Closed transfer system with metered dispensing

Abstract

A closed transfer system (10, 300) for dispensing hazardous material from a storage container includes a container-mounting interface (12), a lock (16) for retaining the storage container engaged with the interface, a robotic manipulator for opening and closing the internal seal, and a metering device (20) for metering a flow of liquid. A controller (36) actuates the robotic manipulator to open the internal seal. It then opens an outlet valve (34), dispenses a metered quantity of liquid and closes the outlet valve. The robotic manipulator then closes the internal seal, and an inlet valve (24) and the outlet valve are opened to flush the hazardous material from the system. The system operates in modes for dispensing both part of a container's contents and for emptying the contents fully.

Description

FIELD AND BACKGROUND OF THE INVENTION

[0001] The present invention relates to closed transfer systems and, in particular, it concerns a closed transfer system with metered dispensing.

[0002] In order to protect operators and the environment from hazardous chemicals, systems have been developed to allow for transfer of chemicals from a source container to target container, typically for mixing with water and other chemicals, without opening the source container to the atmosphere. One such example is a closed transfer system for pesticides used for spraying agricultural crops. Legislation requiring the use of such systems is being introduced in some countries, and the required connection systems are commercially available from BASF SE. A typical container cap design suitable for use in a closed transfer system (CTS) is illustrated in FIG. 1, and includes a cap 100 which is provided with an external seal 102, which is removed manually by the user, and an internal seal (inner cap) 104, which is opened and resealed by a dispensing device after the container is mounted and sealed to the dispensing device. Requirements for implementation of a CTS are defined in ISO 21191: Equipment for crop protection - Closed transfer systems (CTS).

[0003] The various requirements for implementation of CTS presents challenges for metering of the quantity of chemicals dispensed.

[0004] An example of a closed transfer system (CTS) for handling hazardous materials from containers is described in US 2021 / 0340003 A1 to BASF SE. This document discloses a coupling device (100) configured to mechanically couple to a cap (102) of a container (123). This container features an opening with a re-sealable closure insert (101) that acts as an internal seal. BASF SE describes a system where the coupling device includes a first mechanism (e.g., a claw element 103) that draws the container and its cap towards the coupling device to achieve a sealed and locked engagement. It also describes a second mechanism that axially moves a probe (124) to disengage the closure insert (101) and lift it into the container. Furthermore, BASF SE outlines flow arrangements within its coupling device for guiding air into the container for venting, and rinsing water into the container. While BASF SE generally mentions the possibility of volume measurements via a separate measuring device in a connected sprayer system (para.

[0028] ), it does not disclose an integrated metering device configured for metering a flow of liquid from the container directly via a defined second flow path from the container-mounting interface, nor a first flow path from a water inlet controlled by an inlet valve to the container-mounting interface for diluent water. Furthermore, BASF SE does not disclose a robotic manipulator for automatically mounting and removing the storage container, a controller configured to control such a robotic manipulator, or a third flow path for a flow of water from a metering device to a target container, as featured in the present invention.SUMMARY OF THE INVENTION

[0005] The present invention is a closed transfer system. The invention is set out in the appended set of claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The invention is herein described, by way of example only, with reference to the accompanying drawings, wherein: FIG. 1, described above, is an isometric view of a typical container cap design suitable for use in a closed transfer system (CTS); FIGS. 2A and 2B are isometric views of a closed transfer system (CTS), constructed and operative according to an embodiment of the present invention, for dispensing material from a container, shown before and after mounting the container on the CTS, respectively; FIG. 3A is a block diagram of the CTS of FIG. 2B, including a container-mounting interface; FIG. 3B is an enlarged block diagram of the container-mounting interface of FIG. 3A and associated components; FIG. 4 is a flow diagram illustrating two modes of operation of the CTS of FIG. 2B; FIG. 5 is a partial isometric view similar to FIG. 2B with a front cover of the CTS removed to reveal the internal components; FIGS. 6 and 7 are front and back isometric views, respectively, of the internal components of the CTS of FIG. 5 with the entire casing removed; FIG. 8 is a side view similar to FIGS. 6 and 7; FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 8; FIG. 10 is a partially cut-away partial isometric view of a linear actuator assembly from the CTS of FIG. 2B; FIG. 11A is an enlarged view of an upper part of FIG. 9; FIG. 11B is an upper isometric view of the region of the CTS shown in FIG. 11A; FIG. 11C is a partially cut-away lower isometric view of the region of the CTS shown in FIG. 11A; FIG. 12 is an isometric view of a gripper component of a robotic manipulator of the CTS of FIG. 2B for gripping an internal seal of the cap of FIG. 1; FIGS. 13A-13C are enlarged views of an upper part of FIG. 9 illustrating a container placed on the CTS, and showing the effects of successive stages of motion of the linear actuator of the CTS; FIG. 14 illustrates a further stage of motion of the linear actuator, but shown in cut-away isometric view; FIG. 15A is a cross-sectional view taken along line XV-XV in FIG. 13C showing a further stage of motion of the linear actuator, and illustrating a flow path for draining of contents from the container; FIG. 15B is a partial cross-sectional view taken on the same plane as FIG. 9 in a state similar to FIG. 15A illustrating a container rinsing process; FIG. 16A is an isometric view of the linear actuator column from the CTS of FIG. 2B with other components hidden for clarity; FIGS. 16B and 16C are views similar to FIG. 16A with the container hidden, and showing the linear actuator in a fully-lowered and a fully-raised state, respectively; FIG. 17 is an enlarged view of the lower part of FIG. 9; and FIG. 18 is a block diagram of a closed transfer system, constructed and operative according to a further embodiment of the present invention, for dispensing material from a container. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The present invention is a closed transfer system with metered dispensing, and corresponding methods.

[0008] The principles and operation of systems according to the present invention may be better understood with reference to the drawings and the accompanying description.

[0009] By way of introduction, the present invention will be presented with reference to two exemplary embodiments, a first employing a flow meter for metering the quantity of the chemical to be dispensed, and a second employing a positive-displacement pump to achieve metering. Even within each of these embodiments, the invention includes a number of different aspects, each of which is believed to be of patentable significance in its own right, but which are most preferably used in synergy to provide a particularly advantageous overall system.

[0010] The invention is described in the context of a CTS interface compatible with the BASF SE cap, and similar caps made by other manufacturers, providing a similar interface for engaging the container, engaging and opening the inner cap (referred to below as the "internal seal"), and reclosing the inner cap. Clearly, the invention could be adapted to other CTS interfaces if required. The terms "hazardous material", "liquid", "chemical" etc. are used herein interchangeably to refer to materials dispensed using a CTS system.

[0011] Referring now to the drawings, FIGS. 2A, 2B and 3 show schematically a closed transfer system (CTS), generally designated 10, constructed and operative according to a non-limiting but particularly preferred exemplary embodiment of the present invention, for dispensing a metered quantity of a hazardous material from a storage container 106, for dilution with water in a target container 108. The storage container 106 has an opening, preferably defined by cap 100 with an internal seal 104, as described above with reference to FIG. 1. As shown schematically in FIGS. 3A and 3B, closed transfer system 10 includes a container-mounting interface 12, which is shown in more detail with its associated components in FIG. 3B: a seal 14 for sealing against the opening of the storage container 106, a lock mechanism 16 for retaining the storage container engaged with the interface, and a robotic manipulator 18 for opening and closing the internal seal 104. Closed transfer system 10 also includes a metering device 20 for metering a flow of liquid. A flow arrangement includes a water inlet 22 controlled by an inlet valve 24, a first flow path 26 from the inlet valve 24 to the container-mounting interface 12, a second flow path 28 from the container-mounting interface 12 to the metering device 20, and a third flow path 30 from the metering device 20 to an outlet 32 to the target container, the third flow path controlled by an outlet valve 34.

