US3452435A - Electric safety razor with stationary cap and improved electromagnetic drive means - Google Patents

Description

July 1, 1969 D. H. HOLDT 3,452,435

ELECTRIC SAFETY RAZOR WITH STATIONARY CAP AND IMPROVED ELECTROMAGNETIC DRIVE MEANS Filed Dec. 27, 1966 Sheet FIG 2 INVENTOR DONALD H. HOLDT BY fiw 0 A ATTORNEYS July 1, 1969 D. H. HOLDT 3,452,435

ELECTRIC SAFETY RAZOR WITH STATIONARY CAP AND IMPROVED ELECTROMAGNETIC DRIVE MEANS 2 Sheet of 3 Filed. Dec. 27, 1966 INVENTOR DONALD H. HOLDT F/G: 6 BY WQ Q O 7/ F ATTORNEYS July 1, 1969 D. H. HOLDT 3,452,435

ELECTRIC SAFETY RAZOR WITH STATIONARY CAP AND IMPROVED ELECTROMAGNETIC DRIVE MEANS Filed D80. 27, 1966 1 Sheet 3 of3 FIG. 12 I00 INVENTOR DONALD H. HOLDT ATTORNEYS 3,452,435 Patented July 1, 1969 US. Cl. 30-45 6 Claims ABSTRACT OF THE DISCLOSURE An electric safety razor having a head unit on which a blade is mounted for reciprocatory movement in a direction parallel to its edges and a body portion for holding the head unit and for sealingly housing an alternating flux electromagnetic drive means. The blade reciprocates relative to a cap member and guard rollers which are stationarily mounted immediately above and immediately below the blade edge, respectively. The top of the body portion has a recess between the legs of the electromagnet, and a permanent magnet attached to the blade extends into this recess to be driven by the electromagnet.

This invention relates to an electric safety razor having a reciprocating blade, and more particularly to an electric safety razor wherein the safety razor is caused to be reciprocated by a power driven means in a direction parallel to its cutting edges.

Electric safety razors of this general type are disclosed in US. Patent application Ser. No. 435,005, filed Feb. 24, 1965, now patent no. 3,327,387, issued June 27, 1967, and US. patent application Ser. No. 467,935, filed June 29, 1965, now Patent No. 3,321,831, issued May 30, 1967.

Various problems have arisen in the use of previous razors of this type. First, the means for imparting reciprocatory end to end movement of the razor blade has not provided sufiicient power, as a result of which the effectiveness of the razor blade has been impaired. The power driven means normally includes an electric drive comprising an electromagnetic core contained in the handle of the razor and having an energizing winding wound around one leg of the core. The magnetic polarity of the legs, or poles, of the core alternates in accordance with the frequency of the alternating current source supply. A conventional electric outlet may be used to provide the alternating current source. The head unit of the razor is normally provided with a permanent magnet which is reciprocated by means of the alternation of the polarity of the magnetic flux between the poles of the core. The permanent magnet is connected through various means to the blade which is thereby reciprocated in a direction parallel to the edges of the razor blade. However the previous electric razors have been unsatisfactory since the permanent magnet has been spaced from the direct path of the magnetic flux between the poles of the electromagnetic core, as a result of which the driving force has been relatively weak. The force driving the permanent magnet has been especially weak when the permanent magnet is positioned at the end limits of its travel. Therefore the blade has not been reciprocated with suflicient force and has therefore been inadequate in use.

A second disadvantage of the previous razors has been that the blade cap mounted on the head unit above the razor blade has been reciprocated together with the blade relative to the stationary guard rollers causing the skin to move with the razor blade. This minimizes the cutting and shearing effectiveness of the blade, and results in uncomfortable and inefiicient shaves.

