US3579824A

US3579824A - Electric dry shaver

Info

Publication number: US3579824A
Application number: US827847A
Authority: US
Inventors: Masamiki Matsumoto; Motohisa Nishino; Yoshimasa Tanaka
Original assignee: Matsushita Electric Works Ltd
Current assignee: Panasonic Electric Works Co Ltd
Priority date: 1968-05-31
Filing date: 1969-05-26
Publication date: 1971-05-25
Anticipated expiration: 1988-05-25
Also published as: GB1254137A; DE1927032A1

Abstract

An electric dry shaver having a shaving blade part, which comprises an outer cutter blade provided with side cutting surfaces respectively continuous to its upper cutting surface, at least a pair of inner cutter blades reciprocally driven inside and relative to the outer cutter blade in its longitudinal direction and provided respectively with a side blade part to oppose to one of the side cutting surfaces of outer cutter blade and with an upper blade part to be opposed to a part of the upper cutting surface of outer cutter blade adjacent said side cutting surface, and a biasing means to urge the inner cutter blades to resiliently engage inner surfaces of the outer cutter blade. Said biasing means is provided with a means to distribute its biasing force uniformly to each of the inner cutter blades and, specifically to those inner blades having the side blade part, in a diagonal direction with respect to axial line of the biasing means toward respective corner edges between the upper cutting surface and side cutting surfaces of outer cutter blade, so that such inner cutter blades are always pressed against the upper and side surfaces of outer blade simultaneously.

Description

United States Patent [72] Inventors Masamiki Matsumoto:

Motohisa Nishino; Yoshimasa Tanaka, Kadoma-shi, Osaka, Japan [21] Appl. No. 827,847 [22] Filed May 26, 1969 [45] Patented May 25, 1971 {73] Assignee Matsushita Denko Kabushiki Kaisha Osaka, Japan [32] Priority May 31, 1968, Nov. 30, 1968, Dec. 6, 1968,

Dec. 13, 1968, Feb. 26, 1969 [3 3] Japan [31] 43/45,514, 43/104,450, 43/106,847,

43/109,426 and 44/14,496

[541 ELECTRIC DRY SHAVER 12 Claims, 8 Drawing Figs.

[52] US. Cl 30/4332, 30/346.Sl [51] Int. Cl B26b 19/02 [50] Field of Search 30/4392, 43.91, 346.51, 208, 209, 210, 34.1

[5 6] References Cited UNlTED STATES PATENTS 2,793,430 1/1955 Carissimi 30/43 3,396,463 6/1966 Neumann ABSTRACT: An electric dry shaver having a shaving blade part, which comprises an outer cutter blade provided with side cutting surfaces respectively continuous to its upper cutting surface, at least a pair of inner cutter blades reciprocally driven inside and relative to the outer cutter blade in its longitudinal direction and provided respectively with a side blade part to oppose to one of the side cutting surfaces of outer cutter blade and with an upper blade part to be opposed to a part of the upper cutting surface of outer cutter blade adjacent said side cutting surface, and a biasing means to urge the inner cutter blades to resiliently engage inner surfaces of the outer cutter blade. Said biasing means is provided with a means to distribute its biasing force uniformly to each of the inner cutter blades and, specifically to those inner blades having the side blade part, in a diagonal direction with respect to axial line of the biasing means toward respective corner edges between the upper cutting surface and side cutting surfaces of outer cutter blade, so that such inner cutter blades are always pressed against the upper and side surfaces of outer blade simultaneously.

PATENIED was um SHEU 1 OF 4 INVENTORS NASA mm MA rsuno TO MoroH/SA Nosnmo YOSHIMAYSA TANAKA b Wo%,MNMJ,1/J 9 @m ATTORNEYS PATENTE-D HAY25 1911 SHEET 2 0F 4 INVENTORS MASAMIKI Mnrsunoro MoroH/sA NISHINO YosH/MAsA TANAKA VJ&WATTORNEY5 PATENTED "M25197! saw u or 4 HIIll!IHIHIHHHIHHIIIH llllllHHHHHHHHHHHH LHI IIIHHHIIIHIlllll lllll HHIHI .H O 7 3 8 2 8 O 8 INVENTORS MASAMIKI Mnrsumoro MOTOHISA NISHINO i 1', YOSHIMASA TANAKA J. ATTORNEYS ticularly, to an improved dry shaver having an improved excellent shaving effect with its improved cutting blades and being of a structure that is easy to be handled and cleaned.

In conventional dry shavers, it has been ordinary that a single inner cutter blade is employed with respect to a single outer cutter blade. In such structure, it has been practically impossible to have upper and both side surfaces of the inner cutter blade closely engaged with respective inner surfaces of the outer cutter blade simultaneously in three directions under a proper pressure, in view of certain problems with respect to mechanical precision, and thus such shavers have not been able to be provided with cutting surfaces arranged in three directions of upper face and both side faces. In order to solve this problem, certain types of shavers have been suggested, in one of which, for example, a plurality of the cutting blades comprising respectively an outer blade and an associated inner blade therewith as above have been arranged radially so as to enable the shaver to have a wider range of cutting direction or area. However, in such arrangement, each of a plurality of the cutting blades has had to be provided with a means for biasing each inner cutter blade to urge it toward inner upper surface of each outer cutter blade, that is, such shavers that having a plurality of cutting blades has had to have a corresponding number of the biasing means for the respective inner cutter blades. Consequently, it has been inevitable that the structure of the cutting blade of such shavers has had to become complicated in structure in order to make the cutting direction or area wider, which structure has not been easy to be manufactured, to be assembled, or even to be cleaned by users.

