US2227625A - Traveling electrical contactor - Google Patents

Description

Jan. 7, 1941. B, w. BENBOW 2,227,625

TRAVELING ELECTRICAL CONTACTOR Filed July 18, 1938 2 Sheets-Sheet 1 /3b /5c bb F'JLIE. E FIIE EI INVENTOR. 602m: W. Ber/[10y By 6222 WQL A TYURNEY Jane 7, 1941. 3 w, BENBow TRAVELING ELECTRICAL CONTAGTOR Filed July 18, 1938 2 Sheets-Sheet 2 Bu/eT/J W. BEA/601d A TTURNEY Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE TRAVELING ELECTRICAL CONTACTOR Burtis W. Benbow, Benbow, Calif. Application July 18, 1938, Serial No. 219,692

Claims.

This invention relates generally to electrical equipment of the type making use of a traveling contacting device together with one or more extended electrical conductors. It can be used to advantage where a trolley arrangement is desired to supply current to movable appliances like hoists, cranes, or small locomotives.

It is a primary object of the invention to provide apparatus of the above character which will afiord utmost insurance against accidental contact with the current carrying conductors. A further object is to aiford means for securing positive and continuous electrical engagement with the conductors, while at the same time enabling use of an effective protective sheath about the conductor or conductors.

Further objects of the invention will appear from the following description in which the preferred embodiments of the invention have been set forth in detail in conjunction with the accompanying drawings.

Referring to the drawings:

Fig. 1 is a vertical cross-sectional view taken along the line ll of Fig. 2, and showing one embodiment of my invention.

Fig. 2 is a vertical cross-sectional view taken along the line 2-2 of Fig. 1.

Fig. 3 is a vertical cross-sectional view taken along the line 33 of Fig. 1.

Fig. 4 is a side elevational View of a suitable hanger for the conductors and enclosing sheath.

Fig. 5 is a fragmentary plan view of the conductor sheath shown in Fig. 1.

Fig. 6 is a cross-sectional view taken along the line 66 of Fig. 4.

Fig. 7 is a cross-sectional view showing an embodiment using a single extended conductor.

Fig. 8 is a cross-sectional view showing a modified form of sheath.

Fig. 9 is a side elevational view of the sheath shown in Fig. 8, partly in cross-section.

The apparatus illustrated in Figs. 1 to 6 inclusive of the drawing, consists of a plurality of extended electrical conductors Illa, Iflb and I00,

which may be in the form of hard drawn copper wire. These conductors are disposed within a sheath H of insulating material, and they cooperate with the traveling contacting device l2. While the preferred form of contacting device will be presently described in detail, it may be pointed out that it includes at least two sets of trolley wheels, one set being designated by numerals l3a, 13b and I30, and the second by numerals Ma, Nb and I40.

The material from which the sheath 1 I is made may-vary in different instances, but I prefer to make use of a molded .plastic which will have sufficient strength to properly retain the conductors. A molded plastic such as Bakelite or like phenolic condensate product, which may be 5 reinforced with fabric, will afford proper strength. In physical form I prefer to manufacture the sheath I l in two parts l6 and I1. Between the conductors the part I6 is shown provided with grooves l8, adapted to accommodate raised ribs [9 formed on the inner'face of part I1. Such an arrangement aids in locking the two parts together and affords better insulation between the conductors. The part 16 is also shown provided with raised ribs 2| to afford greater 151 strength, and the lower part I! is provided with ribs 22 for the same purpose, and also for the purpose of guiding the trolley wheels, as will be presently explained.

The lower part ll of the sheath is provided with a plurality of openings 23a, 23b and 230. These openings are disposed in three rows, there being one row for each of the conductors. Preferably the openings of adjacent rows are staggered as illustrated in Fig. 5, in order to afford 25 greater mechanical strength and to preclude improper application of .the trolley wheels. It will be noted from Fig. 5 that these openings serve to expose spaced portions of the conductors Illa, Oh and H10.

