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Теги: weapons military affairs patent
Год: 1912
Текст
A. A. ACKERMAN. MEANS FOB PREVENTING THE EROSION OF GUNS. APPLICATION FILED DEO. 21, 1911. 1,036,171. Patented Aug. 20,1912. 2 SHEETS-SHEET 1.
A. A. ACKERMAN. MEANS FOB PREVENTING THE EROSION OF GUNS. APPLICATION FILED DEO. 21, 1911. 1,036,171. Patented Aug. 20,1912. 2 SHEETS-SHEET 2.
UNITED STATES PATENT OFFICE. ALBERT AMMERMAN ACKERMAN, OF THE UNITED STATES NAVY. MEANS FOR PREVENTING THE EROSION OF GUNS. 1,036,171. Specification of Letters Patent. Patented Aug. 20,1912. Application filed December 21, 1911. Serial No. 667,121. To all whom it may concern: Be -it known that I, Albert Ammerman Ackerman, captain, United States Navy, retired, and a citizen of the United States, 5 residing at San Diego, in the county of San Diego and State of California, have in- vented certain new and useful Improve- ments in Means for Preventing the Erosion of Guns; and I do hereby declare the fol- 10 lowing to be a full, clear, and exact descrip- tion of the invention, such as will enable others skilled in the art to which it apper- tains to make and use the same. My present invention relates to improve- 15 ments in means for preventing the erosion of guns, and it is especially intended to sup- ply means carried by the shell, which may be used in guns of ordinary construction without necessitating changes in the shape 20 of the bore of the gun, or any of the acces- sories of the gun proper. The purpose of this invention is to pre- vent erosion; restore the efficiency of eroded guns; lubricate the bore in advance of the 25 rotating band; and in general, reduce the wear and tear of high powered guns. The principle is accepted that erosion is caused by the escape-of powder'gases past the projectile before it has moved from its 30 loaded position. Once started, the rotating baud is swaged into the rifling and prac- tically stops the leaks. Before that moving pressure is attained, however, and through- out a large part of the elapsed time between 35 ignition and expulsion, there are lower pres- sures which, though unable to overcome the inertia of the projectile, give an intense velocity to the light, nascent gases of early combustion escaping through chamber leaks. 40 Obviously larger, hotter, and chemically more active, volumes of gas escape,-—under greater pressure,—in the case of large cali- bers and high velocities, than with the re- verse. 45 Corrosion by the hot, but overloaded and almost inert gases following the projectile is practically non-existent. Their velocity, while pushing the shell, especially past the parts of the bore, commonly showing ero- 50 sion, is infinitesimal compared with that of the first , gases freely escaping under pres- sure; the late and slow moving gases are re- ducing rather than oxidizing. Abrasion by them should lie greater with the higher 55 velocity attained part-way down the bore than at the projectile’s seat. These follow- ing gases too would naturally attack, if they corrode or abrade at all, the salient lands of the rifling rather than the grooves or erosion gutters. Finally, erosion by following gases 60 and powder fragments, would be distributed with fair uniformity around the bore at the shell seat and beyond, rather than confined to deepening and extending the erosion gut- ters near the origin of rifling. 65 The rotating band, especially of heavy projectiles, is easily deformed in transporta- tion or handling; the clearance necessary to load puts the shell out of axial alinement with the bore: particles, as powder residu- 70 urn, are also swept along and jammed be- tween shell and bore in loading. . Some or all of these conditions are generally present and produce crevices for lhe escape of gases, even in new and uneroded guns. 75 The lost gases are those which affect com- bination most readily,—they are in fact, the moving agents of combustion; only through their combination with the unconsumed powder can they liberate fresh oxidizing 80 material. Should any of these gases escape past the projectile in the early stage of charge combustion, there is a double disas- trous effect :—not only is their nascent avid- ity exercised in corroding the avenues of 85 escape, instead of extending combustion, but their leakage carries with it heat, pressure and affinity, so that the combustion of the remainder of the charge is retarded or even rendered incomplete. After leakage of this 90 first formed gas, there is left in the cham- ber an overweight of base as compared with acid in the reaction of explosion. That is,— of part to be dissolved and gasified as to the means for accomplishing the solution. 95 Hence, when the breech is opened immedi- ately after the discharge, and atmospheric oxygen comes in contact with the heated, combustible gases, smothered in the bore, there is or may be a flare-back. 100 To summarize:—On ignition of the charge, a volume of super-oxidized gas flows through the crevices between projectile and bore with a velocity increasing to many times that of the projectile at the muzzle. 105 This leak continues for at least a large part of the time interval between ignition and movement of the projectile. In effect this leak is like the oxidizing flame of a blow- pipe, playing with great force on certain no small areas of the bore. Similar but more minute leaks, past the breech gas-check disks,
