Pneumatic Control of High-Temperature Molten Liquid Dispensing Systems

Abstract

A system and method for controlling air pressure in a hot molten liquid dispensing system is disclosed. One example of a hot molten liquid dispensing system includes a pump that delivers hot molten liquid to an applicator. The hot molten liquid dispensing system also includes an air flow path that supplies compressed air to the pump and an electronic pressure sensor associated with the air flow path. The hot molten liquid dispensing system also includes a controller that receives an electronic signal from the electronic pressure sensor indicative of the air pressure in the air flow path and causes an adjustment to the air pressure in the air flow path based on the electronic signal from the electronic pressure sensor.

Description

[Background technology]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 62 / 903,575, filed September 20, 2019, which is incorporated by reference in its entirety.

[0002] [Technical field] The present invention relates generally to fluid dispensing, and more particularly to pneumatic control of high temperature melt (hot melt) fluid dispensing systems.

[0003] [background] Hot melt liquid dispensing systems are used in a variety of applications. For example, such systems may apply hot melt adhesives during the manufacture of disposable hygiene products. As another example, hot melt liquid dispensing systems may apply hot melt adhesives to assemble and / or seal various types of packaging, such as paper-based packaging for food and beverages.

[0004] In an exemplary configuration of a hot melt liquid dispensing system, a solid form of hot melt adhesive (or other type of hot melt material) is fed into a melter containing a heated reservoir and / or a heated grid to produce a molten hot melt adhesive. After heating, the molten adhesive may be pumped through a heated hose to an applicator. The applicator includes a valve and a nozzle and is sometimes referred to as a dispensing "gun" or gun module. The applicator then dispenses the molten adhesive, often as a series of dots or lines, onto a desired surface or substrate. In many applications, precise location, timing, and amount of adhesive application are always paramount. For example, dispensing an insufficient amount of adhesive can result in an ineffective bond, while excessive amounts of adhesive not only waste material but can also result in undesirable flow as the adhesive is applied to a surface.

[0005] In some hot molten liquid dispensing systems, the molten adhesive is forced to the applicator via a pump that is activated and / or controlled by a supply of compressed air. Because the pump affects the pressure and rate at which the molten adhesive is delivered to the applicator, it is often beneficial for the pressure of the air supplied to the pump to be carefully controlled. Yet, achieving improved air pressure control in hot molten liquid dispensing systems remains a challenge. For example, systems that rely on manual mechanical adjustments to air pressure can have several drawbacks. For example, such methods can be subject to human error and insufficient operator attention. Operators may make unauthorized changes to air pressure or may be insufficiently trained in the task. Systems that rely on manual mechanical pressure adjustments can also suffer from a lack of repeatability—even the most diligent operator is unlikely to be able to set the air pressure to the same value multiple times with the utmost precision and accuracy. Furthermore, locating a hot molten liquid dispensing system within a production facility can make physical access to the air pressure adjustment mechanism difficult or even dangerous due to the high-temperature parts and materials in the area.

[0006] These and other shortcomings are addressed in the present invention. Summary of the Invention

[0007] Disclosed herein are systems and methods for pneumatic control in a hot molten liquid dispensing system.

[0008] An example of a hot molten liquid dispensing system includes a pump configured to deliver hot molten liquid to an applicator, an air passage configured to supply compressed air to the pump, and an electronic pressure sensor associated with the air passage, and a controller configured to receive an electronic signal from the electronic pressure sensor indicative of air pressure in the air passage and cause an adjustment to the air pressure in the air passage based on the electronic signal from the electronic pressure sensor.

[0009] In one example method for controlling air pressure in a hot molten liquid dispensing system, an electronic signal is received from an electronic pressure sensor associated with an air flow path configured to supply compressed air to a pump of the hot molten liquid dispensing system, the electronic signal is indicative of air pressure within the air flow path, and an adjustment is made to the air pressure within the air flow path based on the electronic signal from the electronic pressure sensor.

[0010] An example controller includes one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the controller to receive an electronic signal from an electronic pressure sensor indicative of an air pressure in an air passage configured to supply compressed air to a pump of a hot molten liquid dispensing system, the instructions, when executed by the one or more processors, further cause the controller to cause an adjustment to the air pressure in the air passage based on the electronic signal from the electronic pressure sensor.

[0011] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments and, together with the following detailed description, serve to explain the principles of the method and system of the present invention. [Brief explanation of the drawings]

[0012] [Figure 1A]FIG. 1A is a perspective view of an adhesive dispensing device according to one embodiment of the present invention.

[0013] [Figure 1B] FIG. 1B is another perspective view of the adhesive dispensing device shown in FIG. 1A.

[0014] [Figure 1C] FIG. 1C is yet another perspective view of the adhesive dispensing device shown in FIG. 1A.

[0015] [Figure 2] FIG. 2 is a cross-sectional view of the adhesive dispensing device shown in FIG. 1A taken along line 2-2 of FIG. 1A.

[0016] [Figure 3] 3 is a cross-sectional view of the adhesive dispensing device shown in FIG. 1A taken along line 3-3 in FIG. 1A.

