Electrically actuated foam density controller related technology

Abstract

An electrically actuated foam density controller assembly includes a housing structure enclosing an elongated structure (e.g.. an adjustment rod) and a disc structure (e.g., a slug). The density controller assembly may be configured to dispense a foam substance comprising a specified mixture of adhesive, such as hot melt, and gas, such as nitrogen, the specified mixture of adhesive and gas obtained in response to movement of the disc structure with respect to the elongated structure. The assembly may also include an electrical actuator configured to modify a position of the elongated structure with respect to the disc structure to control a flow of the gas into the density controller assembly. In one embodiment, the electrical actuator may include a motor and a linear actuator, the linear actuator configured to convert rotary' motion of the motor into linear motion of the elongated structure.

Description

ELECTRICALLY ACTUATED FOAM DENSITY CONTROLLER RELATED TECHNOLOGYRELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 651,697, entitled Electrically Actuated Foam Density Controller Related Technology, fded May 24, 2024, incorporated herein by reference in its entirety.BACKGROUND

[0002] The disclosure relates to multi-mode electrically actuated foam dispensers for hot melt adhesives. Specifically, this disclosure relates to an electrically actuated foam density controller that may be used with traditional hot melt adhesive foam dispensers.

[0003] Dispensing equipment involving the mixture of hot melt adhesive and nitrogen gas to create a foam adhesive requires the ability to control the ratio of gas to adhesive in order to sustain various different application requirements. Current foam adhesive dispensers require a manual operation in order to maintain a desired density reduction percentage, and do not provide adequate control of the foam density rate. The manual process of controlling the introduction of gas leads to inconsistent density reduction rates and leaves the operator blind with regard to how far to adjust a manual gas flow control knob. This makes it challenging to precisely control the density of the resulting foam as well as causing too much gas to be introduced into the system. Providing an automated, electrically actuated, foam density controller would allow for a precise way to control the amount of gas introduced in the system under a broader range of conditions and to sustain and reach the required density of the foam adhesive product.SUMMARY

[0004] In one embodiment, a foam adhesive dispensing apparatus includes an electrically actuated foam density' controller assembly having a housing structure enclosingan elongated structure (e.g., an adjustment rod) and a disc structure (e.g., a slug). The density controller assembly may be configured to dispense a foam substance comprising a specified mixture of adhesive, such as hot melt, and gas, such as nitrogen, the specified mixture of adhesive and gas obtained in response to movement of the disc structure with respect to the elongated structure. The apparatus may also include an electrical actuator configured to modify a position of the elongated structure with respect to the disc structure to control a flow of the gas into the density controller assembly . In one embodiment, the electrical actuator may include a motor and a linear actuator, the linear actuator configured to convert rotary motion of the motor into linear motion of the elongated structure. The linear actuator may be an electromechanical structure or an electro-pneumatic structure. In one embodiment, the motor may be a stepper motor.

[0005] The apparatus may also include a coupler structure, coupling the electrical actuator to the density controller assembly. The coupler structure may include a first coupling, a coupling shaft, and a second coupling, the first coupling connecting a first portion of the coupling shaft to the linear actuator and the second coupling connecting a second portion of the coupling shaft to the elongated structure.

[0006] In another embodiment, the electrical actuator may be configured to automatically move the elongated structure in a first direction towards the disc structure until the elongated structure electrically contacts the disc structure to transmit a control signal to a gas valve configured to inj ect the gas into the adhesive to achieve a predetermined specified density of the foam substance.

[0007] In another embodiment, the electrical actuator may be configured to move the elongated structure, either manually or automatically, in a second direction away from the disc structure until the elongated structure electrically disconnects from the disc structuredisabling the control signal to the gas valve thereby disabling a flow of the gas into the adhesive.

[0008] In another embodiment, the apparatus may include an electrically conductive spring electrically connected to the elongated structure, the electrically conductive spring configured to further enable electrical contact between the elongated structure, the disc structure, and the gas valve. In another embodiment, the electrical actuator is configured to automatically move the elongated structure in the first direction in response to a control signal provided by a control system.

[0009] In one embodiment, the movement of the disc structure with respect to the elongated structure is in response to the adhesive flowing through the housing and applying pressure to a first side of the disc structure to move the disc structure in a first direction towards the elongated structure until the disc structure electrically contacts the elongated structure to transmit a control signal to a gas valve configured to inject the gas into the adhesive to achieve a specified density of the foam substance.

