US4589231A — Apparatus and process for dry cutting of plastic …

Claim 1

Independent Claim 353 words

A lens generating apparatus for generating lenses made from plastic in a dry operation without the use of a liquid coolant including a base, a lens blank holder having a plastic lens blank to be generated thereon and being extensible and retractible relative to the base, and for shifting the same in an extensible and retractible direction relative to the base, a revolvable tool holder being revolvable and laterally oscillatable relative to the base, means for revolving the tool holder, and means for laterally oscillating the tool holder relative to the base, a multiple grit-plated diamond tool mounted on said tool holder for rotation therewith and engaging the lens blank during the lens generating operation to remove material from the blank, a chamber structure, including a top wall, a bottom wall, a vertical peripheral wall, a pair of openings in the peripheral wall of the chamber structure, the tool holder and grit-plated diamond tool projecting through one of the openings in the peripheral wall and the lens blank holder projecting through the other opening in the peripheral wall during lens generation, said other opening having a cross-sectional area substantially larger than the cross-sectional area of the lens blank holder so that a relatively large unobstructed zone around the lens blank holder is defined by said other opening, said chamber structure having an opening in the top wall thereof located above the tool and lens blank when the tool and blank are disposed in engaging relation with each other, an elongate vacuum conduit having one end thereof connected to the opening in the top wall of the chamber structure in communicating relation with the interior of the latter adjacent the other opening in the peripheral wall thereof, and having its other end connected to a power driven vacuum fan device so that operation of the vacuum fan device during the lens generating operation produces high volume, high velocity ambient air flow through the other opening in the peripheral wall and the cut swarf material produced in the lens grinding operation will be entrained in the stream of air and evacuated through the vacuum conduit.

Claim 2

Dependent Claim 353 words

A lens generating apparatus for generating lenses made from plastic in a dry operation without the use of a liquid coolant including a base, a lens blank holder having a plastic lens blank to be generated thereon and being extensible and retractible relative to the base, and for shifting the same in an extensible and retractible direction relative to the base, a revolvable tool holder being revolvable and laterally oscillatable relative to the base, means for revolving the tool holder, and means for laterally oscillating the tool holder relative to the base, a multiple grit-plated diamond tool mounted on said tool holder for rotation therewith and engaging the lens blank during the lens generating operation to remove material from the blank, a chamber structure, including a top wall, a bottom wall, a vertical peripheral wall, a pair of openings in the peripheral wall of the chamber structure, the tool holder and grit-plated diamond tool projecting through one of the openings in the peripheral wall and the lens blank holder projecting through the other opening in the peripheral wall during lens generation, said other opening having a cross-sectional area substantially larger than the cross-sectional area of the lens blank holder so that a relatively large unobstructed zone around the lens blank holder is defined by said other opening, said chamber structure having an opening in the top wall thereof located above the tool and lens blank when the tool and blank are disposed in engaging relation with each other, an elongate vacuum conduit having one end thereof connected to the opening in the top wall of the chamber structure in communicating relation with the interior of the latter adjacent the other opening in the peripheral wall thereof, and having its other end connected to a power driven vacuum fan device so that operation of the vacuum fan device during the lens generating operation produces high volume, high velocity ambient air flow through the other opening in the peripheral wall and the cut swarf material produced in the lens grinding operation will be entrained in the stream of air and evacuated through the vacuum conduit.

Claim 3

Dependent Claim 103 words

The apparatus as defined in claim 1 wherein the grit-plated diamond tool is of cup-shaped configuration including a cylindrical portion having a shank projecting therefrom, said cylindrical portion having an outer cylindrical surface and an inner cylindrical surface, and an arcuate end surface extending between the inner and outer cylindrical surfaces, a diamond grit-plating including a plurality of spaced apart diamond elements covering said inner cylindrical surface, said outer cylindrical surface, and said arcuate end surface, the spacing between the diamond elements on the arcuate end surface being denser than the spacing of the diamond element on said inner and outer cylindrical surfaces.

Claim 4

Dependent Claim 31 words

The apparatus as defined in claim 2 wherein the inner and outer cylindrical surfaces are covered with a 20 grit-plating and said arcuate end surface is covered with a 30 grit-plating.

Claim 5

Dependent Claim 42 words

The apparatus as defined in claim 1 and a misting nozzle positioned in said chamber structure and being connected to mist generating means for producing a mist at the interface between the lens blank and grinding tool during the lens generating operation.

Claim 6

Dependent Claim 176 words

A lens generating process for generating plastic lenses in a dry operation without the sue of liquid coolant, the lens to be ground being mounted on a horizontal lens holder, consisting in the steps of: positioning the lens blank in a chamber and while engaging one surface thereof with a revolvable multiple grit-plated diamond medium, the diamond grinding medium being comprised of a plurality of diamond particles having a spacing between each diamond particle so that a sharp single point stock removal occurs during the lens grinding operation to thereby minimize the occurrence of heat buildup during the grinding and cutting operation, introducing a high volume, high velocity flow of air into the chamber and simultaneously evacuating the air through a vacuum conduit to form a high volume, high velocity stream of air across the interface between the lens blank and the grinding medium to entrain the cut plastic awarf in the stream of air to thereby continuously cool the lens blank and grinding medium and continuously remove the cut plastic swarf material from the chamber.

Claim 7

Dependent Claim 176 words

A lens generating process for generating plastic lenses in a dry operation without the sue of liquid coolant, the lens to be ground being mounted on a horizontal lens holder, consisting in the steps of: positioning the lens blank in a chamber and while engaging one surface thereof with a revolvable multiple grit-plated diamond medium, the diamond grinding medium being comprised of a plurality of diamond particles having a spacing between each diamond particle so that a sharp single point stock removal occurs during the lens grinding operation to thereby minimize the occurrence of heat buildup during the grinding and cutting operation, introducing a high volume, high velocity flow of air into the chamber and simultaneously evacuating the air through a vacuum conduit to form a high volume, high velocity stream of air across the interface between the lens blank and the grinding medium to entrain the cut plastic awarf in the stream of air to thereby continuously cool the lens blank and grinding medium and continuously remove the cut plastic swarf material from the chamber.

Claim 8

Dependent Claim 26 words

The process as defined in claim 5 and introducing a fine lubricant mist into the chamber across the interface between the lens blank and grinding medium.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-05-19	1989-11-18	1990-05-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-05-19	1993-11-18	1994-05-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-05-19	1997-11-18	1998-05-20	$7700.00	Window Closed / Lapsed

Apparatus and process for dry cutting of plastic optical lenses

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