Note: Descriptions are shown in the official language in which they were submitted.
CA 02523551 2005-10-25
1
Chain remover
The present invention concerns a chain remover that guarantees the failure-
free
sliding off a chain wheel of the return strand of a link chain.
For conveyor systems that accelerate large masses to heights the conventional
measures, involving the chain tension, respectively acceleration depended
final-,
respectively loading of the pull or return strands, are not adequate. In
particular, in
the case of ammunition guide chains that are linked to an automatic firearm
and that
supply it with ammunition, extremely high positive and negative accelerations
take
place. In essence, stationary operating conditions do not occur.
Known measures that address this problem are, for example, known from DE 199
03 346. The ammunition guide chain that is exhibited there consists of two,
highly
tear proof, parallel guided transport chains (link chains), that are at a
distance with
respect to each other that essentially corresponds to the length of the
bullets. Both
link chains are, at a constant distance, connected to each other via cross
bridges.
The, in this way constructed, endless ammunition guide chain is in several
loops led
over pulleys through an ammunition magazine. During operation the ammunition
guide chain system transfers the ammunition through an ammunition supply chain
to an automatic firearm that collects and fires the bullets, and that supplies
the guide
chain with the shot-empty shells through the ammunition
CA 02523551 2005-10-25
2
supply chain, in order to lead them back to the magazine. The speed of this
procedure is determined by the firing procedure, respectively the rate of
fire, of the
weapon that via the ammunition supply chain via corresponding couplings also
drives the gear of the guide chain system.
Even though various, in the magazine itself included, measures to lead the
objects
(the ammunition) that are to be transported and the guide chain over guide-
and
rolling elements, and to reduce the acceleration of the masses that adjoin the
chain
when starting (beginning of a firing procedure), as well as to maintain the
chain
tension, in particular in the return strand of the chain, the following
problem arises
at the driven chain wheels of the guide chain:
Despite of all the measures mentioned in the above the sliding of the chain
links of
the chain wheel on the side of the return strand is not always secured because
of the
extremely high initial accelerations. Fig. 5 illustrates this situation. The
corresponding chain link follows thus the circumference of the chain wheel and
kinks the chain. In addition this increases the anyway already extreme loads
of the
link chain and the chain wheel. The result is increased wear and tear of the
corresponding components or, in the extreme case, an interruption of the
ammunition supply that interrupts or completely blocks the operation of the
weapon.
Therefore, the present invention sets out to secure, for feed systems
constructed
with link chains, also in case of high accelerations, a problem free sliding
of the
chain links off the chain wheels.
The chain remover according to claim 1 solves this task.
The working principle consists in that a supply region is provided that
accepts
already the unrolling chain, as long as
CA 02523551 2005-10-25
3
it is as planned, still in contact with the chain wheel. This succeeds because
the
guide region does not take in the chain sockets or rollers themselves but the
lateral
splice plates of the chain, the flanks of the chain, which on both sides of
the chain
wheel run pass the teeth. The guide region guarantees also that the chain runs
to a
large extent tangentially from the chain wheel. The dependent claims concern
the
advantageous constructions of the invention. Claim 15 concerns an ammunition
magazine in which a chain remover according to the invention preferably is
utilized.
The claims 2 to 3 concern thereby constructions that take into account the
specific
construction of link chains. Claim 2 thereby concerns advantageous dimensions
of
the guide region that are appropriate for the chain guidance. Claim 3 concerns
a
realization in which the chain flanks are guided on both sides of the chain
wheel and
claim 4 concerns the connection of both areas into one unit.
The further realizations according to claims 5 to 8 concern a construction in
which a
guide region or guide regions are present at the return strand as well as at
the pull
strand of the chain. This allows a change of direction of the chain without
that
additional measures for guidance have to be taken. Claims 6 and 7 are thereby
aimed at the, manufacturing technical, very favorable realization in one
piece, in
which the chain remover can be produced in a few simple mechanical production
steps from a plate-shaped blank or as complete molding piece. Claim 8 concerns
a
realization in which the chain remover can be constructed for the angle of
contact
that can be above or below 1800, that is
CA 02523551 2005-10-25
4
the pull and return strand separate from each other or they approach each
other as
the distance to the chain wheel increases.
Claims 9 to 12 concern advantageous realizations in which the chain remover
can
be guided to the chain wheel for optimal operation without costly fixings and
adjustments. The construction identified in claim 9 makes possible a
particularly
simple positioning of the chain remover in the radial direction of the chain
wheel
that is realized by corresponding radial guide surfaces - namely, the shoulder
passage and the shaped as a circle segment shaped front surface of the
clearance.
