USRE26332E

USRE26332E - Method op making a coupling device

Info

Publication number: USRE26332E
Authority: US
Publication date: 1968-01-09

Description

Jan. 9, 1968 J. J. ANTALEK METHOD OF MAKING A COUPLING DEVICE 2 SheetsSheet 1 Original Filed June 22, 1959 FIG.3

INVENTOR JOHN J. ANTALEK BY jvm flfw mz f ATTORNEYS Jan. 9, 1968 .1. J. ANTALEK METHOD OF MAKING A COUPLING DEVICE 2 Sheets-Sheet Original Filed June 22, 1959 FIG FIG

JNVENTOR.

JOHN J. ANTALEK BY h Q/744 ATTORNEYS United States Patent 0 METHOD OF MAKlNG A COUPLING DEXICE John J. Antnlek, Glenview, Ill., assignor, by mesne assignments, to TRW Inc, a corporation of Ohio Original No. 3,222,760, dated Dec. 14, 1965, Ser. No.

328,547, Dec. 6, 1963, which is a division of Ser. No.

821,802, June 22, 1959, now Patent No. 3,130,350, dated Apr. 21, 1964. Application for reissue Feb. 15, 1966,

Ser. No. 536,936

14 Claims. (Cl. 29-602) Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

ABSTRACT OF THE DISCLOSURE A coupling device having a pair of disc capacitors positioned on edge within the top opening recess 0 a base member of insulating material. A pair of windings are positioned between the capacitors and the ends of the windings are connected to upstanding portions of terminal members which are positioned in slots in the base member. Pairs of opposed terminals are provided with inturned arm portions which engage opposite sides of each disc capacitor and provide physical support as well as electrical connection thereto.

The present invention relates to coupling devices such as transformers, and, more particularly, to tuned coupling devices and transformers of the type used in radio and television circuits. For example, the invention may be employed in a transformer arrangement wherein the windings of the transformer are wound on a tubular coil form and one or more tuning capacitors are connected to the windings of the transformer, the entire assembly being positioned Within a so-cnllcd shield can which is mounted to the chassis of the receiver or other electronic circuit. This application is a division of my copending application Serial No. 821,802, now Patent No. 3,130,350, filed June 22, i959, and assigned to the same assignee as the present invention.

While many coupling device arrangements have been proposed in the past wherein the tuning capacitors are mounted within the shield can and are connected to the windings of the transformer, these arrangements have in general not been readily adaptable to mass production techniques. On the other hand, those constructions which have been designed with mass production methods in mind have not provided a suitably reliable electrical connection between the tuning capacitors and the transformer windings, such arrangements relying on pressure between the terminals of the transformer and the plates of the capacitors for establishing the requisite electrical connection. In one such prior art arrangement employing pressure to maintain electrical contact, the capacitors are in the form of plated mica strips which are positioned in a sandwich type of construction in the base of the transformer, connection to the terminals of the transformer being solely by the pressure exerted on the sandwich by means of a spring washer and stud arrangement extending through the center of the transformer base.

It is, therefore, an object of the present invention to provide a new and improved coupling device arrangement wherein good electrical contact is established and maintained between the electrodes of a disc type coupling unit and the terminals of the device, while, at the same time, providing a construction which may be readily manufactured on a mass production basis.

It is another object of the invention to provide a new and improved transformer assembly wherein one or more Reissuecl Jan. 9, 1968 ice tuning capacitors can be conductively bonded to the terminals of the transformer by means of a single dip-soldering operation, or the like.

It is still another object of the present invention to provide a new and improved base construction which facilitates fabrication of transformer assemblies on a mass production basis.

A further object of the present invention is to provide a new and improved base member construction for a transformer assembly whereby either large or small diameter coil forms may be employed with the same base member to facilitate assembly of the transformers on a mass production basis.

It is a still further object of the present invention to provide a new and improved method of assembling transformer components wherein the tuning capacitors are first positioned on the base member and secured to the terminals of the transformer by means of a dip-soldering operation before the coil form which supports the transformer windings is secured to the base member.

It is a still further object of the present invention to provide a new and improved shield can arrangement for a transformer assembly which facilitates insertion of the transformer assembly Within the can and which is readily secured to the base member of the transformer.

