US1472257A - Servo-motor for aeroplanes - Google Patents

Description

Oct. 30, 1923. 1,472,257

M. M. TITTERINGTON SERVO MOTOR FOR AEROPLANES Filed Nov, 9, 1917 2 Sheets-Sheet 1 IN VE IV TOR Morr/sMTner/ggton Oct. 30, 1923. 1,472,257

M. M. TITTERINGTON SERVO MOTOR FOR AEROPLANES Filed Nov. 9, 1917 2 Sheets-Sheet 2 INVENTOH Morris-MT/Cte r/ngton Patented Oct. 30. 1923.

UNITED STATES PATENT OFFICE.

MORRIS M. TITTERINGTON, OF

BROOKLYN, NEW YORK, ASSIGNOR TO THE SPERRY GYROSCOPE COMPANY, OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

SERVO-MOTOR FOR AEROPLANES.

Application filed November 9, 1917. Serial No. 201,057.

To all whom it may concern:

Be it known that I, Monms M. Trrrna- ING'I'ON, a citizen of the United States of \merica, residing at 64 Remsen Street, Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Servo-Motors for Aeroplanes,

a specification. This invention relates to means for controlling the position of a device by means of a manually operable member eitherdirectly orthrough a motor. More particularly the invention relates to mechanism for controlling the position of the controlling planes of aircraft, although it may be employed in other connections.

Some modern aeroplanes, especially bombing planes, are of such design that the actuation of the controlling planes by the pilot or pilots requires the expenditure of considerable physical effort. In order to avoid this a servo-motor is provided for actuating the planes which servo-motor is controlled by a steering wheel or other manually operable member.

()ne of the principal objects of the present invention is to provide a device in! which the servo-motor, its manually operable controlling member and a driven shaft operated by said motor and adapted to be dire: tly connected to a controlling plane,

. are all embodied in a single compact unitary structure adapted to be applied to any aeroplane or other aircraft. ,v

Another object is to provide a device in which the driven shaft may be actuated directly by means of the manually operable member, preferably Without car ing the motor and its gearing as a load. ther objects and advantages will appear as the invention is hereinafter developed.

Referring to the drawings which illus- 0 trate what I now consider the preferred form of my invention:

Fig. 1 is a central longitudinal section of one form of my device shown detached and disconnected from the aeroplane.

Fig. 2 isan end elevation of the gear casing looking in the direction of the arrow 2 in Fig. l and certain parts.

Fig. 3 is a detail of one form of circuit ,a preferred form of of which the following is inafter term a, servo-motor,

cap 19 maybe screwed on the controller for the motor, with the cover plate removed.

Fig. 4 is a wiring diagram illustrating connections.

Fig. 5' illustrates, in a somewhat diagrammatic manner, my invention connected to a controlling lane and provided with an auxiliary contro ling wheel.

Fig. 6 is a sectional detail taken on the line 6-6 of Fig. 1.

Fig. 7 is a diagram of ,a modifiedform of the invention. v

Calling attention to Figs. 1 and 5 it will be seen that I have provided a frame or casing 1 adapted to be secured to an aircraft or other device by means of legs 2 and provided with a detachable lid or closure 3. A motor shaft 4 and what I term a driven shaft 7 are journaled in the frame or casing 1 preferably by means of ball bearings 6 and 8, respective] or other anti-friction. bearings. An additional bearing 10 may be provided, in the partition 9 within casing 1 for shaft 7. 1

While the motor 11, which I will heremay be mount ed within casing 1 I prefer to mount it exteriorly thereof, but detachably secured The motor is preferably of steel, cylindrical in form and provided with cooling ribs 12. The cylinder 13 is shown as having detachably secured thereto at its and opposite casing 1, a journal bracket 15, screws 16 forming the connection. The bracket 15 besides carrying a ball bearing 17 for the motor shaft 4 is provided with an exteriorly screw threaded outwardly projecting sleeve or hub 18. A cup-shaped last mentioned member thereby rendering the gear casing 1 and motor casing both dust and Weatherproof.