The electric razor of the present invention overcomes the deficiencies of prior electric razors, is more simple and economical to manufacture, and provides an eminently more satisfactory shaving device. The improved blade drive means provides a more powerful drive, significantly improving the operation of the razor. Th electric drive is wholly contained in the waterproof and moistureproof handle of the razor. A more powerful drive is obtained by inserting a portion of the driven permanent magnet of the razor, which is contained in the head unit, into the direct flux path between the poles of the electrically excited electromagnetic core. This has been accomplished by providing a recess in the upper surface of the handle between the poles of the electromagnetic core and thereafter positioning a portion of the driven permanent magnet into the recess. Since a portion of the permanent magnet is thereby inserted in the main flux area of the core, it is driven in a more positive manner. The upper surface of the handle below the recess fully seals the electromagnetic core and the remaining portions of the electric drive from both water and moisture. Thus there is no open electrical structure and there is no danger of an electric .shock when using the electric razor of this invention. The razor can therefore be used on a dry skin surface; or the skin may be lathered, if desired, without fear that the user will receive an electric shock.

In the razor blade of this invention both structural members adjacent the blade edges and touching the skin are held stationary while the blade is reciprocated relative to the two stationary structural members. The blade cap which touches the skin above the blade edge is pivotally connected to the guard rollers which contact the skin below the blade edge and the razor blade is caused to reciprocate between the guard rollers and the cap. Thus in the present razor, unlike the previous razors, the cap no longer reciprocates with the blade. Both the cap and the guard rollers prevent movement of the shavers skin and thereby allow the reciprocating blade to cut with maximum effectiveness. The cap is pivotally connected to the shaft ends of one guard roller and pivots about the axis of that guard roller. The cap is further provided with protuberances which are received in recesses in the shaft ends of the other guard roller. The cap is therefore pivoted about the shaft ends of one guard roller and is adapted to be snapped into operative position releasably engaging the shaft ends of the other guard roller. Thus the stationary cap and guard rollers enable the blade to function more effectively and allows the user to get a more efficient and more comfortable shave.

It is, therefore, an object of my invention to provide an improved drive means for an electric razor which will enable the user to get a more satisfactory shave.

It is a further object of my invention to provide a nonreciprocating skin contacting cap member for an electric safety razor which cooperates with non-reciprocating skin contacting members to provide a more satisfactory shave.

Still another object of my invention is to provide a drive means wherein a portion of a permanent magnet is placed in the direct magnetic flux path between the poles of an electromagnetic core and wherein the electrically driven core is totally insulated from the driven permanent magnet by a moisture proof cover.

A further object of this invention is to provide a stationary skin contacting cap member which is mounted above a reciprocating blade and which is easy to assemble and reliable to use.

Other objects and novel features of this invention will appear more fully hereinafter from the following detailed description of the invention when taken in connection with the accompanying drawings wherein:

FIG. 1 is a perspective view of the electric safety razor constructed in accordance with the principles of this inventlon;

FIG. 2 is a partial side view showing the head portion of the razor;

FIG. 3 is a partial end view of the head portion of the razor;

FIG. 4 is a partial perspective view showing the cap member of the razor in a pivoted inoperative position;

FIG. 5 is a partial section view of the razor head taken along line 5-5 of FIG. 3;

FIG. 6 is a partial section view of the razor head taken along line 66 of FIG. 2;

FIG. 7 is a partial section view taken along line 77 of FIG. 3 showing the releasable connection of the cap member to a guard roller;

FIG. 8 is a partial section view taken along line 8-8 of FIG. 3 similar to FIG. 7 showing the cap member similar reference characters refer to similar parts throughout the several views, an electric safety razor indicated generally by 10, comprises a body portion in the form of a handle 12 which houses the electric drive and is provided with a removable head unit 14. The head unit 14 is removably supported on the handle 12 by means which I provide for firm interengagement between the head 14 and the handle 12.

