U.S. patent application number 10/704995 was filed with the patent office on 2005-01-27 for slides and methods for finishing a lock surface of a slide in a firearm.
Invention is credited to Bantle, Hans-Peter, Weldle, Helmut.
Application Number | 20050016639 10/704995 |
Document ID | / |
Family ID | 7684254 |
Filed Date | 2005-01-27 |
United States Patent
Application |
20050016639 |
Kind Code |
A1 |
Weldle, Helmut ; et
al. |
January 27, 2005 |
Slides and methods for finishing a lock surface of a slide in a
firearm
Abstract
Slides and methods for finishing a lock surface of a slide in a
firearm are disclosed. A disclosed method of finishing a lock
surface comprising a rearward facing wall adjacent an ejection
window of a slide of an automatic firearm includes: (a) pointing a
laser at at least one of the lock surface and a material surface
bordering the lock surface; and (b) heating the at least one of the
lock surface and the material surface bordering the lock surface
with a laser beam to harden the lock surface.
Inventors: |
Weldle, Helmut; (Oberndorf,
DE) ; Bantle, Hans-Peter; (Dunningen-Seedorf,
DE) |
Correspondence
Address: |
GROSSMAN & FLIGHT LLC
Suite 4220
20 North Wacker Drive
Chicago
IL
60606-6357
US
|
Family ID: |
7684254 |
Appl. No.: |
10/704995 |
Filed: |
November 10, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10704995 |
Nov 10, 2003 |
|
|
|
PCT/EP02/03954 |
Apr 9, 2002 |
|
|
|
Current U.S.
Class: |
148/525 |
Current CPC
Class: |
F41A 3/66 20130101 |
Class at
Publication: |
148/525 |
International
Class: |
C22F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 10, 2001 |
DE |
101 22 663.2 |
Claims
What is claimed is:
1. A method of finishing a lock surface comprising a rearward
facing wall adjacent an ejection window of a slide of an automatic
firearm, the method comprising: pointing a laser at at least one of
the lock surface and a material surface bordering the lock surface;
and heating the at least one of the lock surface and the material
surface bordering the lock surface with a laser beam to harden the
lock surface.
2. A method as defined in claim 1, wherein the laser beam is
directed toward an edge between the lock surface and the material
surface.
3. A method as defined in claim 2, wherein the laser beam is
oriented at an angle of approximately 45.degree. relative to a line
parallel to the lock surface.
4. A method as defined in claim 1, wherein the laser beam is
directed toward a corner between the lock surface and the material
surface.
5. A method as defined in claim 4, wherein the laser beam is
oriented at an angle of approximately 45.degree. relative to a line
parallel to the lock surface.
6. A method as defined in claim 1, wherein pointing the laser at
the least one of the lock surface and the material surface
bordering the lock surface comprises pointing the laser beam at a
point that cannot be seen from outside of the firearm.
7. For use with a firearm, a slide having a lock surface adjacent a
side of an ejection window, the slide being finished by a process
comprising: pointing a laser at at least one of the lock surface
and a material surface bordering the lock surface; and heating the
at least one of the lock surface and the material surface bordering
the lock surface with a laser beam to harden the lock surface.
8. A slide as defined in claim 7 wherein the slide has a
nitrocarburized and oxidized outer surface.
9. For use with a firearm, a slide comprising: a lock surface
adjacent a side of an ejection window; and a hardened area located
in the lock surface, the hardened area having a first surface
extending from a lower edge of the lock surface toward an upper
edge of the lock surface, and a second surface extending from the
lower edge of the lock surface along a bottom of the slide.
10. A slide as defined in claim 9 wherein the first and second
surfaces are joined via a laser-hardened portion of the slide.
11. A slide as defined in claim 10 further comprising a structural
separation area between a non-laser-hardened portion of the slide
and the laser-hardened portion of the slide.
12. A slide as defined in claim 9 wherein the hardened area
comprises a gusset-shaped strip.
13. A slide as defined in claim 9 wherein the hardened area has a
generally triangular cross-section
14. A slide as defined in claim 9 wherein a width of the first
surface is less than approximately 1.5 mm, and a width of the
second surface is less than approximately 1.5 mm.
15. A slide as defined in claim 9 wherein the slide comprises a
high-alloy steel.
Description
RELATED APPLICATION
[0001] This patent issues from a continuation of International
Patent Application Serial No. PCT/EP02/03954, which was filed on
Apr. 9, 2002, and which is hereby incorporated by reference in its
entirety.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates generally to firearms, and, more
particularly, to slides and methods for finishing a lock surface of
a slide in a firearm.
