Saturday, August 23, 2014

A Spring Gate Latch


I’ve been clearing out old items from the shop to provide more working space.  I found this model I made for a gate project.  It never got real finish work or a protective coating so it is a bit rusty but the design should still be easy to see.

I remember this type of gate latch from my childhood.  It seems so familiar and I can fee the satisfying positive locking of the mechanism.
I remember them as all being factory made but back then I wouldn’t have recognized forge work.

The short latch spring bar in my model is made from a piece of 1/2” mild steel square bar 19.5” long.  I sawed a split about 2” at one end and opened the split so flat tapers could be forged.  Scroll tongs were used to create the grip finial shape.  The section just below the finial was left 1/2” square to show the parent stock.  The 4.5” below that was chamfered to roughly octagonal shape.  The rest of the bar was flattened and drawn out to create the spring section which is about 11.5” in length and angled to create the offset needed for the spring to function.  Two holes for the mounting lag screws were made near the bottom end.

The keeper-catch and the guide hoop were formed from 3/16” x 3/4” flat bar.  The hoop needs no forging only bending to shape.  The keeper has a center portion forged the-hard-way.  A kerf is cut out and filed there to catch the spring bar as seen in image 06.

In an actual installation I’d check the performance and if I felt the spring needed to be a bit stiffer I’d heat the flat spring section and quench it.
The rusty model.

2" split.

Partially forged spring bar.

Finials finished.

Long and short spring bars with offsets bent.

Rough forging of the keeper-catches before notching.

Guide, spring bar and keeper-catch in locked position.

Spring bar mounting.

Grip finial detail.


Here is a commercial example.



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