Field

The present invention relates to a bearing assembly, in particular a bearing assembly suitable for use in food processing devices such as hand blenders or stick blenders.

Background

Food processing appliances including hand blenders and the like commonly include a motor unit in which the driving motor is housed and at least one attachment member. The attachment member may be removable for cleaning purposes. Some food processing appliances of this type may include a plurality of attachment members each configured for a different specific use, and which may be swapped as required by the user. Often, removable attachment members include an engaging portion at one end thereof configured to removably couple with the motor unit, and a transmission shaft having a spline connection at one end to couple to the corresponding spline connection at the end of the driving shaft of the motor unit. The transmission shaft is supported by a bearing, allowing rotational movement of the transmission shaft within the attachment member housing.

In one example of prior art devices, the transmission shaft has at least one blade fitted at the opposing end to the engaging portion, so that the blade(s) can spin and perform the processing action as required in use.

It is known that the processing of food often causes liquids to be released from the food, for example in mixing, beating or blending. The processing action can additionally cause food particles to enter the food processing appliance. Therefore, it is a requirement of certain food processing appliances to protect the electrical and mechanical components from water damage or damage from the ingress and build-up of food particles. In existing devices this problem is solved by the provision of a seal located between the transmission shaft and the attachment member housing, so that the bearing and motor components are on one side of the seal and the blades of the attachment member are on the other side of the seal.

However, food processing appliances, in particular stick blenders and hand-held blenders, commonly have a degree of radial misalignment between the components, for example, between the motor drive shaft and the attachment transmission shaft, or the motor coupling inside the motor unit. During use, this misalignment corresponds to angular or radial movement of the transmission shaft. Radial in this context means normal to the central axis. This movement is accounted for by placing the bearing assembly in the housing via a flexible fixing which allows the bearing assembly to move slightly allowing certain angular or radial movement of the shaft. The shaft is therefore caused to move angularly within the seal. Due to some elasticity in the material of the seal, the seal is able to deform slightly to account for the movement of the shaft without compromising the seal effectiveness. Sometimes a further seal is required in the area of the shaft bearing.

However, these prior solutions do not account for when the transmission shaft is short (for example less than 10cm). Such short transmission shafts are needed for hand held food processing appliances having an upside-down arrangement. An upside- down arrangement is one in which the attachment member is located above the motor unit during use. Such an arrangement may be used for a blending attachment, for example to prepare smoothies, which includes a container which can be removed to carry the processed material (eg a ‘to go’ bottle). This is compared to stick blender arrangements, for example, wherein the motor unit is located above the blending arrangement during use, and the attachment shaft tends to be longer.

In the case of short transmission shafts, the radial misalignment causes a greater angular movement of the transmission shaft within the attachment member housing. This degree of angular movement creates problematic levels of deformation in the seal, causing buckling and gaping, which as a result leads to leakages. Further, the bearing assembly is subjected to radial forces which are much greater than in the processing devices having longer transmission shafts. Over time, the ingress of liquid and food particulates prevents the attachment member from being able to work and shortens the working lifetime of the hand-held appliance. Further, the radial forces may lead to damage of the bearing assembly.

The present invention aims to at least partially ameliorate the above-described problems of the prior art.

Summary of Invention According to a first aspect of the invention there is provided a bearing assembly comprising a body having a flexible mounting member located around at least a portion of the body, the body comprising a rotational shaft bearing and an annular seal located therein.

By providing the seal within the body of the bearing assembly, for example being mounted directly within the body, the seal may have a fixed alignment with the bearing and may be constrained to move together with the bearing. This can reduce radial deformation of the seal. When placed on a shaft, the flexible mounting member allows the body as a whole to move together with the shaft. This can allow for radial movement of the body to compensate for misalignment between the rotational shaft and a motor shaft to which it is to be attached.

