Minnesota Mining and Manufacturing Company

James A Weldon

John H Ko

Forrest J Rouser

Debra L Wilfong

Lawrence W Craighead

Michael Govek

Carole Sedlock

Richard Louis Fry

Gerald L Bergsrud

Russell J Maland

The present invention provides a block assembly for mounting an optical lens blank onto a lens processing machine, comprising a compliant lens block with a relatively thin double-sided adhesive tape having differential adhesion. This assembly affords a very cost efficient system for attaching a lens blank to a lens processing machine. In contrast to traditional thick adhesive pads, the tapes of the present invention do not suffer from shear displacements which may cause processing errors or inaccuracies. In addition, the double-sided adhesive tapes of the present invention achieve greater adhesion to the lens block than to the lens. This feature promotes and ensures a 'clean' removal of the tape from the lens when the block is deblocked. The present invention also provides a method for mounting an optical lens blank onto a lens processing machine. This method comprises the steps of: disposing a compliant block assembly in close proximity to an optical lens blank (the block assembly comprising a base structure having a compliant receiving surface adapted to conform to a surface on an optical lens blank to be processed in a lens processing machine and a mounting means for mounting the block onto a chuck of a lens processing machine, wherein at least a portion of said compliant receiving surface is covered with a thin double-sided adhesive tape having differential adhesion); adhesively attaching the optical lens blank to the compliant block by applying the block to the optical lens blank with sufficient pressure to conform the receiving surface to the surface of the optical lens blank while the adhesive tape joins the block and optical lens blank together; and mounting the block and the adhesive tape joined optical lens blank onto the lens processing machine.

Compliant lens block and tape

The present invention provides thermoplastic ophthalmic lens blocking compositions that have many advantages over traditional metal alloy materials. Preferred compositions comprise a blend of (i) a hydrocarbon resin, preferably an aromatic hydrocarbon resin; (ii) a side chain crystallizable hydrocarbon polymer or copolymer; and (iii) optionally an modifier or mixture of modifiers, preferably straight chain alcohols. The composition may also comprise one or more modifiers, fillers or heat absorbing materials. In one embodiment, the composition is used to fill the cavity between a preformed lens block and a lens. In another embodiment the composition is used to form a lens block. Methods of holding a lens blank are taught. Tapes that provide a receptive surface against which the composition may be adhered are disclosed.

Thermoplastic lens blocking material

A method of processing a lens is disclosed. A lens blank and a lens block are each provided with a structured surface having a plurality of tapered elements. The lens blank is releasably attached to the lens block by pressing the structured surface of the lens blank against the structured surface of the lens block, followed by subjecting the mounted lens blank to lens processing operations.

Method of processing a lens and means for use in the method

A concatenation of circular abrasive discs each having a layer of abrasive material on a first surface, and means on a second surface for releasably attaching said discs to a drive member. The discs are attached to two adjacent discs at opposite edges by two narrow tabs along each edge spaced by at least 0.32 centimeter (1/8 inch) along the edge and generally equally spaced on opposite sides of a center line extending between the centers of the attached discs. Also the discs are separated between the tabs and the tabs are folded to position abrasive discs in a stack within a container with each abrasive disc in the stack having its layer of abrasive against the layer of abrasive of one adjacent disc, and its means for attaching adjacent the means for attaching of the other adjacent disc.

Growing community of inventors

Eagan, MN, United States of America

James A Weldon