US3379906A

US3379906A - Electric appliance with selective motion conversion means

Info

Publication number: US3379906A
Application number: US483061A
Authority: US
Inventors: Albert R Spohr
Original assignee: Sunbeam Corp
Current assignee: Sunbeam Corp
Priority date: 1965-08-27
Filing date: 1965-08-27
Publication date: 1968-04-23
Anticipated expiration: 1985-04-23
Also published as: GB1070637A; DE1532804B2; DE1532804C3; CH459141A; DE1532804A1

Description

A. R. sPoHR 3,379,906

ELECTRIC APPLIANCE WITH SELECTIVE MOTION CONVERSION MEANS April 23, 196s 4 Sheets-Sheet l Filed Aug. 27, 1965 lp. a. Z Wr. 5 4 2 @I @w 4 4 5 2 .M m. 2 2 w. m w m f J A M I l w 1 r L f 14. Il..1 W N m m. l .im w m m. f +I H .m\ ad 7 l a.` I+ L Z 3 7 w I ,/1# @a v 5 1% 3 M .f

www, +1-- 9 A. R, SPOHR April 23, 1968 ELECTRIC APPLIANCE WITH SELEGTIVE MOTION CONVERSION MEANS 4 Sheets-,Sheet 2 Filed Aug. 27, 1965 /A/x/E/Vroe ALD/ser R. Spa/l2 @man 'lae A. R. SPOHR Apri 23, 1968 ELECTRIC APPLIANCE WITH SELECTIVE MOTIGN CONVERSION MEANS 4 Sheets-Sheet 3 Filed Aug. 27, 1965 Arron/Ef April 23, 1968 A. R. sPoHR 3,379,906

ELECTRIC APPLIANCE WITH SELECTlVE MOTION CONVERSION MEANS /A/VENTUR Ams/2r R. .9pol-1R /irroeA/EY United States Patent O 3,37,906 ELECTRIC APPLIANCE WITH SELECTIVE MTIN CONVERSEON MEANS Albert R. Spohr, Park Ridge, Ill., assigner to Sunbeam Corporation, Chicago, lill., a corporation of Iliinois Filed Aug. 2'7, 1965, Ser. No. 483,061 18 Claims. (Cl. S10-50) The present invention relates generally to an electrical appliance and, more particularly, to a rechargeable battery operated electric toothbrush having a plurality of selectively different brush motions.

Power driven toothbrushes for use in the home generally include a single hand held power unit and a plurality of detachable individual toothbrush attachments so that each individual member of a family may have a separate brush. When not in use, the power unit and the individual toothbrushes or brush attachments are stored in a stand or case havino a charging unit therein for recharging a battery embodied in the power unit. One such arrangement is disclosed and claimed in copending Spohr application Ser. No. 353,327, filed Mar. 20, 1964, and assigned to the same assignee as the present application. Because of the separate charging unit, such toothbrushes are often referred to as cordless toothbrushes.

In one type of cordless toothbrush, the brush is driven by the power unit so as to oscillate about the axis of the brush shank through an angle of about ten to thirty degrees. In another type the power unit causes the brush to reciprocate in the direction of the axis of the shank. Some disagreement exists as to the relative merits of these two different brushing actions. Accordingly, it would be desirable to provide a cordless toothbrush capable of selectively providing either type of brushing action.

It is, therefore, an object of the present invention to provide an electric toothbrush capable of providing either an oscillatory brushing action or a reciprocating brushing action with simple means for selecting either type of brushing action as desired by the individual operator using the toothbrush.

Another object of the present invention resides in the provision of an electric toothbrush having new and improved selector means for selecting one or the other of two different types of brushing actions.

Yet another object of the present invention is the provision of a new and improved drive mechanism capa-ble of selectively converting rotary motion to either reciprocal or oscillatory motion of a driven member.

It is a further object of the present invention to provide an electric appliance having a drive mechanism with new and improved selector means for selecting either reciprocal or oscillatory motion of an output member.

Still another object of the present invention is the provision of an electric toothbrush having reversible motor means operable in selected opposite directions for producing either reciprocal or oscillatory brushing action.

Yet another object of the present invention is the provision of an electric toothbrush having selector means movable to control the direction of rotation of a reversible motor and to positively select either reciprocal or oscillatory brushing action.

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. l is a perspective view of an electric toothbrush constructed in accordance with the present invention with the power unit shown in solid lines and the detachable 3,379,906 Patented Apr. 23, 1968 ICC toothbrush member illustrated in phantom and with the switch shown in the off position;

FIG. 2 is an enlarged fragmentary side elevational view of the upper portion of the power unit of FIG. l with certain portions broken away more clearly to illustrate the present invention;

FIG. 3 is a sectional view taken substantially along line 3-3 of FIG. 2 assuming that FIG. 2 shows the complete structure;

FIG. 4 is a sectional view taken substantially along line 4-4 of FIG. 3 assuming that FIG. 3 shows the cornplete structure;

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

FIG. 6 is a partial sectional view taken substantially along line 6 6 of FIG. 3 again assuming that FIG. 3 shows the complete structure;

FIG. 7 is a view similar to FIG. 3 with certain portions of the casing omitted and with certain other portions not shown in section but showing the switch in a particular closed position thereof causing reciprocating type motion of the output shaft;

FIG. 8 is a perspective view with certain parts shown in section illustrating the drive mechanism of the power unit with the parts in the position of FIG. 7 for causing reciprocating motion of the output shaft;

FIG. 9 is a perspective View similar to FIG. 8 but showing the parts in the position for causing oscillating motion of the output shaft;

FIG. l0 is an enlarged fragmentary sectional view taken substantially along line 16v-10 of FIG. 5 assuming that FIG. 5 shows the complete structure;

FIG. l1 is a sectional view taken substantially along line 11-11 of FIG. 10 assuming that FIG. l0 shows the complete structure;

FIG.` l2 is an exploded perspective view of the selector switch means and a portion of the housing of the power unit; and

FIG. 13 is a schematic circuit diagram of the electrical circuit of the present invention with the switch in the open position, as shown in FIG. 1 of the drawings.

