174 F. 141 | 7th Cir. | 1909
after stating the facts as above, delivered the opinion.
Both of the patents relate to certain improvements in meters for measuring. and recording the amo'unt of electric current flowing in or drawn from a circuit with which they may be connected, the meters being of that special class known as mercury meters, for the reason that they have armatures of conducting material immersed in a chamber containing mercury. In meters of this kind (they existed in the prior art previous to the Halsey patents under consideration) the motive device is a disk or cylinder of copper or other good conducting material, immersed in a body of mercury, and mounted between the poles of a magnet in such a manner that when a current of electricity is passed through that portion of the disk which lies immediately under the magnetic poles, the disk will be set in rotation in accordance with a well-known law of operation resulting from the reaction between the current in the disk and the magnetic field through which its path lies. From this class of mercury meters, the Halsey invention, letters patent No. 626,832 is sought to be differentiated by the designation of the mercury chamber as a “narrow” slot, and the magnetic field as being one of “small area.” But for these features, letters patent No. 626,832 would be fully anticipated in the prior art.
Though these features doubtless carry with them many practical advantages, they are, in our opinion, anticipated both in purpose and
Patent No. 661,265 is meant as an improvement in the same class of meters, and so far as the present suit is concerned, differs from the prior art in completefy amalgamating the entire disk instead of seeking to insulate it so as to overcome the tendency to amalgamation. His thought in this respect is set forth in the following paragraph from his testimony (Rec. p. 73) :
"T have found, through experiments running through one or two years, that a copper disk armature running in the narrow, slot and field gap, which is essential or desirable, that unless the disk armature he thoroughly amalgamated, small air pockets are liable to exist at points which are unamalgamated or poorly amalgamated, thereby causing friction (by the aeeumulaiion in such pockets of copper oxide or mercury scum) which may vary from a small amount, affecting the meter only in small loads, to any amount up to an amount that will in some cases slop the meter at full load, or absolutely prevent it from starting. I have found repeatedly iu m.v early experiments that a meter which at one time would run apparently all right, at another time, would, with no visible cause, scop running entirely, or would indicate internal friction of some kind which I at first had difficulty in locating. I also found that some of these armatures which had been in use and constantly submerged in mercury for more than a year had not become thoroughly amalgamated, and I am of the opinion that they would never become perfectly amalgamated of themselves. The effect of non-amalgamation or imperfect amalgama (ion Is to interfere with the perfect and complete tilling of the mercury space with mercury, and after once tilled, or apparently so, on account of the meter being slightly out of level or the armature running closer to one wall than another on account of being slightly out of true, the close approach to one of the walls of one of the imperfectly amalgamated spots or portions of the armature, will sometimes cause the receding of the mercury at this point, forming an air pocket and space for mercury film or swims, which very materially increases friction. This also decreases the hydrostatic pressure at this point, whereby this portion of the armature is drawn still closer to the wall, and on account of the elasticity of the shaft or play in the bearings often canses actual contact or rubbing friction, thereby preventing rotation altogether.'’
This, we think, is shown to have been a departure from the thought of the prior art.
True, our attention is called to the Perry British Patent No. 7219 (1890), to the Evershed & Vignoles British Patent No. 7484 (1896), and to Reason’s British Patent No. 17764 (1898), the latter two of which show copper armatures completely submerged in mercury; and in the former of which it is stated that it is only “sometimes” that the copper cylinder, except where the current is received and given off, is covered with an insulating varnish — the implication argued for being that in other instances the cylinder is not insulated by varnish
These exhibits from the prior art do- not disclose complete amalgamation, for in order to make copper amalgamate when immersed in mercury, all traces of foreign substances must first be chemically removed (something not pointed out or hinted in the British patents); nor do they disclose initial complete amalgamation as an element of the combination — something that must be attended to, irrespective of what may occur incidentally as the result of the immersion of the armature. Indeed, though in constructing meters in accordance with the teachings of the prior art more or less amalgamation is a direct and necessary result, the amalgamation is partial only and not complete, and has been looked upon as an incident to be avoided, not an end to be purposely attained.
We think that, under the circumstances, the departure practiced by Halsey and pointed out in his patent is patentable invention. Undeniably, his initial amalgamation of the disk is the result of his experiments, not of what he read in prior inventions. Undeniably, no-one in the prior art-purposely set about to amalgamate; whatever amalgamation took place, was incidental only. And undeniably the disks of the appellee are subjected now to this specific process of amalgamation before they are inserted in the instrument — convincing evidence that the defendant has learned from Halse)^ patent and not from the prior art.
The decree of the Circuit Court will be affirmed as to-patent No. 626,832, and reversed as to patent No. 664,265 and the case remanded, with instructions to enter a decree finding Claim 2 of that patent valid, and finding it to be infringed by appellee (the infringement is not seriously denied) and entering an injunction accordingly.
