View source for Slinky

{{for|the London skyscraper nicknamed "The Slinky"|Baltimore Tower}}
{{Use mdy dates|date=July 2023}}
{{Short description|Helical spring toy}}
{{Infobox toy
| name = Slinky
| image = 2006-02-04 Metal spiral.jpg
| image_size = 200px
| image_upright = 
| alt = 
| caption = A Slinky made out of metal
| othernames = 
| type = Spring toy
| inventor = {{ubl|[[Richard T. James]]|[[Betty James]]}}
| company = James Industries
| country = United States
| from = 1945
| to = present
| materials = 
| features = 
| slogan = 
| website = 
}}

The '''Slinky''' is a [[helix|helical]] [[Spring (device)|spring]] [[toy]] invented and developed by American naval engineer Richard T. James in 1943 and successfully demonstrated at [[Gimbels]] department store in [[Philadelphia]] on November 27, 1945.<ref name=TIME>{{cite magazine|title=How the Slinky Sprang Into Stores 70 Years Ago |url=https://time.com/4127170/slinky-70-years/ |date=November 27, 2015 |magazine=Time |first=Merrill |last=Fabry |access-date=January 3, 2018|quote=It was exactly 70 years ago, on the evening of Nov. 27, 1945, that Richard James demonstrated a new product at Gimbels department store in Philadelphia.}}</ref>

It can perform a number of tricks, including travelling down a flight of steps end-over-end as it stretches and re-forms itself with the aid of gravity and its own momentum; and appearing to levitate for a period of time after it has been dropped. These interesting characteristics have contributed to its success in its home country of the United States, and it has inspired many popular toys with Slinky-like components, in a wide range of countries. 

==History==

===Creation===

In 1943, [[Richard T. James]], a naval mechanical engineer, observed a spring "stepping" downward after being knocked off a shelf, then coming to rest in a vertical position.<ref name="MIT">{{cite web |url=http://web.mit.edu/Invent/iow/slinky.html |title=Inventor of the Week: The Slinky |publisher=[[MIT School of Engineering]] |access-date=February 24, 2009 |archive-url=https://web.archive.org/web/20090222210634/http://web.mit.edu/Invent/iow/slinky.html |archive-date=February 22, 2009}}</ref><ref name="Walsh" /> James's wife Betty later recalled, "He came home and said, 'I think if I got the right property of steel and the right tension, I could make it walk.'"<ref>{{cite news |title=Novel Ideas |first=John  |last=Przybys  |url=http://www.reviewjournal.com/lvrj_home/1998/Mar-01-Sun-1998/lifestyles/7021869.html |url-status=deviated |archive-url=https://web.archive.org/web/20031026221441/http://www.reviewjournal.com/lvrj_home/1998/Mar-01-Sun-1998/lifestyles/7021869.html |archive-date=October 26, 2003 |newspaper=[[Las Vegas Review-Journal]] |date=March 1, 1998 |access-date=February 21, 2024}}{{cbignore}}</ref> James experimented with different types of steel wire over the next year, and finally found a spring that would "walk".  Betty was skeptical, but changed her mind when the toy was fine-tuned and neighborhood children expressed an excited interest in it.<ref name="Walsh" />

Richard and Betty formed James Industries and began manufacturing slinkys in [[Clifton Heights, Pennsylvania]], selling them for $1 each.<ref name="Walsh" /> They were {{convert|2+1/2|in}} tall, and included 98 coils of high-grade blue-black Swedish steel.<ref name="Rich" /> They initially had difficulty selling Slinky to toy stores, but in 1945, they were granted permission to set up an [[inclined plane]] in the toy section of [[Gimbels]] Department Store in Philadelphia to demonstrate it on the Tuesday after Thanksgiving.<ref name=TIME/> It was an instant hit; the first 400 units were sold in 90 minutes.<ref name="Walsh" /><ref name="Rich">{{cite book |last=Rich |first=Mark |title=Warman's 101 Greatest Baby Boomer Toys |publisher=KP Books |year=2005 |location=Iola, Wisconsin |pages=58–59 |isbn=0-89689-220-4}}</ref> In 1946, Slinky was introduced at the [[American International Toy Fair|American Toy Fair]].{{cn|date=October 2024}}

