CA1164319A - Magnetic safety device, inter alia for a food processor - Google Patents
Magnetic safety device, inter alia for a food processorInfo
- Publication number
- CA1164319A CA1164319A CA000358880A CA358880A CA1164319A CA 1164319 A CA1164319 A CA 1164319A CA 000358880 A CA000358880 A CA 000358880A CA 358880 A CA358880 A CA 358880A CA 1164319 A CA1164319 A CA 1164319A
- Authority
- CA
- Canada
- Prior art keywords
- magnet
- safety device
- duct
- pusher
- bowl
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J43/00—Implements for preparing or holding food, not provided for in other groups of this subclass
- A47J43/04—Machines for domestic use not covered elsewhere, e.g. for grinding, mixing, stirring, kneading, emulsifying, whipping or beating foodstuffs, e.g. power-driven
- A47J43/046—Machines for domestic use not covered elsewhere, e.g. for grinding, mixing, stirring, kneading, emulsifying, whipping or beating foodstuffs, e.g. power-driven with tools driven from the bottom side
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J43/00—Implements for preparing or holding food, not provided for in other groups of this subclass
- A47J43/04—Machines for domestic use not covered elsewhere, e.g. for grinding, mixing, stirring, kneading, emulsifying, whipping or beating foodstuffs, e.g. power-driven
- A47J43/07—Parts or details, e.g. mixing tools, whipping tools
- A47J43/075—Safety devices
- A47J43/0761—Safety devices for machines with tools driven from the lower side
- A47J43/0766—Safety devices for machines with tools driven from the lower side activated by the proper positioning of the mixing bowl
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J43/00—Implements for preparing or holding food, not provided for in other groups of this subclass
- A47J43/04—Machines for domestic use not covered elsewhere, e.g. for grinding, mixing, stirring, kneading, emulsifying, whipping or beating foodstuffs, e.g. power-driven
- A47J43/07—Parts or details, e.g. mixing tools, whipping tools
- A47J43/075—Safety devices
- A47J43/0761—Safety devices for machines with tools driven from the lower side
- A47J43/0772—Safety devices for machines with tools driven from the lower side activated by the proper positioning of the cover
- A47J43/0777—Safety devices for machines with tools driven from the lower side activated by the proper positioning of the cover in which the activating element on the cover transmits a signal to a safety device in the base element via the mixing bowl removably seated on this base element, e.g. pin on the cover moves a pushrod in the bowl handle to operate safety switch in the base element
-
- A—HUMAN NECESSITIES
- A47—FURNITURE; DOMESTIC ARTICLES OR APPLIANCES; COFFEE MILLS; SPICE MILLS; SUCTION CLEANERS IN GENERAL
- A47J—KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES
- A47J43/00—Implements for preparing or holding food, not provided for in other groups of this subclass
- A47J43/04—Machines for domestic use not covered elsewhere, e.g. for grinding, mixing, stirring, kneading, emulsifying, whipping or beating foodstuffs, e.g. power-driven
- A47J43/07—Parts or details, e.g. mixing tools, whipping tools
- A47J43/075—Safety devices
- A47J43/0761—Safety devices for machines with tools driven from the lower side
- A47J43/0794—Safety devices for machines with tools driven from the lower side in which operation is not possible without the use of a food pusher
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Food Science & Technology (AREA)
- Food-Manufacturing Devices (AREA)
Abstract
ABSTRACT
A magnetic safety device, inter alia for a food processor, wherein, when a cover (10) is locked on a bowl (3), which in turn is locked -to a base (1), a permanent magnet (12) is brought towards a magnet-ically controlled working contact (11) connected in series in the supply circuit of a motor (2).
A magnetic safety device, inter alia for a food processor, wherein, when a cover (10) is locked on a bowl (3), which in turn is locked -to a base (1), a permanent magnet (12) is brought towards a magnet-ically controlled working contact (11) connected in series in the supply circuit of a motor (2).
Description
3 :~ ~
DESCRIPTION
The invention relates to a magnetic safety device of use more particularly though not exclusively in a ~ood processor.
Devices of the aforementioned kind conven-tionally comprise a base enclosing an electric motor haYing a shaft on which various tools such as knives or scrapers can be mounted. The drivè shaft projects into a bowl adapted to enclose the tools and the products which have been or are being processed. In some cases-the bowl is removably mounted on the base for ease in cleaning. The bowl is closed by a like-wise removable cover, the main purpose of which is to prevent material from being thrown out of the bowl.
The devices have to be fitted with a safety means. They are dangerous because the tools are driven at high speed in the bowl and any contact with a rotating tool may result in serious injury. This need is all the more urgent in that the devices are for use by people without special trainingO
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The safety means must meet two conditions.
The motor must be stopped (a) when the bowl is not properly fitted on the base and (b) when the bowl is properly fitted on the base but the cover is not locked on the bowl. The first condition corresponds to the case where the tool is mounted directly on the drive shaft without the bowl~ The second oondition corresponds to the case where the bowl is in the proper position but the cover is not dispose on it, so that a hand or finger can be inserted during operation. In short, -any contact wi-th the rota+ing tool must be prevented~ This result can be obtaine~
by disposing a workir~ contact in the base, the contact being connected in series in the motor supply circuit ~nd being open or clo~ed depending on whether the bowl and cover are properly positioned, i.e~ the cover is locked to the bowl and the bowl is locked to the base.
One solution has already been proposed in United States Patent Specifica-tion 3 892 365 in the name of Pierre Verdun. In this specification, tne bowl is secured to the base by a bayonet means which ensures accurate positionin~. The cylindrical ~essel has a 4 3 :~ ~
duct extending along a generatrix and enclosing a pusher. The cover is locked in the raised position by stops and a cam bears against the top end of the pusher so that when the cover is locked the pusher is pushed downwards and its bottom end bears against an electromechanical switch, via a hole formed in the base. The aforementioned conditions are fulfilled SinGe the pusher cannot enter the base unless the duct is opposite the hole, i.e. the bowl is properly posi-tiQned on the base, and unless the cam bears on theto~ end of the pusher, io e 9 the cover is locked on the bowl.
~ owever, the aforementioned device cannot be considered perfectly reliable since a child, for example, c~n actuate the working contact by inserting a pointed ~bject into the ori~ice in the base when the bowl is not in position, thus rotating the drive Shl~ft. When the bowl is in position~ it is also possi~e to start the motor by pressing the top end of the pusher. Finally, there may be difficulties in cleaning and maintaining the pusher, which is pushed upwards by a spring.
t ~ ~3~ ~
The aim of the invention is -to obviate the aforementioned disadvantages and cons-truct a safety device which is more reliable.
The invention relates to a magnetic safety device~ inter alia ~or a food processor comprising a base ~rom which a drive sha~t extends and is adapted to receive various tools~ the processor also comprising a ~irst element detachably mounted on the base and bearing means for securing to the base so as to hold it in a given position, a second ele-ment bearing means for locking to the first elemen-t in a given positionD and a duct extending along a generatrix o~ the first element so that in the operating position a substantially punctiform region of the base is geometrically in line with the axis of the duct and a point on the second element, char-acterised in that at least one magnetically controlled contact is disposed in the base and at least one per-manent magnet is secured to one of t~e two elements.
In the preceding patent, the pusher enters the base and thus mechanically transmits the inform-ation that the cover has been locked and thus enables the rnotor to start. In the present invention, by 3 ~ ~
contrast, this information is transmit-ted by the flux of a magnet, which is not applied to the working relay until all the elements are properly locked. This has an îmmediate advantage. It is no longer necessary to form a hole in the base, since the base is moulded in non-magnetic plastics. The position of the magnetically controlled contact cn the periphery of the base is not visible, as a hole must be. Furthermore t-~e safety device cannot be inactivated unless by a person in possession of ~
magnet~ which greatly reduces the risk of imp~operly starting the motor.
