# US 8,739,424 B2 · Structure for protecting scale graduations > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,739,424 B2 - Document ID: US8739424B2 - Status: Granted - Kind: B2 - Application number: 13/524,239 - Filed: 2012-06-15 - Published: 2012-12-27 - Granted: 2014-06-03 - Earliest claimed: 2011-06-24 - Assignees: Mitutoyo Corporation - Applicants: Hiroaki Kawada - Inventors: Hiroaki Kawada - Web page: https://patentgrep.com/patent/US8739424B2 ## CPC - G01D 5/24438: {Special design of the sensing element or scale} - G01D 5/34707: {Scales; Discs, e.g. fixation, fabrication, compensation} - G01D: MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR ## Abstract In a structure for protecting scale graduations, in which a graduation unit formed on a scale base is protected by a scale cover arranged on the top surface side of the graduation unit, a space between the scale base and the scale cover along the entire lateral periphery of the graduation unit is sealed using an adhesive agent mixed with a powder material such as a glass powder for blocking penetration of graduations-deteriorating components, to form a periphery adhesive layer. The scale cover may be supported on the scale base by a height regulating unit provided along the periphery of the graduation unit, so that variations in encoder output due to unevenness in thickness of the adhesive agent for joining the scale cover with the graduation unit can be prevented. ## Claims ### Claim 1 A structure for protecting scale graduations in which a graduation unit formed on a scale base is protected by a scale cover arranged on a top surface side thereof, wherein a space between the scale base and the scale cover along an entire lateral periphery of the graduation unit is sealed using an adhesive agent mixed with a powder material blocking penetration of graduations-deteriorating components. ### Claim 2 (depends on 1) The structure for protecting scale graduations according to claim 1, wherein the powder material is glass, ceramic or metal. ### Claim 3 (depends on 1) The structure for protecting scale graduations according to claim 1, wherein the powder material is transparent or nontransparent. ### Claim 4 (depends on 1) The structure for protecting scale graduations according to claim 1, wherein the powder material has a globular shape or an amorphous shape. ### Claim 5 (depends on 1) The structure for protecting scale graduations according to claim 1, wherein the powder material has a particle diameter of several nm to several μm. ### Claim 6 (depends on 1) The structure for protecting scale graduations according to claim 1, wherein a space between an upper surface portion of the graduation unit and the scale cover is also sealed using an adhesive agent. ### Claim 7 A structure for protecting scale graduations in which a graduation unit formed on a scale base is protected by a scale cover arranged on a top surface side thereof, wherein the scale cover is supported on the scale base by a height regulating unit provided along a periphery of the graduation unit. ### Claim 8 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein: the height regulating unit is formed on a lower surface of the scale cover in advance to have a pattern corresponding to the periphery of the graduation unit, and a lower end of the height regulating unit is allowed to abut against a top surface of the scale base; and the scale base and the scale cover are joined with each other using an adhesive agent provided along the periphery of the height regulating unit. ### Claim 9 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein the height regulating unit is deposited on the lower surface of the scale cover. ### Claim 10 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein the height regulating unit is formed to have the same thickness continuously on the lower surface of the scale cover at a position corresponding to the entire periphery of the graduation unit. ### Claim 11 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein the graduation unit has a thickness of 100 nm to 30 μm, and the height regulating unit has such a thickness that allows a space between the cover glass and the graduation unit to be 30 nm to 0.1 mm. ### Claim 12 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein the height regulating unit is formed from metal including chromium, copper or aluminum. ### Claim 13 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein the height regulating unit is deposited from the same material as that of the gradation unit. ### Claim 14 (depends on 7) The structure for protecting scale graduations according to claim 7, wherein a space between the scale base and the scale cover along an entire lateral periphery of the graduation unit is sealed using an adhesive agent mixed with a powder material blocking penetration of graduations-deteriorating components.