US3160723A

US3160723A - Power

Info

Publication number: US3160723A
Authority: US
Publication date: 1964-12-08
Anticipated expiration: 1981-12-08

Description

United States Patent greases V contra-oi APRARATUS USlNG sneer ways nivsnov Joseph E. Wallace, Endicott, N.Y., assignor to ln'ternw tional Business Machines tiurporation, New York, NE a corporation oi New York Filed .luly 2'7, 1962, tier. N 2.112525 11 Claims. (6i. EARL-83) This invention relates to control apparatus actuated by the shockwave energy from a controlled electrical discharge, and more particularly relates to an improved high-speed electrical switching device actuated by shockwave energy.

Solid state switching devices and reed relays are two types of commercially available switching devices that are capable of completing electrical circuits in less than 1 millisecond. Solid state devices switch very rapidly; but in this class of devices, the contact is of low impedance or high impedance-in other words, never completely open. Reed relays can be used to control circuits having relatively high currents; but they must be used in low-voltage circuits because the reeds are separated by very small gaps, such as about .003 inch. Hence, it the reeds formed part of a circuit including a source of high potential, such as 1,900 volts, breakdown of the air gap undoubtedly would occur; and also arcing of the con tacts and contact wear would increase substantially. Moreover, since the operating time or a relay is dependent upon the air gap, a slight increase in air gap will result in a substantial increase in the operating time of the reed relay. Also, reed relays are subject to contact wear due mainly to contact bounce from the high impact kinetic energy of the reeds.

Furthermore, with conventional electromagnetic relays, the energy available at the instant the energizing circuit is closed is approximately zero. This energy must thereafter build up to a predetermined degree before the armature will move.

One object of this invention is therefore to provide an improved control apparatus including a movable control member that is variously positionable by shockwave energy produced by a controlled electrical discharge.

Another object of this invention is to provide an electrical switching device which can be controlled from a high-voltage source to complete circuits capable of carrying relatively high currents.

Another object is to provide a high-speed electrical switching device in which contact bounce is substantially eliminated and contact wear is accordingly minimized, and fast response times are accomplished despite relatively large air gaps.

Still another object of this invention is to provide an electrical switching device which will remain latched in position after dissipation of the shoclrwave energy.

A further object of this invention is to provide an electrical switching device wherein the energy available at the instant of actuation is at a maximum (rather than a minimum).

According to these objects, the device embodying the invention comprises a flexible strip anchored at one or both ends. A pair of coaxially aligned electrodes have their tips separated by an air gap provided in a recess disposed at one side of the flexible strip. When a high voltage source is connected to these electrodes, the gap will be ionized. The resultant shocltwave is focused against the side of the flexible strip to shift it laterally to perform a desired control operation; e.g., translationally shift a contact element to a circuit-making or circuit- 3,160,?23v l atentecl Dec. 8, 1964 lowing more particular description of preferred embodiments of the invention, as illustrated in the accompanyins drawing, wherein:

FIG. 1 is a schematic View of a control apparatus including a pair of high-speed electrical switching devices constructed according to one embodiment of the invention to provide transfer-type switching operations in both directions as a result of shockwave energy;

FIG. 2 is a variation of the arrangement shown in FIG. 1, in that it shows a single switching device actuated to one position by shockwave energy and mechanically returned to a normal position; and

H65. 3 and 4 are modified versions of the switching devices shown in FEGS. l and 2, wherein a flexible shockwave-actuated contact control member is cantilever supported at one end instead of at both ends.

DESCRIPTION As shown in PEG. 1, the apparatus constructed according to this embodiment of the invention comprises a pair of electrically-controiled switching devices, it it). As illustrated, each or" these devices comprises a pair of coaxially aligned electrodes Ill, that are embedded or otherwise carried within a ceramic electrode block 13. The tips of the electrodes are separated by an air gap. This gap is provided within a bore-like recess 14 that extends inwardly from a concave surface 315 formed in one side of the electrode block.

A thin flexible metallic strip to has both of its ends anchored, such as by screws 17, to the side or block 3.3 in which surface i5 is formed. These screws are spaced closely enough so that the strip will normally be bowed and assume either of the two stable positions indicated in PK}. 1 (wherein the degree Oi catenary curvature is exaggerated for clarity). The spacing of screws 17 and the curvature of surface 15 are so selected that when the strip 16 is in one of its two stable positions, the strip will contact surface 15' in such manner as to at least partially seal oil" the end of recess M.

