US3217534A

US3217534A - Apparatus for stopping bullets

Info

Publication number: US3217534A
Application number: US233330A
Authority: US
Inventors: Charles T Bingham; David I Miller; Kozlowski Edward
Original assignee: TRW Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1962-10-26
Filing date: 1962-10-26
Publication date: 1965-11-16
Anticipated expiration: 1982-11-16

Description

APPARATUS FOR STOPPING BULLETS Filed Oct. 26, 1962 4 Sheets-Sheet 1 INVENTORS Char/9s I 5/0 /1007 BY Dov/o M/Y/er Edward @zbwsh' 3(4; 4 W @ZATTORNEYS NOV. 16, 1965 c BlNGHAM ETAL 3,217,534

APPARATUS FOR STOPPING BULLETS Filed Oct. 26, 1962 4 Sheets-Sheet 2 II I I Ill/- 3 \III I 1 INVENTORS Char/es 7? 5/09/7007 APPARATUS FOR STOPPING BULLETS 4 Sheets-Sheet 5 Filed Oct. 26, 1962 INVENTORS Umr/es 7.506960? BY Dov/oZ M/Y/Qr Edu/ rd Aoz/o ws/ ZWAQZ TTORNEYS Nov. 16, 1965 c. T. BINGHAM ETAL. 3,217,534

APPARATUS FOR STOPPING BULLETS 4 Sheets-Sheet 4 Filed 001;. 26, 1962 m b a J M f o MW 60M w United States Patent 3,217,534 APPARATUS FOR STOPIING BULLETS Charles T. Bingham, Lyndhurst, and David 1. Miller and Edward Kozlowski, Euclid, Ohio, assignors to TRW Inc., a corporation of Ohio Filed Oct. 26, 1962, Ser. No. 233,330 3 Claims. (lCi. 73-167) The present invention relates to an improved apparatus for stopping bullets from small arms fire. The invention has particular applicability in proving ranges for the functional testing of rifies and rifle components.

Heretofore, conventional bullet trap assemblies frequently made use of sand as a backing material. The use of sand presents several distinct disadvantages. For one, the attrition which the sand undergoes during repeated firings creates a dust problem which requires expensive and elaborate dust removal equipment when the proving range is located indoors. Secondly, when the sand has been reduced to the consistency of flour, as it is after continued use, the sand loses its effectiveness as a barrier, and the entire installation must be removed and rebuilt with new sand.

The present invention provides an improved apparatus for stoping bullets which does not employ sand or other solid material to dissipate the energy of the bullet but rather provides a circulating water system for that purpose. Broadly speaking, the invention comprises means for test firing bullets which includes means for directing a bullet into a moving, confined column of water which then fiows into a larger body of water from which the spent bullet can be very easily recovered. The invention also embodies control means for assuring safe operation of the device at all times.

An object of the present invention is to provide an improved apparatus for test firing bullets from small arms.

A further object of the present invention is to provide an improved apparatus for dissipating the energy of high velocity bullets and permitting their rapid recovery.

A further object of the invention is to provide an improved apparatus for test firing small arms which eliminates the use of sand or other solid materials.

A still further object of the invention is to provide an apparatus for the functional testing of small arms which employs a completely controllable water circulating system as the means for dissipating the energy of the bullets.

The preferred form of the present invention involves the combination of a tank, a water header communicating with the tank, a tube extending between the header and the tank, and spray means in the header which include a plurality of spaced nozzles arranged to provide water streams which converge within the tube. The converging water streams thereby form a moving column of water which fills the tube extending between the header and the tank without, however, creating excessive turbulence. The piece to be tested is fired into this moving column of water which, under the proper condition of pressure and flow rate, presents a solid wall of liquid to the bullet which completely dissipates the energy of the bullet. The moving column of water has been found to be a particularly effective energy dissipating device, as it has been determined that bullets having a very high muzzle velocity are completely spent within a few feet after hitting the moving column of water.

A further description of the present invention will be made in conjunction with the attached sheets of drawings which illustrate a preferred embodiment.

In the drawings:

FIGURE 1 is a plan view of a bullet trap assembly according to the present invention;

FIGURE 2 is a front elevational view of the assembly shown in FIGURE 1;

FIGURE 3 is a side elevational view of the assembly shown in FIGURES 1 and 2;

FIGURE 4 is a fragmentary view, partially in crosssection, of the water header and tank assembly shown in the preceding figure; and

FIGURE 5 is a cross-sectional view taken substantially along the line V-V of FIGURE 4.

