VIBRATORY CONVEYOR FOR CONVEYING ITEMS AND RELATED FILLING MACHINE AND METHODS
A vibratory conveyor includes a feed tray, an electromagnetic linear actuator and a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator. A sensor assembly is positioned to detect movement of the electromagnetic linear actuator. A controller connected to receive an output of the sensor assembly and connected to control energization of electromagnetic linear actuator, wherein the controller is configured to adjust energization of the electromagnetic linear actuator based upon the output of the sensor assembly. A vibratory conveyor in which the movable drive train includes at least one parallel spring element therealong is also disclosed.
This application relates generally to conveying systems for moving items and, more specifically, to a vibratory conveying system of a type that may be used in filling machines in which items are being conveyed, checked, counted and grouped for purposes of filling a container, package or other receptacle with a set number of the items.
BACKGROUNDIn the packaging of bulk items, such as pharmaceutical tablets or capsules, the items must be counted and grouped in order to fill containers, packages or other receptacles with a desired number of the items. Conveying the items to particular locations is important in such systems, and a variety of conveyance systems have been used in the past, including vibratory conveyors.
For example, vibratory conveyors that utilize a rotary motor with an eccentric mass are known. These conveyors allow for good frequency control. However, controlling or adjusting the amplitude of the vibration is difficult. The full three-hundred and sixty rotation of the eccentric mass also tends to create excess vibration on the frame of the machine, where it is not desired.
Hydraulic vibratory conveyors are also known and provide for good directional control of the vibration and a high degree of precision. However, such conveyors suffer from a lack of speed, and require the incorporation of an independent system for control of the hydraulic drive. Pneumatic vibratory conveyors provide for higher speeds than hydraulic conveyors but lack precise control of distance/amplitude.
Electric rotary vibratory conveyors utilize a servo-motor coupled with a crankshaft and piston. These systems provide good precision, based upon control of servo-motor speed. However, it is difficult to adjust the amplitude because of mechanical limits inherent in such systems. These systems also suffer from high cost, and high wear, and typically require the use of an oil bath, which is undesirable in most filling machine applications.
Accordingly, an improved vibratory conveyor system for use in filling machines would be desirable.
SUMMARYIn one aspect, a vibratory conveyor includes a feed tray, an electromagnetic linear actuator and a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator. A sensor assembly is positioned to detect movement of the electromagnetic linear actuator. A controller connected to receive an output of the sensor assembly and connected to control energization of electromagnetic linear actuator, wherein the controller is configured to adjust energization of the electromagnetic linear actuator based upon the output of the sensor assembly.
In another aspect, a vibratory conveyor includes a feed tray, an electromagnetic linear actuator and a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator. The movable drive train includes at least one parallel spring element therealong.
In a further aspect, a vibratory conveyor includes a feed tray, an electromagnetic linear actuator including a moving body portion within a fixed housing body and a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator. A flexural end cap is associated with the fixed housing body, wherein the moving body portion of the electromagnetic linear actuator is connected to the flexural end cap such that the flexural end cap guides movement of the moving body portion of the electromagnetic linear actuator.
In yet another aspect, a vibratory conveyor includes a feed tray, a drive system including an actuator, the drive system connected to move the feed tray in a reciprocating manner. The feed tray comprises a titanium material. In one implementation, the feed tray is formed by a titanium component and a non-titanium component fixed together with an adhesive material.
The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, items, and advantages will be apparent from the description and drawings, and from the claims.
Referring now to
In the illustrated embodiments, each electromagnetic linear actuator is formed as a “moving coil” type actuator or “voice coil linear actuator” in which linear motion is achieved by magnetic field interaction between a movable coil (or winding or bobbin) and one or more fixed permanent magnets. However, in alternative implementations the electromagnetic linear actuator may be formed a “moving magnet” type actuator in which the coil (or winding or bobbin) remains fixed and the permanent magnet(s) move linearly.
The initial feed tray C43 is configured differently and driven separately and differently than feed trays C46 and C48 because the function of the initial feed tray C43 is different than that of feed trays C46 and C48. In particular, the initial feed tray C43 is vibrated at a frequency and amplitude intended to cause items to spread out in a relatively uniform manner as they move toward the drop end C54 of the tray. The initial feed tray includes boundary walls at the upstream end and lateral sides. Notably, the upstream portion of the item support surface or body of the initial feed tray is substantially planar and the downstream portion, near the drop end C54, includes a set of rising guide walls C55 that form distinct drop paths C58 that begin to segment the items on the initial feed tray into groups that align with pairs of feed channels C60 formed on the feed tray C46. Here, four drop paths or groupings C58 are formed on the initial feed tray C43, and each drop path or grouping drops into two respective item feed channel paths C60 on the next feed tray C46. However, the number of paths/groupings and the number of channels could vary.
