[LB012019], Letter from Richard Nott Dyer to Thomas John Handford, April 3rd, 1882


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[LB012019], Letter from Richard Nott Dyer to Thomas John Handford, April 3rd, 1882

Editor's Notes

Your three letters of the 9th, 11th and 14th ult. have been received. Primarily as a means of advancing Mr Edison's interests, and secondly as a benefit to myself, I am greatly pleased at the thoroughness with which you have examined the cases so far forwarded to you, and have carefully noted the general bearing that your criticisms have on English practice, with a view of drawing [-----] cases more in conformity with your practice.##Case 43 -##I have noted the changes in the title and in the provisional specification.##In regard to the complete specification, I see that the changes suggested by you will make it necessary for me to revise the description considerably. An additonal drawing will also be furnished showing the modificatins not illustrated by the present drawing. I wish you would let me know, the latest date I can forward these and still give you plenty time to make your examination and have the drawings and specification prepared. [---] the necessity under English practice of a full description and illustration of evrything referred to in the specificatin. It is a matter which is everyday becoming of more importance here, the Examination the U.S. Patent Office frequently requiring the illustration of described modificatins. I think however that the claims you sugest are rather too limited. One claim is undoubtedly as good as a dozen, if it covers the essential points of the invention.##The second claim in my opinion shuld be broad enough to cover one or two magnetic alarms. It might be about as follows: 2d The combinatin with one or more electrical generators, of an electro magnet in a [devised] or multiple arc circuit, and an armature lever therefore, completing circuits at its front and back can [-] [-tachs] to electrically operated alarm or alarms; substantially as hereinbefore described.##The two-alarm arrangement will be thrown in the additional drawing and fully described##The 3rd claim should I think also be broader. The arrangement is a simple one, and a single claim to the combination of the two features - one causing the other to act would undoubtedly be sufficient if it is broad enough. It is highly probable that the same result could be accomplished without arranging the alarm in a shunt around the safety catch. One might be an equivalent of the other, but the claim should not be limited to one form. I think the following would cover the point.##3d The combination with a "safety catch or shunt circuit breaking device between the translating devices and the generator or generators, [of] an electrically operated alarm arranged to be sounded when the main circuit is opened by the "safety catch" or safety device, substantially as hereinbefore described.##An electro magnetic device, like that shown in figure 7 of Mr Edison's patent no. 5306 of 1878, might be used in place of the lead wire and the alarm could be in a shunt around it I have not decided to put this in the complete. If I do not, the words underlined in this alarm can be left out. On second thought, it would not be desirable to put this in the complete, since Mr. Edison considers the fusible wire as far better and cheaper -o so much so that a magnetic device would not be used. The third part of the invention (the continuously operating mechanism) is a matter of some importance, and should I think be covered by a broader claim than your 4th claim. The two following claims embody my ideas of the points involved.##rth. As a means for regulating the generation capacity of a dynamo or magneto electric machine, or a battery or number of such machines, a continuously operating mechanism both activated and controlled by the current generated substantially as herewhile described##5th. The arrangement described with reference to figure 2 for regulating the generative capacity & for dynamo or magneto electric machine, or a battery or number of such machines.##You will see that this last claim includes the adjustable resistance. An arrangement somewhat different rom that shown in figure 2, although not as good in practice could be used. The armature lever might be used to operate a current reverser in the circuit of a small Gramme [rug] motor, which could be used to adjust the contact lever. Hence the 4th claim as I have drawn it becomes of importance. I would like to know if it is considered good practice in England to insert in the complete, modifications of a broad principle which is claimed, when only the broad principle and one way of carrying it into effect are set out in the provisional.##I would like to hear from you on this point and on my modifications of your claims. The result of our correspondence I will embody in the final draft.




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Thomas A. Edison Papers, School of Arts and Sciences, Rutgers University
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