US2559988A

US2559988A - Terminal structure for coil forms

Info

Publication number: US2559988A
Application number: US36081A
Authority: US
Inventors: Jr Atherton Noyes
Original assignee: AIRCRAFT RADIO CORP
Current assignee: AIRCRAFT RADIO CORP
Priority date: 1948-06-30
Filing date: 1948-06-30
Publication date: 1951-07-10
Anticipated expiration: 1968-07-10

Description

July 10, 1951 A. NOYES, JR

TERMINAL STRUCTURE FOR COIL FORMS Filed June 30, 1948 g wk M M l Patented July 10, 1951 TERMINAL STRUCTURE FOR COIL FORMS Atherton Noyes, J12, Mountain Lakes, N. J., as-

signor to Aircraft Radio Corporation, Boonton, N. J a corporation of New Jersey Application June 30, 1948, Serial No. 36,081

Claims.

This invention relates in general to electrical coils and in particular to an improved construction for a combined coil form and lead-off assembly for the terminal ends of the coil.

In the past, considerable difficulty has been experienced in providing a satisfactory anchor and lead-off for the terminal ends of the coil, and the problem has been especially difficult where the form and coils are of small diameter i. e. of the order of one-fourth of an inch or less and a multiplicity of leads are taken out at the same end of the form. Ceramic coil forms have the advantage of permanence of dimensions with age and under conditions of high humidity, temperature variations and the like, and they can readily be ground to very close diametral tolerances, but the characteristics of the material are such that the attachment of coil terminals in a satisfactory manner to the end or ends of ceramic coil forms has long been a problem.

Primary objects of this invention are to provide improved lead-off arrangements for formmounted coils which have relatively few and different parts, are easily and quickly assembled, and which assure a rigid, fixed position of the lead-off conductors which makes accidental short-circuiting of the coil leads virtually impossible. Objects are to provide a coil form and lead-elf assembly including two insulated terminals in each end of small diameter coil forms 7 without materially increasing the effective diameter of the assembly, whereby a close mounting of a number of such assemblies in a compact array is made possible. Further objects are to provide coil terminals or lead-off assemblies of the type stated which may readily be mounted on the ends of ceramic rod coil forms.

Other objects and advantages of the improved construction will become more apparent from the following detailed description of a preferred embodiment of the invention and the accompanying drawings in which:

Fig. 1 is a side elevation showing an assembly of form-mounted coil units, each of which is constructed in accordance with the principles of the invention; Fig. 2 is an end view of the same; Fig. 3 is a fragmentary view in perspective of one of the coil forms showing the lead-oil conductor assembly at one end of the form; Fig. 4 is an exploded View showing the various com ponents of the assembly illustrated in Fig. 3; Fig, 5 is a fragmentary view of one of the coil forms, partly in section and partly in elevation with the lead-cit conductors assembled; Fig. 6 is an end view at an intermediate stage in the assembly showing the inner, grooved clamping disc with the lead-off conductors in place; Fig. 7 is an end view of one of the clamping discs with the lead-off conductors removed; Figs. 8 and 9 are diametral sectional views taken on lines 8-8 and 99, respectively of Fig. '1; and Figs. 10 and 11 are fragmentary perspective views of rod coil forms having different constructions for anchoring the lead-off wires against displacement.

Referring now to the drawings, and in particular to Figs. 1 and 2, I have there illustrated a twelve unit group of form-mounted coils, there being four rows of wire wound forms in one direction and three rows in the other direction. The coil forms, designated by reference numeral l, are held in spaced relation between mounting plates 2, 3 which in turn are received in grooves 4 in parallel spaced plates 5, 6 secured to opposite walls of a box I.

In the illustrated embodiment, each of the forms I has two

coils

8, 9 of insulated wire wound together upon it and the opposite ends of each coil 8a, 8b and 9a, 9?) lie at opposite ends of the form. All twenty-four coils are electrically connected in series resulting in two leads Ill, II by which the coil group can then be connected into the circuit for which it is intended.

As previously explained, the primary object of the present invention is to provide an improved lead-off arrangement for the ends Ba-8b and 9a% of the coils at the ends of the cylindrical forms I, the Figs. 3-9 clearly illustrate the principal structural features upon which patentable novelty is predicated. As shown in these views. each end of the forms I is recessed and tapped at l 2 to receive a screw I3 having a slotted cylindrical head I3 1 by which two lead-olT conductors l6, I! are secured tightly in place between a pair of insulating discs I4, I5 and upon the end of the form I. The two leads I6, I! which are identical are preferably made from comparatively stifl round wire and include intermediate, arcuate laterally offset portions Ilia, Ila. The latter which lie in a plane perpendicular to the end por tions I51), I and I71), I10 and extend through substantially of arc are seated in a shallow circular groove Ida in one face of a circular inner clamping disc I4, i. e. the disc next to the end face la of the form, and the inner ends lib, I'I'b of the two lead-01f conductors pass through axially extending apertures Mb in the disc I4, it being noted that these two apertures are located apart and are in radial alignment with the groove M11 in relation to the disc axis. Flats Ic, Id spaced 180 apart are provided tween the mounting plates 2, 3.

