Overhead purge rejector for a conveyor line

Abstract

A device (16) for removing objects from a conveyor belt (12) of a conveyor line, comprising a housing (20) adapted to be attached to the conveyor line, and a kick-out portion (22) suspended from the housing to rotate about a pivot (40) such that a lower end (64) of the kick-out portion maintains a constant vertical spacing from the conveyor belt during rotation.

Description

[0001] Cross Reference to Related Applications

[0002] This application is a non-provisional application which does not claim priority. TECHNICAL FIELD

[0003] After a product is determined to be outside of a specified range of product parameters, the overhead sweep rejector removes the product from the conveyor line. The overhead sweep rejector uses a sliding plate to reduce the human safety hazard of slightly lifting the product when removing it. BACKGROUND

[0004] In many industries, particularly the food and pharmaceutical industries, product inspection for at least one product parameter is a critical step. Brand protection requires identification of non-conforming products and their removal from the production line. Many product parameters can be measured as the product moves along the conveyor line. These parameters include, for illustration purposes only, weight, presence of contaminants, product color, defects in the container, and incorrect labeling. Once a product is identified as non-conforming, it needs to be removed from the conveyor belt as soon as possible.

[0005] The Applicant has extensive experience in providing systems for removing non-conforming products from production lines, particularly for products that are outside of a predetermined weight tolerance. This experience is summarized in a white paper from 2013 entitled "How to Choose the Right Rejection System." This document lists types of rejection devices and types of scrap containers.

[0006] Prior art overhead sweep rejectors, such as those described in the white paper, operate with a swinging motion that originates from a pivot point above the conveyor belt. Before use, the swing arm is pulled back to an "at rest" position so as to swing across the direction of motion of the conveyor belt when released. As the bottom of the arm swings in an arcuate path centered on the pivot point, it moves downward toward the conveyor belt, passing through a low point when the arm is vertical, and then moves upward. Unlike a push rod that acts strictly horizontally, the arcuate motion of the swing can provide a vertical component to the force imparted to the product that is moved to the scrap container. The arcuate motion is also smooth and positive, which is desirable when moving larger delicate products. When a scrap container is provided on each side of the conveyor belt, the known overhead sweep rejector can be arranged to move from an "at rest" position on one vertical side to a corresponding "at rest" position on the opposite side, thereby using two scrap containers to have the product moved alternately to opposite sides of the conveyor belt.

[0007] When using this type of overhead sweep rejector, the bottom of the swing arm presents the possibility of crushing or shearing objects in the path toward the conveyor belt surface. This is a hazard to personnel that has not been addressed in the known prior art.

[0008] It is therefore an unachieved goal to minimize or eliminate this danger while maintaining as completely as possible the desirable aspects of the over-the-top cleaning action. SUMMARY

[0009] This goal is achieved by a device for removing objects from a conveyor belt of a conveyor line and a method for removing objects from a conveyor belt of a conveyor line.

[0010] According to the present invention, a device for removing objects from a conveyor belt of a conveyor line comprises a housing adapted to be attached to the conveyor line and a kicker suspended from the housing to rotate about a pivot such that a lower end of the kicker maintains a constant vertical spacing from the conveyor belt during rotation.

[0011] According to a preferred embodiment, the housing has a rear wall and a top wall and the kicker comprises a wall extending downward around a side and a front of the top wall of the housing, said wall defining an interior of the kicker.

[0012] According to another preferred embodiment, the wall of the kicker further comprises a portion that interacts with a slot in the rear wall of the housing to limit angular rotation of the kicker in a direction away from the vertical direction.

[0013] According to another preferred embodiment, the device further comprises a contact plate arranged to slide along a front side of the wall of the kicker.

[0014] According to another preferred embodiment, the device further comprises a vertical slot in the wall of the kicker and a plate connected to the contact plate through said vertical slot to limit sliding motion of the contact plate.

[0015] According to another preferred embodiment, the device further comprises a guide rail housing affixed to the housing and a pair of guide rails whose horizontal motion is constrained by said guide rail housing, an end of each guide rail being pivotally secured to the contact plate.

