SherbyNet - /page/wikibook/entry.mu

Micron Document

<!DOCTYPE html>

<title>Interrupted screw</title>

</head>

<span id="openzim-page-title" class="mw-page-title-main"><span class="mw-page-title-main">Interrupted screw</span></span>

</h1>

</header>

/* start https://en.wikipedia.org/ */

.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}

/* end https://en.wikipedia.org/ */

</style><style data-mw-deduplicate="TemplateStyles:r1248332772">

/* start https://en.wikipedia.org/ */

.mw-parser-output .multiple-issues-text{width:95%;margin:0.2em 0}.mw-parser-output .multiple-issues-text>.mw-collapsible-content{margin-top:0.3em}.mw-parser-output .compact-ambox .ambox{border:none;border-collapse:collapse;background-color:transparent;margin:0 0 0 1.6em!important;padding:0!important;width:auto;display:block}body.mediawiki .mw-parser-output .compact-ambox .ambox.mbox-small-left{font-size:100%;width:auto;margin:0}.mw-parser-output .compact-ambox .ambox .mbox-text{padding:0!important;margin:0!important}.mw-parser-output .compact-ambox .ambox .mbox-text-span{display:list-item;line-height:1.5em;list-style-type:disc}body.skin-minerva .mw-parser-output .multiple-issues-text>.mw-collapsible-toggle,.mw-parser-output .compact-ambox .ambox .mbox-image,.mw-parser-output .compact-ambox .ambox .mbox-imageright,.mw-parser-output .compact-ambox .ambox .mbox-empty-cell,.mw-parser-output .compact-ambox .hide-when-compact{display:none}

/* end https://en.wikipedia.org/ */

</style>

<p>An <b>interrupted screw</b> or <b>interrupted thread</b> is a mechanical device typically used in the <a href="Breech-loading_weapon" class="mw-redirect" title="Breech-loading weapon">breech</a> of <a href="Artillery" title="Artillery">artillery</a> guns. It is believed to have been invented in 1845.<sup id="cite_ref-Bunch_1-0" class="reference"><a href="#cite_note-Bunch-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup>

</p><p>The system has also been used to close other devices, including the joint between helmet (bonnet) and breastplate (corselet) of <a href="Standard_diving_suit" class="mw-redirect" title="Standard diving suit">standard diving suit</a> helmets, and the locks of <a href="Diving_chamber" title="Diving chamber">diving chambers</a>.

</p>

<div class="mw-heading mw-heading2"><h2 id="Design">Design</h2></div>

<p>An interrupted screw has a section of thread along its axis removed. The screw is mated with a partially threaded hole in the receptacle: threadless channels in the breechblock screw line up with the threaded parts of the receptacle, and vice versa. The screw can thus be smoothly inserted all the way into the receptacle, after which as little as one-eighth of a turn can engage the two sets of threads securely, sealing the joint.

</p><p>The amount of rotation required to achieve full closure depends on the number of unthreaded sectors. The minimum balanced arrangement has two sectors of 90°, and requires 1/4 turn to lock. three sectors of 60° requires 1/6 turn to lock, and the typical arrangement on a diving helmet, four sectors of 45°, requires 1/8 turn to lock.<sup id="cite_ref-USN_1963_2-0" class="reference"><a href="#cite_note-USN_1963-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup>

</p>

<div class="mw-heading mw-heading2"><h2 id="Applications">Applications</h2></div>

<p>In the artillery application, the screw is set into the breechblock and mated with a partially threaded hole at the rear of the weapon's chamber.

</p><p>American engraver Benjamin Chambers, Sr.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> received a patent<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> in 1849 for a <a href="Wrought_iron" title="Wrought iron">wrought iron</a> <a href="Built-up_gun" title="Built-up gun">built-up gun</a> "dissected screw breech" with "sectional screws" "cut therein for the purpose of speedily opening the breech for swabbing, depositing the load, and readily closing it again when the gun is to be discharged". His gun was built and tested with metallic cartridges, center-primed with a <a href="Percussion_cap" title="Percussion cap">percussion cap</a>, because the <a href="United_States_Navy" title="United States Navy">US Navy</a> was initially interested, and chief of the <a href="Bureau_of_Ordnance" title="Bureau of Ordnance">Bureau of Ordnance</a> <a href="Charles_Morris_(naval_officer)" title="Charles Morris (naval officer)">Charles Morris</a> recommended more developments, but the system was too expensive for the time and cheaper <a href="Dahlgren_gun" title="Dahlgren gun">Dahlgren guns</a> were adopted instead.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup>

</p><p>Breech sealing was improved with the <a href="De_Bange" class="mw-redirect" title="De Bange">de Bange obturator</a> in 1872, and all interrupted screw breeches with this system were generally known as the De Bange type.

