Patent Description:
Hot melt liquid dispensing systems find use in a variety of applications. For example, such a system may apply hot melt adhesives during the manufacture of disposable hygiene products. As another example, a hot melt liquid dispensing system may apply hot melt adhesive to assemble and/or seal various types of packaging, such as paper-based packaging for food and beverages.

In an example configuration of a hot melt liquid dispensing system, a solid form of hot melt adhesive (or other type of hot melt material) is supplied to a melter comprising a heated reservoir and/or a heated grid to produce molten hot melt adhesive. After heating, the molten adhesive may be pumped through a heated hose to an applicator, which is sometimes referred to as a dispensing "gun" or a gun module, comprising a valve and a nozzle. The applicator then dispenses the supplied molten adhesive to the desired surface or substrate, often as a series of dots or lines. In many applications, the adhesive should be applied with precise positioning, timing, and volume. For example, an insufficient volume of dispensed adhesive may result in ineffective bonds while an excessive volume of adhesive may result in not only wasted material but also undesirable flow once the adhesive is applied to a surface.

In some hot melt liquid dispensing systems, the molten adhesive is forced to the applicator via a pump that is actuated and/or controlled by a supply of pressurized air. Since the pump affects the pressure and rate at which the molten adhesive is supplied to the applicator, it is often beneficial that the pressure of the air supplied to the pump be carefully controlled. Yet challenges remain in achieving improved air pressure control in hot melt liquid dispensing systems. For example, a system that relies on manual mechanical adjustments to air pressure may have a number of drawbacks. For example, this method may be subject to human error or insufficient operator attention. An operator may make un-authorized changes to the air pressure or may be inadequately trained for the task. A system that relies on manual mechanical pressure adjustments may also suffer from a lack of repeatability - even the most diligent operator is unlikely to be able to set the air pressure at the same value time after time, and with the utmost precision and accuracy. In addition, the position of a hot melt liquid dispensing system within a production facility may make physical access to air pressure adjustment mechanisms difficult or even dangerous due to the high temperature parts and material in the area.

These and other shortcomings are addressed in the present disclosure.

Disclosed herein are system and methods for air pressure control in a hot melt liquid dispensing system.

An example hot melt liquid dispensing system comprises a pump configured to pump hot melt liquid to an applicator. The hot melt liquid dispensing system further comprises an air flow path configured to supply pressurized air to the pump and an electronic pressure sensor associated with the air flow path. The hot melt liquid dispensing system further comprises a controller configured to receive an electronic signal from the electronic pressure sensor indicative of an air pressure in the air flow path and cause adjustment to the air pressure in the air flow path based on the electronic signal from the electronic pressure sensor. The hot melt liquid dispensing system according to the invention is defined in the appended claims <NUM>-<NUM>.

In an example method for air pressure control in a hot melt liquid dispensing system, an electronic signal is received from an electronic pressure sensor associated with an air flow path configured to supply pressurized air to a pump of the hot melt liquid dispensing system. The electronic signal is indicative of an air pressure in the air flow path. An adjustment is caused to the air pressure in the air flow path based on the electronic signal from the electronic pressure sensor. The method according to the invention is defined by the appended claims <NUM>-<NUM>.

An example controller comprises one or more processors and 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 flow path configured to supply pressurized air to a pump of a hot melt liquid dispensing system. The instructions, when executed by the one or more processors, further cause the controller to cause adjustment to the air pressure in the air flow path based on the electronic signal from the electronic pressure sensor.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments and together with the description, serve to explain the principles of the methods and systems:.

Aspects of the disclosure will now be described in detail with reference to the drawings, wherein like reference numbers refer to like elements throughout, unless specified otherwise.

The systems and methods of the present disclosure relate to air pressure control in a hot melt liquid dispensing system.

