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Publication numberUS2987636 A
Publication typeGrant
Publication dateJun 6, 1961
Filing dateJul 9, 1953
Priority dateJul 9, 1953
Publication numberUS 2987636 A, US 2987636A, US-A-2987636, US2987636 A, US2987636A
InventorsJepson Ivar
Original AssigneeSunbeam Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Electric mixer
US 2987636 A
Images(6)
Previous page
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Description  (OCR text may contain errors)

June 6, 1961 JEPSON 2,987,636

ELECTRIC MIXER Filed July 9. 1953 6 Sheets-Sheet 1 JuneG, 1961 6 Sheets-Sheet 5 Filed July 9. 1953 a. a 9M PM & a Z 1 WWW [HAW @LW'- A m 1 6 y q 9 1 W 3 M 4 0.6 L

g AIM 3 June 6, 1961 l. .JEPSON 2,987,636

ELECTRIC MIXER Fileci July 9, 1955 6 Sheets-Sheet 4 IN VEN TOR.

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ELECTRIC MIXER Filed July 9, 1953 6 Sheets-Sheet 5 IN VEN TOR.

June 6, 1961 L JEPSON 2,987,636

ELECTRIC MIXER Filed July 9, 1953 6 Sheets-Sheet 6 IN V EN TOR. [ya/z United States Patent 6 2,987,636 ELECTRIC MIXER Ivar Jepson, Oak Park, 111., assignor to Sunbeam Corporation, Chicago, Ill., a corporation of Illinois Filed July 9, 1953, Ser. No. 366,910 36 Claims. (Cl. 310-50) This invention relates to a portable electrically powered mixing apparatus, and more particularly to a relatively inexpensive as well as relatively small electrical household mixing appliance which is capable of operating at a plurality of different speeds.

The electrical household mixing appliance or food mixer has become a necessary tool of the housewife, and applicants assignee alone has sold many millions of such mixers. The bulk of the mixers which have been sold heretofore have comprised a suitable support or stand for an electric motor and also for one or more mixing bowls associated therewith. In general, the mixing operation was performed while the motor and associated beater were mounted on said support or stand, although the mixing operation could be performed by removing the motor driven beater from the support, whereby the housewife could hold the same during a mixing operation.

In recent years there has been a tendency to build homes, apartments and the like with very small kitchens which really have no space for the heretofore conventional household mixer. There is, therefore, a demand for a small, portable, electrically powered mixing unit which can be stored in a minimum of space and yet which is capable of performing a satisfactory mixing operation. Obviously, with such an arrangement the electrical control circuit must be confined to a very small space. Consequently, it is desirable that the switching apparatus be housed within the mixer at a position which does not interfere with the operation of the motor and the mechanical driving apparatus for the agitators or heaters of the mixer. Moreover, the switching apparatus should have a long operating life so that the necessity for repair or replacement is minimized, and to this end it is desirable that the make and break circuits be designed to prevent arcing and to avoid pitting of the contact elements.

In such a small portable mixer the mixer motor nevertheless should be capable of operation at a number of preselected speeds covering a wide range of revolutions per minute so that the mixer may perform a variety of household functions, which include beating or whipping at high speed, stirring and mixing at intermediate speeds, and blending or folding at low speeds.

Accordingly, it is an object of the present invention to provide a new and improved power driven household mixer.

It is another object of the present invention to provide a small, portable mixing device in which the elements are arranged and positioned in such manner that a minimum of space is required.

Still another object of the present invention is to provide a hand-operated mixing device in which the electrical control unit is positioned in the handle of the mixer out of the way of the mechanical structure in the mixing body; and in this connection my invention contemplates an improved motor control switch assembly designed to be inserted into the handle through an opening in the bottom thereof, thereby facilitating the initial assembling of the mixer as well as subsequent repair operations.

A further object is to provide an electrical control circuit for small mixers in which the switch is efiiciently indexed at a contact position and is prevented from arcing when moved from the indexed position.

A still further object of the invention is to provide an electrical control for portable mixers in which a movable switch arm is moved over a ridged member to insure proper making and breaking of the electrical circuits.

Another object is to provide a speed control for small electrical motors used in mixing devices in which the contacts of the switch are staggered radially with respect to the movable switch arm so as to prevent pitting and in which the switch arm is indexed in a contact position by a member having a plurality of raised portions thereon.

A further object is to provide an electrical control device for small portable mixers in which the electrical elements of a multicontact rotary switch are positioned on a single plate in order to conserve space.

Another object is to provide a new and improved means for securing the handle containing the switching means to the gear housing and the motor casing by the use of a resilient plate which results in an extremely simple and economical manner of mounting the handle.

A further object of the invention is to so mount the cooling fan on the armature shaft that it can be readily removed for access to the brush plate or armature in the event repairs to these parts should become necessary.

A still further object of my invention is to provide an exhaust path for the air used to cool the motor which delivers said air at a point remote from the bowl in which ingredients are being mixed.

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 a perspective view of a small mixer embodying the present invention shown to indicate how the mixer is used for a mixing operation;

FIG. 2 is an enlarged elevational view of the mixer of FIG. 1;

FIG. 3 is a front view looking endwise of the device of FIG. 2;

FIG. 4 is a top plan view of FIG. 2;

FIG. 5 is a partial rear view of FIG. 2;

FIG. 6 is an enlarged sectional view of the mixer of FIG. 2 taken along a vertical plane through the longituclinal axis of the mixer motor;

FIG. 7 is a sectional view taken along line 7--7 of FIG. 6, assuming that the entire mixer had been shown in FIG. 6;

FIG. 8 is a sectional view taken along line 8-8 of FIG. 6, looking in the direction of the arrows, and again assuming that the entire mixer was shown in FIG. 6;

FIG. 9 is a sectional view similar to FIG. 8 taken along line 9-9 of FIG. 6;

FIG. 10 illustrates a sectional view similar to FIG. 8 taken along line 1010 of FIG. 6;

FIG. 11 is a sectional view similar to FIG. 9 taken along line 1111 of FIG. 6, but omitting the walls of the motor housing;

FIG. 12 is a sectional view similar to FIG. 8 taken along line l212 of FIG. 6;

FIG. 13 is an enlarged view primarily of the switch mechanism shown in FIG. 6, with the switch in a different position than that shown in FIG. 6;

FIG. 14 shows a view similar to FIG. 13 but looking at the opposite side of the switch mechanism;

FIG. 15 is a sectional view of the switch mechanism taken along line 15-15 of FIG. 13;

FIG. 16 is a sectional view taken on line 16-16 of FIG. 13 and shows the details of the base plate for mounting the switch in the handle of the mixer;

FIG. 17 is a view illustrating one lamination of the asaaeae pole pieces of the field coil assembly employed in the mixer motor;

FIG. 18 is a view showing the assembled pole pieces and field windings of the mixer motor;

FIG. 19 illustrates in diagrammatic form the electrical control circuit for the mixer motor;

FIG. 20 is an enlarged sectional view taken along'line 20-20 of FIG.

