US2986941A - Rate gyroscopes - Google Patents

Description

June 6, 1961 w. K. HORATH 2,986,941

RATE GYROSCOPES Filed Feb. 17, 1960 3 Sheets-Sheet 1 J ne 6, 196 w. K. HORATH 2,986,941

RATE GYROSCOPES Filed Feb. 17, 1960 3 Sheets-Sheet 2 June 6, 1961 w. K. HORATH 2,986,941

RATE GYROSCOPES Filed Feb. 17, 1960 3 Sheets-Sheet 3 United States Patent 2,986,941 RATE GYROSCOPES Werner Karl Horath, Palaiseau, France, assignor to S- ciete de Fabrication dInstruments de Mesure (S.F.I.M.), Massy, France Filed Feb. 17, 1960, Ser. No. 9,369 7 Claims priority, application France Feb. 23, 1959 2 Claims. (Cl. 74-5) The present invention includes improvements in the construction of rate gyroscopes, with particular reference to floating rate gyroscopes, the purpose of these improvements being to simplify units of this type.

According to the invention, the hermetically sealed enclosure containing the gyroscope wheel is integral with a sensor rotor and the spring-loaded pivot of this assembly is located between said enclosure and said rotor.

Such a pivot would preferably consist of a system of dual rectangular crossed blades the paired ends of which are rendered integral with said enclosure and with the main support of said apparatus respectively.

The rotor referred to above is preferably mounted on a hollow hub through which it is easy to pass the necessary flexible electrical leads required to supply the electrical elements which are integral with the movable unit comprising said enclosure and said rotor.

The second pivot for this movable unit is preferably constituted by a non-friction bearing mounted on the end of the enclosure which is opposite the pivot referred to precedingly.

It is furthermore preferable to provide the envelope, which supports the apparatus and which forms a bowl, with a bubble-trap to act at the same time as an expansion compensator.

In a simplified apparatus of this type, the crossed-blade pivot is preferably formed out of a relatively thick disc in the centre of which a full portion is retained to act as attachment for the blade roots, this full portion being perforated according to a square perforation pattern and said blades being equally spaced. The full portion is thus associated to a rim which stands proud on either side, this rim being provided with two opposed semi-circular slits, one on each side of the full portion. These two semi-circular slits are placed in communication, via their ends, by diametrically-opposed axial cuts located on the diagonal of the square formed by the perforation pattern.

Thus the articulation in reality comprises two coaxial circular rim elements uniquely connected to each other by the crossed resilient blades, and these circular rim elements are easier to fix and to locate, both inside the fixed support and inside the movable unit, both the latter being provided with suitable mating features, both recessed and in relief, which are easier to fashion accurately.

The bubble-trap is of the same type as that described in the US. patent application Serial Number 4,641 which is entitled Improvements to Floating Integrating Rate Gyroscopes, filed in the name of the applicant on January 26, 1960.

The description which follows with respect to the accompanying drawings, given by way of example only and not in a limiting sense, willgive a clear understanding of how the invention may be performed.

' .In the drawings:

FIG. '1 is an axial sectional view of a rate gyro according to the invention.

FIG. 2 is a sectional view along the lines II-II in FIG. 1, the envelope being assumed to have been removed.

FIG. 3 is a sectional view along the lines III-III in FIG. 2. e

2,986,941 Patented June 6, 196 1 FIG. 4 is a partial sectional view through the lines IVIV in FIG. 1.

FIG. '5 is a profile view of the articulation.

FIG. 6 is a plan view with partial cutaway of the ole ment in FIG. 5, along the lines VI-VI in FIG. 5.

FIG. 7 is a sectional view through the lines VIIVII in FIG. 6.

FIG. 8 is a sectional view through the lines VIIIVII[ in FIG. 6.

Referring now to the drawings, the illustrated device comprises a cylindrical casing 1 into which is fitted, at. one end, a flanged cover 2 and, at the other end, a bubbletrap 3 of the type described in the patent application referred to. The bottom of this bubble-trap is equipped with a support 4 which falls within the compass of the casing 1 and which cooperates with the inner race of a ball bearing 5.

A shoulder 6, which is provided on the inside wall of the casing 1, supports the ring of a pivot having two crossed blades 65 and 66 of the type described below, this ring 68 being further supported by welding onto the casing 1 ahead of the lip 10 of the cover 2.

