US1311768A - Gyrostatic apparatus - Google Patents

Description

I. AND J. G. GRAY. GYROSTATIC APPARATUS.

1,31 1,768. APPLICATION FILED OCT. 22. I918- Patented 29,

4 SHEETS-SHEET l- TKI CDLUMIIA PLANOGIAIH CO-, WAIIIIMTON. Iii-Q 1. AND J. G. GRAY. GYROSTATIC APPARATUS.

APPLICATION FILED OCT. 22, I918. 1,31 1,768. Patented July 29, 1919.

4 SHEETS-SHEET 2- U @4 %34 U 5 z D? 7 1 1 4 5 fl 0 X6 6 6' I. AND .I. G. GRAY.

GYROSTATIC APPARATUS.

APPLICATION men OCT. 22. ms.

1,31 1 .768. Patented July 29, 1919.

4 SHEETS-SHEET 3- 'Iflfjpra:

I. AND J. G. GRAY.

GYROSTATIC APPARATUS.

APPLICATION FILED OCT. 22. I918.

Patented July 29, 1919.

4 SHEETS-SHEET 4 UNITED STATES PATENT OFFICE.

JOHN GRAY, OF LONDON, ENGLAND, AND JAMES GORDON GRAY, OF GLASGOW SCOTLAND.

GYROSTATIG APPARATUS.

Application filed October 22, 1918.

To all whom it may concern k 1 Be it known that we, JOHN GRAY and JAMES- GORDON GRAY, subjects of the King of the United Kingdom of Great Britain and Ireland, and residing at London, Eng land, and Glasgow, Scotland. respectively, have invented a certain new and useful Improvement in Gyrostatic Apparatus, of which the following is a specification.

This invention relates to improvements in gyrostatic apparatus applicable to various devices, notably, for example, to a gyrostatic pendulum to be carried by a moving vehicle, which pendulum shall be unafiected to any appreciable extent by acceleration or retardation, or by side motion, pitching or rolling of the moving body.

A preferred construction of apparatus according to the invention comprises a gyrostat the casing of which is mounted by means of gimbal frames, with the axis of the spinning element Vertical; on a moving vehicle, such as a ship, air-ship, aeroplane or the like, and an erecting device comprising a propelling element preferably arranged to rotate around an axis coincident with or parallel to the axis of rotation of the spinning element in the same circular direction as the spinning element but much more slowly than the spinning element and masses (6. 9., balls or quantities of liquid) movable with and relatively .to the propelling element, the said masses being preferably confined to move in a plane perpendicular to the axis of rotation of the spinning element; the arrangement being such that when the spinning element is not spinning and the axis is vertical and the planes of the gimbals and erector are horizontal the system composed of the gyrostat, the erector and the driving device therefor hangs as a double pendulum, or the system is unstable about each of the {Iimbal axes, or it is in neutral equilibrium about each of the gimbal axes, and that when the spinning element is spinning rapidly and the erector rotated slowly in the direction of rotation of the spmning element the system is automatically stabilized into the vertical by the dynamical action ofthe combination of gyrostat and rotating erecting device, the movement of the masses relatively to the propelling element being such that in consequence of the rotation of the propelling element the masses so Specification of Letters Patent.

Patented July 29, 1919.

Serial No. 259,261.

dispose themselves relatively to the gimbal axes as to render the equilibrium position of the system that in which the axis of spin is vertical, and, the precessional periodof the gyrostatic system beingeither infinite or very great, the system is not disturbed to Eng appreciable extent by movements of the o y. a

The spinning element may be rotated by any suitable means, and the propelling element of the erecting device may be rotated by independent means or may be rotated by power derived directly or indirectly from the gyrostat fiy-wheel.

In conjunction with suitable attachments, the apparatus above briefly described may be utilized to indicate the true vertical on aircraft, or to stabilize instruments of precislon such as bomb sights, cameras, sun mirrors, compasses, etc., against both pitchmg and rolling of the craft on which they are mounted.

