|Publication number||US3744169 A|
|Publication date||Jul 10, 1973|
|Filing date||Dec 1, 1971|
|Priority date||Dec 1, 1971|
|Publication number||US 3744169 A, US 3744169A, US-A-3744169, US3744169 A, US3744169A|
|Original Assignee||Straight F|
|Export Citation||BiBTeX, EndNote, RefMan|
|Non-Patent Citations (1), Referenced by (3), Classifications (6)|
|External Links: USPTO, USPTO Assignment, Espacenet|
United States Patent 1 Straight F LINTLOCK MECHANISM  inventor: Frank W. Straight, 4326-l206h St.
S.E., Bellevue, Wash. 98006  Filed: Dec. 1, 1971 211 App]. No.: 203,700
 US. Cl 42/69 R  Int. Cl F4lc 27/00, F410 19/00  Field of Search 42/51, 69 R, 83
 References Cited OTHER PUBLICATIONS W. W. Greener, The Gun and Its Development, 9th edi- [111 3,744,169 July 10, 1973 tion; 1910; pages 84-86 and 106-110.
Primary Examiner-Benjamin A. Borchelt Assistant Examinen-C. T. Jordan Attorney-Ford E. Smith [5 7] ABSTRACT The action of a flintlock mechanism for firing rifles and the like is materially benefitted by the incorporation of an aluminum oxide, self-knapping ceramic flint.
5 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION Flintlocks for firearms apparently became well developed in the mid-17th century, having derived from the Italian and Dutch or Dutch-type snap haunces of earlier origin. The elements of a flintlock by which a shower of sparks was produced included a frizzen disposed over a flash pan containing priming powder and a hammer carrying a flint which struck the frizzen when the frizzen was pulled and the hammer released. The flints were derived from a glossy, usually opaque quartz, or any of the metallic sulphides called pyrites. Such materials have the capability of creating sparks upon being sharply struck upon steel. Approximately shaped for use in flintlock mechanisms, pieces of such materials are called flints or gunflints or occasionally gunspalls. Pieces of raw material of quartz or chert origin have been shaped by skilled artisans practicing the art of knapping. A pick-like hammer, which upon striking a stone concentrates great force on a small area, is used in knapping. The knapper breaks away spalls or chips from his starting materials and trims or gnaws them into the desired size and shape by light hammer taps along the edges. Generally, the knapping taps are back from the edge being produced and result in small, thin chips being loosened and removed. As the procedure progresses the edge being worked on becomes thinner and sharper and eventually a desirably sized and shaped gunflint resulted. Good handmade gunflints and the arts of producing them reached their peak with the generally universal acceptance and use of flintlock firearms in the late 18th and into the 19th century. With the advent of improved firearms employing other means for producing fire the flintlock became less universally used. However, interest has always been evident among gun-buffs in flintlock firearms and today it surprisingly continues with growing numbers of shooters.
But the waning of widespread use of flintlocks almost spelled the doom of the art of knapping. This, plus an everlasting dissatisfaction with the short-lived natural gun flints accompanied by a modern-day desire for perfection in the operation of the old flintlocks has sustained a demand for better sparking and longer-lived gunflints.
It is a main object of this invention to provide in combination with a flintlock mechanism a superior sparkproducing system. A related object has been to provide an improved self-knapping gunflint useful in flintlock firing mechanism which has a long and useful life, much improved over the prior art gunflints.
These and other objects of this invention will become apparent during the course of the following description taken in view of the accompanying drawings showing a preferred form of the invention.
DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view of a self-knapping flintlock mechanism;
FIG. 2 is a perspective view of a self-knapping gunflint;
FIG. 3 is an enlarged fragmentary view illustrating self-knapping; and
FIG. 4 is a perspective view of a self-knapped flint.
