Abstract:
A tortilla forming machine for molding dough into a tortilla shell having a top, a bottom, a peripheral edge, and a thickness. The forming machine includes a first member having a first forming surface, a second member having a second forming surface moveable toward and away from the first forming surface, and at least one removable sizing ring. The sizing ring includes a first edge and an opposing second edge, an inner surface and a height defining a cavity between the first and second forming surfaces when the first forming surface is adjacent the first edge and the second forming surface is adjacent the second edge such that the inner surface of the ring forms the peripheral edge of the tortilla shell and the height of the ring forms the thickness of the tortilla shell.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the art of making tortilla shells and, more particularly, to a tortilla forming machine for making a tortilla shell from a ball of dough. 
     BACKGROUND OF THE INVENTION 
     It is, of course, well known that a ball of dough can be molded into various shapes and sizes to produce food products. Traditionally, once the desired dough was properly mixed, the dough was rolled to the proper thickness and then cut into the shape needed to produce the food product. However, this method is labor-intensive and costly with respect to retail food products and restaurant services. 
     Over the years, machines have been utilized to overcome this problem by mechanically forming dough into the desired thickness and shape. In this respect, U.S. Pat. No. 5,996,476 discloses a device for pressing and imprinting bread products. The disclosed device utilizes a mold cavity which is permanently attached to the upper support frame of the device, wherein the upper mold portion is pivotally interengaged with the base mold portion for forming the dough thereagainst. Accordingly, the device disclosed in the &#39;476 patent is utilized for the production of high volumes of bread products in one size. U.S. Pat. No. 3,814,005 discloses a pizza crust forming device. As with the &#39;476 patent, the &#39;005 patent discloses a dough forming device with pivotal engagement; however, the mold cavity of the &#39;005 device is produced by a recess in the lower mold portion. Further, the mold cavity is attached to the lower mold portion which inhibits the ability to change the thickness or peripheral geometry of the finished dough product. 
     U.S. Pat. No. 5,800,844 discloses a dough pressing machine which utilizes linear motion between the upper and lower forming surfaces. The quantity of dough can be pressed from a dough ball into a desired thickness by controlling the stroke of the upper forming surface; however, the dough formed between the upper and lower planer surfaces will not have a controlled peripheral shape. U.S. Pat. Nos. 3,949,660 and 5,074,778 also disclose dough forming machines that utilize linear motion to mold a dough ball into a desired thickness. However, the &#39;660 and &#39;778 patents disclose a mold cavity attached to the upper portion of the mold to control both the thickness and the peripheral shape of the finished dough product. 
     U.S. Pat. No. 5,417,149 discloses a dough press for making pizza crust which also utilizes linear motion of an upper forming portion with respect to the stationary base portion. However, the &#39;149 patent discloses a device which can be utilized to produce a dough product of more than one thickness and peripheral shape. In this respect, the mold cavity of the &#39;149 patent is produced by the upper surface of a pizza pan and the recessed lower surface of an upper mold when the upper mold is directly adjacent the pizza pan. The mold cavity includes a disk shaped portion for the body of the pizza crust and a larger peripheral gap for the raised edge portion of the pizza crust. Accordingly, two independent components must be in proper alignment to form the dough into a pizza crust. This is accomplished by guide pins on the upper surface of the base portion which engage the outer peripheral edge of the pizza pan thereby aligning the pizza pan with the upper mold. As a result, a change in crust size requires a different pizza pan and adjustment of three guide pins so the pizza pan remains coaxial with the upper mold portion. Further, the upper mold portion must be replaced to correspond with the new pizza pan size. 
     As will be appreciated from the above, dough forming machines exist in the prior art; however, they are not well adapted to producing dough products of differing thickness and peripheral shape without considerable modification. Further, some machines are designed to be used to produce only one configuration of dough product. In addition, each of the devices in the prior art include a mold cavity on one of its forming surfaces which requires the molded dough to be scooped therefrom after the forming process. 
     SUMMARY OF THE INVENTION 
     In accordance with the present invention, a tortilla forming machine is provided which advantageously allows dough products to be produced having a uniform thickness and peripheral shape. Further, the tortilla forming machine allows changes in the thickness and peripheral shape to be accommodated quickly without requiring extensive modifications to the forming machine. Moreover, the forming machine allows for easy removal of the formed dough from the mold cavity after the forming process. 