[0016] According to another preferred embodiment, the device further comprises a hydraulic cylinder extending through the rear wall of the housing, a rod having a first end contained in said hydraulic cylinder and a second end directed toward an inner wall of the kicker, and a pair of plates affixed on each side of said second end of the rod and coupled to the inner wall of the kicker, respectively.

[0017] According to another preferred embodiment, each of the pair of plates has a slot formed therein. And the device has a limit rod coupled to the second end of the rod and extending transverse to an axis of said rod, each end of the limit rod engaging in a respective one of the slots to define horizontal motion of said rod.

[0018] According to another preferred embodiment, the device further comprises first and second side plates removably secured to the rear wall of the housing and covering the sides of the kicker.

[0019] According to the present application, a method for removing objects from a conveyor belt of a conveyor line comprises:

[0020] positioning, along the conveyor line, a device for removing rejected objects and a container for receiving rejected objects downstream of at least one parameter inspection unit opposite each other;

[0021] identifying, in an evaluation unit, objects to be removed from the conveyor belt as the objects move past each parameter inspection unit;

[0022] the evaluation unit of the parameter inspection unit issues an output signal to provide an actuation impulse to the device for removal as the object to be removed passes the device for removal; and

[0023] generating a horizontal force in the device for removal according to the actuation impulse, rotating a kick-out portion of the device from an unactuated vertical state to an actuated state, wherein the force, having horizontal and vertical components, is applied to the object to be removed, pushing the object to be removed into a reject container;

[0024] wherein a vertical spacing of a lower end of the kick-out portion from the conveyor belt remains constant throughout the actuated state.

[0025] According to one preferred embodiment, a contact plate on a wall of the kick-out portion moves along the wall to maintain the vertical spacing when the device is in the actuated state. BRIEF DESCRIPTION OF DRAWINGS

[0026] The concepts of the present application will be better understood when referring to the appended drawings, in which identical or similar components are denoted by the same reference numerals, and in which:

[0027] Figure 1 is a front perspective view of a product inspection line with an overhead sweep rejector incorporating the concepts of the present application;

[0028] Figure 2 is a front perspective view of an assembled overhead sweep rejector, separate from a product inspection line;

[0029] Figure 3 is Figure 2 is a side view of the overhead sweep rejector of

[0030] Figure 4 is a rear perspective view of the overhead sweep rejector, with a portion of the kick-out portion removed to show internal structure;

[0031] Figure 5A is Figure 4 is a side view of the overhead sweep rejector of

[0032] Figure 5B isFigure 4 side view of the overhead sweep rejector with the rejector in an actuated second position. DETAILED DESCRIPTION

[0033] Figure 1 A perspective view is shown of a portion of a product inspection line 10 having a conveyor belt 12, a parameter inspection unit 14, an overhead sweep rejector 16, and a reject bin 18. Objects to be inspected are placed on the conveyor belt 12 and pass through the parameter inspection unit 14 in the direction of travel of the conveyor belt. In the embodiment shown, the parameter inspection unit 14 includes a device 141 for detecting metal contaminants in the objects and a device 142 for determining whether the objects fall within an acceptable range of deviation from a predetermined target weight. Other exemplary parameters that can be evaluated include the color of the product, radiation contamination, packaging defects, etc. Data from the devices 141, 142 is provided to an evaluation unit 143 for comparison with predetermined product quality targets.