[0017] [Figure 4] FIG. 4 is another perspective view of the adhesive dispensing device shown in FIG. 1A with some exterior cover portions hidden.

[0018] [Figure 5] FIG. 5 is a schematic diagram of a hot molten liquid dispensing system configuration according to one embodiment of the present invention.

[0019] [Figure 6] FIG. 6 shows a method flowchart according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Aspects of the present invention will now be described in detail with reference to the drawings, in which like reference numerals refer to the same elements throughout unless otherwise specified.

[0021] The systems and methods of the present disclosure relate to pneumatic control in high temperature molten liquid dispensing systems.

[0022] 1A-4, an adhesive dispensing apparatus 10 according to one embodiment of the present invention is illustrated. The adhesive dispensing apparatus 10 includes a melt module 12 and a control module 14 electrically and / or physically coupled to the melt module 12. The melt module 12 is configured to include components related to receiving and melting a solid adhesive, while the control module 14 is configured to include electronic components for controlling the operation of the melt module 12. Each of the melt module 12 and the control module 14 is described in further detail below. Each of the melt module 12 and the control module 14 may be mounted to and supported by a base 18. The base 18 may include a metal body and be configured to releasably couple to each of the melt module 12 and the control module 14, such as via fasteners, which may include bolts, screws, etc. Although the melt module 12 and the control module 14 may alternatively be coupled to the base 18 in other embodiments.

[0023] When the melting module 12 and the control module 14 are coupled to the base 18, a thermal gap 32 may be defined between the melting module 12 and the control module 14. The thermal gap 32 may be configured to minimize and / or substantially eliminate heat transfer from the melting module 12 to the control module 14 to prevent damage to electronic components included in the control module 14 caused by heat generated by the melting module 12. The thermal gap 32 may include the space between the melting module 12 and the control module 14. Furthermore, while no particular type of material or construction is required, it is contemplated that the thermal gap 32 may include materials configured to prevent heat transfer, such as various types of insulation.

[0024] 1C, adhesive dispensing apparatus 10 may define a particular footprint F. The lower end of base 18 may define footprint F, which may be defined as the cross-sectional shape and area defined by the lower end of base 18. Footprint F may additionally or alternatively be defined by the collective lower ends of melt module 12 and control module 14.

[0025] The adhesive dispensing apparatus 10 may include a melt module cover 26 and a control module cover 30 configured to provide selective access to the melt module 12 and the control module 14, respectively. The melt module cover 26 is configured to house components of the melt module 12 and at least partially insulate the melt module 12 from the ambient environment, while the control module cover 30 is configured to house components of the control module 14 and insulate the control module 14 from the melt module 12 and the ambient environment. The control module cover 30 includes a top cover 31 that is separately removable from the remainder of the control module cover 30. The aforementioned thermal gap 32 may be specifically defined between the melt module cover 26 and the control module cover 30.

[0026] The control module 14 may include a controller 36 disposed within the controller housing 15. The controller 36 may include any suitable computing device configured to host software applications for monitoring and controlling various operations of the adhesive dispensing apparatus 10, as described herein. It will be understood that the controller 36 may include any suitable integrated circuit. In particular, the controller 36 may include memory and may be in signal communication with the human-machine interface (HMI) device 34. The memory may be volatile (such as some types of RAM), non-volatile (such as ROM, flash memory, etc.), or a combination thereof. The controller 36 may include additional storage (e.g., removable and / or non-removable storage), including, but not limited to, tape, flash memory, smart cards, CD-ROMs, digital versatile disks (DVDs) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, universal serial bus (USB) compatible memory, or any other medium that can be used to store information and that can be accessed by the controller 36. The memory of the controller 36 may be configured to store and recall on demand various metering operations to be performed by the adhesive dispensing device 10. The control module 14 may further include electrical connections 44 extending through the control module cover 30, which may be configured to establish a connection with an applicator and / or heated hose, transmit electrical power to the applicator and / or heated hose, and exchange communication signals.

[0027] As mentioned above, the control module 14 may include an HMI device 34 in signal communication with the controller 36. In the illustrated embodiment, the HMI device 34 may include a display, such as an OLED screen. However, the HMI device 34 may also include various types of inputs, additionally or alternatively providing the ability to control the controller 36 via, for example, buttons, soft keys, a mouse, voice-activated controls, a touch screen, movement of the controller 36, visual cues (e.g., moving a hand in front of a camera on the controller 36), etc. The HMI device 34 may provide output, including visual information, such as a visual representation of current conditions within the adhesive dispensing apparatus 10, via a graphical user interface, as well as acceptable ranges for these parameters via a display. Other outputs may include audio information (e.g., via a speaker), mechanical information (e.g., via a vibration mechanism), or a combination thereof. In various configurations, the HMI device 34 may include a display, a touch screen, a keyboard, a mouse, a motion detector, a speaker, a microphone, a camera, or any combination thereof. The HMI device 34 may further include any suitable device for inputting biometric information, such as fingerprint information, retinal information, voice information, and / or facial feature information, to require specific biometric information to access the controller 36. In addition to the HMI device 34, the control module 14 may include a pressure dial 40 to easily display pressure readings, such as air pressure readings.

