US1388528A - Trolley-shoe - Google Patents

Description

L. H. SHIPMAN TROLLEY SHOE.

APPLICATION FILED JULY 18, I918.

Patented Aug 23, 1921.

zfewa'a 711,576 6707766172 UNITED STATES PATENT OFFICE.

LEWIS H. SHIPMA'N, 013 BOSTON, MASSACHUSETTS.

TROLLEY-SHOE.

Application filed July 18,

To all whom it may concern:

Be it known that I, LEWIS H. SHIPMAN, a citizen of the United States, and resident of Boston, county of Suffolk, and State of Massachusetts, have invented an Improvement in Trolley-Shoes, of which the following description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My present invention is an improved sliding shoe for electrical transmission from a trolley wire to a vehicle or car and the object of my invention is to improve and perfect such trolley shoes.

The advantages of a sliding shoe, as distinguished over a rotating wheel, are numerous and well known, employing a conducting member with a relatively long contacting surface which gives more eflicient conductivity, eliminates the wearing of a constantly rotating member on its axles or bearings, is capable of long use, and is economical. However, the use of sliding shoes in practice has been restricted because of certain practical difficulties. such as keeping the shoe in proper contact with the wire, and difficulties in providing a device which would slide in either direction upon wearing. My present invention obviates the difficulties heretofore experienced in sliding shoes of this type and I have devised a novel form of shoe which is of extremely simple construction, economical to build, apply, and most efficient in use, furthermore being capable ofinterchangeability while also being equally eflicient in sliding move ment in either forward or backward directions and at all times being readily retained in contact with the trolley wire, In my present invention I have eliminated undue weight, springs, or other attachments and have devised a practicable trolley shoe which operates to automatically maintain the long sliding wire-engaging portion of the shoe on the wire during either forward or backward movement of the trolley harp or car.

In carrying out my invention I provide a trolley harp and a shoe supported thereby with pivotal connection from the harp to the shoe at a point substantially at the extreme end of the long wire-engaging portion, forming two such wire-engaging portions on either side of the shoe and in planes Specification of Letters Patent.

Patented Aug. 23, 1921.

1918. Serial No. 245,491.

intersecting each other at a point removed from the pivot, uniting said planes at the pivot end by a curved line concentric with said pivot. This enables the shoe to be normally positioned in a substantially vertical plane while suspended from the harp before contact with the trolley wire and when first positioned inv contact with the trolley wire. In this position the shoe will be automatically swung into proper wireengaging position, either for forward or backward movement of the harp or car, simply by the forward or backward move ment of the harp or car, such action serving to rock the shoe on the concentric wireengaging portion and swing said shoe into proper position for its eflicient operation with either of the long wire-engaging portions in contact with the wire with no tendency on the part of the shoe to overthrow. My trolley shoe is therefore at all times in position for either forward or rearward movement of the car with equal facility or efficiency without danger of the shoe jumping off the wire. As in practice the shoe would ordinarily be used principally for forward movement it is a further advantage of the present construction to enable the shoe to be reversed in the harp so that wear on each side may be utilized for the forward travel where the greatest wear goes, thus doubling the life and usefulness of my shoe.

Referring to the drawings illustrating the perfect embodiment of my present invention,

Figure 1 is a side view of a fragmentary portion of atrolley pole, the trolley harp attached thereto and my novel form of shoe in this normally suspended position;

Fig. 2 is a similar view showing the position of the shoe on the wire during the forward movement of the car with the trolley harp and pole at the usual rearwardly extending angle;

Fig. 3 is a similar side View showing the shoe in proper position on the wire when the car is moved backwardly;

Fig. -l is a cross-sectional view on the line 4-4 on Fig. 2; and

Fig. 5 is a longitudinal cross-sectional view through the trolley shoe.

As shown in the drawings I have indicated the upper portions of the trolley pole 1 which is held upwardly by a spring at its arms and6, and the loop 7 to which the trolley cord is attached is also shown. The

I end portions of the arms 5 and 6 are enlarged slightly as shown at 8 with a hub 9 perforated to receive the axle 10 on which the trolley shoe 12 is pivotally mounted.

"I prefer to also provide a bushing in two parts 13 and 14 as clearly indicated in Fig.

4. Preferably this bushing is of suitable conducting material and may be employed,

therefore, to carry the current from the shoe through the-bushing to the harp. By

having this bushing in two parts the current is divided and conducted equally through the arms 5 and 6. This relieves the pivot 10 of current carrying and therefore may make the pivot of. less conductivity than where the current is transmitted through the pivot, although the latter method ma be employed whenever considered advisable. The pair of cotter pins ..15-16 hold the axle 10 in position, said bushin s preferably extending slightly beyond t e hubs 9 of the arms 5 and 6 at each side of the harp and having V- shaped recesses 17, 17 therein through which the cotter pins. are fitted so that the bush- 5 ,ings on the axle are thus retained in assembled position.