The switching devices 19, it? are spaced with their respective recesses lid generally aligned and facing each other. A mechanical operating connection is provided between the spaced flexible strips in of the respective devices by a single intervening rod-like element 18. This element makes end contact with each strip at the point where displacement of each strip is greatest; namely, at a point midway between the screws 17 and just opposite the corresponding recess. Element ll; is of such length that it will substantially contact each strip it? when one of the strips overlies its corresponding recess lid and the other strip is bowed the maximum degree away from its recess. Thus, motion will be transmitted from one strip through element l to the other strip; and hence, under stable conditions, both strips will be concurrently disposed in their lettwardly flexed positions, as shown in FIG. 1, or in their rightwardly flexed positions. Thus, as the strips 16 flex between these stable positions, element 38 will be displaced axially a corresponding degree.

As illustrated, element if; has slidably guided contact with the walls of aligned bores that extend through a container This container is partitioned into three laterally spaced

chambers

21, 22, 23, each containing iercury or amalgam or some other electrically conducrive liquid. The element it; is formed of non-conductive material except for a sleeve 24 that is formed of electricaliy conductive material. This sleeve is long enough to electrically interconnect the liquid in middle chamber with thatin either, but not both, of the end chambers 21, This sleeve 2% encircles a reduced diameter portion of the rod-like clement lib so that the outer diameter of both that portion and remaining portion of the element are substantially equal. Hence, no conductive liquid will flow between the chambers as the element 15 is moved axially in either direction relative to the container 20. In so moving, element 18 will alternatively complete either of two circuits by selectively connecting a wire 25 either to a wire 26 or to a wire 27.

Identical, but separate, control circuits are associated with each switching device ill, ll) to control their selective operation and consequently control the displacement of element 13. Each control circuit comprises a high voltage power source 28 for charging an energy capacitor 29 when a switch Eli is closed. The source 28 and capacitor 29 of each circuit are connected in parallel with the

respective electrodes

11, 12 through a switch 31.

In operation, assume initially that both switches 3t? are closed to charge the corresponding capacitors that both switches 31 are open; and that element 16 is positioned as shown in FIG. 1 to connect wire with wire 26. To connect

wires

25 and 27 and disconnect wire 25 from wire 26, the switch 31 associated with device 119 is closed to apply a high potential across the electrodes ll, 12 suflicient to break down the air gap therebetween. As the capacitor 2? associated with device 16 discharges along the air gap, it will create an increase in air pressure within the corresponding recess 14. Because of its shape, that recess 14 will act like a nozzle and focus the resultant shockwave against the midpoint of the flexible strip 16 of device lit. The shockwave energy will thus flex the strip inside out. In so doing, it will displace element 18 rightwardly for causing sleeve 24 to successively disconnect wire 25 from wire 26 and then connect wire 25 to wire 27. Also, as element 18 moves rightwardly, it will transmit some of the shockwave energy from device Irtl to the flexible strip 16 of device Ill) for flexing the latter strip inside out to its other stable position in which it Will come to rest against concave surface 15 of the corresponding electrode block 13. This will serve to define the rightmost position of element 18, just as the leftmost position of said element is defined by contact of strip 16 with the electrode block of device ltl.

Switch 31 of device lit) may now be opened. Upon subsequent closure of switch 31 of device ill, element 18 will be driven to its leftmost position, in which it is shown, by a shockwave that is produced in recess 14- of device Ill in the same manner as already described.

Thus, upon breakdown of the air gaps in first one and then the other of the devices ltl, iii, the contact element 18 will be displaced between its two stable positions; i.e., it will remain latched in each position until positively actuated to the other position.

According to the variation of the invention illustrated in FIG. 2, the contact element id is displaced to its leftmost position by shockwave energy upon breakdown of the gap in switching device lit, in the manner already described. However, the element 18 is mechanically returned automatically to its rightmost position by a cam 32. The control or triggering circuit for the electrodes ll, 12 of device it) contains the same elements as in FIG. 1; but a circuit breaker cam CB has been placed in the triggering circuit to open said circuit while the high point of the cam 32 is in contact with element if. This cam CB is driven from the same shaft as cam 32 and so disposed as to prevent damage to the apparatus which might otherwise occur if no cam CB were provided and the switch 31. were closed while the cam 32 was positioned as shown in FIG. 2.

