Cases (e.g. cardboard boxes) are commonly sold in a folded flat (i.e. a knocked down) configuration. A case erector is a machine that assembles cases from the folded flat configuration into a three-dimensional form, typically having bottom box flaps taped or glued shut.
Known case erectors have two arms, typically configured with suction or vacuum cups, which grasp two adjacent sides of the box, respectively. Each arm then moves through 45 degrees thereby opening the box. In an application with a single arm, the single arm may move through 90 degrees. In either application, such arms are supported by bearing surfaces, which allow the pivotal rotation.
It is desirable to locate the fold between the two adjacent sides of the box that are grabbed by the two arms co-linearly with an axis about which the two arms pivot. This results in a design challenge, in that it is desirable to locate a (usually) vertical shaft (about which the arms pivot) in the same location that it is desirable to locate the fold in the box.
Two solutions are common. In a first solution, the fold in the box (between the two adjacent sides that are grasped by the arms) can be located “near” (but not exactly collinear with) the shaft about which the two arms pivot. This will cause the box to skew as it is opened. The skew occurs because the fold between the two adjacent sides of the box and the two arms do not pivot about the same virtual center point. This skew is generally unacceptable, and therefore a second solution is common.
In the second solution, the shaft about which the two arms pivot is located above (or below) the box, so that if the shaft were extended in one's imagination, the shaft would be co-linear with the fold between adjacent sides of the box. Since the shaft is located above the box as the box is moved into position to be opened, the arms must extend laterally outward from the shaft and also extend down to the box, so that vacuum cups carried by the arms may contact the adjacent sides of the box. This makes the overall device heavier and more complex, and requires arms having increased strength due to their length and other factors. While this solution allows the arms to be kept parallel to the box sides, (the arms reach down from above or up from below) the structure required to support the erecting arms must be more robust which will increase cost, complexity and overall size of the mechanism.
A case erector is configured to open folded cases. In one example, the case erector provides first and second arms, each having at least one suction or vacuum device. A planar bearing surface allows at least one of the arms to move between an open position and a closed position. The planar surface defines a semi-circular channel about a virtual center point. In operation, a fold between two adjacent sides of the case is moved into a virtual line passing through the virtual center point while the arms are in the open position, thereby allowing space for the case to enter. The arms are then moved to the closed position, wherein the first and second arms grasp the two adjacent sides, respectively, of the folded flat case. The case is then opened by moving the arms into the open position while the arms maintain their grasp of the case. Movement to the open position is performed by moving each arm through 45 degrees or one arm through 90 degrees. Movement of the arms in a rotary manner about the virtual line results from rotation of a plate supporting each arm, wherein each plate moves against the planar bearing surface and wherein the plate has one or more attached flanges moving through the semi-circular channel defined in the planar bearing surface.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended for use as an aid in determining the scope of the claimed subject matter.
The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items.
The following discussion is directed to systems and methods that erect cases (e.g. systems that open cardboard boxes from a disassembled state to an assembled state). In one example, a case erector configured to open folded cases provides first and second arms, each having at least one attachment device, such as a suction or vacuum device or clamp assembly. A planar bearing surface allows at least one of the arms to move between an open position (wherein a folded flat case is received) and a closed position (wherein the folded case is grabbed) and then moved to the open position (wherein the case is opened into a 3-D box-like shape with open or no flaps on the top and flaps on bottom). In a preferred configuration, each of the two arms moves through approximately 45 degrees. The planar bearing surface defines a semi-circular channel about a virtual center point. In operation, a fold between two adjacent sides of the case is moved into coincidence with a virtual line passing through the virtual center point. Once the fold of the case is in position in the virtual line passing through the virtual center point, the first and second arms move from the open position to the closed position to grasp the two adjacent sides, respectively. Each arm is supported by a plate that moves against a planar bearing surface, wherein the plate is held in place by at least one flange that moves within a semi-circular channel defined within the planar bearing surface. Thus, the plate supporting each arm moves (rotates) in a circular manner, about the virtual center point. The case is then opened as both arms move through 45 degrees from the closed position to the open position, thereby opening the case. Because the fold (i.e. the corner) of the case was located in a virtual line passing through the virtual center point of the semi-circular channel, the arms will remain parallel to the two adjacent box sides, as the box opens in a square or non-skewed manner.
Examples of Case Erectors
The arm 102 is supported by a plate 108 that rotates against a planar bearing surface 110. (The arm 104 is supported by a similar plate, which is on the other side of base 118 and therefore unseen in
The channel 114 defined in the bearing surface 110 is typically semi-circular in shape, and may extend over approximately 270 degrees of a circle, depending on the application. The center of the circle (about which the semi-circular channel 114 is defined) can be thought of as a “virtual center” since no component is positioned at that location. In fact, the bearing surface 114 defines a notch (best seen as 308 in
The arms 102, 104 are moved by actuators 116 and 117, which may operate using a compressed air power source. Alternative technology, such as motor and/or gears may be substituted. In one example, the actuators 116, 117 are attached to plates 108 and 604 (see
Both arms 102, 104, supporting plates and bearing surfaces, actuators 116, 117 and other components are supported by a base 118 and two bearings 120. The bearings 120 allows the arm assembly to move along a shaft 122. Typically, the case, once opened, is moved along the shaft 122 into a plow, which aids in closing and sealing the bottom flaps of the case. A hose assembly 124 has a linkage design, which supports the hoses as the arm and bearing surface assembly moves along the shaft 122.
In the example of
A comparison of
Note that in the view of
Although aspects of this disclosure include language specifically describing structural and/or methodological features of preferred embodiments, it is to be understood that the appended claims are not limited to the specific features or acts described. Rather, the specific features and acts are disclosed only as exemplary implementations, and are representative of more general concepts.
This patent application claims priority to U.S. Provisional Patent Application Ser. No. 60/977,317, having title “Case Erector”, filed on 3 Oct. 2007 in the United States, commonly assigned herewith, and hereby incorporated by reference.
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Number | Date | Country | |
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20090093354 A1 | Apr 2009 | US |
Number | Date | Country | |
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60977317 | Oct 2007 | US |