In an exemplary embodiment, the body comprises a bearing cartridge, which may comprise a unitary element. Optionally, the bearing cartridge may comprise a hollow cartridge tube being partially closed at one or both ends, for example having an open end and a partially closed end, wherein the partially closed end(s) may comprise an axially aligned aperture therethrough. Optionally, the seal may be located between the partially closed end of the bearing cartridge tube, and the rotational shaft bearing. Therefore, the bearing cartridge is able to house both the bearing and the seal together around a shaft, when assembled on a shaft.

In an exemplary embodiment of the invention, the hollow cartridge tube may comprise a flange around an end, preferably the open end. The flange is configured to support the flexible mounting member and to provide a defined position of the mounting member with respect to the cartridge.

In one embodiment of the invention, the bearing cartridge may comprise a cartridge body and a cartridge cover comprising a partially closed face having a central aperture therethrough and a collar shaped and sized to fit over the open end of the cartridge body or tube. Optionally, the cartridge cover may comprise a shoulder extending from the edge of the collar. In this embodiment, the provision of a cartridge cover assists in containing the bearing and seal within the cartridge body. The shoulder of the cartridge cover provides the support for the flexible mounting member. In an exemplary embodiment of the invention the flexible mounting member may comprise chamfered edges. This improves the elastic deformability of the flexible mounting member and thus the assembly.

In one exemplary embodiment of the invention, the flexible mounting member comprises an annular ring shaped and configured to be fixed around the circumference of the body. The provision of an annular ring in this embodiment means that the flexible mounting member provides flexible mounting in all radial directions. Optionally, the flexible mounting is constructed from an elastically deformable material. Optionally, the flexible mounting is constructed from rubber.

In one exemplary embodiment of the invention, the flexible mounting member may comprise a second seal between the bearing cartridge and a surface in which the bearing is to be mounted.

In an embodiment of the invention, the annular seal within the body may be a lip seal.

In accordance with a second aspect of the invention, there is provided an attachment member for food processing device comprising a housing, a food processing assembly comprising a rotational shaft, and a bearing assembly as described above mounted within the housing and supporting the rotational shaft. Therefore, the aforementioned problems are addressed by the provision of a flexibly mounted bearing assembly containing the bearing and the seal and which moves together with the shaft. The flexible mounting member may also provide a seal between the bearing assembly and the housing.

In an exemplary embodiment the processing assembly is a blending assembly. Optionally, the blending assembly comprises at least one blade mounted to an end of the rotational shaft, and preferably comprises a coupling such as a spline at an opposing end of the shaft.

In an exemplary embodiment of the invention, the rotational shaft is less than 10 centimetres in length, and may be shorter, such as less than 8 centimetres or less than 6 centimetres in length. In this embodiment, the attachment member is suitable for use with a motor unit in the aforementioned “upside-down” arrangement, wherein the attachment member is placed on top of a motor unit, and the motor unit forms the base.

According to a third aspect of the invention, there is provided a food processing device comprising a motor unit, a container and an attachment member as described above. In an exemplary embodiment of the invention, the motor unit is removably connectable to the attachment member, and the attachment member is removably connectable to the container.

Optionally, the motor unit forms the base of the food processing device when assembled. Thus the food processing unit can be used in the upside-down arrangement, wherein the attachment member is used on top of the motor unit

In a fourth aspect of the invention there is provided a kit of parts comprising a motor unit, a container and at least one attachment member as described above.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.

It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.

In this specification the word 'or' can be interpreted in the exclusive or inclusive sense unless stated otherwise.

Furthermore, features implemented in hardware may generally be implemented in software, and vice versa. Any reference to software and hardware features herein should be construed accordingly.

Whilst the invention has been described in the field of domestic food processing and preparation machines, it can also be implemented in any field of use where efficient, effective and convenient preparation and/or processing of material is desired, either on an industrial scale and/or in small amounts. The field of use includes the preparation and/or processing of: chemicals; pharmaceuticals; paints; building materials; clothing materials; agricultural and/or veterinary feeds and/or treatments, including fertilisers, grain and other agricultural and/or veterinary products; oils; fuels; dyes; cosmetics; plastics; tars; finishes; waxes; varnishes; beverages; medical and/or biological research materials; solders; alloys; effluent; and/or other substances, and any reference to “food” herein may be replaced by such working mediums.

