Refractor cross-cylinder apparatus
Patent 4185896 Issued on January 29, 1980. Estimated Expiration Date: 
February 27, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
February 27, 1998. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3498699 3698799 3860330 InventorAssigneeApplicationNo. 05/881341 filed on 02/27/1978US Classes:351/235, Having plural disc carrier351/234Mounted on rotatable discExaminersPrimary: Sacher, Paul A.Attorney, Agent or FirmInternational ClassesA61B 3/036 (20060101)A61B 3/02 (20060101) AbstractA pair of cylinder lenses have a combined power of zero when their cylinder axes are parallel and a small cross cylinder power when one lens is rotated until its axis is perpendicular to the cylinder axis of the other lens. Cross-cylinder lenses are used to determine the accuracy of the cylinder power and cylinder axis selected by the practitioner. By mounting one cylinder lens in a motor-driven ring-like lens mount having a member which engages another ring-like lens mount, a single motor can be used to drive both lenses; select between parallel cylinder axes and crossed cylinder axes; and rotate the crossed axis lenses as an assembly to the desired position. | |
