US 20030010222 A1
Safety device for food processor in a bowl (2) closed by a cover (3), comprising a chute for introducing products into the working bowl, a pusher (5) slidably mounted in a pusher-guide (4) which is pivotally mounted onto the cover (3), and a set of rods connecting the pusher-guide (4) to the safety rod (2 a) of the bowl (2).
1. Safety device for food processor with a rotating tool, comprising an electrical motor unit (1) on which is mounted a bowl (2) which is closed by a cover (3), the motor shaft, passing inside the bowl, being able to receive various tools, the cover (3) comprising a chute (3 b) for introducing the food, a safety rod (2 a) being arranged according to a generatrix of the bowl (2) and bearing on a switch (1 a) arranged in the feeding circuit of the motor unit, characterized in that a pusher (5) is guided into translation in the chute (3 b) by a pusher-guide (4), said pusher-guide, being articulated at top of the chute (3 b) and being mechanically connected with means for pushing on top of the safety rod (2 a), the mechanism causing the motor to stop for a small angular clearance of the pusher-guide (4) in the clockwise direction.
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 The present invention relates to a safety device designed in particular, but not exclusively, to food cutting apparatuses.
 These apparatuses which are well known in the field and are called vegetable cutters or meat/vegetable cutter units, comprise, among others, a motor unit enabling control and motorization of the cutting tool and a device, commonly called vegetable cutter head, for feeding and cutting the products. The vegetable cutter head comprises a bowl, which is removable or integrated with the motor unit, of a suitable shape, enabling or not a continuous discharge of the treated products (closed bowl or open bowl); a cutting disk or tool located inside the bowl and which, as moved by the motor, makes the desired cut (slicing, grating, etc.); a cover; and, in case, a discharging disk.
 The cover enables an introduction of the products to be processed by guiding them through one or a plurality of vertical tubes or chutes. It also provides a protecting function for the user by avoiding projections of the processed product outside the bowl and, above all, avoiding the user to touch the moving disk.
 Introduction of the food products within the machine is made by positionning them in a suitable chute and by pushing them against the disk with help of a pusher. In use, removing the pusher leaves the disk appearing through the chute. For large sized chutes, it is advisable, if it is desired to protect the user from injury risks, to control working of the motor to presence of a physical element obturating the chute inlet.
 It is known by FR-A-2 147 361 (VERDUN) to provide a mechanical safety of the presence of the cover on the bowl, this safety being obtained by means of a sliding rod arranged according to a generatrix of the bowl and the lower part of which comes to bear, when the cover is positionned, against a switch included within the base under action of a cam which is carried by the cover. But this device does not permit to provide a suitable chute safety, which leads to chutes having a great height and/or a limited cross-section.
 A device for magnetically making this control function between the pusher and the motor drive is known by U.S. Pat. No. 4, 821,968 and uses a set of magnets and flexible blade switches, or switches of the Hall effect type. This device necessitates a transformation of the electrical power and, moreover, the control by a magnetic field is more delicate to design for the consideration of safety standard regulations.
 Mechanical devices are already known which consist in operating a power circuit breaker when the position without risk of working of the chute pusher is reached. Such a device is described in U.S. Pat. No. 4,674,690 in which the chute is surrounded by a sleeve, provided with means for activating the power circuit breaker, in which the pusher is enclosed.
 The subject of the invention is to cope with all these problems and to bring a solution to the control between the pusher which pushes the products inserted in the chute and the drive of the motor. This mechanical solution enables to use a chute having a great cross section.
 According to the invention, the safety device for a food processor with a rotating tool, comprising an electrical motor unit on which is mounted a bowl which is closed by a cover, the motor shaft, passing through the bottom of the bowl, being able to receive various tools, the cover comprising a chute, a safety rod being arranged according to a generatrix of the bowl and bearing on a switch arranged in the feeding circuit of the motor unit, is characterized in that a pusher is guided into translation in a pusher-guide, said pusher-guide being articulated at top of the chute and being mechanically connected with means for pushing on top of the safety rod, a small pivoting of the pusher-guide from its lower position causing stoppage of the motor.
 The mechanical safety device for a food processor which necessitates or not an action from the user on the products during the cutting thereof, comprising a motor unit on which is mounted, in a removable or not manner, a bowl which is closed by a cover, itself removable or not with respect to the bowl, provides a control of the motor to the position of one or a plurality of movable parts which prevents access to the risking area. In the circumstances, a pivoting movable part is formed by a pusher-guide, the pusher while sliding inside the pusher-guide permitting or not the same to pivot. The necessary obturation of the upper portion of the chute may be made, either by means of the pusher properly so called, or by the pusher-guide. The pusher is generally made by a handle of a reduced cross section, at the lower end of which is formed a plate having a cross section which is substantially equal to that of the chute. Obviously, the pusher handle freely slides in the pusher-guide. The plate of the pusher can be extracted from the chute only when it is brought above the same by a traction on the handle.