1,036,171 2 are sometimes shown, by a corroded surface of oxid of iron. In the case of oxidation at the projectile seat, the burned surfaces are scoured, if not reduced, by the later flow of 5 gas and powder fragments. Many inadequate appliances have been designed, but hone so far as I am aware have been successfully used to confine the expansion of the powder gases to useful 10 work on the base of the projectile. There have been greased patches, wads, sabots, expanding rings, and so-called mechanical fits. As a rule, the more efficient the device was for low pressures, the less resistant it 15 was for high: the more resistant it was for high pressures, the less readily it adapt- ed itself to checking the low. Thus pack- ing and devices initially insecure were penetrated or blown away before the pro- 20 jectile started; while the energy required to mold the stiffer types, as expanding rings, so as to close minute crevices, approxi- mates that necessary to start the projectile, a,nd therefore acts only after the escape of 25 uncertain but large volumes of gas. Later types of projectile gas-checks rely more or less entirely Upon the pressure of the powder gases for their operation; hence their obstruction is delayed and incomplete 30 following as it does the arrival and passage of gases which, in their initial condition, they are unable to check. Other varieties require some movement of the projectile after discharge before they become effective. 35 These act later, of course, than those de- pending upon gas pressure to overcome the lesser inertia of movable parts of the de- vice attached to the projectile. Still other methods employ a series of 40 non-resilient flanges and interspersed pack- ing to obtain a piston or plunger fit and action intended to choke the crevices about the projectile. All of these methods show weakness in the description of their opera- 45 tion. Drawing a series of inelastic flanges in over the gun slopes, while it unquestion- ably decreases the area of possible leaks, cannot be a positive closure of all of them. There is a minute but certain lack of uni- 50 formity in the loaded position of shell; loading dents, scratches, incipient and actual erosions, particles of powder residu- um, etc.,—all tend to form openings which no inelastic material subject to casual 55 pressure along 1 the slopes instead of at right angles to them, can be expected to fill. In fact, all such methods correspond closely in their initial action to the use of unground and. ill-fitting automatic gas 60 valves; there is bound to be considerable leakage before they can be crushed into firm contact and made tight by an over- whelming pressure. These designs are as a rule complicated, add a prohibitive cost 65 to the projectile, and are ineffective, through requiring the development of considerable pressure and a certain time interval to over- come the inertia of plungers, change the shape of material, as expanding rings, sleeves or capsules, or force the flow of a ma- terial. zIt need hardly be pointed out that a material so soft as to flow before the lower gas pressures, is detrimental in a modern high powered gun; it cannot resist the tor- sional stress of the rifling, and is certain to 75 clog the grooves. Before describing my invention, it is well ' to state that a positive shell gas-check must withstand practically the same pressure as the breech gas-check. The latter, although go mobile when warmed, is subjected to great pressure in closing the breech so as to be forced into close contact with the cleaned surface of the gas-check slopes. In this condition, it can hardly be indented by a 35 hammer stroke. Nevertheless, the slightest mal-adjustment of the device causes it to leak, The packing is cut or torn away be- fore the pressure, and the exposed metal parts are oxidized in a manner never shown 90 in the chamber itself. This is explained by the fact that the first formed gases are super-oxidized and in escaping through in- effectively closed or minute crevices, act with a concentrated blow-pipe effect. The 95 damage is ordinarily confined to the period of lower pressures,—before the inertia of the mushroom is overcome and it is driven back so as to readjust and enforce closure of the check. No comparative, progressive, or 100 step-by-step device of shell gas-check thus far proposed can be expected to withstand such an attack so as to insure protection against erosion. An efficient gas-check to' prevent erosion must operate successively, 105 even when conditions are unfavorable. However small the avenue of approach may be, it is impossible for any easily compres- sible material to check even the lower pres- sures. Powder gas is capable of leakage 110 through all the convolutions of the screw thread of a -base plug though covered by a flange, before the projectile has left its seat. Moreover, this gas retains sufficient heat.to ignite the bursting charge. These state- 115 ments are believed necessary in order to in-, dicate what is required of a positive and complete projectile gas-check as compared with all other partial or step-by-step de- vices. 120 My invention consists of a positive act- ing projectile gas-check; initially secure 'against high as well as low pressures; unique in that its action, when the shell is properly and vigorously seated in its loaded 12? position, is independent of the pressure of the powder gases or further movement of the projectile. It is determinedly effective before discharge. The nature and position of the gas-check are such as to cause its 131
