CN1142050C - Rasor - Google Patents

Abstract

A safety razor including at least one movable blade. The blade is moveable with respect to other parts of the razor. Movement of the blade increases the blade tangent angle in response to forces encountered during shaving.

Description

safety razor blade assembly

technical field

This invention relates to safety razors, and more particularly to blade assemblies for safety razors. The blade assembly of the present invention is either a clip for use replaceably mounted on the handle, or a shaving head of a disposable razor, the blade loading portion of the disposable razor being permanently attached to the handle. Safety razor clips currently on the market comprise a generally rectangular molded plastic frame with guard and cover surfaces extending along the length of the frame. Within the shelf opening are a pair of blades arranged in tandem, with their edges parallel to each other and facing the face of the guard. The blades are placed on and firmly connected to the respective brackets, the ends of the blade brackets being slidably positioned in grooves in the end walls of the frame so that the blades can be retracted under force when shaving. A spring acting on the blades pushes them to their normal rest position.

Background technique

It is well known that the so-called shaving geometry of the blade unit plays an important role in determining the shaving performance of the blade unit. The shaving geometry determines the position and orientation of the blade relative to other skin contacting components, particularly the guard and cover. One parameter of the shaving geometry is blade exposure orientation, which is the vertical distance that the blade edge protrudes above the shaving plane, which is tangent to the surfaces of the front and rear skin-engaging members next to the blade edge. The blades in the prior blade assemblies described above are mounted such that when a load sufficient to overcome the spring force acts on the blade, the exposed orientation decreases. Another important factor in shaving geometry is the blade tangential angle, which is the angle at which the midplane of the blade meets the tangential plane, which is the plane tangent to the blade edge and the surface of the skin-contacting part immediately in front of the blade. For example, in a dual blade clip, the blade tangential angle of the primary or primary blade is the angle at which the blade intersects a tangent plane to the guard surface and primary blade edge.

When shaving, the blade of the blade assembly is subjected to the joint action of traction force and load force. The traction force is the force substantially parallel to the plane of shaving, while the load force is the force directed from the skin towards the blade in a direction substantially perpendicular to the plane of shaving.

Proposals have been made, for example US patents 4709477 and 4774765 to mount the blades so that the blades can move to increase the exposed azimuth and blade tangential angle as traction increases. However, strain gauge measurements showed that the traction force did not change substantially during shaving. Usually beards do not grow perpendicular to the skin surface, but in most men's beards, the beard slopes down relative to the face. It is believed that in shaving, when the blade moves substantially against the rough side of the skin, i.e., upwards, a man uses the razor against his face with less pressure than downwards, with the net result that there is not much difference in traction during the upward and downward strokes. Based on the desire to achieve a closer shave by applying the razor against the skin surface under greater load pressure, it is desirable to have a blade geometry that is more active in this state. However, in the prior art, razors with movable blades do not respond to load forces in this manner.

US Pat. No. 5,251,376 also discloses a blade assembly whose blades can move independently relative to other skin contacting members during shaving.

Contents of the invention

Therefore, the object of the present invention is to overcome the deficiencies of the prior art and provide a blade assembly, when the pressure of the razor on the skin is increased, the tangential angle of the blade increases accordingly, thereby providing a better shaving effect. To this end, the present invention provides a safety razor blade assembly, at least one of the blades having a shaving edge, said blade being mounted so as to come into contact with the other skin of the blade assembly when a force is applied to the blade edge during shaving Parts move independently, the blade assembly defines a tangent plane and a tangential angle, wherein the blade is mounted to rotate around a pivot axis during shaving with load forces acting on the blade , the pivot axis is located in or immediately adjacent to the tangent plane so that the tangential angle increases, and the pivot axis is located between the edge of the blade and the skin contacting member immediately forward of the blade.

In a preferred embodiment of the invention, the blade assembly comprises a frame, and the or each blade is fixedly mounted in a blade holder, the blade holder being connected to the frame by means of a pivot, the movement of the blade under load comprising The angular displacement performed by the fulcrum axis is closer to the edge of the blade than the point where the tangent plane intersects the skin-contacting surface immediately in front of the blade. Also, the fulcrum is at or very close to the tangent plane. This arrangement minimizes the change in the exposed orientation of the blade as the blade tangential angle increases, it does vary in blade exposed orientation but it decreases as the blade tangential angle increases. In addition, the angular displacement of the blade is largely insensitive to the tractive forces acting on the blade, whereas the blade span, the distance measured in the tangential plane between the blade edge and the skin-contacting surface in front of the blade edge, increases as the blade tangential angle increases. , the change is not significant. It is expedient for the fulcrum to have a distance in the range of 0.2 mm to 0.6 mm from the edge of the blade.