Claims 10 and 11 concern the fastening that prevents that the chain remover
frees
itself from the chain wheel,
Claims 12 and 13 specify constructions and the cooperation of different
characteristics that realize a particularly low tear and reliable floating
bedding of
the chain remover. The chain remover behaves thereby practically as a self
adjusting element that, according to the operation conditions, takes in an
optimal
working position.
Claim 14 concerns material properties that are very advantageous for the
introduced
chain remover.
The present invention is in the following clarified in detail with the aid of
accompanying drawings that exhibit an implementation example. There is shown
Fig. 1 a schematic sectional view of a section of the ammunition
magazine;
CA 02523551 2005-10-25
Fig. 2 a section of a top view of a drive and deflection section of an
ammunition supply chain;
Fig. 3 a perspectival view of a drive source with a chain wheel
arranged on it as well as a chain remover arranged in its
operating position;
Fig. 4 a side view from the outside of a chain wheel with a chain
remover and a, partly shown, link chain; and
Fig. 5 the view of fig. 4 without chain remover and with a kinked link
chain.
Fig. 1 shows an ammunition magazine 2 in which an endlessly guided ammunition
supply chain 4 supplies bullets 6 in supply direction A. The ammunition supply
chain system 4 consists of two, highly tear proof, parallel guided link chains
7, that
are at a distance with respect to each other that essentially corresponds to
the length
of the bullets. The two parallel link chains 7 are via cross bridges 8
connected to
each other at a constant distance. The distance between the cross bridges is
essentially equal to the bullet diameter plus the diameter of a cross bridge 8
and a
certain tolerance for the clearance of the guided bullets 6. The in this way
constructed endless ammunition supply chain 4 is guided in several loops over
pulleys 10, 12 through the section of the ammunition magazine 2 shown in fig.
1.
Inside the ammunition magazine 2 the bullets 6 are guided in guide regions 14
that
are provided with slide and roll regions made from appropriate materials, for
example, low wear synthetic materials.
CA 02523551 2005-10-25
6
Fig. 2 shows the rigid, thin cross bridge 8 that every time separates two,
each other
following, bullets 6, respectively shells 6', from each other and that at same
time
serves in the supply as a pusher of these through the guide region 14 in the
ammunition magazine 2.
The cross bridges 8 could have a profile that is adapted to the shape of the
bullets
and with which a tilting of the bullets 6 can be avoided. Furthermore, the
cross
bridges 8 can be attached axially rotatable between the two link chains 7 in
order to
facilitate the rolling off of the bullets 6, respectively the shells, inside
the guide
region 14 as well as on the cross bridges 8 themselves. In the extension of
the cross
bridge 8 guide heads 16 are provided that guide the supply chain 4 into guide
regions, which are not shown, through the ammunition magazine 2.
The link chains 7 consist of lateral flanks 18 that are connected to each
other via
sockets, respectively shells 20, that lie in between them, whereby the flanks
18 are
interleaved in the running direction of the link chain 7. The link chains 7
are flexible
in the plane running perpendicular to their socket axis, so that they can be
guided
over a corresponding chain wheel 22, whose teeth 24 clamp into the, in between
the
sockets/shells 20 arranged, gaps.
In the present realization example, two such chain wheels 22 are arranged
torque
proof on a shared drive source 26 via a tooth profile. The teeth of the chain
wheel 24
are thereby aligned, so that the cross bridges 8 of the ammunition supply
chain 4 run
parallel to the axis 27 of the drive source 26 (fig. 2). Drive source 26 is
thereby
housed in an appropriate manner inside the casing 28 and driven by a
corresponding
(not shown) gear system.
It is the task of this gear system to drive the ammunition supply chain 4 in
such a
way that an (not shown) automatic
CA 02523551 2005-10-25
7
firearm is supplied with the bullets 6 in accordance with their firing rhythm.
In the present realization example (fig. 1 ) this takes place via an
ammunition supply
system 30 that is arranged in between the ammunition magazine 2 and the
weapon,
and that accepts at a pulley 10, supported by transmission gears 32, loaded
bullets
from the supply chain 4 and guides the bullets to the weapon and discharges
the
empty shells 6' from the weapon and transfers these via an additional
transmission
gear 32 to the ammunition supply chain 4 and that thereby guides them to the
ammunition magazine 2.
