https://www.datamp.org/ Recently added patents en-us https://www.datamp.org/patents/displayPatent.php?id=42314&pn=1,896,437 Pipe Wrench Patentee: Andrew B. Allen - Lockland OH Granted:1933-02-07

The patent claims the facing jaw surfaces of differing curvatures, and edges of the outer curved jaw in planes aligning with the bearing surface of the inner jaw. An ALLEN RED HEAD WRENCH has the hammer poll and grooved inner jaw. The patent also appears to correspond to the STEEL CITY ELECTRIC CO. PATENT PENDING "RED HEAD" curved jaw alligator wrench brought to market in 1932 / 1933. This design outwardly resembles the INVOLUTE WRENCH based on patent no. 661,011
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