Loading Coil Packaging Arrangement

Abstract

A coil tray assembly is provided which not only permits a number of loading coils to be more easily packaged, but further permits coil cases of various standard sizes to be constructed using the coil trays. The coil tray is a molded L-shaped plastic tray with either twelve or thirteen terminated coil assemblies inserted and potted therein with an encapsulating compound. This basic coil tray assembly can be used in the construction of either a 6 inch square, 11 .times. 6 inch rectangular or a 11 inch square coil case. Provisions for wire-wrapped termination of cable leads to coils instead of using special connectors and lead out wires also are provided. Further still, greater coil density with coil cases is possible, and the spaced and orientated coils within the trays eliminate the need for crosstalk plates and/or production tuning of the coils.

Description

This invention relates to an improved loading coil packaging arrangement.

Loading coils are used in telephone communication systems for improving the electrical characteristics of the voice frequency cables. The number of loading coils may vary in any particular installation from, for example, 25 to 600 loading coils. These loading coils generally are mounted on or in trays of various different configurations, and then hermetically sealed in a coil case which is of a standard design and adapted to hold a number of these trays.

In accordance with the present invention, a new basic coil tray assembly is provided which not only permits a number of loading coils to be more easily packaged, but further permits coil cases of various standard sizes to be constructed using the coil trays. The coil tray is a molded L-shaped plastic tray with either twelve or thirteen terminated coil assemblies inserted and potted therein with an encapsulating compound. This basic coil tray assembly can be used in the construction of either a 6 inch square, 11 inches .times. 6 inches rectangular or a 11 inch square coil case. Provisions for wire-wrapped termination of cable leads to coils instead of using special connectors and lead out wires also are provided. Further still, greater coil density with coil cases is possible, and the spaced and orientated coils within the trays eliminate the need for crosstalk plates and/or production tuning of the coils.

Accordingly, it is an object of the present invention to provide an improved loading coil packaging arrangement.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of the coil tray;

FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1;

FIG. 3 is a sectional view taken along lines 3--3 of FIG. 1;

FIG. 4 is a sectional view taken along lines 4--4 of FIG. 1;

FIG. 5 is an end plan view of the coil tray of FIG. 1;

FIGS. 6 and 7 are side and end plan views of the terminal used with the coil tray;

FIGS. 8 and 9 are side and end plan views illustrating the manner in which the coils are affixed to the terminals;

FIG. 10 is a top plan view of a coil tray with the coils loaded therein;

FIG. 11 is a sectional view taken generally along lines 11--11 of FIG. 10;

FIG. 12 is a top view generally illustrating the manner in which the coil trays are loaded into a coil case;

FIG. 13 is a side view, partly sectionalized, to illustrate the manner in which the coil trays are loaded in the coil case of FIG. 12; and

FIGS. 14 and 15 are top views generally illustrating the manner in which the coil trays are loaded into two other standard coil cases.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to the drawings, in FIGS. 1-5, there is illustrated a coil tray 10 which is generally L-shaped in configuration and which has a number (12 in the illustrated embodiment) of semi-circular shaped cavities 12 therein for receiving loading coils. The coil tray 10 preferably and advantageously is molded of a thermoplastic material. As can be best seen in FIG. 11, the coil tray 10 also has side walls 14 extending about its perimeter, and the height of the side walls and the depth of the cavities 12 preferably are proportioned so that the loading coils 20 do not extend above the side walls. The spacing and the orientation of the loading coils within the cavities 12 in the coil tray 10 is such that the need for crosstalk plates and/or production tuning of the loading coils is eliminated. Adjacent to each of the cavities 12 there are a number of holes 16 for receiving therethrough the terminal pins 18 on a terminal block 21 described more fully below. It may be noted that an additional generally square-shaped, flat cavity 22 is formed in the coil tray 10, for receiving another loading coil 20 which lies flat in the cavity, rather than vertically disposed as in the case of the cavities 12. A hole 24 is provided through the coil tray 10, for securing a number of coil trays in stack relationship, on a rod in a coil case, as generally illustrated in FIG. 13. Also, a pair of slots 26 and 27 are formed on the ends of the two legs of the coil tray, for receiving therethrough alignment bars 28, as can be best seen in FIGS. 12 and 13.

In FIGS. 6 and 7, a terminal block 21 is shown as having a pin base 29 which may be molded of a thermoplastic material, with a number (4 in the illustrated embodiment) of terminal pins 18 integrally molded therein and extending from the opposite sides thereof. As can be seen in FIGS. 8 and 9, the lead wires 31 of the loading coils 20 are connected to the terminal pins 18 of the terminal blocks 21.

