US2426724A - Receiving coil for train communication apparatus - Google Patents

Description

Sept. 2, 1947. E. w. BREISCH RECEIVING COIL FOR TRAIN COMMUNICATION APPARATUS Filed Jan. 25, 1946 2 Sheets-Sheet 1 INVENIOR lbga W 51 9690/2.

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HIS ATTORNEY P 1947. E. w. BREISCH I 2,426,724

RECEIVING COIL FOR TRAIN COMMUNICATION APPARATUS Filed Jan. 25, 1946 2 Sheets-Sheet 2 INVENTOR v Edgar W 51 6 6966 BY avzhfll zu H19 A TTORNE Y Patented Sept. 2, 1947 RECEIVING COIL FOR TRAIN COMMUNICA- TION APPARATUS Edgar W. Breisch, Edgewood, Pa., assignor to The Union Switch & Signal Company, Swissvale, Pa., a corporation of Pennsylvania Application January 25, 1946, Serial No. 643,418

9 Claims. 1

My invention relates to receiving coils for train communication apparatus, and more particular- 1y to coils mounted on a vehicle of a railway train for picking up energy inductively from trackway conductors.

In railway train communication apparatus of the carrier inductive type energy is picked up on a train by means of a coil or an inductor mounted on the train in inductive relation to the rails and conductors paralleling the rails. These coils are subjected to' abuse and severe operating conditions and are exposed to all kinds of weather. Furthermore, these coils are generally air core coils of relatively large cores and possess definite characteristics due to the character of the service and such coil characteristics must be maintained unvaried to provide efficient and reliable operation.

Accordingly, a feature of my invention is the provision of an improved receiving coil for train communication apparatus.

Another feature of my invention is the provision of a receiving coil of simple, rugged and economical construction which can be readily tuned, and having a housing that does not deflect the magnetic lines from threading the winding.

A further feature of the invention is the provision of a" receiving coil of the type here involved incorporating novel means to adequately terminal a coaxial cable at the receiving coil lead wires.

Other features, objects and advantages of my invention will appear as the specification progresses.

To attain the foregoing features, objects and advantages of my invention, I provide a circular shell of identical halves with adjoining surfaces falling along the central vertical plane. These two half shells are of molded non-magnetic material and have a diameter predetermined to enclose the winding of the coil. The two half shells also are of a depth such that when joined together they form a compartment of a length sufficient to enclose the predetermined length of winding. A rim is molded on each half shell to receive a group of screws spaced. along the rim to secure the half shells together with adjoining surfaces forming a weathertight seal. To obtain a perfect seal an annular groove is molded in the joining surfaces and a suitable gasket fitted into the groove.

A winding of a diameter and number of turns predetermined according to the associated communication apparatus is wound on a tube of nonmagnetic lnsulating material and the tube is mounted in the compartment of the shell by the ends of the tube fitting into annular grooves molded one in each half shell. A lug is molded to each half shell so that when the two halves are assembled a suitable outer surface is formed to which there is attached a junction box, a

groove being molded in the lug to provide an opening from the outer surface to the compartment through which lead wires may be drawn. This junction box is provided with terminal posts to which the lead wires may be connected to the outside circuit connections and the junction box is formed with a surface that fits the outer surface of the lug so that the junction box may be attached to the shell with a weathertight seal.

This lug formed on the shell is proportioned to provide surfaces to which mounting brackets can be secured, two brackets being located, one

on each side of the box, and provided with means for attaching the entire assembled receiving coil to brackets mounted on the vehicl on which the coil is to be located.

The mounting brackets are preferably heavy steel U-shaped brackets which straddle the molded surfaces of the half shells on each side of the junction box and are drilled in the base of the bracket to be bolted to brackets mounted on the vehicle on which the coil is to be located. In this way strains on the molded shell are minimized and failure of the shell is avoided.

The number of turns and size of wire of the winding are preferably preselected to permit the coil to be tuned by the use of a coaxial cable of a given length. However, in order to compensate for variations of cable capacitance, a small winding wound on a small diameter tube may be provided and held in place in the compartment of the shell by annular grooves formed in the half shells. A powdered iron core may also be disposed inside of this small winding in a manner that it can be adjusted as to its position inside the winding from outside of the shell by two screws of non-magnetic materialwhich thread through hubs of the half shells. These screws thus serve to position the iron core from the outside of the 'shell by backing off one screw and tightening up on the other, the iron core being locked in any desired position.