The intermediate and end feed trays C46 and C48 are configured and driven in a manner to singulate the items being conveyed such that only one item at a time drops from the drop end C56 of the end feed tray C48 to move through the item sensing arrangement. Here, the feed trays C46 and C48 take the form of plate structures that are configured to provide a plurality of V-channels, each of which defines a respective feed channel path C60 for items. Here, by way of example, four sets or pairs C62 of adjacent feed paths C60 are provided, where a lateral spacing between the adjacent sets or pairs C62 is larger than the lateral spacing between the adjacent feed paths C60 of each pair.
In the illustrated embodiment, two channeled feed trays C46 and C48 are provided, with feed tray C46 dropping items to feed tray C48. The use of the pair of stepped feed trays C46 and C48 provides an advantage, as compared to a single feed tray having a length comparable to the combined length of trays C46 and C48. In particular, a single long feed tray would tend to flex more when subjected to high acceleration as a result of frequency and stroke length settings for reciprocating movement, reducing or inhibiting desired item feed control, and placing more restrictive limits on the amplitude and speed at which the feed tray could be driven.
In one implementation, in order to maximize feed tray rigidity per unit weight, the feed trays C46 and C48 may be formed of a titanium material (e.g., Titanium Grade 2). Each titanium feed tray is assembled together using an adhesive, such as structural adhesive. In the case of an assembly process using an adhesive,
As seen in
Although titanium is preferred for the tray body, in some cases, an aluminum material may be used for the feed trays. In addition, rather than an adhesively assembled tray, a single casting could be used or a single part machined out of solid block could be used, or multiple welded together pieces could be used. In addition, in some embodiments the feed trays need not incorporate titanium material (e.g., a single piece or multipiece feed tray of aluminum or stainless steel). The adhesive assembly process could also be used for feed trays that do not include titanium (e.g., feed tray body of stamped aluminum or stainless plate and rigid sub-frame of stamped aluminum or stainless plate).
Referring again to
The electromagnetic linear actuator C80 includes a cylindrical housing body C80A that is secured to a mount plate C82 that extends between two side frame plates C83. The side frame plates C83 are in turn fixed to another frame/housing portion of the machine by mounts C85. Here, the mounts are designed to engage with a top plate 70 (
Referring again to
In the case of both the connection of the electromagnetic linear actuator C80 to the driven frame C70, the connection of the electromagnetic linear actuator C81 to the dummy weight C120, and similarly for the connection of actuator C50 to driven frame C71 and the connection of actuator C53 to dummy weigh C121, spring/flexural elements may be used. By way of example, as seen in
This type of connection functions to guide/align coaxially the moving bobbin/coil in the housing C80A by blocking two degrees of freedom (up/down translation and translation transverse to the axis of motion) while permitting translation along the axis C346.
The coil/bobbin of each electromagnetic linear actuator is energized to produce electrical current through the bobbin. The resulting electromagnetic field has a field orientation dictated by the direction of the electrical current in the conductor. The electromagnetic filed interacts with the magnetic field of the permanent magnet(s) structure C342 to produce movement of the coil/bobbin body C340 into or out of the actuator body C80A depending upon the orientation of the magnetic field produced by the coil.
As best seen in
In the case of any of the above-noted electromagnetic linear actuators, a closed loop control of the actuator is preferably provided to enhance performance of the vibratory conveyor. In particular, as schematically depicted in
The closed loop actuation is important to achieve the previously explained dynamic balancing of opposed actuators. For example, the front actuator C80 driving the font trays C48 and C46, the position control of which is achieved with the sensor C174, is electronically cammed to or synchronized with the rear actuator C81, the position control of which is achieved with a separate sensor. This electronic camming provides consistent synchronized opposed movement of the actuators in order to assure smooth running (low undesirable/residual vibration), and reduces the need for further damping elements. Performance of the electromagnetic linear actuators is enhanced by the inclusion of parallel spring assemblies for each actuator. By way of example, referring to the schematic of
The use of one or more parallel spring assemblies in the drive train acts to store energy and therefore reduces the overall power consumption and reduces the peak force required by the electromagnetic linear actuator to achieve a desired reciprocating motion. When the actuator is in a neutral stationary state, there is no motion and no potential energy. If the actuator is energized to bring the spring element to a compressed position, there is still no motion but there is potential energy stored in the spring. If the hold on the position of the component is then released, and if the actuator is not being energized, the drive assembly will then start to oscillate naturally for some time until it stops again at its neutral position. This movement is a damped harmonic oscillation (e.g., see curve C260 in
As used herein, the term controller is intended to broadly encompass any circuit (e.g., solid state, application specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA)), processor(s) (e.g., shared, dedicated, or group—including hardware or software that executes code), software, firmware and/or other components, or a combination of some or all of the above, that carries out the control functions of the device/machine or the control functions of any component thereof.
It is to be clearly understood that the above description is intended by way of illustration and example only, is not intended to be taken by way of limitation, and that other changes and modifications are possible.
Claims
1. A vibratory conveyor, comprising:
- a feed tray;
- an electromagnetic linear actuator;
- a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator;
- a sensor assembly positioned to detect movement of the electromagnetic linear actuator; and
- a controller connected to receive an output of the sensor assembly and connected to control energization of electromagnetic linear actuator, wherein the controller is configured to adjust energization of the electromagnetic linear actuator based upon the output of the sensor assembly.
