United States Patent
`Roszyketal.
`
`191
`
`3,840,795
`(1)
`[45] Oct. 8, 1974
`
`
`
`
`
`8/1964
`3,143,697
`[54]. HAND HELD BATTERY OPERATED
`Springer....sccccccscsesssesesseeesses 220/2
`
`
`3,145,404 . 8/1964—Fielden... eecsesteensenees 2
`
`
`THEREROR CHARGING MEANS 10/1966=Nicholl voces3,277,358 reneneee 320/2
`
`
`
`
`3,329,880 TIN96T=Boyles... ee csctcsessesneenernees 320/2
`
`12/1968 Holmes...
`cecesseeereneeeeneees 320/2
`{75]
`Inventors: Leon M. Roszyk, Berwyn; Louis A.
`3,418,552
`Barnas, Jr., Cary, both of Ili. 3,510,747=S/1970— Petrides veces 320/57
`
`[73] Assignee: Sunbeam Corporation, Chicago,Ill.
`Primary Examiner—William M. Shoop,Jr.
`[22]
`Filed:
`.
`Jan. 21, 1970
`Attorney, Agent, or Firm-—George R. Clark, Esquire
`{21] Appl. No.: 4,712
`
`ABSTRACT
`[57]
`Related U.S. Application Data
`A battery operated appliance comprising a power unit
`{63] Continuation of Ser. No. 380,839, July 7, 1964.
`having a rechargeable battery therein and a charging
`unit having a recess for insertion of the power unit
`therein for recharging the battery within the power
`ee Us.& ecenesaenevseeseseesesaseetsetsetesstes aeaTTe
`unit, a transformerincluding one winding in the power
`[58]
`Field ofSearchcrerseenss390/2.53,87,59: 336/83
`unit and one winding in the charging unit. In one em-
`.
`bodiment the magnetic core structure associated with
`336/86, 87, 90, 96, 119, 136, 182; 310/47, 50
`one of the windings is at least in part defined by the
`.
`casing of the rechargable battery. Various core struc-
`References Cited
`tures may be employed to ensure good inductive cou-
`UNITED STATES PATENTS
`
`2,415,688=2/1947 Halll, Ire eeeegeeee 219/25 pling between the respective windings.
`
`2,967,267
`1/1961
`Steinmanetal. ows. 317/101
`.
`.
`.
`3,142,852
`8/1964. Phaneuf... .eecccsssesecsssseneee 320/2
`5 Claims, 9 Drawing Figures
`
`[56]
`
`
`
`
`
`
`
`
`1
`
`APPLE 1069
`Apple v. GUI
`IPR2021-00471
`
`1
`
`APPLE 1069
`Apple v. GUI
`IPR2021-00471
`
`

`

`SERNSRARIASMASSA
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`PATENTED OCT
`
`81974
`
`3,840,795
`
`SHEET 1 OF 4
`
`
`
`Meat&ObankeVObnbLATT'Y
`
`INVENTORS:
`LOUIS A. BARNASJdr
`LEON M. ROSZYK
`
`2
`
`

`

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`3,840,795
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`LOUIS A. BARNASdr
`LEON M. ROSZYK,
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`‘ ATT'Y
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`3
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`

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`PATENTEu Oct
`
`81574
`
`SHEET 3 0F 4
`
`3,840,795
`
`INVENTORS:
`LOUIS A. BARNASJr
`LEON M.. ROSZYK
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`PATENTED OGT
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`81974
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`3,840,795
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`FIG.
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`INVENTORS:
`
`LOUIS AsBARNAS Jr
`LEON M. ROSZYK
`
`eo BClank,
`
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`ATTY
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`5
`
`

`

`3,840,795
`
`1
`HAND HELD BATTERY OPERATED DEVICE AND
`CHARGING MEANS THEREFOR
`
`The instant application is a continuation of the co-
`pending application of Leon M. Roszyk and Louis A.