[0012] The closed transfer system 10 is controlled by a controller 36, including at least one processor 38, which is associated with robotic manipulator 18, inlet valve 24, outlet valve 34 and metering device 20, as well as various other sensors and control components that will be detailed below. The connections of controller 36 are not shown, for clarity of presentation. The controller 36 is preferably configured to operate the CTS in a number of different modes, with various forms of automation, and employing various sensor inputs and additional information obtained by the system in order to detect and correct various faults or error conditions, to avoid various problems that might be caused by human error and to provide safe and precise dispensing of the hazardous materials.

[0013] In one mode of operation according to one aspect of the present invention, controller 36 is configured to ascertain a quantity of a hazardous material to be dispensed, for example, by user input or by downloading of a treatment program. Then, while a storage container containing the hazardous material is locked in engagement with the interface, controller 36 actuates the robotic manipulator 18 to open the internal seal 104, opens outlet valve 34 and dispenses a metered quantity of liquid as measured by the metering device. The controller then closes the outlet valve 34 and actuates robotic manipulator 18 to close internal seal 104. Once the internal seal 104 is closed, inlet valve 24 and the outlet valve 34 are opened to allow a flow of water from water inlet 22 to outlet 32, thereby flushing the hazardous material from the flow arrangement and cleaning the outside of the container opening and the internal seal.

[0014] Other preferred features of the non-limiting but preferred implementation illustrated here include a pressure sensor 46, associated with controller 36 and deployed to sense a pressure within the flow arrangement. Pressure sensor 46 preferably provides a range of important safety functions. Firstly, the controller is preferably responsive to sensing of a pressure above a threshold pressure value to interrupt operation of the closed transfer system. This threshold pressure is preferably set to less than 1 bar, more preferably less that 0.5 bar (50 kPa), and most preferably around 0.3 bar (30 kPa). It is important to ensure that pressure within the CTS does not build up beyond these very moderate limits, since storage containers for chemicals dispensed by the CTS are not designed to withstand elevated pressures, and all risk of bursting must be avoided.

[0015] If above-threshold pressure is encountered, the inlet valve is immediately closed to prevent further pressure increase. The subsequent action and / or instructions to the user for debugging of the possible causes of the fault depend on the stage of operation at which the fault occurs, but typically include verifying that suction is properly applied to the outlet. Optionally, for emergency relief of excess pressure, a pressure relief valve 48 may be provided. This may be an autonomous pressure-actuated valve which opens in the event of a raised pressure, or may be simply an additional solenoid-operated valve which can open a bypass flow channel to the outlet in case of pressure build-up. In cases where a fault cannot otherwise be resolved during operation, certain particularly preferred implementations of the CTS allow for manual override of the system operation to allow draining of the system, as will be described further below.

[0016] The system preferably also includes a temperature sensor 50 deployed to measure the temperature of the liquid being dispensed from the container, or more simply, the ambient air temperature within the system, which is usually a good approximation also for the liquid temperature. This measurement together with information about the type of composition being delivered allows calculation, or retrieval from a look-up table, of viscosity information for the composition being dispensed, which is advantageously used for automatic calibration of the flow meter measurements. The temperature sensing is preferably also used to generate a warning and / or prevent use of the system if the temperature reaches a level which might adversely affect operation of the system and / or properties of the composition. For example, controller 36 preferably interrupts operation of the closed transfer system if the temperature within the closed transfer system falls below a frost-warning temperature, i.e., a temperature of a few degrees above freezing at which there would be a risk of water freezing within the conduits and preventing proper operation of the system. Information regarding the temperature may also be used in defining processing time parameters, and rinse time parameters.

[0017] As mentioned, the system is preferably provided with electrically controlled inlet and outlet valves 24 and 34, and optionally additional valves controlling one or more internal flow path (such as priming valve 44 and / or pressure relief valve 48), that are operated synchronously according a specific sequence to achieve the different stages of operation of the system, or under certain operating conditions. Particularly in the case of outlet valve 34, which is exposed to the undiluted chemicals dispensed by the CTS, a preferred implementation of the valve is a relatively large-gauge corrosion-resistant diaphragm valve which is controlled by pressure delivered to a control chamber by a small-gauge control conduit 52 that is selectively provided with water pressure from the inlet by a small solenoid pilot valve 54. The inlet valves and control valves 24, 44 and 54, which are only exposed to water, can provide sufficient flow rates via smaller apertures, and are typically implemented using simpler solenoid-controlled valve structures.

[0018] A one-way air inlet valve is preferably provided to allow air to enter the container to replace dispensed fluid, and to allow draining of the system. The one-way valve may be implemented using one or more passive silicon valves, such as an umbrella valve 56 (best seen in FIG. 11B) with sufficient valve seat support to withstand the range of working pressures in the reverse direction. In the non-limiting embodiment illustrated here, an air inlet conduit 58 passes up axially within the robotic manipulator 18, thereby delivering air directly to the interior volume of the storage container during dispensing of the contents and facilitating free flow of liquid from the container.

[0019] The different modes of flow control typically include initial rinsing and priming of the system, dispensing, rinsing the container (in the case of finishing the container contents), rinsing of the container opening and inner plug, flushing of the metering system, and draining of the system. Initial filling of the system is preferably performed by opening both the inlet and outlet, prior to opening of the container, so that water flows through and fills the system, and then closing the outlet valve momentarily before the inlet valve. The inlet valve is preferably a progressively-controllable valve and / or a rapidly-switchable valve which can be actuated to provide various rinsing flow patterns (e.g., varying flow rates or pulsing) in order to enhance the rinsing effect.

[0020] A flow chart indicative of a typical scheme of operation of the CTS 10 is shown in FIG. 4. Actions shown in a rectangular text box are operations performed by the system. Actions shown in rounded text boxes are actions which the user is prompted to perform.

[0021] In various particularly preferred implementations, particularly where the CTS is integrated with various external systems for inputting a treatment program, determining material properties and / or for recording and reporting chemical usage, the system preferably starts by identifying the material to be dispensed (step 200). This may be done by manual input of the name of the chemical about to be dispensed via a user interface 60 (FIGS. 2A-3A and 5), such as by selecting the chemical from an inventory list. In some cases, a crop treatment program may be uploaded to the CTS, or selected from a list of defined crop treatment programs, resulting in a short list of the relevant compositions from which the current material is chosen, or alternatively, the system may generate an instruction to the user as to what composition should be loaded on the system next, which the user can confirm or override.

[0022] Alternatively, the material can be identified by employing a reader 62 (FIG. 3A) configured for reading information associated with the storage container. The reader 62 may be an optical scanner for reading an optically-readable label, such as 1D or 2D barcode or a spectrally-encoded tag. Alternatively, or additionally, reader 62 may include components for reading a wirelessly-readable element such as an RFID chip. In any of the above cases, the reader reads the container information, either automatically as the container is brought close to, or mounted on, the CTS, or by use of a hand-held scanner, and conveys the corresponding information to the controller. In some cases, the hand-held scanner may be a portable communications device, such as a general-purpose cellular communications device operating an APP with suitable optical and / or RF scanning capabilities, or a dedicated mobile communications device.

[0023] The information associated with each storage container contains at least the composition of the material contained in the container, preferably also with its concentration. Information regarding the viscosity and / or other physical properties of the material that are relevant to dispensing and metering of the contents may also be included, or may be retrieved based on the material composition from reference information, which may be stored locally or remotely accessed. In certain preferred cases, the information also conveys the volume of the contents, and preferably also information about the container shape and / or dimensions, which can be used to select appropriate rinse cycles. In some preferred implementations, the information may also include a batch number, useful for tracking possible recalls or quality control issues. In certain preferred implementations, each container may carry information including a unique container identifier, which may be used for tracking inventory and / or product usage, and may allow tracking of the remaining contents of containers which have already been used for dispensing metered doses of the material, either based on locally stored records or via a remotely-maintained database.

