US2690126A - Projectile fuse recovery assembly - Google Patents

Description

Sept. W5 3 W. 5. FINKEN ETAL Filed Feb. 10. 1948 3 Sheets-Sheet l IN V EN TORS LEO/V490 P l-k/sosp BY WQLTER 5. F/NKEN IQTTOPNEY S p 1954 w. s. FINKEN ETAL fi PROJECTILE FUSE RECbVERY ASSEMBLY Filed Feb. 10. 1948 3 Sheets-Sheet 2 Wm 75/? 5. F/NKE/v p 1954 W. s. FlNIKEN ETAL Z69@12$ PROJECTILE FUSE RECOVERY ASSEMBLY Filed Feb. 10, 1948 3 Sheets-Sheet 3 INVENTORS LEO/V490 P FQ/EDEQ BY Wm 75/? 5. HNKE/v HTTOPNEY Patented Sept. 28, 1954 TET OFFIC P. Frieder,

Great Neck,

mesne assignments, to

1110., New York, N. Y., a c

N. Y., assignors, by General Textile Mills,

orporation of Delaware Application February 10, 1948, Serial N 0. 7,454

6 Claims.

to a projectile fuse remore particularly, to an assembly enabling the firing of projectile fuses from large caliber rifles for the purpose of testing them and then recovering the fuses for examination and inspection.

During the last war and currently, research is proceeding with a view to developing new types of fuses for exploding projectiles such as proximity fuses and the like. It is highly desirable in connection with the development of these fuses to test them under actual firing conditions. Unfortunately however it is diflicult to recover a fuse after it has been fired from a rifle in that the force of impact upon landing is such as to destroy the fuse. In event of malfunctioning of the fuse, the scrap which remains gives no clue to the reason for the failure of the fuse to function.

One object of our invention is to provide an assembly in which a new type fuse may be installed in a large caliber projectile, fired from the rifle and the fuse recovered after it has been fired and inspected to ascertain whether it functions properly or, in event of malfunctioning, the reason for its failure to function.

Another object of our invention is to provide an assembly in which the fuse to be tested is expelled from the test projectile and recovered by means of an attached parachute.

A further object of our invention is to provide an assembly for recovering fuses fired from large caliber projectiles by parachute in which means are provided for providing a time delay to permit the projectile to slow down sufficiently to enable a parachute to open and lower the fuse safely without injury thereto.

Other and further objects of our invention will appear from the following description.

In general, our invention contemplates the provision of a test projectile fitted with a fuse to be tested and containing a canister housing a parachute fo lowering the fuse to the earth. After a predetermined interval of time, means are provided for expelling the canister housing the parachute and the fuse from the test propredetermined period Our invention relates covery assembly and,

The fuse to be tested is parachute and may thus be safe- 2,604,849, we have disclosed an illuminating projectile in which a canister containing a flare and a supporting parachute are adapted to be expelled from a projectile and, after a predetermined delay, to permit the parachute to open.

In the instant application, we have provided an improved structure, permitting a period of delay after the expulsion of a canister within which the canister may reduce its velocity before the opening of the supporting canopy, thus reducing the shock upon the canopy when it is opened and reducing the danger of fouling the shroud lines of the parachute.

We use a parachute having a hemispherical canopy and a floating hem cord such as described in United States Patent to Walter S. Finken 2,412,392 dated December 10, 1946.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

Fig. 1 is the sectional view of a test projectile containing one embodiment of our invention;

Fig. 2 is a fragmentary sectional view drawn on a large scale taken on the line 22 of Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2;

Fig. '4 is a fragmentary sectional view similar to Fig. 3 showing another construction of a delay action release mechanism forming part of our invention;

Fig. 5 is a fragmentary sectional view showing modification of the construction shown in Fig. 4;

Fig. 6 is an elevation drawn on a small scale showing the position of the parts during the expulsion of the canister and the fuse;

Fig. 7 is an elevation showing the parachute at the instant of being streamed;

Fig. 8 is a view showing the parachute canopy open and the fuse to be tested being lowered for recovery.

