US3444814A

US3444814A - Acceleration-sensitive fluid actuator

Info

Publication number: US3444814A
Application number: US619125A
Authority: US
Inventors: Raymond W Warren
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1967-02-23
Filing date: 1967-02-23
Publication date: 1969-05-20
Anticipated expiration: 1986-05-20

Description

y 1969 R. w. WARREN 3,444,814

ACCELERATION-SENSITIVE FLUID ACTUATOR Filed Feb. 23, 1967 Sheet of 2 RAM AHZ \O\ FlG.l

y 0, 1969 R. w. WARREN 3,444,814

ACCELERATION-SENSITIVE FLUID ACTUATOR Filed Feb. 25, 1967 Sheet 2 of 2 ATM/ME Y:

3,444,814 ACCELERATION-SENSITIVE FLUID ACTUATOR Raymond W. Warren, McLean, Va., assignor to the United States of America as represented by the Secretary of the Army Filed Feb. 23, 1967, Ser. No. 619,125 Int. Cl. F42c 5/00, 15/32 U.S. Cl. 102-81 11 Claims ABSTRACT OF THE DISCLOSURE Acceleration-sensitive control means are placed in an explosive projectile and control a pure fluid circuit therein. Depending on whether the projectile undergoes an acceleration or deacceleration the .acceleration sensitive control means will direct the pure fluid circuit to either arm or disarm the projectile.

This invention relates to the arming of an ordnance device and in particular to a pure fluid arming system.

Explosive projectiles are intended to damage a designated target in response to a target orientated firing influence. A. firing influence may be produced by impact, by a proximity sensing device, or by a timing device. Maximum effectiveness and maximum safety for the personnel who launch the projectile require the use of a highly effective safety and arming device. When the projectile is in the safe, or unarmed, state it can be handled safely as it is immune to detonation by the accidental receipt of a firing influence. When the projectile is in the armed state it is ready to detonate in response to a firing influence. The safety and arming device must dependably keep the projectile unarmed until it has traveled a safe distance after being launched to protect the launching crew, if the projectile should accidentally receive a firing influence, and must dependably arm the projectile by the time the projectile receives a target orientated firing influence.

A particular arming situation arises in what is called for convenience a dual acceleration explosive projectile. A dual acceleration projectile receives an initial or primary acceleration upon launching. The projectile is designed so, if desired, a secondary acceleration may be applied to it to increase the range of the projectile beyond that it is capable of achieving from a primary acceleration alone.

A special problem arises, which the present invention is partly concerned with, when a dual acceleration projectile is fired at an enemy target located between the launching means and friendly troops (hereinafter called a near target) and also when the enemy target is located a certain distance on the side of friendly troops away from the launching means (hereinafter is called a far target). In the case of a near target, because of its closeness to the launching means, the projectile will be programmed to receive only a primary acceleration with the result that the arming of the projectile must occur shortly after launching, yet at a suflicient distance from the launching crew to insure their safety upon accidental receipt of a firing influence. It a secondary acceleration is accidentally applied to a projectile that is aimed at a near target, the projectile will pass over friendly troops and therefore must, upon receipt of a secondary acceleration, be disarmed to insure against harm to the friendly 3,444,814 Patented May 20, 1969 ice troops. If the projectile is aimed .at a far target it will pass over friendly troops with the aid of a secondary acceleration on its path to its designated target. Safety of the friendly troops requires that the projectile be maintained in an unarmed state until it safely passes over the friendly troops to protect them against accidental receipt of a firing influence.

It is therefore an object of the present invention to provide an effective safety and arming system for a dual acceleration explosive projectile.

Another object of the present invention is to provide means to arm a dual acceleration projectile that is programmed to receive a primary acceleration to land at a near target as it approaches the target and to disarm the projectile if it should accidentally receive a secondary acceleration passing it over friendly troops.

A further object of the present invention is to provide a dual acceleration projectile that is programmed for a far target, by use of a secondary acceleration boost, with means to maintain it in an unarmed condition until it is close to the far target and away from friendly troops over which it must pass on the way to the far target.

