US 2813144 A
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Description (OCR text may contain errors)
Nov. 12, 1957 c. F. vALAcH v COAXIAL ANGLE CONNECTOR 2 Sheets-Sheet l Filed Dec. 20, 1950 Nov. 12, 1957 c. F. VALACH COAXIAL ANGLE CONNECTOR 2 Sheets-Sheet 2 Filed Dec. 20, 1950 www;
COAXIAL ANGLE CONNECTOR Charles F. Valach, Berwyn, Ill., assignor to Amphenol Electronics Corporation, a corporation of Illinois Application December 20, 1950, Serial No. 201,813
2 Claims. (Cl. 174-87) This invention relates to electrical connectors and has particular reference to connectors for coaxial transmission lines. More specifically it relates to angle connectors so designed as to be suited for use at higher frequencies than practicable with connectors of the types heretofore known.
The need for improvments in all connectors suited to such frequencies has long been felt, but it is particularly pressing in connection with angle connectors. This may well be due to the fact that the technical considerations governing the perfomance of transmission lines meeting at an angle to each other are not fully understood even by persons most closely associated with this field of endeavor and most learned in the art, but in any event it is a fact that there has heretofore been an unsatised demand for a connector which is capable of the requisite electrical and electronic performance. This involves many requirements, but particularly requires that the connector be of such design and construction that it maintains a low VSWR (voltage standing wave ratio) characteristic over a wide band of frequencies. This is due to the known fact that any abrupt deviation from the desired characteristic impedance along successive incremental portions of the propagation path of the signal gives rise to undesired rellections of signal energy and produces standing7 waves in the line unless compensated. Such uncompensated reections decrease the efficiency of the line in all radio frequencies, and are particularly troublesome in the higher frequency ranges.
There are angle connectors commercially available which have been employed rather widely and are well suited to certain uses, but when used in the extreme upper frequency ranges, any of the types heretofore developed have shown themselves to be subject to certain shortcomings which have seriously interfered with their acceptability in the more technical phases of the electronic arts. The reasons for these shortcomings may not be fully understood, but it is believed that they stem primarily from the fact that in structures of the types heretofore proposed, the configuration of the line is so abruptly changed at the point of junction between the angularly disposed lines as to produce high electrical field distortions, increase the shunt capacitance, and thus produce a high standing wave ratio.
it is, therefore, an important aim to provide an improved angle connector for a high frequency coaxial transmission line, wherein these shortcomings of prior art devices are overcome and a higher standard of performance than heretofore possible is attained. More specifically, it is an object of the present invention to produce an angle connector wherein the VSWR of the line remains substantially constant even in the extreme frequency ranges, not only at the point at which the direction of the path of propagation of the signal is changed, but throughout the connector. This is accomplished according to the present invention by a structure wherein compensation for field distortion through decrease in shunt capacitance and subsequent reduction in nitecl States Patent ice VSWR is obtained by increasing the internal volume at the intersection of the coaxial lines through termination of at least one of the bores in a dat bottomed surface.
Notwithstanding the need for extremely efiicient performance, it is important from a manufacturing standpoint that connectors of this type have their several parts so designed, constructed and related that they are capable of manufacture by economical methods, are easily assembled, and are at the same time so constructed that the various and sundry varieties of connectors required may be assembled from a relatively small number of component parts.
All of the requirements enumerated above are essentially conicting, and not easily reconciled to simultaneous accomplishment. This is amply evidenced by the fact that no mechanically simple device capable of satisfactory electronic performance has heretofore been proposed.
As a matter of fact, the mechanical aspects alone present a serious production problem in connectors of this type, for the reason that the various types of angle connectors (including X connectors, simple angled connectors and T-connectors) required in the art give rise to a need for a surprisingly large number of different variations of structure, particularly in the various permutations of male and female terminal fittings thereon. This brings about a situation wherein all of the various forms of connectors that may be required can be manufactured by conventional methods only by stocking an unusually large variety of component parts.
Even the seemingly simple T-connector requires many variations in structure to provide the variety of fittings called for. For example, it may require all male terminals or all female; or it may require male terminals at the opposite ends with a female center terminal, or female terminals at the opposite ends with a male center terminal. It may further require one end and the center terminal male, and vice versa. Thus, with the numerous possible permutations of ttings required, a single basic type of T-connector has in actuality some six different body types. There are three additional possibilities for the right angle connector, and an even larger number for an X connector, for example.
