US2807987A - Directional mounting for a gun - Google Patents

Description

Oct. 1, 1957 R. G. VICKERS 2,307,987

DIRECTIONAL MOUNTING FOR A GUN Filed July 16, 1954 3 Sheets-Sheet 1 INVENTDR my GILBEW' Iva 5P5,

ATTDHNEY Oct. 1, N57 R. e. VICKERS DIRECTIONAL MOUNTING FOR A GUN 3 Sheets-Sheet 2 Filed July 16, 1954 IN VE N TOR Kay east-le wave/as,

ATTORNEY R. cs. VICKERS 2,807,987

DIRECTIONAL. MOUNTING FOR A GUN 5 Sheets-Sheet 3 Filed July 16, 1954' MM ATTDHNEY United. States atent Patented Oct. 1, 1957 DIRECTIONAL MOUNTING roa A GUN Roy Gilbert Vickers, Grantham, England, assignor to Brevets 'Aero-Mecaniques S. A., Geneva, Switzerland, a society of Switzerland Application July 16, 1954, Serial No. 443,861

Claims priority, application Great Britain July 22, 1953 6 Claims. (Cl. 89-41) This invention relates to mountings for apparatus to be directed or aimed by an operator on the mounting and it will be described as applied to a gun mounting. The invention can however be applied to other directional mountings such as for searchlights, radarapparatus or television or other cameras.

The object of the invention is to provide improved means to enable an operator seated on a mounting to train the mounting, that is to turn the mounting about a normally vertical central axis, by the power and control of his feet on a pair of pedal levers.

Pedal lever training mechanism for gun mountings already known comprises, fixed on the base of the mounting, a horizontal circular rack coaxial with a turntable or equivalent part of a training structure which carries a pinion meshing with the rack and driven, through transmission gearing, by a pair of pedal levers to turn the training structure about the rack.

Rack and pinion training mechanisms with other drives, such as hand-wheel drives, also are known and in fact some form of rack and pinion, or worm and worm-wheel, has been the standard means of training mountings.

The present invention has a different principle, requiring no toothed gearing, and provides means enabling an operator to thrust with his feet on pedal levers and obtain a purchase against the base of the mounting from which to turn, just as though he were able to apply his feet directly to the base but with the advantages of additional leverage and a simple leg action as compared with the rather complex action of a thrust exerted through the operators seat from the ground or a fixed pedal.

The invention is applied to a directional mounting comprising a base rotatably supporting a turntable or equivalent part of a training structure provided with a pair of pedal training levers for actuation by an operator on the training structure and, according to the invention, the base has a fixed circular track coaxial with the training axis, the turntable has, journalled relatively thereto and coaxially therewith, a pair of arms extending radially in opposite directions from the training axis to the circular track, each arm is spring-loaded, to a given angular position relatively to the turntable, and each arm has a shoe to engage against the track, to provide a fixed point from which the turntable can be turned, under thrust transmitted through connecting means from one of the pedal levers respectively. 1

Conveniently the track is provided by the smooth inside cylindrical surface of an upstanding base ring, the shoes are simple friction shoes pivoted in the arms and the connection between each shoe and its respective pedal lever consists of a cam lever pivoted in the arm to bear on the shoe and a connecting rod universally jointed to the cam lever and pedal lever respectively.

The spring-loading of each arm, conveniently provided at the axis by a helical torsion spring with crossed ends,

is eifective also on the pedal lever to which its shoe is connected and preferably it is arranged so thatin the normal position the pedal lever is vertical and the arm and the pedal lever have movement, relatively to the training structure, equally in both directions from, the normal position, against the spring-loading, up to the limit of stops on the training structure.

The invention as applied to a gun mounting is illustrated on the drawings accompanying the provisional specification, in which: i

Fig. 1 is a side elevation of a light anti-aircraft gun mounting.

Fig. 2 is a side elevation on a larger scale, partly broken away, of the base and of the turntable which carries the remainder of the training structure of the mounting shown by Fig. 1.