Suitable gearing is provided between the motor shaft 4 and the driven shaft 7. I prefer to mount this gearing within the casing 1 and to make one of the gears disengageable from its corresponding gear by means of a manually operable member exterior to the casing l, for a purpose which will appear hereinafter. The shaft 41 carries a pinion 21 which meshes with a gear 23 keyed thereto as by means of screws. frame or casing 13 or otherwise secured to a shaft 27 rotatable in journals 26 in a fixed sleeve 25. The latter is carried by one side of easing 1 and by the partition 9. Preferably the end 22 of shaft 4 is threaded so that a larger pinion slipped ovcr pinion 21 may be secured in place by screwing a nut, similar to the nut 24 of shaft 27, upon said threaded end. The gear 23 may be replaced by a different gear simply by removing nut 24, so that the gear ratio between shafts 4 and 27 may be readily changed. The shaft 27 carries a pinion 28 which meshes with the gear 29, a slot 40 being provided in sleeve 25 for this purpose. The gear 29 is rotatably mounted in a frame 30 pivoted at one end on sleeve 25 and normally in the position shown in Fig. 2. A pinion 31 rigidly mounted on the same shaft as gear 29 is shown engaging a gear 32 keyed to shaft 7.

The gear train above described forms a driving connection between the motor shaft 4 and driven shaft 7. Under certain conditions it is desirable to break this connection. I have accordingly provided a cam 33, mounted on a shaft 41, within the gear casing 1, and betwen the bifurcated end of the pivoted frame 30. This cam may be operated by a hand lever 36 on shaft 41 on the exterior of easing 1. In the position shown (see Fig. 2) the cam 33 holds the frame 30 down so that pinion 31 is held in mesh with gear 32. By throwing the lever 36 in a. counterclockwise direction the cam will raise the frame 30 and pull the pinion 31 out of mesh with its gear wheel 32. A sector 34 may be fixed on the cam shaft 35 and may be provided with a locking pawl 37 mounted on casing 1 for automatically locking the cam in either of its two positions.

Instead of using a. wind-driven servomotor I prefer to employ an electric motor as the device can thereby be made much more compact. While this motor could assume a variety of types I have illustrated but one, i. e., a compound wound D. C. motor 11. The latter comprises the usual armature 5, a series field 42 and a shunt field 43.

I also provide an electrically controlled brake for the armature shaft 4 which will automatically bring the said shaft rapidly to rest when the motor is deenergized and which normally locks the parts against movement. This brake is preferably mount.- ed within the. cylinder 13 and comprises an annulus 45 of magnetic material and a disk 48. One of these elements, for example, the annulus 45. is secured to the cylinder 13 while the other is slidably but non-rotatably secured to shaft 4 by a key or other suitable means. A spring 49 may be provided for urging the disk 48 to disengaged position and a coil 46 may be provided in the annulus 45 for the purpose of pulling said disk to active or braking position. The adjacent portions of the annulus and disk are preferably faced with friction material and 47 respectively. Obviously when coil 46 is energized the disk 48 will engage the annulus and brake the motor shaft 4.

Preferably the brake should be adjustable and for this purpose the annulus 45 is screwthreaded on its exterior and the cylinder 13 is provided with corresponding internal serew-tln'eads. Obviously by turning the annulus the latter is moved in a direction toward or away from the disk 48 so that the braking torque for a given value of ampere-turns in coil 46 is varied. The adjustment may be effected from the exterior of the motor casing by removing the door 51 and moving a pin 52 inserted in any one of a circumferential series of radially extending holes in the annulus, a circumterentia-lly extending slot 53 being provided in the cylinder 13 for permitting the above operation. When adjusted, the annulus may be locked against turning by inserting a pin in each of the holes nearest the ends of slot The driven shaft 7 is also adapted to be driven by a wheel, or other manually operable member 64 mounted thereon, preferably through a lost motion connection. The hub 56 of the member 64 is shown loosely mounted on a sleeve keyed or otherwise secured to shaft 7 and a nut 57 is provided on shaft 7 for holding the said hub and sleeve in position. The sleeve 55, as shown in Figs. 1 and 6,,is provided with a downwardly extending arm 58 carrying a post 59 adapted to be engaged by one or the other of opposite sides of a sleeve 61 secured in a bore in the hub 56. The wheel 64 may be centralized with respect to post 59 by means of a pair of springs 65 (see Fig. 6) secured at one end to hub 56 by means of a through-bolt 63 and engaging the arm 58 at their free ends.

