US3583420A

US3583420A - Fluid operated devices

Info

Publication number: US3583420A
Application number: US788840A
Authority: US
Inventors: Peter J Campbell
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1969-01-03
Filing date: 1969-01-03
Publication date: 1971-06-08
Anticipated expiration: 1988-06-08

Abstract

A fluidic switching device comprising a liquid globule in one chamber of a generally hourglass-shaped structure is adapted, via a vent associated with the chambers and via common input connections, to function as a binary counter, an oscillator, or as two stages of a ring counter. A pulsed input provides binary counter operation, and a continuous input provides oscillation of the liquid globule between the hourglass chambers.

Description

United States Patent (72] Inventor I PcterJ. Campbell 3,438,384 4/1969 Hurvitz 137/81.5 Columbus, Ohio 3,450,340 6/1969 Reader 235/ I me 1 1 PP 7883409 OTHER REFERENCES med Fluid Decimal Counter," D. J. Truslove, 1.B.M. Technical pa'emed 0' 1 B n r 1 s N 3 A 1963 2627 [73] Assignee Bell Telephone Laboratories, Incorporated u e (copy Murray Hm Berkeley Heigms NJ in Scien. Lib. & Gp. 282, 235 201m.e.)

Fluid Binary Memory Cell A. E. Mitchell ct al., IBM. Technical Disclosure Bulletin, vol. 8, No. 3, Aug., 1965, pp. [54] FLUID OPERATED DEVICES 429, 430. (copy in Scien. Lib. & Gp. 282, 235- 20lm.e.)

4 Chill", 4 Drawing 8 Primary Examiner-Samuel Scott 52 us. Cl. l37/8L5, Attorneys-R Guemher and Kenneth Hamlin 235/201 [51] IIILCI F156 3/06 Flt of Search ..I l37/8L5; ABSTRACT: A fluidic switching device comprising a liquid i 235/201 globule in one chamber of a generally hourglass-shaped struc- 56 R t Ci ed ture is adapted, via a vent associated with the chambers and l l e t via common input connections, to function as a binary UNITED STATES PATENTS counter, an oscillator, or as two stages of a ring counter. A 3,151,623 10/1964 Riordan 235/201me pulsed input provides binary counter operation, and a con- 3,17l,915 3/1965 Johnson 137/81.5X tinuous input provides oscillation of the liquid globule 3,181,546 5/1965 Boothe 137/81.5 between the hourglass chambers.

VENT

5 H5 I02 "hs-- i i I r I I I0 n2 I07 1 i 1 l i 7 l g I *a v mo 0/ l l l |2| 1 i 122 5 i l 1 I r l l O Q I O l l 1 i I :32 g a a 1 i i I I I I j l y PATENTEUJUN 8l97l 3583420 SHEET 2 BF 2 FIG. 4

FLUID OPERATED DEVICES This invention relates to fluid operated devices and, more particularly, to fluid pressure operated switching devices adapted to perform various logic functions.

Fluid pressure operated devices are typically of two types; the so-called pure fluid devices having no moving elements, and fluid devices having moving elements. In the latter devices the moving elements may be, for example, sliding members, rotating valves, liquid globules, or the like. Fluid devices with moving elements are particularly useful where increased system stability is desired. Additionally, the moving elements in such devices can be employed advantageously to manifest various forms of output signals, such as for interfacing with other systems, for signaling, or for visual display. Thus, displacement of the moving element under control of fluid pressure can reveal or conceal a light beam, for example, or, if the moving element is of a conductive material, displacement thereof can make or break electrical connections.

The major disadvantages of known moving element fluid devices concern the relative complexity and the number of moving elements required to provide certain basic logic functions such as binary counting.

SUMMARY OF THE INVENTION A principal object of this invention, therefore, is to provide a simple, economical and reliable moving element, fluid pressure operated binary counter.

A further object of this invention is to provide a simple, economical and reliable fluid pressure operated device which is adaptable in tandemly connected combinations to function as a shift register or a ring counter.

In an illustrative embodiment of the present invention, the above and other objects are attained through the use of a fluid pressure operated, two-state switching device comprising two compartments or chambers interconnected with one another through a restricted passage in the manner, for example, of an hourglass-shaped structure. One of the compartments contains a globule of liquid, which may be electrically conductive material such as mercury, of sufficient quantity and of sufficiently high surface tension to prevent free movement of the material through the restricted passage. Sensing apparatus is disposed in at least one of the two compartments to provide an output manifestation of the position of the liquid globule. For example, assuming the liquid globule to be conductive material, the sensing apparatus advantageously includes a pair of electrical contacts disposed in one of the compartments so as to be bridged by the conductive material when the material is in the one compartment, thereby providing an electrical connection between the bridged pair of contacts.