Referring to <FIG>, an adhesive dispensing device <NUM> in accordance with one embodiment of the invention is shown. The adhesive dispensing device <NUM> includes a melt module <NUM> and a control module <NUM> electrically and/or physically coupled to the melt module <NUM>. The melt module <NUM> is configured to include the components related to receiving solid adhesive and melting the solid adhesive, whereas the control module <NUM> is configured to include the electronic components for controlling operation of the melt module <NUM>, where each of the melt module <NUM> and the control module <NUM> will be described in detail further below. Each of the melt module <NUM> and the control module <NUM> may be mounted to and supported by a base <NUM>. The base <NUM> may comprise a metal body and is configured to releasably couple to each of the melt module <NUM> and the control module <NUM>, such as through fasteners that may comprise bolts, screws, etc., though it is contemplated that the melt module <NUM> and the control module <NUM> may be alternatively coupled to the base <NUM> in other embodiments.

When the melt module <NUM> and the control module <NUM> are coupled to the base <NUM>, a thermal gap <NUM> may be defined between the melt module <NUM> and the control module <NUM>. The thermal gap <NUM> may be configured to minimize and/or substantially eliminate heat transfer from the melt module <NUM> to the control module <NUM> so as to prevent damage to the electronic components contained by the control module <NUM> caused by the heat created by the melt module <NUM>. The thermal gap <NUM> may comprise a space between the melt module <NUM> and the control module <NUM>. Additionally, it is contemplated that the thermal gap <NUM> may further include materials configured to prevent heat transfer, such as various types of insulation, though any specific type of material or structure is not required.

As shown in <FIG>, the adhesive dispensing device <NUM> may define a specific footprint F. The lower end of the base <NUM> may define the footprint F, which may be defined as a cross-sectional shape and area defined by the lower end of the base <NUM>. The footprint F may be additionally or alternatively defined by the collective lower ends of the melt module <NUM> and the control module <NUM>.

The adhesive dispensing device <NUM> may include a melt module cover <NUM> and a control module cover <NUM> configured to provide selective access to the melt module <NUM> and the control module <NUM>, respectively. The melt module cover <NUM> is configured to house the components of the melt module <NUM> and at least partially insulate the melt module <NUM> from the surrounding environment, while the control module cover <NUM> is configured to house the components of the control module <NUM>, as well as insulate the control module <NUM> from the melt module <NUM> and the surrounding environment. The control module cover <NUM> includes a top cover <NUM>, which is separately removable from the other portions of the control module cover <NUM>. The previously-described thermal gap <NUM> may be specifically defined between the melt module cover <NUM> and the control module cover <NUM>.

The control module <NUM> may include a controller <NUM> disposed within a controller housing <NUM>. The controller <NUM> may comprise any suitable computing device configured to host a software application for monitoring and controlling various operations of the adhesive dispensing device <NUM> as described herein. It will be understood that the controller <NUM> may include any appropriate integrated circuit. Specifically, the controller <NUM> may include a memory and be in signal communication with a human-machine interface (HMI) device <NUM>. 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 <NUM> may include additional storage (e.g., removable storage and/or non-removable storage) including, but not limited to, tape, flash memory, smart cards, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, universal serial bus (USB) compatible memory, or any other medium which may be used to store information and which may be accessed by the controller <NUM>. The memory of the controller <NUM> may be configured to store and recall on demand various metering operations to be performed by the adhesive dispensing device <NUM>. The control module <NUM> may further include electrical connections <NUM> extending through the control module cover <NUM>, which may be configured to establish a connection with an applicator and/or heated hose so as to transmit power to the applicator and/or hosed hose and exchange communication signals.

As noted above, the control module <NUM> may include an HMI device <NUM> in signal communication with the controller <NUM>. In the depicted embodiment, the HMI device <NUM> may include a display, such as an OLED screen. However, it is contemplated that the HMI device <NUM> may also include, in addition or alternatively, various types of inputs that provide the ability to control the controller <NUM>, via, for example, buttons, soft keys, a mouse, voice actuated controls, a touch screen, movement of the controller <NUM>, visual cues (e.g., moving a hand in front of a camera on the controller <NUM>), or the like. The HMI device <NUM> may provide outputs via a graphical user interface, including visual information, such as the visual indication of the current conditions within the adhesive dispensing device <NUM>, as well as acceptable ranges for these parameters via a display. Other outputs may include audio information (e.g., via speaker), mechanically (e.g., via a vibrating mechanism), or a combination thereof. In various configurations, the HMI device <NUM> 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 <NUM> may further include any suitable device for inputting biometric information, such as, for example, fingerprint information, retinal information, voice information, and/or facial characteristic information, for instance, so as to require specific biometric information for accessing the controller <NUM>. In addition to the HMI device <NUM>, the control module <NUM> may include a pressure dial <NUM> for easily displaying pressure readings, such as air pressure readings.

