US3724072A

US3724072A - Shearhead for dryshowers

Info

Publication number: US3724072A
Application number: US00134682A
Authority: US
Inventors: W Messinger
Original assignee: Braun GmbH
Current assignee: Braun GmbH
Priority date: 1970-04-23
Filing date: 1971-04-16
Publication date: 1973-04-03
Anticipated expiration: 1990-04-03
Also published as: AT307267B; NL7105228A; GB1278393A; NL7105229A; DE2019744B2; DE2019744A1; FR2089829A5; BE766211A; CH523119A; FR2089828A5; BE766210A; NL162007C; AT319809B; DE2019745A1; CH523120A; NL162007B; US3771842A; GB1287713A

Abstract

An elongated mounting body of a shearhead for dryshavers has opposite lateral side faces. A plurality of cutter blades are mounted on the mounting body straddling the same transversely of its elongation and having free edge portions which project laterally beyond the side faces thereof. Ribs are provided on and laterally project from the respective side faces and each surround and embed one of the edge portions of the respective cutter blades.

Description

Unite tates [191 [111 3,724,72 Messinger [4 1 Apr. 3, 1973 [54] .SHEARHEAD FOR DRYSHAVERS [56] References Cited [75] inventor: Werngr Messinger, Kronberg, Tau- UNITED STATES PATENTS nus, erman y 3,319,333 5/1967 Futterer ..30/43.92 [73] Assignee: Braun Aktiengesellsehait, Frankfurt an Germany Primary Examiner-Robert C. Riordon [22] Filed: Apr. 16, 1971 Assistant Examiner-Gary L. Smith [21] AppL No; 134,682 AttorneyfMichael S. Striker 57 ABSTRACT [30] Foreign Application Priority Data 1 An elongated mounting body of a shearhead for Apr. 23, 1970 Germany ..P 20 19 744.8 dryshavers has pp lateral side faces. A plurality Y of cutter blades are mounted on the mounting body (gill Straddling the Same transversely of its elongation and [581 I 346.51 having free edge portions which project laterally beyond the side faces thereof. Ribs are provided on and laterally project from the respective side faces and each surround and einbed one of the edge portions of the respective cutter blades.

7 Claims; 2 Drawing Figures PATENTEDAFR3 ma 3. 724,072

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SHEARHEAD FOR DRYSHAVERS BACKGROUND OF THE INVENTION The present invention relates generally to an article of manufacture, and more particularly to an improved shearhead construction for use in dryshavers.

It is known to provide dryshavers with shearheads in form of an elongated mounting body on which a plurality of cutter blades is mounted straddling the mounting body. The mounting body is connected in suitable manner with the drive of the dryshaver and is reciprocated or oscillated in its longitudinal direction. The cutting edges of the cutter blades are located closely adjacent the inside of a so-called shea'rfoil, that is a very thin flexible piece of perforated-sheet material which is pressed into engagement with the skin of the user so that the beard stubble extends through the apertures and comes into contact with the cutter blades on the reciprocating cutter head or shearhead, thereby being severed. (U.S. Pat. Nos. 3,527,093 and 3,379,333)

It is already known to make the cutter blade mounting member of the shearhead from synthetic plastic material, frequently from a glass fiber filled or glass fiber reinforced synthetic plastic material. The purpose of utilizing such material, instead of metal which was originally employed, is to reduce the weight and therefore the oscillating mass of the shearhead and the resulting inertial forces as much as possible. The cutter blades straddle the cutter blade mounting member as already pointed out, that is they surround the substantially hollow-cylindrical outer side of the cutter blade mounting member in direction transversely of the elongation thereof and have free edges which can cause difficulties. It must be understood that the cutter blades themselves are of substantially semi-circular configuration and that these free edges are located at the opposite ends of the cutter blades. Because the cutter blades once mounted must subsequently be subjected to a post-treatment to re-sharpen them and eliminate any damage that may have been done to their cutting edges during installation on the cutting blade mounting member, it is necessary that the free edge portions at the opposite ends of each of the semi-circular cutter blades project laterally beyond the lateral side faces of the cutter blade mounting member for sharpening purposes. If that were not the case then the relatively small grinding wheels utilized for this sharpening would very quickly become clogged with particles of synthetic plastic material which are abraided off the cutter blade mounting member, and particularly in mass production such grinding wheels would very rapidly become unuseable.

While the prior art has solved this problem, that is as indicated above by having the lower edge portions of the semi-circular cutter blades project laterally beyond the lateral side faces of the cutter blade mounting member, it has created a different problem in that these projecting edge portions are quite capable of damaging the very thin and very flexible sheet-metal shearfoil whenever the latter is deflected by engagement with the skin of the user during operation of the dryshaver, inwardly in a sense which can bring it into engagement with the projecting edge portions of the cutter blades which oscillate or reciprocate with the cutter blade mounting member. Also, there is the danger that when from time to time the cutter blades must be cleaned, that is the shearfoil is removed and the shearhead is exposed for cleaning purposes, a user might hurt himself on these sharp portions.

SUNIMARY OF THE INVENTION It is, accordingly, an object of the present invention to overcome the aforementioned disadvantages.

More particularly, it is an object of the present invention to provide as a novel article of manufacture an improved construction which is not possessed of these disadvantages outlined above.