As shown in the drawings:

The system shown in the drawings includes three basic components, a tank 10, a water header 11 communicating with the tank 10 and a bullet entrance chamber 12 into which the barrel of the piece to be tested is inerted, as will be apparent from succeeding portions of the specification. The tank 10 is secured to a floor 13 in which there is formed a sump generally indicated at numeral 14. While only one bullet trap assembly is shown in the drawings, it will be evident that where more than one assembly is employed, a common sump can be provided for all.

The tank 10 shown in the drawings is of generally rectangular configuration and is provided with supporting legs 16 which are secured to the floor 13. Water is circulated through the tank and the header assembly by means of a pump 17 which picks up water from the sump 14 and directs it through a pipe 18 controlled by a globe valve 19. The water thereupon passes through a U- shaped supply line 21 which is provided with a water pressure gauge 22. The U-shaped supply tube 21 is secured at its outlet end to a supply connection flange 23 forming part of the water header 11.

As seen in the drawings, the header 11 includes a cylindrical shell 24 which is secured to the tank 10 by an assembly including a flange 26 having a sealing gasket 27 interposed between it and the wall of the tank 10, and a holding plate 28 having a sealing gasket 29 interposed between it and the opposite side of the tank wall. A plurality of bolts 31 secured by nuts 32 hold the water header 11 in tightly sealed relation against the forward wall of the tank 10.

As best illustrated in FIGURE 4, the bullet entrance chamber includes a tube 36 which is secured along its length to a closure plate 37 of the water header 11 and is also provided with a T-joint 35 having a drain fitting 38 communicating with a drain line 39 which extends to the sump 14. The drain fitting for the bullet entrance chamber is added strictly as a precautionary measure, as it is highly unlikely that water would ever enter the bullet entrance chamber in the normal functioning of the assembly.

Water entering the water header 11 through the supply connection flange 23 fills the space between the closure plate 37 and a nozzle holding plate 41 secured to the inner wall of the cylindrical shell 24 and also secured to the bullet entrance tube 36. As illustrated in FIGURE 5, the nozzle holding plate 41 is provided with a series of circumferentially spaced apertures 42 whose axes are disposed at an acute angle with respect to the axis of the bullet entrance tube 36. Into the apertures 42 are threaded a plurality of nozzles which may take the form of threaded pipes 43. The water pressure behind the nozzle plate 41 forces the water through the pipes 43 into converging streams of water which meet and form a solid, moving column of water within a tube 44 extending between the water header 11 and the tank 10. The forward end of the tube 44 is provided with a nozzle cone 46 which acts as a shield and confines the water jets emanating from the pipes 43 into a solid mass of moving water.

The column of water passing through the tube 44 then enters the tank 10. As indicated in FIGURE 3, the tank 10 is provided with an overflow trough 51 which is deeper at its downstream side than it is on the upstream side because it was found that the firing of the bullet into the moving column of water produced a shock wave which travelled the length of the tank 10. Making the overflow trough 51 deeper at the downstream end accommodates this surge of water. The overflow from the trough 51 is directed by means of a pipe 52 back into the sump 14.

It will thus be seen that there is a continuous circulating body of water being pumped from the sump 14, through the header 11 and into and out of the tank 10. The muzzle of a rifle to be tested is secured with its axis coinciding with the axis of the bullet entrance chamber 12. When the piece is fired, the bullet strikes the solid moving column of water provided by the pipes 43 and is carried along with the moving body of water into the body of water located in the tank 10. Within a matter of a few feet, the energy of the bullet is dissipated, and the spent bullet then drops into a wire basket 56 located within the tank 10 and it is then a simple means to collect the spent bullets by lifting the basket 56 out of the tank so that the water is drained from the basket and the bullets are retained therein.

The assembly of the present invention incorporates several safety features to assure that there is sufficient water in the tank before a bullet is fired, and to prevent a back surge of water into the bullet entrance chamber. One of the safety features includes a plurality of electrodes disposed within an electrode holder 58 located in a corner of the tank structure shown in FIGURE 1. The electrode holder 58 is provided with a series of apertures 59 which permit flow of water into the electrode holder. In the particular embodiment of the invention shown in FIGURE 3, the electrode holder includes a low level electrode 61, an intermediate electrode 62, and a high level electrode 63. In order for the assembly to be in operative condition, three conditions must exist:

(1) The pump 17 has to be running.

(2) The level of water in the tank 10 must be above the level of the highermost electrode 63.

(3) There must be overflow in the discharge line 52.