[0010] In one embodiment, a spring may be disposed within the housing structure, the spring configured to apply pressure to a second side of the disc structure to move the disc structure in a second direction away from the elongated structure until the disc structure electrically disconnects from the elongated structure disabling the control signal to the gas valve thereby disabling a flow of the gas into the adhesive. The density controller assembly may also be configured to monitor a position of the disc structure with respect to the elongated structure.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a front perspective view of one embodiment of a foam adhesive dispenser.

[0012] Figure 2 is a front perspective view of one embodiment of an electrically actuated foam density controller assembly attached to internal components of a foam adhesive dispenser.

[0013] Figure 3 is an exploded front perspective view of the electrically actuated foam density controller assembly attached to internal components of a foam adhesive dispenser shown in Figure 2.

[0014] Figure 4 is a front perspective view of one embodiment of the electrically actuated foam density controller assembly attached to internal components of a foam adhesive dispenser.

[0015] Figure 5 is an exploded view of one embodiment of the electrically actuated foam density controller assembly.

[0016] Figure 6 is a front view of one embodiment of the electrically actuated foam density controller assembly attached to internal components of a foam adhesive dispenser.

[0017] Figures 7 and 8 are cross-sectional side views of the manifold and foam density controller portions of the foam density controller assembly.

[0018] Figure 9 is a front view cutaway of the foam density controller assembly of Figure 6.DETAILED DESCRIPTION

[0019] As shown in Figure 1, a foam adhesive dispenser 10 may be used to dispense an adhesive, such as hot melt, that is combined in the dispenser 10 with a gas, such as nitrogen, to create a foam adhesive. The foam adhesive dispenser 10 may include a human machineinterface (HMI) 12 that receives parameter inputs from the user, such as temperature, pressure, duty’ cycle, etc., which define the resulting properties of the foam. In one embodiment, the HMI 12 is configured to communicate with, among other systems, a PLC, or programmable logic controller, that is configured to operate an electrically automated foam density controller assembly 14. As shown in Figures 2 and 3, the foam density controller assembly 14 may be attached, or retrofitted, to a main body 16 of an existing foam adhesive dispenser 10 or may be part of a foam dispenser 10 specifically designed to house the foam density' controller assembly 14.

[0020] As shown in Figure 4, the main body components of the foam adhesive dispenser 10 may include, but are not limited to, a hopper 18 configured to receive the adhesive material, a pump motor 20 configured to move adhesive material through the dispenser 10, a reservoir designed to receive the melted hot melt adhesive 22, an assembly guard structure 24 disposed about the density controller assembly 14, and an alignment plate 26 configured to stabilize the density’ controller assembly 14 in relation to the main body components 16. It should be apparent that additional components of the dispenser 10 may be included in the device as a whole.

[0021] Referring now to Figure 5, the electrically actuated foam density controller assembly 14 includes a first housing or manifold 28, a disc structure (not shown ), foam density controller portion 30, and an electrical actuator system 32, the components of which will be discussed in more detail herein. Figure 6 shows an example of the internal main body components of one embodiment of a foam adhesive dispenser 10 attached to the electrically actuated foam density controller assembly 14. In one embodiment, the density of a foam adhesive output is dictated by the amount of nitrogen gas mixed with the hot melt adhesive.

[0022] As shown in Figures 6, 7. and 8. the first housing, or manifold. 28 of the assembly 14 may be configured as an outer casing and may include an inlet port 34 capable of receiving melted adhesive material within the manifold and an outlet port (not shown) configured to dispense the adhesive and gas mixture (i.e. foam) from the assembly 14.

[0023] As shown in Figures 7 and 8, the manifold 28 may also be configured to include a disc structure 36, or slug, and a spring 38, disposed within an internal chamber 40 of the manifold 28. The slug 36 may generally be capable of moving within the chamber 40 from a first position A to a second position B, as molten the adhesive material is injected through inlet port 34. In one embodiment, the pressure of the injected adhesive causes the slug 36 to move between position A to position B, compressing and decompressing spring 38, depending on the amount of adhesive and pressure at which the adhesive enters the manifold 28.

