US2085316A - Mercury switch - Google Patents

Description

June 29, 1937. K. HUNCIKER MERCURY SWITCH Filed April 12, 19:53

FIB!

INVENTOR KARL HUNGIKER BY 4 Fig.5

Patented June 29, 1937 UNITED STATES PATENT- orr cs MERCURY SWITCH Karl Hunciker, Chicago, 111., assignor to In E.

McCabe, Chicago, Ill.

Application April 12, 1933, Serial No. 665,628

Claims.

This invention relates to improvements in mercury switches and more particularly to that type of mercury switch in which the tube and contained mercury remains stationary and move- 5 ment is imparted to elements also contained within the tube to make and break the circuit therein.

The mercury tube switch comprising a sealed tube or envelope, usually of glass, containing a movable body of mercury and an inert gas having spaced apart electrodes sealed in the walls and entering the interior so that upon tilting the mercury is' caused to flow from end to end to close and open the circuit between the electrodes is a commercial product well known in the switch art.

It is an object of this invention to produce a but a small amount of mercury and in which the tube and mercury remain stationary while one or more of the electrodes are caused to move into and out of contact with the mercury to make 'and break' the circuit therein, thereby not only making a saving in the cost of the mercury employed but also obviating the internal stresses g5 and strains upon the tube heretofore caused by the mercury hammer in the tilting tube type.

It is also an object of this invention to actuate one or more of the electrodes by magnetic force, thereby obviating the necessity of a mechanical 3o snap movement heretofore used in the rapid tilting of the tube to throw the mercury from one position to another, and allow mercury tube switches to be employed under conditions where snap action switches would be impracticable.

With these and other objects in view reference is made to the accompanying sheet of drawings which illustrates preferred embodiments of this invention with the understanding that minor detail changes may be made therein with out departing from the scope thereof. In the drawing- Figure 1 is a vertical central sectional view, with parts shown in front elevation, of one form of this invention. 4.5 Figure 2 is a view partly in side elevation and partly in central vertical section of Figure 1.

Figure 3 is a view similar to Figure 1 of a modification. A

Figure 4 is a view similar to Figure 2 of Figure 3. Figure 5 is a view similar to Figure 1 of another modification.

Figure B is a view similar to Figure 1 of a further modification.

Figure '7 is a view similar to Figure 1' of a 55 still further modification.

switch of this general character which requires envelope or tube l,closed at the lower end pref-. .10

erably to form a' depending'pocket or cup 2 adapted to receive and retain a small body of mercury or other vfluid electrical conductor 8. The upper end is preferably closed by a pinch seal which embraces and sealsin the body thereof 15 one or o e leadin r n wires 4 and a filling stein c 5 through which the gas is substituted for the contained air, mercury inserted and the start: then tipped off. The leading-in wires are of such character as to seal readily in the body'cf the envelope 4 20 wires. 1 r

In Figures 1 and 2. one electrode 8 is inn form of a rigid wire which extends from its leading-in wire to engage the mercur g "11:

cup 2 and is terminated below the surface thereof. The other electrode 1 is preferably flattened, as shown in Figure 2, and corrugated or fluted: adjacent its leading-in wire as at I to'increase its flexibility and resiliency and then extended .1

over the mercury I and terminated in a bent; 35 down end 8 normally out of contact 'with the 1 mercury I, so formed that the-bend is normally; spaced a lesser distance from the tube 1 than v ,,:-'j Y the distance of the extremity 8 from the mercury 3. That part of theelectrode between the corru- 40 gation 8 and extension which passes over the mercury 3 supports a preferably semi-cylindrical f section or member ll of .magnetic meta l, spacedapart from the wall of the tube! andadapted to respond as an armature when affectedby the 45""- field of a magnet, such as the fixed magnet ll shown inFigurel, so that when e magnet is brought sumciently close to the tube l the armature is caused to move toward it flexing the portion 8 or the electrode 1 until the armature ll contacts the wall'ofthe tube and such movement causes the end 9 of the electrode ,1 to contact and enter the mercury Lthereby closing the circuit through the switch. when the magnet is moved away tube 1, the pullonthe armature III is released and the electrode I straightens out to remove the end 9 from the mercury and thereby break the circuit.

While a fixed magnet is shown by way of example, an electro-magnet may be employed which may be stationary, if desired, with means to energize it when it is desired to close the circuit. When it is desired to use a fixed magnet, such as II, any desired means may be employed to reciprocate it toward and away from the tube I.