It is to be understood that the

switches

30, 31 shown in FlGS. 1 and 2 are illustrated as being of the manually operable type for purposes of simplified illustration.

They may, of course, be replaced with other switches, operable electrically, electro-magnetically or electronically. Also, the wetted contact arrangement shown in FIGS. 1 and 2 and provided by container fill may be replaced by other types of contact-making and breaking arrangements. Moreover, if preferred, the element 18 may be axially displaced by shockwaveenergy in the manner herein disclosed for performing some other type of useful work, not necessarily an electrical switching function.

According to the embodiment shown in FIG. 3, a thin flexible strip 16a is cantilever-supported by being clamped at one end between an electrode block 13a. and a nonconductive (such as plastic) contact support 35. When in its free state, strip lea overlies a bore-like recess 14:: extending inwardly from a flat surface 15a of the block 13a; and the free end of the strip makes electrical connection with a normally closed contact point 36 carried by block 136:.

When the gap between the tips of

electrodes

11a, 12a is broken down, such as by circuitry described in FIG. 1, the resultant shockwave created in recess 14a will be focused against the flexible strip 16a and drive it into electrical connection with a normally open contact point 37 carried by the support 35. After the shockwave energy dissipates, the flexible strip 16a will be returned by its inherent resiliency to its normal position in which it is shown in FIG. 3. Hench, an electrical circuit will normally be established between the flexible strip 16 and contact point as except immediately following ionization of the air gap in recess Ma, thus providing what may be called a monostable switching device.

In the modified arrangement shown in FIG. 4, a flexible strip 165 is cantilever-supported between electrode blocks 33b, 13c having respective bore-like recesses 14b, that face each other and are substantially coaxially aligned at opposite sides of said strip. The tips of electrodes ill), 12b are separated by a gap within recess 14!); and electrodes Me, 120 are separated by a similar gap in recess Me.

When unfiexed, the flexible strip 16b is spaced substantially equal distances from the ends of the

recesses

14b, 14c and also from contact points it) and 41. By associating

permanent magnets

42, 43 with the respective contact points as, all, the relay will operate as a latch type. In such case, the flexible strip lea will be held by the magnet 32 or all in contact with the corresponding contact point 4% or 41 until it is actuated by shockwave energy into contact with the other of the contact points. However, if this latch function is not desired, the

magnets

42, 43 may be eliminated. In such case, the electrical circuit will be completed through strip 16b and contact 40 only momentarily after the air gap is broken down in recess 14c; and, similarly, an electrical circuit will be completed through said strip and contact point 41 only momentarily after the gap is broken down in recess 14b.

The following is a tabulation, given by way of example only, of illustrative operate times that have actually been obtained with switching devices of the type shown in H68. 1, 2 and 3, where:

E is elcctromotive force in volts;

C is capacitance in microfarads;

W is energy in joules;

S is the air gap in inches; and

0/1 is the operate time in microseconds.

(l) Latch Relay, as shown in FIGS. 1 and 2, using flexible strip (116) having an unclarnped length of 2 /2 inches, width of .150 inch, and thickness of .005 inch:

(2) Monostable Relay, as shown in FIG. 3, using flexible strip (16a) having an unclamped length of 1 inches,

width of .150 inch, and thickness of .005 inch:

(:2) To close Normally Open Point (37)- E o W s O/T (11) To open Normally Closed Point (36)- n 0 W s O/T 1, 000 .5 .25 12 1, 500 .5 .50 0 2,000 .5 1.00 7 2,500 .5 1. 50 0 1,000 .25 .13 15 1,500 .25 .2s 14 2,000 .25 .50 1s 2, 500 .25 .78 12 1, 000 .1 .05 22 1,500 .1 .11 2,000 .1 .20 18 2,500 .1 s1 17 While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. Control apparatus comprising a movable member having two stable positions in which it is selectively positionable to perform desired control operations,

a plurality of electrodes separated by a gap means disposed beside said member,

circuit means for applying an electrical potential to said electrodes for producing a controlled electrical discharge across said gap means to create a shockwave, and

means for focusing said shockwave against said member to operatively actuate it from one of its stable positions to another of its stable positions.

