US3555676A - Electric dry shaver - Google Patents

Abstract

ELECTRIC SHAVER OR OTHER APPLIANCE HAVING A PAIR OF PARALLEL OSCILLATING SHAFTS OF RECTANGULAR CROSS SECTION, EACH OF THESE SHAFTS DRIVERS A SEPARATE CUTTER OR OTHER DRIVEN MEMBER. A POWER UNIT IS PROVIDED HAVING MOTOR MEANS WITH A DRIVE PROJECTION MOVABLE TOWARD AND AWAY FROM THE PARALLEL SHAFTS. A UNITARY BIFURCATED CONNECTING ROD INTERCONNECTS THE PROJECTION AND THE TWO PARALLEL SHAFTS. THIS CONNECTING ROD IS SUFFICIENTLY RESILIENT TO PERMIT FLEXING SO THAT NO BINDING OCCURS. SPRING MEANS IN THE SHAPE OF A SHORT HANDLED MULTI-TINED FORK HAVING THE HANDLE PORTION SECURED TO THE RECTANGULAR SHAFTS BIAS THE CUTTER INTO SHEARING ENGAGEMENT WITH THE PERFORATED COMB. THE COMB IS DEFINED BY TWO JOINED ARCUATE PERFORATED SECTIONS.

Description

Jan. 19, 1971 c, BAUER 3,555,676

' ELECTRIC DRY SHAVER Original Filed May 27, 1966 3 Sheets-Sheet 1 CHARLES L. BA UER 2 X fur enter Jan- 19, 1971 c, BAUER 3,555,676

ELECTRIC DRY SHAVER Original Filed May 27, 1965 5 Sheets-Sheet 2 In fan to," CHARLEJ L. BAUER QM e,

Jan. 19, 1971 c. L. BAUER ELECTRIC DRY SHAVER 3 Sheets-Sheet 3 Original Filed May 27. 1966 I72 fen for CHARLES L. BA (1512 B fit e.

United States Patent 3,555,676 ELECTRIC DRY SHAVER Charles L. Bauer, Columbia, S.C., assignor to Sunbeam Corporation, Chicago, Ill., a corporation of Illinois Original application May 27, 1966, Ser. No. 553,393, now

Patent No. 3,401,453. Divided and this application Mar.

22, 1968, Ser. No. 715,248

Int. Cl. B26b 19/04 US. Cl. 30-4332 7 Claims ABSTRACT OF THE DISCLOSURE Electric shaver or other appliance having a pair of parallel oscillating shafts of rectangular cross section. Each of these shafts drives a separate cutter or other driven member. A power unit is provided having motor means with a drive projection movable toward and away from the parallel shafts. A unitary bifurcated connecting rod interconnects the projection and the two parallel shafts. This connecting rod is sufficiently resilient to permit flexing so that no binding occurs. Spring means in the shape of a short handled multi-tined fork having the handle portion secured to the rectangular shafts bias the cutters into shearing engagement with the perforated comb. The comb is defined by two joined arcuate perforated sections.

This application is a division of copending application Serial No. 553,393, filed May 27, 1966, Patent No. 3,401,- 453 to Charles L. Bauer and assigned to the same assignee as the instant application. It relates to apparatus for removing beards or face hair as well as hair on the arms, legs, and other portions of the human body, and is generally referred to as an electric dry shaver. More particularly, the present invention is in the nature of an improvement on the electric dry shaver disclosed and claimed in Iepson et a1. Patent No. 3,196,539, granted July 27, 1965, and assigned to the same assignee as the present invention. Moreover, certain features disclosed in the present application are also disclosed in copending applications, both filed of even date herewith. Serial No. 553,510, Stahly et al., now United States Patent No. 3,447,058 and Serial No. 553,575, Bauer, now United States Patent No. 3,421,215, both assigned to the same assignee as the instant application.

Electric shavers of several different types are extensively employed by many persons as the sole means of shaving. The type of electric shaver disclosed in the above-mentioned Jepson et a1. patent has proven to be unusually 0 satisfactory for reducing shaving time while still furnishing a very satisfactory shave. Moreover, this shaver has been designed so that it may be held comfortably and conveniently in the hand of the operator. As disclosed in this Jepson et a1. patent, the electric dry shaver is provided with a plurality of oscillating cutter blades mounted on an oscillating shaft and cooperating with a perforated comb and depending upon centrifugal force and spring means for moving the cutters into shearing engagement with the comb. The oscillating shaft carrying the cutter blades is connected through suitable cranks and a connecting rod to a rotary motor.

