EP0124171B1

EP0124171B1 - Shaving apparatus

Info

Publication number: EP0124171B1
Application number: EP84200568A
Authority: EP
Inventors: Eduard Willem Tietjens
Original assignee: Philips Gloeilampenfabrieken NV; Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 1983-04-27
Filing date: 1984-04-19
Publication date: 1989-02-08
Also published as: BR8401936A; EP0124171A3; JPS59207180A; EP0124171A2; NL8301481A; AR230804A1; DE3476640D1; ATE40659T1

Description

The invention relates to a shaving apparatus having a rotatably drivable first cutting member with a central part which carries cutters each formed substantially by a blade at one end of a cutter arm which extends at least partly in a radial direction with respect to the axis of rotation of the first cutting member and the other end of which is connected to said central part, and comprising a second cutting member having a wall which comprises hair-entry apertures and over which wall the blades are movable.
Such a shaving apparatus is known, for example, from US-A-3,890,705.
It is the object of the invention to provide a simple construction which consequently is cheap to manufacture and in which there is no need for separate resilient elements for urging the first cutting member against the second cutting member and a good engagement of the first cutting member against the second cutting member is ensured.
This object is solved for a shaving apparatus as specified above by the features of the characterising part of claim 1.
A special embodiment is claimed in Claim 2.
An embodiment of the invention will now be described in greater detail with reference to the accompanying drawings, in which

Fig. 1 is an exploded perspective view of first and second cutting members,
Fig. 2 is an axial sectional view of the cutting members of Fig. 1 in the assembled condition, and
Fig. 3 is a sectional view showing parts of the two cutting members during the cutting of a hair, the section being taken in a plane perpendicular to a radius of the first cutting member.

The first cutting member 1 in Figs. 1 to 3 is rotatable around an axis 2 with respect to the second cutting member 3. The cutting member 3 comprises a wall 4 having hair-entry apertures 5. The cutters 6 of cutting member 1 comprise blades 7 at the ends of cutter arms 8 extending radially with respect to the axis of rotation 2. The other ends of the cutter arms 8 are connected to a central part 9 of the cutting member 1. The central part 9 comprises a sleeve 10 with which the cutting member 1 is secured to the shaft 11.
The cutting members 1 and 3 are components of a shaving apparatus, the remainder of which, for simplicity, is not shown in the drawings. The cutting member 1 is driven in known manner, for example, by means of an electric motor coupled to the shaft 11. When a hair protrudes through a hair-entry aperture 5, it will be cut off by a cutter blade 7 in cooperation with the second cutting member 3.
The arms 8 are resiliently flexible so that with a slight deflection of said arms the cutter blades 7 press against the wall 4 of the second cutting member 3 with a small force. Because of the resilience of the arms 8 there is no need for separate resilient elements for urging cutting member 1 against cutting member 3. It is essential that the force exerted per blade be kept as small as possible because the overall force exerted between the two cutting members is the sum of the forces exerted by all the cutters, and in order to minimize mean and energy loss by friction.
By constructing each arm 8 as a leaf spring extending radially with respect to the axis of rotation 2 and which is flexible in directions perpendicular to the cutting edge of the blade and rigid in directions parallel to the cutting edge of the blade, a construction in which small forces are exerted by the cutter blades on the second cutting member can be obtained in a simple manner. However, it is necessary to prevent a cutter blade being moved away from the second cutting member too rapidly by the forces occurring during cutting, since this would adversely affect the cutting action. For this purpose, each cutter arm 8, which as already mentioned is in the form of a leaf spring, lies substantially in a plane which is inclined with respectto the axis of rotation 2 to that in the direction of width the arm extends substantially according to a helical line which extends according to the arrow P both in the axial direction towards the cutting member and in the direction of rotation. In the embodiment shown each cutter blade 7 is arranged in the same inclined plane as the associated cutter arm 8.
The plane each cutter arm 8 encloses an acute angle a, for example 30°, with the portion of the wall 4 of the second cutting member 3 which is immediately to the rear of the associated cutter blade with respect to the direction of movement P (Fig. 3). The angle a is so chosen that in most cases it will be larger than the angle P which the cutting force K makes with said wall portion when the cutter blade 7 meets a hair 12. The cutting force K may be decomposed into a component K₁ extending across the cutter blade and a component K₂ at right angles thereto. Each cutter arm 8 will have a considerable stiffness in the direction of component K₁ so that the deflection of the arm in this direction will be small. As a result of the low stiffness in the direction of component K₂, this component of the force K will keep the cutter blade 7 urged against the wall 4 during the cutting of the hair 12, which is the best position for cutting the hair.
The first cutting member 1, comprising the central part 9, the cutter arms 8 and the cutter blades 7, is preferably manufactured as a single component from one piece of sheet material.
Because the cutter blades 7 are individually resiliently supported, they will become disengaged from the wall 4 due to unevenesses in the surface of said wall less rapidly than if the cutter blades were to form a rigid assembly with the cutter arms and the central part 9. As a result of this, less stringent accuracy requirements need be imposed upon the manufacture of the second cutting member, so that said component can also be manufactured more cheaply without this being at the expense of the action of the cutting members.

Claims

1. A shaving apparatus having a rotatably drivable first cutting member (1) with a central part (9) which carries cutters (6), each cutter (6) formed substantially by a cutter blade (7) at one end of a cutter arm (8) which extends at least partly in a radial direction with respect to the axis of rotation (12) of the first cutting member (1) and the other end of which is connected to said central part (9), and a second cutting member (3) having a wall (4) which comprises hair-entry apertures (5) and over which the cutter blades (7) are movable, characterized in that each cutter arm (8) or a part thereof which extends in a radial direction is constructed as a leaf spring which lies substantially in a plane which is inclined with respect to the axis of rotation (12), said plane being inclined both axially towards the second cutting member (3) and in the direction of rotation (P), whereby the cutter blade (7) is inclined in a manner similar to that of the cutter arm (8).

2. A shaving apparatus as claimed in Claim 1, characterized in that the first cutting member (1), comprising the central part (9), the cutter arms (8) and the cutter blades (7), is manufactured as a single component from one piece of sheet material.