Additionally, the controller <NUM> may be in signal communication with a remote device <NUM> (shown in schematic in <FIG>) spaced from the control module <NUM>. In one embodiment, the remote device <NUM> may comprise a display spaced from the control module <NUM>, such as an OLED display, though various types of conventional displays are contemplated. Alternatively, the remote device <NUM> may comprise an external computing device, examples of which include a processor, a desktop computing device, a server computing device, or a portable computing device, such as a laptop, tablet, or smart phone. Accordingly, the remote device <NUM> may provide the operator with the ability to interact with and control the controller <NUM> at a distance from the adhesive dispensing device <NUM>. The remote device <NUM> may be used as part of a cloud control system for the adhesive dispensing device <NUM>. The remote device <NUM> may comprise a PLC (programmable logic controller) or factory computer.

The melt module <NUM> will be described in greater detail. The melt module <NUM> comprises a melter subassembly <NUM> configured to receive solid or semi-sold pellets of adhesive material, either from manual filling by opening a lid assembly <NUM> or through an automatic fill mechanism. The melter subassembly <NUM> may heat the pellets to a specified temperature to form molten adhesive. The melt module <NUM> may also include a pump <NUM> configured to pressurize and dispense the molten adhesive to one or more downstream applicators <NUM> (shown in schematic in <FIG>). An applicator <NUM> may also be known as a dispenser gun. An applicator <NUM>, as used herein, may refer to an applicator module configured with a bank of applicators.

The melt module <NUM> may include a manifold <NUM> configured to receive pressurized molten adhesive from the pump <NUM> and distribute said adhesive to one or more outputs <NUM> at an external portion of the manifold <NUM>. The manifold <NUM> and some portions of the pump <NUM> may be integrated as a single structural component (e.g., a manifold block). For example, a fluid chamber <NUM> portion of the pump <NUM> may extend into such a common structural component to supply the manifold <NUM> portions with pressurized molten adhesive. The manifold <NUM> may be configured with one or more heaters <NUM> (e.g., heating elements) to maintain the adhesive flowing through the manifold <NUM> at a specified temperature. The heaters <NUM> may also serve to re-melt any adhesive material that has cooled within the manifold <NUM>.

The manifold <NUM> may include an external manifold cover <NUM> with openings for the outputs <NUM>. The manifold cover <NUM> may be integral with the manifold <NUM> or may be separately attachable and detachable. A heated hose <NUM> may be attached to an output <NUM> to receive pressurized molten adhesive from the manifold <NUM> and carry the adhesive to an applicator <NUM> for dispensing. The applicator <NUM> and heated hose <NUM> may be each configured with one or more heaters to maintain the adhesive at a specified temperature. The heaters of the applicator <NUM> and heated hose <NUM> may also serve to re-melt any adhesive material that has cooled within the component. The heaters of the applicator <NUM> and heated hose <NUM>, as well as the heater <NUM> of the manifold <NUM>, may be in signal communication with the controller <NUM> to transmit status information (e.g., temperature readings) to the controller <NUM> and receive control signals from the controller <NUM>. When not connected to an applicator <NUM>, each of the plurality of outputs <NUM> may be sealed using a plug.

The melt module <NUM> may comprise a melter subassembly <NUM>, which may define a receiving space <NUM> that is configured to receive solid material, as well as contain adhesive that has melted. The top wall of the melter subassembly <NUM> may define an opening <NUM> in communication with the receiving space <NUM>, such that when the lid assembly <NUM> is pivoted to an open position, material may be manually deposited into the receiving space <NUM> through the opening <NUM>, but when the lid assembly <NUM> is in a closed position, the lid assembly <NUM> may block introduction of adhesive into the receiving space <NUM> through the opening <NUM>. The receiving space <NUM> may define a specific volume that is designed for a particular adhesive operation. For example, the receiving space <NUM> may be configured to receive <NUM> of adhesive, though other sizes are contemplated.