In a blade unit embodied according to the invention, the blade or blade group is initially set to have a minimum tangential angle, which then increases as the load force increases. As a result, the present invention is more comfortable than other devices that initially set the blade tangential angle to a maximum.

The blade holder may conveniently be connected to the frame so that the fulcrum is fixed relative to the frame, but this is not essential and a certain degree of controlled movement of the fulcrum is possible.

Description of drawings

A better understanding of the invention can be obtained from the following detailed description when taken in conjunction with the accompanying drawings, in which:

Figure 1 is a cross-section of the razor blade clip proposed by the present invention, showing the blade in its normal rest position;

Figure 2 shows the clip of Figure 1 with the blades in a position of maximum angular displacement;

Figure 3 is an exploded perspective view of the clip shown in Figure 1;

Fig. 4 is an enlarged view, which shows a part of the blade assembly and its support in detail;

Fig. 5 is a perspective view showing a modified blade mounting arrangement;

6A and 6B are perspective and end views showing an alternative blade mounting arrangement with hinges;

7A and 7B are perspective and end views showing another alternative blade mounting arrangement with housing bearings;

8A and 8B are perspective and end views showing yet another alternative blade mounting arrangement with a movable fulcrum;

Figures 9A and 9B are perspective and end views showing the blade mounting arrangement comprising a four-bar linkage system; and

Figure 9C shows this embodiment in the state where the blade displacement is at its maximum.

Detailed ways

The safety razor blade assembly shown in Figures 1-4 is a shaving clip. The clip mounted handle is not shown, it could be of normal form. The clip comprises a generally rectangular molded plastic frame 1 . The front of the shelf comprises a protective bar 2, and is equipped with a protective strip 3 of elastic material, which has vertical wings extending along the protective strip. The back of the shelf defines a cover surface 5 and is provided with strips 6 of lubricating material. Three blades 7 with parallel edges are mounted in the rack between the guard bar 2 and the cover surface 5 so that when shaving, the blades pass sequentially over the skin. Each blade is fixedly mounted to the blade holder 8, as best seen in Figure 4, joined to each end of the blade holder is a forward and upwardly inclined arm 9 having at its free end a Journal 10. The axis of the journal is parallel to the edge of the blade and thus spaced forward by a distance of 0.2 to 0.6 mm. The journal rests in a bearing defined by the spring seat 12 and the end wall of the clip frame. The spring seat has connecting parts 13 which engage with a snap fit in sockets in the shelf wall and integral with the spring seat are spring clips 14 which act on the underside of the respective blade in order to push the blade into position as shown in Figure 1 their resting positions. Upwardly pointing key members 15 on the spring seat are arranged to protrude into slits formed in the end walls of the frame so as to clamp the journals 10 in their bearings defined at the upper ends of these slits, which can be seen from FIGS. 1 and 2 . See. With this arrangement, each blade 7 is mounted in the clip frame 1 for pivotal rotation about an axis defined by a journal 10 between the edge of the blade and the skin contacting part immediately in front of the blade, which axis is at or Next to the cutting face T of the blade. Spring clips 14 bias the blades into the rest position of FIG. 1 in which the blades or their supports rest against shoulders 18 formed on the end walls of the shelf. When the blade 7 is subjected to a load force acting on the edge of the blade and substantially perpendicular to the plane of the shaving face, and the load force is large enough to overcome the prestress of the spring clip 14, the blade pivot is caused, so that when the load force continues to increase, the cutting force of the blade Angle A gradually increases. As can be seen from Figure 2, the exposure of the blades is reduced, but only slightly if required, and the reduction in exposure can be counteracted by arranging the guard bar 2 to be mounted by its own spring, or elastically deformable, so that when As the blade pivots under the load force transmitted to the blade, the guard bar will be progressively pressed downward under the corresponding load force acting on it. It can be seen that under this clip structure, when the razor user increases the force that the razor presses against the skin to be shaved, the tangential angle of the blade will also increase thereupon.

As shown in FIG. 5 , instead of being integrally formed with the blade holder, the cantilever 9 and journal 10 can be formed as a separate molded part 20 which can be formed with a slot to receive the end of the blade holder 8 .

FIGS. 6A and 6B illustrate a device in which the fulcrum about which the blade 7 is pivoted is formed by a living hinge 22 incorporated in the part comprising the cantilever 9 . This part can be integrally formed with the clip frame 1, or it can be molded separately and then mounted thereon.