More particularly, referring now to the drawings, projectile I9 is provided with the usual rotating band l2. A base plug it is secured to the projectile body by means of shear pins 26. A liner I 8 is secured within the projectile body in any appropriate manner. A pair of split sleeves 29 and 22 house a parachute 26. The lower end of sleeve 28 is provided with a flange 25 adapted to seat in a re-entrant portion formed in the body 28 of a fuse 38 to be tested. The lower end of sleeve 22 is formed with a flange 32 adapted to seat in a re-entrant portion formed in the body 28. The sleeves to and 22 are held in assembled position by means of a tie member 34 which may be of any suitable material such as nylon, wire or a strap of thin metal. The securing member is such that it will rupture upon the application of a suitable force, as will be pointed out hereinafter '1 .ore fully. The interior side of the base plug i l is threaded to receive the threaded portion. 3&5 of a conventional fuse The fuse 352 is well known to the art and is such that, on setback occasioned by the shock of firing, a powder train will be ignited. A plurality of openings ii? are provided through which the of the powder train of the fuse 38 is adapted to blow into an annular space 42. The space l2 communicates with an expulsion powder charge i l through a number of vents ME. A spacer ring id of Wood or the like rests upon a washer 59, secured to the sleeve it in any appro priate manner. The fuse 33 is provided with adjusting rings at and 5A. which regulate the effective length of the powder train as is well known to the art. A plate '55 is secured to the fuse 3B and carries a sleeve-separating mechanism indicated generally by the reference nu meral as.

The parachute shroud lines Eli terminate in a rat tail 5?. which is secured to a swivel member supported by ball. bearings 65 acting against race ring 6% threadedly secured to the body 23 of the fuse 3b to be tested.

The upper end of sleeve iiil is provided. with screw threads it adapted to engage the external threads formed on the ring l2. Similarly the upper end of sleeve 22 is provided with threads l i adapted to engage the external threads formed upon the ring '52, which ring is positioned between the time fuse 3i; and the base plug 14.

Referring now to Figs. 2 to 5 inclusive, the sleeve-separating mechanism indicated generally by the reference numeral 53 is shown in detail.

t comprises a stationary body member '56 which is secured by bracket l8 and screws 80 to the plate 55. The body member is adapted to telescope within a movable member 32. The body member "it may be considered a stationary piston and the movable member 82 acts as a movable cylinder. The cylinder iii? is closed by a plug 35 provided with a seating point 88 adapted to seat in a re-entrant portion formed in the sleeve 22 as can readily be seen by reference to Figs. 2 and 3. Threadedly secured to the body member "it and positioned within the cylinder 82, we provide a pellet-supporting assembly 88. A member 9o supports a detonating cap 92. A firing pin 9 is releasably secured to a trigger stem 96 by means of a sleeve 98. The firing pin 9 is carried by a plate Hill which is formed integrally with a firing pin stem 192. The trigger stem 96 and the firing pin stem Hi2 are formed with interfitting inclined surfaces ltd. The ring as normally interlocks the firing pin stem H32 and the trigger stem 96. A ring spring Hi6 normally maintains the ring as in the position shown in Fig. 3. A firing pin spring 183 is normally under slight compression. The trigger stem 95 is provided with a cross pin H 3 carried by the body member 75 as can readily be seen by reference to Fig. 2. A. trigger member H2 is slidably mounted within body member '58 and the housing H carried thereby. The trigger member has an inclined surface lit extending into a slot H8 formed in the upper end of the liner it. The trigger member H2 is formed with a lug l2l adapted to contact the ring 98 when the trigger is moved to the left as viewed in Fig. 3.

The trigger is provided with an annular shoulder I22 against which the firing pin spring rests. When the trigger is moved to the left, as viewed in Fig. 3, the firing pin spring i9?- is first compressed against the plate iilt which is held by the firing pin stem m2 when it is locked to the trigger stem 96 by the ring 93. After the spring is compressed, the lug I20 is adapted to slide the ring 98 forwardly, thus permitting the engaging inclined surfaces it to cam the trigger Q 'e downwardly around the axis of the rod iii] to free the firing pin stem IM and thus permit the firing pin ed to fire the detonating cap at. When the assembly moves upwardly, carrying the re lease mechanism with it, the trigger washer Edi is adapted to earn the trigger to the left as will be hereinafter more fully described.

When the detonator 92 is fired, it will ignite a powder pellet 52 3, the gases of which through ducts lZii past supporting spider E25 into the space Hill, building up pressure tending to move the movable cylinder 32 to the left. The right hand side of the body member it bears against the right sleeve 28. The cylinder plug fi l against the left hand sleeve 22. The sleeves held in position by the frangible member The burning of the powder in pellet .ilili takes a predetermined period of time. The terminal flare of pellet I24 will ignite a second pellet the gases from the combustion of which pass through ducts [fi l into the interior 530 of the movable piston $2 continuing to build up pressure. As the pellet I32 burns, gases will. also escape through the opening I38 into the chamber E38. It will be seen that the pressure is equalized on both sides of pellets i2 1 and i32. The area on the right hand side of pellet rim 523 is greater than on the left hand side so that the pressure will hold the pellet on its seat. Similarly the exposed area on the right hand side of pellet rim I3l is greater than that on the left hand side of the pellet so that pellet I32 is likewise held on seat. The detonator 92 is firmly secured in its holder 99 and is further held in position by the pressure of the firing pin spring M53. The pressure builds up by the burning of the pellets 62d and NZ to such degree that the frangible securing member 3 3 will be ruptured, freeing the split sleeves, as will be hereinafter more fully described.