[0024] Referring now to Figures 5-9, the foam density' controller portion 30 of the controller assembly 14 is configured to open and close a gas valve (not shown) within the assembly 14, facilitating the mixture of nitrogen gas, for example, with the adhesive disposed yvithin the internal chamber 40 of the manifold 28. In one embodiment, the foam density controller portion 30 includes an elongated structure or adjustment rod 42 having an adjustment rod tip 44, disposed through a second housing 46 and an internal seal / insulator 48, as show n in Figures 7-9. In one embodiment, the proximal end of the second housing 46 is connected to the distal end of the manifold 28 and further includes an opening therethrough configured to allow the adjustment rod 42 to stably extend between and within the internal chamber 40 of the manifold 28 at its proximal end and through the distal end of the housing 46 at its distal end.

[0025] The density controller portion may also include a brass (or other suitable material) linear bearing 50 with a set of screws 51 and wire leads (not shown), which is affixed the distal end of the second housing 46. In one embodiment, the screws 51 and wire leads are further configured to facilitate the opening and closing of the gas valve as the adjustment rod 42 contacts the slug 36 (as discussed below).

[0026] In one embodiment, the brass linear bearing 50 is further configured to attach to the second housing 46, while allowing the adjustment rod 42 to extend through an opening having an internal wall through the middle of the bearing 50. In one embodiment, the bearing 50 may also be configured to be fitted with an electrically conductive coil spring 52 that is designed to sit within a cut out in the internal w all of the linear bearing 50. As the adjustment rod 42 passes through the opening in the inner w all of the linear bearing 50, at least a portion of the rod 42 is configured to be in contact with the conductive spring 52, providing an enhanced electrical connection to the assembly 14.

[0027] The foam density controller portion 30 may be connected to the electrical actuator system 32 using a coupling structure 54. In one embodiment, the electrical actuator system 32 includes a motor 56, such as a stepper motor, a motor coupling 58, and a linear actuator 60, such as an electromechanical cylinder. In one embodiment, the coupling structure 54 includes a first coupling member 62, a second coupling member 64, and a coupling shaft 66 disposed there between. The first coupling member 62 may be an alignment coupling configured to attach a first end of the coupling shaft 66 to the linear actuator 60. In this embodiment, at least a portion of the linear actuator 60 extends through the alignment plate 26 (Figures 4 and 6) to attach to the first coupling member 62, stabilizing the electrical actuator system relative to the internal components 16 of the dispenser 10. Thesecond coupling 64 may be a clevis pin coupling and be configured to attach a second end of the coupling shaft 66 to the elongated adjustment rod 42.

[0028] The motor 56 of the electrical actuator system 32 may be used to automate the movement of the adjustment rod 42 in a linear direction. The linear actuator 60 may be used to convert the rotational movement of the motor 6 to linear motion, thereby allowing a user to precisely control the movement of the adjustment rod 42. It should be appreciated that the linear actuator 60 may be an electromechanical or electropneumatic actuator. It should be appreciated that any suitable actuator maybe used to convert the rotary movement of the motor to the linear movement of the rod. The overall movement of the rod 42 may be about 40 mm, as the linear actuator extends and retracts. In one embodiment, the motor 56 and linear actuator 60 may be capable of moving the adjustment rod in increments of 0.1 mm, providing precision of movement and location to the system.

[0029] Referring again to Figures 6, 7 and 8, the operator of the dispenser enters application parameters and target density' reduction values into the HMI 12 of the dispenser 10. The dispenser’s controller (e.g., a programmable logic controller (PLC)) then sets the required system pressure and pump speeds for the application. The dispenser’s PLC then uses computer logic, a motor 56 (e.g., a stepper motor), and the linear actuator 60 (which is configured to move from a retracted to extended position) to micro adjust the position of adjustment rod 42 relative to the slug 36. When the tip 44 of the adjustment rod 42 contacts the slug 36 within the manifold (as shown in Figures 7 and 8), an electrical circuit is completed and the gas valve is opened, allowing nitrogen gas to mix with the molten adhesive.

[0030] In one embodiment, the PLC continuously adjusts the motor 56, linear actuator 60, and therefore the adjustment rod 42, to provide the desired amount of gas to the system.By continuously adjusting the flow and amount of gas within the system, the desired level of foam density (i.e., the desired density reduction of the adhesive) may be achieved. The assembly 14 may be operated by the PLC in a manual, hybrid, or fully automated mode, providing continuous feedback to the dispenser system.