`Barnas, Jr., Ser. No. 380,839, filed on July 7, 1964.
`The present invention relates to a cordless electric
`appliance and moreparticularly to an appliance oper-
`ated by a rechargeable battery and to a combination
`stand and charging unit therefor.
`In a copending application of Albert R. Spohr, Ser.
`No. 353,327, filed Mar. 20, 1964, now U.S. Pat. No.
`3,274,631, and assigned to the sameassigneeasthe in-
`stant application, there is disclosed and claimed a cord-
`less appliance and specifically a power driven tooth-
`brush which comprises a battery operated power unit
`and a charging unit for receiving the power unit of the
`toothbrush when the latter is not in use and charging
`the rechargeable battery contained within such power
`unit. The power operated toothbrush and charging unit
`disclosed in the above-mentioned copending applica-
`tion has been extensively sold on the market and has
`been found to be very satisfactory.
`In the above-mentioned copending Spohr applica-
`tion, the power unit is provided with a pair of electrical
`contacts brought outside a casing enclosing the power
`unit, which contacts are engageable with cooperating
`contacts in the charging unit to complete the charging
`circuit for the rechargeable battery. Since such an ap-
`plicance is used with liquids, such as water and tooth-
`paste in somewhatliquified form, these liquids occa-
`sionally run down along the appliance unit necessitat-
`ing sealing of the casing where these charging contacts
`are brought out. Moreover, such liquid may also en-
`gage the cooperating contacts in the charging unit with
`deleterious effect. It would be desirable to eliminate
`such charging contacts entirely.
`In other words,
`it
`would be desirable to provide a means for completing
`the charging circuit of the rechargeable battery when
`the powerunitis not in use without the use of any elec-
`trical contacts to complete this circuit.
`Accordingly, it isan object of the present invention
`to provide a new and improved electric battery oper-
`ated appliance including a hand held power unit and a
`charging unit for recharging the battery in the hand
`held power unit, wherein electrical contacts for electri-
`cally interconnecting the power unit and the charging
`unit are completely eliminated.
`It is another object of the present invention to pro-
`vide a cordless, contactless battery operated tooth-
`brush and charging unit therefor.
`It is another object of the present invention to pro-
`vide a cordless, contactless battery operated tooth-
`brush which is light in weight, compact in size, fool-
`proof in operation and lendsitself to mass production
`manufacturing techniques.
`Further objects and advantages of the present inven-
`tion will become apparentas the following description
`proceeds and the features of novelty which character-
`ize 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
`wherein:
`FIG, lisa perspective view of the improved battery
`operated appliance of the present invention showing
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`the combined support and charging unit with the power
`unit in the position it assumes for the recharging of the
`battery included in the power unit;
`FIG. 2 is a perspective view of the hand held power
`unit of FIG. 1 removed from the support and charging
`unit and shownin association with a toothbrush attach-
`mentso as to be ready for a brushing operation;
`FIG. 3 is an enlarged partly sectional and partly sche-
`matic view of the power unit of FIG. 2 in order better
`to illustrate the features of the present invention;
`FIG. 4 is an enlarged sectional view of the charging
`and support unit taken substantially on line 4—4 of
`FIG. 1 with the power unit shown disposed in charging
`position but with the toothbrush attachments removed;
`
`FIG. 5 is an exploded perspective view of magnetic
`core structures employed in the power unit and charg-
`ingunit, respectively, to show the relationship of these
`parts during a battery charging operation;
`FIG.6 is a schematic diagram illustrating the electric
`circuit of the appliance of the present invention with
`the units in the relationship of FIG. 1 and with the
`charging unit and power unit shown in diagrammatic
`form;
`FIG.7 is a fragmentary sectional view of a power unit
`illustrating a modification of the present invention;
`FIG. 8 is a fragmentary sectional view of a power unit
`and charging unit illustrating still another modification
`of the present invention; and
`FIG,9 is a fragmentary sectional view similar to FIG.
