Patent Application
20090056562
Commercial potato processors typically prepare frozen processed strips by washing and sometimes peeling whole potatoes, inspecting the whole potatoes to trim defects and sort them if necessary, cutting the whole potatoes into strips, and then subjecting the strips to additional processing and freezing steps. Institutional and business customers, such as fast food restaurants, who purchase the frozen potato strips from the potato processor typically prepare the strips by frying them in oil and serve them to customers as french fries. Fast food restaurants and other purveyors of french fries often require the packaged frozen potato strips to meet exacting length or “count” specifications which limit the number of “short” strips allowed per pound as well as the number of “long” strips allowed per pound. Short strips are strips shorter than a specified length, and long strips are strips longer than a specified length. Long strips are produced when unusually long potatoes (exceeding six or seven inches, for example) are sliced into strips by a strip cutter, such as a “water gun.”
Fast food restaurants and many other french fry purveyors view long strips as undesirable because they adversely affect serving yield and do not fit well in disposable serving containers sized to hold strips of shorter length. Commercial potato processors also view long strips as undesirable because they are more prone to break during processing and shipping and may be crushed during packing if the length exceeds the headspace of the packing enclosure. Traditionally, commercial processors have controlled the number of long potatoes in the conveyor line by having inspectors manually pull long potatoes at the trimming station, cut the potatoes into halves or thirds and then return the cut pieces to the moving conveyor line.
More recently, two commercial systems have been introduced to provide a more automated solution to the problems associated with long potatoes. The Farmco Division of Key Technology offers a commercial cutting system in which whole potatoes are transferred to one of a series of flights mounted on an endless, steeply inclined (almost upright) conveyor. The conveyor is tilted away from vertical to keep the potatoes from rolling off the conveyor belt. Each flight conveys a single potato upwardly toward a rotating but otherwise fixed cutting blade. The blade has a horizontal axis of rotation and rotates in a vertical plane aligned with the center of the conveyor bolt. Spring-biased fingers engage opposite ends of the potato as it approaches the blade to keep its midsection generally aligned with the cutting edge of the blade. The flight conveys the potato upwardly into cutting engagement with the blade, which cuts the potato in half transversely. Each flight is split into two sections, with a gap therebetween, to permit the sections to pass on either side of the blade as the potato is sliced.
GME, Inc. offers an automated commercial potato cutting system having a generally horizontal “U” shaped trough with a longitudinal slot in the bottom. The slot allows longitudinally spaced paddles in the trough to be mounted to an endless conveyor chain underlying the trough. The paddles advance the potatoes in the trough, one by one, to a cutting station. At the cutting station, a pivotally mounted swing blade is actuated to slice the advancing potato in half crosswise as the blade swings forward across the path of the potato or, alternatively, into thirds as the blade slices the advancing potato on its forward swing and then again on its backswing. A sensor upstream of the cutting station apparently senses the length of the potato and transmits the length data to a controller which determines when to actuate the blade to intersect the path of the moving potato and whether to actuate the blade to cut the potato roughly into halves with one cut or into thirds with two cuts.
In the commercial potato industry there remains a need for a durable commercial proportional length cutting system having a simple construction, more precise cutting action and capacity to flexibly cut potatoes or the like into a broad range of proportional lengths, and yet is able to operate efficiently, reliably and consistently in a continuous, demanding high production commercial operation.
This invention includes a system for cutting food products including potatoes into proportional length pieces. In one embodiment, the system includes a cutting assembly having a housing which defines a passageway, at least one stop movable between a retracted position on one side of the passageway to an extended position obstructing the passageway, and at least one blade movable between a retracted position on one side of the passageway to an extended position spanning the passageway. An actuating device actuates the stop to provide an abutment in the passageway against which the food product rests, and actuates the blade to make a crosswise cut through the stationary food product. The cutting assembly preferably is oriented to give the passageway a downwardly inclined slope to allow the food product to move downwardly, with the assistance of gravity, to the cutting zone.
In a preferred embodiment, the cutting assembly includes at least two separately actuatable stops and two separately actuatable blades spaced longitudinally from one another, and a control system for controlling the actuation of the stops and blades. In a typical cutting cycle, the control system actuates one of the stops and one or more of the blades to cut the food product into two pieces or, alternatively, more than two pieces. The control system cooperates with sensors located upstream of the cutting assembly, which sense the passage of the food product and generate data from which the control system automatically determines the length of the food product. For each food product, the control system applies a length based algorithm to select a particular stop/blade combination and then signals the actuating device to actuate the selected stop and blade(s). Each stop and blade retracts automatically after the cutting step is complete, thereby releasing the cut pieces to enter an exit tube and move away from the cutting station. The control system is programmed not to actuate a stop or blade if a potato passes the sensors prematurely, during the cutting cycle of the preceding potato, and instead allow the potato to pass straight through the cutting assembly without delay.
