US3868854A

US3868854A - Sampling mechanism

Info

Publication number: US3868854A
Application number: US376013A
Authority: US
Inventors: Bruce W Travor; Lennord L Pitney
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1973-07-02
Filing date: 1973-07-02
Publication date: 1975-03-04
Anticipated expiration: 1992-03-04

Abstract

A sampling mechanism of a needle penetration system for obtaining content specimens from a thick steel container in which a recoil compensator minimizes the recoil effect on the penetration gun and facilitates the use of lightweight equipment to mount the penetration gun on the container in a minimum period of time.

Description

[ Mar. 4, 1975 3,321,122 5/1967 Seghezzi 227/10 3,534,613 10/1970 Travor............................... 73/4256 Primary Examiner-S. Clement Swisher Attorney, Agent, or FirnzNathan Edelberg; Robert P. Gibson; William Sommer 57] ABSTRACT A sampling mechanism of a needle penetration system for obtaining content specimens from a thick steel container in which a recoil compensator minimizes the recoil effect on the penetration gun and facilitates the use of lightweight equipment to mount the penetration gun on the container in a minimum period of time,

7 Claims, 3 Drawing Figures SAMPLING MECHANISM inventors: Bruce W. Travor, Holland, Pa.;

Lennord L. Pitney, Park Rapids, Minn.

Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC

Filed: July 2, 1973 Appl. No.: 376,013

US. 73/421.S, 73/425, 137/318, 227/10 Int. Cl. G0ln 1/22 Field of Search................... 73/421, 425, 421.5; 137/318; 227/9, 10

References Cited UNITED STATES PATENTS United States Patent Travor et a1.

a o 2 e-E a sum 2 or g SAMPLING MECHANISM 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 sampling apparatus, and more particularly, to sampling arrangements employing a pyrotechnically operated penetration gun to drive a grooved sampling pin into a container to remove a sample of its contents.

One of the objects of the invention is to provide sampling apparatus in which the recoil reaction in the penetration gun is minimized.

Another object of the invention is to provide such sampling apparatus that enables the use of lightweight equipment to rapidly mount the penetration gun on the container.

A further object of the invention is to provide such sampling apparatus which is substantially reactionless when the penetration gun is operated.

These and other objects, features and advantages will become more apparent from the following description and accompanying drawings in which:

FIG. I is an elevational view, partially in section, of a preferred arrangement mounting a sampling apparatus upon a container for sampling the contents thereof in accordance with the principles of the invention.

FIG. 2 is an enlarged, sectional view of the FIG. 1 arrangement with certain parts omitted or partially broken away.

FIG. 3 is a view similar to FIG. 2 but of a modified arrangement.

The mounting arrangement, shown generally at (FIG. 1), for rapidly securing the sampling mechanism penetration gun 11 with its novel recoil compensating mechanism 12 upon a thick steel cylinder 13 the contents 14 of which are to be sampled, includes a pair of lightweight chains 15, only one of which is shown, that each extend around a corresponding bifurcated leg portion 16 (FIGS. 1, 2, 3) of the base alignment block 17 for the penetration gun. A snap-wrench 18 on each chain is adapted to render the chain taut so as to securely mount block 17 and the penetration gun 11 with its grooved needle 20 (FIGS. 2, 3) in a predetermined position substantially normal to the container or cylinder wall portion that is to be penetrated thereby. Although the cylinder 13, which is representative of a bomb wall or the like, has been designated to be of cylindrical shaped, the wall contour may be tapered or conical wherein one of the chains 15 would necessarily have a relatively larger or smaller effective length.

