US 3493022 A
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Description (OCR text may contain errors)
Feb. 3, 1970 3. MANTELET 3,493,022
' mmcme MACHINES Filed May 16, 1966 Y 4 Sheets-Sheet'l Awe-N704 JEAN Maw-457 Feb. 3, 1970 J. MANTELET MINCING MACHINES 4 Sheets-Sheet 2 Filed May 16, 1966 m m V y J54 Mmvrasr ,4 rrya.
Feb. 3, 1970 J. MANTELET MINCING MACHINES 4 -SheeiLs-Sheet 3 Filed May 16, 1966 J54 M/f/VTELET United States Patent Int. 01.13025 13/18, 13/31 US. Cl. 146-68 7 Claims ABSTRACT OF THE DISCLOSURE A mincing machine has an upright spindle on which is mounted a hub that carries the blades. The hub is formed as a single component of plastic molded about the inner ends of the blades. The motor is housed in a lateral extension of the casing and is disposed with its axis horizontal. A removable cover has a lower skirt that fits into an annular recess to close two diametrically opposed switches in series. Springs resist the movement of the cover skirt into this recess with a force greater than the weight of the cover, so that as a safety feature, the operator must press down on the closed cover to actuate the mincer.
This invention relates to mincing machines, and more particularly to domestic mincers for finely dividing foodstuffs such as meat, fish, hard-boiled eggs, cheese, vegetables or seasoning herbs.
The main object of the present invention is to provide a small compact mincer suitable for domestic use which is more convenient and safer to use, easier to clean, and more effective and reliable in operation than mincers known hitherto.
According to the present invention, a mincing machine comprises a working bowl of generally cylindrical shape closed by a removable cover and supported on a stand containing a driving assembly, the output spindle of which passes through the central area of the bottom of the bowl and drives in rotation a hub within the bowl carrying one or more suitably sharpened blades, the blade-carrier hub being drivingly connected to the driving spindle by helical splines on the lateral surface of the spindle engaging with correspondingly shaped clearance grooves in the surface of a central bore of the hub, the pitch of the said splines and grooves being selected such that one rotation of the spindle in its normal direction of rotation fully engages the splines in the grooves.
Since the blade-carrier hub is fitted on the driving shaft onlv. it can easily'be removed for cleaning purposes, and replaced in position by a simple movement. During the latter operation the hub need not be pushed home on the spindle since, by virtue of the inclination of the coupling ramps, this hub automatically engages correctly on the ramps as soon as the appliance is started. In addition, the risk of the blade-carrier hub slipping off the driving spindle during the operation of the appliance is minimised.
Equally in order to facilitate cleaning of the appliance after use, the invention makes provision for the working bowl to be removably mounted on the stand. To this end, the driving spindle passes freely through a central hole in the bottom of the bowl, whilst the stand has a housing or seat which removes the bowl in such a manner that centering of the bowl relative to the said spindle is ensured.
The bowl is thus merely placed on the stand, and can be removed and replaced in position by a simple movement.
To facilitate removal and refitting in position of the blade-carrier hub, the invention equally makes provision for this hub to have an upwardly directed projection by 3,493,022 Patented Feb. 3, 1970 which the hub may be grasped without the risk of the operator injuring his hands on the blades.
For the purpose of improving the safety of the appliance in operation, the invention further makes provision for the driving assembly to remain inoperative if the cover is not applied to the bowl; i.e., in the case of an electrically operated machine the electrical supply to the driving assembly is interrupted by suitable means thereby obviating the risk of the blades causing injury to the operator during their rotation.
In one preferred embodiment, which is electrically driven, the supply circuit of the driving assembly includesin seriesat least one pressure-operated switch the actuating means of which is housed in the bottom of an upwardly open cavity wrought in the stand and sufiiciently narrow and deep to prevent any direct operation of the means by the operator, but arranged to receive a projection on the cover which is adapted to engage in the said cavity and to operate the said actuating means when the cover is applied on the bowl.
