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Dec
05

On the Subject of Gibs.

Door gibs, specifically hoistway door gibs, have gotten a lot of attention over the last couple of years. With the prevalence of motorized scooters, the point of impact in a hoistway door strike in more and more cases has dropped to the bottom of the door, putting more force on the gibs vs. the hanger assembly. Also, the lateral force that can be created by these scooters is significant. When we spec heavy duty (colleges, etc) elevator systems, we always call for reinforced door gibs. SEES’ Enforcer is a great choice, claiming to be able to “handle over 18,000 lbs of force!”

At any rate, here is a scary, trash-chute door situation I came across last week during an inspection. (The fire tabs were also not bent down on the gib assembly)

4 comments

  1. Elevator Radio Show – Video/Audio Show #316 – Week 12/12/2012 | Elevator Radio Show Podcast says:

    […] of the week The secrets of elevator design Schindler wins national service contract with Simon On the Subject of Gibs MAEC Christmas Event KONE to deliver elevators to Oslo Airport Elevator offline? Try rebooting […]

  2. Doug Witham says:

    Daniel

    Great topic. Door gibs have been an issue forever. A couple of points to stir up conversation:

    1 – No mater how strong you make the gib itself, the point of failure is most often where it is screwed into the sheet metal door. This is often done with ‘self tapping screws’. The bottom of a door panel is the first place for rust to show up. This is a tough issue to overcome.

    2 – If you change the door gib to a more robust one that was not part of the assembly when the fire test was done, have you voided the label?

    1. daniel says:

      Thanks Doug!
      Yes – the gib assembly/door interface is really important. Some of the “stronger” gibs do have an extra/more spaced out row of screw holes for door attachment, and a thicker plate for the door interface. Maybe they should extend the plate up to cover more of door surface and get away from the rust. In this case, however, the actual nylon gib was not attached to the gib assembly (which was still on the door).
      Good question on the fire testing. I’d imagine mechanics replace gibs out there every day. If not like for like, then now there are open holes in the door and different gibs from when the door was tested. I’ll see if I can find out about it!

    2. Richie says:

      Hey guys, I’m an installer/inspector in NYC and what we’ve been doing to comply with local law code is adding a z bracket 8″ wide and about 1/8″ thick.

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