US1936094A - Electric mercury bulb switch - Google Patents

Description

Nov. 21, 1933. MccABE ELECTRIC MERCURY BULB SWITCH Filed April 26, 1929 Fig.12

INVENTOR IRA E M CABE ya ATTORNEY Patented Nov. 21, 1933 UNITED STATES PATENT OFFICE ELECTRIC MERCURY BULB swrron Ira E. McOabc, Chicago, 111. Application April as, 1929. Serial No. 358,225

4 Claims. (or. 200-152) This invention relates to improvements in electric mercury bulb switches and more particularly to an improved manner in sealing the open end and positioning the leading in wirestherein.

It is an object of this invention to provide an electric switch of the mercury type in which a glass bulb is manipulated by machinery to support the leading in wires in the sealed closed end of the bulb by pressing the glass about the wires in such a manner as to not only allow the connecting leads to be brought back upon themselves to lead out from the bulb adjacent its longitudinal center but also to so form the sealed end of the bulb to form protecting projections between which the connecting portions of the lead connections are received and held.

The particular bulb switch is of the same general type as that described in my prior pending application, Serial No. 329,548, filed December 31, 1928, and possesses all the advantages as set forth in said application and is a continuation of said invention in that the formation of the end seal of the bulb as disclosed herein provides decided advantages in the manner of attaching the connecting leads, aifords protection to such attachment, maintains such attachment, insulates the connections of the respective leading in wires to the connecting leads, and directs the departing portions of the connecting leads toward the middle of the bulb, whereby when the bulb is mounted in a tiltable support the connecting leads, departing from adjacent the pivot point of the bulb do not impede its movement.

With these and other objects in view, reference is made to the accompanying sheet of drawing which illustrates preferred forms of this invention with the understanding that minor detail changes may be made without departing from the scope thereof.

In the drawing:

Figure 1 is a longitudinal horizontal sectional view, taken on the line 11, Figure 2, of one embodiment of this invention.

Figure 2 is a view in elevation of the sealed. end of the bulb switch.

Figure 3 is a view in side elevation of the same.

Figure 4 is a view similar to Figure 2 illustrating the connecting leads secured in place.

Figure 5 is a view in side elevation of Figure 4.

Figure 6 is a view in side elevation of a modified form of bulb switch.

Figure 7 is a top plan view of Figure 6 with the connecting leads secured in place, and parts or the-bu1b brokenaway.

Figure 8 is a view in end elevation of Figure 7.

Figure 9 is a view in end elevation of another modification.

Figure 10 is a view in side elevation of Figure'9.

Figure 11 is a view in end elevation of a fur- 8o leading in wires 2 and 3 and a filling stem 4,

heated and the heated walls pressed together to seal the leading in wires and stem, as described in said prior application Serial No. 329,548.

In this instance the leading in wires are arranged in pairs. The two wires forming the upper pair 2 are parallel to each other, enter the solid pressed end of the bulb above and in parallel relation to the longitudinal center line of the bulb and then a short distance from the sealed end are bent toward each other and downward to enter within a cup 5 of insulation material. The lower pair of leading in wires 3 are formed in one piece bent back upon itself in a loop within the bulb, the ends are parallel to each other,

enter the solid pressed end of the bulb below and 30 in parallel relation to the longitudinal center line of the bulb, and a short distance from the sealed end are bent downward and toward each other to engage and support the cut 5 so that its open top slopes downward toward the lower opposite end of the bulb and then the wires are extended parallel to the bottom of the bulb and out of engagement therewith to a point beyond its longitudinal vertical center, in the manner described in my prior application Serial Nos. 237,632 which became Patent No. 1,757,436 May' 6, 1930 and 290,287, filed July 4, 1928.

When describing the above leading in wires 2 and 3, it is with the understanding that this term applies to the usual construction of both leading in wires and electrodes welded thereto, as is customary, and as described in my prior Patent No. 1,705,989, dated March 19, 1929.