</p>

<div class="mw-heading mw-heading2"><h2 id="Weakness">Weakness</h2></div>

<p>The major weakness of the original designs was that only half of the circumference of the breechblock could be threaded, hence a fairly long breechblock was still required to achieve a secure lock. <a href="Axel_Welin" title="Axel Welin">Axel Welin</a> solved this problem with his stepped interrupted screw design: the <a href="Welin_breech_block" title="Welin breech block">Welin breech block</a> of 1890. This design has threads of the block and breech cut in steps of successively larger <a href="Radius" title="Radius">radius</a>. For example, this allows a breechblock with four steps to allow four-fifths of the block circumference to be threaded, allowing for a much shorter breechblock while still requiring only one-fifth of a turn to open or close. This is the basic design still in use with <a href="Shell_(projectile)#Separate_loading_bagged_charge" title="Shell (projectile)">bagged charge</a> artillery.

</p><p>Interrupted screws are occasionally seen in loose gunpowder rifles, as this mechanism was historically one of the few practical ways to achieve a gas-proof seal with a breech-loading firearm that does not employ metallic <a href="Cartridge_(firearms)" title="Cartridge (firearms)">cartridges</a>. An earlier method was the use of a wedge to block the rear of the gun.<sup id="cite_ref-Bunch_1-1" class="reference"><a href="#cite_note-Bunch-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> The interrupted screw arrangement enables more precise and repeatable lock up in-battery position, increasing accuracy on high powered sniper rifles.

</p><p>The system has also been used to close other applications, including the joint between helmet (bonnet) and breastplate (corselet) of <a href="Standard_diving_suit" class="mw-redirect" title="Standard diving suit">standard diving suit</a> helmets, and the locks of <a href="Diving_chamber" title="Diving chamber">diving chambers</a>.

</p>

<ul><li><a href="Locked_breech" title="Locked breech">Locked breech</a></li>

<li><a href="Rotating_bolt" title="Rotating bolt">Rotating bolt</a></li></ul>

<div class="mw-heading mw-heading3"><h3 id="Firearms_using_the_Interrupted_screw">Firearms using the Interrupted screw</h3></div>

<li><a href="Thompson_Autorifle" title="Thompson Autorifle">Thompson Autorifle</a></li>

<li><a href="Walther_WA2000" class="mw-redirect" title="Walther WA2000">Walther WA2000</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

/* start https://en.wikipedia.org/ */

.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}

/* end https://en.wikipedia.org/ */

</style><div class="reflist">

/* start https://en.wikipedia.org/ */

.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("./mw/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("./mw/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("./mw/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("./mw/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}

/* end https://en.wikipedia.org/ */

</style><cite id="CITEREFBunchBunchHellemans2004" class="citation book cs1">Bunch, Bryan; Bunch, Bryan H.; Hellemans, Alexander (2004). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=MlQ7NK9dw7IC&pg=PA355"><i>The History of Science and Technology: A Browser's Guide to the Great Discoveries, Inventions, and the People who Made Them, from the Dawn of Time to Today</i></a>. Houghton Mifflin. p. 355. <a href="ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <bdi>978-0-618-22123-3</bdi>.</cite></span>

</li>

<li id="cite_note-USN_1963-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-USN_1963_2-0">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="https://www.youtube.com/watch?v=V_QiyUJxf78"><span class=""> "Deep Sea Diving: Assembling the Deep Sea Outfit – 1963 – US Navy Training"</span></a> on <a href="YouTube_video_(identifier)" class="mw-redirect" title="YouTube video (identifier)">YouTube</a></span>

</li>

<li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><cite id="CITEREFHinman2019" class="citation web cs1">Hinman, Janet Evans (August 28, 2019). <a rel="nofollow" class="external text" href="http://thehouseandhomemagazine.com/api/content/6bda02c2-c9b8-11e9-becb-12f1225286c6/">"Stamped in Time: The "Chambers Shop""</a>. <i>thehouseandhomemagazine.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2023-03-30</span></span>.</cite></span>

</li>

<li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><span><a rel="nofollow" class="external text" href="https://patents.google.com/patent/US6612A">U.S. patent 6612A</a></span></span>

</li>

<li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><cite class="citation book cs1"><a rel="nofollow" class="external text" href="https://books.google.com/books?id=9JotAAAAYAAJ&pg=PA9"><i>Naval Armament: Pamphlet Collection</i></a>. 1874.</cite></span>

</li>

</ol></div></div>

<div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2></div>

<ul><li><a rel="nofollow" class="external text" href="https://web.archive.org/web/20120225021630/http://www.riv.co.nz/rnza/hist/ord/breech.htm">Interrupted Screw Breech Mechanisms</a></li>

<li><a rel="nofollow" class="external text" href="http://www.navweaps.com/Weapons/Gun_Data.htm">Interrupted Threads Used On Naval Guns</a></li></ul></div><div><div class="zim-footer">

This article is issued from <a class="external text" title="Last edited on 2025-08-07" href="https://en.wikipedia.org/wiki/?title=Interrupted_screw&oldid=1304615873">Wikipedia</a>. The text is available under <a class="external text" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en">Creative Commons Attribution-Share Alike 4.0</a> unless otherwise noted. Additional terms may apply for the media files.

</div>

</div></div>

</div>

</main>

</div>

</body></html>