SETTABLE PNEUMATIC ALTITUDE DETECTION EQUIPMENT
United States Patent 3827361
A settable pneumatic altitude detection device provides an electrical sig to a missile or projectile for arming and destructing the missile or projectile at preset altitudes. The present invention's main structural elements are a pair of sphere supports which hold therein a rotatable sphere assembly. The sphere support structure has two spherically shaped gas bearing pads which are separated and fixedly held to a circularly shaped collar. Two separate gas supplies are operatively positioned in the sphere support structure and in the rotatable sphere. An electrical initiating signal causes a gas release mechanism and a time delay valve, for each gas supply, to controllably release gas therefrom. Gas is forced through peripherally positioned jet nozzles on the sphere, and through operatively positioned venting ports and calibrated orifices in the sphere support structure. After the missile is fired, the sphere is pneumatically uncaged from its polar supporting structure so that it can freely spin on a nearly frictionless gas cushion. A pneumatically controlled distance meter operatively located in the sphere activates pressure operated switches on the ascent and the descent of the missile trajectory. The aforesaid switches provide an electrical signal which arms the missile on ascent and causes the missile to self-destruct on descent.
US Patent References:
Differential barometric fuze
Loren et al. - June 1960 - 2940392
Summit sensing guidance initiation device
Halling - July 1967 - 3332642
Inertial altimeter
Blazek et al. - January 1968 - 3365942
/3620165.html
Henderson - November 1971 - 3620165
ENVIRONMENTAL FUZE FOR PYROTECHNIC DEVICE
Kulesza - December 1973 - 3780659
Differential barometric fuze
Loren et al. - June 1960 - 2940392
Summit sensing guidance initiation device
Halling - July 1967 - 3332642
Inertial altimeter
Blazek et al. - January 1968 - 3365942
/3620165.html
Henderson - November 1971 - 3620165
ENVIRONMENTAL FUZE FOR PYROTECHNIC DEVICE
Kulesza - December 1973 - 3780659
Inventors:
Zechnowitz, Alvin L. (Rockland, NY)
Xenakis, James A. (Nassau, NY)
Barbieri, John D. (Queens, NY)
Chang, Nai Chai (Westchester, NY)
Xenakis, James A. (Nassau, NY)
Barbieri, John D. (Queens, NY)
Chang, Nai Chai (Westchester, NY)
Application Number:
05/397526
Publication Date:
08/06/1974
Filing Date:
09/17/1973
View Patent Images:
Export Citation:
Assignee:
The United States of America as represented by the Secretary of the Army (Washington, DC)
Primary Class:
Other Classes:
74/5.430, 74/5R, 102/263, 73/178R
International Classes:
F42C5/02; F42C9/16; F42C5/00; F42C9/00; G01C21/00; F42C5/00; G01C19/30
Field of Search:
102/7R,7B,7.2R 73/178,179,384 74/5R,5.12,5.22,5.41,5.43,5.8 200/81,81.4
Primary Examiner:
Borchelt, Benjamin A.
Assistant Examiner:
Jordan C. T.
Attorney, Agent or Firm:
Kelly, Edward Berl Herbert Webb Thomas J. R.
Claims:
Having thus fully described the invention, what is claimed as new and desired to be secured by Letters Patent of the United States is
1. A settable pneumatic altitude detection device for initiating an arming and a destruct electrical signal to a missile which comprises:
2. A settable pneumatic altitude detection device as recited in claim 1 wherein said external regulating gas supply means comprises:
3. A settable pneumatic altitude detection device as recited in claim 2 wherein said external gas release means comprises:
4. A settable pneumatic altitude detection device as recited in claim 1 wherein said pressure switching means comprises:
5. A settable pneumatic altitude detection device as recited in claim 1 wherein said pneumatic caging means comprises:
6. A settable pneumatic altitude detection device as recited in claim 2 wherein said first time delay pneumatic valve means comprises:
7. A settable pneumatic altitude detection device as recited in claim 1 wherein said pneumatic signal generator means comprises:
1. A settable pneumatic altitude detection device for initiating an arming and a destruct electrical signal to a missile which comprises:
2. A settable pneumatic altitude detection device as recited in claim 1 wherein said external regulating gas supply means comprises:
3. A settable pneumatic altitude detection device as recited in claim 2 wherein said external gas release means comprises:
4. A settable pneumatic altitude detection device as recited in claim 1 wherein said pressure switching means comprises:
5. A settable pneumatic altitude detection device as recited in claim 1 wherein said pneumatic caging means comprises:
6. A settable pneumatic altitude detection device as recited in claim 2 wherein said first time delay pneumatic valve means comprises:
7. A settable pneumatic altitude detection device as recited in claim 1 wherein said pneumatic signal generator means comprises:
Description:
GOVERNMENTAL INTEREST
The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.