[0028] Additionally, the controller 36 may be in signal communication with a remote device 38 (shown schematically in FIG. 1A ) that is remote from the control module 14. In one embodiment, the remote device 38 may include a display that is remote from the control module 14, such as an OLED display, although various types of conventional displays are contemplated. Alternatively, the remote device 38 may include an external computing device, examples of which may include a processor, a desktop computing device, a server computing device, or a portable computing device such as a laptop, tablet, or smartphone. Thus, the remote device 38 may provide an operator with the ability to interact with and control the controller 36 at a location remote from the adhesive-dispensing apparatus 10. The remote device 38 may be used as part of a cloud control system for the adhesive-dispensing apparatus 10. The remote device 38 may include a PLC (programmable logic controller) or a factory computer.

[0029] The melt module 12 will now be described in more detail. The melt module 12 includes a melter subassembly 75 configured to receive solid or semi-solid pellets of adhesive material, either from manual loading by opening the lid assembly 50 or via an automated loading mechanism. The melter subassembly 75 can heat the pellets to a specific temperature to form a molten adhesive. The melt module 12 can also include a pump 150 configured to pressurize and dispense the molten adhesive to one or more downstream applicators 144 (shown schematically in FIG. 1B). The applicators 144 are also known as dispenser guns. As used herein, the term applicator 144 can refer to an applicator module comprised of a bank of applicators.

[0030] The melt module 12 may include a manifold 140 configured to receive pressurized molten adhesive from a pump 150 and distribute the adhesive to one or more outputs 54 on an exterior portion of the manifold 140. Portions of the manifold 140 and the pump 150 may be integrated into a single structural component (e.g., a manifold block). For example, a fluid chamber 158 portion of the pump 150 may extend into such a common structural component and supply pressurized molten adhesive to the manifold 140 portion. The manifold 140 may be configured with one or more heaters 148 (e.g., heating elements) to maintain adhesive flowing through the manifold 140 at a particular temperature. The heaters 148 may also serve to remelt adhesive material that has cooled within the manifold 140.

[0031] The manifold 140 may include an external manifold cover 142 with an opening for the output 54. The manifold cover 142 may be integral with the manifold 140 or may be separate and attachable and removable. Heated hoses 146 may be attached to the output 54 to receive pressurized molten adhesive from the manifold 140 and convey the adhesive to the applicator 144 for dispensing. The applicator 144 and heated hoses 146 may each be configured with one or more heaters to maintain the adhesive at a particular temperature. The heaters of the applicator 144 and heated hoses 146 may also serve to remelt adhesive material that has cooled within the component. The heaters of the applicator 144 and heated hoses 146, as well as the heater 148 of the manifold 140, may be in signal communication with the controller 36 to send status information (e.g., temperature measurements) to the controller 36 and to receive control signals from the controller 36. When not connected to the applicator 144, each of the multiple outputs 54 may be sealed with a plug.

[0032] The melt module 12 may include a melter subassembly 75 configured to receive solid material and define a receiving space 94 configured to accommodate molten adhesive. An upper wall of the melter subassembly 75 may define an opening 86 communicating with the receiving space 94, such that material may be manually deposited into the receiving space 94 through the opening 86 when the lid assembly 50 is rotated to the open position. However, when the lid assembly 50 is in the closed position, the lid assembly 50 may block the introduction of adhesive through the opening 86 into the receiving space 94. The receiving space 94 may define a specific volume designed for a particular adhesive operation. For example, the receiving space 94 may be configured to receive 4 kg of adhesive, although other sizes are contemplated.

[0033] The melter subassembly 75 may further include a level sensor 98 disposed within the receiving space 94. In particular, the level sensor 98 may be mounted to the interior surface of one of the side walls of the melter subassembly 75 and may be in signal communication with the controller 36 of the control module 14. The level sensor 98 may include a capacitive level sensor, although other types of level sensors are also contemplated. During operation, the level sensor 98 may monitor the level of material within the receiving space 94 and may send a signal to the controller 36 indicative of the adhesive level.

[0034] The melter subassembly 75 may further include a heater 114 configured to melt the adhesive. While depicted as being attached to and extending at least partially through the base of the melter subassembly 75, the heater 114 may alternatively or additionally be attached to any portion of the melter subassembly 75. It will be understood that the heater 114 may include any type of known heating device configured to melt the adhesive within the melter assembly. The melter subassembly 75 may further include a plurality of fins 118 extending upward from the base into the receiving space 94, which may be configured to be heated by the heater 114 to provide an increased surface area for heating and melting the adhesive. While a particular number, arrangement, and configuration of the fins 118 is illustrated, it is contemplated that the fins 118 may be alternatively configured as desired. Additionally, an outlet 122 may be defined within the base and may be in fluid communication with the receiving space 94 and configured to allow molten adhesive to flow through the outlet 122 and exit the receiving space 94. A cage 130 may be positioned adjacent the outlet 122. The cage 130 may be configured to act as a filter to prevent unmelted adhesive particles of a certain size from reaching the outlet 122 and solidifying around it, thereby blocking it.

