US3272019A

US3272019A - Gyro-vertical apparatus

Info

Publication number: US3272019A
Application number: US230040A
Authority: US
Inventors: Barnes Jeffery Walton
Original assignee: Ferranti PLC
Current assignee: Ferranti International PLC
Priority date: 1961-10-14
Filing date: 1962-10-12
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13
Also published as: GB944828A

Description

Sept. 13, 1966 J. w. BARNES 3,272,019

GYRO-VERTIGAL APPARATUS Filed Oct. 12, 1962 2 Sheets-Sheet l l2 4 a m 46 f-PSO A ttorney;

Sept. 13, 1966 J. w. BARNES 3,272,019

GYRO-VERTICAL APPARA'VI'US Filed Oct. 12, 1962 2 Sheets-Sheet 2 POLLIAX/S I PITCH AX/S I nventor I W. BARNES WA}, W 7% y United States Patent 3,272,019 GYRO-VERTICAL APPARATUS Jelfery Walton Barnes, Farnborough, England, assignor to Ferranti, Limited, Hollinwood, Lancashire, England, a company of Great Britain and Northern Ireland Filed Oct. 12, 1962, Ser. No. 230,040 Claims priority, application Great Britain, Oct. 14, 1961, 36,933/ 61 12 Claims. (Cl. 74-5.43)

This invention relates to gyro-vertical apparatus.

In gyro-vertical apparatus it is known to cause erection of the gyroscope about the pitch and roll axes by torques produced by the discharge of a gas, usually air, from jets disposed on opposite sides of the rotor axis, the apertures of the jets being varied by means of gravity controlled shutters responsive to tilts of the gyroscope, about the pitch and roll axes. In apparatus using an air driven rotor the air supply for the jets is held off from the rotor supply.

Previously known systems have suffered from the disadvantage that the air or other gas supplied to the jets has not been of constant density and the erection rate of the gyroscope has varied accordingly. Furthermore precautions have had to be taken to ensure that the air or other gas has been clean and dry.

It is an object of the present invention to provide gyrovertical apparatus employing a gas erection system in which the gas pressure supplied to the jets is self generated and of constant density.

According to the present invention, gyro-vertical apparatus includes within a hermetically sealed gas filled housing, an electrically driven rotor, a centrifugal pump driven by said rotor for supplying gas to first and second pairs of jets symmetrically disposed with respect to the spin axis or" said rotor and adapted to discharge in a direction parallel to the spin axis of said rotor, and first and second sets of gravity controlled shutters responsive to movements in the pitch and roll axes respectively, each of said sets of shutters being pivoted about an axis parallel to the spin axis of said rotor, said sets of shutters being adapted to co-operate with said jets to control erection of the gyro about the pitch and roll axes.

Said first and second pairs of jets may be disposed on lines at an angle to the pitch and roll taxes respectively, which angle may be 45, and said first and second sets of gravity controlled shutters may each comprise four shutters such that the discharge from each jet is controlled by a shutter from said first set and a shutter from said second set.

Said first and second sets of shutters may be caused to operate in such a manner that for tilts of the gyro of less than a predetermined angle said shutters are restrained in a first position and for tilts of the gyro greater than said predetermined angle said shutters overcome said restraint and move to a second position.

The present invention will now be described by way of example with reference to the accompanying drawings in which:

FIGURE 1 is a sectional elevation along the roll axis of gyro-vertical apparatus in accordance wit-h the invention,

FIGURE 2 is a plan view of the pitch erection shutters of the apparatus shown in FIGURE 1,

FIGURE 3 is a plan view of the roll erection shutters of the apparatus shown in FIGURE 1, and

FIGURE 4 is a part-sectional elevation along the roll axis of a modification to the apparatus shown in FIGURE 1.

Referring now to FIGURES 1, 2 and 3 of the drawings the gyro-vertical apparatus shown includes within an air-filled hermetically sealed housing 1, a rotor 2 mounted on a shaft 3 supper-ted by bearings 4 in a cas- 3,272,619 Patented Sept. 13, 1966 ing 5. The gyro rotor 2 is the rotor of an induction motor, the stator 6 of which is mounted on an extension 7 of the casing 5. The casing is mounted within the housing 1 with two degrees of freedom by means of an outer gimbal 9, the casing 5 acting as an inner gimbal.

The rotor 2 is provided on its upper surface with vanes 10 which, in operation, act as a centrifugal pump to supply air from inlet holes .11 in the casing 5 to two pairs of jets 12 and 13, and 14 and 15, symmetrically disposed with respect to the spin axis of the rotor 2, the jets discharging in a direction parallel to the spin axis of the rotor 2. The pair of jets 12 and 13 is disposed on a line at 45 to the pitch axis and the pair of jets 14 and '15 is disposed on a line at 45 to the roll axis.