More recently a cutting head has been developed which employs a pair of such oscillating shafts, each of which carries a plurality of oscillating cutter blades cooperating with an arcuate portion of a perforate comb. It has been proposed to drive such a cutter head assembly from a rotary motor by means of a pair of connecting rods each driven from a respective one of a pair of eccentric projections each extending from a gear driven by a motor pinion, as more fully described in the above-identified Stahly et al. application. However, it will be appreciated that although the cost of any one driving arrangement may be small, nevertheless electric dry shavers of this general type are produced in very large volume, and the consumer market for the sale of electric dry shavers is highly competitive. Accordingly, it is desirable to provide an electric dry shaver which will compete favorably in price on the consumer market. In this regard it is desirable to provide a drive means interconnecting a rotary motor and a pair of oscillating drive shafts which may be manufactured and assembled at a. minimum cost.

Moreover, in the design of a cutter head employing a pair of joined arcuate comb surfaces, some difficulty may be experienced in maintaining a comparatively soft, flexible comb in the desired configuration. Further, in the consumer market it is important that the cutting blades be positively and economically secured to the respective cutter shaft so that the shaver may be economically produced and perform reliably for the ultimate user.

Accordingly, it is an object of the present invention to provide a new and improved electric shaver.

It is another object of the present invention to provide a new and improved electric shaver which overcomes the difficulties mentioned above.

It is another object of the present invention to provide an electric dry shaver having an improved cutting head.

A further object of the present invention is to provide an electric dry shaver of the type having a pair of oscillating cutter shafts provided With improved connecting means drivingly interconnecting the motor with the respective oscillating shafts.

A still further object of the present invention is to provide a new and improved cutting head assembly for a shaver.

It is another object of the present invention to provide an electric shaver which may be economically manufactured and assembled and which will provide foolproof operation.

Further objects and advantages of the present invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of the present invention reference may be had to the accompanying drawings in which:

FIG. 1 is an elevational sectional view through the cutter and easing portion only of an electric shaver embodying the present invention;

FIG. 2 is a fragmentary sectional view taken along line 22 of FIG. 1, assuming that FIG. 1 illustrates the entire shaver;

FIG. 3 is a fragmentary sectional view taken along line 33 of FIG. 1, again assuming that FIG. 1 shows the entire shaver;

FIG. 4 is a fragmentary somewhat enlarged sectional 'view taken along line 44 of FIG. 1, again assuming that FIG. 1 illustrates the entire shaver;

FIG. 5 is a sectional view taken along line 55 of FIG. 4 assuming that FIG. 4 shows the complete structure; and

FIG. 6 is a perspective view of the cutter shaft, blade supports, and blade biasing springs of the shaver according to the present invention.

The present invention is particularly adapted for use with an electric shaver of the type having a shaving head unit including a uniformly curved comb and an elongated cutter blade adapted to be moved along the inner surface of the comb in shearing engagement therewith. One feature of the invention is particularly adapted for use with an electric shaver having a double shaving head unit, that is, of the type having a comb defined by joined arcuate surfaces and including a pair of oscillating cutter shafts each carrying one or more cutting blades for moving the blades in shearing engagement with the comb.

In accordance with one feature of the present invention, the cutter shaft is rectangular. A rectangular shaft permits the use of an improved blade support which may be of generally U shape having groove means in its bight portion to receive the shaft, and provided with aligned slots in its outwardly extending legs for receiving the cutter blade. Additionally, there is provided an improved blade biasing spring which may be shaped like a shorthandled multi-tined fork having the handle portion thereof secured to the flat surface of the shaft in any suitable manner as by welding, and having one of the tines each extending into the path of a different one of the cutter blades.

