Stirling Engine and absolute sealing

Referring to the sketches, the alternative rotation of shaft (101) allows for absolute sealing between the left side and the right side of seal (1020). A device for total sealing around a shaft in alternating rotation is characterized in that a seal (1020), the main part of the device, called a torsion disc, constitutes the material insulator and is fixed on a shaft (101) by means of two spacers (610) and (620), where the spacer (610) is held in position by the bearing (710) and the spacer (620), which clamps the seal (1020), is held in position by the bearing (720). Along the shaft (101) on both sides of the seal (1020), O-rings (510) and (520) and possibly temperature insulating rings (410) and (420) can be arranged. On both sides of the seal (1020) there are possibly two pressure isolating stops (210) and (220), which slide in rotation on two other stops (110) and (120). The two bearing housings (228) and (8) are positioned relative to each other by means of shims (7) in order to clamp the seal (1020) at the bore and at the shaft. Connecting screws connect the bearing housings (228) and (8) and further connecting screws connect the housing (8) and the wall (22). Absolute sealing of a kinematic Stirling engine is now achievable. A French patent was taken out on August 27th, 2020.

Stirling Engine and oil-free compressors

Refering to figure 1 [Fig.1], an oscillating « flipper » piston (1) and its associated chamber (2) are maintained without reciprocal contact. No oil is required because there is no contact and so no friction. An oscillating shaft (22) maintains the oscillating « flipper »piston (1). Around shaft (22), a twisting seal (8) allows for absolute sealing. This characteristic is important for Stirling engines and oil-free compressors. Referring to figure 4 [Fig.4], the two oscillating « flipper » pistons on the left belong to a Stirling-Franchot engine, more particularly to a Stirling-Franchot engine with two oscillating « flipper » pistons and so with two quadric crank mechanisms. The oscillating « flipper » piston on the right belongs to an oil-free compressor. The Stirling engine shaft (11), which is in alternative rotation, directly powers the oil-free compressor shaft (22). This prevents the use of a third quadric crank mechanism from shaft (33) to shaft (22). A Stirling engine connected to an oilfree compressor is useful when the fluid is precious or dangerous. A French patent was taken out on Februar 1st, 2020.

The Patent System during the French Industrial Revolution: Institutional Change and Economic Effects

The influence of the patent system on the economic performance of Western countries during the Industrial Revolution is an important but difficult question to address. With the United Kingdom and the United States, France was one of the first countries to adopt a modern patent legislation in 1791. The aim of this paper is to understand the paradox of such a system, which was based on a democratic and natural-right conception of invention but turned out to be restrictive. It analyses the legal framework and its evolution from 1791 to the late 1850s and reveals its contradictory aspects: a natural right inspiration vs a restrictive access due to the cost of the patent. It shows how the 1844 Patent Act reform did not end the criticism of the French patent system. Then, in a second part, it considers the diffusion of patents in time, in different regions and industries and stresses the heterogeneity of the patent system.

Examining inventions, shaping property: The savants and the French patent system

In 1791, the Loi relative aux découvertes utiles instituted a new patent system in France. Because patents were seen as the expression of the natural right of inventors, prior examination was abolished. However, only a few years after the law was passed, an unofficial examination was reinstated, and it was entrusted to the Comité Consultatif des Arts et Manufactures – a consultative body composed of prominent scientists. I analyze the political significance of the involvement of the savants in the patent system, and based on the archives of the Comité, I study the scope and practicalities of the examination process, paying close attention to the ways through which the savants of the Comité directly intervened in the writing and drawing of specifications. I show how a distinct regime of intellectual property emerged in France and how it was constructed by the interests and norms of scientists, eager as they were to distinguish ‘science’ from ‘industry’ and establish the superiority of the former over the latter.