US3634936A

US3634936A - Shaving unit for electric shaver

Info

Publication number: US3634936A
Application number: US805170A
Authority: US
Inventors: Giancarlo Battigalli
Original assignee: MISTRELETTRICA Srl
Current assignee: MISTRELETTRICA Srl
Priority date: 1968-03-08
Filing date: 1969-03-07
Publication date: 1972-01-18
Anticipated expiration: 1989-01-18
Also published as: SE336974B; NL6903688A; DE1911346A1; FR2003549A1; GB1241124A; BR6906972D0; CH507784A; ES365081A1; BE729569A

Abstract

A shaving unit for electric shaver comprising a comb provided with a plurality of perforations of rectangular shape, said perforations being spaced from one another and being arranged along sloping parallel rows forming an angle of about 10* with the longitudinal axis of the comb, the perforations of two adjacent rows being staggered between each other, and the comb having the form of a continuous curve consisting of three waves, and three shaving elements of semitubular shape for engaging the comb at the waves to cut hair received in the perforations of the comb.

Description

[ Jan. 118, 1972 2,266,885 l2/l94l Martin........ ...30/346.5l X 3,052,022 9/1962 Wahl............................r.... .30/43.92 3,376,636 4/1968 Schuessler ...30/43.92 X

Primary Examiner-Granville Y. Custer, Jr. Att0rney-Finnegan, Henderson & Farabow [57] ABSTRACT A shaving unit for electric shaver comprising a comb provided with a plurality of perforations of rectangular shape, said perforations being spaced from one another and being arranged along sloping parallel rows forming an angle of about 10 with the longitudinal axis of the comb, the perforations of two adtlnited States Patent Battigalli [54] SHAVHNG UNIT F OR ELECTRIC B N m ma w M 333 5. m z E g :3: c 2 2 mm m c C v m DEF/1., Elli/ell: .1 t f 1 r B uni F5521? it? aj ajllljl t e. 2 Z w a 2 A of? z m EFLEQIELETlH/K r U 110 112 LQQ GIANCARLO BATTIGALLI INVENTOR filleyamjfeadaso/z QJciaafiow ATTORNEYS SHAVING UNIT FOR ELECTRIC SHAVER BACKGROUND OF THE INVENTION The present invention relates to a shaving unit for electric shaver. Electric shavers of the comb and blade type have many drawbacks, as shaving is a time consuming operation with such shavers, because of the imperfect contact between blades and comb. Moreover, blades and comb are subject to wear and soiling, requiring frequent servicing and cleaning operations.

SUMMARY OF THE INVENTION One object of the present invention is to provide a shaving unit for electric shaver made of few members easy to manufacture, to assemble and to keep in good operative conditions.

Another object of the the present invention is to provide a shaving unit for electric shaver having a larger shaving surface in comparison with prior art shavers, in order to-reduce the shaving time.

Another object of the present invention is to provide a shaving unit for electric shaver providing a closer contact between moving shaving elements and comb.

A further object of the present invention is to provide a shaving unit for electric shaver comprising a comb having rectangular perforations arranged along sloping parallel staggered rows.

A further object of the present invention is to provide a shaving unit for electric shaver comprising three shaving elements of semitubular shape mating the inner shaped surface of the comb.

BRIEF DESCRIPTION OF THE DRAWINGS The components of the shaving unit for electric shaver according to the present invention, the advantages, features and manufacturing techniques thereof are described in detail hereinafter in one preferred embodiment, given by way of nonlimiting example only, and with reference to the accompanying drawings, in which:

FIG. I is a diagrammatic top plan view of the comb, ar ranged flat FIG. 2 is a very enlarged view of a little portion of the comb,

showing the array of the perforations;

FIG. 3 is a top plan view of the comb supporting frame group;

FIG. 4 is a front elevation of the group shown in FIG. 3;

FIG. 5 is a side view of the same group of FIG. 3;

F IG. 6 is a sectional view taken along line A-A of FIG. 3;

FIGS. 7, 8, 9 and 10 are front elevation, top plan, bottom plan and end views of the central shaving element, respectively; and

FIGS. ll, l2, l3 and 14 are front elevation, top plan, bottom plan and end views of one lateral shaving element, respec tively.

