An Annular Fluidic Control Device

Abstract

A fluidic apparatus comprises an annular shaped body which includes a centrally located aperture extending through a thickness of the body. The body includes a plurality of fluidic devices formed therein and which are positioned about the aperture. A flow channel means for each of the devices communicates between the aperture and an associated device while a gas flow manifold extends into the aperture and conveys a gas from a source to the flow channel means. Through this arrangement, the operating characteristics of the apparatus are enhanced.

Description

This invention relates to fluidic apparatus. The invention relates more particularly to an improved arrangement of a fluidic apparatus.

A fluidic device, as is well known, comprises a means for defining a carrier fluid flow channel and a channel for a control fluid which operates on the carrier fluid to provide amplification or switching. A plurality of such fluidic devices have been arranged in a single body to form a fluidic apparatus. The apparatus includes inlet and outlet couplings to the various fluidic devices as well as intercoupling between the devices of the apparatus.

Present day fluidic apparatus have a parallelpiped shaped configuration. This configuration leads to several disadvantages which reduce operating reliability and usefulness of the apparatus and result in relatively inefficient fabrication. The fluidic devices are generally formed in a plastic material which exhibits a shrinkage characteristic. This characteristic can differ in magnitude over the cross-sectional area of the apparatus and results in varying operating characteristics for similar fluidic devices of the apparatus. Additionally, this nonuniform shrinkage undesirably alters alignment and sealing between components of the device. Furthermore, the relatively large dimensions of a body of this configuration which incorporates a large number of fluidic devices necessitates the establishment of flow paths between devices within the body which are relatively long and which undesirably increase the response time of operation of the devices. In certain apparatus of this configuration a carrier gas inlet manifold is provided which communicates with one or more of the devices in the apparatus. The plurality of devices in a parallelpiped arrangement deriving carrier gas from a common inlet manifold has resulted in the spacing of the devices along a length of the body and contributes to an apparatus having a form factor which provides an apparatus packing density less than is desirable.

The present day fabrication of a parallelpiped configuration is relatively inefficient in view of the fact that the setting of a large number of rivets is generally required in order to complete the assembly of the apparatus. This setting of a large number of rivets generally results in nonuniform distribution of pressures between members of the body which ultimately degrades performance of the apparatus. Finally, the fluidic devices have relatively small dimensions and have been reproduced commercially by providing a relatively large art work and photoreducing the art work to final dimensions. The rectangular surface of a body member of a parallelpiped shaped apparatus does not readily conform to the general shape of lens systems employed for photoreduction. The portion of the apparatus being photoreduced by the lens system near the peripheries of the lens exhibits non-uniformities attributable to lens distortions. For these and other reasons, the operating characteristics and fabrication efficiency of the parallelpiped shaped fluidic apparatus have been less than desirable.

Accordingly, it is an object of this invention to provide an improved fluidic apparatus.

Another object of the invention is to provide a fluidic apparatus having a plurality of fluidic devices and which is configured to enhance the operating characteristics and to reduce the fabrication costs of the apparatus.

Another object of the invention is to provide a fluidic apparatus of reduced dimensions.

Another object of the invention is to provide a fluidic apparatus having enhanced response times.

A further object of the invention is to correct one or more of the above enumerated disadvantages in the operation and fabrication of a fluidic apparatus.

In accordance with the general features of the invention, a fluidic apparatus comprises an annular shaped body which includes a centrally located aperture extending through a thickness of the body. The body includes a plurality of fluidic devices formed therein and which are positioned about the aperture. A flow channel means for each of the devices communicates between the aperture and an associated device while a gas flow manifold extends into the aperture and conveys a gas from a source to the flow channel means. Through this arrangement, the operating characteristics of the apparatus are enhanced because of relatively shorter flow paths extending between intercoupled fluidic devices in the apparatus and because the annular configuration contributes to a uniform shrinkage of the body thereby resulting in an equal variation in characteristic for each of the devices as well as maintenance of alignment and gas seal between the devices. Additionally, the fabrication costs are reduced over present day arrangements and a uniform pressure can be exerted on members of a body by virtue of a single connector secured to a manifold body.

