US2027393A

US2027393A - Cathode ray device

Info

Publication number: US2027393A
Application number: US508932A
Authority: US
Inventors: Harold J Mccreary
Original assignee: FORREST B BRUNNER; HENRY HUGO ENGELHARDT; RODNEY G RICHARDSON
Current assignee: FORREST B BRUNNER; HENRY HUGO ENGELHARDT; RODNEY G RICHARDSON
Priority date: 1931-01-15
Filing date: 1931-01-15
Publication date: 1936-01-14
Anticipated expiration: 1953-01-14

Description

Jan. 14, 1936. H. J. MCCREARY cATHoDE RAY DEVICE Filed Jan. 15, 1931 Patented Jan. 14,119.36

UNITED STAT-Es PATENT OFFICE 2,027,393 cA'rHonE nar nevica Application January 15, 1931, Serial No. 508,932

\ 18 Claims.

My invention relates in general to 4cathode ray devices, and more in particular to a cathode ray device in which use is made of the deection of the cathode ray or beam by an external field. A special object of the invention is a cathode ray devicein which the cathode ray is deflected by the earths magnetic iield, the device operating as a compass or direction indicator.

One embodiment of my invention, which may be termed a cathode ray compass, is illustrated in the accompanying drawing, comprising Figs.

. 1, 2, and 3. Fig. 1 is a plan view, partly in section, showing the mechanical construction of the compass, Fig. 2 is a diagrammatic drawing of the electrical circuits involved, while Fig. 3 is a fragmentary drawing showing the method of suspending the cathode ray tube, a detail which does not appear from Fig. 1. j

Referring to Fig. 1, the reference character indicates a base which may be of wood or other suitable material. Mounted on the base I is a bearing member 3. The reference character 5 indicates a platform, which is secured to a hub 6, the lower end of which is formed into a shaft 4. Suitable roller and ball bearings are provided between the shaft 4 and the bearing member 3. Thus the platform 5 is supported for rotation on the base I. A motor 23 is adapted to rotate the platform 5 by means of a worm I8 and a spur gear 1, the latter of which is secured to the hub 6.

Mounted on the platform 5 are two upright standards 8 and 9, Figs. land 3. The cathode ray tube 20 is pivotally supported at the upper end of these standards. By reference to Fig. 3,

it will be seen that lthe tube 20 is held in a ring or band Ill. The ring I0 has two laterally extending shafts II and I2 which pass through bearings, in the standards 9 and 8, respectively.

The reference character 2l indicates the elevating motor. By means of gears I1 and I6 this motor is able to rotate the vertical shaft I5, held in suitable bearings projecting from standard 8. Shaft I5 carries a worm I4 which meshesA with the spur gear I3. The latter is secured to shaft I2, from which it will'be evident that rotation of the gear will rotate the band I0 to elevate or lower the upper end-of' the cathoderay tube 2li depending on the direction of rotation. V Referringto Fig. 2, the cathode ray tube 20 comprises a glass envelope, a hot cathode 30, a

perforated shield 3l, an anode 32, and a plate or target 35 against which the cathode ray impinges. In general the cathode ray tube maybe of the usual construction. It is desirable, how- (ci. ss-,zon

ever, to make the openings inthe shield 3| and anode 32 larger than usual so as to secure a good sized ray or beam. With an opening one fourth inch in diameter a ray carrying one milliampere can be obtained. The target 35 is suit- 5 ably secured in the end of the tube opposite the cathode. This target comprises four segments, 36, 31, 38, and 33, which are insulated'from each other. Each segment has a separate termina! wire extending outside the tube. lo

For the purpose of controlling the elevating motor 2| there is provided a polar relay 40 and relays 46 and 41. The rotating motor 23 is controlled by means of a polar relay and relays 64 and 65. Current is supplied by batteries B, 15 B1, and B2. p

The necessary circuit connections between the base and the apparatus mounted on the rotatable platform 5 are taken through slip rings and brushes, so as to permit unlimited rotation of the 20 platform. Referring to Fig. y1, a cylindrical block of insulating material 25 encircles the bearing member 3 and has embedded in its surface. a series of slip rings 23. Ambrush holder 2B is secured to the gear 1, and carries a series of spring 25 actuated brushes Z'I'Which bear on the rings 26. An opening 34 drilled in the block 25 permits conductors to be `connected to the slip rings 26. These conductors may be taken through a conduit 83 to the box 24. -This latter may lcon- 30 tain the batteries and the

relays

60, 84, and 65. Italso 'serves as a support for the motor 23. Suitable conduits such as 80, BI, and B2 may also be provided for protecting the conductors leading to and connecting together the apparatus mount- 35 ed on the platform 5. The box 22 contains the

relays

44, 4,8, and 41.