Individual input fluid pressure paths are associated with each of the compartments and are connected, for example, to fluid logic circuitry. Increasing the fluid pressure in one of the input fluid pressure paths effects transfer of the liquid globule from the compartment associated with the one path through the restricted passage to the other compartment.

In accordance with one aspect of my invention, the input fluid pressure paths to the two compartments are connected to a common input path, and a vent path is associated with the two compartments. The vent path is adapted to vent or decrease the input fluid pressure in the empty compartment, that is, the compartment not containing the liquid globule, until transfer of the globule from the other compartment through the restricted passage has at least been initiated. Thus, successive fluid pressure pulses applied to the common input path effects transfer of the liquid globule back and forth between the two compartments to provide binary counter operation.

According to a further aspect of my invention three or more such compartments may be connected advantageously in tandem to provide shift register or ring counter operation. Individual input fluid pressure paths associated with each compartment are connected to a common input path, successive input fluid pressure pulses advancing the liquid globule through successive ones of the tandemly connected compartments. Sensing apparatus associated with each compartment provides an output manifestation of the particular compartment in which the liquid globule is positioned.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects and features of the invention may be fully apprehended from the following detailed description and the accompanying drawing in which:

FIG. 1 shows an illustrative embodiment of a basic two-state fluid pressure operated switching'device in accordance with the principles of my invention;

FIG. 2 shows an alternative illustrative embodiment of a two-state fluid pressure operated switching device according to the principles of my invention;

FIG. 3 shows another alternative illustrative embodiment of a fluid pressure operated switching device according to my invention particularly adapted to function as an oscillator; and

FIG. 4 shows an illustrative embodiment of a fluid pressure operated ring counter in accordance with the principles of my invention.

DETAILED DESCRIPTION OF THE INVENTION In the illustrative embodiment of a two-state fluidic switching device, shown in FIG. 1, two compartments or chambers I00 and 102 are interconnected with one another through a restricted passage 105. One of the compartments of the switching device, such as compartment 100, contains a globule of liquid 107 which is preferably nonwetting and which is of sufficient quantity and of sufficiently high surface tension to prevent free movement of the globule through the restricted passage 105.

Sensing apparatus is disposed in one or, as shown in FIG. 4, in both of compartments 101 and 102 to provide an output manifestation of the position of liquid globule 107. For example, assuming the liquid globule to be of a conductive material such as mercury, the sensing apparatus may comprise a pair of

electrical contacts

120 and 121 disposed in compartment and a pair of

electrical contacts

122 and 123 disposed in compartment 102, as shown illustratively in FIG. 1.

Contacts

120 and 121 are bridged by globule 107 when the globule is in compartment 100 so as to provide an output manifestation thereof at terminals I30 in the form of an electrical connection between

contacts

120 and 121. Similarly, when globule 107 is in compartment 102,

contacts

122 and 123 are electrically bridged to provide an output manifestation at terminals 132.

Individual input

fluid pressure paths

110 and 112 are associated with

switching device compartments

100 and 102, respectively. Increasing the fluid pressure in one of input fluid pressure paths I10 and 112 effects transfer of liquid globule 107 from the switching device compartment associated with the one fluid pressure path through restricted passage 105 into the other switching-device compartment. For example, if the fluid pressure in fluid pressure path is increased sufficiently, relative to the pressure in fluid pressure path 112, globule 107 will be urged through restricted passage 105 into compartment 102.

However, in accordance with my invention, input

fluid pressure paths

110 and 112 are connected to a common input path 150 which, in turn, may be connected, for example, to fluid logic circuitry (not shown). lncreasing'the fluid pressure in common input path 150, therefore, increases the fluid pressure in both of

paths

110 and 112 to

respective compartments

100 and 102. Vent path 115 isassociated with compartments I00 and 102 and is adaptedto vent or decrease the inputfluid pressure in the empty one of

compartments

100 and 102, that is, the compartment in which globule 107 is not located.

Thus, when an input fluid pressure pulse, illustratively on the order of 0.2 to 2 p.s.i. and having a duration onthe order of l to ID milliseconds, is applied to common input path and extended over

paths

110 and 112 to

compartments

100 and 102, vent path 115 decreases the pressure in empty compartment 102, permitting the pressure extended to compartment 100 to initiate transfer of globule 107 through restricted passage 105 to compartment 102. There is, of course, a tendency for the surface tension forces to assist in transfer of globule 107 into compartment 102 once transfer through passage 105 has been initiated.