Other features and advantages of the ir~ve~-tion will be clear fro~ the following description of preferred embodiment~ of the invention, given with reference to the accompanying drawings i~
which:-Figure 1 is a diagrammatic view, partly ~section through a vertical plane, of a food processor i comprising a rotary tool and equipped with two safety devices, one beia~ mechanical and the o~her magnetic according to the invention;
3 ~ 9 Figures 2 and 3 show the two positions o~ a single magnetically-controlled safety device mounted on a means of the same kind as in Figure 1;
Figure 4 is a view in section through a vert-ical plane of another embodiment o~ the device, inwhich the magnet is disposed in the cover;
Figure 5 is a view in vertical section of a device in which the motor is started by inserting a pushe~ ~nto a chute;
Figure 6 shows an embodiment similar to Figure 51 likewise in vertical section;
~ igure 7 is a top view of the device shown in Figure ~; ¦
~ i~ure 8 is a vertical section of a pusher;
Fl~ures 9 and 10 show the two positions o~
a devi~e ~ccording to the invention involving the movement Gf a rod, ~hich is mounted on apparatus of a ki~-d ~om~on ~o all the embodiments;
F~gure 11 is a view of the cover in the embo~iment sh~wn in Figures 12 and 13; and ~ igure~ 12 and 13 show the two posi~tions (operat?~e and inoperative) o~ another device according ~o t~e invention.
J ~3~9 In all the Figures, like references denote like elements. Figure 1 shows a hollow base 1 made e.g. of moulded plastics. It encloses an electric ~otor 2 mounted so that its axis is vertical and extends through the top wall 1a of the base~ Alter-natively9 the ver-tical output shaft of a speed reduction gear can extend through wall 1a and its input shaft can be coupled to the output shaft of motor 2, which can be disposed parallel to the bowl.
A removable~ e.g. cylindrical bowl 3 has a bottom 3a formed with an aperture forthe end of the sha~t or motor 2 or the output shaft of a speed reduction gear, when the bowl is mounted on b~se 1 and in Figure 1. A tool 4 comprising radial knives 4a can be coupled by any appropriate means to the end of the shaft in bowl 3 mounted on base 1~ The afore-mentioned known processor, which comprises a rotary tool, is fitted with a mechanical safety device known from the cited pa-tent. The de~ice mainly ~0 comprises a working contact 5 having a control push-button 5a and secured inside base 1 above a hole 6 formed in a horizontal flat portion 1b of the base or casing, disposed below a cylindrical skirt 3b -~ :l6~3~
g which downwardly prolongs the bottom 3a of bowl 3.
Hole 6 is dispose~ so as to be exactly below a duct 7 formed along a generatrix of bowl 3. Duct 7, which is preferably moulded integrally with bowl 3 and made o~ synthetic material such as polycarbonate, is adapted to receive a pusher 8, preferably made of electrically insulating material. A spring 9, which bears on the bottom of duct 7 and on a central part of rod 8, tends to push rod 8 towards a top position, illustrated in Figure 1, in which a collar secured to the top part of pusher 8 abuts the top end of duct 7.
Pusher 8 is also prolonge,l at the bottom by a cylin-drical actuating means 8a which can engage in hole 6 to actuate the pusher 5a of switch 5. The top end of pusher 8 is prolonged by an actuating means 8b which can co-operate with a slo?e lOb forming a cam and disposed in a substantially peripheral position on a flange or external projection lOa inteyrally moulded with cover 10 or secured to the cover by any approp-riate means. Cam lOb is disposed so that when cover 10 is brought into a give:n position by pivoting the skirt 20, cam lOb pushes the pusher 8 downwards, com-presses spring 9 and enables the bottom actuating means 8a to engage in hole 6 an~ thus act on contactor 5.
~ ~6~3~g According to the invention, a second working contact 11 is mounted inside base 1 below a flat part lc, e.g. diametrical]y opposite part la and substantially at the same level, so as to extend below the cylindrical skirt 3b of bowl 3. ~ perman-ent magnet 12, made e.g. of ferrite~ is secured to skirt 3b in a position sueh that it is exactly below the magnetically controlled eontaet 11, so as to aetuate it when bowl 3 is mounted in base 1 in a position such that pusher 8 is exactly above hole 6.
Aceording to another feature of the invention, the magnetie working contact Ll and the mechanical work-ing contact 5 are conneeted in series in the suppl,v eireuit of the motor (not shown).
In the ease of t]le deviee shown in Figure 1, tool 4 eannot be driven in rotation unless (a) bowl 3 is mounted on base 1 in the eorreet position for pusher 8 and magnet 12 to be above eontaet 5 and 11 respectively and (b) eover 10 of vessel 3 is in the proper elosure position where its eam lOb aetuates pusher 8 so as to eompres~ spring 9. In this position likewise, a flange lOe on the eover engages a stop 17 whieh prevents any lifting movement of the eover.
J 1~43~g If the cover is not in position or is improperly closed, the mechanical contact 5 opens the circuit -and the motor cannot s-tart~ The same happens if bowl 3 is not mounted on the base, since the supply circuit of motor 2 is then also cut by the magnetic contact 11. In the lat-ter case a child, ~or example, can mount tool 4 on the end of the shaft emerging from the top wall 1a of the base and can actuate pusher 5a of contact 5 by inserting a poin-ted obJect into hole 6. This operation, however, is insufficient to cause dangerous rotation of tool 4 since th~ supply circuit of motor 2 is interrupted by contact 11~
Figures 2 and 3 show the top right p~rt of the device in Figure 1~ equipped with a sing~
magnetically controlled safety device. The on~
difference between this variant and ~igure 1 i~ that a magneti.cally controlled contact 11 is mounted in base 1 below a ~lat surface 1b which does not ha~e any orifice. A cylindrica1 permanent magnet 1~ is secured to the bottom end of pusher 8. In this ~ase~
a single working contact 11 is inserted into ~he supply circuit oi motor 2.
1 3 ~ g When bowl 3 is not mounted on base 1, contact 11 cannot of course be actuated by the magnet 12 secured to bowl 3, so that no mechanical action on base 1 can start the motorO The same applies when bowl 3 in properly moun-ted on the base but cover 10 is not closed or is improperly closedO It is only when cover 10 has been rotated into its proper posi-tion tha-t cam 10b exerts a downward force on usher 8 via the top actU~ting component 8b so as to compress spring 9 and appr~ac-i~ the permanent magne~ 12 of contact 11 (Figure 3~. It is only then that conta~t 11 closes so as t~ supply the electric motor ~nd dri~e tool 4.
A slightly ~i~ferent embodiment is sho~m in Figure 4~ whic~ i~ likewise a vertical section : through a food pr~c~ssorr In Figure 4, the ~e~vice : comprises a magnet 12 secured by any appropriate meanS to cover 10~ a~ more specificall~ in a fla~-ge 10a in the cover. ~s before, a magnetic -flux m~s~
be applied to contac~or 11. According to another feature, the magn~ti~ flux is transmitted fro~ ma~net : 12 to contactor 11 b~ a rod 12a of ferromagn~tic material such as soft iron or ferrite, th~ rod being ~ ~6~3i~9 -- ~3 mounted in duct 7 and secured inside it. In Figure 4, the device is in the operating position~ i.e.
ro-tation of cover 11 on bowl 3 resul-ts (a) in engage-ment of flange 10c with top 17, a similar device being provided at flange 10a but not being shown in the cross~section and (b) the permanent magnet 12 is brought above rod 7 which is thus magnetically polarized and transmits the polarization to contact 11, which closes the supply circuit of motor 2.
'~0 When the cover rotates, ~uided by the internal skirt 20 which also ensureæ sealing-tightness, the flanges are released from the stcps and thus unlockcover 10 and magnet 12 moves from rod 12a; the magnetic field disappears and the working contact of relay 11 opens and stops -the motor.