These and other objects and features of the invention will become apparent with reference to the following specifications and to the drawings wherein:

FIG. 1 is an elevation view of a fluidic apparatus constructed in accordance with features of this invention;

FIG. 2 is an exploded view illustrating members of a fluidic apparatus body;

FIG. 3 is an enlarged plan view of a portion of a fluidic device flow disc incorporated in an embodiment of this invention; and,

FIG. 4 is an enlarged sectional view of the fluidic apparatus of FIG. 1.

Referring now to the drawings, the fluidic apparatus is shown to include an annular shaped body 10 which comprises a plurality of annular shaped body members defining a plurality of fluidic devices. FIG. 4 illustrates a two-tier body wherein each tier defines a separate array of symmetrically positioned fluidic devices. Each body, or tier in a multi-tier apparatus, comprises a circular shaped plastic flow disc 12 [FIG. 2] having an aperture 13 located in the center thereof, and formed of polystyrene for example; a circular shaped gasket body 14 having an aperture 15 located in the center thereof and formed of Buna rubber for example; a circular shaped circuit disc 16 having an aperture 17 located in the center thereof and formed of a beryllium copper alloy for example; and a circular shaped gasket body 18 having a centrally located aperture 19 and fabricated of Buna rubber for example. As indicated in greater detail hereinafter, the flow disc 12 and the circuit disc 16 includes a plurality of apertures and transversely extending grooves which define desired flow paths for the fluidic devices. In order to inhibit the relatively soft material of gaskets 14 and 18 from deforming into and obstructing these recesses, there is sandwiched between the flow disc 12 and gasket 14, a circular plastic disc 20 formed of Mylar for example and having a centrally located circular aperture 21. Similar discs 22 and 24 are sandwiched between the circuit disc 16 and the gasket 14 and between gasket 18 and the circuit disc 16 respectively. One or more assemblies of these body members are provided to form a second tier as illustrated in FIG. 4.

The body members are positioned about an elongated, annular-shaped manifold body 26 which provides a means for conveying a carrier gas from a source, not illustrated, to the fluidic devices of the apparatus. The manifold body 26 includes a segment 27 of reduced outside diameter, a centrally located bore 28 and an aperture 30 extending transversely through a wall of the bore. The aperture 30 communicates with an enclosed volume 31 formed by the segment 27 and the body members. A flow stream of carrier gas which comprises air under pressure for example flows to the space 31 over an enclosed path defined by a plastic elbow 32, the bore 28 and the aperture 30. This supply of carrier gas is filtered by a nylon screen 34 which extends into the bore 28 from a distal edge segment 36 of the body 26. The filter screen includes a shoulder 38 which abuts the distal segment 36 of the body 26 and restricts further entry into the bore 28. A press fit is provided between the elbow 32 and body 26 and a force exerted on a lower surface of the shoulder 38 by a shoulder 40 which is formed in the plastic elbow 32 secures the screen 34 in place.

In addition to the body members enumerated herein before, the apparatus includes means for securing the body members in alignment and for mounting members to the manifold body 26. This means includes upper and lower plates 42 and 44 respectively which are circular shaped and have apertures centrally located therein. Indexing pins 45 extend through alignment apertures 46 formed in the body members and through apertures formed in the upper and lower plates in order to provide alignment of the various members of the assembly. These apertures are preferably assymertically positioned about the manifold body in order to inhibit improper assembly of the body members. The upper plate 42 is restrained by a shoulder 47 formed in the manifold body 26. A force is exerted against the lower surface of the plate 44 which secures and mounts the assembly to the manifold body 26. This fore is established by a spacer body 48 and lock nut 49 which engages an exterior threaded surface 50 of the manifold 26. A star washer 51 is located between the spacer 48 and locknut 49 and O-ring gasket 52 provides a leakproof seal between the manifold body 26 and the lower plate 44.