[0034] When an inspected object fails to meet the predetermined target range for the parameter being inspected in the parameter inspection unit 14, the evaluation unit 143 generates an output signal causing the overhead sweep rejector 16 to be actuated. As the object passes through the conveyor belt 12 between the overhead sweep rejector 16 and the reject bin 18, the actuation pulse causes the overhead sweep rejector to move the non-conforming object from the conveyor belt 12 into the reject bin 18. As shown, the overhead sweep rejector 16 is attached to the conveyor belt along a side rail of the conveyor belt. Figure 1

[0035] Figure 2 A front perspective view is provided of an exemplary embodiment of the assembled overhead sweep rejector 16, Figure 3 A side view thereof is provided. In this assembled state, the rejector 16 has a number of parts. These parts include a housing 20, a kickout 22 pivotably suspended from the housing, and a support structure 24 adapted to attach the housing proximally to the housing and to position the kickout above the conveyor belt at a fixed predetermined gap. In Figure 2 the kickout 22 is in an unactuated position in which it is generally retracted into the housing 20. Figure 2 ​Other features seen in the figure are a hydraulic cylinder 26 containing a rod that receives an output signal from the evaluation unit, and a pair of rails 30 contained within the rail housing 32. Positioned as the primary element that contacts the object being removed from the conveyor belt to the reject container is the contact plate 34 of the kickout 22. As a safety feature, a pair of side panels 36 make up a portion of the housing 20 that substantially covers the moving parts of the overhead sweep rejector 16 other than the contact plate 34. Since one feature of the inventive concept is to provide a device that eliminates or minimizes injury, the side panels 36 of the illustrated embodiment are shown as being removably fastened to a portion of the housing by screws 38 or similar fasteners from which the kickout 22 is suspended, for example by a pin 40 or similar pivotable mounting device.

[0036] Figure 4 A later perspective view shows internal features of the overhead sweep rejector 16 and the kickout 22, with one of the side panels 36 and a portion of the wall 42 of the kickout 22 removed to show the internal structure. The side panel 36 distal to the housing 20 is in place, but only the screws 38 that attach the side panel proximally are shown. The screws 38 connect the side panel to a rear wall 44 of the housing 20. The rear wall 44 is shown as a separate element from a top horizontal wall 46, with each wall removably attached to the other by screws 48, bolts, or the like. However, some embodiments can have these walls integrally formed, while others can have them integrally connected by welding or the like. The top horizontal wall 46 provides the pivotable suspension of the kickout 22 using the pin 40. The wall 42 of the kickout 22 is shown in Figure 4 with a portion removed to show other features. This wall 42 surrounds the sides and front of the top horizontal wall 46. The wall 42 is pivotally pinned to the top horizontal wall 46, and notably, the pivot connection is the only connection between the kickout 22 and the housing 20. In the illustrated embodiment, a portion 50 of the wall 42 is shaped and positioned to limit the rotation of the kickout 22 toward the rear wall by interacting with a slot 51 in the rear wall.

[0037] From the outside, as shown in Figure 2 and 3 , the contact plate 34 appears to be attached to the wall 42, but as shown in Figure 4 , 5A and 5B, the contact plate is arranged to slide on the wall 42. Figure 4 The removal of a portion of the wall 42 in allows the internal structure to be seen and understood. A rod 52 has a first end in a hydraulic cylinder 26 that extends through the rear wall 44, with the cylinder fixed to the rear wall on the inside of the rear wall. Preferably, all moving parts of the hydraulic system, and in particular the rod 52, are contained within the housing 20, thereby minimizing any hazards that arise. Figure 4Also shown are fittings 28 and 29 for connection to a source of hydraulic fluid. The second end 54 of the rod 52 is coupled to a short rod 56 which is transverse to the axis of the rod 52. Each end of the short rod 56 is engaged in a respective one of a pair of slot-shaped grooves 58 formed in a pair of plates 60 which are respectively on one side of the second end 54, each plate being fixed to the rear surface 62 of the wall 42 of the kick-out 22. This engagement of the ends of the short rod 56 in the slot-shaped grooves 58 restricts horizontal movement of the rod 52, which will be further shown in Figure 5A and 5B .

[0038] Figure 4 Also shown is that the lower end 64 of the contact plate 34 is pivotably fixed to the pair of rails 30 on each side by a pivoting fixing such as a pin 66. Figure 4 Also shown is that these rails 30 are restricted in horizontal movement by the rail housing 32.