Fig. 3 is an axial half-section through the base and turntable of Fig. 2, taken on the line lII-III of Fig. 4 and Fig. 4 is a fragmentary plan, partly broken away and partly in section, of the base and turntable of Fig. 2 with some parts omitted for clarity of illustration.

The mounting shown by the drawings has a circular base 1 held down on a horizontal support, such as the deck of a ship, by bolts passed through holes 2. (See Fig. 3.) The base has a stout central pivot 3 and, towards its periphery, an upstanding flange ring 4 which respectively support roller bearings 5 and 6 at the inner and outer peripheries of an annular turntable 7 which is thus mounted to turn easily but truly on the base and to carry the load of the remainder of the training structure. The turntable 7 is of inverted dish shape.

As shown by Fig. l, on the turntable 7 is built a turret cabin 8 in which is cradled a pair of guns 9, only one of which appears in Fig. 1, provided with hand-lever elevating or laying controls 10, and a sight 11 for a gunner on a seat 12'. The detailed construction and operation of the cabin and guns are not relevant to the present invention which is concerned only with training the mounting by turning of the turntable 7 on the base 1.

The training mechanism will now be described with particular reference to that part operated by thrust of the gunners left foot for training the mounting tothe right. This left-foot mechanism is shown'in detail by the drawings and it will be remembered that it is duplicated, with the necessary lateral inversion, on the other side of the mounting for the right-foot drive.

Convenient to each of the gunners feet is a pedal lever which will be referred to generally by the reference number 13 but, as shown in Figs. 2 and 3, in fact comprises a pedal or foot-bar 13, a pedal arm 13 a cross-shaft 13. in a pillow-block bearing 14 on the turntable 7, and a drop-arm 1?) extending down into the interior of the turntable 7 through a slot therein (not shown). The pedal lever has a normal vertical position and a movement of about 30 on each side of the vertical. on the turntable 7 to be encountered by the drop-arm 13 provides a stop limiting forward movement of the pedal lever. (See Fig. 2.)

The lower end of the drop-arm 13 is formed as-a socket seat to make a joint with one ball-end of a dumbbell shaped connecting rod 16 the other end of which (see Fig. 4) is similarly jointed to the radially inner end of a cam lever 17 pivoted by a vertical pin 18 in the outer end of a radial arm 19 journalled by plain bearing bushes 20 on the central pivot 3. Fig. 3 shows how the two arms 19 are knuckle-jointed around the pivot 3 so as to lie in the same horizontal plane and have bearin g surfaces of adequate overall length.

Around a spacer ring 21 on the central pivot 3 is coiled a helical torsion spring 22, one for each arm 19. The ends of the spring 22 are set to project substantially radially and the spring is pro-loaded so that its ends cios's An abutment 15 one another and anchor circumferentially in opposite directions against axial pins 23 and 24 fixed in the turntable 7 and arm 19 respectively. (See Figs. 3 and 4.) Thus the spring 22 tends to maintain the arm 19 in a givenposition relatively'to the turntable 7. This position is shown in the drawings and is that in which the pins 23 and 24 are radially aligned, under the load applied equally and oppositely by the .ends of the spring 22 against the pin 24. The spring 22. acting on the arm 19 also thrusts or pulls on the pedal lever 13 through the connecting rod 16 and thus also acts as a return spring for the pedal lever tending always to return the pedal lever to its vertical position as shown.

Angular movement of the turntable 7 relatively to the arm 19, in the direction to move the pedal 13 rearwardly, islimited by an abutment 25 on the inside of the turntable arranged to encounter a boss 26 on the arm 19. (See Fig. 4.) This also limits rearward movement of the pedal 13. The abutment 15 for the drop-arm 13 (see Fig. '2)", by limiting forward movement of the'pedal, limits angular movement of the arm 19 relatively to the turntable 7 in the rearward direction away from the pedal lever.