FIG. 21 is a sectional view taken on line 2121 of FIG. 8 showing the manner in which the handle is secured to the gear and motor housings;

FIG. 22 is a sectional view taken on the line 2222 of FIG. 21 with the switch mechanism removed and assuming the entire mixer to be shown in FIG. 21;

FIG. 23 is a bottom view of the handle portion only as shown in FIG. 22, looking in the direction of the arrows;

'FIG. 24 is a sectional view taken on line ,24-24 of FIG. 7; and

FIG. '25 is a sectional view taken along line ZS-25 .of FIG. 24.

The present invention accomplishes the objects set forth above in a small hand-operated mixer by providing a mixer motor of the tapped field type, and an efficient, compact, switching unit for changing the field connections to alter the speed of the motor. The switching device is mounted in the handle of the mixer out of the way of the mechanical components of the mixing apparatus and is operable by slight finger pressure applied to the outer end of a switch arm which extends into the mixer handle. The switch is provided with a number of contacts, each of which is electrically connected to one of the taps on the field winding of the motor. A wiper arm is connected to the switch arm so that the wiper makes successive contact with a predetermined one of the contacts as the switch arm is actuated to a desired position. The switch unit also includes a ridged member for maintaining the wiper arm out of contact with the contacts when the arm rides upon a ridge and for properly indexing the wiper arm in one of the speed control positions when the arm is positioned between the ridges on the member.

Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGS. 1 and 6 a small portable household mixer 30 which is adapted to be held in the hand of the housewife or other person while being used to agitate a substance which may be contained in a mixing vessel 31 or other similar utensil. The mixer 30 is powered by a fractional horsepower electric motor designated generally as 32 in FIGS. 6 and 7, which motor is of the universal type designed for A.C. or DC). operation.

In order to vary the speed of the motor 32 by preselected steps, an electrical control means designated generally as 33 may be secured in a cavity or hollow portion 34 of a switch encasing handle 35 of the mixer. With this arrangement the control means are disposed at a position removed from the congested area of the mixer body defined by a casing or housing 78 which contains the mechanical components of the mixer. The control means 33 includes a multicontact rotary switch 37 which is electrically connected to a plurality of taps on a tapped field winding 33 (FIG. 19) of the motor 32 so that the speed of the motor may be varied by altering the number of energized turns of the field winding. Actually, the field winding is illustrated as comprising two portions 38, one portion being a tapped winding.

As best shown in FIGS. 13 to 16, all of the elements of the switch 37 are mounted on a single insulating plate 39 on which is positioned a control arm 40 mounted, for pivotal movement about a pivot pin 41 at the upper extjremity of the plate 39. To provide for fingertip control of the switch 37 and for facility of operation in changing.

the speed of the moton the upper portion; of. the control arm extends through an elongated opening 35b in the top of the handle 35 so that a knurled finger engaging knob 42 may be applied over the protruding end of the control arm '40. The handle 35 is provided with a cavity 43 for receiving the knob 42 and the protruding end of the control arm, so that the knob 42 is positioned partially in the cavity and is operable by a slight actuating force applied preferably with the thumb along'the curved contour of the outer surface of the mixer handle 35 in a convenient manner.

In order to perform a switching operation, the control arm 40 is rigidly connected to a contact wiper arm 44 through an insulating washer 45, best shown in FIG. 15, to which the wiper arm is secured by outwardly depending lugs 46 which engage lug receiving slots 47 in the washer 45. Similar lugs and slots may be provided in order to secure the control arm 40 to the washer so that rotation of the control arm causes the wiper arm 44 to be pivoted about the pivot pin 41. The pivot pin 41 retains the elements 39, 4t 44 and 45 in assembled relationship with the aforementioned lugs in engagement with the slots. It will be noted that with the control arm 40 insulatedly connected to contact Wiper arm 44 by means of washer 45 the switch can be operated without danger of shock even though the knob 42 should become detached.

For the purpose of controlling the efiectiveness or inefiectiveness of the wiper arm 44 and to provide an electrical circuit for part of the switch, there is mounted on the insulating plate 39 in any suitable manner a curved contact control strip or bus bar 48 formed of conducting material upon which the wiper arm 44 rides as it is pivoted about the pivot pin 41. The wiper arm is constructed of spring metal material and is stressed or biased toward the insulating plate 39 and, consequently, toward the strip 48 in order to insure continuous electrical contact between the Wiper arm and the bus bar or strip 43.

To accommodate certain contacts engageable by the Wiper arm 44, a plurality of circumferentially aligned spaced apertures 49, 5t and 511 are defined in the insulating plate through which contact tabs 52, 53 and 54, respectively, extend. The contact tabs are formed integral with electrical contacts 55, 56 and 57, respectively, which are secured to the side of the insulating plate 39 opposite from the side to which strip 43 is secured, so that the tabs extend through the apertures and protrude slightly above the surface of the plate 39 adjacent wiper contact 44. The inherent resilience of the contacts 55, 56 and 57 biases the contact tabs 52, 53 and 54 into contacting engagement with the wiper arm 44 when permitted to do so by control strip 48.

As best shown in FIG. 19, each of the contacts 55, 55 and 57 is electrically connected to a different tap on the field winding 38 of the electric motor 32, the contact 55 being connected through a conductor 58 to a tap 55, the contact 56 being connected through a conductor 60 to a tap 61, and the contact 57 being connected through a conductor 62 to a tap 63. The three conductors 58, 6t and 62 are preferably included with a fourth conductor in a suitable insulating sheath 64 to facilitate the electrical interconnection of the switch contacts and the tapped field winding.

Electrical power for the motor 32 is supplied to the mixer through a conventional power plug -65 and twin conductor wire 66 which enters the mixer through a cable connection joint 67 positioned adjacent an indentation 68 (FIG. 6) in the underside of the mixer body. The twin conductor 66 is connected as indicated in FIG. 19 with the field winding 38 and also through conductors 70 with the bus bar 48.

In the o position of the switch 37, the control arm 40 is disposed in its extreme clockwise position as viewed in FIG. 13, in which position the wiper arm 44 engages a stopv 69 as viewed in FIG. 6 and rests upon a raised portionitonthe busbar 48. It is. apparent that-inthisposition the wiper arm is maintained in' a raisedposition away from the insulating plate--39 and out of contact with the tabs on the electrical contacts, so that an open circuit exists between the input power supply and the field windings 38 of the motor 32. When the circuit supplying energization for the field windings is broken, the motor will not operate and the mixer is maintained in a de-energized condition.

As the control arm 40 is moved in a counterclockwise direction from the position shown in FIG. 6 as viewed in FIG. 13, the wiper arm 44 rides across the raised portion 71 which is part of the bus bar 48, and then drops into a space located between the raised portion 71 and 'a raised portion 72 positioned closely adjacent thereto. The space between the raised portions 71 and 72 is the low speed position of the switch 37, at which position the motor is caused to turn at low speed of the order of 365 r.p.m. so that the mixer may be used in performing such steps as blending or folding. Whenthe wiper arm is snapped by the spring metal action of the wiper arm 44 into the space between the raised portions 71 and 72, the wiper arm 44 electrically engages the contact tab 52 which is radially aligned with the space between the raised portions 71 and 72. Electrical contact between the wiper arm 44 and the contact tab 52 completes the electrical circuit to the field winding tap 59 and causes the electrical motor to turn at relatively low speed. The motor turns at low speed, since the maximum number of turns of the tapped field winding section are energized between a conductor 73 leading from the input supply through one field windin section 38, a motor armature 87 and the tapped field Winding section 38 to the tap 59 when the tab 52 is contacted. The electrical circuit for energizing these comparatively large number of turns of the field windings includes the conductor 70 which is connected directly to one side of the input supply, the bus bar 48, the wiper arm 44, the contact tab 52, the contact 55, the conductor 58, the tap 59 on the field winding section 38, and the circuit mentioned above including the conductor 73 leading to the input power supply.