Briefly, the toothbrush of the present invention compri-ses a power driven unit having electric motor means with a motor armature selectively rotatable in either a forward or a reverse direction. A drive mechanism is included in the uni-t for converting rotation of the motor to either reciprocating or oscillating motion of an output shaft. The output shaft is intended to drive a toothbrush removably connected thereto. The drive mechanism provides reciprocal movement of the output shaft in response to rotation of the motor armature in one direction and oscillatory movement of the output shaft in response to rotation of the motor armature in the opposite direction. Selectively operable switch means are provided for selectively controlling the direction of rotation of the motor shaft to obtain the desired output..

The rechargeable battery operated toothbrush of the present invention is illustrated as having an exterior appearance substantially like that of the battery operated toothbrush disclosed in copending Spohr application Ser. No. 353,327 referred to above. Certain of the details of the copending application, such as, the arrangement of the battery and contacts, the construction of the output shaft,

f etc. are disclosed and claimed in the above-mentioned copending application and are only briey described in this application. It will be understood that the charging unit disclosed in the above-mentioned copending application may be used to charge the battery in the power operated electric tooth-brush, described hereinafter. Moreover, the power operated toothbrush of the present invention is adapted to be used with the identical charging unit, and

no description whatever of a charging unit is included in this application.

Referring now to the drawings, there is illustrated an electric power unit generally designated at 20 constructed in accordance with the present invention. This hand held power unit 20 is preferably a relatively compact device so that it may be held readily by the user, whether the user be an .adult or child. In a 4device built in accordance with the present invention, .the power unit 20 has an -outer diameter of between an inch and a quarter and an inch and a half, and an over-all length of less than live inches. The power unit 20 is adapted to dr-ive a suita'ble toothbrush, shown by dashed lines in FIG. l and designated by the reference numeral 21, so as either to refciprocate or oscillate. The brush 21 forms no part o-f the present invention but is representative of the brushes which could be used with a power unit such as 20. The brushes such as 21 are adapted to be drivingly secured to one end of a drive shaft 22 projecting from the hand held power unit 20. The driving engagement between the brushes 21 and the drive shaft 22 of 4the power unit 20 may tbe that disclosed and claimed in copending application Ser. No. 313,898, tiled Oct. 4, 1963, and also assigned to the same assignee as the present application.

Considering now the power unit 2t) in a little more detail, as mentioned above, it is quite similar to that disclosed in copending application Ser. No. 353,327 referred to above, and that application should be referred to for 'some of the details which form no part of the present invention and are not further described herein. The power unit 20l comprises a housing 24 of cylindrical configuration open at the bottom and closed at the top by an inte- -gral Wall portion 24a (FIGS. 3 and 4). Preferably, the wall 24a is provided with a pair of counterbored openings for sui-table fastening means, described hereinafter, an an opening 25 through which the driving end of the drive s'haft 22 projects (FIG. 4).

The details of the lower end of the power unit 24 and how the open lower end of the housing 24 is closed form no part of the present invention but are fully disclosed in the aforesaid copending Spohr application Ser. No. 353,327. With reference to FIGS. 1 and 13 of the drawings, the lower end of the housing 24 is closed by suitable molded end cap 27 which is illustrated as a cup-shaped member having an upper portion 27a of reduced diameter to be received snugly in the open lower end fof the housing 24. Upon final assembly a suitable cement is applied sealingly to secure the end cap 27 to the cylindrical housing 24. The end cap 27 is illustrated as being provided with a reentrant portion defining a central recess 28 (FIG. 13) to accommodate a pair of concentrically arranged contacts 29 and 30 by means of which the power unit may be connected in a suitable recharging circuit. These contacts may be identical with those disclosed in .the above-mentioned copending Spohr application Ser. No. 353,327.

In order to provide a source of electrical energy within the power unit 20, there is disposed within the lower portion of the housing 24 a suitable rechargeable battery 32, which is shown only schematically in FIG. 13 of the drawings and which is adapted -to energize a low voltage d-irect current motor 33, shown in FIGS. 2, 3, 4 and 13 of the drawings. The battery 32 and motor 33 form no part of the present invention except insofar as they are a part of the power unit 20 and are preferably identical with the corresponding battery and motor disclosed in copending application Ser. No. 353,327 referred to above. Suitable means will, of course, be provided to maintain the battery 32, which is preferably of cylindrical contiguration and disposed in the lowermost part of the housing 24, and the motor 33 in suitably supported relationship within the housing 24.

From the above description, it is apparent that the lower open end of the housing 24 is sealed against the entrance of moisture. Obviously, moisture should not enter .4 the housing 24 through the opening 2S for the drive shaft 22, and to accomplish this there is provided a drive shaft seal 35 (FIGS. 4 and 7) which is preferably of tubular configuration including an annular flange at the lower end thereof designated as 35a. This flange, as is clearly s-hown in FIG. 4 of the drawings, is adapted t-o be clamped 'between a surface defined on the ins-ide of the top wall 24a of the housing 24 and a suitable disk or platelike bearing support member 37, described in detail hereinafter, thereby sealing the opening 25 against the entrance of moisture. In order that moisture may not creep along the output or drive shaft 22, the latter is provided with a portion 22a of reduced cross section (FIG. 4) snugly to retceive therein a thickened annular portion 35b of the drive shaft seal 35. It will be understood that the heads of any fastening means, described hereinafter, disposed in counterbored openings in the end wall 24a of the housing 24 must also be sealed against the entrance of moisture in a manner well understood by those skilled in the art.

