Honeywell Chevron with biazzare DPDT mercury bulb switch

Awhile ago I got this <LINK_TEXT text=" "> </LINK_TEXT> Honeywell Chevron. As you can notice from the pictures, this one has a large black box containing what I believe to be a mercury bulb switch or two. I have tested it, and the two pairs of terminals are both isolated from each other and both activate when the station is activated. As you can hear in the video, the station contains some kind of liquid. The wire going between two of the terminals is a EOL resistor. My best guess is that Couch (probably) decided that it was easier to use a mechanical lever connected to two bulb switches in order to keep them isolated. Does anyone else have any other examples or documentation on this? What other strange switches have you found on pull stations before?

That’s got to be pretty rare just like mine!


That looks very nice with the NY stripe. Is there anything else notable about it?

That thing looks brand new! Love the stripe!

Very rare version, exclusively made for the city of New York, which has some interesting code requirements.

It’s brand new! Made in the 90’s I believe

Nice pull station! Honeywell-branded versions of these devices don’t appear to be too common. I have a Simplex-branded model (4251-111) from the 1960s, but it uses a typical momentary pushbutton instead of a mercury switch. Oddly enough, despite its switch being much smaller, my 4251-111 still features the large black plastic housing behind the back plate.

If I’m not mistaken, Gamewell also offered mercury switches with their Vitaguard non-coded pull stations.

I always thought the Mirtone 73201/73204 featured a rather unique switch design. Instead of using a typical toggle switch or momentary pushbutton, these devices have a sort of knife switch that is integrated within the pull station’s body. There is a plastic tab with a small metal “button” (similar to a rivet) that sticks out behind the lever. Upon activation, this tab passes through a set of metal jaws. As the metal button meets both metal jaws, the circuit is closed.

The Edwards 274-series stations also featured a unique switch. These devices use an odd momentary pushbutton that is integrated within the device’s body. Resetting the pull station involves sticking a key through the button to release it. A demonstration of this device can be seen in this video, which was produced by another member of this forum (EdwardsFan).

The Edwards 78 pull station also has a bizzare switch mechanism. When the glass plate is installed and the station is normal, the contacts are separated. When you pull the ring at the front of the pull station and break the glass, the contacts touch.

It’s surprising how simplistic and cheap that pull station is, and to this day I’ve never seen one in person before.

Oh man. I have an Edwards 274 and it is the worst device in my collection. It is very hard to pull due to the cheap plastic and insane friction that the hinge creates. It is so cheap and so strong in fact, that it broke itself after I pulled it a few times. It will probably break if you look at it the wrong way. Also, I never noticed the switch lock in place like it did in the video. Maybe there is something wrong with mine. I don’t really care, it’s broken after all. It just makes me wonder how that thing could even be considered a life saftey device, or how it passes yearly inspections, if it even does. Maybe thats why many of us have never seen them in buildings.

I agree. The locking tabs on the sides of the front cover make it quite hard to activate. The sound it makes when being reset doesn’t inspire much confidence; it’s a symphony of snaps, creaks and squeaks unlike anything I’ve ever heard. I’ve owned a 274-111 for seven years and have activated it perhaps a total of three times, for fear of breaking it. There was even a recall for these pull stations as the switch could fail to activate.

The switch on my 274-111 does not lock either. This appears to be a common issue. In fact, I only found out that it was supposed to lock upon activation when I first saw EdwardsFan’s video. My 274-111 came with a reset key, but the key is useless as the front cover can simply be pushed back up. The switch’s rather odd mechanism is explained in the patent.

It appears that these switches were designed to be easily configurable for NO or NC operation, according to the patent:

Sounds familiar to a Notifier pull I’ve seen, they looked like the Mircom MS-401. I can’t remember the model #, but I remember when you pulled it there were these metal tabs, and to reset it, you had to stick a terminal screwdriver in the side of the pull station to lift the tab back up and close the station.

I happen to own one of those pull stations. Mine is rebranded by Simplex (model MS-301C).

These pull stations feature two design quirks with respect to the switch’s operation. Firstly, the switch is not directly actuated by the lever. Instead, the lever releases a spring which, in turn, actuates the switch. The only other pull stations I can think of that use a similar mechanism (with no direct contact between the lever and the switch) are round Standard Electric Time models.

Secondly, the switch is released in normal position; upon activation, the spring presses down on the switch. Pull stations that use momentary pushbuttons or micro switches typically use the opposite configuration, whereby activating the lever releases the switch.