DETAILED DESCRIPTION OF THE PREFERRED EM BODIMENT With reference now to the figures of the accompanying drawings, the shaving unit of the instant invention is substantially comprised of two main parts, that is a comb supporting frame group and three shaving elements.

The comb supporting frame group in turn comprises a punched or electrically formed comb (FIGS. 1 and 2), a comb holder and a comb supporting frame (FIGS. 3'6), while the three shaving elements are of two different types, namely a central shaving element provided with symmetrical cutting blades (FIGS. 7-10) and two lateral shaving elements having a greater diameter and asymmetrical cutting blades in respect of the longitudinal axis (FIGS. 1lI4).

The punched or electrically formed comb I01 is divided into three sections or areas, A, B and C (FIG. I), each having an array of staggered perforations 102 of rectangular shape (().35 0.80 mm. In each section or area the perforations I02 are sloping 10 to the longitudinal axis. At the lateral sections A and C the inclination of the staggered rows of perforations 102 is in the same direction, while at the central section B the inclination is in the opposite direction. Comb thickness is about 0.05 mm. There are 997 perforations in section A, 1,002 perforations in section B and 997 perforations in section C, so as to have a total amount of 2,996 perforations.

Taking into account that section A has a perforated surface area of about 763 sq. mm. section B a perforated surface area of about 775 sq. mm., and section C a perforated surface area of about 763 sq. mm., the total shaving surface area is of about 2,301 sq. mm.

Along the peripheral edges of the comb and between the sections there are no perforations for preventing accidental strains and distortions, however without reducing the elasticity required for a perfect fit to the shape imposed by the comb retainers and for assuring an efficient contact with the shaving elements in the operative areas.

The rectangular shape and the particular inclination given to the rows of perforations provide for a progressive cutting of hair which is being continually engaged between comb and shaving elements, so that the operation of the shaving unit is similar to a pair of scissors, i.e., hair is progressively cut between the shaving elements and perforations in the comb as the shaving element is moved. The perforations are staggered in each adjacent row so as to give the comb an even bending strength.

On each side of the comb 101 there are two greater rectangular bores 103 for clamping the comb to the comb retainers. When inserted into the comb-supporting frame group, the comb takes the fonn of three radiused waves or arcs so as to form a continuous curve, as clearly illustrated in FIG. 6. The comb is held in the right position by both the comb holder and the comb-supporting frame. The comb retainers 104 are fastening members having the purpose of supporting and locking the comb in its seat.

The comb-supporting frame 105 has the specific object of hindering accidental impacts of the comb. Two rods 106 are anchored on the frame 105 and said rods 106 have a slight contact with the comb 101 at the two areas between the perforated sections in it continuous curve between the waves or arcs. As shown in FIG. 6, each rod 106 contacts comb 10] at two points, and vertical position of the rods I06 is determined by their diameter.

The two end sides 107 of the comb holder have such a shape that the curved pattern of the comb is enclosed within their shape so as to prevent damage to said comb.

From the foregoing it is now possible to understand the simplicity of the parts'forming the comb-supporting frame group. These features allow also a very easy comb-assembling operation so that the user may replace it when required or desired. In fact, the assembling steps are the following:

The two bores 103 of one comb end are inserted into the corresponding comb retainers I04; comb 101 (which will be supplied as a wound tubular piece) is unwound and is laid on the two continuous curves of the comb-supporting frame 105, then the other comb end is fixed to the corresponding comb retainers 104 and the whole comb-supporting frame with the fixed comb is inserted into the comb holder. The rods I06 compel the comb 101 to follow the three waves of comb-supporting frame 105 (FIG. 6). In operation, comb 101 is limited to movement in the gap or space between the continuous curves of comb-supporting frame 105 and rods 106.