Any suitable means can be utilized for holding the two par-ts l6 and I! together. In Fig. 5 a simple type of holding means is illustrated consisting of U-shaped clips 24 extending over the side edges of the parts [6 and I1, and engaging within grooves whereby the two parts are held together. As shown in-Fig. 1 the parts l6 and l! are preferably made in lengths of suitable size which are overlapped in order to ail-0rd substantially a continuous sheath of any desired length withoutuse of special couplers. The abutting end faces I 5 can be on an angle as shown in Fig.

5 to avoid interrupting an opening. The assembly of conductors and insulating sheath as described can besupported in any suitable manner for cooperating with the contacting device I2. For example it can be supported at spaced points by brackets 26 of suitable desi with these brackets in turn being attached to structural parts 21 of a building. It is also possible to provide the insulating sheath with integral tabs 28, for attachment to supporting means.

The trolley wheels of the contacting device l2 are formed of suitable material ,such as hard copper or bronze. The wheels of each set may be carried by an individual mounting or as shown they may be carried on a common operating axis Thus taking the set formed by wheels I3a, I31) and I30, the wheel |3a is insulated from the rotatable shaft 3|, and is secured to a concentric hub or sleeve. The ends of this shaft are journalled to the body or frame 32 of the contacting device. Wheels I3?) and I30 are likewise attached to shaft 3|, there being insulating material 33 and 34 in order to avoid short-circuiting. One end of the shaft 3| and the extended portions of the hubs for wheels I3a, l3?) and I30, form a series of collector rings 36a, 36b and 360, with which the brushes or blocks 31a, 31b and 310, may make electrical engagement. The insulation for securing the wheels to the shafts may be resilient synthetic rubber in order to afford a certain amount of give or self-aligning action. 7

The set of wheels Ma, Mb and 140 are mounted in the same manner as described above and they likewise are provided with collector rings for electrical connection with the corresponding brushes or blocks 31a, 37b and 310. The corresponding brushes or blocks for the two sets of trolley wheels can be directly inter-connected as by the resilient bus conductors 38a, 38b and 380, and these conductors in turn can connect to a suitable terminal block 39.

Each trolley wheel has its periphery provided with a series of spaced notches 4] (see Fig. 1) thus providing a series of circumferentially spaced teeth 42. In contour the end face of each tooth is curved to a radius corresponding to the axis of rotation of the wheel, and the pitch distance between two adjacent teeth corresponds to the distance between .centers of the openings in the sheath. In order to afford a greater area of contact for each tooth with its associated conductor, the teeth can be grooved as indicated at 43.

As will be evident from the above, each trolley wheel may track within a particular row of openings in the insulating sheath, with the teeth of that wheel being brought successively into rolling contact with the successive exposed areas of the conductor wire. As previously pointed out there are at least two trolley wheels for each conductor, and as shown in Fig. 1, two corresponding trolley wheels, as for example wheels I 3a and Ma, have an angular relationship with respect to each other whereby one wheel is displaced by an an' gular distance equal to one-half the pitch between adjacent teeth. The purpose of this is to insure positive contact at all times between either one or both of the wheels l3a or Mb, thus making for continuous flow of current without arcing.

Operation of the apparatus described above can be reviewed as follows: The contacting device IZ .can be carried by a suitable trolley pole or any other movable mechanism tending to urge this device toward the conductors Ina, lb and I00. All of the trolley wheels track within the openings 23a, 23b and 230, and the engagement between each trolley wheel and an associated conductor is one in which the .contacting surfaces are brought into rolling contact, as the trolley wheel is moved along the conductor. The electrical conductors llla, lflb and We are thoroughly insulated with respect to accidental contact. For example when used to take the place of overhead trolley wires, it is practically impossible for a workman to accidentally make electrical engagement with one of the conductors", even though a portion of the body should be placed directly against the lower side of the insulating sheath. The thorough character of the insulation afforded does not in any way interfere with the good electrical contact between the conductors and the trolley wheels. In fact the contact alforded by my apparatus is as good if not superior to the contact afforded by an ordinary trolley arrangement as applied to an exposed trolley wire.