In the accompanying drawings Figure 1 is an elevation illustrating diagrammatically one construction embodying the invention. Fig. 2 is a plan of the erecting device showmg the position normally occupied by the movable masses in this case ballswhen the axis of spin is vertical. Fig. 3 is an instantaneous view showing the balls in the position occupied when a couple is being applied tending to restore the yrostat to a position in which the axis 0 spin is vertical. Fig. 4 is a plan showing a modified form of erector. Fig. 5 is a part sectional elevation and Fig. 6 a plan showing a further modification. Figs. 7 and 8 show alternative constructions' of erecting devices. Figs. .9 and 10 are, respectively, a side elevation and a plan showing diagrammatically the device adapted to a bomb sight. Fig. 9 is a view similar to Fig. 9, but somewhat larger and partly broken away to show some internal parts. Fig. 11 shows an alternative construction applicable to a camera or bombsight- Figs. 12, 13 and 14 show diagrammatically in plan, side elevation and end elevation, respectively, an arrangement adapted to a. bomb sight. Figs. 15 and 16 show in vertical section and in plan a complete construction embodying the invention.

In the drawings known elements such as the gyrostat casing are illustrated conventionally, it being understood that the gyro stat fiy-wheel or spinning element may be electrically driven, air spun or otherwise rooted at as 2 to a gim'bal frame 3 which in-- turn is pivoted at 4, 4 to uprights 5, 5 carried by a base (3, the axes of the pivots 2 and 4 being perpendicular to one another.

The erecting device includes a propelling element 7 coaxial with the spinning element and rotatable in the same direction as the spinning element but at greatly reduced speed. For example, assuming that the spining element performs 20,000 revolutions per minute. the propelling element 7 may conveniently perform from 20 to 25 revolutions per minute, and may be driven through any convenient form of speed reducing train by powerderived from the gyrostat or independently.

The propelling element is shown in Figs. 2 and 3 as provided with a plurality of compartments 8, say three, each of which accommodates a heavy ball 9. \Vhen the creator is horizontal, that is, when the axis of the gyrostat is vertical, the balls 9 occupy positions in the compartments 8 remote from the axis of rotation, but should the erector become inclined to the horizontal the balls 9 automatically dispose themselves so that, by virtue of their weight, they restore the gyrostat to the vertical position. Thus, suppose the pendulum inclined so that the erector leans toward the reader. lVith the spin of the gyrostat clockwise as viewed from above a torque or couple applied in the plane of the paper, and counterclockwise as seen by the reader, applied to the gyrostat. will restore the latter to vertical position. Such a couple is automatically applied by the balls. an instantaneous view of which is shown in Fig. 3. The erector is there supposed to be in an inclined position and to be turning clockwise (the direction of rotation of the gyrostat fly-wheel). Each ball 9 is remote from the axis of rotation of the erector when moving uphill and adjacent to said axis when moving downhill in this inclined position of the erector. When the inclination of the plane of the erector to the horizontal has reached a certain value, depending on the diameter of the erector and its speed, the balls 9 are confined to positions remote from the axis of rotation of the erector. It will be seen, however, that the balls are allowed a considerable amount of play when remote from the axis of rotation, so that the erection may be completed.

Fig. 4 shows a modified form of erector. The race 10, which is circular in shape, is fixed to the casing of the gyrostat, and so does notrevolve. The balls 9' roll around the race, the motive power being supplied by a spider 11 which revolves continually and constitutes the propelling element. Should the plane of the race become inclined to the horizontal, the balls 9 move ahead of the spider 11 when traveling downhill, but are in contact with it when traveling uphill; the spider being forcibly rotated in the direction of spin of the spinning element (counterclockwise in this case), the effect is to supply to the gyrostat a torque which erects it into the vertical position. Vhen the race 10 is horizontal, the rolling friction experienced by the balls 9 is sntti cientto keep them in contact with the spider 11, thus insuring that they form a perfectly balanced system.

In the forms shown in Figs. 5, 6 and 7 the containing boX 6 for the balls 9 remains at rest and the balls are rotated by means of a disk or plate 12 carried by the spindle 13, the distance of the plate from the bottom of the erector being half the diameter of the equal sized balls. Slots 14 of one or other of the forms shown in Figs. 5'and 6 are out in the plate 12 to permit movement of the balls relatively to the plate 12.