The contact end 74 of the wiper arm is of substantially V-shaped cross section, so that the sides of this portion of the wiper arm conform to the sides of the raised portions 71 and 72 on the bus bar. By this configuration the wiper arm 44 is firmly indexed in a contact position between the raised portions 71 and 72, with the apex of the V-shaped contact end in simultaneous contact with the tab 52 and the space on the bus bar between the raised portions 71 and 72. As the control arm 40 is moved further in a counterclockwise direction, as viewed in FIG. 13, to break the contact between wiper arm 44 and the tab 52, the wiper arm is lifted upon the raised portion 72 and electrical contact between the tab and the arm is sharply severed. The lifting action induced by the raised portion 72 prevents arcing between the wiper arm and the contact tab by elfecting a sharp make and break action.

When the wiper arm rests upon the raised portion 72, the electrical energizing circuit for the field winding of the motor is broken and the motor is de-energized. The de-energization of the motor as the control arm 40 is moved from one speed control position to another prevents the simultaneous application of energizing power to the motor from both the higher and lower speed taps of the windings of the field coil whereby overheating of the motor is prevented.

The switch 37 is moved to an intermediate position, such as might be used to enable the mixer to stir or mix, by movement of the control arm 40 until the wiper arm 44 is positioned between the raised portion 72 and a raised portion 75 formed on the bus bar closely adjacent to the ridge 72. When the V-shaped contact end 74 is positioned between the ridges 72 and 75 on the bus bar, electrical contact is established between the bus bar and the contact tab 53 so that the tap 61 on the field winding section 38 is energized. The electrical circuit energizing the intermediate field tap 61 comprises the input conductor 70, the bus bar 48, the wiper arm 44, the tab 53, the contact 56, the conductor 60, the tap 61, and the circuit through the remainderof the field windings 38 and the armature 87 to the common field conductor 73 which is connected directly to the input supply. The energization of an intermediate number of turns on the field windings 38 causes the motor 32 to rotate at intermediate speed.

To actuate the mixer at high speed of the order of 1030 rpm, the control arm 40 is rotated still further in a counterclockwise direction as viewed in FIG. 13 by application of finger pressure to the cap 42. Rotation of the control arm causes the wiper arm 44 to be raised up on the raised portion 75 to break the electrical contact between the wiper arm and the tab 53 in a manner similar to the breaking action between the wiper arm 44 and the tab 52 heretofore described. The wiper arm passes over the ridge 75 and into contact with the main body of the bus bar 48 to establish electrical contact between the bus bar and the contact tab 54. The tab 54 is electrically connected to the high speed tap 63 on the tapped field winding section 38, so that the motor rotates at high speed and the mixer may be used to perform such functions as beating or whipping. The high speed electrical circuit includes the conductor 70, the bus bar 48, wiper arm 44, contact tab 54, contact 57, conductor 62, the tap 63 on the field winding section 38 as well as the remainder of the circuit through the armature 87 and the other field winding section 38, and the common field conductor 73.

The apertures 49, 50 and 51 are circumferentially aligned in such manner that the center line of these apertures is a circle which is concentric with the segmental bus bar or curved strip 48. The centers of the apertures are, therefore, positioned at equal radial distances from the arcuate inner edge of the bus bar. The center of the circle along which the apertures are circumferentially aligned is offset a small distance from the center of the pivot pin 41 so that the wiper arm 44 is pivoted about a point which is slightly offset from the center of the circle aligning the apertures. Therefore, the contact tabs 52, 53 and 54 are positioned at slightly difieren't radial distances from the center of the pivot pin 41 and the spaces between the raised portions on the bus bar are likewise positioned at slightly different radial distances from this center point. The wiper arm, therefore, strikes the contact tabs at somewhat different points along the longitudinal extent of the apex of the V-shaped contact end 74. In this manner the life of the wiper arm is prolonged considerably since the wear on the arm is spread over a relatively large area by staggering its contact points.

As was indicated above, the switch 37 is positioned in a hollow cavity 34 defined in the mixer handle 35 by a horizontal resilient base plate 76 to which the switch is secured by any suitable means such as the screws 76a, so that the insulating plate 39 of the switch extends vertically upward from this base plate. This base plate, in accordance with the present invention, provides a simple means for securing the handle to the motor unit as will become apparent from the following description. A downwardly protruding extension 77 on the base plate supports the conductors 58, 60, 62 and 70, and prevents them from coming in contact with a cooling fan described hereinafter.

The assembly of the switch 37 in the handle 35 can be accomplished in a very simple manner. The leads 58, 60, 62 and are first connected to the proper contacts on the switch plate 39. The plate is then inserted into the hollow cavity 34 through the opening 34a in the bottom of the handle (see FIG. 8). The plate 39 is fitted into slots 34c, 34d, located in the front and rear walls respectively of cavity 34. Next the resilient base plate 76 is secured to the handle 35 by means of screws 76a bearing plate. 'is secured to the plate 85, as clearly shown in FIG. 9

thereby positioning the switch in the handle. The switch plate is firmly located in the cavity S t-inasmuch as its movement is restrained bythe slots 34c and 3411, the base plate 76 and the shoulders 140, 141 in the upper portion of the hollow cavity against'which'the "switch plate "39 abuts. When the indexing tab 42 is secured to operating arm 40, the switch isc'om'pletely assembled in thehandle.

In accordance with the present inventiomthe housing 78 is a cup-shaped one for receiving therein the motor 32. It preferably comprises a 'die'casting such as a magnesium die casting, but it might also comprise a housing molded from a suitable plastic. Coaxially disposed within the housing 78 and integral with the closed end thereof is a bearing support 79 extending into the motor chamber. The b'earingsupport 79 is illustrated as supporting a bearing 80 in order rotatably to journal one end of armature shaft 81 of the motor 32. Also formedintegral with the motor housing are a-pair of spaced longitudinal inwardly protruding ribs 82, each of which is provided with a threaded opening for threadedly receiving 'a field supporting stud 83. These ribs 82 are disposed adjacent the closed end of the housing 78 and extend parallel with the bearing support 79 and somewhat farther toward the open end of the housing 78 than the bearing support 79, as best shown in FIG. of the drawings. The studs 83 serve to support the stator of the motor 32, as will become apparent from the following description, and alsohold in position a closure plate 85 for enclosing the motor chamber defined by housing 78 and closure plate 85. The closure plate 85 has suitable openings for receiving the studs 83, and suitable nuts 83a secured to these stud clamp the closure plate 85 into interfitting relationship with the open end of housing 78,

suitable interfitting means as shown in FIG. 7 preferably being provided. Closure plate 85 also is a bearing plate and includes a centrally disposed bore for receiving a bearing 86 for the other end of the armature shaft 81 which extends from the motor housing through this A suitable bearing retaining member 86a of the drawings. The bearing plate 85 includes an enlarged lug 85a which defines a lubrication channel 85b (FIG. 9) which connects with an oil hole 850 (FIG. 4)

in the housing 78. At the end'of' the lug 85a is a bifurcated portion 850? which engages a lug 85e on the interior wall of housing 78 to properly position plate 85. The studs 83, which include an integral intermediate nut portion 83b, serve to'hold the motor stator assembly within housing 78, and likewise hold the end bearing plate 85, which interfits with the open end of the housing 78 in position.