A second input fluid pressure pulse subsequently applied at common input path 150 similarly effects transfer of globule 107 from compartment 102 back through passage 105 into compartment 100. In this manner the illustrative embodiment of FIG. 1 operates as a binary counter, globule 107 from compartment 102 back through passage 105 into compartment 100. In this manner the illustrative embodiment of FIG. 1

operates as a binary counter, globule 107 switching back and forth between

compartments

100 and 102 in response to successive fluid pressure pulses applied at common input path 150 and providing corresponding output manifestations at

terminals

130 and 132.

As globule 107 passes through passage 105, vent path 115 is blocked thereby. Accordingly, the transfer of energy to globule 107 from an input fluid pressure pulse applied at input in FIG. 2 in which individual vent paths 216 and 2l8 are associated with each of

compartments

200 and 202, thereby permitting a greater interval for energy transfer to globule 107. Operation of the embodiment of FIG. 2 is substantially similar to the operation of the embodiment of FIG. 1 described above, successive fluid pressure pulses'applied at common input 250 effecting the transfer of globule 207 back and forth between

compartments

200 and 202. The

individual vent path

216 or 218 associated with the empty compartment decreases the pressure in the empty compartment decreases the pressure in the empty compartment such that the input pulse issufficient to initiate transfer of globule 207 through restricted passage 205 to the empty compartment.

Sensing means, illustratively comprising interrogation port 280 and sensing port 281 in FIG. 2, provide an output manifestation of the location of globule 207. Thus, when a fluid pulse is applied at port 280 at a time when globule 207 is located in compartment 200, no output pulse occurs at port 281. On the other hand, when an input pulse is applied at port 280 and globule 207 is located in compartment 202, the pulse is extended through empty compartment 200 to sensing port 281 as an output manifestation.

The embodiment in FIG. 2 also comprises foraminous interface material 211, which may be a porous ceramic or plastic material, for example, disposed in

input paths

210 and 212 and in

vent paths

216 and 218. Foraminous interfaces 211 prevent globule 207 from entering

paths

210, 212, 216 and 218 but are porous to fluid pressure flow therethrough. Additionally, interfaces 211 provide further control of the resistance to input fluid pressure flow in

paths

210 and 212.

Although the fluid device embodiments of FIGS. 1 and '2 have been described above in terms of their operation as binary counters in response to input pulses, these devices may also be operated advantageously as fluid oscillators in response to a continuous fluid pressure input applied at path 150 or path 250. Considering the embodiment of FIG. 1, by way of example, when fluid pressure is initially applied at input path 150, globule 107 is urged through passage 105 into compartment 102 in the manner described above. However, as globule 107 is transferred through passage 105 and enters compartment 102, vent path 115 is unblocked. The fluid pressure differential between

compartments

100 and 102 therefore reverses, the fluid pressure applied to compartment 100 over path being now decreased by venting through path 115. The fluid pressure extended to path 112 from the continuous pressure input at path 150 thus urges globule 107 back through passage 105 into compartment 100. Again, as globule 107 is transferred through passage 105 vent path 115 is first blocked and then unblocked by the globule. Movement of globule 107 into compartment 100, unblocking vent 115, once again reverses the fluid pressure differential so as to initiate transfer of the globule back to compartment 102. Oscillation of globule 107 between compartments 100and 102 continues in this manner until the fluid pressure input at path is terminated.

Another alternative fluid pressure operated switching device embodiment is shown in FIG. 3 which, although it may be operated as a binary counter in substantially the same manner as the embodiments of. FIGS. 1 and 2, is particularly adapted to function as a fluid oscillator. For this purpose

individual paths

360 and 362 corresponding generally to vent

paths

216 and 218 in FIG. 2 are associated with

respective compartments

300 and 302 and are interconnected via compartment 365.

Compartment 365 functions as a fluid capacitor and, in conjunction with foraminous interfaces 311 and

paths

360 and 362, functions as an R-C circuit for principally determining the frequency of oscillation of the embodiment of FIG. 3.

According to a further aspect of the invention, additional switching device compartments may be connected in tandem to the basic two-state device to provide additional states such as for ring counter operation, n compartments providing n states of operation. For example, an illustrative three-state ring counter embodiment is shown in FIG. 4 comprising three

compartments

401, 402 and 403. Each compartment is connected in tandem to the next through a restricted passage; compartment 401 is connected to compartment 402 through passage 421, compartment 402 to compartment 403 through passage 422, and compartment 403 to compartment 401 through passage 423. Individual input

fluid pressure paths

411, 412 and 413, respectively associated with

compartments

401, 402 and 403 are connected via manifold 451 to common input path 450.