In order to r~duc~ the air gaps, the ferro-magnetic rod 12a~ embedded eqg. in plastics in duct 7, comes in contact ~-ith ~ very thin end bottom wall 29 and top wall 30, in order to avoid loss of flux.
A different kind of tool from that previously mentioned is sho~n in broken lines in Figure4 , i.e, a scraper disc 15 which can be mounted on the shaft of motor 2 via a hub 14. To use the scraper, ~he ~ 1~43~g products must be brought against disc 15 when it rotates, This can be done in known manner by means of a chute 13 into which a pusher 16 can be inserted.
As in all emhodiments 9 the magnetic working contact is preferably an "I.L.S." type contactor, also known as a Reed relay of the kind manufactured by Messrs R.T.C. LA RADIOTECHNIQUE-COMPE~EC3 refer-ences RI 22 3A, RI 22 AA or RI 42.
The previously-described embodiment has the advantage of not kaving any parts which move when switch 11 is opened or closed. Note that the device is mounted on a means comprising a base 1 bearing a first element (bowl 3). A second element (cover 10) can be locked in a fixed position so that magne-t 12, the axis of duct 7 and the magne-tic working contact 11 are in line; in the latter case the magnet is secured to the cover.
Figures 5 - 8 illustrate another embodiment in ~hich the locking information is as before trans-mitted by a rod of ferromagnetic material~ InFigures 5 - 8, magnet 12 is secured not to the cover but to the pusher which penetrates into chute 13.
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- 15 ~
Figure S is a view in section in a vertical plane of a food processor or kitchen robot of the previously-described kind. Figure 7 is a top view oE the same device in section along line VII-VII of Figure 5. Figure 5 shows a base 1 bowl 3 and eover 10 surmounted by a chute L3 for inserting products and containing a pusher lfi for pushing the products downwards without any po sible contact between the hand and the rotating -tool 15. As before the bowl can be locked to the base by a bayonet fitting or a screw thread/ for example in a given position in which duct 7 is aligned w:ith the actuating contact 11 which is included in the base. Cover 10 is locked by stops 17 whieh are moulded integrally with the bowl and at the top thereof above flanges lOa lOc formed in the cover. A stop 17 is shown in Figure 7.
The stop co-operates with a diametrically opposite stop (not shown in Figure 7) to defin~ a given position of the cover on the bowl and consequently define a given position oE the cover relative to the base.
According to the invention bowl 3 has a duct 7 along one of its generatrices the duct 3 ~ g containing a rod 12a o~ ferromagnetic material such as soft iron. When the bowl is mounted on the base as shown in Figure 5, the bottom end of rod 12a is opposite a magnetic switch 11~ disposed immediately below the flat surface 1b of face 10 In the embod-iment in F'igure 5, duct 7 extends above bowl 3 and is substantially egual in height to the sum of the heights of bowl ~, cover 10 and chute 13. Pusher 16 has a per~anent magnet 12 having a strong field (e.g. 40,000 Gauss~ along cne of its side walls.
The mode of operation of the device is self-evident~ When pusher 16 is inserted into chute 13 magnet 12 comes oppos~te rsd 12a and magnetically polarizes it~ The polariæation is transmitted to the 1~ bottom part of rod 12a an-d acts on contactor 11~ thus closing it and enabling ~he motor to start, since it is connected to the motor supply circuit. As shown in Figure 73 contact~r ~1 cannot be actuated unless magnet 12 is exactly opposite the rod, i.e. unless the cover is locked on the ~
This feature provl~es a considerable advan-tageO For safety reasons~ the dimensions of known 4 3 ~ ~
chutes must be such that it is impossible to inser-t a hand or even a finger, since the height of the chute is greater than the length of a finger. Consequently, existing chutes are high ~nd have a small cross-sectior. which makes it diffi-cult to scrape certain vegetables, since they first have to be cut into small piecesO As a result of the invention, the cross-section of the chute can be increased as much as required for cooking, since it is the pusher itself which starts the motor when inserted in the chute. Consequently, neither the hand or any part of it can come in contact with the rotating -tool. As shown in Figure 7, the cross-section o~ chute 13 has been considerably increased.
Rod 12a can also be protected from any external mag-netic influence by disposing a magnetic screen, e.g. of ~ metal, inside duct 11 round its entire per_phery except the region opposite magnet 120 Figure 6 shows an embodiment in which, in order to simpli~y certain manufacturing problems, rod 12a is divided into two parts, i.e~ a part 12a1 secured to cover 10 and a part 12a2 secured to bowl 3 The two parts can be directly moulded on the bowl or 3 ~ g cover or can be secured thereto after moulding.
If elements 3 and 10 are properly mounted, the rod parts 12al and 12a2 are brought in lina with one another an~ 12al is polar:ized by magnet 12, thus polarizing 12a2 and consequently changing -the state of contactor 11. In the rase where knives are used, all the ingredients may be introduced into the bowl before it is closed by the cover, and the motor can be started by inserting pusher 16 into chute 13.
In such cases the pusher ,erves only as a safety closure means. It may ha?pen, however, that pro-ducts have to be inserted during operation of the device without stopping it. In such cases it is possible to use a "pusher" ]6a fitted with a magnet 12 but having a funnel-shaped internal wall such as the wall 18 of pusher 16a shown in Figure 8. Wall 18 is designed for inserting liquid or pulverulent pro-ducts but prevents a finger being inserted.
In the case of high elements, however, the reluctance of the resulting magnetic circuit may be too powerful for perfectl~y reliable operation, in which case -the safety device will not be inactivated when the aforementioned conditions are fulfilled~
l 18~3 The following description relates to means for obviating this disadvantage. Figures 9 and 10 show two states of a single safety device according to the invention, applied as before to a food processor~ only part of which is shown in the drawing.
As before, Figures 9 and 10 show a base 1, a vessel 3 and a cover 1~ surmounted by a chute 13. The drawings are sections in a ~ertical plane extending through the axis of the bowl-and the axis of duct 7. As a result the permanent ~agnet 12 is shown only in Figure 100 As in a p~eceding embodiment9 magnet 12 is secured to a ~lange 10a on cover 10~ However, the ferromagnetic rod in duct 7, which as before is positioned above the m2gnetic working contact 11, is replaced by a mobile ~ssembly comprising a rod 23 bearing permanent magnets at both ends, i.e. a magnet 19 at the bott~m end and a ma~net 22 at the top end. Duct 7 is ~ocked at the bottom and top by thin covers 29~ 30 re~ectively. Rod 23 is slidably mounted by any appropriate means inside duct 7 and between walls 29 and ~. The central part of rod 23 has a collar 24 abutting an end o~ a return spring 9 which also bears agaL~st a ring 25 formed inside 3 1 ~
duct 7. According to a feature o.~ the last-mentioned embodiment/ the facing poles of magnets 12 and 22 nave the same polarity, i.e. if the north pole of magnet 12 is at the bottom, the north pole of magnet 22 will be at the top or vi e versa.
Operation of this device is very simple:-In Fîgure 9, the bowl is locked on the basebut the cover is not locked on the bowlO Magnet 12 does not exert any action on magnet 22, and spring 9 presses the top sur~ace of magnet 22 against wall 30.
When cover lO is rotated on bowl 3, guided by the inner skirt 20, the cover is locked and magnet 12 is brought above duct 7. Magnets 12 and 22 repel one another, thus lowering the rod assembly. As sh~
in Figure 10, spring g is compressed as a result and magnet 19 comes in contact with wall 29. The air gap between magnet 19 and the magnetic element of the contactor is small, so that contactor 11 changes state and closes the motor supply circuit. As soon as the cover is unlocked, spring 9, which was compressed during the descent of rod 23, expands and returns : magnet ~2 to the top position, so that màgnet 19 moves away from contac-tor 11 and opens the motor supply circuit. Ring Z5 can guide the aforementioned move-ments and the magnets can bear very slightly against the inner walls of duct 7.