I shall describe one form of receiving coil embodying my invention, and shall then point out the novel features thereof in claims.

In the accompanying drawings, Fig. 1 is a side elevational view showing one form of a receiving coil embodying my invention, the cover of the junction box being removed. Fig. 2 is an end 3 view of the coil of Fig. 1, and Fig. 3 is a sectional view taken on the line TIL-III of Fig, 1.

In each of the three views like reference characters designate similar parts.

Referring to the drawings, the reference character HS designates a shell of a receiving coil. The shell HS is of any suitable non-magnetic material and preferably it is of a molded material and a phenolic material may be used. This, shell is made up of two identical halve l and ll, which when placed together Joint along a center vertical plane. In this way the shell can be made from a single mold of relatively simple construction. The half shells l0 and ii are of a diameter predetermined according to the receiving coil required for the specific equipment with which the coil is to be associated. Also the half shells are of a depth predetermined by the required length of the coil. Each half shell 10 and I l is formed with a Joining face 9 of a rim 8, and the two halves are assembled with the faces 9 Joining and bolted together by a group of brass machine screws i2 spaced alongthe rim 5. Although the joining faces 8 of the two half shells are smooth and level either as molded or by subsequent grinding making it possible to provide a watertight assembly by a suitable cement, a further precaution is taken to obtain a perfect seal by molding an annular groove ii in the face 9 of the half shells and fitting a rubber gasket l4 into the groove. When the two halves are joined together the gasket I4 is suppressed to completely fill the opening made by the two matched grooves The actual receiving coil consists of a winding l5 wound on atube IS, the tube I5 being of any suitable non-magnetic material and preferably it is of an insulation material. The winding 15 is made of a preselected number of turns symmetrically wound on the tube. The diameter of this winding and the size of wire and the number of turns are preselected as required for proper operation with the associated apparatus. The tube i6 is held in place in the compartment of the shell by means of annular grooves i1 formed in the half shells. To avoid any loosening of the tube after the shell is assembled, a waxed twine 40 is inserted in at least one of the grooves H. The ends of the winding l5 are connected to lead wires l8 and is which are brought into a junction box to be described later.

A lug 42 is molded to the lower portion of each half shell and when the two halves are assembled an outer surface 43 is formed and which surface is connected to the compartment of the shell by an opening 44 formed by grooves molded in the lugs 42.

A junction box 2| of non-magnetic material such as cast aluminum is attached to the outer surface 43 by cap screws 22, a gasket being interposed between the box and the surface 43 to form an airtight and watertight seal. Terminal posts 20 of standard design are mounted in the junction box 2| on a suitable insulation base. secured to the junction box. The junction box 2| is also formed wtih a conduit or pipe opening 24, through which outside conductors or cables can be brought into the Junction box and connected to the terminal post 20 for connection to the lead wires from the winding. The box 2! is provided with a cover 25 which can be unscrewed to provide access to the terminal posts 20 for making circuit connections.

An important factor in the construction of the receiving coil is the provision of integral U -shaped metal mounting brackets 26 and 21. These two brackets are alike and are bolted to a section of the lug 42 by means of bolts 28, the two brackets being located one on each side of the Junction box 2|. Each of the brackets 26 and 21 is drilled at 29 for bolting the receiving coil to brackets attached to the roof or other portion of the car or locomotive on which the receiving coil is to be mounted. The bolts 28 for securin the brackets to the shell also serve as an aid in clamping the two half shells I0 and II together. It is to be pointed out that if the coil shell is bolted directly against the mounting brackets on the car or locomotive, such mounting brackets are large and stiff and may not be properly aligned, and the molded shell of the coil may be put under a strain which would result in premature failure of the shell. When the shell is bolted to the U brackets 26 and 21 and these brackets in turn are bolted to the vehicle bracket, the danger of strain bein set up in the shell of the receiving coil is minimized.

A receiving coil of the form here provided can be tuned by using a required capacitor, such as a capacitor 45 connected to the coil at the terminals 20 of the junction box, or the receiving coil may be properly tuned when relatively high frequency carriers are used by a proper length of coaxial cable for connecting the coil to the associated equipment, such cable having an inherent capacitance needed to tune the coil at the frequency of the carrier used. I have found that a coaxial cable of approximately 55 feet in length will tune a suitable receiving coil when a carrier of the frequency of 88 kc. is used.