The Slinky was originally priced at $1, but many paid much more due to price increases of spring steel in Pennsylvania. It has, however, remained modestly priced throughout its history as a result of Betty James' concern about the toy's affordability for less affluent customers. In addition to its use as a toy, it has been used as a classroom teaching tool; as a portable and extendable radio antenna in wartime (particularly the Vietnam War).<ref>{{Cite web|url=https://www.smithsonianmag.com/innovation/accidental-invention-slinky-180973016/|title = The Accidental Invention of the Slinky}}</ref> It was inducted into the [[National Toy Hall of Fame]] at [[The Strong]] in [[Rochester, New York]] in 2000. In 2003, it was named to the [[Toy Industry Association]]'s Century of Toys List.<ref>{{cite press release |url=http://www.toy-tia.org/industry/news/press/tf03_centuryoftoys.html |archive-url=https://web.archive.org/web/20030401214230/http://www.toy-tia.org/industry/news/press/tf03_centuryoftoys.html |archive-date=April 1, 2003 |date=January 20, 2003 |title=Toy Industry Association Announces Its 'Century of Toys List' | publisher=Toy Industry Association}}</ref> In its first 60 years, about 300 million Slinkys were sold.<ref>{{cite magazine|title=How the Slinky Sprang Into Stores 70 Years Ago |url=https://time.com/4127170/slinky-70-years/ |date=November 27, 2015 |magazine=Time |first=Merrill |last=Fabry |access-date=January 3, 2018}}</ref>

===Subsequent developments===
In 1960, after his wife filed for divorce, Richard James left the company and he became an evangelical missionary in [[Bolivia]] with [[Wycliffe USA|Wycliffe Bible Translators]].<ref>{{Cite web|title='Slinky' brainchild |newspaper=[[Delaware County Daily Times]] |date=November 25, 1976 |url=https://www.newspapers.com/newspage/19524766/ |access-date=January 25, 2014}}</ref> Betty James moved the company to [[Hollidaysburg, Pennsylvania]] in 1964 and the company grew under her direction.<ref name="Walsh" /> She attributed the toy's success to its "simplicity".<ref name="Betty">{{cite news |title=Betty James, who cofounded Slinky company, dies |url=http://www.kxmb.com/getArticle.asp?ArticleId=300881 |access-date=February 25, 2009|date=November 22, 2008|agency=[[Associated Press]]|publisher=[[KXMB-TV]]}}</ref> The company was sold to Poof Products, Inc. in 1998.<ref name="Walsh" /><ref name="NYTimes" /> Slinky continued production in Hollidaysburg.<ref name="Walsh" />

Betty James died of [[congestive heart failure]] in November 2008, at age 90, after serving as James Industries' president from 1960 to 1998.<ref name="NYTimes">{{cite news |title=Betty James, Who Named the Slinky Toy, Is Dead at 90 |url=https://www.nytimes.com/2008/11/25/business/25james.html |access-date=February 25, 2009|last=Hevesi|first= Dennis|newspaper=[[The New York Times]] | date=November 25, 2008}}</ref>

In July 2012, Poof-Slinky, Inc. was acquired by the private equity firm Propel Equity Partners.<ref>{{Cite web |date=May 28, 2013 |title=Propel Equity Partners Acquires ALEX® |url=https://www.businesswire.com/news/home/20130528005951/en/Propel-Equity-Partners-Acquires-ALEX%C2%AE |access-date=January 22, 2023 |website=www.businesswire.com |language=en}}</ref> In 2014, Propel Equity Partners consolidated Poof-Slinky and several other toy brands into Alex Brands.<ref>{{Cite web |date=January 29, 2014 |title=ALEX TOYS®, POOF-SLINKY® and ZOOB® Come Together Under New Collective Brand Identity |url=https://www.businesswire.com/news/home/20140129005283/en/ALEX-TOYS%C2%AE-POOF-SLINKY%C2%AE-and-ZOOB%C2%AE-Come-Together-Under-New-Collective-Brand-Identity |access-date=January 22, 2023 |website=www.businesswire.com |language=en}}</ref>

In July 2020, the Slinky brand was sold to Just Play.<ref>{{Cite web|url=https://www.licenseglobal.com/toys-games/just-play-acquires-slinky-and-shrinky-dinks-brands|title = Just Play Acquires the Slinky and Shrinky Dinks Brands|date = July 2020}}</ref>