The control system also may operate simultaneously and independently plural sets of sensors and cutting assemblies, each defining a separate cutting lane, to increase throughput. Other features and aspects of the present invention are described with reference to exemplary embodiments in the following detailed description.
A proportional length cutting system in accordance with one exemplary embodiment of the present invention is shown in
It will be apparent from the following description that the present invention is not limited to slicing potatoes (or other food products) into pieces of precisely the same length and, in fact, with most potatoes the cut pieces will not have precisely the same length. The term “proportional length” is used to distinguish the present invention from cutting systems which operate to cut food products, such as potatoes, into many elongated strips, as well as systems which operate to dice or otherwise cut food products into numerous relatively small cubes or pieces.
While the present invention is described in the context of a system having multiple lanes and cutting assemblies for simultaneously cutting more than one potato, it will be appreciated that the present invention can be constructed and operated as a single lane system with only one cutting assembly. Except as otherwise noted, the construction and operation of the components in each cutting lane are identical.
As shown in
Referring to
With the belt tilted to one side, each potato conveyed thereon will roll to the lower side of the belt and ride against the side rail 28 as it moves downstream toward the cutting assembly. The natural tendency of the potato is to ride against the side rail with its longitudinal axis aligned with the direction of travel of the belt. Thus, the slant conveyor helps to position the food product in the desired orientation for cutting downstream. An inner surface 30 of the side rail, which faces the conveyor belt, preferably is provided with spaced apart, parallel grooves 32 (
In operation, the conveyor belt 24 is driven at a speed greater than the effective conveyor speed of the shaker conveyor, so as to increase the spacing of the potatoes in each lane (relative to the shaker conveyor) and give the downstream cutting assembly sufficient time to perform the cutting operation on each potato.
As shown in
After the potato passes the sensors, the slant conveyor delivers the food product to the cutting assembly 18, shown in greater detail in
In the exemplary embodiment shown, the housing 40 preferably includes a series of parallel, longitudinally spaced support plates 50a, 50b, 50c, or 50d, each of which supports one of the blades/stops for pivotal movement and mounts the pneumatic actuator to which the blade/stop is attached. The housing also includes spacer members 54a, 54b, and 54c, each of which is disposed between an adjacent pair of support plates to create a desired spacing therebetween. The relative spacing of the blades and stops may be easily adjusted simply by replacing one or more existing spacers with substitute spacers having greater or lesser thickness. The support plates may be fabricated from metal such as stainless steel, and the spacer members from a plastic material such as ABS or Delrim® acetal homopolymer.
The support plates 50 and spacer members 54 preferably are sized and shaped to allow the support plates, spacer members, blades, stops and pneumatic actuators to be assembled together in a compact, tightly nested arrangement, as illustrated best by
By way of example, the construction and operation of the actuating device for actuating the blades and stops will now be described with reference to the actuator 52a and blade 46a detachably fastened thereto. One type of actuator that works well is a conventional rotary vane-type pneumatic actuator such as Model PV36-090BSE32-B, made by Parker Hannifin Corp., Richland, Mich. With reference to
Referring to
Unless otherwise indicated, the blades and stops have the same construction, are mounted and actuated in the same manner and are substantially identical in all respects.
As shown in
By way of example,
In a preferred embodiment, the blades are thinner than the stops to enable each blade to slice more easily through the potatoes and enable each stop to better withstand stress caused by potatoes impacting the stop. For example, each blade may have a thickness of 1/32 inch and each stop a thickness of 1/16 inch.
The operation of the cutting assembly will now be described. After whole potatoes are singulated into one of several lanes by the shaker conveyor, spaced at least a minimum distance from preceding and following potatoes by the slant conveyor, and profiled for length data by the sensors, each potato is deposited into the enlarged mouth 38 of the infeed tube 36. As best seen in
Notably, the entire passageway leading to the cutting zone, including the infeed tube, preferably has a pear- or egg-like cross section (see
Before the potato reaches the cutting zone, the control system (described in greater detail below) actuates one of the two stops 48a, 48b to close the passageway, as illustrated in
The following is an exemplary cut table which illustrates one method for slicing potatoes into proportional length pieces, wherein F1 is the upper stop, F2 is the lower stop, K1 is the lower blade, K2 represents the upper blade, F1 and F2 are spaced 1½ inches apart, F1 and K1 are spaced 3¼ inches apart, K1 and K2 are spaced 3¼ inches apart, the first piece represents the lowermost cut section of the potato, the second piece represents the cut section adjacent the first piece and the third piece (where applicable) represents the uppermost cut section of the potato:
By way of example, the table illustrates that a potato eleven inches long may be cut into three pieces of 3¼ inches, 3¼ inches and 4½ inches or, alternatively, two pieces of 4½ inches and 6½ inches, depending on which stops and blades are actuated. A 12 inch food product may be cut into three pieces of 4½, 3¼ and 4¼ inches or, alternatively, 3¼, 3¼ and 5½ inches, depending on which stop is actuated. It will be appreciated that the illustrated cut options shown can be varied by changing the spacing between the blades and stops and/or the number of blades or stops available to be actuated. Whatever cut profile is selected by the processor, the present invention provides a highly accurate and precise cutting action. The potato is stationary during the cutting action. The blades are not part of a timing cycle designed to hit a moving target.
