US2508531A - Current collector - Google Patents

Description

May 23, 1950 A. J. MOSLEY CURRENT COLLECTOR Filed Feb. 14, 1949 INVENTOR Alfred 4!. Masley /fi/La/ r a ATTORNEYS 7 Patented May 23, 1950 CURRENT COLLECTOR Alfred J. Mosley, Cleveland, Ohio, assignor to National Bronze & Aluminum Fdry. (30., Cleveland, Ohio, a corporation of Ohio Application February 14, 1949, Serial No. 76,359

Claims. 1

This invention relates to electrical current collecting devices, more particularly to slider shoes such as are employed on trolley poles used on electric busses, street cars, and the like.

Current collectors or slider shoes are replaced or rebuilt from time to time on busses and street cars because of the wear that occurs in use. Such shoes or collectors are designed to minimize wear on the conductors or trolley wires of transit systems, not only because of the great expense involved in replacing trolley wires, but also because of the disruption to the transit system caused by discontinuance of service for trolley wire replacement.

It is therefore one of the principal objects of the present invention to provide a generally improved collector shoe or trolley slide of the type employing a suitable wear resistant insert or wire contacting brush, the collector shoe being simple in design and construction for economical mass production as by casting so that when renewal is necessary, it is feasible to replace the entire shoe and discard the worn one.

Another object is to provide a rugged, long wearing collector shoe relatively light in weight and substantially free of internal or structural strains, such characteristics being achieved without objectionably increasing the relative wear on trolley wires. Preferentially the slider includes a wear insert and a one piece holder or frame cast about the insert, the frame incorporating simple wiper or scraper means to remove objectionable foreign material from trolley wires in advance of the insert, thus preventing the movement of abrasive particles between such wires and the wear insert. More specifically, the invention seeks to provide a unitary slider shoe incorporating an elongated carbon Wear block or brush, preferably of rectangular transverse section, embedded in a one piece cast metal body or frame of relatively lightweight construction.

Another object is to provide a current collector shoe of the carbon insert type suitable for manufacture by high speed casting of light metal alloys.

A further object is to provide a lightweight collector shoe capable of carrying relatively high energy electrical current without objectionable heating, yet being cheap to make and having a brush insert for long wear.

Other objects and advantages relate to certain details of construction and combinations and arrangements of parts, as set forth in the following detailed description of the invention made in connection with theaccompanying drawings forming a part of the specification. Like parts throughout the several views are indicated by the same numerals of reference.

In the drawings:

Figure l is a side elevational view, with parts broken away and removed, of the upper or head end of a trolley pole structure showing the replaceable collector shoe of the present invention mounted thereon;

Fig. 2 is an end elevational view of the collector shoe of Fig. 1;

Fig. 3 is a top plan view of the collector shoe;

Fig. 4 is a transverse sectional view taken substantially on the line indicated at 4-4 of Fig. l, the trolley pole head being omitted;

Fig. 5 is an elevational view, partly in section and with parts removed, showing a modified form of collector shoe; and

Fig. 6 is an end elevational view partly in section and with parts removed of the trolley shoe shown in Fig. 5.

The collector shoe or slider of the present invention is suitable for mounting on conventional types of trolley poles, a representative and simplified trolley pole head being shown in Fig. 1. The assembly includes a head member l suitably secured on the upper end of the trolley pole and formed with a yoke or harp 2 which carries a transverse pivot bolt 3 for tiltably mounting a. carrier or tilt block 4. The structure desirably includes conventional means, not shown, permitting the slider shoe to turn about a, vertical axis which permits lateral or side to side movement of the trolley pole under the trolley wire.

The replacement shoe or current collector itself comprises an elongated wear block or insert 5 formed as by pressure molding of carbon or carbonaceous material of graphitic character. This block may be suitably treated or impregnated in a conventional manner with the customary metal, plastic, or other friction reducing and binding materials. Although various cross-sectional shapes may be employed, it is preferable to make the wear insert of substantially uniform rectangular transverse or cross section from end to end. Desirably the block is of greater height than width for long life.

Mounting the wear insert or carbon element on the top flat surface of the tilt block 4 and protecting the carbon element against damage from shock and impact is a guard frame or body formed, preferably in one piece, as by casting of a metal such as brass, bronze or aluminum and its alloys. The cast body is designed with particular reference to the shrinkage that occurs in metal such as aluminum, upon cooling from the molten state. Considerable difficulty has been encountered in casting carbon and graphitic wear inserts in aluand connected as to interlockingly 1 1a and m; brace the insert do not pose undesirable stresses or forces on such insert upon cooling from the molten state. The cast metal partsor elements comprising the body may be connected,

preferably integrally, by relatively thin portions for embracing and confining the majorportions of the wear insert.

in contacting relation to the latter for wiping the trolley wire free of dirt and foreign material in advance of the carbon block. This feature is particularly advantageous in localities Where ice forms on the trolley wires, since the relatively tough brass or aluminum of the webs I! removes depending ice particles in'advance of the more fragile or brittle carbon block.