The invention described here may be used in any kitchen appliance and/or as a stand alone device. This includes any domestic food-processing and/or preparation machine, including both top-driven machines (e.g. stand-mixers) and bottom-driven machines (e.g. blenders). It may be implemented in heated and/or cooled machines. It may be used in a machine that is built-in to a work-top or work surface, or in a stand alone device. The invention can also be provided as a stand-alone device.

“Food processing” as described herein should be taken to encompass chopping, whisking, stirring, kneading, mincing, grinding, shaping, shredding, grating, cooking, freezing, making ice-cream, juicing (centrifugally or with a scroll), or other food processing activities involving the physical and/or chemical transformation of food and/or beverage material by mechanical, chemical, and/or thermal means.

As used herein, the term "removable attachment" (and similar terms such as “removably attachable”), as used in relation to an attachment between a first object and a second object, preferably connotes that the first object is attached to the second object and can be detached (and preferably re-attached, detached again, and so on, repetitively), and/or that the first object may be removed from the second object without damaging the first object or the second object; more preferably the term connotes that the first object may be re-attached to the second object without damaging the first object or the second object, and/or that the first object may be removed from (and optionally also re-attached to) the second object by hand and/or without the use of tools (e.g. screwdrivers, spanners, etc.). Mechanisms such as a snap-fit, a bayonet attachment, and a hand-rotatable locking nut may be used in this regard. Any apparatus feature as described herein may also be provided as a method feature, and vice versa.

As used herein, means plus function features may be expressed alternatively in terms of their corresponding structure, such as a suitably programmed processor and associated memory.

Brief Description of Drawings

One or more aspects of the invention will now be described, by way of example only and with reference to the accompanying drawings having like-reference numerals, in which: Figure 1 shows a cross-sectional drawing of an attachment member and bottle for a food processing appliance according to an embodiment of the invention;

Figure 2 shows a cross-sectional drawing of the attachment member of Figure 1 ;

Figure 3 shows a cross-sectional drawing of a bearing cartridge according to an embodiment of the invention, for use in the attachment member of Figure 1 ; Figure 4 shows a cross-sectional drawing of an attachment member and bottle for a food processing appliance according to a second embodiment of the invention;

Figure 5 shows a cross-sectional drawing of the attachment member of Figure 4;

Figure 6 shows a cross-sectional drawing of a bearing cartridge according to a second embodiment of the invention, for use in the attachment member of Figure 4; and Figure 7 shows a partial cross-sectional drawing of a food processing appliance including an attachment member and bottle assembled to a motor unit.

Specific Description

An attachment for a food processing appliance comprises an attachment member 100 and bottle 200, as illustrated in Figures 1 and 2. The food processing appliance is of an upside-down arrangement as shown in Figure 7; that is, the attachment member 100 is configured to be used on top of a motor unit 101 of the food processing appliance when assembled for use. The bottle 200, also called a food container, or container, may be constructed from a plastics material and may be transparent or translucent to allow visibility to the contents of the bottle 200 by the user. The bottle 200 is generally cylindrical in shape, though may include indents and embossments on its inner or outer surfaces for ergonomic reasons, to improve grip, to improve processing performance or for aesthetic purposes, and is closed at one end 210. At an opposing end, the bottle has an opening for receipt of food and items to be processed. The opening has a collar 220 comprising a screw threaded portion 222 on the outer surface thereof. The screw threaded portion 222 is configured to engage with a corresponding screw threaded portion 122 on the inner surface of a lip 120 of the attachment member 100. Thus, the bottle 200 and the attachment member 100 can be connected and disconnected as required. This particular means of connecting the bottle 200 and attachment member 100 ensures liquid from food being processed is not ejected from the food processing appliance when in use. Other suitable connection means will be known in the art and the invention is not necessarily limited in this regard.

