US 3824519 A
A coil form with an integrally formed terminal boards which is adopted to mate with another form having a similar terminal board to form enclosed, electrically insulated compartments. A crimp-solder terminal formed by a coil of wire is also provided.
Claims available in
Description (OCR text may contain errors)
United States Patent [1 1 Miller July 16, 1974 COIL FORMS AND TERMINAL  Inventor: lmrich M. Miller, Paterson, NJ.
 Assignee: Universal Manfuacturing Corporation, Paterson, NJ.
 Filed: Feb. 16, 1973  Appl. No.: 333,222
 U.S. Cl 336/192, 336/208, 339/275 R  Int. Cl H011 15/10, HOlf 27/28  Field of Search 336/198, 208, 192;
174/88 R, 94 R; 339/275 R, 275 C  References Cited UNITED STATES PATENTS 3,008,119 11/1961 Svvengel 174/88 R 3,066,274 11/1962 Ellis, .lr.
3,089,223 5/1963 Walker 174/94 R 3,096,796 7/1963 Dittrich 174/94 R 3,189,772 6/1965 Wingler et a1. 336/198 R 3,189,857 6/1965 Jones 336/208 X 3,359,395 12/1967 Bruce 336/208 X 3,566,322 2/1971 Horbach.. 336/198 X 3,585,450 6/1971 Lane 336/198 X 3,605,055 9/1971 Grady 336/208 X 3,661,342 Sears 336/208 X Primary Examiner-Thomas J. Koz'ma Attorney, Agemyor FirmDarby & Darby 57] ABSTRACT A coil form with an integrally formed terminal boards which is adopted to mate with another form having a similar terminal board to form enclosed, electrically insulated compartments. A crimp-solder terminal formed by a coil of wire is also provided.
12 Claims, 7 Drawing Figures PATENTED JUU 6 74 SIEUIBFZ fig. 1
PATENIEHmsmu SHEE'I 2 OF 2 fig. 7
BACKGROUND OF THE INVENTION Many devices require forms over which one or more coils of electrical wire are wound. A typical device is the ballast transformer used in a fluorescent lighting system. In a typical ballast transformer two coils for the primary and'secondary windings are wound on one or more forms and placed adjacent one within the transformer laminations. Where the windings are wound on separate forms, they are spaced from each other on the center leg of the laminations. The entire assembly of windings plus the laminations are then placed within an enclosure. Connections from the windings t the other parts of the ballast, such as the leads to be connected to the AC source and the leads to be connected to the lamp sockets, are made on a terminal'board, i.e., a fiber board which has upstanding solder lugs. The terminal board is usually independent of the coil form and is located at an end of the stack of laminations. The connections are made either by any one or combination of soldering, crimping or wrapping the various coilsto terminals on the board.
In a typical case, a wire from the coil winding is crimped to a terminal on the board and the lead wire is then soldered to some other portion of the board through which an electrical connection can be made to the same terminal. Special types of terminal devices have been developed to permit the combination of a crimp and a solder connection. Typical types of such terminals are manufactured by Amp Inc. and are illustrated on page 62l of the AMP Terminal and Connector Handbook (Third Ed.).
The previously available terminal devices providing a combination of solder and crimp connections are, for
their intended purposes, relatively complex and costly. Further, these prior art devices do not provide the efficiency and ease of use needed in an assembly line operation setup for the economical production of a commercially competitive product.
The prior art arrangement of having the terminal board separate from the coil forms does not advantageously employ the space available between the two coil winding forms when the forms are spaced from one another during their use in a ballast transformer.
Also, the prior art devices required the coil wire to be extended away from the winding coil form for some distance to the terminal board. This increased the possibility of a coil wire being damaged during the manufacture or packaging of the ballast transformer.
OBJECTS It is therefore an object of the present invention to provide coil forms having integrally formed terminal boards.
A further object is to provide a novel terminal device which is useful for both crimp and solder electrical connections.
Another object is to provide a crimp and solder terminal which cooperates with the terminal board of the 'coil forms.
An additional object is to provide a first coil form which when combined with a second cooperating coil form produces a mounting for electrical terminals having individual semi-enclosed compartments for the ter- 2 minals toreduce the possibility of the short-circuiting of the coil wires.