A further form of erector is shown in Fig. 8. As therein shown, two or more sleeves 15 are fitted on a vertical stud 16 carried by a frame 17 attached to the casing 1 of the gyrostat or the equivalent. Attached to the sleeves 15 are arms 18 terminating in equal weights 19, 19. A spindle 20, to which are attached pushers 21, rotates slowly in the direction of the spin of the spinning element. If the stud 16 be vertical when the gyrostatic system is upright, the erector will stabilize the device into the vertical. If the erector be inclined to the horizontal, the weights 19 apply to the system a couple whose moment is such as to restore the system to the upright position. The weights then form a balanced system. If more than two pnshers be employed, they should be symmetrically arranged on the spindle 20.

Figs. 9, 9 and 10 show the device as adapted to stabilize a bomb sight The casing 1 of the gyrostat is pivoted at 2 to a gimbal frame 3. One of the pivots 2 is ex tended and rigidly fixed to the sight 22 as shown. The sight 22 is also attached to the frame 3 by a pivot 23. Thus, the sight and gyrostat casing are rigidly connected to one another. The frame 3 is pivoted at 4 to no rights 5 carried by a base 6 which is rigidly attached to an aeroplane say. A tube 24 is led from the inside of the periphery of the gyrostat casing 1 to a turbine wheel 24* contained in a casing 25 and having peripheral vanes or buckets. (See Fig. 9 The flywheel acts as a centrifugal pump and supplies air to the tube 24. This air plays on the turbine wheel and rotates it at approximately 1800 revolutions per minute. The

turbine drives the erector 7 through speed reducing gearing 24 contained within the casing 25. The crector 7 is situated directly above the intersection of the axes of the pivots 2, 4. The pivots are mounted so as to reduce friction to a minimum and the precessional period of the gyrostat pendulum is made upward of 20 minutes. By means of shot boxes 26, two of which are shown in Figs. 9 and 9 the pendulum is adj nsted so that the equilibrium position of the pendulum is that in which the erector is horizontal/ The shot boxes 26 are carried by a bar 26 suspended from a depending part on the casing 1 by wires 26". The sight 22 is the-n flat.

The gyrostat may be driven by means of three-plrise current derived from a generator wired below the aeroplane so as to be exposed to the slip stream of the aeroplane propeller, the generator being inclosed in a stream-line body and driven by an air-screw.

Fig. 11 shows an alternative construction applicable to a camera. The erector 7 is mounted as shown above the casing l of the gyrostat, which is pivoted at :2 to a gimbal frame 3. The camera 27 is likewise pivoted at 28 to the frame 3, the axes of the pivots 2 and 28 being parallel and in the plane of the gimbal frame 3. The camera 2]" and gyrostat easing 1 are connected together by a connecting rod 29 which is pivoted to the casing 1 of the gyrostat and to the camera, respectively. The gimbal frame 3 is pivoted at :t o uprights 5 fixed to a base 6. It will be evident that the camera '27 partakes of all motions of the gyrostat casing 1, that is, it is stabilized by the gyrostat. WVhen the gyrostat is upright, the camera is flat. A slot is cut in the base 6 immediately below the object lens of the camera.

Figs. 12, 13 and 14! show the apparatus applied to a bomb sight. WVith a view to allowing an uninterrupted view through the sight the gimbal frame 3 terminates as shown in a fork within which the sight 22 is pivoted. The sight and gyrostat casing 1 are connected together by a connecting rod 2-9 as described in connection with Fig.11.

Figs. 15 and 16 show in elevation and plan one complete form of the invention. Surrounding and attached to the casing 1 of the gyrostat is an annular race or channel 30, in which rotate three heavy balls 9 The balls are rotated by'means of a spider 11 the free extremities of the arms of which act as pushers for the balls. The arms of the spider 'adiate from a central boss 31 which is carried on a sleeve spindle 32 mounted on a bearing 33. The spindle 32 carries a worm-wheel 31 which meshes with a worm which is rotated by a turbine wheel 36. To rotate the turbine wheel 36, advantage is taken of the fact that the gyrostat fly-wheel 37 may be caused to act as a centrifugal pump: a supply of high velocity air is delivered from the periphery of the gyrostat casing and is led up to the turbine wheel by means of the tube 24'.

