WO2012083033A2

WO2012083033A2 - Unitary body diverter arm

Info

Publication number: WO2012083033A2
Application number: PCT/US2011/065188
Authority: WO
Inventors: Bernard Joseph Cummings; Brian Charles Evans; Gregory R. Judge; Stuart Martin; Slawomir Pawel Milewski; J. Dean Terrell
Original assignee: Globe Composite Solutions, Ltd.
Priority date: 2010-12-15
Filing date: 2011-12-15
Publication date: 2012-06-21
Also published as: WO2012083033A3

Abstract

The present disclosure is directed to a unitary body diverter arm used in a sorting system. The diverter arm pivots to displace an article traveling on a conveying surface of the sorting system. The diverter arm includes a pivot member that defines a rotational axis of the diverter arm. The pivot member is supported by a unitary body.

Description

UNITARY BODY DIVERTER ARM

PRIORITY CLAIM

[0001] This application is a continuation-in-part application and claims the benefit of U.S. Application Serial No. 13/253,667, filed on October 5, 2011 and entitled Diverter Swing Arm, which claims the benefit of United States Provisional Application for Patent No. 61/423,394, filed December 15, 2010, and also claims the benefit of U.S. Provisional Application for Patent No. 61/434,251, filed on January 19, 2011, the disclosures each of which are hereby incorporated by reference.

TECHNICAL FIELD

[0002] The present invention relates to material handling systems, and more particularly to diverter systems including a diverter arm for use in diverting articles from a conveying surface.

BACKGROUND

[0003] In conveying and sorting packages, diverter swing arms (also known as diverter blades or paddles) are used to divert an article from a conveying surface onto another conveying surface or some form of discharge chute for further downstream collating and sorting. Diverter arms are thus important in the automated sorting of articles. After many cycles, diverter arms may wear and ultimately fail. Therefore, there is a need for a durable diverter arm configured to be used in existing as well as new sorting systems. The diverter arm should be cost effective to manufacture.

[0004] U.S. Patent No. 5,918,724 (which is incorporated herein by reference) describes and claims a diverter blade that includes an inner metallic section (or skeleton) and an outer plastic section. The inner metallic section includes an upper and a lower parallel plate, which are each attached to a shaft having an axis about which the diverter arm rotates. The shaft is generally not a load bearing member but rather provides a bearing surface about which diverter arm may rotate.

[0005] The plastic section is molded over and envelopes the inner metallic section, including part of the shaft and the upper and lower plates. The plastic section includes a front wall that is adapted to engage articles on the conveying surface.

[0006] An outer metallic linkage section is adapted to be connected to a drive motor. When an article is to be diverted the drive motor activates and torques the linkage section. This torque is transmitted to the plastic section by the internal skeleton (i.e. the upper and the lower plates).

[0007] However, such a two-material diverter blade still has a metal linkage arm and a inner metal skeleton that is prone to metal fatigue, which eventually causes fracture and failure.

SUMMARY

[0008] The present disclosure is directed to a unitary body diverter arm used in a sorting system. The diverter arm pivots to displace an article traveling on a conveying surface of the sorting system. The diverter arm includes a pivot member that defines a rotational axis of the diverter arm. The pivot member is supported by a unitary body. The unitary body has a displacement portion and a linkage portion. The displacement portion has a displacement face that contacts articles traveling on the conveying surface causing them to divert. The linkage portion is configured to be adapted to an actuating mechanism. The unitary body is formed of a polymer material.

[0009] Embodiments of the present disclosure include the unitary body being molded to a pivot shaft. The pivot shaft may have certain retention features to enhance the bond between the polymer material and the metal pivot shaft.

[0010] Technical advantages of embodiments of the present disclosure include a unitary body diverter arm that does not have an internal skeleton that may fail. The unitary body diverter arm is durable over many cycles. In addition, a diverter arm according to the teachings of the present disclosure is economically and reliably fabricated due to few components to assemble. The configuration of the diverter arm also supports improved performance in less power required to cycle the diverter arm and strength in diverting heavy articles.