BACKGROUND OF THE INVENTION
Various means have been used in the prior art to perform arming and self-destruct functions for a missile or a projectile. These prior art methods include barometric devices, electronic counters, mechanical timers, and acceleration sensing switches. One method, under U.S. Pat. No. 3,365,942, employs an inertially stabilized sphere supported by a gas bearing, in which is housed a rotating helix doubly integrating accelerometer. The aforementioned accelerometer is aligned to the launch vertical, and directly measures vertical distance. Other devices, generally similar in concept, employ stabilized gimballed platforms and conventional force-balanced accelerometers whose outputs are integrated.
The problem with the aforementioned prior art devices has been their relatively high cost of manufacture because of complexity of design, the lack of accuracy because of changing environmental conditions, and their lack of reliability because of the intricacy of design and multiplicity of parts.
SUMMARY OF THE INVENTION
The present invention relates to settable pneumatic altitude-detection equipment, hereinafter referred to as SPADE, which is completely independent for its functioning of climatology and missile trajectory. The present device, after receiving an electrical initiating signal, requires no electrical power for operation as it is totally pneumatic in operation. The present invention contains no electronic circuits or components and therefore is insensitive to nuclear radiation; it is also reliable, economical to manufacture, and has an extremely long shelf life because it requires no batteries. The gas bearing supported rotating sphere provides an altitude detecting means which has altitude freedom, and high acceleration loading capability. The simple spin stabilization scheme of the present device avoids the complexity of electro-mechanical closed loop torque type servo systems.
A sphere assembly is initially caged on polar axes within a right circular cylinder that comprises two spherical gas bearing pads separated by a collar, the spherical pads providing a nearly frictionless bearing for the sphere after it has been given an initial spin and has been uncaged. Pressurized gas supplies, a pneumatic time delay valve, and an internal and external gas release mechanism are each respectively contained in the sphere assembly and in the upper pad. Both spherical pads have gas manifolds, orifices, and gas passages for supplying gas to a spherically shaped gap which exists between the rotating sphere and the pads. The lower pad has two pressure-operated switches therein for arming and firing the missile; these switches are pneumatically connected to a gas output chamber formed in the space adjacent to the outer surface of the sphere and the collar.
The sphere is pneumatically uncaged after an electrical "fire" signal is sent to SPADE which simultaneously activates the gas release mechanisms. The released gas spins the sphere, by means of spin jets, about the sphere's vertical axis, uncages the sphere, starts the functioning of the time delay valve, and also controls the functioning of a distance meter. When a preset arming altitude has been reached by the missile the distance meter dumps gas from an ascent dump chamber into the output chamber, actuating a low-pressure arming switch. A calibrated exhaust port in the collar permits depletion of the gas after the arming switch is closed. A relatively short interval of time after the low pressure switch is actuated the distance meter causes a descent dump chamber to be exhausted into the output chamber. The build up of pressure in the output chamber due to the larger volume of gas held in descent pump chamber causes a rise in pressure in this chamber greater than before. The higher pressure activates a high pressure switch and causes the missile to receive a destruct signal.
One of the objects of this invention is to provide a settable pneumatic altitude-detection device which will arm and destruct a missile completely independent of the missile's environment and trajectory.
Another object of this invention is to provide a settable pneumatic altitude-detection device which requires no electrical power for operation after launch of the missile.
Another object of this invention is to provide a settable pneumatic altitude-detection device which contains no electronic circuits or components.
Another object of the present invention is to provide a settable pneumatic altitude-detection device which is insensitive to nuclear radiation.
Another object of the present invention is to provide a settable pneumatic altitude-detection device which is reliable in operation, low in cost, and has very long shelf life.
A further object of this invention is to provide a settable pneumatic altitude-detection device which has a gas bearing supported sphere which has all altitude freedom, and high acceleration and loading capability.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric, partially sectioned view of the rotatable sphere and the sphere support structure.