The centrally apertured coupling or retainer 22 (FIGS. 2, 3) is externally threaded for securement to the hub portion of the base alignment block 17 and rigidly mounts the tubular penetration gun body 11, spacer 23 and needle adapter 24 in their desired positions with the needle adapter O-ring seal 25 in engagement with the container wall. The needle adapter has an appropriate seal seated in one end of its central passage that receives the forward portion of the grooved needle 20. The lateral surface of needle 20 has a plurality of longitudinally extending grooves 27 that place the interior of a penetrated container wall 13 in fluid communication with internal passages 28 and the enlarged central passage 29 formed in the enlarged needle head portion 30 which is slidably mounted in gun body tubular passage 31. The enlarged needle central passage 29 is an extraction orifice and contains a predetermined amount of self-sealing room temperature vulcanizing rubber 29A which permits the entry of ahyperdermic needle of a syringe unit (not shown) to remove container contents or samples after the needle 20 has been driven to its penetrating position by piston 32 and all of the penetrating gun and mounting apparatus have been removed. At this moment only the needle 20, adapter 24 and its seals remain in mounted position.

A suitable shock absorbing snubber 33 surrounds piston 32 and retards the stroke of the seal carrying piston head 34 that is slidably mounted in the enlarged tubular passage 31A of the gun body 11. The penetration gun body carries a cartridge 35 and its sealing adapter 36, and is externally threaded for connection of one internally threaded end of a recoil compensating cylinder 41 having an internal annular groove 48.

The other end of cylinder 41 has external threads 42 by which an internally threaded cap 43 is secured with its externally threaded reduced portion or fitting 44 adapted to have attached thereto a universal firing head (not shown). A sleeve 45, carrying an O-ring seal 46 in its internal surface, is press-fitted in an enlarged central recess of the cap, such that the sleeve interior is in fluid communication with the cap longitudinal passage 47.

. A compensator piston 50, carrying a peripheral O- ring seal 51 adjacent one end thereof, is slidably mounted in cylinder 41 and has a stepped central passage extending longitudinally therethrough that slidably receives firing pin 53 and a steel tube 54 which is of predetermined length and is slidably received in sleeve 45. A multi-apertured firing pin retainer 55 is positioned in one recessed face of piston 50 adjacent the primer 38 of cartridge 35. The other end of piston 50 is recessed to receive annular or cylindrical shockabsorbing snubber 57 that surrounds tube 54 and is adapted to slide over sleeve and strike sleeve flange 45A to retard compensator piston motion in the direction opposite to the motion of the cartridge actuated piston 32.

A peripheral edge of the compensator piston adjacent the snubber recess is provided with a tapered annular cam surface 60 which, upon cartridge actuated motion of the compensator piston, is adapted to temporarily spread or cam expansion lock ring 61 into cylinder groove 48 until the annular dove-tail shaped groove 62 in the external surface of piston 50 receives the selfretracted lock ring 61 as piston groove 62 is moved past cylinder groove 48. Upon assembly, the expansion lock ring retains the compensator piston and its associated parts in their desired pre-operative positions. Since the piston groove 62 is adjacent cam surface 60, the lock ring will be expanded for only a short period of time before contracting into the piston groove.

As pressure gas from the firing head flowsthrough passage 47 and tube 54, firing pin 53 will initiate cartridge 35 to develope cartridge pressure gas sufficient to impart the desired motion to both

pistons

32, 50 in their respective opposite directions until retarded by substantially simultaneous functioning by their corresponding

shock absorbing snubbers

33, 57 whereby the resulting counteracting forces of the penetration gun and recoil compensating mechanism have the effect of cancelling each other.

In the FIG. 3 modification a dual firing adapter has a lateral passage 71 fluidly communicating the laterally extending threaded fitting 72 for a universal firing head (not shown) with the mid-portion of a longitudinally extending stepped passage 73 containing a pair of oppositely operated

firing pins

74, 74 and their

retainers

75, 75. The end faces of the adapter 70 have internally threaded

recesses

76, 77 for respective securement to externally threaded end portions on the penetration gun tubular body 11 and the compensator cylinder 80 which

house corresponding cartridges

35, 35 and their

sealing adapters

36, 36.

Compensator piston 81, carrying O-

ring seals

82, 83, is slidably mounted in cylinder 80 intermediate the respective cartridge 35 and the shock absorbing hydraulic fluid buffer 84 which is normally retained by the compensator cylinder partition 85. Partition 85, carrying a peripheral O-ring seal 88, rupturable sealing disc 86 and the threadedly secured seal disc retainer 87, is held in position against a cylinder internal recess by a cupshaped expansion chamber end cap 90 that is externally threaded for securement to the internally threaded cylinder end portion adjacent O-ring seal 89.

