EP0209503B1

EP0209503B1 - Transverse feeding facility

Info

Publication number: EP0209503B1
Application number: EP19860850221
Authority: EP
Inventors: Leif Eriksson; Sven Lindberg; Bengt Karlsson
Original assignee: Bofors AB
Current assignee: Saab Bofors AB
Priority date: 1985-06-19
Filing date: 1986-06-17
Publication date: 1989-05-03
Also published as: DE3663193D1; SE460074B; SE8503046D0; EP0209503A1; SE8503046L

Description

TECHNICAL FIELD

The present invention relates to a round feeding apparatus for fully- and semi-automatic artillery pieces for the parallel feeding of the rounds transversely of their own longitudinal direction from, for example, the discharge position of a magazine to the ramming position of the gun. The round feeding apparatus according to the present invention may, for example, be employed for the transverse feeding of rounds in a magazine provided with a plurality of round compartments, of the type described in our co-pending EPO Patent Application No. 0 207 033, relating to such a magazine.

BACKROUND ART

Generally speaking, the transverse feeding of rounds in the gunnery Art is impaired by the fact that the rounds taper conically towards the nose of the shell. As a rule, Prior Art round feeders have, because of this and other factors, included special pawls or dogs raisable against the rounds which have been given different configurations for the nose end and case end of the shell respectively. These dogs are then driven either by parallel chains or by linearly reciprocating feed carriages.
Transverse feeding systems which do not take in consideration that artillery rounds generally taper conically already from the rim of the cases towards the front end of the shells and which thus only can feed rounds which have the same diameter on every part of the round which cooperate with the feeding system are well known in the art. Such a feeding system provided with two spiral feed members or feed screws with the same pitch, profile and diameter but with oppositively wound helices and which rotate in the opposite direction is described in US-A 2 647 442.

OBJECT OF THE PRESENT INVENTION

The object of the present invention is to propose a novel solution to the problem of transverse feeding which just takes in consideration that artillery rounds taper conically.

SOLUTION

The round feeding apparatus according to the function of the present invention is, thus, based on the employment of two feed screws of the type known per se which extend transversely of the longitudinal direction of feed of the rounds in the feeding direction thereof, these being rotationally interconnected, being both of the same pitch, but whose each respective outer diameter and screw thread flange thicknesses have been adapted to the differing diameters of the rounds on a level with the placing of the feed screws along the nose and case ends of the rounds, respectively, such that the rounds, on rotation of the feed screws, are conveyed in parallel transversely of their own longitudinal direction.
By employing two rotationally interconnected feed screws whose flange thicknesses have been adapted to the current diameters of the rounds on a level with the placing of the screws, immediate account is taken of the conical configuratioin of the rounds and correct transverse conveyance of the rounds thereby ensured.
The round feeding apparatus according to the invention may further be adapted for stepwise or intermittent feeding, so that the rounds are fed a predetermined distance for each shell discharged by the piece. A preferred stepwise feeding apparatus comprises, apart from the feed screws, an axially compressible helical spring which is interconnected with the feed screws and is compressed by the recoil of the gun, the spring being, on its compression, disengaged from the feed screws, and, on recuperation of the gun, being disengaged therefrom and driving, by its own return action, the feed screws a requisite number of revolutions to advance the rounds one step. In this context, it is appropriate if the pitch of the feed screws be made equal to one feeding step. Thus, the screws are to be driven one revolution for each shell discharged by the gun. Apart from driving of the feed screws a requisite number of revolutions, it is further necessary that the screws be arrested after a dead accurate feeding step. We have solved this problem by a cam disk steered brake device in which the cam disk for governing the brake device is mounted on the same shaft as by means of which the axial spring return is converted as rotational movement to the feed screws. According to this variation, the connection between the spring and the feed screws consists of a rack which is fixedly connected to the spring and in its turn drives a gear wheel fixedly mounted on the above-mentioned shaft and in mesh with the rack. Furthermore, a second gear wheel is journalled on the shaft and is connected to the shaft by the intermediary of a snaplock which disengages in the compression direction of the spring. This second gear wheel is in turn in mesh with a further gear wheel mounted on one of the two feed screws, these being rotationally interconnected, for example by means of a chain and requisite sprocket wheels.

BRIEF DESCRIPTION OF THE ACOOMPANYING DRAWING

The nature of the stepwise feeding apparatus, as briefly outlined above, will now be described in greater detail with reference to the accompanying Drawing, which shows a general, oblique projection of the apparatus in question. The skilled reader of this specification will readily percieve that the Drawing Figure should be considered as a non-restrictive example of the invention as-defined in the appended Claims.