==Physical properties==
The rules that govern the mechanics of a Slinky are [[Hooke's law]] and the effects of [[gravitation]].{{cn|date=October 2024}}

===Period of oscillation===
The oscillation of a vertically suspended Slinky has the periodic duration<ref>{{Cite journal |last=Pretz |first=Jörg |date=July 1, 2021 |title=Oscillations of a suspended slinky |url=https://iopscience.iop.org/article/10.1088/1361-6404/abcddf |journal=European Journal of Physics |volume=42 |issue=4 |pages=045008 |doi=10.1088/1361-6404/abcddf |arxiv=2005.12203 |bibcode=2021EJPh...42d5008P |s2cid=218869730 |issn=0143-0807}}</ref>

<math>T = \sqrt{\frac{32 L}{g}} \, ,</math>

where  <math display="inline">L</math> is the length of the Slinky in the gravitational field of the Earth  and <math display="inline">g</math> the acceleration due to gravity <math display="inline">g=9.81 \,\mathrm{m/s}^2</math>. Please note, that the expression for <math display="inline">T</math> is independent of the spring constant <math display="inline">k</math> and the mass <math display="inline">m</math> of the Slinky. For a spring pendulum one would expect such a dependence. This is because the dependence on  <math display="inline">k</math> and <math display="inline">m</math> is hidden in the length <math display="inline">L(k,m)</math>:

<math>L(k,m) = \frac{mg}{2k} = \frac{W}{2k}\, ,</math>

this allows one to write:

<math>T = 4 \sqrt{\frac{m}{k}} \, .</math>


This expression differs from the ordinary spring pendulum

<math> T_{\mbox{spring pendulum}} = 2\pi \sqrt{\frac{m}{k}} \, ,
  </math>

because for the spring pendulum one assumes a massless spring with a mass <math display="inline">m</math> attached at the bottom.

===Phenomena===

When set in motion on a stepped platform such as a stairway, the Slinky transfers energy along its length in a longitudinal wave. The whole spring descends end over end in a periodical motion as if it were "walking" down one step at a time.<ref>Ikenson, Ben. Patents: Ingenious Inventions: How They Work and How They Came to Be.</ref>

When the top end of the Slinky is dropped, the information of the tension change must propagate to the bottom end before both sides begin to fall; the top of an extended Slinky will drop while the bottom initially remains in its original position, compressing the spring.<ref>{{cite AV media | url=http://blogs.discovermagazine.com/badastronomy/2011/09/26/slinky-drop-physics/ | title=Slinky drop physics - video of extended Slinky being dropped | magazine=Discover magazine | date=September 26, 2011}}</ref> This creates a suspension time of  ~0.3 s for an original Slinky,<ref name="arXiv.free">{{cite journal|title=Modeling a falling slinky|arxiv=1208.4629|last=Cross|first=Rod C.|author2=Wheatland, Mike S. |date=August 22, 2012|doi=10.1119/1.4750489|volume=80|issue=12|journal=American Journal of Physics|page=1051|bibcode=2012AmJPh..80.1051C|s2cid=33704140}}</ref><ref name="Journal.abstract">{{cite journal|last=Cross|first=Rod C.|author2=Wheatland, Mike S. |title=Modeling a falling slinky|journal=American Journal of Physics|year=2012|volume=80|issue=12|pages=1051|doi=10.1119/1.4750489|publisher=American Association of Physics Teachers|arxiv=1208.4629|bibcode=2012AmJPh..80.1051C|s2cid=33704140}}</ref> but has potential to create a much larger suspension time.
A suspended Slinky's center of mass is accelerating downward at 1[[Gravity of Earth|g]] (about {{Convert|32|ft/s2|m/s2|abbr=out|disp=or}}); when released{{snd}}the lower portion moves up toward the top portion with an equivalent, constant upward acceleration as the tension is relieved. As the spring contracts, every point along its length will accelerate downward with gravity and tension, and experience a decrease in overall downward acceleration related to height along the spring due to the spring force changing with extension{{snd}}at the bottom of the spring the upward initial acceleration reduces in accordance with Hooke's law as the spring contracts, but the centre toward which it is moving gets closer{{snd}}meaning the base will have been displaced sufficiently toward the centre of inertial mass for it to appear to have hung still. Should this phenomenology extend to very light strings with heavy suspended masses (which have approximately linear tension distributions), different mathematics would be needed to explain the phenomenon.{{cn|date=October 2024}}