The melter subassembly <NUM> may further include a level sensor <NUM> disposed within the receiving space <NUM>. Particularly, the level sensor <NUM> may be attached to the inner surface of one of the sidewalls of the melter subassembly <NUM> and may be in signal communication with the controller <NUM> of the control module <NUM>. The level sensor <NUM> may comprise a capacitive level sensor, though other types of level sensors are contemplated. In operation, the level sensor <NUM> may monitor the level of material within the receiving space <NUM> and send signals to the controller <NUM> that are indicative of the adhesive level.

The melter subassembly <NUM> may further include a heater <NUM> configured to melt the adhesive. Though depicted as attached to and at least partially extending through the base of the melter subassembly <NUM>, the heater <NUM> may alternatively or additionally be attached to any portion of the melter subassembly <NUM>. It will be appreciated that the heater <NUM> may comprise any type of known heating device configured to melt adhesive within a melter assembly. The melter subassembly <NUM> may further include a plurality of fins <NUM> extending upwards from the base and into the receiving space <NUM>, where the fins <NUM> are configured to be heated by the heater <NUM> and provide an increased surface area for heating and melting the adhesive. Though a particular number, arrangement, and configuration of the fins <NUM> is shown, it is contemplated that the fins <NUM> may be alternatively configured as desired. Additionally, an outlet <NUM> may be defined in the base and in fluid communication with the receiving space <NUM>, where melted adhesive is configured to flow through the outlet <NUM> and exit the receiving space <NUM>. A cage <NUM> may be positioned adjacent the outlet <NUM>, where the cage <NUM> is configured to act as a filter to prevent adhesive pieces of a particular size that are not melted from reaching the outlet <NUM>, as such adhesive pieces may congeal around and clog the outlet <NUM>.

A passage <NUM> may extend from the outlet <NUM> to the pump <NUM> to supply the pump <NUM> with molten adhesive from the melter subassembly <NUM>. The pump <NUM> may be a double-acting piston pump, though other types of pumps are contemplated. The pump <NUM> may be actuated according to a pressurized air supply. The pump <NUM> may operate to expel the molten adhesive from one or more of the outputs <NUM> via the manifold <NUM>. The pump <NUM> may be controlled by the controller <NUM> of the control module <NUM> to deliver the desired flow rate of molten adhesive through the outputs <NUM>. The controller <NUM> may regulate the air supply to the pump <NUM> (e.g., air pressure) to effectuate, at least in part, the desired operation of the pump <NUM>.

With particular attention to <FIG>, which illustrates a view of the adhesive dispensing device <NUM> with various covers, etc. hidden, the adhesive dispensing device <NUM> comprises a pressure control assembly <NUM> relating to air pressure control. The pressure control assembly <NUM> is generally (although not exclusively) housed within a space <NUM> (see <FIG>) defined between the top cover <NUM> of the control module cover <NUM> and the controller housing <NUM>. The pressure control assembly <NUM> comprises a regulator <NUM>, a pressure control board <NUM>, a manual adjustment mechanism <NUM>, the pressure dial <NUM>, and various air lines (e.g., tubing or hoses) and electrical connections. It will be noted that not all electrical connections or air lines are necessarily shown in the Figures, including <FIG>.

Generally, the regulator <NUM> may receive pressurized air from an external air supply via an input air line <NUM>. An air filter (not shown) may be attached to the external inlet of the input air line <NUM>. The external air supply may comprise a plant air supply. The regulator <NUM> may adjust the pressure (and/or other parameters) of the un-regulated input air supply as needed and output the regulated air supply to a pump air valve <NUM> via an air line <NUM>, a pressure discharge valve <NUM>, and an air line <NUM>. The pump air valve <NUM> may cause actuation of the pump <NUM>. For example, in the case of a pneumatically-actuated double-acting piston pump, the pump air valve <NUM> may direct air into either an upper or lower portion of the associated air cylinder to cause a piston stroke. The pressure discharge valve <NUM> may allow for pressurized molten adhesive within the pump <NUM> and manifold <NUM> to be bypassed back to the melter subassembly <NUM> when the pressurized air supply is removed, such as when the pump <NUM> is shut down.