1,038,171 s compression, in the process of seating, be- tween the projectile and the bore, molding it firmly and solidly into all inequalities of surface so as to prevent leakage. It is car- 5 ried along with the projectile out of the gun, functioning throughout the entire pas- sage of the bore. It is so recessed and placed as to avoid masking the rifling or reducing the rotating effect of the band, and 10 is securely held against the side pressure of the powder gases which tend to blow it out of position. Finally, through being com- posed of tenacious material, loaded -with heavy lubricants, in proportions merely suf- 15 ficient to obtain impressionable qualities under high pressure, it incidentally reduces friction between rotating band and rifling; closes the minute leaks which form under. the shifting ridges of the rotating band, 20 and so prevents the enlargement and exten- sion of fire-cracks in the grooves of the rifling. I Having thus described the general nature and purpose of my invention, the details 25 thereof will be understood by reference to the accompanying drawings, in which the same parts are indicated by the same let- ters throughout the several views. Figure 1 shows diagrammatically that 30 portion of the gun in rear of the rifling, with the shell partly entered in the projec- tile chamber, the gun body being shown in section and the shell in elevation. Fig. 2 shows a vertical section, on a larger scale, 35 of the parts of the device shown in Fig. 1, with the shell in the position indicated in said figure. Fig. 3 shows a similar section to Fig. 2, except that the shell has been pushed home, and the rifling band is en- 40 gaging the compression slope. Fig., 4 shows a similar view to Figs. 2 and 3, but with the anti-erosion device applied to the rear end of the rifling band. Fig. 5 shows still another modification, but with the anti-ero- 45 sion device applied to the front end of the rifling band, and Fig. 6 is a detail, showing the expanding ring removed from the ap- paratus. Referring first to Figs. 1, 2, and 3, A rep- 50 resents the inner tube of the gun body, pro- vided with the usual gun slope a and the usual compression slope a!. В shows the projectile carrying the band C, commonly known as the rifling band, which by e’ngag- 55 ing the rifling imparts- rotary motion to the shell. This band is mounted in the dove- tailed groove Ъ in the periphery of the shell, in the usual way. This band is re- cessed at its forward end, as shown in Figs. 60 2 and 3, and has the overhanging lip c", and the inclined annular face c. D represents a ring, pad, or coil, of packing, which is composed Of any suitable spun or absorbent material, preferably covered with canvas. 65 The constituent parts of the packing are preferably boiled in a mixture of tallow, or graphite, or other heavy lubricant, until, when cold and subjected to heavy pressure, | it assumes a substantially rigid shape, but still impressionable under shock. This ring 70 D of compressible material is held between the inclined faces c and c' and the follower ring F, which has inclined faces f and engaging the compression ring D; and it also has the inclined face /3, adapted to en- 75 gage the compression slope a', and also the shoulder /2, which engages the abutting face of the groove in the shell, as shown in FiS- 2- Inside the ring D is a split metal ring E, 80 having wedge-shaped ends e, and split as at e' (see Fig. 6). This ring is sprung into place before the rings D and F are applied. As the shell is rapidly shoved home, the inclined face f2 of the follower ring F will 85 strike the compression slope a', and the I momentum of the.shell will cause the va- rious wedging surfaces, including the ring E, to force the expansible ring D outward from the position shown in Fig. 2 to the 90 position shown in Fig. 3. At the same time, the shoulder f2 of the ring F will be forced backward, as shown in Fig. 3. Should the gun already be eroded, the force of arresting the shell will be sufii- 95 cient to cause the expansible ring D to press out and fit into the eroded grooves, the result being that an effective gas-check will be secured, which will in a large mea- sure, if not entirely, prevent the rush of юо gases forward from the powder chamber past the rifling band. In the form of device shown in Fig. 4, the follower ring F' is mounted in the groove near the rear end of the rifling band, and is Ю5 provided with inclined faces f and Д in rear of which is mounted the ring I)', similar to that already described with reference to Figs. 1 to 3, and a ring E' similar to the ring E already described. After these two no rings 1)' and E' are in place, the follower ring H is screwed onto the rear end of the rifling band, and this ring is also provided with inclined surfaces h and h'. An addi- tional compression slope a2 is provided in the 115 gun body; and as the shell is shoved home toward the compression slope, the ring F' strikes this slope a2 and compresses the ring I)', forcing it outward and forming a tight joint, as before. This form of device is es- 120 pecially suited for guns already eroded, in that the powder chamber may be slightly bored out, leaving the slope a2, as shown in Fig. 4. Referring now to Fig. 5г a compound fol- 125 lower ring is shown, made of two rings Fz and I, fastened together in any convenient way, as by the rivets K. Moreover, there is an elongated annular groove c° in the rifling band c, to permit travel backward of the 130
