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US5005633A Expired / Lapsed US ⏱️ 0.0 years remaining

Lens blocking apparatus

Assignee: Pilkington Visioncare Inc
•
Filing: 1989-12-08
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Granted: 1991-04-09
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Expires: 2009-12-08
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Abstract

Abstract A blocking mechanism comprises a similified rotary dial mechanism and a l clamp which automatically depressurizes a molten alloy tank in response to a release of the lens clamp pressure. A lens seat is provided with a raised resilient pad to accommodate the recessed portion of a bifocal lens. The application of final lens clamping pressure cannot occur until the lens clamp contacts the lens in order to assure that an operator's finger cannot become accidentally pinched.

Inventors

  • 👤 Herbert H. Mathews
  • 👤 Joseph L. Welch

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 06:27
CPC Classifications
B; B23; B23Q; B23Q3/00; B23Q3/02; B23Q3/06; B23Q3/08; B23Q1/00; B23Q1/25; B23Q1/44; B23Q1/50; B23Q1/54; Y; Y10; Y10S; Y10S425/00; Y10S425/808

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 215 words
A lens blocking apparatus comprising: a base including means for removably receiving a block insert, an axis ring mounted on said base for rotation about a first axis, said axis ring having a graduated axis scale, a lower prism ring mounted on said base for rotation about said first axis and including a support surface defining a second axis inclined by a first acute angle relative to said first axis, said lower prism ring having a first prism scale graduated exponentially from zero to six diopters over a ninety degree region of said lower prism ring, an upper prism ring mounted on said support surface of said lower prism ring for rotation about said second axis, said upper prism ring carrying a lens seat defining a third axis inclined by a second angle relative to said first axis, said second angle being equal to two times said first angle, said upper prism ring including a second prism scale graduated exponentially from zero to nine diopters over a one hundred eighty degree region of said upper prism ring, said lens seat arranged to define the upper edge of a space disposed between said seat and the block insert, and means for conducting a molten alloy to said space for adherence to the lens and block insert.
Claim 2
Dependent Claim 215 words
A lens blocking apparatus comprising: a base including means for removably receiving a block insert, an axis ring mounted on said base for rotation about a first axis, said axis ring having a graduated axis scale, a lower prism ring mounted on said base for rotation about said first axis and including a support surface defining a second axis inclined by a first acute angle relative to said first axis, said lower prism ring having a first prism scale graduated exponentially from zero to six diopters over a ninety degree region of said lower prism ring, an upper prism ring mounted on said support surface of said lower prism ring for rotation about said second axis, said upper prism ring carrying a lens seat defining a third axis inclined by a second angle relative to said first axis, said second angle being equal to two times said first angle, said upper prism ring including a second prism scale graduated exponentially from zero to nine diopters over a one hundred eighty degree region of said upper prism ring, said lens seat arranged to define the upper edge of a space disposed between said seat and the block insert, and means for conducting a molten alloy to said space for adherence to the lens and block insert.
Claim 3
Dependent Claim 67 words
A lens blocking apparatus according to claim 1, wherein said lens seat comprises a portion of an adjustable ring mounted on said upper prism ring for rotation about said third axis, means releasably securing said adjustable ring in selected positions of adjustment, and a raised resilient pad extending around only a portion of said lens seat for engaging and sealing against a recessed portion of a lens.
Claim 4
Dependent Claim 71 words
A lens blocking apparatus according to claim 1 including clamping means for clamping the lens against said lens seat, said clamping means including a clamping arm and a soft tip mounted on said clamping arm for engaging the lens, said tip being adjustably displaceable relative to said clamp arm for contacting the lens at selected locations to ensure that sufficient clamping force is exerted in the vicinity of said resilient pad.
Claim 5
Dependent Claim 139 words
A lens blocking apparatus according to claim 1 including a tank containing a molten alloy and communicating with said space, means for pressurizing the interior of said tank for forcing molten alloy into said space, a pressure release valve for relieving pressure in said tank, clamping means for securing the lens against said seat, said clamping means including a clamp arm and being movable between a clamping position in which said clamp arm presses said lens against said lens seat, and a non-clamping position in which said clamp arm releases said lens, and means for closing said pressure release valve in response to said clamping means being shifted toward said clamping position to enable said tank to be pressurized, and for opening said relief valve in response to release of clamping pressure from said lens to depressurize said tank.
Claim 6
Dependent Claim 30 words