[0024] Once the material to be dispensed is correctly identified, the user opens the outer seal 102 which, in the case of a first use of a given container, typically requires tearing of a container cap lock (step 202), and places the container, still sealed by internal seal 106) on the container-mounting interface 12 (step 204), so that the opening of the container seals against seal 14, typically implemented as an O-ring seal which abuts against an internal cylindrical surface of cap 100 (FIG. 11A).

[0025] CTS 10 preferably includes a container-seating sensor generating an output indicative of when a storage container 106 is fully engaged with the container-mounting interface 12 (step 206) and a lock mechanism 16 selectively deployable for locking the storage container 106 in engagement with the container-mounting interface 12 (step 208). According to one particularly-preferred aspect of the present invention, considered to be of utility independent of all the other features described herein, controller 36 is responsive to an output from the container-seating sensor indicative of a storage container 106 being positioned on, and fully engaged with, the container-mounting interface 12 to actuate the lock mechanism 16 so as to lock the storage container in engagement with the interface. In other words, step 208 preferably occurs automatically in response to step 206. This greatly facilitates user-handling of the heavy storage containers, as the user can focus on lifting and positioning the container correctly, and does not need to perform any additional action while balancing the container in position in order to initiate locking.

[0026] The container-seating sensor preferably includes two sensing elements associated with diametrically-opposed regions of a rim around the container opening so that proper seating of the container is only confirmed by the sensor if the storage container is engaged "straight-on" to the interface, and not tilted. In one particularly-preferred but non-limiting implementation, the container-seating sensor includes two depressible tabs 64 (FIG. 11B) located on opposite sides of, and adjacent to, seal 14, which are depressed against a spring bias (springs not shown) by the rim of the container opening, typically provided by the rim of cap 100. Although two such tabs are typically considered to be sufficient, clearly, three or more angularly-spaced-apart tabs could also be used if further redundancy is desired. Sensing of the raised / depressed state of tabs 64 may be achieved by use of various sensing arrangements, such as microswitches, magnetic sensors or optical sensors. According to one particularly-preferred but non-limiting example, optical sensors 66 (FIG. 11C) are deployed on an underside of the container-mounting interface 12 to sense the position of (a downwards extension of) the tabs 64.

[0027] Once locked, it is a particularly-preferred feature of lock mechanism 16 that it is configured to maintain locking of the storage container 106 in engagement with the container-mounting interface 12 in the event of a power outage, thereby maintaining safety of the user and the surroundings. The structure and operation of one non-limiting but particularly-preferred implementation of lock mechanism 16 is best understood by reference to FIGS. 11B, 13A, 13B and 14. Specifically, as seen in FIG. 11B, seal 14 is surrounded by a series of teeth 68 which are positioned for engaging behind a rim bead 110 (FIG. 1) of the container. These teeth 68 may initially be in a radially-outwards (non-engaging) position, or may be resiliently biased to a radially-inwards position while being shaped to allow the rim bead to resiliently displace them outwards as the container is mounted and removed. A locking collar 70 that is generally cylindrical circumscribes the base of teeth 68 and is axially displaceable to as to bear on the teeth and force them inwards (see the transition of FIG. 13A to FIG. 13B) and, in its raised position, to trap teeth 68 in positive engagement with bead 110.

[0028] In order to maintain locking of the container in the event of a power loss, locking collar 70 is preferably biased to maintain its raised position by a number of springs 72 (FIG. 13B). Release of the lock mechanism is achieved by pulling locking collar 70 downwards against the spring bias.

[0029] According to one particularly-preferred but non-limiting implementation described further below, actuation of various functions of the CTS 10 is advantageously achieved the motion of a single linear actuator. According to one particularly-preferred option, the linear actuator is mechanically linked to lock mechanism 16 such that a part of the motion of the linear actuator prior to performing the other functions causes deployment of the lock to a locked state.

[0030] In the specific implementation illustrated in FIGS. 10 and 16A-16C, the linear actuator is implemented as a motor 74 which drives a threaded bolt 76 so as to displace a carriage 78 along bolt 76 in an axial direction (up-and-down as illustrated). Locking collar 70 is linked by a number of rods 80 to a base plate 82, which is here formed as an annulus in order not to interfere with the threaded bolt 76. When carriage 78 is lowered to its fully-lowered position (FIG. 16B), carriage 78 bears downwards on base plate 82, thereby pulling rods 80 and locking collar 70 downwards against the bias of springs 72, thereby releasing teeth 68 to allow dismounting and mounting of containers. When motor 74 rotates threaded bolt 76 so as to begin to raise carriage 78, springs 72 raise locking collar 70 (together with rods 80 and base plate 82) towards its raised locking position, so as to secure the container. Further motion of carriage 78 (with functions described below) occurs without further motion of rods 80 or base plate 82. At the end of the operation, when the user confirms that he is ready to remove the container, return of the carriage to its fully-lowered position again retracts locking collar 70 and unlocks the container from the CTS.

[0031] As best seen in FIG. 10, in a particularly-preferred implementation illustrated here, base plate 82 has a cylindrical wall which slides against guide surfaces 84, and carriage 78 slides along rods 80, employing them as guides for its linear motion. Guide surfaces 84 are supported by a motor mounting plate 86, which is maintained in fixed spatial relation to the container-mounting interface 12 by clamping rods 88, thereby unifying the entire actuator column.

[0032] Motor 74 may be any type of motor that produces sufficient torque and operates with sufficient precision. The motor design, a step-down transmission if used, and the pitch of thread and diameter of bolt 76 should be chosen to provide sufficient linear force for effective opening and closing of the internal seal of the storage containers, which may require tens of kgf (hundreds of Newtons), while offering a range of speeds of displacement from a controlled slow motion of a few millimeters per second up to more rapid displacements of tens of millimeters per second. One particularly-preferred option is a stepper motor.

[0033] As mentioned, maintenance of the locked state in the case of various faults is a preferred safety precaution. Preferred implementations of the present invention provide manual override functionality to allow drainage and / or container closure, and release of the container, as will be described further below.

[0034] Referring again to FIG. 4, after locking of the container in place, the controller is preferably configured to open the inlet valve and the outlet valve so as to rinse an external surface of the opening of the storage container and of the internal seal (step 210). This ensures that any dirt or other foreign matter that may have collected around the opening is flushed away before opening of the internal seal, so that it cannot interfere with the more delicate processes of opening and closing of the internal seal, or with metering of the composition being dispensed.

[0035] Then, at step 212, the system is preferably primed with water. A preferred process for priming the system with water, and how this facilitates precise metering of the quantity of the composition being dispensed are discussed further below.

[0036] It is a particular feature of one aspect of the present invention that the closed transfer system 10 can be operated in two distinct modes: a partial (dosed) dispensing system in which only a metered quantity of the container contents is dispensed and the container is then resealed for storage, and a full-contents mode in which the entire remaining contents of the container are dispensed, and the container is rinsed internally in preparation for safe disposal. At step 214, a selection is made between these two modes, which may be based on a user input via user interface 60, or may be derived automatically from an uploaded treatment plan in combination with information provided to the system regarding the quantity of material within the container.

[0037] In the case of partial dispensing of the contents (left branch), the system ascertains the quantity Q of the contents to be dispensed (step 216), actuates the robotic manipulator 18 to open the internal seal 104 (step 218), moves the head of the manipulator (with the internal seal) away from the container opening in order to open up a fluid flow passageway and allows the container contents to drain into the flow path (step 220). The outlet valve 34 is then opened (step 222), exposing the contents of the flow path to the suction applied to the outlet, and the flow meter measures out the required quantity of the material (less any offset correction and valve operation delay correction, as discussed below) at step 224. During the dispensing process, air enters the container along flow path 58 and one-way valves 56 to replace the drained contents, keeping the internal pressure close to atmospheric pressure. Once the required quantity has been measured by the flow meter, outlet valve 34 is preferably closed (step 226).