[0035] A passageway 126 may extend from the outlet 122 to the pump 150 to supply the pump 150 with molten adhesive from the melter subassembly 75. The pump 150 may be a double-acting piston pump, although other types of pumps are contemplated. The pump 150 may be operated in response to a compressed air supply. The pump 150 may operate to discharge molten adhesive from one or more of the outputs 54 via the manifold 140. The pump 150 may be controlled by the controller 36 of the control module 14 to provide a desired flow rate of molten adhesive through the outputs 54. The controller 36 may adjust the air supply (e.g., air pressure) to the pump 150 to at least partially achieve the desired operation of the pump 150.

[0036] With particular reference to FIG. 4, adhesive dispensing apparatus 10 includes a pressure control assembly 159 associated with pneumatic control. FIG. 4 shows a view of adhesive dispensing apparatus 10 with various covers and the like hidden. Pressure control assembly 159 is typically (but not exclusively) housed within space 33 (see FIG. 2) defined between top cover 31 of control module cover 30 and controller housing 15. Pressure control assembly 159 includes regulator 172, pressure control panel 174, manual adjustment mechanism 160, pressure dial 40, and various air lines (e.g., tubing or hoses) and electrical connections. It should be noted that not all electrical connections or air lines are necessarily shown in the drawings, including FIG. 4.

[0037] Generally, regulator 172 may receive compressed air from an external air source via input air line 162. An air filter (not shown) may be attached to the external inlet of input air line 162. The external air source may include a shop air supply. Regulator 172 may adjust the pressure (and / or other parameters) of the unregulated input air supply as needed and output the regulated air supply via air line 164, pressure exhaust valve 170, and air line 166 to pump air valve 168. Pump air valve 168 may initiate activation of pump 150. For example, in the case of a pneumatically operated double-acting piston pump, pump air valve 168 may direct air to either the top or bottom of an associated air cylinder to initiate a piston stroke. Pressure exhaust valve 170 may allow compressed molten adhesive within pump 150 and manifold 140 to bypass and return to melter subassembly 75 when the compressed air supply is removed, such as when pump 150 is stopped.

[0038] As previously mentioned, pressure control assembly 159 (or portions thereof) may generally be configured to control the pressure and / or other parameters of the compressed air supplied to pump 150 to trigger activation of pump 150. Pressure control assembly 159 may be configured for automatic air pressure control via controller 36 and / or remote device 38. Air pressure control may additionally or alternatively be based on user input, such as user input received via HMI device 34 or remote device 38.

[0039] Pressure control assembly 159 may adjust the pressure of the air supply to pump 150 based on pressure sensor readings from one or more pressure sensors disposed in the air supply flow path, such as pressure sensor 180. The one or more pressure sensors may include electronic pressure sensors configured to output an electrical pressure signal (e.g., digital or analog), such as a digital pressure transducer sensor or a pressure-to-current (or voltage) transducer. While connections to the air flow path are not shown in FIG. 4, pressure control board 174 may include, for example, a digital on-board pressure sensor 176. The digital pressure readings may be sent to controller 36, pressure control board 174, and / or regulator 172 for control processing.

[0040] The pressure of the air supply may be controlled based on pressure measurements of the unregulated (e.g., upstream) air supply in the air flow path, such as measurements from a pressure sensor (not shown) in input air line 162 prior to regulator 172. Pressure control may additionally or alternatively be based on pressure measurements in the air flow path downstream of a pressure regulating element (e.g., regulator 172). For example, pressure control may be based on pressure measurements from pressure sensor 180 in air line 164 and / or a pressure sensor (not shown) in air line 166. Downstream and / or upstream air pressure measurements may also be obtained by one or more sensors at or within regulator 172. The downstream pressure measurements may be utilized to establish closed-loop control of the air pressure.

[0041] Regulator 172 may control the pressure of the air supply to pump 150 (e.g., pump air valve 168) via pressure transducer 178. Pressure transducer 178 may be configured to receive an electronic signal (e.g., analog or digital) and provide a proportional (e.g., linear) air pressure output to the air flow path. Pressure transducer 178 may include a current-to-pressure converter, a voltage-to-pressure converter, or similar device that converts an electronic signal to pressure. Although illustrated as part of regulator 172, pressure transducer 178 may generally be located elsewhere within pressure control assembly 159 or adhesive dispensing apparatus 10.

[0042] Regulator 172 may be configured to selectively enable or disable downstream air supply to pump 150. For example, regulator 172 may be configured with a solenoid valve operable to selectively open and close output air flow from regulator 172.

[0043] Pressure control assembly 159 further includes a manual adjustment mechanism 160 and a pressure dial 40. Manual adjustment mechanism 160 provides an alternative method for adjusting the pressure of the air supply to pump 150. An operator may operate manual adjustment mechanism 160 with a hex tool, screwdriver, or the like to make manual adjustments to the air pressure. The operator may observe pressure dial 40 while doing so. However, it should be noted that such manual adjustment methods may present challenges in making accurate, precise, and repeatable adjustments. Physical access to manual adjustment mechanism 160 and / or hazardous exposure to nearby heating components may also hinder such manual pressure control.