The illustrated articulation comprises a full portion 60 the outer edge of which is circular and the inner edge constituted by the outline of four perforations 61, 62, 63 and 64 whose axes are perpendicular to the plane of the full portion and arranged to form a square which is approximately inscribed in a circle concentric with said outer edge.

These perforations allow partitions to be maintained which are thinned down into two crossed blades 65 and 66, which are separated and offset from each other.

The outer edge of the full portion 60 forms part of a socket which stands proud, to a roughly equal degree, on either side of this full portion, but one of the protruding portions 67 is of slightly smaller outer diameter than the protruding portion 68.

A slit 69 is provided, parallel to the full portion 60 and as near as possible to it, in the socket portion 67. This slit 69 is semi-circular in shape and terminates, at each end, in drillings 70 and 71 respectively. On the other side of the full portion 60, the socket portion 68 is likewise provided with a semi-circular slit 72 the extremities of which also terminate in drillings 73 similar to the drillings 70 and 71. These drillings are thus aligned two by two along generating lines of the cylinder contained within the aforementioned socket. These generating lines are diametrically opposed and are located in the plane which bisects the angle formed by the blades 65 and 66.

These drillings also communicate with each other, two by two, through the medium of slits 74 and 75 let into the disc 60 itself, said slits 74 and 75 creating in this disc the solution of continuity that separates the disc in question into two parts, of which one is thus rendered integral uniquely with the socket element 67 while the other remains integral with the socket element 68. The socket element 67 is consequently integral with the roots located on one side of the blades 65 and 66 whereas the socket element 68 is integral with the roots of said blades located opposite. The lips formed on these slits act as abutments to limit possible rotating motion of the whole assembly.

These socket elements constitute convenient means of locating the pivot described thus, it being likewise convenient to execute'the fixing means by the screwing method, by means of perforations 76 in the plane of the full portion 60, it being possible for some of these perforations to be tapped or otherwise shaped.

' The cover 2 forms a bowl to which is fixed the stator 1-1 of a motion sensor, said stator partially surrounding a 3 7 central internal boss 12 in said cover, through which emerge the electrical connecting wires, as will be explained in greater detail below.

The second ring 67 of the pivot with the blades 65 and 66 encompasses a seating 14' provided at the foot of the box 15 which is equipped with a cylindrical wall and which is contained in the casing -1 with a slight degree of sideplay. The covering end of the box 15 is a sealing fit on the support 16 embodying the seating 14 and is mounted on the outer race of the ball-bearing 5, the lat-, ter being thus contained in a blind housing 17 in said covering end with a degree of play which allows the casing to be filled through the roller bearing.

The support 16 is provided, inside the box 15, with a pair of parallel arms which terminate in eyeholes 1 8. These eyeholes each enclose a liner 19 which is tightened up by screws 20 and into which is screwed the threaded end of a fixed spindle 21. This spindle 21 is hollow and through it passes an electrical conductor 22 which terminates in a suitably insulated strip 23, this strip'b eing itself connected to an axial conductor 24. The spindle referred to comprises two identical ends and a central hollow core 25 about which is mounted the magnetic armature 26 and the windings 27 of a motor used to spin a wheel assembly.

The latter is constituted by two bells 28 each of which is mounted on ball-bearings 29, the inner races of the latter being driven onto the ends 21. These bells are driving fits on a rim 30 of toridal shape and said rim contains a magnetizable ring 31 located opposite the armature of the inner motor.

The conductors 24 are threaded through welded insulating bushes 32 and thus cross the bottom 33 of the support 16.

The bottom 33 also embodies arms 34 of which the inward portion is machined to provide circular-sector seatings 35.

The conductors Z4 and the arms 34 pass through apertures in the pivot formed by the rings 67 and 68 and the crossed blades 65 and 66,, a degree of play being provided which prevents any form of contact during resilient movement of the moving unit of the rate gyroscope.

The conductors 24 which feed the motor are connected by arcs 24a made of spring metal to fixed terminals 36, the latter being close to the spindle and integral with an insulating strip 37 screwed into the rim of the ring 67. Furthermore, the bottom 33 features a nozzle 38 passing through an aperture 39 in the pivot, the purpose of which is to create a vacuum within the box 15 and to sustain this vacuum by plugging the orifice by means of a glob of solder 40.

