US 2849923 A
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Description (OCR text may contain errors)
F. D. COTTERMAN GUN BARREL LINER Filed Sept. 30. 1954 Sept. 2, 1958 GUN BARREL LINER Frank D. Cotter-man, Lagrange, Ind., assignor to Crane Co., Chicago, 111., a corporation of Illinois Application September 30, 1954, Serial No. 459,402
Claims. (Cl. 89-16) This invention relates to improvements in a gun barrel or the like, and, more particularly, it is concerned with a novel liner therefor.
Heretofore, in connection with the manufacture of gun barrels of certain special material-s, for example, it has been diflicult to obtain such special materials in the form required for best performance in ultimate use. Specifically, for example, it has been relatively diflicult and costly to obtain a molybdenum barrel made integrally with the usual rifling required. Similarly, the construction of an inner liner integrally made and formed of molybdenum or other special materials has also been diflicult and relatively costly.
Therefore, it is one of the more important objects of this invention to provide a gun liner formed from a series of identical washers stamped from desired sheet material, and which are assembled and accurately aligned axially, with the lands and the grooves formed comprising the rifling formed in each washer preferably during the stamping operation.
Other objects and advantages of the invention will become more readily apparent upon proceeding with the description of a preferred form of the device read in light of the accompanying drawings, in which Fig. 1 is a fragmentary sectional assembly view of the breach end of a gun barrel embodying my invention.
Fig. 2 is a fragmentary sectional assembly view of the forward end of a gun barrel embodying my invention.
Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2.
Fig. 4 is a sectional view taken on the line 4-4 of Fig. 2.
Fig. 5 is a plan view of a preferred form of washer.
Fig. 6 is a transverse sectional assembly view employing a modified form of washer.
Fig. 7 is a plan view of a modified form of washer.
Similar reference numerals refer to similar parts throughout the several views.
Referring to the drawings, particularly Fig. 1, the gun barrel generally designated 1 is shown having at the breach end 2 a suitable bushing 3 threadedly attached thereto as at 4 and apertured as at 5 with the usual receiving end portion 6 which may be suitably formed as determined by the nature -of the service for which the gun barrel is intended to be used. As shown more clearly in Fig. 2 at the forward end 7 of the barrel 1 it is provided with a second bushing 8, non-rotatably received as at key 9 and the outlet 20. Applied in snug face to face assembly between the respective bushing 3 at the breach end and the bushing 8 at the forward end of the barrel respectively, the identical washers 10 having the form shown in plan in Fig. 5 are positioned. These washers are preferably stamped with the rifling grooves 11 and the lands 12. The outer grooves 13 are subsequently located in each washer periphery after assembly, so that the lands '12 and grooves 11 form the desired rifling continuous extending transversely through each washer to form the general configuration of rifling shown at 14 in Figs. 1
2,849,923 Patented Sept. 2, 1958 and 2. Initially, they are preferably fitted upon a mandrel (not shown) suitably rifled to receive the washers 10 and the slots 13 are then machined for the key 9.
In the modified from shown in Figs. 6 and 7, each of these washers 15 is also identical in shape and preferably provided with the outer annularly spaced projections 16 for engagement with similar spaced rifling grooves (not shown) within the gun barrel. Thus, this insures the proper position rotatively of each of the washers relative to each other to form the rifling desired. In this modification, each of the washers snugly fits the rifled grooves of the gun barrel, the grooves of the barrel having the same twist and spacing as the rifling desired. Thus, the washers when placed in the barrel rifled groove with the lugs 16 engaging the barrel rifling will then be oriented so that the normal rifling will appear in the liner bore produced by the assembled washers with only slight steps between each washer. It will, of course, be apparent that these washers may be stamped, if desired, so that the edges of the lands 14 will have a proper slope in each washer to minimize the sharp step arrangement normally formed by the corners 17 of the rifling grooves 18 and the lands 19.
It will also be apparent that the lands 19, the grooves 18 and projections 16 may be formed on the modified washers 15 during the stamping operation.
In summary, it should be understood that the rifling in the assembly liner washers is formed by properly orienting the washers relative to each other either by assembling the Washers on an externally rifled mandrel (not shown) and then machining one or more straight longitudinal grooves for keys 9 which mate with the corresponding grooves in the barrel recess, or else each washer may be stamped with one or more lugs 16 extending from the outer circumference and then completing the assembly with the gun barrel by cutting spiral grooves therewithin having the same twist as the rifling within the barrel recess. The washers are then inserted in the barrel recess so that the lugs engage the spiral grooves with the washers in the desired position rotatively.
In considering this invention, it will, of course, be appreciated that by means of such assembly, a composite liner has been provided having in addition to other desirable properties great strength and yet satisfactory ductility to resist the internal forces created by firing pressures. In the latter connection, it should be noted that it has been found that the longitudinal cracking of liners due to the exertion of such forces are detrimental because erosion tends to localize in the crack-ing formed and to wash out the liner material or the steel beneath it. Transverse cracks on the other hand can usually be tolerated.
While I have shown only two forms of the invention, it will be clear that other forms may be used without departing from the spirit of the invention as set forth in the appended claims.
1. In a gun barrel and liner, the combination of a liner formed by the assembly of a plurality of washers in abutting face to face relation, the said washers being pre-rifled and having outer projecting portions for engagement with suitably formed interior surfaces of the said barrel, the inner peripheral edges of the washers being formed with grooves and lands therebetween to create when assembled a rifled path extending transversely continuously through each washer for a projectile, and means cooperating with the barrel for retaining said Washers in said face to face relation and in predetermined non-rotatable position relative to each other.
2. In a gun barrel and liner, the combination of a liner comprising a plurality of pre-rifled washers assembled in abutting face to face' relation, the washers having outer portions for. engagement with: the interior of the said barrel to hold the washers against relative rotation, inner peripheral surface portions of the washers being relieved to produce when assembled aztcontinuous interconnected rifled path for a projectile,,the interior of saidwgun barrel also defining the relative rotativerpositionof the said" washers to. each other:
3. A-gun barrel andrliner combination, thelinenbeing comprisedof aplur-ality of pre-rifled washers vtransversely; extending in abuttingface to facerelation within. the.
barrel, the washers: having plain outer-surfaces with suitably formed portions guidedtby an interior portion of the. said. barrel, the 'inner' surfaces: of the Washers being formed with predeterminately relievedportions .to pro? vide .when. assembled a continuous .rified passage. for? a projectile, and means-cooperating withv the gun barrel to hold the said washerszagainstendmovement.
4'. A.-gun barrel and liner combination, theliner being formed with a plurality of pre-rifled:washers innabutting' face to face relation, the washers having outer portions for engagement withtthe said vbarrel, the inner edgeszof the Washersbeing relieved to providetransversely extending openings and forming when assembled a rifi'edpath for av projectile, the gun barrel having, inner annularly,
jectile; the said gun barrel cooperating;;with1 said washersa to define the extent of. said; rifled means: and rthe relative rotative position of. said washers.
ReferencesnCited in the file.of=this patent UNITED STATES PATENTS 1,544,469 Malaval June 30, 1925 2,499,944 Brace Mar. 7, 1950 FOREIGN 'PATENTS 25,191 France .i1859,.'60'