Further in the conventional dry shavers, the inner cutter blade has been provided with an allowance of slight movement only in downward direction, but has not been allowed to move sidewise or in its rotatory direction with respect to its longitudinal axis. This has been resulting in such defect that, when upper cutting blade area of the outer cutter blade would be pressed by the user's face so as to be slightly bent or deformed inwardly, the inner cutter blade would also be pressed downwardly through the bent portion of the outer cutter blade so that a certain amount of clearance between inner surface of the outer blade and upper surface of the inner blade would be caused to exist, which clearance would apparently reduce original sharpness of the cutting blade. That is, the inner cutter blade in any of the conventional dry shavers has been provided only with a strictly limited allowance of movement to follow the bending or deformation of the outer cutter blade. For solving this problem, it would be considered possible to provide a certain resiliency to the inner cutter blade in some way, but this has been difficult in view of the structure and required sharpness of conventional types of the outer and inner cutter blades.

Further in the conventional types of the dry shavers, the biasing means for urging the inner cutter blade toward the inner surface of outer cutter blade has been employed only for the purpose of pressing the inner cutter blade. Hence, the biasing means has not been able to securely hold the inner cutter blade as disassembled from the outer cutter blade for the purpose of cleaning inside the blades. Therefore, in the case where a plurality of the cutting blades are employed, each of which comprising an outer cutter blade and an inner cutter blade, the respective inner cutter blades will have to be disassembled from the respective outer cutter blades one by one and, thus, reassembling operation of such inner cutter blades in pieces into the respective outer cutter blades is troublesome. The same trouble will happen even in the case where only a single outer cutter is employed with respect to a plurality of the inner cutter blades.

The present invention has been suggested to eliminate these defects of the conventional dry shavers as referred to in the above.

A principal object of the present invention is, therefore, to provide a dry shaver which having cutting surfaces directed in three directions lying respectively along the longitudinal direction of the cutting blades, in each of which surfaces the outer and inner cutter blades are kept all the time positively in a close contact with each other.

Another object of the present invention is to provide the dry shaver in which the inner cutter blade is enabled to reciprocally vibrate while always keeping close contact with inner surface of the outer cutter blade even during the time when the outer cutter blade is bent or deformed downwardly by external pressure applied thereto at the time of shaving.

A further object of the present invention is to provide the dry shaver embodying a novel structure that enabling disassemble and reassemble of the respective blade members and their circumferential part with an extremely easy operation at the time of cleaning said members and parts.

A still further object of the present invention is to provide the dry shaver that enabling the shaving much easier with a cutting surface inclined with respect to main body of the shaver which is established by a simple mechanism.

Other objects and advantages of the present invention will become apparent upon reading the following disclosures with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view showing external appearance of an embodiment of the electric dry shaver according to the present invention;

FIG. 2 is a side view of the dry shaver shown in FIG. 1;

FIG. 3 shows partly in section an exemplary arrangement of the cutting blades, pushup biasing member for the inner cutter blades and driving lever for the same according to the present invention, in a vertical sectioned view taken along the line II-II in FIG. 5;

FIG. 4 is a perspective view showing respective one of the outer cutter blade, inner cutter blades, pushup biasing member and driving lever, as disassembled, shown in FIG. 3;

FIG. 5 is a front side view of the main part of the dry shaver showing partly in section the cutting blade portion as in FIG. 3, a means for locking the blade portion to main body of the shaver and an opening and closing mechanism for side cover for longitudinal end sides of the blade portion;

FIG. 6 is a fragmentary vertical section taken along the line VlVI in FIG. 5 showing a mechanism for connecting respective receptacle members of the shaver body at its top portion;

FIG. 7 is a vertical side section at the center of the shaver according to the present invention for showing driving mechanism of the same; and

FIG. 8 is a front view of the shaver with the front side receptacle member as removed.

The present invention shall now be described in detail with reference to a preferred embodiment as illustrated. However, it should be understood that the intention is not to limit the invention to the particular embodiment illustrated but rather to include all alterations, modifications and equivalent arrangement to be included in the scope of the invention as defined in appended claims.

In the drawings, outward shell structure of the exemplary dry shaver according to the present invention comprises, as shown in FIGS. 1 and 2, a rear side receptacle member 1 containing such driving source, driving force transmitting mechanism and almost all of other electrical and mechanical components fixed to the member as will be explained later, a front side receptacle member 2 to be laid over the rear side receptacle member 1, and an upper joint member 3 and a lower joint member 4 for jointing the rear side and front side receptacle members I and 2 at their upper and lower edges, respectively. 5 is a shaving blade part comprising such a fixed outer cutter blade and inner cutter blades as will be referred to later, the latter of which are engaged with inner surface of the former in slidable manner and driven reciprocally in the longitudinal direction of the outer cutter blade. 6 and 6' are side cover members for covering respective open side ends of the

blade part

5, 7 and 7' are pushbuttons for opening the respective

side cover members

6 and 6', and 8 is a slideswitch for opening and closing power circuit for the driving source.

