Abstract:
An apparatus for cutting optimally sized fruit and vegetable pieces comprised of a dump chute, a trough, a conveyor, a drive means, at least one sensor, a programmable logic controller (PLC), and a cutter assembly. The apparatus is configured to receive materials from a source, load these materials onto a conveyor move these items by means of the conveyor to a cutting portion where the materials are cut into appropriate sized pieces, as determined by a programmed logic sensor based upon the input from a plurality of sensors and pre-selected criteria from a user.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to the art of cutting vegetable products, and more particularly relates to a device for cutting optimally sized vegetable and fruit pieces. 
     2. Background Information 
     This specification is presented in the context of cutting potatoes into optimally sized pieces. However it is to be understood that the apparatus described and claimed herein is capable of use with a variety of vegetable and fruit products, including, but not limited to, potatoes, carrots, cucumbers, pineapples, along with a host of other fruits and vegetables. 
     In commercial potato processing, potatoes are received into a receiving area where they are cleaned to remove excess dirt and rocks. Then, through a series of processes these potatoes are converted from raw potatoes into potato products having various desired attributes. 
     Certain varieties and sizes of potatoes are better suited for certain types of commercial applications. One of the most common and valuable potato products is called “french fry” potatoes. French-fries are made by a process, wherein washed potatoes are deposited into a steam cooker where the outsides of the potatoes are steamed and the potato skins are removed. These potatoes are then carried within an aqueous solution through tubing to a cutter head wherein the force of the fluid stream pushes the potatoes through the cutter head. As a result, the potatoes are cut into pieces having a desired shape or design according to the specifications and configuration of the blades on the cutter head. A more complete description of this process is found in U.S. Pat. No. 4,807,503, the teachings of which are hereby incorporated by reference. The cutter head assembly, however, only has the ability to make cuts in the potato in one direction. Thus a 3-inch potato will yield 3-inch pieces, a 4-inch potato will yield 4-inch pieces and a 10-inch potato will yield 10-inch pieces, or worse, some 1-inch pieces and a plurality of randomly sized broken potato pieces. 
     Under current market conditions, the ideal length for french-fries after processing through the cutter head is about four inches (4″). However, the varieties of potatoes that have the attributes best suited for french fries, such as Russet Burbanks, Nor-Golds, Rangers, and Shepodys, often grow to a length substantially larger than four inches (4″). As a result, in order to obtain optimal length potato pieces, the potatoes must be sorted or cut before entering into the french fry making apparatus. 
     One method for obtaining ideal sized potato pieces is to accept only 4-inch potatoes from the growers. This is impracticable, because these varieties having the desired characteristics for storage, cooking, texture, and water content generally grow longer than 4 inches. Furthermore, inherent natural differences prevent all potatoes from being one standard size. 
     Processors attempt to reduce the number of non-optimally sized potatoes by rejecting or paying lower prices for loads from producers that contain too great a number of oversized potatoes. In as much as most producers do this, the price of optimally sized potatoes is generally greater than the price of non-standard sized ones. The fewer non-standard sized potatoes that exist in a load of potatoes, the greater the price of that load. However, even when attempting to have all standard sized potatoes by paying a higher price, non-standard sized potatoes will be processed. Furthermore, the cost of obtaining such potatoes could prove to be commercially impracticable. 
     Another method for obtaining ideal sized potatoes is to mechanically cut all of the potatoes to one length such as four inches (4″). However, by engaging in such a method, the cut off portions of the potato which are not four inches (4″), are either separated and wasted, resulting in decreased efficiency and increased costs, or mixed with the ideal length cut potatoes and also processed. If they are processed as french fries, the result is an increased number of non-standard, non-ideal, therefore less valuable french fries. If they are separated and either disposed of or passed along for further processing, waste will result or increased costs will be incurred. 
     Another method for obtaining ideal sized potatoes is to employing people to manually view and cut the potatoes into as many optimally sized pieces. This process is slow and expensive. 
     Attempts have been made in the past to construct machines which cut oversized potatoes in half, most of which have been technically successful, to one degree or another, in achieving this goal. However, these methods have been commercially unsuccessful because of the inevitable result that some half-pieces will be too short, and others too long. 