`8 illustrating still another embodiment of the present
`invention.
`Briefly, the electric cordless, contactless toothbrush
`of the present invention includes a compact hand held
`powerunit adapted to be stored in a charging and sup-
`port unit which is also adapted to hold several tooth-
`brush attachments for use with the power unit. The
`power unit includes a rechargeable battery and a rotary
`electric motor adapted to be driven thereby.It also in-
`cludes the secondary winding of a transformer,the pri-
`mary winding of which is associated with the charging
`unit. The appliance of the present invention includes
`improved and novel inductive coupling means for in-
`ductively couplingthe charging unit and powerunit so
`that the power unit casing may be completely sealed
`without the necessity of any charging unit contacts.
`Moreover, this must be accomplished without substan-
`tially increasing the size or weight of the power unit.
`The powerunit also includes a rectifier to convert the
`low voltage alternating current from the secondary
`winding of the transformerto direct current for charg-
`ing a low voltage rechargeable battery. In one embodi-
`ment the battery casing forms a part of the inductive
`coupling and in other embodiments various modifica-
`tions of inductive coupling means are provided.
`Referring now to FIGS. 1 to 6 of the drawings which
`disclose what at present is believed to be the preferred
`embodiment of the present invention, there is illus-
`trated a cordless electric appliance generally desig-
`nated in FIGS. 1 and 6 by the reference numeral 10.
`This cordless, contactless battery operated electric
`toothbrush 10 comprises a combined charging and
`storage unit 11, a hand held power unit 12 and a plural-
`ity of toothbrush attachments 13, shown in FIG. 1 as
`disposed in the storage and charging positions. The
`storage and charging unit 11, described in greater de-
`tail hereinafter, is preferably provided with means de-
`6
`
`6
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`

`3,840,795
`
`3
`fining a recess 14 for receiving the power unit 12 dur-
`ing a charging operation thereof. It is also provided
`with a plurality of recesses 15 for receiving and storing
`the brush attachments 13 when not in use. If desired,
`the storage and charging unit 11 may be provided with
`a suitable cover, not shown, such asdisclosedin the co-
`pending Spohr application referred to above, which
`acts as a dust protector and yet will permit the desired
`air circulation for the drying of any moisture associated
`with the power unit 12 and the stored brush attach-
`ments 13.
`The present invention is concerned primarily with
`the particular arrangement of certain components
`within the power unit 12 and within the charging and
`storage unit 11 to eliminate the necessity of any electri-
`cal contacts to render the charging operation effective.
`Accordingly, the construction of the brush attachments
`13 and the particular construction of other facets of the
`power unit 12 and the combined storage and charging
`unit 11 form no part of the present invention and,
`hence, will only very briefly be described. They, how-
`ever, may be very similar or identical with those dis-
`closed in the copending Spohr application referred to
`above.
`Before considering the details of the present inven-
`tion, reference should be had to the schematic diagram
`of FIG. 6 of the drawingsillustrating the essential com-
`ponents of the battery operated appliance of the pres-
`ent invention. The charging and storage unit 11 is sche-
`matically illustrated with the recess 14 for the power
`unit 12. The latter is also schematically illustrated as
`being disposed within this recess 14 for recharging of
`the battery thereof. The combined storage and charg-
`ing unit 11 is illustrated as being provided with the con-
`ventional power cord 17 connected to a primary wind-
`ing 18 of a suitable step-down transformer, the latter
`also including a secondary winding 19 disposed within
`the power unit 12. When the powerunit 12 is in the re-
`cess 14, the windings 18 and 19 are inductively cou-
`pled, as schematically illustrated in FIG. 6. Also in-
`cluded within the power unit 12 is a low voltage direct
`current electric motor 20 connected to a rechargeable
`battery 21 through a switch 22 having a movable
`contact 22a and a stationary contact 22b. Manual
`means 23 for actuating the switch 22 is schematically
`indicated by the reference numeral] 23. Asillustrated,
`the positive terminal 21a of the battery 21 is connected
`through a suitable conductor 24 to the movable switch
`contact 22a. Similarly, negative termina) 21b of the re-
`chargeable battery 21 is connected by. a suitable con-
`ductor 25 to one terminal of the motor 20. The other
`terminal of the motor 20 is illustrated as being con-
`nected through a conductor 26 with the stationary
`switch contact 22d. It will be obvious that when the
`switch 22 is closed motor 20 will be energized from the
`battery 21.