To improve the appearance of the upper end of the housing 24 and, particularly, to conceal the fastening means, described hereinafter, and the drive shaft seal 3S, there is provided a flanged housing cap 38 preferably formed of somewhat resilient molded platic material. In order to secure the cap 38 in position, it is preferably provided with lugs, not shown, projecting inwardly from the flange thereof, which lugs are receivable in an annular groove 39 (FIG. 3) delined adjacent the closed end of housing 24. Preferably, the housing 24 is provided with an annular shoulder 40` (FIGS. 3 and 4) adjacent groove 39 for engagement by the flange of the cap 38 whereby the cap 38 appears as a continuation of the housing 24. Preferably, the cap 38 is provided with an annular projecting flange 38b (FIGS. 2, 3, 4 and 6) surrounding an opening 41 defined in the cap 38 through which the drive or output shaft 22 may extend.

In order to actuate the drive or output shaft 22 for either oscillating or reciprocal movement of the latter in response to the direction of rotation of the motor 33, there is provided a subassembly including the electric motor 33 and a mechanism support 42 for supporting the mechanism of the present invention generally designated at 44 and best shown in FIGS. 2, 3, 5, 7, 8 and 9 of the drawings. The electric motor 33 may, of course, be any suitable low voltage direct current motor which has an output shaft 45 which may be rotated in either direction depending upon the energization of the electric motor 33. The mechanism support 42 preferably closes or defines the upper end of the housing for the motor 33 whereby the motor 33 and the mechanism support 42 are more or less of an integral assembly. The mechanism support 42 may be a die casting, as was the case in the copending Spohr .application Ser. No. 353,327 referred to above, or it may be molded from a suitable plastic material, in which case it also serves as an insulator for suitable electrical components, described hereinafter. The lower portion 42a of the mechanism support 42 preferably has a diameter of the order of the diameter of the casing for the motor 33 so that when the two are assembled the motor 33 is substantially a continuation of the lower portion 42a of the mechanism support 42.

`In order to support the driving mechanism 44 with which the present invention is particularly concerned and which is described in detail hereinafter, the mechanism support 42 immediately above the lower portion 42a thereof comprising an upwardly directed cylindrical portion generally designated at 42b defining a mechanism chamber 47 therein (FIGS. 2, 3 and 7) which is open at one side, as 'best shown in FIGS. 2 and 5 of the drawings, to devline a sort of window 49. The upstanding portion 42b is of generally cylindrical configuration except that it has a flat wall section 42C, as best shown in FIGS. 3, 5 and 7 of the drawings, to support the suitable switching means, described hereinafter. Thus, the opstanding portion 42h defines the mechanism chamber 47 for housing the drive mechanism 44, described in detail hereinafter. Actually, the upstanding portion 42h of the mechanism support 42 is of somewhat horseshoe shape but flattened over a portion of the area ofthe bight portion of the horseshoe. The upper -dege of the portion 4211 of the mechanism support 42 is provided with a pair of more or less diametrically opposed tapped openings for accommodating suitable fastening means (FIGS. 4 and 5) whereby the subassembly comprising the motor 33, the mechanism support 42 and the driving mechanism 44 may be secured within the housing 24 to the wall 24a thereof. The fastening means 50 are received in the counterbored openings referred to above.

So that the armature or motor shaft 45 may project into the mechanism chamber 47 defined by the mechanism support 42 to actuate the driving mechanism 44 from the motor 33, the lower end 42a of the mechanism support 42 is provided with a central opening 51 for accommodating an upper bearing 52 for the armature shaft 45. In addition to the opening 51 in the lower end 42a of mechanism support 42, there are provided two recesses 53 and 54 (FIGS. 3 and 4). The recess 53 (FIG. 4) is disposed in a projection 42e (FIGS. 2, 4 and 5) integral with mechanism support 42 and accommodates .a sleeve bearing 55 for the lower end of the drive or output shaft 22. The recess 54 (FIG. 3), on the other hand, is disposed in a projection 42d (FIGS. 3, 7, 8 and 9) of the mechanism support 42 and is adapted t0 receive as by a force t the lower end of a stationary gear spindle 56, the function of which is described hereinafter. In order to support the upper portion of the drive or output shaft 22, there is provided a flanged bearing 57 which is supported in a suitable opening in the plate 37.

So that this upper bearing support plate 37 is properly orientated wit-h respect to the mechanism support 42 and also securely to relate the two elements, the top of portion 42b thereof is preferably provided with short circular projections 42f (FIG. 5) receivable in suitable recesses, not shown, formed in the lower surface of the support plate 37 coaxial with the fastening means 50. The fastening means 50, of course, clamp the plate 37 to the upper end of the mechanism support 42 as well as secure the motor 33, the mechanism support 42 and the mechanism 44 to the closed end 24a of housing 24. Additionally, the fastening means 50 clamp the ange 35a of the seal 35, as described above. The supporting plate 37 thus effectively becomes a part of the mechanism support and, of course, supports the anged bearing 57, described above.

An important feat-ure of the present invention is the driving mechanism 44 capable of converting rotatable motion of the armature shaft 45 to either oscillating motion of the output shaft 22 about its own axis or reciprocating motion of the shaft 22 longitudinally of this same axis. The output shaft 22, already described, and the stationary gear spindle 56 effectively comprise a part of the driving mechanism 44. This driving mechanism additionally comprises a pinion 60, a gear 62, a cam member 63, a drive pin 65, a drive fork 66 and a cam follower 67. The

elements

60, 62, 63 and 66 are preferably molded of nylon or the like. As illustrated, the upper end of the `armature shaft 45 projecting into the mechanism chamber 47 through the opening 51 is provided with a knurled portion 45a (FIGS. 3 and 7) whereby the pinion 6) may be pressed thereon thereby to be driven by the motor shaft 45. The gear 62 is rotatably mounted on the stationary gear spindle 56 in driving engagement with pinion 6i). A suitable lthrust Washer 68 is interposed between the lower end of the gear 62 and the projection 42d, as best shown in FIGS. 3 and 7 of the drawings. lIn .accordance with the present invention, the upper portion of the gear 62 is provided with a large cylindrical recess 69 for receiving therein a cylindrical extension 63a of the cam member 63. The cam member 63 is also rotatably mounted about the stationary gear spindle 56 and includes an enlarged dislike upper portion 63b from the periphery of which project a plurality of spaced integral lugs 63e, the purpose of which will be described hereinafter.