The attachment member 100 includes a housing 110. The housing 110 forms the main structure of the attachment member. The housing 110 may be constructed from plastic or metal, but should be rigid to ensure structural integrity of the attachment member 100 during use and lightweight so that it is easy to use by the user. The housing 110 is generally cylindrical in shape, though has a stepped profile, and is hollow except for an inner structure connected to the outer structure and dividing the interior into two separate cavities. The inner structure is described in detail hereinafter.

The housing 110 will now be described according to three main regions. In the present exemplary embodiment the housing is formed of a single piece of moulded plastic. It will be understood by those skilled in the art that the housing may be alternatively formed from multiple parts fused, welded, glued, or otherwise joined together, and the invention is not necessarily intended to be limited in this regard.

In a first bottle connection region, the housing has a lip 120, the inner surface of which comprises a screw threaded portion 122, configured to engage with a corresponding screw threaded portion 222 on the outer surface of the collar 220 of the bottle 200. The first region has the largest diameter and is deep enough to receive the collar 220 of the bottle. Depth is measured along the longitudinal axial direction of the housing. This region forms the uppermost region of the attachment member 100 when oriented for use.

The second region is the blending region of the attachment member 100, and is formed integrally between the first and third regions. The housing 110 at the second region comprises an inner structure defining a cavity or well 130 in which food items collect when the attachment member is oriented for use. The inner structure extends inwardly at the base of the second region 112 to form a floor 132 to the well 130. The floor 132 is generally “U”-shaped in cross-section, forming an incline toward the axial centre of the attachment member 100. At the very centre of the inner structure is an aperture 134 through the floor 132 configured to receive and retain the blade assembly 140. The aperture 134 is substantially circular in shape. The blade assembly 140 extends through the aperture 134 and into the third region of the housing 110. The blade assembly 140 is illustrated best in Figure 2 of the drawings, and is described in further detail hereinafter.

The third region of the housing 110 is the motor unit coupling region. As with the rest of the housing the third region is cylindrical and hollow. This region has the smallest diameter of the three housing regions, for the purpose of engaging with a motor unit, for example by fitting into and being held in the motor unit 101 , during use and/or storage. The skilled person will therefore understand that the diameter of the coupling region is defined by the shape and configuration of the motor unit, and the invention is not necessarily intended to be limited in this regard. The part of the inner structure of the housing 110 which forms a floor 132 for the second region also forms a roof 150 for the third region in which a recess 152 is formed centrally. The recess 152 is connected to the aperture 134. The recess 152 is shaped and configured to receive the bearing and sealing components, which are described in more detail hereinafter.

The transmission shaft 142 of the blade assembly 140 extends into the main cavity defined by the third region through aperture 134. A suspended collar 154 extends from the roof 150. The suspended collar 154 is to help guide the driving shaft to couple with the transmission shaft 142 of the blade assembly 140 and to stabilise the attachment member on the motor unit. At the end of the third region, an undulating edge 160 is provided. Indentations 170 are located near the edge 160. The indentations 170 are suitable for securing the attachment member 100 to the motor unit 101 when the food processing appliance is assembled for use, for example by receiving a ratchet tooth clip.

Referring now specifically to Figure 2 of the drawings, the blade assembly 140 includes a transmission shaft 142 positioned along a central longitudinal axis of the attachment member 100. The transmission shaft 142 protrudes through the floor 132 of the blending region and extends into the cavity defined by the coupling region of the housing 110. At one end, the transmission shaft terminates in a connector in the form of a male spline 144 in this example. The male spline 144 is configured to engage with a corresponding connection in the form of a female spline of the drive shaft in a motor unit of the assembled food processing appliance. Thus, torque is transferred from the motor unit to the transmission shaft.