The particular feature of this invention resides in the formation of the closed or sealed end of stated in forming the construction .01 the completed bulb switch, the open end of the bulb is heated until it becomes plastic and then is I clamped about the leading in wires and filling stem. In this instance the plastic walls of the open end of the bulb are brought together by clamping in the form 01' a cross, as shown in Figure 2 oi the drawing, whereby the equidistant and oppositely disposed right angular depressions 8 form walls to embrace and seal the filling stem and each of'the respective lead wires so that the filling'stem and lead wires are each sealed within the closed end or the bulb in the same manner as described in my prior application, Serial No. 329,548, except that the filling stem is enclosed in the center or main portion of the closed end, and each leading in wire is enclosedand supported in a radial portion '7, as shown. As illustrated in Figure 3, each leading in wire of the pairs 2 and 3 extend slightly beyond the outside of the closed end portion, and the filling stem 4 is tipped ofl a slight distance beyond the exterior terminations of the lead in wires. The connecting leads are preferably formed of tubular wires braided together as described in Patent No. 1,640,- 869, dated August 30, 1927, and each connecting lead is connected or joined to each exterior end or each leading in wire in the manner described in said patent. After the connecting leads are secured in place, each one is bent back upon itself over the radial portion 7 of the sealed end embracing its respective leading in wire. The body of said connecting lead being received within the right angular depression 6 adjacent said radial portion, as clearly shown in Figure 5. A sleeve of any desired material is then placed over the sealed end to snugly engage the outer terminations of the radial portions, and is aflixed thereto either by the tension oi. the sleeve or by cementitious material whereby the connecting leads are held in place as shown in Figures 4 and 5.

Figures 6, '1 and 8 illustrate a three wire mercury bulb switch wherein a pair of lead wires 2' enter the closed end and are sealed therein similarly to the leading in wires 2, illustrated in Figure 1. In this case a single lead wire 3' enters below and in a plane passing through the vertical longitudinal center line of the bulb 1, which leading in wire is bent upward as it leaves the interior oi the seal and then downwardly in the direction of the opposite lower end of the bulb. In this particular form the leading in wire is curved to engage and position the cup of insulating material upon one side thereof to support the open end of said cup sloping in the direction of the opposite lower end of the bulb 1. The leading in wire is then continued parallel to the bottom of the bulb until adjacent the closed end, and is then bent upward and around the exterior of a second cup 5' oi insulating material to engage and support this second cup with its open end sloping in the direction of the bottom of the opposite sealed end of the bulb, and the wire is then continued parallel to the bottom of the bulb to engage and pass about the first cup 5 until it meets the other portion thereof, and is attached thereto. In this type the plastic open end of the bulb 1 is pressed about the filling stem 4 to form radial portions 7' embracing and sealing the three leading in wires as shown in Figure 8. One of the upper leading in wires 2' is bent downwardly at right angles to enter the interior of the cup 5 and the other of this pair is extended'and then bent downwardly to enter the other cup 5'. In this form the lead connections 8 are connected or joined to the exterior portions of the leading in wires in the same mannerasinthefirstiormandeachotthese lead connections are bent back upon itself and is received within the depression between the radial portions and a securing sleeve 8 is placed about the radial portions of the sealed end in the same manner as described'in connection with the firstiorm,andasshowninFigures7and8.

Figures 9 and 10 illustrate the application of this invention to another type of bulb switch in which four leading inwires 9, 10, 11 and 12 are provided which enter the sealed end in parallel relation to the longitudinal center line thereof but which areal-ranged in planes at right angles 'to each other as shown in Figure 9. In this form the lowermost leading in wire 11 extends within the bulb to approximately its middle portion. The uppermost leading in wire 9 extends within the bulb to a point adjacent the closed end, and then is bent downwardly at right angles to a point adjacent its bottom wall. The two leading in wires 10 and 12 arranged in the plane at right angles to the plane of the wires just described, each extend within the bulb and are then bent downwardly at right angles to a point adjacent the bottom wall and in such relation that an equal space separates the terminations between each of the four leading in wires, as shown in Figure 10.

Figures 11 and 12 illustrate another type of mercury bulb switch constructed somewhat similarly to that illustrated in Figures 9 and 10 with the exception that the lowermost lead 11 is terminated in an enlarged electrode 13 adjacent the sealed end, and the two leading in wires 10 and 12 arranged in the plane at right angles to the plane or the upper and lower leading in wires are both bent downwardly at approximately the same distance from the sealed end, and the upper leading in wire 9 is bent downwardly and provided with an enlarged electrode 13 at approximately the middle portion of the interior of the bulb, so that the terminations of the pair of leading in wires 10 and 12 arranged in the plane at right angles to the plane of the upper and lower leading in wires are approximately equidistant from the enlarged electrodes 01' said upper and lower leading in wires as shown in Figure 12. In this type of switch, as shown in Figures 9, 10, 11 and 12, the connecting leads are secured in the same manner as heretofore described to the exterior portions of the said leading in wires, and are bent back upon themselves and enclosed in a surrounding sleeve in the same manner as shown in Figures 5 and 7.