[0038] Where the entire contents of the container are to be dispensed (right branch of FIG. 4), steps 228, 230, 232 and 234 generally parallel steps 218, 220, 222 and 224, respectively, as described above. In this case, the outlet valve 34 remains open until the entire contents of the container have drained, as identified by liquid sensor 40 sensing the presence of air (step 236). Controller 36 then actuates a rinse process (step 238), typically with outlet valve 34 remaining open and inlet valve 24 being actuated to generate pulses of spray into container 106 while the user rotates the container. For the purpose of rinsing the internal surfaces of containers, the first flow path 26 from inlet valve 24 to the container-mounting interface 12 preferably terminates at one or more nozzles 90 (FIG. 12) associated with the robotic manipulator 18 so as to be displaceable into an internal volume of the storage container. The nozzles 90 are here formed as part of a gripper 92 configured to engage internal seal 104 of the storage container, as will be described further below.

[0039] The parameters of the rinsing cycle are preferably varied according to the available information to ensure effective rinsing for different types of materials with different viscosity and other physical properties, and for different sizes and shapes of container, while keeping rinse cycles as time-efficient as possible. Variable parameters may include: water pulse duration, time between pulses, number of pulses in a cycle, number of cycles time between cycles, and the height of the cleaning head at each stage of the rinsing cycle. Use of pulses of water flow is preferred, since it provides efficient cleaning while avoiding the risk of sudden pressure build-up in the case of a fault, thereby allowing time for sensing of the fault and taking corrective action. Information which is preferably taken into consideration in defining the rinse parameters preferably include one or more of: a viscosity of the hazardous material, which may be derived from information associated with the container and read by reader 62, or based on information provided by the user or downloaded in the form of a treatment program; ambient temperature, which directly impacts the viscosity of the hazardous material; and a size and / or shape of the storage container, which information is particularly used to vary a displacement distance of the nozzle into the internal volume of the storage container.

[0040] After the rinse process, the inlet valve 24 and the outlet valve 34 are closed (step 240), and the process reunites with the metered dispensing process at step 242.

[0041] At step 242, the robotic manipulator 18 is actuated to reclose the internal seal 104. The inlet valve 24 and outlet valve 34 are then opened (step 244) so as to rinse the external surfaces of the cap 100 and internal seal 104, as well as to flush out any remaining chemicals from the CTS flow path, and the valves are closed in sequence, first the inlet valve 24 and then, after sufficient time to allow draining of water from within the flow path, outlet valve 34 (step 246).

[0042] At this point, the dispensing sequence is essentially complete, and the container is ready for removal from the CTS 10. However, for safety reasons, lock mechanism 16 should only be released when the user is ready to hold the container and remove it from the container-mounting interface 12. Accordingly, at step 248, the system preferably provides a user prompt, such as via user interface 60, requiring the user to confirm when ready to remove the container. Once confirmed, the lock mechanism 16 is actuated to release the container (step 250), thereby allowing the user to remove the container (step 252) for transfer to storage (step 254) or for disposal (step 256), according to whether the container was partially or fully discharged.System priming and precision measurement

[0043] One aspect of the present invention relates to how to achieve precision measurement. The requirements of a CTS system require that the composition to be dispensed is flushed out of the system at the end of the dispensing sequence. This presents a challenge for precise metering due to the dead space between the container and the metering arrangement. According to one aspect of the present invention, this issue is addressed by priming (i.e., at least partially filling) the volume between the inner seal of the container and the metering arrangement with water prior to dispensing, thereby achieving a pre-defined and known airspace volume, which is filled by the material to be dispensed before any flow volume is measured by the flow meter. This known airspace volume is then added as an offset to the amount measured by the flow sensor, i.e., that the flow sensor measures the desired amount to be dispenses less the airspace volume offset. Despite the fact that the measured quantity includes in part water that is introduced during this priming process, the total amount of material which has been delivered from the storage container corresponds accurately to the desired quantity. Once the correct quantity has been measured, the container is resealed. (Most preferably, this is done by closing an outlet valve to stop flow, and then closing the internal seal of the storage container, since the container closure process is preferably performed slowly. The outlet valve is then reopened for flushing of the system.) The subsequent rinsing and flushing process then carries all of the chemical that was in the dead space into the destination container. As a result, although the liquid measured by the metering arrangement was in part water, the exact desired quantity of the dispensed composition is correctly delivered.

[0044] Closure of outlet valve 34 once the calculated amount of material has passed through the flow meter also enhances precision of measurement, since it prevents further liquid passing through the flow meter and being "counted" as dispensed material when, in fact, it may be passage of material in the dead space which is being replaced by air from the one-way air inlet valve without further material being dispensed from the container. This lack of clarity is avoided by closing outlet valve 34 once the calculated amount of material has passed through the flow meter, and only reopening it after the internal seal 104 has been reclosed.

[0045] For enhanced precision of the priming process to achieve a precisely defined level of filling and a corresponding well-defined volume of airspace, a liquid / air sensor 40 is preferably deployed in second flow path 28 and configured to provide a signal to the controller indicative of a water level reaching a predefined level corresponding to a known airspace volume. According to a further optional but preferred feature, the flow arrangement may also include a fourth flow path 42 from water inlet 22 via a priming valve 44 to the second flow path 28 for providing water into the second flow path up to a predefined level (typically corresponding to the level sensed by sensor 40), corresponding to a known airspace volume, prior to opening of the internal seal.

[0046] Certain particularly preferred implementations include additional features for enhancing the precision of the metering measurement. According to one example, as discussed further below, a controller of the system may advantageously input information indicative of a viscosity of the hazardous material, and that information may be used to adjust a measurement derived from the metering device. In this case, the viscosity adjustment is most preferably made only after a quantity of liquid has been measured that corresponds to the water which was introduced during the priming process.

[0047] The following aspect describes an alternative for offset correction not covered by the claimed invention. Although priming of the flow path with water is generally preferred, in certain cases, sufficient accuracy may be obtained without such priming, by prior calibration of the empty dead space between the inner seal of the container-mounting interface and the flow meter, and assuming that this entire volume will be filled by the material to be dispensed prior to any flow being measured by the flow meter. In this case, this entire dead space becomes the offset correction.

[0048] An additional, or alternative, accuracy enhancement relates to preemptive closing of the flow path when approaching the desired quantity for dispensing. Specifically, an outlet control valve or, where no such valve is used, the process of closure of the internal seal of the storage container, takes a certain amount of time until the flow path is closed. An amount of flow that occurs during the response time of the outlet valve, or during the time taken to close the internal seal, can be calibrated, and the system controller preferably preemptively triggers the closure process according to the calibration quantity prior to reaching the target quantity.Preferred Exemplary Structural Implementation

[0049] FIGS. 5-17 illustrate various structural features of a particularly-preferred embodiment of closed transfer system 10, some of which have already been discussed above. Thus, as already discussed, CTS 10 includes a container-mounting interface 12 including a seal 14 for sealing against the opening of the storage container 106, a lock mechanism 16 for retaining the storage container engaged with the container-mounting interface, and a robotic manipulator 18 for opening and closing the internal seal 104. A flow arrangement of the CTS includes: a water inlet 22 controlled by an inlet valve 24, a first flow path 26 from the inlet valve to the container-mounting interface 12, and a second flow path 28, 30 controlled by an outlet valve 34 from the container-mounting interface to an outlet 32 to the target container 108.