 Pivoting the pusher-guide causes translation of a cover rod the lower end of which bears against the upper part of the safety rod of the bowl, pivoting can only be made when the pusher plate is brought into abutment against the pusher-guide.
 There is therefore made a control of the drive of a motor to the position of a movable part which obturates access to the risking area formed by the aperture of a chute having a great cross section.
 According to another feature of the invention, the pusher-guide drives a connecting rod by means of a first articulation, which connecting rod forcing, by means of the articulation of its second end, rotation of a crankshaft around a second pin which is fixed with respect to the cover, said crankshaft driving in its turn, by means of its first articulation which is common with said connecting rod, a first rod which acts on the switch located in the motor unit through the second rod, guided into translation in the wall of the bowl, said second rod being upwardly returned by a spring.
 Mechanical devices are economical since they can directly act on an electric switch which supports currents compatible with those of the motor which are used. Therefore, the apparatus remains very simple and reliable and its manufacturing cost is more moderate than that of other safety devices.
 The pusher is connected to the cover of a vegetable cutter by means of an intermediary part which is called a pusher-guide. The pusher-guide pivots around an horizontal pin which is positionned at the upper part of the chute and permits translation of the pusher. Therefore, when the pusher is in the chute, introduction of the products to be processed is made by upwardly drawing the pusher up to the upper level of the chute, and then pivoting the pusher-guide in order to free the inlet of the chute. When the chute is filled, the pressure which is exerted on the products is made by causing the pusher-guide to pivot so that the pusher will be at the upper level of the chute, and then causing the pusher to vertically descend inside the chute. Raising the pusher and then removing it enables to refill the chute. Closing the guide and descending the pusher enables to push the product against a tool such as a cutting disk.
 Controlling the motor operation to position of the pusher-guide enables to be sure that the motor does not operate when the pusher sufficiently obturates the inlet of the chute. An assembly of rods, arranged between the cover and the pusher-guide, controls a safety switch which is set near the motor. Transmission of the translation movement which activates the switch is provided by the safety rod located in the bowl of the vegetable cutter of the type as described in the prementioned French patent. A return spring is used for returning the rod in an upper position when the pusher-guide is not in a working position.
 The inventive kinematics solves two joint problems connected with this type of system:
 When the pusher-guide is closed, the system must exert a resisting force to opening, which is just enough for permitting to raise the pusher without driving the pusher-guide before the pusher is completely raised. This is required since, if not, an untimely rocking of the pusher-guide will produce a rubbing of the pusher in the chute, which is a minima detrimental to ergonomics, and is able to lead to a complete blocking of the mechanism by buttressing. In the same time, the resistance force to opening must not be too high since it would then be a constraint for the user.
 The system must also cause stoppage of the motor even when the pusher-guide is not rocked very much, i.e. much before access of the hand to the tool will be possible. It is therefore necessary that the mechanism will produce a relatively important stroke of the rod which is contained in the cover for a small angular clearance of the pusher-guide.
 A small upwardly pivoting of the pusher-guide of the chute from its lower position causes the motor to stop. Upon descending the pusher inside the chute, it is possible to trigger the motor while authorizing the products to be processed to slightly pass beyond the upper level of the protected chute.
 Other features and advantages of the invention will be revealed during the following description of a particular embodiment given only as a non limitative example, with respect to the drawings which show:
FIG. 1, a perspective view of a complete machine;
FIG. 2, a perspective and half cross-sectionnal view brought together aside;
FIG. 3, a diagram of the mechanical device which provides, according to the invention, an action of the pusher on the rod of the bowl, when the pusher is completely descended;
FIG. 4, a drawing in cross section of the mechanism in the condition described in FIG. 3;
FIG. 5, a diagram with the pusher being raised immediately when the device causes the motor to stop;
FIG. 6, a drawing in cross-section of the mechanism in the condition described in FIG. 5;
FIG. 7, a diagram with the pusher completely open;
FIG. 8, a drawing in cross-section of the mechanism in the condition described in FIG. 7.
 In all the figures, the same references designate the same items.
FIG. 1 shows all the machine, the mechanism which is necessary to kinematics being protected from smears by an assembly of suitable hoods.
 In FIG. 1, the base 1 enclosing the motor (not shown) in used as a support for the bowl 1, closed by the cover 3, which comprises a smaller chute 3 a, and a greater chute 3 b, inside of which may penetrate a pusher 5 which slides in a guide 4.
FIG. 2 shows thanks to the cross-section of the vegetable cutter head, the smaller chute 3 a which does not necessitate any safety device and the greater chute 3 b the use of which is protected by the safety system of the invention. The head is shown in the position for filling the greater chute. In FIG. 2, a safety switch 1 a is arranged inside the base 1, beneath a safety rod 2 a which is slidingly mounted according to a generatrix of the bowl 2 and on which the rod 6 of the cover 3 will act.