`To recharge the battery 21 there is provided in the
`power unit 12 (FIG. 6) a charging circuit comprising
`the secondary winding 19 and a diode 28 for rectifying
`the low voltage alternating current output of this wind-
`ing. As illustrated, one terminal of the secondary wind-
`ing 19 is connected by a conductor 30 with one termi-
`nal of the diode 28, and the other terminalof the diode
`28 is connected by a conductor 31 with the positive ter-
`minal 21a of the battery 21. The other terminal of the
`secondary winding 19 is connected by a conductor 32
`with the negative terminal 21b of the battery 21. It will
`
`4
`be appreciated that whenever inductive coupling be-
`tween windings 18 and 19 is effected, battery 21 will
`tend to be recharged if power cord 17 is connected to
`a suitable source of alternating current energy.
`In a device incorporating the present
`invention,
`motor 20 was a rotary direct current motor having a
`voltage rating of between one and one and one-half
`volts, the battery 21 was a nickel cadmium recharge-
`able battery having a voltage rating of the order of one
`and two-tenths volts, and the primary winding 18 com-
`prised 7,200 turns while the secondary winding 19
`comprised between 600 and 650 turns, thus resulting in
`a voltage reduction from 120 volts A.C. to approxi-
`mately one and four-tenths volts D.C.
`Referring further to FIGS.
`1
`to 6 of the drawings,
`wherein the corresponding parts are designated by the
`same reference numerals, the power unit 12 is illus-
`trated as comprising a moldedplastic housing 34 closed
`at the bottom,as clearly shown in FIG. 3 of the draw-
`ings. This housing or casing 34 is illustrated as having
`a generally cylindrical configuration so as to be readily
`receivable within the recess 14 of charging and storage
`unit 11. Preferably, the housing 34 has an outer diame-
`ter of somewhere between an inch and one-fourth and
`an inch and one-half, and a length of the order offive
`inches, whereby it may readily be manipulated by the
`user even if the user is a relatively small child. The
`upper end of the casing 34 (not shown) must be open
`in order that the secondary winding 19, the battery 21,
`the motor 20 and the switch 22 may be inserted
`therein.
`The particular mounting arrangement of the switch
`22 and the motor 20 within the casing 34 is preferably
`essentially that described in the above-mentioned
`Spohrapplication and forms no part of the present in-
`vention. However, the lower portion of the motor 20is
`illustrated in FIG. 3 of the drawings. Preferably the
`motor 20, as in the aforementioned Spohr application,
`has associated therewith and secured thereto as a sub-
`assembly, a suitable mechanism support and drive
`mechanism for converting the rotary motion of the
`motor 20 to oscillating motion of an output shaft 35
`(FIGS. 1, 2 and 3). Preferably also suitable means for
`supporting the switch 22 are provided near the upper
`open end of casing 34 and the switch actuating member
`23 is illustrated in FIGS. 1, 2 and 3 as a slidable mov-
`able member whose function is to move contact 22a to
`the closed position to connect the terminals of motor
`20 across the terminals of battery 21.
`In view of the fact that a toothbrush is commonly
`used with toothpaste and water,it is important to seal
`the casing thereof against the entrance of moisture.
`Since the lower end of casing 34 has unbroken walls,
`it is obviously sealed against the entrance of moisture.