A first set of shutters comprising four single knifeedge shutters 16, 17, 18 and 19 mounted on a spider 2!) is pivoted about an axis parallel to the rotor axis by means of a spindle 21 positioned slightly off-center on the pitch axis and provided with hearings in two

support plates

22 and 23 mounted on the top of the casing 5. The shutters 16 19 are gravity controlled by means of a weight 24 mounted on an arm 25 of the spider 20, the arm 25 extending in a direction parallel to the pitch axis such that the weight 24 is responsive to movements about the pitch axis. To limit the movement of the shutters 16 19, two

leaf springs

26 and 27 are provided which bear against

stops

28 and 29.

In operation, when there is no tilt about the pitch axis the shutters 16, 17, 18 and 19 obscure half of the opening of the jets 12, 13, 14 and respectively and there is no resultant torque on the gyro rotor. If the top of the gyro is tilted forwards, however, the weight 24 moves into engagement with the spring 26 which exerts a contant force such that for tilts of less than seven degrees the movement of the weight is stopped and the shutters 16 19 are restrained in a first position in which the shutters 16 and 18 oifer no restriction to the jets 12 and 14 and the shutters 17 and 19 wholly cover the jets .13 and 15. A resultant torque is therefore exerted on the gyro rotor causing procession towards the vertical. For tilts greater than seven degrees the force exerted by the weight 24 is suflicient to overcome the force exer-ted by the spring 26 and the weight '24 therefore moves until the arm engages the stop 28. The shutters 16 .19 are then restrained in a second position in which they offer no restriction to any of the jets 12 15 and there is therefore no restoring torque exerted on the gyro rotor.

If the top of the gyro is tilted rearwards the spring 27 and the stop 29 act in a similar manner to restrain the shutters in a first position in which the shutters 17 and 19 offer no restriction to the jets 13 and 15 and the shutters 16 and 18 wholly cover the jets 12 and 14, and a second position in which no restriction is offered to any of the jets 12 15.

A solenoid 30 is provided which, when energized,

moves a peg 31 into a hole 32 in the spider 20, the diameter of the hole 32 being such that the weight 24 is free to move to the first position only in either direction. When the solenoid 30 is energized, therefore, a restoring torque is exerted on the gyro rotor for all angles of tilt.

A second set of shutters comprising two

double knifeedge shutters

33 and 34 and two single knife-edge shutters 35 and 36 mounted on a spider 37 is pivoted about an axis parallel to the rotor axis by means of a spindle 38 positioned slightly off-center on the roll axis and provided with hearings in the two

support plates

22 and 23. The shutters 33 36 are gravity controlled by means of a weight 39 mounted on an arm 40 of the spider 37, the arm 40 extending in a direction parallel to the roll axis such that the weight 40 is responsive to movements about the roll axis. To limit the movement of the shutters 33 36 two

leaf springs

41 and 42 are provided which bear against stops 43 and 44.

In operation, if the top of the gyro is tilted by less than seven degrees to the left the weight 39 moves into contact with the spring 42 which exerts a constant force such that the weight is stopped and the shutters 36 36 are restrained in a first position in which the shutters 33 and 36 offer no restriction to the jets 12 and 15 and the shutters 34 and wholly cover the jets 14 and 13. Similarly, if the top of the gyro is tilted to the right by less than seven degrees the shutters 33 36 are restrained in a first position in which the

shutters

34 and 35 offer no restriction to the jets 14 and 13 and the shutters 33 and 36 wholly cover the jets 12 and 15.

For lateral tilts greater than seven degrees the force exerted by the weight 39 is sufiicient to overcome the force exerted by the

spring

41 or 42 and the weight 39 moves until the arm engages one or other of the stops 43 and 44. The shutters 33 36 are then restrained in a second position in which for tilts to the left the shutters 34 and 36 offer no restriction to the jets 14 and 15 and the

shutters

33 and 35 wholly cover the jets 12 and 13, and for tilts to the right the

shutters

33 and 35 oifer no restriction to the jets 12 and 13 and the shutters 34 and 36 wholly cover the jets 14 and 15.

The spider 37 is. provided with a hole 45 which receives the peg 31 when the solenoid 30 is energized, the diameter of the hole 45 being such that when the solenoid 30 is operated the movement of the weight 39 is limited to the first position in either direction.

Although the two sets of shutters 16 19 and 33 36 have been shown separately in FIGURES 2 and 3 respectively it is emphasized that both sets act simultaneously on the jets 12 15 as may be seen from FIGURE 1. For tilts of the gyro of less than seven degrees, or for all tilts when the solenoid 30 is energized, the combined operation of the two sets of shutters 16 19 and 33 36 is as follows. If the top of the gyro is tilted forward and to the left, the jets 13, 14 and 15 are closed and the jet 12 is open.