Another embodiment is shown in Figures 11 - 13.
Figure 11 is a perspective view of the cover 10 of a device fitted with a me2ns according to the invention.
At its periphery there are two diametrically opposite lugs or flanges 10a and 10~. Flange 10c is bent into a "U'l so as to surround a stop borne by bowl 3, when -the cover rotates. The same feature is applied to lug 10a, which also abut~ ~n edge of the bowl (not shown in the drawing) so as to limit the angular moti-on ofthe cover on t~e ~owl~ The cover also bears two vertical magnets 12 and 31 secured to flange 1Oa ~nd having poles dispose~ head to tail, i.e. if the south pole of magnet 12 i~ at the bottom the south po1e of magnet 31 is at ~he top and vi~e versa.
Figure 12 is a ~a-~al section in a vertica-plane extending through ~v~e axis of bowl 3 and the axis of duc-t 7. As before~ the safety device comprises a magnetic working contac~ 11 disposed below duct 7.
In Figure 12, however, th~ movable assembly comprises a tube 27 filled with gas~ e.g. air, and closed at t ~43~9 bo-th ends by magnets 19 (bottom) and 32 (top)O
Inside duct i the assembly is immersed in a liquid 28 such as oil having a density such that tube 27 is substantially in neutral balance, since the Archimedean thrust is of the same order as the weight of the tube. As shown in Figure 119 there are two positions of -the cover, corresponding to the cases when magnet 12 or magnet 31 is brought above duct 7. In the case show~ in Figure 12, the cover is in the locked positio~ and magnet 12 is above - duct 7. The polarities of magnets 12 and 32 are identical and consequently, as a result of magnetic repulsion, tube 27 is pushed downwards and brings magnet 19 towards contactor 11~ which changes state and closes the motor supply circuit. When, after using the device, the co~er is turned so as to unlock it and extract the products from bowl 3, magnet 12 is replaced at the top of duct 11 by magnet 31 which, since it has t~e opposite polarity from ZO magnet 12, also has the ~posite polarity from magnet 32. Conse~uently magnetic repulsion is replaced by magnetic attr~ction. Tube 27 rises and magnet 19 moves away fro~ contactor 11, which breaks - 23 ~
the contact and stops the motor~ Note that the rotation which replaces magnet 12 by magnet 31 also releases flanges 10a and 10c from stops 17.
In an another embodiemen~ the cover need have only a single magnet having a polarity such that its pole is of the same nature as the pole of the facing magnet 22 In that case9 however, the density of liquid 28 and/or the weight of the tube must be such that tube 27 rises through simple pressure and in the absence of any magnetic force, thus automatically breaking the magnetic connection between 19 and 11~
The description o~ the last-mentioned embod-iment relates to the case where the actuating magnet 12 is secured in cover 10, but of course it can be usefully applied to the case where the motor is enabled to start by inserting a pusher into the chute. ~
In the examples which have been described and shown~ reference has been made hitherto to only a single magnetic relay, contractor or switch. Of course, according to the invention, more than one contactor can be connected in series in the motor supply circuit. For example, a safety switch for the 16~319 cover and a safety switch for the chute can be supplied. A safety switch for the bowl position can also be connected in serles.
Finally, in the case where the motor is disposed not below the bowl but parallel thereto in a casing~ the invention may be applied even more advantageously in view of the pr~ximity of the bowl, cover and chute to the casing, inside which one or more contactors can be disposed.
Of course, the invention is in no case limited to the examples which have bee~ described and shown.
DESCRIPTION
The invention relates to a magnetic safety device of use more particularly though not exclusively in a ~ood processor.
Devices of the aforementioned kind conven-tionally comprise a base enclosing an electric motor haYing a shaft on which various tools such as knives or scrapers can be mounted. The drivè shaft projects into a bowl adapted to enclose the tools and the products which have been or are being processed. In some cases-the bowl is removably mounted on the base for ease in cleaning. The bowl is closed by a like-wise removable cover, the main purpose of which is to prevent material from being thrown out of the bowl.
The devices have to be fitted with a safety means. They are dangerous because the tools are driven at high speed in the bowl and any contact with a rotating tool may result in serious injury. This need is all the more urgent in that the devices are for use by people without special trainingO
' i 1 643~ ~
The safety means must meet two conditions.
The motor must be stopped (a) when the bowl is not properly fitted on the base and (b) when the bowl is properly fitted on the base but the cover is not locked on the bowl. The first condition corresponds to the case where the tool is mounted directly on the drive shaft without the bowl~ The second oondition corresponds to the case where the bowl is in the proper position but the cover is not dispose on it, so that a hand or finger can be inserted during operation. In short, -any contact wi-th the rota+ing tool must be prevented~ This result can be obtaine~
by disposing a workir~ contact in the base, the contact being connected in series in the motor supply circuit ~nd being open or clo~ed depending on whether the bowl and cover are properly positioned, i.e~ the cover is locked to the bowl and the bowl is locked to the base.
One solution has already been proposed in United States Patent Specifica-tion 3 892 365 in the name of Pierre Verdun. In this specification, tne bowl is secured to the base by a bayonet means which ensures accurate positionin~. The cylindrical ~essel has a 4 3 :~ ~
duct extending along a generatrix and enclosing a pusher. The cover is locked in the raised position by stops and a cam bears against the top end of the pusher so that when the cover is locked the pusher is pushed downwards and its bottom end bears against an electromechanical switch, via a hole formed in the base. The aforementioned conditions are fulfilled SinGe the pusher cannot enter the base unless the duct is opposite the hole, i.e. the bowl is properly posi-tiQned on the base, and unless the cam bears on theto~ end of the pusher, io e 9 the cover is locked on the bowl.
~ owever, the aforementioned device cannot be considered perfectly reliable since a child, for example, c~n actuate the working contact by inserting a pointed ~bject into the ori~ice in the base when the bowl is not in position, thus rotating the drive Shl~ft. When the bowl is in position~ it is also possi~e to start the motor by pressing the top end of the pusher. Finally, there may be difficulties in cleaning and maintaining the pusher, which is pushed upwards by a spring.
t ~ ~3~ ~
The aim of the invention is -to obviate the aforementioned disadvantages and cons-truct a safety device which is more reliable.
The invention relates to a magnetic safety device~ inter alia ~or a food processor comprising a base ~rom which a drive sha~t extends and is adapted to receive various tools~ the processor also comprising a ~irst element detachably mounted on the base and bearing means for securing to the base so as to hold it in a given position, a second ele-ment bearing means for locking to the first elemen-t in a given positionD and a duct extending along a generatrix o~ the first element so that in the operating position a substantially punctiform region of the base is geometrically in line with the axis of the duct and a point on the second element, char-acterised in that at least one magnetically controlled contact is disposed in the base and at least one per-manent magnet is secured to one of t~e two elements.
In the preceding patent, the pusher enters the base and thus mechanically transmits the inform-ation that the cover has been locked and thus enables the rnotor to start. In the present invention, by 3 ~ ~
contrast, this information is transmit-ted by the flux of a magnet, which is not applied to the working relay until all the elements are properly locked. This has an îmmediate advantage. It is no longer necessary to form a hole in the base, since the base is moulded in non-magnetic plastics. The position of the magnetically controlled contact cn the periphery of the base is not visible, as a hole must be. Furthermore t-~e safety device cannot be inactivated unless by a person in possession of ~
magnet~ which greatly reduces the risk of imp~operly starting the motor.