[0044] FIG. 5 shows a schematic (block diagram) 500 of an exemplary air pressure control configuration for a hot molten liquid dispensing system (e.g., adhesive dispensing apparatus 10 and / or related systems or devices of FIGS. 1A-4). In the exemplary configuration, a compressed air flow path 520 is provided from an air supply 502 to a pump 510. The air flow path 520 passes through (or is acted upon by) a pressure control assembly 504 (e.g., pressure control assembly 159 of FIG. 4), which controls the pressure of the air flow path 520 to the pump 510. The portion of the air flow path 520 after the pressure control assembly 504 is referred to as the downstream (or regulated) air flow path 520b, and the portion of the air flow path 520 before the pressure control assembly 504 is referred to as the upstream (or unregulated) air flow path 520a.

[0045] An electronic pressure sensor 508 is disposed in downstream air flow path 520b to obtain pressure measurements and transmit those pressure measurements to system controller 512 and / or remote controller 514. System controller 512 and / or remote controller 514 may cause pressure control assembly 504 to adjust the pressure in air flow path 520b based on the downstream pressure measurements from electronic pressure sensor 508. For example, transducer 506 of pressure control assembly 504 may cause adjustments to the air pressure in downstream air flow path 520b, such as based on an electronic signal transmitted to transducer 506.

[0046] Air supply 502 may include a compressed external air source, such as a shop air supply. Air supply 502 may be received via an input air line of the dispensing system. Upstream air flow path 520a may be received by pressure control assembly 504. Pressure control assembly 504 may include a regulator (e.g., regulator 172 of FIG. 4 ) configured to adjust the air pressure in air flow path 520 to achieve a desired air pressure in downstream air flow path 520b. The regulator may include a transducer 506 (e.g., pressure transducer 178 of FIG. 4 ), which may be utilized to adjust the air pressure in air flow path 520. Transducer 506 may be configured to cause air pressure adjustments based on an electronic signal sent to transducer 506, such as from system controller 512, remote controller 514, or another component of pressure control assembly 504. Transducer 506 may include a current-to-pressure converter, a voltage-to-pressure converter, or a similar type of transducer.

[0047] The system controller 512 and / or the remote controller 514 may receive one or more pressure measurements from the electronic pressure sensor 508. The one or more pressure measurements may be received as an electronic signal (analog or digital) generated by the electronic pressure sensor 508. The electronic signal from the electronic pressure sensor 508 may indicate the air pressure in the air flow path 520b. The electronic pressure sensor 508 may have a digital pressure transducer sensor or a pressure-to-current (or voltage) transducer. Based on the air pressure setpoint (e.g., set range) and the one or more pressure measurements from the electronic pressure sensor 508, the system controller 512 and / or the remote controller 514 may determine a pressure adjustment in the incoming upstream air flow path 520a. For example, the current pressure measurement may be compared to the air pressure setpoint or set range and, if necessary, the necessary adjustment may be determined. Other control algorithms or techniques, such as a closed-loop controller (e.g., a PID controller), may also be utilized. The system controller 512 and / or the remote controller 514 may send electronic signals to the pressure control assembly 504 (e.g., the transducer 506) to implement pressure adjustments that preferably bring the air pressure in the downstream air flow path 520b to a pressure setpoint or within a pressure setpoint range.

[0048] The system controller 512 may be integrated with or connected to an adhesive dispensing device of a dispensing system (e.g., controller 36 of FIGS. 2 and 3 ), but is not limited to such. For example, the system controller 512 may comprise a PLC or other computing or logic device at a facility. The remote controller 514 (e.g., remote device 38 of FIG. 1A ) may be located external to the dispensing system. For example, the remote controller 514 may comprise a cloud or server-based controller. The remote controller 514 may comprise a remote personal computing device (e.g., a laptop, tablet, smartphone, or desktop computer) in communication with the dispensing system via a cloud or server system. The remote controller 514 may comprise a PLC or other similar device at a facility. The various control logic, user interface, and other functions described herein may be implemented by either or both the system controller 512 or the remote controller 514, in various combinations and to various degrees.

[0049] The system controller 512 and the remote controller 514 may provide respective user interfaces 526, 527 (e.g., graphical user interfaces) to facilitate interaction between an operator (local or remote) and the dispensing system. For example, the user interfaces may allow the operator to input an air pressure setpoint. By inputting the air pressure setpoint through the user interface, the operator can input the setpoint as a precise numerical value rather than the imprecise trial-and-error method using mechanical adjustment mechanisms and analog pressure dials. As another example, the user interface may display the current air pressure reading to the operator. The user interface may also display one or more past air pressure readings. In this regard, the user interface provides greater accuracy and precision in displaying the current air pressure reading than an analog pressure dial. This advantage is further enhanced by the electronic pressure sensor 508, which provides more accurate and precise pressure measurements than a corresponding analog pressure sensor.

[0050] Furthermore, an interactive user interface on the remote controller 514 (and / or in some configurations the system controller 512) may enable a remote operator to monitor and control the pneumatic parameters (and other system parameters) of the dispensing system. As previously mentioned, it can often be difficult, or even dangerous, for an operator to physically access manual air pressure adjustment mechanisms. Yet, remote control via the system controller 512 and / or the remote controller 514 may largely eliminate these challenges. This configuration may also enable centralized control of multiple dispensing systems so configured. A remote or off-floor operator may simultaneously monitor and control multiple dispensing systems via their respective remote user interfaces, without having to repeatedly move from dispensing system to dispensing system on the production floor.

