https://www.datamp.org/ Recently added patents en-us https://www.datamp.org/patents/displayPatent.php?id=85919&pn=771,169 Wrench Patentee: George McKercher - Jackson MI Granted:1904-09-27

Improvement to previous McKercher designs, with the adjustment positioning mechanism being a spring-tensioned slide. Known McKercher wrenches did not incorporate this feature. Relevant McKercher patents include: 643,504, 729,504 and this patent.
This is one of 85,209 patents currently in the database at datamp.org

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