The cavity housing the switch preferably also contains at least one resilient element to exert an upward thrust on the projection on the cover, the stiffness of this element being such that the actuating means cannot be operated by the weight of the cover alone when the latter is placed on the appliance.
In order to ensure the starting of the appliance, a certain pressure must be exerted on the cover in position on the bowl of the appliance. One thus has the assurance that before the device is started, the cover will be firmly held on the bowl and will thus be prevented from being hurled upwards during operation owing to impact against the inner face of the cover of the substances contained in the bowl.
In order that the invention may be fully understood, various embodiments in accordance therewith will now be described, by way of example, with reference to the accompanying drawings in which:
FIG. 1 illustrates a domestic mincer of the invention in vertical section along the broken line II of FIG. 2;
FIG. 2 is a plan view of the mincer after removal of the cover;
FIG. 3 is a partial vertical section along the line III- III of FIG. 1;
FIG. 4 is a partial vertical section of the stand along the line IVIV of FIG. 2;
FIG. 5 is a partial vertical section of the appliance without the lid, in which the blade-carrier hub has been illustrated uncoupled from its driving spindle and the bowl lifted off the stand;
FIG. 6 illustrates a variant embodiment of the cover, in which it forms a mould intended to shape croquettes from the substance minced;
FIG. 7 illustrates the working bowl in the case in which it forms a croquette mould itself.
Referring to the drawings, these show an electrically operated mincer comprising a working bowl 10 of generally cylindrical shape closed by a removable cover 12 and carried on a stand 14 containing a driving or motor assembly 16 whose vertical output spindle 18 traverses the central area of the bottom 20 of the bowl and within this bowl.drives in rotation a hub 22 carrying two blades 24 and 26 which are parallel to the bottom of the bowl and are suitably sharpened.
The bottom 20 of the bowl has a wide central hole 28 (FIG. 5) through which passes freely the driving spindle 18, and the stand 14 has a housing 30 formed by a cylindrical wall or enclosure 32 which receives the bowl and ensures its centering relative to the spindle 18 as well as its retention against any angular displacement. As is more clearly apparent from FIG. 5, the coupling between L6 blade-carrier hub 22 and the driving spindle 18 is 'oduced by means of inclined ramps or fins 34 wrought 1 the lateral surface of the spindle, on which are entged with a clearance correspondingly inclined grooves S wrought in the lateral surface of a central bore 38 of re hub, the inclination of these fins and grooves being =lected such that one rotation of the spindle 18 in its norlal direction of rotation (arrows F of FIGS. and 2) nds to engage the fins 34 in the grooves 36, that is to say I draw the hub 22 downwards. To obtain such an autotatic engagement of the hub 22 on the spindle 18 as soon i the appliance is started, and equally to ensure that this 1th cannot fly off the spindle 18 during operation in any tse, the angle of inclination of the fins and grooves 34 1d 36 to the vertical should lie between 20 and 40, 1d preferably between 25 and 35. For example, if the ab 22 and the fins 34 are made of a plastic material lch as Nylon, an angle of approximately 30 is parcularly appropriate.
As will be seen from FIGS. 1 and 5, the hub 22 is )rmed by a single component of plastic material, and the lades 24 and 26 are fastened to this hub by overmould- 1g this component on the blades during production. This ub has an upwardly directed projection 40, forming a tanipulating handle.
The blades 24 and 26 extend in opposite directions from 1e hub 22. The blade 24 is situated in a plane close to te bottom of the bowl, whereas the blade 26 is situated l a plane which is offset upwards relative to the plane E the blade 24. The sharpened active edge 42 of each lade (FIG. 2) is angled rearwards on the radius relave to the direction of rotation and has two reactilinear :ctions 44 and 46 joined by a curved section, the outer :ction 44 being more extensively angled rearwards than 1e inner section 46. This form assures satisfactory peneation of the blades into the material to be minced.