     In this respect, a tortilla forming machine is provided to produce the foregoing advantages by utilizing thin rings to produce the mold cavity. Further, the ring which produces the desired mold cavity can quickly and easily be replaced with a ring of a different size to allow the dough to be made into a dough product of different thicknesses and peripheral shapes. Moreover, the sizing ring is separate from the upper and lower forming surfaces and, therefore, can be separated from the forming machine to facilitate the removal of the dough product. 
     It is accordingly an outstanding object of the present invention to provide an improved tortilla forming machine for molding tortilla shells of a desired thickness and peripheral shape. 
     A further object of the present invention is to provide a tortilla forming machine which can quickly form a dough ball into the desired tortilla shell. 
     Yet another object of the present invention is to provide a tortilla forming machine that allows the tortilla shell to be easily removed from the mold cavity. 
     Yet still another object of the present invention is to provide a tortilla forming machine that can be quickly and easily modified to produce tortilla shells of a different size. 
     Still yet another object of the present invention is to provide a tortilla forming machine that can produce a number of differently sized tortilla shells. 
     Yet a further object of the present invention is the provision of a tortilla forming machine of the foregoing character which is economical to manufacture, easy to manipulate with respect to forming the dough ball, and which is effective in repeatedly producing a tortilla shell of the desired thickness and peripheral shape. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing objects and others will in part be obvious and in part be pointed out more fully hereinafter in conjunction with the written description of the preferred embodiments of the invention illustrated in the accompanying drawings in which: 
     FIG. 1 is a partial section of a side elevational view of a tortilla forming machine in accordance with the present invention; 
     FIG. 2 is a partial section top plan view of the tortilla forming machine illustrated in FIG. 1; 
     FIG. 3 is a perspective view of a sizing ring used in connection with the tortilla forming machine illustrated in FIG. 1; 
     FIG. 4 is a sectional elevation view showing another embodiment of the tortilla forming machine shown in FIG. 1; 
     FIG. 5 is a partial section top plan view of the tortilla forming machine shown in FIG. 4; 
     FIG. 6 is a sectional elevation view of the tortilla machine shown in FIG. 4 showing another embodiment of the sizing ring; and 
     FIG. 7 is a sectional elevation view of the tortilla forming machine shown in FIG. 6 with a different sizing ring. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting the same, FIGS. 1-3 show a first embodiment of a tortilla forming machine  10  which includes a base  12  and a lid  14  pivotally connected to base  12  by a hinge  16 . The tortilla forming machine further includes at least one sizing ring  18  which determines the thickness t and peripheral shape, which is preferably a diameter d, of a tortilla shell  20 . 
     Base  12  includes a bottom surface  22  and a top forming surface  24 . While base  12  can be made from various materials such as, but not limited to, metal, plastic or wood, it is preferred that top forming surface  24  is made from materials designed for use with food products. This can include stainless steel and hard woods. Further, in order to facilitate the removal of the tortilla shell after the forming process, forming surface  24  can be made from a non-stick material such as TEFLON®, produced by E. I. DuPont DeNemours and Company. While the bottom surface  22  of base  12  can be any well-known stable shape, it is preferred that top forming surface  24  be circular. Bottom surface  22  can include base feet  26  to facilitate stability and prevent lateral movement of base  12 . 
     Hinge  16  pivotally connects lid  14  to base  12  to allow pivotal movement of lid  14  about an axis  28  and to allow transverse movement of lid  14  relative to axis  28 . In this respect, hinge  16  includes base hinge leaves  30  and  32  which respectively have hinge slots  34 ,  36 . Lid  14  includes lid hinge leaf  38  which has opposing hinge pins  40  and  42  coaxial with axis  28 . Further, hinge pins  40  and  42  are received in hinge slots  34 ,  36  to allow pivotal movement of lid  14  with respect to base  12 . Transverse movement of lid  14  relative to axis  28  is provided by the elongated shape of hinge slots  34 ,  36 . More particularly, hinge slots  34 ,  36  are generally oval in shape wherein the slot height “sh” is greater than the slot width “sw” such that the slot width sw is slightly greater than the diameter of the corresponding hinge pin  40 ,  42  and height sh is greater than the diameter of hinge pins  40  and  42  to allow the transverse movement of lid  14  relative to axis  28 . Base hinge leaves  30 ,  32  further include vertical holes  44 ,  46  which contain hinge springs  48 ,  50  respectively that engage hinge pins  40 ,  42 . In this respect, hinge springs  48 ,  50  maintain hinge pins  40 ,  42  at their lowermost positions within hinge slots  34 ,  36  that is dependent on the position of lid  14  and the height “H” of the sizing ring  18  which will be discussed in more detail below. It should be noted that other hinge designs that provide both pivotal and transverse movement could be utilized. 
