Commutators for Electrical Machines.
Year: 1890

page_text: Date of Application, 5th Aug., 1890-Accepted, 27th Sept., 1890
COMPLEIN DIUITIATION.
Commutators for Electrical Machines.
I WILLIS WILL.SON VAIL, of Quakertown, in the County of Hunterdon, in the
State of New Jersey, one of the United States of America, Gentleman, do hereby
declare the nature of my invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention relates to commutators, or devices for shifting the electric current
from a continuous to an alternating current, and consists in an improved construction
for such devices as hereinafter described and claimed.
In the accompanying drawings-
Fig. 1 represents a side view of a commutator provided with my improvements.
Fig. 2 is an end view of the same.
Fig. 3 is a top view of the same.
Fig. 4 is a section taken on the line a- of Fig. 3.
Fig. 5 is a section taken on line y-y of Fig. 4.
The commutator is cylindrical in form and is mounted on a shaft A which is
journaled in the standards B on the base C. On the shaft A is placed a tubular
piece a which forms a seat for the brass rings e c¹ placed thereon, the seat a being of
vulcanite, or other suitable non-conducting material, and provided with a rib or collar e
which separates the said rings. The collars are placed on the shaft A at the
extremities of the seat a, and the rings c c are thus insulated by the said collars and
seat.
The cylinders dd, extending along the shaft from the collars bb, are of brass,
vulcanite, or other suitable material for supporting other parts. Outside of the parts
above described, is a vulcanite spool or cylinder D, provided with heads at its
extremities. one of which is male solid with the cylinder and the other is secured
thereto as shown.
Secured to the cylinder D and extending along the same, are a series of bars F, E
and E', the said bars F extending from one head to the other, and the bars E E' being
short bars and arranged two on the same line between the bars F as shown. At their
inward ends, the bars E E' are separated by blocks of vulcanite, and thin longitudinal
strips, of vulcanite or mica are placed hetween the bars for severally insulating them.
The bars E E are connected by screws with the rings e c'.
Four brushes. GG and H. extent upward from the base C, in positions to bear
against the bars F. E and E', as the cylinder is rotated, two brushes being arranged on.
each side. A binding post I is connected with each of the brush-holders as shown.
In the drawings-see Fig. 5-the commutator is shown with six bars F and six coupies
of bars E E', the latter being arranged two on a line, so that all occupy twelve lines,
and the cylinder should be so constructed that the number of lines of bars would be
divisable by four.
When the commutator is in position so that the brush G bears against one of the
bars F, the brush G' bears against the same bar, and the brushes H H bear against a
bar diametrically opposite. If the position of the commutator is such that the
brush G bears against a bar E, the brush G' will bear against the bar E¹ which is in
line with said bar E, and the brushes H H will bear respectively against the bars E E¹
which are diametrically opposite to those in contact with brushes & G¹.
In operation, suppose a continuous current to enter the machine at G, the brush G
resting against a bar F, the current will then leave the commutator by the brush,G',
on the circuit employed, and returning to the brush H, passes from thence through a
bar F to the brush H', and thence back to the dynamo. If the position of the com-
mutator is such that the brushes G G¹ bear against two bars E E, then the current

page_text: entering at G, passes through a bar E and a screw i to a brass ring c; thence around,
through another screw i to a bar E diametrically opposite the bar E which it first
entered, and thence out at the brush H on another circuit employed. Returning to
the brush G¹, the current passes through a bar El, a screw ', a ring c¹, another screw i¹
and a bar E, to the brush H' and from thence to the dynamo..
As will be seen, the current, while flowing continuously in one direction, in the
wires from the dynamo connected with brushes G and H¹, may be caused to flow
alternately in one way and the other through wires connecting brushes G¹ and H.
The device may driven by any suitable motor, an electro-motor of low resistance,
introduced in the circuit being preferable. The entire current may be passed through
the motor, or a shunt may be employed, so that just a sufficient amount passes through
it to give the required speed. The number of alternations per second may be varied
by varying the speed of the motor, or by increasing or decreasing the number of bars
of the commutator.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim is-
1. In a commutator, a cylinder placed on a rotative shaft, a series of insulated.
longitudinal bars F and intervening short bars E E', secured to said cylinder, and
insulated devices, with:n said cylinder, connecting said short bars, in combination with
four brushes, two of which are placed on each side of the commutator, in positions to
bear against opposite bars of said cylinder, substantially as and for the purposes
described.
2. The combination with a rotative cylinder, provided with longitudinal bars F,
short bars E E' and insulating material placed between said bars, of the tubular
scat a, on the shaft of the cylinder, collars, insulated rings c c', connected by
screws with said bars E E', cylinder D and four brushes, two of which are placed at
each side of said rotative cylinder, substantially as set forth and described.
Dated this 1st day of An
1800
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.