From my notes:
En France la loi de 1844 stipule que les brevets sont délivrés « sans examen préalable, aux risques et périls des demandeurs, et sans garantie soit de la réalité, de la nouveauté ou du mérite de l’invention, soit de la fidélité ou de l’exactitude de la description ». Des brevets avec les initiales S.G.D.G. (sans garantie du gouvernement) furent délivrés en France jusqu’en 1968.
Translation:
In France the law of 1844 stipulates that patents are issued "without screening, the risk of applicants, and no guarantee either the reality, novelty or merit of the invention, either the fidelity or the accuracy of the description. Patents with the initials S.G.D.G. (without Government Guarantee) were awarded in France until 1968.
Which would mean that this padlock must have been patented between 1844 and 1968. It would therefore have an age between 42 years up to 166 years.
I have been told that the style of the letters and numbers stamped on it was popular around the time of the 1st world war, 1914-1918. Also when this law came out in France in 1844 it was not very popular with only a few patents beening taken out each year. It was only after the Franco-Prussia War (finished 1871) did the idea of patenting one’s work really take off and the number of new patents taken out each year went up to several thousand a year.
This little bit of crude logic would give a patent date between say 1880 and 1920; which would give the padlock an age between 90 and 130 years.
Observations and comments welcomed
Lionel
