[LB007632], Letter from Richard Nott Dyer to Thomas John Handford, July 1st, 1882


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[LB007632], Letter from Richard Nott Dyer to Thomas John Handford, July 1st, 1882

Editor's Notes

I now wish to reply in detail to your letter of April 20th [-] in regard to Case 47##I inclose a paper of the changes which I think describe in view of your letter and also an additional view for the drawing. The matter on pages [9] and 11 relating to [ordinary dynamo connections wherein the [first] coils are in series with the armature coils. The circuit controller being placed in a shunt circuit around the field coils. Mr Edison thought best to [erase] since it relates more especially to machines of the Brush and similar constructions designed for high tension currents. You will see that with the exception of the weight operated circuit controller, I have not furnished additional drawings of the modified forms of connections set out in the specification The reason for this course is that the modified connections would be clearly abvious to persons skilled in the art from the general description, and in addition, are the clear equivalents of the connections shown.##I inclose some rough pencil sketches of my own illustrating these modified connections. No. 1 shows the magnets in series which [throw] in and cut out the sections of the spark [awaiting] resistance (p. 3 & 5 [from toh]).##No 2 and 3 show relay arrangements: In [no 2] the magnet which works circuit controller is a shunt from a main conductor. In no 3 this magnet is in a shunt around the section of the spark arresting resistance which is always in circuit.##Nos 2 and 3 show clear equivalents of the forms shown in figures 3, 4 & 5 of the drawing: while No. [1] is an equivalent of the connections shown in figure 6.##It would be unnecessary it seems to me to [s---ate] all the modifications in the connections that could be made, and highly impracticable to attempt to illustrate them all. The best connections are illustrated and other connections that would answer the purpose well, are described in such terms that any person having the ordinary knowledge gained by practical experience in the business would be able to make them.##With reference to the paragraph on 3d page referring to the relay arrangement, I do not see why it is necessary to illustrate such an arrangement in connection with each form of the apparatus, such an arrangement being illustrated in connection with the principal form, as it is in figures 3, 4 and 5.##In regard to the claims, I see no objections to leaving out the 3d, 7th 8th and 9th claims, but the 4th claim I think should be left [in for] the reason that the location of the controlling electro magnet in multiple arc is a very important feature in connection with the vibrating circuit controller. A magnet in that position is affected exactly the same as a lamp by changes in number of lamps in circuit and in speed of engine, while an electro-magnet in the line (for instance) will only regulate for lamps and not for speed. If this claim is retained, the words "or magnets" should be erased in view of the changes proposed in my [amendating] papers.






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