Patent GB-1400240-A (GB)
Title: Food comminuting device
IPC: A47J43/046
Filed: 1972-11-22
Abstract: 1400240 Food comminuting device ETUD SA 22 Nov 1972 [30 Dec 1971] 54031/72 Heading A4C [Also in Divisions B1 and B2] FOOD CHOPPER: A food chopper comprises a base 12, Fig. 1, a drive-shaft 27 extending upwardly from the base 12, a generally cylindrical chamber 10 surrounding the shaft 27 and open upwardly and having a laterally opening outlet 22, a rotatable cutter 30 carried by the shaft 27 in an upper region 19 of the chamber 10 and a rotatable impeller 31, 32 carried by the shaft 27 in a lower region 20 of the chamber 10, a cover 14 defining a well 15 opening into the upper region 19 and a motor 54 in the base 12 for rotating the shaft 27 whereby a foodstuff inserted into the upper region 19 through the well 15 is sectioned by the cutter 30 and thereafter ejected by the impeller 31, 32 through the outlet 22. A two-part telescopic plunger (16, 17), Fig. 4 (not shown) fits in the well 15. CHOPPING CHAMBER: A chopping chamber 11 is mounted inside the chamber 10 on the base 12. A disc 13 is removably connected to the cover 14 and has an oval opening 23 in it and defines the top of the chamber 10. The members 10, 11, 12 and 13 may be made from synthetic resin. A partition 18 divides the chamber 11 into the upper and lower regions 19, 20 and has an opening 25, Fig. 3, through it in the form of a 90 degrees sector. The openings 25 and 23 are angularly offset from each other by an angle which may be raised by rotating the cover 14 relative to the chamber 11 which is fixed by a tongue in the chamber 10 so that an outlet 21 in the chamber 11 is always in register with the outlet spout 22. The chamber 10 has three tongues (37) engageable in notches (36) in the edge of the disc 13, one of the tongues (37) and one of the notches (36) being wider than the others to ensure correct positioning of the cover 14 on the chamber 10. In an alternative embodiment, three chambers (19', 19", 20'), Fig. 10 (not shown) separated by partitions (18', 18") having angularly offset orifices may be provided. Sets of blades (30', 30", 31') may be provided, one in each chamber, to obtain very fine comminution. Similarly four or more chambers could be so stacked. CUTTERS: The cutter 30 comprises a pair of coplanar blades which sweep just below the mouth of the well 15 and the impeller comprises blades 31, 32 which sweep in upper and lower regions respectively of the region 20. Each blade is crescent shaped with a convex leading cutting edge and a concave trailing edge and tapers towards its free end. The blades 31 and 32 are set at 180 degrees to each other and at 90 degrees to the blades 30. In an alternative embodiment, the chamber 11 is not used and a pair of stainless steel discs (39, 40), Fig. 5 (not shown) are used. The upper disc (39) had four sharp-edged perforated regions and acts as a grater whereas the lower imperforate disc (40) acts solely as an impeller. The disc (39) may be replaced by a disc (52), Fig. 11 (not shown) which has a single sharpedged radial slot (52') that slices the foodstuff. SWITCHES: The motor 54 is normally operated at 3000 rpm by a double-pole double-throw switch (50) which is controlled by the chamber 11. The switch (50) is connected to the field windings of the motor 54 and is operated by a rod (41), Fig. 6 (not shown) which is displaceable in a bore (42) in the chamber 10. When the chamber 11 is set in the chamber 10, the rod (41) is urged downwardly against the bias of a spring (43) to actuate a leafspring 44'which operates the switch (50), which in turn switches the motor 54 to a speed of 6000 rpm. When the chamber 11 is not used, the motor 54 rotates at 3000 rpm. A safety switch (48) is connected to the switch 50 to prevent operation of the motor 54 when the cover 14 is not in position on the device. A pin (45), Fig. 7 (not shown) on a spring (46) engages another pin (47) which operates the switch (48). The end of the pin (45) projects into the seat of the cover 14 which depresses the  pin (45) and closes the switch (48) when the cover 14 is placed on its seating. A similar switch (49), also connected to the switch (50), is provided to prevent operation of the motor (54) until the chamber 11 is seated in the chamber 10. OPERATION: Chunks of food are inserted into the well 15 and forced downwardly by the plunger (16, 17). The blades 30 section the food and displace it around in the region 19 until it falls through the opening 25 into the region 20 where the blades 31, 32 further comminute the food and impel it towards the opening 21 through which it is ejected. If finer chopping is desired, the angle over which the food is moved before passing through the opening 25 is increased by rotating the cover 14. The blades rotate anti-clockwise as seen from the top, so that the positions of the opening 23 corresponding to finest and coarsest comminuting are shown in broken and whole lines respectively in Fig. 3. Fineness indicia may be provided on the cover 14 and the base 12.