A Beater

Field of the invention

The present invention relates to a beater, and in particular to a beater for use with a food mixer.

Background of the invention

Food mixers are often used in domestic and commercial kitchens to mix ingredients.

One common type of food mixer includes a pivotable arm which carries a motor and two beaters. Each beater commonly includes a number of metallic mixing blades attached to a shaft. When in use the motor rotates each of the beaters (often in different directions) in order to mix the desired ingredients. The arm may be pivoted between a use position in which the beaters are located in a mixing bowl containing the ingredients to be mixed, and a clearance position in which the beaters are lifted clear of the bowl. Often the beaters are removable from the arm to allow for easy cleaning and storage.

One problem that exists with such electric mixers is that mixing blades of the beaters can scratch or otherwise mark the mixing bowl where they come into contact with the mixing bowl.

One way of preventing such marking is to provide a button or similar of a softer but hard wearing material (such as nylon) at the end of the beater. The button extends beyond the shaft and mixing blades of the beater thereby preventing the mixing blades (and shaft) from coming into contact with the bowl.

In some electric mixers the rotation of the beaters is used to cause the mixing bowl to rotate. In such electric mixers the above mentioned button can also serve the purpose of contacting the inner surface of the mixing bowl to cause this rotation.

While use of such buttons does aid in preventing the mixing blades and shaft of the beaters from contacting and marking the mixing bowl, they also introduce a further

problem in that the button prevents the mixing blades of the beaters from mixing ingredients at the very bottom of the mixing bowl. If a recipe calls for minimal amount of ingredients to be mixed (such as, for example, one or two egg whites) it is often the case that ingredients can pool in the bowl with the beaters either insufficiently immersed in the ingredients to enable mixing, or even ineffectually operating in the air above the ingredients. The problem, of course, being that the button which stops the mixing blades of the beater from contacting the mixing bowl also distances the mixing blades of the beater from the bottom of the mixing bowl where the ingredients lie.

To attempt to overcome this problem use of various scraper type elements attached to beaters has been proposed. One such example of this proposed solution can be found in published US application US 2007/0064523. In that document a four-blade beater is provided with paddle elements mounted to the lowest portion of each of the four mixing blades (i.e. the portion of the blades which, in use, are closest to the bottom of the mixing bowl). The paddle elements attempt to solve the above problem by providing a non-metal contact with the bowl, which allow ingredients at the very bottom of the mixing bowl to be mixed.

Unfortunately, solutions such as this may introduce yet further problems. One such problem is the additional design and manufacturing complexity associated with securely mounting several paddle elements or scrapers onto the beaters.

Another problem is the health hazard associated with the potential of the paddle elements becoming dislodged during use. If dislodgement of the paddle elements is not noticed (or the elements cannot be found in the ingredients being mixed) they present a choking and/or ingestion hazard. Additional friction is also introduced by the contact of the scrapers or paddles with the mixing bowl.

It will be understood that any reference herein to prior art does not constitute an admission as to the common general knowledge of a person skilled in the art.

Summary of the invention

In one aspect the invention provides a beater for use with a mixing apparatus, the beater including: a shaft defining a central axis of rotation and including an upper end adapted to engage with the mixing apparatus and a lower end; a mixing blade arrangement extending from the shaft, the mixing blade arrangement having an operatively lowermost recess in the region of the central axis; a spacer mounted within the recess, the spacer configured to prevent contact between the mixing bowl and the mixing blade arrangement, the spacer having a thickness which is marginally greater than the depth of the recess to define a marginal mixing clearance between the mixing blade arrangement and the mixing bowl.

In a second aspect, the present invention provides a beater for use with a mixing apparatus, the beater including: a shaft defining a central axis of rotation and including an upper end adapted to engage with the mixing apparatus and a lower end; a mixing blade arrangement extending from the shaft, the mixing blade arrangement defining a volume of rotation about the central axis; a spacer mounted along the central axis at an operatively lowermost end of the mixing blade arrangement, the spacer being configured to prevent contact between the mixing bowl and the mixing blade arrangement, the spacer defining a marginal mixing clearance between the mixing blade arrangement and the mixing bowl, said marginal mixing clearance being sufficient to enable functional mixing of residual contents of the mixing bowl without the mixing blade arrangement contacting the mixing bowl.

