Keystone module

<h2 id="types">Types</h2>
<p>Many types of jacks are available in the keystone module format, limited mainly by their physical size, including:
</p>
<ul><li><a href="/facts/6P6C/M3BYRSFV">6P6C</a> (<a href="/facts/RJ-11/FJIzzlpD">RJ-11</a>) <a href="/facts/Modular_connector/M3BYRSFV">modular jacks</a> (telephone)</li>
<li><a href="/facts/8P8C/M3BYRSFV">8P8C</a> (<a href="/facts/RJ45_(telecommunications)/FJIzzlpD">RJ-45</a>) modular jacks (computer networking), unshielded for UTP cable and shielded for STP.</li>
<li><a href="/facts/F_connector/XV88T6fV">F connector</a> (TV antenna/cable/satellite), 75 ohm coaxial</li>
<li><a href="/facts/RCA_jack/A9etkIUn">RCA jacks</a> (audio/video)</li>
<li><a href="/facts/Mini-DIN_connector/AvyX39tF">4-pin mini-DIN</a> (<a href="/facts/S-Video/shm26vB5">S-Video</a> jacks)</li>
<li><a href="/facts/HDMI/HuNwzm04">HDMI</a> jacks (high-definition video and audio)</li>
<li><a href="/facts/Optical_fiber_connector/uIC3170n">Optical fiber connectors</a></li>
<li><a href="/facts/BNC_connector/JCfgK3cf">BNC connector</a> (50 ohm coaxial)</li>
<li><a href="/facts/USB/XcIKWLyg">USB</a> jacks</li>
<li><a href="/facts/Speaker_terminal/gkhvsADh">Speaker terminals</a></li>
<li><a href="/facts/Banana_connector/yeGBr5PG">Banana connectors</a></li>
<li><a href="/facts/Binding_post/nnInjBd1">Binding posts</a></li>
<li><a href="/facts/Phone_connector_(audio)/KvpIlV94">3.5 mm TRS connector</a> (miniature stereo headphone jack)</li>
<li><a href="/facts/British_telephone_socket/1XrhdgDr">British telephone socket</a> either as a master socket or a secondary socket</li></ul>

<h2 id="history">History</h2>
<p>The origin of the "Keystone" module may be traced back to US Patent 4261633 of Aug 27, 1979 for a "Wiring module for telephone jack" - by Amp Incorporated.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>
The module referred to in that patent was affixed by "A pair of diagonally inclined mounting flanges (which) include stepped, panel bearing surfaces .. at the outer free ends thereof." The unit was "inserted through the panel opening, with the sides of the opening resiliently deflecting the (mounting flanges), until they pass through the opening and spring outwardly away from the remainder of the housing, with the panel bearing surfaces .. thereof seated against the front surface of the panel".
</p><p>However, the current design (now called "Keystone") is first referenced in US Patent US 5624274 of Nov 7, 1995 for a "Telephone connector with contact protection block" - by International Connectors And Cable Corporation.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> In this design the module is affixed by a single diagonally inclined mounting flange, together with a protuberance (ramp) on the opposite side. In the patent description, it is stated that "the jack assembly may be mounted to a face plate by first inserting the bottom of the jack assembly into a jack opening until the ramp of the housing engages a mounting surface of the face plate. The jack assembly is then rotated and snapped into place due to deflection of the cantilever latch of the housing."
</p>

<h2 id="external-links">External links</h2>
<p> Media related to Keystone modules at Wikimedia Commons
</p>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"Wiring module for telephone jack". <a href="https://patents.google.com/patent/US4261633" target="_blank">https://patents.google.com/patent/US4261633</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>"Telephone connector with contact protection block". <a href="https://patents.google.com/patent/US5624274" target="_blank">https://patents.google.com/patent/US5624274</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
</ol>

Keystone module open-in-new

Keystone module