Patent Application
20140271091
1. Technical Field
The disclosure relates to the field of automatic separation of items. More specifically, the present disclosure relates to the automatic singulation of articles from a bulk stack of articles.
2. Description of the Related Art
Articles, such as items of mail, are frequently provided in bulk and must be separated in order to properly sort and route each article. The process of separating a bulk stack of articles into individual articles, known as singulation, can be done automatically by placing the bulk stack of articles into a feeder. Current feeders include one or more conveyor belts for moving the articles, as well as a vacuum for applying suction to one side of an article piece positioned at the front of the bulk stack. This suction works to separate the lead article from the remainder of the bulk stack. The lead article can then be moved by a conveyor belt in a direction different from the direction of the bulk stack. Such a design frequently causes problems when used to sort some articles, such as magazines, catalogs, and other similar items having a plurality of unbound edges. The vacuum often applies suction to only a front portion of such articles, thereby inducing only the front portion to move in a different direction than the remainder of the bulk stack. In such situations, at least some of the internal pages and the back cover resist the directional change in motion, possibly resulting in folding, tearing, and/or other damage to the article.
The present disclosure describes devices and methods used to reduce rotation of an article during singulation of a bulk stack of articles. In some embodiments, the devices and methods disclosed herein are intended to apply a frictional force to a back surface of an article, while suction and an accelerating force are applied to a front surface of the article. In some such embodiments, the frictional force is intended to hold the article together, to resist tearing, and cause the article to move as a single, unitary article. Some embodiments disclosed herein reduce the amount of folding, tearing, or other damage experienced by articles during the article separation and sorting process.
The embodiments disclosed herein each have several innovative aspects, no single one of which is solely responsible for the desirable attributes of the invention. Without limiting the scope, as expressed by the claims that follow, the more prominent features will be briefly disclosed here. After considering this discussion, one will understand how the features of the various embodiments provide several advantages over current singulation methods and devices.
One aspect of the disclosure relates to a device for reducing rotation of an article during singulation of a stack of articles. In some embodiments, the device includes a torsion element connected directly or indirectly to a base, a rotatable member coupled to the torsion element and rotatable about an inner axis of the torsion element between at least a first position and a second position, and a revolving member coupled to the rotatable member and configured to revolve about a central axis extending angularly relative to an elongated axis of the rotatable member. In the first position of the rotatable member, an outer surface of the revolving member is in contact with a drive belt. In the second position of the rotatable member, the torsion element applies a torque to the rotatable member and the revolving member, and the outer surface of the revolving member is in contact with, and applies a force to, a back face of an article, the article having a front face in contact with the drive belt.
In some embodiments, the torsion element is a torsion bar connected to the base. In other embodiments, the torsion element is a helical torsion spring disposed within or around a structural support member, and the structural support member is connected to the base.
In various embodiments, the rotatable member is configured to transition from the first position toward the second position when the drive belt brings the article in contact with the revolving member. The rotatable member of some embodiments is a lever arm.
In some embodiments, the central axis, which the revolving member is configured to spin about, extends perpendicularly relative to the elongated axis of the rotatable member.
In some embodiments, the force applied by the revolving member to the back face of the article includes a frictional force.
The revolving member of some embodiments includes a plurality of wheels. In some embodiments, the device also includes a shaft positioned along the central axis. The shaft is coupled to the rotatable member, and the revolving member is disposed about, and configured to spin relative to, the shaft. In other embodiments, the revolving member includes a shaft portion and an extended wheel portion fixed to the shaft portion. The shaft portion and the extended wheel portion are configured to spin about the central axis, and the shaft portion is coupled to the rotatable member.
An additional aspect of the disclosure relates to a system for singulating a stack of articles while reducing damage to each article. The system of various embodiments includes a conveyor belt configured to move a stack of articles forward, a drive belt configured to laterally accelerate an article in the stack of articles, and an anti-rotation device configured to provide a frictional force to a back face of the article to resist upward motion of the back face during lateral acceleration of the article. The anti-rotation device includes a torsion element connected directly or indirectly to a base, a rotatable member coupled to the torsion element and rotatable about an inner axis of the torsion element between at least a first position and a second position, and a revolving member coupled to the rotatable member and configured to revolve about a central axis extending angularly relative to an elongated axis of the rotatable member. In the first position of the rotatable member, an outer surface of the revolving member is in contact with the drive belt. In the second position of the rotatable member, the torsion element applies a torque to the rotatable member and the revolving member. Also in the second position, the outer surface of the revolving member is in contact with the back face of the article, the front face of the article being in contact with the drive belt.