[0039] Figure 4 The last notable feature in Figure 5A and 5B is the plate 68 which appears to be attached directly to the rear surface 70 of the contact plate 34 but in fact enables a limited sliding movement of the contact plate 34 along the wall 42, which will be shown in

[0040] Figure 5A and 5B The operation of the overhead sweep ejector 16 is shown in side cross-sectional view. In Figure 5A the ejector 16 is in the non-actuated state; in Figure 5B the ejector is in the actuated state. The mechanism disclosed in these figures retains the advantages of an oscillating movement for moving objects while eliminating the risk of crushing or shearing by the lower end of a fixed length pendulum.

[0041] In the retracted position of Figure 5A the kick-out 22 of the overhead sweep ejector 16 hangs down from the pivot attachment to the housing. In this position the lower surface of the rails 30 hang a predetermined minimum distance, preferably about 6 mm, above the conveyor belt. In this position the lower edge of the contact plate 34 also hangs at a predetermined minimum distance.

[0042] Upon an actuation signal the actuator delivers hydraulic fluid to the hydraulic cylinder 26 to act on the ejector 16, moving it from the position of Figure 5A to the fully actuated position of Figure 5B . In the embodiment shown the hydraulic cylinder 26 is arranged as a pusher which applies a horizontal pushing force through the rod 52. It can also be arranged to apply a horizontal pushing force on the pair of rails 30 or, although not preferred, it can be arranged to apply a rotational torque at the pin 40.

[0043] In any particular case, and as shown in Figure 5A and 5B , the pushing force exerted by the lever 52 causes the kick-out portion 22 to rotate clockwise about the pivot defined by the pin 40. In particular, when this happens through the lever 52, the plate 60 abuts against the rear surface 62 of the wall 42, effectively increasing the distance between the plate and the pin, measured along the rear surface. As the rotation occurs, the horizontal force exerted by the contact plate 34 onto the object decomposes into a resultant vector having a horizontal and a vertical component. The vertical component will tend to lift the object rather than just make it slide, thus reducing the contact area between the object and the conveyor belt. This provides the advantageous effect of the swing rejector.

[0044] However, the rotation of a swing having a fixed length causes a vertical separation between the swing bottom and the horizontal surface below it, thus creating a shear or crushing hazard. In the inventive concept rejector 16, this is avoided by providing a swing effect in which the length of the swing arm effectively changes during rotation, thus keeping the vertical separation above the surface constant.

[0045] This result is achieved through the combined interaction of the contact plate 34 and the plate 68 with the wall 42, and in particular with the vertical slot 72 in the wall 42. This vertical slot 72 is not really visible in Figure 4 but can be seen in Figure 5A and 5B . The pin 74 connects the contact plate 34 to the plate 68 through the slot 72 in the wall 42. It is easy to see, with reference to Figure 5A and 5B , that, in particular by comparing the position of the plate 68 relative to the pin 66 and the plate 60, it is easy to see that when the rejector 16 is rotated to the actuated state of Figure 5B , the plate 68 maintains a constant distance from the pin 66 but moves away from the plate 60, both measurements being taken along the line from the pin 40 to the pin 66. This movement lengthens the swing arm defined along this line. There is no crushing or shear hazard. In doing so, the length of the vertical slot 72 can be used as a limit for the angular rotation of the kick-out portion.

