This list is a small selection of patents pertaining to multi-tool wrenches.  The patents are arranged by the patent number.  Each patent number is linked to the relevant patent document on Google Patents.  The notes are not part of the patent document. 

This list will be expanded and similar lists will be created for multi-tool pliers, multi-tool scissors, and other multi-tools.  

Improvement in combined implements
U.S. Patent number: 170934
Filing date: Dec 15, 1874
Issue date: Dec 1875
Inventor: Broadbooks

Notes: The patent document specifies that "a set screw, g, may be used to clamp the sliding rule in any position so that it may be used as a wrench...".

Pocket-knife
U.S. Patent number: 586453
Filing date: Apr 15, 1895
Issue date: Jul 1897
Inventor: Normand

Pocket-knife
U.S. Patent number: 603847
Filing date: Jun 2, 1897
Issue date: May 1898
Inventor: John Francis Harvey

Compound tool
U.S. Patent number: 742764
Filing date: Feb 14, 1903
Issue date: Oct 27, 1903
Inventor: John F. Watermolen

Wrench
U.S. Patent number: 803007
Filing date: Mar 11, 1905
Issue date: Oct 31, 1905
Inventor: John J. A. Miller

Combination Tool
U.S. Patent number: 888795
Issue date: May 1908
Inventor: Charles C. Fields

Notes: The C.P. Wrench Knife, manufactured by C.P. Wrench Co. of TN, combined a knife and screwdriver with a quick adjusting wrench.  The quick adjusting wrench was also patented by Charles C. Fields (U.S. Patent number: 706042).

references:
American Wrench Makers 1830-1930, p. 86
Levine's Guide to Knives and their Values 4th Edition, p. 295

Combined knife and wrench
U.S. Patent number: 1258396
Filing date: Mar 8, 1917
Issue date: Mar 5, 1918
Inventor: Tint Champlin 

Notes: The wrench knife, manufactured by Cattaraugus of New York, combined an alligator wrench and a screwdriver, a wire stripper, and a punch.  On two later versions of the wrench knife, 1-W and 3-W,  the alligator wrench was replaced with a crescent wrench and the folding tools were replaced with either a knife and punch (1-W) or a knife and a combination screwdriver and cap lifter (3-W).

references:
Levine's Guide to Knives and their Values 4th Edition, p. 293-4

Wrench
U.S. Patent number: 1351519
Filing date: Dec 24, 1919
Issue date: Aug 31, 1920
Inventor: L. Kelly

Knife adapted for multiple uses
U.S. Patent number: 1811982
Filing date: Jun 6, 1928
Issue date: Jun 1931
Inventor: Albert Soustre

Integrated universal tool
U.S. Patent number: 4122569
Filing date: May 27, 1976
Issue date: Oct 31, 1978
Inventor: Thomas H. Hitchcock

Combination hand tool
U.S. Patent number: 5920935
Filing date: Jan 22, 1998
Issue date: Jul 13, 1999
Inventor: Martin E. Beck
Assignee: Spyderco, Inc.