In order to compensate for variations of cable capacitance, a small diameter coil or winding may be included in the receiving coil. Such an adjusting coil includes a winding 30 wound on an insulation tube 3| which is held by annular grooves 32 molded in the half shells III and II. The ends of the winding 30 are connected through lead wires 33 and 34 to selected terminals of the junction box 2|. A powdered iron core 35 is inserted inside of the winding 30 to vary the inductance thereof by changing the position of the core 35. External adjustment of the position of the core 35 is effected through two screws 35 and 31 of non-magnetic material threaded to engage with threads molded in the hub of the half'shells l0 and II. By backing off screw 36 and tightening screw 31 or vice versa, the core may be moved to any position within the winding 30 and locked in that position. Molded nuts 38 and 39 screw onto the screws 36 and 31, respectively, to seal against entry of moisture and to lock the screws against accidental movement while the receiving coil is in service.

It is apparent that the adjusting coil 30 and the associated structure can be omitted when this added means for tuning the coil is not required.

A receiving coil such as here disclosed has the advantages of being of simple and economical construction, it is rugged to withstand abuse, it is sealed against weather conditions affecting the winding itself, the winding can be readily tuned either by capacitance housed in the associated junction box, or by proper length of connecting cable, or by an additional winding enclosed within the housing of the coil itself, and the special U-shaped brackets for mounting the coil assure that strains in the molded shell will not be set up when the receiving coil is mounted on the locomotive or car of a train.

Although Ihave herein shown and described but one form of receiving coils for train communication apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In receiving coils for inductively picking up communication energy,-the combination comprising, two molded non-magnetic shells provided with a joining surface for the twoshells to be assembled with a weathertight fit, said shells shaped to form a compartment when said shells are assembled, a winding wound on a non-magnetic tube proportioned to be housed in said compartment, each said shell molded with a groove into which the ends of said tube fit to position the winding in said compartment, a projection molded on said shells to form an outer surface when the shells are assembled, a groove formed in said projection to provide an opening from said compartment to said outer surface, and a junction box attached to said outer surface and provided with terminal posts for connection of lead wires of said winding brought out through said opening.

2. In receiving coils for inductively picking up communication energy, the combination comprising, two identical molded non-magnetic half shells provided with a joining surface for the two half shells to be assembled with a weathertight fit, said half shells shaped to form a compartment when said half shells are assembled, a winding wound on a non-magnetic tube proportioned to be housed in said compartment, each said half shell molded witha groove into which the ends of said tube fit to position the winding in said compartment, a projection molded on said half shells to form an outer surface when the halves are assembled, a groove formed in said projection to provide an opening from said compartment to said outer surface, a non-magnetic junction box attached to said outer surface and provided with terminal posts for connection of lead wires of said winding brought out through said opening, and two metallic U-shaped mounting brackets to straddle surfaces formed on the outside of said half shells and bolted thereto to mount, the receiving coil.

3. In receiving coils for inductively picking up communication energy, the combination comprising, two identical molded non-magnetic half shells provided with joining surface for the two half shells to be assembled with a weathertight fit, said half shells shaped to form a compartment when said half shells are assembled, a winding wound on a non-magnetic tube proportioned to be housed in said compartment, each said half shell molded with a groove into which the ends of said tube fit to position the winding in said compartment, a projection molded on said half shells to form an outer surface when the halves are assembled, a groove formed in said projection to provide an opening from said compartment to said outer surface, a non-magnetic junction box attached to said outer surface and provided with terminal posts for connection of lead wires of said winding brought out through said opening, said projection formed to provide two mounting surfaces one on each of said outer surfaces, and two U-shaped metal mounting brackets one bolted to each of said mounting surfaces for mounting said coil without strains to the assembled half shells.

4. In a receiving coil for train communication apparatus, the combination comprising, a circular shell of two identical parts of molded nonmagnetic material each said part having a preselected depth and a mating surface to form a compartment of preselected diameter and depth when the parts are assembled with their mating surfaces engaging, a rim molded on said parts to assemble the parts with a weathertight joint of said mating surfaces by screws spaced around said rim, a winding wound on a cylindrical nonmagnetic tube of a diameter and length predetermined by the diameter and depth of said compartment, an annular groove molded in each of said parts to receive the ends of said tube to position said winding, said parts molded with a lug which is formed with an outer surface and a bolted to each of said mounting surfaces to mount 1 the receiving coil with strains to said molded shell avoided.