The wheel 64 besides being so connected as to operate shaft 7 directly may also be provided with a circuit controller for operating the said shaft through the motor 11. One form of controller is shown in Fig. 1 at and in detail in Fig. 3. The post 59 is provided with a reduced portion 62 which engages in a slot 74 (see Fig. 3) in a crank arm 71 secured to a shaft 72 rotatably mounted in the base 75 of the circuit controller. The base 75 may be secured to the steering wheel in any suitable manner. The other end of shaft 72 has secured thereto an arm 73 provided with a plurality of inwardly extending pins 76, 77 and 78 adapted to operate the various contacts on movement of arm 73. Thus pin 76 is adapted to move one or the other of contact levers 79 away from the bridging piece 80 and into contact with a corresponding contact lever 81. A spring 82 may be provided between levers 79 for the purpose of lit biasing the latter to bridge-piece-engaging position, and a spring 83 may be provided between the levers 81 for the purpose of normally holding the last mentioned levers against stop pins 84 but permitting movement away from the stop pins. The pins 77 and 78 are each adapted to engage a corresponding pivoted contact lever 86 and cause the latter to break contact with a corresponding fixed contact 85. The levers 86 may be biased to contact position by means of a spring 87 engaging at each of its ends one of said levers and at its middle the bottom portion 88 of a U-shaped member 89 secured to the pivots of levers 86. The

parts are preferably so designed as to operate in the following sequence. When wheel 64 -1S turned in either direction, arm 73 1s moved in a correspondlng direction causing a corresponding one of pins 77, 78

to engage its contact lever 86 to move the latter away from its contact 85. The pin 76 then engages a corresponding one of levers 79 to cause the latter to disengage bridge-piece and to engage its contact lever 81. All of the above described operation takes place before the post 59 is engaged by sleeve 61. When the wheel is allowed to assume central position with re: spect to post 59 the contact levers are re stored by their springs to the normal position shown in Fig. 3. 'A cover plate 90 adapted to screw on base 75 may be provided to protect the circuit controller 70.

As the wheel 64 turns with respect to the motor 11 and the brake, I provide the shaft 7 with a longitudinal bore indicated by dot-ted lines at 92 in Fig. 1. The electrical conductors between the circuit controller 70 and the controlled devices may be led through this bore and each connected to a corresponding slip ring 93 secured on the inner end of said shaft 7. Brushes 94 mounted on a holder 95 on partition 9 and engaging the slip rings, may be utilized to connect, electrically, the bore contained wires to the motor and brake as indicated in Fig. 4.

The last mentioned figure is illustrative of a preferred form of electrical connections. Energy may be supplied from any suitable source of E. M. F. through a switch 102 to line wires and 101. By connecting the shunt field across line 100, 101, at all times, as indicated, the motor will be more sensitive in responding, i. e., in starting and stopping, than otherwise. The series field 42 is shown connected to line wire 101. and to a conductor 106 connected to both of contact levers 81, contact levers 79 each being connected to a corresponding one of the brushes of armature 5 by means of conductors 107 and 108. Bridge piece 80 is shown connected to the line wire 100 by means of a common return 103. The

brake magnet 46 is shown connected at one end to'line wire 101 and at the other end to a contact 85 by means of the wire 104, the other of contacts 85 is connected ti common return 103 and levers connected.

The operation of my invention as thus far described is substantially as follows. Assuming that switch 102 is closed and the handle 36 in the position shown in Fig. 2 and it is desired to turn the driven shaft. 7 in one direction or the other, the hand wheel 64 is simply turned in the desired direction to asufficient extent to operate the circuit controller 70. This causes the brake magnet to release the brake, the armature short circuit to be broken and the armature to be energized in such a direction as to drive the shaft 7 in the same direction as the wheel 64 is turned. The motor 11 will continue to drive shaft 7 until the wheel 64 is allowed to resume its normal position with respect to post 59 when the armature energizing circuit will be broken, the armature short-circuited, thereby producing a braking effect due to the generz-itor action of the armature and the brake magnet 46 will be re-energized to apply the friction brake, rapidly bringing the motor and shaft 7 to rest; If for any reason such. as of the motor, it is desired .to operate the shaft 7 directly by the wheel 64 the switch 102 may be opened, or the hand e 36 may be thrown in the direction of the arrow in Fig. 2, or both of these operations may be performed. On pulling switch 102 or on failure of the source of supply the motor brake will be released so that the shaft 7 may then be rotated by the wheel 64. By throwing lever 36 the shaft 7 is disconnected from the motor and train of gears and therefore much easier to rotate .by the hand wheel.