As noted, the pressure control assembly <NUM> (or portions thereof) may be generally configured to control the pressure and/or other parameters of the pressurized air supplied to the pump <NUM> to cause actuation of the pump <NUM>. The pressure control assembly <NUM> may be configured for automated air pressure control via the controller <NUM> and/or the remote device <NUM>. The air pressure control may be additionally or alternatively based on user input, such as user input received via the HMI device <NUM> or the remote device <NUM>.

The pressure control assembly <NUM> may regulate the pressure of the air supply to the pump <NUM> based on pressure sensor readings from one or more pressure sensors positioned in the air supply flow path, such as the pressure sensor <NUM>. The one or more pressure sensors comprises an electronic pressure sensor 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. Although the connection to the air flow path is not shown in <FIG>, the pressure control board <NUM> comprises a digital on-board pressure sensor <NUM>, for example. Digital pressure readings may be sent to the controller <NUM>, the pressure control board <NUM>, and/or the regulator <NUM> for control processing.

The pressure of the air supply may be controlled based on pressure measurements of un-regulated (e.g., upstream) air supply in the air flow path, such as measurements from a pressure sensor (not shown) in the input air line <NUM> before the regulator <NUM>. Pressure control may be additionally or alternatively based on pressure measurements in the air flow path downstream from pressure regulation elements (e.g., the regulator <NUM>). For example, pressure control may be based on pressure measurement from the pressure sensor <NUM> in the air line <NUM> and/or a pressure sensor (not shown) in the air line <NUM>. Downstream and/or upstream air pressure measurements may also be taken by one or more sensors at or in the regulator <NUM>. Downstream pressure measurements may be used to establish closed loop control of the air pressure.

The regulator <NUM> may control the pressure of the air supply to the pump <NUM> (e.g., the pump air valve <NUM>) via a pressure transducer <NUM>. The pressure transducer <NUM> is configured to receive an electronic signal (e.g., analog or digital) and provide a proportional (e.g., linear) pneumatic output to the air flow path. The pressure transducer <NUM> may comprise a current-to-pressure transducer, a voltage-to-pressure transducer, or a similar device that converts an electronic signal to pressure. Although depicted as part of the regulator <NUM>, the pressure transducer <NUM> may be positioned elsewhere in the pressure control assembly <NUM> or the adhesive dispensing device <NUM> generally.

The regulator <NUM> may be configured to selectively enable or disable the downstream air supply to the pump <NUM>. For example, the regulator <NUM> may be configured with a solenoid valve operable to selectively open or close an output air flow from the regulator <NUM>.

The pressure control assembly <NUM> further comprises the manual adjustment mechanism <NUM> and the pressure dial <NUM>. The manual adjustment mechanism <NUM> provides an alternative method to adjust the pressure of the air supply to the pump <NUM>. An operator may manipulate the manual adjustment mechanism <NUM> with a hex tool, screwdriver, or the like to make manual adjustments to the air pressure. The operator may observe the pressure dial <NUM> while doing so. Although it is noted that this manual adjustment method may present challenges in performing accurate, precise, and repeatable adjustments. Physical access to the manual adjustment mechanism <NUM> and/or dangerous exposure to nearby heated parts may also frustrate such manual pressure control.

<FIG> illustrates a schematic diagram <NUM> of an example according to the invention of an air pressure control configuration for a hot melt liquid dispensing system (e.g., the adhesive dispensing device <NUM> of <FIG> and/or associated systems and devices). In the example configuration, a pressurized air flow path <NUM> is provided to a pump <NUM> from an air supply <NUM>. The air flow path <NUM> passes through (or is otherwise acted upon by) a pressure control assembly <NUM> (e.g., the pressure control assembly <NUM> of <FIG>) to control the pressure of the air flow path <NUM> to the pump <NUM>. The portion of the air flow path <NUM> after the pressure control assembly <NUM> shall be referred to as the downstream (or regulated) air flow path 520b and the portion of the air flow path <NUM> before the pressure control assembly <NUM> shall be referred to as the upstream (or un-regulated) air flow path 520a.

