SE507747C2 - Light weight field howitzer - Google Patents

Abstract

The light weight field howitzer includes a barrel (101) which is supported by a cradle constructed from hollow members (119,119A) and which is pivotally mounted about a trunnion bearing (113) secured to a chassis (117). The trunnion bearing (113) lies on the barrel axis and is positioned beyond the limit of maximum recoil of the barrel. Front stabilisers and rear trail support legs are provided to spread the load of the howitzer and spades (106) are rigidly but removably secured to the chassis. The howitzer includes a single hydraulic accumulator arrangement (136,177,185,130,189,119) constituting a combined recoil buffer and recuperator system. A barrel elevating device (Figure (7) not shown)is provided comprising a geared manual device (115,116,153,149,139) assisted by a precompressed gas system (114,119A). Hydraulically pivoted wheels and a pivotted towing lunette may be provided and the howitzer may be split easily into units which can be carried by a light helicopter.

Description

10 15 20 25 30 35 507 747 2 trailing legs with "shovels" at their distal ends; the intention of the "shovels" are to dig into the ground and thus absorb carry the recoil forces. Despite their construction are such conventional field hobbits are far too heavy to carry of small or medium-sized lift helicopters, which are used close by the current battle zone.

NATO is standardizing artillery and ammunition systems of a single caliber. There is therefore one need for an ultra-lightweight version of the standardized The 155 mm field hobbits that can be transported as a single unit of a battlefield helicopter.

According to a first aspect of the present invention, there is provided a field hobbit, comprising: i) a fire tube for the howitzer, (ii) a cradle carrying the barrel and having a rear End, (iii) a chassis, and ' (iv) a suspension support structure attached to the chassis and comprising a neck layer around which the rear end of the cradle is pivotally arranged, wherein the neck bearing is located on the shaft of the barrel and is oriented behind the limit of the barrel maximum recoil.

The neck layer should be placed as far as possible in accordance with other requirements for a field hobbit (eg training, towing, loading, etc.) and the orientation of the neck bearing behind the point of maximum recoil so that the barrel does not recoil through the neck layer, this allows to be achieved and also ensures that the howitzer exhibits a high degree of imbalance.

To enable the field hobbits to be as light as possible, the chassis should be a lightweight chassis and 10 15 20 25 30 35 507 747 3 saving design principles shall be used in the effect of the other components of the howitzer.

This aspect of the invention combines the features of both a field hobbit and a grenade launcher and the smallest suspension height greatly facilitates the transmission of the recoil forces to the ground. The weight-saving design principles the principles used include the use of lightweight ga, strong alloys, undivided structures, etc. It simple lightweight chassis should rest on the contrasting ground against the conventional chassis resting on a base plate that has contact with the ground. This feature is one radical change of previous design practices.

The position of the suspension support structure on the chassis is the same as for other field hobbits. Relative to conventional constructions, however, is the barrel moved forward, so that all this, including all and, whether or not it is a state of emergency firing or maximum recoil position, always in front neck stored. This leads to a high degree of imbalance that acts to counteract the recoil moment, especially when the cannon fired at low elevation angles.

In a preferred embodiment, shovels are attached directly to the chassis and howitzers include front stabilizers and posterior tail support legs, set up to spread the load over a larger surface area when not fired and the latter aids per also to absorb recoil energy while they counteracts overturning and lateral forces.

Such shovels, stabilizers and support legs can be incorporated into other howitzers than those with a neck bearing lying on the geometric axis of the barrel behind the maximum recoil limit in accordance with the first aspect of the invention. 10 15 20 25 30 35 507 747 4 Thus, a second aspect of the present invention provides a field hobbit comprising: i) a chassis, ii) ground contacting shovels, which are rigidly attached to haubitsens chassis, iii) front stabilizers, designed to disperse the howitzers weight over a large surface area when not fired, and (iv) hind tail support legs, designed to disperse the howitzer weight over a large area of land and to contribute to absorb recoil energy while providing rollover and lateral stability.

Preferably, the shovels are of the "self-digging" type, so that they are completely effective when the first ointment is fired. Attaching the shovels directly to the rear of the chassis part in combination with a low neck bearing weight gives a substantial rigid means for holding back the cannon during recoil.

Front stabilizers and tailbones generally improve the stability and consequently the aiming of the cannon, but plays also a role in the absorption of recoil energy. Out- the pressure "tailbone" is a generally accepted expression for this type of howitzer. Although the intention is not to then according to the invention is towed by "tailbone", is maintained the term for descriptive conformity.

The shovels can be attached directly to the chassis or they can be used brought at the ends of the hind tail support legs, provided that they are relatively short and inflexible.

The shovels are preferably removable when the howitzer is finds itself in the position of towing / transport.

In a preferred embodiment, the rear tail support legs are pivotally mounted on the chassis and hydraulic dampers are arranged at or near the attachment points for the rear tailbones at the chassis to assist in the absorption of 10 15 20 25 30 35 507 747 5 recoil energy. These cushions for the hind tail bones can automatically compensate for uneven ground and provide protection against violent recoil forces.

In a further embodiment, the howitzer's fire tube is mounted on the chassis so that it is displaceable from a first to a second position relative to the chassis as a consequence of the recoil when firing and the howitzer includes one recoil buffer system to absorb the energy of the recoil when the barrel during firing is displaced, as well as a recuperation door system to return the displaced barrel from it second position to the first position, said recoil buffer system and said recuperator system are combined and utilizes a single hydraulic accumulator arrangement.

Such a combined recoil buffer / recuperator system can used for howitzers that are of a different kind than the one that defined according to the first and second aspects of the invention.

According to a third aspect of the present invention there is provided a field howitzer including: i) a chassis, ii) a fire tube for the howitzer mounted so on the chassis, that it is displaceable from a first to a second position relative to the chassis, as a result of the recoil when firing, iii) a recoil buffer system for absorbing recoil energy when the barrel is fired during firing, and (iv) a recuperator system for returning the offset the barrel from the second position to the first position, wherein said recoil buffer system and said recuperation rator systems are combined and use a single hydraulic accumulator arrangement.