[0011] Other technical advantages of a diverter arm according to the teachings of the present disclosure will be understood by one of ordinary skill in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a schematic view of a sorting system employing a unitary body diverter arm according to an embodiment of the present disclosure;

[0013] Figure 2 is an isometric rear view of a unitary body diverter arm with mounting hardware and an actuating mechanism illustrated as exploded;

[0014] Figure 3 is an isometric front view of a unitary body diverter arm according to an embodiment of the present disclosure;

[0015] Figure 4 is a detailed isometric view of a pivot shaft of a unitary body diverter arm according to an embodiment of the present disclosure;

[0016] Figure 5 is an isometric rear view of a unitary body diverter arm with mounting hardware and an actuating mechanism illustrated as exploded from a top-drive configuration;

[0017] Figure 6 is a partial isometric rear view of a unitary body diverter arm with mounting hardware and an actuating mechanism illustrated as exploded from a bottom-drive configuration;

[0018] Figure 7 is an isometric front view of an alternate embodiment of a unitary body diverter arm; and

[0019] Figure 8 is an isometric rear view of the diverter arm of Figure 7. DETAILED DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 illustrates an environmental view of a sorting system for sorting articles (which are generally indicated by reference numeral 100) traveling along a conveying surface 102. A diverter arm 110 is mounted for rotation with respect to the conveying surface 102, so that the diverter arm 110 can be selectively rotated by an actuator 112 to engage and displace a particular article so as to divert it from the conveying surface 102. In the example shown in Figure 1, the article is diverted onto a discharge chute 104.

[0021] Because the diverter arm 110 is used to sort a significant volume of articles, the diverter arm 1 10 must often perform a complete cycle (i.e., rotate and engage the article, and then return to a home position) in fractions of a second. For example, in some implementations, the diverter arm 110 may cycle at speeds in excess of one-quarter second per cycle. The diverter arm 110 may also be able to displace an article 100 weighing up to 70 lbs or more.

[0022] An embodiment of a diverter arm 10 according to the teachings of the present disclosure is illustrated in Figures 2 and 3. The diverter arm 10 has a unitary body, which makes it very strong and durable over many cycles.

[0023] As used herein, the term "unitary body" refers to a single, indivisible part. Conventional diverter arms are not deemed to be a unitary body diverter arm at least in part because separate components make up a linkage portion of the arm and a pusher or displacement portion. This is so even though the portions of conventional diverter arms are molded together to form an in integral combination of multiple components.

[0024] The diverter arm 10 includes a displacement portion 12 and a linkage portion 14. The displacement portion 12 moves across the conveying surface 102 to divert articles 100. The linkage portion 14 provides a structure for connection with an actuating mechanism 60. The actuating mechanism 60 displaces the linkage portion 14, which causes the diverter arm 10 to rotate about a longitudinal axis of a pivot shaft 20. This rotation causes a displacement face 16 to apply a force to an article 100 and divert that article from the conveyor. A displacement face 16 (see Figure 3) is a generally flat surface that makes contact with the articles on the conveyor.

[0025] The displacement portion 12 and the linkage portion of the diverter arm 10 are formed integral with the pivot shaft 20. The pivot shaft 20 is typically made of metal such as steel and is placed in a mold having a negative of the desired shape of the diverter arm 10. A molten high- strength polymer material is injected or otherwise introduced into the mold and envelopes at least a medial portion of the pivot shaft 20 to form an integral body. In addition to the pivot shaft 20, mounting hardware may also be molded into the diverter arm 10. The mounting hardware ensures that load bearing portions of the diverter arm 10 will function properly and be durable. According to alternate embodiments, metal members similar to the two ends of the pivot shaft 20 may be press fit in a corresponding orifice in the diverter arm 10.