In some such embodiments, the drive belt and the conveyor belt are positioned on different, non-parallel planes. The drive belt of some embodiments is perforated. In some embodiments, the system also includes an air-moving component configured to apply a suction force to the front face of the article in order to couple lateral movement of the drive belt with lateral movement of the article.
A further aspect of the disclosure relates to another system for singulating a stack of articles while reducing damage to each article. The system includes means for moving a stack of articles forward, means for separating and laterally accelerating a forward-most article from the stack of articles, and means for applying friction to a back face of the article to resist upward motion of the back face during lateral acceleration of the article.
In some embodiments, the means for moving the stack of articles forward includes a first conveyor belt. In some embodiments, the means for separating the article from the stack of articles includes an air-moving apparatus and a second conveyor belt having an air hole. The air-moving apparatus of some such embodiments includes a vacuum; in other embodiments, the air-moving apparatus includes a forward-blowing fan. In some embodiments, the means for applying friction comprises a revolving member indirectly coupled to a torsion element.
In another aspect of the disclosure, a method of singulating a stack of articles is provided, which reduces damage to the articles in the stack. In various embodiments, the method includes moving a stack of articles forward, separating and laterally accelerating a forward-most article from the stack of articles, and applying a force to the forward-most article in order to resist upward motion of the back face during lateral acceleration of the forward-most article. The force is applied to the back face by a revolving member indirectly coupled to a torsion element.
In some embodiments of the method, the force comprises a frictional force. The frictional force of some such embodiments is applied by the revolving member when a lever arm coupled to the revolving member rotates about an elongated inner axis of the torsion element from a first position to a second position and the torsion element exerts a torque on the lever arm. In some such embodiments, the torsion element is a torsion bar or a helical torsion spring.
The above-mentioned aspects, as well as other features, aspects, and advantages of the present technology will now be described in connection with various embodiments, with reference to the accompanying drawings. The illustrated embodiments, however, are merely examples and are not intended to be limiting.
In the following detailed description, reference is made to the accompanying drawings, which form a part of the present disclosure. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and form part of this disclosure.
To assist in the description of the devices and methods described herein, some relational and directional terms are used. “Connected” and “coupled,” and variations thereof, as used herein include direct connections, such as being contiguously formed with or attached directly to, on, within, etc. another element, as well as indirect connections where one or more elements are disposed between the connected elements. “Connected” and “coupled” may refer to a permanent or non-permanent (i.e., removable) connection.
“Secured” and variations thereof as used herein include methods by which an element is directly fastened to another element, such as being glued, screwed or otherwise affixed directly to, on, within, etc. another element, as well as indirect means of attaching two elements together where one or more elements are disposed between the secured elements.
The devices, systems, and methods described herein provide for improved separation or singulation of articles provided in bulk stacks. For example, in various embodiments, the disclosed devices, systems, and methods provide for improved separation of articles, such as articles of mail. Various embodiments reduce rotation of an article during singulation by applying a frictional force to a back surface, such as the back cover of the article. This frictional force is often applied while suction and an accelerating force are applied to a front surface, such as the front cover of the article. The frictional force is intended to hold the article of mail together to reduce the amount of folding, tearing, or other damage experienced by the article during singulation. While various embodiments included herein are described in relation to stack feeders and the process of singulating articles of mail, this example is provided for ease of discussion, and the disclosure is not limited thereto. One of skill in the art will appreciate that various embodiments disclosed herein are applicable to a variety of manufacturing and assembly applications involving the separation of individual articles from a bulk stack of goods, and all such applications are hereby expressly contemplated and incorporated herein.
Bulk stacks of articles are often sorted via a singulator. For example, as shown in the partial view of an article feeder 100 in
The horizontal conveyor belt 102 and the vertical conveyor belt 104 are positioned in perpendicular planes. As the bulk stack of mail 110 is carried along by the horizontal conveyor belt 102 toward the vertical conveyor belt 104, a front surface of a lead article 114 approaches the vertical conveyor belt 104. The vertical conveyor belt 104 is perforated with air holes 106. An air-moving component (not shown) is positioned in front of the vertical conveyor belt 104 to form a vacuum-backed vertical conveyor belt assembly. The inclusion of the air-moving component causes air to move from the rear, mail carrying side 108 of the vertical conveyor belt 104 through the air holes 106, thereby creating a suction force on the rear side 108 of the vertical conveyor belt 104. The air-moving component may be a forward-blowing fan, a pump, a vacuum, or any other partial-vacuum-inducing component known to one of skill in the art. The suction created by the air-moving component works to separate the lead article 114 from the remainder of the bulk stack 110. The suction causes at least the front surface of the lead mail article 114 to couple to the vertical conveyor belt 104, inducing the front-most mail article 114 to move laterally with the vertical conveyor belt 104. More detail regarding the operation of an automatic feeder for a stack of articles can be found in U.S. patent application Ser. No. ______, filed on ______ and referred to as Attorney Docket USPS.062PR, the contents of which are herein incorporated by reference in their entirety.
