Patent US-1920-1454944

Two helicopter screws turning in opposite directions, which may be angled away from vertical in any direction. Refers to warping and "periodical differential" and variable differential incidence" and angle-of-attack.

• Tech category: CPC B64C27/54 Mechanisms for controlling blade adjustment or movement relative to rotor head, e.g. lag-lead movement
• Inventor location: Calle de la Buena Suerte 20, Barcelona, Spain ; citizen of Argentine Republic
• had filed an application in Spain dated July 3, 1919 -- haven't found that on google patents

Patent family descending from Patent ES-1919-07-03-Pescara

• Patent US-1920-1454944 (English title: Helicopter propeller system, Supplementary to patent: Patent ES-1919-07-03-Pescara, National tech categories: USPC 416/112 • USPC 416/127)

Sources

• Patent 1454944 document and bibliographic info on espacenet
• Patent 1454944 at google patents

Year filed	1920
Year granted	1923
Office	US
Patent number	1454944
Inventors	Raúl Pateras Pescara
Inventor country	ES, AR
Applicant person	Raúl Pateras Pescara
Applicant firm
Applicant type	INDIV
Applicant is inventor?	1
Original title	System of helicopter screws
English title	Helicopter propeller system
Tech fields	helicopter, propeller
Filing date	1920-07-15
Full specification filed date
Application number
Grant date	1923-05-15
Granted?	1
Publication date
Supplementary to patent	Patent ES-1919-07-03-Pescara
Related to aircraft?	1
Serial number	396597
Patent agent	B. Singer
Assigned to
National tech categories	USPC 416/112, USPC 416/127
IPCs	IPC B64C27/00, IPC B64C27/54
CPCs	CPC B64C27/54
Family year	1919
First filing?	0
Cites these patents
Citations from after 1930
Application ID
INPADOC family ID
Number of text pages	4
Number of diagram pages	1
Number of figures	1
Number of claims	5