Pasta Maker

This invention relates to an apparatus used for the preparation of food pastes and in particular to a device for the mixing, kneading and extrusion of pasta paste.

In order to produce farinaceous pastes such as those used for various types of pasta, intense mixing and kneading are necessary to create correct paste homogeneity. Because farinaceous paste is denser than other paste such as used in breads or cakes, devices to mix and knead farinaceous paste were specifically designed to overcome obstacles associated with the need for intense mixing and kneading. For example, the high torque necessary to drive mixing shafts was overcome by utilizing larger motors, and the process of kneading was simplified by adding a kneading blade to the mixing shaft. Furthermore, the process of extruding the paste into pasta noodles has been combined with the same apparatus used for mixing and kneading. One common characteristic of machines capable of mixing, kneading and extruding is that such machines have ordinarily been designed for use at the industrial level for production of large volumes of food pastes.

In recent years, there has been an increased demand for smaller scale devices having the ability to make farinaceous pastes within the home. Such devices must substantially depart from previous methods because it is well known that large and bulky industrial devices cannot be used in the average domestic kitchen. It is one object of this invention to provide a simple yet effective means for producing smaller volumes of pasta or other food pastes within the constraints of a common domestic kitchen. It is yet another object to provide an apparatus which can simultaneously mix, knead, and extrude the food paste into the desired pasta shape. It is another object to provide for an apparatus in which mixing and kneading can occur at continually varying levels within a container having food paste.

U.S. Pat. No. 4,219,318 to Cavalli discloses a pasta making machine usable in the home. This invention employs the use of a plurality of mixing blades, a scraper blade, and a kneading blade in which all said blades are attached to a central shaft which rotates within a container. This invention makes use of a biasing means on the kneading blade to maintain pressure on the food paste such that the paste is kneaded to the correct homogeneity. The biasing means biases only the kneading blade while the remaining elements remain in fixed relation to a bottom wall of the container. The kneading blade is designed such that the trailing blade edge is positioned at a closer distance to the bottom wall of the container than that of the leading blade edge. Once the paste is mixed and kneaded, it is transferred to an extrusion chamber whereby an extrusion screw pushes the paste through a set of dies having the cross sectional shape of the desired pasta noodle.

While the prior art may be useful for its intended purpose, the art is absent of any device for home use in which mixing and kneading can take place at variable levels within a container due to a vertical biasing of both mixing and kneading blades. Furthermore, the prior art is absent of any device in which the kneading blade can achieve proper kneading action without having to mount the blade such that the trail and leading edges of the blade are positioned at varying distances from the bottom wall of the mixing container.

Accordingly, the present invention comprises an apparatus for preparing food paste such as farinaceous paste wherein small volumes can be prepared for domestic use. The apparatus includes a container which holds the food paste to be processed. The container includes a circular bottom wall, an open top side and a cylindrical side wall perpendicular to and integral with the bottom wall. Within the interior of the container is a centrally located mixing and kneading assembly having a movable part and stationary part. Both parts are placed over a spindle which is rotated by a drive means having adequate torque to spin the mixing and kneading assembly, thus overcoming the dense farinaceous paste. The spindle defines a vertical axis which serves as a reference line in describing the configuration of the apparatus elements. Attached to the movable part is a plurality of mixing blades and a single kneading blade which extend in a radial direction away from the vertical axis. Typically, the mixing blades are vertically and radially spaced along a cylinder of the movable part. The mixing blades may be configured in any spacial relationship to effect the needed mixing. The kneading blade has a leading edge and a trail edge that are substantially parallel to the bottom surface of the container. Kneading is achieved by the unique configuration of the bottom side of the blade. Typically, the bottom side of the kneading blade is of a convex configuration such that as the kneading blade is spun, the convex portion acts to compress and pull the paste thus achieving proper kneading action. The convexity of the bottom side may be altered in any geometric configuration to achieve the desired kneading action. An increase in the convexity of the bottom side of the blade results in more effective kneading action. Attached to the fixed part is a scraper blade which extends in a radial direction away from the vertical axis. The scraper blade has a trailing edge which is positioned in close proximity with the bottom wall of the container such that paste is prevented from adhering to the bottom wall of the container as the scraper blade is spun.