The head unit 14 comprises a support member 16 having a pair of upwardly extending shoulders 21 and 23 and a pair of downwardly extending gripping members 18 and 20 formed integrally therewith. The gripping elements 18 and 20 frictionally retain the support member 16 securely on the handle 12 and substantially prevent relative movement between the member 16 and the handle 12. The handle 12 has upwardly projecting holding members 22 with laterally projecting outer edges 25, which are located adjacent the interior of the downwardly extending gripping elements 18 and 20 to frictionally retain the support member 16 securely on the handle 12. A second retaining means is provided for preventing movement of the head 14 relative to the handle 12. To this end, referring to FIG. 6, the holding members 22 are provided with gripping recesses 28 which cooperate with a pair of inwardly bent shoulders 26 on the head unit 14.

The top portions of the holding members 22 are beveled at 27. Upon attachment of the head unit 14 on the handle 12 the bent shoulders 26 of the support member 16 ride along the beveled surfaces 27 causing the holding members 22 to move inwardly. Upon alignment of the bent shoulders 26 with the recess 28, the holding members 22 snap to their normal position and securely hold the head unit 14 on the handle 12. Thus, the head unit 14 is securely retained on the handle 12 by both the frictional gripping of the elements 18 and 20 with the outer edges of the holding members 22 and the intercooperation of the shoulders 26 and the recesses 28.

To remove the head 16 from the handle 12, release members 24 on the resilient holding members 22 are pushed inwardly as a result of which the holding members 22 are moved inwardly and the recesses 28 are moved out of engagement with the bent shoulders 26 of the head 14, thus allowing the head unit to be readily removed by the application of a pulling force on head 14 sufficient to overcome the frictional engagement between gripping elements 18 and 20 and projecting edges 25.

The upwardly extending shoulders 21 and 23 provide support means for a pair of eccentrically mounted guard rollers 30 and 32. The operation and functions of the guard rollers 30 and 32 are fully set forth in copending application Serial No. 435,005, now Patent No. 3,327,387, referred to above. The guard rollers 30 and 32 have shafts 31 and 34 respectively, extending outwardly from both ends thereof, said shafts being integral with the guard rollers and being eccentrically mounted with respect to the centers of said guard rollers. Openings are provided in the shoulders 21 and 23 of support member 16 which openings are adapted to receive the shafts 31 and 34, so that the rollers 30 and 32 are rotatably mounted in support member 16 with the center of rotation offset with respect to the centers of the guard rollers. Handles 36 and 38 are provided for rotating the guard rollers 30 and 32, respectively. The handles 36 and 38 have projections which cooperate with spaced indentations 37 on the shoulder 21 to provide for incremental adjustment of the position of rollers 30 and 32.

A blade carrier 40, a blade 42, and a blade retainer 44 are resiliently mounted by said support member 16 by means of double arm leaf springs 43 for reciprocatory end to end movement in a direction parallel to the cutting edge of the razor blade as seen in FIG. 5.

The top ends of the springs 43 are connected to the blade carrier 40 by means of rivets 45 while the lower ends of the springs are secured to gripping elements 18 and 20 of support member 16 by means of rivets 49. The spring elements 43 are preferably made of resilient metal so that while the springs permit endwise reciprocatory motion they also cooperate to substantially prevent any side-to-side motion. Blade carrier 40 is positioned above the support member 16 and is mounted for reciprocatory end to end movement by means of the springs 43. The blade carrying member 40 has two upwardly extending blade positioning prongs (not shown) which are positioned to receive the razor blade 42 and prevent movement of the blade relative to the blade carrying member 40. The blade carrier 40 has a pair of magnet retainers 48 extending downwardly therefrom. The retainers 48 have interior arcuate surfaces 50 which are adapted to receive and frictionally retain a permanent magnet 52 member.

The blade carrier 40 has an opening 54 which houses the blade holding and ejecting spring member.