The shaving blade part of the dry shaver as shown in FIGS. 1 and 2 is inclined by a certain angle with respect to axial line of the shaver body. This arrangement may be established simply by making a part of the driving force transmitting mechanism inclined, for the purpose of improving easincss of the shaving operation. However, it will be readily understood that the shaver may take an upright standing type as ordinary shavers without deviating the spirit of the present invention.

Structure of the shaving blade part 5 according to the present invention shall be disclosed with reference to FIGS. 3 and 4. In the drawings, is an outer cutter blade, which forms together with a plurality of inner cutter blades 11 and pushup spring or an upward biasing member 12 for the inner cutter blade the featured shaving blade portion in the present invention. The outer cutter blade 10 is provided with

ribs

13, 13, as support beam 14 and a stiffener 15 jointed between both downward ends of the blade 10. Other upper area and both side areas than the said parts of the blade 10 are made to be of extremely thin layer and are provided with many holes for introducing hairs into the blade. Said supporting beam 14 is effective in downwardly bending the upper area of blade 10 in a uniform manner with respect to the longitudinal direction of the blade upon receiving an external pressure applied to the blade, so that sliding engagement of the blade 10 with the inner blades 11 will be protected from being limited to be only partial area and, thus, the outer cutter blade 10 or the inner cutter blade 11 will be protected from being damaged. 16 is a driving lever for driving the inner cutter blades, and the lever 16 is supported at an axial hole 17 in a rockable manner, which rocking or vibrating motion will be transmitted to the respective inner cutter blades through a coupling bar 18 provided at the top of the lever 16. The respective inner cutter blades 11 is provided with an opening 19 substantially at the central portion of its lower edge for receiving both ends of the coupling bar 18.

In the particular embodiment as shown, a pair of the inner cutter blades 11, 11' has been utilized as the most preferable example of the present invention. Each of the said pair of inner cutter blades l1, 11 is provided with a

base part

20 and 20, U-shaped in section, a

blade part

21 or 21 formed continuously to the base part 20 and facing to

blade part

22 or 22 of the outer cutter blade 10, and a further blade part 23 or 23' L-shaped in section and facing to

blade part

24 or 24 of the blade 10 between the rib 13 or 13' and one of the side face areas. Each of the blades 11 and 11 is further provided with

tongue pieces

25 and 25' and 26 and 26' adjacent both ends of the U-shaped base part 20 or 20' and ending outwardly, respectively. Aforementioned inner cutter blade pushup spring 12 serves as a biasing means for urging the respective inner cutter blades 11 and 11' to resiliently engage with inner or lower surface of the outer cutter blade 10 so as to increase the shaving effect. Thus, the spring 12 is provided at its both ends inner cutter blade supporting arms 27 and 27' upstanding for supporting the inner cutter blades 11 and 11' at the portions adjacent both ends of the respective U-shaped base parts of the blades. In the supporting arms 27 and 27', a pair of windows 28 and 28' and another pair of

windows

29 and 29 are formed, to each of which pairs said respective sets of

tongue pieces

25, 25 and 26, 26' will be registered in freely movable manner. That is, each of the supporting arms 27 and 27' will have a set of

windows

28, 29 and 28, 29, respectively, so that the pair of windows 28 and 28' will receive the pair of

tongue pieces

25 and 25 and the other pair of windows 29 and 29 will receive the other pair of 26 and 26'. The distance between each of the

windows

28 and 28' or 29 and 29' in the inner cutter blade supporting arms 27 nd 27' is set to be smaller than the distance between each root part of the tongue pieces of each of the inner cutter blades 11 and 11'. 30 is a springing part formed between each of the said inner cutter

blade supporting arms

27 and 27 and 31 is an engaging part formed at the center of the spring part 30 by bending so as to upwardly project so that the coupling bar 18 of the driving bar 16 will be engaged at its central portion in the engaging part 31, thereby the inner cutter blade pushup spring 12 will be urged upwardly. Consequently, said pushup spring 12 will be effective in urging the respective inner cutter blades 11 and 11 to engage resiliently with lower surface of the outer cutter blade 10.

It should be here appreciated that intended effect of the pushup spring 12 under its operative condition is to merely resiliently urge the respective inner cutter blades 1 1 and 11 to engage with the lower surface of outer cutter blade 10 while coupling the blades 11 and 11 to itself, and that the transmission of driving force from the driving lever 16 to the respective inner cutter blades is carried out as referred to in the foregoing at the coupling part between the both ends of coupling bar 18 of the driving lever 16 and the respective openings 19 of inner cutter blades 11 and 11 receiving the bar 18. These respects are effective in preventing the engaging position of the pushup spring 12 with the respective inner cutter blades 11, 11' from being displaced in the longitudinal direction of the blades at the time when the shaver is operating, and also preventing root or base parts of

respective tongue pieces

25, 25' and 26, 26' from contacting with circumferential parts of the pushup spring 12. Thus, the engaging position of the respective inner cutter blades 11 and 11' with the pushup spring 12 therefor is limited to contacting point of the lower curved surface of the

respective tongue pieces

25, 25' and 26, 26 of the inner cutter blades 11 and 11 with the lower edges of the

respective windows

28, 28 and 29, 29 in the pushup spring 12, so that a smooth engagement of the respective inner cutter blades 11 and 11 with the pushup spring 12 therefor will be effectively carried out.

