I was just thinking to myself how nice it would be to have a night off…actually, since it’s already 8:30 p.m. it’s more like a half-night.  Then I remembered that last week I received an article from a “guest blogger.”  Woohoo!  Thanks TJ!

IT’S A DOG EAT DOG WORLD
By: T.J. Gottwalt, AHC, CDC, CSI, CCPR, MAI, Ingersoll Rand Security Technologies

Ever wonder about some of the strange terminology we use for specific construction products, especially door hardware?  Twisted, I know.  Take, for example, the term “dogging”.  Webster defines dogging as a transitive verb and as follows:
1. a. to hunt, track, or follow like a hound
….b. to worry as if by pursuit with dogs
….c. to bother or pester persistently
2. to fasten with a dog (Aha! Read on, friend…)

Dogging in Scotland refers to truancy.  Wikipedia lists dogging as a British English euphemism (which we will not go into in this article), but also lists it as “the use of a mechanical device called a ‘dog’ to fasten something to something else (for example, doors, hatches, or shafts)”.  I think this is where we’re onto something, because the term dogging in the hardware world refers to the use of a mechanical device to hold a latch in a retracted position.  Most commonly, dogging is a feature used in exit (or panic) devices to hold the push rail or bar in a retracted position, thus allowing a door to operate in push/pull mode without latching.  Dogging can also be done to aluminum door latchsets and other latching devices.

Figure 1: Von Duprin 98 with hex-key dogging

Most exit devices are “dogged down” by depressing the push rail and, using a common allen wrench inserted in a hole, turning a cam which holds the rail (and thus the latchbolt) in a retracted position.  This dogging serves several functions.  On a door with pull trim, this essentially locks or unlocks the door for daily use.  It also serves to minimize the cycles the exit device push bar and latch are subject to, thereby extending the life of the hardware immeasurably.  It also means the door operates much more quietly, a valid concern if you’re specifying for a courtroom, an office, a theater, or a performing arts center.

Figure 2: cylinder dogging

If relying on something as simple as an allen wrench (or hex key) to secure perimeter doors sounds a bit foolish, you’d be right.   That’s why cylinder dogging is an oft used option on exit devices.  This option requires that a key be used in a cylinder in order to “dog” the exit device (see Figure 2).  Whenever I’m consulting on a school project, I’m sure to remind the architect about how school kids love to dog down the exit devices on exterior doors late on a Friday afternoon by using an allen key taken from their parents’ toolbox.  (I have no personal experience with this, of course.)  This basically leaves these doors unsecured for the entire weekend.  Cylinder dogging can eliminate this potential security threat.

It is important to note that fire rated exit devices cannot be dogged manually.  Since one of the requirements for a fire door is that they be self-latching, dogging an exit device would not allow the door to latch.  For that reason, fire rated exit devices have no manual means of dogging.  However, there are electrical means of dogging an exit device so that, in case of a fire alarm, the device can automatically “undog” and allow the door to latch.  That’s a topic for another exciting article…

So, it really is a dog-eat-dog world out there… just don’t be caught wearing milkbone underwear!

This post was contributed by T.J. Gottwalt, a specification writer for Ingersoll Rand Security Technologies.

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