US2308378A - Marine ignitron - Google Patents

Description

Patented Jan. 12, 1943 MARINE IGNITRO Donald E. Marshall, Allwood, N. J., assignor to- Westnghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application November 27, 1940, Serial No. 367,344

12 Claims.

My invention relates to discharge devices and especially to such devices utilizing a mercury pool cathode.

An object of my invention is to provide a structure for a mercury pool discharge device which can be utilized on board ship and other places where excessive tilting of the device, even up to 45, will be experienced.

Another object of the invention is to locate the ignitor of a mercury pool device so that its relatonship to the surface of the mercury will be constant even though the device is'tilted at an angle of 45.

Other objects and advantages of the invention will be apparent from the following description and drawing in which:

Fig. 1 is a view in cross section of a preferred embodiment of the invention with dotted lines illustrating the device tilted at a 45 angle.

Fig. 2 is a cross-sectional view illustrating a modification of the structure of Fig. 1. While my invention may be applied to other types of discharge devices utilizing mercury pools, it is especially adapted for the mercury pool type of device known as an ignitron and employing an igniting electrode of high resistance material partially immersed in the mercury pool cathode. One of the problems that has been preventing the application of such devices to utilization on board ship and othersituations subject to movement is that as the ship rolls, the mercury surface will take various angles and emergent depths relative to the ignitor. The ignitor may be completely removed from the mercury. The result will be that even if the control of the discharge is not completely eliminated, at least the characteristics of the igniting circuit due to the varying contact of the ignitor with the mercury will bevaried so as to upset the control circuit.

It is accordingly one of the objectsof my invention to maintain the relationshipbetweenthe ignitor and the mercury pool cathode surface constant so that there will be no variation in the control of the discharge. l

i In Fig. 1 I have disclosed a preferredembodiment of my invention in which an envelope, I preferably of steel has a mercury pool cathode Il in the bottom portion thereof.- The anode I2 preferably of carbon is diagrammatically illustrated in the upper portion of the casing, and this anode may have its connection thereto insulatingly sealed through the casing I0 in any desired manner. The length of the casing is such that the mercury pool will not touch the anode when tilted at a 45 angle.

I preferably insert a header I3 to fornil the bottom of this casing I ll and. welded thereto. `This upward from the bottornplane I5 of the header.

,This projection I4 is preferably of conical shape,

and specifically may have the fru'sto-conical shape illustrated, with the vtop flat portion I6 having a large central hole I'I therein. A conductor I8 for the ignitor circuit passes through this open.- ing I 'i and has a rod `IS sealed through a glob of glass 26. The rodi I9 is prr'eferablyv of ironnickel-cobalt alloy sold under the trade-name of Koi/ar, and the glass 20 is preferably borosilicate glass. I

'An eyelet 2| of .the same material as the rod has its circularV edge sealed into the glob 0f glass and surrounds a portion of the rod I9. This eyelet 2| is preferably welded to the top of asteel eyelet 22 welded in turn tothe top surface of the top `portion I6 of the frusto-conical extension I4. If desired, the eyelet 2I could have been enlarged to be directly welded to the truste-conical extension I4. The rod I9, after passing through the glass 20 sealing the opening through theeyelets', is connected to a flexible cable 23 preferably of twisted steel Wires. This flexible cable 23 is connected in turn to amake-alive 24 of high resistance material such as boron or silicon carbide having its tapered tip 25 immersed at 26iin' the mercury pool cathode Il.

One of the problems which my invention solves is to maintain constant the depth of `immersion of this ignitingelectrode inthe mercury pool in spite of the tilting of the device through an angle of 45. In order to ido this, I surround the Lsteel eyelet 22 with an arbor 2J having a lower portion welded or otherwise secured tothis steel eyelet. The central portion of this arbor 2l is in the shape 0f a sphere 28 \vith its horizontal diameter 29 atthe surface of the mercury pool. Surrounding this sphere 29 is a ring-shapedloat- 30 having a plate 3l extendingV towards the sphere of thearbor. This yplate 3l has a central opening 32 just large enough to be confined by the sphere 28, but permitting Auniversal lmovement; therearound with thetilting of the device. A flange 28 on the upper part of the arbor 2l prevents any mercury from splashing inside the arbor. The arbor 21 and thev eyelet 22 could obviously be integral instead of separate pieces, if desired.