Another object of the present invention resides in the provision of a new and improved coupling device arrangement which is reliable in operation, simple in design and may be readily produced on a mass production basis.

Briefly, in accordance with one phase of the present invention, the base member of the coupling device is providcd with a top opening recess within which the tuning capacitor, or other disc type unit having exposed electrodes on opposite sides thereof, is positioned on edge and is held in position by means of inturncd arm portions of the terminal members of the device which are secured to the base member. These arm portions engage the edge positioned disc type unit at points spaced above the top surface of the base member so that the base member with a disc unit held therein may be inverted and conductively bonded to the inturned terminal arm portions by means of a single dip-soldering operation.

If the coupling device is a transformer the coil form is secured to the base member after this dip-soldering operation and the ends of the windings on the coil form are then secured to the transformer terminals. In accordonce with a further feature of the present invention, the base member may be provided with a tubular coil form mounting sleeve which is adapted to receive either a large diameter or a small diameter coil form so that a universal mounting arrangement for dillerent size coil forms is provided. In accordance with a still further phase of the present invention, the shield can of the coupling device is provided with straight sides and a central opening in the top thereof defined by means of a vertically extending sleeve portion, the portion of the shield can connecting the straight sides and this sleeve portion being inclined so as to act as a guide for the upper end of the coil form and facilitate insertion of the upper end of the coil form into the central opening upon assembly of the coupling device in the can. In accordance with still another phase of the present invention, a snap locking arrangement is provided for securing the shield can on the base member without requiring any lugs to be turned down to hold the coupling device within the can.

The invention, both as to its organization and operation, together with further objects and advantages thereof, will best be understood by reference to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a front elevation view of a coupling device embodying the features of the present invention, portions of the shield can of this assembly being broken away to show certain features of construction;

FIG. 2 is a right side elevation view of the coupling device with the shield can broken away and a portion of the coil form assembly being shown in section through the center line thereof;

FIG. 3 is a sectional view taken along the lines 33 of FIG. 2;

FIG. 4 is a sectional view taken along the lines 44 of FIG. 3;

FIG. 5 is a sectional view on an enlarged scale taken along the lines 55 of FIG. 3 and showing a relatively small diameter coil form positioned on the base member;

FIG. 6 is a sectional view similar to FIG. 5 but showing the manner in which a relatively large diameter coil form is supported on the base member;

FIG. 7 is a sectional view taken along the lines 77 of FIG. 6;

FIG. it is a perspective view of the base member of FIG. 1 showing the manner in which a capacitor or other L pling device arrangement according to the present invention which is indicated generally at 11 and comprises a base member indicated generally at 12, a coil form 13 which is positioned on the base member 12 and carries a pair of

multilayer coils

14 and 15 thereon, and a shield can indicated generally at 16. The

coils

14 and 15 may conveniently be wound of insulated copper Wire on the coil form 13 and the ends of these coils are secured to terminal members indicated generally at 20, 21, 22 and 23. these terminal members being secured in the base member 12 by means to be discussed in more detail hereinafter. It will be understood that although the transformer shown in FIG. 1 utilizes a pair of

coils

14 and 15. a greater or lesser number of coils may be provided on the form 13 if desired.

In order to adjust the magnetic coupling between the

coils

14 and 15 as well as to change the inductance of each of these coils, the ferromagnetic core members 25 and 26 (FIG. 2) may be adjustably positioned in the coil form 13. The coil form 13 may be provided with a plurality of thin ribs 27 which extend longitudinally along the inner surface of the coil form 13 whereby the

cores

25 and 26 may be adjustably positioned with respect to the

coils

14 and 15, this construction of the coil form 13 being described and claimed in US. Letters Patent No. 2,838,738, granted to John J. Antalek and Robert W. Saville on June 10, 1958. While such construction of the coil form 13 cooperates with the specific form of base construction of the present invention, it will be understood that any other suitable coil form and tuning slug arrangement may be employed whereby a variable inductance device is provided insofar as the other features of the present invention are concerned. Furthermore, it will be understood that the

coils

14 and 15 need not be variable insofar as the present invention is concerned although it is customary to provide variation of the transformer windings to facilitate alignment of the transformer once it is assembled in its electronic circuit.