[0026] As explained further below, the pivot shaft does not bear any of the load generated in rotating the diverter arm 10. However, it does bear at least a portion of the load in displacing an article traveling on the conveyor. The pivot shaft 20 primarily functions as an axis of rotation for the diverter arm 10 and the ends of the shaft 20 provide bearing surfaces to support the rotation of the diverter arm 10. To provide this functionality, it may not be necessary for the shaft to extend completely through the diverter arm 10.

[0027] The polymer composite material used to make the diverter arm 10 may comprise a urethane formulation (with a 75 D durometer) for impact strength, wear resistance, and low coefficient of friction. An example of this material is commercially available from Globe Composite Solutions, Ltd. under the trade name Brandonite.

[0028] To enhance the structural rigidity of the diverter arm 10, the backside of the displacement portion 12 includes one or more stiffening ribs 32. In the embodiment illustrated in Figures 1 and 2, the stiffening ribs 32 include ribs that are generally upright and ribs that run diagonal. The stiffening ribs 32 generally define recesses 34. Stiffening ribs 32 and recesses 34 and their respective form and functions are well understood by those having ordinary skill in the art of thin-walled plastic part design and fabrication. In other embodiments, the stiffening ribs 32 may run the length of the diverter arm (see Figures 7 and 8), but nevertheless serve to stiffen and enhance the structure of the displacement portion 12.

[0029] The linkage portion 14 has a generally triangular shape, increasing in width from a free end toward the displacement portion 12. The linkage portion may also include one or more ribs 44. The ribs 44 strengthen the linkage portion 14. In the embodiments illustrated in Figures 2 and 3, the rib 44 generally defines two triangularly- shaped openings 42.

[0030] The linkage portion 14 supports the displacement portion 12. For example, the linkage portion 14 generally extends to a midpoint of the backside of the displacement portion 12. As a result, the diverter arm 10 can accommodate the forces generated in rotating and diverting articles processed by an automated sorting system. Furthermore, the mass of the additional material closer to the axis of rotation reduces rotational inertia and allows for a faster rotational speed of the diverter arm 10, given the same gear, motor, and horsepower ratio as used with conventional diverter arms.

[0031] The linkage portion 14 terminates in a clevis 44, which includes upper and lower clevis ears 46, 48 that each define an opening. In the exemplary embodiment shown in Figures 2 and 3, each clevis ear 46, 48 includes a molded-in bushing 50

[0032] As illustrated in Figure 4, the pivot shaft 20 is provided with several retention features which assist in retaining the pivot shaft 20 within the encapsulating composite material forming the displacement portion 12 and the linkage portion 14 of the diverter arm 10. An example retention feature is a circumferential groove 22. This groove 22 assists in performing axial retention of the shaft 20 within the composite material of the arm. The composite material fills the circumferential groove 22 and thus inhibits axial displacement of the pivot shaft. Another retention features is one or more apertures 24 that pass radially through the pivot shaft 20. In certain embodiments, the apertures 24 may not pass completely through the shaft 20. The composite material fills the apertures 24 and thus inhibits twisting (or torque) displacement of the pivot shaft 20. Other types of retention features could also be used. For example, the outer surface could be knurled, or a slot may be formed in the outer surface in the axial direction, or a flat may be formed on the outer surface. Any combination of retention features could be used as desired.

[0033] Reference is made to Figures 2, 5, and 6, each illustrating the unitary body diverter arm 10 and the actuating mechanism 60. Figure 2 illustrates a central drive configuration. In this configuration, the actuating mechanism 60 is received through a cavity 47 in the clevis portion 46. There it is fixed with a bolt that is inserted through a through hole 52 in the upper clevis ears 48, more specifically the bolt is received through a hole in each of the upper and lower bushings 50. A nut 63 or other fastener is used to secure the actuating mechanism 60 in position.

[0034] This central drive connection configuration may significantly reduce torsional loading on the linkage portion 14 of the diverter arm 10 by providing multiple points of engagement with respect to the actuating mechanism 60. Specifically, the clevis portion 46 captures both a top portion and a bottom portion of a spherical bearing of the actuating mechanism 60.