It is therefore seen that, from a manufacturing standpoint, it is an extremely important aim to be able to produce any one of these various types of angle connectors which may be required, yet to do so without undue complications and without an unnecessarily large variety of component parts.
These desirable results are attained by the novel types of connectors here disclosed, in which the conflicting mechanical and electronic requirements are reconciled so well that connectors according to the present disclosure have electronic characteristics surpassing the best of the previously known types, yet are so designed mechanically that the units are simpler and more convenient to manufacture than those heretofore known. This may be best explained in connection with the drawings of the present specifications, wherein several preferred commercial em bodiments of angle connectors made according to the present teachings are illustrated.
In the drawings:
Figure l is a central sectional view through a right angle coaxial connector constructed in accordance with the teachings of this isclosure;
Figure 2 is a detail sectional view taken on the plane of the line 2 2 of Figure l;
Figure 3 is a detail sectional view taken on the plane of the line 3-3 of Figure l;
Figure 4 is an exploded sectional view showing the principal component parts of the shell or housing of the right angle connector illustrated, showing the manner in which the connector is preferably assembled;
Figure 5 is an exploded perspective View of the priucipal internal component parts of the connector; that is, the central terminals, the conductors integral therewith and the insulating tubes which form the dielectric of the device;
Figure 6 is a central sectional View through an angle connector of a T type, constructed in accordance with the present teachings;
Figure 7 is a central sectional view taken on the plane of the line 7--7 of Figure 6;
Figures 8, 9, l() and l1 are perspective views of the four principal component parts of the connector shell utilized in the several types of angle connectors illustrated; and
Figures l2 to 19, inclusive, are reduced scale elevational views of the various styles and types of angle connectors which may be assembled from the same principal component parts employed in the connectors heretofore illustrated.
it is contemplated that the teachings of the present invention may be utilized in any one of the various types of angie connectors employed in connection with coaxial transmission lines, but the right angle connector illustrated in Figures l to 3, inclusive, is probably the simplest form of the invention, and will accordingly be described first. The component parts of this connector are illustrated in Figure 4, where it will be seen that the connector comprises a body portion 16 which is of cubical exterior shape (see Figure 8), a female connector subassembly 11 (Figure 9), a male connector subassembly 12 (Figure l0), and a pair of closure plugs 13 (Figure 1l). The body portion has a plurality of counterbored apertures which, in the present example of the inventive teaching, comprise apertures 14, 15, 16 and 17 spaced on the opposite faces of the body and arranged at right angles to each other. These apertures are at the opposite ends of a pair of cylindrical bores 18 and 1% which extend into the body and intersect each other at the center of the body portion. That is, the bore 1S extending from the aperture 14 to the aperture 16 intersects the bore 19 extending between the apertures 15 and 17. The point of axial intersection of the bores 1S and 19 is at the geometric center of the body 1t! as indicated at 21. It is to be particularly noted, however, that even when the apertures 16 and 17 are closed by the plugs 13, the bore from each of the apertures 14 and 15 extends beyond the point of axial intersection and continues as a cylindrical portion, with the inside faces 22 of the plugs 13 providing each bore with a flat bottom at right angles to its opposite side walls 23 (Figure 2). The bottom of the bore 18 is in line with the lower wall of the bore 19, and the flat bottom at the right end of the bore 19 is in line with the right side of the bore 18.
The bores 18 and 19 and the counterbores of their respective apertures 14, 15, 16 and 17 are of identical size and shape, so that the counterbored mouths of either of these apertures may receive and mate with the pilot portion 24 and bore 26 of a terminal sleeve 27 of the female connector subassembly 11, or the pilot portion 28 and bore 29 of one of the male fittings subassembly sleeves 12 (Figure 4). The terminal sleeve 27 of the female subassembly 11 has an external coupling ring 31 rotatably locked thereon by a ange 32 and locking ring 33. The coupling ring 31 has internal bayonet slots 34 arranged to engage the external pins 35 of the male subassembly 12. The bore 29 of the male terminal sleeve 12 has a tapered counterbored portion 36 to receive the end portion 37 of the sleeve Z7 of another connector of the same design (see Figure l). Similarly, the female subassembly 11 is adapted to receive the mating male assembly of another connector. In either case, when a pair of the interengaging male and female subassemblies are united, the inside walls of the bore are smooth, concentric and of uniform diameter throughout. This is an important feature in maintaining the desired constant impedance characteristic throughout the point of union between two connectors, as will appear.
