Safety Car Heating & Lighting Co. v. Gould Coupler Co.

• Decision Date: 22 June 1915
• Docket Number: A-86.
• Citation: 229 F. 429
• Parties: SAFETY CAR HEATING & LIGHTING CO. v. GOULD COUPLER CO.
• Court: U.S. District Court — Western District of New York

229 F. 429

SAFETY CAR HEATING & LIGHTING CO. v. GOULD COUPLER CO.

No. A-86.

United States District Court, W.D. New York.

June 22, 1915

On Rehearing, February 8, 1916.

Duell Warfield & Duell, of New York City, for complainant.

Kenyon & Kenyon, of New York City (Wm. Houston Kenyon, Richard Eyre and Gorham Crosby, all of New York City, of counsel), for defendant.

Duell Warfield & Duell, of New York City, for plaintiff.

Kenyon & Kenyon, of New York City (Walter C. Noyes, Wm. Houston Kenyon, and Richard Eyre, all of New York City, of counsel) for defendant.

HAZEL District Judge.

This action was brought to enjoin infringement of letters patent No. 1,070,080, issued to the Safety Car Heating & Lighting Company, as assignee of Harrison G. Thompson, inventor, on August 12, 1913, on an application dated August 22, 1908, for improvements in electric car-lighting systems, in which a shunt wound generator is driven from the car axle and charges current to the storage battery and lamps; the battery operating as a reservoir for emergency purposes and supplying the lamps with current when the car is standing still, or running so slowly that the generator output is insufficient to supply the demand. Before the Thompson invention in controversy there were a number of patents for train or car lighting systems wherein the current was generated by the car axle, and indeed such prior lighting systems included a storage battery, a generator regulator for keeping constant the generator current, and a carbon pile resistance in combination for maintaining constant the flow of current to the battery and lamps. But such prior patents were not free from objection on account of the danger of overcharging the battery, which interfered with efficient lighting. Specific improvements are claimed to have been made by the patentee to overcome such objections and to produce a constantly useful current in spite of the varying speed of the car and generator, especially with relation to the use of such current in charging the battery and to simultaneous protection of the battery from injurious or wasteful overcharging.

The claims in controversy are the fourth, ninth, tenth, eleventh, twelfth, and thirteenth. The fourth claim reads as follows:

'4. In car-lighting apparatus, in combination, an electric generator, a storage battery connected to be charged thereby, a variable resistance medium comprising a plurality of contacting members adapted to vary their aggregate resistance with pressure thereon, said resistance medium being connected in the field circuit of said generator, a current coil serially connected between said generator and said battery, a voltage coil connected across the charging circuit, separate movable cores respectively coacting with said coils, and means mechanically connected with said cores and tending normally to compress said medium and adapted upon either of said cores being attracted to tend to weaken the pressure upon said medium.'

It is a combination claim for car axle lighting, and has the following elements: (1) A generator; (2) a storage battery connected for charging; (3) a variable resistance medium, consisting of a carbon pile rheostat having a plurality of contacting members adapted to vary their aggregate resistance with the pressure thereon; (4) a field circuit; (5) a current coil connected between the generator and battery; (6) a voltage coil connected across the charging circuit; and (7) separate movable cores tending normally to compress the carbon pile, and adapted to weaken the pressure thereon as either of the movable cores is attracted. The asserted new elements of the claim include the voltage coil, the manner of its connection, and the mechanism by which a plurality of disks in the carbon pile are compressed or pressure on the medium weakened.

