to enable the processing of a lens for “granny's glasses” and to which a lens fixing cup is to be fitted;
a second lens rotating shaft having mounted thereon a lens retaining member that is so shaped as to enable the processing of the lens for “granny's glasses”;
rotating means for rotating said first and second rotating shafts independently of each other; and
adjusting means for adjusting the angle of rotation of said second rotating shaft such that when the lens to be processed is an ordinary lens having a large diameter to work on and an astigmatic component, a direction of said second lens rotating shaft which is perpendicular to a direction of the long side of said lens retaining member generally coincides with the astigmatic axis of said lens to be processed.
(2) The lens grinding apparatus according to (1), wherein said cup receptacle member has a means for fitting said lens fixing cup such that the astigmatic axis of said lens to be processed is positioned to satisfy a specified relationship.
(3) The lens grinding apparatus according to (1), wherein said lens retainer member is prolate in shape having two parallel edges and two arcs each having a center on the rotation axis.
(4) The lens grinding apparatus according to (1), wherein said adjusting means includes:
input means for entering the direction of the astigmatic axis of the lens to be processed; and
control means for controlling said rotating means such that the angle of rotation of said second lens rotating shaft is rotated relative to said first lens rotating shaft based on the entered direction of astigmatic axis.
(5) The lens grinding apparatus according to (1), further comprising:
processing mode selecting means for selecting between a mode for processing a lens for “granny's glasses” and a mode for processing an ordinary lens having a large diameter to work on, and
control means which, when the mode for processing the lens for “granny's glasses” is selected, controls the rotation of said rotating means such that the direction of the long side of said lens retaining member generally coincides with that of the cup for fixing the lens for “granny's glasses”.
(6) A lens grinding apparatus for grinding an eyeglass lens to conform it to the shape of an eyeglass frame, said apparatus comprising:
a first lens rotating shaft for mounting a cup receptacle member to which a lens fixing cup is to be fitted;
a second lens rotating shaft for mounting a lens retaining member; and
rotating means for rotating said first and second lens rotating shafts independently of each other.
(7) A lens grinding method for grinding an eyeglass lens to conform it to the shape of an eyeglass frame, said method comprising the steps of:
mounting a lens fixing cup fixed to the lens to be processed on a cup receptacle member, the cup receptacle member being so shaped as to enable the processing of a lens for “granny's glasses” and mounted on a first lens rotating shaft for holding the lens to be processed; and
adjusting the angle of rotation of a second lens rotating shaft, which is for holding the lens in combination with the first lens rotating shaft, such that a direction perpendicular to a direction of the long side of a lens retaining member mounted on said second lens rotating shaft generally coincides with the direction of the astigmatic axis of said lens to be processed if the lens to be processed is an ordinary lens having a large diameter and has an astigmatic component.
(8) A lens fixing cup for use in a lens grinding apparatus, which is formed of a rigid material.
(9) A cup receptacle member for use in a lens grinding apparatus, which is so shaped as to enable the processing of a lens for “granny's glasses” and has a means for fitting a lens fixing cup that is fixed to satisfy a specified relationship with a lens to be processed such that the astigmatic axis of said lens to be processed is positioned to satisfy a specified relationship.
(10) A lens chucking part for use with an eyeglass lens grinding apparatus having first and second shafts rotatable about an axis, and relatively movable toward and away from each other for chucking a lens to be processed, said lens chucking part comprising:
a lens retainer mounted on an end of said first shaft, said lens retainer having an oblong shape in section as viewed in a plane perpendicular to said axis;
a cup holder mounted on an end of said second shaft facing said end of said first shaft, said cup holder having an oblong shape in section as viewed in a plane perpendicular to said axis;
a fixing cup adapted to be fixedly mounted on the lens to be processed and received by said cup holder.
(11) A lens chuck part according to (10), wherein said fixing cup has a cylindrical base received by said cup holder and a substantially conical cup portion to be mounted on the lens, and wherein an outermost perimeter of said cup portion about said axis is oblong.
(12) A lens chuck part according to (10), wherein said oblong shape of said lens retainer is substantially coincident with said oblong shape of said cup holder.
(13) A lens chuck part according to (11), wherein said oblong outermost perimeter of said fixing cu
Butler Rodney A.
Nidek Co. Ltd.
Sughrue Mion Zinn Macpeak & Seas, PLLC
LandOfFree
Lens grinding apparatus and lens grinding method and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Lens grinding apparatus and lens grinding method and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lens grinding apparatus and lens grinding method and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2510184