The conductors connecting to thewtube 20 are taken through condult'l and are preferably flexible leads which extend from theend of the con- 40 duit to the terminals of the tube. These leads should be long enough to provide for a considerable range of movement of the tube. It may be pointed out that the compass herein described specifically is not intended to provide for an un- 45 limited movement of the tube about a horizontal` axis because in most commercial uses, such as on ships or airplanes, such movement is not required. In certain cases. however, as in the case of a military or stunting plane, an unlimited 50 rotation of the tube about its horizontal axis may have `to be provided for. 'I'his can readily be done by using a system of brushes and slip rings, such as are shown for carrying the electrical connections between the platform and the base. u

- and 51.

The operation of the cathode ray tube in producing the cathode ray needs `no extended explanation. Current for heating the cathode 3|)y is supplied by battery B, which is connected by a pair oi' slip rings and brushed to conductors 56 These conductors also supply current from battery B for operating relays 46, 41, 64, and 65, and the motorsr 2| and 23. The proper accelerating potential is supplied to the anode 32 by battery B1, which is connected through a slip ring and brush to conductorI 58. The standards 8 and 9 and other parts near the cathode ray tube should be made of non-magnetic material.

The operation of the compass will now be described, it being assumed that the device is mounted in an airplane. The base is suitably secured in the cockpit of the plane in a horizontal position, and the circuits are connected up as shown in Fig. 2. It may be pointed out now that the principle of operation is to maintain the cathode ray beam parallel to the lines of force of the earths magnetic field. 'I'his is accomplished lby rotating the platform 5 or by changing the elevation of the tube 20, or both, depending on the movement of the plane.

. VHThe operation will be explained herein on the the cathode end pointing to the north. In the l northern hemisphere the lines of force of the earths field make an angle with the surface of the earth the apex of which is toward the north. The amount of the angle, of course, depends on the latitude. The position of the tube, therefore, will be somewhat as shown in Figs. 2 and 3, the exact angle of inclination depending on the latitude of the plane.

For convenience it may be assumed that the plane is traveling due south. The tube points south and the cathode ray, which is parallel to the earths field, impinges on the center of the target 35. This is the normal position of the beam. If the beam is small enough it will impinge on insulating material at the center of the target and little or no current will fiow through

relays

40 and 60. However, the beam may be large enough to impinge simultaneously on

segments

36, 31, 38, and 39 of the target, but this produces no effect because the

relays

40 and 60 are differentially wound as will appear presently.

Suppose now that the plane noses down toward the earth. This causes the cathode ray to cut the earths field, with the result that it is deflected to the right and impinges equally on segments 31 and 38 at some distance from the center of the target. A circuit is thus established which includes the cathode 30, cathode ray, segments 31 and 38, windings 42 and 43 of polar relay 40 in parallel, conductors 54 and 55 in parallel, brushes 21, slip rings 26, windings 6| and 62 ofl polar relay 60 in parallel, and the batteries B2 and B1 in series. The windings 6| and 62 of relay 60 oppose each other and the relay is not operated. Windings 42 and 43 of polar relay 40 assist each other and the relay is operated to close a circuit for relay 46 in an obvious manner by means of armature 45. Upon energizing relay 46 closes a circuit for the armature winding of motor 2| at armature 50, and at armatures 48 and 49 it closes a circuit for the field winding of the motor. The motor 2|, therefore, starts up and rotates in such a direction as to elevate the target' end of the tube. As the tube is elevated the point at which the cathode ray impinges the target moves back toward the center of the target. When the tube is once more parallel to the earths field the point of contract with the target will be at the center and relay 40 will release its armature. This breaks the circuit of relay 46 which deenergizes and stops the motor 2|.