Considering now the manner in which the tuning capacitors or other disc type units in the assembly of the present invention are supported on the base member 12 and are conductively bonded to the transformer terminals, attention is first directed to the terminals 20 to 23, inclusive, themselves and more particularly to FIGS. 9 and 10 which show the delaiis ot' the terminal 21. As there shown, the terminal 21 is provided with a bifurcated upper portion Ill comprising a normally vertically positioned arm portion 30 and an inturned arm portion 31, these bifurcations or

arm portions

30 and 31 being positioned above the upper rim 32 of the base member 12.

The terminal 21 is mounted in a vertically extending slot 35 provided in the base member 12,

similar slots

35, 37 and 38 being provided respectively for the

terminals

20, 22 and 23. Each of these slots, such as the slot 35, is provided with a groove 40 which is adapted to receive an outwardly protruding reinforcing rib 41 provided in the lower portion of the terminal member 21 and there is also provided a groove 42 in the other side of the slot 35, the groove 42 having a sloping shoulder or step 42a at the upper end thereof over which a tang or projection 44 which is struck out of the body portion of the terminal 21 is adapted to snap and thereby retain the terminal 21 in position after it has been inserted into the slot 35 from the top of the base 12, as best shown in FIG. ll). The slot 35 is al o provided with shoulders 35a at the ends thereof and the terminal 21 is provided with a relatively widc portion above the tang 44 so that this wide portion is held against the shoulders 35a when the tang i -'4 is snapped in place, as best shown in FIG. 9. With this construction the terminal 21 is rigidly held and is prevented from twisting within the slot 35 so that the inturncd arm portion 31 thereof can exert a substantial size thrust on the edge mounted disc unit as will now be described.

In accordance with an important feature of the present invention, the inturned arm portions of opposed pairs of terminal members are employed to support a tuning capacitor or other disc type unit on edge on the base member 12 by engagement with opposite sides of the tuning capacitor. More particularly, considering the pair of

terminals

20 and 21, the inturned arm portion of the terminal 20 and the intnrned arm portion 31 of the terminal 21 are adapted to engage the opposite sides of a disc type tuning capacitor indicated generally at 51, the capacitor 51 being supported on edge on the base member 12.

The disc type unit 51 comprises a wafer-like self supporting base portion 52 (FIG. 11) constructed of a solid dielectric material, such, for example, as a ceramic material, the plates of the capacitor unit 51 consisting of two

metallic layers

53 and 54 which are provided on the opposite flat surfaces of the dielectric member 52, the edge of the dielectric member 52 being, however, free from conductive material. It will thus be understood that the plates or

electrodes

53, 54 are separated by the dielectric material 52 and having a capacitance therebetween which is dependent upon the areas of the plates and the thickness and dielectric constant of the base member 52. If it is desired. the capacitor 51 may be constructed by means of the arrangement disclosed in the copending application of Hal F. Fruth, S.N. 514,880, filed June 13, 1955, now abandoned, wherein there is disclosed an arrangement in which the dielectric core member is coated over the entire surface thereof With a conductive layer and therefater the conductive material is removed from the edge of the disc to provide a capacitor consisting of conductive surface portions separated by the dielectric core member. It will also be understood that the capacitor 51 may alternatively be formed by painting or printing a conductive varnish or metal on the opposed flat surfaces of the dielectric disc 52 so as to provide the

capacitor plates

53 and 54, insofar as the features of the, present invention are concerned. However, it is pointed out that in accordance with an important feature of the prescnt invention, the opposed electrodes 53 and S4 of the disc type unit, such as the capacitor 51, are not coated with any insulation or impregnation material but instead are left bare so as to permit the iuturncd arm portions 5!? and 31 to establish electrical contact thereto.

Considering now the manner in which the capacitor 51 is supported on the base member 12, the base member 12 is provided with a top opening recess, the edge of the capacitor 51 resting on the bottom surface 55 of this top opening recess. In order to facilitate positioning of the capacitor 51 on edge on the base ember 12 with the

arm portions

50 and 31 in engagement with opposite sides thereof, the base member 12 is provided with a pair of opposed positioning posts or

studs

60 and 61 adjacent the

terminals

26 and 21 which extend upwardly from the bottom surface 55 of the recess in the base member 12, the

studs

60 and 61 being connected to the side wall of the base member 12 by means of the web portions 62 and 63 (FIG. 8). In addition, a further positioning post or stud 64 extends upwardly from the bottom surface 55 of the top opening recess in the member 12, the stud 64 being spaced from the positioning stud 61. and an inwardly projecting vertically extending rib or lug portion 65 (FIG. 3) is provided on the outer wall 66 of the base member 12 adjacent to but spaced from the positioning stud 60.