As pressure gas from the firing head flows through passages 71 and 73, firing

pins

74, 74 will simultaneously initiate their

corresponding cartridges

35, 35 to develope cartridge pressure gas for imparting the desired motion to both

pistons

32, 81 in their respective opposite directions until retarded by their

corresponding shock absorbers

33, 84, resulting in a reactionless mechanism as the sealing disc 86 ruptures and some of the fluid 84 passes through the central opening 91 of retainer 87 and into the expansion chamber 92.

Various modifications. changes or alterations may be resorted to without departing from the scope of the invention as defined in the appended claims.

We claim:

1. In a sampling mechanism having a grooved needle for sampling the contents of a container secured to said mechanism, a first piston responsive to fired cartridge gases for driving said needle in a first direction toward said container, and a first shock absorber for retarding motion of said first piston after predetermined movement thereof in said first direction.

a compensator piston responsive to fired cartridge gases for movement in a direction opposite to said first direction,

a second shock absorber for retarding motion of said compensator piston after predetermined movement thereof in said opposite direction,

extraction orifice means in said needle, and

vulcanized rubber sealing said orifice means.

2. The structure of claim 1 wherein a single cartridge is positioned between said first piston and said compensator piston, and both said pistons are actuated by gases generated from said single cartridge.

3. The structure according to claim 2 wherein said first piston is slidably mounted in a tubular body, said compensator piston is slidably mounted in a cylinder, said cylinder being secured to said tubular body, an expansion lock ring for momentarily restraining initial motion of said compensator piston, said cylinder hav ing an internal annular recess for temporarily accommodating said lock ring upon expansion thereof, said compensator piston having an external annular groove for accommodating said lock ring upon subsequent contraction thereof.

4. The structure according to claim 3 wherein said compensator piston has a central longitudinally stepped passage carrying one end of a steel tube and housing a slidably mounted firing pin in one end thereof, said firing pin being aligned with said cartridge, said steel tube being slidably mounted in a centrally apertured cap and sleeve unit secured to said cylinder, said second shock absorber being an annular snubber surrounding said steel tube and slidably positioned in a recessed face of said compensator piston, and an annular cam surface on a peripheral edge of said compensator piston adjacent said recessed face for expanding said lock ring.

5. The structure according to claim 1 wherein said second shock absorber is an hydraulic fluid buffer.

6. The structure of claim 5 wherein a dual firing adapter is positioned intermediate said first piston and said compensator piston, said dual firing adapter carrying a laterally extending firing head fitting and a pair of oppositely operated firing pins, a first cartridge located between one of said firing pins and said first piston, and a second cartridge positioned intermediate the other of said firing pins and said compensator piston.

7. The structure of claim 6 wherein a compensator cylinder is secured to one end of said adapter and contains said second cartridge, said compensator piston, said hydraulic fluid buffer, and an expansion chamber end cap, and a rupturable partitioning seal adjacent said hydraulic fluid buffer and longitudinally spaced from said end cap.

Claims

1. In a sampling mechanism having a grooved needle for sampling the contents of a container secured to said mechanism, a first piston responsive to fired cartridge gases for driving said needle in a first direction toward said container, and a first shock absorber for retarding motion of said first piston after predetermined movement thereof in said first direction. a compensator piston responsive to fired cartridge gases for movement in a direction opposite to said first direction, a second shock absorber for retarding motion of said compensator piston after predetermined movement thereof in said opposite direction, extraction orifice means in said needle, and vulcanized rubber sealing said orifice means.

3. The structure according to claim 2 wherein said first piston is slidably mounted in a tubular body, said compensator piston is slidably mounted in a cylinder, said cylinder being secured to said tubular body, an expansion lock ring for momentarily restraining initial motion of said compensator piston, said cylinder having an internal annular recess for temporarily accommodating said lock ring upon expansion thereof, said compensator piston having an external annular groove for accommodating said lock ring upon subsequent contraction thereof.