`The upper open end of casing 31 must also be sealed
`by suitable means, not shown, including meansfor seal-
`ing the place where the output shaft 35 emerges from
`casing 34. The particular sealing means for the upper
`end of casing 34 form no part of the present invention
`and they may be identical with those disclosed in the
`copending Spohrapplication mentioned above. To im-
`prove the appearance of the upper end of housing 34
`by enclosing the means for securing the motor 20 and
`associated drive means as well as switch 22 within
`housing 34 andalso the sealing means for output shaft
`35, there is provided a closure cap 37 which preferably
`is of molded somewhatresilient plastic material includ-
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`3,840,795
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`ing means for interlocking it with the casing 34 as a
`final assembly operation.
`In accordancewith the present invention, thereis dis-
`posed in the bottom of casing 34 a resilient pad 38
`(FIG. 3) which preferably may be made of polyure-
`thaneorother suitable cushioning means. Disposed im-
`mediately above the pad 38 in accordance with the
`present invention is the battery 21 and the secondary
`winding 19 in concentric relationship, as best shown in
`FIG. 3 of the drawings. In order that the winding 19
`may readily be inductively coupled with the primary
`winding 18 in the charging unit 11, the former is wound
`on a suitable bobbin 40 formed of soft iron or similar
`material providing a low reluctance flux path, as best
`shownin FIG. § of the drawings. For ease of manufac-
`ture the bobbin 40 may be formed in two halves joined
`at a center line 39 (FIG. 5). Preferably the bobbin com-
`prises a pair of spaced flanged pole pieces 40a and 40b
`interconnected by a tubular center portion 40c,thelat-
`ter defining a battery chamber 41 (FIGS. 3 and 5) for
`receiving the battery 21. The spacing between secon-
`dary pole pieces 40a and 40b must coincide with the
`spacing between primary pole pieces described herein-
`after. It will be appreciated that by concentrically posi-
`tioning the battery ‘21 and winding 19 the length and
`diameter of casing 34 may be kept at a minimum.
`In accordance with the present invention, the casing
`of the battery 21 defines a portion of the flux path be-
`tween the secondary pole pieces 40a and 40b thereby
`to improve the inductive coupling between the wind-
`ings 18.and 19, as will become apparentfrom the ensu-
`ing description. For maintaining the elements compris-
`ing power unit 12 properly positioned within the hous-
`ing or casing 34, a flanged insulating sleeve 43 is prefer-
`ably interposed between the motor 20 and the upper
`secondarypole piece 40a. The lower end of member 43
`is illustrated as being received within the space defined
`by flanged upper pole piece 40a. To reduce weight, the
`secondary winding 19 preferably comprises an insu-
`lated aluminum wire, layer-wound on the portion 40c
`of bobbin 40, and the ends of this winding are brought
`out in any suitable manner, such as through openings
`(not shown) in the pole pieces 40a and 40b soas to per-
`mit electrical connection in a charging circuit in the
`manner. shown in FIG. 6 of the drawings. To better in-
`sulate the secondary winding 19 from bobbin 40, a
`layer of insulating tape 44 may surround portion 40c.
`A similar layer 44 may also surround the completed
`winding 19. The physical details of the electrical con-
`nections between battery 21, motor 20 and winding 19
`form nopart of the present invention, and theelectrical
`circuit is only schematically indicated in FIG. 3 of the
`drawings. The casing of battery 21 is ordinarily the neg-
`ative terminal, and a central portion at one end (FIG.
`3) usually defines the positive terminal. However, the
`diode 28 must be suitably mounted within the casing 34
`either within sleeve 43, as shown in FIG. 3 of the draw-
`ings, or, if desired, within the space between the insu-
`lating sleeve 43 and the casing 34.