DESCRIPTION OF THE INVENTION The flintlock mechanism of FIG. 1 includes the lock plate 10 which is a structurally strong element normally attached at one side of the gunstock. The external face is shown in FIG. 1. On its backside plate 10 carries spring means and the means whereby the cock or hammer 12 is held at half-cock or full-cock and released upon pressure being applied to the usual trigger. These are not illustrated as their form and construction may be conventional and are well known to the art.
The cock or hammer 12 is shown as goose-necked or S-shaped. It pivots on pivot screw 14 supported by plate 10. Cock 12 includes flint clamping means comprising the lower fixed jaw 16 and upper movable jaw 18 tightened by screw 20. The gunflint 22 is firmly held in a fold of the leather 24 between jaws l6, 18.
On plate forward of cock 12 is flashpan 26 which has an upwardly open cavity or pan to receive the priming powder. Adjacent pan 26 and extending through plate 10 into the breech of a barrel is vent 27.
Flash pan 26 is surmounted by an L-shaped cover 28 which includes the upstanding frizzen or battery 34. Cover 28 pivots on screw 30 mounted on base plate 10. Feather spring 32 cooperates with horn 31 extending from cover 28 in both the closed and open positions of the L-shaped cover 28.
The frizzen or battery has a curved striking face 35 against which the flint 22 snaps or impacts to create the desired shower of sparks and to direct them into the flash pan.
When the usually finer priming powder has been placed in the recess of flash pan 26 adjacent the touchhole on vent 27, the L-shaped flash pan cover 28 is swung on pivot screw 30 to a position covering the powder in pan 26. In this position of cover 28, the frizzen or battery 34 stands upright in the path of flint 22.
The hammer 12, fully cocked, stands as shown in FIG. 1 The mechanism is fired by pulling a trigger (not shown) releasing the cock or hammer 12 and the flint 22 carried thereby. The flint 22 snaps rapidly forward under actuatingforce supplied by a mainspring to hammer l2. Flint 22, at its forward angular edge, sharply strikes the upright frizzen 34. Almost simultaneously several events occur. The impact knocks the frizzen 34 backward and away causing the pan cover 28 to rise from the flash pan 26, thus exposing the priming powder. A plentiful shower of hot sparks is generated as the tip of flint 22 snaps against the striking face 35 of battery or frizzen 34. The sparks rain into and ignite the priming powder in pan 26. A flash occurs in pan 26.
The priming burns from pan 26 through touchhole or vent 27 at one side of the pan recess into the main charge in the breech of the gun and a shot is fired.
The composition of flint 22 which is man-made is practically pure aluminum oxide A1 0, employed in very fine grain form. Its structure is composed of multitudes of crystals having a grain size of about 5 microns. Very fine milled aluminum oxide in powder form is introduced to a cavity in a graphite die and compacted and then hot pressed and densified. The hot pressed molded block has a density of 3.99 actual as compared with 4.00 theoretical. The slug is desirably free of voids or pores. A desirable flint is produced from blocks originating with VR/Wesson Company, Waukegan, Ill., and designated by that source as VR-97 Ceramic. They have a compressive strength of about 450,000 psi and as to hardness are rated:
Knoop hardness (K100) of I000 Rockwell A value of 94.0
With values such as described, a right rectangular block 22 of such ceramic material being X =34 inch and three-sixteenths inch thick is mounted in a fixture and, employing a rotary diamond cutting wheel, provided with cutting edges 23 each having a negative rake angle.
By reason of this shaping operation, the finished flint 22 will have a top surface of about X 11/16 inch and a bottom surface dictated by the angular undercuts as shown in FIG. 2.
It has been found preferable to form the angular striking edges 23 of flint 22 with an initial included angle of about 40. Normally when the flint 22 is first clamped between jaws l6 and 18 it is disposed with edge 23 arranged so that the sloping surface is downward and extends angularly rearward. Edge 23 is desirably normal or perpendicular to frizzen face 35. The hammer is then cocked and released three or four times, preferably without the gun being loaded or primed. As edge 23 snaps or impacts on face 35 sparks will be generated in a downward path; but, surprisingly, the flint is knapped at its top surface adjacent the upper side of edge 23. Knapping is the removal from the flint of small and fine chips somewhat as shown in FIG. 4. This results in the sharpening of edge 23 and, to a degree, accommodating it to the profile of frizzen face 35.