While my invention is applicable to various devices I have illustrated it in connection with a controlling plane of an aeroplane. Thus a sprocket wheel 110 secured to shaft 7 by being connected to sleeve 55 may actuate a chain 111 and wires 112 to actuate a controlling plane 113 (see Fig. 5). An auxiliary manually operable wheel or other member 64 may be chain connected to a sprocket 115 provided on hand wheel 64 for convenience in operation when there are two pilots.

The circuit controller 70 may assume the form illustrated in Fig. 7 and designated as 70'. In this form the arm 73' corresponds to the arm 73 shown in 'Fig. 3 and is actuated in the same way. The arm 73 is normally in engagement with a contact 303 but is adapted to disengage this contact and engage either of the contacts 304 or 305, epending on the direction in which steering wheel 64 is turned. With this form of con- 86 are electrically jamming l troller, relay mechanism shown as relays 301 and 302 are interposed between the controller and the controlled elements.

In Fig. 7 the elements designated by". reference numerals with rimes added, correspond to the elements s iown in Fig. 4; and the remaining figures. The relay coils 301 and 302 are shown each connected on one side to a line wire 100 while the other side of each of the relay coils is connected to a corresponding contact 305 and 304; the arm 73 being connected to the opposite line wire 101'. The armatures of the two relays are shown connected across the terminals of the motor armature 5. The front contacts of the relays are connected together and to one side of the line, while the back contacts, which are also connected together, are connected to the opposite side of the line.

It will be noted that as in the other form of connections the leads from the circuit controller 70 are connected through brushes 94' and slip rings 93 to the controlled elements. The remaining connection in Fig. 7, as well as the operation of this form of the invention will be readily apparent, without further description, to any person skilled in the art, in View of the explanation set forth in connection with Fig. 4.

In accordance with the provisions of the patent statutes, I have herein described theprinciple of operation of my invention, together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and elements in the combination and relations described, some of these may be altered and others omitted and some of the features of each modification may be embodied in the others without interfering with the more general results outlined, and the invention extends to such use.

Having described my invention, what I claim and desire to secure by Letters Patcut is:

1. In an aircraft steering apparatus, abase, a servo-motor'mounted on said base, a shaft, a gearing connection between said motor and shaft, manually operated means for breaking said gearing connection, a steering wheel on said shaft and a motorcontrolling switch operated by said wheel to render the motor effective to drive said shaft, said manually-operated means enabling said steering-wheel to drive said shaft independently of said gearing.

2. In a controller device, a motor having a shaft, a second shaft, reduction gearing connectin said motor shaft and said second sha t, a manually-operable member whereby said gearing may be rendered ineffective so that said second shaft is disconnected from said motor shaft, and a sec ond manually operable member connected to said second shaft whereby the latter may be operated independently of the gearing or motor.

A controller handle including a casing, a. motor having a shaft journalled in said casing, a second shaft journalled in said casing, reduction gearing connecting said motor shaft and said second shaft, a manually operable member carried by said second shaft and means for disconnecting said two shafts at a point adjacent said second shaft whereby said member may drive the same without driving the gearing or motor.

4. In an aircraft steering apparatus, a base, a servo-motor mounted on said base, a shaft rotatably supported on said base, a gearing connection between said motor and shaft, means for breaking said gearing connection at a point adjacent said shaft and remote from said servo-motor, a steering wheel on said shaft and a motor controlling switch operable by said steering wheel, said means for breaking said gearing connection enabling said steering-wheel to drive said second shaft independently of said gearing.

5. A controller handle for airplanes including a casing, a motor having its shaft journaled in said casing, a second shaft journaled in said casing, means mounted in said casing forming a driving connection betewen said shafts. means including a handle mounted on said casing for breaking said driving connection and a manually operable member carried by said second shaft.

6. A controller handle for airplanes in cluding an enclosed servo-motor, an electrically controlled brake within the motor frame having a part secured to the shaft of said motor and a part threaded in said casing and means for adjusting said last named part from without the motor frame.

7. In combination, a servo-motor, a shaft, double reduction gears connecting said motor and shaft, a manually-operable member mounted on said shaft, means responsive to operation of said member for causing operation of said motor, and means for rendering one set of reduction gears ineffective so that said manually-operable member may operate said shaft independently of said motor and gears.

In testimony whereof I have afiixed my signature.

1 MORRIS M. TITTERINGTON.

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