In a particularly preferred embodiment, the barrel is supported in a suspension support structure by means of a cradle and the cradle 10 15 20 25 30 35 507 747 6 is made of hollow members, the space inside them hollow organs are used in whole or in part to provide volume for the compressed inert gas, which forms part of said single hydraulic accumulator arrangement.

The hydraulic accumulator arrangement for the combined the recoil buffer system and the recuperator system serve as a "spring", which absorbs some of the energy from it recirculating barrel. The absorbed energy is thereby released after in a controlled manner to return the barrel to firing position. Hydraulic accumulators work against a given volume of compressed, inert gas. "Spring con- the constant "is determined by the volume of the gas and the amount by which this is reduced by the compression, caused by the volume of hydraulic fluid displaced by the recoil. In order to to obtain a relatively even "spring constant", a large gas amount compared to the volume of displaced fluid. When it is desirable to allow the barrel to have as long a recoil as possible, needs a fairly large volume of hydraulic fluid stupid is shifted and consequently such a large one is needed gas volume possible. Since the importance of thick-walled, pressure resistant gas cylinders would be very high, can the gas volume is achieved by using boreholes in two of, say, the four hollow organs that form the cradle of the cannon.

Communicating passages can be affixed to allow the gas pressure to be equalized between said two means, as such needed.

In one embodiment, the howitzer comprises a height alignment means for pivoting the barrel about a horizontal axis and said height alignment means comprises a gear provided manual means, assisted by precompressed gas.

Such a height alignment means may be included in howitzers which are not designed in accordance with the first, second and third aspects of the invention. 10 15 20 25 30 35 507 747 7 Thus, a fourth aspect of the present invention provides a field hobbit comprising: i) a chassis, ii) a fire tube for the howitzer, which is supported in a cradle and mounted in a neck bearing on the chassis, so that it be able to pivot about a horizontal axis, and height alignment means for swinging the barrel around said shaft and said height alignment means comprise a geared, manual body, assisted by precompressed gas.

In a particularly preferred embodiment, the howitzer is the fire tube mounted so that it is in imbalance and the degree of assistance through the precompressed gas is sufficient to i essentially counterbalance the weight of the barrel depending on its positive imbalance.

Preferably, the weight of the barrel is balanced by gas springs consisting of cylinders pressurized by a tank of inert gas acting on the pistons in the cylinders. In that case the cradle consists of hollow organs, the space inside the hollow can the organs are used in whole or in part to achieve the volume of the gas. If some of the, say, four hollow organisms The vein of the cradle was used for the combined recoil buffer / - the recuperator system, as described above, the hollow means are used for the height adjustment gas body. The gas connection between the hollow members and the cylinders of the gas springs can either be via flexible, pressure-resistant pipes or via a bore along the shaft of piston rods of the pistons with the other ends of the piston rods attach to said hollow member. The actual student of the electric tube is achieved by means of a geared drive via a handwheel, but this would require minimal physical exertion due to the counterbalancing effect. The gas springs may also include hydraulic fluid, if required. 10 15 20 25 30 35 507 747 8 In a particularly preferred embodiment, the height adjustment comprises a lead screw, substantially pivotally fixed at one end and along which a nut can be screwed and this nut is fixed relative to the sledge for the howitzer fire tube, but rotatable, so that the resulting moving along said lead screw causes the sled to move in a direction of rotation around the neck bearing and thus elevated / lowered the howitzer's barrel. Preferably, the nut can easily rotated, e.g. via a steering wheel and teeth and a reverse lock bodies are used.

It is especially preferred for the substantially pivotable fixed the end of said lead screw that it is provided with a flexible adjustable clamping, comprising: i) a spring means aligned parallel to the lead screw shaft, and ii) a damper; whereby the spring constant, the preload and the motion resistance the provided by the damper are adjustable to provide one tunable system. The spring suitably comprises a series spring washers and the damper are hydraulic.

In one embodiment, the howitzer's fire tube is mounted on the chassis seat by means of a directional bearing for pivotability about one vertical axis and said directional bearing comprises (a) a small, centrally located bearing with inner and outer bearings surfaces, one of which is immovably attached to the chassis and the others are immovably attached to a support for the barrel, and (b) a separate large diameter support bearing, designed as part of a concentric arc on the opposite side of it small, centrally located bearing at the barrel.

Such a storage system may be incorporated into a howitzer such as is not constructed with the first, second, third and fourth aspects of the invention. 10 15 20 25 30 35 507 747 9 Thus, a fifth aspect of the present invention provides a field hobbit, comprising: i) a chassis, ii) a fire tube for the howitzer, mounted on the chassis by means of a bearing system for pivotability about a vertical shaft, said bearing system comprising (a) a small, centrally arranged warehouse with interior and exterior bearing surfaces, one of which is immovably attached to the chassis and the other immovably attached to a support for fire the tube, and (b) a separate large diameter support bearing designed as part of a concentric arc on the opposite side of the small, centrally located warehouse at the barrel.

The hubits suitably comprise a directional rack integrated with a part of the support bearing arch.

In one embodiment, the howitzer's barrel includes an orifice brake and a swivel lightning bolt attached to the barrel near the muzzle brake to allow the howitzer to be towed.

Such a muzzle brake and lightning can be incorporated into one howitzers not constructed in accordance with the 1-5 aspects of the invention.

Thus, a sixth aspect of the present invention provides a field hobbit, comprising: i) a chassis, ii) a fire tube for the howitzer, mounted on the chassis, a muzzle brake on the barrel, and (iv) a pivoting lightning bolt, attached to the barrel near the muzzle the brake to enable the howitzer to be towed.

It is common in conventional howitzer constructions that they can be towed through the (rear) tailbones. The novelty of it The sixth aspect of the invention is that the towing device is 10 15 20 25 30 35 507 747 10 attached to the barrel, just behind the muzzle brake and the forward to protrude behind the muzzle brake for interaction with the hook of the towing vehicle. In that case the cannon is out of balance, this gives a downward net load on the towing hook, which is normal towing practice.

