US2230086A

US2230086A - Mobile target

Info

Publication number: US2230086A
Application number: US293517A
Authority: US
Inventors: Scott-Paine Hubert
Original assignee: Individual
Current assignee: Individual
Priority date: 1938-04-22
Filing date: 1939-09-05
Publication date: 1941-01-28
Anticipated expiration: 1958-01-28

Description

Jan. 28, 1941.

Filed Sept. 5, 1959 H. SCOTT-PAINE MOBILE TARGET 4 Sheets-Sheet 1 Jan- 28, 1941- H. SCCTT-PAINE MOBILE TARGET Filed Sept. 5, 1939 4 Sheets-Sheet 2 Jan. 28, 1941.

H. SCOTT-PAINE MOBILE TARGET Filed Sept. 5, 1959 4 Sheets-Sheet 5 Jan. 28, 1941. E 2,230,086

' MOBILE TARGET Filed Sept. 5, 1959 4 Sheets-Sheet 4 Patented Jan. 28, 1941 UNITED STATES PATENT GFFICE Application September 5, 1939, Serial No. 293,517 In Great Britain April 22, 1938 9 Claims.

This application corresponds to the applications of Hubert Scott-Paine, Serial No. 12,158/38, which was filed in Great Britain on April 22, 1938, Serial No. 5811/39, which was filed in Great Britain on April 22, 1938, and Serial No. 5011/39, which was filed in Great Britain on February 15, 1939.

This invention relates to an improved mobile target and more particularly to an improved mobile target which is to be towed or self-propelled at sea.

Mobile floating targets must afford an object comparable, in so far as visibility is concerned, with that of the actual boat to be fired at, and at the same time must be capable of being towed or propelled at a similar speed to that of the boat itself.

One object of the invention is to provide a mobile target which, while being of the required size, is of low aerodynamic resistance.

Another object is to ensure that the target, although of low aerodynamic resistance and light construction, is easily discernible at a distance.

A further object is to provide a floating target, the size and shape of which simulates that of a vessel, such as a particular type of war vessel, but which is of simple construction and low aerodynamic resistance.

A further object is to provide a target which requires a minimum of repair after it has been under fire.

According to the invention a. mobile target comprises an open frame or structure carrying sheets, which may be pivotally-mounted rigid vanes or flexible streamers or the like, of sufficient surface area to render the target discernible at a distance, the sheets being so mounted on the frame work as to adjust themselves according to the direction of the wind and thereby to reduce the aerodynamic resistance of the target when in motion.

For a mobile floating target, there is preferably provided, according to the invention, a raft carrying a superstructure and provided with two underwater planin surfaces spaced apart longitudinally in the direction of travel, to provide an adequate moment opposing the tipping moment of the air forces on the target superstructure.

These, and other features and objects of the invention, will be evident from the following description of preferred examples of the invention which are illustrated in the accompanying drawings, in which:

Figure 1 is a side elevation of a floating target,

Figure 2 is a sectional view on the line 2-2 of Figure 1,

Figure 3 is a plan view of the target, and

Figure 4 is a side elevation of an alternative form of target.

Referring to Figures 1, 2 and 3, the base of the target is constituted by a raft which is indicated generally by the reference 5. The raft 5 is formed with two under-water planing surfaces 6 and l separated by a transverse step 8. The transverse step 8 is situated at a position along the length of the raft so as to provide an adequate moment opposing the tipping moment of the air forces on the target superstructure.

The forward planing surface 6 is substantially fiat in a transverse direction and towards the bow 9 is inclined upwards and forwards from the forward planing surface 6.

The after planing surface I of the raft is con' cave in transverse section on its under-surface as may be seen from Figure 2, and its longitudinal edges are provided with keels H) which afford additional transverse and directional stability. This construction prevents the escape in a lateral direction of the air and water gathered in the concave under-surface and by so constraining the water flow in the fore and aft direction, the maximum possible lift and stability are obtained.

The step 8 is provided with holes 21 (Figure 2) any water collecting forward of the step 8 is eX- tracted through the holes 21 by the suction created in the under-surface aft of the step when the target is under way.

When the target is at rest, it is supported by expanded rubber buoyancy boxes 26 which compensate for any water which fills the raft through the holes 21.

In order to give sufficient lateral stability to the target, the beam of the raft should be considerable in relation to its length.

I'he raft is preferably provided with rubbercovered sponsons 30 which act as fenders to prevent damage when it is brought alongside the boat from which it is towed.

The target superstructure is constituted by two vertical braced frames indicated at l2 (Figure 3), which are placed at an angle to each other and face forward in the manner of an arrow head. The rear vertical edges of the two frames arev cross-braced at I 3 thus closing the triangleand diagonal members It to give additional stiffness and to avoid rackin movements.

