Abstract:
A safety device for a food processor, enables operation of the motor only when a pusher occupies the chute through which food products are introduced, thus preventing injury to the hands. The pusher has a rib, the lower end of which bears against a slider that can have a parallelogram cross section with inclined opposite end faces. When the pusher is advanced so the rib passes the slider, the rib displaces the slider laterally. The displaced slider in turn displaces a lid rod. The lid rod bears against a bowl rod. The lower end of the bowl rod operates a switch.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to food processors or other appliances for processing food and, in particular, to a device intended to be used with the said processors to allow them to process large-sized food while at the same time avoiding any possible contact between the hand and the rotating tool. 
     Such processors comprise a base containing an electric motor, the shaft of which projects from the upper part of the base to receive a rotating tool inside a bowl mounted removably on the base, the said bowl being closed by a lid from which there projects a chute through which the food to be processed is introduced, the base including a switch against which the lower end of a safety rod extending along one generatrix of the bowl bears, the upper part of the rod coming into contact with a cam borne by the lid. A processor such as this is described in U.S. Pat. No. 3,892,365 (Verdun). 
     The lid is fixed to the bowl removably and the food to be processed is introduced into the chute and then pushed through it by a pusher designed to slide in the chute. 
     To avoid any contact between one of the user&#39;s hands and the rotating tool driven by the electric motor, the hopper is generally tall and of small cross section, preventing the user from inserting a hand. A safety lock is provided to inhibit operation of the processor until the lid is locked in place on the bowl in the operating position. 
     This locking effect is obtained by a cam formed at the lower part of the lid and which closes a switch fixed in the base of a processor only when the lid is appropriately locked onto the bowl. Various embodiments allow the command needed to be applied to the switch directly or via mechanical or magnetic linkages. 
     Unfortunately, the geometry of the chute, while it prevents hands from being introduced, also limits the size, shape and amount of food that can be processed. It has already been proposed that use be made of wider chutes for processing food of a larger size, but safety considerations also need to apply in this case. 
     A chute protector is described in U.S. Pat. No. 4,226,373, this protector comprising a sleeve designed to slide around the chute, the said sleeve including a safety control member for the motor which cannot be started except if the sleeve is appropriately positioned on the chute. A pusher is mounted captively at the upper part of the sleeve so that this pusher can be moved back and forth inside the chute but cannot be withdrawn from the sleeve. In that patent, the pusher of the food introduced into the chute closes access to the widened chute when the sleeve is appropriately positioned on the chute, to allow the processor to work. 
     Another protective solution is described in U.S. Pat. No. 4,523,720. A cylindrical hopper of a diameter roughly equal to the diameter of the working bowl closed by a lid is fixed onto the working bowl. The cylindrical hopper is closed by a hopper lid which needs to be appropriately positioned thereon before the motor of the processor can be switched on. 
     In both instances, the protective device has to be completely removed when the food to be processed is loaded into the widened chute. This results in a discontinuous mode of operation which is disagreeable. 
     To alleviate this drawback, U.S. Pat. Nos. 4,614,306 and 4,614,690 also propose protecting the chute with something articulated to the lid of the bowl between a closed position over the opening of the chute and a position away from the opening. To validate the switching-on of the motor using the aforementioned switch, that patent envisages, above a control rod arranged along a generatrix of the bowl, a second control rod which is pushed by hand when the chute protector is in the closed position. 
     Although the arrangements described in these patents lead to a simplification in terms of operation by comparison with American U.S. Pat. No. 4,226,373, it nonetheless remains the case that filling the chute once again entails an additional operation of pivoting the chute protector out of the way. 
     To remedy this drawback, it has already been proposed that the member controlling the switching-on of the motor be included not in a chute protector but in the pusher itself. Such a proposal appears in the embodiments of FIGS. 5 to  7  of U.S. Pat. No. 4,741,482. In that patent, the control member is a magnet fixed into the pusher and which, when the pusher is introduced into the chute, faces a magnetic rod and transmits the field of the magnet of the pusher to a magnetic switch situated in the base. The magnetic rod may be made in two parts, one borne by the working bowl and the second by the lid. Aligning the two rods corresponds, on the one hand, to the locking of the bowl on the base and, on the other hand, to the locking of the lid on the bowl. Thus, it is possible for the chute to be refilled only by extracting the pusher, which simplifies operation. 