3 at each end of the form I, and when assembled, the inner ends I6b, [lb of the lead-off conductors lie flat against them so as to prevent any accidental turning of the lead-off conductors about the axis of the form.

The outer disc I is structurally identical with the inner disc I4 and the circular groove and apertures therein through which the outer ends I60, I of the lead-off conductors are passed are identified by numerals I5a, I511. The depth of the grooves Ila, I5a is made somewhat less than one half the diameter of the lead oif conductors I6, I! so as to provide a good clamping action on the latter.

The manner of assembly is obvious from the exploded view in Fig. 4 in which all component parts have been oriented with respect to the axis of the form to the exact positions they occupy upon assembly. Referring to Fig. 4 it will be observed that the grooved surfaces of the discs I4, I5, confront each other and that their respective apertures Mb, I51) are displaced 90 with respect to the form axis. Hence when the components are assembled and screw I3 which passes through axial openings I40, I50 in the discs is screwed into the end face Ia, the intermediate arcuate offset portions Ifia, I'Ia of the two lead-ofi conductors will be clamped tightly between the discs I4, I5 in the co-registering grooves I la, I511; the inner ends I61), I11) of the conductors will lie against the form flats Ic, Id which look the parts against rotation; and the outer ends Ific, Ilc of the lead-off conductors will extend parallel to the form axis and 180 apart so as to provide a maximum spacing between the conductors.

As shown in Figs. 1 and 2, the inner ends Ifib, I'Ib of the lead-off conductors are then soldered to the coil ends 8a, 8b and 9a, 9b, and the outer ends I60, We of the adjacent coils interconnected by soldering at both ends of the twelve unit assembly to provide the desired series coil connection.

Finally it will also be observed from Figs. 1 and 2 that nothing additional in the way of structure is necessary for support of the coil forms I be- The latter are provided with as many apertures 2a, 3a as there are forms to be supported, these apertures being so sized as to make a snug lit with the cylindrical heads I3a of the screws, and a pair of small openings are provided closely adjacent to each aperture 2a, 3a to pass the lead-off conductor ends I60, I10. It is often desirable, as shown in Fig. 1, to make the thickness of the mounting plates 2, 3 slightly in excess of that of the screw heads so that when assembled, the screw heads lie below the outer faces of the plates thereby to facilitate interconnections between the several coils and also to reduce the possibility of a short circuit between leads.

The coil forms I are preferably of ceramic material when dimensional and mechanical stability are important and, whether of ceramic or of other insulating material, means other than the flats I'c, Id may be employed for preventing inadvertent angular displacement of the lead-off wires, for example short and shallow grooves I extending longitudinally in a diametrical plane at the ends of the coil forms I as illustrated in Fig. M), or a short diametrically disposed slot or saw kerf I" as illustrated in Fig. 11.

In conclusion, I wish it to be understood that the specific structural embodiment of the leadofi arrangement for small sized form-supported windings which has been illustrated and described is but typical of the invention and that various modifications thereof may be preferred by others in this art but without, however, departing from the spirit and scope of the invention as expressed in the appended claims.

I claim:

1. A combined coil support and lead-off assembly comprising an elongated form adapted to receive the coil, a lead-off conductor having a lateral offset portion intermediate the terminal ends thereof, a pair of confronting discs at one end of said form each of which is provided with an aperture extending between the opposite faces thereof, said offset portion of said conductor being seated between the confronting faces of said discs with the terminal ends of said conductor extending through the disc apertures aligned therewith, and means securing said discs together and to the end of the said form thereby to clamp the oifset portion of said conductor between said discs.

2. A combined coil support and lead-01f assembly as defined in claim 1 wherein the end of said form is provided with a flat against which rests the inner terminal end of said lead-off conductor.

3. A combined coil support and lead-off assembly as defined in claim 1 wherein the end of the coil form is provided with a shallow longitudinally extending groove in which the inner end of the lead-off conductor is seated.

