The present invention relates generally to inductor pumps for pumping highly viscous fluid from containers. In particular, the present invention relates to platens used to push the fluid from a drum or the like.
Inductor pumps typically comprise linear pneumatic actuators that force a pipe having a platen into a drum. The platen includes a central bore that leads to a passageway in the pipe. As the platen is lowered into the drum by the pneumatic actuators, the highly viscous fluid is forced into the central bore and up the passageway. The fluid is pushed into a pump that forces pressurized fluid through a hose into spray device where an operator can dispense a metered amount of fluid into some other typically smaller container. In order to ensure advantageous operation of the inductor pump and to reduce waste, it is desirable to provide adequate sealing between the platen and drum, to prevent leakage of the fluid out of the container. Platens include flexible wipers that deflect against the drum and form a seal. The flexible wipers are selected based on the type of fluid and the type of drum in which the fluid is stored. For example, more viscous fluids require stiffer wipers. Also, some fluids are stored in containers that have variable geometry that require longer wipers or multiple wipers. Furthermore, containers have various diameters that require platens of different sizes. Attempts have been made to design platens that can be used in a variety of containers. For example, U.S. Pat. No. 5,117,998 to Handzel, which is assigned to Graco Inc., discloses a universal platen that can be used in different wiper configurations when mounted to an inductor plate hub. However, such a universal platen must be completely disassembled at the hub to replace or reconfigure the wiper. As such, there is a need for a more easily configurable universal platen.
The present invention is directed to a modular platen assembly for use with an inductor pump. The modular platen assembly comprises an annular hub, a wiper ring assembly and a coupling ring. The annular hub is for connecting to a ram of an inductor pump. The wiper ring assembly includes an annular wiper for sealing with a container. The coupling ring is independently joined to the hub and the wiper ring assembly at first and second connections, respectively.
A container of a fluid that is to be dispensed by system 10 is stored on platform 26 so that the container is accessible to modular platen assembly 12. Wheels 28A and 28B are mounted on axle 29, which is connected to platform 26. Platform 26 is maintained level by wheels 28A and 28B and kickstand 30. However, by tipping cart 24 backwards on wheels 28A and 28B, such as by tilting ram 16 using handle 32, cart 24 can be easily moved to different locations. Once at the desired location, a dispenser device connected to pump 20 at outlet 44 is used to meter fluid pushed from the container by ram 16 and modular platen assembly 12. Modular platen assembly 12 of the present invention can be easily removed and replaced or reconfigured to allow system 10 to be used with a variety of containers.
Ram 16 comprises pneumatic cylinder 34 in which piston 36 is disposed. As shown in
In operation, ram 16 is used to lift support bracket 38 up and away from platform 26 such that a container can be positioned between platform 26 and modular platen assembly 12. Specifically, on/off valve 56 is opened to supply pressurized air to inlet 50, relieving valve 62 is positioned to direct air to ram 16 by allowing air to enter line 52B. The pressurized air travels to the bottom of cylinder 34 through piston 36 and pushes piston 36 out of cylinder 34, pushing support bracket 36 away from platform 26. Subsequently, a container storing a viscous fluid is positioned on platform 26 below wiper ring assembly 66. Relieving valve 62 is repositioned to stop providing pressurized air to cylinder 34, allowing modular platen assembly 12 to fall into the container. The speed of travel of piston 36 is controlled by the rate at which air is permitted to leave cylinder 34 at a relief orifice in relieving valve 62. Additionally, the descent of modular platen assembly 12 can be paused by depressing pushbutton 60 while relieving valve 62 is closed to prevent air from reaching the relief valve in relieving valve 62 and leaving cylinder 34.
Wiper ring assembly 66 engages the side of the container to push the viscous fluid downward, which forces the fluid up into a central bore located in hub 64 such that the fluid travels into ram pipe 22 and to pump 20. On/off valve 56 is positioned to permit pressurized air to flow to air motor 18, which causes air motor 18 to actuate drive shaft 48. Depending on the type of pump used, drive shaft 48 rotates or reciprocates to drive pump 20. Pump 20 pressurizes the fluid provided by ram pipe 22 and distributes the pressurized fluid to outlet 44 whereby the dispensing device can be used to meter measured amounts of the fluid. As fluid from the container is consumed, modular platen assembly 12 falls to the bottom of the container.