     In as much as processors attempt to reduce the number of non-optimally sized potatoes by rejecting or paying lower prices for loads from producers that contain too great a number of oversized potatoes, the price of optimally sized potatoes is greater than the price of potatoes of a non-standard size. A processor with the ability to process large potatoes by cutting them into optimally sized pieces would have an advantage over its competitors. That processor could buy non-ideally sized potatoes at a decreased price from the producer, process these potatoes with less waste and obtain a premium product for which they could obtain a better price. A competitor, to obtain the same result, would have to pay the premium price for smaller potatoes, cut these potatoes, and waste the non-ideal sized potato pieces. The cost to such a competitor would place it at a significant disadvantage to the processor who could obtain ideally sized product. 
     Accordingly, it is an object of the invention to provide an apparatus and means for cutting optimally sized fruit and vegetable pieces. Furthermore, it is an object of the invention to provide a method for cutting optimally sized fruit and vegetable pieces from non-standard sized fruit and vegetables in a mechanized environment. It is also an object of the invention to provide a method and apparatus for cutting optimally sized potato pieces from non-standard sized potatoes. 
     SUMMARY OF THE INVENTION 
     These objects are achieved using an apparatus for cutting optimally sized fruit and vegetable pieces, such as potatoes, that is made of a frame, a dump chute, a trough, a conveyor having paddles forming paddle pockets, a drive means, at least one sensor, a programmable logic controller (PLC), and a cutter assembly. The dump chute with a heel stop is pivotally connected to the frame and receives potatoes and loads them singly on to a conveyor within a paddle pocket defined by two paddles disposed along the conveyor, and located within said trough. The drive means moves the conveyor, which then advances the potatoes from the dump chute toward the cutter. 
     As the potatoes move along the trough, the sensor determines the first and second ends of the potato and inputs this information to the PLC. This PLC has a human interactive component for selecting the criteria to be used in selecting the dimensions of the desired potato pieces to be obtained. The PLC receives the information from the sensors, applies an algorithm based upon pre-selected dimensions to be obtained and determines the number and sizes of the pieces that the potato should be cut into to achieve the optimal results based upon the pre-selected criteria. This information is then passed to the cutter. 
     The cutter receives input from the programmable logic controller. Then, it makes the directed number of cuts necessary to obtain the predetermined number of optimally sized potato pieces. The potato pieces then pass along to other areas for further processing. 
     Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective representational view of the invention. 
     FIG. 2 is a perspective representational view of the cutter assembly and swing blade. 
     FIG. 3 is a front view of the cutter assembly and swing blade. 
     FIG. 4 is a front plan view of a paddle 
     FIG. 5 is a representational view of the flow of information between sensors and control devices as a conveyor moves 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. 
     As previously stated, this invention is presented and described in this description in the context of cutting potatoes. However it should be apparent to those skilled in the art that the invention described herein can easily be adapted or modified to cut other fruits and vegetables, for example carrots, cucumbers, pineapples, bananas and the like. Modifications would include dimensional sizing, conveyor speed, the cutting assembly and perhaps whether the conveyor is temporarily stopped during cutting operations. 
     Referring now to FIG. 1, shown is an embodiment of the invention adapted for cutting optimally sized potatoes. This apparatus  10  is comprised of a frame  22  having a frame first end  24  extending to a frame second end  26 . A dump chute  28  with a heel stop  30  is pivotally connected to said frame  22  and loads material such as potatoes into trough  34 . Trough  34  has a trough first end  35  and trough second end  37  connected to the frame  22  and lies in a generally linear orientation. A conveyor  32 , having a plurality of equally spaced paddles  36  attached thereto, and extending outwardly from the conveyor  32 , is adapted to fit within the trough  34  and is attached to a drive means  40  whereby the movement of conveyor  32  rotates the paddles  36  up and through trough  34  from the first end  35  to the second end  37 . The drive means  40  can be any means of driving a conveyor  32 . 
     The space between the paddles  36  is a known distance. The space between them form pockets as shown in FIG. 1, wherein paddles  36 ′,  36 ″ form a pocket  38  adapted for receiving a fruit or vegetable such as a potato from dump chute  28 . For definitional purposes, each paddle  36  serves a dual function with respect to the sequence of pockets, namely each paddle serves as the rear paddle of one pocket, and as the front paddle of the next pocket. 
     A programmable logic controller (PLC)  56  is provided. One input includes an input signal representing the speed of conveyor  32 . If the speed on the conveyor is fixed, this is a known input. Another input includes location of each of the paddles  36  as each individual paddle passes sequentially by sensor  52 . Other inputs for the PLC could exist with slight modifications. A programmable logic controller (PLC) was selected for use in the preferred embodiment, however it should also be apparent to those skilled in the art that other computing devices may be used. 