In accordance with another feature of the present invention, there is provided improved means for transfer ring power from a power unit to drive the pair of oscillating cutter shafts. It will be understood that such oscillating cutter shafts, provided with an offset projection defining a crank, create a change in spacing between the cranks as the shafts oscillate. The shafts are driven from the power unit by a unitary bifurcated connecting rod defining a body portion connected to the crank or drive member of the prime mover, and provided with a pair of spaced arms each connected to a respective one of the cranks and sufiiciently resilient to permit flexing of the arms relative to each other as the cutter shafts oscillate. To provide the necessary resilience to the arms of the connecting rod, the arms may be provided with reduced cross-sectional areas adjacent the body portion of the connecting rod, and the connecting rod may be built of suitable resilient material such as nylon.

The single connecting rod with the bifurcated arms considerably simplifies the connecting rod design providing an economical arrangement. Moreover, the rectangular shaft cross section simplifies the connection to the shaft of both the blade supports and the blade springs, thus reducing cost and simplifying assembly thereof.

Referring now to the drawings, the present invention is directed to an electric shaver or shaving unit 20 which includes a casing 21 defined by a generally cup-shaped casing member 22 and a pair of end caps 24 and 25, all preferably molded from a suitable plastic. 'For supporting the motor and cutter described hereinafter, there is provided a support member 26 which effectively closes the open top of the cup-shaped casing member 22 to divide the casing .21 into a motor chamber below support 26, generally designated as 27, and a cutter chamber above the support 26 and between end caps 24 and 25, general- 1y designated as 28. Disposed within the cutter chamber 28 is a cutting head assembly generally designated as 29. Disposed within the motor chamber 27 is an electric motor 30 secured to the underside of the support member 26.

Considering the motor 30 in more detail, it may be of a known type such as disclosed in copending Jepson et al. application Ser. No. 322, 795, filed Nov. 12, 1963, now U.S. Pat. No. 3,349,263 and assigned to the same assignee as the instant application. As illustrated, motor 30 is of the rotating armature type having a generally U-shaped stator member 33, the ends of the legs of the stator member 33 having a somewhat arcuate configuration defining 4 opposed pole pieces in a known manner. A field winding 34 is carried on the bight portion of the stator member 33. A hanger bracket 35, as shown in the above-mentioned Jepson et al. application, and a pair of U-shaped bail clamps 37 and a bail hanger 38 hold the field structure in position relative to support 26.

The motor includes an armature 39 having an armature shaft 40 supported in suitable self aligning spherical bearings in the manner described in the aforesaid Jepson et al. application. One end of the armature shaft carries a commutator assembly 45, while the other end thereof is the crank end. Secured to the crank end of the armature shaft 40 is an eccentrically mounted crank pin 46.

In order that a power connection can be made to the shaver 20 for driving the motor 30, the casing member '22 is provided with a recess or opening 53 in its end adjacent its bottom defining a receptacle opening for receiving a power connection. A terminal board 54 within the casing 21 of the shaver 20 carries a pair of terminal members 55 extending into the recess 53 for engaging cooperating contacts of a power cord. The lower end of the terminal board is keyed to an arm or projection 35a of the hanger bracket 35 so as to provide support for the terminal board 54.

To provide a manual control for starting and stopping the motor 30, the terminal board 54 additionally supports a known electrical switch, shown generally at 58. A manually operable switch knob 58a extends through an opening 24a in the end cap 24 to control the on-off condition of the switch 58.

Referring now to the cutting head unit 29, it includes a comb 60 defining a cutting surface. Comb 60 comprises a pair of joined arcuate perforated sections 66a and 60b, FIGS. 3 and 4, cooperating with a pair of substantially identical oscillating blade assemblies 61 and 62. The oscillating blade assemblies 61 and 62 are adapted to be oscillated through suitable driving means by the motor 30 at a suitable speed which may be in excess of 8000 cycles per minute. Each of the blade assemblies 61 and 62 includes a plurality of cutters or cutter blades 63, individually referred to as 63a, 63b and 630.