The superstructure as a whole is in addition supported by tie-wires 28 which are connected to the raft through spring coupling members 29 so as to reduce the effect on the superstructure of any sudden shock which may be imparted to the raft.

This open structure is light, easily manufactured and affords low wind resistance, but is not by itself easily visible; in order to render it more easily visible there are mounted on the framework a number of light streamlined vanes I! (Figure 1). The vanes I? are pivotally-mounted about a vertical axis at their forward edges by means of hinges l8 so that they can adjust themselves freely according to the direction of the wind. These vanes thus provide an easily visible target but at the same time do not increase the wind resistance of the open superstructure to any appreciable extent.

Figure 4 shows an alternative arrangement of floating target. The target consists of a hull 3|, which may be armour-plated. The superstructure of the target is in four main parts, forward and after

parts

32 and 33. on the centre line of the hull, and two parts 34 on the port and starboard sides respectively at the centre of the hull. The outline of this frame simulates the outline of a boat and in order to make the framework appear solid when viewed from a distance, without the addition of bulky or weighty parts which might also increase the wind resistance of the target, streamers are attached within the framework: and are supported by wires 35 as. indicated at. 33. It will be understood that only a few streamers are shown inv the drawings but that in practice suflicient streamers are employed to occupy the space enclosed by the profile of the framework and. it therefore presents an apparently bulky' construction but is in. fact of light construction and only small power is required to move it.

The streamers 36 are preferably of cloth and it will. be appreciated that when the target is in motion the movement of the strips on the target aifords an easily discernible object. To assist visibility the strips are preferably distinctively coloured or they may be made of iridescent material such as aluminium coated fabric so that they reflect the light, and the waving of the streamers in the wind affords a flashing effect which is readily apparent to the eye.

Each

main part

32, 33 and 34 of the framework is separately removable from the hull 3i, and in addition each consists of three small sections indicated respectively at I32, 232, 332; 933, 233, 333; and I34, 234, 334. These sections are readily detachable from one another and the purpose of this arrangement is to enable the target to be readily dismantledand folded up, and in addition, to enable any part which has been damaged to be replaced without necessitating replacement or repair of the target structure as a whole.

I claim:

1.. A mobile floating target comprising a base, a rigid open framework mounted on the base, and a plurality of closely spaced sheets, of sufficient total surface area. to form an easily visible objective, freely mounted on the framework so as thereby to adjust themselves according. to the direction of the wind independently of the direction of movement of said target.

2. A mobile floating target comprising a rigid superstructure in the form of an open framework, a raft carrying the framework and having forward and aft underwater planing surfaces spaced apart longitudinally in the direction of travel, to provide a moment opposing the tipping moment of the air forces on the superstructure, and a plurality of closely spaced sheets, of suficient total surface area to form an easily visible objective, freely mounted on the framework so as thereby to adjust themselves according to the direction of the wind independently of the direction of movement of said target.

3. A mobile target as claimed in claim 1, in which the sheets are in the form of rigid vanes, each pivotally mounted on a vertical axis on the framework.

4. A mobile target as claimed in claim 1, in

which the sheets are of flexible material secured to the framework only at their forward ends.

5. A mobile target having. a floating base, an open framework mounted on the base and having an outline simulating the outline of a vessel, and a plurality of closely spaced sheets, simulating the surface area of the vessel, freely mounted on the framework so as thereby to adjust themselves according to the direction of the wind independently of the direction of movement of said target.

6. A mobile target comprising a floating base, a superstructure formed by a number of sections readily detachable from one another and from the base, and a plurality of closely spaced sheets, of suflicient total surface area to form an easily visible objective, freely mounted on the framework of the superstructure so as thereby to adjust themselves according to the direction of the wind independently of the direction of movement of said target.

7. A mobile floating target comprising a superstructure in the form of a rigid framework provided with a plurality of. framed openings, a sheet freely mounted in each of said framed openings which sheets and framework together are adapted to form an easily visible object and which sheets are adapted to adjust themselves according to the direction of the wind independently of the direction of the towing of the target, and a single bodied raft carrying the said superstructure.

8. A mobile floating target adapted to be towed at high speed and comprising a superstructure in the form of a rigid framework provided with a plurality of framed openings, a rigid vane pivotally mounted in each said opening to move about a vertical axis near its leading edge, which pivoted Vanes' provide a greater part of the visible surface of said target, and a raft carrying said superstructure.

9. A mobile floating target comprising a superstructure in the form of a rigid framework provided with a plurality of framed openings, a sheet,

freely mounted in each of said framed openings, which sheets and framework together are adapted to form an easily visible objective and which sheets are adapted to adjust themselves according to the direction of the wind independently of the direction of the towing of the target, and a single bodied raft carrying the superstructure and having forward and aft underwater planing. surfaces arranged in the direction of travel to provide a moment opposing the'tipping moment of the air forces on the superstructure.

HUBERT SCOTT-PAINE.