     In the preferred embodiment, sensor  52  is a magnetic proximity sensor, however it is to be recognized that there are a plurality of various proximity sensors which could be used in alternative embodiments of this invention, including light sensors and even mechanical sensors, all of which are known in the prior art. 
     Dump chute  28  is synchronized to move in relation to paddles  36  on conveyor  32  to ensure that one piece of material, such as a potato, falls into each paddle pocket  38 . While in this embodiment the dump chute  28  is activated pneumatically or electronically it is to be understood that any other means for activation such as mechanical or hydraulic may also be utilized. 
     When dump chute  28  is in a dumping position, the material, while in a conventional hopper (not shown), which feeds dump chute  28  from behind the dump chute  28 , is prevented from advancing into dump chute  28  by the heel stop  30 , which is attached to dump chute  28 . When the dump chute  28  returns to its loading position, which in the preferred embodiment is a horizontal position, the next piece of material enters over the heel stop  30  and is then dumped into the next paddle pocket  38 . Heel stop  30  on the dump chute ensures that only one piece of material is placed in each paddle pocket  38 . Trough  34  is formed in a generally ‘V’ configuration and sized for the particular material to be cut so as to frictionally engage the material to the sides of trough  34  to a sufficient degree to retard movement of the material within trough  34  until it is engaged and pushed by the rear paddle  36  of pocket  38  into which it has been dropped. 
     A second sensor  54  is provided to detect the leading edge of the food product in each pocket  38  as it approaches swing blade cutter assembly  70 . Since the speed of conveyor  32  is a known input as well as both the distance between paddles  36  and the location of a particular paddle  36  passing by sensor  54 , when sensor  54  senses the initial presence of the leading end of the material, a signal, representing the time interval between the passage of the first, or front paddle forming pocket  38  and the front of the piece of material to be cut, can be generated. This signal will be inversely proportional to the length of the piece of material. That is to say, the shorter the time interval, the longer the piece of material, in this case, a potato is. Thus, computing means in this case a programmable logic controller processor  56  is capable of determining the length of each piece of food product in each pocket  38  as it approaches swing blade cutter assembly  70 . In the preferred embodiment, first sensor  52  is positioned to identify the passage of the forward paddle of a pocket  38  while second sensor  54  senses the location of the forward edge of the food product contained within that particular pocket  38 . It should be apparent to those skilled in the art that there may be other suitable locations for each sensor, or that their functions may be combined in a single sensor. 
     Programmable logic controller (PLC)  56  then selects a pre-programmable mathematical formula to cut the pieces of material into optimally sized portions for desired recovery. This programmable logic controller  56  has human interactive capabilities that allow the criteria for the desired sizes of pieces to be selected. These parameters can be changed according to the needs of the processor. Programmable logic controller  56  then passes the information regarding the cuts to be made to control means  60 , in this instance an air powered actuator. Control means  60  receives input from programmable logic controller  56  and activates the cutting assembly  70  to make the number of cuts necessary to obtain the predetermined number of optimally sized potato pieces. Any device with the ability to perceive information and make cuts according to that input may be used as a control means and a cutting means. Guillotine type knives, band or rotary saws or other types of cutting devices may be appropriate depending upon the type of food product being cut. 
     The type of cutting blade selected would depend on the type of food product being cut, the required production rate and whether the conveyor will be temporally stopped during the cutting process, or whether it will continue moving during the cutting process. As is later described in this specification, the type of cutter blade assembly selected for use with potatoes is a swing blade, which cuts in both directions. This speeds up the cutting process since the swing blade will not have to return to a reset position after each cut is made. 
     In use in a potato processor, optimally sized pieces range from three (3″) to four-inches (4″) in length. Therefore, programmable logic controller  56  makes a decision based upon the length of the potato as to how many optimally sized pieces within that three (3″) to four inch (4″) range may be produced for any given length of uncut potato. For example, for a ten inch (10″) potato, the inputs from sensors  52  and  54  would enable programmable logic controller  56  to determine and then calculate, based upon a preprogrammed algorithm, what cuts would need to be made so that the maximum number of optimally sized potato pieces would be produced. The potato could then be cut into two (2) three inch (3″) sections and one (1) four inch (4″) section; or into two (2) three and a half inch (3½″) sections and a three inch (3″) section depending upon the criteria desired and chosen by the operator. Each potato would then be measured and cut to obtain the maximum number of optimally sized potato pieces based upon the size of the potato and the pre-selected criteria. Potatoes that are under length are passed without cutting at all and are fed directly into the subsequent potato processes. This may include passing, without cutting, some less than ideal sizes, such as five-inch (5″) potatoes. In some situations it would be better to have an uncut five inch (5″) potato rather than one four inch (4″) piece and a one inch (1″) piece of scrap. In any event, in the preferred embodiment, these are decisions left to the discretion of the processor. 
