Патент USA US2404179код для вставки
E. B. KING £944,179 ELECTRICAL SWITCHING DEVICE Filed June 28,v 1943 53 3"Q N E 5%48 InveJor‘ I ?ytiriajlit?m Attorney B v Patented July 16, 1946 2,404,179 UNITED STATES PATENT OFFICE 2,404,179 ELECTRICAL SWITCHING DEVICE Edward Bolton King, Haslemere, England Application June 28, 1943, Serial No. 492,616 In Great Britain April 17, 1942 4 Claims. (Cl. 200-33) 1 2 This invention relates to electrical switching bined with a relay for initiating detonation of the arrangements and has as its main object the production of a, switching arrangement, for ex charge of a rocket or other non-rotated pro jectile, in which case the switches are so con structed and supported as to withstand the ample, for controlling a relay device, which is responsive to changes in velocity of apparatus 5 stresses due to the high acceleration of the pro jectile. Another application of such arrangement carrying the arrangement. is in combination with a relay for controlling ele The improved switching arrangement, accord vators and/or steering mechanism of an aircraft, ing to the invention, comprises an acceleration the relay being energised to e?ect a control op switch arranged to operate its contacts due to the inertia of a moving part during acceleration in 10 eration when the aircraft decelerates following a high speed evolution; for example, a steep dive. a predetermined direction and a deceleration Such an arrangement can also be used for con“ switch arranged to operate its contacts due to the trolling the detonation of a projectile or bomb inertia of a moving part during deceleration, one when it reaches a predetermined depth below the of the switches being irreversible, that is. remain ing closed (or open) after operation, so that both 15 surface of the water, the acceleration switch be ing operated during an initial acceleration period switches are in their operated positions after an whilst the deceleration switch operates when the acceleration period followed by a deceleration pe projectile slows up immediately following its im mersion in the water. ried, or vice versa. Preferably the irreversible switch consists of a switch of the type employing a conducting liq uid, such as mercury, and including a. capillary tube substantially parallel to the direction of motion along which the liquid is forced to close contacts at the remote end of the tube when the rate of change of velocity (the acceleration or the deceleration) exceeds a predetermined value for a predetermined time. Conveniently A construction of the switch arrangement ac cording to the invention which is particularly suitable for controlling the arming of a prox imity fuze for rockets or other non-rotating pro jectiles will now be described by way of example 25 with reference to the accompanying drawing in 20 which ‘ Fig.v 1 shows a preferred form of capillary one or more intermediate “traps” or bulbs are switch; provided between the ends of the capillary tube Fig. 2 shows a preferred form of non-capillary switch; and Fig, 3 shows the method of assembling the switches. to prevent closing of the switch due to accidental 30 shocks or to vibration. The switch which is not irreversible may com prise a tubular non-capillary switch employing a conducting liquid, such as mercury, and arranged _ The function of a switching arrangement, ac“ cording to the invention, in a proximity fuze is substantially parallel to the direction of motion 35 mainly as a two-stage arming device to ensure with the contacts to be closed at the appropriate that the projectile is safe to handle before it end of the tube. is ?red, that electrical apparatus, such as ther The capillary switch may be so arranged and mionic valves, forming part of the fuze is pre pared for operation during the preliminary part dimensioned that it closes when the force is a large multiple of the force required to close the 40 of the ?ight of the proectile without the fuze be non-capillary switch, or the switches may be so ing completely armed whilst it is close to and dimensioned and the conducting liquids so chosen therefore sensitive to the ground, and, ?nally, that the forces which cause closing of the re that complete arming is e?ected when the pro spective switches may be of substantially the same jectile is at a su?icient distance from the ground 45 to be substantially immune from ground eiiects. order of magnitude. ' In a convenient practical arrangement a capil lary acceleration switch and a non-capillary de celeration switch have their contacts connected In such fuzes, detonation is controlled by a re~ lay which preferably comprises a gas-?lled ionic valve, such, for example, as a valve sold under in