The shaving elements of the shaving unit of the present invention are comprised of a central element 108 and two lateral elements 109. The lateral elements are of greater diameter and while the central element 108 has blades symmetrical to the longitudinal axis, the lateral element 109 have asymmetrical blades.

This contrivance gives to the shaving unit a shaving surface much larger than that of the shavers presently available on the market, and allows to greatly reduce shaving time.

The shaving elements are preferably made of hardened and tempered carbon spring steel (0.95l.05 percent) having a thickness of 0.6 mm. From the steel strip, by means of a step progressive piercing die, the punched parts are obtained, having both the slots 112 between the blades and the lightening holes 113. The finished parts are obtained by means ofa forming die, and these parts have a semitubular or semicircular section with a straight bottom portion. The forming operation is followed by an austenitic solution treatment in a neutral quenching salt bath so as to obtain a cone Rockwell hardness R 5860 and a minimum brittleness. Then cylinder grinding and frame chromium plating are effected.

In the lower or bottom portion of the shaving elements there are a central bore 115 for connecting the element to the swinging plate of the shaver and the lightening holes 113, serving also for the passage of cut hair and for noise dampening. A nylon piece is preferably inserted into the central bore 115 of the lateral shaving elements and this piece has a central keyhole 114 having the function of limiting noise during operation.

The pins connecting the shaving elements to the swinging plate have the shape of a T with the lower knurled stem forced into the swinging plate and the flange directed toward the short side of the plate. Fixing of the shaving elements to the swinging plate is very easy. In fact, it is sufficient to place the shaving elements near the corresponding T-shaped pins, to bring the keyhole provided in the bottom portion of the element to match the flange of the T-shaped pin, and then to thread the shaving element on the pin, locking it by a rotation of 90. These T-shaped connecting pins are better disclosed in copending U.S. Pat. application Ser. No. 805,172 of the same applicant filed on Mar. 7, 1969, entitled: Drive system for controlling motion of the shaving elements of an electric shaver."

The shaving elements have the following features: simplicity of manufacture, a cutting angle which provides a clean and sharp hair cut and excellent contact with the comb, because after the forming and hardening operations, a cylindrical grinding of them is effected. With the latter operation eventual hardening distortions and forming defects are prevented. Moreover the cutting surface is always kept clean because the blade walls are very narrow as well as because the swinging movements of the shaving elements cause cut hair to come off and fall down.

it is to be understood that sizes, materials and number of perforations are given only for a complete illustration of the preferred embodiment, and that many variations and modifications may be resorted to without departing from spirit and scope of the invention as defined in the appended claims.

lclaim:

1. A shaving unit for electric shaver, comprising in combination a comb provided with a plurality of perforations of rectangular shape, said perforations being spaced from one another and being arranged along sloping parallel rows forming an angle of about with the longitudinal axis of the comb. the perforations of two adjacent rows being staggered between each other, said comb having the form of a continuous curve consisting of three waves, and three shaving elements of semitubular shape for engaging said comb at said waves to cut hair received in said perforations ofsaid comb.

2. A shaving unit according to claim 1, wherein the comb is divided into three perforated areas, the inclination of the perforated rows being oriented in the same direction in the two lateral areas and being oriented in the opposite direction in the central area.

3. A shaving unit according to claim 2, wherein the three perforated areas are spaced by short intermediate stiffening solid bands and having two side solid edges provided with the holes for fixing the comb to a comb-supporting frame.

4. A shaving unit according to claim 1, wherein the size of the comb perforations is not exceeding 0.5Xl .0 mm. 50 as to prevent an injury to the user. I

. A shaving unit according to claim 1, whereln sald shaving elements include a plurality ofcutting blades for engaging said comb at said waves to cut hair received in said perforations of said comb, and said perforations are inclined relative to said cutting blades to provide progressive cutting of hair which is being continually engaged between said comb and said shaving elements to cut the hair ofa scissorlike operation.