The plugs 13 (Figures 4 and ll) each include a center pilot portion 41 of size and shape to fit any one of the bores 18 or 19, and a flange 42 is dimensioned to close any one of the counterbores of the apertures 14, 15, 16 and 17. Thus, it will be apparent that by employing various combinations of the female subassemblies 11, the male subassemblies 12, the body portions 10 and the plugs 13, it is possible to provide any one of a large Variety of different angle connector types. For example, by utilizing one of each of these parts, the simple male and female angle connector illustrated in Figures l to 3 may be constructed, while by utilizing a body 10 with two female subassemblies or a body with two male subassemblies, the modified right angle connectors illustrated in Figures 18 and 19 may be assembled. Similarly, by utilizing three of the terminal sleeve subassemblies and eliminating one of the plugs 13, any one of the different angle connectors of the several T types illustrated in Figures 12 to 17, inclusive, may be assembled, yet all of these may be assembled from a relatively small number of identical external component parts.
To assemble a connector, a body portion 16 is rst fitted with male subassembly sleeves 12 and female subassembly sleeves 27 as desired. Plugs 13 are placed in any unused apertures. These several components of the shell of the connector are then clamped together in fixtures provided for the purpose, and soldered or brazed, This is conveniently done by placing a thin ring of silver solder between the body portion and each of the terminal sleeves or plugs thereof, holding the parts together under pressure and heating the entire unit by induction heating apparatus to melt the solder and fuse the terminal sleeves and plug in firm electrical union with the bores and countersunk apertures in the body.
The dielectric body of the connector consists of a pair of insulating tubes which support a metallic center conductor (Figure 5). In the angle connector of Figure l, the sleeves 43 and 44 have internal bores and 46 to fit the conductors 47 and 48, respectively. The tubes 43 and 44 are mitered at their inner ends 49 so that the parts, when assembled, may lie in the relationship illustrated in Figures l to 3. The dielectric tubes 43 and 44 may be of any suitable insulating material, but in the preferred form of the invention, the plastic known under the trade name of Teon is employed, since it has the desired electrical characteristics and is capable of withstanding high temperatures, not only during the assembly of the fitting, but when in use in applications designed for such temperatures.
The tube 44 has a reduced end portion 51 at its outer end and the tube 43 has a counterbore 52 of corresponding size and shape so that when male and female connectors are coupled together, they will interfit as shown in Figure l to aord a substantially uninterrupted dielectric body of uniform thickness throughout. This avoids variations in impedance that might otherwise give rise to reections and standing waves.
The central conductor 47 has a tapered connecting pin 53 at its outer end and a reduced inner end portion 5a bent at right angles and brazed or soldered into the end bore of the conductor A solder port 56 is provided to facilitate soldering. The outer end of the conductor 48 is end drilled and split at S7, to afford a spring receptacle for the Contact pin 53 of a mating connector.
From the foregoing it will be apparent that to assemble a simple angle connector such as illustrated in Figures l to 3, inclusive, it is only necessary to insert the internal metallic parts 47 and 48 (which have been previously soldered together), into a connector shell prepared as previously described, and to slide the sleeves 43 and 44 into position. These sleeves may be pressed into the bores 0f the shell if desired, or held by small indentations of the shell or other means. It is to be noted, however, that in the assembled structure the dielectric inserts are fitted closely into the bores of the body portion, but that since 'the bore 18 extends to the dat bottom surface 22 of one of the plugs 13, the walls 23 extend beyond the walls of the bore 19 with which it intersects. This provides open voids or air spaces 50 adjacent the intersection of the bores (Figure 2). Similarly, it is seen that when the right hand end of the bore 19 is closed by the plug 13 (Figure 3), the plug forms a dat bottom 22 for the bore, and provides for similar voids or air spaces 50a.