The marginal mixing clearance may be sufficient to enable functional mixing of ingredients at a bottom of the mixing bowl without the at least one mixing blade contacting the mixing bowl.

The mixing blade arrangement may include a pair of mixing blades.

The mixing blade arrangement may include four mixing blades.

Each mixing blade may define a closed substantially convex loop

The central axis of rotation may pass through the recess.

The marginal mixing clearance may be between 1.0mm and 0.5mm.

The mixing blade arrangement may not carry scraper elements.

The spacer may define a drive rim configured to contact an inner surface of the mixing bowl to rotate the mixing bowl. Alternatively, the spacer is shaped to provide minimal surface area contact of the spacer with the mixing bowl.

The spacer may be secured to the shaft by a screw, the head of the being counter screw sunk so as to not extend beyond the spacer. Alternatively, the spacer may be secured to the beater by a screw, the head of the screw being embedded within the spacer. Further alternatively, the spacer may be moulded to the mixing blade arrangement. Still further alternatively, the spacer may be provided with clips to clip to the mixing blade arrangement.

In a third aspect, the present invention provides a mixing apparatus including a body, at least one beater according to any one of the preceding claims receivable in the body, and a beater motor for rotating the at least one beater.

The mixing apparatus may include an inner beater and an outer beater.

The mixing apparatus may further include a mixing bowl, and wherein the inner beater may include a spacer shaped to provide minimal surface area contact of the spacer with the mixing bowl, the outer beater may include a spacer which defines a drive rim configured to contact an inner surface of the mixing bowl to rotate the mixing bowl, and wherein in use the mixing bowl is rotated by the drive rim of the outer beater.

Alternatively, the mixing apparatus may include a mixing bowl adapted to be driven by a mixing bowl motor, wherein the inner beater and outer beater may each include a spacer shaped to provide minimal surface area contact of the spacer with the mixing bowl.

An inner surface of the mixing bowl and the outer beater may be complementarily profiled to provide the marginal mixing clearance between the or each beater and the mixing bowl.

Brief description of the drawings An embodiment of the invention will now be described with reference to the following drawings, in which:

Figure 1 provides a perspective view of a mixing apparatus for use in the preferred embodiment of the present invention;

Figure 2 provides a side view of a beater in accordance with an embodiment of the present invention;

Figure 3 provides a perspective view of the beater of figure 2;

Figure 4 provides a side view of the beater of figure 2 driving a mixing bowl;

Figure 5 provides a side view of a beater in accordance with an alternative embodiment of the invention;

Figure 6 provides a perspective view of the beater of figure 5;

Figure 7 provides a perspective view of a pair of beaters for use with an electric mixer with mixing bowl adapted to be driven by one of the beaters;

Figure 8 provides a perspective view of a pair of beaters for use with an electric mixer with a mixing bowl driven directly by a motor;

Figures 9A to 9C provide side views of spacers with alternative securing means; and

Figure 10 provides a perspective view of an alternative embodiment of the beater.

Detailed description of the embodiments

Referring to figure 1 , one example of an electric food mixing apparatus 100 suitable for use with embodiments of the present invention is depicted. ^'

The mixing apparatus 100 includes a base 102 and a body/housing 104. The base section 102 provides support for the mixing apparatus 100 and includes a seat 106 for a mixing bowl 108. The mixing bowl may, for example, be constructed of glass, stainless steel, or polypropylene. Depending on the type of mixing apparatus the seat 106 may be in the form of a turntable and adapted to rotate freely (if the mixing bowl 108 is to be driven by one of the beaters 110), or may be connected to a motor (not shown) which rotates the mixing bowl 108.

The body/housing 104 of the mixing apparatus 100 is pivotally connected to the base 102 at a pivot 112. The pivot 112 allows the body/housing 104 to pivot between a use position and a clearance position (shown in dotted outline). The body/housing 104 includes attachment recesses 114 at which beaters 110 can be removably attached to the mixing apparatus 100. The body/housing 104 also includes a motor (not shown) for rotating the beaters 110 when attached to the body/housing 104.