[0051] Due to the electronic nature of the pressure regulation by the transducer 506 and the pressure measurements from the electronic pressure sensor 508, the system controller 512 and / or remote controller 514 can efficiently create and store a correlation record of such pressure regulation (e.g., electronic control signals to the transducer 506) and measurements (e.g., electronic signals from the electronic pressure sensor 508). A record of the air pressure set points can also be created and stored. Records of the pressure regulation, pressure measurements, and / or pressure set points can be displayed on the user interface of the system controller 512 and / or remote controller 514 for efficient operator review.

[0052] The records may also be used in various types of data analysis and control algorithms. For example, analysis of pressure adjustment records and pressure measurement records may reveal trends in the relationship between pressure adjustments and corresponding pressure measurements. Such trends may indicate system malfunctions, such as loose or leaking air hoses. The records may also be used for quality control purposes. For example, an out-of-specification batch of product may be traced back to an incorrectly entered air pressure setpoint or an out-of-threshold pressure measurement. Furthermore, product quality control indicators may be analyzed using the corresponding pressure setpoint, pressure adjustment, and / or pressure measurement records to identify correlations. For example, particular pressure setpoints that correlate with historically high-quality product batches may be identified and reused for the same or similar operations. As mentioned above, such identified pressure setpoints may be easily entered via a user interface and implemented by the electronically controlled transducer 506. Such records may be implemented as logs 524 and 525 on the system controller 512 and remote controller 514, respectively.

[0053] FIG. 6 illustrates a method flow diagram of a method 600 for pneumatic control in a hot molten liquid dispensing system (“dispensing system”), such as the adhesive dispensing apparatus 10 and related systems and components of FIGS. 1A-4. The method 600 may be performed, at least in part, by a controller associated with the dispensing system. The controller may be a local controller or a remote controller. The dispensing system may include a pump configured to pump hot molten liquid to an applicator associated with the dispensing system. The hot molten liquid may be received from a melter of the dispensing apparatus.

[0054] The dispensing system may include an air flow path configured to supply compressed air to a pump. The air flow path may originate at an input air line that receives air from an external air source, such as a shop air supply. The air flow path may include various air lines in the dispensing system and may terminate at the pump. For example, the air flow path may terminate at an air valve on the pump. The pump may be pneumatically actuated by compressed air from the air flow path.

[0055] The dispensing system may include an electronic pressure sensor associated with the air flow path. The electronic pressure sensor may be configured to measure air pressure in the air flow path. The electronic pressure sensor may be configured to transmit an electronic signal indicative of the measured air pressure in the air flow path. The electronic pressure sensor may include a pressure-to-current converter or a pressure-to-voltage converter. The dispensing system may include a pressure control assembly configured to control the pressure in the air flow path. For example, the pressure control assembly may be configured to increase or decrease the pressure of air in a portion of the air flow path downstream of the pressure control assembly. The pressure control assembly may include a transducer operable to adjust the pressure in the air flow path. The transducer may include a current-to-pressure converter or a voltage-to-pressure converter. The transducer may be operable to adjust the air pressure based on electronic signals transmitted to and received from the transducer.

[0056] In step 602, an air pressure setpoint for an air flow path is received, for example, by a controller of the dispensing system. The pressure setpoint may be received via a user interface associated with the dispensing system. For example, an operator may enter the pressure setpoint into the user interface. The user interface may be local to the dispensing system. Additionally or alternatively, the pressure setpoint may be received from a remote device, such as a remote controller. The pressure setpoint may be received via a user interface of the remote device. The pressure setpoint may include a pressure setpoint range. In some embodiments, the pressure setpoint may already be set or received at the dispensing system, in which case method 600 may begin at step 604.

[0057] In step 604, an electronic signal is received from an electronic pressure sensor associated with the air flow path. The electronic signal may be indicative of the air pressure in the air flow path. The electronic signal may be received, for example, by a controller. The electronic signal may include a current signal or a voltage signal generated based on the pressure on the electronic pressure sensor. The measured air pressure in the air flow path may be displayed to an operator or other party. For example, the air pressure may be displayed on a user interface associated with the dispensing system, including a local or remote user interface.

[0058] In step 606, an adjustment is caused (made) to the air pressure in the air flow path based on the electronic signal from the electronic pressure sensor. The adjustment to the air pressure may additionally or alternatively be based on an air pressure set point. For example, the adjustment may be based on a comparison of the measured air pressure in the air flow path to a pressure set point. Other control techniques, such as closed-loop control (e.g., a PID controller), may also be utilized.

[0059] A transducer of the pressure control assembly may be utilized to adjust the air pressure in the airflow path. The air pressure may be adjusted by sending an electronic control signal to the transducer. The transducer may change the pressure in the airflow path based on the received electronic control signal. The transducer may include a voltage-to-pressure converter or a current-to-pressure converter. Thus, the electronic control signal may include a voltage signal or a current signal. An electronic pressure sensor may be positioned in the airflow path downstream of the transducer. Thus, the air pressure measured by the electronic pressure sensor may be the adjusted airflow (as opposed to the airflow initially received from the external air source).