2. Control apparatus comprising a flexible member anchored at at least one end and selectively positionable in either of two stable positions for performing desired control operations,

a plurality of electrodes separated by a gap means disposed beside said element, and

means for applying an electrical potential across said electrodes suiiicient to ionize said gap means and pro duce a shockwave for flexing said member from one of its positions to another of its positions.

3. Control apparatus comprising a thin flexible strip,

means for anchoring the strip at both ends to provide a slight bow therein,

a plurality of electrodes separated by a gap means disposed beside the strip,

means for applying an electrical potential across said electrodes to ionize said gap means and produce a shockwave, and

means for focusing the shockwave against substantially the point of maximum extension of the bowed portion of the strip thereby to flex the bowed portion inside out to an oppositely bowed position for performing a desired control operation.

4. A control apparatus comprising a flexible member anchored at at least one end,

a plurality of electrodes separated by a gap means at one side of said member,

means for applying an electrical potential across said.

electrodes sufiicient to ionize said gap means and produce a shockwave adequate to hex said member, and

an element disposed at the other side of said member and movable translationally by and upon flexing of said member thereby to perform a desired control operation.

5. Electrical switching apparatus comprising a movable member having two stable positions in which it is selectively positionable for controlling the making and breaking of an electrical circuit,

a plurality of electrodes separated by an air gap means disposed adjacent said member, and

circuit means for applying an electrical potential to said electrodes for effecting a controlled electrical discharge across said gap means to produce a shockwave for operatively actuating said member from one of its positions to another of its positions.

6. Electrical switching apparatus comprising a flexible switching member anchored at at least one end,

a contact element operably connected to said member to make and break an electrical circuit including such contact means,

means providing a recess which said member overlies when in one stable position,

a pair of electrodes separated by an air gap provided within said recess, and

circuit means for applying an electrical potential across said electrodes for producing a controlled electrical discharge to break down said air gap and produce a shockwave that is focused toward said member by said recess-providing means to actuate said member from said one position to another stable position.

7. A switch apparatus according to claim 6, wherein said flexible member is anchored at both of its ends such as to have a preset bow overlying said recess, said flexible member being of such configuration as to buckle inside out as it moves from said one position to said other position, thereby to remain in said other position indefinitely until positively returned to said one position.

8. A switching apparatus according to claim 7, including cluding a permanent magnet associated with each contact point to maintain the flexible member engaged with such contact point until the flexible member is positively disengaged from said contact point by a subsequent force.

l1. Electrical switching apparatus comprising a block of non-conducting material having a nozzlelike recess in one side thereof,

a pair of electrodes supported by said block and having their tips spaced by a gap existing within said recess,

a flexible switching control member anchored at both ends at points spaced closeenough together to how such member to one position in which it substantially overlies and at least partially blocks said recess, and

circuit means for applying an electrical potential across said electrodes for producing across said gap 2. controlled electrical discharge and consequent shockwave which is directed laterally by said nozzle-like recess against said flexible member for buckling it inside out to another position in which it is oppositely bowed,

8 whereby said flexible member will remain in said 2,559,227 Rieber July 3, 1951 other position until shifted therefrom by a subse- 2,824,928 Hedlund Feb. 25, 1958 quent force. 2,901,580 Kelly Aug. 25, 1959 References Cited in the file of this patent 5 2920250 Thomas et 1900 UNITED STATES PATENTS OTHER REFERENCES 2,403,990 Mason July 16, 1946 Parr, J. Frederick: Hydrospark Forming, The T001 2,552,389 Mason Sept. 12, 1950 Engineer, vol. 44, N0. 3, March 1960, pp. 81-86.

Claims

2. CONTROL APPARATUS COMPRISING A FLEXIBLE MEMBER ANCHORED AT AT LEAST ONE END AND SELECTIVELY POSITIONABLE IN EITHER OF TWO STABLE POSITIONS FOR PERFORMING DESIRED CONTROL OPERATIONS, A PLURALITY OF ELECTRODES SEPARATED BY A GAP MEANS DISPOSED BESIDE SAID ELEMENT, AND MEANS FOR APPLYING AN ELECTRICAL POTENTIAL ACROSS SAID ELECTRODES SUFFFICIENT TO IONIZE SAID GAP MEANS AND PRODUCE A SHOCKWAVE FOR FLEXING SAID MEMBER FROM ONE OF ITS POSITIONS TO ANOTHER OF ITS POSITIONS.