[0050] A key feature of the closed transfer system (10) is the implementation of the robotic manipulator 18. Specifically, in this case, the robotic manipulator includes a gripper 92, best shown in FIG. 12, configured to engage the internal seal 104 of the storage container. Specifically, gripper 92 preferably has an arrangement of outward-facing teeth 94 that complement corresponding internal features of the internal seal 104, thereby defining an engagement force required to insert gripper 92 into internal seal 104 and engage it, and a disengagement force required to pull back the gripper out of engagement with internal seal 104. The configuration is designed, such as by use of teeth with an inclined upper surface and a near-radial lower surface, to define an engagement force which is smaller than the force required to unseal internal seal 104 from cap 100, thereby allowing gripper 92 to engage internal seal 104 without dislodging it, and only subsequently to continue the motion to open the internal seal. Conversely, the disengagement force is made larger than the force required to reseal internal seal 104 to cap 100, so that retraction of gripper 92 will complete the resealing process of internal seal 104 before the disengagement of gripper 92 from internal seal 104 begins.

[0051] Gripper 92 is displaced by a linear actuator, referred to above with reference to FIG. 10, that includes motor 74 which rotates threaded bolt 76 to displace a carriage 78 which is guided along rods 80. Carriage 78 supports an inner tube 96, which serves as the airflow path, allowing air to reach one-way valves 56 for delivery into the container and / or into the chamber of container-mounting interface 12. Concentrically-external to inner tube 96 is an outer tube 98, to which gripper 92 is mounted. Water flow path 26 for inlet water is supplied to an inlet 26A (FIGS. 16B and 16C) on carriage 78 via a flexible conduit 26B (FIGS. 7 and 8), passes up along the gap between inner tube 96 and outer tube 98, terminating at nozzles 90, through which the water emerges as a directed spray, preferably at different upwards angles from opposite sides of gripper 92 (see FIG. 15B). Gripper 92 also has additional features that facilitate rinsing of the container opening after resealing of the container. Specifically, when the gripper is withdrawn inside the container-mounting interface, instead of generating an outward spray, flushing water passes up external slots 91 and spreads around the upper edge of the gripper, passing inwards and then draining from opening 93 and along slots 95, thereby generating a rinsing flow for the external surface of the internal seal.

[0052] The sequence of operation of the linear actuator and gripper 92 is illustrated in FIGS. 13A-15B. According to a particularly-preferred but non-limiting option, an initial motion of the linear actuator from the state of FIG. 13A to that of FIG. 13B achieves locking of teeth 68 of the lock mechanism, as described earlier. At the end of this motion (FIG. 13B), gripper 92 is still in a pre-engagement position in which teeth 94 are not yet inserted into internal seal 104. Further motion of the linear actuator moves gripper 92 to an internal-seal-engagement position (FIG. 13C) in which the gripper engages the internal seal without unseating the seal, and then further motion brings it to an unsealed position (FIG. 14) in which the internal seal is unseated from the opening of the storage container. Although the container is at this stage unsealed, there is typically only a small clearance between gripper 92 and the opening. In order to facilitate dispensing, the linear actuator preferably moves gripper 92 further, from the unsealed position to a clearance position (FIG. 15A), in which the internal seal 104 is lifted away from the opening of the storage container to facilitate flow of the hazardous material through the opening of the storage container into the flow arrangement. Most preferably, the entire gripper 92 is raised to a level above the container opening, leaving a relatively larger flow path between the opening and outer tube 98. Optionally, and in cases where it is helpful to the efficiency of rinsing, the linear actuator may further raise gripper 92 for at least part of a rinsing process (FIG. 15B) to as to adjust the height of nozzles 90 and / or may vary the height of the nozzles during the rinsing process.

[0053] The internal seal resealing process and subsequent release of the container are preferably actuated by a reverse motion of the linear actuator, performing the inverse of the process described above. Due to the balance of engagement / disengagement forces described above, the opening movement reliably performs engagement followed by opening of the seal, while the return motion reliably performs resealing followed by disengagement.

[0054] The following described details relating to specific motion control parameters are not covered by the claimed invention. The motion of the linear actuator, as controlled by controller 36, is preferably at a non-uniform speed. Specifically, the linear actuator preferably displaces gripper 92 at a velocity no greater than a first velocity, typically in the region of a few millimeters per second, from the pre-engagement position through the internal-seal-engagement position to the unsealed position, since it is important to avoid giving any sudden impact to the internal seal which might dislodge it in an uncontrolled manner. On the other hand, the subsequent motion from the unsealed position to the clearance position is preferably performed at a significantly higher second velocity, which is preferably at least twice the first velocity, and typically at least 5 times greater. This significantly reduces the waiting time for the user during the dispensing process. The motion for locking and unlocking engagement of the container to the CTS is also preferably performed at the second velocity (rapidly).Components and Sensors

[0055] Various motions required for the CTS dispensing and for rinsing are automated, preferably using electro-mechanical components or water pressure-driven components. Certain particularly preferred implementations employ one or more step motors, thereby allowing accurate control of position, speed and / or acceleration.

[0056] One example of this is control of the process of opening and closing the inner seal (plug), where force and accelerations should be within predefined ranges. Optionally, the speed of motion may vary during the motion, typically slowing towards the end of the closing motion.

[0057] The following describes various rinsing features and implementations not covered by the claimed invention. In the case of complete emptying of a container, CTS protocols require rinsing of the container, which is performed by a rinsing head which is extended into the container. The motion is controlled by a suitable actuator, preferably a step motor, and preferably allows extending the rinsing heads to different levels (heights) according to the size and / or type of container. The size and type of container may be known to the system from data received from the operator, or data automatically acquired (as discussed further below), allowing automatic setting of the rinsing head height, and optionally other rinse cycle parameters so as to optimize the rinsing for the container and contents type (e.g., longer rinse process for more viscous compositions). Alternatively, or additionally, mechanical or other sensors may determine the relevant dimensions of the container to set the rinsing height. Optionally, the rinse cycle for some or all container types may include continued rinsing during at least part of the closing process, potentially shortening the cycle time and / or helping in the process of rinsing the internal stopper (also referred to as the internal seal or plug). The rinse sequence may optionally include a plurality of short cycles of raising the rinsing head with stops between them, which may contribute to cleaning efficiency, allowing fresh water to be introduced at the beginning of each cycle and allowing the system to clear the rinse volume between cycles. Optionally, the mechanical interface for engaging and locking the mouth of the container may be configured to allow rotation of the container during rinsing in order to further enhance the rinsing process, powered by a suitable powered actuator operating in coordination with the rinsing mechanism. The rinsing nozzle angle is preferably different on each side of the rinsing head to allow better flushing capability if needed as the container is rotated. In certain embodiments, the container is rotated manually during the rinsing process, typically according to instructions provided by the system to the user. Rotation of the container is performed while the container remains sealed and attached to the container-mounting interface. In certain alternative embodiments (not illustrated), a rotation mechanism may be provided to rotate the container automatically during rinsing.

[0058] Precision of control over the axial motion of the opening mechanism and the rinsing mechanism (which may move together) is preferably achieved by use of a linear encoder arrangement, or in some cases, specifically-positioned sensors, such as magnetic sensors, microswitches or optical sensors, deployed along the shaft or otherwise associated with the axis of motion. Even where step motors are used to provide accurate control of the motion, one or more position sensors 99A, 99B, 99C (FIG. 16A) are preferably provided to ensure correct positioning for certain functions and / or to allow an accurate reset of the system. One such sensor may provide verification that the opening and resealing mechanism has completed its resealing action as a condition for allowing release of the container.

[0059] A further class of sensors that are preferably employed in the metered CTS are sensors for determining the presence of liquid or air at one or more location in the system, such as sensor 40, referred to above. These sensors may be referred to interchangeably as liquid sensors or air sensors, or as liquid / air sensors, typically depending on the context.

[0060] Various types of sensors for this purpose are known, and may be selected from commercially available products. Examples of suitable technologies for such sensors include, but are not limited to, capacitive / electrostatic sensors and conduction sensors.

