Burt v. Bilofsky

120 F. Supp. 822, 101 U.S.P.Q. (BNA) 169, 1954 U.S. Dist. LEXIS 3637
CourtDistrict Court, D. New Jersey
DecidedApril 27, 1954
DocketCiv. No. 6529
StatusPublished
Cited by2 cases

This text of 120 F. Supp. 822 (Burt v. Bilofsky) is published on Counsel Stack Legal Research, covering District Court, D. New Jersey primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Burt v. Bilofsky, 120 F. Supp. 822, 101 U.S.P.Q. (BNA) 169, 1954 U.S. Dist. LEXIS 3637 (D.N.J. 1954).

Opinion

SMITH, District Judge.

This action, which arises under the ^patent laws, was commenced under the Declaratory Judgments Act, 28 U.S.C.A. § 400, now 28 U.S.C.A. § 2201. The plaintiffs, having been previously charged with infringement of the patent in suit, filed a complaint in which they challenged the validity of the patent and denied infringement. The defendants filed a counterclaim in which they charged the plaintiffs with infringement and sought the usual relief. The issues are those common to actions under the patent laws.

The defendant Maxwell M. Bilofsky is the owner of the patent in suit, No. 2,-341,520, which was granted on February 15..1944 on the application of one Maynard A. Babb. The defendant Industrial Electronics Corporation is an exclusive licensee thereunder. The plaintiffs are, and have been, engaged in the manufacture and sale of fluorescent lamp starters. These devices are used in starter circuits, which allegedly infringe the patent in suit. The present action is essentially one for contributory infringement.

The patent in suit relates generally to the starter circuit employed in the operation of fluorescent lamps but covers, particularly, an improvement thereon. The primary object of the invention, according to the specifications of the patent, was to overcome certain disadvantages found in earlier circuits. The purported invention can be more easily appreciated if examined in the light of the art to which it pertains.

State of the Art

The fluorescent lamp now in common use is a gaseous discharge lamp of the hot cathode type. It comprises a cylindrical tube, the inner surface of which is suitably coated, and a filamentary electrode at either end and disposed within the tube. The tube is charged with an ionizable vapor of low conductivity, to wit, mercury vapor to which is added argon, neon or helium. The electrode consists of a coiled tungsten filament, coated with barium oxide, the ends of which are connected to contact pins which extend beyond the sealed ends of the tube. When the lamp is placed in a suitable fixture [824]*824the contact pins are engaged and thus complete both the lamp and starter circuits.

The fluorescent lamp, because of the low conductivity of the vapor, must be started; it will operate on ordinary line voltage only after the vapor is rendered electrically conductive by ionization. The ionization of the vapor is immediately initiated by the emanation of electrons, which occurs when the electrodes are heated to incandescence. The vapor is completely ionized and thus rendered electrically conductive by a discharge of high potential, i. e., a surge of high voltage applied to the two electrodes. The discharge strikes an arc, a flow of electric current, between two electrodes. The flow of current, initiated in the manner described, can be maintained on the ordinary line voltage.

An automatic interrupter disposed in the starter circuit, as distinguished from the lamp circuit, in conjunction with an inductance coil disposed in the lamp circuit, is, and was prior to the patent in suit, utilized as a starter. The interrupter is concededly nothing more than a conventional thermal switch or magnetic switch. The combination operates as follows: When the circuits are energized the interrupter alternately opens and closes, and upon each interruption of the starter circuit the inductance coil releases a high inductive potential, i. e., a surge of high voltage, which is imparted to the electrodes. The voltage is sufficient to strike the arc necessary to the complete ionization of the vapor in the lamp. When the lamp is started the interrupter remains open and the starter circuit is thus locked out.

It was known prior to the patent in suit, and in fact prior to the earlier patent to Gref, infra, that there were certain disadvantages intrinsic in the earlier starters. These disadvantages gave rise to certain problems, which are adequately described in each of the said patents. The inventions of the respective patents had for their object the solution of these problems.

Patent in Suit

Claims 3, 4, 5, 7 and 9 of the patent in suit cover a circuit for “gaseous electric discharge devices commonly embodied in hot cathode gaseous lamps” such as “fluorescent lamps of that type.” The invention is defined in claim 5, which is typical, as follows: “In a safety starting and operating circuit for vapor electric discharge devices equipped with spaced electrodes, means effective to establish a series connection through said electrodes, means to interrupt and maintain interrupted said connection when the arc of the lamp is struck and as long as it is maintained, a normally open by-pass line connected with a difference of potential between its terminals, a temperature responsive switch subjected to the heat evolved in the starting circuit due to starting current and arranged to interrupt said series connection under the excess heat generated in the attempted starting of a defective lamp and to close circuit through said by-pass line, said by-pass line having circuit characteristics such as to pass sufficient current to keep the temperature responsive switch in deflected position.”

The invention as thus defined comprises the following elements: (a) A fluorescent lamp of the type hereinabove described; (b) a conventional thermal interrupter, such as a glow switch, disposed in the starter circuit, in conjunction with an inductance coil disposed in the lamp circuit; (c) a thermal switch of the bimetallic type, in conjunction with a suitable resistance coil, disposed in the starter circuit and in spaced relation to the contact point of a normally open bypass circuit; and (d) a normally open by-pass circuit in conjunction with a resistance coil disposed in the circuit. When closed, the latter circuit functions in the manner hereinafter described. Elements (a), (b) and (c) were in common use and had been employed in starter circuits for fluorescent lamps prior to the patent in suit. Devices strikingly similar to element (d) were in common use and had been employed in other types of circuits.

[825]*825We have heretofore described the normal function and operation of element (b), a conventional thermal interrupter. The essence of the invention is primarily in elements (c) and (d), and we therefore direct our attention to their function and •operation in the circuit of the patent in suit.

Elements (c) and (d) perform no useful function under normal conditions; the combination is generally regarded as a safety device. When the fluorescent lamp fails because of some defect or electrical disturbance the glow switch operates automatically, a disadvantage intrinsic in the earlier starters; it operates continually in the absence of some means to open the starter circuit. The thermal switch, element (c), is such a means. The continual operation of the glow switch quickly generates heat in the resistance coil and this heat is imparted to the bimetallic blade or disk; the blade or disk, which is normally responsive to heat, is deflected and thus the starter circuit is opened. The blade or disk returns to its normal position when cooled in the absence of means to hold it in a deflected position. The bypass circuit, element (d), is such a means. The deflected blade or disk makes contact with the by-pass circuit and is thereafter held in deflected position by the heat imparted by the resistance coil disposed therein. It should be obvious that upon deflection of the blade or disk the starter circuit is opened and the auxiliary circuit is closed.

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Bluebook (online)
120 F. Supp. 822, 101 U.S.P.Q. (BNA) 169, 1954 U.S. Dist. LEXIS 3637, Counsel Stack Legal Research, https://law.counselstack.com/opinion/burt-v-bilofsky-njd-1954.