     Lid  14  includes a top portion  52  and a bottom forming surface  54 . While lid  14  can have a variety of peripheral shapes, it is preferred that at least bottom forming surface  54  of lid  14  is circular and corresponds with the shape and size of top forming surface  24  of base  12 . As with base  12 , lid  14  can be made from a variety of materials such as, but not limited to, steel, plastic or wood. Bottom forming surface  54 , however, should be made from a material designed for food preparation use such as stainless steel or hard wood. Further, bottom forming surface  54  can also be made from a non-stick surface such as TEFLON®. Lid  14  further includes handle  56  which has gripping portion  58  and connecting arms  60 ,  62 . 
     Sizing ring  18  controls the forming of dough ball  64  into tortilla shell  20 . In this respect, height H of sizing ring  18  corresponds with the thickness “t” of tortilla shell  20 . Inner diameter “ID” of sizing ring  18  corresponds with the diameter d of tortilla shell  20 . Sizing ring  18  includes a top edge  66  substantially equal to and opposite of a bottom edge  68  which are parallel to one another and spaced by height H of sizing ring  18 . Further, sizing ring  18  includes an inner cylindrical surface  70  perpendicular to top and bottom edges  66 ,  68  and corresponding to height H and inner diameter ID. As an option which will be discussed in greater detail below, sizing ring  18  can further include ring tab  72  having a bottom surface  74  to assist in the removal of the formed tortilla shell  20  from sizing ring  18 . 
     In this embodiment, the forming surfaces  24  and  54  are planar surfaces. Tortilla shell  20  is formed by first placing the bottom edge  68  of the open ended sizing ring  18  on top forming surface  24  such that bottom edge  68  is coplanar with top forming surface edge  24 . Dough ball  64  is then placed on top forming surface  24  within the inner cylindrical surface  70  of sizing ring  18 . Subsequently, lid  14  is pivoted about axis  28  so that bottom forming surface  54  moves toward top forming surface  24  and engages dough ball  64  thereby forming dough ball  64  within sizing ring  10 . Further, while the inner cylindrical surface  70  controls the shape of the peripheral edge of tortilla shell  20 , the pivotal movement of lid  14  is restricted by sizing ring  18  to maintain the proper thickness t of tortilla shell  20 . In this respect, lid  14  first pivots about axis  23  toward base  12  until bottom forming surface  54  engages top edge  66  of sizing ring  18 . The hinge  16  allows both pivotal and transverse motion of lid  14  about axis  28  to complete the forming process within sizing ring  18 . 
     Pivotal and transverse motion of lid  14  is necessary to form dough ball  64  within sizing ring  18 . In this respect, hinge  16  allows lid  14  to rotate about axis  28  by the rotation of hinge pins  40 ,  42  in hinge slots  34 ,  36  respectively until bottom forming surface  54  engages the leading edge  76  of sizing ring  18 . However, in this position, bottom forming surface  54  is not coplanar with top edge  66  whereby the forming process is not complete. Further rotation of lid  14  about axis  28  requires transverse movement of lid  14  relative to axis  28 . The amount of transverse movement depends on the height H, diameter and position of sizing ring  18  and is provided by slots  34 ,  36 . More particularly, hinge pins  40 ,  42  are allowed to move vertically within hinge slots  34 ,  36  respectively, such that bottom forming surface  54  of lid  14  is able to fully contact top surface  66  of sizing ring  18  eliminating gaps therebetween regardless of the height H of sizing ring  18 . 
