US4257988A — Method and assembly for molding optical lenses

Claim 1

Independent Claim 307 words

A method of molding anoptical lens comprising the steps of: arranging a first generally disc shaped mold part with an outer surface thereof supported by a shelf of a retainer ring, arranging on the inner surface of the first mold part opposite the said surface and near the periphery thereof a pair of adjacent gaskets, one of which is a hard spacer which maintains its shape at elevated temperatures under load, except for elastic deformation, and the other is a soft gasket having the property of softening so as to creep under load at elevated temperatures, and arranging the two gaskets adjacent to each other so that the inside diameter of each forms a part of the cavity, arranging a second generally disc shape mold part with an inner surface thereof against the gasket so as to define an enclosed cavity with the inside diameter of the gasket and the said inner surface of the first mold part, exerting a resilient force to urge the two mold parts toward each other, so as to hold the two mold parts and the gasket together as they form said cavity by a means which is positively located relative to the retainer means to exert the force precisely centered along the axis of the retainer ring, filling said cavity with a liquid capable of being converted into a state in which, upon being heated, it shrinks in volume and becomes hard and insoluble at room temperature, heating the mold assembly with the said liquid filling the said cavity, and wherein the magnitude of the resilient force and the creeping characteristic of the gasket are such that as the liquid shrinks during the heating step, the two mold parts move toward each other to maintain contact with the liquid throughout the said conversion and hardening of the liquid in the cavity.

Claim 2

Independent Claim 307 words

A method of molding anoptical lens comprising the steps of: arranging a first generally disc shaped mold part with an outer surface thereof supported by a shelf of a retainer ring, arranging on the inner surface of the first mold part opposite the said surface and near the periphery thereof a pair of adjacent gaskets, one of which is a hard spacer which maintains its shape at elevated temperatures under load, except for elastic deformation, and the other is a soft gasket having the property of softening so as to creep under load at elevated temperatures, and arranging the two gaskets adjacent to each other so that the inside diameter of each forms a part of the cavity, arranging a second generally disc shape mold part with an inner surface thereof against the gasket so as to define an enclosed cavity with the inside diameter of the gasket and the said inner surface of the first mold part, exerting a resilient force to urge the two mold parts toward each other, so as to hold the two mold parts and the gasket together as they form said cavity by a means which is positively located relative to the retainer means to exert the force precisely centered along the axis of the retainer ring, filling said cavity with a liquid capable of being converted into a state in which, upon being heated, it shrinks in volume and becomes hard and insoluble at room temperature, heating the mold assembly with the said liquid filling the said cavity, and wherein the magnitude of the resilient force and the creeping characteristic of the gasket are such that as the liquid shrinks during the heating step, the two mold parts move toward each other to maintain contact with the liquid throughout the said conversion and hardening of the liquid in the cavity.

Claim 3

Dependent Claim 22 words

The method of claim 1, wherein the said inner surfaces of the first and second mold parts are concave and convex, respectively.

Claim 4

Dependent Claim 19 words

The method of claim 1, wherein the gasket having the property of softening is polyvinyl chloride containing no plasticizers.

Claim 5

Dependent Claim 68 words

The method of claim 1, wherein the retainer ring includes a side wall having a ledge on the inside thereof above the shelf, and said step of arranging the gaskets includes arranging the hard gasket with its lower surface resting on the periphery of said inner surface of the first mold part and also resting on the said ledge, and arranging the soft gasket on the hard gasket.

Claim 6

Dependent Claim 64 words

The method of claim 1, wherein the retainer ring includes a ledge on the inside thereof above the shelf, the inside diameter of the retainer ring being greater above the shelf then below it, and the step of arranging the second mold part on the gasket including locating it asymmetrically on the ledge and hence off center with respect to the first mold part.

Claim 7

Dependent Claim 95 words

The method of claim 1, wherein the step of arranging the first mold part includes positively fixing the retainer ring, with the mold assembly, in a nest, and said step of exerting a resilient force includes applying said force with a clamp arm, the position of which clamp arm is positively determinable with respect to the nest, such that the direction and location of the force exerted by the clamp arm on the mold assembly is positively determined with respect to the retainer ring and hence also with respect to the mold assembly contained therein.

Claim 8

Dependent Claim 116 words

The method of claim 6, wherein the nest includes a raised hollow post and the clamp arm includes a vertical rod part in the raised hollow post with a spring urging it downwardly, and including a horizontal cross-arm connected to the rod part and having a pressure part extending downwardly therefrom to engage the mold assembly, and the step of arranging the retainer ring in the nest including lifting the rod part, cross-arm and pressure part and turning them about the axis of the rod part, placing the retainer ring in the nest, and turning the rod part and lowering it with the cross-arm and pressure part to exert the said force on the mold assembly.

Claim 9

Dependent Claim 46 words

The method of claim 6, wherein the nest includes a circular recess for receiving the retainer ring, with indicia surrounding the recess, and said step of positively positioning the retainer ring includes placing it into the recess and rotating it to a predetermined angular position therein.

Claim 10

Dependent Claim 29 words

The method of claim 8, wherein the step of positively positioning the retainer ring further includes rotating the second mold part angularly with respect to the first mold part.

Claim 11

Dependent Claim 77 words

The method of claim 6, wherein the nest includes a raised hollow post and the clamp arm includes a vertical rod part within the post and a horizontal cross-arm connected to the rod, and a pressure part projecting downwardly toward the retainer ring with the mold assembly therein, and said step of exerting the resilient force includes urging the pressure part downwardly along the central axis of the said retainer ring and against the second mold part.

