Solid material comminution or disintegration – Apparatus – With means to protect operator from injury
Reexamination Certificate
2000-03-08
2001-04-03
Rosenbaum, Mark (Department: 3725)
Solid material comminution or disintegration
Apparatus
With means to protect operator from injury
Reexamination Certificate
active
06209810
ABSTRACT:
The present invention relates to an electric household appliance for the preparation of foodstuffs, such as for example a chopper, comprising a housing enclosing an electric motor group whose output shaft projects from the housing and is adapted to drive in rotation a working tool disposed within a bowl on which is fixed a removable cover comprising a tongue fixed on the periphery of the cover; and a safety device comprising a switch arranged in the electrical supply circuit of the motor, a control pusher for the switch vertically slidably mounted within and on the periphery of the housing, associated with a return spring, and actuated by a manual control member fixedly connected to the pusher and movably mounted on the housing between a stop position and a start position, means permitting, on the one hand, locking the manual control member in the stop position when the cover is not correctly fixed on the bowl such that the pusher remains in an upper position in which it does not actuate the switch, and on the other hand, to unlock this manual control member in the stop position when the cover is correctly secured on the bowl such that, by manipulating the control member toward its start position, the pusher slides to a lower position in which it controls the closing of the switch to permit supply to the motor, as well as retaining means coacting with the tongue of the cover to prevent opening this latter when the pusher is moved toward its low position.
In known electric household appliances with manual control of this type, the safety device permits the starting of the apparatus by actuating the manual control member toward its start position only when the cover is correctly secured on the bowl, whilst preventing in the course of operation of the apparatus the opening of the cover thanks to the retaining means coacting with the tongue of the cover, thereby permitting protecting the user from any risk of harm which would be due to the moving working tool, generally constituted by a slicing tool which is considered dangerous, if the apparatus were started when the cover is not correctly secured on the bowl or if the cover was removed in the case of operating the apparatus. At the end of preparing the foodstuff, the pusher rises again to its upper position under the force of its return spring, so that the switch leaves its open position to cut the electrical supply to the motor, and the manual control member which is fixedly connected to the pusher is then returned to the stop position in which the cover can then be opened and removed.
Although such electric household appliances offer effective safety to the user, there nevertheless remains the risk of harm to the user in the case in which the switch is blocked in its closed position due for example due to sticking of the fixed and movable contacts of the switch, or else to a fault in manufacture of the switch. Thus, in this case, the pusher rises under the action of its return spring, carrying with it the manual control member toward its stop position, and the cover can then be opened and removed; the motor being still supplied, the working tool continues to turn in the bowl without the cover, which is dangerous to the user if he accidentally introduces his hand into the open bowl.
The invention has particularly for its object to overcome this risk and to provide an electric household appliance, of the type mentioned above, in which the safety device offers complete safety to the user.
According to the invention, the safety device comprises means permitting holding the pusher in the lower position when the switch is stuck in its closed position.
Thus, it will be understood that by preventing the pusher from rising to its upper position in the case in which the switch is stuck in its closed condition, the manual control member cannot then be brought toward its top position, and it is hence impossible to take the cover off the bowl. The user must then unplug the apparatus to stop the motor before proceeding to a subsequent disassembly of the appliance.
For a switch of the type comprising a body in which is vertically slidably mounted a contact pusher which has two end positions, respectively upper and lower, projecting from the body, and which carries, adjacent its lower end, a metal ring serving as a movable contact adapted to coact with two fixed contacts mounted on said body, and according to a preferred embodiment of the invention, the pusher is permanently urged against the upper end of the contact pusher, and the holding means of the pusher in the lower position is constituted by a first tongue fixedly mounted on the pusher and which permanently bears against the lower end of the contact pusher.
Preferably, the pusher and the first tongue are made of a single piece of plastic material.
Thus, this continuously urged tongue which is a permanent part of the pusher constitutes a simple member, inexpensive and easy to make, reliable, and completely adapted to mass production.
REFERENCES:
patent: 4373677 (1983-02-01), Kunihiro
patent: 5353697 (1994-10-01), Venturati et al.
patent: 11 65 215 (1964-03-01), None
patent: 2 018 930 (1979-10-01), None
patent: WO 96/22720 (1996-08-01), None
Moulinex (S.A.)
Rosenbaum Mark
Young & Thompson
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