84 - Charles DESNOS-GARDISSAL (1832 - 1882) (2) [1]

Charles Jules Pierre DESNOS-GARDISSAL was a French patent agent who, at the same time, was a prolific inventor himself (see No 69).

In this particular case, however, he applied on 27 April 1865 for a brevet d’importation for a 

Nouveau système d’embrayage électrique et ses applications

based on a French patent of 12 September 1864 belonging to François Ferdinand Auguste ACHARD, ingénieur (1813 - 1893). 

ACHARD is considered to be the inventor of the electromagnetic brake and held patents in this field in many countries, including the USA and United Kingdom. He filed his first patents for electromagnetic control systems as early as 1851 in France under the title of “embrayeur électrique hélicoïdal”. He obtained additional French patents on the system in the years 1856, 1858, 1862 and 1864.

In 1861 ACHARD filed his first patent application outside of France in the United Kingdom under the very broad title of : “Improved electric apparatus applicable to various useful purposes”. [2]

The introduction to the British patent reads as follows :

This Invention relates to the application of electric apparatus or gearing to various useful purposes. Firstly, to the working of brakes, signals, and other apparatus on railways; secondly, to feeding steam boilers, and to water gauges, pressure gauges, and safety valves; thirdly, to regulating the temperature of gas, and of hot or cold air and fluids in general. 

These results are obtained by the action of an electric pile, with optional intermittent contact, acting either manually or automatically upon appropriate gearing or apparatus. The gearing in its turn directs and determines the movement to be obtained, either in applying power to wheels for railway breaks, for instance, or acts upon the first movers or organs themselves, which the said gearing may either actuate or regulate. 

The Luxembourg patent application was directed only to the first two objectives mentioned in the British patent, namely to 

1° l'alimentation automatique de chaudières, ainsi que l'entretien d'une pression constante dans des vases clos enfermant de la vapeur ou de gaz. 

2° le service général des chemins de fer, c'est-à-dire la manœuvre des freins, signaux etc.

The Chambre de commerce appointed Ch. BOURG, ingénieur civil, Directeur du service télégraphique de l’Etat and  J. P. L. KUBORN, employé de la Compagnie des chemins de fer Guillaume Luxembourg as examiners. 

In a lengthy report (drafted by BOURG) the experts pointed out a number of deficiencies, inherent to the proposed regulation systems, especially in relation to the regulation of steam boilers. Their conclusion, however, was positive:

Pour ces raisons les experts soussignés sont d'avis qu'il y a lieu d'accorder le brevet d'importation demandé, en abandonnant toutefois à la Chambre de commerce Royale Grand-Ducale d'apprécier si, à cause des imperfections inhérentes à plusieurs applications de l'embrayage et constatées plus haut, il n'y a pas opportunité à limiter la jouissance du privilège sollicité à une durée moindre que celle de 15 ans.

The Chambre de commerce, when reporting to the Government transcribed the conclusion of the experts in these terms:

Nous joignons le rapport sur le mérite de cette demande, dont les conclusions tendent à l'octroi du brevet sous une légère réserve au sujet de la durée du privilège que nous croyons devoir être limitée à l'expiration du brevet français.

The experts had been clearly misunderstood by the Chambre de commerce, since, by law, the imported Luxembourg patent could not extend beyond the term of the French patent of origin, anyhow. The experts had in mind to reduce the term of the patent to 10 years. 

The Government ignored the duration issue and granted the patent on 10 November 1865 for a period of 15 years.


[1] Bibliothèque nationale de France

[2] GB patent No 1,268/1861