     Referring now to FIGS. 2 and 3 a detailed view of the cutter assembly  70  and control means  60  of this preferred embodiment is shown. In this embodiment, control means  60  is provided with dual action, high pressure, fast action, pneumatic cylinder  62 , hereinafter referred to as actuator cylinder  62 , pivotally mounted to pivot mount  64  which itself is attached to mounting frame  63 . An actuator cylinder rod  68  extends through mounting frame aperture  65  and is pivotally attached to knee joint  74  that is connected to a double-edged swing blade  72 . In practice, a dual action, high pressure, fast action, pneumatic cylinder can, using air at eighty (80) p.s.i.g., can swing swing blade  72  through and cut a potato piece in approximately thirty (30) milliseconds, thus eliminating the need to temporarily stop conveyor  32  to facilitate a straight cut of the potato. While conveyor  32  is still moving as the cut is being made, the cut is made so quickly that, even though it will be slightly angled because the potato is still moving during the cutting process, it will be within acceptable limits for potato processing. 
     Referring now back to FIG. 1, when the actuator cylinder  62  receives input from programmable logic controller  56 , it moves swing blade  72  from whatever side it is on to the other. Two-sided swing blade  72  is specially designed so that a cut can be made on both the forward and reverse movement of the blade. Upon activation from programmable logic controller  56 , actuator  62  activates the knife blade  72  to swing and make the desired number of cuts at the desired distances, thus producing the desired number of optimally sized pieces. 
     Blade sensor  76  determines when and if swing blade  72  has made the appropriate cuts. If blade sensor  76  does not sense that swing blade  72  has made an appropriate cut, it then sends an error message to the programmable logic controller  56 . If the operator so desires, the program can be altered to stop or alarm when a problem is noted. 
     In use in a potato-processing context, potatoes to be cut are deposited in a hopper, preferably a hopper that can be agitated, and are dumped into dump chute  28 . As previously stated, these hoppers are well known in the art and play no part in the present invention. As each potato enters dump chute  28 , it is deposited into a paddle pocket  38 . Each potato frictionally engages the sidewalls of trough  34  and thus it is temporarily retarded until it engages the rear paddle  36 ′ at which time the potato is pushed along through trough  34 . First sensor  52  determines when the forward paddle forming the paddle pocket passes a reference point and second sensor  54  determines the time interval from that point in time until the forward end of the potato passes a second reference point. This information is transmitted to programmable logic controller  56 . Programmable logic controller  56  determines the length of the potato, and the number and location of cuts to be made to obtain optimal results. Conveyor  32  continually moves each potato through trough  34 . At the end of trough  34 , cutter assembly  70  cuts each potato into the number of optimally sized pieces as determined by programmable logic controller  56 . The optimally sized potato pieces then pass along for further processing. The results of this process are maximum numbers of optimally sized potato pieces regardless of whether or not the potatoes at the beginning of the process are optimally sized. 
     In practice, using four of the disclosed conveyor and cutting assemblies, ganged together, for cutting potato pieces, production rates of approximately 28,000 pounds per hour can be achieved. 
     In order to achieve optimal results potatoes must lay flat within each paddle pocket  38 . In the case of potatoes, if a potato enters pocket  38  at too steep an angle it may land in pocket  38  with an end up against the rear paddle  36  of the pocket and the frictional contact of the potato with the trough  34  may hold the potato up. To prevent this standing up and as is shown in FIGS. 1 and 4, each paddle is provided with a roller assembly  46  which is larger in diameter than the thickness of paddle  36  to facilitate the use of the momentum of the potato being dumped into pocket  38  to help deliver the potato to the pocket in a flat orientation. This process is further enhanced by tilting paddles  38  forward about seven degrees (7°) from perpendicular engagement conveyor  32 . 
     While there is shown and described in the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto, but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.