==Commercial history==

===Jingle===
The jingle for the Slinky television commercial was created in Columbia, South Carolina in 1962 with Johnny McCullough and Homer Fesperman writing the music and Charles Weagly penning the lyrics. It became the longest-running jingle in advertising history.<ref name="Walsh">{{cite book | last = Walsh | first = Tim | year = 2005 | title = Timeless Toys: Classic Toys and the Playmakers Who Created Them | publisher = [[Andrews McMeel Publishing]] | isbn = 978-0-7407-5571-2 | pages = 62–65}}</ref>

The jingle has itself been parodied and referenced in popular culture. It is seen in the "Log" commercial on ''[[The Ren & Stimpy Show]]'' and sung by actor [[Jim Carrey]] in ''[[Ace Ventura: When Nature Calls]]''. It is also referenced in the movie ''[[Lords of Dogtown]]'', where it is sung in full by [[Emile Hirsch]], and is sung by [[Eddie Murphy]] as part of the final routine in the stand-up comedy film ''[[Eddie Murphy Raw]]''. It was also parodied in an ad for the [[Isuzu MU|Isuzu Amigo]] used as a promo for the vehicle's return in late March 1998, nearly two months before the ad was pulled due to criticism from the company that made the Slinky.<ref>{{cite magazine | last = Halliday | first = Jean | date = May 18, 1998 | url = https://adage.com/article/news/isuzu-pulls-commercial-parodied-slinky-ads-intro-tv-spot-amigo-suv-drew-criticism-marketer-flight/65788 |url-access=subscription |archive-url=https://web.archive.org/web/20230226171042/https://adage.com/article/news/isuzu-pulls-commercial-parodied-slinky-ads-intro-tv-spot-amigo-suv-drew-criticism-marketer-flight/65788 |archive-date=February 26, 2023 |title = Isuzu Pulls Commercial That Parodies Slinky Ads: Intro TV Spot for Amigo SUV Drew Criticism; Marketer Says Flight Was Over |magazine=[[Ad Age]] |publisher=[[Crain Communications]] |access-date=February 10, 2024}}{{cbignore}}</ref>

===Slinky Dog===
{{Redirect|Slinky Dog|the character in Toy Story|List of Toy Story characters#Slinky Dog}}
Early in the history of James Industries, [[Helen Herrick Malsed]] of [[Washington (state)|Washington state]] sent the company a letter and drawings for developing Slinky pull-toys. The company liked her ideas, and Slinky Dog and Slinky Train were added to the company's product line. Slinky Dog, a small plastic dog whose front and rear ends were joined by a metal Slinky, debuted in 1952. Malsed received royalties of $60,000 to $70,000 annually for 17 years on her patent for the Slinky pull-toy idea, but never visited the plant.<ref name="NYTimes2">{{cite news |last=McDowell |first=Edwin |title=Helen H. Malsed, 88, Creator of Slinky Toys |newspaper=[[The New York Times]] |date=November 28, 1998 |url=https://query.nytimes.com/gst/fullpage.html?res=9E03E3DB1139F93AA15752C1A96E958260 |url-access=subscription |archive-url=https://web.archive.org/web/20160824221309/http://www.nytimes.com/1998/11/29/business/helen-h-malsed-88-creator-of-slinky-toys.html |archive-date=August 24, 2016 |access-date=February 26, 2009}}</ref>

In 1995, the [[Slinky Dog (Toy Story)|Slinky Dog]] (voiced by [[Jim Varney]] and [[Blake Clark]]) was redesigned for all of [[Pixar]]'s ''[[Toy Story (franchise)|Toy Story]]'' movies. James Industries had discontinued their Slinky Dog a few years previously. Betty James approved of the new Slinky Dog, telling the press, "The earlier Slinky Dog wasn't nearly as cute as this one."<ref name="NYTimes1">{{cite news |last=Witchel |first=Alex |date=February 21, 1996 |title=Talking Toys with Betty James; Persevering for Family and Slinky |newspaper=[[The New York Times]] |url=https://query.nytimes.com/gst/fullpage.html?res=9C00E1D61339F932A15751C0A960958260 |access-date=February 26, 2009}}</ref>