A blade retainer 44 is mounted over the blade 42 and has slotted openings which receive the upper portion of the prongs of the blade retaining member 40. The blade retainer 44 has a shaft 56 extending downwardly therefrom. The shaft has opposing cap retaining notches 58 positioned near the base thereof. Positioned in said opening 54 in the blade carrier 40 is an off center Spring 60 which is retained in the recess 54 in the blade carrying member 40 by the rivets 45 which also hold springs 43. The off center spring 60 has two gripping portions 61 and 63 which grip the notches 58 on the shaft 56 of the blade retainer 44 in order to bias the blade retainer and the blade downwardly into their operative position.

A spring 74 is utilized to move said 01f center spring 60 to release shaft 56. The support member 16 has a pair of openings 70 in the downwardly extending gripping elements 18 and 20. The openings 70 receive finger engaging, blade releasing members 72 therein. The blade releasing members 72 are utilized to move the spring 74 upwardly, thereby moving the off center spring 60 upwardly, thereby releasing said blade retainer 44 and said blade 42. The outer faces of members 72 are ribbed at 73 to provide a finger gripping surface. The inner ends of the members 74 are provided with arcuate recesses 76. The initiating spring 74 is curled at its ends 75 and received in the recesses 76 of the members 74. The operation and functions of the off center spring 60 and the initiating spring 74 are fully set forth in copending application Ser. No. 467,935, new Patent No. 3,321,831,

referred to hereinabove. Thus it can be seen that the off center spring 60 and the initiating spring 74 provide an efficient means for ejecting a razor blade. Furthermore, the off center spring 60 grips the shaft 56 of the blade retainer 44 and forces the blade retainer 44 against the razor blade 42 and the blade carrying member 40 thereby facilitaing the movement of said carrying member, said blade, and said blade, retainer as a single unit.

A cap member 80 is pivotally mounted on the head unit 14 above the blade retaining member 44. A small clearance 81 is provided between the cap 80 and the blade retainer 44 to allow the blade retainer to move lengthwise relative to the cap without rubbing against said cap. The cap 80 has a pair of downwardly extending connecting legs 82 near one side of the cap 80 permanently rotatably afiixed to the razor head unit 14, and another pair of downwardly extending legs 84 adapted to removably engage said razor head unit 14 when the cap is in operative position. The permanently affixed legs 82 have holes 85 therein and said legs are rotatably connected to the shaft 34 of the roller 32, (see FIG. 8), and permanently affixed to the head unit 14 by means of the handle 38 on one end and any suitable locking means at the other end. For example the other end of the shaft 34 may be threaded to receive a threaded nut. The legs 82 are pivotable about the shaft 34 and are maintained in permanent engagement with the razor head number unit 14.

The legs 84 are adapted to engage the shaft 31 of the guard roller 30. The legs 84 have downwardly extending portions 86, outwardly extending portions 87, and further downwardly extending portions 88. The portions 88 are provided with inwardly facing protuberances 89 which are utilized to attach the legs 84 to shaft 31. The ends of the shaft 31 are provided with recesses 91. The protuberances 89 are adapted to snap into the recesses 91 when the cap 80 is in operative position as clearly seen in FIG. 7. The legs 84 are constructed of a resilient material. It can readily be seen that the cap is pivotable about its connection with the shaft 34 of the guard roller 32 and is adapted to engage the shaft 31 of the guard roller 30 when the cap is in operative position. The cap '80 may be moved from operative to inoperative position by pivoting it about its connection with the shaft 34 by the application of a light pressure on the cap. In operative position the cap 80 provides a stationary surface for gripping the shavers skin and substantially prevents movement of the shavers skin relative to the movement of the reciprocating razor blade 42. The cap 80 thereby cooperates with the guard rollers 30 and 32 to provide stationary members for engaging the shavers skin both above and below the plane of operation of the razor blade 42 and thus enables the shaver to get a more comfortable and a more satisfactory shave.