A concomitant object is to provide such an improved construction which is simple and inexpensive.

In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides briefly stated in an elongated mounting body having opposite lateral side faces and a plurality of cutter blades mounted on the mounting body straddling the same transversely of its elongation and having free edge portions which project laterally beyond the side faces. Ribs are provided on and laterally project from the respective side faces and each surround and embed the respective edge portions.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view illustrating a fragment of a shearhead embodying the present invention; and

FIG. 2 is a fragmentary detail view on an enlarged scale, illustrating a further embodiment of the invention.

.1 0N F THE PREFERRED EWODIMENTS Discussing firstly FIG. 1, it will be seen that the cutter blade mounting member according to the present invention is of substantially semi-cylindrical hollow configuration. Of course, only a portion of the elongation is shown in FIG. 1, and the transversely extending end walls have been omitted for the sake of clarity. It will be appreciated, however, that the mounting member according to the present invention comprises two longitudinally extending

lateral portions

1 and 2 and a longitudinally extending upper or center portion 3, all of them being of synthetic plastic material, which may or may not contain glass fibers. At the opposite axial ends of this mounting member, the

portions

1, 2, and 3 are all united by transversely extending end walls which are unitary with the opposite ends of the

portions

1, 2 and 3. As pointed out before, these end walls have been omittedfor the sake of clarity and because they do not have a bearing upon the present inventive concept..

In conventional manner a plurality of substantially semi-circular cutter blades 4 is provided which straddle the mounting member transversely ,to the elongation thereof and which consist of a suitable blade of steel. In the constructions according to the present invention the lower edge portions 9 and 10 of the blades 4 project laterally beyond the outer lateral sides 5 and 6 of the

portions

1 and 2, respectively, with the disadvantages which have been outlined in the introductory portion of the specification.

According to the present invention, however, I provide a pair of ribs of which the rib 7 extends along the outer side 5 of the portion 1, whereas the rib 8 extends along the outer side 6 of the portion 2. Each of these ribs embeds the lower free end portions 9 and 70,

. respectively of the cutter blades 4, so that they can no longer constitute a danger to a person cleaning or otherwise working on the shearhead. When the cutter blades 4 are originally embedded in the material of the ribs 7 and 8 they project somewhat laterally beyond but, after the blades 4 have undergone the requisite grinding and sharpening, the edge portions 9 and 10 will be flush with the outer sides of the ribs 7 and 8.

As shown in FIG. 1, the ribs 7 and 8 may be unitary (i.e., of one-piece with) the

respective portions

1 and 2. They can, however, also be separate elements which are adhesively or otherwise secured to the

portions

1 and 2. They may be each elongated and continuous, or, as FIG. 2 shows, they may be each provided in form of a plurality of segments 77 each of which may again be of one-piece with the respective lateral portion only 2 shown, or may be suitably secured thereto, but each of which segment 11 only embeds one edge portion 9 or 10, respectively. In other words, the ribs 7 and 8 may be discontinuous in longitudinal direction according to the embodiment of FIG. 2.

The ribs may be secured to the lateral portions if they are not of one-piece with them in various ways, by adhesive means, as pointed out before, but also by clamping, by pressing or the like. By resorting to the present invention, I have disclosed a simple way of preventing the possibility of damage to the shearfoil by the edges of the blade portions 9 and 10, be it damage by engagement with the shearfoil due to pressure, a blow or a fall, or be it as a result of tearing open of the shearfoil during operation of the shaver under the influence of pressure exerted on the shearfoil when the latter is guided over the skin of the user. At the same time, the possibility of clogging of the grinding wheels utilized for grinding the cutting edges of the blades 4 is reduced to a minimum and damage or injuries as ai 8 is to dampen any tendency of the shearhead to dip or tilt during its reciprocatory movement, whereby such movement is stabilized.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a novel article of manufacture, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the irit of the present invention.

W1thou further analysis, the foregoing Wlll so fully reveal the gist of the present invention that others can, by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. As a novel article of manufacture, a shearhead for dryshavers, comprising an elongated mounting member having opposite lateral side faces; a plurality of cutter blades mounted on said mounting body straddling the same transversely of the elongation thereof and having free edge portions which project laterally beyond said side faces; and ribs provided on and laterally projecting from the respective side faces, each of said ribs surrounding and embedding respective ones of said edge portions.

2. A novel article of manufacture as defined in claim 1 wherein said mounting member is of synthetic plastic material.

3. A novel article of manufacture as defined in claim 2, wherein said synthetic plastic material comprises glass fibers embedded therein.

4. A novel article of manufacture as defined in claim 1 wherein said ribs are of one piece with said mounting member.

5. A novel article of manufacture as defined in claim 1, wherein said ribs are separate elements and secured to said mounting member.

6. A novel article of manufacture as defined in claim 1, wherein said ribs each extend longitudinally of said mounting member.

7. A novel article of manufacture as defined in claim 6, wherein said ribs are each subdivided into a plurality of sections.

Claims

2. A novel article of manufacture as defined in claim 1, wherein said mounting member is of synthetic plastic material.

4. A novel article of manufacture as defined in claim 1, wherein said ribs are of one piece with said mounting member.