[0061] Locations at which such sensors may be deployed to advantage include any or all of the following: As described above, for enhanced precision of a priming process to achieve a precisely defined level of filling and a corresponding well-defined volume of airspace, liquid / air sensor 40 may be deployed in second flow path 28 and configured to provide a signal to the controller indicative of a water level reaching a predefined level corresponding to a known airspace volume, thereby allowing the controller 36 to perform precise priming of the flow path and thereby to know how much material egresses from the storage container when the internal seal is opened before flow is allowed through the flow meter. The same sensor, and / or an additional sensor, preferably warns of a lack of liquid during dispensing, that may be due to running out of the container contents, either when intentionally operating in a "full drain" mode, or if the container contents are insufficient to fulfill the desired dispensing quantity. Where sensor 40 is used to determine a water level during priming, the contents-finished sensing is most preferably performed at the same level, thereby making the measurement of the flow meter as accurate an indication as possible of the quantity of material dispensed from the storage container. In some cases, particularly where the material dispensed has high viscosity, a sensor designed for high sensitivity to the presence of water may not indicate a lack of liquid when the contents are finished, due to a layer of the viscous material which remains on the sensor. In such a scenario in which a single sensor cannot be relied upon to provide a prompt and reliable indication of the presence or absence of liquid under all required working conditions, a pair of sensors (or a single two-level sensor) may be used, with one of the sensors designed and / or set to distinguish between the flow path being full of liquid as opposed to being largely filled with air, even if the walls of the conduit and surfaces of the sensor are still coated with a viscous material. The two sensors may employ the same sensing technology, but designed or set to different levels of sensitivity, or they may employ two distinct technologies, such as an electrostatic / capacitive sensor and an ultrasound sensor. A liquid sensor can also be employed to detect various error conditions. Of particular importance, according to a further aspect of the present invention, liquid sensor 40 or another liquid sensor can be used to detect failure of the system to reseal internal seal 104 at the end of metered dispensing. Specifically, after the calculated quantity has been measured by the flow meter 20 and controller 36 has actuated robotic manipulator 18 to reseal internal seal 104, controller 36 preferably opens outlet valve 34 for a few seconds, which allows the liquid to start to drain through the system, drawn by the outlet suction, and being replaced by air which enters through the one-way valve 56, before reclosing the outlet valve. Under normal operating conditions, this should be sufficient for the liquid level to fall below the liquid sensor, thereby verifying that no further liquid is being released from the storage container. In the event that liquid is still present at the liquid sensor, the above test procedure is preferably repeated. If after a further opening of the outlet valve the liquid level has still not dropped, the control system will generate a warning of suspected failure to reseal the storage container. (A similar error condition might also result from a lack of suction at the system outlet, but this would preferably be identified by an earlier test, typically by monitoring the system pressure during initial flushing of the system, performed prior to opening the internal seal.) The presence of a liquid sensor also helps to ensure that the flow metering arrangement only measures flow of liquid and not of air.

[0062] As mentioned above, the system preferably includes at least one pressure sensor 46 deployed to monitor the pressure in the flow path before and / or after the container. This is an important contribution to safety, allowing prompt identification of the potentially dangerous condition of significant pressure rise in the container. In the case of an extreme increase in pressure, such as if a blockage occurs in the outlet pipe while the rinsing system is operating, operation of the system may be interrupted until the fault is corrected. The system preferably also prevents release of a container while the pressure within the CTS is above atmospheric pressure. The ability to monitor the pressure and maintain it within safe levels also allows for safe operation at somewhat raised pressures, thereby allowing use of faster water flow for rinsing, thereby shortening cycle time. The inlet pressure is preferably set according to predefined system requirements to ensure a suitable water supply pressure for efficient operation. If necessary, a pressure-regulating valve may be provided to ensure that maximum permitted pressure is not exceeded.

[0063] The presence of pressure sensor 46 together with together with sensing of liquid by liquid sensor 40, in timed relation to operation of the inlet valve 24 (and / or priming valve 44) and the outlet valve 34, allow the controller 36 to identify one or more of a wide range of error conditions preferably including: a flow blockage (pressure rising on introduction of water); a failure of the internal seal to reseal (detailed above); a failure of the inlet valve (lack of pressure increase and / or no sensing of water); a failure of the outlet valve (incomplete stop of flow meter); an inlet water pressure above a maximum permitted inlet pressure; a lack of inlet pressure; and a lack of outlet suction.

[0064] Another sensor employed in certain preferred implementations of the present invention is a sensor to ensure that a container is correctly positioned and engaged with the CTS before operation. Suitable types of sensors include mechanical, magnetic and / or optical sensors. Correct positioning and engagement of the container is critical in order to avoid release of the container during the process of opening the internal seal, which might expose the operator to the hazardous chemical composition within the container. The output from this sensor can also be used to warn if the container is not promptly removed from the system at the end of the dispensing process. One particularly preferred implementation of a container-seating sensor was described above with reference to FIGS. 11B and 11C.

[0065] A controller preferably controls operation of the inlet / rinsing valve to vary parameters of the rinsing according to information about the composition in the container, its viscosity and temperature, as well as parameters about the container size and / or type. This ensures efficient rinsing of the container, in compliance with the relevant standards while avoiding unnecessary water wastage and delay.Modes of Operation

[0066] As discussed above, the system preferably operates according to inputs from the operator and / or the available quantity of composition in the container in either of two operating modes: Full emptying, in which the container is completely emptied and, after emptying, is rinsed with water.

[0067] Partial emptying, in which a desired quantity of the composition is dispensed and the container is then resealed and the coupling region rinsed before releasing it for use at a later time.

[0068] Both processes are carried out precisely and with full control of the amount of liquid that is dispensed, which is always measured. Precise metering of the dispensed quantity of the composition in many cases allows the system to predict when a residual quantity of the composition is left in the container, and the container should be closed at the end of the dispensing process, or when it is reaching empty and the rinsing process should be initiated. Additionally, or alternatively, an air sensor in the coupling region provides an indication when the container contents have been exhausted and rinsing should be initiated, preferably followed by an output to instruct the user to mount a further container of the same composition if the required quantity has not yet been dispensed. An air / fluid sensor in this location is also helpful in determining the state of the system at various stages when the container is closed, such as to verify that a prefill process has been successful and / or that there is sufficient suction at the outlet to draw air in through the one-way valve and drain fluid from the system.

[0069] The ability to operate in both of the above modes is of high value, since rinsing of an empty container is typically required by standards of CTS, but the ability to dispense quantities smaller than the contents of a single container ("partial dosing") provides the flexibility desired by farmers to prepare the quantities, concentrations and combinations of substances suitable for their particular application.Pressure Management

[0070] The pressure within the process line is preferably maintained within a predefined range during all stages of the system operation, and preferably monitored by at least one pressure sensor, as described above. The pressure inside the container should not drop significantly below atmospheric pressure during the emptying process in order to avoid partial vacuum (or "underpressure") which could cause collapse of the walls of thin-walled containers. For this purpose, at least one one-way valve is preferably deployed to allow ingress of air at low pressure differential while preventing escape of liquid. One preferred but non-limiting example of a suitable one-way valve is a low-pressure silicone valve.Process Control

[0071] The system preferably employs control logic to coordinate operation of all of the various system components in response to sensor inputs and requested metering information, and preferably also to avoid operator errors and / or prevent improper operation during execution of emptying processes, dosing, attachment and release of the container. Each step in the process is preferably controlled by a central controller with a user interface which displays in real time the steps and operating instructions.

[0072] It is particularly valuable according to certain implementations of the present invention that the system identifies and either generates a warning or prevents execution of dosing instructions that lie outside normal ranges for a concentration of a particular composition, thereby minimizing risks of dangerous dosing of hazardous materials due to operator errors.

[0073] The system preferably includes a locking mechanism to prevent disconnection of a container during operation of the system, and preferably includes additional safety features according to which the controller does not release the locking mechanism until the water inlet valve is closed and preferably additionally until water has stopped draining from the container. Release of the container preferably additionally requires a user input confirming that the operator is ready to remove the container. A sensor is preferably deployed to verify whether the container is correctly attached prior to actuation of the locking mechanism, and to detect when the container has been detached. Most preferably, a locking mechanism preventing removal of the container remains locked if power is cut off to the system, and can only be released when the system is powered and the operator actuates unlocking.

