Sight glass
Patent D538319 Issued on March 13, 2007. Estimated Expiration Date: 
March 13, 2021. 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.
March 13, 2021. 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 374645 2312542 2450330 2538502 Picture frame system Mounting system and method Patent #: 4282668 InventorAssigneeApplicationNo. 29235090 filed on 07/27/2005US Classes:D16/134, Lens or objectiveD16/130OPTICAL ARTICLE NOT ELSEWHERE SPECIFIEDExaminersPrimary: Greene, Paula A.Attorney, Agent or FirmClaimsCLAIM The ornamental design for a sight glass, as shown and described. DescriptionFIG. 1 is a left front perspective view of a sight glass showing my new design, the bottom is a mirror image of the top; FIG. 2 is a front elevational view thereof, the undisclosed rear is unornamented and not part of the claimed design; and, FIG. 3 is a right side elevational view thereof, the left side is a mirror image. * * * * * Field of SearchOPTICAL ARTICLE NOT ELSEWHERE SPECIFIEDTelescope Lens or objective Magnifying or reducing glass MIRROR, FRAME, PICTURE MOUNT, OR EASEL TYPE SUPPORT Fastener or coupling (38) Clamping or gripping (40) Folding type Having structure to secure picture (e.g., tab, catch, slot, etc.) Knockdown or set-up type Corner connector Connector having aperture to receive fastener Picture retainer Having storage for nondisplayed picture Runners, cursors MITER JOINT MISCELLANEOUS Two components OPTICAL APERTURE OR TUBE, OR TRANSPARENT CLOSURE REMOVABLE CLOSURE |
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