The annular race or channel 30. turbine wheel 81, spider 11", etc., are all carried by the casing 1 of the gyrostat or the equivalent. and the system so formed is pivoted at 2, 2 to a gimbal frame 3, which frame is in turn pivoted at -t to uprights 5 carried by a base 0 which is rigidly attached to the moving vehicle. The gimbal frame 3 is provided with arms 3 within which may be mounted, in the manner already described. the sight, camera, compass or other precision instruments to be stabilized. By means of compensating weights 38 attached below the gyrostat casing 1 the apparatus is adjusted so that the center of gravity of the pivoted system lies at, or very slightly below, the intersection of the gimbal axes 2. '2, 1, 1. In general it is advantageous to arrange that the race in which the balls rotate shall lie, as in this case, in the plane. of the gimbal axes.

The balls 9 are rotated slowly in the direction of spin of the fly-wheel. In the apparatus as at present employed the gyrostat rotates normally at 20.000 revolutions per minute, and the spider at '20 to 25 revolutions per minute, although these rates may be widely departed from without interfering with the action of the device.

If the device be tilted from the vertical. it recovers at a speed which is a function of the angular momentum of the fly-wheel, of the diameter of the annular channel 30, of the masses of the balls 9 employed, of the tilt and of the speed of rotation of the spider 11. For a given erector the speed of recovery from a tilt falls off rapidly with increased speed of rotation of the spider. Thus, for one of these instruments, which is in use, when the spider is rotating at 20 revolutions per minute the speed of recovery is 1 in 20 seconds, whereas when the spider rotates at 100 revolutions per minute the speed of recovery becomes 1 in 8 minutes. If the speed of the spider be very great, the apparatus becomes a freely mounted gyrostat provided that the center of gravity of the pivoted system coincides with the intersection of the gimbal axes. Now. when the apparatus is mounted on an aeroplane which moves in a curved path, the device, at each instant, tends to move toward theapparent vertical. Thus, it is advantageous to make the speed of recovery (which is also very approximately the speed with which the de vice falls away from the true vertical toward the apparent vertical) relatively small. when the aeroplane is rounding a curve, and relatively great when the aeroplane is flying in a straight path. Thus, the spideror in general the erectorshould be speeded up when the aeroplane is rounding a curve. If the. erector be rotated by means of a small geared electric motor, the speeding up is conveniently effected, when required, by cutting out electrical resistance inclu ded ln the circuit of the motor; where a turbine is used to drive the erector, the speeding up may be effected by increasing the supply of air delivered to the turbine. The speeding up and slowing down of the creator may easily be effected by automatic means; in any case, it does not involve more than the cutting out or introduction of resistance by means of a switch, or the turning of a tap.

Any suitable form of gyrostat may be employed. Vhere air-spun gyrostats are used, and a supply of compressed alr is available, small turbines may be employed to rotate the erector, to wind and unwind the film spools of stabilized cameras, and to 2LCl]LlSt the transit wires of stabilized sights. It is convenient to carry the air up to such turbines through the gimbal pivots, as the turbine or turbines may then be operated by means of a tap or taps not carried by the pivoted system.

lVhen the invention is applied to stabilize bomb-sights, cameras, etc., on aircraft it is advantageous, as already explained, to pivot the system composed of gyrostat, erector, bomb-sight, etc., so as to be neutral, or at all events very nearly neutral, about each of the gimbal axes. The invention may, however, be employed to stabilize a pendulum into the vertical, or to cause such pendulum to OSClllate to and fro in increasing amplitude.

What we claim is l. The hereindescribed gyrostatic device comprising, in combination, a system of gimbals, a gyrostat comprising a caslng mounted therein and a spinning element rotatable around a vertical axis relatively to said casing, and an erecting device comprising a propelling element rotatable around a vertical axis, and masses movable wlth and relatively to said propelling element and adapted on the rotation of said spinning element to dispose themselves relatively to the gimbal axes in positions such as to establish equilibrium of said gyrostat and erectlng device with the axis of rotation of said spinning element vertical.