If the top of the gyro is tilted forward and to the right,

the jets 12, 13 and 15 are closed and the jet 14 is open. If the top of the gyro is tilted rearward and to the left, the jets 12, 13 and 14 are closed and the jet 15 is open. If the top of the gyro is tilted rearward and to the right, the jets 12, 14 and 15 are closed and the jet 13 is open.

The above shutter actions, which are applicableonly to clockwise gyro spin viewed from above, give normal erection about pitch and roll axes and would operate in substantially unaccelerated flight.

When substantial fore and aft accelerations take place it is desirable to cut out the pitch erection action and this is done by the pitch controlled shutters 16 19 moving to the second position giving no pitch erection as already described. When substantial lateral accelerations take place these, in the case of fixed wing aircraft, are invariably due to turning. In this case it has been found that rather than cut out the roll erection, it is better to control both the pitch and roll erection primarily by the pitch tilt, but to reverse the sense of the roll erection in relation to pitch tilt by the direction of the turn, this being commonly called the pitch-bank erection system. In a turn, therefore, the roll shutters are in their second position but the pitch shutters are in their position, giving for forward tilt and left turn jet 12 open, for forward tilt and right turn jet 14 open, for rearward tiltand left turn jet 13 open and for rearward tilt and right turn jet 15 is open. In each case all other jets are closed. The above shutter'actions apply only for clockwise gyro spin.

The purpose of the solenoid is to enable the user to restore normal erection if the gyro happens to get more than seven degrees oi'I the vertical about either axis.

The seven degrees is a purely arbitrary figure for the transition from first to second positions and this can be varied and may be different for pitch and roll.

In equipment of the kind described above the erecting torque depends on the square of the rotor speed and the momentum depends on the speed. The erection rates are therefore small when the rotor speed is low and, furthermore, fast erection rates are not possible. It is therefore desirable that the gyro should be as near the vertical as possible before switching on so as to reduce the time taken by the gyro to settle. FIGURE 4 shows a modification of the apparatus shown in FIGURE 1 in which it is ensured that the gyro remains substantially vertical when the rotor is stationary.

Referring now to FIGURE 4, the rotor and shutter mechanisms are the same as shown in FIGURE 1 and are therefore not shown. In this embodiment, however, two cylinders 46 are mounted on the casing 5. Each cylinder 46 contains a steel ball 47 which is a sliding fit within the cylinder 46. The bottom of each cylinder 46 is of non-magnetic material and contains the poles of a permanent magnet 48 which exerts an attractive force on the ball 47, this force being adjustable by means of a nonmagnetic screw 49. An air supply is bled off from the jet 12 to the bottom of one of the cylinders 46 by means of a pipe 50, and an air supply is similarly bled oil from the jet 13 (not visible in FIGURE 4) to the bottom of the other cylinder 46.

When the rotor is stationary the balls 47 remain adjacent the bottom of the cylinders 46 where they are held by the magnets 48. The casing 5 is therefore bottom heavy and the gyro axis remains substantially vertical. When the rotor is started the air supply bled oil from the jets 12 and 13 lifts the balls 47 in the cylinders 46 and the balance is adjusted such that when the rotor is running at operational speed the balls 47 are at such a position in the cylinders 46 that the casing 5 is balanced.

In the above described embodiments the air supplied to the pump driven by the rotor is drawn from within the hermetically sealed casing. The air is therefore always clean and dry and is always of the same density.

The apparatus described above may be modified in many ways. For example, if pitch-bank erection is not required the jets 12 and 13 may be positioned on the pitch axis and :co-operate with two single knife-edge shutters and the jets 14 and 15 may be positioned on the roll axis and co-operate with two further single knife-edge shutters in known manner. Also, the single loaf springs shown may be replaced by double leaf springs in which the twoleaves rub against each other when the spring is deflected thus damping the movement of the weight and minimizing the risk of vibration. Alternatively, damping may be achieved by the use of wire cantilever springs which rub on the sides of guide slots. Furthermore, if a linear control of erection is desired further springs may be pro vided which act continuously on the

weights

24 and 39. Also, other means of causing bottom heaviness of the casing 5 may be used. Each ball 47 may, for example, be replaced by a piston or by a weight mounted on a bellows which is expanded by the air pressure when the rotor is running at operational speed which fact may be indicated by means of electrical contacts closed by the balls or other weights when in their raised position. Also, the housing 1 may be filled with a gas other than air.