It will thus be seen t at the

posit oning posts

60, 61 and 64 and the projecting lug 65 define an elongated narrow slot which is adapted to receive the tuning capacitor 51 on edge and loosely supports the same on the base member 12. However, it will also be noted that as soon as the

arm portions

50 and 31 are moved into cn gagement with the opposite sides of the capacitor 51 these arm portions exert a twisting action on the disc capacitor 51, due to the fact that the arm portions 56 and 31 engage the capacitor at laterally spaced points thereon, so that the capacitor 51 is urged against the side of the positioning post 64 and is also urged against the side of the projecting lug 65, as best illustrated in FIG. 3. Furthermore, it will be noted that since it is necessary to move the

arm portions

50 and 31 sidewise away from their initial positions when the tuning capacitor is positioned thercbetwcen these arm portions continuously exert a sidewise thrust on the opposed sides of the capacitor 51 and function to hold this capacitor in an upright position on the base member 12. In this connection it will be noted that the arm portions 51! and 31 are provided respectively with the oppositely directed right angle end portions '70 and 71 which actually contact the opposed bare electrodes on opposite sides of the capacitor 51 so that Contact to the plates of the capacitor 51 is established through the

end portions

70 and 71 at a localized area on the plates.

While the post 64 and lug 65 are of substantial height so that when the capacitor 51 is urged into engagement with the sides thereof the capacitor is held upright on the base 12, it will be noted that the contact making

end portions

70 and 71 of the arm portions as and 3!, respectively, contact the bare plates of the capacitor 51 at points spaced considerably above the upper surfaces of the base member 12 including the tops of the

posts

60, 61, 64 and the lug 65. This construction is provided so that in accordance with a further important feature of the present invention a good conductive bond may be established between the

end portions

70 and 71 and the electrodes of the capacitor 51 and reliance is not placed solely on a pressure contact between these members to maintain good electrical connection. More particularly, after the capacitor 51 has been inserted into the base member 12 and the arm portions t and 31 moved into engagement therewith, it is held in this position due to the above described twisting action which holds the capacilor against the post 64 and the lug 65. This pressure is sufiicient that the base member may be inverted without the capacitor 51 dropping out of its slot in the base member 12. Accordingly, after the capacitor 51 has been positioned in the base member as shown, for example, in FIG. 8, the base member is inverted and is dipped into a pot of solder to a depth sufhcient to submerge the

end portions

70 and 71 but not to a depth sufficient to cause any portions of the base member 12. itself to come in contact with the melted solder. The base member 12 is then removed from the molten solder with the result that the

end portions

70 and 71 are conductively bonded to the opposed electrodes of the capacitor 51. More particularly, the entire upper surface of each of the

plates

53 and 54 is covered with a film of solder 53a and 54a (FIG. 11) and a fillet of solder is provided around each of the

end portions

70 and 71 so that a strong physical as well as an electrically conductive bond is established between the

end portions

70 and 71 and the

conductive plates

53 and 54 of the capacitor 51. One such fillet of solder is indicated at 74 in FIG. 4 whereby the end portion 70 of the arm portion 50 is conductively bonded to the plate 53 of the capacitor 51. However. it will be noted that while the dip-soldering operation completely covers the upper portions of the

plates

53 and 54 of the capacitor 51, the solder does not adhere to the edge of the dielectric disc 52 so that the plates of the capacitor 51 are not conductively shorted together. Furthermore, the solder films 53a and 54a do not appreciably change the capacitance of the capacitor 51 since they do not affect either the area of the

plates

53 and 54 or the spacing thereof.