[0046] List of reference signs

[0047] 10 product inspection line

[0048] 12 conveyor belt

[0049] 14 parameter inspection unit

[0050] 141 metal inspection unit of the parameter inspection unit

[0051] 142 checkweigher of the parameter inspection unit

[0052] 143 evaluation unit of the parameter inspection unit

[0053] 16 overhead cleaning rejector

[0054] 18 reject container

[0055] 20 housing

[0056] 22 kickout

[0057] 24 support structure

[0058] 26 hydraulic cylinder

[0059] 28 hydraulic fluid connection

[0060] 29 hydraulic fluid connection

[0061] 30 pair of rails

[0062] 32 rail housing

[0063] 34 contact plate

[0064] 36 side plate

[0065] 38 screw

[0066] 40 pin, defines pivot

[0067] 42 wall of kickout

[0068] 44 rear wall of housing

[0069] 46 top horizontal wall of housing

[0070] 48 screw

[0071] 50 defined portion of wall 42

[0072] 51 slot in wall 44

[0073] 52 rod, first end in hydraulic cylinder 26

[0074] 54 second end of rod 52

[0075] 56 short rod

[0076] 58 slot

[0077] 60 plate

[0078] 62 rear surface of wall 42

[0079] 64 lower end of contact plate

[0080] 66 pin

[0081] 68 plate

[0082] 70 rear surface of contact plate

[0083] 72 vertical slot in wall 42

[0084] 74 pin

Claims

1. A device (16) for removing an object from a conveyor belt (12) of a conveyor line, comprising: A housing (20) adapted to be attached to the conveyor line; as well as The ejector (22), suspended from the housing, rotates about a pivot (40) such that the lower end (64) of the ejector remains constant at its vertical distance from the conveyor belt during rotation. in, The housing (20) has a rear wall (44) and a top wall (46); and The kickout portion (22) includes a wall (42) surrounding the side and front of the top wall and extending downward, the wall (42) defining the interior of the kickout portion. The device further includes: A contact plate (34) is arranged to slide along the front side of the wall (42) of the kickout (22).

2. The apparatus according to claim 1, wherein, The wall (42) also includes: A portion (50) that interacts with a groove (51) in the rear wall (44) to limit the angular rotation of the kick-out portion in a direction away from the vertical direction.

3. The apparatus according to claim 1, wherein, The device further includes: The vertical groove (72) in the wall (42) of the kick-out part (22); and Plate (68), which is connected to the contact plate (34) via the vertical groove (72) to restrict the sliding movement of the contact plate.

4. The apparatus according to claim 1, wherein, The device further includes: Guide rail housing (32), which is attached to the housing; and A pair of guide rails (30), whose horizontal movement is constrained by the guide rail housing, with the end of each guide rail pivotally fixed to the contact plate.

5. The apparatus according to claim 3, wherein, The device further includes: Guide rail housing (32), which is attached to the housing; and A pair of guide rails (30), whose horizontal movement is constrained by the guide rail housing, with the end of each guide rail pivotally fixed to the contact plate.

6. The apparatus according to claim 1, wherein, The device further includes: A hydraulic cylinder (26) extends through the rear wall of the housing; A rod (52) having a first end contained in the hydraulic cylinder and a second end (54) pointing toward the inner wall of the kick-out portion; and A pair of plates (60) are attached to and coupled to the inner wall of the kickout on each side of the second end of the rod.

7. The apparatus according to claim 6, wherein: Each of the plates has a strip groove (58) formed therein; and The device has a short rod (56) coupled to a second end of the rod and extending transversely to the axis of the rod, each end of the short rod engaging in a corresponding slot to define the horizontal movement of the rod.

8. The apparatus according to claim 1, wherein, The device further includes: The first and second side plates (36) are detachably fixed to the rear wall (44) of the housing (20) and cover the sides of the kickout.

9. A method for removing an object from a conveyor belt of a conveyor line, comprising: The device (16) for removing rejected objects and the container (18) for receiving rejected objects, as described in claim 1, are positioned relative to each other along the conveyor line downstream of at least one parameter inspection unit. As an object moves past each of the parameter verification units, the object to be removed from the conveyor belt is identified in the evaluation unit; When the object to be removed passes the removal device, the evaluation unit of the parameter verification unit outputs an output signal to provide an actuation pulse to the removal device. as well as The actuation pulse generates a horizontal force in the removal device, which rotates the kick-out part of the device from an unactuated vertical state to an actuated state, wherein a force with horizontal and vertical components is applied to the object to be removed, pushing the object to be removed into the waste container. The vertical distance between the lower end of the kick-out portion and the conveyor belt remains constant throughout the actuation state.

10. The method according to claim 9, wherein, When the device is in the actuated state, the contact plate on the wall of the kick-out portion moves along the wall to maintain the vertical spacing.

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