A secondary object of this invention is to provide an effective safety and arming means for a single acceleration projectile.

Briefly, in one embodiment of the present invention, acceleration responsive means selectively direct a power source for a bistable amplifier to one of two output conduits. One output conduit is connected to one side of an arming mechanism while the other output conduit is connected to various fluid logic elements which allow the projectile to be armed during preselective portions of flight. A four-way two position valve in position cooperates with the fluid logic elements to allow the projectile to be armed .as it approaches a near target Without the aid of a secondary boost. In this position the projectile will remain unarmed if accidentally subjected to secondary boost. In a second position of the valve the projectile will be aimed to land at a far target passing over friendly troops with the aid of a secondary boost and Will be armed only in the vicinity of the target.

In second embodiment of the invention an arming device is connected to the output conduits of an acceleration controlled bistable amplifier to allow the projectile to be armed as it approaches the target and disarmed as it is launched. In this embodiment of the invention the projectile does not receive a secondary boost.

The specific nature of the invention, as well as other objects, uses, and advantages thereof, clearly appear from the following description and from the accompanying drawings in which:

FIGURE 1 is a schematic illustration of one embodiment of the present invention.

FIGURE 2 is a view of an element used in the embodiment of the invention as shown in FIGURE 1.

FIGURE 3 is a schematic illustration of a second embodiment of the present invention.

In FIGURE 1 an acceleration sensitive fluid actuator is placed in the nose of a projectile 75 with a conduit 101 adapted to receive the ram air of the projectile. Conduit 101 communicates with a bistable amplifier 190 which has an interaction chamber 106. A left control nozzle communicates left control line 102 with interaction chamber 106. Left control line 102 has a right angle bend which serves to define a conduit section 121 of the line. A seismic mass 105 is positioned to cover the open end of conduit section 121 for purposes which will soon become apparent. The seismic mass 105 is, in the absence of acceleration forces, held in a covering position with respect to the open end of the conduit section 121 by flat leaf springs 125 which are attached to each side of the seismic mass. A right control nozzle 116, a right control 103, .a conduit section 129, a seismic mass 104 and flat leaf springs 130 are similarly positioned with respect to the right side of the bistable amplifier 190.

Bleeds

107 and 108 communicate with interaction chamber 106 in a manner well known in the art. The interior 400 of projectile 75 communicates with ambient.

Bistable amplifier 190 has

output conduits

109 and 110 of which conduit 110 leads to a flow divider 111. The flow divider divides the flow between conduits 112 and 113. Conduit 113 leads to an AND element 134. One AND element that might be employed is described in FIGURE 2 of my US. Patent No. 3,221,990 for a pure fluid shift register. AND element 134 has

conduits

135 and 136 leading to atmosphere and a conduit 137 adapted to direct fluid to the left side 139 of a slider 138. A conduit 109 directs fluid to the right side of the slider. The slider is any well known sliding element such as a piston and reciprocates in a cylinder 141. Slider 138 carries a detonator 142 and a firing in 143 is located above cylinder 141. Conduit 112 leads to a fluid pulse converter 150 which could be constructed in accordance with principles set forth in US. Patent No. 3,001,698 for a Fluid Pulse Converter. Pulse converter 150 is biased to discharge to conduit 158 initially by offsetting splitter 300, curving the power jet or any of the well known techniques in the art.

Pulse converter 150 has

feedback legs

151 and 152 which lead to an interaction chamber 156. A source of pressure 155 communicates with inter-action chamber 156 as do

bleeds

153 and 154.

Output conduits

157 and 158 selectively receive the fluid from interaction chamber 156 and lead to a four-way two position valve 160. Four-way two position valve 160 could be any of the well known two position valves that are available to the skilled mechanic. In position I, which is schematically illustrated in FIGURE 1,

conduits

157 and 158 communicate with

conduits

161 and 159, respectively. In position II, which is schematically illustrated in FIGURE 2, the connections are reversed so that

conduits

157 and 158 communicate with

conduits

159 and 161, respectively. Conduit 161 leads to AND element 134 while conduit 159 communicates with the right side of slider 138.