FIG. 2 is a functional polar cross-sectional schematic view of the sphere assembly and the sphere support structure.
FIG. 3 is a partial cross-sectional view of a gas release mechanism schematically illustrated in FIG. 2.
FIG. 4 is a partial cross-sectional view of a pneumatic time delay valve schematically illustrated in FIG. 2.
Throughout the following description like reference numerals are used to denote like parts of the drawing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 the SPADE comprises two major assemblies, a sphere assembly 10 and a sphere support structure 12. The sphere support structure 12 basic elements are an upper spherical pad 14, a lower spherical pad 16 and a circularly shaped collar 18 which separates upper pad 14 from lower pad 16 and fixedly holds all three aforementioned basic elements together. The sphere support structure 12 helps to provide polar support and floating support for the sphere assembly 10 in a manner described herein.
The upper pad 14 contains a first pressurized gas supply 20, an external gas release mechanism 22, and a pressure regulator 24 all pneumatically connected in series. The output gas line 26 leading from pressure regulator 24 divides into a first upper pad gas passage 28 and a second upper pad gas passage 31. The first external gas passage 28 connects to an upper pad circular manifold 30 which has a plurality of upper pad gap gas orifices 32 therein which feeds directly into the main gap 34. Gas from the first external gas passage 28 is also fed to the lower spherical pad support 16 and the main gap 34 through manifold 30, upper pad connecting passage 36 and lower pad connecting passage 38 through intermediate collar connecting passage 40. Gas from the lower pad connecting passage 38 is distributed to main gap 34 from the lower spherical pad 16, in a similar manner aforedescribed, by a lower circular gas manifold 42 having a plurality of lower pad gap gas orifices 44. A first pneumatic time delay valve 46 has its calibrated input orifice port 48 as shown in FIG. 4 connected to the second external passage 31. An upper pad exhaust port 50 is connected to the first time delay valve exhaust flow through port 52. A pressure relief port 54 of the first time delay valve 46 is connected to a collar output chamber 56 by means of a third upper pad passage 58.
Collar 18, which is disposed between the upper spherical pad 14 and the lower spherical pad 16, is hermetically sealed to these two pads so that no gas can escape from the sphere support structure 12 except through upper pad exhaust port 50 and a calibrated collar exhaust orifice 60. The space between the inside concave collar wall 62 and the outer surface of upper hemisphere shell 64 and the lower hemisphere shell 66 forms the aforementioned output chamber 56.
A bearing hole 68 is located at the polar axis of each pad for holding therein two caging mechanism piston shafts 70. A pair of piston contact surfaces 72 located at the end of piston shafts 70 make electrical contact with a pair of axially aligned insulated caging terminals 74. This contact-terminal arrangement enables a "fire" signal to enter the sphere for initiation of spin as described hereinafter.
The lower pad 16 has two pressure operated switches, a low pressure switch 76 and a high pressure switch 78. Each of these switches is pneumatically connected to the output chamber 56 by means of a second lower pad connecting passage 80. Low pressure switch 76 having output terminals XX is actuated on ascent and causes arming of the missile by activating an arming circuit not shown on FIG. 2. The high pressure switch 78 having output terminals YY is actuated on descent and causes destruction of the missile at a preset altitude by activating a destruct circuit located in the missile and also not shown in the drawings. The lower pad 16 has two threaded holes 82 therein for mounting and orienting the altitude detector to the carrying vehicle or missile frame.
The sphere assembly 10 as previously stated has two hemisphere shells 64 and 66 which are joined at parting 84. The shells contain within them the other working elements of the altitude detector. These include a second pressurized gas supply 86, an internal gas release mechanism 88, and a second pneumatic time delay valve 90 all connected pneumatically in series. The initial gas output of time delay valve 90 is carried by a common gas trunk line 92 to spin-up nozzles 94, to a pair of polar pneumatic cage mechanisms 96, to the ascent dump chamber 98, and the descent dump chamber 100 through ascent check valve 102 and descent check valve 104 respectively of a pneumatic output signal generator system 106. A pneumatic distance meter 108 is also connected to the output of the internal gas release mechanism 88 by internal gas line 110. Second time delay valve 90 has a calibrated orifice 48 connected by gas line 111 to internal gas line 110 and thence to the gas release mechanism 88. The pneumatic distance meter 108, such as described in U.S. Pat. No. 3,365,942, has a net distance piston therein (not shown) mechanically connected to first slide 112 and detent slide 114 which are slidably held adjacent to each other. The output signal generator system 106 further includes a spring loaded detent 116 which slidably holds detent slide 114 in a fixed position after the net distance piston has moved first slide 112 downwardly on ascent. A spring-loaded descent dump valve 118 and a spring-loaded ascent pump valve 120 are in sliding contact with the detent slide 114 and the first slide 112 respectively. These two aforementioned valves control the flow of gas from ascent dump chamber 98 and descent dump chamber 100 to dump passage 122 which is directly connected to output chamber 56.