`;
`Considering now the combined storage and power
`unit 11 in more detail, particularly with reference to
`FIGS.4, 5 and 6 of the drawings,it comprises a molded
`housing member 45, preferably molded of a suitable
`plastic, the housing being more orless closed at the top
`except for the recesses 14 and 15. The recess 14 is de-
`fined by an integral tubular portion 45a while the reces-
`ses 15 are defined by similar wall portions integrally
`
`6
`formed with housing member45.In FIG. 4 of the draw-
`ings the lower portion of the power unit 12 is shown
`disposedin the recess 14 in charging position. To deter-
`mine the correct charging position, the lower open end
`of housing 45 including the tubular recess 14 defined
`by wall portion 45a is closed by a closure plate 46 suit-
`ably secured in position by means not shown in the
`drawings. The closure plate 46 is provided with an
`opening 47 beneath recess 14 of a diameter substan-
`tially less than the diameter of recess 14 whereby the
`edges of opening 47 define a stop for accurately posi-
`tioning the power unit 12 when disposedin its charging
`position, shownin FIG. 4 of the drawings. Opening 47,
`of course, permits any liquid or other foreign matter
`entering recess 14 to exit therefrom. The space in hous-
`ing member 45 surrounding the wall portion 45a defin-
`ing recess 14 is generally designated as chamber48,
`and this chamber is employed to house the primary
`winding 18 and the power cord ‘17. In order that the
`chamber 48 may comprise a storage chamberfor the
`powercord, the cover 46 is provided with a thin wall
`section 46a effectively defining a hinge so that the sec-
`tion 46b defines a pivoted cover portion readily mov-
`able to the open position to afford access to the cham-
`ber 48.
`In order that the primary winding 18, also disposed
`within the chamber 48, may be inductively coupled
`with the secondary winding 19 when the powerunit 12
`is disposed in charging position within the recess 14,
`the winding 18 wound as an annulusis preferably en-
`capsulated in an epoxy resin or similar material provid-
`ing a complete sealed enclosure therefor and desig-
`nated by the reference number 50. Preferably this en-
`closure 50 includesan integral strain relief portion 50a
`encircling the power cord 17 whereit enters the encap-
`sulation. To provide the desired path for the primary
`flux, there is provided a pair of primary pole pieces 51
`and 52, best shown in FIGS. 4 and 5 of the drawings,
`which are rigidly interconnected in spaced parallel re-
`lationship by a bobbin core 53 receivable in the annular
`encapsulated winding 18. The pole pieces 51 and 52
`and the core 53 are formed of a material providing a
`low reluctance flux path. To assemble the core 53 with
`pole pieces 51 and52, the formeris provided with ends
`of reduced cross section received in suitable openings
`in the primary pole pieces, which endsare then peened
`overas indicated at 53a to provide a unitary core struc-
`ture. In a preferred embodiment, the core 53 had an
`overall length of less than two inches. The pole pieces
`§1 and 52, as best shown in FIG. 5 of the drawings,
`comprise flat plates of low reluctance material desig-
`nated as 51a and 52a, respectively, having bifurcated
`ends defined by laterally projecting semicircular
`flanges 51b and 52b, respectively. These semicircular
`flanges 51b and $2b havea radius such asto closely em-
`brace the tubular portion 45a of the housing 45,as best
`shown in FIG. 4 of the drawings.
`The spacing between the primary pole pieces 51 and
`52 should be great enough so as to reduce flux leakage
`therebetween. Asillustrated, the flanges 51b and 52b
`are directed toward each other, as best shownin FIGS.
`4 and 5 of the drawings, and the spacing is such as to
`be the same as the spacing between the secondary pole
`pieces 40a and 40), as is clearly shown in FIG. 5 of the
`drawings. It will be understood that when the power
`unit 12 is positioned in its charging position in recess
`14 as shownin FIG.4 of the drawings, the primary pole
`8
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`3,840,795
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`pieces 51 and 52, and particularly the flanges 51b and
`525 thereof, will be in substantial alignment with the
`secondary pole pieces 40a and 40b. It will be under-
`stood that the flux produced by primary winding 18 will
`have a flux path comprising the primary pole pieces 51
`and 52, and secondary pole pieces 40a and 40b of bob-
`bin 40 which are interconnected by a cylindrical bob-
`bin portion 40c andalso in part by the casing of the bat-
`tery 21.