4. A combined coil support and lead-off assembly comprisng an elongated form adapted to receive the coil, a lead-off conductor having a lateral offset portion intermediate the terminal ends thereof, a pair of confronting discs at one end of said form each of which is provided with an aperture extending between the opposite faces thereof, said offset portion of said conductor being seated in co-registering grooves provided in the confronting faces of said discs with the terminal ends of said conductor extending through the disc apertures aligned therewith, and means se curing said discs together and to the end of said form thereby to clamp the offset portion of said conductor between said discs.

5. A combined coil support and lead oif assembly comprising an elongated form adapted to receive the coil, a pair of lead-ofi conductors each of which is provided with a lateral offset portion intermediate the terminal ends thereof, a pair of confronting discs at one end of said form each of which is provided with a pair of spaced apertures extending between the opposite faces thereof, said offset portions of said conductors being seated in spaced relation between the confronting faces of said discs with the terminal ends thereof extending through an aperture in each disc aligned therewith, and means securing said discs together and to the end of said form thereby to clamp the offset portions of said conductors between said discs.

6. A combined coil support and lead-01f assembly as recited in claim 6 wherein the end of the coil form is provided with a diametrically disposed slot, the terminal ends of the lead-01f conductors being arranged in opposite sides of said slot.

7. A combined support and lead-off assembly for a coil comprising an elongated form adapted to receive the coil, a pair of lead-off conductors: each of which includes an intermediate portion laterally offset from the terminal ends thereof, a. pair of confronting discs arranged at one end of said form, said discs having co-registering groovesin their confronting faces and each including a pair of apertures spaced apart extending from the groove to the opposit face, said discs being disposed with the respective apertures therein in offset relation corresponding to the offset portions of said conductors, and said terminal ends of said conductors extending through said apertures with the offset portions thereof seated in said grooves, and means securing said discs together and to the end of said form thereby to clamp the conductor offset portions between said discs.

8. A combined coil support and lead-off assembly comprising an elongated form adapted to receive the coil, a pair of lead-oh: conductors each of which includes an intermediate arcuate portion extending through 90 laterally offset from the terminal ends thereof, a pair of confronting discs at one end of said form, said discs having co-registering circular grooves in their confronting faces and each including a pair of apertures spaced 180 apart extending from said groove to the opposite face, said discs being disposed with the respective pairs of apertures at right angles, and said terminal ends of said conductors extending through said apertures with the offset portions thereof seated in said grooves, and means securing said discs together and to the end of said form to thereby clamp the offset portions of said conductors between said discs.

9. A combined coil support and lead-off assembly comprisin an elongated form adapted to receive a pair of coils the ends of each of which terminate at opposite ends of said form, and a lead-off assembly at each end of said support for the coil ends, each said assembly comprising a pair of lead-off conductors each of which includes an intermediate portion offset laterally from the terminal ends thereof, a pair of confronting discs each of which is provided with an aperture extendin between the opposite faces thereof, the offset portions of said conductors being seated in spaced relation between the confronting faces of said discs with the terminal ends of said conductors extending through the apertures in said discs aligned therewith, and means securing said discs together and to the end of said form thereby to clamp the offset portions of said conductors between said discs.

10. A combined coil support and lead-off assembly comprising a coil form, a pair of confronting insulating discs each having a central aperture and a second off-center aperture extending between the opposite faces thereof, a lead-off conductor having an intermediate lateral offset portion seated between the confronting faces of said discs with the end portions passing through the off-center apertures, and a clamping screw extending through the central apertures in said discs and threaded into the end face of said form for securing the offset portion of said leadoff conductor between said discs and also securing the latter to said form, the end of said form including means cooperative with said conductor for holding the latter and said discs in predetermined angular relation to said form.

ATHERTON NOYES, J R.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 737,720 Duncan Sept. 1, 1903 936,669 Rypinski Oct. 12, 1909 1,715,018 Von Brockdorff May 28, 1929 2,233,905 Wilson Mar. 4, 1941 FOREIGN PATENTS Number Country Date 242,718 Switzerland Oct. 16, 1946 328,588 Germany June 13, 1919 436,383 Great Britain Oct. 10, 1935 463,348 Great Britain Mar. 30, 1937 Certificate of Correction Patent No. 2,559,988 July 10, 1951 ATHERTON NOYES, JR.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 30, for comprisng read comprising; line 61, for the claim reference numeral 6 read 5 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Ofiice. Signed and sealed this 18th day of September, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,559,988 July 10, 1951 ATHERTON NO-YES, JR.

Column 4, line 30, for comprisng read compacting; line 61, for the claim reference numeral 6 read 5;

and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice. Signed and sealed this 18th day of September, A. D. 1951.

THOMAS F. MURPHY,

Assistant Gammissz'oner of Patents.