A further important feature in the above-mentioned structure is that the lower edges of

respective windows

28, 28 and 29, 29 in the inner cutter blade pushup spring 12 are inclined so as to oppose the ridge line portions respectively forming each of boundary lines between the upper surface and each of both side surfaces of the outer cutter blade 10. This particular structure materializes that, since the biasing force which is presented to each of the inner cutter blades 11 and 11 by means of the pushup spring 12 is directed to each of said ridge lines of the outer cutter blade 10, the respective inner cutter blades 11 and 11 will be biased simultaneously towards the both of upper and side blade portions of the outer cutter blade 10, thereby the close and uniform contact between the outer and inner cutter blades will be established in three directions and, thus, the dry shaver having cutting surfaces distributed in three directions can be obtained by means of the single pushup means as above.

Here, a further effect resulting from the featured structure 7 of the inner cutter blades and upward biasing means therefor according to the present invention shall be referred to. That is, the coupling or engaging condition between the inner cutter blades 11 and 11' and the pushup spring 12 is established at the point of butting position of each curved lower surface of the

respective tongue pieces

25, 25', 26, 26' in the inner cutter blades 11 and 11' with each plane lower edge of the

respective windows

28, 28', 29, 29' in the pushup spring 12 for these blades. Further, it should be noted that the above pointlike butting position is freely movable in response to any downward external pressure applied on the outer cutter blade 10. This will lead to the fact that there is no factor of obstructing rotary movement of the base parts of inner cutter blade in the direction across the longitudinal direction of the blades. Therefore, even when the outer cutter blade 10 is deformed by the external pressure given at the time of shaving, the said butting points of the inner cutter blades 11 and 11' at their curved lower surfaces will freely be shifted toward any sideward directions intersecting the longitudinal axis of the respective inner cutter blades, without varying the shape of cutting blade areas of the inner cutter blade in close opposing relation to corresponding areas of the outer cutter blade. Thus, the close contacting state between each of the said blades over the said areas will be always maintained, thereby an excellent shaving effect will be retained uniformly throughout the time of shaving, against any variations or deformations of the outer cutter blade during the shaving.

In other words, in the structure of shaving blade part according to the present invention, such single upward baising means for the inner cutter blades that providing the internal upward biasingforce perpendicular to the upper blade surface of the outer cutter blade is provided with a means to distribute said upward biasing force equally to each of a plurality of inner cutter blades contacting internally to the outer cutter blade, respectively. Further, due to the feature that said distributing means of the upward biasing force is in possession of the inclined edges or surfaces respectively facing to each of the ridge comers of outer cutter blade, the said means is effective in urging the respective inner cutter blades opposing to the said corners always in the direction of each corner. That is to say, the above feature that the inner cutter blades opposing to the respective corners are always urged toward the said corners is biasing the same inner cutter blade to the ordinary upper shaving surface and simultaneously to one of the side surfaces. Thus, if each of the said inner cutter blades at the corner sections is provided with shaving blades respectively facing to the upper shaving surface and likely each of the side face shaving surfaces formed continuously to the said upper shaving surface of the outer cutter blade, an improved electric dry shaver having the shaving blades at both sides along the longitudinal direction of the blade part can be obtained with a simple structure.

While in the above detailed embodiment the structure employing a pair of inner cutter blades has been shown, it will be appreciated that the same effect can be established by such arrangement that employing, for example, three inner cutter blades including the one which is biased simply upwardly so as to internally contact only with the upper cutting blade of the outer cutter blade. in such arrangement, upper horizontal surface or edge of the respective supporting arms 27 of the pushup spring 12 for the inner cutter blades may be utilized for biasing the said inner blade to be urged upward only, or alternately, a further engaging window having the lower edge in parallel to the said horizontal surface or edge may be provided between the inclined engaging windows so as to be engaged with the tongue piece formed at the base part of the particular inner blade similarly to the other inner blades having the side cutting blades respectively engaged with the respective inclined windows.

Further in the above detailed embodiment, the inner cutter blade pushup means has been referred to in the structure wherein the windows for engaging with the tonguelike projected pieces are provided therein. However, it should be also appreciated here that such arrangement of the tonguelike projections and the windows for engaging therewith as illustrated is not always required for the purpose of only distributing the upward biasing force as referred to in the above. For example, such upward biasing means that having only diagonal end edges at both comers of the upstanding supporting arms 27 for the inner cutter blades of the spring 12, will effectively establish the same purpose of distributing the upward biasing force. In such case, the curved lower base surface of the respective inner cutter blades each having the sideward cutting blade may simply butted to one of the diagonal edges and the further inner cutter blade having only upward cutting blade, if employed, may be also butted at its likely curved lower surface to the horizontal end edge between the diagonal ed es.

similarly in the above embodiment, while the pushup spring formed from a resilient metal plate in a W-shape has been shown as an exemplary upward biasing means for the inner cutter blades, it will be apparent that the particular Spring member is of the most desirable form for making its structure most simple and yet obtaining the largest effect and, thus, that such a member that having a means for providing an upward pushing up force to the inner cutter blades similarly to the above pushup spring and a means for transmitting said upward force uniformly distributed as referred to in the above to each of a plurality of the inner cutter blades may be employed. In such case, also, the said upward force distribution means will undoubtedly have the beforementioned diagonal edge-shaped surfaces. However, it will be apparent that the same effect of the diagonal edges will be established by diagonal surfaces respectively having a certain length extending in the longitudinal direction of the cutting blade.

