US2108493A - Dry shaving device - Google Patents

Description

Patente Feb. is. 193e DRY SHAVING DEVICE Harry Landsiedel, Wilton, Conn., assigner, by

mesne assignments, to General Shaver Corporation, Bridgeport,

Delaware Conn., a corporation of Application March 4, 1937, Serial No. 128,936

4 Claims.

This invention relates to improvements in shaving devices oi' the type which do not necessitate the use of shaving preparations of any kind.

The general object of the invention is to pro- .5 vide an improved form of cutter head comprising an outer shear plate, and an inner cutter, movable transversely with respectl thereto, and involving more particularly improvements in the cutter bar portions of the outer shear plate.

The more detailed objects of the invention will be apparent from the following description.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be described in connection with the attached drawing.

The subject matter of this application is re*- lated to that of my copending application Serial No. 123,162, filed January 30,- 1937 for Shaver.

In the accompanying drawing,

Figure 1 is a part of a side elevational view of the cutter head with many parts broken away lto show other parts in cross section;

Fig. 2 is a vertical transverse sectional view through the cutter head; y Fig. 3 is an enlarged detail side elevational vviewof a portion of the cutter head.

IIn dry shaving devices of the type herein dis-l closed the outer shear plate, which is commonly slotted to provide a plurality of cutter bars, is -applied at its outer face to the surface of the skin, and the inner cutter which operates in back of the shear plate against the rear face of the cutter bars therein. The hairszto be clipped enter the slots and are cut off at the rear edges of the cutter bars of the outer shear plate. It is at once apparent, therefore. that the thickness of the outer shear plate at the cutter bars, in part, at

least, determines how close the hairs are cut oil? to the surface of the skin. The cutter bars are 4o therefore of necessity made extremely thin with the result that they are physically weakened.

The central object of this invention is to provide an improved construction at the cutter bars of the outer shear plate where portions of the active lengths thereof are made much thinner without rendering them impractical.

Referring to' the drawing at I is shown the upper end of the usual handle casing which houses the motor for operating the device. As

shown, the upper end of the vcasing is grooved as indicated at 2 to receive the cutter head assembly. 'I'he cutter head assembly is locked in the groove by a set screw not shown, and posil tioned therein by a pin 3 mounted in the casing so .as to engage a recess in the cutter head.

The cutter head comprises an outer member t which may be made from a solid block of suitable steel, or formed up in other ways, as is known in' the art, 'to provide a hollow upper section having a relatively thin, substantially semicircular wall 6. This wall is provided with a series oftransverse slots 'I extending therethrough and outwardly away from a central portion 8 which forms a continuous band extending longitudinally along the upper face of the wall 6. Aligned with y the slots 1, and' extending` further down vthe sides of the wall 6, are a series of wider slots 9. These sets of aligned slots 'I and 9, on opposite sides of the wall 6, as is clear from Fig. 2, form the cutter bars I0 at the active portion which forms what is commonly termed the outer shear plate. At this point it is apparent thatthe wall 6 is, at the portions under consideration, of substantially uniform thickness. In order to produce the fin-` ished shear plate it is now subjected to a series of grinding operations to reduce the thickness of. the bars Ill and the strip 8, leaving the raised ends as is clear in the figures. 1 To accomplish this the ends of the bars I0 adjacent the strip 8 are ground on iiat planes I I which lie at an angle of approximately 12 degrees to the horizontal.