After pre-assembling the loading coils 20 and the terminal blocks 21, as described above, the loading coils are placed in the cavities 12 and the terminal pins 18 are extended through the holes 16 in the coil tray 10, as can be best seen in FIGS. 10 and 11. Once all of the loading coils and their associated terminal blocks have been loaded into the coil tray 10, the coil tray is filled with an encapsulating compound, so as to hermetically seal the loading coils in the coil tray and to complete the formation of a coil tray assembly. The encapsulating compound also servies to physically hold the loading coils in position in the coil tray 10. In use, the coil tray assembly will be turned upside down as it is inserted into the coil case. Connections to the loading coils 20 may be made on the bottom of the coil tray 10 since the ends of the terminal pins 18 extend through the coil tray. In FIGS. 10 and 11, a load coil 20 is illustrated in the cavity 22.

As indicated above, these basic coil trays or coil tray assemblies are used in the construction of standard coil cases which may be, for example, 6 inches square, 11 .times. 6 inches rectangular or 11 inches square coil cases. In FIGS. 12 and 13, a 6 inch square coil case 41 is illustrated and it includes a rod 42 and two clamping or alignment bars 28. A cable 43 to which the loading coils 20 are to be coupled extends into the coil case. In assembling the coil case, a coil tray assembly is turned upside down and inserted in the coil case, with the rod 42 extending through the hole 24 in the coil tray and with the alignment bars 28 extending through the slots 26 and 27. Then, the cable pairs for this first coil tray are wire wrapped to the terminal pins 18 which project through the bottom of the coil tray. In a like manner, each successive ones of coil trays are inserted and the appropriate connections made. The upper or last one of the coil trays is secured in place by a plate 45 and a suitable holding fixture such as a nut and bolt 46. The completed coil cases are typically metal for environmental protection, since the coil cases will likely be buried in the ground or in manholes, possibly in water. The coil cases therefore need to be air tight. In some cases, the completed coil case may be filled with polyurethane or the like to protect the exposed wire wrapped connections.

In FIG. 14, a 11 .times. 6 inch coil case 50 is illustrated and it can be seen that each level of coil tray assemblies includes two coil tray assemblies placed with the ends of two of the legs abutted together. In this case, the coil case 50 contains two rods 51 and 52, and four alignment bars 53-56 for securing and aligning the coil tray assemblies in the coil case.

In FIG. 15, a 11 inch square coil case 60 is illustrated and, in this case, each layer of coil tray assemblies includes four of them positioned to encircle a cable 61 to which the loading coils are to be coupled. Four rods 62-65 and eight alignment bars 67-73 are provided for clamping and aligning the coil trays in the coil case.

In the case of both of the coil cases of FIGS. 14 and 15, the coil tray assemblies are loaded into the coil case and connections established with the loading coils, in the manner described above.

Accordingly, from the above description, it can be seen that an improved coil tray is provided which is of a basic design which permits it to be used in any one of several different types of standard coil cases. Furthermore, the construction and arrangement is such that the loading coils can be easily and quickly assembled in the coil trays, and when the coil tray assemblies are loaded into a coil case, that connections can be easily and quickly made with the exposed terminal pins 18.

It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained and certain changes may be made in the above construction. Accordingly, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

Now that the invention has been described, what is claimed as new and

1. A coil tray assembly comprising, in combination: a coil tray molded of plastic material and having a plurality of spaced and oriented semi-circular shaped cavities therein for receiving loading coils and a plurality of holes adjacent each of said cavities for receiving therethrough the terminal pins of a terminal block, a terminal block having a base supporting a plurality of terminal pins such that said terminal pins extended from each of the opposite sides thereof, a plurality of loading coils having the ends of the windings thereon coupled with said terminal pins on one side of said base of said terminal block, said loading coils being positioned within said cavities in said coil tray and said terminal pins being extended through said plurality of holes adjacent said cavities so as to project from the bottom of said coil tray, and means hermetically sealing and positionally fixing said loading coils

2. The coil tray assembly of claim 1, wherein said coil tray is generally L-shaped and has side walls about its perimeter, said side walls being proportioned such that said loading coils do not extend above said side walls, thereby permitting said coil tray assemblies to be stacked one atop

3. The coil tray assembly of claim 2, further including an opening through said coil tray for receiving therethrough a clamping rod in a coil case,

4. The coil tray assembly of claim 3, further including a slot on the end of each of the legs forming said L-shaped coil tray for receiving therethrough alignment bars in a coil case, for aligning said coil tray

5. The coil tray assembly of claim 4, wherein said loading coils are

6. The coil tray assembly of claim 2, wherein connections are established with said loading coils by means of said terminal pins projecting through the bottom of said coil tray.