series in a circuit of a relay, for example, in the registered trade-mark “Thyratrcn,” having the anode circuit of a gas-?lled triode relay, 50 a control grid by means of which the relay is trig~ whereby the circuit is prepared by closing of the gered. The triggering impulse may be supplied, preferably through an ampli?er, from a photo pleted by closing of the non-capillary switch electric cell arrangement responsive to changes when deceleration begins. . in illumination caused by the target or by a Such a switching arrangement may be com 55 radio receiver responsive to radio-frequency os capillary switch during acceleration and com 2,404,179 3 4 tube contains su?icient mercury B3 to produce adequate low-resistance contact between the two from the ground. wires when the tube is inverted, but the'amount The switching arrangement according to the of mercury should not be such as to prevent free invention is so arranged that the acceleration switch A, which is the irreversible switch, when UK movement thereof in the wider portion of the cillations re?ected from the target or transmitted it operates completes the ?lament and anode cir cuits of any thermionic valves employed in the ampli?er and other apparatus and also closes a tube. A small quantity of a. suitable powder such as aluminium oxide, may be added to the mer cury to facilitate free movement thereof. The tube may be exhausted or may be ?lled with air point in the anode circuit of the gas-?lled relay. or other gas at a suitable pressure. The circuits are thus prepared for operation dur The dimensions of the acceleration and decel ing the initial acceleration of the projectile. eration switches described above are such that Complete arming of the fuze during this period the acceleration switch will be operated by an is prevented by the open contacts of the decel acceleration of the order of 40 times that of eration switch B, these contacts being included in the anode circuit of the gas-?lled relay. Thus, 15 gravity averaged over a period of from 0.4 to 1 second, whilst the deceleration switch is sensitive when the projectile begins to deceler-ate, that is, to a deceleration force of approximately 0.3 times when, in the case of a rocket, the propelling that of gravity for a very short period. charge is fully burnt, the deceleration switch B The several switches are mounted with their closes and the fuze is then fully armed so that it responds to the re?ected radiations from the 20 axes parallel to one another and to the axis of target as soon as the projectile approaches sufq the projectile, as shown in Fig. 3. In order that ?ciently close thereto. they will withstand the high stresses due to the In such an arrangement a separate accelera rapid acceleration of the projectile, they are as tion switch is provided for each of the independ sembled and bound together in a suitable plastic or semi-plastic material such as para?in-wax. ent circuits to be closed, each switch convenient1y consisting of a glass capillary tube having an Alternatively, they can be mounted in grooves internal bore A! (Fig. 1) of between 0.12 and 0.16 in a former of ebonite or other synthetic insulating millimetre in diameter. The tube, which is about material, and enclosed in a varnished paper tube, 5 centimetres overall length, has at its lower end, the complete assembly being, if desired, impreg that is the end nearest to the rear end of the 30 nated with a suitable bonding material. projectile, a small bulb A2 of between 3 and 4 It is to be understood that the speci?c construc~ millimetres in diameter through the wall of which tion of switching arrangement described above is are sealed two metal Wires A3 of a suitable al by way of example only and that the dimensions loy to form a vacuum-tight seal with the glass, and the mounting of the individual switch ele the inner ends of these wires, which project into 35 ments can be varied as desired to suit the use of the bulb, being spaced apart from one another. the switching arrangement. It will also be ap At the upper end of the tube there is another preciated that whilst various applications of‘ an bulb A4 containing a small amount of mercury. arrangement according to the invention have been The tube is evacuated to a low pressure and sealed speci?cally referred to, such an arrangement can 40 at its upper end. The amount of mercury and be used in any apparatus or vehicle where it is the bore of the capillary are such that, due to desired to complete (or to open) an electric cir~ surface tension, the mercury will not enter the cuit as a result of successive acceleration-decal“ capillary as a result of accidental shocks or nor eration periods or vice versa. When the circuit mal vibration, but, when the switch is subjected 45 is to be opened the capillary switch or switches to high acceleration, for example an acceleration will, of course, be arranged so that normally the of the order of 40 g., the thrust due to the inertia conducting liquid closes the contacts but moves of the mercury is su?