In all aspects of the invention, there is a particular the feature of constructing the howitzer in a way that makes it possible to quickly and easily divide it into two or more parts, as can be easily put together. The advantage of a howitzer that can divided into one or more component parts and easily set together is, that the transport problems to a large extent reduced if two light sections have to be moved instead for a heavy one. In this context, transport can take place with vehicle or helicopter on or near a battlefield or by aircraft, ship or road vehicle to or from the place of the conflict. Smaller sections of a howitzer can fill better in a ship or aircraft when many are going transported. Another advantage is that damaged parts can repaired by replacing an entire section.

To better understand the invention and to show how it can be exercised, will now be referred to, in the form of only one examples, to the accompanying drawings, in which: Fig. 1 shows a side view of a conventional 155 mm field head bits, ready to be fired; Fig. 2 shows a side view of an ultra-lightweight 155 mm field howitzers of the present invention, ready to be fired; Fig. 3 shows a side view of the howitzer according to Fig. 2 in ring mode; Fig. 4 shows a plan view of the howitzer according to Fig. 2, clear that fired; Fig. 5 shows a cross section through the howitzer's fire tube and cradle according to Figs. 2-4; Fig. 6 schematically shows how the howitzer of Figs. 2-5 recoil buffer and recuperator operate; 10 15 20 25 30 35 507 747 ll recoil buffer and recuperator operate; Fig. 7 shows a side view of the height of the howitzer according to Figs. 2-6. alignment mechanism; Pig. 8 shows a section along the line BB (Fig. 9) of the howitzer sense according to Figs. 2-7 directional mechanism; Fig. 9 shows a side section along the line AA (Fig. 8) of the directional mechanism of the howitzer according to Figs. 2-8; Fig. 10 shows a side view of a rear tailbone and shovel of another howitzer according to the present invention ning; and Fig. 11 shows a simplified exploded view of the howitzer according to Fig. 2-10.

The present invention represents an innovative con- cept for the construction of field hobbits. The main theme behind the design process is to produce an ultra-lightweight version of the current standard NATO artillery 155 mm.

This design process has led to the uptake of a large number of innovative features, including the following features, either individually or in any combination of two or more: Highly lowered neck bearing height. 2. Location of the entire barrel, including full recoil length, in front of the neck layer. Single-fabricated chassis with a spherical or cylindrical convex lower surface to act as a combined chassis and base plate. 4. Self-digging shovels that are directly attached to the chassis. 4a. Self-digging shovels that are attached to or near the ends of short, non-elastic hind tail bones.

Positive imbalance in all non-firing positions. 6. Front stabilizers to counteract the imbalance at normal ready-to-fire positions. 7. Short, light, hind tail bones, designed to rather resist tipping effects than full recoil load. 10 15 20 25 30 35 507 747 12 7a. Short, sturdy, hind tailbone, designed to resist rollover Qgh to transmit recoil forces via the shovels to the ground. 8. Hydraulic dampers at or near the rear tail leg and a chassiled to assist in the transfer conduction of recoil energy but which still protects the tailbones from injury due to heavy loads. 9. A combined recoil and recuperator system. 10. The exploitation of hollow insides of forming organs the cradle to get additional accumulator gas volume. ll. Counterbalancing of the barrel while using gas cylinders and a pressurized gas reservoir, local sealed in the hollow inside of the other organ. 12. Device for towing through the muzzle of the barrel and the use of the imbalance to achieve secure sering. 13. Subdued elevation shadow system. 14. Reset (display) device in student system. ' 15. Minimum size of the direction bearing. 16. Segmental arc directional gear (rather than full gear including a biased support bearing arrangement. 17. widespread use of lightweight materials, such as titanium alloys, as well as space technology.

Fig. 1 shows a current construction of a 155 mm field howitzer in a position where it is ready to be fired. The barrel 1 is horizontal and arranged in a suspension on one solid chassis 3. The height of the suspension is such that the barrel axis 1A is at a relatively large distance 2 from the ground.

Two tail legs 4, which are cut off, and the base plate 5 provides a stable 3-point support. A shovel 6 near the end of each tailbone 4 is designed to "dig" into the ground when the howitzer is fired and gives horizontal back pressure 7 against the horizontal component of the recoil force. When firing at a elevated angle, the vertical components 8A and 10 15 20 25 30 35 507 747 13 8B of the recoil reaction at the base plate 5 and the shovels 6 via the legs 4. To withstand the horizontal reaction 7, the vertical component 8B and the rotary component 8T of the recoil the forces, the tailbones 4 are essentially drawer section means. One further advantage of the tailbones 4 is that their weight acts as a counterbalance to that of the barrel l to place the center of gravity 9 above the base plate 5.

Although the tail legs 4 are essentially drawer section means, act they still "spring" when the cannon is fired. If the howitzer would be fired in the position shown in Fig. 1, there would be no vertical component in the recoil.

The recoil would instead consist of a horizontal force (base launched by the reaction 7) and a torque 8T (caused on because the direction of reaction 7 is shifted from the barrel shaft 1A, which is the direction of attack of the force). When the howitzer is fired, the recoil forces horizontal component of the howitzer's main body to move backwards. Then spades 6 should not move, this component would at the recoil cause distortion of the two tailbones 4 and absorb stress energy when transmitting recoil energy to the shovels 6. Since there is also a torque 8T in recoil, the base plate 5 can be lifted from the ground. When the energy of the recoil is consumed by the shovels 6, will the stress energy in the tailbones 4 to be released, and brings the main body of the howitzer to move backwards to (and possibly go beyond) its original position. At the same time falling the main body of the howitzer back on the ground. Thus it leads known construction with shovels 6 at the ends of the tailbones 4 to a rather violent howitzer movement during the recoil.

Fig. 2 shows a side view of the ultralight howitzer according to the invention. The construction is based on: i) a geometrically optimized weapon configuration; (ii) prudent use of high-strength, lightweight material; and 10 l5 20 25 30 35 507 7247 14 iii) minimization of the recoil forces.