     The coplanar contact between forming surfaces  24  and  54  and ring edges  66 ,  68  produce mold cavity  78 , wherein mold cavity  78  is defined by top forming surface  24 , bottom forming surface  54  and inner cylindrical surface  70 . Accordingly, as lid  14  is moved in the above-described manner, dough ball  64  is formed into tortilla shell  20  by the restrictive forming effects of surfaces  24 ,  54  and  70  within sizing ring  18 . Sufficient contact force between top and bottom forming surfaces  24  and  54  and ring edges  66 ,  68  of sizing ring  18  to maintain dough ball  64  within mold cavity  78  is produced by the downward force applied to handle  56  in conjunction with the transverse motion of hinge  16  and hinge springs  48 ,  50 . More particularly, the hinge springs produce sufficient pressure on the leading edge  70  of sizing ring  18 , while the handle force produces sufficient pressure on trailing edge  77  of sizing ring  18  to account for the transverse motion lid  14  about axis  28 . It should be noted that other hinge designs which allow motion transverse to the pivot  28  can be used to account for differing sizes and placements of sizing ring  18 . 
     The tortilla forming machine  10  allows tortilla shells of many different thicknesses t and diameters d to be made based only on the size of the sizing ring  18 . In this respect, many differently sized and shaped sizing rings  18  can be provided so that the user of the tortilla forming machine  10  can easily make a plurality of sizes of tortilla shells  20 . In order to change the size of tortilla shell  20 , sizing ring  18  merely needs to be removed from top forming surface  24  and replaced with a different size or shape sizing ring. No other adjustments are required. 
     The removal of sizing ring  18  from top forming surface  24  for either removing tortilla shells or changing the sizing ring can be made easier by ring tab  72 . In this respect, ring tab  72  produces an additional grasping point away from tortilla shell  20  and also can include a curved portion producing a grasping point above top forming surface  24 . More particularly, ring tab  72  can be curved such that bottom surface  74  of ring tab  72  tapers away from bottom surface  68  of sizing ring  18  in its relaxed state. As a result, ring tab  72  extends away from bottom surface  24  to allow easier grasping of sizing ring  18 . However, as lid  14  is moved toward base  12 , the bottom forming surface  54  of lid  14  engages ring tab  72  which in turn flexes ring tab  72  downwardly so that bottom surface  54  can fully engage top ring edge  66  to form mold cavity  78 . 
     Referring to FIGS. 4-7, another embodiment of the present invention is shown, wherein tortilla forming machine  80  includes a base  81  having a circular recessed portion  82 . Sizing ring  84  fits within recessed portion  82  and defines both a bottom portion  86  and side portion  88  of mold cavity  90 . However, it should be noted that sizing ring  84  could also be used in connection with planar top forming surface  24  shown in FIGS. 1 and 2. With respect to base  81  shown in FIGS. 4 through 7, the top of mold cavity  90  is formed by bottom forming surface  54  of lid  14 . The desired size of tortilla shell  20  is produced by utilizing the sizing ring  84  which corresponds therewith. 
     Sizing ring  84  includes a ring portion  92  having a height “H 2 ” and an inner diameter “ID 2 .” Sizing ring  84  further includes spacer  94  so that top surface  96  of ring portion  92  is coplanar with or slightly raised above top surface  97  of base  81 . 
     Referring to FIG. 6, another embodiment of the present invention is shown, wherein a sizing ring  98  is shown which includes ring portion  100 , base portion  102  and peripheral flange  104 . Mold cavity  106  is defined by the top surface  108  of base portion  102  and inner peripheral surface  110  of ring portion  100  along with bottom forming surface  54  of lid  14 . Upper flange surface  112  is coplanar with or slightly raised above top surface  114  of base  81 . Sizing ring  98  includes a height “H 3 ” and an inner diameter “ID 3 .” 
     FIG. 7 shows a sizing ring  116  which is of the same design as sizing ring  98  except for mold cavity  118  being of a different size than mold cavity  106  of sizing ring  98 . In this respect, sizing ring  116  has a height “H 4 ” and an inner diameter “ID 4 ” which are different from H 3  and ID 3  respectively. 
     While considerable emphasis has been placed on the preferred embodiments of the invention illustrated and described herein, it will be appreciated that other embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principals of the invention. Accordingly, it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.