Other features and advantages of the ir~ve~-tion will be clear fro~ the following description of preferred embodiment~ of the invention, given with reference to the accompanying drawings i~
which:-Figure 1 is a diagrammatic view, partly ~section through a vertical plane, of a food processor i comprising a rotary tool and equipped with two safety devices, one beia~ mechanical and the o~her magnetic according to the invention;
3 ~ 9 Figures 2 and 3 show the two positions o~ a single magnetically-controlled safety device mounted on a means of the same kind as in Figure 1;
Figure 4 is a view in section through a vert-ical plane of another embodiment o~ the device, inwhich the magnet is disposed in the cover;
Figure 5 is a view in vertical section of a device in which the motor is started by inserting a pushe~ ~nto a chute;
Figure 6 shows an embodiment similar to Figure 51 likewise in vertical section;
~ igure 7 is a top view of the device shown in Figure ~; ¦
~ i~ure 8 is a vertical section of a pusher;
Fl~ures 9 and 10 show the two positions o~
a devi~e ~ccording to the invention involving the movement Gf a rod, ~hich is mounted on apparatus of a ki~-d ~om~on ~o all the embodiments;
F~gure 11 is a view of the cover in the embo~iment sh~wn in Figures 12 and 13; and ~ igure~ 12 and 13 show the two posi~tions (operat?~e and inoperative) o~ another device according ~o t~e invention.
J ~3~9 In all the Figures, like references denote like elements. Figure 1 shows a hollow base 1 made e.g. of moulded plastics. It encloses an electric ~otor 2 mounted so that its axis is vertical and extends through the top wall 1a of the base~ Alter-natively9 the ver-tical output shaft of a speed reduction gear can extend through wall 1a and its input shaft can be coupled to the output shaft of motor 2, which can be disposed parallel to the bowl.
A removable~ e.g. cylindrical bowl 3 has a bottom 3a formed with an aperture forthe end of the sha~t or motor 2 or the output shaft of a speed reduction gear, when the bowl is mounted on b~se 1 and in Figure 1. A tool 4 comprising radial knives 4a can be coupled by any appropriate means to the end of the shaft in bowl 3 mounted on base 1~ The afore-mentioned known processor, which comprises a rotary tool, is fitted with a mechanical safety device known from the cited pa-tent. The de~ice mainly ~0 comprises a working contact 5 having a control push-button 5a and secured inside base 1 above a hole 6 formed in a horizontal flat portion 1b of the base or casing, disposed below a cylindrical skirt 3b -~ :l6~3~
g which downwardly prolongs the bottom 3a of bowl 3.
Hole 6 is dispose~ so as to be exactly below a duct 7 formed along a generatrix of bowl 3. Duct 7, which is preferably moulded integrally with bowl 3 and made o~ synthetic material such as polycarbonate, is adapted to receive a pusher 8, preferably made of electrically insulating material. A spring 9, which bears on the bottom of duct 7 and on a central part of rod 8, tends to push rod 8 towards a top position, illustrated in Figure 1, in which a collar secured to the top part of pusher 8 abuts the top end of duct 7.
Pusher 8 is also prolonge,l at the bottom by a cylin-drical actuating means 8a which can engage in hole 6 to actuate the pusher 5a of switch 5. The top end of pusher 8 is prolonged by an actuating means 8b which can co-operate with a slo?e lOb forming a cam and disposed in a substantially peripheral position on a flange or external projection lOa inteyrally moulded with cover 10 or secured to the cover by any approp-riate means. Cam lOb is disposed so that when cover 10 is brought into a give:n position by pivoting the skirt 20, cam lOb pushes the pusher 8 downwards, com-presses spring 9 and enables the bottom actuating means 8a to engage in hole 6 an~ thus act on contactor 5.
~ ~6~3~g According to the invention, a second working contact 11 is mounted inside base 1 below a flat part lc, e.g. diametrical]y opposite part la and substantially at the same level, so as to extend below the cylindrical skirt 3b of bowl 3. ~ perman-ent magnet 12, made e.g. of ferrite~ is secured to skirt 3b in a position sueh that it is exactly below the magnetically controlled eontaet 11, so as to aetuate it when bowl 3 is mounted in base 1 in a position such that pusher 8 is exactly above hole 6.
Aceording to another feature of the invention, the magnetie working contact Ll and the mechanical work-ing contact 5 are conneeted in series in the suppl,v eireuit of the motor (not shown).
In the ease of t]le deviee shown in Figure 1, tool 4 eannot be driven in rotation unless (a) bowl 3 is mounted on base 1 in the eorreet position for pusher 8 and magnet 12 to be above eontaet 5 and 11 respectively and (b) eover 10 of vessel 3 is in the proper elosure position where its eam lOb aetuates pusher 8 so as to eompres~ spring 9. In this position likewise, a flange lOe on the eover engages a stop 17 whieh prevents any lifting movement of the eover.
J 1~43~g If the cover is not in position or is improperly closed, the mechanical contact 5 opens the circuit -and the motor cannot s-tart~ The same happens if bowl 3 is not mounted on the base, since the supply circuit of motor 2 is then also cut by the magnetic contact 11. In the lat-ter case a child, ~or example, can mount tool 4 on the end of the shaft emerging from the top wall 1a of the base and can actuate pusher 5a of contact 5 by inserting a poin-ted obJect into hole 6. This operation, however, is insufficient to cause dangerous rotation of tool 4 since th~ supply circuit of motor 2 is interrupted by contact 11~
Figures 2 and 3 show the top right p~rt of the device in Figure 1~ equipped with a sing~
magnetically controlled safety device. The on~
difference between this variant and ~igure 1 i~ that a magneti.cally controlled contact 11 is mounted in base 1 below a ~lat surface 1b which does not ha~e any orifice. A cylindrica1 permanent magnet 1~ is secured to the bottom end of pusher 8. In this ~ase~
a single working contact 11 is inserted into ~he supply circuit oi motor 2.
1 3 ~ g When bowl 3 is not mounted on base 1, contact 11 cannot of course be actuated by the magnet 12 secured to bowl 3, so that no mechanical action on base 1 can start the motorO The same applies when bowl 3 in properly moun-ted on the base but cover 10 is not closed or is improperly closedO It is only when cover 10 has been rotated into its proper posi-tion tha-t cam 10b exerts a downward force on usher 8 via the top actU~ting component 8b so as to compress spring 9 and appr~ac-i~ the permanent magne~ 12 of contact 11 (Figure 3~. It is only then that conta~t 11 closes so as t~ supply the electric motor ~nd dri~e tool 4.
A slightly ~i~ferent embodiment is sho~m in Figure 4~ whic~ i~ likewise a vertical section : through a food pr~c~ssorr In Figure 4, the ~e~vice : comprises a magnet 12 secured by any appropriate meanS to cover 10~ a~ more specificall~ in a fla~-ge 10a in the cover. ~s before, a magnetic -flux m~s~
be applied to contac~or 11. According to another feature, the magn~ti~ flux is transmitted fro~ ma~net : 12 to contactor 11 b~ a rod 12a of ferromagn~tic material such as soft iron or ferrite, th~ rod being ~ ~6~3i~9 -- ~3 mounted in duct 7 and secured inside it. In Figure 4, the device is in the operating position~ i.e.
ro-tation of cover 11 on bowl 3 resul-ts (a) in engage-ment of flange 10c with top 17, a similar device being provided at flange 10a but not being shown in the cross~section and (b) the permanent magnet 12 is brought above rod 7 which is thus magnetically polarized and transmits the polarization to contact 11, which closes the supply circuit of motor 2.
'~0 When the cover rotates, ~uided by the internal skirt 20 which also ensureæ sealing-tightness, the flanges are released from the stcps and thus unlockcover 10 and magnet 12 moves from rod 12a; the magnetic field disappears and the working contact of relay 11 opens and stops -the motor.
In order to r~duc~ the air gaps, the ferro-magnetic rod 12a~ embedded eqg. in plastics in duct 7, comes in contact ~-ith ~ very thin end bottom wall 29 and top wall 30, in order to avoid loss of flux.