Secured to the armature shaft 81 within'the motor housing 78 is an armatureassembly 87 which is rotatably positioned within the stator including the field windings 38. The field windings are mounted on pole pieces 88 which consist of a stacked plurality of laminations 89 shown in Fig. 17. As is apparent from FIG. 18, the field windings 38 are held in position encircling the pole pieces by coil retaining fingers 90 on the laminations 89. Aligned apertures 91 extending through the laminations receive the field studs 83 tothereby position the stator comprising the pole pieces and the field windings within the motor housing 78surrounding and concentric with the armature 87.

In order to properly position the stator assembly of the motor 32 within housing 78 during the assembly operation, the housing 78 is provided with internal longitudinally extending ribs 78a and 78b. The ribs 781: are extensions ofthe longitudinal ribs 82 and the ribs 78b, of which there are four (FIG. 12) equally' spaced from 'one another, only'two of which are' visible in FIG. 20,'areinterposed between the ribs 78a. The ribs 78b =are1providedwith a -tapered portioninterconnecting; two newts thereof to 'guide the stator assem'bly inte position when inserted in housing 78. 'As best shownin FIG. .20. the ribs 78b define a diameter corresponding to the stator diameter which may be pressed .into position and then secured by the studs 83.

To complete the motor constmctiongthere 'is secured to the armature shaft '81 a "conventional commutator 92, brushes 98 for which are mounted ion a brush plate 93 positioned adjacent to the commutator and secured within the motor housing 78. The brush plate 93 is actually secured against shoulders defined by the ends of'the ribs 78a and 78b, and is provided with openings 93a for receiving studs 83. Suitable nut means may be provided on studs 83 to hold the brush plate 93 against said shoulders. The brush plate 93 is provided with a plurality of spaced peripheral slots 94a and 94b-in order to permit the conductors interconnecting the switch 37 and the field windings 38 to pass therethrough. .The .slot 94a is sufficiently wide to accommodate the four conductors 58, 68, 62 and leading from the switch 33, including the sheath 64, while the slots 94b accommodate suitable brush leads 98a and 98b (FIG. 19). A pair of diametrically opposed, brush retaining channel members 95 are secured to the brush plate by interconnecting the plate and laterally extending side portions 96 on the channel. whereby the brushes 98 are held in position in the channel and are pressed into contact with the commutator 92 by compression springs 97 positioned between the outer end of the brushes 93 and the inner face of the end of channel 95. In this manner continuous contact is assured between the commutator 92 and the brushes 98, and arcing between the commutator brushes is reduced to a minimum.

To permit the flow of cooling air through the motor chamber,'the brush plate 93 is provided with an enlarged central opening 93]) (FIGS. 7 and 10) through which the commutator extends, which opening is large enough to leave sutficient space for air flow even with the commutator in place. This air flow can occur through an opening or cut away portion 85; in end plate 85 through which the switch leads 58, 60, 62 and 70 also pass. A rotating fan 99, best shown in FIGS. 7 and 11 and having a plurality of fan blades 100 formed thereon, is mounted on the armature shaft 81 so that rotation ofthe fan directs a cooling supply of air longitudinally of the motor housing. Because the armature 87 is positioned behind the brush plate 93 and since it cannot 'beremoved without first removing the brush plate and'the fan 99, a novel method of detachably mounting the fan on the armature shaft 81 is employed. Formed integrally with the fan as by a stamping operation are a series of toothed jaws 100a which engage with an enlarged hub section 142 of armature. shaft 81 to hold the fan in place. To remove the fan it is necessary only to pull forward on the toothed jaws thus lessening their tension on the hub section land the fan can then be easily pulled off the armature shaft in order that the brush plate 93 can be 'air is discharged near the topof the mixer the possibility of contaminating the mix with foreign particles from the motor is considerably decreased.

For the purpose of providing a heater supporting and driving means, the mixer of the present invention includes a housing portion 102 adapted to be secured in coaxial alignment with the housing 78. The housing portion 102'is again a cup-shaped portion of relatively shallow depth as contrasted with the housing section 78 and includes a pair of wall sections l03-and HM-arranged l-in spaced parallelrelationship 'and "extending horizontallyjacrossthe housing section 102 as viewed in FIGS; 6 and 8 of the drawings. The wall sections 103 and 104 define therebetween a gear chamber 113, which chamber is completed by a portion of the end plate 85, a suitable gasket 105 being interposed, as clearly shown in FIG. 6 of the drawings, between the ends of the wall sections 103 and 104 and the end plate 85. In order to obtain a gear chamber in which leakage of lubricant is held to a minimum, bearing plate 85 is provided on its front face with a raised bead 153. When gear housing 102 is secured to bearing plate 85 by means of studs 106, extending into threaded embossments 107, then gasket 105 is compressed between the front face of plate 85 and the rear portions of wall members 103, 104. The head 153 bites into the resilient gasket 105 thereby forming a tight lubricant seal. It will be understood that the end plate 85 is secured as already described to the motor housing 78.

To support suitable beater driving means, there are provided in housing 102 a pair of beater bearings 110 which extend through bearing supports 111 defined in the lower portion of the housing section 102, as viewed in FIGS. 6 and 8 of the drawings, and through corresponding bearing supports 112 supported within the gear chamber 113 defined by the partitions 103 and 104. Rotatably journalled within the bearings 110 are beater driving shafts 116, one of which is clearly shown in FIG. 8 of the drawings. Secured to the upper end of each of the beater driving shafts 116 is a suitable Worm gear 117, preferably formed of nylon or the like and secured to the shafts 116 by set screws such as 118 or other suitable means. The worm gears 117 are adapted to receive therebetween a suitable worm 119 effectively comprising an integral extension of the motor shaft 81, whereby rotation of the motor shaft 81 causes similar rotation at reduced speed of the beater driving shafts 116. The lower ends of the beater driving shafts are recessed as indicated at 120 to receive therein the shanks 121 of suitable beater elements 122. The recess 120 is preferably provided with a plurality of diametrically opposed slots 123 (four being provided in one commercial embodiment) to receive extensions 124 defined on the beater shank 121 to permit positive driving connection between the beater drive shaft 116 and the beater shank 121. Suitable spring retaining means 125, supported in a suitable groove 126 defined in the beater shank, are adapted to engage a cooperating groove 127 in the wall of the recess 120 to prevent the extensions 124 of the beater shank from dropping out of driving engagement with the slots 123 in the beater drive shaft 116. In order to provide simple and eflicient means for removing the heaters from the spindles a beater ejector mechanism of the type disclosed in my Patent 2,098,098, dated November 2, 1937, is employed. A suitable enlarged washer 128 is positioned on the beater spindle 121 above an enlarged annular collar 129. To remove the beater the washer 128 is tilted so that one face of the washer contacts the lower end of the spindle sleeve 130 and the opposed face of the washer contacts the collar 129 whereupon continued tilting of the washer causes the beater 121 to move in a direction to force the spring ring 125 out of the annular groove 127. At this point the beater will slide freely out of the spindle 116. The sleeve 130 retains a felt washer 130a and is positioned to prevent any lubricant from the gear chamber 113 from reaching the ingredients with which the mixer is being used.