For the purpose of supporting the cutter blades 63 for oscillation, there are provided a pair of oscillating cutter shafts 65 and 66, each carrying a pair of U-shaped supports 67 and 68, respectively, best shown in FIGS. 1 and 6. The cutter shafts 65 and 66 are of rectangular or square cross section. The bight portions of the blade supports 67 and 68 are provided with slots 64 and 69, respectively, to receive and be secured to the respective shafts 65 and 66, while the legs thereof extend upwardly to define slotted blade support portions 67a, 67b, 68a, 68b in a manner well understood in the art, the blades 63 being receivable in aligned slots in the support portions 67a, 67b, 68a and 68b. The cutter blades 63 are effectively identical and may be similar to those fully described in either the above identified Jepson et al. patent or Jepson et al. application.

For the purpose of biasing the cutter blades 63 into shearing engagement with the comb 60, there is provided for each blade support 67 and 68 a tined spring member 70, best illustrated in FIG. 6. As illustrated each spring member 70 is shaped like a short-handled three-tined fork having the short handle portion thereof secured to the respective shaft 65 or 66 and with the three tines or spring fingers each extending into the path of a different one of the blades 63 and consequently biasing the blades upwardly against the comb 60.

As best illustrated in FIG. 4, the comb 60 comprises a cutting surface formed of a very thin flexible material having a large number of hair receiving openings. Since the cutting surface of the comb 60 is formed of relatively thin material, it tends to conform itself to the shape of the surface with which it is in contact and, therefore, must be supported by a suitable supporting structure or frame, generally designated at 74, comprising a plurality of parallel, double arcuate ribs 74a, 74b, 74c, 74d, 74e, 741, 74g and 74h (FIG. 1) and spaced from one another in a direction running along the longitudinal axis of the cutting blades 63. The end ribs 74a and 74h are effectively end frame members and are somewhat stronger than the remaining ribs. The cutting surface portion of the comb 60 is suitably fastened at its outside edges to the supportting frame 74 as by welding or other suitable means. If desired, it may be removably secured. Moreover, in order to have the cutting surface follow the double arcuate contour of supporting frame 74 with a central depressed portion (FIGS. 3 and 4) there is provided a tubular comb tightener 75 which is held in place by U-shaped spring retaining clips 76, best shown in FIG. 5. This comb tightener is similar to that disclosed and claimed in the abovementioned copending Stahly et al. application.

For retaining the comb 60 in shearing relationship with the rest of the cutting head assembly 29, there is provided a comb lock spring 78 (FIG. 3) clamped in place between the bail hanger 38 and the support 26 by the bail clamps 37. As illustrated, the comb lock spring 78 terminates in downwardly extending pivot flanges 7 8a. A movable comb hinge plate 79 has one edge releasably secured to one lower edge of the comb supporting frame 74. Moreover hinge plate 79 is hook-shaped as indicated at 79a on its other edge so as to make engagement with one of the downwardly depending flanges 78a of the comb lock spring 78. A comb latch plate '80 on the opposite side of the comb 60 from the hinge plate 79 is pivotally related to the other pivot flange 78a on comb lock spring 78. Latch plate 80 is further provided with a centrally disposed latch member 8011 extending through a suitable latch opening in the comb supporting frame 74 thereby to latch the comb 60 in place as part of the cutting head assembly 29. The comb hinge plate 79 and comb latch plate 80 preferably are similar to those more fully described in the prior mentioned Jepson et al. Patent No. 3,196,539.

To support the cutter shafts 65 and 66 for oscillation, each shaft is provided adjacent each end thereof with suitable resilient mounting blocks 82 preferably bonded to the associated shaft, which blocks may be of the type more fully described in a copending Jepson application, Ser. No. 410,115, filed Nov. 10, 1964-, now Pat. No. 3,244,916, and assigned to the same assignee as the present application. As in such copending application, the mounting blocks 82 are clamped securely into position between support member 26 and end caps 24 and 25, suitable recesses for such mounting blocks being provided. As illustrated, the shafts 65 and 66 are each pro vided with integral crank portions 65a and 66a, respectively, (FIGS. 2 and 6) defined by otfset projections of the shafts.