For the purpose of preventing the gear 62 from moving upwardly on the stationary gear spindle 56, the latter is provided with an annular recess 71 for receiving a spring clip 72 (FIGS. 3, 7 and 8). The spring clip 72 engages with the bottom of the recess 69 thereby to hold the gear 62 in the position shown in FIG. 7 of the drawings. Preferably, and as illustrated, the recess 69 is provided with a small depending extension 69a within which the spring clip 72 is disposed whereby the main body of the recess 69 is available for the receipt of the portion 63a of the cam member 63. In FIG. 7, different positions of the cam member 63, as will become apparent from the ensuing description, are shown in solid lines and dotted lines, respectively.

It ywill be understood that the drive fork 66 is provided to impart oscillatory motion to output or drive shaft 22. To this end and as best shown in FIGS. 2, 4, 5, 8 and 9 of the drawings, shaft 22 extends through a tubular portion 66a of the drive `fork 66 the shaft 22 preferably Ibeing provided with a knurled portion or other means for making good driving connection with this tubular portion 66a. The drive fork 66 further includes a laterally projecting portion 66h integral with the tubular portion 66a. An elongated recess 74 is defined in the laterally projecting portion 66b for receiving the drive pin which is secured in an ecentrically disposed recess in the upper surface of cam member 63. This drive pin 65 is shown in FIG. 7 of the drawings as of the type which may be driven into a suitable recess and provided with means whereby it cannot readily be removed once it has been inserted. Moreover, drive pin 65 is provided at the upper end with a head 65a so las to maintain the cam member 63 adjacent the laterally extending portion 66h of the drive fork 66. It will readily be understood that if the cam member 63 is rotated about the axis of stationary gear spindle 56 oscillation of t-he output shaft 22, as designated by the double-headed arrow in FIG. 9 of the drawings, will result.

For the purpose funder certain conditions of having this same mechanism 44 cause reciprocating motion of the drive shaft 22, as designated by the double-headed arrow in FIG. 8 of the drawings, the periphery of the cylindrical portion 63a of cam member 63 receivable wit-hin the recess 69 is provided with an endless groove 75 for receiving therein the cam follower 67. This cam follower is supported by the wall of gear 62 defining the recess 69, as best shown in FIGS. 3, 7, 8 and 9 of the drawings. The groove 75 has a low point and a dametrically opposed high point relative to portion 63a, as viewed in FIGS. 2, 3, 7, 8 and 9 of the drawings, with the portions of the groove interconnecting these points having a uniform slope whereby a predetermined relative rotation of gear 62 and cam member 63 through three hundred sixty degrees yabout the axis of stationary gear spindle 56 would cause one complete cycle of reciprocation of cam member 63 along Isaid axis. As will be described in greater detail hereinafter, cam member 63 is prevented from rotating whenever gear 62 is rotated in the direction of the arrow shown in FIG. 8 of the drawings (clockwise) whereupon cam member 63 will reciprocate into and out of the recess 69. Since this cam member is pinned to the drive fork 66 by the drive pin 65 the output shaft 22 will similarly be caused to reciprocate. It will be understood that not only is the drive shaft seal 3S sufficiently resilient to prevent such reciprocal movement but also the sleeve bearing 55 is suciently long also to permit such movement.

In accordance with the present invention, it is desired that rotation of gear 62 in the direction of the arrow shown in FIG. 9 of the drawings (counterclockwise) will cause the cam 63 and gear 62 to operate as an integral unit. Accordingly, the groove 75 is provided adjacent the high point thereof with a short stub extension 75a (FIGS. 8 and 9) :into which the cam follower `67 will move upon counterclockwise rotation ,of gear 62, as viewed in FIG. 9 of the drawings. When the pin is at the end of this short stub extension 75a (as illustrated in FIGS. 2 and 9), continued counterclockwise rotation of the gear 62 will cause the cam 63 to rotate therewith in the same direction, and under these conditions, the gear 62 and cam 63 are effectively integral with the resulting oscillation of the shaft 22. It will be apparent that for reciprocal or linear movement of the output shaft 22 the armature shaft 45 and the associated pinion 60 must rotate in a counterclockwise direction, as viewed in FIG. 8 of the drawings (see arrow associated with pinion 60), whereas for oscillating movement ,of the output shaft 22, the armature shaft 45 and the pinion 60 must rotate in a clockwise direction, as viewed in FIG. 9 of the drawings (see arrow associated with pinion `60) To hold the cam 63 stationary when reciprocation of the output shaft 22 along its longitudinal axis is desired, there is provided a slide member 78 which Iperforms several functions, as described in detail hereinafter. First of all, it serves as a lock or stop for holding cam member `63 against rotation. To this end it includes a projection 78a receivable between adjacent lugs 63a` of cam member 63. It also functions as a movable contact support, as

described hereinafter. As illustrated, slide member 78 is l preferably formed of a molded insulating material and includes a dat platelike contact support section 7Sb from the upper end of which projects cam stop 78a. The flat portion 78b is adapted to be supported by the mechanism support `42. for reciprocal movement between an upper position (FIG. 9) which, as will become apparent, results in a particular energization of the motor 33 to cause oscillation of the output shaft 22, and a lower position, shown in FIGS. 7 and 8 of the drawings, resulting in locking cam member 63 and also energization of motor 33 to cause reciprocation of output shaft 22 along its longitudinal axis. The slide member 78 is also adapted to be positioned in an intermediate position (FIGS. 3, 4, 6 and 13) wherein the motor 33 is deenergized but the stop 78a is free .of lugs 63e.

As best shown in FIG. of the drawings, the mechanism support 42 is so shaped as to guide the slide memlber 7 8 in its movement between its two extreme positions, described above. As viewed in FIG. 5, portions of the side of the slide member section 78h remote from projection t 78a are engaged with `guiding means deiined on mechanism. support 42. The other side of slide member section 7811 is guided lby vertically extending support post 42g integrally formed with mechanism support 42.