Further, with respect to the structure of the inner cutter blade in its cross section, while a specific structure which is formed by bending in a U-shape a long plate material and further bending each of upward end portions outwardly so as to be upward and sideward blade portions has been referred to, it should be appreciated here that the most important point in the particular structure is, as detailed in the foregoing, the lower surface of the base part of respective inner cutter blades, which is curved with respect to the axial line as a center extending in longitudinal direction of the inner cutter blade in order to converge the engaging area of the lower base part of the blade with the upward urging means, that is, the butting surface area for transmitting the upward urging force, to a single point. That is to say, the inner cutter blades to be utilized in the shaver according to the present invention may take any of the structures that having a curved surface at the butting surface with the upward urging means. Further, while it is most advantageous in view of manufacturing, assembling and disassembling to employ such type of engagement between the respective inner cutter blades and the upward urging means that the engaging tongue pieces formed by cutting a part of lower surface of the blade having the longitudinally extending curved base part are engaged with the receiving windows in the blade-supporting arms of the pushup spring, as in the embodiment detailed in the foregoing, it should be also apparent that the tongue pieces may be formed as simply projected in endwise direction at both ends of lower base part of the inner cutter blades as shown, or may be formed likely as projected at the both ends of lower base part of the blades but the latter having a flat base extending substantially over the entire length and only the tongue pieces having the curved lower surfaces, so that the engaging of the blades with the pushup spring as shown will be established by engaging these endwise projected tongue pieces respectively in each of the windows of the spring member.

The said engagement of the inner cutter blade pushup spring 12 with the respective inner cutter blades 11 and 11' in the embodiment as shown will be carried out in such manner as follows. That is, the supporting arms 27 and 27' of the pushup spring 12 for the inner cutter blades will be expanded manually in outward direction to each other and the engaging

tongue pieces

25, 25 and 26, 26 of the respective inner cutter blades 11 and 11 are brought into free engagement with the

respective windows

28, 28 and 29, 29 made in the respective inner cutter blade supporting arms 27 and 27', after which said

arms

27 and 27 are returned to their original positions with the own resiliency of the spring 12 so as to rest at the positions where the original distance between them will be retained. In this engaging state, the inner cutter blades 1 l and 11' and the pushup spring 12 are maintained in their engaging relation to each other so as not to be easily disengaged. Therefore, even at the time when thus engaged inner cutter blades 11, 11' and pushup spring 12 are disassembled from the outer cutter blade 10, the engaging relation between the plurality of inner cutter blades and the spring is retained, so that the reassembling of the both outer and inner cutter blades will be carried out very easily.

Mounting and dismounting operations of the cutting blade part comprising the outer cutter blade and associated inner cutter blades therewith as described in the above to the electric dry shaver body will be carried out as follows. That is, as shown in FIG. 5, there is provided mounting

holes

32 and 32 in the lower side of the stiffener 15 at the both lateral sides of an opening 19 for inserting therethrough the upper coupling bar 18 of driving lever 16 and adjacent both side end portions of the inner cutter blade. On the other hand, in a holding frame 33 for receiving and holding the said driving lever 16 therein at the upper portion of the shaver body, there is mounted a pair of locking plates 34 and 34' made'of a resilient material. At intermediate portion of the

respective locking plates

34 and 34, coil springs 36 and 36' contained respectively in recesses 35 and 35' of the frame 33 are butted to the

plates

34 and 35, respectively. Lower ends of the plates 34 and 34' are retained in retaining recesses 37 and 37' likely provided in the frame 33, respectively, and upper ends of the same are resiliently urged to be pressed against stoppers 38 and 38' formed on the frame 33 as being given an outward resilient force by means of said coil springs 36 and 36'. Thus, the arrangement is so made that the outer cutter blade 10 will be mounted at the top of the dry shaver body above the upper joint member 3 with a simple one-touch operation of inserting forward ends 'of the locking plates 34 and 34' into mounting

holes

32 and 32, respectively, so that the blade 10 will be resiliently locked by the

plates

34 and 34 at this mounted position.