Vent paths may be associated with the several compartments in the manner, for example, of the two-state embodiment of FIG. 1 Thus, in FIG. 4 vent path 415 disposed in restricted passage 421 is associated with

compartments

401 and 402, vent path 416 is associated with

compartments

402 and 403, and vent path 417 with

compartments

403 and 401. Further, sensing apparatus is associated with each compartment to provide an output manifestation of the location therein of liquid globule 407. Illustratively in FIG. 4 globule 407 is assumed to be of conductive material and pairs of electrical contacts are disposed in each of

compartments

401, 402 and 403 so as to be bridged when globule 407 is located in the compartment, thereby providing corresponding output manifestations at respective terminal pairs 431, 432 and 433.

Advantageously,

input paths

411, 412 and 413 may be angled or biased in the desired direction of movement of globule 407 to insure movement of the globule in a particular direction around the ring of compartments, such as for counterclock'wise movement as shown, by way of example, in FIG. 4. Thus, when an input fluid pressure pulse is applied at input path 450 and extended through manifold 451 to each of

input paths

411, 412 and 413, globule 407 is urged through restricted passage 421 into compartment 402 in a manner substantially similar to that described in connection with FIG. 1 above. A second pulse at input path 450 initiates transfer of globule 407 from compartment 402 through passage 422 into compartment 403 and a third input pulse effects transfer of globule 407 through passage 423 back into compartment 401. Successive input fluid pressure pulses applied at input path 450 thus advance globule 407 through successive ones of tandemly

connected compartments

401, 402 and 403 in a coun- I Although the embodiments of the drawing have been depicted illustratively as generally hourglass-shaped structures, it will be apparent that other shapes may be employed with equal facility as well as other types of moving elements. For example, the restriction to passage of the liquid globule between compartments need not be by virtue of size or shape of the interconnection between the two compartments but may be by virtue of a suitable foraminous material interposed between the two compartments. Moreover, various alternatives exist for moving elements in the form of liquid globules and, in fact, inasmuch as fluid devices are operable at elevated or reduced temperatures without impairment, the globule need not be liquid at ambient temperature. It is to be understood, therefore, that the above-described arrangements are but illustrative of the application of the principles of applicant's invention. Numerous other arrangements may be devised by those skilled in the art without departing from the spirit and scope of the invention.

lclaim:

l. A fluidic device comprising a housing having two compartments separated by a restricted passage, a movable element disposed in one of said compartments, said restricted passage preventing free movement of said movable element between said two compartments, means for directing input fluid pressure signals in common to both of said compartments, said directing means including a single input fluid pressure path and pressure path means connecting said input path in common to both of said compartments, and vent path means associated with said compartments for venting individual of said compartments when said movable element is not disposed therein, said vent path means comprising a single vent path connected to said restricted passage so as to be blocked by said movable element during movement of said element through said restricted passage, whereby an input fluid pressure signal applied to said input path effects movement of said movable element between said two compartments through said restricted passage.

2. A fluidic device comprising a housing having two compartments separated by a restricted passage, a movable element disposed in one of said compartments, said restricted passage preventing free movement of said movable element between said two compartments, means for directing input fluid pressure signals in common to both of said compartments, said directing means including a single input fluid pressure path and pressure path means connecting said input path in common to both of said compartments, and vent path means associated with said compartments for venting individual of said compartments when said movable element is not disposed therein, said vent path means comprising an individual vent path connected to each of said compartments such that each said individual vent path is blocked when said movable element is disposed in said compartment connected thereto, whereby an input fluid pressure signal applied to said input path effects claim 2 of said movable element between said two compartments through said restricted passage.

3. A fluidic device in accordance with claim wherein said vent path means further comprises means interconnecting said individual vent paths.

4. A fluidic device comprising a housing having two compartments separated by a restricted passage, a movable element disposed in one of said compartments, said restricted passage preventing free movement of said movable element between said two compartments, a single input fluid pressure path, pressure path means connecting said input path in common to both of said compartments, vent path means associated with said compartments, said vent path means comprising an individual vent path connected to each of said compartments and means including fluid capacitor means interconnecting said individual vent paths, and means for providing an input fluid pressure signal to said input path to effect movement of said movable element between said two compartments through said restricted passage.

Claims

1. A fluidic device comprising a housing having two compartments separated by a restricted passage, a movable element disposed in one of said compartments, said restricted passage preventing free movement of said movable element between said two compartments, means for directing input fluid pressure signals in common to both of said compartments, said directing means including a single input fluid pressure path and pressure path means connecting said input path in common to both of said compartments, and vent path means associated with said compartments for venting individual of said compartments when said movable element is not disposed therein, said vent path means comprising a single vent path connected to said restricted passage so as to be blocked by said movable element during movement of said element through said restricted passage, whereby an input fluid pressure signal applied to said input path effects movement of said movable element between said two compartments through said restricted passage.