From the above description, it will be apparent that the driving mechanism 44 of the present invention for .one direction of rotation of the armature shaft 45 while cam member 63 is held from rotating by stop 78a results in reciprocation of output shaft 22 along its longitudinal axis. Moreover, for the opposite direction of rotation of the armature shaft 45 when cam 63 is free to rotate about stationary gear spindle 56, oscillation of the drive shaft 22 occurs. In accordance with the present invention, there is provided switch means including manual control means for actuating the same to insure the proper direction of rotation of the armature shaft 45 for the desired motion of output shaft 22. It will be appreciated that this manual control means must be such as to correlate the effectiveness or ineifectiveness of the stop 78a with the direction of rotation of the armature shaft 45.

In order to control the energization of the electric motor 33 to rotate in either a clockwise or a counterclockwise direction, there is provided a control switch suitably supported on the at wall section 42C of the mechanism support 42 and on the flat section 7 8b of slide member 78.

Since mechanism support 42 and slide mem-ber 78 have been described as formed of insulating material, the switch components may be mounted directly thereto. It will be understood that in the event the mechanism support were a metal die casting suitable means would be required to insulate the electrical components, described hereinafter, from the mechanism support. As best shown in FIGS. 6 and 13 of the drawings, the control switch `comprises a plurality of stationary contacts a, 80b, 80C, 80d and 80e mounted in spaced relationship on iiat wall section 42e of mechanism support 42 and a pair of movable contacts y8l. and 82 mounted on section 781; of slide member 78. Preferably, the ilat Wall section 42C of the mechanism support 42 is provided with a plurality of spaced openings 83, eleven such openings being shown in FIGS. 3, 7 and 13 of the drawings. As there illustrated, nine openings are arranged in one vertical row and two openings in a second vertical row. Tubular rivetlike members disposed within iive of the eleven openings dene the

stationary contacts

80a, 80b, 80C, 80d and 80e. Contacts 80a, 80h and 80e are illustrated as disposed within the upper, middle and lower openings 83 lof the row of nine such openings, while

contacts

80d and 80e are disposed in the two openings defining the second row. The remaining openings 83 serve as detent openings for the movable contacts 81 and S2 to determine the three different switch positions. The

contacts

80d and 80e are preferably disposed midway between the contacts 80a and 80h and the contacts 80b and 8tlc, respectively, and slightly displaced to one side thereof, as clearly shown in FIG. 13 of the drawings.

To complete the electrical connections between battery 32, motor 33 and the control switch just described, one terminal 33a of the direct current motor 33 is effectively connected to both contacts 80a and Stic by

conductors

84 and 85. As illustrated, conductor 85 is actually a conducting strip of somewhat U shape which is secured to the at wall section 42C by rivet contacts 80a and 80C. As best shown in FIG. 3 of the drawings, the use of such rivet contacts 80 permits one to insert the end of an associated conductor into the opening in the contact whereby a simple soldering operation completes the connection. The other terminal 33h of the motor 33 is connected by a conductor 86 to contact 80b. The negative terminal of the battery 32 is connected by a conductor 87 to the contact 80d while the positive terminal of the battery 32 is connected to the contact 80e through the conductor 88. It will readily be apparent that if contacts 80a and 80d were electrically interconnected and simultaneously contacts 80'!) and Sile were electrically interconnected the negative terminal of the battery 32 would be connected to terminal 33a of motor 33 and the positive terminal of the battery 32 would be connected to terminal 33b of motor 33. On the other hand, if

contacts

80b and 80d were electrically interconnected and simultaneously

contacts

80e and 80e were electrically interconnected, then the terminal 33a of motor 33 would be connected to the positive terminal of battery 32 and motor terminal 33h would be connected to the negative terminal of battery 32.

For the purpose of selectively accomplishing the connections just described, the movable contacts 81 and l82 are each formed of resilient strip material of somewhat U shape with the legs of the U terminating in tabs 81a and 82a, respectively. These tabs are adapted to extend through suitable slits or openings in the section 78h of slide member 78 after which they are bent over, as indicated clearly in FIGS. 3 and 4 of the drawings. There is thus provided a simple means for securing contacts 81 Vand 82 to the slide member 78. The bight portions of contact members 81 and 82 are also each provided with integral projecting detents `81b and 82h, respectively, for engaging with the detent openings 83 in at wall section 42e of the mechanism support 42 not already occupied by stationary contacts 80. The movable contacts 9 81 and 82 are of sufficient lateral extent, as clearly shown in FIGS. 3, 5, 6` and 13 of the drawings, to be capable of interconnecting contact 80d with either contact 80a or 80h and contact 80e with either contact 8011 or 80C.

With the above-described arrangement, it is obvious that there has been provided a very simple three-position control switch forming a part of the mechanism support and permitting energization of the motor 33 for either direction of rotation thereof as well as providing a switchoif position. It will be understood that the middle detent opening 83 between the contacts 80a and 80b and the middle detent opening 83 between the contacts 80b and 80C receive the detents 81h and 82b, respectively, as shown in FIG. 3 of the drawings, when the control switch is in the open position. The two openings 83 immediately above the middle detent openings just described receive the detents 81b and 82b, respectively, when clockwise rotation of the motor armature 45, as viewed in FIG. 9 of the drawings, is desired with the resultant oscillating motion of the output shaft 22. The two openings 83 immediately below such middle detent openings receive the detents 81b and 82b, respectively (FIG. 7) when counterclockwise rotation of the motor armature 45, as viewed in FIG. 8 of the drawings, is desired with the resultant reciprocating motion of output shaft 22.