Referring now to Fig. 4, we have shown time delay ejector mechanism similar in principle to that shown in Figs. 2 and 3 but having a somewhat different construction. The trigger mcmber I38 carries the cam trigger Hit and is formed with a bore in which the interfitting firing pin stem I02 and trigger stem are seated. Movement of the trigger I38 to the left compresses the firing pin spring Hi8 and at the same time carries the bore clear of the interlocking stems so that the trigger stem 95 may pivot around pin lit to release the firing pin. The ring 98 and the ring spring lot are eliminated. Pellet 26 dischan its gases through ducts I26 which communicate with a manifold duct I42, emptying into the interior I30 of the movable cylinder 82. Similarly, pellet I32 discharges its gases through ducts (34 which communicate with the manifold duct M2. The action of the assembly is similar to that of the construction in Figs. 2 and 3.

Referring now to Fig. 5, we have shown a construction similar to that shown in Fig. 4. The cam trigger however has been replaced by a pivot trigger member Mil normally pivoted about a pin I46. A spring Hi8 biases the trigger member Hi l T to its full line position. The construction enables L In us to assemble the projectile more readily for firing. The time ejector assembly may be inserted through the assembled split sleeves by reason of the pivoting of the trigger member I 44. When it is in position adjacent the slot H8 in the liner Hi, the spring will pivot it to operative position as shown.

In use, a projectile I9 is assembled with a fuse 3D to be tested as shown in Fig. 1. The time fuse S8 is set to fire after a time within which the fuse 3G to be tested should have operated. The pro-- jectile is fired from the rifle and setback initiates the action of the time fuse 38 as is well known to the art. The fuse 38 fires and the flare of the powder charge of the time fuse 38 will ignite the charge 44 positioned adjacent the base plug it. The explosion of the charge 34 will shear the pins l 6 and the assembly comprising the base plug l d, the split sleeves 20 and 22 containing the time delay ejector mechanism tifl, the parachute 24 and the fuse 3b to be tested will be blown rearwardly, that is upwardly as viewed in Fig. 1, out of the shell body It as can readily be seen by reference to Fig. 6. The split sleeves are held in assembled position by the frangible securing member 3 3. The force of the explosion of the powder charge l l is transmitted through the plug 48, through the washer 553, to the stationary liner 18, to the projectile body it].

As the split sleeves, held in their assembled position by the securing member (it, move out of the projectile body It) the inclined surface N6 of the trigger of the time ejector assembly will. wipe past the trigger washer 50, thus camming the trigger member ill! to the left as viewed in the drawings. This action first compresses the firing pin spring Hi8 and then releases the interlocking cam surfaces I04 of the firing pin stem Hi2 and the trigger stem 96 permitting the firing pin 94 to move to the left under the impetus of the compressed firing pin spring I 98. The firing pin fires the detonator 92 upon striking it, thus igniting the first time delay pellet lZ l. The gases discharged from the combustion of this pellet build up pressure within the space i3!) within the movable cylinder 82. As the pressure builds up, the burning of the pellets will increase as an exponential function depending upon the composition of the pellet powder, the size of the pellets and the dimensions of the space into which the gases expand. After the first pellet lZ l has burned, the second pellet 132 will ignite. Since this pellet burns at a greater rate, the ducts I33 for the discharge of the gases from the second pellet are of greater size than the ducts 126 which conduct the gases from the burning of the first pellet [2t A predetermined pressure is achieved within a predetermined period of time by the burning of the pellets 12d and 532. The strength of the frangible member 34 is such that it will release at a predetermined pressure. It will be observed that many variations of delay time may be easily achieved by varying the powder composition of the pellets, the dimensions of the movable cylinder 82 and the strength of the frangible securing member 34.

During the time elapsed between the ejection of the split sleeves, as shown in Fig. 6, and the time to achieve the necessary pressure to break the frangible securing member 35, the ejected assembly of the split sleeves in the parachute will have reduced their velocity to a point when the parachute may be streamed with safety. When the frangible member 34 ruptures, the split sleeves 2t} and 22 will fall away, releasing the base plug M and its associated time fuse 33 as well as the plate 55 carrying the time ejector assembly 58. The parachute is then free to stream as can readily be seen by reference to Fig. 7. Due to the construction of the parachute employing the spherical canopy and the floating hem cord as disclosed in the Finken Patent 2,412,392, the shock of opening will be safely borne.