At an opposing end of the transmission shaft 142, processing blades 146 extend from the shaft in a generally radial direction into the well 130. The blades 146 may be evenly spaced around the circumference of the transmission shaft 142. In the present exemplary embodiment, there are two pairs of blades 146 which are bent at an obtuse angle, with one pair arranged so that the tips of the blades protrude away from the floor 132 of the well 130 toward the lip 120 of the housing, and the other pair bent in the opposite direction towards the floor 132. The blades 146 do not protrude beyond the lip of the housing 120. The distance between the blades 146 and the spline 144 is short, for example less than 10cm, because the assembled food processing device is of the upside-down arrangement, that is, the attachment member 100 is used on top of the motor unit, during blending/food processing.

A pair of washers 180 form an axial bearing between the blades 146 and the bearing assembly 300. At least one may be made from low friction plastics material to prevent friction and wear. A similar washer arrangement 182 is provided adjacent the opposing end of the bearing assembly. The arrangement of washers 180, 182 maintain the axial position of the shaft 142 and thus the bearing assembly 300.

The mid-section of the shaft is supported by a bearing assembly 300 mounted in the recess 152. The bearing assembly 300 is illustrated best in Figure 3 of the drawings. For clarity, the transmission shaft 142 has been omitted from the drawing. A rotational shaft bearing 310 is configured to fit around the mid-section of the transmission shaft 142. Suitable bearings will be known to those skilled in the art and the invention is not necessarily intended to be limited in this regard. The inner surface of the bearing defines a tubular space for receipt of transmission shaft 142. The bearing 310 is elongate in the axial direction. This advantageously provides support along more of the shaft 142. The bearing 310 may have a shallow recess in the outer surface thereof.

At an end of the bearing 310 is a first seal 320. The first seal 320 comprises an annular wall 322 having a similar diameter to that of the bearing 310. At the lower edge of the wall, nearest to the bearing 310, an inwardly protruding flexible flange 324 extends upwardly and inwardly, for example forming an acute angle with the wall 322. The seal 320 is therefore a lip seal. It will be apparent to those skilled in the art that other types of suitable seals may be used. The flange 324 terminates at substantially the same radial plane as the wall 322. The flange defines a circular opening 326 for receipt of transmission shaft 142. The opening 326 is of a slightly smaller diameter to the transmission shaft 142 so that the lip forms a tight seal around the shaft 142 in use. The seal 320 may be constructed from a polymer having a low coefficient of friction. Suitable polymers will be known in the art.

The body of the bearing assembly is a cartridge tube 330 provided to encase the bearing 310 and the first seal 320. The cartridge tube 330 comprises a cylindrical casing defining an inner cavity suitable for receipt of the bearing 310 and the first seal 320. At one end, the cartridge tube 330 has a partially closed surface 332 with a circular opening located centrally therethrough. The opening is for the shaft 142 to pass through. The partially closed surface 332 provides a surface against which the first seal can abut. The cartridge tube 330 is open at the opposing end.

A cartridge cover 340 is provided to fit over the open end of the cartridge tube 330. The cartridge cover 340 also has a centrally located circular opening 342 for a shaft 142 to pass therethrough. The cartridge cover 340 may be shaped and configured to friction fit over the open end of the cartridge tube 330. The annular side wall of the cartridge cover 340 terminates in a radially outwardly extending shoulder 344. Together, the cartridge tube 330 and the cartridge cover 340 form the bearing cartridge. Therefore, the seal 320 is mounted within the bearing assembly.

When the attachment member 100 is assembled for use, the first seal 320 is arranged to abut the shaft 142. Advantageously, the first seal prevents the ingress of liquids or food particulates between the shaft and the bearing 310. A second seal 350 is constructed from an elastically deformable annular ring located around approximately the mid-section of the bearing cartridge 330, 340. The shoulder 344 of the cartridge cover 340 provides a surface for supporting the second seal 350, against which the second seal 350 can sit. The second seal 350 includes chamfered edges, for example allowing for greater expansion of the material as required and to ease assembly over the cartridge tube and into the recess 152. The second seal 350 is slightly smaller than the cartridge tube and is shown in its relaxed condition, thus leading to an interference fit once assembled, as shown in the drawing.