As shown in
In order to reduce damage to mail articles, some embodiments disclosed herein aim to hold each open article closed such that friction is generated between the front cover, back cover, and internal pages of each article. The internal friction then works to resist inertial forces and reduce shearing forces generated on the cover and binding. Additionally or alternatively, some embodiments disclosed herein aim to provide a downward reaction force on the back cover of each mail article as the article is accelerated laterally, thereby distributing the torque that is generated by the inertial forces over both the front and back cover. Some embodiments disclosed herein may achieve one or more of the above-recited aims, at least in part, utilizing spring-loaded high friction wheels having low friction bearings. More generally, various embodiments described herein may achieve one or more of the above-recited aims through the inclusion of an anti-rotation device.
The anti-rotation device of some embodiments comprises a rotatable member, such as, for example, a lever arm 420. In the depicted embodiment, the lever arm 420 has a threaded through hole 422 on a proximal portion of the lever arm 420. The threads of the through hole are configured to be disposed around, and securely engage, complementary threads (not visible) disposed on at least a portion of an outer surface of the torsion bar 410. In some embodiments, any other suitable engagement mechanism known to one of skill in the art may be utilized to secure the lever arm 420 to the torsion bar 410. For example, in some embodiments, a snap fit, a rivet, a screw, a friction fit, or permanent melding or welding, or any other desired engagement mechanism may be used. In some embodiments, the torsion bar 410 and the lever arm 420 may be distinct portions of the same unitary object and are integrally formed, as a non-limiting example, by means of injection molding. As the lever arm 420 is attached to the torsion bar 410, the lever arm 420 is rotatable about the axis of rotation 412 of the torsion bar 410 between at least a first position and a second position. The anti-rotation device 400 of
Some embodiments of the anti-rotation device comprise a revolving member coupled to a distal portion of the lever arm 420. For example, the anti-rotation device 400 comprises a plurality of wheels 440 coupled to the distal portion of the lever arm 420. In some embodiments, the plurality of wheels 440 is coupled to the distal portion of the lever arm 420 by means of a wheel shaft 430. The wheels 440 are disposed around the wheel shaft 430 and rotate relative to the wheel shaft 430 via low friction bearings which are disposed at intervals on the wheel shaft 430.
The wheel shaft 430 is coupled to a distal portion of the lever arm 420 via threads (not visible) positioned on a bottom end of the wheel shaft's outer surface. The threads are configured to securely engage complementary threads disposed around a through hole 424 in a distal portion of the lever arm 420. In other embodiments, any other suitable engagement mechanism known to one of skill in the art may be utilized to secure the wheel shaft 430 to the lever arm 420. For example, in some embodiments, a snap fit a rivet, a screw, a friction fit, or permanent melding or welding, or any other desired engagement mechanism may be used. In some embodiments, the wheel shaft 430 and the lever arm 420 may be distinct portions of the same unitary object.
In some embodiments, the wheels 440 are non-movably fixed to the wheel shaft 430 and the wheel shaft 430 is coupled to the lever arm 420 via a low friction bearing. In such embodiments, the wheel shaft 430 is configured to rotate relative to the lever arm 420, which in turn, rotates the wheels 440. In some embodiments, a rotating cylinder or other revolving member may couple to the lever arm 420 via a wheel bracket or via a shaft portion extending from one end of the revolving member. In various embodiments, the revolving member spins about an axis extending angularly relative to an elongated axis of the rotatable member.
In some embodiments, each of the plurality of wheels 440 has an equal diameter and shares an axis of rotation 445. The wheels 440 spin about the wheel shaft 430 around axis of rotation 445, which is positioned perpendicularly to an elongated axis 426 of the lever arm 420.
The outer surface 542 of the wheels 540 are configured to rotate. Thus, when the drive belt 550 moves, the friction between the outer surface 542 of the wheels 540 and the drive belt 550 causes the wheels 540 to rotate around wheel shaft 530. As described above, the drive belt 550 may be used to singulate an article using a vacuum force exerted through one or more openings in the drive belt 550.