Along the sides of the collector relatively thin "web portions 2!] connect the stirrup uprights 6 and v are preferably integral with the latter.

'These connecting webs are disposed flatwise against the central portions of the block side faces 9 and maybe smooth surfaced, although preferably they are formed with a multiplicity of relatively thin cooling and reinforcing ribs 2|.

A suitable arrangement for the frame comprises a pair of spaced substantially U-shaped :stirrupsarranged in parallel relation; each stir :ruphaving uprights Gintegrally connected by bottom or cross elements, 1; 'The strirrups receive the ends of the wear block 5; sides 9 of the wear blockatthe ends of the latter being em- 5 braced by the upright portions 6 of the stirrups; andportions; of bottom 10 of the wear block at the ends of the latter resting on the'cross or integral connecting portions 1 of V the stirrups. The upper ends of the stirrup'uprights 6 are connected, preferably integrally, by longitudinally extending guide elements 8. The guideelements include angularly disposed end portions 1| presenting inclined or sloping edges l2 which aid in moving thecontactor shoe across switches, crossing-plates, and the like. Preferably, the guideelements 8 are divergently arranged above the wear block 5, as shown in Fig. 2, providing a .tapered channel to receive and confine the trolley wire which is to bereceived and. engaged in groove I9 of the wear block 5. a. r

-:Foreign.material such as dust, dirt and the like, collecting ontrolley. wires, is frequently dislodged by current collectors and trolley shoes moving alongthereunder. 'Such material of a hard Or gritty nature, when caught and held in the open topchannel of a collector shoe, is objectionable because of abrasion to'the trolley Wire and to the shoe and interference with elec trical conductivity. The construction ofthe present collector or trolley shoe leaves substantially the entire marginor periphery of top sur- ;face 14 of the carbon block 5 substantiallyopen and unobstructed laterally so that particles of -foreign material dropping into the trolley wire channel are readily discharged not only through the relatively narrow channel ends but also laterally alongsubstantially the entire length of the carbon block. In the present arrangement the guide elements Bare-disposed wholl above the plane or level'of the top M of ,the wear block fproviding elongatedlateral openings l5 below botto'm edges I 6 of the guide elements. Although these elongated clearance openings may be of less extent, they preferably are continuous along substantially the major portion of the upper edge corners of the carbon wear block-or insert. :Across-the ends of the shoe orcollector the stirrup-uprights 6 are connected as by integral ,relatively-thin webs I! which are disposed flatwise againstend faces [8 of the carbon wear block 5.: Although the endwebs I! may be of any desired height relative to the carbon wear .block, itis preferable to make them of'substan- +tia1lythesame height as the wear block so as to move along the trolley wire closely adjacent or The ribs 2|, which may be sheet metal inserts or, as shown, cast integrally with the webs and stirrups in the formation of the collector shoe. extend longitudinally of the side-webs substantially from end to end thereof, being joined or connected to the stirrup uprights 6. In the aggregate, the areas of the block faces contacted by the relatively thin connecting webs are. greater in extent than the areas contacted by the relatively thick sectioned frame elements.

In mounting the collector or trolley shoe on the tilt block 4 of the trolley pole, conventional arrangements may be employed. The illustrated arrangement comprises integral ears or lugs 22 and 23 connected to or cast integrally on the bottom cross elements 1 of the frame stirrups. The ear 22 includes an offset portion which is receivable against an undercut face 24 on one end of the tilt block 4. The lug 23 is drilled and threaded to receive an angularly disposed looking screw 25 arranged to bear against an angularly disposed .face 26 on the other end of the tilt block. When the screw 25 is tightened against the tilt block face, the bottom face H) of the carbon block 5 and bottom edges 21 of the side webs 20 are drawn snugly against the flat upper surface of the tilt block 4, effecting good electrical connection therewith.