This would leave the stript! triangular in cross section but the top is preferably ground off tothe form shown in Fig. 2 where it is more nearly rectangular in cross section and substantially of uniform thickness.v The bars I0 at their outer ends are again ground along hat planes I2 which lie at an angle of approximately 24 degrees to the horizontal. The result is that the bars I0, viewedv from the side as they are in Fig. 2, take a form as clearly illustrated where it,comprises two parts each thinnest intermediate the ends of the parts as indicated at I3 and of increasing cross section away from the center towards the ends of the parts. This provides a relatively strong cutter bar I0 which at no point is much thinner than four or five one-thousandths of an inch, and which, at the thinnest point, may be made less than two one-thousandths o f an inch thick. The present commercial practice is to make the cutter bars of the order of four one-thousandths of an inch thick. Any attempts to make a bar of uniform thickness any thinner than this, are met with practical diiculty. However, by means of the construction here disclosed, portions at least of the cutter bars, in the case illustrated there are two such portions, may be made much thinner than this in shearing a vvery close shave. By reason of the fact that each bar is provided with l two extremely thin portions, the device shaves very rapidly, and since these portions lie so to speak in diierent planes, the outer shear plate does not have to be held against the skin as accurately as is true with the usual fiat surface shaver. The slots 'l are provided with the wider portions l to permit easy entry of the hair thereinto by means of which they are guided to and into the narrow slots 1 where they may be cut. In practice it is desirable to make the slot 'l about eight one-thousandths of an inch wide and the slots 9, from fifteen to twenty-ve one-thousandths of an inch wide.

The inner cutter it is substantially circular in cross section and is provided with a series of transverse slots I6 on the thinner Wall formed by its eccentric bore to form the inner continuous cutter bars l5. As will be seen from Fig. 2, the length of the cutter bars l5 is suflicient to bridge the expanse of the cutter bars lil. One end of the inner cutter is slotted as indicated at I1 to cooperate with the head I8 of the pin mounted in the member 4 to insure rectilinear reciprocation of the inner cutter. The sides of the inner cutter near the ends of the slots I6 may be ground away as indicated at I9 to give relief and reduce the frictional resistance to movement of the inner cutter.

As is common in this art the inner cutter is engaged by an oscillatable lever 20 operated by the motor not shown. At 2l are indicated a pmr of pins which are resiliently urged by springs not shown in a direction to force the inner cutter against the rear faces of the cutters bars I0.

From the above description it will be apparent to those skilled in the art that some variation in the details of construction may be effected without departure fromthe true scope of the invention. I do not, therefore, desire to be strictly limited to the disclosure as given for purpose, of illustration, but rather to the appended claims.

What I seek to secure by United States Letters Patent is:

1. A dry shaving head comprising an outer shear plate slotted to form a. series of cutter bars, each of the slots being continuous and comprising two portions of uniformly different width and an inner cutter mounted for reciprocal movement across the rear faces of the cutter bars, said cutter bars being curved on their rear faces and having a plurality of fiat intersecting outer faces.

2. A shaving device as described comprising an outer shear plate having a plurality of slots therein, the individual slots each having a wide and a narrow portion, and an inner cutter mounted for reciprocation transversely of the rear faces of the cutter bars formed by said slots, said cutter bars increasing in thickness in both directions from two spaced points intermediate the ends thereof.

3. In a cutter head for a shaving implement an outer shear plate comprising a curved wall having a plurality of parallel slots to form a plurality of cutter bars, the outer faces of the cutter bars forming two planes each lying at an acute angle to a common plane, and said slots each comprising two portions of uniform but different width.

4. A shaver head of the type described comprising an outer member having a passage therethrough forming a wall, the rear surface of which is a portion of a cylinder, the smallest dimension transversely ofthe axis of said passage being at least twice as great as `the radius of said cylindrical portion, an inner reciprocable member mounted in said passage having a portion of its outer surface cylindrical and engaging the cylindrical portion of the outer member, said inner member having a passage therethrough and being transversely slotted to form cutter bars, the outer member being provided with slots which intersect its cylindrical portion and arranged in two rows, the slots of the respective rows terminating short of each other to form a reinforcing bar extending at *right angles to the slots thereby forming two rows of cutter bars, the outer faces of each row of cutter bars being cut away on two flat planes, the corresponding planes of each pair converging and forming acute angles with planes at right angles to the radial plane which includes their lines of convergence respectively.

HARRY LANDSIEDEL.

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