1,036,171 5 10 15 20 25 30 35 40 45 50 55 60 65 •4е compound follower ring. The ring F2 is shown as provided with a shoulder /s to en- gage a corresponding shoulder on the ring I, and the latter ring is provided with a shoulder r, normally engaging the shoulder on the projectile. The rear outer face of the ring I is tapered as at i', to form- a continu- ous wedging face with the tapered surface f of the ring F2. In Fig. 5, the shell is shown as nearly home; but when it is driven home, as in the ordinary process of ramming, the inclined surfaces i2 and f3 of the compound ring will engage the compression slope a', wedging the split ring E outward, and at the same time expanding the ring D. For convenience of .assembly, the ring I may also be split, as is well known in the ordnance art. In any of the forms of the device herein- before described, it will be noted that the more or less plastic ring D will be pressed outward, due to the energy expended in shoving the shell home, supplemented by the inertia of the shell, and that the band or ring D will be pressed outward, making a snug fit, even though there be irregularities in the abutting surface of the inner wall of the bore. It will be obvious that various modifica- tions might be made in the herein described apparatus, and in the construction, combina- tion, and arrangement of parts, which could be used without departing from the spirit of my invention. Having thus described my invention, what I claim and desire to secure by Letters Pat- ent of the United States is:— 1. A gas check for projectiles, comprising the ordinary rifling band provided with a recess therein, a split wedging ring mounted in said recess, a semi-plastic band mounted in said recess exterior to said split ring, and a follower ring provided with a wedge- shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, said follower ring being adapted to engage a wedge face in the bore of the gun, substantially as described. 2. A gas check for projectiles, comprising the ordinary rifling band provided with a recess therein, with an inclined wedge face forming the inner rear wall of said recess, a split wedging ring mounted in said recess, a semi-plastic.band mounted in said recess ex- terior to said split ring, and a follower ring provided with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two out- ward, said follower ring being adapted to engage a wedge face in the bore of the gun, substantially as described. 3. A gas check for projectiles, comprising a rifling band provided with a recess therein, a split wedging ring mounted in said recess, a semi-plastic band, containing lubricating material, mounted in said recess exterior to said split ring, and a follower ring provided with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, said fol- 70 lower ring being adapted to engage a wedge face in the bore of the gun, substantially as described. 4. A gas check for projectiles, comprising a rifling band provided with a recess therein, 75 with an inclined wedge face forming the inner rear wall of said recess, a split wedg- ing ring mounted in said recess, a semi- plastic band, containing lubricating mate- rial, mounted in said recess exterior to said 8o split ring, and a follower ring provided with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, said fol- lower ring being adapted to engage a wedge 35 face in the bore of the gun, substantially as described. 5. A gas check for projectiles, comprising a rifling band provided with a recess therein, and an overhanging lip extending over the 90 rear portion of said recess, a split wedging ring mounted in said recess, a semi-plastic band" mounted in said recess exterior to said split ring, and partly beneath said over- hanging lip, and a follower ring provided gg with a rearwardly extending overhanging lip engaging the upper anterior face of said semi-plastic band, and with a wedgeJshaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the 10c two outward, said follower' ring being adapted to engage a wedge face in the bore of the gun, substantially as described. G. A gas check for projectiles, compris- ing a rifling band provided with a recess 105 therein, and an overhanging lip extending over the rear portion of said recess, with an inclined wedge face forming the inner rear wall of said recess, a split wedging ring mounted in said reeess, a semi-plastic band no mounted in said recess exterior to said split ring, and partly beneath said overhanging lip. and a follower ring provided with a rearwardly extending overhanging lip en- gaging the upper anterior face of said semi- 115 plastic band, and with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, said follower ring being adapted to engage a wedge face in the bore of the 120 gun, substantially, as described. 7. A gas check for projectiles, comprising a rifling band provided with a recess therein, a split wedging ring mounted in said recess, a semi-plastic band, containing lubricating 125 materialj mounted in said reeess exterior to“ said split ring, and a follower ring com- posed of an inner split ring slipped over the projectile, and an outer ring secured thereto, said inner and outer rings being provided 130
1,036,171 with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, and also being adapted to engage a wedge face in 5 the bore of the gun, substantially as de- scribed. 8. A gas check for projectiles, comprising a rifling band provided with a recess therein, with an inclined wedge face forming the 10 inner rear wall of said recess, a split wedg- ing ring mounted in said recess, a semi- plastic band, containing lubricating mate- rial, mounted in said recess exterior to said split ring, and a follower ring composed 15 of an inner split ring slipped over the pro- jectile, and an outer ring secured thereto, said inner and outer rings being provided with a wedge-shaped rear face adapted to engage said split ring and said semi-plastic band, and wedge the two outward, and also 20 being adapted to engage a wedge face in the bore of the gun, substantially as de- scribed. In testimony whereof, I affix my signa- ture, in presence of two witnesses. ALBERT AMMERMAN ACKERMAN. Witnesses: Horner P. Dibble, Samuel A. Faulkner.