Various Yo-Yo Patent Docs

U.S. patent records

Various yo-yo patents, including the “big one”, Haven & Hettrick’s 1866 patent.

The 1866 patent, titled “Whirligig” on the original drawing, claims two metal discs joined at their centers by a rivet and interlocking bosses, with heavier rims that act as flywheels. Its specification calls the toy a bandelore. It records how a nineteenth-century return-wheel toy was built; it is not a claim to every later form of yo-yo. The record gives a grant date of November 20, 1866 and no filing date.

Timeline

Years	Developments
1866–1876	Haven and Hettrick’s US 59,745 joins metal discs with interlocking bosses and a rivet; Weber’s US 179,377 instead joins discs through nested tubular hubs.
1931	Mirafuentes’ US 1,806,485 documents a sound-producing yo-yo with resonant components and threaded disassembly.
1965–1974	Isaacson’s US 3,175,326 documents a ball-bearing yo-yo; Donald F. Duncan, Jr.’s US 3,805,443 later addresses rim weighting, removable covers and axle reinforcement.
1980–1982	Kuhn’s US 4,207,701 provides reversible, tool-free take-apart construction; Caffrey’s US 4,332,102 follows with a centrifugal-clutch automatic-return arrangement.
1990–1992	Amaral’s US 4,895,547 addresses sleeve-spool clearances and return control; Kuhn and Watson’s US 5,100,361 provides adjustable spacing around a bearing-supported tether.
1998–1999	US 5,769,686 addresses axle-groove geometry and inserts, US 5,813,898 claims engagement pads, and O’Sullivan’s US 5,984,759 claims an axially acting automatic-return clutch.
2001–2002	Amaral’s US 6,196,890 covers swaged metal disc-and-hub construction; Brown’s US 6,371,824 covers counterweight apparatus and play methods.
2007	DiFeo’s US 7,175,500 covers a concave bearing surface that guides the string during layered maneuvers.

Patents on record

Each entry was checked against its patent record on Google Patents (inventors, dates, assignee). The year is the grant year. Descriptions summarize the claims and specification; they do not tie a patent to a commercial product unless the patent itself does. Michael Caffrey’s centrifugal-clutch yo-yo is US 4,332,102, filed October 27, 1980 and granted June 1, 1982.

Patent	Granted	Inventor(s)	What it covers
US 59,745	1866	James L. Haven, Charles Hettrick	Two metal discs joined by a rivet and interlocking bosses; the specification calls the toy a bandelore.
US 179,377	1876	Charles Weber	Documents a nineteenth-century metal return-wheel construction using nested tubular hubs to join its two discs without a separate rivet or screw.
US 1,806,485	1931	Alfonso Flores Mirafuentes	Documents a yo-yo with resonant shells, internal discs and a trapped bead for sound, with threaded construction permitting disassembly.
US 3,175,326	1965	Milton S Isaacson	Documents ball-bearing yo-yo construction in a 1965 grant, separating the string-supporting outer race from the spinning body to extend sleep time.
US 3,805,443	1974	Donald F. Duncan, Jr.	Donald F. Duncan, Jr. claims rim-weighted body halves, snap-fitting side covers and a reinforcing axle spool for longer spinning and replaceable covers.
US 4,207,701	1980	Thomas R. Kuhn	Kuhn claims tool-free disassembly, a replaceable center axle and reversible halves that permit traditional, butterfly and pagoda configurations.
US 4,332,102	1982	Michael S. Caffrey	A yo-yo with a string-supporting bearing and a clutch whose spring-biased weighted parts disengage at speed and re-engage as rotation slows.
US 4,895,547	1990	Leonard R. Amaral	Amaral claims a freely rotating sleeve spool with specified axial play and body spacing, addressing long sleep time and controllable return without a centrifugal clutch.
US 5,100,361	1992	Thomas R. Kuhn, Donald W. Watson	Kuhn and Watson claim adjustable side spacing and a bearing-supported tether arrangement that controls return through contact between the string and inner side surfaces.
US 5,769,686	1998	Donald F. Duncan, Thomas J. Van Dan Elzen	Duncan and Van Dan Elzen claim a compound-groove axle block and insert-retaining side members, combining control of string engagement with removable decorative inserts.
US 5,813,898	1998	Hans W. Van Dan Elzen, Thomas J. Van Dan Elzen	Hans W. and Thomas J. Van Dan Elzen claim spaced high-friction engagement pads around the axle, documenting a response system for bearing yo-yos.
US 5,984,759	1999	Brendon M. O’Sullivan	O’Sullivan claims speed-responsive clutch engagement moving substantially parallel to the axle, extending automatic-return mechanisms beyond the earlier Caffrey arrangement.
US 6,196,890	2001	Leonard R. Amaral	Metal yo-yo halves built from separate discs and hubs, secured by swaging the disc metal around each hub. Assigned to Yomega Corporation.
US 6,371,824	2002	Stephen D. Brown	Brown claims a yo-yo with an attached solid body and methods of selectively holding and releasing it during play, documenting counterweight play.
US 7,175,500	2007	Frank P. Difeo	DiFeo claims a smooth concave outer bearing surface that centers the string while allowing lateral movement during string-layering maneuvers.

Attached files