[0074] Flushing the system is controlled by the control system according to the various parameters and variables mentioned above.

[0075] Most preferably, the control system obtains data regarding the type of composition being dispensed, and adjusts the operating parameters accordingly. Data regarding the composition may be acquired automatically, for example by reading a barcode or RFID associated with the container, either using a reader or sensor integrated into the CTS dispenser or through a separate mobile electronic device (e.g., cellular telephone, tablet or other device) operating under control of suitable software (e.g., a cellular telephone APP) which is in data communication with the system, such as via short-range wireless communications connection (e.g., Bluetooth or Wi-Fi). Optionally, the system may communicate with the RFID, again either directly or via an associated mobile electronic device, so as to update information stored in the RFID to reflect the current contents of the container remaining after dispensing, to be read at the beginning of the next dispensing sequence. Alternatively, a replacement, or supplementary, barcode may be printed carrying information about the remaining contents, for adhering over, or next to, the original barcode, respectively.

[0076] Alternatively, or additionally, data may be provided via a user input interface, such as a keyboard or touch screen. The various operating parameters of the system are then preferably adjusted according to the properties of the composition being dispensed. Parameters to be adjusted typically include one or more of cycle times, rinsing times, rinsing height, and container closing speed. Additionally, or alternatively, data regarding the composition being dispensed is preferably used to enhance precision of dosing measurement taking into account the viscosity parameters and properties of the material. Most preferably, this precision enhancement may also take into consideration the output of a temperature sensor, with the temperature used to further refine the viscosity information, for example, by use of look-up tables or a formula for the variation of viscosity with temperature for a given composition.

[0077] The control system preferably also allows predefining a required mixture of two or more compositions dispensed from different containers. The system then instructs the operator and / or directly keeps track of which container having which composition is attached to the system and dispenses the corresponding required quantity of that composition, completes the reclosing or rinsing process, and then instructs the operator to remove the first container and mount the next container. Each dispensing process is performed according to the required parameters for that composition.

[0078] In certain cases, the system may be used for dispensing non-liquid compositions. In that case, water is typically mixed into a dry powder using a process similar to the rinsing process, and the resultant liquid is dispensed.

[0079] Data indicative of the composition being dispensed can advantageously also be retained, shared via a communications interface 63 (FIG. 3A) to a remote data storage system, and used to fulfil various record keeping and statutory reporting requirements as to the type and quantities of compositions used. This is particularly valuable in the case of automatic identification of the composition by reading of a barcode, RFID or other information physically associated with the container, since the information is recorded essentially free from operator error. Additionally, or alternatively, the data can be integrated with various agricultural planning programs (typically software running on a suitable computer, all as known in the art) which may be used to generate a recommended regimen of spraying treatments, load the dosing requirements directly to the system, and monitor whether the regimen has been correctly and fully executed. Any and all of the above may be implemented as, or integrated with, a spray control computer that is part of a crop sprayer.Manual Override

[0080] As discussed earlier, CTS 10 has various safety features which, in case of various error conditions, may interrupt operation of the system. Examples of such situations may include loss of electrical power or failure of the motor.

[0081] For such cases, the present invention preferably provides a manual override capability, which would allow the user to drain the system in a controlled manner and / or reseal and release the container. Specifically, and particularly in view of the fact that the entire closure motion and release motion is driven by rotation of a single threaded bolt 76, an override mechanism can conveniently be implemented by providing a manual handle (not shown), accessible on opening of a panel in the housing, that can be engaged in a socket mechanically linked to bolt 76 so that turning the handle manually rotates the bolt, allowing sequential resealing of internal seal 104, disengagement of gripper 92 from the internal seal, withdrawal of the gripper, and finally, release of the container. Depending on the circumstances, an emergency drain opening may also be used to manually drain any liquid that is currently in the flow path.Flow-Metering Arrangements

[0082] The following describes various exemplary flow metering arrangements not covered by the claimed invention. The present invention includes a number of different embodiments differing in the implementation of the flow-metering arrangement. In a first set of embodiments, metering is performed by a flow meter deployed in the flow path from the container to an outlet of the system (to a spray tank). The flow meter may be an impeller-based flow meter. Although impellers tend to lose accuracy at very slow flow rates, this is typically not problematic, since the CTS can operate well with rapid switching on and off of relatively high flow rates. More challenging is the high dependence of an impeller flow meter on viscosity of the composition. This effect can largely be compensated by determining the viscosity of the composition, such as by identifying the composition and retrieving values from a look-up table, all as discussed above. It is noted that the liquid passing initially through the flow meter is typically water from the dead space between the container opening and the flow meter, as discussed above. However, that volume is generally constant, allowing introduction of the viscosity correction at the transition from water to the dispensed composition. Another suitable technology for the flow meter is an ultrasound flow meter, which may be of any of the commercially-available types.

[0083] In alternatively implementations, a volumetric flow meter can be used to largely eliminate the aforementioned limitations of measurement at low flow rates and / or dependence on viscosity. A volumetric flow meter is a flow meter in which each rotation of a rotor (or cycle of motion of a non-rotary meter) corresponds to a defined volume of flow, substantially independent of the flow rate and viscosity. Examples of such flow meters include but are not limited to oval gear flow meters. Such flow meters typically generate a signal as an impeller turns due to a magnet in the impeller. Enhanced precision of measurement at low flow rates can be achieved by including one or more additional magnet on the hub of the impeller, with a corresponding magnetic sensor.

[0084] In all of the above examples, the flow meter is driven by the liquid flow, and the liquid flow itself is generated in some other manner. In the examples illustrated here, a venturi arrangement through which a bypass water flow line passes generates suction which draws the liquid from the container and through the flow meter, as illustrated in FIG. 3.

[0085] The following describes an alternative embodiment not covered by the claimed invention. FIG. 18 illustrates schematically a further set of embodiments in which the metering arrangement is implemented as a positive displacement pump, also referred to as a volumetric pump. Examples of such a pump include, but are not limited to, a bidirectional piston pump. In this set of embodiments, the pump functions both to generate displacement of the composition and to measure the quantity displaced, since each stroke or cycle of motion displaces a predefined volume of liquid.

[0086] Thus, FIG. 18 shows schematically a further embodiment of a closed transfer system, generally designated 300, constructed and operative according to an embodiment of the present invention, for dispensing a metered quantity of a hazardous material from a storage container 106 for dilution with water in a target container 108. As in the earlier embodiments, the CTS 300 includes a container-mounting interface 12 including a seal 14 for sealing against the opening of the storage container, and a lock 16 for retaining the storage container engaged with the interface, as well as a robotic manipulator 18 for opening and closing the internal seal, all as detailed in FIG. 3B, and in the subsequent description above. CTS 300 differs from CTS 10 primarily in that it employs a positive displacement pump 302. The flow arrangement includes: a water inlet 22 controlled by an inlet valve 24, a first flow path 26 from inlet valve 24 to the container-mounting interface 12, a second flow path 28 from the container-mounting interface 12 to the positive displacement pump 302, and a third flow path 30 from positive displacement pump 302 to an outlet 32 to the target container. A controller 36, including at least one processor 38, associated with the robotic manipulator, the inlet valve and the positive displacement pump, is configured: (i) to ascertain a quantity of a hazardous material to be dispensed; (ii) while a storage container containing the hazardous material is locked in engagement with the interface, to actuate the robotic manipulator to open the internal seal; (iii) to dispense a metered quantity of liquid as measured by the positive displacement pump; (iv) to actuate the robotic manipulator to close the internal seal; and (v) to open the inlet valve and generate a flow of water from the water inlet through the positive displacement pump to the outlet, thereby flushing the hazardous material from the flow arrangement.