Once the cutting step is complete and the stop and blade(s) are retracted, the cut potato pieces drop away from the cutting zone, pass through the exit tube 44, and are deposited onto the outfeed conveyor 20 (
The control system will now be described. The control system preferably is a conventional programmable logic controller, such as the Flexlogix model, made by Allan Bradley. The control system is electrically coupled to the sensors 33a, b, c and 34a, b, c and a multiplexed amplifier (not shown). The sensors sense the length of time any one of the three sets of transmitting and receiving sensors are blocked by a passing potato. The sensors detect the time it takes for each potato to pass through the vertical crosswise plane in which the sensors lie. From this elapsed time data and known speed of the slant conveyor, as programmed into the controller's database, the controller automatically applies an algorithm to calculate the length of the potato, compares the potato length to a database containing the cut table data above, and selects the stop and blade combination to be actuated.
For example, if the elapsed “passing” time is 0.5 second and the conveyor is traveling at a speed of 12 inches per second, the controller calculates that length of the potato as the product of the elapsed time and conveyor speed (or 6 inches). Once the trailing edge of the potato passes the sensors, the controller 22 initiates a timing sequence. In this example, the controller initially transmits an electrical signal to actuate the upper stop 48a (F1) and, after a time delay, the lower blade 40b (K1) in accordance with the exemplary logic embodied in the cut table above.
As another example, if the potato has a length greater than or equal to 9 inches but less than 10 inches, the controller signals the lower stop lower 48b (F2) and lower blade 46b (K1) for actuation, in accordance with the programmed logic set forth in the cut table above. For those potato lengths where two cut options are feasible, the controller automatically selects the option preselected by the operator. Referring again to the cut table above, for potatoes having a length at least ten inches and less than eleven inches the operator may select one of two preprogrammed options, one in which the lower stop 48b (F2) and lower blade 46b (K1) are actuated and another in which the upper stop 48a (F1) and both blades (K1 and K2) are actuated. The controller also can be programmed to allow short potatoes, less than 6 inches, for example, to pass through the cutting assembly without being cut or delayed.
Once the controller selects the appropriate stop/blade combination for actuation, the controller immediately sends an electrical signal to actuate the pneumatic actuator for either stop 48a or 48b. Pressurized air is supplied to the pneumatic actuator to rotate the actuator shaft and stop, closing the passage 42 before the potato reaches the cutting zone. The potato slides down the infeed tube 36, bounces when it contacts the stop, and then after a short time settles on the stop. As part of the programmed timing sequence the controller actuates the designated blade(s) a set time after the potato clears the sensors, the blade actuation time being sufficient to allow the stop to move to its extended position and the potato to settle on the stop with its leading edge resting on the stop. As each actuated blade is extended by the pneumatic actuator, the potato is cut crosswise into two or three pieces, depending on the number of blades actuated. Later in the timing sequence, after the blade has extended fully, the controller signals the appropriate pneumatic actuators to retract each actuated blade and stop. The programmed timing sequence also allows time for the cut pieces to exit the cutting assembly. Notably, the entire timing sequence may take less than two seconds.
In those instances where a second potato passes the sensors prematurely, before the timing sequence for the preceding potato has timed out, the controller is programmed to recognize the timing issue and allow the second potato to pass through the cutting zone without being cut. This “pass through” will continue until the controller determines there is sufficient time to cut the next potato.
The controller 22 can be programmed to operate independently plural side-by-side cutting lanes in which separate slant conveyors are fed by the shaker conveyor and in turn feed separate cutting assemblies, as shown in
As shown in
Having described and illustrated the principles of our invention with reference to a preferred embodiment and several variations thereof, it should be apparent that the invention can be modified in arrangement and detail without departing from its principles.
This is a continuation of U.S. patent application Ser. No. 10/870,701, filed Jun. 16, 2004. This application is incorporated herein in its entirety. This invention relates to a system for slicing potatoes and other food products, especially vegetables, into proportional length pieces.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10870701 | Jun 2004 | US |
| Child | 12245609 | US |