===Plastic Slinky===
[[File:Slinky rainbow.jpg|thumb|Rainbow colored plastic Slinky toy]]
Plastic Slinkys are also available. They can be made in different colors. Many of them are made with the colors of the rainbow in rainbow order. They were marketed in the 1970s as a safer alternative to metal Slinkys as they did not present a hazard when inserted into electrical sockets. The plastic spring toy, known as the Plastic Slinky, was invented by Donald James Reum of Avon Plastics in Albany, Minnesota. Reum came up with the idea as he was experimenting with different techniques to produce a spiral hose for watering plants. However, as it came off the assembly line, according to his children, it looked more like a "Slinky". He worked at it until it came out perfectly and then went to Betty James with his prototype. Reum manufactured the Plastic Slinky for Betty James for several years. Eventually Betty James decided to manufacture the product exclusively through James manufacturing, effectively ending the production of the toy by the small Minnesota company. Reum's patent number, 4120929 was filed on December 28, 1976, and issued by the U.S. Patent Office on October 17, 1978.<ref>{{cite patent | country = US | number = 4120929 | status = patent | fdate = December 28, 1976 | gdate = October 17, 1978 | title = Method for producing a spirally wound plastic article | invent1 = Reum, Donald James}}</ref>

==Awards and honors==
In 1999, the United States Postal Service issued a Slinky postage stamp.<ref>{{cite book |title=Sourcebook for Receptive and Expressive Language  |publisher=Wayne State University Press |location=Detroit, Michigan |year=2006 |page=106 |isbn=0-8143-3314-1 |url=https://books.google.com/books?id=qO0s0Z52IYYC&q=Slinky+postage+stamp&pg=PA106 |access-date=February 25, 2009}}</ref> The Slinky was inducted into the [[National Toy Hall of Fame]] in 2000 in their [[Celebrate the Century]] stamp series. A bill to nominate the Slinky as the [[List of U.S. state toys|state toy]] of [[Pennsylvania]] was introduced by [[Richard Geist]] in 2001 but not enacted.<ref>{{cite web|url=http://www.legis.state.pa.us/cfdocs/billinfo/billinfo.cfm?syear=2001&sind=0&body=H&type=B&BN=1893|title=Regular Session 2001–2002, House Bill 1893|publisher=[[Pennsylvania General Assembly]]|access-date=March 31, 2011}}</ref> The same year, Betty  James was inducted into the [[Toy Industry Association]]'s Hall of Fame.<ref name="NYTimes" /> In 2003, Slinky was named to the Toy Industry Association's "Century of Toys List" of the 20th century's 100 most memorable and creative toys.<ref>{{cite press release |title=Toy Industry Association Announces Its Century of Toys List |publisher=[[Business Wire]] for [[Toy Industry Association]] |date=January 21, 2003 |url=http://www.allbusiness.com/manufacturing/miscellaneous-mfg-doll-toy-games-games/5673984-1.html |access-date=February 19, 2009}}</ref>

==Other uses==

Slinkys and similar springs can be used to create a 'laser gun' like sound effect. This is done by holding up a Slinky in the air and striking one end, causing a metallic sound that sharply lowers in pitch. The effect can be amplified by attaching a plastic cup to one end of the Slinky.<ref>{{cite web|url=http://www.abc.net.au/science/experimentals/experiments/episode19_2.htm|title=the experiMENTALS: experiments - laser canon sound effect - The Lab - Australian Broadcasting Corporation's Gateway to Science|website=www.abc.net.au|access-date=February 19, 2018}}</ref>

The ''Helixophone'' is the name composer and artist [[Sonia Paço-Rocchia]] gave to a musical instrument made with a Slinky and a resonator. ''Hélix'' is a sound installation with up to 20 Helixophones, automated and playing an interactive sound composition.<ref name=":14">{{cite web|access-date=March 10, 2021|language=fr-CA|title=Sonia Paço-Rocchia - Helix - Exposition à Victoriaville – Le Carré 150|url=https://www.lecarre150.com/expoarchives/detail/Sonia-Paco-Rocchia/Helix/15-05-2017-10-00|website=www.lecarre150.com}}<!-- auto-translated by Module:CS1 translator --></ref><ref name=":15">{{cite web|access-date=March 10, 2021|language=fr-ca|last=Sara|title=2017|url=https://www.fimav.qc.ca/fr/2017|website=fimav.qc.ca|date=December 16, 2015 }}<!-- auto-translated by Module:CS1 translator --></ref><ref name=":16">{{cite web|access-date=March 10, 2021|date=January 9, 2018|first=Sophie|language=fr-FR|last=Poisson|title=Rebondir|url=https://journalmetro.com/local/verdun/1337751/rebondir/|website=Journal Métro}}<!-- auto-translated by Module:CS1 translator --></ref><ref name=":17">{{cite web|access-date=March 10, 2021|language=fr|title=ICI Radio-Canada Première {{!}} Balados, livres audio|url=http://ici.radio-canada.ca/premiere/emissions/bon-pied-bonne-heure/segments/entrevue/85115/phos-installation-matane-sonia-paco-rocchia-sonore-interactive-helix|website=Radio-Canada}}<!-- auto-translated by Module:CS1 translator --></ref><ref name=":18">{{cite web|access-date=March 10, 2021|author=Radio-Canada: Ici Alberta|language=fr|title=Hélix au Centre d'arts visuels de l'Alberta|website=[[Facebook]] |url=https://www.facebook.com/icialberta/videos/1936501479705990/}}<!-- auto-translated by Module:CS1 translator --></ref> 

Metal Slinkys can be used as an antenna; it resonates between 7 and 8&nbsp;MHz. During the Vietnam War, it was used as a portable antenna for local HF communication. This setup had many advantages over a long wire shot from M79 grenade launcher: small dimensions, fast and quiet installation, reusability, good takeoff angle for local communication, and adequate performance. It was also used to extend the ranges of handheld radios.<ref>{{cite book|title=Last-Minute Survival Secrets: 128 Ingenious Tips to Endure the Coming Apocalypse and Other Minor Inconveniences|year=2015|publisher=Chicago Review Press, Incorporated|url=https://archive.org/details/lastminutesurviv00gree|url-access=registration|page=[https://archive.org/details/lastminutesurviv00gree/page/24 24]|isbn=9781613749852}}</ref>

In 1985, in conjunction with the [[Johnson Space Center]] and the [[Houston Museum of Natural Science]], [[Space Shuttle Discovery]] astronauts created a video demonstrating how familiar toys behaved in space. One astronaut described the toy as "sort of droop[ing]". The video was prepared to stimulate interest in school children about the basic principles of physics and the phenomenon of weightlessness.<ref name="NYTimes4">{{cite news |title=Toy Time in Space |newspaper=[[The New York Times]] |date=April 16, 1985 |url=https://query.nytimes.com/gst/fullpage.html?sec=health&res=9B07E3DC1239F935A25757C0A963948260 |url-access=subscription |archive-url=https://web.archive.org/web/20121110092247/http://www.nytimes.com/1985/04/16/science/toy-time-in-space.html |archive-date=November 10, 2012 |access-date=February 26, 2009}}{{cbignore}}</ref>

Several online videos have shown that a Slinky can be mounted on the pole of a bird feeder to deter squirrels from climbing up the pole.<ref>{{Cite web|url=https://abc13.com/society/slinky-used-to-keep-squirrels-away/1667062/|title=Woman uses Slinky to keep squirrels from bird feeder|date=December 21, 2016}}</ref>

== See also ==

* [[Spring (device)#Classification|Spring (device) § Classification]]

== References ==

{{refs}}

== External links ==
{{commonscat}}

* {{Official website|https://web.archive.org/web/20050216012555/http://www.poof-slinky.com/|Poof-Slinky, Inc}}
* [http://sydney.edu.au/news/84.html?newsstoryid=10758 University of Sydney] - home institution of Slinky physics researchers

{{Authority control}}

[[Category:Poof-Slinky| ]]
[[Category:Educational toys]]
[[Category:Metal toys]]
[[Category:Toy companies of the United States]]
[[Category:Springs (mechanical)]]
[[Category:1940s toys]]
[[Category:1950s toys]]
[[Category:1960s toys]]
[[Category:Products introduced in 1945]]
[[Category:Goods manufactured in the United States]]