When the cutting blade part is thus mounted on the upper part of electric dry shaver, the coupling bar 18 of driving lever 16 will also reach into its engaging position with the respective openings 19 at the center of the inner cutter blades 11 and 11 while engaging with the engaging part 31 at the center of the pushup spring 12 and urging the same upwardly, at the same time when the forward ends of locking

plates

34 and 34 are inserted into the mounting

holes

34 and 32, respectively, as described in the above. Since these operations are thus established simultaneously by the single downward pressing motion of the blade part 5 so as to lock the same with the resilient plates 34 and 34', such separate fixing operation that the blade part is to be fixed to the shaver body by, for example, a fixing screw after the mounting operation of the blade part into engaging position of the inner cutter blade with the driving lever, as normally required in the conventional dry shavers of the kind, can be entirely eliminated. Further in the case of dismounting the blade part from the shaver body, the locking plates 34 and 34' will be urged respectively inwardly by peripheral edges of the mounting

holes

32 and 32 of outer cutter blade upon pulling up of the blade pan 5 so that the locking by means of the plates 34 and 34' will be released and, at the same time, the engagement between the driving lever 16 and inner cutter blade pushup spring 12 will be also released. At this time, center portion of the pushup spring will be lowered automatically by its own resiliency until it reaches bottom surface of the outer blade member and rests there. Thus, the inner cutter blades will remain in their position held in the outer blade member, but they will be readily pulled out of the outer blade whenever required for the cleaning simply by pushing them laterally from an open end of the cutting blade part 5.

Further according 56 present invention, the present shaver is provided with a novel opening and closing mechanism for the side cover members 6 and 6' normally closing both open ends of the outer cutter blade 10, as shown in FIG. 5 and adapted to further simplify the above-mentioned dismounting of the blade part 5 from the shaver body for its cleaning, a part of which is contained in the holding frame 33. Said opening and closing mechanism for the side covers 6 and 6' comprises operating levers 42 and 42' rotatably secured at their upper and lower ends to fixing axes 40 and 40' of the side covers 6 and 6' and binge holes 41 and 41 of the holding frame 33, respectively, the

pushbuttons

7 and 7 fixed at middle portion of said levers 42 and 42' and butted at their upper ends to lower ends of the cover 6 and 6', respectively, and tension springs 45 and 45' secured at their upper and lower ends to hinge pins 43 and 43' of the

covers

6 and 6 and stepped

parts

44 and 44 of the frame 33, respectively. Thus, in their normally closed position as shown at left-hand part of FIG. 5, the side cover member: 6 and 6' are pulled inward by the tension force of the springs 45, 45' acting on pins 43, 43' and the lower ends of the cover members 6 and 6' are held in place by the

levers

42, 42 so as to close both open ends of blade part 5. When the pushbuttons 7 and 7' are pushed inward by fingertips, lower ends of the covers 6, 6' are pressed inward and simultaneously pulled inward by the levers 42, 42', so that the

cover members

6, 6 are rotated about flanges 46 and 46' of the frame 33 as a fulcrum and, thus, their upper ends swing outwardly up to the position as shown at right-hand part of FIG. 5. At this swung position, the tension force of

springs

45, 45 will be directed downward, so that the covers 6, 6' are drawn through the pins 43, 43' to the pushbutton side and retained in this swung position.

In order to close the covers, a simple pushing up of the cover members 6 and 6' at their upper ends in the swung position by fingertips will throw them into inward urging force range of the springs 45, 45' so that the covers will be again locked in their said closed position. With such arrangement as above, the side cover members 6 and 6' are easily opened and closed by a simple pressing on the buttons 7 and 7' and pushing up at their forward ends with the fingertips of the user's single hand holding the shaver body and, thus, the cleaning of cutting blade part has been further simplified.

Next, the driving mechanism for the electric dry shaver according to the present invention shall be explained in the following. ln FIGS. 7 and 8, the holding frame 33 for integrally holding a motor 50 is secured at the upper portion of the rear receptacle member 1 forming a part of the shavers outer shell structure. Said frame 33 will be fixed to the receptacle 1 with screws 52 as screwed in screw holes 51 made in the receptacle 1. In the present embodiment, the driving lever 16 takes such a structure in its side view that its body is bent at its intermediate position so that the longitudinal axial line is inclined toward shavers front side face. At its upper end, the lever 16 carries the coupling bar 18 for transmitting its vibrating motion to the inner cutter blades ll, 11 as coupled to the bar and, at the same time, for urging upwardly the pushup spring 12 which holds the inner cutter blades. Further, the lever 16 has at its lower end an opening 53 to be coupled with an cecentric cam 55 directly connected with a rotary shaft 54 of the motor 50. The driving lever 16 will be received in a chamber 57 of the holding frame 33 at a rockable state, which state is established by being pivoted with a fixing shaft 56 penetrated through an axial hole 17 made above said bent portion of the lever and arranged in parallel relation to the blade part 5 mounted to the shaver body with an inclination corresponding to the bent angle of the driving lever 16.

As disclosed the above, in the dry shaver according to the present invention the axial line of said fixing shaft 56 and the plane on which the blade part 5 is mounted are parallel to each other. For this reason, the inner cutter blades may happen to be slightly shifted in the longitudinal direction of the blade but will not be shifted in a direction transverse to the longitudinal direction, so that the intimate engagement of inner cutter blades with the outer cutter blade at the both side areas facing to front and rear faces of the shaver body is maintained always in an excellent condition and, thus, the sharp cutting effect will never be deteriorated.