     However, such transmission of magnetic energy entails a pusher magnet with a strong field and, what is more, magnetic disturbances may arise near the pusher and the transmission rods. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to overcome these drawbacks and to propose a mechanical solution for an operating safety device for a wide-cross-section chute which may be of short height. 
     According to the invention, the mechanical safety device for a food processor, comprising a base containing an electric motor, to which there is removably attached a bowl closed by a lid, the bowl being equipped with a bowl safety rod, loaded by a spring, acting on a switch mounted in the base, the lid having at least one chute for introducing the food, is characterized in that the lid is equipped with a lid rod aligned with the bowl rod, the pusher having a longitudinal projection bearing against a member for converting the vertical movement of the pusher into a vertical movement of the lid rod, causing the lower end of the lid rod to bear against the upper part of the safety rod of the bowl and causing the lower part of the rod to bear against the switch. A converting member able to move in horizontal or oblique translation is to be understood as meaning any known means allowing a vertical translational movement to be converted into another vertical translational movement such as a slider, a rocker, a ball, etc. 
     According to another feature of the invention, the independent moving member moves against the upper wall of a housing containing the lid rod and is held in a position the opposite of its starting position once the pusher has been introduced into the chute. 
     According to another feature of the invention, the projection of the pusher has, at its lower end, an inclined surface bearing against an inclined face of a parallel-sided slider, the second face of which presses against the upper end of the second safety rod in the lid. 
     The lid rod or second rod is returned constantly upwards by a return spring. Thus, as soon as the pusher is removed from the chute, the spring, via the lid rod, returns the slider to its starting position, contact with the bowl rod being interrupted and the latter rising towards the top of the bowl, under the action of its spring, breaking contact with the switch which opens again. 
     To take up the lateral clearance of the lid rod, the latter may be made in two parts hinged together, the upper part being able to pivot on the upper end of the lower part. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Features and advantages of the invention will become apparent in the course of the description which will follow of some particular embodiments which are given solely by way of nonlimiting example with reference to the figures which depict: 
     FIG. 1, a view in vertical part section of a processor equipped with a safety device according to the invention; 
     FIG. 2, in vertical section, the upper part of the lid during introduction of the pusher into the chute; 
     FIG. 3, under the same conditions as in FIG. 2, the pusher completely introduced into the chute, 
     FIG. 4, a perspective view of the device in the work position; 
     FIG. 5, under the same conditions as in FIG. 4, the device in the position for extracting the lid. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows, like in numerous processors of this type, a base  10  on which is removably mounted a bowl  7  closed by a lid  8 . The base includes an electric motor driving a tool which, in the example depicted, is a vegetable-cutting disc  16 . Projecting from the upper part of the lid  8  is a chute or hopper  6  for introducing the products that are to be worked. A pusher  5  is slideably mounted in this hopper. Of course, the bowl  7  is locked onto the base  10  and, during operation, the lid  8  is locked onto the bowl  7  by known means (not depicted). As described in U.S. Pat. No. 3,892,365, the bowl has, along one generatrix, a housing  36  inside which is slideably mounted a bowl rod  3 , loaded by a spring  31  and the lower end of which can bear against the control member of a switch  4  mounted in series in the electric circuit that powers the motor  15 . 
     In the aforementioned patent, the lid  8  was equipped with a cam bearing against the upper end of the rod  3  so that, when the lid  8  is in place, the lower end of the rod  3  bears against the control member of the switch  4 , allowing the motor to be switched on by, for example, a control button  12 . 
     Such a cam does not exist in the safety device according to the invention. By contrast, validation of the switching-on of the motor entails pressing on the upper end of the bowl rod  3 . 
     According to the invention, this pressing is exerted by a rod  2  slideably mounted in a housing  9  extending along the chute, the rod  2  being loaded by a spring  21  which, in the absence of any urging, pushes the rod  2  back upwards. 
     It is the introduction of the pusher which will lower the rod  2  which will then bear against the upper part of the rod  3  and lower the latter so that its lower end presses against the control member of the switch  4 . 