In operation, valve 160 is set in accordance with whether the projectile is aimed at a near target or a far target. If the target is a near target valve 160 is switched to position I while if the target is a far target valve 160 is then at position 11. Assuming projectile 75 is aimed a near target valve 160 will be in position I with

conduits

157 and 158 communicating with

conduits

161 and 159, respectively. Thus as projectile 75 starts to accelerate in the direction indicated by arrow 76, seismic mass 104 will block the end of conduit section 129 of fluid control line 103. Seismic mass 105 will tend to move away from the end of section 121 of left control line 102 allowing the end of section 121 to communicate with atmosphere. The ram air from conduit 101 will now attach to the right side of interaction chamber 106 and be directed to conduit 109. The ram air, as it flows

past nozzles

115 and 116, will tend to entrain fluid in the vicinity of these nozzles. Since nozzle 115 is communicated to atmosphere, as seismic mass 105 is not covering the end of conduit section 121, ambient air prevents a low pressure region in the vicinity of nozzle 115. Seismic mass 104 will be covering the end of section 129 because of the acceleration forces received by the seismic mass so that the fluid entrained by the ram air in the region of nozzle 116 cannot be replaced by ambient air creating a low pressure region in the area of nozzle 116. The ram air will be drawn to the side of the interaction chamher in which nozzle 116 is because of the low pressure there and will be directed to conduit 109 from where it will go to cylinder 141 moving slider 138 to left side of the cylinder. This will maintain the projectile disarmed since detonator 142 is not aligned with firing pin 143. Fluid from source 155 will be directed to conduit 158, because of the bias in pulse converter 150, and through valve 160 to conduit 159 to the right side of cylinder 141 to aid in disarming the projectile. When the initial effects of the primary boost are dissipated the projectile will decelerate with seismic mass 104 tending to remain in motion in the direction of the projectile and uncover the end of section 129 and opening right control line 103 to ambient. Seismic mass 105 will similarly tend to remain in motion in the direction of the projectile and will move to cover the open end of section 121 of left control line 102. This will create a low pressure region in the vicinity of nozzle which will switch the ram air to conduit 110 from conduit 109. The fluid in conduit 110 will be directed to conduits 112 and 113. The fluid from conduit 113 will go to AND element 134 while fluid from conduit 112 will enter leg 151 of pulse converter where it will direct power fluid from source to output conduit 157. The fluid from conduit 112 will enter leg 151 because leg 151 will be at a lower pressure than leg 152 for the following reason. The fluid from source 155 issuing from conduit 158 passes adjacent the section of leg 151 near interaction chamber 156 creating a low pressure region in the leg. Thus, a fluid signal directed to pulse converter 150 will enter leg 151 as it will be at a lower pressure than leg 152. The power fluid leaving conduit 157, by conduit 161, will go to AND element 134 where it will be directed to conduit 137 since conduit 113 will also direct fluid through the AND element. As will be recalled, an AND element will direct fluid through a selected output conduit when it receives two fluid signals. The fluid in conduit 137 will move slider 138 to the right side of the cylinder 141 aligning firing pin 143 and detonator 142 arming the projectile. The projectile is now armed to detonate as it approaches a near target. If by accident a secondary thrust is applied to the projectile, it is necessary to have projectile disarmed as it will now be passing over friendly troops. When the projectile receives the secondary thrust it will undergo an ac celeration. As previously pointed out, seismic mass 104 will cover the end of conduit section 129 and seismic mass 105 will uncover the end of conduit section 121. This will create a low pressure region in the vicinity of nozzle 116 switching the ram air from conduit 110 to conduit 109 from where the ram air will be transferred to the right side of slider 138 moving the slider to a disarmed position. Pulse converter 150 will continue to direct fluid to conduit 157 and to conduit 161 to AND element 134 from where the fluid will be discharged to atmosphere as no signal will be applied to AND element conduit 113. After the secondary acceleration, the projectile will decelerate when the effects of the secondary boost dissipates. Since the projectile may still be over friendly troops it is necessary for the projectile to be disarmed. Upon deceleration of the projectile seismic mass 104 will uncover the end of conduit section 129 while seismic mass 105 will cover the end of conduit 121. This will be create a low pressure region in the vicinity of nozzle 115 switching the ram air from conduit 109 to conduit 110 from where the fluid will be directed to conduits 112 and 113. The fluid from conduit 113 will be directed to AND element 134. The fluid from conduit 112 will enter leg 152 of pulse converter 150, for the reasons previously explained, switching the power fluid from conduit 157 to conduit 153. The fluid from conduit 113 will be vented by AND element 134 since no signal will be received by conduit 161 as the pulse converter will be discharging from conduit 158 and from there to conduit 159. Fluid from conduit 159 will be directed to the right side of slider 138 to combine with the fluid from conduit 109 to aid in maintaining the projectile disarrned. Thus, it can be seen that a projectile aimed to detonate at a near target will be armed if no secondary thrust is applied to the projectile, and, if by accident a secondary thrust is applied to the projectile passing it over friendly troops, the projectile will be disarrned eliminating any danger to the friendly troops.