In the extreme outer end of the arm 19 is pivoted by a vertical pin 27 (see Fig. 4) a shoe 28 having a plain friction surface presented against a track 29 provided by. the smooth inside cylindrical surface of the rim of the flange ring 4. It will be noted that the base 1 has radial ribs 1 and integral gusset stays 1 bracing and supporting the flange ring 4. V

The cam lever 17 has a half-round self-aligning pressure pad 30 (see Fig. 4) through which to apply the shoe 28 against the track 29 under the thrust of the pedal lever 13 acting through the connecting rod 16. A pullofi spring 31 is stretched between the toe of the shoe 28 and an anchorage on the arm 19 and a nut 32 on a stud 33 adjustably limits turning of the cam lever 17 away from the shoe 28.

The action of the mechanism is as follows:

In the normal position, the pedal lever 13 is vertical under the influence of the respective spring 22 on the arm 19, the shoe 28 is clear of the track 29 and the turntable 7 carrying the training structure is free to move on its bearings about the central pivot 3 of the base 1.

Initial thrust of the gunners foot on a pedal lever 13, acting through the connecting rod 16 and cam lever 17, applies the shoe 28 firmly against the track 29. This provides a purchase. fixing the arm 19 relatively to the base 1 and continued thrust on the pedal lever, acting about the forward end of the connecting rod as a basefixed fulcrum, turns the whole training structure until the drop-arm 13 encounters the stop 15.

'Itshould be noted that the initial thrust on the pedal lever 13 must overcome the tension of the pull-off spring 31 in order to turn the shoe 28 towards the track and that the spring 22 must be strong enough to hold the arm 19 against such initial thrust until the shoe 28 holds against the track and thus fixes the arm 19.

During the training movement under the thrust on the pedal lever 13, the-pin 23 fast with the turntable 7 entrains in its movement the end 22 of the spring 22 whilst the other end 22 remains held by the pin 24 in the arm 19.

On release of the pedal lever, the pressure on the shoe '28 is relieved and the shoe is pulled by its spring 31 clear of the track 29 allowing the arm 19 to follow up the training structure under the torsion of the spring 22 applied through the end 22 against the pin 24. This also returns the pedal lever to the vertical position.

The arm 19 is now ready for the shoe 28 to take a 'fresh purchase against the track 29 and thus provide a new fixed point for further training under the next thrust on the pedal lever. Each stroke of the pedal lever can be as short or as long, within its limits, as the gunner desires.

If the thrust on the pedal lever is light, as in tracking a target, the training structure will have a dead-beat motion with and proportional to forward pedal movement.

If however a heavier thrust is made on the pedal lever, as in slowing, the training structure will gain momentum and at the end of the forward stroke of the pedal lever, when the load on the pedal has been taken by the stop 15, the pressure of the shoe against the track will relax sufliciently to allow the arm 19 to move with the training structure so long as the latter coasts-or free-wheelsunder the impetus of the thrust on the pedal lever.

The initial relaxation of the pressure of the shoe against the track is due to transfer of pedal load to the stop 15 and the eventual degree of relaxation is determined by the balance of the pull-off spring 31 against the follow-up effort of the spring 22, the latter acting, through the arm 19 and the pin 18, on the cam lever 17 about the rear end of the connecting rod 16 as a fulcrum fixed by the pedal level being held forward. It can be arranged'that any resultant pressure of the shoe against the track, while the pedal lever isheld forward, is so slight as not to affect rotation of the mounting.

The arm 19 will not recover its original angular position relatively to the turntable until the pedal lever is released to allow the spring 22 to bring the pin 24 into alignment with the pin 23, but this can of course be done during the coasting period to be ready for another thrust on the pedal lever.

It will be remembered that the mechanism is duplicated, for the two directions of training. Both pedal levers may be thrust simultaneously to engage their shoes and fix the two arms against the track. From this position, differential 'movement of the gunners feet, equal and opposite with the two pedal levers within the limits of the stops, produces directly a corresponding movement of the training structure as though the pedals were on the ends of a rudder bar.

Either pedal lever can be applied as a brake, to check slewing of the mounting resulting from thrust on the other pedal lever, the braking lever holding its shoe fast against the track and being forced back against. the thrust of the gunners foot until the training structure has turned sufiiciently for the abutment 25 on the turntable 7 to encounter the boss 26 on the arm 19 whereupon the shoe is dragged round the track as a friction brake. This friction braking would only be required to arrest a fast traverse of the mounting. Moderate-speed slewing can be opposed and stopped by thrust of the gunners foot.