In the alternative embodiment of Figures 7A and 7B, the blade holder is curved and the end projections 24 on the holder are positioned to fit in corresponding curved slots in the end wall of the shelf to form a shell bearing , defining the center of pivoting of the blade 7 .

There is no essential difference in constraining each blade to movement about a fixed fulcrum or pivot axis. In the modified construction of Figures 8A and 8B, the arms 9 are shown integrally with the blade holder, although they could also be molded separately as shown in Figure 5, and then mounted to the blade holder, with hooks 26 at the free ends of the arms. The hook rests on a cantilevered support rod 27 which is fixed to the end wall of the shelf and has a substantially planar surface, the opposite ends of which define respective pivot axes. During the initial pivoting of the blade, the boom 9 and the blade 7 pivot about an axis defined by the front edge of the support rod 27, while during subsequent angular movements they pivot about a pivot defined by the rear edge of the support rod. Shaft axis generated.

In the modified embodiment of Figures 9A, 9B and 9C, the blade 7 is supported by an integrally molded four-bar linkage assembly. The first bar 30 constitutes the cantilever 9, the second L-shaped bar 31 is fixed to the clip frame, the third bar 32 is connected to the cantilever 9 by a living hinge 33 defining the fulcrum of movement of the blade 7, and connected to the second bar by another living hinge 34. One end of 31 is connected, and the short fourth rod 35 is connected with the other end of the second rod and the first rod through corresponding living hinges 36,37. The lever 30 moves about a fulcrum limited by the hinge 33 under the action of a load force applied to the edge of the blade. There is some downward movement of the fulcrum due to the hinge 34, but this movement, which would result in less exposure of the blade, is small because of the short length of the fourth rod 35. In all of the illustrated embodiments, the fulcrum positioning is substantially the same as that illustrated in Figures 1-4, and as a result, the desired effect of increasing the blade tangential angle with increasing load force is obtained with insignificant changes in blade span and blade exposure changes are still small.

Claims (10)

1. safety razor blades assembly, have at least a slice blade (7) to have the edge of shaving, described blade (7) is installed into, during shaving, be subjected to the time spent of doing of power when blade edge, energy is other skin engaging member (2 of blade assembly relatively, 5) carry out self-movement, described blade assembly defines a tangent plane (T) and one cut angle (A), it is characterized in that, described blade (7) is installed into, during shaving, can rotate around a pivotal axis along with acting on the load force on the blade, this pivotal axis is positioned at tangent plane (T) or is close to this tangent plane (T), thereby cut angle (A) increased, and described pivotal axis is positioned between the skin engaging member (2) in blade edge and adjacent blade the place ahead.

2. according to the safety razor blades assembly of claim 1, it is characterized in that, blade assembly comprises a framework (1), blade or every blade then are fixedly mounted in the blade support (8), blade support is connected on the framework by forming a fulcrum, the motion of blade comprises the angular displacement of carrying out around described fulcrum, the more close blade edge of point that a shaft position then intersects than the skin contact surface that is close to before tangent plane and the blade.

3. according to the safety razor blades assembly of claim 2, it is characterized in that the relative framework of fulcrum (1) is fixed, and described pivotal axis limits described fulcrum.

4. according to the safety razor blades assembly of claim 3, it is characterized in that described fulcrum comprises and is arranged on blade support (8) opposite end and is engaged on axle journal (10) in framework (1) bearing.

5. according to the safety razor blades assembly of claim 2, it is characterized in that blade support (8) is connected on the framework (1), thereby during the blade angular displacement, fulcrum moves with respect to framework (1).

6. according to the safety razor blades assembly of claim 5, it is characterized in that, blade support (8) has a cantilever (9), this cantilever is meshed with the cramp bar (27) that is fixed in framework (1) and has opposite edges, when the angular displacement of blade (7) increased, cantilever (9) carried out pivot successively around opposite edges and rotates.

7. according to the safety razor blades assembly of claim 2 or 5, it is characterized in that described fulcrum comprises a hinges.

8. according to the safety razor blades assembly of claim 2, it is characterized in that described fulcrum comprises a housing bearing.

9. according to each safety razor blades assembly among the claim 2-8, it is characterized in that the be separated by distance of 0.2mm to a 0.6mm scope of fulcrum and blade edge.

10. according to the safety razor blades assembly of claim 1, it is characterized in that described assembly comprises a plurality of blades (7), has parallel knife edge, each blade (7) is mounted to and can rotates around a pivotal axis, and this pivotal axis is positioned at or is close to the tangent plane (T) of blade.

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