2. The vibratory conveyor of claim 1 wherein the sensor assembly detects movement of the electromagnetic linear actuator by monitoring movement of a portion of the movable drive train.
3. The vibratory conveyor of one of claim 1 or 2, wherein the controller is configured to compare feedback signals from the sensor assembly to an intended movement profile, and to adjust energization of the electromagnetic linear actuator to achieve or maintain the intended movement profile over time.
4. The vibratory conveyor of claim 3, wherein the intended movement profile defines position of the portion of the movable drive train.
5-6. (canceled)
7. The vibratory conveyor of claim 1,
- wherein the movable drive train includes at least one spring element therealong between the electromagnetic linear actuator and the feed tray;
- wherein the spring element has a fixed portion and a moving portion;
- wherein both (i) a moving part of the electromagnetic linear actuator is connected to move in unison with the moving portion of the spring element and (ii) a segment of the drive train between the moving portion of the spring element and the feed tray is connected to move in unison with the moving portion, such that the feed tray also moves in unison with the moving portion of the spring element.
8. The vibratory conveyor of claim 7, wherein the spring element comprises oppositely oriented helical portions.
9. The vibratory conveyor of claim 8,
- wherein the electromagnetic linear actuator includes a stationary cylindrical housing body in which a coil body of the electromagnetic linear actuator is partially disposed;
- wherein the spring element is formed on a flexural end cap positioned at one end of the cylindrical housing body, wherein the flexural end cap is part of the movable drive train.
10. The vibratory conveyor of claim 9, wherein the spring element is formed by a cylindrical rim of the flexural end cap, wherein the cylindrical rim includes at least first and second spiral slots therein to form the oppositely oriented helical portions.
11-14. (canceled)
15. The vibratory conveyor of claim 1, wherein the feed tray is one feed tray of a feed tray assembly, and the vibratory conveyor further comprises an additional feed tray that is operatively driven by an additional electromagnetic linear actuator that is separate from the electromagnetic linear actuator that drives the one feed tray.
16. A filling machine including the vibratory conveyor of claim 1, wherein a discharge end of the vibratory conveyor is located such that items traveling along the vibratory conveyor drop along a fall path that includes a sensor assembly for sensing the items.
17. A vibratory conveyor, comprising:
- a feed tray;
- an electromagnetic linear actuator;
- a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator;
- wherein the movable drive train includes at least one parallel spring element therealong.
18. The vibratory conveyor of claim 17, wherein the parallel spring element comprises a machined spring.
19. The vibratory conveyor of claim 18, wherein the machined spring includes oppositely oriented helical portions.
20. The vibratory conveyor of claim 19,
- wherein the electromagnetic linear actuator includes a cylindrical housing body in which a coil body of the electromagnetic linear actuator is at least partly disposed;
- wherein the spring element is formed on a flexural end cap positioned at one end of the cylindrical housing body, wherein the flexural end cap is part of the movable drive train;
- wherein the spring element is formed by a cylindrical rim of the flexural end cap, wherein the cylindrical rim includes at least first and second spiral slots therein to form the oppositely oriented helical portions.
21. The vibratory conveyor of claim 17,
- wherein the parallel spring element has a fixed portion and a moving portion;
- wherein both (i) a moving part of the electromagnetic linear actuator is connected to move in unison with the moving portion of the parallel spring element and (ii) a segment of the drive train between the moving portion of the parallel spring element and the feed tray is connected to move in unison with the moving portion, such that the feed tray also moves in unison with the moving portion of the parallel spring element.
22. A vibratory conveyor, comprising:
- a feed tray;
- an electromagnetic linear actuator including a moving body portion within a fixed housing body;
- a movable drive train interconnecting the feed tray and the electromagnetic linear actuator such that the electromagnetic linear actuator will move the feed tray during energization of the electromagnetic linear actuator;
- a flexural end cap associated with the fixed housing body, wherein the moving body portion of the electromagnetic linear actuator is connected to the flexural end cap such that the flexural end cap guides movement of the moving body portion of the electromagnetic linear actuator.
23. The vibratory conveyor of claim 22, wherein the flexural end cap includes an intermediate flex region along a length of the flexural end cap and the intermediate flex region is disposed around one of the fixed housing body or the moving body portion to maintain alignment of the intermediate flex region with a movement axis of the electromagnetic linear actuator.
24. The vibratory conveyor of claim 22, wherein the flexural end cap includes a plurality of spiral slots formed in a cylindrical rim of the end cap and the cylindrical rim is disposed around the moving body portion and is connected to an end of the fixed housing body.
25-28. (canceled)
Type: Application
Filed: Oct 5, 2023
Publication Date: Feb 8, 2024
Inventors: Guillaume SAVOIE-LAVIGUEUR (Coteau-du-lac), Simon LAJOIE (Montréal), Alexandre LEBEL (Laval), Tim BEAUDOIN-WALLACE (Terrebonne), Mathieu LAFORTUNE (Mascouche)
Application Number: 18/481,689