Suppose now that the plane noses upward. 'Ihis deects the beam to the left, causing it to impinge on segments 36 and 39. A circuit is thus established which includes segments 36 and 39, and windings 44 and 4| of polar relay 4|), the l remaining elements of the circuit being the' same as previously explained. Relay 60 remains inactive as before, but relay 40 is operated, its

at armature 53 closes a circuit for the armature` winding of motor 2| and at armatures 5| and 52 closes a circuit for the field winding of the motor. The field is connected up reversed and the motor now runs in the proper direction to lower the target end of the tube. When the necessary correction is made the ray will once more contact the target at the center, the relays 40 and 41 will fall away and the motor 2| will stop.

It will now be assumed that the plane turns to the left. As a result the cathode ray is deflected downward, so that it impinges on

segments

38 and 39. A circuit is, therefore, established which `includes the cathode 30, the cathode ray, the

segments

38 and 39, windings 42 and 4| of polar relay 40 in parallel, conductor 54, a brush 21 and a slip ring 26, winding 6| of polar relay 60, and batteries B2 and B1. Windings 4| and 42 of polar relay 40 oppose each other and relay 49 is not operated. Relay 60 is operated and its armature 63 closes a circuit for relay 64, which in turn closes circuits for the armature and eld windings of motor 23. The motor now starts up and rotates the platform 5 in such a direction as to turn the tube 2|Jto the right, thereby bringing the tube back parallel to the earths field. The point of contact with the target moves up to the center of the target, relays 68 and 64 are deenergized, and motor 23 stops.

If we assume now that the plane turns to the right, the cathode ray will be deected upward and will impinge on segments 36 and 31. This establishes a circuit similar to the one previously traced except that it includes windings 43 and 44 of relay 40 and winding'62 of relay 60. Relay 40 does not operate because windings 43 and 44 oppose each other. Relay 60 operates and now closes a circuit for relay 65. The latter relay starts the motor 23, but since the field is connected up reversed, the motor runs in the opposite direction from what was the case before, and turns the platform 5 in a counter-clockwise direction so as to turn the end of the tube 2li to the left. When the necessary correction has been made the ray will once more engage the center of the target, and relays 60 and 65 will deenergize to stop the motor.

In the foregoing, simple movements of the plane have been considered for convenience in explaining the operations which take place in maintaining the axis of the tube parallel to the earths field. It will be clear, however, especially in the case of an air plane, that compound directional changes may take place. For instance, the plane may nose downward and at the same time turn to the left. This causes the cathode ray to impinge on segment 38. A circuit is thus established which includes winding 42 of polar relay 49 and winding 6| of polar relay 60. By the operation of these tworelays, motors 2| and 23 are operated simultaneously to increase the `eletarget toward the center. In case the change of i direction to the left was relatively small, however.

the correction for this change will be accomplished rst and the point 'of contact with the target will be brought to the dividing line between segments 31 and 38. Segment 31 is now rendered active, as well as, segment 38. As aresult winding 43 of relay 40 and winding 62 of relay B0 are included in the circuit. This deenergizes relay 60 to stop the motor 23, but relay 40 remains en-J ergized and motor 2| continues running until the beam reaches the center of the target. The operations which take place in the even of other changes in direction may readily be deduced from the foregoing and it will be unnecessary to further extend the explanation. Suffice it to say that the axis of the tube is maintained -parallel to the lines of force of the earths eld at all times, except for momentary displacements which take place when the plane changes direction, which are promptly corrected for.

Since the tube points in one direction continually, that is, to the south, it constitutes a compass or direction indicator. The direction in which the plane is traveling may be noted directly by observing the position of the tube, and in some cases this is accurate enough. If desired, however, the entire apparatus may be enclosed in a container having a dial forming the top thereof. A forked shaft may be secured to the standards 8 and 9 and extend upward `through the cover of the container at the center of the dial. This arrangement will give a more accurate reading and at the same time the parts will be protected from injury. The dial and pointer may also be located at some distance from the apparatus with a shaft and gears connecting the pointer with the shaft 4 so that the two will move in synchronism.

f It will be apparent that in some situations the compass will not require an elevating mechanism. When the only directional changes which take place are such as can be corrected for by rotation of the device, the segments 36 and 31 may be united, as .are

segments

38 and 39. The resulting half discs are connected'-` directly to a polar relay such as 60, relay 40 and the associated apparatus being omitted. It may be noted also that the apparatus may be used to measure the inclination of the lines of force of the earths field to the surface of the earth at any point. Other modifications and uses are within the scope of the invention.