The said eccentric cam 55 of motor 50 is connected to the holding frame 33 at the position where the same is engaged in the opening 53 of driving lever 16. The motor 50 is firmly fixed to the frame 33 in such manner that a mounting frame 60 for the motor which bearing an end of the rotary shaft 54 and having through holes 61 will be butted to the lower end of said holding frame 33 so that its projections 62 provided at the lower end will be engaged in the through holes 61 of the mounting frame 60 and, also, screw holes 63 made in the mounting frame 60 and through holes 64 will be aligned with each other, in which holes screws 65 are screwed. Electric power for the motor 50 will be supplied thereto through plug blades 71 fixed in a cavity having an open end at the lower end of the rear receptacle 1, a rectifier 72 arranged under the motor and the slide switch 8 fixed to a side portion of the rear and

front receptacles

1 and 2.

A further detailed explanation with reference to the upper joint member 3 and lower joint member 4 forming a part of the outer shell structure of the shaver body of the present invention shall be made here. As shown in FIGS. 6 and 7, bent parts 3' and 3" are formed at front and rear ends of the upper joint member 3 for engaging with upper end edges of the respective rear and

front receptacle members

1 and 2. The member 3 is provided with through holes 75 and 75' made along the centerline at its bottom as seen in FIGS. and 6, through which holes screws 78 and 78' are screwed into nuts 76 and 76' received in receptacle cavities 77 and 77' of the holding frame 33 so as to fasten the member 3 to the upper end edges of both

receptacles

1 and 2 as engaged in the bent parts 3' and 3", thereby the rear and

front receptacles

1 and 2 are firmly joined together at their upper ends. Further, the lower joint member 4 comprises, as seen in FIGS. 7 and 8, a cover member 80 having a flange 81 to be engaged with a stepped part provided at the lower end periphery of the

respective receptacle members

1 and 2 and a fastener 84 contained inside the cover member 80 and receiving a screw 82 inserted through a hole 83 of the cover 80. Thus, by the fastening action of the screw 82 and fastener 84, the .rear and

front receptacle members

1 and 2 are firmly joined also at the lower ends thereof.

For the purpose of facilitating better understanding of the invention, the operation of the above-described embodiment shall now be briefly explained. A commercial alternating electric voltage supplied from the plug blades 71 will be impressed through the slide switch 8 to the rectifier 72 and by an output direct current voltage from therectifier 72 the motor 50 will be rotated. Responsive to the rotation of motor 50, the eccentric cam 55 directly mounted to the rotary shaft of the motor 50 carries out an eccentric motion within the limited space of opening 53 at the lower end of driving lever 16, thereby the driving level 16 will be rocked with respect to the fixing shaft 56 as a center. The rocking motion of driving lever 16 will be transmitted through the coupling between the coupling bar 18 of the lever and the respective openings 19 and 19' of the inner cutter blades 11 and 11' to these blades, so that the blades l1 and 11' urged to closely engage the inner surface of the outer cutter blade by the pushup spring 12 which in turn is likely pressed upward by the bar 18 will be reciprocally moved in the longitudinal direction of the blades. Therefore, any hairs introduced into the blades from holes of the outer cutter blade 10 will be cut by the cutting action of these outer and inner cutter blades 10, Ill and 11'.

Thus, with the above-described structure of the embodiment illustrated, such an excellent electric dry shaver that capable of establishing the various objects as disclosed in the foregoing will be obtained. That is, the dry shaver according to the present invention is provided with additional side shaving surfaces lying along the upper shaving surface, which are established by the blade part having a novel arrangement of the outer cutter blade including the cutting areas distributed in three directions of the upper and both side faces and a plurality of the inner cutter blades urged to closely engage internally said outer cutter blade in the three directions by the upward urging means. Further, in addition to the excellent shaving effect substantially established specifically by the upward urging means, smoother introduction of the hairs coming into contact with the cutting blade upon lateral movement of the shaver will be established so as to remarkably improve the easy shaving. At the same time, by utilizing the easy shaving effect in lateral directions, even a trimming cutting which has not been carried out by the conventional type of shavers may be-made possible. For these purposes, it will be apparent that the inclined shaving surface established by the simple and yet reliable structure of the driving mechanism according to the present invention is effective in improving the excellent effect and easiness of the shaving realized by the shaver of the invention.

Further, since the mounting and holding mechanism for the blade part according to the present invention contributes greatly to making the mounting and dismounting of the blade part to the shaver body in cooperation with the novel structure of the blade part itself and, thus, to the simplicity of cleaning operation. This feature is further made to be unique and remarkable by the opening and closing mechanism for the side covers covering the respective open ends of blade part in its longitudinal direction, which is featured by the one-touch operation.

We claim:

1. An electric dry shaver comprising a receptacle member, a driving member, a driving means contained in said receptacle member, a plurality of inner cutter blades connected to said driving means so as to be urged to reciprocally move, an outer cutter blade for enabling to shave in cooperation with said inner cutter blades, and a means for biasing the inner cutter blades toward said outer cutter blades to engage with the inner surface of the outer cutter blades, said outer cutter blade being provided with an upper blade part and a side blade part formed sequentially to respective side edges of said upper blade part, one of said inner cutter blades which is opposed to one of said side blade parts of the outer cutter blade being provided with a side blade part to be opposed to said one of the side blade parts of said outer cutter blade and with an upper blade part to be opposed to a part of said upper blade part which is sequent to said one of the side blade parts of the outer cutter blade and with an upper blade part to be opposed to a part of said upper blade part which is sequent to said one of I 2. The electric dry shaver according to claim 1, in which each of said inner cutter blades has such a cross section at the position where the blades engage with said force-distributing means of the biasing means that allows the engagement to be at a point.