The base member 12 is also arranged to support a second tuning capacitor, indicated generally at 76. between the spaced apart

terminals

22 and 23. More particularly. the positioning posts 73 and 79 are provided adjacent the

terminals

22 and 23, respectively, these posts being similar to the positioning posts 60 and 61 described above, a positioning post 86 is positioned in spaced relation to the post 78 and a vertically extending lug 81 on the bl'lafi! 12 is provided in spaced relation to the post 79. The inturned arm portions 85 and 8-6 of the

terminals

22 and 23, respectively, are provided with oppositely directed end portions 88 and 89 which are adapted to engage the opposite sides of the capacitor 76 at laterally spaced points thereon so that a twisting action is exerted on this capacitor and it is urged against the sides of the positioning post and the lug 81 so that it is held on edge in the base 12, as shown in FIG. 3.

In the actual manufacture of the transformer in accordance with the present invention both the

capacitors

51 and 76 are assembled on the base 12 and pi 'oncd between the restraining arm portions of the t terminal members before the dip-soldering operation is performed. Accordingly, all four solder connections may be performed in one dip-soldering operation so that a conductive bond is established to both of the tuning capacitors of the transformer in a single soldering operation. Furthermore, it will be appreciated that a number of such base assemblie with tuning capacitors mounted lhClC- on may be mounted in a common jig and inverted so that they are all soldered in a single operation thus ciiccting a material saving in manufacturing time and labor over previous arrangements. Attention is also directed to the fact that the dip soldering operation whereby the terminal members of the transformer are conductively bonded to the electrodes of the tuning capacitors is performed before the coil form 13 is assembled on the base member 12. and before the leads from the coils positioned on the coil form are connected to the vertically extending portions of the terminal members. In this connection it will be understood that the vertically extending portions of the terminal members 20 to 23, inclusive, such as the vertical bifurcation 30 of the terminal 21, are also immersed in the molten solder during the above described dip-soldering operation. However, this operation only has the effect of tinning the ends of the vertically extending terminal portions, such as the portion 30. and thus facilitates the connection of the coil leads to these terminals at a later time. However, if desired, the vertically extending terminal portions, such as the portions 38, may be bent outwardly so that they do not contact the solder during the dipsoldering operation if, for any reason, it is not desired to tin these terminal portions.

Considering now the manner in which the coil form 13 is assembled on the base member 12, a transverse reinforcing rib 95 is provided across the bottom of the reeess in the base member 12 in the center of which rib there is provided an annular mounting sleeve 96 which extends upwardly from a circular base portion 97. The mounting sleeve 96 is arranged to support either the relatively small diameter coil form 13 or a relatively large diameter coil form 98 (FIGS. 6 and 7"). More particularly, in order to receive the relatively small diameter coil form 13 within the mounting sleeve 96, this sleeve is provided with a stepped portion 100 of soiricwhat smaller internal diameter which extends only partially up to the length of the sleeve 96, the stepped portion 100 being provided with a series of vertically extending inwardly projecting ribs 191 which function to grip the outer surface of the coil form 13 when it is inserted into the step porticn 100 of the mounting sleeve 96. An inwardly ex tending shoulder 102. is provided at the bottom of the mounting sleeve 96 so as to seat the bottom of the coil form 13. li will be noted that the coil form 1.3 is sccured within the mounting sleeve 96 by engagement with only the stepped portion 100 thereof so that the outward forte exerted on the mounting sleeve 96 when the coil form 13 is inserted therein is applied only to the base portion of the sleeve and hence cracking or splitting of tlie sleeve is avoided.

The mounting sleeve 96 is also provided with a series of closely spaced vertically extending ribs 1915 on the outer surface thereof. The ribs 105 are provided for the purpo-e of interlocking with the internal longitudinally extent g lbs 136 of a. relatively large diameter coil form 93 when this coil form is inserted over the outside of the mounting sleeve 96, the coil form 98 being forced over the sleeve 96 until it seals on the circular base portion 97. Due to the interlocking of the

ribs

105 and 106 the coil form 95 is not only firmly seated on the mounting sleeve )6 but i also prevented from rotating with respect to the base member 12. In this connection it will be understood that the ribs 1186 may serve the additional function of adjustably pos tioning the tuning slugs within the coil form 98. as described in the above identified Patent No. 2.838.738. Also it will be noted that the positioning posts 64 and R8 are spaced from the outside ribs 105 on the mounting sleeve )6 by an amount sufficient to permit the insertion of the large diameter coil form 98 over the sleeve 96. It will also be noted that the positioning posts 6-1 and 81) serve the additional purpose of providing a positioning means for the tuning capacitors while permit ting the coil form 98 to be inserted over the mounting sleeve 96 after the tuning capacitors have been soldered in place in the manner described above.