Mounted over the spindle and between the movable part and stationary part, in a first embodiment, is a biasing means in which the entire movable part may be vertically displaced along the vertical axis. The biasing means maintains a force on the movable part such that the movable part is urged toward the bottom wall. When an obstruction such as a lump of paste falls to the bottom wall of the container, the kneading blade makes contact with the obstruction, such that some paste will fall below the bottom surface of the blade thus creating an upward force in the opposite direction of the biasing means. As the kneading blade continues to spin, the lump will be compressed and pulled apart. If the upward force is greater than the downward force of the biasing means, the movable part will be pushed upward along the spindle. As farinaceous paste is mixed and kneaded, the movable part will continuously experience varying displacement along the spindle in the vertical direction depending upon the size and density of the paste lump encountered. This cyclical up and down movement is advantageous to mixing because the blades continuously strike the paste at varying levels within the container. Accordingly, the paste is more efficiently mixed and stratification is minimized in the early stages of mixing in comparison to devices in which mixing takes place at a constant level. While the movable part is displaceable along the vertical axis, the stationary part remains fixed in spacial relationship with the bottom wall of the container. This is necessary to ensure the scraper blade continuously removes any paste adhering to the bottom wall of the container. While the up and down movement may be advantageous for mixing in most applications, it may be desired to mix at a constant level. Accordingly, this invention contemplates embodiments which can either accommodate mixing at a constant level or at varying levels due to a biasing means.

In a second embodiment, the movable part and the stationary part are held in fixed vertical relation to each other.

With either embodiment, once adequate mixing and kneading has taken place, the paste is transferred to an extrusion chamber by opening a shutter slide that causes the paste to be fed by gravity force into the chamber. The convex bottom side of the kneading blade further assists transfer of the paste by pushing the paste down into the extrusion chamber. A screw-type extrusion screw then forces the paste in the chamber through extrusion dies having the desired cross sectional shape to form the desired pasta noodle.

FIG. 1 is a perspective view of one embodiment of the present invention;

FIG. 2 is a partial horizontal cross sectional view of the embodiment in FIG. 1 taken along line 2--2 of FIG. 1;

FIG. 3 is a horizontal offset cross-sectional view of the drive means used to rotate the extrusion screw and mixing and kneading assembly taken along offset line 3--3 of FIG. 2;

FIG. 4 is an exploded perspective view of a disassembled mixing and kneading assembly;

FIG. 5 is a cross-sectional view of a movable mixing and kneading assembly taken along line 5--5 of FIG. 2;

FIG. 6 is a cross-sectional view of an immovable mixing and kneading assembly taken along line 5--5 of FIG. 2;

FIG. 7 is a fragmentary, exploded, perspective view of the elements of the extrusion system; and

FIG. 8 is an enlarged cross sectional view of the extrusion system shown in FIG. 2.

FIG. 1 shows an improved pasta maker 10, according to the present invention. The pasta maker 10 includes a housing 12 and base 13 which constitute the outer surface of the pasta maker 10. A cylindrical shaped container 15 is used to hold the pasta ingredients during the mixing and kneading process. The top portion of the container 15 is shown protruding above the housing 12 with the remaining portion of the container 15 hidden inside the housing 12. A top cover 14 is used to cover the top side of the container 15. The top cover 14 includes a first opening 18 and second opening 19 that can be used as entry points for the addition of pasta ingredients into the container 15. The openings 18 and 19 may include shutter type closure elements in order to completely seal the added ingredients from the environment. Conveniently, two cover removal assists 20 are provided to enhance gripping for removal or placement of the top cover 14. Threads on the interior edge of the top cover 14 allow the top cover 14 to be securely fastened to matching threads on the upper exterior of the container 15. An on-off switch 22 is provided on one side of the housing 12 enabling a user to operate the pasta maker.

Referring to FIG. 2, the container 15 includes a circular bottom wall 16, an open top side and a cylindrical shaped side wall 17 perpendicular to and integral with the bottom wall 16.

As shown in FIGS. 1, 7 and 8, the extrusion system 26 includes an extrusion chamber 27 that fits snugly into extrusion housing 33 through extrusion port 31. The extrusion chamber 27 is slidably received in extrusion housing 33 so that it can be removed easily for cleaning. The extrusion screw 34 is placed inside the chamber 27 wherein the horizontal extrusion shaft 36 is keyed with extrusion coupling 99 of FIG. 3. The extrusion disc 30 is held against the face of extrusion port 31 by extrusion nut 28. The extrusion disc 30 has a plurality of extrusion openings 32. The openings 32 are configured in the desired cross sectional shape of the pasta to be extruded. The pasta exits the pasta maker 10 through the extrusion openings 32. The shutter slide 24 is provided to selectively seal the container 15 from the extrusion chamber 27 or to provide entry from the container 15 through the extrusion hole 29 of FIG. 2 to the extrusion chamber 27.

Referring now to FIG. 2 and FIG. 4, inside the container 15 is found a mixing and kneading assembly 40. The assembly 40 comprises two primary components, the movable part 48 and the stationary part 54. The movable part 48 includes a first cylinder 50 and a second cylinder 52 attached to the first cylinder 50 at its lower end. The cylinders 50 and 52 are attached such that they are in axial alignment along a vertical axis A--A. A plurality of mixing blades 56 are fixed to the first cylinder 50 wherein the blades 56 extend perpendicular to the first cylinder 50 and radially outward from vertical axis A--A. The blades 56 may be canted at a desired horizontal angle to achieve proper mixing.