     The way in which the upper part of the processor works will now be described with reference to FIGS. 2 and 3. In FIG. 2, the pusher  5  is beginning to be introduced into the chute  6 . Over its entire height it has a rib, blade or projection  1  which, at its lower part, has a chamfer or cut surface  11 . As the pusher begins to be introduced, the blade  1  bears via the inclined surface  11  on the face  31  of the slider  13  moveable against the upper surface of the housing  9  at right angels to the direction of insertion of the pusher  5 . It is preferably made of a hard plastic such as polyamide or DELRIN, coated with a non-stick coating for example of PTFE, but may just as easily be fitted with rollers. Thus, the entry of the pusher will move the slider  13  to the right in the figure. The side  32  opposite the inclined surface  11  is parallel to the latter, the cross section of the slider consisting of a parallelogram. The upper end  22  of the rod  2  is pressed against this parallel face, the end  22  being shaped in such a way that it can slide against the face  32 . As mentioned previously, the spring  21  returns the rod  2  to a raised position as depicted in FIG.  2 . As soon as the cut surface  11  of the rib  1  escapes from the slider  13 , the latter remains immobilized on the right-hand side of the housing  9  by the longitudinal face of the rib  1  as depicted in FIG.  3 . The movement of the slider  13  to the right converts the lateral force applied by the pushing-down of the pusher  5  into a vertical force which is applied to the head  22  of the rod  2  which causes the latter to move down as depicted in FIG.  3 . At that moment, the rod  2  moves down, its lower end  23  projects beneath the housing  9 . If the bowl and the lid are in the working position, that is to say if the bowl is locked onto the base and if the lid is locked onto the bowl, then the rods  2  and  3  are aligned and the lower end  23  of the rod  2  bears against the upper part of the rod  3 , which causes it to be lowered and its lower part to come into contact with the member controlling the switch  4 . Thus, it is whether or not the pusher is introduced into the chute which validates the starting of the motor using the control button  12 . 
     Operational safety of the processor is ensured by the presence of the pusher inside the chute as soon as the pusher is introduced. The chute can thus have any cross section and a relatively short height without any danger to the user&#39;s hand. 
     The embodiment which has just been described does, however, have one disadvantage, namely that the lid cannot be removed from the bowl unless the pusher is removed from the chute which, as far as the user is concerned, may be a practical disadvantage. What happens is that it may be desirable for the lid and the pusher to be removed simultaneously without the latter having been extracted beforehand. 
     FIG. 4 again shows the elements mentioned previously. The lower part  33  of the rod  3 , the lower part of which is forked, projects and acts on the control of the switch  4  (not depicted in this figure). This position results from the introduction of the pusher into the chute  6  which moves the member  13  sideways and results in a pressure on the rod  2  which pushes the lug  24  down which itself pushes down the rod  3  and causes the end  33  to project. For this purpose, the part  34  has an inclined surface  35  against which the lug  24  bears. 
     In the handle  71  of the bowl  7 , in the upper region where the handle meets the bowl, there are three notches, one of which is reserved for the passage of a tenon  82  (FIG.  5 ). Above this notch there are two other notches, a lower notch  72  and an upper notch  73 , which allow the lug  24  to enter the handle when (notch  72 ) the pusher  5  is in the chute  6  and (notch  73 ) when the pusher is not in the chute. In both instances, the lug  24  can be brought above the part  34  to press on it or to release it. A stop  81  provided on the lid immobilizes the latter in terms of rotation in the desired position which, incidentally, corresponds to the position in which the lid  8  is locked on the bowl  7 . 
     By means of these notches, the lug  24  can enter the chamber  36  of the rod  3 . However, it can also leave it, allowing the lid  8  to be removed without withdrawing the pusher from the chute. 
     FIG. 5 depicts the same device after the pusher has been extracted from the chute and the lid has been rotated in the clockwise direction. Under the action of the spring  31 , the rod  3  has risen back up and its lower end  33  no longer projects. If the pusher  5  is in the chute, the lug  24  occupies the position depicted in solid line. If the pusher has been extracted therefrom, the lug  24  occupies the position depicted in broken line. 
     It goes without saying that variations can be introduced, particularly by substituting equivalent technical means without thereby departing from the scope of the invention.