The coils 14 and may be Wound on the coil form 13 either before or after this coil form is positioned on the base member 12. However, it will be understood that if the

coils

14 and 15 are wound on the coil form 1.3 after this coil form is secured to the base member 12. the upstanding terminal portions such as the portion of the terminal members of the transformer are prefernhlv bent outwardly so as to provide clearance for the coil winding mechanism in the event that the coil is wound relatively close to the base member 12. It has been found that the procedure of winding the

coils

14 and 15 after the coil form 13 has been secured to the base member 12 results in a somewhat simpler manufacturing technique in that the ends of the respective coils can first be secured to the corres onding upstanding terminal portions so that the coil winding operator can trace the start and finish coil leads m re easily. In this connection it will be understood that the start and finish leads 131i and 131 of the coil 1-1 are connected to a pair of terminal members which are positioned on opposite sides of the recess in the base mcmler so that the tuning capacitor connected between the inturned arm portions of these terminal members is c nnected across the coil. Thus, the

leads

130 and 131 are c nnected to the vertically extending

portions

132 and 133 of the

terminals

23 and 22, respectively, so that the tuning capacitor 76 is connected across the coil 14. In a similar manner the

leads

135 and 136 may be connected to the upstanding terminal portions of the

terminals

21 and 20. respectively, so as to connect the capacitor 21 across the winding 15. It will be noted that the upstanding terminal portions, such as the portion 30 of the terminal 21, are provided with a notch 138 in the upper end thereof to facilitate connection of the coil leads to these terminals, it being necessary only to hook the coil lends over the notches 138 and wrap the lead one or two turns around the terni' Ill. After the coil lends have been secured to the upstanding terminal portions in the manner described above, they may be conveniently dip-soldered to these terminals by bending the terminals outwardly so that they extend beyond the edge of the ba e member 12. When so en he termin ls with coil lends attached thereto may be lowered into a pot of molten solder so that the coil leads on one side of the base member may both be soldered simultaneously to their respective terminals, it being understood that the trtn'zsl'nrincr assembly is not lowered into the solder sutiicient y to permit the solder to contact either the base member 1?. or the coils on the coil form 13. The transformer assembly may then be turned over and the terminals of the oppo ite side of the base member soltiered by a similar dip-soldering operation, after which all four of the terminal members are bent back to their initial vertical position. The transformer assembly is then ready for the shield can 16 to be assembled thereon.

In this con action it will be noted that the base member 12 is provided with a pair of terminal receiving

slots

107 and 108 within which may be positioned terminals similar to the terminals 20 to 23, inclusive, but which are, however, not provided with an inturned arm portion such as the arm portion 31. of the terminal 21. These intermediate terminals may be employed to establish connection to other desired connection points on the coils positioned on the coil form 13, such, for example, as a center tap for either of the coils 1 1 or 15. However, since no tuning capacitor is to be connected across these intermediate terminals the iuturned arm portions thereof are not required.

Considering now the manner in which the shield can 16 is formed in accordance with the present invention, it is first pointed out that this shield can may be provided with a grounding lug or terminal 111) which may be secured to the bottom portion of the can 16 by any suitable means such as rivets or the like, the ground strap extending downwardly along the side of the base member 12 so that it projects below the bottom of the shield can 16. In the center of the top portion of the shield can 16 there is provided a vertically extending tubular portion 115 which defines an opening adapted to receive the upper end of the coil form 13. In accordance with a further feature of the invention, the entire top portion 116 of the shield can intermediate the straight sides thereof and the central sleeve 115 is formed so that it slopes inwardly at a substantial angle to the horizontal to form a comically shaped top. Accordingly, as the shield can 16 is inserted over the transformer assembly and the upper end of the coil form engages the conical section 116, this section acts as a guide for the upper end of the coil form and facilitates insertion thereof into the sleeve portion 115 as the shield can is moved downwardly to enclose the base member 12. Since the entire top portion of the shield can 116 is conically shaped no transverse surfaces are presented to the end of the coil form 13 with the result that this coil form slides easily into the sleeve 115, at which point the coil form 113 is accurately centered with respect to the shield can 16 and the base 12. As the shield can 16 is forced downwardly over the base member 12 a snap lot-king arrangement is provided so that the shield can is secured to the base member 12 witl out requiring the bending of any lug porti ns or other arrangements for holding: the shield can in place. More particularly, there is provided on two opposed sides of the base member 12 a pair of wedge-shaped projections 1Z0 and 121 which cooperate with a pair of elongated