The pair of caging mechanisms 96 have piston springs 126 biasedly holding push pistons 128 within piston housings 124, so that piston shafts 70 on pistons 128 enter bearing holes 68, thereby caging and aligning the polar axis of sphere assembly 10 with the axis of the support structure 12. With pressure in caging chamber 130, the piston shafts 70 of the caging mechanisms 96 remain in the bearing holes 68. With gas pressure in main gap 34 and no pressure in caging chamber 130, the piston shafts 70 have a force acting on them to compress piston springs 126, withdrawing the piston shafts 70, and thereby uncaging the sphere assembly 10 from caging mechanism 124.
Referring now to FIG. 3, a partial cross-sectional view of the external and internal gas release mechanism 22 and 88 respectively shown schematically on FIG. 2, the high pressure gas supplies 20 and 86, shown in FIG. 2, have their outputs connected to gas release inlet port 132 of valve housing 133. Port 132 communicates with gas release outlet port 134 when the release mechanisms 22 and 88 are in the open condition. Port 132 is isolated from outlet port 134 by a thin metal diaphram 136 when the gas release mechanisms 22 and 88 are in the closed condition. When a voltage is applied to solenoid terminals 138, the solenoid plunger 140 withdraws, enabling a biased dart spring 142 to advance dart piston 144 and drive dart 145 through diaphram 136 thereby releasing gas from the gas supplies 20 and 86.
Referring now to FIG. 4, the first and second pneumatic time delay valves 46 and 90 have a valve housing 149 which contains therein a "T" shaped poppet valve chamber 151 and a transversely positioned piston chamber 154. Biasedly positioned within poppet valve chamber 151 is a poppet piston 150. Prior to release of gas from the external release mechanism 22, the poppet piston 150 is held in its open position, as shown in FIG. 4, by poppet spring 152 and by a shank 148' on orifice piston 148. With no pressure on calibrated orifice port 48, poppet spring 152 pushes poppet piston 150 upwards while coil spring 146 pushes orifice piston 148 to the left. Under the aforementioned condition, gas can flow from pressure relief port 54 through the poppet valve chamber 151 to the exhaust flow through port 52. When gas from pressure regulator 24 is released to the calibrated input orifice 48, gas enters piston chamber 154 at a controlled rate. Pressure builds up in piston chamber 154 and pushes orifice piston 148 to the right, thereby allowing poppet piston 150 to move downward, thus allowing gas to enter pressure relief port 54 and compress coil spring 152, thereby closing the first time delay valve 46, so that gases from the output chamber can no longer vent to the atmosphere.
In operation, an electrical fire signal, which is sent to SPADE, simultaneously activates the external and internal gas release mechanisms 22 and 88 respectively. Pressure regulator 24 permits gas to enter manifolds 30 and 42 so that the sphere assembly 10 floats on a cushion of gas, and also to enter the first time delay valve 46 at the calibrated orifice 48. At the same time, gas from internal release mechanism 88 releases gas to the spin-up jets 94 through relief port 54 and flow through port 52 and to the caging chambers 130, dump chamber 98, and communicates with the output chamber 56 as shown in FIG. 1, ascent chamber 100, and to the distance meter 108. The spin-up jets 94, which extend through the sphere shell, acting on the sphere 10 in the manner of a hero turbine, spin the sphere assembly 10 about its polar axis. During the brief spin up period, the caging mechanisms 96 maintain vertical alignment, and the upper pad exhaust port 50, whose poppet valve 150 is open, permits spin-up gases to leave output chamber 56, thus precluding operation of pressure switches 76 and 78.