 FIGS. 3 to 8 are diagrams and drawings enabling to explain the working of the mechanism designed to transform the pivoting movement of the pusher-guide into a vertical translation movement of the rod which is mounted in a wall of the bowl, upon pivoting the pusher-guide, after having brought the pusher at the upper level of the chute.
 The pusher-guide 4 is articulated around a pin 4 a which is fixed with respect to the cover 3. The pusher-guide 4 carries also a pin 8 b on which is articulated the connecting rod 8. The second end of the connecting rod 8 is articulated onto one end 7 b of a crankshaft 7 the second end 7 a of which is articulated in a fixed point 7 a of the cover 3. On the end 7 b is also articulated one end of the rod 6 the second end of which is guided in an aperture 3 c of the cover and comes to bear on the safety rod 2 a which is slidably mounted in the bowl.
 Pivoting the pusher-guide 4 moves the pin 8 b, the pin 7 a being fixed, and the distances between 7 a and 7 b and respectively 7 b and 8 b being constant, the point 7 b will then describe an arc of a circle around 7 a. The upper end of the rod 6, which is fixed at 7 b, follows the same movement. It is moreover guided into translation by means of the aperture 3 c made in the cover, which results in vertically moving the lower end 6 a of this rod. Since the spring 2 b ensures a contact between the upper part of the rod 2 a and the lower face of the rod 6, the bowl safety rod 2 a is vertically moved in the same way, up to end of clearance of the pusher-guide 4 in either direction.
 In FIGS. 3 and 4, the pusher-guide is closed and the pusher is completely descended in the chute 3 b. FIGS. 3 and 4 show the position of the assembly when the user has pushed the products through the chute 3 b. The pusher 5 is in its lower position and the rod 6 pushes onto the top of the safety rod 2 a which itself closes the switch 1 a. For returning to its opening position, it is necessary to raise the pusher 5, and then to pivot the pusher-guide 4 in the clockwise direction.
 The diagram of FIG. 3 shows how the device will exert, on the pusher-guide, the above described resisting force to opening. This is obtained by the fact that the crankshaft 7, which has slightly rotated beyond the vertical position, in the movement for closing the pusher-guide, will exert, by means of its pin 7 b, a traction on the connecting rod 8 which, in its turn, will tend to maintain the pusher-guide 4 closed by its connection 8 b, under action of the spring 2 b as transmitted to the rod 6 by means of the rod 2 a.
 In FIGS. 5 and 6, the pusher 5 has been raised at maximum in the chute 3 b and then the pusher-guide 4 has pivoted in an intermediary position in the clockwise direction. This position is that of the system upon triggering the safety switch 1 a, and clearly shows that access of the hand to the tool is prevented when a command to stop the motor is given.
FIGS. 5 and 6 specify the position of the system when the rod 6 is sufficiently raised so that the rod 2 a will free the switch 1 a, which results in stopping the motor. In the opposing position for closing the pusher, this is also practically the position from which it is possible to re-start the motor. This feature of the device enables to fill at 100% the volume of the chute 3 b with products to be processed and maximized therefore performances of the apparatus.
FIGS. 7 and 8 show the device in its completely open position with the pusher completely raised, showing a direct access to all the surface of the chute.
 In FIGS. 7 and 8, the pusher-guide 4 has continued to rotate in the clockwise direction for reaching its maximal opening position which permits the pusher 5 to completely free the aperture of the chute 3 b in order to very easily refill it with products to be processed.
 Since the pusher-guide is articulated on a pin 4, contact of the rod 2 b on the switch 1 a is made when the lower surface of the pusher-guide 4 forms an angle of about 10° with horizontal in the clockwise direction and is interrupted when the lower surface of the pusher-guide forms an angle of about 11° in the anti-clockwise direction. This means that a small pivoting of the pusher-guide will interrupt the contact between the rod 2 a and the switch 1 a, which will stop the motor which is no more supplied in electrical power. In the direction for obturating the chute, a slightly untimely closing enables to operate when food, for example vegetables having an irregular shape, will pass beyond the inlet level of the chute. Thus, the same can be loaded at its maximal capacity.
 A significant advantage of the inventive safety system is the possibility to use a cylindrical chute, or a chute having another shape of a surface equal to that of the pusher and of a height equal to the stroke of the pusher. Thus the worked volume is optimal.
 Another advantage of the kinematics as retained is the safety in use of a chute the products of which may slightly pass beyond it, which avoids to calibrate the products, thus increasing greatly the easiness of use. Simplicity of the mechanics which forms this safety system, with respect to the prior art, enables to clearly show, in addition to the already mentioned advantages, an increased reliability.
 It is obvious that various variants may be brought into effect, in particular by substitution of equivalent technical means, without therefor departing from the scope of the invention.