transverse slots

122 and 123 in the shield can 16 to hold the shield can in place. As the shield can is inserted over the base member 12 the

wedge portions

120 and 121 force the sides of the shield can outwardly until the shoulders therof have been snapped into place in the

slots

122 and 123 at which point the shield can becomes secured to the base member 12 and cannot readily be removed due to the fact that the shoulders of the

wedges

120 and 121 engage the bottom edges of the slots 122 and [132 and] prevent such removal.

While particular embodiment of the invention have been shown, it will be understood, of course, that the invention is not limited thereto, since many modifications may be made, and it is therefore contemplated by the appended claims to cover any such modifications as fall within the true spirit and scope of the invention.

What is claimed as new and is desired to be secured by Letters Patent of the United States is:

1. The method of making a transformer of the type which includes a base member having a plurality of terminal members thereon, a coil form for supporting a coil and a capacitor having opposed electrodes, which comprises [a] the steps of positioning said capacitor on said base member with said terminal members in engagement with the electrodes of said capacitor at points spaced above the upper surface of said base member, conductively bonding said terminal members to said electrodes by immersing tne upper portion of cl capacitor and the ends of said terminal members engaging said opposed electrodes in molten solder, then mounting said coil form on said base member, and connecting the ends of a coil wound on said coil form to said terminal members.

2. The method of making a transformer as recited in cla m 1, wherein said coil is wound on said coil form after said coil form is mounted on said base member by first attaching one end of a length of wire to one of said terminal membes, winding said length of wire on said coil form to provide a coil thereon and then attaching the other end of said length of wire to another of said terminal members.

3. The method of making a transformer as recited in claim 1 which includes the step of ccnductively bonding said ccnnected ends of said coil to said terminal members by dip soldering.

4. The method of making a transformer of the type which includes a base member ha\ a plurality of terminal members thereon, a coil form for supporting a coil and a disc capacitor having opposed electrodes, which comprises the steps of positioning said capacitor on sail base member with said termi Ztl members in engagement with the electrodes of said capacitor at points spaced above the upper portion of said base member, moving said base member to an inverted position while maintaining said capacitor positioned on said base member by engagement of said terminal members with said electrodes, conduclively bonding said terminal members to said electrodes by dip-soldering while said base member is in said in verted position, then mounting said coil form on said base member, and connecting the ends of a coil wound on said coil form to said terminal members.

5. The method of making a transformer of the type which includes a base member having a plurality of terminal members thereon, a coil form for supporting a coil and a capaci or of the disc type having opposed elect odes separated by a layer of dielectric, which comprises the steps of positioning said capacitor on edge on said base member with a first portion of said terminal members in engagement with said opposed electrodes of said capacitor, conrluctivcly bonding said first portions of said terminal members to said electrodes by immersing the same in molten solder, then mounting said coil form on said base member, and connecting the ends of a coil wound on said coil form to a second portion of said terminal members.

6. The method of making an inductance-capacitance assembly of the type which includes a base member having a plurality of terminal members thereon, a coil form for supporting a coil and a disc capacitor having opposed electrodes, which comprises the steps of positioning said capacitor on said base member with a first portion of said terminal members in engagement with said opposed electrodes of said capacitor at points spaced above the upper surface of said base member, conductively bonding said first portions of said terminal members to said electrodes by dip-soldering and without bringing said base member into contact with the molten solder, then mounting said coil form on said base member, and connecting the ends of a coil wound on said coil form to a second portion of said terminal members.

7. The method of making an inductance-capacitance assembly as recited in claim 6 which includes the steps of bending said second portions of said terminal ment hers with said ends connected thereto beyond the edge of said base member, and conductively bonding said connected ends to said second portions of said terminal members by immersing the same in molten solder without immersing said base member.

