Cylinder Assemblies Most Medeco cylinders are UL 437 list- ed. This includes their tubular Maxum deadbolt locks, rim, mortise, cylindri- cal, tubular and auxiliary locksets and padlock cylinders. Among other locking devices, it also includes the 3200 Series interchangeable cores, but not the 3100 Series ICs that are retrofitted to the Yale LFIC. In the factory, cylinders are lubricated Figure 22. Most Medeco cylinders are UL 437 listed. Logically, it would appear that pin stacks should be equal for even pressure on the pins, preserving spring dependability and core integrity. Though in the engineer- ing phase, an “acceptable leeway” was determined, which gives some latitude as to the parameters of spring tension within the cylinder. Now then, let’s focus directly on springs. Spring Tension There does exist a determined amount of opt imum spring pressure that should occur in each chamber of the cylinder within Original Product cyl- inders. As we may know, excessive pressure can result in spring failure and, eventually, core failure. Too little pressure may result in Medeco pins not rotating and being seated properly within the key. Bronze springs are used in most cylin- der chambers, with the exception of IC cylinders. Bronze springs are still used in chambers 1, 2, 5 and 6, though stain- less steel springs are used in the control chambers 3 and 4 to help the pins elevate and rotate through the additional control sleeve area. WWW.ALOA.ORG Medeco Cylinders The traditional Medeco cylinder uses the standard pin tumbler operating princi- ples; however, there are some differences. Those that apply to the IC will first be listed below and then explained more thoroughly. They are: Use of a sidebar at the 2 o’clock position. Sidebar must be positioned correctly. Bottom pins (only) have a slot for side- bar contact. Bottom pins have six possible angled slopes. Bottom pins have “dummy slots” (pick resistance). No master pins should be used in chambers 3 and 4 when originating control key. Control sleeve accounts for third and fourth chambers only. LFICs are not pinned to control; needs no build-up pins. Use only stainless steel springs in third and fourth chambers. I-cores in 3200 Series are UL 437 listed; 3100 Series ICs are not. Care must be used planning master keyed systems. with KeyLube 2.0 (Medeco’s own), which is a white Teflon powder, PTFE. This is important because only this lubricant won’t void the warranty. Thus, graphite and liquid lubricants are discouraged. For lubrication in the field, KeyLube aerosol is recommended. Sidebar The sidebar itself resides within the plug. It’s situated between the plug and the shell by two small springs. When in a re- laxed state, the sidebar is gently pushed partially into a milled, smooth-angled recess in the shell. Six small legs (prongs) are craſted to extend into the chambers of the plug when the bottom pins are in the plug and in the proper position. Un- derstand that any size bottom pin will allow the sidebar prongs to enter, but any bottom pin may not help to operate the shear line. Also, an uncombinated core will allow the sidebar to enter the cham- bers, thus permitting plug rotation. This is mentioned for the reader to understand the function of the sidebar as an anti- picking device. As stated previously, no other pin, nor key, ever comes into contact with the side- bar itself. As a matter of fact, the sidebar is not readily accessible to someone at- tempting to compromise the locking de- vice. Furthermore, there’s a strategically placed hardened steel ball (looks like a ball bearing] that is implanted in the end of the sidebar to make it drill-resistant. DECEMBER 2015 KEYNOTES 45