Claim 12

Dependent Claim 28 words

The method of claim 10, wherein the step of exerting includes applying the downward force with a spring located on the said rod part of the clamp arm.

Claim 13

Dependent Claim 51 words

The method of claim 6, wherein the nest has recess and the retainer ring has a flange on its outer periphery and the step of positively positioning the retainer ring in the nest includes placing the retainer ring in the recess with the flange resting on the edge of the recess.

Claim 14

Dependent Claim 40 words

The method of claim 12, wherein the nest includes angular indicia around the recess, and the step of positively positioning the retainer ring in the recess further includes turning the retainer ring to a proper preselected position in the recess.

Claim 15

Independent Claim 71 words

The method of claims 12, wherein the inner surfaces of the first and second mold parts are concave and convex, respectively, with the outer surface of the first mold part being convex and extending downwardly below the bottom of the retainer ring, said step of positively positioning the retainer ring in the recess thus including permitting the lowermost part of the first mold part to be located down into the recess.

Claim 16

Dependent Claim 263 words

A mold assembly for molding optical lenses comprising: an annular retainer ring having a shelf, a first generally disc shaped mold part poistively positioned on the retainer and supported by such a shelf, a set of a pair of annular resilient gaskets positioned against the inner surface of the first mold part near the periphery thereof, said set being of assentially uniform thickness, one of said gaskets of the set being a hard spacer which maintains its shape at elevated temperatures under load except for elastic deformation, and the other being a soft gasket having the property of softening so as to creep under load at elevated temperatures, a second generally disc shaped mold part positioned with an inner surface against the gasket set so as to define an enclosed cavity with the inside diameter of the gasket set and the inner surface of the first mold part, and resilient means including a spring biased arm for urging the two mold parts toward each other so as to hold the mold parts and the gasket together as they form the said cavity, said resilient means including means for positively locating the spring biased arm, relative to the retainer ring, to apply the resilient force precisely centered on the axis of the retainer ring, whereby when a liquid located in the cavity shrinks and hardens at elevated temperatures, the magnitude of the resilient force and the creeping characteristic of the gasket permit the mold parts to move uniformly toward each other to maintain contact with the liquid as the liquid hardens in the cavity.

Claim 17

Dependent Claim 263 words

A mold assembly for molding optical lenses comprising: an annular retainer ring having a shelf, a first generally disc shaped mold part poistively positioned on the retainer and supported by such a shelf, a set of a pair of annular resilient gaskets positioned against the inner surface of the first mold part near the periphery thereof, said set being of assentially uniform thickness, one of said gaskets of the set being a hard spacer which maintains its shape at elevated temperatures under load except for elastic deformation, and the other being a soft gasket having the property of softening so as to creep under load at elevated temperatures, a second generally disc shaped mold part positioned with an inner surface against the gasket set so as to define an enclosed cavity with the inside diameter of the gasket set and the inner surface of the first mold part, and resilient means including a spring biased arm for urging the two mold parts toward each other so as to hold the mold parts and the gasket together as they form the said cavity, said resilient means including means for positively locating the spring biased arm, relative to the retainer ring, to apply the resilient force precisely centered on the axis of the retainer ring, whereby when a liquid located in the cavity shrinks and hardens at elevated temperatures, the magnitude of the resilient force and the creeping characteristic of the gasket permit the mold parts to move uniformly toward each other to maintain contact with the liquid as the liquid hardens in the cavity.

Claim 18

Dependent Claim 21 words

A mold assembly according to claim 15, wherein the gasket having the property of softening is polyvinyl chloride containing no plasticizers.

Claim 19

Dependent Claim 52 words

A mold assembly according to claim 15, wherein the retainer ring includes a side wall having a ledge on the inside thereof above the shelf, and the hard spacer rests against both the periphery of the first mold part and the said ledge, and the soft gasket lies on the hard gasket.

Claim 20

Dependent Claim 31 words

A mold assembly according to claim 15, said retainer ring having means including said shelf and a side wall for positively positioning the first mold part against movement with respect thereto.

Claim 21

Dependent Claim 24 words

A mold assembly according to claim 18, wherein the said inside surfaces of the first and second mold parts are concave and convex, respectively.

Claim 22

Dependent Claim 101 words

A mold assembly according to claim 15, wherein the first mold part is positively positioned in the retainer ring against either lateral or vertical movement, and including a nest having means for receiving and positively positioning the retainer ring, and said spring biased arm being a clamp arm spring biased downwardly toward the retainer ring and positively positioned with respect to the nest such that the direction and location of the force exerted by the clamp arm on the mold assembly is positively determined with respect to the retainer ring and hence also with respect to the mold assembly contained therein.

Claim 23

Dependent Claim 48 words

A mold assembly according to claim 20, wherein the means in the nest for positively positioning the retainer ring comprises a circular recess with angle indicia located on the edge of the recess, whereby the retainer ring can be rotated within the recess to a desired angular position.

Claim 24

Dependent Claim 92 words

A mold assembly according to claim 20, wherein the nest includes a raised hollow post, a rod part located within the hollow post and rotatable about a vertical axis, a cross-arm connected to the rod part and a pressure part extending from the cross-arm down to the mold assembly, said rod part being rotatable about a vertical axis to move the cross-arm and pressure part laterally to permit positioning of the retainer ring in the nest, and turnable back over the retainer ring and movable downwardly thereonto to exert said resilient force.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1984-03-23	1984-09-22	1985-03-24	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1988-03-23	1988-09-22	1989-03-24	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1992-03-23	1992-09-22	1993-03-24	$7700.00	Window Closed / Lapsed

Method and assembly for molding optical lenses

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag