{"id":783,"date":"2020-09-26T18:43:23","date_gmt":"2020-09-26T16:43:23","guid":{"rendered":"https:\/\/lockanalyst.org\/?page_id=783"},"modified":"2020-10-25T13:08:14","modified_gmt":"2020-10-25T12:08:14","slug":"the-disc-tumbler-design","status":"publish","type":"page","link":"https:\/\/lockanalyst.org\/index.php\/the-disc-tumbler-design\/","title":{"rendered":"The Disc-tumbler design"},"content":{"rendered":"\n
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Origin & development<\/strong><\/h2>\n\n\n\n
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The origin of rotating disc tumbler is an very old concept. In 2nd century AD, romans already used combination padlocks made in bronze with coding-wheels. In 1870, we found some vestiges in Kerameikos near Athens (2).<\/p>\n\n\n\n

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L’origine des s\u00fbret\u00e9s \u00e0 disque est un concept tr\u00e8s ancien. D\u00e8s le 2\u00e8me si\u00e8cle apr\u00e8s J.C-, les romains utilisaient d\u00e9j\u00e0 des cadenas \u00e0 combinaison en bronze munis de rouleaux cod\u00e9s. En 1870, on a retrouv\u00e9 quelques vestiges \u00e0 kerameikos pr\u00e8s d’Ath\u00e8nes (2).<\/span><\/em><\/p>\n\n\n\n

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Early roman’s combination padlock<\/em> (1)<\/figcaption><\/figure><\/div>\n\n\n\n

In 17th century, Kristofer P\u00e5lhammar (afterwards named Polhem) was an swedish mechanical engineer.Around 1684, in his workshop at Stjernsund (3), he improve the coding-wheel mechanism by moving them with a key. The Polhem’s lock have an advantage of holding the freeze well because his padlock is made in copper and have no springs. Like Joseph Bramah, he designed and manafactured lock machinery to produce his revolutionary padlock.<\/p>\n\n\n\n

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Au 17\u00e8me si\u00e8cle, Kristopfer P\u00e5lammar (plus tard dit Polhem) est un ing\u00e9nieur m\u00e9canicien su\u00e9dois. Vers 1684, <\/em>dans son atelier de Stjernsund (3), il am\u00e9liore le m\u00e9canisme \u00e0 rouleaux cod\u00e9s en les actionnant par une clef. La serrure de Polhem a l’ avantage de r\u00e9sister au g\u00e8le car son cadenas est fabriqu\u00e9 en cuivre et ne poss\u00e8de aucun ressort. Comme Joseph Bramah, il con\u00e7ut et fabriqua ces machines afin de faciliter l’industrialisation de son invention.<\/em><\/span><\/p>\n\n\n\n

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Polhem’s padlock<\/em> (mid-19th century)<\/figcaption><\/figure><\/div>\n\n\n\n
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With a key turn 90\u00b0 and shackle retracted<\/em><\/figcaption><\/figure><\/div>\n\n\n\n
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Polhem’s padlock mechanism<\/em><\/figcaption><\/figure>\n\n\n\n
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The principle is very simple and similar than the roman’s combination padlock design. A removable grooved skackle is blocked by disc-tumblers. All discs have two notches on their contour and diametrically opposed to each other. When the right key is inserted, the discs rotate 90\u00b0 and the skackle can be free to move.<\/p>\n\n\n\n

Each disc have a rectangular opening for the inserting of the key. between all disc, a fixed spacer prevents friction and the rotation of the key. At this time, the Polhem’s key has no angular bitting but we can observe some cuts to allow the passage of the spacers used like wards.<\/p>\n\n\n\n

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Le fonctionnement est tr\u00e8s simple et similaire \u00e0 celui des cadenas \u00e0 combinaison romains. L’anse poss\u00e8de de multiples rainures dans lesquelles viennent se loger les disques et bloque sa course. Les disques ont deux encoches sur leur contour diam\u00e9tralement oppos\u00e9es l’une de l’autre. Quand la bonne clef est ins\u00e9r\u00e9e, les disques tournent de 90\u00b0, les encoches sont align\u00e9es et l’anse peut se lib\u00e9rer.<\/span><\/em><\/p>\n\n\n\n

Chaque disque poss\u00e8de une ouverture rectangulaire pour le passage de la clef. Entre chaque disque, une entretoise fixe r\u00e9duit la friction et fait obstacle \u00e0 la rotation de la clef. A cet \u00e9poque, la clef de Polhem ne poss\u00e8de aucune d\u00e9coupe angulaire mais nous pouvons observer que chaque d\u00e9coupe permet le passage des entretoise utilis\u00e9es ici comme des garnitures.<\/span><\/em><\/p>\n\n\n\n

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N\u00b0116,977<\/em><\/figcaption><\/figure><\/div>\n\n\n\n
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N\u00b0167,088<\/em><\/figcaption><\/figure>\n\n\n\n
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N\u00b01,514,318<\/em><\/figcaption><\/figure><\/div>\n\n\n\n
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From 1870 and 1880, scandinavian’s padlock became fashionable in US and will be used for various purposes, in particular to equip prison door. The manufacture of padlocks and its keys has been improved with the evolution of sheet-metal process and die-casting technique (N\u00b0116,977).<\/p>\n\n\n\n

In 1875, Philo S. Felter introduce the first sidebar’s design in a lock cylinder (N\u00b0167,088). But his invention didn’t meet a commercial success, outpassed by the popularity of the Yale lock. That’s why, we will have to wait until 1919 that Emil W. Henriksson imagined the basics of the modern disc-tumbler lock as we know it today. By a patent (N\u00b01,514,318), he fixes his design with a angled-cut key inspired by Mr Ahrend’s patent (N\u00b0156,113).<\/p>\n\n\n\n

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De 1870 \u00e0 1880, le cadenas “scandinave” devient \u00e0 la mode aux Etats-Unis et sera utilis\u00e9 dans divers secteurs, en particulier le domaine p\u00e9nitentiaire. La fabrication du cadenas et de sa clef a \u00e9t\u00e9 am\u00e9lior\u00e9 gr\u00e2ce \u00e0 l’\u00e9volution des techniques de d\u00e9coupe des t\u00f4les et de la fonderie.<\/span><\/em><\/p>\n\n\n\n

En 1875, Philo S. Felter est le premier \u00e0 utiliser un syst\u00e8me de blocage \u00e0 barre lat\u00e9rale associ\u00e9 \u00e0 un rotor. Mais son invention ne connut aucun succ\u00e8s commercial, devanc\u00e9e par la popularit\u00e9 de la serrure Yale.<\/em> Il faudra attendre 1919 que Emil W. Henriksson imagine les bases de la serrure \u00e0 disque telle qu’on la connait de nos jours. Par son brevet (N\u00b01,514,318), il impose le concept d’une clef avec un taillage angulaire inspir\u00e9 par le brevet de Mr Ahrend (N\u00b0156,113).<\/em><\/span><\/p>\n\n\n\n

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Mechanism & terminology<\/strong><\/h2>\n\n\n\n
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Disc-tumbler’s lock mechanism<\/em><\/figcaption><\/figure>\n\n\n\n
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When the correct key is turned 90\u00b0, all disc’s notches are aligned and the sidebar can drop in the groove (green). In the other hand, when an incorrect key is inserted, the sidebar bind against the contour of the disc and block the plug’s rotation. <\/p>\n\n\n\n

The key have an angular bitting allowing to rotate each disc to a determined angle. Six bitting angles are often possible to 0 (no cut) to 90\u00b0 in increment of 18\u00b0. <\/p>\n\n\n\n

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Quand la bonne clef est tourn\u00e9e de 90\u00b0, toute les encoches des disques sont align\u00e9es et la barre lat\u00e9rale peut se glisser dans la rainure form\u00e9e par l’alignement des encoches (en vert ci-dessus). A contrario, si la mauvaise clef est ins\u00e9r\u00e9e, la barre lat\u00e9rale bute contre le disque et bloque la rotation du rotor.<\/em><\/span><\/em><\/p>\n\n\n\n

La clef poss\u00e8de des d\u00e9coupes angulaires permettant de tourner chaque disque d’un angle d\u00e9termin\u00e9. Six tailles angulaires sont souvent utilis\u00e9es de 0 (aucune d\u00e9coupe) \u00e0 90\u00b0 par incr\u00e9ment de 18\u00b0.<\/span><\/em><\/p>\n\n\n\n

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Front view with the sidebar blocking<\/em> system<\/figcaption><\/figure><\/div>\n\n\n\n

When the key is turned in counter-clockwise, 0-discs are first in contact with 0-cuts. During the rotation, the key will drive the others discs. At 90\u00b0, the key tensioned the plug throught them. Its rotation move the sidebar which slides along the vee-groove made in the shell and falls into the aligned notches. When we turn in clockwise to lock the mechanism, 0-discs allow to reset the sidebar in the shell’s groove because the sidebar isn’t springloaded.<\/p>\n\n\n\n

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Quand la clef est tourn\u00e9e dans le sens anti-horaire, les disques 0 sont les premiers en contact avec les tailles 0 de la clef. Au fur et \u00e0 mesure de la rotation, la clef entraine les autres disques. Une fois \u00e0 90\u00b0, la clef entraine le rotor par l’interm\u00e9diaire des disques 0. Le rotor agit sur la barre lat\u00e9rale qui glisse le long de la rainure en v\u00e9 et se loge dans les encoches align\u00e9es. Quand on tourne la clef dans le sens oppos\u00e9 pour verrouiller le m\u00e9canisme, les disques 0 permettent de repositionner la barre lat\u00e9rale dans la rainure du stator car elle n’a aucun ressort de rappel.<\/span><\/em><\/p>\n\n\n\n

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(1) Wikipedia source<\/em> : https:\/\/commons.wikimedia.org\/wiki\/File:Cadenas_romain.jpg<\/p>\n\n\n\n

(2) Hoepfner, W. : “Ein Kombinationsschloss aus dem Karameikos”, 1970, Arch\u00e4ologischer Anzeiger Tome 85 Volume 2 : p 210\u2013213<\/em>.<\/p>\n\n\n\n

(3) “L\u00e4sebok f\u00f6r folkskolan : Faksimilutg\u00e5va efter f\u00f6rsta upplagan”, Norstedts f\u00f6rlag, 1868 : p 348-350.<\/p>\n","protected":false},"excerpt":{"rendered":"

Origin & development The origin of rotating disc tumbler is an very old concept. In 2nd century AD, romans already used combination padlocks made in bronze with coding-wheels. In 1870, we found some vestiges in Kerameikos near Athens (2). L’origine des s\u00fbret\u00e9s \u00e0 disque est un concept tr\u00e8s ancien. D\u00e8s le 2\u00e8me si\u00e8cle apr\u00e8s J.C-,…<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-783","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/pages\/783"}],"collection":[{"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/comments?post=783"}],"version-history":[{"count":13,"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/pages\/783\/revisions"}],"predecessor-version":[{"id":1009,"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/pages\/783\/revisions\/1009"}],"wp:attachment":[{"href":"https:\/\/lockanalyst.org\/index.php\/wp-json\/wp\/v2\/media?parent=783"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}