In order to actuate the switch comprising the stationary contacts 80a, 801;, 80C, 80d and `80e and the movable contacts 81 and 82 from the exterior of the housing 24, there is provided, in accordance with the present invention, a switch slide 91, a switch spring 92, a switch seal 93, a switch rocker arm 94 and a switch detent 95 which are adapted to be associated with a recess 97 deiined near the upper end of the housing 24. As best shown in FIGS. 4 and 12, the recess 97 has a small opening 98 at theV rear thereof leading to the interior of the housing 24. The switch seal 93 is adapted to be inserted into the bottom' of the recess 24 and includes a somewhat tubular projection 93a which extends through the opening 98 and into the housing 24. Preferably, t-he switch seal is formed of neoprene rubber or similar stretchable material and includes a rectangular section 93b which is adapted to seal the bottom of the recess 97. The switch rocker arm 94 is adapted to be inserted next, and it includes a pair of centrally disposed trunnions 94a and a pair of end pins 94b and 94C for transmitting motion from the switch slide 91 to the slide member 78, described above. In order that the switch rocker arm 94 may be pivotally supported within the recess 97 about the trunnions 94a, the recess is provided with extensions 97a on either side thereof terminating in semicircular ends 97b (FIGS. 11 and 12) to accommodate such trunnions. Similarly, the switch seal 93 is provided with laterally projecting semicylindrical ears 93e receivable in the recesses 97a with the convex sides thereof engaging the portions 97b and the concave sides engaging the trunnions 94a in a manner clearly shown in FIG. 11 of the drawings. In order to make sure that no moisture can leak between the switch rocker arm 94 and the tubular portion 93a of the switch seal 93, the rocker arm 94 is provided with a groove 100 into which the tubular portion 93a is deformed by suitable clamping means 99.

So that the pivotal movement of the rocker arm 94 about its trunnions 94a causes movement of the slide member 78, the latter is provided with an integral boxlike projection 78c, best shown in FIGS. 8 and 9 of the drawings. The end of the rocker arm having the projection 94b is adapted to be received within a recess 101 defined by this boxlike projection 78c. Moreover, one wall of this recess is provided with a notch 102 -for receiving therein the projection 94k, as best shown in FIG. 9 of the drawings. It will be obvious that pivotal movement of the rocker arm 94 about the axis of the trunnions 94a will cause the slide member 78 to move in a vertical direction, as viewed in FIGS. 8 and 9 of the drawings and as described in detail above.

For the purpose of holding the switch seal 93 in sealing relationship and also to support the switch slide 91, the switch spring 92, best shown in FIG. 12 of the drawings, is essentially a U-shaped spring member adapted to be pushed into the recess 97 with the bight portion of the spring member against the switch seal 93 and lwith the legs 92a of the U projecting outwardly along the walls of the recess 97, as best shown in FIG. 5 of the drawings. The switch spring 92 is provided at the upper and lower ends with spring fingers 92h which hold the switch spring within the recess 97 when it is forceably inserted therein. The spring fingers 92b engage and clamp against the upper and lower walls of the recess 97, as viewed in FIG. 12 of the drawings. The bight of the switch spring 92 is provided with an opening 103 to permit the rocker arm 94 to extend therethrough and is also provi-ded with laterally projecting semicylindrical ears 92C shaped to conform to the trunnions 94a, as best shown in FIGS. 1l and 12 of the drawings. These trunnions 94a are, therefore, clamped between the ears 93C of the seal 93 and the ears 92C of the spring 92a, as best shown in FIG. 11 of the drawings.

For a purpose which will become apparent from the ensuing description, the switch detent is an L-shaped member having one leg of the L 95a receivable in a slit 104 defined in one wall of the recess 97. The detent 95 has an intermediate resilient boss portion 95b which projects into the recess 97 to engage with the slide 91, as described hereinafter.

Consi-dering now the switch slide 91, it comprises a main body portion 91a including a finger engaging portion on one side. The body portion 91a is of suflicient extent as to completely overlie the recess 97. The switch slide includes a plurality of spaced

projections

91h, 91C, 91d and 91e from the face thereof opposite the finger engaging portion. A recess (FIGS. 4, 5 and 11) is detined between the upper projections 91h and 91e and the lower projections 91C and 91d within which is received one end of the rocker arm 94 and specifically the projection 94C. The

projections

9119, 91C, 91d and 91e are provided with enlargements at the inner ends thereof which are grasped by the spring fingers 92a of the switch spring 92, as best shown in FIG. 5 of the drawings. The detent portion 95h of the switch detent 95 is adapted to engage between the projections '91b and 91C to define the otf position of the switch slide 91. It will be apparent that when the switch sli-de 91 is moved to the upper end of the recess 97 the switch rocker arm 94 is moved as indicated by the arrow in FIG. 8 of the drawings and the motor 33 is energized to cause reciprocating motion of the output shaft along the longitudinal axis thereof. On the other hand, when the switch slide 91 is moved downwardly toward the bottom of the recess 97, the switch rocker arm 94 is moved in the direction of the arrow shown in FIG. 9 of the drawings causing the motor 33 to be energize-:l to cause oscillating motion of the output or drive shaft 22. In FIG. 1 of the drawings, a set of dashed arrows indicates that when slide 91 is moved upwardly the output shaft 22 reciprocates. A set of solid line arrows indicates that when slide 91 is moved downwardly the output shaft 22 oscillates.

In view of the detailed description included above, the operation of the power unit of the present invention will readily be understood by those skilled in the art. It will be apparent that there has been provided a very simple power unit, and the operator may merely actuate the switch slide 91 selectively to obtain oscillating or reciprocating motion of the toothbrush attachment 21 associated with the output shaft 22. A very simple mechanism is provided so that mere reversal of the direction of rotation of the electric motor 33 changes .the nature of the brushing action provided by the power unit 20. Moreover, the power unit is adapted to be associated with a suitable charging unit, -as disclosed in the abovemen- .tioned Spohr application Ser. No. 353,327.

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. An electrical power unit comprising motor means having a rotatable motor shaft, an output shaft mounted in said unit for either reciprocal or oscillatory movement, and drive means interconnecting said roatable shaft and said output shaft for reciprocating said output shaft in response to rotation of said motor shaft in one direction and for oscillating said output shaft in response to rotation of said motor shaft in the opposite direction.