In order to provide an electrically operated drive for the reciprocatory blade carrying member, blade, and blade retainer, the present invention utilizes the permanent magnet member 52 which is held by the magnet retainers 48 which are connected to the blade carrier 40. The part of the motor forming the drive means for driving the permanent magnet member 52 is housed in the handle 12 of the razor. As heretofore pointed out, the motor construction is such that no parts project through openings in the casing wall. More particularly, the motor construction includes an electromagnetic core 100 formed in a generally C-shape, having legs or poles 102 and 104 which are spaced apart to constitute an air gap 105. An energizing winding (not shown) is wound around one leg of the electromagnetic core 100. The energization of the winding from an alternating current source causes the pole pieces 102 and 104 to alternately become north and south poles in accordance with the frequency of the source. Assuming that the lower end of the magnet 52 is a north pole and that at a particular instant the pole piece 102 is a north pole and the pole piece 104 is a south pole, it will be readily understood that the magnet 52 will be moved to the right as viewed in FIG. 9, because of the repelling and attracting magnetic forces acting thereon. Such movement will cause the blade carrier 40, the blade 42, and the blade retainer 44 to be also moved to the right with the respect to the guard rollers 30 and 32 and the cap 80, in a direction parallel to the cutting edges of the blade 42, this action being permitted by the resilient support of the blade carrier 40 by means of the spring elements 43. During the other half cycle of current, the polarity of the pole pieces will be reversed, and the magnet 52, and parts connected therewith will be moved to the left in response to the repelling and attracting forces acting thereon. Thus it is readily seen that the blade carrier 40, the blade 42 and the blade retainer 44 will reciprocate back and forth in a direction parallel to the blade edges, in accordance with the frequency of the supply source, which results in an effective shearing or cutting action.

In order to apply the full effect of the attracting and repelling forces of the poles 102 and 104 on the permanent magnet member 52, it has been found necessary to position the permanent magnet member 52 in the main area of flux; that is, in the direct flux path between the poles. Thus, as seen in FIGS. 10-12, this invention provides for inserting a portion of the permanent magnet member into the main flux area in order to create a more powerful and positive drive.

The electromagnetic core is seated in the handle 12 of the razor. The top surface 13 of the handle 12 is provided with a recess therein. The recess is placed di rectly between the poles 102 and 104 of the electromagnetic core 100 which permits positioning of a portion of magnet 52 in the direct flux path between the poles thereby providing a more powerful drive for the magnet, as explained above. Thus, the parts of the motor construction which must be physically connected with the electrical source are completely within the handle 12 below the recess in the upper handle surface 13 (see FIG. 12).

A modification of the permanent magnet member 52v is shown in FIGS. 10 and 12. The shape of the magnet member is therein modified at the bottom portion thereof to include a laterally extending portion 52 having a V- shaped cross-section to enable the recess to be made smaller. Compare recess 110' in FIGS. 10 and 12 with recess 110 in FIGS. 5 and 11. The magnet 52 is placed between the poles 102. and 104 and is in the main flux area in this modification. The recess may be made of any desired shape and the magnet may also be produced in any desired shape without departing from the spirit and scope of this invention.

Thus it is seen that a new and more powerful drive has been provided for reciprocating the blade assembly of this invention. The blade is driven in an effective reciprocatory movement parallel to the edges of the blade in order to cut the desired material with a shearing action.

From the foregoing, it will be readily apparent that a highly efficient and greatly simplified electric razor construction has been provided by the present invention. The particular type of motor drive employed, and the arrangement of the parts thereof is such that a water tight casing or housing is provided, which eliminates all possibility of moisture damage to the electric drive within the handle or electric shock to the user. In operation, the razor is noiseless and durable since the moving parts are mounted with a clearance to avoid rubbing and sliding friction. An important feature of the invention is the simplified and readily pivotable cap which provides a stationary member which cooperates with the guard rollers in order to provide two surfaces, one above and the other below the reciprocating blade, which prevent movement of the skin along with the reciprocating blade. A further distinctive and novel feature includes the insertion of the permanent magnet driven member into the main flux field of the electromagnetic core thereby providing a more direct and more powerful drive to the blade member.