It will be understood that the gear chamber 113 will be filled with suitable lubricant upon assembly of the beater to insure adequate lubrication of the worm 119 and worm gears 117, as well as the beater drive shafts 116.

When the housing sections 102 and 78 are assembled in the manner shown in FIG. 6 of the drawings, there is defined a rectangular flanged opening for receiving the handle35. The major portion of this rectangular open- 1f) ing is formed by an upstanding flange 102a of gear housing 102. Flange 102a extends across the front and along both sides of housing 102 but is open towards the rear. A mating flange portion 78a is formed on motor housing 78 and is open toward the front but closed on both sides and across the back.

The handle 35 is secured to the gear housing 102 and the motor housing 78 in the following manner. The lowermost portion of the handle has an area of reduced cross-section to define a flange or shoulder 131 having a dimension corresponding with the outside edge of the flanged opening defined by flange 102a and 78a so that the shoulder 131 overlies the flanged members 1020 and 78a as clearly shown in FIGS. 8 and 22 of the drawings. When the resilient base plate 76 is secured to the handle 35 in the manner previously set forth, the shoulder 131 and the protruding portion 144 of the plate 76 define a channel 154 (see FIG. 15) into which the flanged sections 102a and 78a can be inserted, as shown in FIGS. 8 and 22 of the drawings.

In the present invention novel means are employed to retain the handle in its assembled position with the gear and motor housings without the use of any additional fastening means such as screws or the like. Referring to FIG. 6, gear housing 102 is provided at the front with tapered shoulder 145 located directly beneath the front portion of flange 102a. A small projection 146 formed on flange 102a fits into an opening 147 in the handle 35. Base plate 76 has a forwardly extending portion 148 which terminates in a point 149 bent down at a slight angle from the horizontal. When the flange 102a is completely inserted into the channel 154 formed between shoulder 131 and the extending portion 144 of plate 76, the part of forwardly extending portion 148 adjacent pointed segment 149 is forced downward by contact with the tapered shoulder 145 and this wedging action operates to hold the handle 35 in an assembled relationship with gear housing 102. As best seen in FIG. 22 the protruding extensions 144 of resilient base plate 76 are also sprung downwardly by engagement with the lower face 150 of flange 102a. When the handle is firmly seated on the gear housing 102, the projection 146 is received in the opening 147 in handle 35 to additionally secure the handle and gear housing together.

Similar means are provided to secure handle 35 to motor housing 78. Toward the rear of plate 76 there are formed on either side of extension 77 two extending leg portions 151. These extending legs 151 engage with tapered shoulders 152, as best seen in FIG. 21, to secure handle 35 to motor housing 78 when flange 78a is received into the channel defined by shoulder 131 and plate extension 144. Therefore, the wedging action of tapered shoulders 145 and 152 on the respective portions 149, 151 of resilient plate 76 effectively secures the handle to the housings.

It will be understood that the mixer 30 of the present invention must be capable of being supported even when the heaters 122 are covered with material that has been agitated or mixed thereby, and such support should be accomplished Without the beaters 122 coming in contact with the surface supporting the mixer. To this end the outer surface of the motor housing 78 is provided with a pair of enlargements 133 extending slightly above the surface of the housing on opposite sides thereof, and gradually tapering from the front to the back of the housing. Moreover, these enlargements terminate in a pair of diametrically opposed horizontally arranged fins 134 protruding from the rear of the housing to define a pair of legs which with the end of the handle 35 form a threelegged support for the mixer in a manner readily understood by those skilled in the art. Actually, the end of the handle is provided with a tapered portion 35a which is in a horizontal position when the heater is disposed on its three-legged support, including as one of the three legs the handle 35.

assrgeee In view of the detailed description included above, the operation of the mixerofv-the present invention will be readily understoodby thoseskilled in the art. 'In assembling the mixer, the motor :stator with associated field windings is electrically connected with the switch 37, and this subassembly is inserted into the die cast housing 78. The ribs 78a and 78b guide this stator into its proper position, and a suitable pressing operation will move the stator into position, whereupon the studs 83 may be employed to clamp the stator into the position shown in FIG. 7 of the drawings. The armature 87 can then be inserted, with one end of the shaft 81 supported in the bearing 80. Thereafter, the brush plate 93 is inserted into the motor housing 78 and fastened into position by the fastening means 83a engageable with the studs 83. At this stage the end plate 85 may be put in position and suitably secured by the nuts 83a threaded to the studs 83, thus providing complete support for the armature .87 with the worm 119 extending forwardly of the end plate 85. The switch 33 can then be positioned in' the switch chamber 34 in the handle 35, and the resilient plate 76 secured into position.

The handle 35 can then be secured to the motor housing 78 by wedging plate extensions 151 over the tapered shoulders 152. Gear housing 102 is attached to handle 35 by inserting flange 192a into the channel defined by shoulder 131 and plate extension 144. The mixer assembly is completed by securing housing 102 to the bearing plate 85 by the studs 106.

It will be apparent that with the present invention there is provided a very compact and simple mechanism which is very foolproof in operation and which can be manufactured and assembled at a minimum cost. There is also provided a speed control arrangement which will give a Wide range of speeds to perform the different mixing operations.

While there has been illustrated and described what is at present believed to be the preferred embodiment of the present invention, it will readily be understood by those skilled in the art that numerous changes and modifications can be made without departing from the present invention. t is aimed 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. In an electric mixer, an elongated handle, means at one end of said handle for securing the same to said mixer, a cavity in said handle including a narrow groove in said cavity extending along one side of said cavity, means defining an opening in said handle at said one end communicating with said cavity, and an electrical switching device comprising a switch assembly insertable into said cavity through said opening in said handle said switch assembly including a flat plate one edge of which is insertable in said groove, said opening being at the lowermost portion of said handle when said mixer is used during a mixing operation.

2. In an electric mixer, an elongated handle, a hollow portion in said handle, a bottom opening in said handle communicating with said hollow portion, slots formed in the inner walls of said hollow portion, electrical switching means comprising a switch assembly mounted on a plate, said plate being inserted into said slots through said bottom opening in said handle, and a base plate for re taining said first mentioned plate in said hollow handle portion.

3. For use in an electrical household mixing device of the type comprising a housing with an electric motor contained therein together with heaters driven by said motor mounted in said housing and extending therefrom, the combination of an elongated handle having one end only secured to said housing, a cavity in said handle, a bottom opening in said handle communicating with said cavity, and motor "control means comprising a switch assembly Cal i2 insertable into said cavity through said bottom opening in said handle.