[0060] The pressure regulation and / or electronic control signal to the transducer may be displayed on a user interface. One or more of the pressure setpoint, the measured air pressure in the air flow path, the electronic signal from the electronic pressure sensor indicative of the measured air pressure, the pressure regulation and / or the electronic control signal to the transducer may be recorded and saved (stored). For example, the controller may record such data in a log kept by the controller. The log may be used for various analyses, such as diagnostics, quality control, and process control analyses.

[0061] Those skilled in the art will appreciate that the systems and methods disclosed herein may be implemented via a computing device that may include, but is not limited to, one or more processors, a system memory, and a system bus that couples various system components, including coupling the processors to the system memory. For example, a computing device (e.g., a controller) may have one or more processors and memory that stores instructions that, when executed by the one or more processors, cause one or more of the various methods and techniques described herein to be performed.

[0062] For purposes of exemplary illustration, application programs and other executable program components, such as operating systems, are illustrated as separate blocks in the accompanying drawings herein. It is recognized, however, that such programs and components reside at various times in different storage components of the computing device and are executed by the computer's data processor(s). An implementation of the service software may be stored on or transmitted via some form of computer-readable media. Any of the disclosed methods may be performed by computer-readable instructions embodied on a computer-readable medium. A computer-readable medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, computer-readable media may include "computer storage media" and "communications media." "Computer storage media" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical storage devices, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium usable to store desired information and accessible by a computer. Application programs, etc., and / or the storage media may be implemented at least in part on a remote system.

[0063] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Numerical ranges may be expressed as from "about" one particular value and / or to "about" another particular value. When a range is expressed in this manner, other embodiments include ranges from the one particular value and / or to the other particular value. Similarly, when a value is expressed as an approximation, by use of "about," it is to be understood that the one particular value also applies in other embodiments. Moreover, it is to be understood that each endpoint of such a range is valid both in relation to the other endpoint, and independently of the other endpoint.

[0064] Unless expressly stated otherwise, it is not intended that any method described herein be understood as requiring that its steps be performed in a particular order. Thus, if a method claim does not actually specify the order in which its steps must be followed, or if the claims or specification do not specifically state that the steps are limited to a particular order, no order is intended to be implied in any way. This applies to any possible implicit basis for interpretation, including matters of logic regarding the arrangement of steps or operational flow, the plain meaning derived from grammar or punctuation, and the number or type of embodiments described herein.

[0065] It will be apparent to those skilled in the art that various modifications and variations can be made without departing from the scope or spirit of the present application. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice disclosed therein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit being indicated by the following claims.

Claims

1. a pump configured to deliver hot molten liquid to the applicator; an air flow path configured to supply compressed air to the pump; an electronic pressure sensor associated with the air flow path; a pressure control assembly including a transducer and configured to control the air pressure in the air flow path supplied to the pump; a pressure relief valve; A controller; Equipped with the transducer is configured to cause an adjustment to the air pressure in the air flow path; the transducer is configured to provide an air pressure output to the air flow path proportional to an electrical signal sent to the transducer; the transducer is configured to output conditioned air to the pump via the air flow path; the transducer includes at least one of a current-to-pressure transducer and a voltage-to-pressure transducer; The controller receiving an electronic signal from the electronic pressure sensor indicative of the air pressure in the air flow path; sending an electrical signal to the pressure control assembly based on the electronic signal from the electronic pressure sensor, thereby causing an adjustment to the air pressure in the air flow path; It is structured as follows: the controller causes an adjustment to the air pressure in the air flow path by sending an electrical signal to the transducer; the electronic pressure sensor is located in the air flow path downstream of the transducer; a regulator of the pressure control assembly configured to regulate the pressure of an unregulated input air supply and output the regulated air supply to the pump via a first air line and a second air line; the first air line is configured to fluidly connect the regulator to the pressure relief valve; The second air line is configured to fluidly connect the regulator to the pump. A high temperature molten liquid dispensing system comprising:

2. the air pressure output to the air flow path is linearly proportional to the electrical signal sent to the transducer; The regulator of the pressure control assembly is configured to output the regulated air supply to a pump air valve via the first air line and the second air line.

10. The hot molten liquid dispensing system of claim 1.

3. The regulator and the converter are each remote from the pump; The pressure relief valve is configured such that when the regulated air supply is removed from the pump, the hot molten liquid in the pump is bypassed and returned to the melter subassembly.

10. The hot molten liquid dispensing system of claim 1.

4. The controller is further configured to store at least one of the air pressure in the air flow path and the adjustment to the air pressure.

10. The hot molten liquid dispensing system of claim 1.

5. The electronic pressure sensor includes at least one of a pressure-to-current converter and a pressure-to-voltage converter.

10. The hot molten liquid dispensing system of claim 1.

6. the controller is further configured to receive an air pressure setpoint; The adjustment to the air pressure in the air flow path is further based on the air pressure setpoint.