`For the purpose of holding the assembly comprising
`encapsulated primary winding 18 and its associated
`pole pieces 51 and 52 in the position shown in FIG. 4
`of the drawings, the housing 45 is provided with a plu-
`rality of integral stop members, such as 45b and 45c,
`engaging the upper pole shoe 51. A resilient pad 54 is
`then interposed between the cover 46 and the lower
`pole shoe 52, as best shown in FIG. 4 of the drawings,
`the cover 46 holding these parts in the positional rela-
`tionship shown.
`In view of the description included above, the opera-
`tion of the battery operated toothbrush, particularly
`with respect to the contactless charging arrangement,
`will readily be understood by those skilled in the art.
`The power unit 12 comprises a housing with continu-
`ous sealed walls as far as the lower portion thereofis
`concerned, and the secondary winding contained
`therein is inductively coupled with the primary winding
`18 when the powerunit 12 is inserted in the recess 14
`so that recharging of the battery 21 can occur without
`the necessity of interengagement of any electrical
`contacts between the charging unit 11 and the power
`unit 12.
`It should be understood that although the arrange-
`ment described above is what is at present considered
`to be the preferred embodiment of the present inven-
`tion, the battery 21 and secondary winding 19 need not
`be concentrically disposed within power unit 12, as
`shown in FIG. 3 of the drawings, if a short additional
`length of the power unit housing can be tolerated. In
`FIG. 7 of the drawingsthereis illustrated a fragmentary
`sectional view of the lower portion of a powerunitillus-
`trating a modification of the present invention. The
`modified powerunit is generally designated as 12’ and
`includes a casing 34’ closed at the bottom in the same
`manneras casing 34 described above. The motor20 is
`mountedin casing 34’ in the same wayasin the preced-
`ing embodiment. In accordance with the present inven-
`tion and asillustrated in the drawings, the secondary
`winding designated as 19’ is wound on an insulated
`bobbin 60 surrounding an iron core 61 which intercon-
`nects a pair of flanged secondary pole pieces or pole
`shoes 62 and 63. These pole pieces or pole shoes 62
`and 63, like the core.61, are preferably formed of mate-
`rial providing a low reluctance flux path. The core 61
`interconnects the secondary pole pieces 62 and 63 in
`much the same manneras the core 53 of FIGS. 4 and
`§ interconnected the primary pole pieces 51 and 52. As
`illustrated, the pole pieces 62 and 63 are cup shaped
`and disposed with the circular flanges directed in the
`same direction so as to give the maximum spacing to
`prevent flux leakage and at the same time to give the
`shortest over-all length of the unit 12’. Preferably a
`cushioning pad 64 is disposed in the bottom of casing
`34’ engaging the lower pole piece 63 and a portion of ¢.
`the core 61.
`In FIG. 7 of the drawings the rechargeable battery is
`designated by the reference numeral 66 andis illus-
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`trated as havingits positive terminal 66a accessible at
`the lower end of the battery, and, of course, the battery
`casing defines the negative terminal which is desig-
`nated as 66b. To properly position the battery within
`the casing 34 between the motor 20 and the secondary
`winding 19’, a pair of cup-shaped insulating members
`68 and 69 are employed, the member 68 being associ-
`ated with the lower end of the motor 20, while the insu-
`lating member 69 is associated with the upper pole
`piece 62 and actually being disposed within the cham-
`ber defined by this pole piece, as clearly shown in FIG.
`7 of the drawings. An insulating sleeve 70 snugly re-
`ceives the battery 66 and engages the portions of re-
`duced cross section of the flanged cup-shapedinsulat-
`ing members 68 and 69.