To remove modular platen assembly 12 from the container, relieving valve 62 is again positioned to allow pressurized air to flow into cylinder 34. Pushbutton valve 60 is also toggled to alternatively direct air from elevator control 14 to line 52C, which delivers pressurized air into the container through modular platen assembly 12 to prevent a vacuum from forming in the container and to help push wiper ring assembly 66 out of the container. Check valve 53 prevents flow of air from the container into valve 60 or cylinder 34. Additionally, bleed stick 68 can be manually actuated to allow airflow into and out of the container through a valve in hub 64. Further description of the operation of elevator control 14 is located in a related application having Ser. No. ______ and entitled “ELEVATOR CONTROL FOR INDUCTOR PUMP,” which is filed on the same day as this application and is incorporated herein by reference.
As modular platen assembly 12 descends into the container, wiper 72 deflects to engage the sidewalls of the container to seal and scrape against the container. Containers comprise many different configurations, such as the diameter of the sidewalls, the slope of the sidewalls, and the presence or not of ribbing, corrugations or other stiffening features in the sidewalls. Wiper 72 and spacer 74 are not optimally configured to engage all containers. Modular platen assembly 12 of the present invention permits wiper ring assembly 66 and coupling ring 76 to be expediently removed from hub 64 without having to disassembly wiper 72 and spacer 74. As such, other wiper ring assemblies with different spacer and wiper configurations can be quickly secured to hub 64 for use with other containers. Or, if need be, wiper ring assembly 66 and coupling ring 76 can be removed from hub 64 and moved to a convenient location for disassembly and reconfiguration of wiper 72 and spacer 74 without having to move system 10 or remove hub 64.
Hub 64 comprises axial collar 86 and radial flange 88. Collar 86 includes furrow 90 into which ram pipe 22 fits. Fasteners 92 secure ram pipe 22 to hub 64. Axial collar 86 forms a central passageway into which fluid from a container is pushed by wiper ring assembly 6. Radial flange 88 extends radially from a lower or bottom end of axial collar 86. As such, collar 86 extends axially outward and away from flange 88 with reference to the depicted embodiments of
As is shown in
Coupling ring 76 is secured to flange 88 such that a radially inner portion is adjacent flange 88 and a radially outer portion extends radially beyond flange 88. Second connection 84 joins coupling ring 76 to wiper ring assembly 66. In the embodiment shown, second connection 84 comprises an array of fasteners 104 that extend from coupling ring 76. Fasteners 104 are mounted to the radially outer portion of coupling ring 76, such as at a welded connection or via a bolted connection. Fasteners 104 extend through axially aligned holes in the various components of wiper ring assembly 66. As such, nuts 106 secure wiper ring assembly 66 to coupling ring 76 and maintain wiper ring assembly 66 assembled together.
Secondary wiper 80 is positioned on top of, or axially outward of, coupling ring 76. Secondary wiper 80 extends radially outward beyond the radially outer edge of coupling ring 76. In the embodiment shown, secondary wiper 80 has a larger diameter than coupling ring 76. Wiper 72 is positioned on top of, or axially outward of, secondary wiper 80. Wiper 72 extends radially outward beyond the radially outer edge of secondary wiper 80. In the embodiment shown, wiper 72 has a larger diameter than secondary wiper 80. Wiper 72 and secondary wiper 80 are made of a flexible and resilient material, such as silicone, polytetrafluoroethylene (PTFE), rubber or polyurethane. Secondary wiper 80 protects wiper 72 from exposure to fluids within the container in which modular platen assembly 12 is inserted.
Wiper plate 78 is positioned on top of, or axially outward of, wiper 72. Wiper plate 78 extends radially outward beyond the radially outer edge of coupling ring 76. In the embodiment shown, wiper plate 78 has a larger diameter than coupling ring 76. The radially outer end of wiper plate 78 is shaped to engage and secure spacer 74. In particular, wiper plate 78 includes axially extending wall 108 and radially extending flange 110. Secondary wiper 80, wiper 72 and wiper plate 78 are axially stacked adjacent, or radially aligned with, flange 86 such that a seam is formed between hub 64 and wiper ring assembly 66.