In applications requiring the transfer of large electrical currents, the collector shoe described is particularly advantageous by reason of the cooling action of the ribs or vanes 2| which travel longitudinally through the atmosphere. Heat developed in the carbon blocki by reason of the conductivity of electrical current therethrough taken up all along its sides by the closely embracing relatively rapid heat conducting metal of the cast body and is quickly conducted into the cooling vanes 2| for dissipation to the atmosphere. "Thus, overheating of thecarbon and metal .of the'collector shoe is avoided. In applications requiring a less rugged construction, or'where less electrical energy is to be conducted, or where other considerations con- :trol, the modification illustrated in Figs. 5 and 6 maybe employed. In these figures, parts or components of the structure that are the same as in the embodiment of Figs. 1 through 4 are indicated by the same reference numerals. The end webs I 'I are omitted or reduced in height at both ends of the shoe and appear as reinforcing gussets 28 which are preferably cast integrally in the angles between'the uprights 6 and the cross elements I to reinforce the stirrups.

In lieu of the thin side webs 20, the uprights 6 are joined by thin, relatively 'low, connecting webs or elements 30 which arepreferably cast integrally with the stirrup uprights 6. While bottom edges 3| of the connecting elements 39 are straight and substantially flush with the bottom ill of the wear block 5 for contacting the upper surface of the supporting tilt block 4, upper edges 32 are curved, providing reinforcing gussets 33 integrally joined to the stirrup uprights. The major portion of each of the wear block side faces 9 between the stirrups are thus exposed to the atmosphere. Longitudinally extending ribs 36 optionally may be integrally formed along the connecting elements 30, the ends of these ribs being connected to the stirrup uprights 6 and serving not only to reinforce the side structure of the shoe but also to aid in cooling of the shoe.

The opposite sides of the metal holding frames of the slider shoes of the present invention are connected only at the ends of the shoes, the entire bottom surface of each of the wear inserts being exposed for direct bearing contact with the supporting trolley head structure. The thin sections of the connecting webs permit casting the metal bodies about the wear inserts in such a manner that the webs freeze or harden before the heavier sectioned parts of the frame body, thus minimizing stresses imposed on the carbon insert by shrinkage of the cast meal.

In accordance with the patent statutes, the principles of the present invention may be utilized in various ways, numerous modifications and alterations being contemplated, substitution of parts and changes in construction being resorted to as desired, it being understood that the articles shown in the drawings and described above are given merely for purposes of explanation and illustration without intending to limit the scope of the claims to the specific details disclosed.

What I claim and desire to secure by Letters Patent of the United States is:

- 1. A current collector shoe comprising an elongated wear block of substantially rectangular transverse section and a metal frame embracing the block, said frame having elements extending under the block adjacent the ends of the latter, up the block sides at said ends and longitudinally of the block spaced above the top of the latter, the top of the block being open along its side edges intermediate the block ends, and metal web portions thinner than the elements disposed fiatwise against the sides of the block and connected to the upwardly extending elements.

2. A current collector shoe comprising an elongated wear block of substantially rectangular transverse section and a metal frame embracing the block, said frame having elements extending under the block adjacent the ends of the latter, up the block sides at said ends and longitudinally of the block spaced above the top of the latter, the top of the block being open along its side edges intermediate the block ends, and metal web portions thinner than the elements disposed fiatwise against the ends and sides of the block and connected to the upwardly extending elements.

3. A current collector shoe comprising an elongated wear block of substantially rectangular transverse section and a metal frame embracing the block, said frame having elements extending under the block adjacent the ends of the latter, up the block sides at said ends and longitudinally of the block spaced above the top of the latter, the top of the block being open along its side edges intermediate the block ends, metal web portions thinner than the frame elements disposed fiatwise in heat conducting relation against the block sides, and a plurality of relatively thin metal cooling fins integral with the web portions and extending between and integrally connected to the upwardly extending elements of the frame.

4. A current collector shoe comprising an elongated wear block having top, bottom, end and side faces and a cast metal body embracing the block, said body including relatively thick sectioned frame elements contacting the block across the entire width of its bottom face and over the entire height of its side faces, said body also including relatively thin sectioned web elements contacting the block faces, the areas of the block contacted by the frame elements being less than the areas contacted by the web elements.

5. A current collector shoe comprising an elongated Wear block having top, bottom, end and side faces and a cast metal body embracing the block, said body including relatively thick sectioned frame elements contacting the block across the entire width of its bottom face and over the entire height of its side faces, said body also including relatively thin sectioned web elements contacting the block faces, the areas of the block contacted by the frame elements being less than the areas contacted by the web elements and spaced from one another by the web contacted areas.

ALFRED J. MOSLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 638,047 Dunning Nov. 28, 1899 2,044,886 Larsson June 23, 1936 2,169,154 Lapham Aug. 8, 1939 2,185,268 Ryan Jan. 2, 1940 2,457,326 Sloane Dec. 28, 1948

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