When the body/housing 104 is in the use position the beaters 110 depend from the attachment recesses 114 into the mixing bowl 108. When the mixing apparatus 100 is operated the motor rotates beaters 110 to mix any ingredients in the bowl. Typically the motor will counter rotate the beaters to provide counter-rotating for optimal mixing.

When the body/housing 104 is in the clearance position the beaters 110 are held out of the mixing bowl 108. This allows the mixing bowl 108 to be more easily accessed and/or removed from the mixing apparatus 100. The clearance position also allows the beaters 110 to be easily removed from the attachment recesses 114 for cleaning, replacement, and/or storage. A beater release switch 116 is also provided on the body/housing 104 which, when activated, mechanically releases the beaters 110 from the attachment recesses 114.

Turning to figures 2 and 3, a single beater 110 is shown. The beater 110 includes a shaft 202 which defines a central axis of rotation 203 about which the motor rotates the beater 110 when in use. The shaft 202 has an upper end 204 which is provided with engagement means 206 for engaging with the attachment recesses 114 of the mixing apparatus 100. In this particular embodiment the engagement means includes a pair of lugs adapted to engage with the attachment recesses 114 as is known to a person skilled to the art. It will, of course, be appreciated that alternative engagement means to attach the beater 110 to the mixing apparatus 100 may be provided. The attachment recesses 114 of the mixing apparatus are also provided with springs or similar which serve to bias the beaters 110 towards the mixing bowl 108 (when in the use position).

The beater 110 also includes a spacer 210. Mounting of the spacer 210 to the beater 110 is discussed further below. The spacer is advantageously made of a material that will not mark or scratch the mixing bowl 108 where the spacer 210 comes into contact with the bowl 108, though is also wear resistant. Suitable materials for the spacer 210 include nylon, calcium-filled nylon, glass-filled nylon, acetyl, polypropylene. Advantageously the mixing bowl 108 and spacers 210 will be constructed of different materials.

The beater 110 also includes a mixing blade arrangement including, in this instance, four mixing blades 212 extending from the shaft 202. Each of the four mixing blades 212 is secured to the shaft 202 such that the blade 212 defines a closed substantially convex loop. Each mixing blade 212 is also shaped so as to provide a recess 214 at an operatively lowermost end of the beater in the region of the central axis of rotation 203 at the lower end of the beater. As can be seen, in the depicted embodiment the central axis of rotation 203 of the shaft 202 passes through the centre of the recess 214 provided by the mixing blades 212.

While this embodiment is described and represented with four mixing blades 212 it is, of course, possible to incorporate more or fewer mixing blades as required. Advantageously, however, and regardless of their number, the mixing blades will be spaced equiangularly around the axis of rotation 203 of the shaft 202.

As can bθ seen, the spacer 210 is mounted within the recess 214 formed by the mixing blades 212. The size and shape of the spacer 210 is such that contact between the mixing blades 212 and the inner surface of the mixing bowl 108 is prevented. To achieve this the thickness of the spacer 210 is marginally greater than the depth of the recess 214 defined by the mixing blades 212. This provides a marginal mixing clearance 216 between the mixing blades 212 and the mixing bowl 108 when the mixing apparatus 100 is used.

The marginal mixing clearance 216 is sufficiently small to allow the functional mixing of a thin layer of ingredients lying in the bottom of the mixing bowl 108. For example, a recipe may call for a single egg-white to be beaten. When the egg white is placed in the mixing bowl 108 it will, of course, disperse into a thin flat layer at the very bottom of the bowl 108. The marginal mixing clearance is such that the mixing blades 212 of the beater 110 can mix the egg white without contacting the mixing bowl 108.

The size of the marginal mixing clearance 216 is ideally the minimum distance that manufacturing tolerances of the beater 110 and mixing apparatus 100 will allow, such that contact between the mixing blades 212 and the bowl 108 is prevented. In practice

(and with reference to the material and manufacturing tolerances considered) a distance of between 0.5mm and 1.0mm is found to be suitable. If material and manufacturing tolerances are capable it will be appreciated that this distance may be even further reduced to, for example, 0.1 mm.

As will be appreciated, the provision of the marginal mixing clearance allows for small quantities of ingredients to be effectively mixed without the mixing blades 212 of the beaters 110 contacting the mixing bowl 108, and without requiring the use/attachment of additional scraper elements (or such like) to the beater 110.

