Consolidated Car Heating Co. v. Lehigh Traction Co.

51 F.2d 588, 10 U.S.P.Q. (BNA) 83, 1931 U.S. Dist. LEXIS 1546
CourtDistrict Court, M.D. Pennsylvania
DecidedJuly 28, 1931
DocketNo. 618
StatusPublished

This text of 51 F.2d 588 (Consolidated Car Heating Co. v. Lehigh Traction Co.) is published on Counsel Stack Legal Research, covering District Court, M.D. Pennsylvania primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Consolidated Car Heating Co. v. Lehigh Traction Co., 51 F.2d 588, 10 U.S.P.Q. (BNA) 83, 1931 U.S. Dist. LEXIS 1546 (M.D. Pa. 1931).

Opinion

JOHNSON, District Judge.

The bill of complaint charges the defendants with the infringement of letters patent No. 1,293,786, issued February 11,1919; letters patent No. 1,500,566, issued July 8,1924; and letters patent No. 1,664,778, issued April 3, 1928, issued to Lee P. Hynes and by him assigned to the Consolidated Car Heating Company, Inc., of Albany, N. Y., and prays for an injunction and an accounting.

In their answer the defendants deny the validity of the patents in suit and also deny infringement. On the pleadings and evidence, two main questions arise for disposition: First, the validity of the plaintiff’s patents; and, secondly, the infringement by the defendants.

The patents cover improvements in thermostats. The thermostatic device which .is claimed to infringe the plaintiff’s patents was manufactured and sold to the Lehigh Traction Company by the Railway Utility Company of Chicago, Ill. This later company upon petition was allowed to intervene and defend in this suit.

It is charged that claims 6 and 7 of patent No. 1,293,786, all the claims of patent No. I, 500,566, and claims 1, 3, 4, and 5 of patent No. 1,664,778 are infringed.

Patent No. 1,293,786 covers a thermostat having novel means for supporting a [589]*589thermometer bulb within the easing, but claims 6 and 7 of said patent, which are the only ones involved here, are directed to a means for securing the base to the cover and attaching the device to a car wall or other support. This means is a screw extended through a tubular bolt to engage the car wall or other supporting member. This hollow bolt is fitted with a nut concealed under the base so that when the screw is engaged with the wall it is impossible for any one to remove the cover without first removing the device from the wall.

In an earlier device patented by the defendant, the cover and base were secured together by a hollow rivet, through which a screw was passed to fasten the thermostat to the wall of the car. Tubular bólts and tubular rivets are not uncommon, and it does not require a high order of inventive skill to substitute one for the other. Claims 6 and 7 of this patent cannot be read upon the defendant’s device which is alleged to infringe.

In defendant’s device, hollow bolts are used to secure the cover to the back plate, and screws passing through these hollow bolts secure the thermometer inelosure to the base. The base is screwed to the support by other screws, differently positioned, and passing only through the base.

The patent in respeet to the use of the tubular bolt and screw shows so little invention that it should be construed to cover only the actual structure shown. When so restricted it is not infringed by defendant’s device.

Patent No. 1,500,566 discloses a thermostat comprising a metal cover and a base of molded material, a thermometer bulb provided with electric contacts and a heat-sensitive element for conducting the temperature of the car to the thermometer bulb. This heat-sensitive element, as shown, is a thin strip of copper, or other composition that is sensitive to changes of temperature, which is passed through slots in the front wall of the metal cover or easing. The mercury bulb at its lower end is surrounded by this thin strip of copper, which then passes through a slot on one side of the metal easing, around the outside of the easing, being returned by a second slot on the opposite side or breast of the easing and secured.to its opposite end. Between this strip and the outer wall of the casing is interposed a strip of heat-insulating material.

Infringement of all the claims of this patent is alleged. Claim 1, which is representative, reads as follows: “A thermostatic control device comprising a base, a cover cooperating with said base to provide an enclosure, a thermostat and an element of temperature-sensitive material applied to said thermostat within said enclosure, a portion of said temperature-sensitive material being exposed to the atmosphere outside of the enclosure and acting on the thermostat independently of the enclosure and an electric contact controlled by the thermostat.”

One of the defenses advanced by defendant is that this thermostat invented by Hynes and assigned to the plaintiff is anticipated by patent No. 1,386,618, issued on August 9, 1901, to W. G. Hartwig and assigned by him to the defendant the Railway Utility Company. The structure disclosed by the prior patent to Hartwig covers a thermostat comprising a base, a metal cover, a thermometer bulb provided with electric contacts, and a heat-conducting element in contact with the cover and with the thermometer bulb.

The heat-conducting element as shown in the patent, and in defendant’s earlier commercial device, took the form of a thin flat plate or panel of copper, which formed a part of the metal cover or inelosure, and was soldered or otherwise secured to a thin metal clip or clamp adapted to bear upon the thermometer tube on opposite sides of the mercury bulb.

There is nothing in the prior art which shows the use of a heat-conducting element to carry the changes of temperature from the atmosphere to the thermostatic element, before the invention of Hartwig. In his structure the heat-conducting element is not insulated from the cover, but the specification points out that it may be so insulated if greater accuracy is desired.

It is clear that Hartwig was the pioneer in the invention of a thermostat with a heat conducting element, and that the thermostat invented by Hynes was an improvement on the Hartwig patent. What Hynes did was to reduce the extent of the heat-conducting element, changing it from a panel forming part of the inelosure to a comparatively small strip of heat-conducting material passed around the metal cover by means of slots positioned on opposite sides of the cover. It is described in his specification, page 1, line M, as follows: “My invention resides in the use of a comparatively small heat-responsive element which is effectively heat-insulated from the cover or casing but applied directly to the thermometer bulb. This heat-responsive element is exposed to the atmosphere on the outside of the cover or casing but is heat-[590]*590insulated therefrom and passes through narrow slots into the inside of the easing where it is wrapped around the bulb of the thermometer.”

It is claimed by the defendant, in respect to claim 1 of the Hynes patent, that “the Hartwig construction when the sensitive element is insulated, as the patent states it should be when greater sensitiveness is desired, completely anticipates this claim.”

It is true that the insulation of the heat conducting element was old, in view of the Hartwig disclosure, but it appears to be true also that the reduction in extent of the heat-conducting element resulted in a more effective thermostat. The disadvantages of the Hartwig thermostat were pointed out by Hynes in his specification, page 1, line 24, where he says: “Heretofore it has been proposed to connect the thermometer bulb in a thermostat of this type with a cover-plate of a special heat responsive metal, through which the temperature changes in the outer atmosphere are communicated to the bulb. In this device, the large surface of heat-responsive-metal, together with the other metal parts associated therewith tend to make the action of the device sluggish, its response to temperature changes being so gradual as to impair the electric contacts, particularly on the opening of the circuit.”

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51 F.2d 588, 10 U.S.P.Q. (BNA) 83, 1931 U.S. Dist. LEXIS 1546, Counsel Stack Legal Research, https://law.counselstack.com/opinion/consolidated-car-heating-co-v-lehigh-traction-co-pamd-1931.