CA1096597A

CA1096597A - Dry-shaving apparatus with hair-pulling lead cutters

Info

Publication number: CA1096597A
Application number: CA302,623A
Authority: CA
Inventors: Eduard W. Tietjens
Original assignee: Philips Gloeilampenfabrieken NV
Current assignee: Koninklijke Philips NV
Priority date: 1978-05-04
Filing date: 1978-05-04
Publication date: 1981-03-03

Abstract

15.5. 1977 ABSTRACT :
A dry-shaving apparatus having a cutter roller with straight shaving cutters with associated hair-pulling lead cutters, having a skin guide member and a shear-cutting member between which a helical hair-entrance aperture is formed.

Description

PH~ 8447 The invention relates to a dry-shaving apparatus having a cutter roller which is rotatable about a spindle, which roller comprises a plurality of shaving cutters with cutting edges, having a skin guide member and a shear-cutting member between which a slotted hair-entrance aperture is formed.
Such a construction of a shaving .
apparatus is known from United States Patent Specification 664,388.
It is an object of the invention to provide a construction which enables an even :~
close~ shave and the invention is characteriæed in that the cutting edges of the shaving cutters are parallel to the axis of the cutter roller, a hair-pulling lead cutter being associated with each shaving cutter, which lead cutter is arranged for resilience towards the outside, and that the hair-entrance aperture is helical in the longitudinal direction.

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5~3t7 ; It is true tha-t hair-pulling lead-cutters are known per se from United States Patent Specification 3,088,205l but the use thereof in conjunction with the helical shaving cutters from United States Patent Specification 644,388 is very difficult. The helical shape of the slotted hair-entrance aperture prevents the resilient lead cutters from being trapped in said slotted aperture.
Preferably, always at least one shaving cutter co-operates with the edge of the shear-cutting member, which edge bounds the hair entrance aperture.
The invention will now be des-cribed in more detail with reference to an embodi-ment shown in the drawings, in which:
Fig. l is a perspective view of a shaving apparatus, Fig. 2 is a cross-section of the shaving head on an enlarged scale in accordance with the line II-II in Fig. 1, Figs. 3 - 5 schematically repre-sent how the shaving apparatus functions when a beard stubble is cut, and Fig. 6, which is on the same sheet as Fig~ 1, shows a hair-pulling lead cutter consist-ing of resilient lamellae.

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A dry-shaving apparatus in accordance wi-th Figs. 1 and 2 comprises a housing 1 on which a guard 2 is clamped. In the upper part of the housing 1 a cutter roller 3 is rotatably journalled about a spindle 4.
The cutter roller 3 is driven by a motor accom-modated in the housing 1 vla a transmission. The cutter roller 3 comprises a plurality of substant-ially radially extending shaving cutters 5 with straight cutting edges 6 which extend parallel to the spindle 4. Viewed in the direction of rotation P of the cutter roller 3 a lead cutter 7 is dis-posed in front of each shaving cutter 5. The length of these lead cutters is equal to that of the shav-ing cutters. The lead cutters 7 consist of flex-ible strips of oblique U-shaped cross-section, of which one limb 8 co-operates with the shaving cutter 5 and the other limb 9 is attached to the ; back of the preceding shaving cutter. The cons-truct-ion of the lead cutter is such that the limb 8 is arranged for resilience in a radial direction towards the shear-cutting member 12. The shear cutting member 12 with cutting edge 13 is hinge-able mounted in the guard 2 and is urged in the direction of the spindle 4 of the cutter roller 3 by a spring 14. Between the skin guide member 11 and the shear cutting member 12 a slotted hair 5~7 entrance aperture 15 is formed. This aperture has such a shape, preferably helical, that at least one shaving cutter 5 always co-operates with a por-tion of the edge 13 of the resilient shear cutting member 12, so that the resilient cutting member 12 cannot become trapped between the cutting edges 6 of the shaving cutters 5. Moreover, this ensures that the lead cutter 7 cannot penetrate the slotted hair entrance aperture 15. The width of the slotted aperture 15 is selected so great as to allow all beard stubbles to straighten themselves but so small that the skin is not touched by the moving shaving cutter. It is possible to make the width of the slotted aperture adjustable, so that at option an aggressive or less aggressive action can be ~; obtained. It is also possible to have a shaving apparatus with a plurality of slotted apertures.
The operation of the lead cutter 7 is illustrated in Figs. 3 - 5. Fig. 3 shows the situation in which a beard stubble 16 projects through the hair-entrance aperture 15 and is just pressed against the cutting edge 13 of the resi-lient cutting member 12. The lead cutter 7 is just positioned against the beard stubble 16 with its sharp edge 10. In Fig. 4 the shaving cutter 5 and the lead cutter 7 have slightly advanced in ,~
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~965~7 PH~ 8447 the direction of rotation P of the cutter roller 3. The sharp edge 10 has slightly penetrated the beard stubble 16 and the lead cutter 7 has pulled the stubble slightly out of the skin 17 owing to the forces which are produced. Sub-sequently, the stubble can be cut by the shaving cutter 5. In Fig. 5 the beard stubble has been cut completely, whilst the root has withdrawn to a level which is situated below the skin level owing to the natural elasticity of the surround-ing skin tissue.
At the side which is to be posi-tioned against the skin the shear cutting member 11 and skin guide member 12 may be provided with raised portions 11' and 12', which may serve as skin tightening elements.
Preferably, the lead cutter 7 is supported by the shaving cutter 5, which last-mentioned cutter at the front, viewed in the direction of rotation, forms an inclined sur~ace 5' along which the lead cutter 7 can slide.
The lead cutters may be lamellated.
The lamellae are then individuall~ mounted for resilience (see Fig. 6). It is obvious that the individual lamellae should not penetrate the hair-entrance aperture.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A dry-shaving apparatus which comprises a casing provided with a skin-guide member and a shear-cutting member having a cutting edge, a longitudinally extending slot-like helical hair-entrance aperture being formed between said two members, a cutter roller rotatable about a spindle longitudinally mounted in said casing, means to rotate said cutter roller about said spindle, said cutter roller having a plurality of radially extending shaving cutters each having a cut-ting edge parallel to the axis of the cutter roller, the respective cutting edges of said shaving cutters successively engaging the cutting edge of the shear-cutting member as the cutter roller is rotated, and a generally U-shaped flexible lead cutter positioned between each pair of shaving cutters and opening radially outwardly, one leg of said U-shaped lead cutter being attached to the preceding shaving cutter in the direction of rotation and the other leg having a cutter edge and being resiliently supported by the succeeding shaving cutter for radial inward movement upon engagement of a hair protruding through said hair-entrance aperture by the cutting edge of said other leg.

2. A dry-shaving apparatus according to claim 1, in which there is always a cutting edge of at least one shaving cutter in engagement with the cutting edge of the shear-cutting member.

3. A dry-shaving apparatus according to claim 1, in which the other leg of the lead cutter is lamellated.