In Figs. 2, 3 and 4, the same reference numerals are used for the same components as shown in Fig. 1, but preceded by one hundred, e.g. 1 and 101.

The key features of the construction will now be described, either individually or in related groups. technique.

The most striking feature of lightweight construction is is its low building height, compared to the traditional nella construction. The key factor in the design is the distance 102 of the axis 110A of the barrel 101 when it is located in a horizontal position, which is about 650 mm above ground surface, compared to over 1500 mm for the distance 2 for the cannon in Fig. 1. The second most conspicuous feature is that the neck layer 113 of the suspension structure 124 is located behind the maximum recoil position of the barrel 101 and lies on the axis lOlA. This makes the construction one hybrid between the design of a conventional field bits and a grenade launcher. As shown by the center of gravity 109 there is a positive imbalance.

It is a normal design criterion that the structures shall be stable throughout the area of working conditions dena. However, it is a special and new feature of present invention, that there is a pgsitiy imbalance. 10 15 20 25 30 35 507 747 15 Due to the very low weight of this artillery piece it is essential that the existing weight is used on it the most effective way in the most laborious operation the gaze, i.e. launch. The construction is then such that the center of gravity 109 is located so far in front of the neck bearing 113 as possible, ie. to create so much positive imbalance possible to counteract the reversal of the recoil effect l08T. Although the result of this design philosophy is to require front stabilizers 110 to provide stability in the non-firing position, the net benefits are meaning. Detailed studies of a number of alternatives indicate that the embodiment shown provides the best compromise between weight savings on the entire artillery piece (ie depending on the taking into account the 110 weight of the front stabilizers) and minimization of the net recoil torque l08T reversal.

The suspension structure 124 is supported by a platform / - chassis 117. Both of these structures are made of low- important, high-strength alloys, in which metals titanium, magnesium and aluminum, etc. are important constituents parts. Other high-strength, low-weight materials, e.g. glass and carbon fiber, reinforced plastic, can be used, if so appropriate. The construction of the suspension support 124 and the 117 structures of the platform / chassis use technology such as one does not usually associate with artillery weapons to provide robust, lightweight components.

The underside of the platform / chassis 117 is convex, so that it naturally will rest on all types of terrain to provide a stable 3-point support together with torerna llO. (See later points 6 and 7.) At the rear the part of the platform / chassis 117 is the rear tailbone 104 attach via a hinged connection 10AA. Incorporated with these joints are self-digging shovels l06. The guiding method is such that the reverse and downward direction of the recoil forces bring the shovels 106 to lock against the rear of the platform / chassis 10 15 20 25 30 35 507 747 16 117, i.e. the shovels are, when active, attached to chassis 117 and not oriented at different points, bound by "resilient" tailbone 4 (Fig. 1).

Features 1-4 and 17 in combination provide the following benefits: i) greatly reduced mass of metal in suspension and chassis structures; (ii) greatly reduced torques due to recoil forces; iii) high imbalance acting against the torque 108T is due to end of the recoil.

These factors act synergistically, because it reduced the recoil torque requires less mechanical strength for the hanging structure 124 and this allows greater freedom of choice between lightweight materials (feature 17). 7. Short. light rear tailbone to withstand st fi älnninqi 31.11 .. .H .. l _] _15 The front stabilizers 110 were used to counteract haubits. sense imbalance 109. In the normal ready-to-fire position there is a stable three-point support through the chassis 117 and the two feet 111 at the ends of the front stabilizers 110.

The vertical reactions, due to the weight of the howitzer, on chassis 117 and on the front stabilizers 110 are indicated by arrows 1088 and 108D.

The hind tail bones 104 are attached to the body by means of manned joints 104A which also lock the self-digging spa- 106. Hydraulic dampers (not shown) are incorporated in tailbone joints 104a. The construction of these dampers basically comprises hydraulic fluid flowing through lO 15 20 25 30 35 507 747 17 an opening. Under even load, the fluid flows through a constant speed; however, if the load increases noticeably, only a minimal increase in fluid flow occurs.

The recoil force can be considered to consist of three components: - a horizontal component, a vertical component, and - a torque l08T.

Referring to Fig. 2, the recoil is horizontal component balanced by the horizontal reaction 107 at the two shovels 106 in the ground. Although no vertical component is generated when the howitzer is fired horizontally, as shown in Fig. 2, the vertical of the recoil force is balanced component (when the barrel is elevated) through the vertical the reaction 1088 from the ground via the convex base of the chassis 117. Torque l08T is balanced by the vertical reaction l08C on the feet 112 at the end of the hind tailbones 104, plus the imbalance 109. Since the dampers' (not shown) are incorporated with the joints l04A, the howitzer will want tend to rotate slightly clockwise when the torque l08T is consumed; as soon as this has happened, the howitzer will rotate back on its front foot lll under the influence of imbalance 109, possibly lifting the rear foot 112 off the ground - and the rear tailbones 104 will then slowly turn downwards under the control of the dampers (not shown de) until the foot ll2 rests on the ground.

There are no dampers in joints 110A for front stabilization 110 but these stabilizers can be locked in the firing the torque (Fig. 2) or when towing (Fig. 3).

Thus, there is a stable three-point support in both to-fire-position as in recoil, i.e. 2x108D + 108B and 2x108C + 108B resp. It should also be noted that the shovels 106 are articulated in such a way (104A) that the recoil horizontal and 10 15 20 25 30 35 507 7147 18 vertical components act to "lock" them in their operating mode. Every rotation of the howitzer due to the torque 108T should probably be about an axis in largely through the pair leads l04a. Because dampers are used in joints l04A, their action will protect the posterior ones the tailbones 104 from excessive load, so that the bones 104 dimensions can be minimized.

The importance of having the shovels 106 attached to the chassis 117 should not underestimated. The horizontal and vertical of the recoil force components are taken directly via the suspension structure 124 and chassis 117 to ground as reactions 107 and l08B, res- pektive. These recoil components pass through robust structures directly to the ground. This is in stark contrast to the conventional field hobbit (Fig. 1), where the the sontal component passes through long "resilient" tailbones 4.