A further object is to provide a pair of coil forms which permit a reduction in the size of a ballast transformer.
Another object is to provide a-coil form with terminal board and a terminal'which permit increased assembly line speeds, while at the same time increasing the reliability of the electrical connection that are made.
SUMMARY OF THE INVENTION which extend perpendicular to the respective end plate.
The members of a pair of the coil forms are arranged so that when two coil forms are mounted adjacent one another a pluralityof individual semi-enclosed compartmentsare provided .which are open only on the top. One or more electrical terminals can be located in'each of the compartments, spaced and electrically insulated from all of the otherv terminals by the compartment walls.
In a preferred form of the invention, an electrical terminal is utilized which comprises a single strand of electrically conductive wire having a pair of arms and formed with several turns at its mid-section to define an opening. Crimp connections can be made between one or both of the arms of a terminal while one or more lead wires may be soldered in place within the terminals mid-section.
In, the Drawings I FIG. 1 is an exploded perspective view of a pair of coil forms according to the invention;
FIG. 2 is a top view, partially fragmented, showing the terminal boards and the compartments formed by a pair of the coil forms;
FIG. 3 is a fragmentary, perspective view showing a T-shaped divider projection on the terminal board and a terminal;
FIG. 4 is an enlarged perspective view of a portion of a coil form partially broken away and showing a terminal in place; I
FIG. 5 is a side view of a solder and crimp terminal used in cooperation with the terminal boards of FIG. 1;
FIG. 6 is a side view of the solder and crimp terminal of FIG. 4; and
FIG. 7 is a perspective view showing a fully assembled transformer. using a pair of the coil forms.
Referring to FIG. 1, each of a pair of coil forms 10 and 11 has a hollow, generally square or rectangular, center leg 12, formed by four sidewalls l4. Enlarged end plates 22 and 24 are attached to each center leg 12 and extend peripherally and outwardly therefrom. The end plates of 22,24 of each form define a channel in which the coil wire is wound over a respective center leg 12. The center legs 12 can be of any necessary length. As shown, the center leg 12 for form 11 is larger than that for form 12.
A terminal board 28, whose details are described below, is integrally formed on the outer face of at least one of the end plates 22 or 24 of each coil form. In FIG.
l, the boards 28 are on the end plates 22 which will face each other in the final assembly of the transformer. I
In the preferred embodiment, the coil forms and their respective terminal boards are made of a suitable plastic material and may readily be manufactured by any of the well-known processes for molding plastic such as, for example, injection molding. Any suitable plastic material can be used, for example, ABS plastic, XT plastic, CRY OLAC, etc. Any suitable electrically nonconductive material can be used for the coil form, depending on the particular application of the coil form.
As seen in FIG. 1, the terminal board 28 of each coil form is formed to include a like number of partial vertical walls 30-34. The walls 30-34 are parallel to one another and project generally perpendicular from the respective end plate. The vertical walls 30-34 of the form are shown as being in reverse order from those of form 11 so that they will match up whenthe two forms are placed together.
Each terminal board also has a lower wall formed by two sections 41 and 43. The lower wall closes off the bottoms of the vertical walls 30,32,34,36,38. Section 43 is inset slightly from section 41 to aid in the alignment of two of the terminal boards. I
As shown in FIGS. 2 and 7, when the two coil forms 10 and 11 are aligned, the vertical walls -34 match up, as do the two pairs of bottom wallsections 41 and 43, to form individual compartments 44,45,46,47. Each of the compartments 44-47 is enclosedon four sides and its bottom.
Each of the terminal boards 28 also has one or more raised platforms 50 spacedfrom its bottom wall section 41 and 43. One such platform 50 is shown on coil form 10 in the area between the walls 33 and 34. A platform 50 is shown respectively in the areas between walls 30,31 and 32,33 of the coil form '11. Each platform 50 extends beyond the bottom wall 41 or 43 of-its respective terminal board. This is shown, for example, in FIG. 3. The lengths of the platforms 50 is substantially equal to the length of one of-the compartments 44, 45 or 47, formed when the two coil forms are mated together.