The insulating sheath I I can be readily applied about the conductors at the time the conductors are being installed for use with a particular apparatus. As previously stated, it is preferable to mold the parts It and I! in convenient lengths, with these individual lengths overlapped in order to avoid the necessity of special coupling device.

In the foregoing I have described an arrangement making use of three extended conductors, such as are suitable for a three phase circuit arrangement. It is also possible to use two conductors, or more than three conductors, depending upon the requirements, or in certain installations a single conductor can be employed, with the contacting device l2 provided with only two trolley wheels for making electrical engagement with the one conductor. The manner in which the insulating sheath can be formed in this instance, is illustrated in Fig. 7. Thus the sheath is formed in two parts 46 and 41, which enclose the single linear conductor 48. A single row of openings 49 afford access to spaced portions of the conductor. The lower part 41 of the sheath can be formed to provide spaced ribs 5| alongside the openings, in order to guide the trolley wheels.

The embodiment of the insulating sheath shown in Figs. 8 and 9 is similar to that shown in Figs. 5 and 6, except .that features have been simplified to facilitate manufacture. The sheath is formed by the two molded parts 53 and 54 which are held together by the side clips 53. At spaced intervals along the upper part 53, threaded pads 51 are provided, for making attachment to a suitable support. The part 54 is provided with simple grooves 58 to receive the conductors, and the lower part 54 is provided with ribs 59 to interfit the grooves 58. The lower part 54 is provided with spaced openings iii, the same as shown in Fig. 5, and ribs 62 on the lower face of part 5 serve to guide the trolley wheels. The upper face of part 53 may serve to guide rollers or wheels 63 and which in turn may serve to support the contacting mechanism.

I claim:

1. In electrical apparatus of the character described, a pair of parallel electrical conductors, a. sheath of insulating material formed about the conductors, said sheath being provided with a plurality of rows of spaced openings, whereby spaced areas of each conductor are exposed through said openings, there being a row of openings for each conductor, with one row of openings being staggered with respect to an adjacent row, a member adapted to travel longitudinally of the conductors, and means carried by said member serving to maintain continuous electrical connection with said conductors through said openings, as said member is traversed longitudinally of the conductors.

2. In apparatus of the character described, a pair of parallel conductors, a sheath of insulating material formed about the conductors, said sheath having a plurality of rows of spaced openings through one side of the same whereby spaced areas of the conductors are exposed through said openings, there being one row of openings for each conductor and adjacent rows of openings being staggered, a member adapted to travel longitudinally of said conductors, and a plurality of trolley wheels rotatably carried by said member and adapted to make electrical connection with said conductors through said openings, there being two trolley wheels for each conductor, the peripheries of said trolley wheels being notched to enable said wheels to make rolling electrical engagement with saidconductors through said openings.

3. In electrical apparatus of the character described, a pair of parallel conductor wires, a sheath of molded insulating material formed about both said wires, one side of said sheath being provided with two rows of spaced openings through which spaced areas of each conductor are exposed for electrical engagement, there being one row of openings for each conductor, the two rows of openings being staggered.

4. In apparatus of the character described, an electrical cable comprising a substantially linear conductor covered by a sheath of insulating mater'ial, said insulating sheath being interrupted by a row of spaced openings whereby spaced areas of the conductor are exposed through said openings, a member adapted to travel along the length of said cable, at least two toothed trolley wheels rotat-ably carried by said member, each of said trolley wheels having a toothed periphery with the teeth of each trolley wheel adapted to enter said openings to establish rolling contact with the exposed areas of the conductor, the angular relation-ship between the two trolley wheels being such that one wheel is displaced with respect to the other wheel by an angle substantially equal to one-half the tooth pitch.

5. In electrical apparatus of the character described, an extended sheath of substantially rigid molded insulating material, two extended conductors carried within the sheath, said sheath being formed of an imperfora-te part and a perforaited pant clamped together and having longitudinally extending inter-engaging rib and groove means, said perforated part providing two rows of spaced openings through which spaced areas of each conductor are exposed for electrical engagement, there being one row of openings for each conductor and the two rows of openings being staggered.

BURJTIS W. BENBOW.

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