The release of stress energy in these resilient tailbones 4 is like a second recoil and the combined effect makes that the howitzer moves around violently. In contrast, gives each recoil on the ultra-lightweight field hubits according to the present invention the shovels 106 and the chassis 117 one more more stable base due to a small degree of rotation due to torque effect.

For the ultra-lightweight field hobbits of the present invention invention, the shovels 106 provide the anchorage to the structures 124 and 177 where the recoil forces are generated. On conventional field hobbits, the anchor is remote and is effectively bound by a "feather".

To the fleeting observer, it may seem as if the need fitting two front stabilizers is an additional penalty loading. However, the unambiguous ones have not been realized then the benefits of the imbalance, e.g .: A) the imbalance acts against the recoil torque l08T; B) the position of the neck bearing allows vertical and horizontal 10 15 20 25 30 507 747 19 sontella recoil components go straight into the ground and this allows: i) short, light posterior tailbone 104, ii) small, lightweight suspension support structure 124, iii) small, lightweight chassis 117.

The net weight saving due to the above it rises with the front stabilizers 110. 9. Combined requi and recuperator system. 10. Exploitation of hollow insides of structural organs f. 1 1 ll. The barrel weight is counterbalanced using gas E., :: Fig. 5 shows a cross section through a cradle that supports fire tube 101. The cradle has a rear end that is articulated mounted around the neck bearing 113 (see fig. 2, 3 + 4). The cradle consists of four hollow tubes 119 and 119A, ° position oriented through transverse members 125 and 126. The fire tube 101 can move axially (101A) within the cradle via ears 127 sliding in recesses 128 in bodies 126. The interior of the hollow tubes 119 and 19A volumes are denoted by 129 resp. 129A. These volumes are cleaned and tested for the conditions that apply to pressure vessel. Cross joints (not shown) in the transverse joints the means 125 interconnects the pairs of internal volumes 129 and 129A, respectively. Similar connections may, if desired, arranged in the transverse members 126.

Once the howitzer is fired, there is a massive release of chemical energy that causes the barrel 101 to move rapidly backwards from a first to a second position, i.e. the recoils. The energy of the recoil is absorbed in several ways, by which are the main ones: i) through the muzzle brake 118 (Fig. 4) ii) in the recoil buffer and recuperator systems 10 15 20 25 30 35, 507 747 20 iii) through the shovels 106 and the tailbones 104.

The muzzle brakes 118 are standard articles on many gun barrel. They consist of a series of angled baffles, fixed in attach to the barrel, and which links of the exhaust gases backwards and thus exerts a braking effect on the rear movement. Depending on the angle of the baffles and other factors, the size and efficiency of the braking action can be varied. In this case, the special muzzle brake is selected in such a way that together with the design of the recoil buffer and trolley geometry, you get rid of the recoil energy at most acceptable way. In this context, "wagon" covers it the synergistic construction of the cradle (incl. suspension), frame, tailbone and shovels.

Conventional recoil systems use a recoil buffer and recuperator on the yard side of the barrel to sym- trically dissipate the recoil energy, i.e. there are a total of four cylinders. In the present case, the recoil buffer and recuperation perator (Fig. 6) combined in a single cylinder, so that in total there are only row cylinders - one on each side the barrel. This further contributes to a total weight loss. saving on the whole howitzer.

When the howitzer is fired, the barrel 101 recoils to the right (Fig. 6) and the ears 127 force, via the piston rods 134, the pistons 136 into the cylinders 177. Inside the cylinders 177 there are perforated sleeves 174, so that the movement of the pistons 136 allows hydraulic fluid in the central volume of the cylinder 173 forced, via the perforated sleeves 174, into rings 175 and from there, via pipes 185, 186, to the tank 130. the rings in the sleeves 174 are not uniform but decrease in number and / or size from left to right. When sol- If the rollers 136 move to the right, the number (and the sizes of) the perforations, through which hydraulically fluid can flow and consequently the resistance increases 10 15 20 25 30 35 507 747 21 the rearward movement of the barrel 101. By thus varying size and / or number of perforations, the recoil characteristic The technique is varied to suit specific requirements. The piston rods 134 passes through seals 135.

Inside the tank 130 is a floating piston 188 with hydraulics fluid 187 on one side and inert gas 131 on the other.

A pipe 189 connects the tank 130 to two of the four pipe formations. miga means 119 (or l19A), so that the total volume inert gas to the left of the piston 188 is in the spaces 131 and 129 (or 129A). During the recoil is essentially forced incompressible hydraulic fluid from volume 173 via the perforated sleeve 174 to the ring 175 and thence via the tubes 185, 186 to the space 187 and thereby force the piston 188 to the left and compression of inert gas 131, 129 (or 129A). Since the inert gas volume is 131 plus 129 (or 129A) is large, compared to that driven by the pistons 136, the pressure in the tank 130 remains relatively constant.

When the howitzer is fired, the pistons 136 to the right are forced along pressure increase in volume 173. The flow of incompressible fluid through an opening is proportional to the square root of the pressure difference across it; if thus the pressure difference then doubled, the flow will only increase by 41%. Recoil The buffering effect is thus to exert a high and increasing braking effect on the rearward movement of the barrel 101 and progressive chest it to stay. In contrast, it is the recuperator's purpose of returning the barrel to the firing position at a slow and steady speed. This is done through to use it with the inert gas 131, 129 (or 129A) and that in volume 173. Despite the smaller pressure difference, fluid flows through the perforated sleeves 174 with a appropriate speed to move the barrel 101 back to firing position in time for the next shot. Inert gas 131, 129 (or 19A) are pre-compressed into a suitable one pressure, so that the barrel 101 in all conditions, except 10 l5 20 25 30 35 507 747 22 in recoil, makes a full recoil, regardless of the elevation Angle.

The use of a hydraulic tank 130 on field hobbits is conventional, but, due to the fact that the additional gas volumes 129 (or 129A) is used to supplement the volume but 131, the total size of the tank 130 is reduced. This is a additional weight savings. Due to the larger volume pressurized inert gas 131, 129 (or 132A) is also recuperated. rator characteristics better.