Referring now to FIGS. 2 and 3, the body member configurations for the fluidic apparatus will be described in greater detail. The flow disc 12 includes recesses formed in the surface thereof which when combined with a sealing gasket 14 defines a plurality of fluidic devices equally spaced about a longitudinal axis 60 of the disc. Although, the fluidic devices illustrated in FIG. 2 and 3 are shown to be comprised of flow-mode type amplifiers it is understood that other fluidic devices, as for example wall attachment and proportional amplifier flip-flop and one-shot devices, can equally well be employed in accordance with the general features of this invention. The flow-mode turbulence amplifier device is shown to include a carrier gas emitter channel 62 for conveying carrier gas to a control chamber 64. Positioning of the flat gasket surface 14 on the disc 12 encloses grooves formed in the disc 12 thereby establishing channels and chambers. Carrier gas flowing from the chamber 64 will flow to a collector groove 66 and port 67 and then to an outlet of the device or through vent channel 68 and 70 to vent ports 72 and 74 respectively. Control gas inputs are provided through control gas grooves 76,78,80 and 82 and their associated ports 77, 79, 81 and 83 respectively. The carrier gas for each fluidic device will flow from the manifold aperture 30 (FIG. 4) into the space 31 through a circular manifold formed by a ridge 84 and gasket 14 and through an inlet port 85 to the emitter channel 62. Gasket 15 includes apertures 86 which index with those ports of a fluidic device which are utilized in a circuit while the surface of the gasket seals off the unused ports. Similarly, the discs 20,22, and 24 include apertures 87 which index with the disc ports and apertures 86. These discs may be interchangeably employed by establishing apertures 87 at each port location on a disc 12.

Intercoupling means between the fluidic devices in a flow disc 12 is provided in part by the apertures 87 formed in the Mylar discs 20 and 22, the aperture 86 formed in the rubber gasket 14 and aperture 88 formed in the metal disc 16. The apertures in the discs 20 and 22 and in the rubber gasket 14 index to provide a flow path between a particular groove of a device and conductive path formed in the metal disc 16. For example, in the illustration of FIG. 2, the fluidic device referenced generally as 90 will include a collector groove which indexes with apertures in the disc 20, the rubber gasket 14, the disc 20 and the metal disc 16. A flow path 92 is defined in the disc 16 between the aperture indexed with the collector groove of the device 90 and an aperture indexed with a control groove of another device 94 located on the disc 12. Thus the outlet of the fluidic device 90 is employed as a control input to the device 94. Various other circuit arrangements can be readily provided by establishing the desired flow paths in the disc 16 and by providing proper indexing holes between the desired control and emitter grooves in the flow disc 12.

In addition to the intercoupling between the different flow devices formed on a single flow disc, there is provided intercoupling between the flow discs in different tiers of the apparatus. FIG. 4 illustrates this form of coupling arrangement. In FIG. 4 a collector groove outlet port 100 of a fluidic device indexes with with a port 102 in the circuit disc 16. A channel, not illustrated, is formed in the circuit disc 16 between the port 102 and a second port 104 which indexes with a channel 106 extending in an axial direction and formed in the thickness of a second flow disc 108. This channel 106 indexes with a control groove inlet port 109 for a fluidic device formed on the flow disc 108 in a second tier. Another control groove port 110 of the dame device is shown to index with an aperture 111 in a metal disc 112 and a channel in the disc 112, not shown, couples the aperture 111 to an aperture 114 which indexes with an inlet tubulation 116. A control gas comprising a control input to a fluidic device is supplied from a source not shown to the tubulation 116 through a flexible plastic tubing 118. Through channels, not shown, are also formed by the body members for coupling the inlet tubulation directly to devices of the lower tier. Thus, control of the fluidic devices in the apparatus is provided both by the coupling of an outlet of one device to an inlet of other devices as well as through the application of control gas to the device from an external source. One or more external control sources can be coupled to one or more control inlet tubes. In a similar manner, an outlet tubulation 120 indexes with an aperture 122 for a channel in the circuit disc 117. The channel, not shown, communicates with a collector groove of a fluidic device. The gas outlet flow from he fluidic device is then coupled through a tubulation 124 or alternatively a plug-in coupling, not illustrated, to a utility device. A plurality of such outlet tabulations can also be provided. Through channels, not shown, are also formed by the body members for coupling the outlet tubulation directly to devices of the lower tier.