In the form shown in. Figures 3 and 4, one electrode Ia is corrugated or fluted to provide resilient flexibility, and supports a magnetic member ID, in the same manner as shown in Figures 1 and 2, however, the portion extending over the mercury passes through an insulating material yoke I2 before terminating in the bent down end 9 normally out of contact with the mercury 3. The other electrode I3 is also preferably flattened and corrugated or fluted at 811 adjacent its leading-in wire to provide resilient flexibility then terminates in a round portion passing through the yoke I2 spaced apart from the other electrode and ends in a portion I4 parallel to the end 9 of the other and also normally out of contact with the mercury 3.

In this form when the armature is actuated by a magnet to move in the direction of the adjacent wall of the tube I both ends 9 and I4 are, by means of the yoke I2, brought into contact with the mercury 3 to close the circuit therethrough and when the magnetic force is removed the armature I0 is released and the corrugated or fluted portions 8 and 8a straighten out, removing the ends 9 and I4 from the mercury to break the circuit.

In the form shown in Figure 5, one leading-in .wire 4 passes through the pinch seal and another 4a is sealed in the wall of the pocket 2 to which is welded or otherwise secured a short electrode I5 which is always submerged in the mercury 3, the other electrode 11) is Welded or otherwise socured to the leading-in wire 4, is corrugated or fluted, as at 8, adjacent thereto to provide resilient flexibility and supports a magnetic memb r III in the same manner as shown in Figure 1. In this form the electrode Ib terminates in an end I 3 which normally contacts'the mercury 3 and enters below the surface thereof, thereby completing the circuit through the switch.

When a magnetic force is applied to draw the armature I0 toward the adjacent wall of the tube I, the end I8 of the electrode 1b is withdrawn. out of contact with the mercury to break the circuit, as shown in Figure 5.

In the form illustrated in Figure 6, the electrode 1b is constructed in the manner shown in Figure 5 with the end I6 normally in contact with the mercury 3 and the electrode I3 constructed in the manner shown in Figure 3 with the end I4 normally out of contact with the mercury 3, the two ends I4 and I6 passing through the yoke I2 holding them in spaced relation and when the armature I0 is drawn toward the adjacent, wall of the tube I, the end I6 is moved out of contact with the mercury 3 and .through the yoke I2 the end I I is moved into contact with the said mercury. Since the electrode I5 01 the leading-in wire 4a is always in contact with the mercury 3, a circuit is always closed through the switch from the electrode I5 through either electrode lb or electrode I3, depending upon the actuation of the armature III.

Figure '7 illustrates a modification in which the electrodes 1c and I3a are both flattened to produce resilient flexibility and the electrode 10 is preferably provided with one corrugation or fluted portion 8b to add to its flexibility, otherwise, they are both of the same construction as shown in Figures 3 and 4 with the ends passing through the yoke I2 and both normally out of contact with the mercury 3. In this form the leading-in wire la is sealed in the walls of the pocket 2 and supports the electrode I5 always submerged in the mercury 3, so that when the circuit is closed the current flowing from electrode I5 divides and passes through the electrodes I0 and I 3a.

Figure 8 illustrates another form of this general type of switch illustrating the application of this principle to two actuating means. In this instance, the electrode Ib is constructed in the same manner as shown in Figure 5 and the electrode I3b is corrugated or provided with a fluted portion 8a to provide resilient flexibility and therebelow supports a magnetic member Illa similar to the member III, and the end I! is bent to normally terminate above and out of contact with the mercury 3, as shown in full lines. Under normal conditions, that is when the switch is removed from the influence of an electromagnetic field, and the armature IOa attracted by the magnet II, the electrode ID will through its end I6 contact the mercury 3, while the end I I of the other electrode I 30. will be out of contact with the mercury so that the circuit is broken within the tube I.

This switch is of particular use where one magnet II will normally operate to open and close the circuit through the switch and another magnet IIa, such as an electro-magnet, may be employed, when energized to openthe circuit when closed by the magnet II by withdrawing the end I6 out of the mercury. An example of such use may be found in a control system for an electrically operated and controlled fluid fuel burner mechanism when the magnet II may be reciprocated to close and open the burner motor circuit, or a control circuit thereof, by a room thermostat and the other magnet IIa being an electro-magnet, as shown, may be connected in a circuit containing a commercial boiler control responsive to interior conditions of the boiler which circuit is normally open in the boiler control but which is caused to close upon excessive temperature or pressure within the boiler. The energization of the magnet I I a will draw the armature I0 towards the adjacent wall or the tube I and withdraw the end I6 01' the electrode ID from the mercury 3 and maintain it out of contact irrespective of the position of the magnet II until the conditions within the boiler become normal and the circuit again opened within the boiler control.