4. For use in an electrical household mixing device of the type comprisinga hollow casing open at one end with an electric motor. contained within said casing to-. gether with a cup-shaped housing abutting with said casing and heaters mounted in said housing and extending therefrom, the combination of an elongated handle secured to said casing and said housing, a cavity in said handle, a bottom opening in said handle communicating with said cavity, motor control means comprising a switch assem bly insertable into said cavity through said bottom opening in said handle, a resilient plate secured to the bottom of said handle for retaining said control means in the cavity thereof and means located on said casing and said housing for engagement with said resilient plate for securing said handle to said casing and said housing.

5. For use in an electric mixing device of the type comprising a hollow casing having a closed end portion with a power unit contained within said casing and acup-like member abutting with the open end of said casing to form an enclosed housing together with beaters mounted in said cup-like member and extending therefrom perpendicular to the longitudinal axis of said housing, the combination-of a handle having a cavity defined therein, electrical control means for said power unit positioned in said cavity, means electrically interconnecting saidcontrol means and said power unit, a resilient plate secured to the bottom of said handle, and means located on said housing for engagement with said resilient plate for securing said handle to said housing.

6. The combination as set forth in claim 5 in which the resilient plate is provided with an extension which projects into the casing for supporting theelectrical interconneoting means.

7. For use in an electric mixing device of the type comprising a hollow easing having a closed end portion with a power unit contained within said casing together with a cup-like housing abutting with the open end of said casing to form an enclosed unit and heaters mounted in said housing and extending therefrom perpendicular to the longitudinal axis of said casing, the combination of a handle having a cavity therein, electrical control means for said power unit positioned in said handle, means elec trically interconnecting said control means and said power unit, a resilient plate secured to the bottom of said handle, and means located on said casing and said housing for engagement with said resilient plate for securing said handle to said casing and saidhousing.

8. For use in an electric mixing device of the type comprising a hollow casing having a closed end portion with a power unit contained within said casing together with a cup-like housing abutting with the open end of said casing to form an enclosed unit and heaters mounted in said housing and extending therefrom perpendicular to the longitudinal axis of said casing, the combination of a handle having a cavity therein, electrical control means for said power unit positioned in said cavity, electrical interconnecting means between said control means and said power unit, a resilient plate secured-to the bottom of said handle for retaining the control means in the hollow thereof and means located on said casing and said housing for engagement with said resilient plate for securing said handle to said casing and said housing.

9. In an electric mixer, a hollow casing having a closed end and an open end, a cup-shaped housing abutting with said open end to define a chamber within said casing and said housing, an electric motor contained within thecasing portion of said chamber, an opening in'the-topportion of said chamber partly in said casing and partly in said housing, a handle, a resilient plate secured to the bottom of said handle, and means on 'saidho'usingand said casing for engagementwit'h said plate to secure said handleto-said housing and said casing'so thatsaid handle covers said opening in the top portion of said chamber.

10. In an electric mixer, a motor housing, a hollow handle having one end connected to said housing, an electrical switching device comprising a plate supported in said hollow handle, a plurality of electrical contact members on said plate, a bus bar positioned on said plate adjacent to said contact members, a wiper arm pivotally mounted on said plate in continuous contact with said bus bar and adapted to successively contact each of said contact members as the arm is moved across the bus bar, and a plurality of raised portions on said bus bar over which the wiper passes whereby the wiper arm is maintained out of contact with the contact members as the arm passes over the raised portions and is indexed in a position in contact with said contact members in the spaces between said raised portions.

ll. In an electric household food mixing device, a tapped field electrical motor, an electrical circuit for controlling the speed of said motor, an electrical switch mounted in the handle of said mixing device, a plurality of contacts on said switch, conducting leads interconnecting each of the contacts with a tap on the field windings of said motor, a contact arm on said switch operable to successively engage said contacts to change the speed of the motor, a pivotal operating arm for moving said contact arm into engagement with said contacts, a portion of said operating arm extending through the handle of said mixer so as to be operated by finger pressure on the extendingportion, a ridged common contact bar on said switch electrically connected in circuit with said motor, said contact arm continuously contacting the bar whereby the contact arm is maintained out of contact with said contacts as the arm passes over the ridges on the bar and is indexed in contact with said contacts as the control arm is positioned between the ridges.

12. An electric household mixing device as set forth in claim ll in which the pivotal operating arm is insulatedly connected to the contact arm.

13. In a portable food mixing device including a variable speed motor, an electrical circuit for controlling the speed of said motor comprising a switch, and means electrically interconnecting said switch and said motor, said switch including an insulating base positioned in the handle of the mixer, a plurality of electrical contact members on said base, a bus bar on said base adjacent to said contact members, a wiper arm pivotally mounted on said base in continuous contact with said bus bar, a control arm secured to said wiper arm and a portion of which extends through the handle of the mixer, an operating tab secured to said control arm and positioned in a cavity in the handle of the mixer so that finger pressure on the tab moves the wiper arm across the bus bar and into successive contact with the contact members to alter the speed of the motor, said bus bar being provided with raised portions over which the wiper arm passes whereby the wiper arm is maintained out of contact with said contact members as it moves over the raised portions and is indexed in a position in contact with one of said contact members in the spaces between said raised portions.

14. In a portable household mixer comprising a handle, an electrical switch, comprising an insulating plate supported in said handle and having a plurality of spaced apertures therein, a plurality of electrical contacts secured to one side of said plate in spaced relationship thereon, each of said contacts having a contact tab extending through one of said apertures, a bus bar secured to the opposite side of the insulating plate from the contact members and positioned closely adjacent the contact tabs, a wiper arm pivotally mounted about a pivot point on said plate and stressed toward the plate so that the wiper arm is in continuous contact with the bus bar, a switch arm positioned in the handle of the mixing device and connected to said wiper arm so that movement of the switch arm moves the wiper arm along the bus bar, a plurality of raised portions on said bus bar in the path of movement of the wiper arm whereby the wiper arm is maintained 14 away from the plate and out of contact with said tabs when the arm passes over said raised portions and is moved toward the plate and into contact with the tabs when the wiper arm is positioned in the spaces between said raised portions.

15. In an electric portable food mixing device having an electric motor including a handle for said mixing device, an electrical switch, comprising an insulating plate supported within said handle and having a plurality of spaced circumferentially aligned apertures therein, a plurality of electrical contacts secured to one side of the plate in spaced relationship thereon, each of said contacts having a contact tab extending through one of the apertures, a segmental bus bar secured to the opposite side of the insulating plate from the contact members and positioned adjacent the contact tabs so that the arc of the bar is concentric with the circle along which the apertures are circumferentially aligned, a wiper arm pivotally mounted about a pivot point on said plate and in continuous contact with the bus bar, a switch arm positioned in the handle of said mixing device and connected to said wiper arm so that movement of the switch arm moves the wiper arm along the bus bar, a plurality of raised portions on said bus bar in the path of movement of the wiper arm whereby the wiper arm is maintained away from the plate and out of contact with said tabs when the arm passes over said raised portions and is moved towards the plate and into contact with the tabs when the wiper arm passes into the spaces between said raised portions, the pivot point of said wiper arm being offset from the center of the circle along which said apertures are circumferentially aligned.