I do not wish to be limi-ted, therefore, to the precise structure shown and described herein but desire to secure by Letters Patent all forms and modifications of my invention which are covered by the appended claims.

I claim:

1. In a compass, means for producing a cathode ray, a movable member, and means controlled by the ray for maintaining said member parallel to the lines of force of the earths field, said last means including mechanism for moving said member to correct for angular displacement in both vertical and horizontal planes.

2. In a compass, a cathode ray tube, and means for automatically maintaining the axis of said tube parallel to the lines of force of the earths eld, said'means comprising mechanism responsive to deflection of the ray when it cuts the eld.

3. In a compass, a support, a cathode ray tube mounted on saidl vsupport,'means for moving the tube relative to said support in two-different planes, and circuits including said ray'and estab- Y lished responsive to deflection of the ray when'the v position of lthe support is altered relative to a magnetic field for controlling said movingmeans go 1rtiiaintain the said tube in fixed relation' to said 4. In combination, a cathode ray tube having its axis normally in agiven position, and means responsive to the deflection of the ray by a field of force when the position of the tube is'changed relative to said field for restoring said tube to its original position.

5. In combination, a cathode ray tube, a circuit completed by deflection of the ray by a eld of force when the tube is moved in a direction such that the ray cuts said field, and means controlled over said circuit for moving the tube in another direction.

6. In combination, apparatus for generating a cathode ray and located in a magnetic field, a circuit completed by deflection of the ray when the position of said apparatus relative to the field is changed, and means controlled over said circuit for restoring said apparatus to its initial position.

7. An instrument comprising means for generating a cathode ray, a reference member, a member angularly movable with respect to said reference member, and means responsive to deflection of said ray when subjected tothe earths eld for positioning said second member to indicate the inclination of the earths field with respect to said reference member. Y

8. An Iinstrument comprising means for generating a cathode ray, a movable member, means for positioning said member at different angles to the surface of the earth, and means responsive to deflection of said ray when influenced by the earths field for controlling said positioning means.

9. A climb and dive indicator for aircraft, for use on courses which are not substantially normal to the lines of force of the earths field, said indicator comprising indicating means, means for producing a cathode ray, means for operating said indicating means, and means including a circuit completed by deflection of the cathode ray by the earths field for controlling said operating means.

10. A compass for indicating direction toward `or away from the surface of the earth, said compass comprising a movable member, means for moving said member to maintain it at a known angle to the earths surface, means for producing a cathode ray, and means controlled by said cathode ray due to a change in its position in the earths field for controlling said moving means.

11. A compound compass for indicating direction in two different planes, said compass comprising a cathode ray tube, means for positioning said tube in both said planes, and means responsive to deection of the ray by the earths field for controlling said positioning means to restore the ray to underlected position.

12. An instrument comprising a cathode ray tube, means for moving said tube in two different planes, and means responsive to deflection of the ray by an external eld for controlling said moving means.

13. In combination, a support, a cathode ray tube rotatably mounted on said support, rotatingk means for said tube, and means for operating said rotating means-responsive to deflection offsaid ray by a magnetic field.

14. In a compass, a main supporting member, a cathode ray tube mounted thereon, mechanism for moving said tube relative to said member, and means controlled by deflection of the ray when the compass is moved relative to the earths iield for operating said mechanism to restore the ray to undeected position.

15. -In combination, a cathode ray tube, a circuit completed by deflection of the ray by a. field of force when the tube is moved in a direction such that the ray cuts said field, and means controlled over said circuit for producing further movement of said tube.

16. An instrument comprising means for generating a cathode ray, a horizontal member, a member movable about a horizontal axis, means foi` supporting said axis adjacent said horizontal member with the second member at a variable angle thereto depending on its position on said axis, and means responsive to deflection of said ray by the earths magnetic field for moving said 'second member on said axis to indicate the inclination of the earths field with respect to said horizontal member.

17. An instrument comprising means for generating a cathode ray, a member angularly movable relative to the surface of the earth, and meansrgntrolled by deflection of said ray by the earths field for positioning said member by angular movement thereof to indicate the inclination of the earths eld where 'the instrument is located.

t" 18. In combination, apparatus for producing a and means controlled over said circuit for restori ing the relation between the tube and field so that the latter is not cut by the ray.

HAROLD J. MCCREARY.