An electronic pressure sensor <NUM> is positioned in the downstream air flow path 520b to take pressure measurements and transmit those pressure measurements to a system controller <NUM> and/or remote controller <NUM>. The system controller <NUM> and/or remote controller <NUM> causes the pressure control assembly <NUM> to adjust the pressure of the air flow path <NUM> based on the downstream pressure measurements from the electronic pressure sensor <NUM>. According to the invention, a transducer <NUM> of the pressure control assembly <NUM> causes adjustments to the air pressure of the downstream air flow path <NUM>, based on an electronic signal sent to the transducer <NUM>.

The air supply <NUM> may comprise a pressurized external air supply, such as a plant air supply. The air supply <NUM> may be received via an input air line of the dispensing system. The upstream air flow path 520a may be received at the pressure control assembly <NUM>. The pressure control assembly <NUM> may comprise a regulator device (e.g., the regulator <NUM> of <FIG>) configured to adjust the air pressure of the air flow path <NUM> to achieve a desired air pressure in the downstream air flow path 520b. The regulator may comprise the transducer <NUM> (e.g., the pressure transducer <NUM> of <FIG>), which is used to adjust the air pressure in the air flow path <NUM>. The transducer <NUM> is configured to cause an air pressure adjustment based on an electronic signal transmitted to the transducer <NUM>, such as from the system controller <NUM>, the remote controller <NUM>, or another component of the pressure control assembly <NUM>. The transducer <NUM> may comprise a current-to-pressure transducer, a voltage-to-pressure transducer, or a similar type of transducer.

The system controller <NUM> and/or the remote controller <NUM> may receive one or more pressure measurements from the electronic pressure sensor <NUM>. The one or more pressure measurements may be received as electronic signals (analog or digital) generated by the electronic pressure sensor <NUM>. The electronic signals from the electronic pressure sensor <NUM> may be indicative of the air pressure in the air flow path 520b. The electronic pressure sensor <NUM> may comprise a digital pressure transducer sensor or a pressure-to-current (or voltage) transducer. Based on an air pressure setpoint (e.g., a setpoint range) and the one or more pressure measurements from the electronic pressure sensor <NUM>, the system controller <NUM> and/or remote controller <NUM> may determine a pressure adjustment for the incoming upstream air flow path 520a. For example, the current pressure measurement may be compared to the air pressure setpoint or setpoint range to determine the necessary adjustments, if any. Other control algorithms or techniques may be used, such as a closed loop controller (e.g., a PID controller). The system controller <NUM> and/or remote controller <NUM> may send an electronic signal to the pressure control assembly <NUM> (e.g., the transducer <NUM>) to effectuate the pressure adjustment. The pressure adjustment preferably brings the air pressure of the downstream air flow path 520b to the pressure setpoint or within the pressure setpoint range.

The system controller <NUM> may be integrated with or connected to an adhesive dispensing device of the dispensing system (e.g., the controller <NUM> of <FIG> and <FIG>), although it is not so limited. For example, the system controller <NUM> may comprise a PLC or other computing or logic device at a facility. The remote controller <NUM> (e.g., the remote device <NUM> of <FIG>) may be located external to the dispensing system. For example, the remote controller <NUM> may comprise a cloud or server-based controller. The remote controller <NUM> may comprise a remote personal computing device (e.g., a laptop, tablet, smartphone, or desktop computer) that is in communication with the dispensing system via a cloud or server system. The remote controller <NUM> 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 of the system controller <NUM> or remote controller <NUM>, in varying combinations and degrees.