A different kind of tool from that previously mentioned is sho~n in broken lines in Figure4 , i.e, a scraper disc 15 which can be mounted on the shaft of motor 2 via a hub 14. To use the scraper, ~he ~ 1~43~g products must be brought against disc 15 when it rotates, This can be done in known manner by means of a chute 13 into which a pusher 16 can be inserted.
As in all emhodiments 9 the magnetic working contact is preferably an "I.L.S." type contactor, also known as a Reed relay of the kind manufactured by Messrs R.T.C. LA RADIOTECHNIQUE-COMPE~EC3 refer-ences RI 22 3A, RI 22 AA or RI 42.
The previously-described embodiment has the advantage of not kaving any parts which move when switch 11 is opened or closed. Note that the device is mounted on a means comprising a base 1 bearing a first element (bowl 3). A second element (cover 10) can be locked in a fixed position so that magne-t 12, the axis of duct 7 and the magne-tic working contact 11 are in line; in the latter case the magnet is secured to the cover.
Figures 5 - 8 illustrate another embodiment in ~hich the locking information is as before trans-mitted by a rod of ferromagnetic material~ InFigures 5 - 8, magnet 12 is secured not to the cover but to the pusher which penetrates into chute 13.
~ ~6431~
- 15 ~
Figure S is a view in section in a vertical plane of a food processor or kitchen robot of the previously-described kind. Figure 7 is a top view oE the same device in section along line VII-VII of Figure 5. Figure 5 shows a base 1 bowl 3 and eover 10 surmounted by a chute L3 for inserting products and containing a pusher lfi for pushing the products downwards without any po sible contact between the hand and the rotating -tool 15. As before the bowl can be locked to the base by a bayonet fitting or a screw thread/ for example in a given position in which duct 7 is aligned w:ith the actuating contact 11 which is included in the base. Cover 10 is locked by stops 17 whieh are moulded integrally with the bowl and at the top thereof above flanges lOa lOc formed in the cover. A stop 17 is shown in Figure 7.
The stop co-operates with a diametrically opposite stop (not shown in Figure 7) to defin~ a given position of the cover on the bowl and consequently define a given position oE the cover relative to the base.
According to the invention bowl 3 has a duct 7 along one of its generatrices the duct 3 ~ g containing a rod 12a o~ ferromagnetic material such as soft iron. When the bowl is mounted on the base as shown in Figure 5, the bottom end of rod 12a is opposite a magnetic switch 11~ disposed immediately below the flat surface 1b of face 10 In the embod-iment in F'igure 5, duct 7 extends above bowl 3 and is substantially egual in height to the sum of the heights of bowl ~, cover 10 and chute 13. Pusher 16 has a per~anent magnet 12 having a strong field (e.g. 40,000 Gauss~ along cne of its side walls.
The mode of operation of the device is self-evident~ When pusher 16 is inserted into chute 13 magnet 12 comes oppos~te rsd 12a and magnetically polarizes it~ The polariæation is transmitted to the 1~ bottom part of rod 12a an-d acts on contactor 11~ thus closing it and enabling ~he motor to start, since it is connected to the motor supply circuit. As shown in Figure 73 contact~r ~1 cannot be actuated unless magnet 12 is exactly opposite the rod, i.e. unless the cover is locked on the ~
This feature provl~es a considerable advan-tageO For safety reasons~ the dimensions of known 4 3 ~ ~
chutes must be such that it is impossible to inser-t a hand or even a finger, since the height of the chute is greater than the length of a finger. Consequently, existing chutes are high ~nd have a small cross-sectior. which makes it diffi-cult to scrape certain vegetables, since they first have to be cut into small piecesO As a result of the invention, the cross-section of the chute can be increased as much as required for cooking, since it is the pusher itself which starts the motor when inserted in the chute. Consequently, neither the hand or any part of it can come in contact with the rotating -tool. As shown in Figure 7, the cross-section o~ chute 13 has been considerably increased.
Rod 12a can also be protected from any external mag-netic influence by disposing a magnetic screen, e.g. of ~ metal, inside duct 11 round its entire per_phery except the region opposite magnet 120 Figure 6 shows an embodiment in which, in order to simpli~y certain manufacturing problems, rod 12a is divided into two parts, i.e~ a part 12a1 secured to cover 10 and a part 12a2 secured to bowl 3 The two parts can be directly moulded on the bowl or 3 ~ g cover or can be secured thereto after moulding.
If elements 3 and 10 are properly mounted, the rod parts 12al and 12a2 are brought in lina with one another an~ 12al is polar:ized by magnet 12, thus polarizing 12a2 and consequently changing -the state of contactor 11. In the rase where knives are used, all the ingredients may be introduced into the bowl before it is closed by the cover, and the motor can be started by inserting pusher 16 into chute 13.
In such cases the pusher ,erves only as a safety closure means. It may ha?pen, however, that pro-ducts have to be inserted during operation of the device without stopping it. In such cases it is possible to use a "pusher" ]6a fitted with a magnet 12 but having a funnel-shaped internal wall such as the wall 18 of pusher 16a shown in Figure 8. Wall 18 is designed for inserting liquid or pulverulent pro-ducts but prevents a finger being inserted.
In the case of high elements, however, the reluctance of the resulting magnetic circuit may be too powerful for perfectl~y reliable operation, in which case -the safety device will not be inactivated when the aforementioned conditions are fulfilled~
l 18~3 The following description relates to means for obviating this disadvantage. Figures 9 and 10 show two states of a single safety device according to the invention, applied as before to a food processor~ only part of which is shown in the drawing.
As before, Figures 9 and 10 show a base 1, a vessel 3 and a cover 1~ surmounted by a chute 13. The drawings are sections in a ~ertical plane extending through the axis of the bowl-and the axis of duct 7. As a result the permanent ~agnet 12 is shown only in Figure 100 As in a p~eceding embodiment9 magnet 12 is secured to a ~lange 10a on cover 10~ However, the ferromagnetic rod in duct 7, which as before is positioned above the m2gnetic working contact 11, is replaced by a mobile ~ssembly comprising a rod 23 bearing permanent magnets at both ends, i.e. a magnet 19 at the bott~m end and a ma~net 22 at the top end. Duct 7 is ~ocked at the bottom and top by thin covers 29~ 30 re~ectively. Rod 23 is slidably mounted by any appropriate means inside duct 7 and between walls 29 and ~. The central part of rod 23 has a collar 24 abutting an end o~ a return spring 9 which also bears agaL~st a ring 25 formed inside 3 1 ~
duct 7. According to a feature o.~ the last-mentioned embodiment/ the facing poles of magnets 12 and 22 nave the same polarity, i.e. if the north pole of magnet 12 is at the bottom, the north pole of magnet 22 will be at the top or vi e versa.
Operation of this device is very simple:-In Fîgure 9, the bowl is locked on the basebut the cover is not locked on the bowlO Magnet 12 does not exert any action on magnet 22, and spring 9 presses the top sur~ace of magnet 22 against wall 30.
When cover lO is rotated on bowl 3, guided by the inner skirt 20, the cover is locked and magnet 12 is brought above duct 7. Magnets 12 and 22 repel one another, thus lowering the rod assembly. As sh~
in Figure 10, spring g is compressed as a result and magnet 19 comes in contact with wall 29. The air gap between magnet 19 and the magnetic element of the contactor is small, so that contactor 11 changes state and closes the motor supply circuit. As soon as the cover is unlocked, spring 9, which was compressed during the descent of rod 23, expands and returns : magnet ~2 to the top position, so that màgnet 19 moves away from contac-tor 11 and opens the motor supply circuit. Ring Z5 can guide the aforementioned move-ments and the magnets can bear very slightly against the inner walls of duct 7.
Another embodiment is shown in Figures 11 - 13.