As described above, the drive belt 550 is configured to move an article 560, for example, an open article such as a magazine, catalog, or any other article, laterally into the stack feeder as part of the process of singulation. As the drive belt 550 moves the article 560, the article 560 contacts a portion of the outer surface 542 of the wheels 540, the article 560 applies a force to the lever arm 520, which causes the torsion bar 510 to rotate. The rotation of the torsion bar 510 allows the wheels 540 to move away from the belt 550, and to roll onto an outer, back cover of the article 560. The lever arm 520 is pushed by the laterally moving mail article 560 into the second position, thereby making room for the article 560 to pass between the drive belt 550 and the outer surface 542 of the wheels 540. The push from the moving mail article 560 causes the lever arm 520 to angularly rotate within its plane of rotation, which is parallel to the base 505 and the floor. This rotation of the lever arm 520 applies torque to a portion of the torsion bar 510, causing the torsion bar 510 to twist or rotate about an axis. As will be described below, the torsion bar 510 is configured to resist such motion, and the twisting generates tension or potential energy in the torsion bar 510. The tension causes the torsion bar 510 to apply a counter-torque to the lever arm 520, thereby resisting the rotation, and biasing the lever arm 520 back towards the first position. The rotation, tension, counter-torque and resulting forces generated by the twisting torsion bar 510 cause the wheels 540 to apply a force onto the article 560, which effectively pushes the article 560 into the drive belt 550, and pushes a back cover 562 towards a front cover of the mail article 560.
Moreover, by pushing the back cover 602 toward the front cover using the wheels 640 and the resistance of the torsion bar, friction is created within the article 600 between the covers, and the friction acts to resist inertial shearing forces generated on either one of the covers. Thus, the anti-rotation device of various embodiments allows acceleration forces 610 to be applied to the article 600 without damaging the binding 604, the front cover or the back cover 602. Additionally, the wheels 640 rotate freely about the wheel shaft 630 via low-friction wheel bearings so that the presence of the wheels 640 does not add any new significant shearing forces to the article 600.
One embodiment of a torsion element, specifically, a helical torsion spring 800, is depicted in
In anti-rotation device embodiments having a torsion spring 800, such as, for example, the anti-rotation device partially depicted in
In operation, an article exerts a force felt on the lever arm, and the movement of the lever arm 820 results in movement of the top end 804 of the torsion spring 800. The bottom end 808 is fixedly attached, and thus, does not move. The movement of the top end 804 compresses the tension spring and stores potential mechanical energy within torsion spring 808, and resists the movement of the lever arm 820. In some embodiments, the torsion spring 800 is affixed to, and disposed around, the structural support member 810, within a bearing surrounding the structural support member 810. In such embodiments, a top end 804 of the torsion spring 800 is again integrated into, or coupled to, the lever arm 820 such that movement of the lever arm 820 from a first position 800a to a second position 800b causes the top end 804 of the torsion spring 800 to move accordingly. Such movement generates tension within the torsion spring 800 and causes the torsion spring 800 to apply a force to the lever arm 820 which resists rotational movement of the lever arm 820.
Using such a stack feeder 900, a method of singulating a stack of articles 910 can be performed. In one embodiment, such a method includes moving a stack of articles 910 forward, separating and laterally accelerating the leading article 914 from the stack of articles 910, and applying friction to a back cover of the leading article 914 to resist upward motion of the leading article 914 during lateral acceleration. In various embodiments, friction is applied to the back cover by a plurality of wheels 922 coupled to a spring-loaded lever arm 924, which form part of an anti-rotation device 920. By including an anti-rotation device 900 into the method of singulation, acceleration forces 930 can be applied to the mail article 914 without damaging the mail.
The foregoing description details certain embodiments of the systems, devices, and methods disclosed herein. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the systems, devices, and methods can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the technology with which that terminology is associated.
It will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the scope of the described technology. Such modifications and changes are intended to fall within the scope of the embodiments. It will also be appreciated by those of skill in the art that parts included in one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and/or depicted in the Figures may be combined, interchanged or excluded from other embodiments.
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
It will be understood by those within the art that, in general, terms used herein are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to “at least one of A, B, and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B.”
All references cited herein are incorporated herein by reference in their entirety. To the extent publications and patents or patent applications incorporated by reference contradict the disclosure contained in the specification, the specification is intended to supersede and/or take precedence over any such contradictory material.
The term “comprising” as used herein is synonymous with “including,” “containing,” or “characterized by,” and is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.
All numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.
The above description discloses several methods and materials of the present invention. This invention is susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims.