BACKGROUND
[0003] Throughout this document, positional references refer to a
firearm held in a normal firing position, that is, a firearm held
in a generally horizontal direction pointing away from the
shooter.
[0004] The lateral surface defining the ejection window of an
automatic handgun is a substantially flat surface that extends
almost vertical to the horizontal firing direction. When referring
to this "lateral surface" in this document, we do not refer to a
geometrical surface alone, but rather we also refer to a narrow
area under this surface. This "surface" must be hard and/or strong
enough to resist surface pressure.
[0005] Modem automatic handguns constructed according to the
modified Colt-Browning system have a projecting part, (i.e., the
so-called lock button), on the top surface of the barrel. When the
lock of the slide is closed, the ejection window of the slide is
blocked by the barrel from below. When a shot is fired, the recoil
pushes the slide backwards, while the barrel is pulled forward due
to the friction of the bullet accelerated in it. As a result, the
lock (and, thus, the slide) can only open after the bullet has left
the barrel, the gas pressure has decreased, and the barrel has
moved backwards a bit. This sequence of events occurs, for example,
with the newer automatic pistols of Heckler & Koch GmbH, the
assignee of this patent.
[0006] During the lock process, considerable force is transferred
from the front lateral surface of the ejection window, (i.e. the
lock surface), to the lock button of the barrel. The surface
pressure experienced by the front lateral surface is even larger
when very strong ammunition is employed. This surface pressure can
increase even more as the weapon unlocks, since the
force-transferring material strips become more and more narrow.
[0007] This force is not a problem for the lock button, since the
barrel is coated. (Incidentally, the barrel of standard issue
weapons is usually a wear-out part.)
[0008] The slide could also be hardened and then, if necessary,
polished around the front lateral surface of the ejection window,
(i.e. its lock surface) to increase its tolerance of this force.
However, the rust protection coating of the slide would be damaged
by such a hardening/polishing process. The slide will only be
bronzed after the hardening process, since the weapon would
otherwise have an open, irregular, shiny spot on its top side that
would not only be unsightly, but could also rust.
[0009] Modern standard issue weapons are usually nitrocarburized
and then oxidized, whereby a black, extraordinarily hard, rust
resistant protection coating is achieved. This coating is
considerably more resistant to abrasion and chemicals than
bronzing. However, this process takes place at such a high
temperature that, if the lock surface was previously hardened, the
material structure of the lock surface would be damaged by the
thermal blackening treatment. An additional hardening, (i.e., a
hardening after this blackening treatment), is also not
appropriate, since this would discolor the blackening layer in the
hardening area. A portion of the blackening layer would also be
removed through the polishing process which is usually needed after
the hardening. For example, if the material is warped, the
polishing process should recreate the exact geometry of the lock
surface, because even a slight warping could lead to the hardened
lock surface no longer having a close fit with the lock button.
This polishing process could, thus, reduce the supporting surface
and thereby increase the surface pressure experienced by the
remaining material when a shot is fired. Such a result would negate
the effect sought by the hardening.
[0010] In fact, one part of the slide is already hardened and then
polished, but this part is located inside the weapon and is,
therefore, not visible from the outside. Thus, its discoloration
does not matter. The heat treatment of the area to be hardened does
not damage the outer rust protection coating, since the area to be
hardened and the areas coated with rust protection on the outer
surface are located too far apart.
[0011] In the past, it has been possible to successfully avoid
damage to the unhardened lock surface by using high-quality
polishing material, widening the slide and, thus, the lock surface,
and/or increasing the wall strength of the slide on the lock
surface. However, if unusually strong ammunition is used, visible
deformations could still appear after a very high number of shots.
Further widening of the slide to address this issue could make the
weapon heavy and bulky. Further increasing the slide wall strength
also causes construction problems. Also, using a higher quality
material than what is already currently used would hardly be
possible and would be, in any case, too costly.
[0012] It would be possible to use a stop made of hardened spring
steel as the lock surface. But this solution would be difficult and
costly. It would also be possible to perform induction hardening of
the slide edge from below with simultaneous cooling of the already
finished topside of the slide and later polishing and deburring of
the lock surface. However, slightly visible discolorations on the
topside of the slide might occur in this process. This process
would also be rather expensive. Nonetheless, the aforementioned
discoloration problem could be solved with a state-of-the-art
procedure, and the high costs and other disadvantages could perhaps
be minimized.