Figure 11 is a perspective view of the cover 10 of a device fitted with a me2ns according to the invention.
At its periphery there are two diametrically opposite lugs or flanges 10a and 10~. Flange 10c is bent into a "U'l so as to surround a stop borne by bowl 3, when -the cover rotates. The same feature is applied to lug 10a, which also abut~ ~n edge of the bowl (not shown in the drawing) so as to limit the angular moti-on ofthe cover on t~e ~owl~ The cover also bears two vertical magnets 12 and 31 secured to flange 1Oa ~nd having poles dispose~ head to tail, i.e. if the south pole of magnet 12 i~ at the bottom the south po1e of magnet 31 is at ~he top and vi~e versa.
Figure 12 is a ~a-~al section in a vertica-plane extending through ~v~e axis of bowl 3 and the axis of duc-t 7. As before~ the safety device comprises a magnetic working contac~ 11 disposed below duct 7.
In Figure 12, however, th~ movable assembly comprises a tube 27 filled with gas~ e.g. air, and closed at t ~43~9 bo-th ends by magnets 19 (bottom) and 32 (top)O
Inside duct i the assembly is immersed in a liquid 28 such as oil having a density such that tube 27 is substantially in neutral balance, since the Archimedean thrust is of the same order as the weight of the tube. As shown in Figure 119 there are two positions of -the cover, corresponding to the cases when magnet 12 or magnet 31 is brought above duct 7. In the case show~ in Figure 12, the cover is in the locked positio~ and magnet 12 is above - duct 7. The polarities of magnets 12 and 32 are identical and consequently, as a result of magnetic repulsion, tube 27 is pushed downwards and brings magnet 19 towards contactor 11~ which changes state and closes the motor supply circuit. When, after using the device, the co~er is turned so as to unlock it and extract the products from bowl 3, magnet 12 is replaced at the top of duct 11 by magnet 31 which, since it has t~e opposite polarity from ZO magnet 12, also has the ~posite polarity from magnet 32. Conse~uently magnetic repulsion is replaced by magnetic attr~ction. Tube 27 rises and magnet 19 moves away fro~ contactor 11, which breaks - 23 ~
the contact and stops the motor~ Note that the rotation which replaces magnet 12 by magnet 31 also releases flanges 10a and 10c from stops 17.
In an another embodiemen~ the cover need have only a single magnet having a polarity such that its pole is of the same nature as the pole of the facing magnet 22 In that case9 however, the density of liquid 28 and/or the weight of the tube must be such that tube 27 rises through simple pressure and in the absence of any magnetic force, thus automatically breaking the magnetic connection between 19 and 11~
The description o~ the last-mentioned embod-iment relates to the case where the actuating magnet 12 is secured in cover 10, but of course it can be usefully applied to the case where the motor is enabled to start by inserting a pusher into the chute. ~
In the examples which have been described and shown~ reference has been made hitherto to only a single magnetic relay, contractor or switch. Of course, according to the invention, more than one contactor can be connected in series in the motor supply circuit. For example, a safety switch for the 16~319 cover and a safety switch for the chute can be supplied. A safety switch for the bowl position can also be connected in serles.
Finally, in the case where the motor is disposed not below the bowl but parallel thereto in a casing~ the invention may be applied even more advantageously in view of the pr~ximity of the bowl, cover and chute to the casing, inside which one or more contactors can be disposed.
Of course, the invention is in no case limited to the examples which have bee~ described and shown.
Claims (16)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A magnetic safety device, incorporated in apparatus such as a food processor in which a drive shaft extends from a base and receives a rotat-ing tool, the device including:- a first element detachably mounted on the base and having means for securing to the base of the apparatus so as to hold it in a predetermined position, a second element having means for locking to the first element in a predetermined position, and a duct extending along a generatrix of the first element, characterised in that at least one magnetically controlled contact is disposed in the base and at least one permanent mag-net is secured to one of the two elements.
2. A safety device according to claim 1, characterised in that the magnetically controlled contact is disposed in the base below the duct.
3. A safety device according to claim 19 characterised in that it comprises a pusher slidably mounted inside the duct, the bottom end of the pusher being actuated by a cam borne by the top end of the second element so that the bottom end of the pusher bears on the push-button on an electro-mechanical switch, a permanent magnet being disposed on the first element so as to come opposite a magnetically controlled contact, the switch and the contact being connected in series in the motor supply circuit.
4. A magnetic safety device according to claim 1 or 2, characterised in that a pusher is slid ably mounted inside the duct, the bottom end of the pusher being secured to a permanent magnet which modifies the state of the magnetic contact when the magnet approaches or moves away from the magnetic contact under the action of a cam borne by the second element and coming in contact with the top end of the pusher.
5. A magnetic safety device according to claim 1 or 2, characterised in that a rod made of ferromagnetic material is disposed all the way up the aforementioned duct and the permanent magnet is secured to the second element and comes above the duct when the second element is locked on the first element.
6. A safety device according to claim 1, characterised in that a mobile assembly is slidably mounted inside the aforementioned duct, a permanent magnet comes above the assembly when the elements are locked, and the assembly bears a magnet at each end, the polarity of the permanent magnet being the same as the polarity of the magnet at the top end, so as to produce repulsion.
7. A safety device according to claim 6, characterised in that the mobile assembly comprises a rod which is returned to its top position by a spring.
8. A safety device according to claim 6, characterised in that the mobile assembly comprises a gas-filled tube immersed in a liquid in the afore-mentioned duct.
9. A device according to claim 8, characterised in that the aforementioned lockable element bears a second permanent magnet mounted parallel to the first and having the opposite polarity, the aforementioned tube being in neutral balance inside the duct.
10. A food processor comprising a base enclosing an electric motor on which a bowl is mounted and is closed by a lockable cover, the cover comp-rising a chute for inserting products, and the processor including a magnetic safety device as claimed in claim 1, characterised in that the perman-ent magnet is secured to a pusher for pressing the inserted products into the chute, a magnetic circuit being adapted to convey the flux introduced by the magnet, when inserted into the chute, to the afore-mentioned magnetically controlled working contact.
11. A food processor according to claim 10, characterised in that the magnetic circuit comprises a rod of magnetic material extending along a gener-atrix and in a duct secured to the bowl between the base and the top of the chute.
12. A food processor according to claim 10, characterised in that the aforementioned magnetic circuit is made up of two rods of ferromagnetic material, one secured to the bowl and the other to the cover, the two rods coming in line with the working contactor when the bowl is locked to the base and the cover is locked to the bowl, thus magnetically coupling the magnet to the contactor.
13. A food processor according to claim 10, characterised in that the cross-section of the pusher is such that when it is inserted in the chute, the magnet comes opposite and near the ferromagnetic rod.
14. A food processor according to claim 10, characterised in that the pusher has funnel-shaped inner walls for inserting products.
15. A food processor characterised in that it comprises at least one safety device according to any of claims 1, 2 or 3, the magnetically controlled working contacts being connected in series in the motor supply circuit.
16. A food processor characterised in that it comprises a magnetic safety device according to any one of claims 1, 2 or 3, and another safety device mounted in series.