The trolley shoe 12 is formed with its My wire-engaging groove substantially in three sections or lengths, the relatively long it straight wire-engaging portions for operat- H o ing-jcontact during either forward or rearward movement, being indicated at 20 and p 21 and these substantially straight grooves being united by the curved section 22 concentric with the axis of the pivot 10. These I the flangps or sides 23 extending entirely grooves are of approximately equal depths,

around e shoe and grooves to the extreme yrear portion 24, the numbers 20, 21, and

p I 22' indicating the base of the grooves and the wire-engaging surfaces of the shoe. The thickness of the metal which preferably is of any suitable wear-resisting and electrically conducting material, between the base of the grooves and the recess for the pivot may be pro ortioned for length of service and wearabi ity as may be desired, it being possible to use my shoe until the metal is worn downon one groove almost entirely to the pivotfand then to reverse the shoe and use the othergroove for the forward moving portion, the rearwardly moving service to which the shoe is subjectbeing relatively slight and intermittent. I may also lighten the shoe by coring the recess 25 when deemed advisable. In the operation of my improved sliding shoe it is easily and quickly assembled upon the harp, and when the harp and trolley pole are elevated to position of contact with the trolley wire 30, the shoe is normally pendant presenting the curved or wheel-like grooved ortion 22 for initial contact with the tro ey wire and with the shoe in this position it is thus ready for instant and automatic operation through movement of the car into the position for its proper and efficient use during the forward propulsion of the car as shown in Fig. 2, or for backward movement of the car as shown in Fig. 3. The instant that the car moves in either direction, the friction between the shoe and wire automatically rocks the shoe on the circular grooved portion 22 urtilthe shoe is swung with the tangential straight portions 20 or 2 1 respectively, into contact with the wire, continued moving of the car maintaining the shoe in this position with the long straight surface of the shoe in sliding contact with the wire and in osition for most eflicient conductivity. oreover the shoe isthus maintained with a degree of yielding or resilient action due to the lifting of the weight of the lower portion of the shoe, because of its eccentriemounting. This function of yielding is important as it enables the shoe to follow the sinuosities in the trolley wire due to differences in height, ield,.sw1ng, or sag ofthe wire, retaining t e shoe in wire-en-- gaging position and very largely eliminating the danger of the shoe jumping off 1 the wire. When one groove is worn the shoe may be instantly reversed in position and the unworn grooved portion brought into use, by simply withdrawing one cotter in and removing the axle, reversin the s cc and replacing the axle. Althoug 1 I prefer to use the bushing as the conductor, as above described, because of the slight wearin upon the pivot, the axle may be made 0 electrical conducting material, if desired, although it is possible also on account of the slight oscillation and wear, to utilize the contact sides of the shoe, with the arms 5 and 6, as indicated at 26 and 27 taking the current directly therethro h and thence 115 from the harp by the wire %not shown) to the car.

My invention is further described in the form of claims as follows:

1. A sliding trolley shoe of the kind de- 120 scribed, com rising two wire-engaging surfaces exten ing in divergent planes connected at the point of greatest divergence by a wire-engagin are shaped surface.

2. A sliding tro ley shoe of the kind described, comprising a trolley harp, a contact member pivoted to said harp, wire-engaging grooves extending at an angle relatively to each other and being farthest separated substantla-lly opposite the pivot, and a wire- 130 engaging groove formed in an arc substan tially concentric with said pivot, and uniting said Wire-engaging grooves.

30 A sliding trolley shoe of the kind described, including a trolley harp, a pivotal mounting for the shoe eccentric to its center oi gravity, two straight Wire-engaging grooves extending longitudinally and di verging from a common point with their point of greatest divergence substantially opposite the axis of the pivot and a curved Wire-engaging groove uniting said straight grooves and extending around the pivot,

whereby the shoe will normally hang verti- I cally from its pivot with the curved portion upward for initial Wire-engagement and in position to bring either straight groove into Wire-engaging contact by the-movement of the trolley harp either forwardly or back- Wardly.

4. A sliding trolley shoe of the kind described having approximately the shape of one half of a trolley Wheel, extended from the ends of the are by flat surfaces lying in approachin planes, said shoe being pivoted at substantially the same point at which a complete trolley Wheel having the same are would be pivoted.

5. A sliding trolley shoe of the kind described comprising a trolley harp, a substantially triangularly shaped sliding shoe pivoted to said harp, permitting partial rotative movement and a counterbalancing weight in said shoe to cause the shoe to normally hang on its pivot in a predetermined position.

In testimony whereof, I have signed my name to this specification.

LEWIS H. SHIPMAN.

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