As indicated hereinbefore, a pair of vent ports 72 and 74 are provided in a flow disc for each of the fluidic devices. These vent ports are formed in the peripheral surface of the flow disc 12. These vents, as indicated, communicate with the channels 68 and 70 respectively and provide a venting path to atmosphere for a device. In order to inhibit the backflow into the device of dust and of other particles which may interfere with its proper functioning, a screen 130 is formed about the peripheral surface of the apparatus body. The screen 130 extends between the upper and lower plates 42 and 44 and abuts against the peripheral surfaces of the various apparatus members. The screening is formed of a suitable fine mesh to inhibit backflow of particles and maintain an unrestricted gas venting flow path. A suitable screen is formed for example of 160 .times. 160 stainless steel mesh or a Monel plain weave. The screen 130 is itself protected from deformations by a second more coarse screen 132 which is positioned about it and which is weaved from polypropylene for example. This screen is secured in position by O-rings 134 and 136 which are positioned over the outer surface of the screen and abut against the upper and lower surfaces 42 and 44 respectively.

The operation of a fluidic device of the flow mode amplifier type referred to hereinbefore will now be described with reference to FIG. 3. Fluid under pressure flows from the manifold body 26 through the emitter channel 62 and forms a laminer jet which is directed into the axially aligned collector groove 66. Fluid thus flows through this channel to a second device or to an apparatus which is to be controlled or operated. Any simultaneous fluid flow in the interaction chamber 64 which does not flow into the collector groove 66 will leave the system via the venting channels 68 and 70 and the associated venting ports 72 and 74. In this mode of operation or condition, the fluid recovery pressure in the collector groove 66 will be relatively high. When it is desired to change the operative condition of the device, a fluid pressure control signal is introduced through any one of the four control line ports 77,79,81 or 83 and their associated grooves 76,78,80 and 82 respectively. When an appropriate fluid pressure control signal is introduced through any one of these ports for example and against the side of the laminer jet, three significant changes occur. First, the laminer jet issuing from the emitter groove becomes turbulent; secondly, the jet of fluid issuing from the emitter groove is caused to deflect to a substantial extent towards a side wall, the axis of this turbulent fluid flow in this case being deflected toward the left when an input is applied to the control port 77 for example; and thirdly, the deflected turbulent fluid stream effectively interacts with the side wall in flowing toward the venting ports 72 and 74 at the downstream end of the chamber 64. Most of the fluid flow during this turbulent mode of operation will exit through the venting ports 72 and 74 and only a relatively small amount will enter the collector groove 66. Thus, in this second operative mode or condition, the fluid recovery pressure in the collector groove 66 will be relatively low. As the fluid control signal applied to the control port 77 is terminated, the fluid flow in the chamber 64 will immediately return to its first or normal operative condition of laminer flow.