2. The hereindescribed gyrostatic device comprising, in combination, a systenr of gimbals, a gyrostat compr sing a casing mounted therein, and a spinning element rotatable around a vertical axis relatively to said casing, and an erecting device comprising a propelling element rotatable around a vertical axis in the same circular direction as said spinning element but at a greatly reduced speed, a track, and balls movable in said track together with and relatively to said propelling element, said balls adapted on the rotation of said spinning element to dispose themselves in positions relatively to the gimbal axes such as to establish equilibrium of said gyrostat and said erecting device with. the axis of rotation of said spinning element vertical.

3. The hereindescribed gyrostatic device comprising, in combination, a system of gimbals, a gyrostat comprising a casing mounted therein, and a spinning element rotatable around a vertical axis relatively to said casing, and an erect-ing device comprising a propelling element rotatable around a vertical axis in the same circular direction as said spinning element but at a greatly reduced speed, an annular ball track whose center lies in the axis of rotation of said propelling element, and balls within said track in the path of said propelling element, said balls adapted on rotation of said spinning element to dispose themselves in positions relatively to the gimbal axes such as to establish equilibrium of said gyrostat and said erecting device with the axis of rotation of said spinning element vertical.

4. The hereindescribed gyrostatic device comprising, in combination, a system of gimbals, a gyrostat comprising a casing mounted in said gimbals, and a spinning element rotatable around a vertical axis relatively to said casing, a circularly arranged normally horizontal ball-receiving surface, partitions dividing said ball-receiving surface into compartments, and balls arranged to travel on said ball-receiving surface and adapted, when said ball-receiving surface is tilted out of the horizontal, to travel more slowly uphill than downhill, as and for the purpose specified.

5. The hereindescribed gyrostatic device comprising, in combination, a system of gimbals, a gyrostat comprising a casing mounted in said gimbals, and a spinning element rotatable around a vertical axis relatively to said casing, a circularly arranged track carried by said casing, a rotatable spider having arms dividing said track into compartments and adapted to serve as pushers for said balls, and means for imparting rotary movement to said spider in the same circular direction as said spinning element but at a greatly reduced speed.

6. The hereindescribed gyrostatic device comprising, in combination, asystem of gimbals, a gyrostat comprising a casing mounted in said gimbals, and a spinning element rotatable around a vertical axis relatively to said casing, an annular track rigid with said casing, balls movable around said track, and a spider rotatable around a vertical axis much more slowly than the spinning element and having arms adapted to serve as pushers for the balls, said track being normally in a horizontal plane which contains the center of gravity of the system, but When tilted presenting sloped surfaces on which the balls move more slowly uphill than downhill.

7. The hereimlescribed gyrostatic device comprising, in combination, a system of gimbals, a gyrostat comprising a casing mounted therein and a spinning element rotatable around a vertical axis relatively to said casing, a propelling element rotatable around a vertical axis in the same circular direction as said spinning element, speed reducing connections for transmitting rotary movement from said gyrostat to said propelling element, and masses movable with and relatively to said propelling element and adapted, on rotation of said spinning element, to dispose themselves relatively to the gimbal axes in positions such as to establish equilibrium of said gyrostat and said erecting device with the axis of rotation of said spinning element Vertical.

8. The hereindescribed gyrostatic device comprising, in combination, a system of gimbals, a gyros-tat casing mounted therein and provided with a normally horizontal annular hall track. a spinning element rotatable relatively to said casing around a vertical axis containing the center of said track, a propelling element rotatable around the same axis in the same circular direction as said spinning element but at a greatl) reduced speed. and balls within said track in the path of said propelling element, the arrangement being such that when said track is horizontal said balls travel in said track with uniform speed. but when said track is inclined to the horizontal said balls move more slowly uphill on said track than downhill.

In testimony whereof we have signed our names to this specification in the presence of two subscribing Witnesses.

JOHN GRAY. JAMES GORDON GRAY. Witnesses:

HENRY MASON, FLORENCE HoUsToN.

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