Applications Claiming Priority (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR7921651A FR2464047A1 (en) | 1979-08-29 | 1979-08-29 | Magnetic safety device for food chopper - has motor switch operable only when bin and lid are secured |
| FR7921651 | 1979-08-29 | ||
| FR7931062 | 1979-12-19 | ||
| FR7931062A FR2474298A1 (en) | 1979-12-19 | 1979-12-19 | Magnetic safety device for food chopper - has motor switch operable only when bin and lid are secured |
| FR8006490 | 1980-03-24 | ||
| FR8006490A FR2478456B1 (en) | 1980-03-24 | 1980-03-24 | SAFETY DEVICE FOR A KITCHEN ROBOT |
| FR8016882A FR2488038A1 (en) | 1980-07-31 | 1980-07-31 | Magnetic safety device for food chopper - has motor switch operable only when bin and lid are secured |
| FR8016882 | 1980-07-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1164319A true CA1164319A (en) | 1984-03-27 |
Family
ID=27446406
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000358880A Expired CA1164319A (en) | 1979-08-29 | 1980-08-25 | Magnetic safety device, inter alia for a food processor |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0024992B1 (en) |
| CA (1) | CA1164319A (en) |
| DE (1) | DE3068351D1 (en) |
| ES (1) | ES494562A0 (en) |
Families Citing this family (30)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3031382A1 (en) * | 1980-08-20 | 1982-03-25 | Braun Ag, 6000 Frankfurt | DEVICE WITH A SECURITY LOCK |
| US4629131A (en) * | 1981-02-25 | 1986-12-16 | Cuisinarts, Inc. | Magnetic safety interlock for a food processor utilizing vertically oriented, quadrant coded magnets |
| FR2513870A1 (en) * | 1981-10-02 | 1983-04-08 | Dito Sama | WORKING MACHINE FOR FOOD AND OTHER PRODUCTS, PARTICULARLY FOR CHOPPING AND MIXING |
| ATE21616T1 (en) * | 1982-01-15 | 1986-09-15 | Robot Coupe Sa | DEVICE FOR PROCESSING FOOD. |
| US4471915A (en) * | 1982-08-17 | 1984-09-18 | Scovill Inc. | Food processor having enlarged feed tube with safety guard |
| DE3311291A1 (en) * | 1983-03-28 | 1984-10-04 | Braun Ag, 6000 Frankfurt | MAGNETIC SAFETY DEVICE, ESPECIALLY FOR A KITCHEN EQUIPMENT |
| DE3540370A1 (en) * | 1985-11-14 | 1987-05-21 | Braun Ag | Safety device for kitchen appliances |
| FR2646074A1 (en) * | 1989-04-24 | 1990-10-26 | Ronic Ind | Electric safety device controlled by lid of vessel in a food preparing apparatus |
| US5403997A (en) * | 1989-08-15 | 1995-04-04 | Aladdin Synergetics, Inc. | Rethermalization system and cart |
| US5285051A (en) * | 1989-08-15 | 1994-02-08 | Aladdin Synergetics, Inc. | Rethermalization system including food service dish |
| US5274216A (en) * | 1989-08-15 | 1993-12-28 | Aladdin Synergetics, Inc. | Food rethermalizing and satelliting tray |
| WO1991002481A1 (en) * | 1989-08-15 | 1991-03-07 | Aladdin Synergetics, Inc. | Food service system and method of rethermalizing food |
| FR2657518B1 (en) * | 1990-01-26 | 1993-12-03 | Moulinex | MULTIPURPOSE HOUSEHOLD APPLIANCES FOR PROCESSING FOOD. |
| DE9006927U1 (en) * | 1990-06-21 | 1990-08-23 | Maschinenfabrik Palmer Gmbh, 7140 Ludwigsburg, De | |
| EP0546208A1 (en) * | 1991-12-11 | 1993-06-16 | MASCHINENFABRIK KURT NEUBAUER GmbH & Co. | Deep-fat fryer |
| SE9201626L (en) * | 1992-05-22 | 1993-05-17 | Haellde Maskiner Ab | SAFETY DEVICE FOR CUTTING MACHINERY FOOD PREPARATION |
| FR2717361B1 (en) * | 1994-03-15 | 1996-05-31 | Robot Coupe Sa | Safety device for a food preparation appliance. |
| US7086111B2 (en) | 2001-03-16 | 2006-08-08 | Braun Gmbh | Electric dental cleaning device |
| DE10159395B4 (en) | 2001-12-04 | 2010-11-11 | Braun Gmbh | Device for cleaning teeth |
| KR100735645B1 (en) | 2001-03-14 | 2007-07-06 | 브라운 게엠베하 | Method and device for cleaning teeth |
| US6609821B2 (en) | 2001-04-13 | 2003-08-26 | Sunbeam Products, Inc. | Blender base with food processor capabilities |
| EP2550938B1 (en) | 2011-07-25 | 2015-01-14 | Braun GmbH | Oral hygiene device |
| CN103703668B (en) | 2011-07-25 | 2016-12-07 | 博朗有限公司 | Linear electro-polymer motor and the device with described linear electro-polymer motor |
| PL2550937T3 (en) | 2011-07-25 | 2014-07-31 | Braun Gmbh | Magnetic connection between a toothbrush handle and a brush head |
| US9855535B2 (en) | 2013-03-01 | 2018-01-02 | Vita-Mix Management Corporation | Blending system |
| WO2014134600A1 (en) | 2013-03-01 | 2014-09-04 | Vita-Mix Corporation | Blending system |
| US11478766B2 (en) | 2017-06-30 | 2022-10-25 | Vita-Mix Management Corporation | Intelligent blending system |
| CN107468098B (en) * | 2017-09-14 | 2023-07-28 | 鹤山市金宝力电器有限公司 | Food stirring cup with double protection switches and stirrer |
| CN113243785B (en) * | 2020-04-20 | 2022-12-30 | 九阳股份有限公司 | Food processor with detachable crushing cutter assembly |
| EP3973831A1 (en) * | 2020-09-24 | 2022-03-30 | Vorwerk & Co. Interholding GmbH | Kitchen appliance and method for removing a food sample |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2740019A (en) * | 1951-04-14 | 1956-03-27 | Knapp Monarch Co | Switch for automatic coffeemaker |
| DE1198316B (en) * | 1957-05-29 | 1965-08-12 | Siemens Elektrogeraete Gmbh | Lid switch for washing machines, spin dryers or the like with electric drive |
| DE1111348B (en) * | 1959-09-11 | 1961-07-20 | Siemens Elektrogeraete Gmbh | Coffee mill or similar electrical household appliance |
| US3198902A (en) * | 1962-05-28 | 1965-08-03 | Jr Emile C Deshautreaux | Proximity magnetic reed switch assembly |
| AT314683B (en) * | 1969-02-03 | 1974-04-25 | Beteiligungs Ag Haustechnik | Electrical appliance, in particular household appliance |
| US3612126A (en) * | 1969-08-14 | 1971-10-12 | Dynamics Corp America | Liquidizer safety clutch |
| CH495142A (en) * | 1969-09-23 | 1970-08-31 | Gut Otto | Process for separating egg white and egg yolk |
| DE7023506U (en) * | 1970-06-23 | 1970-12-10 | Demag Ag | Electrical switch operated through a door |
| FR2129193A6 (en) * | 1971-03-18 | 1972-10-27 | Verdun Pierre | |
| US3717830A (en) * | 1971-07-29 | 1973-02-20 | Hobart Mfg Co | Magnetic switch control and interlock system |
| DE2625791C2 (en) * | 1976-06-09 | 1984-12-20 | Braun Ag, 6000 Frankfurt | Household coffee machine with calcification display |
| US4216917A (en) * | 1978-11-13 | 1980-08-12 | Cuisinarts, Inc. | Safety interlock for the food pusher in a food processor |
-
1980
- 1980-08-25 CA CA000358880A patent/CA1164319A/en not_active Expired
- 1980-08-27 DE DE8080401224T patent/DE3068351D1/en not_active Expired
- 1980-08-27 EP EP80401224A patent/EP0024992B1/en not_active Expired
- 1980-08-28 ES ES494562A patent/ES494562A0/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| EP0024992B1 (en) | 1984-06-27 |
| DE3068351D1 (en) | 1984-08-02 |
| ES8103958A1 (en) | 1981-04-01 |
| ES494562A0 (en) | 1981-04-01 |
| EP0024992A1 (en) | 1981-03-11 |
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Legal Events
| Date | Code | Title | Description |
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| MKEX | Expiry |