In valve position II it is intended that the projectile be fired over friendly troops at a far target by subjecting the projectile to a secondary thrust. It is therefore imperative that the projectile be disarrned while it passes over friendly troops to eliminate any danger to the friendly troops from a premature explosion. To insure this, valve 160 is set to connect conduit 157 with conduit 159 and conduit 158 with conduit 161. Upon an initial acceleration applied to the projectile, seismic mass 104 will cover end of conduit section 129 and seismic mass 105 will uncover the end of conduit section 121. This will create a low pressure region in the vicinity of nozzle 116 directing ram air to conduit 109 moving slider 138 to the left maintaining the projectile disarrned. Pulse converter 150 will discharge to conduit 158, because of its built in bias from where the fluid will be directed to conduit 161 and to AND element 134 from where it will discharge to atmosphere as no signal will be applied to the AND element from conduit 113 since the bistable amplifier will discharge to conduit 109. On deceleration of the projectile the ram air will be switched to conduit 110 as previously explained. Fluid from conduit 110 will divide to conduits 112 and 113. The fluid in conduit 112 will enter leg 151 of pulse converter 150 for the reasons previously given. This will switch the power fluid from conduit 158 to conduit 157 and to conduit 159 where it will be directed to the right side of slider 138 maintaining the slider in a disarrned position. The fluid from conduit 113 will be discharged to atmosphere by conduit 135 of AND element 134 since only one fluid signal is applied to the AND element. When the secondary boost is applied to the projectile seismic mass 104 will cover the end of conduit section 129 while seismic mass 105 will uncover the end of conduit section 121 switching the ram air from conduit 110 to conduit 109. The fluid in conduit 109 with the fluid from conduit 159 will act on slider 138 to maintain the slider in the left portion of cylinder 141 which corresponds to a disarrned position of the projectile. Pulse converter 150 will continue to discharge to conduit 159 as no signal will be received by the pulse converter. After the secondary boost and the accompanying acceleration that goes with it dissipates the projectile will undergo a deceleration as it approaches the target area. This will cause seismic mass 104 to uncover the end of conduit section 129 and seismic mass 105 to cover the end of conduit section 121 which will switch the ram air to conduit 109 to conduit 110. Conduit 110 will direct fluid to conduits 112 and 113. The fluid from conduit 112 will enter leg 152 of pulse converter 150, for reasons previously explained, which will switch the power fluid from conduit 157 to conduit 158 which communicates with AND element 134 by conduit 161. As conduit 113 is also directing fluid to the AND element, the latter will discharge fluid to conduit 137 which will move slider 138 to the right of cylinder 141 which corresponds to an armed position of the projectile. Thus, it can be seen that the projectile will be armed as it approaches the target with the aid of a secondary boost and disarrned in the vicinity of friendly troops over which it passes. It is also apparent that if the projectile does not receive a secondary boost it will be in a disarrned position while it is over the friendly troops and if it should land among the friendly troops detonation will not occur.