6. A shaving unit according to claim 1, wherein the perforations are staggered between two adjacent rows of perforations in order to give the comb an even bending strength required for curving it into three continuous waves matching the semitubular shape of the shaving elements.

7. A shaving unit according to claim 3, further comprising semitubular comb holder for fixing the comb and following its shape with three continuous waves, the end sides of said comb holder being provided with comb retainers for locking the comb edges, the outer sizes of said comb holder being such to have a close fit with the comb supporting frame.

8. A shaving unit according to claim 1, wherein said semitublar shape of the shaving elements comprises a circular portion provided with parallel blades the area matching the comb and a bottom flat portion toward the shaver driving system.

9. A shaving unit according to claim 8, wherein each of the shaving elements comprises a steel strip having slots between the blades.

10. A shaving unit according to claim 9, wherein the shaving elements are chromium plated.

11. A shaving unit according to claim 8, wherein the lateral shaving elements have a diameter greater than that of the cen tral shaving element, said lateral shaving elements having asymmetrical blades in respect of the vertical plane at the lon gitudinal axis of the element, while the blades of the central shaving element are symmetrical, giving the unit a large shaving surface.

12. A shaving unit according to claim 9, wherein lightening holes are provided on the bottom portion of the shaving elements and are also used for discharging cut hair and for noise dampening.

13. A shaving unit according to claim 12, wherein a central bore is provided on the bottom of the shaving elements for connection to the electric shaver.

14. A shaving unit for an electric shaver comprising, in combination, a comb provided with a plurality of perforations of rectangular shape, said perforations being spaced from one another and arranged in sloping parallel rows at an angle to the longitudinal axis of said comb, the perforations of two adjacent rows being staggered between each other, said comb having the form of a continuous curve consisting of a plurality of waves, and a plurality of semitubular shaving elements for engaging said comb at said waves to cut hair received in said perforations of said comb.

15. The shaving unit of claim 14, which includes a comb holder having sides in the shape ofa continuous curve including a plurality of waves for supporting said comb, and a combsupporting frame for receiving said comb and comb holder. said comb-supporting frame including a plurality of rods extending perpendicularly to the sides of said comb holder and located between the waves of the continuous curve of said comb for maintaining said comb in its curved shape.

16. The shaving unit of claim 15, wherein said comb holder includes comb retainers located on opposite sides of said comb holder, and said comb is provided with bores for receiving said comb retainers to fasten said comb to said comb holder.

Claims

1. A shaving unit for electric shaver, comprising in combination a comb provided with a plurality of perforations of rectangular shape, said perforations being spaced from one another and being arranged along sloping parallel rows forming an angle of about 10* with the longitudinal axis of the comb, the perforations of two adjacent rows being staggered between each other, said comb hAving the form of a continuous curve consisting of three waves, and three shaving elements of semitubular shape for engaging said comb at said waves to cut hair received in said perforations of said comb.

4. A shaving unit according to claim 1, wherein the size of the comb perforations is not exceeding 0.5 X 1.0 mm. so as to prevent an injury to the user.

5. A shaving unit according to claim 1, wherein said shaving elements include a plurality of cutting blades for engaging said comb at said waves to cut hair received in said perforations of said comb, and said perforations are inclined relative to said cutting blades to provide progressive cutting of hair which is being continually engaged between said comb and said shaving elements to cut the hair of a scissorlike operation.

11. A shaving unit according to claim 8, wherein the lateral shaving elements have a diameter greater than that of the central shaving element, said lateral shaving elements having asymmetrical blades in respect of the vertical plane at the longitudinal axis of the element, while the blades of the central shaving element are symmetrical, giving the unit a large shaving surface.

15. The shaving unit of claim 14, which includes a comb holder having sides in the shape of a continuous curve including a plurality of waves for supporting said comb, and a comb-supporting frame for receiving said comb and comb holder, said comb-supporting frame including a plurality of rods extending perpendiCularly to the sides of said comb holder and located between the waves of the continuous curve of said comb for maintaining said comb in its curved shape.