In the form illustrated in Figure 9, one electrode 6 is similar to the one shown in Figure 1, and terminates below the surface of the mercury 3 while the other is so formed to support the armature I 0 independently 'of the resilient flexible portion. In order to accomplish this, the electrode Id is provided with an offset 10 between its leading-in wire 4 and the flattened and corrugated or fluted portion 8 formed to normally maintain its end I8 out of contact with the mercury 3. The upper portion of the armature I0 is provided with ears Illa pivotally mounted upon a vertical support I9 depending from the offset 10 and the lower portion with a forked extension Illb, as shown, adapted to embrace the end I8 of the electrode and normally hold the armature I0 against the end 20 of the support I9, whereby the weight of the armature acts as a stabilizer in the event of vibration of the switch mounting.

,There have been many types of magnetic tubes used such as disclosed by the Hatfield Patent No. 1,094,440 and the Hewitt Patent No. 1,110,548 wherein the armature is used to bridge two pools of mercury or as disclosed in the Keyes Patent No. 1,461,038 and the Phelan et al. Patent No. 1,558,277, wherein the armature is pivoted and swung.

These latter types ofler difliculties in that the current must be carried between the bearings and arcing occurs causing unsatisfactory and unreliable performance since the surface which must act as a pivot may become pitted, welded or otherwise deformed or defaced as to make unsatisfactory contact or an unsatisfactory bearing.

This invention overcomes the weakness and difficulties of the prior art and will perform the requirements of such a switch satisfactorily.

It is also possible with this type of construction, as evident in Figure 1, to insure the opening of the circuit through the switch upon failure of the magnetic field or failure of the magnet operating mechanism, and further the flexible armature carrying electrode may be made resilient enough to prevent its movement by gravity, to make or break contact with the mercury, should the switch be tilted out of vertical position when not under the influence of the magnetic field. As the body of mercury is small and well contained in the'cup and with its natural tendency to adhere to the glass it requires considerable rotation of the switch to shift the position of the mercury so that, except in extreme cases, rotation from the vertical will not effect a make or break in the switch.

When the switch is mounted as to be sub- 40 jected to shocks or vibrations the construction must be such that the movable electrode is not caused to flutter in and out of contact with the mercury pool and cause a succession of make and breaks.

Figure 1 illustrates one method to prevent such operation. In this instance, the movable electrode is formed-at its extremity which contacts the mercury-so thatit rests against the inner wall of the tube when the switch cir- 50 cult is open or else is so positioned that the distance from the electrode to the glass is less than that from the electrode to the mercury so thatthe amplitude of movement is confined to that of the shorter distance.

Figure 9 illustrates another method by supporting the armature independently of the flexible electrode and causing the movement of {the armature to flex the electrode, the armature is provided with a forked extension through which the movable electrode passes, and the weight of the armature acts as a stabilizer to prevent vibrations of the electrode during those periods in which the circuit is desired open. When constructed in the manner shown, 0.; the armature is not used as .a conductor and the possibility of arcing or unsatisfactory bearing is thereby eliminated.

its free end, in combination with means exterior of said container to actuate said flexible electrode to close the circuit through said fluid including a magnet adapted to include said armature within the magnetic field thereof.

2. An electric switch including an elongated cylindrical vertical sealed container, a body of conducting fluid in the bottom thereof, two electrodes sealed in the upper end thereof, one entering the said body of conducting fluid and the other fluted and flexible throughout the upper portion thereof and terminated out of contact with said conducting fluid, a rectangular armature having curved sides parallel to said container wall secured upon said electrode below the fluted portion and above the free end thereof adapted to be flexed by a magnetic fleld exterior of the container to submerge the end of said electrode within said conducting fluid.

3. An electric switch comprising a sealed container, a body of electrical conducting fluid therein, a wire electrode including a flexible portion having one end free and normally out of contact with said fluid,- a second electrode adapted to make contact with said fluid, a rectangular curved armature mounted upon said first electrode intermediate its length and spaced .apart from its free end, in combination with a magnet adapted to include said armature within the magnetic field thereof to flex said first electrode and cause its free end to make contact with said fluid.

4. An electric switch comprising a sealed container, a body of electrical conducting fluid therein, an electrode including a flexible portion having one end free and normally out of contact with said fluid, a second electrode adapted to make contact with said fluid, a pivoted curved armature within the container in engagement with the free end of the first electrode, in combination with a magnet adapted to include said armature within the magnetic field thereof to flex said flrst electrode and ,cause its free end to make contact with said bracing the free end of said electrode to normally hold the armature in contact with the free end of said support to stabilize vibra tion of the free end of said electrode.

KARL HUNCIKER...

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