2. The power unit of claim 1 including selector means for selectively controlling the direction of rotation of said motor shaft.

3. The power unit of claim 2 wherein said selector means includes stop means for restraining a portion of said drive means against movement when said selector means is operated to select one direction of rotation of said motor shaft.

4. An electrical appliance comprising a casing, an electric motor in said casing having a rotatable armature shaft selectively rotatable in either direction, Ian output shaft projecting from said casing, drive means interconnecting said shafts, said drive means causing oscillation of said output shaft upon rotation of said armature shaft in one direction and reciprocation of said output shaft upon rotation of said armature shaft in the opposite direction, control means movable between first and second positions for selectively controlling the direction -of rotation of said armature shaft, locking means included in said control means and movable to a locking position for restraining ra portion of said drive means when said control means is in one of said two positions.

5. The appliance of claim 4 wherein when said locking means is in its locking position only reciprocal movement of said output shaft can occur, said locking means being movable to its unlocked position when said control means is in the other of said positions.

6. In a power unit the combination of a casing, a prime mover in said casing having a rotatable first shaft selectively rotatable in either direction, a second shaft projecting from said casing and mounted for both reciprocating motion along its longitudinal axis `and oscillating motion about said axis, drive means in said casing interconnecting said shafts and causing oscillating motion of said second shaft in response to rotation in one direction of said rst shaft and reciprocating motion of said second shaft in response to rotation in the opposite direction of said first shaft, and control means movable between a plurality of positions for selectively controlling the direction of rotation of said first shaft.

7. A power unit for a -cordless electric toothbrush comprising a casing, a battery operated electric motor disposed within said casing and having a rotatable armature shaft selectively rotatable in either direction, a battery for supplying electric energy to said motor disposed in said casing, an output shaft projecting from said casing and mounted for both reciprocating motion along its longitudinal axis and oscillating motion about said axis, drive means interconnecting said shafts and causing oscillating motion of said output shaft in response to rotation of said armature shaft in one direction and reciprocating motion of said output shaft in response to rotation of said armature shaft in the opposite direction, and control means movable between a plurality of positions for selectively controlling the direction of rotation of said armature shaft.

8. In a power unit for a cordless electric toothbrush the combination of a casing, a battery operated electric motor mounted within said casing and having a rotatable armature shaft selectively rotatable in either direction, a rechargeable battery for supplying electric energy to said motor mounted within said casing, an output shaft projecting from said casing and mounted for both reciprocating motion along its longitudinal axis and oscillating motion about said axis, drive means interconnecting said shafts and causing oscillating motion of said output shaft in response to rotation of said armature shaft in one direction yand reciprocating motion of said output shaft in response to rotation of said armature shaft in the opposite direction, control means movable -between a plurality of positions for selectively controlling the direction of rotation of said armature shaft, and means included in said control means for restraining a portion of said drive means in a predetermined manner when said control means is in one of said plurality of positions.

9. The power unit of claim 8 wherein said control means includes a switch for reversing the connections between said battery and said motor.

10. The power unit of claim 6 wherein said drive means comprises gear means drivingly connected to said first shaft, means defining a recess in said gear means, a cam member disposed in said recess, connecting means drivingly relating said cam member to said gear means, pin and fork means interconnecting said cam member and said second shaft for oscillating said second shaft in response to rotation of said cam member, means included in said control means for holding said cam member against rotation when said control means is in one of said plurality of positions, and means included in said connecting means for causing said cam member to move into and out of said recess when said cam member is held against rotation and said gear means is driven by said first shaft.

11. In a power unit for a cordless electric toothbrush the combination of a casing, a battery operated electric motor in said casingdhaving a rotatable armature shaft selectively rotatable in either direction, a battery for supplying electric energy to said motor disposed in said casing, an output shaft projecting from said casing and mounted for both reciprocating motion along its longitudinal axis and oscillating motion about said `axis, drive means interconnecting said shafts and causing oscillating ymotion of said output shaft in response to rotation of said armature shaft in one direction and reciprocating motion of said output shaft in response to rotation of said armature shaft in the opposite direction, control means movable between a plurality of positions for selectively controlling the direction of rotation of said armature shaft, said drive means comprising a gear driven from said armature shaft, a cam member disposed in said recess, connecting means ydrivingly relating said cam lmember and said gear, pin and fork means interconnecting said cam and said output shaft for oscillating said output shaft in response to rotation of said cam member, means included in said control means for holding said cam member against rotation when said control means is in one of said plurality of positions, and means included in said connecting means for causing said cam member to move into and out of said recess when said cam member is held against rotation and said gear is driven by said armature shaft.

12. An electric toothbrush comprising a power unit including a casing, motor means in said casing having a rotary shaft selectively rotatable in opposite directions, a toothbrush supporting output shaft extending outwardly from said casing mounted for both reciprocating and oscillating movement with respect thereto, drive means in said casing interconnecting said rotary shaft and said output shaft, said drive means including first means for reciprocating said output shaft when said rotary shaft is rotated in one direction, and second means for oscillating said output shaft when said rotary shaft is rotated in the opposite direction, and control means for selectively controlling the direction of rotation of said rotary shaft, said control means including means for disabling one of said first and second means upon actuation of said `control means to select a predetermined direction of rotation.

13. The power unit of claim 6 wherein said drive means includes yoke means extending radially from said second shaft and a cam member mounted for reciprocal and rotational movement about a fixed axis with respect to said casing, said drive means further including an eccentric pin secured to said cam member and drivingly connected to said yoke means, said drive means also including a gear driven by said first shaft for rotation about said fixed axis and means for actuating said cam member from said gear to reciprocate said cam member along said fixed axis when said gear is rotated in one direction and to rotate said cam member about said xed axis when said gear is rotated in the opposite direction.

14. The power unit of claim 13 wherein locking means are proivded for restraining said cam member against rotation when said control means is moved to one of said positions.