The span of the blades, measured from tip to tip, is E the order of nine-tenths of the internal diameter of the owl 10. It will be noted in this connection that too ."eat a radial extension of these blades would result in tcessive load on the motor, specifically when the apliance is used to process tough meats, or would require pplication of a motor of a size incompatible with the impact nature of the appliance. On the other hand, if [686 blades are too short, the mincing work is not perrmed in sufliciently uniform manner, and a Span equal approximately nine-tenths of the diameter of the bowl ssures adequate uniformity of the mincing work, without owever imposing excessive load on the motor.
The inner lateral face of the bowl comprises a lower :ction 48 which has grooves or flutes 50 extending vercally, and which extends from the bottom 20 up to a :vel 52 situated above the plane of the upper blade 26, well as a smooth upper section 54 which extends up the top edge 56 of the bowl. The inner face of the cover 2 has two circular webs or fins 58 and 60 concentric 'ith the axis of the cover and of the bowl.
The flutes of the lower section 48 of the inner face of 1e bowl have the function of braking the material to e minced, which within the working space tends to spin t the same speed as the blades, thus causing it to remain l engagement with the blades. The smooth section 54 as ell as the webs 58 and 60 of the cover on the contrary llow the material to be minced to circle freely in the uper part of the bowl without sticking to the side, and thus romote its return into the range of action of the blades. As is apparent in FIG. 1, the driving assembly 16 omprises an electric motor whose axis extends horizonally, followed by a gearbox 64 whose vertical output pindle forms the driving spindle 18 of the blade-carrier ub 22. The motor 62 is a motor of universal type turnig at high speed, The gearbex 64 contains a speed reduc- .on mechanism adapted to reduce the speed of the spinle 18 o a value lying between 3,000 and 8,000 revolutions per minute, when operating respectively under full load, and without load.
To ensure safe operation of the appliance in this embodiment, the electric supply to the motor 62 depends on the application of the cover 12 on the bowl 10. To this end, the supply circuit of the motor 62 includes in series two switches 66 and 68 whose actuating knobs or keys 70 and 72 are housed at diametrically opposed points in the bottom of a narrow annular cavity 74 formed between the centering partition 32 of the bowl and a second cylindrical partition 76 adjacent thereto and extending from the stand 14, whereas the cover 12 close to its edge has a downwardly extending cylindrical skirt 78- adapted to engage in the cavity 74 and to operate the keys 70 and 72 when the cover 12 is placed on the bowl 10. Each switch comprises two blades 80 and 82 (FIGS. 1 and 5) each carrying a contact and being upwardly directed from an insulating bracket 84 internal to the stand 14; the blade 82 is flexible and has an upper extremity outwardly inclined relative to the vertical and forming the key 70 or 72 housed in the bottom of the cavity 74 for reception of the descending skirt 78 of the cover 12. The lower edge of this skirt itself has an inclined profile adapted to slide in contact with and actuate the keys 70 and 72 when the cover is placed in position, thus causing the flexible blades 82 to bend towards the fixed blades 80, and causing the switches to close.
The housing cavity 74 of the switches 66 and 68 also contains three return springs 86, 88 and 90' (FIG. 2) adapted to repel the skirt 78 of the cover upwards. The stifiness of these springs is such that the weight alone of the lid 12 when placed on the appliance, is insufiicient to deflect the springs enough to enable the skirt 78 of the cover to operate the actuating keys 70 and 72 of the switches.
Since the closing of the switches 66 and 68 depends on the placing in position of the cover on the bowl, the operator does not risk injury by placing the hand on the blades during their rotation. In addition, owing to the fact that there are two switches, it will be understood that the jamming of one of them by accident in its closed position does not jeopardise the safety of the appliance. Moreover, owing to the fact that these switches are widely separated, one is certain that a child cannot be injured if it manipulates the switches by means of tools or other objects, since it must use both hands to do so.