In order to assure the latter condition, the overflow line 52 is provided with a flow switch 66. The

electrodes

61, 62, 63 and the flow switch 66 are connected in series in a control circuit, and when all of the switches represented by these electrodes are closed, the system is operative. If one of these switches should remain open, an appropriate signal is transmitted to the firing line to warn the operator that there is insufficient water in the tank to commence firing. The purpose of using a plurality of electrodes is an added safety feature, as it is always possible that any electrical element functioning as a switch can be shorted out accidentally. A drain for the tank 10 is provided by a fitting 67, the size of the drain being such that it will drain more water from the tank 10 than is being pumped in by the pump 17. Opening and closing of the drain is controlled by a solenoid operated valve 7 (FIG. 1). Upon shutdown, the valve 70 is operated and the pump 17 continues to run. However, since the drain capacity is larger than the flow rate, the water level will drop until it drops below the tube 36 whereupon a suitable level sensing means electrode 61 operates to close the drain.

An additional drain 68 is provided in the water header 11 to discharge any water which might back-up in the cone 46. This fitting communicates with a conduit 69 which directs the liquid back into the sump 14. A drain is also provided to drain the water from the water inlet Zone behind the plate 41.

For best results, the pressure in the water header 11 should not be so high as to cause turbulence in the converging streams issuing from the pipes 43, as the existence of excessive turbulence in the moving column of water increases the length of water column required to dissipate the energy of the bullet completely. We have achieved satisfactory results by maintaining a water pressure in the header 11 on the order of five pounds per square inch gauge. At pressures on the order of pounds per square inch, the effects of turbulence are manifest.

It should be evident that various modifications can be made to the described embodiments without departing from the scope of the present invention.

We claim as our invention:

1. An apparatus for test firing small arms comprising a tank, a water header secured to said tank, a tube communicating said header with said tank, a bullet entrance chamber coaxial with said tube and extending therefrom, nozzle means directed into said tube to form a solid column of flowing water therein, overflow means on said tank, sump means associated with said tank and receiving water from said overflow means, pump means for directing water from said sump into said nozzle means, electrode means in said tank for detecting the existence of a predetermined water level therein, and a flow switch actuated by the overflow from said tank, said electrode means and said flow switch being connected in series and operating to provide a signal when the water in said tank is below a predetermined height.

2. An apparatus for test firing small arms comprising a tank, a water header secured to said tank, a tube communicating said header with said tank, a bullet entrance chamber coaxial with said tube and extending therefrom, a plate secured to the periphery of said chamber and to the interior of said header, nozzle means extending through said plate and directed at said tube to form a solid column of flowing water therein, overflow means on said tank, sump means associated with said tank and receiving water from said overflow means, pump means for directing water from said sump into said nozzle means, electrode means in said tank for detecting the existence of a .predetermined water level therein, and a flow switch actuated by the overflow from said tank, said electrode means and said flow switch being in series and operating to provide a signal when the water in said tank is below a predetermined height.

3. The apparatus of claim 1 in which said overflow means includes a trough which is deeper at the downstream end of said tank than at its upstream end.

References Cited by the Examiner UNITED STATES PATENTS 2,202,197 5/1940 Ewertz 73-304 2,356,992 8/1944 Gilson 73-167 2,422,284 6/1947 Andresen et al 73-167 2,518,445 8/1950 Benson 73-167 2,525,843 10/1950 Walker 73167 2,813,422 11/1957 Schuessler 73167 RICHARD C. QUEISSER, Primary Examiner.

DAVID SCHONBERG, Examiner.

Claims

1. APPARATUS FOR TEST FIRING SMALL ARMS COMPRISING A TANK, A WATER HEADER SECURED TO SAID TANK, A TUBE COMMUNICATING SAID HEADER WITH SAID TANK, A BULLET ENTRANCE CHAMBER COAXIAL WITH SAID TUBE AND EXTENDING THEREFROM, NOZZLE MEANS DIRECTED INTO SAID TUBE TO FORM A SOLID COLUMN OF FLOWING WATER THEREIN, OVERFLOW MEANS ON SAID TANK, SUMP MEANS ASSOCIATED WITH SAID TANK AND RECEIVING WATER FROM SAID OVERFLOW MEANS, PUMP MEANS FOR DIRECTING WATER FROM SAID SUMP INTO SAID NOZZLE MEANS, ELECTRODE MEANS IN SAID TANK FOR DETECTING THE EXISTENCE OF A PREDETERMINED WATER LEVEL WHEREIN, AND A FLOW SWITCH ACTUATED BY THE OVERFLOW FROM SAID TANK, SAID ELECTRODE MEANS AND SAID FLOW SWITCH BEING CONNECTED IN SERIES AND OPERATIVELY TO PROVIDE A SIGNAL WHEN THE WATER IN SAID TANK IS BELOW A PREDETERMINED HEIGHT.