FR2770121A1 - Hand blender for food preparation - Google Patents

Abstract

The portable hand blender has a housing (3) for the electric motor, with a handle (4) at the outer end and a driveshaft housed in a fixed tube (2) at the other end. The end of the tube carries an attachment (1) for a tool that is fitted on the free end of the tube, connecting to the drive shaft. An internal seal at the tool fitting prevents food being thrown into the tube.

Description

MIXING PLUNGER
The present invention relates to a dipping mixer intended in particular, but not exclusively, for the preparation of food.

Such devices are well known and commonly used.

They include a casing, provided with a handle, inside which is mounted an electric motor driving in rotation a first end of a shaft included in a fixed tube or sleeve, the tool being mounted on the other end of the tree. Trained at high speed, the tool is immersed inside the food to be prepared and it cuts, mixes, emulsifies, etc.

French patent NO 97 09012 describes an apparatus of this type including an electric motor driving, in rotation, a first end of a shaft included in a tube integral with the casing, a tool being mounted on the second end of said shaft, characterized in that on the free end of the tube is mounted a removable endpiece secured to the tool. The tool is removably mounted inside the tip. It is thus possible to disassemble not only the tip, but also the tool for more thorough cleaning or maintenance.

In the above patent, the mixer comprises from the bottom up a removable nozzle fixed to a tube or sleeve. The tube is secured to the casing of the electric motor as well as to electrical connection means with a current source. A handle is integrated in the upper part of the housing.

The removable tip includes a metal bell molded into the plastic tip, the bell surrounding the tool. This is driven by the electric motor by a mechanical connection including a metal drive shaft and a bearing also mechanical.

In certain particular applications with continuous fire under the container, in which the food is brought to a temperature which can reach 1000C, one notes a significant rise in temperature at the level of the bearing of the bell, the heat being transmitted to the bearing by the metal shaft of the tool. The bearing being included in the plastic, heat insulating material, the heat transmitted by the tool can only be dissipated with difficulty. This phenomenon is increased by the proper heating of the bearing resulting from the rotation of the axis of the tool at a speed of up to several thousand revolutions. This results in a serious risk of overheating.

The object of the present invention is to overcome this drawback and to establish a thermal bridge between the bell and the bearing. Thus, the heat can be removed under the right conditions.

According to the invention, the mixer comprising a removable tip partially made of plastic, including a metal bell surrounding a tool carried by a rotating shaft in a bearing secured to the tip is characterized in that a heat conducting ring is mounted between the bearing and the bell.

The bearing is thus in thermal connection with the bell whose large surface allows heat dissipation from the bearing.

Other characteristics and advantages of the present invention will appear during the description which follows of a particular embodiment, given only by way of nonlimiting example, with reference to the single figure which represents in section the lower part. a hand blender with removable tip.

The removable end piece 8, mechanically connected to the tube 2 and including means for transmitting the movement, allows covering of the metal parts so as to present a surface free of food retention zones.

In the single figure, the axis 12 of the tool rotates in a cylindrical bearing 16. One end of the axis 12 carries the tool 13 which, in the example shown is a knife with three blades. The second end 12a of the axis 12 is mounted inside the drive cage 11 by means of a drive hub 17. A seal is ensured, from the tool 13, by the bellows 14, for example made of neoprene, one side of which bears on a surface of the part 15 with a low coefficient of friction, which is, for example made of graphite.

During the operation of the device, the rotation of the axis 12 in the bearing 16 generates a rise in temperature which cannot be dissipated when the bearing 16 is embedded in the plastic and therefore isolated from the bell 9. whence risk of damage to the device.

According to the invention, a heat-conducting ring 39, for example made of stainless steel, of generally frustoconical shape, the external surface 40 of which is in contact with the upper part 49 of the bell 9, is inserted between the bearing 16 and the bell 9. and whose internal orifice 41 encloses the bearing 16 over the greater part of its length.

This ring 39 creates a thermal bridge between the bearing 16 and the bell 9 which allows the dissipation of heat to the outside of the device.

It goes without saying that many variants can be made, in particular by substitution of equivalent technical means, without departing from the scope of the invention.

Claims (1)

 CLAIM 1 Plunge mixer including a casing for a motor  electric driving in rotation a first end  a shaft included in a fixed tube (2), a tool (13)  rotating in a bearing (16) being connected by  via an axis (12) at the second end of  the shaft inside the tube (2), inside a nozzle  (8) removable, partially made of plastic, and  including a metal bell (9) surrounding the tool  (13), characterized in that a conductive ring (39)  heat is mounted between the bearing (16) and the bell (9).