As soon as the velocity of the fuse to be recovered 38 has been sufiiciently reduced, the main canopy it will fully open and the fuse 3-53 will be lowered. It is to be understood of course that the entire assembly is gyrating under the influence of the twist imparted to the projectile and its contents by the rifling of the gun from which the projectile it was fired. The swivel connection comprising the ball bearings 66 and the raceways s4 and 68 will prevent the twisting of the shroud lines of the parachute.

In our co-pending application, Serial No. 786,861, filed November 13, 1947, now Patent No. 2,582,113, we have shown a delay assembly in which the latching means comprises a combustible or fusible connection. This connection is placed in the path of the delay pellet and is adapted upon its destruction to initiate the desired action. It will be clear to those skilled in the art that this type of release can be combined with the release assembly disclosed in the instant application. A combustible securing member may be passed through the split sleeves through opening 53s in Figure 4 so that it must be released first before the release action disclosed in the instant case will be efiective.

It will be seen that we have accomplished the objects of our invention. We have provided an assembly in which new type fuses may be installed in large caliber projectiles and the fuse recovered after the firing, in order that it may be inspected to ascertain Whether it has functioned properly or not and, in event of a malfunctioning, to determine the reason for its failure. We have provided an assembly in which the fuse to be tested is expelled from the test projectile and recovered by means of an attached parachute. We have provided a canister assembly in which the fuse to be tested and a canister containing the parachute is ejected from the projectile body and released after a predetermined time delay. We have provided a novel time delay ejector mechanism which is operated by the pressure of burning gases from time delay pellets.

It will be understood that certain features and sub-combinations are of utility and may be employed without reference to other features and sub-combinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

1. A projectile fuse recovery assembly including in combination a projectile body, a canister positioned in said body, a parachute positioned in said canister, the canister comprising a. pair of sleeves surrounding the parachute, means for holding the sleeves in parachute-enclosing position, a fuse to be recovered, interengaging means formed on the sleeves and said fuse for releasably holding said fuse to the canister against longitudinal relative movement with respect thereto, means for attaching the parachute to the fuse, an expelling charge, a time delay fuse adapted to to be set into operation by the firing of the projectile from a gun for igniting said expelling charge, the expelling charge being positioned to expel the canister from the projectile body, pressure responsive time delay means carried within the canister for releasing the holding means, trigger means carried by said pressure responsive means and projecting outside of the canister and trigger actuating means mounted on the pro jectile body and positioned in the path of move ment of the trigger means to coact with the trig ger means, the construction being such that the trigger means will be actuated by the trigger actuating means during the movement of the canister out of the projectile body.

2. A projectile fuse recovery assembly as in claim 1 in which said sleeve-holding means comprises a frangible member.

3. A projectile fuse recovery assembly as in claim 1 in which said time delay means for rendeering said holding means inoperative includes an ignition cap, a firing pin, a powder pellet adapted to be ignited by said ignition cap, and means responsive to the pressure of the gases of combustion of said pellet for releasing said holding means.

4. A projectile assembly including in combination a projectile body, a parachute, a canister comprising a pair of sleeves surrounding the parachute, means adapted to be supported by the parachute, interengaging means formed on said parachute supported means and said sleeves for releasably holding said supported means to the canister against longitudinal movement with respect thereto, means for holding the sleeves in parachute enclosing position, means for attaching said supported means to the parachute, an expelling charge, a time delay means adapted to be set into operation by the firing of the projectile from the gun for igniting said expelling charge, said expelling charge being positioned to expel the canister and the supported means from the projectile body, pressure responsive time delay means carried within the canister for releasing the holding means, trigger means carried by the pressure responsive means and projecting outside the canister and trigger actuating means mounted on the projectile body and positioned in the path of movement of the trigger means during its expulsion from the projectile body by said expelling charge.

5. In a projectile fuse recovery assembly, a time delay releasing means including in combination a cylinder, a piston lodged within said cylinder for relative motion with respect thereto, a powder train, an ignition cap for igniting said powder train, a firing pin adapted to strike said ignition cap, a normally unbiased spring for actuating said firing pin, a trigger member, means actuated by the trigger member for first compressing said spring, means actuated by the trigger member for releasing said firing pin, said trigger member being provided with a cam surface and means providing communication between said powder train and said cylinder behind the piston whereby the gases of combustion are adapted to build up pressure within said cylinder to cause it to move relatively to said piston.

6. An assembly as in claim 5 in which said trigger member is mounted for pivotal movement and means for limiting the pivotal movement of said trigger member.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,290,763 McCombs Jan. 7, 1919 1,305,186 Bergman May 2'7, 1919 1,309,982 Darling July 15, 1919 1,365,865 Svejda Jan. 18, 1921. 1,943,292 Babbitt Jan. 16, 1934 1,988,446 Fischer Jan. 22, 1935 FOREIGN PATENTS Number Country Date 347,180 Germany Jan. 16, 1922 863,101 France Dec. 23, 1940

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