In the embodiment of the invention shown in figures 2 and 3 the spacer 210 defines a rim 218 configured to contact an inner surface of the mixing bowl. When the beater 110 is rotated by the motor the rim 218 drives the mixing bowl 108 to rotate it. The contact of the rim 218 is shown more clearly in figure 4 (the length of the spacer has been exaggerated in figure 4 to clearly depict the contact of the spacer with the bowl). This

type of spacer 210 is for use with a mixing apparatus 100 which does not use a motor to directly drive the mixing bowl 108.

Figures 5 and 6 provide depictions of a beater 110 which, with the exception of the shape of the spacer 502, is the same as that described in relation to figures 2 and 3. The spacer 502 depicted in figures 5 and 6 is shaped to provide minimal surface area contact with the mixing bowl 108. In this particular embodiment this is achieved by providing the spacer with a point 504, the point aligned with the central axis of rotation 203 of the beater 110. The minimal surface area contact could, by way of alternative, be provided by a spacer 502 with a convex dome.

Figure 7 shows a perspective view of a pair of beaters for use with an electric mixer with mixing bowl adapted to be driven by one of the beaters (i.e. the mixing bowl not directly driven by a motor). In this case the mixing apparatus 100 is advantageously provided with an outer beater 702 (of the type depicted in figures 2 and 3), and an inner beater 704 (of the type depicted in figures 5 and 6). In this way the rim 214 of the spacer 212 on the outer beater 702 contacts the inner surface of the mixing bowl 108 to drive the bowl 108, while point 505 of the spacer 502 on the inner beater 704 provides minimal friction when contacting the bowl 108.

Alternatively, and as shown in figure 8, if the mixing apparatus 100 does make use of a motor to directly drive the mixing bowl 108 both the outer beater 802 and inner beater 804 may be of the type depicted in figures 5 and 6, the point 504 of the spacers 502 providing minimal friction on the bowl 108.

Referring now to figures 9A to 9C, a number of different securing means for securing a spacer 210 or 502 to a beater 110 are shown.

Figure 9A shows a spacer 504 to be secured to the shaft 202 of the beater 110 with a screw 902. The head 904 of the screw 902 is moulded into the spacer 504 with the thread 906 of the screw projecting beyond the spacer 502. The spacer 502 may be secured to the beater 110, for example, by passing the thread 906 of the screw 902

through an aperture in the blades and securing a nut or similar thereto. While depicted in relation to spacer 502, this securing arrangement is also suitable for spacer 210.

In figure 9B the spacer 210 is provided with a recess 908 shaped to accommodate the screw head 904 and a bore 910 through which the screw thread 906 can pass. The recess 908 is sufficiently deep such that the screw head 904 is sunk within the spacer 210 and does not extend beyond the lowermost edge 912 of the spacer (clearly if the screw head 904 did extend beyond the lowermost edge 912 of the spacer 210 the screw head 904 and not the spacer 210 would contact with the mixing bowl 108.

Figure 7C depicts a spacer 502 provided with clips 916 for securing the spacer 502 to the beater 110. The clips may 916, for example, be of a snap fit type to clip around the lower edges of the mixing blades 212 of the beater 110. This type of securing means may also or alternatively be used for a spacer of 210.

The securing means shown and described in relation to figures 9A to 9C are shown by way of non-limiting example only. It is recognised that alternative securing means are possible. By way of further non limiting example, the spacer 210 of 502 may alternatively be glued to the beater .110 or integrally moulded to the beater 110.

Figure 10 depicts an alternative embodiment of the invention. In this embodiment the mixing blades 212 of the beater 110 do not define a recess 214. Rather, the marginal mixing clearance 216 (as described above) is provided purely by the thinness of the spacer element 150. Once again this arrangement allows for functional mixing of ingredients located at the bottom of the mixing bowl 108 without requiring additional scrapers or the like.

While the beaters 110 have been described for use with a stand mixing apparatus, it will be appreciated that the beaters may be adapted for use with any mixing apparatus, whether electrical or manually driven, supported by a stand or hand held.

It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features

mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.