Spacer 74 is positioned on top of, or axially outward of, a radially outer portion of wiper 72. Spacer 74 comprises a resilient block of material that allows wiper 72 to deflect against sidewalls of the container in which modular platen assembly 12 is used. In one embodiment, spacer 74 is comprised of a polyurethane elastomer. In the embodiment shown, spacer 74 includes a first end surface that engages wiper 72, a second end surface that engages flange 110 of wiper plate 78. Also, spacer 74 includes a first side surface that engages wall 108 of wiper plate 78 and a second side surface that extends at an oblique angle between the first and second end surfaces. In the embodiment shown, the second side surface is sloped radially inward as it extends from wiper 72 to wiper plate 78. The slope of the second side wall affects the stiffness of wiper 72. For example, the further radially outward spacer 74 extends at the first end surface, the stiffer wiper 72 becomes. As such, spacer 74 can be flipped over such that the second side surface is sloped radially outward as it extends from wiper 72 to wiper plate 78 to lessen the stiffness of wiper 72.
Cover 70 is positioned at the axially outward end of modular platen assembly 12 between wiper ring assembly 66 and hub 64. Cover 70 comprises a lid that prevents fluid from the container in which modular platen assembly 12 is disposed from falling into the space between spacer 74 and hub 64. Cover 70 rests on flange 110 of wiper plate 78 and on the tops, or axially outer ends, of fasteners 104. Cover 70 includes ports 112 that receive tips of fasteners 104. Some of ports 112 include windows that permit access to fasteners 104 from the outside of cover 70 such that cover 70 can be secured to fasteners 104. Cover 70 can, however, be configured to connect to assembly 12 in other ways, such as by catches located within ports 112.
Hub 64 and coupling ring 76 comprise elements as discussed with reference to
Secondary wipers 118 and 126 are similar to that of secondary wiper 80 of
Spacer 122 is made of similar materials as spacer 74 of
The dual wiper configuration of wiper ring assembly 116 is advantageously used in storage containers having annular stiffening corrugations on the sidewalls. For example, with wiper ring assembly 116 inserted into a container, first wiper 120 and second wiper 124 are deflected against the container sidewall. As wiper ring assembly 116 is withdrawn upward and outward from a container, second wiper 124 will initially engage a corrugation in the sidewall and become less deflected or completely straighten out. First wiper 120 will, however, remain engaged with the sidewall to maintain a seal. As second wiper 124 disengages the corrugation and deflects to produce a seal, first wiper 120 will engage the corrugation and straighten out. Thus, the at least one wiper is always in engagement with the sidewall to maintain a seal at all times. The height of spacer 122 can be changed in different embodiments for containers having corrugations of different axial heights.
Wiper ring assembly 116 is an example of alternative embodiments of modular platen assembly 66 that can be used with the present invention. Wiper ring assemblies having different components and configurations can be made for use with coupling ring 76 and hub 64 of the present invention. For example, wiper ring assemblies can be configured with different platen and wiper diameters, different wiper stiffnesses, different spacer shapes, different numbers of wipers, different materials, etc. The wiper ring assemblies are easily mounted to coupling ring 76 and secured with fasteners to provide a modular assembly that can be easily assembled with and removed from hub 64 without having to disassemble the individual wipers, secondary wipers and spacers of the wiper ring assembly. When disassembly of individual components is desired, the wiper ring assembly can be removed from hub 64. As such, alterations and repairs of system 10 can be more rapidly and easily conducted.
While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
This application claims priority under 35 U.S.C. §120 to U.S. provisional application Ser. No. 61/294,331, entitled “MODULAR PLATEN DESIGN,” filed Jan. 12, 2010 by inventors Derek R. Shaw and Paul R. Quam, the contents of which are incorporated by this reference.
Number | Date | Country | |
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61294331 | Jan 2010 | US |