US336629A

US336629A - Leo daft

Info

Publication number: US336629A
Authority: US
Publication date: 1886-02-23
Anticipated expiration: 1903-02-23

Description

(No Model.)

L. DAFT. ELECTRIC MOTOR. No. 336,629. Patented Peb. 23, 1886.

llNrTeD STATES PATENT Gerlos.

LEO DAFT, OE GREENVILLE, NEWT JERSEY.

ELECTREC MOTOR.

PECIFICATION forming part of Letters Patent No. 336,629, dated February 23, 1886.

Application led May 26, 1F85.

To all whom it' may concern.-

Be it known that I, LEO DAFT, a citizen of the United States, residing at Greenville. in the county ot' Hudson and State of New LTersey, have invented certain new and uset'ul Improvements in Electric Motors, of which the following is a specification.

Myinvention relates to electric motors, and more particularly to the means for reversing the same; and it has for its object to improve the construction of the reversing mechanism or brush-carriers, so that they may be readily and easily operated, and so that the brushes shall bear upon the commntator when in use in such a manner as to secure the highest ef ciency and the least wear at the points of contact, and so that they may be readily thrown out of contact with the commutator when desired.

To these ends my invention consists in a mechanism constructed substantially as hereinafter pointed out.

In the accompanying drawing is shown a side view oi' one well-known type of motor with my improvements attached.

It is w ell'lr nown that in the use of electric motorssuch, for instan ce, as are employed on electric locomotives-it is necessary to frequently change or reverse the direction of rotation ot' the armature, and one convenient way of so doing is to change the relative positions ofthe brushes on the com mutator, so as to cause the current to pass through the coils of the armatures in diii'erent directions. It often happens, also, that it is desired to withdraw the current entirely from the commutator, as when the locomotive is running by its momentum alone.

It is well recognized that the most efficient way of placing the brushes is to lhave them inclined to the face of the commutator in the direction ot' its rotation, and not only does the current pass with less resistance, but the wear upon the brushes is much less than when they are placed. in a radial line to the axis of the commutator or at an inclination opposed to the direction of rotation of the armature.

In carrying out these improvements I construct the brushes and make the circuit-counections as follows; In the drawing, the eldmagnets are represented by F, the armature by M, with the commutator O xed upon the Serial No. 166,718. (No model.)

armature-shaft P, supported in the frame Q. Alsolooselysupported upon thearmature-shaft is the rocking lever B. Secured to the ends of this lever, by pins or bolts passing through insulating-bearings I). are the gnide-levers A, the outer ends ot which are provided with guides a, ruiming in slots c in the extension ot' the frame Q. rIhe lnush-carriers D are rigidly secured to the inner ends ofthe guidelevers A, and properly insulated therefrom, and each brush-carrieris provided with apair of brushes. as l 3 and 2 4, placed at an angle to each other, as shown. Some suitable operating means is connected tothe rocking` lever, as the rod E, and attached handle, E, moving over t-he sector E2. The circuit-connections are made so that one brush on each side of the connnutator, as l and 2, have a common terminal, which, for example, in the drawing is shown to be connected to the inner end ofthe field-magnet coil, and similarly the brushes 3 and 4. are connected to the line-circuit.

From this construction it will be seen that when the reversinglever is thrown over, as shown in the drawing, the brushes l and 4 only will bear upon the commutator at diametrically-opposite points, and the direction of rotation of the armature will be that indicated by the arrow, and it will be evident when the rocking lever is thrown over to the other extreme of the sector that the brushes 2' and 3 will engage with the commutator at diametrically-opposite points, and the direction of rotation of the armature will be reversed by the evident reversal of the relations be tween the currents passing through the armature and the held-magnets. A

It will be observed that whatever the direc` tion ot' the armature the brushes will bear upon the commutator in such a position as to produce the best results electrically and produce the least wear. Then it is desired to allow the motor to run by its momentum or otherwise, independent of the current,the reversing-lever will occupy an intermediate position on the sector, and all the brushes will be free from the commutator.

It is evident that the construction and ar rangement of the mechanical devices may be varied from that shown to meet the exigen` cies of the particular construction of the various motors without departing from the spirit of my invention, and that parts of the mechanismdescribed may be used alone or with other equivalent devices.

l. In an electric motor, a rocking lever having a pair of brushes at each end arranged With their inner ends projecting from each other, one of the brushes of each pair having a common terminal, and mechanism, substantially as described, whereby each diametrically-opposite pair may be brought into contact with the commutator at an angle to the direction of rotation of the commutator, as set forth.

2. The combination, in an electric motor,of a rocking lever, guidelevers secured to the ends of the lever and Working in guide-slots, a pair of brushes secured to the rods, and operating devices, substantially as described, whereby either pair of the diametrically-opposite brushes may be brought into contact ,with the commutator, as set forth.

3. The combination, in an electric motor,of an armature-shaft and commutator securedthereto, a rocking lever on said shaft, guide1evers secured to the ends of said lever and Workingin slots in the frame of the machine, a pair of brushes secured to the guide-levers, having outwardly-projecting rods, and one brush of each pair havinga common terminal, and a 3o hand-lever forn changing the position of the brushes, so that they will bear upon the commutator at an angle to the direction of rota tion of the same, or so that none of the brushes will touch it, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.

LEO DAFT.

Witnesses:

J No. N. BRUNs, F. H. REED.