`The diode 28 is indicated as being disposed in the
`space between the flanged cup-shaped member 69 and
`the upper pole piece 62. However,it could also be dis-
`posed in the space between the sleeve 70 and casing
`34’. The electrical connections will be identical with
`those shownin FIG.6 of drawings, and the same charg-
`ing and storage unit 11 may be employed, the impor-
`tant criteria being that the spacing between the flanges
`§1b and 525 of the primary pole pieces be substantially
`identical with the spacing between the secondary pole _
`pieces 62 and 63 so that when the power unit 12’ is dis-
`posed in the recess 14 in charging position the mag-
`netic coupling between windings 18 and 19’ is at a max-
`imum. To reduce the weight the winding 19’ preferably
`should be formed of insulated aluminum wire.
`In view of the description included above, the con-
`struction, assembly and operation of the powerunit 12’
`will readily be understood by thoseskilled in the art.
`It will be appreciated that the inductive coupling be-
`tween the primary winding in a charging unit and a sec-
`ondary winding in a power unit containing a recharge-
`able battery may take considerably different forms. In
`FIG.8 of the drawings thereis illustrated a fragmentary
`sectional view of a portion of a power unit 72 and an
`associated charging and storage unit 73. Asillustrated,
`the power unit 72 comprises a casing 74 closed at the
`bottom similar to the casings 34 and 34’ described
`above. Mounted within the lower end of casing 74 is a
`magnetic core structure generally designated at 75
`comprising a circular inverted cup-shaped portion 75a,
`having a circular central portion 75b so as to define an
`annular chamber 76 within the core structure 75. The
`core structure should be formed of material providing
`a low reluctance flux path and, to facilitate manufac-
`ture, may be constructed of powdered iron or similar
`material. Disposed within the annular chamber 76 of
`the secondary core structure 75 is a suitable hollow in-
`sulating bobbin 77, preferably formed of nylon or simi-
`lar insulating material, supporting a secondary winding
`78 which functions in the same manner as the secon-
`dary windings 19 or 19’ described above and would be
`connectedin an electrical circuit similar to that shown
`in FIG. 6 of the drawings. The center circular portion
`75b of the core structure is received within the hollow
`bobbin 77.
`For the purpose of inductively coupling the secon-
`dary winding 78 andits core structure with a suitable
`primary winding designated as 79 and mounted in the
`storage and charging unit 73 like the winding 18 de-
`scribed above, the latter is provided with a molded
`housing 80 having a tubular integral wall portion 80a
`defining a recess 81 closed at the bottom for receiving
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`therein the power unit 72 during a storage and charging
`operation thereof, the recess 81 functioninglike the re-
`cess 14 described above. Asillustrated, the primary
`winding 79 is associated with a magnetic core structure
`designated as 82 which comprises an outer circular
`cup-shaped. portion 82a and a central circular portion
`82b defining an annular chamber 83 therebetween for
`receiving the winding 79. Asillustrated, the winding 79
`is suitably wound on an insulating bobbin 84.
`Preferably the primary winding 79 andits associated
`core structure 82 are suitably supported within the
`storage and charging unit 73 on a bottom closure mem-
`ber 87 having integral projections 87a for holding the
`winding 79 and corestructure 82 in a predetermined
`position closely adjacent the bottom of recess 81, as
`shownin FIG. 8 of the drawings. The core structures 75
`and 82 are such that a flux path of minimum reluctance
`is produced, the low reluctance path being interrupted
`only bythe thickness ofthe wall defining the bottom of
`recess 81 and the thickness of the bottom of casing 74.
`
`In an embodiment employing the construction of
`FIG. 8 the core structures 75 and 82 each had an out-
`side diameter of one and one-eighth inches, and an
`over-all length of one inch, with the center core por-
`tions 75b and 82b being one-quarter inch in diameter.
`The wali thicknesses of the portions 75a and 82a were
`of the order of one-eighth of an inch.
`In the embodiments described above, the core struc-
`ture for the secondary winding was enclosed within the
`powerunit. It might be desirable to eliminate this mag-
`netic structure from the power unit to reduce the
`weight thereof. In FIG. 9 of the drawings thereis illus-
`trated another embodiment of the present invention
`wherein the core structure for the sec