Патент USA US2137067код для вставки
Nov. l5, 1938. ` l.. c. SPENCER 21,137,067 SUCTION INSULATOR FOR TROLLEY SYSTEMS Filed June 26, 1936 INVENTOR ¿,027 SiS/vencer: 7: ' ¿l I ,w 7 ATToRN Patented Nov. 15, 1938 UNITED STATES PATENT OFFICE 2,137,067 SECTION INSULAT'OR FOR TROLLEY > SYSTEMS Lon G. Spencer, Indianapolis, Ind. Application June 26, 1936, Serial No. 87,359 9 Claims. My invention relates, generally, to overhead trolley systems, and it has reference in particular (Cl. lill-_39) the necessary strength, the construction of a section insulator becomes decidedly bulky when to section insulators for overhead trolley sys- tems. Generally, it is desirable to sectionalize the Ul power supply for overhead trolley systems. That is, instead of having one continuousI overhead trolley line with power supplied from a number of sub-stations, the trolley line is sectionalized, 110 each section being insulated from the other and fed through a separate feeder. In this way, should a fault such as a grounded trolley wire occur in one section, the other sections will not be affected. Continuity of service is thus im- `15 proved, and also amore balanced loading of substations is secured, as the length of line which hickory is used. > Resinous compounds have been used as insu lating material in section insulators, but while `5 they have good electrical qualities, they do not have the mechanical strength to withstand the high stresses imposed upon them. In some cases, rubber compounds have been used but while they have both the desirable mechanical and electrical 10 properties, their cost is excessive, as also is their weight. It may, therefore, be seen that with the con tinued rapid growth of trolley-bus systems, and with the increasing scarcity of hickory as an 15 insulating material, there is a decided need for any one sub-station may feed is limited. some new material or combination of materials In trolley bus power systems, both the positive and negative conductor must be carried over- to give an insulator the desired electrical and mechanical qualities. The object, therefore, of my invention is to 20 provide a high strength, single beam section in sulator which will have high resistance to the deleterious effects of exposure to moisture. Another object of my invention is to provide a super-rigid single beam section insulator that 25 shall not swell, buckle or warp under the most adverse weather conditions. A further object of my invention is to provide a super-rigid section insulator having renewable wearing parte 30 Another object of my invention is to provide a section insulator having an insulating member with a metallic core of magnetic material, which fune'ßiOIlS' t0 greatly reduce or prevent the burn 20 head as there is no ground return, the bus being insulated from the ground by rubber tires. This greatly complicates the construction of the overhead trolley at intersections, as it is necessary to provide insulating means between the conductors v25 of opposite polarity where they intersect. This is usually accomplished through the use of section type insulators together with the necessary interlocking end fittings, and the usual metallic frogs or crossings. „3o lAs such an insulator is inserted directly into the line, it must withstand the full tension of the conductor, which may amount to from 2000 to 4500 lbs. This necessitates that the insulators not only have good dielectric qualities but also k35 have a high tensile strength. In addition, as the insulator is directly exposed to the effects of the weather, a further requirement is that it be unaifected by moisture, heat, cold, etc. These factors make the selection of a material 40 for the body of a section insulator a difiicult matter. Fiber, which has been used to a great extent, is a good insulator and has a high tensile strength, but in applications where continually subjected to moisture, such as in locations along `4.5 the seacoast, it has shown a decided tendency to swell. In some installations the swelling has been so serious as to hinder the passage of the current collector. Further exposure to moisture has resulted in a warping and buckling of the .50 body member, and in many cases, complete failure through softening of the fibers. ‘ Hickory, which is one of the best insulators, is rapidly becoming scarce, and even the best hickory when impregnated is in time decidedly vt5 affected by weathering. Also, in order to secure ing 0f the insulating member by the arc. Still another object of my invention is to pro 35 vide a weather proof super-rigid beam section insulator that shall be protected from the de structive effects of arcing. A still further object of my invention is to 4o provide a single beam section insulator having a core of interlocking metal strain plates molded in an insulating material and renewable insu lating wearing parts designed to protect the main body from destructive eiîects of arcing. 