In as much as mercury switches of this general type are well known in this art and the operation of the same as applied to the first eight figures of the drawing have been described in my prior co-pending applications, a further description is not deemed necessary. It is readily seen that in Figure 10 when the bulb is tilted in the manner shown in said figure, the body of mercury flows toward the sealed end and covers the lowermost electrode, or leading in wire 11, while the other three electrodes are uncovered, and therefore the circuit is broken through the switch. As the switch is tilted in the opposite direction, and the mercury flows toward the closed end oi! the bulb, opposite the sealed end, three circuits will be consecutively closed between the lowermost leading in wire as the mercury contacts and embraces the lower extremities of each of the other three leading in wires respectively.

Theadvantagesof my improved construction are many. It permits the use of bulbs for making the mercury switch instead of tubing. It has long been customary to make use of glass tubing for the construction of mercury switches. I refer to my prior Patents Nos. 1,658,013, January 31, 1928; 1,662,122, March 15, 1928; 1,674,601, June 19, 1928; and 1,705,989, March 19, 1929, and Patent 1,757,436, May 6, 1930, in which a tipping oiI of the tube at each end of the switch is the usual practice. The adoption of a bulb has long been desirable. Bulbs are blown in machinery with the aid of molds which permit the maintaining of more accurate and uniform standards, and reduce the amount of material necessary to produce them as compared with the tube type. Furthermore, in the use of the old style tip type tube, it has always been necessary to tubulate the end with a filling stem, with a constriction whereby additional operations became necessary to produce them. In my design the only glass needed is the bulb which comes from a bulb blowing machine ready to be used, and a piece of straight glass tubing which serves as the filling and sealing oif stem. Also where necessary a bead is used on the various electrodes. The entire assembly including electrodes, filling stem and bulb is sealed and blow in one operation. This permits of great economies in manufacture since automatic machinery may be used to produce the device, also the standard of manufacture may be readily maintained due to the design of the various parts. These standards are maintained in 1,757,436, May 6, 1930, a limited number of termer methods and structure. In my Patent 1,757,436 May 6, 1930, a limited number of terminals or leading in wires were provided. In this application the scope of the design has been greatly extended and made practical due to the separation of the various sealing in wires.

What I claim is:

1. An electric bulb switch including a tubular glass bulb containing a quantity of mercury and a plurality of more than two leading in wires entering the interior of the bulb in parallel relation to its longitudinal center line, the open end of the bulb closed to provide a plurality of radial portions in the walls thereof each embracing and sealing a respective leading in wire, connecting leads joined to each respective leading in wire, each lead bent back upon itself to contact the walls between two adjacent radial portions, and a sleeve surrounding the respective bent back connecting leads and engaging the outer extremities of said radial portions of said closed end.

2. An electric bulb switch including a tubular bulb of insulating material containing a quantity of electrical conducting fluid, a plurality of more then two leading in wires and a filling stem entering the interior of the bulb, the leading in wires in parallel relation to its longitudinal center line and the stem on said center line, and the side walls of the bulb about the open end of the bulb brought together and closed about said leading in wires and filling stem to separately embrace and seal each leading in wire in equally spaced relation to each other at the same distance from said stem.

3. An electric bulb switch including a tubular glass bulb containing a quantity of mercury and a plurality of more than two leading in wires entering the interior of the bulb in parallel relation to and equidistant from its longitudinal center line and a filling stem arranged on said center line, the side walls about the open end of the bulb brought together and closed about said leading in wires and stem to provide a plurality of prolonged radial portions each embracing and '100 sealing a respective leading in wire, connecting leads joined to contact the walls and each respective leading in wire, each lead bent back upon itself to be received between two adjacent radial portions, and a sleeve surrounding the respective bent back connecting leads and engaging the outer extremities of said radial portions of said closed end to hold the connecting leads first against the stem and then between said radial portions.

4. An electric bulb switch including a tubular glass bulb containing a quantity of mercury and four leading in wires entering the interior of the bulb in parallel relation to its longitudinal center line with a filling stem entering the interior 1 5 of the bulb upon its longitudinal center line, the walls about the open end of the bulb brought together and closed to embrace and seal the filling stem and to provide four integral radial extending portions each embracing and sealing a respective leading in wire, said filling stem closed and said leading in wires terminated in line with the exterior of the closed filling stem, connecting leads joined to each respective leading in wire and each lead bent back upon itself to engage the wall between two adjacent radial portions, and a sleeve binding the radial portions and holding the respective leads from displacement.

CERTIFICATE or CORRECTION.

Patent No. 1,936,094. November 21, 1933.

IRA E. McCABE.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring'correction as follows: Page 1, line 84, for "cut" read cup; page 3, line 30, for "blow" read blown; and line 36, strike out the number and words "1,757,436, May 6, 1930, a limited number of ter-" and insert instead a manner not possible or practical with the for-; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 6th day of March, A. D. 1934.

F. M. Hopkins (Seal) Acting Commissioner of Patents.

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