It has been found that a flint according to this invention, once initially self knapped as described, will produce, on a single edge, as many as 300 spark showers, each of a character to insure ignition of the priming. In comparison, a natural flint cannot be expected to produce more than about 50/60 firings and these of decreasing sparking effectiveness due to the dulling of the striking edges. It has been noted with the instant ceramic flint that some knapping occurs at all times. Apparently the striking edge tends to sharpen itself rather than dulling as generally occurs with conventional flints. Fine chips fly off the upperside of striking edge 23 and its sharpness is substantially continually renewed, thus providing the very long and effective life of the instant flint 22.
The flint upon striking the frizzen 34 scores the latter very finely and over a long series of shots the edge 23 tends to conform to the profile across the scored frizzen. As a result sparking efficiency may decrease. In that event all the user need do is loosen screw 20 sufficiently to permit transverse shifting of the flint 22 in jaws 16/18 to misalign the edge 23 profile with the scored profile of frizzen face 35. This movement generally need be no more than a few thousandths of an inch. Spark efficiency will normally increase spectacularly and almost at once. It is believed that misalignment of the profile of edge 23 with the pattern on frizzen face 35 changes the stress pattern in flint 22 very slightly and, as a result, self-knapping is restored and the provision of a new, very sharp edge 23 is the result.
When flint 22 has been used to such an extent that edge 23 has an angle more closely approaching a right angle than originally, due to spalling of the upper surface of the flint, one may overturn the flint in the jaws of the cock and snap the cock until a new, but somewhat rougher, edge 23 is produced by knapping due to striking the frizzen. When edge 23 is thus newly sharp, the flint is turned back to its original disposition and reinstalled in jaws 16/18 of the cock. A heavy shower of sparks will again be produced.
Of course, as noted with respect to FIG. 2, the flint is normally produced with two edges 23 as shown. By reversing the flint and knapping the newly presented edge, double use and double-life is provided.
What is claimed is:
1. In a flintlock firing mechanism wherein a flint carried by a cock of such mechanism upon triggered release of the latter, snaps forward and strikes an upstanding frizzen disposed above a flashpan, the improvement, comprising:
a manmade ceramic flint composed of densified substantially pure aluminum oxide.
2. The subject matter of claim 1 in which the flint at its striking edge has a negative rake angle.
3. The subject matter of claim 2 in which the negative rake angle is between 40 and 60.
4. The subject matter of claim 1 in which the density of the flint approximates density 3.99 on the basis of a theoretical maximum of 4.0.
5. A flintlock firing mechanism, comprising:
a base plate;
a flashpan on said base plate for containing priming adjacent a touchhole of a firearm;
a cover, said cover being pivotally supported from said base plate over said pan and including an upstanding frizzen;
a cock pivotally mounted on said base plate adjacent said pan and frizzen and including means to clamp a flint thereto;
a manmade ceramic flint formed of densified, substantially pure aluminum oxide, the density thereof closely approaching the theoretical maximum of said flint having a negative rake angle at its striking edge of between 40 and 60.
|1||*||W. W. Greener, The Gun and Its Development, 9th edition; 1910; pages 84 86 and 106 110.|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4422255 *||Mar 29, 1982||Dec 27, 1983||Lapp Michael L||Matchlock convertor|
|US4471550 *||Jun 15, 1982||Sep 18, 1984||Kyper Thomas W||Flint assembly for flintlock firearms|
|US4682434 *||Aug 7, 1986||Jul 28, 1987||Wurm Thomas J||Flintlock ignition mechanism|
|U.S. Classification||42/69.1, 42/51|
|International Classification||F41C9/08, F41C9/00|