As shown in FIG. 4, each of the platforms has, an upstanding lug whose rear portion 62 adjacent to the back wall of the terminal board, that is, the end plate 22 of the coil form, is curved upwardly.
A. pair of holes 76 and 78 are formed through each of the platforms 50,54, one hole on each side of the respective platform lug 60. One of the holes 78 is positioned further away from the end plate 22 than is the other 76. The purpose of these holes 76 and 78 is explained below.
As shown in FIG. 1, each of the partial vertical walls 30-38 has'a respective generally semi-circular cut-out 90. Where a wall is adjacent a platform, the cut-out 90 is slightly above the platform. The cut-outs 90 on the respective walls 30-34 of the two coil forms form a complete generally circular openings 92 in the vertical walls 30-34 when coil forms 10 and 11 are mated. This is shown in FIG. 7'. Each of the openings 92 is made large enough to accept the insulated portion of a lead wire which is used to connect, the coil wires of the transformer to the remainder of the circuit, such as the lamp sockets and A.C supply (not shown).
The preferred embodiment of the invention utilizes the solder and crimp terminal 80, shown in FIGS. 4 and solder orit is. tinned or plated for this use. The wire used in forming the electrical terminal is also relatively soft to permit the armsto be readily manipulated and for the various portions of'the terminal to remain set when moved to a given position.
The diameter of the wire forming the terminal 80 is such that the arms 86 and 88 can pass through the holes 76 and 78 of the platforms 50,52 and 54. As shown in FIGS. 3 and 4, a respective'terminal 80 rests on a lug 60. The arcuate rear surface 62 of the lug 60 accommodates the round shape of the terminals body. The offset of the holes 76 and'78 readily accepts the offset of the arms 86 and 88 of the terminal which, as shown in FIG. 4, do not extend from a common line.
Slotsand gaps 66,68 of different widths are provided in each'end plate 22 so that one or more of the coil wires can pass from the coil into the various compartments formed by the terminal board where they are electrically connected to a terminal 80. Each slot 66 extends down to the floor section 41 or 43 of the respective terminal board while'each slot 68extends only part way down. Slots 66 are made deeper so as to accommodate the coil wire from a lower part of the coil.
In a typical application where a transformer is to be produced, the start (lower) end of the coil is placed through one of the slots 66 on the terminal board. A
- sufficient length of the free end is left for further processing. The coil is then wound over the center leg of the respective form of the desired number of turns. The finish (upper) end of the winding is then brought back out to the terminal board through slot 68.
As shown in FIG. 1, the coil 15 on form 10 has two ends brought back out to the terminal board while coil 16 on form 11 has three ends. Coil 15 is, for example, a transformer secondary winding, while coil 16 is, for example, a primary winding that is tapped. The latter accounts for the four wires a pair of which from the tap point are brought out through the wider gap 66.
After the coils are wound, a terminal is mounted on a respective platform 50 by inserting its arms 86,88 through the respective holes 76,78. The arms can be bent or spread to hold the terminal in place. If the end,
or ends, of the lead wire of a coil 15 or 16 is, or are, to
be connected to a terminal 80 or the terminalboard of the respective coil form, a crimp connector 98 can be used. FIG. 3 shows end 15a of coil 15 connected to arm 88 of the terminal 80. The other end 15b is wrapped over a holding pen 99 on the terminal board. The ends 16a of coil 16 from the top of coil 16 are both connected to the same terminal 80 by acrimp connector or connector 98 (not shown). One of the other two ends is connected by a crimp connector 98 to an arm of the other terminal 80 on form 11. The fourth end is wrapped around a holding pin 100.
As shown in FIGS. 2 and 7, the two coil forms 10 and 11 are mated so that the two terminal boards 28 come together forming individual compartments 44-47 which are open on the top. Laminations, which may be of an L-T-L, F-T-F or other suitable configuration, are fixed in place surrounding the two coil forms and maintain the coil forms in fixed relationship.
The free ends of the primary and secondary coils which were held in place by the holding pins 99,99 are now crimp-connected to one to complete the connec-- tions between the windings.