For the purpose of converting rotary motion of the motor armature 39 to oscillating motion of the cutter shafts '65 and 66, there is provided in accordance with the present invention an improved connecting rod 84 (FIGS. 1 and 2). The connecting rod 84 is generally fork-shaped with a bifurcated portion defining two crank arms 84a, 84b, each receiving a respective one of the crank portions 65a, 66a of the respective cutter shafts 65 and 66 and a body portion 84c. The body portion 840 receives the crank pin 46 and is held assembled with the crank pin 46 by means of a hairpin type lock spring 85. Because of the variation in spacing between the driven ends of the oscillating shafts 65 and 66, the arms 84a, 8417 on the connecting rod 84 must flex to accommodate this variation as the shafts 65 and 66 are oscillating. Accordingly the connecting rod 84 is made of suitable resilient or springy material, such as molded nylon, and the arms 84a and 84b have a reduced cross-sectional area (FIG. 2) where they join with the body portion 840 to provide the desired flex of the arms 84a, 8412.

For cutting longer hair such as trimming a moustache, sideburns and the like, one of the end caps 25 carries a trimming cutter assembly 87 (FIG. 1) driven by a projection from one of the cutter shafts 66. The trimmer cutter assembly 87 may be identical with that described in the above mentioned Stahly et al. application and forms no part of the present invention. Accordingly the trimmer cutter assembly is not described in the present application.

The twin cutter shafts driven by a single connecting rod simplifies the drive of the double shaft head and provides a simple design which is inexpensive to manufacture. The single oscillating connecting rod can replace two separate connecting rods, gears and pinion because of its ability to flex sufficiently to accommodate the variations in the shaft spacings of the cutter shafts as they oscillate. Moreover the rectangular cross section of the cutter shafts and 66 permits the use of simple blade supports 67 of formed metal pieces which may be merely spot welded to the supporting shaft, and further permit the simple tined blade springs 70 to be readily spot welded or otherwise secured to the cutter shafts.

While there has been shown and described a particular embodiment of the present invention, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the invention in its broader aspects and it is, therefore, contemplated in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. A cutting head for an electric shaver including a comb defined by two joining arcuate sections having a plurality of parallel double arcuate ribs spaced along the longitudinal axis of said comb defining a supporting structure for said comb, a perforated plate formed of thin flexible material secured to said ribs and conforming to the shape of said ribs to provide a cutting surface comprising two adjacent perforated arcuate sections, a pair of blade supporting means each including a cutter shaft provided with a plurality of blade supports extending radially therefrom and spaced apart longitudinally thereof, the ends of each of said supports having at least one slot de fined therein, a slot in one support aligned with a slot in another support spaced longitudinally thereof and in a plane parallel to the axis of said shaft carrying said supports, a plurality of elongated cutters in said aligned slots, spring means biasing each of said cutters radially outwardly, and means mounting each of said shafts for angularly oscillatory motion with its cutters in shearing engagement with a respective one of said perforated arcuate sections.

2. The cutting head of claim 1 wherein said ribs define a central depressed portion, and wherein there is provided a comb tightener securing the comb around the contour of said supporting structure.

3. The cutting head of claim 2 wherein said retainer is cylindrical, open at its ends, including U-shaped spring retaining clips each having one leg extending into a respective end of said retainer and its other leg secured below said depressed portion.

4. The cutting head of claim 1 wherein said blade supports are provided with a plurality of slots, the corresponding slots on each support receiving one of said elongated cutters.

5. The cutting head of claim 4 wherein said spring means are each formed like a short-handled multi-tined fork having the handle portion thereof secured to the respective cutter shaft, the tines of each spring means engaging and biasing a different one of said cutters.

6. The cutting head of claim 5 wherein said cutter shafts are square in cross section and spring means is welded to its respective cutter shaft.

7. A cutting head for an electric shaver including a pair of parallel positioned cutter shafts each mounted for oscillating movement about their respective longitudinal References Cited axes, cutter means carried by each of said cutter shafts,

and a comb comprising a pair of arcuate cutting surfaces UNITED STATES PATENTS cooperatively positioned relative to said cutter means, 3,196,539 7/1965 Jepson 3043.9 said pair of arcuate cutting surfaces being defined by a supporting frame comprising a plurality of parallel double FOREIGN PATENTS arcuate ribs spaced along the longitudinal axis of the 932, 3/ 1955 ycomb and a thin flexible perforated plate secured at its outside edges to said frame and conforming throughout ANDREW JUHASZ Pnmary Examiner its surface area with said supporting frame. 10 G. F. GRAFEL, Assistant Examiner

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