The invention operates as follows. An alternating current is supplied to core 100 thereby alternating the polarity of pole pieces 102 and 104, thereby causing the permanent magnet 52 to reciprocate in recess 110, first towards one pole, and then towards the other, and so on. Of course as the magnet reciprocates it carries with it those elements with which it is rigidly connected, namely the blade carrier 40, spring 60, blade retainer 44 and, of course, blade 42. Meanwhile the remaining elements of the head form a stationary portion of the head unit which does not partake in the reciprocatory movement. This stationary portion would include, inter alia, support member 16, gripping elements 18 and 20, shoulders 21 and 23, rollers 30 and cap member 80.

While two embodiments of the invention have been shown and described, it will be understood by those skilled in the art that many modifications may be made without departing from the spirit of the invention. It is to be expressly understood however, that the drawings are utilized for purposes of illustration only, and are not designed as a definition of the limits of the invention, references being had for this purpose to the appended claims.

What is claimed is:

1. An electric safety razor comprising a body portion and a head unit, said head unit comprising a stationary portion which is held stationary relative to said body portion and a means for mounting a blade for reciprocatory movement relative to said stationary portion in a direction parallel to the blade edges, elongated roller elements mounted on said stationary portion, said mounting preventing the rollers from reciprocating with the blade, and said rollers positioned immediately below each blade to contact the skin of the user immediately below the blade edge, and a cap member mounted on said stationary portion above the blade, said mounting preventing the cap member from reciprocating with the blade and said cap member positioned such that its edge contacts the skin of the user immediately above the blade edge, the edge of the blade projecting outwardly beyond the edge of the cap between the roller elements and the edge of the cap member while undergoing reciprocatory movement parallel to its edges.

2. An electric safety razor as claimed in claim 1 including a blade carrier for holding the blade and adapted to reciprocate therewith, and means for reciprocating the blade carrier and the blade relative to the stationary portion.

3. An electric safety razor as claimed in claim 2 including a blade retainer positioned between the blade and the cap member for rigidly holding the blade on the blade carrier, said blade retainer mounted to reciprocate with the blade and the blade carrier.

4. An electric safety razor as claimed in claim 1 wherein the cap member is removably connected to said roller elements.

5. An electric safety razor as claimed in claim 1 wherein the cap member includes vertically extending legs, said legs removably engaging the outer ends of said roller elements so that the cap member is pivotable about the axis of at least one roller element.

6. An electric safety razor comprising a body portion and a head unit, said head unit comprising a means for mounting a blade having cutting edges for reciprocatoiy movement in a direction parallel to the blade edges, and a cap member mounted on the head unit above the blade, said mounting preventing the cap member from reciprocating with the blade, said cap member being positioned to contact the skin of the user above the blade and being stationarily mounted with respect to the said head unit, the said head unit further comprising roller elements positioned immediately below each blade, said mounting preventing the rollers from reciprocating with the blade, said rollers being positioned to contact the skin of the user below the blade edge, and said cap member including vertically extending legs, said legs, removably engaging the outer ends of said roller elements so that the cap member is pivotable about the axis of at least one roller element.

References Cited UNITED STATES PATENTS 2,054,287 9/ 1936 Hartmann 30-45 2,105,855 1/1938 Caise 30-45 2,182,571 12/1939 Savary 30-83 2,301,147 11/1942 Schaaf et al. 3045 2,530,759 11/1950 Collins et al. 30--45 2,609,602 9/1952 Harshberger 30-45 2,991,554 7/1961 Somers et a1. 3034.2 3,321,831 5/1967 Han et al. 3045 3,327,387 6/1967 Harr et al. 30-342 FOREIGN PATENTS 835,413 3/ 1952 Germany.

MYRON C. KRUSE, Primary Examiner.

US. Cl. X.R. 30-342, 83

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