The system controller <NUM> and remote controller <NUM> may provide respective user interfaces <NUM>, <NUM> (e.g., graphical user interfaces) to facilitate interaction between an operator (local or remote) and the dispensing system. For example, a user interface may enable the operator to input an air pressure setpoint. By inputting the air pressure setpoint via a user interface, the operator is able to enter this setpoint as a precise numerical value, rather than the imprecise trial-and-error method using a mechanical adjustment mechanism and analog pressure dial. As another example, a user interface may display a present air pressure reading to the operator. A user interface may also display one or more past air pressure readings. In this regard, a user interface offers greater precision and accuracy than an analog pressure dial in displaying a present air pressure reading. This advantage is further enhanced by the electronic pressure sensor <NUM>, which provides more accurate and precise pressure measurements than a counterpart analog pressure sensor.

In addition, an interactive user interface on the remote controller <NUM> (and/or the system controller <NUM> in some configurations) may enable remote operator oversight and control of the dispensing system's air pressure parameters (as well as other system parameters). As discussed above, it often may be difficult or even dangerous for an operator to gain physical access to manual air pressure adjustment mechanisms. Yet remote control via the system controller <NUM> and/or remote controller <NUM> may largely eliminate these challenges. This arrangement may also enable centralized control over multiple dispensing systems so-configured. A remote or off-floor operator may simultaneously monitor and control the multiple dispensing systems via respective remote user interfaces without having to repeatedly move from dispensing system to dispensing system on a production floor.

By virtue of the electronic nature of the pressure adjustments by the transducer <NUM> and the pressure measurements from the electronic pressure sensor <NUM>, the system controller <NUM> and/or remote controller <NUM> may efficiently create and store correlated records of such pressure adjustments (e.g., the electronic control signals to the transducer <NUM>) and measurements (e.g., the electronic signals from the electronic pressure sensor <NUM>). Records for air pressure setpoints may also be created and stored. The pressure adjustment, pressure measurement, and/or pressure setpoint records may be displayed on a user interface of the system controller <NUM> and/or remote controller <NUM> for efficient operator review.

The records may also be used in various types of data analytics and control algorithms. For example, analysis of the pressure adjustment records and the pressure measurement records may reveal a trend in the relationship between pressure adjustments and corresponding pressure measurements. The trend may be indicative of a system malfunction, such as a loose or leaking air hose. The records may also be used for purposes of quality control. For example, a sub-standard batch of products may be traced back to an incorrectly entered air pressure setpoint or out-of-threshold pressure measurements. In addition, product quality control metrics may be analyzed with corresponding pressure setpoint, pressure adjustment, and/or pressure measurement records to identify any correlating relationships. For example, a certain pressure setpoint that historically correlates to high quality product batches may be identified and used again for the same or similar operations. As noted above, this identified pressure setpoint may be easily entered via the user interface and implemented by the electronically-controlled transducer <NUM>. The above records may be implemented as the logs <NUM>, <NUM> on the system controller <NUM> and the remote controller <NUM>, respectively.

<FIG> illustrates a method flow diagram for a method <NUM> for air pressure control in a hot melt liquid dispensing system ("dispensing system"), such as the adhesive dispensing device <NUM> of <FIG> and associated systems and components. The method <NUM> 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 comprise a pump configured to pump hot melt liquid to an applicator associated with the dispensing system. The hot melt liquid may be received from a melter of the dispensing device.

The dispensing system may comprise an air flow path configured to supply pressurized air to the pump. The air flow path may originate at an input air line that receives air from an external air supply, such as a plant air supply. The air flow path may comprise various air lines of the dispensing system and terminate at the pump. For example, the air flow path may terminate at an air valve for the pump. The pump may be pneumatically actuated by the pressurized air from the air flow path.

The dispensing system comprises an electronic pressure sensor associated with the air flow path. The electronic pressure sensor is configured to measure the air pressure in the air flow path. The electronic pressure sensor is configured to transmit an electronic signal indicative of the measured air pressure in the air flow path. The electronic pressure sensor may comprise a pressure-to-current transducer or a pressure-to-voltage transducer. The dispensing system may comprise a pressure control assembly configured to control the pressure in the air flow path. For example, the pressure control assembly may be configured to raise or lower the pressure of the air in the portion of the air flow path downstream from the pressure control assembly. The pressure control assembly comprises a transducer operable to adjust the pressure in the air flow path. The transducer may comprise a current-to-pressure transducer or a voltage-to-pressure transducer. The transducer may be operable to adjust air pressure based on an electronic signal sent to and received by the transducer.