Over their seating 35, the arms 34'locate with the flared flanged portion 41 of the conical portion 42 of the hollow hub 43 of the sensor rotor 44, this rotor being. comprised within the stator 11. This hollow hub threads through it conductors 45 which are formed of very' flexible braided lines which are welded to the terminals *36 and which pass through tubes 46 which are rigidly grippedin pertorations in the bottom 12 by means of insulated bushes 47. 'Hermetic sealing ofv the outer end of the tube 46 is ensured by means of globs of, solder'48. .A tube 49' is likewise fixed into the bottom 2 by'means ofan insulating bush 50.

The spindle 4 is hollow and can beobturated by means of a screw-in plug 51 provided with a conical: head 52 which cooperates with a correspondingseatingin said spindle, the seating being surrounded by oblique channels 4a. Similarly, the bottom of the bubble-trap is obtur-ated by a screW-in-plug 53 providedwith a spherical head 54 which cooperates witha conicalbearing surface 55 that acts as a seat, a suitablearea 56 being provided about this seat to take a cast-sealing gasket.

The manner of operation ofsuch an apparatus does not call for a more" detailed description and it. will easily beseen that such a constructional method provides for improved balancing of the movable unit of such a rate gyro on either side of the spring-loaded pivot, the ball-bearing 5 being designed to provide a light form of guidance only. This roller bearing could be replaced by a resilient pivot of the aforementioned type. As will be observed from FIG. 4, balancing of the movable unit is rendered dependent upon screws 57 which are made to penetrate in varying degree ihto'blind holes 58' drilled radially into the bottom 15a of the box 15 A vacuum can be produced inside the box without difiiculty by means of the nozzle-38. Filling of the easing with a liquid can be effected by introducing said liquid through the tapped hole which appears when the plug 53 is withdrawn, and through the oblique channels 4a. Once the degassing, debubbling and complete filling operations have been accomplished, the plug 53 is replaced after suitable filling of the bubble trap 3'.

It is also to be clearly understood that many modifications can be made to the specific embodiments described hereinabove without departing from the scope of the invention.

What I claim is:

1. In a rate gyroscope, in. combination, an external casing, a sensor stator internally disposed in said casing, a sensor rotor disposed in the vicinity of said stator, a hollow hub supporting said rotor, a wheel box internally disposed in said casing, arms protruding at one of the extremities of said box facing the corresponding extremity of said hub, said arms being seated on said extremity of said hub, a shoulder lformed'in the internal wall of said casing, a second shoulder formed in the external wall of said box, a spring loaded pivot comprising a first ring inserted on said first shoulder and a second ring inserted on said second shoulder, each of said rings being integral with a corresponding part of a two part partition having facing extremities, in which are machined four apertures according to a square drilling pattern, apertures through which said arms pass respectively and two thin crossed separated blades the roots of which are integral by pairs with said partition parts, the facing. extremities of said partition parts constituting abutment surfaces.

2. In a rate gyroscope, in combination, an external casing, a sensor stator internally disposed in said casing, a sensor rotor disposed in the vicinity ofsaid stator, a hollow hub supporting said rotor,.said hub beingopen at both ends, at least one fluid-tight insulating bush forlat least oneelectrical conductor in one bottom of said casing, said electrical conductor extending through said :hollow hub, a wheel box, a wheelin said box with an electrical actuating motor, a hollow spindle for said wheel, internal supports for saidspindle, hearings on said spindle for said wheel, electrical conductors in said hollow spindle, electrical connectingme'ans connected tosaid'conductors, fluid-tight insulating bushes for each of said conductors in one bottomof said box, flexible bladesconnecting said electrical conductors'in saidhub and said connecting means, arms protruding on said box mounted on one extremity of said hub, a spring loaded pivot formed with a pair of crossed blades'interposed between-said casing and said box, saidarmsipassing'through the open spaces between said crossed blades, apertures machined in said pivot through which the extremities of'said connecting means pass with clearance, and a ball bearing pivot at the extremity of said box oppositeto thatextremity at which is mounted said spring loaded pivot, said ballbearing resting on a hollow axle inserted in a correspondingly perforated wall of abubble-trap which. is inserted in an open end of said casing, said bubbl'e trap comprising an external wall in. which is disposed. a plug. fluid-tight inserted in a corresponding filling aperture.

References Cited inthe file ofthis patent UNITED STATES PATENTS 2,687,648 Konet Aug. 31', 1954 2,700,739 Orlando Jan. 25, 1955 2,899,828 Lynn Aug. 18, 1959

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