As previously stated, the center of gravity 109 gives location howitzers and large imbalances. If only a conventional height directional device would be used, it would work as needed to be either very demanding or would be a lot high gear ratio may have been needed. In both cases, the gear would be heavy and unwieldy in use. To minimize this work, elevation cylinders 114 filled with are used compressed, inert gas to provide a "counterbalancing" effect. Again, the gas spring principle with volume is used here 129 / 129A of the other two members 119 / 19A, giving one increased gas volume. By appropriate pressurization of the inert the gas, the force exerted by the cylinders 114 can be set approximately equal to the balancing of the barrel 101 and related equipment, e.g. 119, 119A, 130 etc. (Someone underbalance is preferable). Under these conditions can the fire tube 101 is elevated via a lightweight rack (with a acceptable exchange) using a conventional steering wheel, because only minimal work is required.

As the angle of elevation 101 of the barrel increases, so does the total the volume inside the cylinders 114 and the means 119 (or 19A) to increase and thereby reduce the pressure and degree of counterbalance ring. However, this will to a large extent offset by the fact that an elevation of the barrel 101 will tend to shift the center of gravity 109 to the right 10 15 20 25 30 35 507 747 23 (Fig. 2), so that the net imbalance will also decrease.

In the particular example described here, the volume 129 of the two upper hollow members 119 in conjunction with the cylinders 129 of the two upper hollow members 119 in compound with the cylinders 114 and volumes 129A of the two lower members 1919A are used as part of the recoil buffer. This arrangement is chosen to provide the best direction of attack for the cylinders 114 on the barrel / cradle assembly. This arrangements can, however, be varied according to special requirements.

Similarly, the 2-2 can divide the members 119 / 119A internal volumes 129 / 129A are varied, e.g. 3-1 or 4-0, depending on the claims.

Significant weight savings result from their use internal volumes 129 / l29A in conjunction with the hydraulic tank 130. If these volumes were not used, would instead, equivalent volumes of pressure resistant are required cylinders. This would not only contribute to a pure weight loss punishment of the whole howitzer, but would also give some problem was where the cylinders were to be physically oriented. If the cylinders sat on the barrel, the imbalance would increase and consequently also the elevation problems, because a placement on the chassis / platform 117 would prevent access to others components and would require a larger (and consequently heavier) chassis would be used.

By using the internal volumes of the members 119 / ll9A 129 / l29A there will be little or no extra weight. Organs 119 / ll9A dimensions can be calculated by taking the load and an appropriate stress level for the material (including an appropriate safety factor) and evaluate the desired one the metal thickness of the desired pipe diameter. From the area for available standard thicknesses in this diameter shall then the next thickness is selected larger than the one evaluated, which provides an additional safety margin. In this case 10 15 20 25 30 35 507 747 24 the voltage in the metal comes from the sum of the voltages depending on the loads plus the voltage depending on it internal pressure. Since the voltage depending on the internal pressure would probably be small compared to the loads, e.g. bending forces, it is quite likely that you would not need to increase the wall thickness. ll) 13) 14) Restoration (reproduction) of the device in the student As previously mentioned, the elevation gear must be designed to adapted to the load depending on the net weight of fire pipes, cradles, etc. It must also be correct enough for setting the barrel at a precisely determined angle, e.g. arcseconds. If there was no gas cylinder football effect, the load on the gear unit would surely be much larger, which would require massive gear elements and / or a high gear ratio. A high gear ratio allows precision in terms of angle adjustment, but it would also involve many turns with the steering wheel, which can be time consuming, especially in a combat situation.

The solution to this problem is to provide a gas spring motor. balancing to make the barrel, cradle, etc. effective "Weightless", while getting a very precisely damped elevation means to provide an optimized new concept for an elevation switch.

The counterbalancing body has been described previously. Eleva- The mechanism is shown in Fig. 7. It consists essentially of a lead screw 139 which is pivotally fixed thereto right end towards the suspension support structure 124 and passes through the main elevator gearbox 148 near its left end. 10 15 20 25 30 35 507 74-7 25 The main delivery gearbox 148 is fixedly connected to the cradle 119, 119A (non-movable part of the support for the barrel 101), a reset box 147 is hinged at 147A against the suspension the support structure 124 and the arrangement is such that The screw screw 139 is parallel to the axis 101A of the barrel 101 and suitably vertically below this. The lead screw 139 passes through a planetary roller screw 149 in the gearbox 148, so that the gearbox 148 moves as the roller screw 149 rotates, along the lead screw 139 in the direction shown through arrows 155. Then, however, both the main elevation gearbox 148 as the reset gearbox 147 are positively oriented, so the result is to bring the barrel 101 and the cradle 119, 119A to be elevated (or lowered), i.e. that angular motion then occurs around the horizontal axis through the neck bearing 113 and around the joint 147A to maintain the barrel 101 shaft 101A parallel to that of the lead screw 139.

The elevation means comes from an elevation knob 115 via bevel gears 156, elevation hand / drive 116, bevel gears 152, input shaft 153 and bevel gears 150 to the roller screw 149. The guide screw 139 is arranged and the shaft 153 rotates in bearing 154. A non-return mechanism 151 operates on shaft 153 to maintain the elevation angle as a once preset.

The right end of the lead screw 139 is mounted by a flexible, tunable arrangement to protect the elevation system from shock loads after firing. Near the lead screw 139 end there is a screw threaded part 140, on which it sits a push nut 142 and a lock nut 141. The push nut 142 abuts against a spring 143, e.g. a series of spring washers, which is arranged at the other end by a fixed pressure means 144. The end of the lead screw 139 terminates in a piston (and / or opening) 145 in a cylinder 146 full of a hydraulic fluid 146A; this arrangement is, of course a hydraulic damper. By thus adjusting the spring l0 15 20 25 30 35 507 747 26 143 stiffness and the size of the opening 145 to vary damping characteristic, the reset gearbox 147 "tuned" to dampen any movement of the barrel 101 after firing and at the same time protect the elevation system in generally and the lead screw 139 in particular. Friction damping can be used instead of the hydraulic dampers 145, 146, 146A.