At step <NUM>, an air pressure setpoint for the air flow path is received, such as 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 comprise a pressure setpoint range. In some embodiments, the pressure setpoint may be already set or received at the dispensing system, in which case the method <NUM> may begin at step <NUM>.

At step <NUM>, an electronic signal is received from the 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 by the controller, for example. The electronic signal may comprise an electric current or voltage signal generated based on pressure to the electronic pressure sensor. The measured air pressure in the air flow path may be displayed to an operator or other interested party. For example, the air pressure may be displayed on a user interface associated with the dispensing system, including a local or a remote user interface.

At step <NUM>, an adjustment is caused 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 be additionally or alternatively based on the air pressure setpoint. For example, the adjustment may be based on a comparison of the measured air pressure in the air flow path to the pressure setpoint. Other control techniques may be used, such as closed loop control (e.g., a PID controller).

The transducer of the pressure control assembly is used to adjust the air pressure in the air flow path. The air pressure is adjusted by transmitting an electronic control signal to the transducer. The transducer may alter the pressure in the air flow path based on the received electronic control signal. The transducer may comprise a voltage-to-pressure transducer or a current-to-pressure transducer. As such, the electronic control signal may comprise a voltage signal or a current signal. The electronic pressure sensor may be positioned in the air flow path downstream from the transducer. Thus, the air pressure measured by the electronic pressure sensor may be regulated air flow (as opposed to the air flow initially received from the external air supply).

The pressure adjustment and/or the electronic control signal to the transducer may be displayed on the 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 adjustment, or the electronic control signal to the transducer may be recorded and stored. For example, the controller may record such data in a log stored by the controller. The logs may be used for various analytics, such as diagnostic, quality control, or process control analysis.

One skilled in the art will appreciate that the systems and methods disclosed herein may be implemented via a computing device that may comprise, but are not limited to, one or more processors, a system memory, and a system bus that couples various system components including the processor to the system memory. For example, a computing device (e.g., a controller) may comprise one or more processors and memory storing instructions that, when executed by the one or more processors, effectuate one or more of the various methods and techniques described herein.

For purposes of illustration, application programs and other executable program components such as the operating system are illustrated herein as discrete blocks, although it is recognized that such programs and components reside at various times in different storage components of the computing device, and are executed by the data processor(s) of the computer. An implementation of service software may be stored on or transmitted across some form of computer readable media. Any of the disclosed methods may be performed by computer readable instructions embodied on computer readable media. Computer readable media may be any available media that may be accessed by a computer. By way of example and not meant to be limiting, computer readable media may comprise "computer storage media" and "communications media. " "Computer storage media" comprise volatile and non-volatile, removable and non-removable media implemented in any methods or technology for storage of information such as computer readable instructions, data structures, program modules, or other data. Exemplary computer storage media comprises, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which may be used to store the desired information and which may be accessed by a computer. Application programs and the like and/or storage media may be implemented, at least in part, at a remote system.

As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment.

Unless otherwise expressly stated, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that an order be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps or operational flow; plain meaning derived from grammatical organization or punctuation; the number or type of embodiments described in the specification.

Claim 1:
A hot melt liquid dispensing system (<NUM>), comprising:
a pump (<NUM>) configured to pump hot melt liquid to an applicator;
an air flow path (<NUM>) configured to supply pressurized air to the pump (<NUM>);
an electronic pressure sensor (<NUM>) associated with the air flow path (<NUM>); characterized by the hot melt liquid dispensing system (<NUM>) further comprises:
a transducer (<NUM>) associated with the air flow path (<NUM>); and
a controller (<NUM>) configured to:
receive an electronic signal from the electronic pressure sensor (<NUM>) indicative of an air pressure in the air flow path (<NUM>), and
cause adjustment to the air pressure in the air flow path (<NUM>) based on the electronic signal from the electronic pressure sensor (<NUM>),
wherein the controller is further configured to cause adjustment to the air pressure in the air flow path (<NUM>) by transmitting an electronic signal to the transducer (<NUM>).