45 Other objects will in part be obvious and in part appear hereinafter. My invention, accordingly, is disclosed in em bodiments hereof shown in the accompanying drawing, and comprises the features of construc- i' 0 tion, combination of elements, arrangement of parts which will be exemplified in the construc tion hereinafter set forth, and in the scope of the application of which will be indicated in the appended claims. 5_5 2 2,137,067 For a more complete understanding of my invention reference may be had to the following detailed description, taken in connection with the accompanying drawing, in which: Figure l is a partially-sectionalized plan view of a trolley section insulator embodying the principal features of my invention, showing one preferred method of construction. Fig. 2 is a side elevational View of the section 10 insulator of Fig. 1. Fig. 3 is a sectional view taken along the line III-III of Fig. 2, and Fig. 4 is an end elevational view of Fig. 2. Referring more particularly to Figs, 1 and 2, the reference character I0 denotes a beam section trolley insulator embodying my invention. The insulator IU comprises generally a> longitudinal beam insulating member II having end fittings I2, such as shown, of well-known construction, secured thereto for engaging adjacent ends of It appears that under normal operating con ditions section insulators are exposed to serious arcing as the current collector leaves the line section of the conductor. This arcing is usually most destructive not only to the end fittings of the insulator but to the insulating member also. With a section insulator embodying my inven tion, however, it has been observed that such an arc may be drawn and the end fittings may even be severely burned, without any appreciable dam age resulting to the insulating member where the strain members are of a magnetic material. It is therefore obvious that the inclusion in the vicinity of the arc of the magnetic material of the reinforcing members has certain desirable effects, tending to draw the arc out, cool it, and reduce its harmful burning effects. It may be seen, therefore, that my invention provides a single beam section insulator which not only combines high tensile strength, high a trolley wire I3 or other well known forms of insulating value and immunity to moisture, but ñxtures. In one form of my invention, in order to secure which uses well known fittings, is easy to manu the necessary tensile strength and insulating Since certain further changes may be made in the foregoing construction, and different em 25 bodiments of the invention may be made without departing from the scope thereof, it is intended that all the matter set forth in the foregoing de scription or shown in the accompanying draw ing shall be considered as illustrative and not in 30 qualities, the beam I I may comprise both insulat ing material and metallic members formed as a unitary member. In this instance, the beam II comprises similar metallic strain members I5 which fimction as a metallic core for the beam 3o and through which the bolts I6 extend to secure the end iittings I2 in position. As will be readily understood, the metallic members I 5 must not only be securely joined to gether but must be insulated from one another. 135 They may be jointed together by means of a facture, and inexpensive to maintain. a limiting sense. I claim as my invention: 1. A single-beam section insulator for over head trolley systems, comprising, in combination, a main insulating member formed with a pair 35 joint comprising two complementary beveled of similarly shaped relatively thin interlocked surfaces having a plurality of interlocking mem metallic reinforcing members therein, the in sulating material of said insulating member being bers thereon, such as the flaring tenons I 1. These surfaces are so disposed that the tenons Il of the one strain member I5 are positioned in the grooves I8 of the other strain member. Suitable insulating material I9 is interposed between the interlocking tenons I'.' and grooves I8 to main tain the strain members I5 in fixed relation and 45 insulate them from each other. 'I‘o aid in binding the strain members I5 to gether and to protect the insulating material I9 from exposure to the weather, an enveloping in sulating shell 2| may be provided _about the in tei-locked strain members I5 in any suitable manner, such as by winding impregnated paper formed about and between said reinforcing mem bers to secure them in fixed relation with each other, end means secured to the main member disposed to secure adjacent ends of a trolley wire, and a renewable wearing surface and arcing shield having outwardly Iiaring sides detachably secured about the under side of the insulating member. 45 2. A beam insulator for overhead trolley sys tems comprising, in combination, an insulating main body member having a pair of similar re enforcing metallic members oppositely disposed in spaced relation and separated and enveloped 50 by an insulating sheath to provide a unitary or cloth about them under pressure from heated body member, end fittings for securing the main rolls. body member in operating relation in the over head system, and a removable arcing shield and wearing surface secured about the runner edge 55 of the main body member. 