8. The method of making an inductance-capacitance assembly as recited in claim 6 which includes the steps of bending said second portions of said terminal members with said ends connected thereto beyond the edge of said base member, conductively bonding said connected ends to said second portions of said terminal members by immersing the same in molten solder without immersing said base member, and then bending said second portions of said terminal members to points within the periphery of said base member to permit enclosure of said base member and coil form within a. metallic housing.

9. The method of making an inductance-capacitance assembly as recited in claim 6, wherein said coil is wound on said coil form after said coil form is mounted on said base member by first attaching one end of a length of wire to said second portion of one of said terminal members, winding said length of wire on said coil form to provide a coil thereon, and then attaching the other end of said length of wire to said second portion of another of said terminal members.

16. The method of making an inductance-capacitance assembly which comprises the steps of positioning a disc capacitor between spring arm portions of a pair of terminals mounted on a base member with said spring arm portions in engagement with conductive electrode portions on opposite sides of said disc capacitor, moving said base member with said capacitor positioned thereon to a position in which the points of engagement of said spring arm portions with said conductive electrode portions are below said base member and conductively bonding said spring arm portions to said conductive electrode portions by immersing the same in molten solder, then mounting a coil form on said base member, and connecting the ends of a coil wound on said coil form to other portions of said terminal members.

11. The method of making an inductance-capacitance assembly as set forth in claim 10 wherein said second por tions of said terminal members are conductively bonded to said connected ends of said coil by immersing the same in molten solder without bringing said base member and coil form into contact with the molten solder.

12. The method of making an inductance-capacitance assembly which comprises the steps of positioning a disc capacitor between spring arm portions of a pair of terminals mounted on a base member with said spring arm portions in engagement with conductive electrode portions on opposite sides of said disc capacitor, said spring arm portions engaging said electrode portions at points above the upper edge of said base member, moving said base member with said capacitor positioned thereon to a position in which the points of engagement of said spring arm portions with said conductive electrode portions are below said base member and conductively bonding said spring arm portions to said conductive electrode portions by immersing the same in molten solder, said spring arm portions engaging said opposite sides of said capacitor with sufiicient force to hold said capacitor on said base member during said soldering operation, then mounting a coil form on said base member, and connecting the ends of a coil wound on said coil form to other portions of said terminal members.

13. The method of making an inductance-capacitance assembly which comprises the steps of positioning a disc capacitor on edge within the top opening recess of a base member and between spring arm portions of a pair of terminals extending through said base member, said spring arm portions extending above the upper edge of said base member and engaging conductive electrode portions on on posite sides of said disc capacitor, moving said base member with said capacitor positioned thereon to a position in which the points of engagement of said spring arm portions with said conductive electrode portions are below said upper edge of said base member and conductively bonding said spring arm portions to said conductive electrode portions by immersing the same in molten solder, said spring arm portions engaging said opposite sides of said capacitor with sufiicient force to hold said capacitor within said recess in said base member during said soldering operation, then mounting a coil form on said base member, and connecting the ends of a coil wound on said coil form to second portions of said terminal members which extend above said upper edge of said base member.

14. The method of making a transformer, which comprises the steps of positioning a pair of terminals in elongated slots in a base member with bifurcated portions of said terminals extending upwardly above said base member, one bifurcation of each terminal extending inwardly over a top opening recess in said base member of said inwardly attending bifurcations are below said upper edge of said base member, condnctivcly bonding said inn 'm'dly extending bifurcations to said condnctire portions by immcrsing the some in molten soldcr, said inwardly extending bifurcations engaging said opposite 15 sides of said capacitor with snflicfcnr force to hold said capacitor within said rcccss in said busc nzcmhcr during said solder immersing operation, and mounting a coil form on said base membcr and connecting the ends of a coil wound on said coil form to second portions of said terminal mcmbcrs which cxtcnd above said nppcr edge of said base member.

References Cited The following references, cited by the Examiner, are

of record in the patented file of this patent or the original patent.

UNITED STATES PATENTS 2,751,665 6/1956 De Roovere 29-1555 2,869,041 1/1959 De Cola 29155.5 2,946,026 7/1960 Rollefson 29155 5 2,974,258 3/1961 Garthwaite 29--155.5 2,954,117 9/1960 Frceburg.

JOHN F. CAMPBELL, Primary Examiner.

R. W. CHURCH, Assistant Examiner.