Semple

[Bellifortis]

Today I have been reading in the Microsoft digitized book of the University of California's copy of "Shrapnell shell Manufacture" 1915. There a SEMPLE Tracer is noted for US shells. I remember reading the name SEMPLE before in US ordnance publications about fuze design. A search brought up US 2415262 patent of 1941, I assume this is the often mentioned "Semple Plunger". Another search brought up 9 british patents between 1902 and 1917 to John Bonner Semple. I wonder if this is the same John B. Semple as about 35 years lie between the british and the US patents. A question to the fuze buffs out there : Do you know of any other fuze parts that carry the name of Semple, besides the plunger.
Regards,
Bellifortis.

 

[Gspragge]

I have various ww1 and prior tracers marked Semple , tracers in ww1 French aerial projectiles are also made by Semple. Some are Semple tracer/Fuzes but these are for 1 & 3 Pr base fuzed projectiles. Wether there are other larger types of fuzes made by Semple I don't know.

 

[Bellifortis]

Semple was not the manufacturer, but the inventor of different fuze designs. The manufacturers were very many. This is what the above mentioned book is all about. A very nice read. What is a "SEMPLE Tracer" or what makes is different to other designs so that it carries the name of the inventor ?
Bellifortis.

 

[Bellifortis]

I'm surprised to not have gotten any reaction from US members on "Semple". Over the weekend I found a multitude of patents by John Bonner Semple taken out mainly in US,GB,Fr between 1902 and 1974. It is very seldom that ordnance items carry the name of their inventor. I don't know of any other US inventor that worked over the long time span of 70 years and whose inventions, like the "Semple Plunger" are still used today. By the way, because this is the section about literature, the book "Shrapnell Shell Manufacure" 1915 is really worth a read. Seldom one sees such detailed construction information, with measurements of every single screw, on US, GB and RU shells and their fuzes, as in this publication.
Regards,
Bellifortis.

 

[Gspragge]

It appears he had a firm in Pittsburg PA.

 

[US-Subs]

I know that I've seen it in a number of places, but this is the only thing I've found so far.

 

[bacarnal]

It seems that John B. Semple was very prolific in fuze design and that a lot of his innovations were incorporated in US WWI fuzes. The "Semple Device" concussion (impact inertia) back up in the M1907M "Scoville" fuze and it's progeny is but an example. The same concussion device is found in the US 1.457" Sub Caliber smoke round (as Gordon pointed out to me). Semple also had what seems to be a great influence in US Naval fuzes of the period. I've tried to search for any reference to him, his company or anything else and come up pretty much empty. Not much reference to his name is had after WWI and none that I can find after WWII. For the amount of influence that he seemed to have in fuze design and components, it is kind of mysterious that you can find hardly any mention of him now. Cheers, Bruce.

 

[Bellifortis]

Looking over the many patents that were granted to John B.Semple, I think that the Semple Tracer, as detailed in the above mentioned book and the photos shown, is based on the following 2 patents : GB 190911252 and 190911458 both from 1909 where the tracer is not ignited directly by the burning propellant but by a seperate percussion cap which is ignited by a plunger-needle actuated by the propellant gases.
Bellifortis.

 

[Gspragge]

This is the semple tracer as used in 1915 in British projectiles. The description of how it works is excellent.