3. The electric dry shaver according to claim 1, in which said force-distributing means of the biasing means has a diagonal surface facing diagonally outward at the position where each of the inner cutter blades respectively having the side blade part engages therewith.

4. The electric dry shaver according to claim 1, in which said plurality of inner cutter blades comprises a pair of the inner cutter blades respectively provided with an upper blade part to oppose to respective one of longitudinal halves of the upper blade part of outer cutter blade and a side blade part to oppose to respective one of the side blade parts of outer cutter blade.

5. The electric dry shaver according to claim 1, in which said outer cutter blade has at its lower surface of the upper blade part at least one rib member extending in longitudinal direction of the blade so that the blade deforms about said rib member due to an external pressure applied thereto.

6. The electric dry shaver according to claim 1, in which said biasing means for the inner cutter blades comprises a resilient plate member having at each of both ends thereof an upright standing part for engaging with the respective inner cutter blades, each of said upright standing parts being provided at the position where engaging with the inner cutter blades with a pair of left and right diagonal surfaces respectively symmetrical to each other and faced to externally diagonal directions.

7. The electric dry shaver according to claim 6, in which said inner cutter blades has respectively at the position where engaging with said biasing means of a resilient plate member a pair of tongue pieces having in the cross section a U-shaped and extending at their ends outwardly in the longitudinal direction of the blades, said upright standing part at each end of the resilient plate member having a corresponding number of windows to the number of the inner cutter blades for receiving respectively each of said tongue pieces at an end of the respective inner cutter blades, and said windows being provided with a diagonal lower edge facing to externally diagonal directions, respectively.

8. The electric dry shaver according to claim 6, in which said biasing resilient plate member has a smaller distance between the respective windows at both ends of the resilient plate member at the time of free condition before engaged with the tongue pieces than the distance between the respective tongue pieces at both ends of each inner cutter blade, whereby the engagement of resilient plate member with the tongue pieces of inner cutter blades will be continued when the blades are dismounted from the outer cutter blade.

9. The electric dry shaver according to claim 6, in which said driving means comprises a driving source and a driving lever to be urged to rockingly move by said driving source, each of said inner cutter blades having substantially at the center of its lower surface a recessed part, and said biasing resilient plate member having substantially at its center a bent part in a shape for receiving forward end of said driving lever, so that said driving lever will provide an additional urging force to said resilient plate member as assembled therewith at said bent part of the member while each of the inner cutter blades will be engaged directly with said forward end of the driving lever through said recessed part so as to be driven by the lever.

10. The electric dry shaver according to claim 1, in which said driving member has an angle of inclination with respect to longitudinal axis of the shaver body in a transverse direction of longitudinal axis of the cutting blade and mounting position for the cutting blade of said receptacle members being inclined by a corresponding angle to said angle of inclination of the driving member.

11. The electric dry shaver according to claim 1, in which said outer cutter blade has a bottom wall for receiving the inner cutter blades, which bottom wall has holes adjacent its respective ends in the longitudinal direction, and the mounting position of said receptacle members for the cutting blade has a pair of locking plate members projecting out of engaging surface of the mounting position with said bottom wall of the outer cutter blade and being biased respectively outwardly in said longitudinal direction, so that when the cutting blade is mounted said locking plate members will engage respectively in each of the holes in said bottom wall of the outer cutter blade and will resiliently press outward end edges of said holes with their outward biasing force so as to hold the cutting blade part.

12. The electric dry shaver according to claim 1, in which said mounting position of the receptacle members for the blade part includes side cover members for the blade part respectively pivoted rotatably at a lower end to each longitudinal side end of the receptacle members and normally biased toward inside the receptacle members, and pushbuttons respectively butted to each of said side cover members at a point which is opposite to said inward biasing point of the cover members with respect to said pivoted point, whereby when said pushbuttons are pressed inward said side cover members are rotated outwardly at their upper ends and are rested at their said rotated position.

Claims

1. An electric dry shaver comprising a receptacle member, a driving member, a driving means contained in said receptacle member, a plurality of inner cutter blades connected to said driving means so as to be urged to reciprocally move, an outer cutter blade for enabling to shave in cooperation with said inner cutter blades, and a means for biasing the inner cutter blades toward said outer cutter blades to engage with the inner surface of the outer cutter blades, said outer cutter blade being provided with an upper blade part and a side blade part formed sequentially to respective side edges of said upper blade part, one of said inner cutter blades which is opposed to one of said side blade parts of the outer cutter blade being provided with a side blade part to be opposed to said one of the side blade parts of said outer cutter blade and with an upper blade part to be opposed to a part of said upper blade part which is sequent to said one of the side blade parts of the outer cutter blade and with an upper blade part to be opposed to a part of said upper blade part which is sequent to said one of the side blade parts of the outer cutter blade, and said biasing means for the inner cutter blades having means to uniformly distribute the biasing force to the respective inner cutter blades, said distributed force to the inner cutter blades provided with the side blade part being in externally diagonal direction.

2. The electric dry shaver according to claim 1, in which each of said inner cutter blades has such a cross section at the position where the blades engage with said force-distributing means of the biasing means that allows the engagement to be at a point.