DESCRIPTION OF PREFERRED EMBODIMENT

Referring to the Drawing, the apparatus illustrated therein comprises two feed screws 1 and 2 of the same pitch, in which the pitch is equal to one feed step, and in which the diameters of each respective screw and the flange thicknesses, a) and b), respectively, have been adapted to the diameters of the rounds on a level with the position of the feed screws along the nose and case ends, respectively of the rounds.
The feed screws are rotationally interconnected by means of a chain 3 which runs over sprocket wheels 4 fixedly mounted on the end of each respective feed screw. The round intimated on the feed screws has been designated 5. In practice, a number of parallel rounds would be recumbent beside one another on the feed screws, but, to avoid unnecessarily ensnaring the skilled reader, only one round is shown.
The drive means employed for driving the feed screws 1 and 2 consists, in its turn, of an axially compressible helical spring 7 and a rack 6 fixedly anchored thereto. The spring 7 is compressed on recoil of the gun and is subsequently disengaged from the piece during its recuperation. Details illustrating the connection between the spring and the artillery piece proper have been dispensed with from the Figure for purposes of clarity.
A gear wheel 8 is now in constant mesh with the rack 6. In its turn, the gear wheel 8 is fixedly connected to a shaft 9 which carries, at its other end, a fixedly mounted governor and drive curve (cam disk) 12 and snaplock 11 disengaging in the compression direction of the spring, and a second gear wheel 10 connected to the snaplock and freely rotatable on the shaft, this second gear wheel being, in its turn, in mesh with a third gear wheel 14 fixedly mounted on the shaft of one of the feed screws 2. The take-off diameter of the gear wheel 14 is half of that of the gear wheel 10.
A fixed trip block 15 is disposed on the shaft of the feed screw 1. This trip block cooperates with a reverse stop 16 biased by a spring 18, and a brake arm 13 governed by the cam 12, the arm being provided with a spring buffer 19 at its end facing the trip block 15. A spring 17 is also provided to ensure the abutment of the brake arm 13 against the cam surface 12.
When the spring 7 and its fixedly connected rack 6 are actuated in the direction of the arrow F on recoil of the gun attendant upon discharge of a shell, the gear wheel 8 is driven half a revolution. At this point, the snaplock 11 is disengaged until reengagement is attained after half a revolution. The gear wheel 10 and, thereby, also the feed screws, are, hence, stationary. On the other hand, the cam 12 accompanies the movement of the shaft 9 and raises the brake arm 13 so that the buffer 19, at is other end, is dislodged from the trip block 15. In other words, the buffer is moved from position A to position B.
On recuperation of the gun, the spring 7 is disengaged and begins its return stroke. At this point, the gear wheel 8 is driven in the opposite direction and now the snaplock 11 drives the wheel 10 half a revolution, this wheel in turn driving the gear wheel 14 and the interconnected feed screws 1 and 2 half a revolution. In the initial phase of this feeding revolution, the buffer 19 is felled to the position B so that the trip block 15 may pass, but the buffer is progressively returned to the arrest position, so that, when the trip block 15 passes the reverse stop 16 - which is resiliently yieldable in the direction of feed - the buffer will once again be in its raised, arrest position and there effectively arrests and blocks the movements of the feed screws, by the intermediary of the trip block 15.
The spring 7 having now reached its end position, the system is ready for the next feed step, all rounds carried on the feed screws 1 and 2 having been advanced one feed step. Each feed step is a direct repetition of its precourser.

Claims

1. A round feeding apparatus for fully- and semi-automatic artillery pieces, for the feeding of rounds (5), for example from a magazine to the ramming position of the gun transversely of the longitudinal direction of the rounds (5), comprising two parallel, rotationally interconnected, equal-pitch round-carrying feed screws (1, 2) extending in the desired direction of feed of the rounds, characterized in that the outer diameters and screw thread flange thicknesses (a and b respectively) thereof having been adapted to the differing diameters of the rounds (5) on a level with the placing of the feed screws (1, 2) along the nose and case ends of the rounds (5), respectively, such that the rounds (5), on revolution of the feed screws (1, 2) are conveyed in parallel, transversely of their own longitudinal direction.

2. The round feeding apparatus according to claim 1, adapted for stepwise feeding of the rounds (5) characterized in that the pitch of the feed screws (1, 2) has been rendered equally divisible by one feed step, and the feed screws (1, 2) have been connected to feed means which drive the feed screws a requisite number of revolutions corresponding to one feed step for each shell discharged by the piece.

3. The round feeding apparatus according to claim 2, characterized in that the stepwise advancement of the feed screws (1, 2) is catered for by a spring (7) compressed by the recoil of the piece, the spring, on its release, positively revolving the feed screws.

4. The round feeding apparatus according to claim 3, characterized in that the spring (7) employed for revolving the feed screws consists of a helical spring which is axially compressed by recoil of the gun and is fixedly connected to a rack (6) axially movable on compression and release of the spring, the rack being connected to the feed screws (1, 2) by the intermediary of a gear wheel (8) in mesh with the rack, and by a snaplock (11) disengaging in the direction of compression of the spring (7).

5. The round feeding apparatus according to claim 4, characterized in that the feed screws (1, 2) are connected with a rotationally governed brake device (12, 13, 19 and 15) which, after each consummated number of revolutions corresponding to one feed step, brings same to an immediate state of arrest.

6. The round feeding apparatus according to claim 5, characterized in that the gear wheel (8) in mesh with the rack (6) is fixedly connected to a shaft (9) which also carries a co-rotary governor and driving curve (cam disk) (12), which, in its turn, governs the brake means of the feed screws (1, 2) the shaft (9) being moreover connected, by the intermediary of a snaplock (11) disengaging in the compression direction of the spring, with a second gear wheel (10) which, in turn, drives, by the intermediary of a third gear wheel (14), one (2) of the two feed screws (1, 2) interconnected by the intermediary of a drive chain (3) and associated sprocket wheel (4).

7. The round feeding apparatus according to claim 6, characterized in that the brake means of the feed screws (1, 2) include a spring-biased reverse stop (16, 18) and a barrier arm (13) raisable, by the cam disk (12) at the end of each feed revolution, against a trip block (15) disposed on the one feed screw shaft.

8. The round feeding apparatus according to claim 7, characterized in that each revolution of the feed screws corresponds to one feed step; and that the spring (7), on its compression and release, respectively, drives the first gear wheel (8) and the cam disk (12) half a revolution, and the cam disk (12) raising, at its one extreme position, the barrier arm (13) of said brake means against the trip block (15) of the feed screws, and, at its other extreme position, wholly dislodges same.