[0013] Using laser hardening in weapons technology is already known
from DE 199 18 794 A1 (Rheinmetall). However, the known case
concerns the hardening of a layer of the inner surface of the
barrel with the help of a revolving mirror inserted into the
barrel. The layer hardened in this manner is then coated with a
hard metal layer and is, thus, invisible. Warping will not occur,
because the surface to be hardened is axially symmetrical.
[0014] A process for chromium-plating the outer surface of the
barrel of an M 1911, M 1911 A1 or similar US military pistol is
described in U.S. Pat. No. 3,110,223. The lock buttons of the
barrel are also chromium-plated.
[0015] As in DE 199 18 194 A2, a process for laser-hardening the
inner surface of a barrel is also described in U.S. Pat. No.
5,664,359.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a partially cut-away, side view of a partially
opened slide of an automatic pistol.
[0017] FIG. 2 is an enlarged illustration of area II of FIG. 1.
DETAILED DESCRIPTION
[0018] FIG. 1 illustrates an example slide 1 of an automatic
pistol. (The direction of firing points to the left in FIG. 1.) The
slide 1 consists mainly of a high-alloy steel such as 42 CrMoS4 and
has, due to heat treatment, a blackened outer surface 3. Its upper
slide wall 9 defines an upward-pointing ejection opening 4. The
ejection opening 4 is bordered toward the front by a vertical lock
surface 5. The lock surface 5 of the illustrated example extends
perpendicularly to the direction of fire. The lock surface 5
engages a complementary lock button of a barrel (not shown) when
the pistol is ready to be fired. The height of the lock surface 5
is preferred regardless of the thickness of upper slide wall 9.
[0019] As shown in FIG. 2, the lock surface 5 is located forward of
the ejection opening 4 of the slide 1.
[0020] After final completion of the slide 1, (including the final
blackening of its outer surface 3), the slide 1 is clamped and a
known type of laser is arranged so that its laser beam is directed
toward the slide 1 in the direction of arrow 15 in FIG. 2. The
laser is then shifted perpendicularly to the focal plane;
preferably at a rate of 100 mm per minute. The average power of the
laser is preferably a few hundred Watts (W), the impulse duration
of the laser is preferably a few milliseconds (ms), and the
frequency of the laser is preferably approximately 100-150 Hertz
(Hz).
[0021] This finishing process leaves no detectable marks on the
outside surface 3 of the slide 1. It also results in a
gusset-shaped hardened area 11 in the material of the upper slide
wall 9. The hardened area 11 is bordered in the front by the
slanted, clearly outlined, flat transition area 13. The hardened
area 11 is bordered toward the back by the lock surface 5. The
hardened area 11 is bordered toward the bottom by the lower surface
7 of the upper slide wall 9. The slide material 4 in the
laser-hardened, gusset-shaped area 11 is a fine-structured,
martensitic structure.
[0022] Although the above description referred in particular to an
automatic pistol, the teachings of this disclosure may be applied
to any automatic weapon for which an overstrained surface needs to
be subsequently hardened.
[0023] From the foregoing, persons of ordinary skill in the art
will appreciate that the above disclosed methods provide a process
for finishing a lock surface 5 of an automatic handgun, wherein the
lock surface 5 already has its final form. In particular, the
example methods disclosed above are applicable to finishing the
lock surface 5 that is formed by the front lateral surface of the
ejection window 4 of the slide 1 of an automatic handgun (i.e., the
surface bordering the ejection window 4 and facing toward the back
of the firearm). The lock surface 5 and/or the adjoining material
surface is finished by coating it with a hardening laser beam.
[0024] This laser beam can be set to emit relatively low energy.
Because of its high concentration, it causes sufficient heating in
a narrow area. The laser beam, thus, creates a high temperature at
its point of impact that is sufficient for hardening, but that
decreases extremely quickly outside of this area. The material
surrounding the point of impact quickly dissipates the heat. This
happens so quickly that tempering is not required. Unexpectedly, no
warping of the lock surface 5 occurs.
[0025] In the disclosed example, the laser beam is pointed directly
at the lock surface 5 to be hardened. If the laser beam only
touches one line running within the lock surface 5, then the
thereby created hardening decreases quickly on both sides. On the
other hand, if it touches the entire lock surface 5 to be hardened,
then the lock surface 5 can overheat and cool too slowly. The
result would be an undefined crystal mixture in the material.
[0026] However, it has been determined that a laser beam causes
very good hardening of the lock surface 5 if the point of impact of
the laser runs along the bottom edge of the lock surface (i.e., the
corner formed by the generally vertical surface 5 and the bottom
surface 7). This area of impact is heated considerably so that, as
a result of this heating, hardening can occur. Due to the sharp
edge, significant heating occurs rapidly. As soon as the laser beam
is no longer present, the corner immediately cools and hardens.
