CA2523551A1

CA2523551A1 - Chain remover

Info

Publication number: CA2523551A1
Application number: CA002523551A
Authority: CA
Inventors: Rudi Beckmann
Original assignee: Heckler & Koch Gmbh; Rudi Beckmann
Current assignee: Heckler und Koch GmbH
Priority date: 2003-04-25
Filing date: 2004-04-15
Publication date: 2004-11-11
Also published as: DE10318829A1; DE10318829B4; US20060144215A1; KR20060013523A; WO2004097256A1; EP1618318A1

Abstract

The invention relates to a chain remover (34) that ensures the trouble-free sliding of the return strand of a link chain (7) off a sprocket gear (22).
This is achieved by guide areas (36) that are located next to the sprocket gear (22) and starting, in essence, from the root circle (38) of the sprocket gear, extend tangentially in the direction of travel of the chain. The guide areas are wide enough to accommodate the narrow sides of the chain flanks (18). The chain remover (34) can be provided as a single part and can be mounted in a floating a self-centering manner while being guided by the sprocket wheel (22) and held by another fastening

Description

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 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 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 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;

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.

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 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.

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 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 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 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.

Claims

1. Chain remover (34) for the guiding of a link chain (7) that runs over a chain wheel (22), in particular a roller chain, that contains a, at an end that faces the chain wheel in the release region of the link chain, on both sides of the chain wheel located, U-shape joined guide region (36), in between which the chain wheel (22) passes, whereby the guide regions run approximately tangentially, starting from the root circle diameter (38) in the direction of the motion of the chain, along the coign of the chain flanks and the chain remover (34) is held at an end that is turned away from the chain wheel (22) by an attachment element (48) characterized by that, the chain remover is arranged in such a way that it can rotate around a rotation axis (49) of the attachment element (48), whereby the chain wheel (22), the chain remover (34), and the attachment element (48), are arranged together in such a way that the chain remover (34) guides floating, in the axial direction away from the toothed rim (23) of the chain wheel (22), and guides floating in the plane that runs transversely to the rotation axis (27) away from the attachment element (48), a partly extensive clearance (46) in the shoulder (42) constructed on a chain wheel and the shoulder (42) and/or the tooth tips (50) of the chain wheel (50).

2. Chain remover (34) according to claim 1 in which the width of the guide region (30) corresponds at least to the thickness of the side flank (18) of a chain, and the length corresponds at least to the length of a chain link.

3. Chain remover (34) according to claim 2 or 3, that is constructed as one piece, in particular from a plate.

4. Chain remover (34) according to claim 3, in which the initial thickness of the plate corresponds to the chain width.

5. Chain remover (34) according to one of the preceding claims that contains a guide region (36) on the pull and the return strands of the link chain.

6. Chain remover (34) according to claim 5, whose height at the end that is facing the chain wheel (2) corresponds at most to the root circle diameter (38).

7. Chain remover (34) according to one of the preceding claims, in which the clearance is shaped as a circle segment whose radius corresponds approximately to the shoulder (42) constructed on the chain wheel.

8. Chain remover (34) according to one of the preceding claims that is constructed in such a way that, during normal progression of the chain, it does not affect it.

9. Chain remover (34) according to one of the preceding claims, that is composed of a material that can be used in a temperature range of -80 to 200 °C, in particular -40 °C to 110 °C, in particular of 42 CrMO 4.

10. Ammunition magazine (2) with a, without a belt, guided endless ammunition guide chain (4) with a link chain (7), that is driven by a chain drive that is provided with a chain remover (34) according to one of the preceding claims.