Yo-yo facts for kids
 |
|
| Availability | 500 BC – present |
|---|---|
A yo-yo (also spelled yoyo) is a toy consisting of an axle connected to two disks, and a string looped around the axle, similar to a spool. It is an ancient toy with proof of existence since 500 BCE. The yo-yo was also called a bandalore in the 17th century.
It is played by holding the free end of the string known as the handle (by inserting one finger—usually the middle or ring finger—into a slip knot), allowing gravity (or the force of a throw and gravity) to spin the yo-yo and unwind the string (similar to how a pullstring works). The player then allows the yo-yo to wind itself back to the player's hand, exploiting its spin (and the associated rotational energy). This is often called "yo-yoing" or "playing yo-yo".
In the simplest play, the string is intended to be wound on the spool by hand; the yo-yo is thrown downward, hits the end of the string then winds up the string toward the hand, and finally the yo-yo is grabbed, ready to be thrown again. One of the most basic tricks is called the sleeper, where the yo-yo spins at the end of the string for a noticeable amount of time before returning to the hand.
Contents
Etymology and history
The word yo probably comes from the Ilocano term yóyo, or a cognate word from the Philippines.
A Greek vase painting from 440 BC shows a boy playing with a yo-yo (see right). Greek records from the period describe toys made out of wood, metal, or painted terra cotta (fired clay). The terra cotta disks were used to ceremonially offer the toys of youth to certain gods when a child came of age—discs of other materials were used for actual play.
First yo-yo company
In 1928, Pedro Flores, a Filipino immigrant to the United States, opened the Yo-yo Manufacturing Company in Santa Barbara, California. The business started with a dozen handmade toys; by November 1929, Flores was operating two additional factories in Los Angeles and Hollywood, which all together employed 600 workers and produced 300,000 units daily.
The principal distinction between the Filipino design popularized by Flores and more primitive yo-yos is in the way the yo-yo is strung. In older (and some remaining inexpensive) yo-yo designs, the string is tied to the axle using a knot. With this technique, the yo-yo just goes back and forth; it returns easily, but it is impossible to make it sleep. In Flores's design, one continuous piece of string, double the desired length, is twisted around something to produce a loop at one end which is fitted around the axle. Also termed a looped slip-string, this seemingly minor modification allows for a far greater variety and sophistication of motion, thanks to increased stability and suspension of movement during free spin.
Shortly thereafter (c. 1929), entrepreneur Donald F. Duncan recognized the potential of this new fad and purchased the Flores yo-yo Corporation and all its assets, including the Flores name, which was transferred to the new company in 1932.
The name "Yo-yo" was registered in 1932 as a trademark by Sam Dubiner [he] in Vancouver, Canada, and Harvey Lowe won the first World Yo-Yo Contest in London, England. In 1932, Swedish Kalmartrissan yo-yos started to be manufactured as well.
In 1933, yo-yos were banned in Syria, because many locals superstitiously blamed the use of them for a severe drought.
In 1946, the Duncan Toys Company opened a yo-yo factory in Luck, Wisconsin. The Duncan yo-yo was inducted into the National Toy Hall of Fame at The Strong in Rochester, New York, in 1999.
1960s resurgence
Declining sales after the Second World War prompted Duncan to launch a comeback campaign for his trademarked "Yo-Yo" in 1962 with a series of television advertisements.
In a trademark case in 1965, a federal court of appeal ruled in favor of the Royal Tops Company, determining that yo-yo had become a part of common speech and that Duncan no longer had exclusive rights to the term. As a result of the expenses incurred by this legal battle as well as other financial pressures, the Duncan family sold the company name and associated trademarks in 1968 to Flambeau, Inc, which had manufactured Duncan's plastic models since 1955. As of 2020[update], Flambeau Plastics continued to run the company.
Rise of the ball bearing
As popularity spread through the 1970s and 1980s, there were a number of innovations in yo-yo technology, primarily regarding the connection between the string and the axle. In 1979, dentist and yo-yo celebrity Tom Kuhn patented the "No Jive 3-in-1" yo-yo, creating the world's first "take-apart" yo-yo, which enabled yo-yo players to change the axle.
Swedish bearing company SKF briefly manufactured novelty yo-yos with ball bearings in 1984. In 1990, Kuhn introduced the SB-2 yo-yo that had an aluminum transaxle, making it the first successful ball-bearing yo-yo.
In all transaxle yo-yos, ball bearings significantly reduce friction when the yo-yo is spinning, enabling longer and more complex tricks. Subsequent yo-yo players used this ability to their advantage, creating new tricks that had not been possible with fixed-axle designs.
There are many new types of ball bearings in the market which deviate from the original design and/or material of the standard stainless steel ball bearing. For example, a certain type of bearing has an inward facing curved surface, to prevent the string from rubbing on the sides of the yo-yo, which would cause unwanted friction when performing intricate string tricks. Other manufacturers replicate this with a similar inwardly curved surface, but use minor modifications. Some high-end bearings use ceramic composites in the balls of the bearing, to reduce internal friction, again making for a smoother spinning yo-yo. Precious materials such as ruby have also been used as a material in prototype ball bearings for its properties such as extreme hardness. The material was first tested in a prototype bearing made by Wolf Yoyo Works in May 2018.
Modern yo-yo
The era following the yo-yo boom of the late 1990s is often referred to as the "modern" era of yo-yo. The modern era of yo-yo is characterized by markedly more complicated and sophisticated yo-yo techniques than came before in addition to a plethora of different yo-yo designs created to serve various niche purposes. This increased complexity of yo-yo play was allowed by the introduction of the ball-bearing technology to yo-yos, which enabled yo-yos to spin much longer than was previously possible. This, in addition to the advent of the bind technique and unresponsive yo-yoing equipped yo-yo players with an essentially limitless amount of freedom, with which they were able to create myriad yo-yo tricks and techniques.
In the wake of this revolution that took place in yo-yo, a landscape of yo-yo competitions tailored towards this modern style of yo-yo play emerged. (See, for example, World Yo-Yo Contest.) Outside of the competition scene, yo-yo players regularly share videos of their yo-yo tricks on the Internet; a common place players do so is on Instagram, using the hashtag "#trickcircle". Some yo-yo players have also found modest success outside the yo-yo community, going viral on TikTok, gaining significant YouTube followings, or being featured guests on television programs.
Physical mechanism
When the yo-yo is first released, the gravity (and the throw) give it translational kinetic energy and necessarily, since the string must unwind, much of this energy is converted into rotational kinetic energy establishing the free movement of the yo-yo, and causing it to spin rapidly. As the yo-yo unwinds downward, it also converts potential energy from gravity to translational energy in its rotation to overcome gravity all the way back up to the hand.
Because the sense of spinning does not change during the whole move, the string winds up in the opposite direction upon the return of the yo-yo. If the shaft of the yo-yo is connected to the string with a loop, there may not be enough frictional force to overcome the weight of the yo-yo, which is necessary to begin winding up the string. In this case, the yo-yo will continue to spin in the loop at the end of the string (or sleep), just being slightly braked by the small dynamic friction, instead of returning. However, if the string is jerked slightly up, or the hand is lowered, the slack created in the string will allow it to begin winding around the shaft, thereby increasing friction and allowing it to catch as the static friction force rises above the gravitation force holding the yo-yo at the bottom of the string, making the yo-yo wind up the string returning to the hand.
Patents have been issued to create more complicated mechanisms to allow tension control and an adjustable mechanism.
See also
In Spanish: Yo-yo para niños