5. In a receiving coil for train communication apparatus, the combination comprising, a winding wound on a cylindrical tube of insulating material, an annular shell of two identical parts of molded non-magnetic material having joining surfaces falling along the central vertical plane of the shell and'a rim for assembling the two parts with a weathertight joint by a group of screws located in the rim, said assembled two parts forming a compartment for housing said winding, each of said parts molded with an annular groove to receive the ends of said tube to position the winding, a lug molded on each of said parts and formed with a, groove and an outer surface to provide a junction box surface connected to the compartment by an opening through the associated grooves when the parts are assembled, a junction box attached to said junction box surface and provided with terminal posts to terminal lead wires of the winding brought out through said opening, said lugs formed with two molded surfaces one on each side of said junction box surface, and two U-shaDed brackets to straddle the mounting surfaces formed by the parts assembled and bolted thereto to aid in clamping the parts together and to mount the shell without strains to the shell.

6. In a receiving coil for train communication apparatus, the combination comprising, a winding wound on a cylindrical tube of insulating material, a circular shell of two identical parts of molded non-magnetic material having joining surfaces falling along the central vertical plane of the shell and a rim for assembling the two parts with a weathertight joint by a group of screws located in the rim, said assembled two parts forming a compartment for housing said winding, each of said parts molded with an annular groove to receive the ends of said tube to position the winding, 9. lug molded on each of said parts and formed with a groove and an outer surface to provide a junction box surface connected to the compartment by an opening through the associated grooves when the parts are assembled, a junction box attached to said junction box surface and provided with terminal posts to terminal lead wires of the winding brought out through said opening, another winding wound on another insulation tube-housed in said compartment, the last mentioned tube of a small diameter to go inside of the first mentioned tube and positioned in the compartment by other annular grooves molded in each of said parts to receive the ends of said last mentioned tube, and the last mentioned winding having lead wires terminaled at posts of said junction box for connection as required for tuning said first mentioned winding.

7. In a receiving coil for train communication apparatus, the combination comprising, a main winding mounted on an insulation tube of relatively large diameter, an auxiliary winding mounted on an insulation tube of relatively small diameter, an annular shell of two identical parts of molded non-magnetic material having joining surfaces falling along the central vertical plane for assembling the two parts by screws along the outer rim of the parts, said assembled shell forming a compartment to house said windings concentrically through grooves molded in said parts to receive the ends of said tubes, an iron core slidable within said smaller tube, two non-magnetic screws threaded in hubs of said parts t ngage opposite ends of the iron core to adjustably position the core in the smaller tube, and an opening formed in said shell to bring out lead wires from said windings whereby said windings can be connected to variably tune the main winding according to the setting of said iron core.

8. In a receiving coil for train communication apparatus, the combination comprising, a main winding mounted on an insulation tube of relatively large diameter, an auxiliary winding mounted on an insulation tube of relatively small diameter, a circular shell of two identical parts of molded non-magnetic material having joining surfaces falling along the central vertical plane to receive the ends of said tubes, an iron core slidable within said smaller tube, two non-magnetic screws threaded in hubs of said parts to engage opposite end of the iron core to adjustably position the core in the smaller tube, said shell provided with an opening to bring out lead wires from said windings whereby said windings can be connected to variably tune the main winding according to the setting of said iron core, and molded nuts to screw one on each of said screws to avoid entry of moisture into said shell and to prevent movement of the screws while in service.

9. In a receiving coil for train communication apparatus, the combination comprising, a winding mounted on an insulation tube of relatively large diameter, a circular shell of two identical parts of molded non-magnetic material having joining surfaces falling along the central vertical plane and a rim to assemble the parts by screws spaced around the rim, said shell forming a compartment for housing said winding by the ends of the tube fitting into annular grooves molded one in each of said parts, said joining surfaces molded with an annular groove to receive a gasket for sealing the assembled shell, 2. lug molded to each of said parts to form two mounting surfaces and an outer surface when the parts are assembled, said outer surface being connected to said compartment by an opening to bring out lead wires of said winding to a terminal box attached to said outer surface, and two U-shaped metal brackets bolted one to each of said mounting surfaces to mount the receiving coil to brackets with said shell substantially free of strains.

EDGAR W. BREISCH.

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