16. In a food mixer comprising a motor and a handle, an electrical switch, comprising an insulating plate supported in said handle and having a plurality of spaced apertures therein, a plurality of electrical contacts secured to one side of said plate in spaced relationship thereon, each of said contacts having a contact tab extending through one of said apertures, a bus bar secured to the opposite side of the insulating plate from the contact members and positioned adjacent the contact tabs, a wiper arm pivotally mounted about a pivot point on said plate and stressed toward the plate so that the wiper arm is in continuous contact with the bus bar, a switch arm positioned in the handle of said mixing device and connected to said wiper arm so that movement of the switch arm moves the wiper along the bus bar, a plurality of raised portions on said bus bar in the path of movement in the wiper arm whereby the wiper arm is maintained out of contact with said tabs when the arm passes over the raised portions and is moved into contact with the tabs when the wiper arm passes into the spaces between the raised portions, said wiper arm being of substantially V-shaped cross section to enable the sides of the raised portions to index the wiper arm in a contact position.

17. In an electric food mixer including an electric motor and a handle, an electrical switch for controlling said motor comprising an insulating plate supported in said handle and having a plurality of spaced circumferentially aligned apertures therein, a plurality of electrical contacts secured to one side of said plate in spaced relationship thereon, each of said contacts being provided with a contact tab extending through one of said apertures, a segmental bus bar secured to the opposite side of the insulating plate from the contact members and positioned ad jacent the contact tabs, a wiper arm of spring metal pivotally mounted about a pivot point on said plate and stressed toward the plate so that the wiper is in continuous contact with the bus bar, a switch arm positioned in the handle of said mixing device and connected to said wiper arm so that movement of the switch arm moves the wiper arm along the bus bar, a plurality of raised portions on said bus bar in the path of movement of the Wiper arm whereby the wiper arm is maintained out of contact with the tabs when the arm is passing over aeezeae said raised portions and is moved into contact with the tabs when the wiper arm passes into the spaces between the raised portions, said wiper arm being of substantially V-shaped cross section to enable the sides of the raised portions to index the wiper arm in a contact position, and each of said tabs being positioned at a different radial distance from the pivot point of the wiper arm so as to increase the life of the wiper arm.

18. In a. portable electric mixing device, a hollow casing, a power unit contained within said casing, a plurality of spaced inwardly extending ribs formed along the inner surface of said casing, a closure plate positioned at one end of the casing, a plurality of supporting studs securing said closure plate to at least two of said ribs, a retaining member on said studs for holding the stator of said power unit in position on the studs between said two ribs and the retaining members, a plurality of said ribs being somewhat longer than said two ribs and being tapered to guide the stator within the casing as it is assembled on the studs.

19. In a portable electric mixing device, the combination of a hollow casing having a closed end portion, a motor unit including a stator, arotor and a driving shaft positioned in said casing, 21 first plurality of inwardly ex tending longitudinal ribs formed on the casing, a second plurality of internally extending longitudinal ribs on the casing of somewhat greater length than the first plurality of ribs, a closure plate for enclosing the open end of said casing, a plurality of studs interconnecting the closure plate and the first plurality of ribs and extending longitudinally within the casing, each of said studs including a retaining member which abuts with the stator of said motor to hold the stator on the studs between the retaining members and the first plurality of ribs in a p'ositionsurrounding the rotor, said second plurality ofribs havinga. tapered portion for guiding the statorinto position on said studs when the mixing device is assembled, a commutator assembly mounted on said driving shaft, .a positioning lug on each of said studs, a brush plate held in position between the positioning lugs and theend ofsaid second plurality of ribs adjacent the commutator, anda plurality of brushes mounted on said brush plate in contact with the commutator.

20. For use in an electric food mixer of the type comprising an electric motor and beater means drivingly connected thereto by means of a rotatable drive shaft, the combination of air cooling meansfor said motor including a fan, means for driving said fan from said driveshaft including means forremovably securing said fan to said shaft by means of opposed toothed jaws formed integrally with said fan.

21. In an electric mixing device, an elongated casing having means defining a vent in one end, an electric motor located within said casing including a driving shaft, an opening at the top of said casing remote from the end containing said vent, a handle having a cavity defined therein and a bottom opening communicating with said cavity, said bottom opening overlying the opening in said casing, a switch in said cavity, an exhaust slot in said handle communicating with said cavity, means for securing said handle to said casing, and a cooling fan mounted on said shaft to direct the flow of cooling air over said motor from said vent to the exhaust slot in said handle.

22. In an electric mixer, a hollow motor casing having a closed and an open end portion,.an electric motor located within said casing, a cup-shaped gear housing abutting the open end of said casing, said housing havinga gear chamber defined by parallel wall sections extending inwardly from the front of said housing, a plate for closing the open end of said casing positioned between said oasing and said housing, means for securing said plate to said casing, a raised bead on said plate adjacent said housing, a gasket disposed between said bead and said wall sections of said gear chamber and means for securing said housing to said plate.

23. In an electric mixer, an elongated handle, a hollow portion in said handle, a bottom opening in said handle communicating with said hollow portion, a slot formed in at least one wall of said hollow portion, electrical switching means comprising a switch assembly mounted on a plate, said plate being inserted into said slot through said bottom opening in said handle, and a base plate for retaining said plate in said hollow handle portion.

24. In an electric power unit a housing, an electric motor in said housing, gear means driven by said motor, a gear chamber for said gear means disposed within said housing, a handle having one end thereof secured to said housing at a position overlying said gear chamber, means defining a hollow portion in said handle, a bottom opening in said handle interconnecting said hollow portion with the interior of said housing above said gear chamber, electrical switching means comprising a switch assembly mounted on a plate, said plate being insertable into said hollow portion through said bottom opening in said handle, and means for supporting said plate in said hollow portion.

25. A mixing device comprising, an electric motor adapted to drive a mixing element, a housing for said motor, a handle having a portion extending along the longitudinal axis of said housing, the said handle including an integral post portion secured to said housing, a recessed portion in said post portion of said handle, means defining a groove in one of the walls of said recessed portion, switch means for said motor, the said switch means including a plate, one edge portion of said plate being disposed in said groove thereby to position said switch means in said recessed portion, the said recessed portion having top and bottom openings, switch actuating means extending through said top opening and accessible upwardly of said handle post portion, and electric current conductors for said switch means extending through said bottom opening into said housing for connection to said motor, said switch means being insertable into said recessed portion only through said bottom opening.

26. A mixing device comprising, an electric motor adapted to drive a mixing element, a normally substantially horizontally disposed housing for said motor, a handle extending laterally above said housing, the said handle including an integral and substantially upright forepost secured to said housing, a recessed portionin said forepost defined by upright walls, upright grooves and shoulders in opposed walls of said recess, switch means for said motor, the said switch means including a plate, edge portions of said plate being supported in said grooves and against said shoulders whereby to mount said switch means in said recessed portion, thesaid recessed portion having top and bottom openings, switch actuating means extending through said top opening and accessible upwardly of said handle forepost, and electric current conductors for said switch means extending through said bottom opening into said housing for connection to said motor, said switch means being insertable into said recessed portion only through said bottom opening.