[0087] Other than this functionality, the other structural and functional features of CTS 300 are generally analogous to those of CTS 10, and will be clear to a person ordinarily skilled in the art on the basis of the above description.

[0088] It will be appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.

Claims

1. A closed transfer system (10) for dispensing a metered quantity of a hazardous material from a storage container (106) for dilution with water in a target container (108), the storage container (106) having an opening with an internal seal (104), the closed transfer system (10) comprising: (a) a container-mounting interface (12) including a seal (14) for sealing against the opening of the storage container (106) and a lock (16) for retaining the storage container (106) engaged with said interface (12); (b) a metering device (20) for metering a flow of liquid; and (c) a flow arrangement including: a water inlet (22) controlled by an inlet valve (24), a first flow path (26) from said inlet valve (24) to said container-mounting interface (12), and a second flow path (28) from said container-mounting interface (12) to said metering device (20), characterized in that said flow arrangement further includes a third flow path (30) from said metering device (20) to an outlet (32) to the target container (108), said third flow path (30) controlled by an outlet valve (34), and in that the closed transfer system further (10) comprises: (d) a robotic manipulator (18) for opening and closing the internal seal (104); and (e) a controller (36) comprising at least one processor (38), said controller (36) associated with said robotic manipulator (18), said inlet valve (24), said outlet valve (34) and said metering device (20), said controller (36) configured: (i) to ascertain a quantity of a hazardous material to be dispensed; (ii) while a storage container (106) containing the hazardous material is locked in engagement with said interface (12), to actuate said robotic manipulator (18) to open the internal seal (104); (iii) to open said outlet valve (34) and dispense a metered quantity of liquid as measured by said metering device (20), and then to close said outlet valve (34); (iv) to actuate said robotic manipulator (18) to close the internal seal (104); and (v) to open said inlet valve (24) and said outlet valve (34) to allow a flow of water from said water inlet (22) to said outlet (34), thereby flushing the hazardous material from said flow arrangement.

2. The closed transfer system (10) of claim 1, wherein said controller (36) is configured to dispense a metered quantity of liquid corresponding to said quantity of the hazardous material to be dispensed less an offset volume corresponding to an airspace volume present when the internal seal (104) is opened.

3. The closed transfer system (10) of claim 2, further comprising a liquid sensor (40) deployed in said second flow path (28) and configured to provide a signal to said controller (36) indicative of a water level reaching a predefined level corresponding to a known airspace volume.

4. The closed transfer system (10) of claim 3, wherein said flow arrangement further comprises a fourth flow path (42) from a priming valve (44) to said second flow path (28) for providing water into said second flow path (28) up to a predefined level corresponding to a known airspace volume prior to opening of the internal seal (104).

5. The closed transfer system (10) of claim 3, wherein said controller (36) is further responsive, during dispensing of the hazardous material, to a signal from said liquid sensor (40) indicative of a lack of presence of liquid to determine an empty state of the storage container (106).

6. The closed transfer system (10) of claim 5, further comprising a supplementary high-sensitivity liquid sensor deployed for sensing a partial lack of liquid so as to determine an empty state of the storage container (106) when dispensing high-viscosity hazardous materials.

7. The closed transfer system (10) of claim 1, wherein said controller (36) is further configured, prior to opening the internal seal (104), to open said inlet valve (24) and said outlet valve (34) so as to rinse an external surface of the opening of the storage container (106) and of the internal seal (104).

8. The closed transfer system (10) of claim 1, further comprising a pressure sensor (46) associated with said controller (36) and deployed to sense a pressure within said flow arrangement, said controller (36) being responsive to sensing of a pressure above a threshold pressure value to interrupt operation of the closed transfer system (10).

9. The closed transfer system (10) of claim 3, further comprising a pressure sensor (46) associated with said controller (36) and deployed to sense a pressure within said flow arrangement, wherein said controller (36) is further responsive to variations in pressure within said flow arrangement and sensing of liquid by said liquid sensor (40), in timed relation to operation of said inlet valve (24) and said outlet valve (34), to identify at least one error condition selected from the group consisting of: a flow blockage; a failure of the internal seal (104) to reseal; a failure of said inlet valve (24); a failure of said outlet valve (34); an inlet water pressure above a maximum permitted inlet pressure; a lack of inlet pressure; and a lack of outlet suction.

10. The closed transfer system (10) of claim 1, wherein said controller (36) is further configured to input information indicative of a viscosity of the hazardous material, said information being used to adjust a measurement derived from said metering device (20), and wherein, optionally, the closed transfer system (10) further comprises: (a) a user interface panel (60) associated with said controller (36), and wherein said information indicative of a viscosity of the hazardous material includes information input by a user via said user interface panel (60); or (b) a wireless communications interface, and wherein said information indicative of a viscosity of the hazardous material includes information received via said wireless communications interface; or (c) a reader (62) for reading information associated with the storage container (106), said reader (62) being associated with said controller (36), and wherein said information indicative of a viscosity of the hazardous material includes information derived by said reader (62); or (d) a temperature sensor (50) associated with said controller (36) and deployed to sense a temperature within the closed transfer system (10), said temperature being used together with said information to estimate a viscosity of the hazardous material.

11. The closed transfer system (10) of claim 1, wherein said first flow path (26) from said inlet valve (24) to said container-mounting interface (12) terminates at a nozzle (90) associated with said robotic manipulator (18) so as to be displaceable into an internal volume of the storage container (106), and wherein said controller (36) is further selectively operable in a contents-draining mode wherein said controller (36) is configured: (a) while the storage container (106) is locked in engagement with said interface (12) with the internal seal (104) closed, to actuate said robotic manipulator (18) to open the internal seal (104); (b) to open said outlet valve (34) and dispense the entire content of the storage container (106); (c) to open said inlet valve (24) to deliver water via said nozzle (90) so as to rinse an internal surface of the storage container (106); (d) to close said inlet valve (24) and wait for the water to drain from the storage container (106); (e) to actuate said robotic manipulator (18) to close the internal seal (18); and (f) to open said inlet valve (24) and said outlet valve (34) to allow a flow of water from said water inlet (22) to said outlet (32), thereby flushing liquid within said second flow path (28) out through said outlet (32).

12. The closed transfer system (10) of claim 11, wherein said controller (36) is further configured to input information indicative of a viscosity of the hazardous material, said information being used to vary at least one parameter of a rinse sequence implemented by said controller (36), said at least one parameter being selected from the group consisting of: a pulse sequence of a rinse cycle; a rinse cycle duration; and a number of repetitions of a rinse cycle.

13. The closed transfer system (10) of claim 11, wherein said controller (36) is further configured to input information indicative of a size of the storage container (106), said information being used to vary at least one parameter of a rinse sequence implemented by said controller (36), said at least one parameter including a displacement distance of said nozzle (90) into the internal volume of the storage container (106).

14. The closed transfer system (10) of claim 1, further comprising a communications interface (63) for connecting said controller (36) via a wide-area network to a remote computing resource, said controller (36) receiving from said remote computing resource a dispensing plan including a quantity to be dispensed for each of a plurality of hazardous materials, and wherein said controller (36) sets a quantity to be dispensed for each hazardous material according to the dispensing plan, and optionally further comprising a reader (62) for reading information associated with the storage container (106), said reader (62) being associated with said controller (36), and wherein said quantity to be dispensed for each hazardous material is determined automatically based on said dispensing plan and said information associated with the storage container (106).

15. The closed transfer system (10) of claim 1, further comprising a communications interface (63) for connecting said controller (36) via a wide-area network to a remote computing resource, said controller (36) sending to said remote computing resource a report of a quantity of each hazardous material dispensed, and optionally further comprising a reader (62) for reading information associated with the storage container (106), said reader (62) being associated with said controller (36), and a type of each hazardous material dispensed is determined automatically based on said information associated with the storage container (106).

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