Thus, an improved fluidic apparatus has been described which provides a plurality of fluidic devices in a relatively small apparatus thereby enhancing the packing density for a fluidic system employing such apparatus. In addition, the annular configuration of the fluidic apparatus results in uniform shrinkage of plastic flow disc members and a resulting uniform variation in the characteristics of all of the elements when such shrinkage occurs rather than an undesirable varying shrinkage. The alignment and seal between the members is thus maintained. Furthermore, the annular configuration is particularly beneficial when photo-reducing the flow disc and other body members which are initially produced through large scale art work and are then reduced to smaller dimensions. Fringe effects and edge distortions occuring in lens systems employed for reducing this art work are substantially avoided with the circular configuration described. In addition, the use of a single fastner which applies a uniform pressure throughout the body results in a more uniform structure and substantially reduces the fabrication costs by eliminating the need for many rivet connections as has been provided in the past.

The described fluidic apparatus is further beneficial in that the intercoupling paths between different fluidic devices in the apparatus is substantially reduced over prior arrangements by virtue of the configuration disclosed. The reduction in these flow paths substantially reduces the response times of a system employing the fluidic devices. For example, the fluidic device illustrated in FIG. 4 and including the flow disc of FIG. 2 and 3 is particularly useful when intercoupled as a ring counter. The uniform and symmetrical geometry of these devices positioned about a central axis contributes to the reduction in the length of flow path and renders this configuration particularly useful as a ring counter form of digital device.

While I have described and illustrated a particular embodiment of my invention, it will be apparent to those skilled in the art that various modifications may be made thereto without departing from the spirit of the invention and the scope of the appended claims.

Claims

What is claimed is:

1. A fluidic apparatus comprising:

a plurality of annular shaped body members each having a thickness thereof and including a centrally located aperture extending through the thickness of the member, said plurality of members including a flow disc having a plurality of grooves formed in a surface thereof, and a gasket having apertures for converting said grooves into channels and chambers and for providing input and output ports to said channels and chambers;

a manifold body adapted to extend through the central aperture of each of said members; and

means directly connected to the manifold body for mounting said body members on said manifold body with the apertures of all said body members being in alignment and said manifold body extending through said aligned apertures, said flow disc and gasket defining between them a plurality of fluidic devices each having at least an emitter channel, a chamber, and input and output ports;

said manifold body defining a gas flow passage communicating between a gas source and each of said emitter channels for providing a gas supply input to said fluidic devices.

2. The apparatus of claim 1 wherein at least one of the channels of one of the fluidic devices communicates with the periphery of said body for venting the fluidic device to atmospheric pressure.

3. The apparatus of claim 1 wherein said fluidic devices are defined by a tier of said annular shaped body members, and said annular shaped body members include a plurality of several such tiers mounted on the manifold body.

4. The apparatus of claim 3 wherein means are provided for establishing flow paths between the devices in different tiers of said apparatus.

5. The apparatus of claim 1 wherein said body members are circular shaped, said plurality of devices are symmetrically positioned about the axis of said aperture in said flow disc, and said emitter channels extend in a radial direction from said aperture.

6. The apparatus of claim 1 wherein said gasket is formed of a relatively soft sealing material, and said body members include a disc, formed of a relatively more firm material, which is positioned between said flow disc and gasket.

7. The apparatus of claim 1 wherein said manifold body is cylindrically shaped and includes an axially extending bore and a transversely formed aperture extending between the bore and an outer surface of said body for providing a fluid flow path through said bore to said aperture and through said aperture to said fluidic devices, and said means for mounting said body members comprises first and second annular shaped plates each having apertures therein and through which said manifold body extends, said plates positioned on said body for positioning therebetween said plurality of annuarly shaped apparatus body members, and a locking means secured to said manifold body and establishing a force between said first and second plates.

8. The apparatus of claim 7 wherein said manifold body includes an externally formed threaded segment and said locking means comprises a means for engaging said threaded segment and for applying a force to said second plate.

9. The apparatus of claim 8 wherein said manifold body includes a shoulder formed therein near a distal segment thereof for restricting motion of said first plate in an axial direction, a spacer body abutting against said second plate and means for forming a gas tight seal between said manifold body and said plate, and a nut engaging said thread and abutting against said spacer means for establishing a force against said second body.