The same types of component parts of the shell employed to make the simple twobranch, right angle connector shown in Figures 1 to 3 may also be employed to produce three-branch connectors as shown in Figures 6 and 7, and various combinations of these components may be employed to manufacture any one of the several forms of two' or three-branch angle connectors illustrated in Figures 12 to 19, inclusive. nector of Figures 6 and 7, for example, the body portion 10 is provided with two male subassernblies 12 on the ends and one female subassembly 1.1 in the center. Modied dielectric sleeves or tubes 58 and S9 are provided, and the central metallic conductor 61 is threaded at 62 to receive a reduced threaded portion of a conductor 63 having an integral male contact pin 64 thereon. The conductor 61 is supported in the tubular dielectric insert 58 which has a ninety-degree notch intermediate its ends, and the conductor 63 is similarly supported by the tubular dielectric insert 59, which has its innermost end mitered to tit within the notch as shown.
From the foregoing it should be clear that the present teachings provide an important advance in the connector art in two resrects. ln the first place, they make possible the convenient, economical and expeditious manufacture of the youter shells of any one of a large variety of slightly different types of angle connectors from one or more units of only four separate component parts. This is of considerable advantage from a manufacturing standpoint in that it permits flexibility of assembly and reduces inventory requirements, while at the same time providing for all contingencies as to demands for the various types of connectors involved.
In addition to this, the present teachings provide an angle connector which is of novel internal construction such that it achieves electronic eciency not possible with types heretofore developed, This is due to the unique interior configuration of the body portion 10, wherein the bores 18 and 19 may both be bottomed with a surface at right angles to the axis of the bore and `in the same plane as one of the wall surfaces of the bores which it intersects. The continuation of either or both bores beyond the point of axial intersection and the termination of the bores in a fiat bottomed surface increases the internal volume of the connector at the intersection of the coaxial lines, decreases the electrical field intensity and standing wave ratio, and reduces electrical field distortions. The overall result is that a connector of lower VSWR is provided and that performance characteristics are improved, particularly in the higher frequencies.
it is also to be noted that connectors as disclosed herein maintain a constant characteristic at the point of union with other connectors, as well as at the point of intersection with an angularly disposed line. In the present connectors the several parts are so proportioned In constructing the conand dimensioned that the mating parts of the connector coact to produce a coaxial line having uniform bore diameter and uniform internal conductor diameter at all points, with the dielectric body extending entirely therethrough. The internal and external surfaces of the conductors are thus smooth and uniform throughout, and there is no variation of the dielectric constant due to air gaps, etc. t follows that the connector presents a constarrt characteristic impedance to the signal, not only at the angle between the connector fittings, but also throughout union between connectors.
Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:
1. In a junction between a coaxial cable terminal and a coaxial transmission line connector, the combination of a pair of mating terminal sleeves with connector fittings externally thereof, one of said sleeves having a counterbore at its outer end constructed and arranged to receive the outer end of the other sleeve; said sleeves having cylindrical bores of the same internal diameter extending therethrough, with said bores being of uniform diameter throughout their effective length; a dielectric within said bores comprising a pair of straight hollow cylindrical insulating tubes having the same internal and external diameters, with a complementary interitting counterbore and reduced portion at their outer ends, together with a central conductor of uniform exterior diameter extending through said tubes and having mating intertting connections at the outer ends thereof.
2. In a junction between a coaxial cable terminal and a coaxial transmission line connector, the combination of a pair of mating terminal sleeves having interlitting connections at their outer ends and connector fittings externally thereof, said sleeves each having a cylindrical bore extending therethrough, with said bores being of the same diameter at their outer ends and of uniform diameter throughout their eifective length; a dielectric within said bores, and central conductors of the same exterior diameter extending through each of said sleeves and having mating interritting connections at the outer ends thereof.
References Cited in the file of this patent UNITED STATES PATENTS 2,152,504 Scott Mar. 28, 1939 2,335,041 Brund Nov. 23, 1943 2,422,982 Quackenbush June 24, 1947 2,425,010 Smith Aug. 5, 1947 2,425,834 Salisbury Aug. 19, 1947 2,446,982 Pound Aug. 10, 1948 2,449,983 Devol Sept. 28, 1948 2,452,168 Warren Oct. 26, 1948 2,504,104 Arnold Apr. 18, 1950 2,509,928 Klein May 30, 1950 FOREIGN TENTS 846,069 France May 27, 1939 OTHER REFERENCES Publication I, Ragan, Microwave Transmission Circuits, vol. 9, M. I. T. Rad. Lab. Series, published 1948, McGraw-Hill, pages 260-273.
Publication ll, U. S. Army Navy CoAXial Connectors, Bulletin 4, Internatl Resistance Co., 401 No. Broad Street, Philadelphia 8, Pa. Copy in 174-882.