To complete the wiring for the external circuit, the required number of lead wires 115 each has the insulation stripped from its end and is then inserted through an opening 92 into a respective compartment 44-47. The bare end of a respective lead wire 92, which is preferably pre-tinned is placed into the opening in the central section 84 of a terminal 80. It is then soldered in place. The terminals 80 are preferably pre-tinned.
Since the terminal board compartments 4447 fully insulate and isolate the terminals 80 from the coil windings, the soldering operation will not result in damage to the insulation of any of the windings. Additionally, the openings 90 in the walls of the terminal board fit closely around the insulated portions of the lead wires 92 and hold the lead wires in place and reduce the stress transmitted along the wire to the soldered connection, thereby improving the reliability of the connection.
Terminal 80 of the subject invention is very simple and provides a marked advantage over the previously available crimp and solder terminal. The terminal is inexpensive to make, does not have any complex parts and is subject to an absolute minimum of operational failure. Further, such a terminal is very simple to use, particularly in an assembly line production operation.
The terminal board structure itself is also very reliable and provides full and complete insulation between the leads, the coil windings and the terminals.
In addition, the terminal boards occupy the space between the two forms that is normally unused. This results in a decrease in the overall length of the transformer.
What is claimed is:
l. A coil form comprising a center winding leg over which a coil is to be wound,
at least one end plate on an end of said winding leg,
terminal board means attached to said end plate and extending outwardly therefrom, said terminal board means including at least one terminal mounting platform extending generally transverse to said end plate and having an accessible bottom portion, an electrical terminal adjacent thetop of said terminal mounting platform, said terminal comprising a coil of at least one turn of electrically conductive wire having an arm extending from one end thereof, at least one opening in said platform, an arm of said terminal extending through a said opening'to mount the terminal to said platform. 2. A coil form as in claim 1, wherein said terminal board means includes at least a pair of walls also extending generally transverse to said end plate, said walls defining at least a portion of a compartment.
3. A coil form as in claim 2, wherein'there is a said wall on each side of a terminal mounting platform.
4. Electrical apparatus'comprising first and second coil forms each having a center leg on which a coil of wire is wound and an end plate on an end of each such leg;
a respective terminal board means extending outwardly from said end plate of each coil form, each said terminal board means including at least a pair of elongated walls spaced apart and extending generally transverse to the respective end plate and generally transverse to the same edge of the respective end plate leaving an open space between said walls at said edge of a said plate for access to the space therebetween;
means mounting said first and second coil forms with the end plates thereof opposing each other and spaced apart to align said walls of the respective terminal board means of said end plates of said first and second coil forms to form with said end plates at least one semi-enclosed compartment for housing an electrical connection in a protected relationship which is fully accessible from the exterior in the space between the said walls of each said end plate, and an opening formed in at least one of the end plates forming the semi-encl0sed compartment to permit passage of a wire through said opening into the compartment, and a terminal support base projecting outwardly from at least one of said end plates generally transverse thereto and into a said semi-enclosed compartment. 7
5. Apparatus as in claim 4, wherein said support base includes an upstanding lug.
6. Apparatus as in claim 5, wherein said lug includes an upwardly rising rear portion.
7. Apparatus as in claim 5, wherein said terminal base support includes at least one hole on each side of said lug.
8. Apparatus as in claim 7, wherein one hole on one side of said lug is located further from the end plate of the corresponding terminal board than the hole on the other side of the lug.
9. Apparatus as in claim 4, further comprising a terminal connector mounted on a said terminal support base, said terminal connection of electrically conductive wire having a hollow central body portion adapted for a solder connection of another wire and an arm extending from at least one end of said coil adapted for a mechanical connection of another wire.
10. Apparatus as in claim 9, wherein an arm extends from each end of said coil, said arms being generally transverse to the central longitudinal axis of said hollow central body portion.
11. Apparatus as in claim 4, wherein two aligned walls on each of the terminal boards of said first and second coil forms each have a portion of an opening therein which forms an opening when the two walls are aligned to permit passage of a wire through said opening into a portion of the compartment.
12. Electrical apparatus as in claim 4 further comprising a bottom wall on each said end plate extending transversely thereto and joining the pair of walls of each said terminal board at the end thereof remote from said edge of the said end plates.