In order to fire the howitzer, the elevation is set via elevation knob 115. After firing, the barrel 101 to recoil and the elevation mass will sway, which causes the lead screw 139 to move axially 155 in advance holding to the reset gearbox 147. This brings the spring 143 to be compressed / slackened to its damper 145, 146, 146A action stops the movement and the spring 143 regains its original length and barrel elevation returns to it before firing.

The firing of the hubits and its recoil are violent processes, but by carefully controlling the recoil and allowing limited subdued freedom of movement, these processes can be clay by relatively lightweight organs, compared to where it there is rigid mounting. The example here of a lightweight cushion elevation system coupled with the counterbalanced system then gives a net weight saving in relation to it conventional rigid construction of the gear arch, drive and gearbox. The lighter system is also more precise sensitive and physically easier to handle. 15. minimum size of ri'k1; ni'ngs1ager 16.

The reduced suspension height and consequently reduced recoil overturning torque 108T allows a size reduction of the suspension support structure 124 on the chassis 117. Due to the manner in which the forces are transmitted from the neck bearing 113 to 10 15 20 25 30 35 507 747 27 ground, the drive arrangement (Figs. 8 and 9) can be simplified to a small bearing system 158, 159 at the front, which works as a center of rotation, and a support bearing fixed arc 160 at the buttocks. The current directional mechanism 163 is small bow at a toothed ring. This contrasts sharply with those massive ring bearings and complete gear ring that has so far used. The new design also provides a significant weight saving. Like the elevation shadow, mechanism through a steering wheel via gear (not shown). On due to the light weight of the directional mass can also here use a lighter gearbox than the conventional one the field hobbits.

The principle of construction is shown in Fig. 8 (plan view) and 9 (side view). The hubits are oriented around a vertical cal directional axis 157 via a bearing, e.g. with internal bearing race 158 fixed with chassis 117 and rotatable outer bearing race 159 fixed with the suspension support structure 124. Upper and lower support stock, 161 resp. 162, are biased on the bearing frame 160.

These are shown as rolls, but each type of layer or damping link can be used. Rollers 162 support the positive the imbalance and rollers 161 are tensioned during the recoil. Directional the rack 163 is arranged on the edge of the bearing frame 160 and a directional gear 163, driven by the shaft 165, provides the directional drive. The roller bearing tracks 161 and 162 and toothed the wheel 164 are all mounted on the suspension structure 124, although the actual mounting means are not shown to Avoid confusion with other details. 5) Positive imbalance in all non-disposable positions 12) 3 J EH l. 11 U _ There are various methods by which the ultra-light howitzer then can be converted to towing ready. According to one method, can one or two men hold the end of the barrel 101 and at the same time lightweight wheels 123 are hydraulically lowered around the link 122 with 10 15 20 25 30 35 507 747 28 partly hydraulic cylinders 120 (see fig. 3). The men would then support the positive imbalance. The other men in the group would then lead up the front stabilizers 110 and the tail legs 104 (104B) and remove the shovels 106 (106A) as stowed on the platform / chassis 117. A towing bracket in in the form of a lightning bolt 137 pivots forward about the joint 138 and hooked on the towing vehicle. (In Fig. 2, the wheels have 123 etc. omitted so as not to obscure other details).

The positive imbalance, which is a result of the investment of the center of gravity 109, gives a downward load, via lightning bolt 137, on the towing hook of the vehicle in accordance compliance with safe towing practices.

The reduction of barrel height 102 complicates charging somewhat. arrangements. One of the best solutions is to place the charge washer above the barrel 101. The position of a grenade 121 is shown (Fig. 2), but not the one on the charge the washer or charging link system, as these would obscure other details.

The problem with the shovels 6 (fig. 1), attach at the ends of long resilient tail legs 4 is that the legs 4 are elastic and absorbs a lot of recoil energy to be released as a further and subsequent reaction. The net effect is to heal the artillery piece "bounces" around violently. An alternative placement of the shovels in the vicinity of the chassis 117, as in Fig. 2, is to secure them by bolts 106B at the ends of short, non-elastic legs 104B (see Fig. 10 where the shovels given the reference numeral 106A) and to apply a hydraulic damper including cylinder 166 and piston 167 to allow the artillery piece limited angular movement around the joint 104A. The hydraulic damper includes a 10 15 20 25 30 35 507 747 29 cylinder 166 which is articulated through the connection 169 on the chassis fixture 168, and a piston in the cylinder and tied to a piston rod 167, articulated by means of the bond 171 on the bone fixture 170. The symbol 172 indicates that the legs 104 are not shown in their full length.

The advantage of using such a system is that after the recoil, the chassis 117 and the shovels l06A will stand still sink back to the ground. The horizontal elements of the recoil 107 would be spread over a larger area of land than that two shovels 106, which are located relatively close to each other.

After several firings from the same place, the shovels would 106 dig deep into the ground and obstruct the chassis 117 from sinking to the ground, as safely as desired. Spa- 106 eliminates this possibility.

A further advantage of the shovels 106A at the end of the tailbones l04B is that they make it possible to make smaller con- changes to the chassis 117 that provide an even smaller lowering of the neck layer 113. This provides a further level of improvement for many of the previously described features.

The present invention encompasses a large number of radicals innovations on a standard piece in a field artillery. As has emerged, the whole reasoning behind the new construction to save weight and produce an ultra-lightweight field hobbits. Although this radical way of attacking pro- led to some additional components, e.g. front stabilizers 110, the net effect is a new concept for an ultra-lightweight field hobbits. The new concept provides also a much lower artillery piece, which consequently is much easier to hide on a battlefield.

Throughout this description, reference has been made to the use of light and strong materials. As one of those foremost among these class of metals are titanium and its 10 15 20 25 30 35 507 747 30 alloys widely used, where stress levels so admits. Where structures can be constructed in space technology principles to combine low weight and strength, these will to be used. These principles also apply where a given component can fulfill two or more functions.