A lens blocking apparatus according to claim 4, wherein said means for opening and closing said relief valve means includes a cam connected to said clamping means for movement therewith.
Claim 7
Dependent Claim 178 words
A lens blocking apparatus for joining an ophthalmic lens blank to a block insert, comprising: a lens seat for positioning said lens adjacent a block insert to form a confined space therebetween, clamp means for securing the lens against said lens seat, a tank containing therein a molten alloy and communicating with said space, means for pressurizing the interior of said tank for forcing molten alloy into said space, said molten alloy hardening in adherence with both said lens and said block insert, relief valve means for relieving pressure in said tank, clamping means including a clamp arm, said clamping means being movable between a clamping position in which said clamp arm presses said lens against said lens seat, and a non-clamping position in which said clamp arm releases said lens, and means for closing said relief valve means in response to said clamping means being shifted toward its clamping position to enable said tank to be pressurized, and for opening said relief valve in response to release of clamping pressure from said lens to depressurize said tank.
Claim 8
Dependent Claim 178 words
A lens blocking apparatus for joining an ophthalmic lens blank to a block insert, comprising: a lens seat for positioning said lens adjacent a block insert to form a confined space therebetween, clamp means for securing the lens against said lens seat, a tank containing therein a molten alloy and communicating with said space, means for pressurizing the interior of said tank for forcing molten alloy into said space, said molten alloy hardening in adherence with both said lens and said block insert, relief valve means for relieving pressure in said tank, clamping means including a clamp arm, said clamping means being movable between a clamping position in which said clamp arm presses said lens against said lens seat, and a non-clamping position in which said clamp arm releases said lens, and means for closing said relief valve means in response to said clamping means being shifted toward its clamping position to enable said tank to be pressurized, and for opening said relief valve in response to release of clamping pressure from said lens to depressurize said tank.
Claim 9
Dependent Claim 30 words
A lens blocking apparatus according to claim 6, wherein said means for closing and opening said relief valve means includes a cam connected to said clamping means for movement therewith.
Claim 10
Dependent Claim 50 words
A lens blocking apparatus according to claim 6, wherein said means for pressurizing said tank comprises a pneumatic pump connected to an air inlet conduit communicating with said tank, said air inlet conduit including a rubber one-way valve for resisting the entry of molten alloy into said air inlet conduit.
Claim 11
Dependent Claim 32 words
A lens blocking apparatus according to claim 6, wherein said seat means includes a raised resilient pad extending around only a portion thereof for sealing against a recessed portion of a lens.
Claim 12
Dependent Claim 37 words
A lens blocking apparatus according to claim 9, wherein said clamping arm carries a soft tip for engaging the lens, said tip being displaceable relative to said clamp arm to be located closer to said raised pad.
Claim 13
Dependent Claim 76 words
A lens blocking apparatus for joining an opthalic lens blank to a block insert, comprising a rotatable lens seat for positioning said lens adjacent a block insert to form therebetween a space adapted to receive a molten material which hardens in adherence with both to the lens and the block insert, and a raised resilient pad extending around only a portion of said lens seat for engaging and sealing against a recessed portion of the lens.
Claim 14
Dependent Claim 76 words
A lens blocking apparatus for joining an opthalic lens blank to a block insert, comprising a rotatable lens seat for positioning said lens adjacent a block insert to form therebetween a space adapted to receive a molten material which hardens in adherence with both to the lens and the block insert, and a raised resilient pad extending around only a portion of said lens seat for engaging and sealing against a recessed portion of the lens.
Claim 15
Dependent Claim 20 words
A lens blocking apparatus according to claim 11, wherein said pad extends for one hundred eighty degrees around said seat.
Claim 16
Dependent Claim 66 words
A lens blocking apparatus according to claim 11 including lens clamping means for clamping said lens against said lens seat, said clamping means including a clamp arm carrying a soft tip engageable with the lens, said tip being shiftable relative to said clamp arm to engage the lens at selected locations to ensure that sufficient clamping force is exerted in the vicinity of said resilient pad.
Claim 17
Dependent Claim 34 words
A lens blocking apparatus according to claim 13, wherein said tip includes a mounting portion rotatably adjustably disposed in said clamp arm and a lens engaging portion arranged eccentrically relative to said mounting portion.

References Cited (Backward Citations)

US3468366A Cited
US3866667A Cited
US3946982A Cited
US3951203A Cited
GB2017546A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-04-08 1994-10-08 1995-04-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-04-08 1998-10-08 1999-04-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-04-08 2002-10-08 2003-04-09 $7700.00 Window Closed / Lapsed

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