Because of the, today common, high firing rates of such an automatic weapon
and
the relative large masses of the bullets, extremely high acceleration forces
act on all
components and in particular also on the ammunition supply chain 4,
respectively
its link chains 7, in particular during firing bursts - that is during
discontinuous
operation of the weapon. From DE 199 03 347, whose disclosure is explicitly
included by reference in the present description, constructive measures that
improve the behavior of the ammunition supply chain during operation, for the
tightening of the supply chain 4 with tightening elements, and for the mass
compensating couplers of the pulley loop, are known.
However, fig. 5 shows an operation situation that cannot as yet be avoided by
these
known measures. Conditioned by the high surface pressures that are present
when
starting, that is at the beginning of the firing, the tendency exists during
the sliding
of the chain 7 off the chain wheel 22, that the chain wheel 22, which is in
contact
with the shells/sockets 20 of the link chain 7, does not release the last
element in the
direction of the motion of the chain but drags it along in the circumferential
direction of the chain wheel 22. This leads to the shown kinking of the chain.
CA 02523551 2005-10-25
g
The in Fig. 3 and 4 depicted chain remover 34 prevents this effect.
The construction of the chain remover is described with the aid of fig. 3.
There, for
a clearer visualization, only the drive source 26, the chain wheel 22, and the
chain
remover 34, are depicted. The chain remover 34 is constructed in one piece
from a
plate. It consists of a material that can be used in the temperature range of -
80 to 200
°C, in particular between -40 °C and 110 °C. An
appropriate steel quality is, for
example, 42 CrMO 4. Other, non metallic, materials with similar properties can
be
used (for example, fiber-reinforced composites).
The depicted chain remover 34 contains in total four guide regions 36 that run
to
both sides of the chain wheel 22. If necessary, the guide regions 36 guide the
coigns
of the flanks 18 of the chain essentially tangentially off the chain wheel and
avoid in
this way that the, in fig. 5 depicted, effect occurs.
In essence, the chain remover 34 is a split disk that can be manufactured by
mechanical processing of an initial piece. This initial piece can be a similar
plate
piece, a cast or forged molding or a fiber-reinforced composite piece. The
scope of
the mechanical post-processing depends on the manufacturing tolerances with
which the semi-finished blank product can be manufactured. The chain wheel
remover can be manufactured also without post-processing as a molding, for
example, in a precision casting.
The chain remover 34 contains between the guide regions 36 a slit, running
perpendicular to the rotation axis 27 of the drive source 26, that is at least
as wide
the teeth 24 of the chain wheel 22. The splice plates contain, between the
essentially
tangentially with respect to the root circle 38, running guide regions 36, a
radial
CA 02523551 2005-10-25
9
clearance whose diameter corresponds approximately to the diameter of a, on
the
chain wheel 22 constructed, shoulder 42. The shoulder 42 contains a
cylindrical or
conical shoulder surface 44 that supports the, to the rotation axis 27
directed, radial
surface 45 of the chain remover 34. In this way the chain remover surrounds
the
toothed rim 23 of the chain wheel 22. The guide regions 36 are thereby
constructed
at the ends of the furcated running splice plate 40. In other words, the chain
remover
is guided in the direction of the rotation axis 27 through the side flanks of
the
toothed rim 23 and is fixed between the pull and return strands of the link
chain 7
over the radial surface 44 of the shoulder 42. In order that the chain remover
34
cannot free itself from the chain wheel in the direction of the progression of
the link
chain 7, a clearance 46 is provided at the end that is located at a distance
from the
chain wheel, in which a support means 48 clamps into and fixes the chain
remover
34. The support means 48 can thereby be a rod that runs in between the casing
parts
28 parallel to the rotation axis 27 of the drive source 26. However, it can
also be
constructed as a bolt, rivet, screw, or another equivalent fastening. The
thickness of
the chain remover is reduced in the area of the clearance 46. However, it can
also be
implemented with a constant thickness over its total length. The depicted
chain
remover 34 is thus mounted floating between the support means 48 and the chain
wheel 2. Furthermore, all active surfaces are processed and toleranced in such
a way
that a low tear utilization of the corresponding components is guaranteed.
Besides this self centering, floating mounting, it is just as well possible to
provide
the casing 28 itself with the guide regions 36 that are necessary for the
frictionless
sliding-off of the link chain (not shown).
It is also possible that, instead of the depicted tribological pairing between
the radial
surfaces 44, 45, a tribological pairing between the radial head regions 50 of
the teeth
24 and the bottom surface 52 that faces them, can be constructed that
CA 02523551 2005-10-25
l
extends in the slit that runs between the guide regions 36 and the splice
plates 40.
The bottom surface 52 must then also be built as a surface radial with respect
to the
rotation axis 27 which has about the same radius as the tip circle of the
chain wheel.