The spin-up period is ended when the second pneumatic time delay valve 90 shuts off gas to the spin-up jets 94, the dump chambers 98 and 100, and the caging mechanism chambers 130. Check valves 102 and 104 maintain high pressure gas in the dump chambers 98 and 100. The loss of pressure in caging chambers 130 causes the caging pistons 70 to withdraw thereby leaving the sphere assembly 10 spinning about its vertical axis on a cushion of gas. The first pneumatic time delay valve 46 at this time closes, as indicated above, the spin-up exhaust flow through port 52 so that these gases cannot vent through upper pad exhaust port 50.
When the system is at the stage aforedescribed, it is considered operational, and the vehicle carrying SPADE is launched. The spinning of the sphere assembly 10, and the low torque forces from the gas bearing in main gap 34 enable the sphere assembly to act as a free gyroscope, therefore the sphere assembly's initial vertical alignment is maintained throughout the vehicle's subsequent turns and maneuvers.
When a preset safing/arming altitude has been reached, the pneumatic signal generator 106 activates the low pressure switch 76 in the following manner. A net distance piston (not shown) of pneumatic distance meter 108 moves first slide 112 downward, enabling the ascent dump valve 120 to open, suddenly dumping gas from ascent dump chamber 98 into the output chamber 56 at the same time detent 116 locks 114 in a downward position. First slide 112 in its downward movement on ascent holds dump valve 118 in a closed position. The pressure rise in the output chamber 56 is sufficient only to operate low pressure switch 76 and not high enough to actuate high pressure switch 78, thus sending the required unsafing signal or arming signal to the missile. The calibrated collar exhaust orifice 60 permits depletion of some of the gas from output chamber 56 after closure of the low pressure switch 76. When upon descent, the preset self-destruct altitude is reached, the net distance piston of the distance meter 108 moves upward. Upon descent the net distance piston moves first slide 112 upwardly far enough to release descent dump valve 118 and cause it to open, thereby dumping the gas contained within the descent dump chamber 100 into the output chamber 56 and thus operating the high pressure switch 78. The descent dump chamber 100 is larger than the ascent dump chamber 98, therefore high pressure switch 78 is activated and provides the required destruct signal to the missile thus completing the mission. It can be readily seen that in this manner simultaneous activation of both switches upon reaching ascent setting is prevented. Ascent and descent altitude settings are made by adjusting the positions of the dump valves 118 and 120 so that they are nearer or further away from caming surfaces of the net distance piston.
The foregoing disclosure and drawings are merely illustrative of the primciples of this invention and are not to be interpreted in a limiting sense. I wish it to be understood that I do not desire to be limited to exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.
The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.
BACKGROUND OF THE INVENTION
Various means have been used in the prior art to perform arming and self-destruct functions for a missile or a projectile. These prior art methods include barometric devices, electronic counters, mechanical timers, and acceleration sensing switches. One method, under U.S. Pat. No. 3,365,942, employs an inertially stabilized sphere supported by a gas bearing, in which is housed a rotating helix doubly integrating accelerometer. The aforementioned accelerometer is aligned to the launch vertical, and directly measures vertical distance. Other devices, generally similar in concept, employ stabilized gimballed platforms and conventional force-balanced accelerometers whose outputs are integrated.
The problem with the aforementioned prior art devices has been their relatively high cost of manufacture because of complexity of design, the lack of accuracy because of changing environmental conditions, and their lack of reliability because of the intricacy of design and multiplicity of parts.
SUMMARY OF THE INVENTION
The present invention relates to settable pneumatic altitude-detection equipment, hereinafter referred to as SPADE, which is completely independent for its functioning of climatology and missile trajectory. The present device, after receiving an electrical initiating signal, requires no electrical power for operation as it is totally pneumatic in operation. The present invention contains no electronic circuits or components and therefore is insensitive to nuclear radiation; it is also reliable, economical to manufacture, and has an extremely long shelf life because it requires no batteries. The gas bearing supported rotating sphere provides an altitude detecting means which has altitude freedom, and high acceleration loading capability. The simple spin stabilization scheme of the present device avoids the complexity of electro-mechanical closed loop torque type servo systems.
A sphere assembly is initially caged on polar axes within a right circular cylinder that comprises two spherical gas bearing pads separated by a collar, the spherical pads providing a nearly frictionless bearing for the sphere after it has been given an initial spin and has been uncaged. Pressurized gas supplies, a pneumatic time delay valve, and an internal and external gas release mechanism are each respectively contained in the sphere assembly and in the upper pad. Both spherical pads have gas manifolds, orifices, and gas passages for supplying gas to a spherically shaped gap which exists between the rotating sphere and the pads. The lower pad has two pressure-operated switches therein for arming and firing the missile; these switches are pneumatically connected to a gas output chamber formed in the space adjacent to the outer surface of the sphere and the collar.
