Sundh Electric Co. v. General Electric Co.

198 F. 116, 1912 U.S. Dist. LEXIS 1279
CourtDistrict Court, N.D. New York
DecidedJuly 29, 1912
StatusPublished
Cited by4 cases

This text of 198 F. 116 (Sundh Electric Co. v. General Electric Co.) is published on Counsel Stack Legal Research, covering District Court, N.D. New York primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Sundh Electric Co. v. General Electric Co., 198 F. 116, 1912 U.S. Dist. LEXIS 1279 (N.D.N.Y. 1912).

Opinion

RAY, District Judge.

These patents to Lindquist are marked as the Senior patent and the Junior patent, and will be referred to as such or under that name. The complainant is the owner of both patents. The manufacture and sale by defendant of the alleged infringing device is admitted.

[ 1 ] The defendant denies infringement, and alleges that the patents are invalid in view of the prior art, and for the added reason that Lindquist was not the original inventor, if any invention is shown. The main question is that of infringement, as I am satisfied that the patents are valid and that Lindquist was the original inventor.

The claims in issue of the Senior patent read as follows:

‘•1. An electromagnet Raving a plurality of coils symmetrically disposed around a central axis, the individual axis of each of said coils being parallel to said central axis, and means for producing currents of different phase in said coils.
“2. An electromagnet having a cylindrical core and a plurality of symmetrically disposed coils thereon, the said coils having their individual axes parallel to the axis of said core, and means for producing currents of different phase in said coils.
“3. An electromagnet having a cylindrical core, with symmetrically disposed pole-pieces at one end thereof, coils on said pole-pieces and means for producing currents of different phase in said coils.
“4. An electromagnet having a cylindrical laminated core with integral symmetrically disposed pole-pieces at one end thereof, coils on said pole-pieces and means Cor producing currents of different phase in said coils.”

The claims in issue of the Junior patent read as follows:

“1. An electromagnet having a polygonal core and a plurality of symmetrically disposed coils thereon, the said coils having their individual axes parallel to the axis of said core and means for producing currents of different phase in said coils.
“2. An electromagnet haring a polygonal core with symmetrically disposed pole-pieces at one end thereof, coils on said pole-pieces and means for producing currents of different phase in said coils.
“3. An electromagnet having a polygonal laminated core with integral symmetrically disposed pole-pieces at one end thereof, coils on said pole-pieces and means for producing currents of different phase in said coils.”

It may be said here that the second Lindquist patent is an improvement. on the first and simplifies and lessens the cost of construction.

There seems to be three essentials in this electromagnet, viz., the coil, the core, and the armature. To the coil the energizing current is supplied; the core, an iron body, becomes magnetic when the current passes and the armature is attracted. It is established that traction electromagnets energized by a direct current have been known and in use for many years, and as the direct current flows in one direction, and constantly and with substantial uniformity, there has been a constant, direct, and unvarying magnetic pull and holding of the arma[118]*118ture. It is a matter of common.'knowledge that an alternating current, which flows alternately in opposite directions, would not and could not operate in this way, as with an alternating current the armature is attracted and then released in rapidl succession, and the result is a constant hammering and chattering — a destruction of parts and unendurable noise. It was therefore a problem to devise an electromagnet which could be efficiently worked with the alternating current. .I-am satisfied that Lindquist did this, and that his invention went into immediate use arid was successful. It is evident that if a unitary magnet core is subjected to the energizing effect of a number of coils, in each of which the reversal of the current occurs at different times, there will be a pull on the armature at all times, a constant pull, and that hammering and chattering will cease. However, it is also evident, that the net pull of all the coils must be constant, and in one and the same straight line, and that this line must be coincident with the axis of symmetry of the core. In other words, if the support of or pull on the armature should -shift from place to place, there would be more or less hammering and chattering. There must be a constant and' uniform pull on all points of the armature in the same arid in the proper direction. The patent, therefore, provided the central coré with a definite longitudinal axis of symmetry passing through its center, which fixed the line of pull, and the magnet coils were arranged symmetrically around this axis and with special reference to their magnetic effects on the core.

This last, magnetic effect on the core, is of the utmost importance. The currents are of a different phase; when one is pulling and another is not. • Kennelly, complainant’s expert, describes the Senior patent in suit in detail, but sums up the mode of organization of the same as follows:

“A central axis, or axis of symmetry, and around this axis are placed a plurality of coils. The coils are to be disposed symmetrically with respect to this axis, and the symmetry is to be such that each of .said coils has an axis and each axis is parallel to the said central axis or axis of symmetry of the whole; that is, I understand that, of all the possible types of symmetrical arrangement about an axis which may theoretically exist in such a structure, that particular disposition is to be employed which involves the parallelism of the axis of each of the plurality of the coils with the axis of symmetry'of the whole.”

I.do not think the.geometrical arrangement of the magnet coils about the axis of much importance. The claims call for a symmetrical'.disposition of -the coils around! a central axis. That degree of symmetry and geometric arrangement was necessary which would secure a substantial degree of uniformity in the direction and magnitude of electromagnetic attraction upon the armature under the conjoint action of out of phase electric currents. Constant and uniform pull on the armature was 'the main and controlling idea.

Claims.2, .3, and 4 of the’ Senior patent call for an electromagnet having a “cylindrical core,” but claim 4 says “cylindrical laminated core,” and claim 1 has a. central axis around which the coils are disposed,. Me^ns for producing currents of different phase in the coils, and 'coils are essential elements o,f each claim; but no specific method [119]*119of winding and connections are claimed or essential, and any method may be adopted which will produce different phases. We have as the main feature a single solid laminated mass, with pole-pieces so formed therein that a substantially uniform distribution of symmetrically balanced magnetic forces results. These magnetic forces, as I have said result, in a mechanical pull constant in strength, direction, and point of application. The patent involved a proper conception of the relation of things and their utilization when brought into proper relation.

The defendant’s switch, the alleged infringing device or structure, has the alternating current traction electromagnet to control the opening and closing of switch contacts disposed in circuit.

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Bluebook (online)
198 F. 116, 1912 U.S. Dist. LEXIS 1279, Counsel Stack Legal Research, https://law.counselstack.com/opinion/sundh-electric-co-v-general-electric-co-nynd-1912.