[0035] The end of the actuating mechanism 60 opposite the linkage portion 14 of the diverter arm may also have a spherical bearing. This bearing may be configured for a slip fit on a corresponding component of the actuator 112 (see Figure 1). The actuator may include a fly wheel attached to a motor/gearbox drive, which makes one complete revolution per diverter arm cycle. This revolution produces the desired rotation of the diverter arm 10 about an axis of the pivot shaft 20. To support this rotation, the opposed ends of the pivot shaft 20 are mounted to a set of pillow block bearings.

[0036] Upper and lower bushings 50 may be molded into the clevis portion 46 of the unitary body diverter arm 10. Alternatively, the bushings 50 may be press fit into the clevis portion 46. The bushings 50 may be generally annular and made of steel. They may include features such as cavities 54 that enhance bonding between the composite material and the steel during molding. The bushings 50 reinforce the clevis portion 46 such that it better withstands compression resulting from torquing the nut 63 on the bolt 62. Thus, the compressive force is opposed by the pair of bushings 50 as opposed to the composite material of the unitary body diverter arm 10.

[0037] Alternate connection configurations of the diverter arm 10 and the actuating mechanism 60 are illustrated in Figures 5 and 6. Figure 5 illustrates a top drive configuration, and Figure 6 illustrates a bottom drive configuration. According to these embodiments, the actuating mechanism 60 is secured to either the top or the bottom of the linkage portion 14 with a nut/bolt combination. To accommodate the compressive forces of the top and bottom drive configuration, an extended bushing or sleeve 56 is molded into the end of the linkage portion 12. Similar to the upper and lower bushings 50, the sleeve 56 is generally annularly shaped and includes features known in the art to enhance the steel of the sleeve 56 bonding with the composite material. For example, the retention features described above with respect to the pivot shaft 20 may be used with the sleeve 56. According to these embodiments, a single sleeve having a length approximately equal to the thickness of the linkage portion 14 is molded integral with the composite material. [0038] An alternative to a bolt/nut fastening configuration is illustrated in Figure 6. The illustrated pin fastener 58 may be used with any of the disclosed diverter arm embodiments and with any of the top, center, or bottom drive configurations. In this embodiment, a pin fastener 58 is substituted for the bolt 62. The pin fastener 58 includes holes that are configured to mate with corresponding tapped holes 59 formed in the sleeve 56 (or upper or lower bushings 50). Socket head cap screws or other suitable threaded fasteners are secured in the tapped holes 59 in the sleeve 56. A nut may be used to secure the actuating mechanism 60 to the bottom of the linkage portion 14. By securing a flance of the pin 58 into the sleeve 56, unwanted rotation of the pin 58 may be countered by this radial constraint. This may enhance wear resistance over a fastening configuration employing a bolt without such a radial constraint.

[0039] Reference is made to Figures 7 and 8, which illustrate an alternate embodiment of a unitary body diverter arm 70 according to the teachings of the present disclosure. Similar to the embodiment illustrated in Figures 2, 3, 5, and 6, this embodiment includes a single unitary body of molded composite material making up the displacement portion 72 and the linkage portion 74 of the diverter arm 70. The molten composite is molded to be integral with the pivot shaft 76. In addition, connection hardware, such as steel bushings and the like may be molded into the linkage portion 74 to reinforce the connection between the linkage portion 74 and the actuating mechanism.

[0040] As illustrated, one or more generally horizontal rearward extending stiffening ribs 78 may reinforce the displacement portion 72. One or more generally vertical upward extending stiffening ribs 80 may reinforce the linkage portion 74. The overall shape of the diverter arm 70 may generally follow that of conventional diverter arms, such as that shown in U.S. Patent No. 5,918,724. This may be particularly beneficial in applications where a unitary body diverter arm according to the teachings of the present disclosure is retrofit into an existing sorting system, particularly if the sorting system has space constraints that may not accommodate a wider linkage portion 74 of the diverter arm.