‘icient to force mercury along under the in?uence of the appropriate accelera the bore of the tube. If such acceleration is tion or deceleration to an empty bulb at the re maintained for a su?icient time, which depends 50 mote end of the capillary. on the length of the tube, the mercury will ?ll I claim as my invention: the bulb at the lower end of the tube and thus 1. In a body subject to changes of velocity, an complete a low resistance contact between the electrical switching arrangement for controllingr wires projecting into the bulb. The switch thus electrical circuits carried by the body comprising closed will remain closed unless it is subjected 55 a ?rst switch adapted to operate in response to a to a correspondingly high acceleration in the op change in velocity of one sign and thereafter to posite direction. remain locked in the operative position and a In order to ensure that vibration will not cause second switch adapted to operate in response to mercury to reach the lower bulb, an interme a change in velocity of the opposite sign said first diate trap or bulb A5 may be formed in the capil 60 switch comprising a capillary tube for each pair lary about midway between the ends. of contacts to be operated, a bulb at each end of If mercury should penetrate to such trap due said capillary, a pair of said cont-acts protruding to vibration, it is likely to return to the upper through the wall into one bulb and a conducting bulb as a result of further vibration. in one bulb, and said second switch com A preferred construction of deceleration switch 65 ?uid prises a non-capillary tube for each pair of con is shown in Fig. 2 and comprises a glass tube hav tacts to be operated, a pair of said contacts pro ing a length of approximately 4 centimetres and truding through the wall into one end thereof and an internal diameter of between 4 and 5 milli a conducting fluid at one end thereof. ‘ metres. In this case, contact wires Bl , B2 project 2. In a body subject to changes of velocity an into the upper end of the tube which is prefer ably of slightly reduced internal diameter, the 70 electrical switching arrangement for closing in inner ends of the contact wires preferably project— ing beyond the point at which the diameter of the tube is reduced, for example, from the up per end of the tube to a. distance of between a. half and a third of the length of the tube. The two stages electrical circuits carried by the body comprising for each pair of contacts to be closed in the ?rst stage a capillary tube, a bulb at one end of said tube, a pair of said contacts in the bulb and a mercury reservoir at the other end of 5 2,404,179 said tube, said mercury ?owing through said tube into the bulb in response to a change of velocity of one sign to bridge said pair of con tacts and to complete the ?rst stage of closure of electrical switching arrangement for controlling electrical circuits carried by the body comprising. a ?rst switch adapted to operate in response to a change of velocity of one sign and thereafter to said circuits, and for each pair of contacts to be 5 remain locked in the operative position, and a closed in said second stage a non-capillary tube, second switch adapted to operate in response to a pair of said contacts protruding into one end a change in velocity of the opposite sign, said of the bore of the tube, a globule of mercury ?rst switch including a pair of contacts to be adapted to move freely in the bore in response operated, a mass of material arranged to move to a change of velocity of the opposite sign to 10 freely in one direction from one position to an bridge the contacts and to complete the second other and to close said contacts in one of said stage of closure of said circuits. positions and means for preventing the return of 3. An electrical switching arrangement ac the mass in the opposite direction, and said sec cording to claim 2 wherein each capillary tube iS provided with an intermediate bulb substan tially midway between its ends, said intermediate bulb acting as a trap to prevent mercury reaching the contacts as a result of vibration. 4. In a body subject to changes of velocity, an ond switch includes non-capillary tube, a pair of 15 contacts to be operated protruding through the Wall into one end thereof, and a conducting ?uid at one end thereof. - EDWARD BOLTON IHNG.