The sphere is pneumatically uncaged after an electrical "fire" signal is sent to SPADE which simultaneously activates the gas release mechanisms. The released gas spins the sphere, by means of spin jets, about the sphere's vertical axis, uncages the sphere, starts the functioning of the time delay valve, and also controls the functioning of a distance meter. When a preset arming altitude has been reached by the missile the distance meter dumps gas from an ascent dump chamber into the output chamber, actuating a low-pressure arming switch. A calibrated exhaust port in the collar permits depletion of the gas after the arming switch is closed. A relatively short interval of time after the low pressure switch is actuated the distance meter causes a descent dump chamber to be exhausted into the output chamber. The build up of pressure in the output chamber due to the larger volume of gas held in descent pump chamber causes a rise in pressure in this chamber greater than before. The higher pressure activates a high pressure switch and causes the missile to receive a destruct signal.
One of the objects of this invention is to provide a settable pneumatic altitude-detection device which will arm and destruct a missile completely independent of the missile's environment and trajectory.
Another object of this invention is to provide a settable pneumatic altitude-detection device which requires no electrical power for operation after launch of the missile.
Another object of this invention is to provide a settable pneumatic altitude-detection device which contains no electronic circuits or components.
Another object of the present invention is to provide a settable pneumatic altitude-detection device which is insensitive to nuclear radiation.
Another object of the present invention is to provide a settable pneumatic altitude-detection device which is reliable in operation, low in cost, and has very long shelf life.
A further object of this invention is to provide a settable pneumatic altitude-detection device which has a gas bearing supported sphere which has all altitude freedom, and high acceleration and loading capability.
For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric, partially sectioned view of the rotatable sphere and the sphere support structure.
FIG. 2 is a functional polar cross-sectional schematic view of the sphere assembly and the sphere support structure.
FIG. 3 is a partial cross-sectional view of a gas release mechanism schematically illustrated in FIG. 2.
FIG. 4 is a partial cross-sectional view of a pneumatic time delay valve schematically illustrated in FIG. 2.
Throughout the following description like reference numerals are used to denote like parts of the drawing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 2 the SPADE comprises two major assemblies, a sphere assembly 10 and a sphere support structure 12. The sphere support structure 12 basic elements are an upper spherical pad 14, a lower spherical pad 16 and a circularly shaped collar 18 which separates upper pad 14 from lower pad 16 and fixedly holds all three aforementioned basic elements together. The sphere support structure 12 helps to provide polar support and floating support for the sphere assembly 10 in a manner described herein.
The upper pad 14 contains a first pressurized gas supply 20, an external gas release mechanism 22, and a pressure regulator 24 all pneumatically connected in series. The output gas line 26 leading from pressure regulator 24 divides into a first upper pad gas passage 28 and a second upper pad gas passage 31. The first external gas passage 28 connects to an upper pad circular manifold 30 which has a plurality of upper pad gap gas orifices 32 therein which feeds directly into the main gap 34. Gas from the first external gas passage 28 is also fed to the lower spherical pad support 16 and the main gap 34 through manifold 30, upper pad connecting passage 36 and lower pad connecting passage 38 through intermediate collar connecting passage 40. Gas from the lower pad connecting passage 38 is distributed to main gap 34 from the lower spherical pad 16, in a similar manner aforedescribed, by a lower circular gas manifold 42 having a plurality of lower pad gap gas orifices 44. A first pneumatic time delay valve 46 has its calibrated input orifice port 48 as shown in FIG. 4 connected to the second external passage 31. An upper pad exhaust port 50 is connected to the first time delay valve exhaust flow through port 52. A pressure relief port 54 of the first time delay valve 46 is connected to a collar output chamber 56 by means of a third upper pad passage 58.
Collar 18, which is disposed between the upper spherical pad 14 and the lower spherical pad 16, is hermetically sealed to these two pads so that no gas can escape from the sphere support structure 12 except through upper pad exhaust port 50 and a calibrated collar exhaust orifice 60. The space between the inside concave collar wall 62 and the outer surface of upper hemisphere shell 64 and the lower hemisphere shell 66 forms the aforementioned output chamber 56.