In any case, the goal has been to manufacture a howitzer, which, together with its crew and ammunition, may be carried of a single battlefield helicopter and this goal has been achieved, smaller helicopters are also used on the battlefield. Haubitsen has thus been designed so that it can be taken quickly and easily apart in two or more parts, so that you can also separately transport the howitzers, crew and ammunition in two smaller ones helicopters or land vehicles. Hood bits that can be easily shared up in components and mounted on a battlefield, is a lot easier to transport in large numbers, because separate parts can be more easily stowed in a ship or an aircraft than fully assembled objects. A further feature of hau- bits that can be disassembled into two or more main components is that malfunctions in some can be remedied by replace the entire component and the faulty one can be sent back to a repair shop.

There are two main occasions when this may be necessary to divide the howitzer into parts. The first is on the battlefield, where speed can be significant. In this case (fig. ll), the howitzer can be divided into "elevation mass" and "carriage" by removing suspension bases etc. Each part is light enough to be carried by a truck or small battlefield helicopter. The second opportunity could be when large numbers of howitzers are to be transported from a base to the site of a possible conflict. Here would speed not be as important as packing tightly. In this case, can other parts, such as stabilizers 101, tailbone 104B, wheels 123 etc. is removed. 507 747 31 Another feature is a lightning bolt 137 (Fig. 4) that can be guided vertically downward and locked to form a "leg" to support the muzzle end 101 of the barrel. This would be significant facilitate disassembly and assembly of the two howitzers main parts.

Claims (18)

10 15 20 25 30 35 507 747 32 Field hubits comprising: i) a fire tube for the howitz (101), ii) a cradle (119.119A, 125.126) carrying the fire tube (101) and having a rear end; iii) a chassis (177); and iv) a suspension support structure (124) attached to the chassis and comprising a neck bearing (113) about which the rear end of the cradle is pivotally disposed, the neck bearing being on the shaft of the barrel (101A) and oriented behind the limit of the maximum recoil of the barrel. Field hobbits according to claim 1 and further comprising: v) ground contacting shovels (106) (106A); vi) front stabilizers (110) arranged to spread the load of the haubit over a large area of ground when not fired; and vii) rear tail support legs (104) (104B) arranged to spread the load of the howitzer over a large surface area and to assist in absorbing recoil energy while providing lateral and upward stability. Field hobbits according to Claim 2, characterized in that the paddles (106) are fastened directly to the chassis. Field hobbits according to claim 2, characterized in that the paddles (106A) are oriented at or near the ends of the rear tail support legs. Field hubits according to claim 2 or 3, characterized in that the rear tail support legs are articulated (104A) mounted on the chassis and that hydraulic dampers (166, 167) are arranged at or near the attachment points of the rear tail supports. 747 33 legs on the chassis to help absorb recoil energy. Field hobbits according to Claim 2, 3, 4 or 5, characterized in that the shovels (106) are removable. Field hubits according to claim 1, wherein the barrel is mounted on the chassis so that it can be displaced from a first to a second position relative to the chassis as a result of the recoil during firing, characterized in that the howitz also comprises: v) a recoil buffer system to absorb recoil energy when the barrel is fired upon firing, and vi) a recuperator system for returning the offset barrel from the second position to the first position, said recoil buffer system and said recuperator system being combined and using a single hydraulic accumulator arrangement (ll7, l30 ). Field hubits according to claim 7, characterized in that the cradle consists of hollow members (119) (119A), all or part of the space (129) (132a) inside said hollow members being used in whole or in part to provide the volume of compressed, inert gas forming part of said hydraulic accumulator arrangement. The field howitzer of claim 1, wherein the barrel is pivotable about a horizontal axis, the howitzer further comprising: v) elevating means for pivoting the barrel about said axis, said elevating means comprising a toothed manual means (115) assisted by pre-compressed gas. Field hubits according to claim 9, characterized in that the main tube's fire tube is mounted with an imbalance and the degree of assistance from the pre-compressed gas is sufficient to substantially counterbalance the fire tube weight due to its positive imbalance. Field hubits according to claim 10, characterized in that the barrel weight is balanced by gas springs, consisting of cylinders pressurized by a tank (114) with inert gas. Field hubits according to claim 9, 10 or 11, characterized in that the cradle is made of hollow means (119) (119A) and all or part of the space (129) (129A) inside the hollow means is used to house the gas. Field hubits according to claim 9, 10, 11 or 12, characterized in that the elevating means comprises a lead screw (139) which is substantially articulated fixed at one end and along which a nut (148) can be screwed, said nut being fixed in relative to the cradle but rotatable so that the resulting translational movement of the nut along said lead screw causes the cradle to move in a rotating direction around the neck layer, whereby the howitzer's fire tube elevates / is pressed down. Field hubits according to claim 13, characterized in that the substantially articulated fixed end of said lead screw is provided with a resilient tunable device, comprising: i) a spring member (143) aligned parallel to the axis of the lead screw, and ii) a attenuator (145,146,146A); whereby the spring constant, the preload and the resistance of movement produced by the damper are adjustable to provide a tunable system. Field hubits according to claim 14, characterized in that the spring means comprises a series of spring washers and that the damper is a hydraulic damper. Field hubits according to any one of the preceding claims, characterized in that the barrel of the howitzer is mounted on the chassis by means of a directional bearing for being able to pivot about a vertical axis, the directional bearing comprising (a) a small, centrally oriented bearing with inner (158) and outer (159) bearing surfaces, one of which is immovably attached to the chassis and the other immovably attached to a support (124) for the barrel and (b) a separate large diameter support bearing, formed as part of a concentric arc (160) on opposite side of said small, centrally orienting bearing with respect to the orientation of the bearing relative to the barrel. Field hubits according to claim 16, characterized in that it comprises a directional rack (163) integrated with a part of the support bearing arch. Field hubits according to claim 1, characterized in that it further comprises: 1 v) an orifice brake (118) on the barrel, and vi) an articulated lightning bolt (137), attached to the barrel near the orifice brake to enable the howitzer to towed.