15. In a power unit for a cordless electric toothbrush, the combination of a casing, an electric Imotor in said casing having an armature shaft selectively rotatable in a forward and reverse direction, an output shaft projecting from said casing and mounted for both reciprocating movement along its longitudinal axis and oscillating motion about said axis, shaft means parallel to said output shaft, rst cam means mounted for rotation on said shaft means and driven by said armature shaft, second cam means mounted on s-aid shaft means for rot-ation and reciprocating move-ment thereon, one of said cam means including -drive pin means engageable with groove means in the other cam means for lreciprocating said second cam means upon rotation of said first cam means in said forward direction and locking said first and second cam means against relative rotation upon rotation of said rst cam means in sai-d reverse direction, yoke means on said output shaft extending radially outward thereof for reciprocating and oscillating said out-put shaft, said second cam means including a drive pin eccentric of said shaft means for drivingly engaging said yoke means to drive said output shaft, `and selector means movable between a first position engaging said second cam means to prevent rotation thereof but permit reciprocation and a second position free of engagement with said second cam member.

16. In a power unit for a cordless electric toothbrush, the combination of a casing, an electric motor in said casing having an armature shaft selectively rotatable in a forward and reverse direction, an output shaft projecting from said casing and mounted for both reciprocating movement along its longitudinal axis and oscillating motion about said axis, drive -means for drivingly interconnecting said armature shaft and said output shaft including `a frame, shaft means carried by said frame parallel to said output shaft, first cam means mounted for rotation on said shaft means and driven by said armature shaft, second cam means mounted on said shaft means for rotation and reciprocating motion thereon, one of said cam means including drive pin means enga-geable with Igroove means on the other earn means for reciprocally moving said second cam means upon rotation of said armature shaft in said forward direction and locking said first and second cam means against relative rotation upon rotation of said armature shaft in 'a reverse direction, yoke means on said output shaft projecting radi-ally outward of the longitudinal axis thereof, a drive pin on said second cam means engaging said yoke means and eccentric of said shaft means for driving said yoke means in reciprocating and oscillating motion, switch means in said casing .movable between selected positions to energize said `motor to rotate in said forward and reverse directions, said switch means including a body member slidable on said frame and an operator pivotally mounted on and projecting outwardly of said casing for lmoving said body member between said selected positions, said body member including lug means engageable with said second cam means to prevent rotation but permit reciprocation thereof when said switch means is moved to energize said motor in said forward direction.

17. In a power unit for a cordless electric toothbrush, the combination of a casing, an electric -motor in said casing having an armature shaft selectively rotatable in a forward and a reverse direction, an output shaft projecting from said casing and mounted for both reciprocating movement along its longitudinal axis and oscillating motion about said aixs, said output shaft including yoke means lwithin said casing extending radially outward from said longitudinal axis, and cam means interconnecting said yoke means and said armature shaft, said cam means including a driving cam member rotatably engaging said armature -shaft and a driven cam member mounted for rotation about and reciprocation along an axis of said cam means, one of said cam members including a drive pin engageable with groove means on the other cam member for reciprocally driving said driven cam member upon rotation of said armature shaft in a forward direction and locking said cam members against relative rotation upon rotation of said armature shaft in an opposite direction.

18. In a power unit for an electric toothbrush, the combination of a sealed casing, an electric motor in said casing having an armatu-re shaft selectively rotatable in a forward and a reverse direction, an output shaft projecting through said casing and mounted therein for both reciprocating movement along its longitudinal axis and oscillating motion about said axis, said output shaft including drive yoke -means extending radially outward of said longitudinal axis, drive means interconnecting said armature shaft an-d said drive yoke -means including a frame, said drive means including cam means comprising la driving member rotated by said armature shaft and a driven member connected to said yoke means, means interconnecting said driving and driven members whereby said yoke means is moved in oscillating motion around said longitudinal axis in response to forward rotation of said armature shaft and Isaid yoke means is driven to reciprocate said output member longitudinally of its axis in response to reverse rotation of said armature shaft, switch means in said casing slidably mounted on said frame for movement between selected positions for energizing said motor in said forward and reverse direction, said switch means including lug means engageable with said driven member to prevent rotation thereof when said s-witch means is moved to reverse said armature shaft, a toggle actuator pivotally mounted on said casing and having an inward projection engaging said switch means and an 'actuating ar-m projecting outwardly of said casing, and means for sealing said casing against the entrance of moisture adjacent said toggle actuator.

References Cited UNITED STATES PATENTS 2,531,849 11/1950 Karleen 74-57 2,548,411 4/1951 Vache 74-57 2,858,701 11/ 1958 Willcox 74-22 3,233,265 2/1966 Hartmann 15--22 3,270,360 9/1966` Kropp 15-22 FOREIGN PATENTS 1,174,293 7/1964 Germany. 1,200,250 9/1965 Germany.

MILTON O. HIRSHFIELD, Primary Examiner.

D. F. DUGGAN, Assistant Examiner.

Claims

8. IN A POWER UNIT FOR A CORDLESS ELECTRIC TOOTHBRUSH THE COMBINATION OF A CASING, A BATTERY OPERATED ELECTRIC MOTOR MOUNTED WITHIN SAID CASING AND HAVING A ROTATABLE ARMATURE SHAFT SELECTIVELY ROTATABLE IN EITHER DIRECTION, A RECHARGEABLE BATTERY FOR SUPPLYING ELECTRIC ENERGY TO SAID MOTOR MOUNTED WITHIN SAID CASING, AN OUTPUT SHAFT PROJECTING FROM SAID CASING AND MOUNTED FOR BOTH RECIPROCATING MOTION ALONG ITS LONGITUDINAL AXIS AND OSCILLATING MOTION ABOUT SAID AXIS, DRIVE MEANS INTERCONNECTING SAID SHAFTS AND CAUSING OSCILLATING MOTION OF SAID OUTPUT SHAFT IN RESPONSE TO ROTATION OF SAID ARMATURE SHAFT IN ONE DIRECTION AND RECIPROCATING MOTION OF SAID