A bearing hole 68 is located at the polar axis of each pad for holding therein two caging mechanism piston shafts 70. A pair of piston contact surfaces 72 located at the end of piston shafts 70 make electrical contact with a pair of axially aligned insulated caging terminals 74. This contact-terminal arrangement enables a "fire" signal to enter the sphere for initiation of spin as described hereinafter.
The lower pad 16 has two pressure operated switches, a low pressure switch 76 and a high pressure switch 78. Each of these switches is pneumatically connected to the output chamber 56 by means of a second lower pad connecting passage 80. Low pressure switch 76 having output terminals XX is actuated on ascent and causes arming of the missile by activating an arming circuit not shown on FIG. 2. The high pressure switch 78 having output terminals YY is actuated on descent and causes destruction of the missile at a preset altitude by activating a destruct circuit located in the missile and also not shown in the drawings. The lower pad 16 has two threaded holes 82 therein for mounting and orienting the altitude detector to the carrying vehicle or missile frame.
The sphere assembly 10 as previously stated has two hemisphere shells 64 and 66 which are joined at parting 84. The shells contain within them the other working elements of the altitude detector. These include a second pressurized gas supply 86, an internal gas release mechanism 88, and a second pneumatic time delay valve 90 all connected pneumatically in series. The initial gas output of time delay valve 90 is carried by a common gas trunk line 92 to spin-up nozzles 94, to a pair of polar pneumatic cage mechanisms 96, to the ascent dump chamber 98, and the descent dump chamber 100 through ascent check valve 102 and descent check valve 104 respectively of a pneumatic output signal generator system 106. A pneumatic distance meter 108 is also connected to the output of the internal gas release mechanism 88 by internal gas line 110. Second time delay valve 90 has a calibrated orifice 48 connected by gas line 111 to internal gas line 110 and thence to the gas release mechanism 88. The pneumatic distance meter 108, such as described in U.S. Pat. No. 3,365,942, has a net distance piston therein (not shown) mechanically connected to first slide 112 and detent slide 114 which are slidably held adjacent to each other. The output signal generator system 106 further includes a spring loaded detent 116 which slidably holds detent slide 114 in a fixed position after the net distance piston has moved first slide 112 downwardly on ascent. A spring-loaded descent dump valve 118 and a spring-loaded ascent pump valve 120 are in sliding contact with the detent slide 114 and the first slide 112 respectively. These two aforementioned valves control the flow of gas from ascent dump chamber 98 and descent dump chamber 100 to dump passage 122 which is directly connected to output chamber 56.
The pair of caging mechanisms 96 have piston springs 126 biasedly holding push pistons 128 within piston housings 124, so that piston shafts 70 on pistons 128 enter bearing holes 68, thereby caging and aligning the polar axis of sphere assembly 10 with the axis of the support structure 12. With pressure in caging chamber 130, the piston shafts 70 of the caging mechanisms 96 remain in the bearing holes 68. With gas pressure in main gap 34 and no pressure in caging chamber 130, the piston shafts 70 have a force acting on them to compress piston springs 126, withdrawing the piston shafts 70, and thereby uncaging the sphere assembly 10 from caging mechanism 124.
Referring now to FIG. 3, a partial cross-sectional view of the external and internal gas release mechanism 22 and 88 respectively shown schematically on FIG. 2, the high pressure gas supplies 20 and 86, shown in FIG. 2, have their outputs connected to gas release inlet port 132 of valve housing 133. Port 132 communicates with gas release outlet port 134 when the release mechanisms 22 and 88 are in the open condition. Port 132 is isolated from outlet port 134 by a thin metal diaphram 136 when the gas release mechanisms 22 and 88 are in the closed condition. When a voltage is applied to solenoid terminals 138, the solenoid plunger 140 withdraws, enabling a biased dart spring 142 to advance dart piston 144 and drive dart 145 through diaphram 136 thereby releasing gas from the gas supplies 20 and 86.