27. An electric motor device for hand tools which comprises, an electric motor adapted to actuate a tool element, a housing for said motor, a handle secured to said housing, said handle providing a finger grip body portion and a thumb rest at one end thereof, a recessed portion in said handle at the thumb rest end thereof, a groove in at least one wall defining said recessed portion, thumb controlled switch means for said motor including a switch plate, one edge of said plate being supported in said groove whereby to mount said switch means in said recessed portion, and means remote from said thumb rest for holding said plate in said recessed portion.

.28. Anelectric motor device for hand tools which comprises, an electric motor adapted to actuate a tool element, a housing for said motor, a handle secured to said housing, said handle providing a finger grip body portion and athumb rest at oneendthereof, a recessed portion in said handle at the thumb rest end thereof, a shoulder provided by the walls defining said recessed portion, thumb controlled switch means for said motor including a switch plate, an edge of said plate being supported in said recessed portion against said shoulder whereby to at least partially suppont said switch means in said recessed portion, and additional means remote from said thumb rest for further supporting said switch means in said recessed portion.

29. The device of claim 28 wherein said hand tool is a mixing device and said tool element is a mixing element.

30. In an electric mixer, a hollow motor casing having a closed end portion and an open end portion, an electric motor located within said casing, a cup-shaped gear housing abutting the open end of said casing, said housing having a gear chamber defined by parallel wall sections extending inwardly from the front of said housing, bearing supporting means disposed at the open end of said casing, means for securing said bearing supporting means to said casing, sealing means disposed between said bearing supporting means and said wall sections )f said gear chamber, and means for securing said housing to said bearing supporting means.

31. In an electric mixer, a hollow motor casing having a closed end portion and an open end portion, an electric motor located within said casing, a cup-shaped gear housing abutting the open end of said casing, said housing having a gear chamber defined by parallel wall sections extending inwardly from the front of said housing, a plate for closing the open end of said casing positioned between said casing and said housing, means for securing said plate to said casing, switch means located outside of said casing, said plate having an opening permitting communication between said casing and the portion of said housing above said gear chamber, electrical current conductors extending from said switch through said plate opening into said casing to connect said switch to said motor, and sealing means cooperating with said wall sections of said gear chamber.

32. The electric mixer of claim 31 wherein said cupshaped gear housing is provided with an opening in the sidewall adjacent the opening in said plate, a handle for said mixer extending laterally above said casing, said handle including a substantially upright forepost abutting said housing, a recessed portion in said forepost having an opening in communication with said sidewall opening in said housing, and said switch means disposed at least partially in said recess.

33. In an electric mixing device, a hollow tubular casing having a closed end portion and an open end portion, a power unit contained within said casing, a plurality of radially spaced longitudinally extending ribs formed along the inner surface of said casing, a plurality of supporting studs secured to said casing and extending parallel to the axis of said casing, a stator mounted in said casing with said studs extending through holes formed in said stator, retaining means on said studs for holding said stator against said housing to prevent longitudinal displacement of said stator, said ribs engaging the periphery of said stator and locating said stator with respect to said tubular casing, a closure plate secured to said open end portion by means of said studs which extend through holes provided in said closure plate, assembly means on the ends of said studs engaging said closure plate to prevent displacement thereof from said open end portion, an armature assembly mounted for rotation in said casing on longitudinally spaced bearings, one of said armature bearings being mounted in said closed end portion, and the other armature bearing being mounted on said closure plate, said armature assembly including a commutator located between said closure plate bearing and said stator, a brush plate positioned between said closure plate and said stator with said studs extending through holes in said brush plate, assembly means on said studs engaging said brush plate and retaining said brush plate against said tubular casing, and a plurality of brushes mounted on said brush plate in contact with said commutator.

34. In an electric mixer, a hollow tubular motor casing having an open end portion and a bearing supporting end portion, an electric motor located within said casing, said motor including an armature assembly mounted for rotation within said casing, said bearing supporting portion having an armature bearing mounted thereon, a cupshaped gear housing abutting the open end of said casing, said housing having a gear chamber defined by parallel wall sections extending inwardly from the front of said housing, a plate for mounting a second armature bearing in said open end portion, said plate serving as a closure for said gear chamber, means for securing said plate to said casing, a gasket disposed between said plate and said wall sections of said gear chamber, and means for securing said housing to said plate.

35. A motor construction, comprising: a generally cupshaped hollow casing section including side walls; a pair of spaced apart first and second bafiies with the first bafie being adjacent to but spaced from one of said side walls to define a first chamber between said one wall and first baffie and a second chamber between said bafiles, at least said first bafile being substantially lubricant impervious; a switch mechanism in said first chamber; gearing in said second chamber; and a substantially lubricant impervious plate member extending between the inner edges of said baflles forming an inner side wall on said second chamber and containing an opening for a gear-engaging driving gear, the second chamber being adapted to contain a lubricant for said gearing.

36. A mixer motor construction, comprising: a generally cup-shaped hollow casing section including integral side walls; a pair of spaced apart first and second integral bafiles with the first baffie being adjacent to but spaced from one of said side walls to define a first chamber between said one wall and first bafile and a second chamber between said baffles, at least said first bafile being substantially lubricant impervious; a switch mechanism in said first chamber; gearing in said second chamber; a substantially lubricant impervious plate member extending between the inner edges of said bafiles forming an inner side wall on said second chamber and containing an opening for a gear-engaging driving gear, the second chamber being adapted to contain a lubricant for said gearing; and walls in said casing section integral therewith forming a passageway communicating with said second chamber and with the exterior of the casing section through a side wall thereof for rotatably receiving a beater shaft for operative engagement with said gearing.

References Cited in the file of this patent UNITED STATES PATENTS 493,361 Immisch Mar. 14, 1893 1,411,538 Sweetland Apr. 4, 1922 1,626,463 Harrington Apr. 26, 1927 1,754,222 Connell Apr. 15, 1930 1,810,469 Dremel June 16, 1931 1,850,191 Wilcox Mar. 22, 1932 1,871,274 Nielsen Aug. 9, 1932 2,103,922 Van Guilder Dec. 28, 1937 2,179,745 Kochner Nov. 14, 1939 2,192,845 Bean Mar. 5, 1940 2,309,583 Franz Jan. 26, 1943 2,336,721 Dermond Dec. 14, 1943 2,348,341 Gough May 9, 1944 2,381,077 Obszarny Aug. 7, 1946 2,554,506 Schwarz May 29, 1951 2,615,942 Edman Oct. 28, 1952 2,637,824 Kessel May 5, 1953 FOREIGN PATENTS 605,675 Great Britain Jan. 3, 1946 312,494 Germany May 27, 1919

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Classifications
U.S. Classification310/50, 366/129, 366/301, 200/293.1, 200/11.00R, 366/601
International ClassificationA47J43/08, H02K7/14
Cooperative ClassificationA47J43/082, Y10S366/601, H02K7/145
European ClassificationH02K7/14B, A47J43/08B