In 1939, Alexandre Horowitz, inventor from Philips, developed the first Rotary shaving head construction. In that time the shaver; named steelbeard had only one shaving head. Nowadays the rotary shavers have mostly 3 shaving heads. In 50's and later all kind inventors patented there new ideas based on this Philips invention.
Shaver Part's double ring foils is free from patent because the idea is very old. In that time of the invention it was technical to complicated to produce in mass production to get good quality. Shaver Parts double foils with cutter, reduces shaving time and the shaving performance is also good because each ring has his own concave groove also called "Rille". In the middel of the ring the foil is a little thinner to cut the hairs shorter. Our double ring foils fits in most of older Philishave shavers with single ring.
Below our alternative universal replacement for HP1915, HQ3, HQ4, HQ5, HQ55, HQ56 & HQ6.
NOTE: Philips HQ6 have "lugs" but not our replacement but still fits.
Coupling spindle according US00000475998A (1987)
Below our alternative universal replacement for HQ8 (HQ177) & HQ9
NOTE: These foils don't have "lugs" but our replacement foils still fits.
The form of plastic core is not a patent because it is made according DIN32711
Below old patent examples of double and triple shaving rings.
In that time it was not possible to make good quality in mass production.