Friday, December 27, 2013

Hahl Pneumatic Master Clock

This Blog follows my restoration of a Hahl Pneumatic Master Clock.

If you have a Hahl clock or parts for a Hahl clock please email me at stotlarj@gmail.com.

Hahl made Pneumatic master clocks that in turn ran slave clocks throughout schools, factories, office buildings, etc.

The clock compresses or expands one or two bellows every minute. This change in pressure would cause all slave clocks to advance one minute.

This particular clock came from the Mentor High School in Mentor, Ohio.

This clock would have operated the slave clocks in the school and it would have also operated the bells for class periods. The bell program unit is the cylindrical unit below the clock.

I obtained it locally from a lady who has owned it for years. it was in very bad shape when I picked it up.

Clicking on pictures will enlarge them.

Video of Hahl Pneumatic Master Clock in Action



Finished at last

I finally wrapped up my clock project. Today I put the restored movement in the case and ran new cable for the weights. It is keeping perfect time.


Picture shows weights, pendulum and bell relays. Each weight is 70 pounds. The brass tube on the left side of the clock contained a glass vial that was filled with glycerine and red dye. This was a visual check to see if you had an air leak in the system.

Cylinder below clock mechanism is the device to program when the school bells would ring




Monday, October 22, 2012

My New Hahl Clock

I just picked up this Hahl Pneumatic Master Clock. Not sure of the year, but it probably dates to around 1910 or so. This clock is unrestored but complete. Some models had two pneumatic plungers, but this one has only one. It was obviously built to power fewer clocks than the two plunger models.

The clock has the original programmable bell dial with it. It also has the original relays and buttons for the four bells that it rang.

This looks like it will be a fun project!!!













Friday, October 21, 2011

Wanted: Wenzel Pneumatic Master Clock

Here is a picture of a Wenzel pneumatic master clock. This clock used glass jars filled with glycerine instead of bellows to power the slave clocks.

If you have one or know where I can get one please let me know.

stotlarj@gmail.com