Plates, Clamping No. 11
 

Anyone know what the two holes at the upper centre of these plates are for? I cannot recall running across an explanation for them anywhere.

Perhaps anchor points for small chains or cords to retain the 1/16" x 1/2" split (cotter) pins used to lock the burled nuts from loosening on the big canvas straps? They would certainly be in the right location, either side of a 19-Set.


David

Good question! Although I can't see how anything can protrude through the back as the plate is very tight to the set when slotted into the keyholes :confused Ron

That's a good point, Ron.

I was suspect of any small chains working for that reason, but the cord idea stuck in my mind only because an NOS Plate assembly in my spare bits bin, came with a burled nut attached. The attachment was done through one of those holes using that 1mm thick waxed cotton, or linen, cord that shows up from time to time with wartime packaging.

The cording 'might' work for keeping the split pin around for a while, but the other thing I notice on this plate is the edges of the metal are quite sharp and it would not take much load against a cord to slice it.

It's possible these plates were not unique to the 19-Set equipment and these holes had other uses elsewhere. If one was able to pass small bolts or screws through them into something, two plates might make a set of fixed carry handles, maybe???:blink:

Then again, not knowing much at all about metal forming techniques, maybe these two holes are nothing more than guides for aligning the plate when the two shoulder pins are riveted into place.

Gosh I hate a mystery when I'm between beer runs! :(


David

I don't think there's sufficient clearance between plate and case to admit a rivet head, and the holes are most likely to assist in the production process (which must have been quite fierce, given some of the curves and bends).

The plates were only used at one end of the strap, the fixed end had a much simpler plate - effectively flat but with a folded top edge for rigidity.

They were used with a lot of the Pye designed cases: WS19, WS22, PCR and the post-WW2 WS (or SR) C12. (Also the RF Amplifier for the British WS19HP, and most likely parts of the WS10 since the receiver used that type of case.

Chris.

Yes, Chris, on reflection these holes must be a production item rather than something for the end user to actually utilize. Probably helped stabilize the rectangular steel blanks during the stamping/forming process.

On the NOS one, you can actually see fine, parallel stress lines running perpendicular to the major curves, and when I think on it, I have seen a lot of these plates over the years that have failed by the web of metal to the outside of the main belt screw hole, cracking off. The crack lines would be parallel to these stress lines. Maybe it pays not to overtighten the burled nuts.

David