[0027] The area 11 hardened in this manner can be very narrow.
Despite the uneven heating, the material does not warp. Rather, the
lock surface 5 retains its shape and, thus, requires no additional
finishing.
[0028] The laser beam is preferably aimed at an angle sloping
toward the lock surface 5. For example, it is preferred that the
laser beam be aimed at an angle of approximately 45.degree.
relative to a line extending downward and parallel to the lock
surface 5 (see FIG. 2). It is particularly advantageous if the
laser beam hits the lower edge of the lock surface 5 from behind
and below (wherein the slide 1 lies horizontal as when closing and
the direction of firing is forward).
[0029] At most, the laser beam leaves behind an unobtrusive
slash-like marking on the material surface that it hits. However,
if this material surface was previously treated with a rust
protectant, then the rust protection layer will be damaged or
destroyed by the laser beam. It is, thus, preferred that the laser
beam be pointed at a material surface that is not visible from the
outside of the weapon. The outer surface 3 of the slide 1, which is
located opposite from the material surface engaged by the laser
beam, can be treated with almost any type of rust protectant,
because the beam intensity and the discharge frequency of the laser
can be set so that the rust-protected outer surface 3 is not heated
to a temperature that would harm the rust protection coating. The
edge hardened by the laser beam is the most affected area.
[0030] From the foregoing, persons of ordinary skill in the art
will further appreciate that firearms have been disclosed with
include a lock surface 5 on the front side of the ejection window 4
of the slide I wherein the lock surface 5 has an area which has
been hardened by a laser based heating process.
[0031] It is preferred that the slide 1 be provided with a
nitrocarburized, oxidized outer surface 3. This is particularly
advantageous for standard issue models for which markings or other
types of scratches should be avoided on the visible surface so that
the troops using this weapon do not try and "wipe off" the
marking.
[0032] The hardened portion of the lock surface 5 preferably
includes a wedge-shaped portion 11 of the slide material. The
wedge-shaped portion 11 has the same structure as the remainder of
the slide material. The wedge-shaped portion 11 may be termed a
gusset.
[0033] This gusset 11 has two open surfaces leading from the lower
edge of the lock surface 5. A first one of these open surfaces
extends from the lower edge of the lock surface 5 upwards
approximately to the upper edge of the lock surface 5. The other
one of these open surfaces extends from the lower edge of the lock
surface 5 forward along the bottom 7 of the slide 1. Both of these
surfaces are connected through the material of the slide along a
structure transition area 13. Thus, a hardened area 11 is formed
that is bordered on the outside by the lock surface 5 and the
thickness of which increases towards the outside. Unexpectedly,
this is highly advantageous.
[0034] Namely, if the barrel of the weapon sinks downward when it
is unlocked, then the slide 1 over the lock surface 5 supports
itself on a narrowing strip of the lock button of the barrel. Thus,
the surface pressure on the bottom of this lock surface can
increase. But, the durability of this underside is also increased
because of the thicker hardness layer 11.
[0035] In the upper part of the lock surface 5, the structure
transition area 13 tapers off between the hardened layer 11 and the
non-hardened layer in the upper edge. Thus, the surface-treated
outer surface 3 of the weapon remains protected from all types of
changes, because the transition area 11 does not meet this outer
surface 3.
[0036] It is preferred that each of the two open surfaces of the
hardened material gusset 11 extend approximately 1 to 1.5 mm away
from the lower edge of the lock surface 5. Thus, the widths of
these surfaces never exceed the height of the lock surface 5 and,
thus, these surfaces never meet the upper, blackened outer surface
3 of the weapon. An average preferred value of the thickness of the
hardness layer in the lock surface 5 is 0.5 mm in the direction of
fire and 1.0 mm perpendicular to the direction of fire.
[0037] The slide 1 itself mainly consists of strong high-alloy
steel that, even unhardened, possesses the required tenacity. For
example, 42 CrMoS.sub.4 is particularly suitable as the material
for the slide 1. As a second treatment, the finished slide 1 is
nitrocarburized and black-oxidized within the framework of a heat
treatment. After this second treatment, the lock surface 5 is
laser-hardened as explained above.
[0038] Although certain example methods and apparatus have been
described herein, the scope of coverage of this patent is not
limited thereto. On the contrary, this patent covers all methods,
apparatus and articles of manufacture fairly falling within the
scope of the appended claims either literally or under the doctrine
of equivalents.
* * * * *