[0031] It should be appreciated that both the pressure of the adhesive moving distally through the manifold against the slug and the position of the rod moving automatically in a proximal and distal direction, to contact the slug from the opposite side, according to the system parameters, dictates the ultimate movement of the rod within the assembly to precisely control the foam characteristics.

[0032] This written description sets forth the best mode of carrying out the invention and describes the invention so as to enable a person of ordinary skill in the art to make and use the invention, by presenting examples of the elements recited in the claims. The detailed descriptions of those elements do not impose limitations that are not recited in the claims, either literally or under the doctrine of equivalents.

Claims

What is claimed is:

1. An electrically actuated foam density assembly comprising: a housing structure configured to enclose an elongated structure and a disc structure, the foam density controller assembly configured to dispense a foam substance comprising a specified mixture of adhesive and gas, the specified mixture of adhesive and gas obtained in response to movement of the disc structure with respect to the elongated structure; and an electrical actuator system configured to automatically modify a position of the elongated structure with respect to the disc structure to control a flow of the gas into the density controller assembly.

2. The electrically actuated foam density assembly of claim 1, wherein the electrical actuator comprises a motor and a linear actuator, the linear actuator configured to convert rotary motion of the motor into linear motion of the elongated structure.

3. The electrically actuated foam density assembly of claim 2, wherein the linear actuator is an electromechanical structure.

4. The electrically actuated foam density assembly of claim 2, wherein the linear actuator is an electropneumatic structure.

5. The electrically actuated foam density assembly of claim 2, wherein the motor is a stepper motor.

6. The electrically actuated foam density assembly of claim 2, further comprising a coupler structure coupling the electrical actuator to the density controller assembly.

7. The electrically actuated foam density assembly of claim 6, wherein the coupler structure comprises a first coupling, a coupling shaft, and a second coupling, the first coupling connecting a first portion of the coupling shaft to the linear actuator and thesecond coupling connecting a second potion of the coupling shaft to the elongated structure.

8. The electrically actuated foam density assembly of claim 1, wherein the electrical actuator is configured to automatically move the elongated structure in a first direction towards disc structure until the elongated structure electrically contacts the disc structure to transmit a control signal to a gas valve configured to inject the gas into the adhesive to achieve a specified density of the foam substance.

9. The electrically actuated foam density assembly of claim 8, wherein the electrical actuator is configured to automatically move the elongated structure in a second direction away from the disc structure until the elongated structure electrically disconnects from the disc structure disabling the control signal to the gas valve thereby disabling a flow of the gas into the adhesive.

10. The electrically actuated foam density assembly of claim 8, further comprising: an electrically conductive spring electrically connected to the elongated structure, the electrically conductive spring configured to further enable electrical contact between the elongated structure, the disc structure, and the gas valve.

11. The electrically actuated foam density assembly of claim 8, wherein the electrical actuator is configured to automatically move the elongated structure in the first direction in response to a control signal provided by a control system.

12. The electrically actuated foam density assembly of claim 1, wherein the movement of the disc structure with respect to the elongated structure is in response to the adhesive flowing through the housing and applying pressure to a first side the disc structure to move the disc structure in a first direction towards the elongated structure until the disc structure electrically contacts the elongated structure to transmit a control signal to a gasvalve configured to inject the gas into the adhesive to achieve a specified density of the foam substance.

13. The electrically actuated foam density assembly of claim 12. further comprising a compression spring within the housing structure, the compression spring configured to apply pressure to a second side of the disc to move the disc structure in a second direction away from the elongated structure until the disc structure electrically disconnects from the elongated structure disabling the control signal to the gas valve thereby disabling a flow of the gas into the adhesive.

14. The electrically actuated foam density' assembly of claim 1, wherein the density controller assembly is configured to monitor a position of the disc structure with respect to the elongated structure.

15. The electrically actuated foam density' assembly of claim 1, wherein the adhesive comprises a hot melt adhesive.

16. The electrically actuated foam density' assembly of claim 1, wherein the gas comprises nitrogen gas.

17. The electrically actuated foam density' assembly of claim 1, further comprising a fan structure configured to maintain an operating temperature of the electrical actuator.

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