This invention relates to haircutting tools and more particularly to motor-driven clippers which are connected to suction devices such as vacuum cleaners; wherein the airflow is used to pull the air to a convenient cutting position and to efficiently evacuate the clippings.
Various devices of this type have been proposed in the past. In a first group best exemplified by U.S. Pat. Nos. 1,238,461 Bourdelat, 2,980,994 Stachon and 3,138,870 Stachon, a rotating blade is mounted across the vaccum flow channel. A second group of such clippers as disclosed in U.S. Pat. Nos. 1,730,889 Hoberecht, 3,979,825 Baumann, 4,077,122 Rollor, Jr. et al., and 4,188,720 Korf uses oscillating blades, the latter with the added improvement of a translating movement of the oscillating blades across the airflow channel. The avowed object of such an improvement was to cause a straight alignment of the air under the vacuum pull and an even cutting of the hair to a constant length. The Korf approach requires a complex mechanism and suffers from the fact that large quantities of hair drawn into the vacuum channel, when attacked by the advancing blade may bunch up and and bend away from the blade. This may result in a very uneven clipping of some of the hair. The translating movement of the blade carriage takes time and consumes a great deal of energy.
In some of the earlier devices the rotary blades interfered with the regular flow of air through the housing, causing pulsations and turbulences which interfered with the proper alignment of the hair.
In his quest for a solution to the problem presented by the prior types of clippers, the applicant began experimenting with some concept akin to some of the older and simple designs such as disclosed in Hoberecht. He eventually devised a new blade configuration which palliates all the defects of the prior art.