As shown in FIG. 4, the mixing blades are of a triangular type cross sectional shape with the distal end 57 of the blades 56 slightly upturned. It will be understood that any number of mixing blades 56 and any spacial arrangements of such blades may be utilized to achieve desired mixing. Additionally, the cross sectional shape of the blades 56 may be varied to achieve the desired mixing. A single kneading blade 60 is attached to the second cylinder such that the blade 60 extends perpendicular to second cylinder 52 and radially outward from axis A--A. The kneading blade 60 has axis B--B through leading edge 61 and trailing edge 62 in which axis B--B is substantially parallel with the bottom wall 16 of the container 15. The kneading blade 60 has a substantially flat top surface 63 and a convex bottom surface 64, as best shown in FIG. 2. The convexity of the bottom surface 64 may be configured to achieve the desired kneading action. The stationary part 54 includes a shaft 65 attached to base section 70 such that the shaft 65 and base section 70 are aligned along axis A--A. A flat 72 and flat 74 are found on the shaft 65 and base section 70, respectively and extend parallel with axis A--A. A scraper blade 67 is attached to and extends perpendicular to base 70 and radially outward from axis A--A. The trailing edge 68 of scraper blade 67 may be canted downwards such that it comes in closer proximity than the leading edge 69 with the bottom wall 16 of the container 15.

As the mixing and kneading assembly 40 is spun in direction S, the scraper blade 67 removes pasta material which may have fallen and adhered to the bottom wall 16 of container 15. To assemble the assembly 40, a spring 46 is placed over the shaft 65 so that the lower end of spring 46 rests against stop 47 formed around the inside of cylinder 50, as shown. The movable part 48 is then placed over the stationary part 54 such that the flats 72 and 74 are aligned with corresponding interior flats found inside cylinders 50 and 52. A cutout 76 fits over scraper blade 67. At the top end of the shaft 65 are threads 66 that engage a fixing nut 44. The fixing nut 44 secures the movable part 48 to the stationary part 54 whereby the spring 46 serves to cause the movable part 48 freedom of movement in an up or down direction along axis A--A.

Referring to FIGS. 2 and 3, the drive means includes a drive motor 82 that turns main drive shaft 84. Main drive shaft 84 has a rigidly attached drive gear 85 that drives a first gear 86. First gear 86 is fixed to and supported by first support shaft 87. First gear 86 is stacked on top of and rigidly connected to second gear 88. Second gear 88 in turn drives third gear 89. Third gear 89 is stacked on top of and rigidly connected to fourth gear 90. Fourth gear 90 is fixed to and supported by second support shaft 91. Fourth gear 90 drives fifth gear 92. Fifth gear 92 is fixed to secondary drive shaft 93. Secondary drive shaft 93 is journaled at the bottom in gear bushing 94 and at the top in gear bushing 94'. The middle section of shaft 93 has secondary drive gear 95 which engages spindle gear 96. The spindle 78 is rigidly attached to spindle gear 96 such that rotation of gear 96 causes the spindle 78 to rotate. The upper end of shaft 93 has a rigidly attached worm gear 97. Worm gear 97 contacts helical gear 98 that is fixed to extrusion coupling 99. The rotation of shaft 93 causes the worm gear 97 to engage helical gear 98 and thus turn extrusion coupling 99. The coupling 99 is keyed and aligned with horizontal extrusion shaft 36 causing the extrusion screw 34 to spin. The screw type configuration of extrusion screw 34 causes paste in the extrusion chamber 27 to be forced through the extruder openings 32.

Referring to FIG. 5, the mixing and kneading assembly 40 is placed over spindle 78 and secured to the spindle 78 by spindle nut 80. The spindle 78 defines axis A--A and protrudes through the center of the bottom wall 16 of container 15. The spindle 78 extends downward through the container 15 into the interior of the pasta maker 10 and terminates at spindle bushing 79 located on the interior side of base 13.

FIG. 5 and FIG. 6 illustrate cross-sectional views of the mixing and kneading assembly 40. In FIG. 5, the assembly 40 utilizes spring 46 to bias the movable part 48. In some applications, it may be desired to fix the movable part 48 to the stationary part 54. FIG. 6 shows the spring 46 replaced with a sleeve 49 which causes movable part 48 to no longer be displaceable with respect to stationary part 54.

This invention has been described in detail with reference to particular embodiments thereof, but it will be understood that various other modifications can be effected within the spirit and scope of this invention.