Referring additionally to Figure 2 of the drawings, the second seal 350 allows for flexible mounting of the bearing cartridge within the recess 152 so that angular or radial movement of the transmission shaft transfers to compression and deformation of the second seal. Therefore, a second seal also provides a flexible mounting member. The first seal 320 and the bearing 310, being mounted to the transmission shaft 142, may move together with the shaft 142. In addition, the second seal prevents liquid ingress between the bearing cartridge and the housing 110.

Referring to Figures 4, 5 and 6 of the drawings, a second exemplary embodiment of the invention is illustrated. Like features have been given the same reference numerals as in the embodiment described in relation to Figures 1 , 2 and 3 of the drawings.

As with the first embodiment, an attachment member 100 and bottle 200 for a food processing appliance are illustrated in Figures 4 and 5. The food processing appliance is of an upside-down arrangement, that is, the attachment member 100 is configured to be used on top of the motor unit of the assembled food processing appliance.

In this exemplary embodiment, the bearing assembly 400 comprises a cartridge tube 430 containing a first seal 420 and a shaft bearing 410, the tube being a single piece and having an open end. The first seal 420 may comprise an annular wall 422 and a lip or flange 424 with an aperture 426 for the transmission shaft, as described above. The open end of the cartridge tube 430 comprises a shoulder 438 created by an outwardly extending flange around the edge of the open end of the cartridge tube 430. The cartridge tube 430 forms the bearing cartridge as in the first embodiment.

The shoulder 438 of the cartridge tube 430 provides a surface against which the second seal 440 can sit to locate the second seal 440 when pushed onto the tube 430. Referring additionally to Figure 4 of the drawings, as before, the second seal 440 allows for flexible mounting of the bearing cartridge within the recess 152.

The bearing 410 can be a press fit in the tube 430, so that it is inhibited from moving out of the tube 430 in use. Alternatively or in addition, the washer arrangement 182 on the coupling side of the shaft 142 also inhibits axial movement of the bearing 410.

For both embodiments of the invention as described above, when the attachment member 100 is assembled for use, the second seal is pressed between the inner surface of the recess 152 and the outer surface of the bearing cartridge. This advantageously allows the bearing cartridge to be flexibly mounted in position, during use. The bearing assembly 300, 400 thus can exert the necessary pressure on the shaft 142 required to support the shaft during use. Due to the elastically deformable secondary seal 350, 440, any lateral movement of the shaft is compensated for and a tight seal is maintained between the housing 110 forming the blending region and the housing forming the coupling region. The body of the bearing assembly, including the bearing 310, 410 and first seal 320, 420 is advantageously permitted to move angularly and radially as the shaft does, in use, thus limiting deformation in the first seal 320, 420. Further, the exertion of radial or angular forces on the bearing 310, 410 by the transmission shaft 142 is limited.

Referring now to Figure 7, in use, a food processing device 102 is assembled by connecting the bottle 200 to the attachment member 100, and the attachment member is mounted on a motor unit 101. The processing device 102 is arranged to be positioned upright in use, with the motor unit 101 forming a base of the device 102, which may be supported on an end face 103 of the motor unit 101. Torque from the motor unit is transferred to the blades 146 via a motor drive shaft which is coupled to the transmission shaft 142, allowing the blades to spin and perform the necessary processing action. Food from the bottle 200 falls into the well 130 and, due to the rotational movement of the blades 146, is processed or blended. This releases water and creates small particles of food. If the transmission shaft 142 of the attachment member 100 moves laterally, a water-tight seal is maintained by the provision of the first seal 320, 420 within the bearing cartridge of either embodiment of the invention because the first seal 320, 420 does not deform significantly. The bearing cartridge, being flexibly mounted, moves with the movements of the transmission shaft 142. The second seal 350, 440 expands and contracts as required to allow the bearing cartridge to move laterally.

It will be understood by those skilled in the art that the blades of the above described embodiment(s) may be replaced with other processing blade arrangements or other suitable rotary food processing armatures, such as a mixer, whisk, and so on.

It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Reference numerals appearing in the claims are by way of illustration only and shall have no limiting effect on the scope of the claims.