Claim 9 includes broadly the shunting mechanism, consisting of a magnetic member arranged to co-operate with the current coil to increase the resistance, and 'means adapted automatically to complete a shunt about said coil upon the voltage of said generator falling below that of said battery. ' Claims 10 and 11 specify the various elements in detail, and concededly are limited to contacts positioned upon the main switch as shown in Fig. 2 of the patent drawings; while claim 12 includes all the essential elements and the arrangement of the parts by which a co-operative result is obtained, and reads as follows:

'12. In car-lighting apparatus, in combination, an electric generator, a storage battery adapted to be charged thereby, lamps connected across said battery, a variable resistance medium comprising a plurality of contacting members adapted to vary their aggregate resistance with pressure thereon, said resistance medium being connected in the field circuit of said generator, a current coil, a magnetic member positioned in the field of said coil, means coacting with said magnetic member and variable resistance adapted to vary the pressure upon said resistance with a variation in current flowing in said coil and tending normally to compress said medium, a switch comprising a voltage coil connected across said generator, and a movable core having a contact member at one end thereof, said switch being adapted to disconnect said generator upon its voltage falling below that of said battery by movement of said contact member, a shunt about said first coil, means coacting with the remaining end of said core adapted to complete said shunt upon said switch being opened, a second voltage coil and means adapted upon said battery reaching a certain state of charge to render said second voltage coil effective in reducing the pressure upon said variable resistance medium.'

Claim 13 omits the feature of shunting the current coil by the main switch, but specifies:

'A normally ineffective voltage coil adapted upon becoming effective to control said generator current by acting on the resistance of the generator field circuit, and means adapted upon the voltage of said battery attaining a certain value to render said voltage coil effective in controlling said generator current.'

The defense is that the claims, if broadly construed, are invalid in view of the prior art, and, if limited to the device shown and described, scribed, are not infringed; that in any event the defendant's generator regulator is a patentable departure from complainant's; and that the defendant was the first to substitute voltage regulation for current regulation to avoid overcharging the battery.

There were irreconcilable differences of opinion among the witnesses as to the fundamental conception of the patent, and the different disclosures of the specification and claims, as well as concerning the result attained. Complainant claims that the specification and claims are clear and definite with regard to substituting voltage regulation for current regulation when the battery is nearly charged, while the defendant asserts that the described means are for charging the battery at one time and discharging it at another, or for positively disconnecting the generator from the battery and permitting the generator to resume action regardless of the speed of the train. The argument is that the patentee contemplated another construction operating on an essentially different principle from the apparatus of the defendant company; that the original claims were improperly amended and broadened to include the defendant's regulator, after its mode of operation had become known to the patentee.

The case was tried in open court by able counsel, aided by competent expert witnesses, and the technicalities made as clear as possible; but nevertheless the abstruseness of the subject-matter and the perplexities arising from contradictory testimony render it difficult for me to clearly determine the many questions involved. My conclusions as to the proper construction of the patent have been formed after careful consideration of the evidence and the arguments thereon; but before stating them it will no doubt be helpful to an understanding of the patent from my point of view if I first direct attention to what I believe to be the objects of the invention as indicated by the specification. It is therein shown that the patentee designed by his invention to provide practical and efficient means for charging storage batteries, to provide reliable and sensitive means for rendering the generator inoperative upon its function being performed, and to provide automatic means for enabling the generator to resume its charging action independently of the speed of the train. A general reference to the specification shows that in the shunt field of the generator there is positioned a carbon pile rheostat of a type concededly known in the art at the date of the invention, which operated to change the aggregate resistance of the disks upon the yoke pressing against them, which yoke was caused to move oppositely by a core when coil 12 became energized. Thus the compression of the carbon pile resulted in a decreased aggregate resistance corresponding to the varying spring pressure imposed upon it, and permitted more current to flow through the shunt field circuit, which resulted in the regulation of the current and the generator output.

Figure 2 of the drawings, which is an embodiment of the invention, is herewith reproduced:

(Image Omitted)

This sketch shows the field coil in shunt across the generator circuit, the main switch being open and the carbon pile compressed through the mechanism while the spring 10 is pressed against the yoke, with the result that the resistance in the shunt field circuit is decreased. A plunger or core, about which coil 41 is wound, has also a coil 50 which opposes or substantially...