Referring now to FIG. 4, the first and second pneumatic time delay valves 46 and 90 have a valve housing 149 which contains therein a "T" shaped poppet valve chamber 151 and a transversely positioned piston chamber 154. Biasedly positioned within poppet valve chamber 151 is a poppet piston 150. Prior to release of gas from the external release mechanism 22, the poppet piston 150 is held in its open position, as shown in FIG. 4, by poppet spring 152 and by a shank 148' on orifice piston 148. With no pressure on calibrated orifice port 48, poppet spring 152 pushes poppet piston 150 upwards while coil spring 146 pushes orifice piston 148 to the left. Under the aforementioned condition, gas can flow from pressure relief port 54 through the poppet valve chamber 151 to the exhaust flow through port 52. When gas from pressure regulator 24 is released to the calibrated input orifice 48, gas enters piston chamber 154 at a controlled rate. Pressure builds up in piston chamber 154 and pushes orifice piston 148 to the right, thereby allowing poppet piston 150 to move downward, thus allowing gas to enter pressure relief port 54 and compress coil spring 152, thereby closing the first time delay valve 46, so that gases from the output chamber can no longer vent to the atmosphere.
In operation, an electrical fire signal, which is sent to SPADE, simultaneously activates the external and internal gas release mechanisms 22 and 88 respectively. Pressure regulator 24 permits gas to enter manifolds 30 and 42 so that the sphere assembly 10 floats on a cushion of gas, and also to enter the first time delay valve 46 at the calibrated orifice 48. At the same time, gas from internal release mechanism 88 releases gas to the spin-up jets 94 through relief port 54 and flow through port 52 and to the caging chambers 130, dump chamber 98, and communicates with the output chamber 56 as shown in FIG. 1, ascent chamber 100, and to the distance meter 108. The spin-up jets 94, which extend through the sphere shell, acting on the sphere 10 in the manner of a hero turbine, spin the sphere assembly 10 about its polar axis. During the brief spin up period, the caging mechanisms 96 maintain vertical alignment, and the upper pad exhaust port 50, whose poppet valve 150 is open, permits spin-up gases to leave output chamber 56, thus precluding operation of pressure switches 76 and 78.
The spin-up period is ended when the second pneumatic time delay valve 90 shuts off gas to the spin-up jets 94, the dump chambers 98 and 100, and the caging mechanism chambers 130. Check valves 102 and 104 maintain high pressure gas in the dump chambers 98 and 100. The loss of pressure in caging chambers 130 causes the caging pistons 70 to withdraw thereby leaving the sphere assembly 10 spinning about its vertical axis on a cushion of gas. The first pneumatic time delay valve 46 at this time closes, as indicated above, the spin-up exhaust flow through port 52 so that these gases cannot vent through upper pad exhaust port 50.
When the system is at the stage aforedescribed, it is considered operational, and the vehicle carrying SPADE is launched. The spinning of the sphere assembly 10, and the low torque forces from the gas bearing in main gap 34 enable the sphere assembly to act as a free gyroscope, therefore the sphere assembly's initial vertical alignment is maintained throughout the vehicle's subsequent turns and maneuvers.
When a preset safing/arming altitude has been reached, the pneumatic signal generator 106 activates the low pressure switch 76 in the following manner. A net distance piston (not shown) of pneumatic distance meter 108 moves first slide 112 downward, enabling the ascent dump valve 120 to open, suddenly dumping gas from ascent dump chamber 98 into the output chamber 56 at the same time detent 116 locks 114 in a downward position. First slide 112 in its downward movement on ascent holds dump valve 118 in a closed position. The pressure rise in the output chamber 56 is sufficient only to operate low pressure switch 76 and not high enough to actuate high pressure switch 78, thus sending the required unsafing signal or arming signal to the missile. The calibrated collar exhaust orifice 60 permits depletion of some of the gas from output chamber 56 after closure of the low pressure switch 76. When upon descent, the preset self-destruct altitude is reached, the net distance piston of the distance meter 108 moves upward. Upon descent the net distance piston moves first slide 112 upwardly far enough to release descent dump valve 118 and cause it to open, thereby dumping the gas contained within the descent dump chamber 100 into the output chamber 56 and thus operating the high pressure switch 78. The descent dump chamber 100 is larger than the ascent dump chamber 98, therefore high pressure switch 78 is activated and provides the required destruct signal to the missile thus completing the mission. It can be readily seen that in this manner simultaneous activation of both switches upon reaching ascent setting is prevented. Ascent and descent altitude settings are made by adjusting the positions of the dump valves 118 and 120 so that they are nearer or further away from caming surfaces of the net distance piston.
The foregoing disclosure and drawings are merely illustrative of the primciples of this invention and are not to be interpreted in a limiting sense. I wish it to be understood that I do not desire to be limited to exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.