US 3830103 A
A Projectile having a rain impact gage nose portion for use in determining the frequency and force of raindrops encountered by the projectile as it travels through a rain field. The gage has a forward impact table responsive to raindrop impacts and secured to a ground electrode housed with a hot electrode and an intermediate piezoelectric sensor in a cylindrical nylon insulator. The sensor receives the raindrop impact initiated shock waves from the ground electrode and transmits an electrical output charge through the hot electrode and its output lead to a coaxial cable after which the electric signal can be recorded on board or transmitted to a receiving station for recording.
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Description (OCR text may contain errors)
United States Patent Andrjkovics et al.
[451 Aug. 20, 1974 RAIN IMPACT GAGE  lnvent0rS Richard S. Andrejkovics, Marlton,
N.J.; John F. Sikra, Feasterville, Pa.
 Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.
 Filed: July 5, 1973  Appl. No.: 376,663
 U.S. Cl. 73/170  Int. Cl G01w 1/08  Field of Search 73/170, 167
 References Cited UNITED STATES PATENTS 2,944,250 7/1960 Outt 73/170 R Primary Examiner-James J. Gill Assistant Examiner-Anthony V. Ciarlante Attorney, Agent, or FirmEdward J. Kelly; Herbert Berl; William Sommer [5 7 ABSTRACT A Projectile having a rain impact gage nose portion for use in determining the frequency and force of raindrops encountered by the projectile as it travels through a rain field. The gage has a forward impact table responsive to raindrop impacts and secured to a ground electrode housed with a hot electrode and an intermediate piezoelectric sensor in a cylindrical nylon insulator. The sensor receives the raindrop impact initiated shock waves from the ground electrode and transmits an electrical output charge through the hot electrode and its output lead to a coaxial cable after which the electric signal can be recorded on board or transmitted to a receiving station for recording.
5 Claims, 1 Drawing Figure PAIENIEBmszomn a I I.
-. m HH A a a m w/////////L RAIN IMPACT GAGE The invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without the payment to us of any royalty thereon.
This invention relates to gages, and more particularly to a rain impact gage.
The performance of munitions in rain fields has not been entirely satisfactory in that on occasion projectile impact with raindrops has resulted with premature ignition and failure of ignition.
One of the objects of the invention is to provide a rain impact gage arrangement on a projectile for determining the frequency and force of raindrops encountered by the projectile as it travels through a rain field.
Another object is to provide such an arrangement that will enable valuable information to be gathered which will be useful in the design of future munitions.
A further object is to provide such an arrangement that will produce information that will be of assistance to weather analyst personnel or the like.
These and other objects, features and advantages will become more apparent from the following description and accompanying drawing which is a longitudinal 'sectional view of a preferred projectile rain impact gage arrangement embodying the principles of the invention.
The projectile body includes a forward nose portion 16 having a conical outer surface and an internally threaded rearwardly opening recess by which it is secured to the external threads on the pre-loading lead screw 17 of the rain impact gage. A loading lock set screw 18 in a laterally extending tapped opening of the projectile nose 16 has its inner end in locking engagement with a forwardmost reduced smooth surface of lead screw 17. The projectile main body portion 35 has a forwardmost internally threaded surface for securement to the rain impact lead screw 17.
Appropriate recesses or passages in the projectile nose l6 and lead screw 17 house a pair of cylindrical insulators l3 and 21 which are of nylon material. Insulator 13 has a centrally apertured base portion for seating the rearward surface of a hot electrode 15. The hot electrode is a cylinder of lead material having the rearward surface provided with an internally threaded recess in which is secured the forward threaded portion of a hot output lead 19, a major portion of which is surrounded by insulator 21. An insulating disc 22 surrounds a rearward portion of the hot output lead 19 and extends laterally between the rearward surface of lead screw 17 and the head 23 of the hot output lead 19. Insulator 13 houses the hot electrode 15, the ground electrode 14, and an intermediate piezoelectric sensor or crystal 12 which will produce a current when under a compressive load. The forward surface of the ground electrode cylinder 14 has an internally threaded recess in which is secured a reduced threaded portion of a forwardmost impact table 11 that extends through a suitable opening in the forward end of nose l6 and is responsive to raindrop impacts.
Secured to lead screw 17 by a plurality of bolts or cap I screws 30 are an annular ring 26 and the mounting disc 27 of a coaxial cable connector 28 for the coaxial cable 29 that extends rearwardly in the projectile body portion 35 and within the housing 32 of an electronic recorder or an electronic transmitting system having an appropriate amplifier, radio transmitter and antenna (not shown). The copper core forwardmost end 24 of insulated wire 25 is appropriately secured in the lateral passage means 23A, 23A provided in the bifurcated head 23 of hot output lead 19 and the copper core rearmost end 24A is suitably secured to the forward element 28A of coaxial cable connector 28.
The arrangement is such that raindrops impacting on the impact table 11 will initiate shock waves through the impact table 11 and the ground electrode 14 to the piezoelectric sensor 12 which in turn transmits an electrical output charge through the hot electrode 15 and its output lead 19 to wire 25 and coaxial cable 29. The electrical signal transmitted through coaxial cable 29 can thus be recorded by an on board electronic recorder or be transmitted by an electronic transmitting system to a remote receiving station for recording. Preferably the conical lateral surface of the assembled nose 16 is provided with an elastomer coating of polyurethane so that raindrops impacting on the coated surface will have minimal effect on the gage.
Various modifications, changes or alterations may be resorted to without departing from the scope of the invention as set forth in the appended claims.
1. In a projectile body having a nose portion and a main body portion,
said nose portion comprising a rain impact gage having a forwardmost impact table responsive to raindrop impacts,
a ground electrode secured to a portion of said impact table,
a cylindrical insulator housing said ground electrode and a hot electrode,
a piezoelectric sensor located intermeidate said ground and hot electrodes for receiving a raindrop impact initiated shock wave from said ground electrode and transmitting an electrical output charge through said hot electrode, and
a hot output lead secured to said hot electrode for transmitting said output charge through a rearwardly extending coaxial cable.
2. The structure according to claim 1 wherein said cylindrical insulator is of nylon material and has an apertured base portion surrounding a portion of said output lead and in abutment with an end surface of said hot electrode, and said hot electrode being of lead material.
3. The structure in accordance with claim 2 wherein a second cylindrical insulator surrounds a major portion of said hot output lead rearwardly of said apertured base portion and is carried by a pre-loading lead screw, said projectile nose and main body portions being secured to said lead screw.
4. The structure of claim 3 wherein said hot output lead has an enlarged head at its rearward end, said head having a lateral opening, a coaxial cable connector mounted in said projectile main body portion, and a copper core of one end of an insulated wire secured in said head lateral opening, the other end of said wire being secured to said coaxial cable connector.
5. The structure of claim 4 wherein an insulating disc surrounds a rearward portion of said hot output lead and extends between said head and said lead screw.