10. The hot molten liquid dispensing system of claim 1.

7. the air pressure setpoint is received via a user interface associated with the hot molten liquid dispensing system; The controller is configured to identify correlations by analyzing quality control indicators using the corresponding pressure setpoint records, the corresponding pressure adjustment records, and / or the corresponding pressure measurement records.

7. The hot molten liquid dispensing system of claim 6.

8. The user interface includes a user interface for a remote control device.

8. The hot molten liquid dispensing system of claim 7.

9. The controller is further configured to provide an indication of the air pressure in the air flow path via the user interface.

8. The hot molten liquid dispensing system of claim 7.

10. 1. A method for pneumatic control in a hot molten liquid dispensing system, comprising: receiving an electronic signal from an electronic pressure sensor indicative of air pressure within an air flow path configured to supply compressed air to a pump of the hot molten liquid dispensing system; causing an adjustment to the air pressure in the air flow path by sending an electrical signal to a pressure control assembly including a transducer and configured to control the air pressure in the air flow path supplied to the pump based on the electronic signal from the electronic pressure sensor; Equipped with causing an adjustment to the air pressure in the air flow path includes sending an electrical signal to the transducer; the transducer is configured to cause an adjustment to the air pressure in the air flow path; the transducer providing an air pressure output to the air flow path proportional to an electrical signal sent to the transducer; the transducer outputs conditioned air to the pump via the air flow path; the transducer includes at least one of a current-to-pressure transducer and a voltage-to-pressure transducer; the electronic pressure sensor is located in the air flow path downstream of the transducer; a regulator of the pressure control assembly configured to regulate the pressure of an unregulated input air supply and output the regulated air supply to the pump via a first air line and a second air line; the first air line is configured to fluidly connect the regulator to a pressure relief valve; The second air line is configured to fluidly connect the regulator to the pump. A method characterized by:

11. the air pressure output to the air flow path is linearly proportional to the electrical signal sent to the transducer; the regulator and the converter are each remote from the pump; The pressure relief valve is configured such that when the regulated air supply is removed from the pump, the hot molten liquid in the pump is bypassed and returned to the melter subassembly.

11. The method of claim 10.

12. storing at least one of the air pressure in the air flow path and the adjustment to the air pressure; 11. The method of claim 10, further comprising:

13. receiving an air pressure setpoint; Identifying correlations by analyzing quality control indicators using the corresponding pressure setpoint records, the corresponding pressure adjustment records, and / or the corresponding pressure measurement records; Further provided with The adjustment to the air pressure in the air flow path is further based on the air pressure setpoint.

11. The method of claim 10.

14. The air pressure setpoint is received via a user interface associated with the hot molten liquid dispensing system.

14. The method of claim 13.

15. providing an indication of the air pressure in the air flow path via the user interface.

15. The method of claim 14, further comprising:

16. A pressure relief valve; A controller; 1. A hot molten liquid dispensing system comprising: The controller one or more processors; a memory storing instructions that, when executed by the one or more processors, cause the controller to receive an electronic signal from an electronic pressure sensor indicative of air pressure in an air passage configured to supply compressed air to a pump of a hot molten liquid dispensing system, and cause an adjustment to the air pressure in the air passage based on the electronic signal from the electronic pressure sensor by sending an electrical signal to a pressure control assembly including a transducer and configured to control the air pressure in the air passage supplied to the pump; Equipped with the controller causes the adjustment to the air pressure by sending an electrical signal to the transducer configured to cause the adjustment to the air pressure in the air flow path; the transducer is configured to provide an air pressure output to the air flow path proportional to an electrical signal sent to the transducer; the transducer outputs conditioned air to the pump via the air flow path; the transducer includes at least one of a current-to-pressure transducer and a voltage-to-pressure transducer; the electronic pressure sensor is located in the air flow path downstream of the transducer; a regulator of the pressure control assembly configured to regulate the pressure of an unregulated input air supply and output the regulated air supply to the pump via a first air line and a second air line; the first air line is configured to fluidly connect the regulator to the pressure relief valve; The second air line is configured to fluidly connect the regulator to the pump. A high temperature molten liquid dispensing system comprising:

17. the air pressure output to the air flow path is linearly proportional to the electrical signal sent to the transducer; the regulator and the converter are each remote from the pump; The pressure relief valve is configured such that when the regulated air supply is removed from the pump, the hot molten liquid in the pump is bypassed and returned to the melter subassembly.

17. The hot molten liquid dispensing system of claim 16.

18. The instructions, when executed by the one or more processors, further cause the controller to receive an air pressure setpoint; The adjustment to the air pressure in the air flow path is further based on the air pressure setpoint.

17. The hot molten liquid dispensing system of claim 16.

19. the air pressure setpoint is received via a user interface associated with the hot molten liquid dispensing system; The instructions, when executed by the one or more processors, cause the controller to cause a display of the air pressure in the air flow path via the user interface and identify correlations by analyzing quality control indicators using corresponding pressure setpoint records, corresponding pressure adjustment records, and / or corresponding pressure measurement records.

20. The hot molten liquid dispensing system of claim 18.

Images