This oat preferably has its plate 3l depressed as indicated at 33, and this platehas openings 34 therethrough for the owing of mercury to the restricted surface inside the ring. On top of the ring is secured an eyelet 35 of iron-nickelcobalt alloy known under the trade name of Kovar, and a globule of glass 36 is sealed thereto. Within this globule of glass is sealed a rod 31 likewise of this iron-nickel-cobalt alloy, and to this rod is attached a clamp 38 that is secured to the connection 39 between the flexible conductor 23 and the high resistance make-alive 24. The tip of the ignitor 24 is preferably located in one of the openings 34 of the dampening ring.

It will be noted that as the discharge device is tipped sideways through an angle of 45 because of the roll of the ship, the mercury on the righthand side of the device will ow around the conical extension from the bottom and flow into the left-hand side, as illustrated by the dotted lines. The level of the mercury will be the same., however, in relationship to the dampening ring. The point of immersion 26 of the igniting device will remain as it is. The arbor 21 will tilt, but this is permitted by the opening I9 in the ring. The main effect within the device will merely be a flexing of the flexible conductor 23. The makealive 24 will continue to control the discharge through the device with exactly the same characteristics as in the upright position of the device because the relationship of the make-alive with the mercury pool has been changed in no way from the preceding position.

In Fig. 2 I have disclosed a still further modification of the device that has preferably the same steel casing I0, mercury pool II, and anode I2. The bottom header I3' has the same conical, and preferably frusto-conical, extension into the mercury. The tapered sides I4 can start their taper directly from the outer wall in this modification because the make-alive 24 will be maintained at the exact center of the mercury pool. The flexible conductor I8 is connected, as in the preceding modification, to a rod I9 preferably of the ironnickel-cobalt alloy sold under the trade name of Kovan A large globule of borosilicate glass 40 is sealed to this conductor and an eyelet 4I of this nickel-iron-cobalt alloy has its circular edge sealed into this glass and its other end welded at 42 to the underside of the upper plate I6 of the frusto-conical extension I4. This upper plate I6 has a central hole I'I through which the conductor I9 extends. The conductor I9, after passing through the opening II, is bent slightly to one side and has an extension 43 to some height above the mercury pool. This extension 43 of the rod I9 is also preferably well-covered with an insulating coating such as a continuation 44 of the borosilicate glass from the globule 40 to near the end of the extension 43.

To the other end of the rod connection 43 is an arm 45 extending towards the axial center of the device. At the axial center this arm 45 is connected to a rod 46 extending downward and having at its end the make-alive 24, positioned to be immersed at the position 26 thereon for proper depth of immersion in the mercury pool at the axial center of the pool.

In dotted lines is illustrated the position of the device when tilted through a 45 angle. The make-alive 24 and its connections will tilt with the tube. However, since the point 26 is at the axial center of the tube, the average immersion of the lower tip of the make-alive will remain the same. In other words, the slightly more conacted by a slight withdrawal of the mercury from tact of the mercury on one side will be counterthe other side of the make-alive. There will, however, be no large diierence in immersion of the make-alive from its original upright position as there would be if the make-alive were located at a point other than the axial center of the device.

Both constructions shown embody the feature of the bottom portion of envelope III, having the conical formation such that the mercury pool I I is comparatively shallow at its central portion and progressively deepens away from the central portion. Furthermore, with the envelope in its normal upright position there is a point in the surface plane of the mercury on the axis or extended axis of the conical formation which remains in the surface plane of the pool on tilting the envelope to an angle up to 45 from normal. A further advantageous result from provision of the conical formation is that its presence as part of the lower header provides a large saving in mercury which would otherwise be necessary.

Itis apparent that many further modifications may be made in my preferred embodiments, and accordingly I desire only such limitations to be imposed on my invention as are necessitated by the spirit and scope of the following claims.

I claim:

1. A discharge device comprising an envelope having a mercury pool cathode resting on the bottom portion thereof, the bottom portion of said envelope having a projection producing a comparatively shallow central portion of said pool and a deepening of the pool away from said central portion, a connection passing through said central portion, a make-alive electrode connected thereto, means on said projection sealed to and passing said connection through and free from electrical contact with said projection, means maintaining said make-alive electrode partly immersed in the pool in fixed relationship to the normal central portion of the pool, and an anode cooperating with said mercury pool.