[0041] Although the present disclosure has been described in detail with reference to particular embodiments, it should be understood that various other changes, substitutions, and alterations may be made hereto without departing from the spirit and scope of the present disclosure. For example, the generally horizontal stiffening ribs shown in Figure 7 may be used with the linkage portion shown in Figures 2, 3, 5, and 6 having the triangularly-shaped openings. Also, a clevis ear central-drive linkage portion configuration may be used in connection with embodiments shown in Figures 7 and 8. Thus, any of the features described herein may be used with any of the other features to create multiple embodiments of unitary body diverter arms according to the teachings of the present disclosure.

Claims

WHAT IS CLAIMED IS:

1. A diverter arm for displacing articles traveling on a conveying surface, comprising:

a pivot member defining a rotational axis of the diverter arm; and

a unitary body supporting the pivot member and having a displacement portion and a linkage portion, the displacement portion having a displacement face for contacting articles, the linkage portion being adapted to be connected to an actuating mechanism; and

wherein the unitary body is formed of a polymer material.

2. The diverter arm of claim 1, wherein the pivot member comprises a pivot shaft having a medial portion enveloped by the polymer material.

3. The diverter arm of claim 2, wherein the pivot shaft includes at least one retention feature adapted to retain the pivot shaft within the enveloping polymer material.

4. The diverter arm of claim 1, wherein the polymer material comprises a urethane material.

5. The diverter arm of claim 4, wherein the polymer material comprises

Brandonite.

6. The diverter arm of claim 1, wherein the linkage portion includes a clevis portion adapted to receive the actuating mechanism.

7. The diverter arm of claim 6, wherein the clevis portion supports at least one bushing.

8. The diverter arm of claim 1, wherein the linkage portion includes a sleeve and is adapted to support the actuating mechanism secured to a bottom of the linkage portion.

9. The diverter arm of claim 8, wherein the sleeve is configured to receive a pin, the pin further configured to receive a screw constraining rotation of the pin with respect to the sleeve.

10. The diverter arm of claim 1, wherein the linkage portion includes at least one upward projecting stiffening rib.

11. A diverter arm, comprising:

a pivot member defining a rotational axis of the diverter arm; and a unitary body supporting the pivot member and having a displacement portion and a linkage portion, the displacement portion having a displacement face for contacting articles, the linkage portion being adapted to be connected to an actuating mechanism; and

wherein the displacement portion does not have an internal member bearing a load generated by rotation of the diverter arm about the rotational axis.

12. The diverter arm of claim 11, wherein the unitary body is formed of a polymer material.

13. The diverter arm of claim 12, wherein the pivot member comprises a pivot shaft having a medial portion enveloped by the polymer material, the pivot shaft including at least one retention feature adapted to retain the pivot shaft within the enveloping polymer material.

14. The diverter arm of claim 13, wherein the retention feature comprises a circumferential groove formed in an outer surface of the pivot shaft.

15. The diverter arm of claim 14, wherein the linkage portion includes a clevis portion adapted to receive a spherical bearing of the actuating mechanism.

16. A sorting system, comprising:

a conveying surface adapted to transport a plurality of articles;

a diverter arm adapted to be rotated to displace an article transported on the conveying surface, the diverter arm, comprising:

wherein the unitary body is formed from a polymer material.

17. The sorting system of claim 16, wherein the pivot member is received by a pair of bearings supporting the rotation of the diverter arm about the rotational axis.

18. The sorting system of claim 17, wherein the pair of bearings comprises pillow block bearings.

19. The sorting system of claim 16, wherein the pivot member comprises a pivot shaft having a medial portion enveloped by the polymer material, the pivot shaft including at least one retention feature adapted to retain the pivot shaft within the enveloping polymer material.

20. The sorting system of claim 16, wherein the linkage portion includes a sleeve and the actuating mechanism is connected to the linkage portion.