3. A beam insulator for overhead trolley sys tems comprising, in combination, an insulating body member having a pair of similar overlapping reenforcing members of magnetic material dis 60 posed within said body member in parallel spaced This provides a unitary beam structure having the necessary strength and insulating 55 qualities. In order to relieve the body member II from wear and the destructive effects of arcing, an insulating sheath 22 may be detachably secured 60 to the lower side of the body member II in any well known manner, such as by insulating bolts 23 passing through the body member II . The insulating sheath 22 may be formed in any desirable manner, such as a U-section 'chan 65 nel having iiaring sides which tend to disperse an arc away from the body member as it rises, thus protecting the body member II from the burning effects of arcing. It has been observed that a section insulator 70 of a type embodying my invention has shown additional advantages. Where the metallic strain members of the insulating member have comprised a magnetic material, such as iron, im proved electrical performance as well as me chanical strength has resulted. relation, a laminated sheath of fibrous insulating material formed about and between said members to provide a unitary structure, end members se cured to the body member adapted to position 65 said body member, and a fixed wearing sheath re movably secured about the under side of the body member to provide a renewable wearing surface and an arc shield for said body member. 4. In a single beam insulator for trolley sys 70 tems, in combination, a main insulating body member including a pair of thin tapered inter locking metal plates overlapping in opposed re lation, insulating material between the plates disposed to hold them apart to maintain them in 75 2,137,067 ñxed relation to each other, a plurality of layers of impregnated fibrous insulating material mould ed about said plates, and detachable end means secured to the body member disposed to position Ul said body member in the trolley system. 5, In an insulator of the single beam type, in combination, a body member comprising a pair of interlocking end plates, insulating material disposed between the end plates to hold them 10 apart, and a shell of insulating material disposed about the plates, terminal members secured to -each end plate disposed to engage adjacent ends of a trolley wire, and a renewable sheath of in-> sulation disposed to provide a wearing surface and arc-shield secured to one edge of the body mem ber. 6. An insulator of the single beam type for trolley systems comprising, in combination, a main insulating body member including a pair of tapered interlocking metal reenforcing end plates formed within the body member and sepa rated by the insulating material of the member, end means secured to the body member for posi tioning said body member in a trolley system, and 25 a renewable under-run and arc-shield having out wardly inclined upstanding edges adapted to en close an edge of the main body secured about the lower edge thereof. 7. An insulator of the single beam type for trolley systems comprising, in combination, an insulating main body member having a pair of similar tapered metallic reenforcing members dis 3 posed therein in insulated interlocking relation to relieve the insulating material of incident strain, end means secured to the ends of the body mem ber adapted to position the insulator in the trolley system, and a renewable wear portion and arc shield having outwardly flaring upstanding sides secured about an edge of the body member. 8. A section insulator for trolley systems, corn prising, in combination, a main insulating mem ber having a reenforcing core of overlapping metal strain plates so disposed within the main member and insulated from each other that the insulation of the insulating member surrounds said strain plates and maintains them in fixed relation with each other, means secured to the 15 ends of the main member disposed to position the body member in a trolley system, and a detach able wearing sheath and arc-shield secured to the under side of the main member. 9. A section insulator for trolley systems com 20 prising, in combination, a longitudinal insulat ing beam member of at least two overlapping and interlocking metal plates separated by and en veloped by an insulating material disposed to in- ` sulate the plates from each other and to main tain them in ñxed relation, end means secured to the beam member for engaging adjacent ends of `a trolley wire, and a sheath of insulating ma terial detachably secured to the lower edge of the beam to provide a renewable wearing surface and 30 arc-shield. LON C. SPENCER.