FIGURE 3 is the same as FIGURE 1 with respect to the seismic masses and the bistable amplifiers and like elements are identically numbered. However,

output conduits

109 and 110 of bistable amplifier 190 directly communicate with slider 138. The acceleration sensitive fluid actuator of FIGURE 3 is intended to disarm projectile 75 without regard to the location of friendly troops with respect to the target location and without any consideration to a possible secondary boost applied thereto. When the projectile is accelerated during launching the seismic masses of FIGURE 3 will act identical to those of FIG- URE 1 in covering the end of conduit section 129 and uncovering the end of section 121. As will be recalled this will direct ram air to conduit 109 which will disarm the projectile. When the projectile undergoes deceleration as the primary boost dissipates the seismic masses will cover the end of conduit section 121 and undercover the end of conduit section 129 which will switch the ram air to conduit which will arm the system. Thus it can be seen the projectile will be disarrned while it is launched and armed as it decelerates approaching the target.

It is thus apparent that I have invented a novel and flexible arming system that can be used in a dual or single acceleration arming system. Obviously instead of aligning a firing pin and detonator a fluid activated switch in projectile 75 could be activated to complete an arming circuit.

I claim as my invention:

1. An acceleration-sensitive fluid arming device comprising:

(a) a projectile,

(b) means in said projectile to maintain said projectile disarrned upon an initial acceleration applied to said projectile,

(c) means in said projectile to arm said projectile upon said projectile being subjected to an initial deceleration,

(d) means in said projectile to again disarm said projectile upon a second acceleration applied to said projectile, and

(e) means in said projectile to keep said projectile disarmed when said projectile is subjected to a second deceleration.

2. An acceleration-sensitive arming device comprising:

(a) a projectile,

(b) a bistable fluid amplifier in said projectile having a power source and two output conduits,

(c) acceleration-sensitive means to selectively direct saii power source to either of said output conduits, an

(d) arming means controlled by said output conduits to arm said projectile.

3. A device according to claim 2 wherein:

(a) said bistable amplifier has a plurality of control conduits, each having an open end to selectively control said power source to said output conduits,

(b) said acceleration sensitive means includes means to cover said open ends of said control conduits.

4. A device according to claim 3 wherein said acceleration-sensitive means comprise seismic masses.

5. A device according to claim 4 wherein said arming means comprises:

(a) a detonator carried by a slider, and

(b) a firing mechanism positioned above said slider.

6. A device according to claim 5 wherein said power source comprises the ram air of said projectile.

7. A device according to claim 2 wherein said arming means comprises:

(a) a cylinder having two sides and at least one port in each side,

(b) a slider housed in said cylinder,

(0) a detonator carried by said slider,

(d) a firing mechanism positioned above said slider,

and

(e) one of said output conduits communicates with one of said ports on one side of said cylinder.

8. A device according to claim 7 wherein:

(a) an AND element communicates with said other of said output conduits, and

7 8 (b) said AND element further communicates with one References Cited of said ports in said other side of said cylinder. UNITED STATES PATENTS 9. A device according to claim 8 wherein: (a) a pulse converter having two output conduits com- 1850196 3/1932 Bardsley 102 81 rnunicates with said other of said output conduits, 5 3,229,638 1/1966 Woolston et 102 81 X (b) a four way valve communicates with said output 3,237,712 3/1966 Horton 181 -5 conduits of said pulse converter, (c) said four way valve further communicates with SAMUEL FEINBERG Exammersaid AND element and said one side of said cylinder. G, H. GLANZMAN, Assistant Examiner. 10. A device according to claim 8 wherein said pulse 10 converter is biased to one of its output conduits.

11. A device according to claim 10 wherein said four 13781.5 way valve is a two position valve.

US. Cl. X.R.