The training mechanism of the present invention provides the gunner, or the operator of any similar direc tional mounting, with the facility to train his mounting instinctively and with the same fineness of control as,

and even greater strength'than, he would have with his feet directly on the base or ground.

The above description and the drawing referred to, illustrate one practical embodiment of the invention but modifications could of course be made.

For example, the opposed faces of the shoe 28 and track 29 being simple friction surfaces, they have, in the absence of slip, an infinite capacity for interengagement throughout the training circle. With some loss in infinite finenessof angular position, the interengagement of these faces could be made positive, such as by the provision of very fine axial serrations to avoid the possibility of slip although this would'complicate the braking action. However, by so proportioning the leverages of the pedal lever and cam lever it can be ensured that the friction torque of the'shoe on the track is always greater than the torque available to turn the mounting so that .slip is avoided, even with the relatively low coefiici'entof friction for opposed plain metal surfaces subject to intermittent lubrication. Consequently plain or metal or metal-faced shoes are preferred.

Another possible modification is that the transmission of pedal pressure to the shoe could be hydraulic instead of mechanical, means being provided relieving the hydraulic pressure to release the shoe for coasting of the mounting when the pedal has been thrust against its stop.

What I claim is:

l. A directional mounting which comprises, in combination, a base, a training structure support rotatable on said base about a training axis perpendicular to said base, a circular track fast on said base and coaxial with said training axis, a pair of pedal levers pivoted on said support and adapted to be thrust respectively by the feet of an operator seated on said support, a pair of arms angularly movable about said training axis relatively to both said base and said support, said arms extending separately from said training axis radially towards said track, springloading means urging each of said arms respectively to a given angular position relatively to said support, a shoe on each said arm and movable relatively to said arm so as to engage against and disengage from said track, and means connecting one of said pedal levers to one of said shoes and the other of said pedal levers to the other of said shoes, said connecting means being arranged to transmit thrust from the respective pedal lever to the respective shoe to engage said shoe against said track and thereby provide a fixed point purchase for movement of said pedal lever to rotate said support on said base.

2. A directional mounting according to claim 1, in which each said shoe is pivoted on the respective arm and the means connecting the respective pedal lever to said shoe comprises, a cam lever pivoted on the same arm as said shoe and bearing on said shoe to move said shoe against said track and a connecting rod universally jointed at one end thereof to said cam lever and at the other end thereof to the respective pedal lever.

3. A directional mounting according to claim 2, in which a pull-off spring is provided between each said shoe and the respective arm to urge said shoe away from said track and against said cam lever.

4. A directional mounting according to claim 1, in which each said pedal lever is pivoted on said support 6 about an axis parallel to the plane of said base and abutments are provided on said support, said abutments limiting angular movement of each said pedal lever to an arc of movement substantially equal on either side of a position in which said respective pedal lever is substantially perpendicular to said base.

5. A directional mounting according to claim 1, in which said spring-loading means comprises a pair of helical torsion springs located coaxially about said training axis, each said spring having its ends crossed one over the other and projecting substantially radially from said training axis, and, for each of said springs, a pair of anchor pins engaged by the crossed ends of the respective spring, one pin of each pair being fast on said support and the other pin of said pair being fast with the respective arm.

6. In a directional mounting comprising a base, a training structure support rotatable on said base and pedal means for an operator on said support to rotate said support on said base; a circular track fast on said base and axially perpendicular to said base, purchase means operative between said pedal means and said circular track to provide a purchase for said pedal means against said track, and comprising a pair of arms angularly movable about the axis of said track relatively to both said base and said support, said arms extending separately and radially towards said track, spring-loading means urging each of said arms to a given angular position relatively to said support, and a shoe on each of said arms, said shoe being directed towards said track and pivoted on the respective arm to engage against said track under thrust from said pedal means and means interconnecting said pedal means and said shoes.

References Cited in the file of this patent FOREIGN PATENTS

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