Owing to the presence of the springs 86, 88 and 90, the operator must, in order to ensure the starting of the appliance, not only place the cover on the bowl, but must also exert a certain pressure thereon. One thus has the assurance that the cover will be held firmly on the bowl during operation of the machine thus preventing it from being flung upwards owing to impact against the 1ijnner face of the cover of the materials contained in the owl.
The bowl 10 and the blade-carrier hub 22 are easily removable, which facilitates their cleaning. Refitting the blade-carrier hub in position on its driving spindle does not entail any difficulty: in point of fact, it is unnecessary for the housewife to push the hub home on the spindle since, by virtue of the inclination of the coupling ramps or fins 34, this hub is engaged automatically and correctly on the fins as soon as the appliance is started. In addition, there is no risk of this hub flying off the driving spindle during the operation of the appliance.
It will be noted that the arrangement of the motor 62 shelters it from slight leaks of water or other liquid which could occur around the spindle 18. It will be noted in this connection that a sealed passage has been arranged at the point at which the spindle 18 passes through the stand, but that on the contrary no sealing is provided at the point at which the spindle 18 passes through the bottom of the bowl, which does not raise any difficulties since the materials to be minced contain practically no liquid.
As illustrated in FIGURE 6, the invention makes provision for the cover 12 to form a mould intended to shape croquettes from the substance minced by means of the appliance: to this end, the circular web 58 of the cover has been extended to a sufiicient height for the compartment it surrounds to contain the amount of substance intended to form a croquette, whereas the mould thus formed is associated with a base plate 92 and a pressure plate 94, both being circular and adapted to engage in this compartment. To facilitate production, the plates 92 and 94 are identical.
As shown in FIGURE 7, the bowl may itself form a croquette mould. It is co-ordinated with a base plate 96 and a pressure plate 98.
What is claimed is:
1. A mincing machine comprising a working bowl of generally cylindircal shape closed by a removable cover and supported on a stand containing a driving assembly having an output spindle which passes through the central area of the bottom of the bowl and rotatably drives a hub within the bowl carrying at least one sharpened blade, characterized in that the blade-carrying hub is formed as a single component of moldable material, said at least one blade being fastened to the hub by overmolding the hub thereon during production.
2. A mincing machine as claimed in claim 1, the bladecarrying hub being drivingly connected to the output spindle by helical splines on the laterial surface of the spindle engaging with correspondingly shaped clearance grooves in the surface of a central bore of the hub, the pitch of said splines and grooves being such that one rotation of the spindle in its normal direction of rotation fully engages the splines in the grooves.
3. A mincing machines as claimed in claim 1, in whch the sharpened edges of said at least one blade are angled 6 rearwardly on the radius relative to the direction of IO- tation.
4. A minicing machine as claimed in claim 3, in which said sharpened edges comprise two substantially rectilinear sections connected by a curved section, the outer section being more extensively angled rearwardly than the inner section.
5. A mincing machine as claimed in claim 1, in which the radial extent of each blade is equal to approximately 9/ 10th of the internal radius of the bowl.
6. A mincing machine as claimed in claim 13, in which the inner lateral face of the bowl comprises a lower section which has vertically directed fiuting and which extends from the bottom up to a level situated above the plane of the upper blade, and a smooth upper section that extends up to the top edge of the bowl.
7. A mincing machine as claimed in claim 1, said cover having at least one downwardly depending circular web on its under side concentric with the axis of the cover and of the bowl.
References Cited UNITED STATES PATENTS 1,480,914 1/ 1924 Poplawski 259-108 2,028,595 1/ 1936 Flegel 259-108 3,093,982 6/1963 Staeger 6411 3,139,917 7/1964 Elmore 146-68 FOREIGN PATENTS 1,386,353 12/1964 France.
835,167 5/1960 Great Britain.
W. GRAYDON ABERCROMBIE, Primary Examiner