2. A discharge device comprising an envelope having a metal bottom portion, a mercury pool therein, said metal bottom having a metal projection providing a comparatively shallow central portion with gradual deepening of the pool away from said central portion, said mercury pool having in its surface plane a central point in normal upright position of the envelope, which point remains substantially in the surface plane of the pool and centrally of the envelope on tilting the envelope to an angle up to 45 from normal, a conductor vextending through the projection, insulation insulating said conductor from said metal projection, casing and pool, a makealive connected to said connection and partially immersed in said pool and maintained with substantial constancy of immersion and relation to said point.

3. A discharge device comprising an envelope having a metal bottom portion, a mercury pool therein, said metal bottom having a projection providing a comparatively shallow central portion with gradual deepening of the pool away from said central portion, said mercury pool having in its surface plane a central point in normal upright position of the envelope, which point remains substantially in the surface plane of the pool and centrally of the envelope on tilting the envelope to an angle up to 45 from normal, a conductor extending through the projection, insulation insulating said conductor from said metal casing and pool, a make-alive connected to said connection and partially immersed in said pool at a position oifset from the most shallow central portion of the mercury pool and maintained with substantial constancy of immersion and relation to said central point.

4. A metal tank discharge device having a conical upward metal projection in the bottom portion thereof, a mercury pool on said conical projection in electrical contact therewith, a make-alive electrode partially immersed in said pool and having a connection passing through and out of contact with said conical projection, and means maintaining said make-alive in xed position with respect to the top of said conical projection.

5. A metal tank discharge device having an upward projection in the bottom portion thereof, a sleeve on the upper portion of said projection, a connection extending through said projection and sleeve, a make-alive attached to said connection, a mercury pool in the bottom portion of said tank reaching said sleeve, a iioat having a universal joint connection with said sleeve, said make-alive supported by said float.

6. A metal tank discharge device having an upward conical projection in the bottom portion thereof, a sleeve on the upper portion of said projection, a connection extending through said projection and sleeve, a make-alive attached to said connection, a mercury pool in the bottom portion of said tank reaching said sleeve, a float having a universal joint connection with said sleeve, said make-alive supported by said iloat.

7. A metal tank discharge device having an upward projecting construction from the bottom portion thereof, a spherical portion on the upper portion of said construction, a mercury pool having its surface in contact with said spherical portion, a float on said mercury making'a universal joint with said spherical. portion, and a makealive secured to said iloat.

8. A metal tank discharge device having an upward projecting construction from the bottom portion thereof, a spherical portion on the upper portion of said construction, a mercury pool having its surface in contact with said spherical portion, a iloat on said mercury making a universal joint with said spherical portion, a make-alive secured to said float, and a connection from said make-alive extending through said upward projecting construction.

9. A metal tank discharge device subject to tilting and comprising a bottom portion having an upwardly diminishing truncated conical metal projection of which the axis is normally vertically disposed and of which the conical surface is substantially at an angie of 45 to the said axis, a sleeve surrounding an opening in the top portion of said projection, insulation sealed to said sleeve, a conductor sealed through said insulation, a mercury pool about said projection completely immersing the said projection up to 45? angle tilting of said tank, and a make-alive for said pool attached to said conductor.

10. A metal tank discharge device comprising a bottom portion having an upward truncated conical projection, a sleeve surrounding an opening in the top portion of said projection, insulation sealed to said sleeve, a conductive rod projecting above the mercury out of contact therewith and sealed through said insulation, a mercury pool about said projection, a float on said mercury, a make-alive attached to said oat, and a ilexible connection from said make-alive to said rod.

11. A metal tank discharge device comprising a bottom portion having an upward truncated conical projection, a sleeve surrounding an opening in the top portion of said projection, insulation sealed to said sleeve, a conductive rod sealed through said insulation, a mercury pool about said projection, a float on said mercury, a makealive attached to said float, and a flexible connection from said make-alive to said rod, a universal joint between said sleeve and said oat.

12. A discharge device comprising an envelope having a metal bottom portion, a mercury pool therein, said metal bottom having a projection providing a comparatively shallow central portion with gradua1 deepening of the pool away from said central portion, said mercury pool having in its surface plane a central point in normal upright position of the envelope which remains substantially in the surface plane of the pool and centrally of the envelope on tilting the envelope to an angle up to 45 from normal, a conductor extending through the projection, insulation insulating said conductor from said metal casing and pool, a make-alive connected to said connection and partially immersed in said pool at a position substantially coinciding with said central point in the surface plane of the mercury pool, whereby substantially constant immersion is maintained with varying angular positions up to 45 of said envelope.

DONALD E. MARSHALL.

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