What we claim is:

1. Gyro-vertical apparatus having pitch and roll axes including within a hermetically sealed gas filled housing an electrically driven rotor, first and second pairs of jets symmetrically disposed with respect to the spin axis of said rotor and adapted to discharge in a direction parallel to said spin axis, said first pair of jets being disposed on a line at 45 to the pitch axis and said second pair of jets being disposed on a line at 4 to the roll axis, a centrifugal pump driven by said rotor for supplying gas to said first and second pairs of jets, and first and second sets of gravity controlled shutters responsive to movements about the pitch and roll axes, respectively, each of said first and second sets of shutters being pivoted about an axis parallel to said spin axis and comprising four shutters adapted to so cooperate with said jets that the discharge from each jet is controlled by a shutter from said first set and a shutter from said second set to control erection of the gyroscope about the pitch and roll axes.

2. Gyro-vertical apparatus as claimed in claim 1 including yieldable means operable to restrain said shutters in a first position for tilts of the gyro of less than a predetermined angle, and stop means defining a second position to Which said shutters move when said gyro is tilted through an angle greater than said predetermined angle and said shutters overcome said yieldable restraining means.

3. Gyro-vertical apparatus as claimed in claim 2 in which said yieldable restraining means comprises for each direction of tilt a leaf spring adapted to engage part of said shutters to hold said shutters in said first position until the tilt of the gyro exceeds said predetermined angle.

4. Gyro-vertical apparatus as claimed in claim 2 including additional means operable to prevent said shutters from moving to said second position.

5. Gyro-vertical apparatus as claimed in claim 4 in which said additional means comprises a hole contained in each of said sets of shutters, a peg insertable into and retractable from each of said holes, each of said holes having such dimensions that when said peg is inserted therein said shutters are free to move to said first position but not to said second position, and solenoid means operable to control the insertion and retraction of said peg into and from said holes.

6. Gyro-vertical apparatus as claimed in claim 2 in which said first set of shutters is such that in said first position one jet of each of said pairs of jets is wholly covered by a shutter of said first set and the other jet of each of said pairs of jets is not covered at all by a shutter of said first set, and in said second position said first and second pairs of jets are not covered at all by shutters of said first set.

7. Gyro-vertical apparatus as claimed in claim 2 in which said second set of shutters is such that in said first position one jet of each of said pairs of jets is wholly covered by a shutter of said second set and the other jet of each of said pairs of jets is not covered at all by a shutter of said second set, and in said second position one of said pairs of jets is covered by shutters of said second set and the other of said pairs of jets is not covered at all by shutters of said second set.

'8. Gyro-vertical apparatus as claimed in claim 1 including means for maintaining the spin axis of said rotor approximately vertical when said rotor is stationary.

9. Gyro-vertical apparatus as claimed in claim 8 in which said means includes weights symmetrically disposed with respect to the spin axis of said rotor, said weights being removable by means of gas pressure derived from said centrifugal pump from a first position in which they cause bottom heaviness of the gyro to a second positon in which they do not alfect the balance of the gyro.

10. Gyrovertical apparatus as claimed in claim 9 in which each of said weights is in the form of a steel ball contained as a close fit within a cylinder mounted in fixed relationship to the spin axis of said rotor.

11. Gyro-vertical apparatus as claimed in claim 10 in which each of said cylinders is provided with means for holding said steel ball adjacent the bottom of said cylinder when said rotor is inoperative.

12. Gyro-vertical apparatus as claimed in claim 11 in which said means for holding said steel ball adjacent the bottom of said cylinder includes a permanent magnet.

References Cited by the Examiner UNITED STATES PATENTS 2,297,274 9/1942 Wunsch 745.1 2,368,058 1/1945 Whatley 745.43 2,486,578 11/ 1949 Summers 74-5.43

FRED C. MATTERN, JR., Primary Examiner. BROUGHTON G. DURHAM, Examiner. K. I. WOOD, T. W. SHEAR, Assistant Examiners.

Claims

1. GYRO-VERTICAL APPARATUS HAVING PITCH AND ROLL AXES INCLUDING WITHIN A HERMETICALLY SEALED GAS FILLED HOUSING AN ELECTRICALLY DRIVEN ROTOR, FIRST AND SECOND PAIRS OF JETS SYMMETRICALLY DISPOSED WITH RESPECT TO THE SPIN AXIS OF SAID ROTOR AND ADAPTED TO DISCHARGE IN A DIRECTION PARALLEL TO SAID SPIN AXIS, SAID FIRST PAIR OF JETS BEING DISPOSED ON A LINE AT 45* TO THE PITCH AXIS AND SAID SECOND PAIR OF JETS BEING DISPOSED ON A LINE AT 45* TO THE ROLL AXIS, A CENTRIFUGAL PUMP DRIVEN BY SAID ROTOR FOR SUPPLYING GAS TO SAID FIRST AND SECOND PAIRS OF JETS, AND FIRST AND SECOND SETS OF GRAVITY CONTROLLED SHUTTERS RESPONSIVE TO MOVE-