Improvements in or relating to Automatio Circuit Breakers for Use in Electric Tram Cars or other Electrically Propelled Vehicles.
Year: 1896

page_text: Date of Application, 21st Apr., 1896-Accepted, 15th Aug., 1896
COMPLETE SPECIFICATION.
Improvements in or relating to Automatio Circuit Breakers for
Use in Electric Tram Cars or other Electrically Propelled
Vehicles.
I, JAMES DEVONSHIRE, Secretary of the British Thomson-Houston Limited,
of 38 Parliament Street, Westminster, London do hereby declare the nature of
this invention (a communication from abroad by William B. Potter, Electrical
Engineer, of Schenectady, in the State of New York, United States of America)
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention relates to circuit breakers, particularly such as are adapted for use
on electric tram cars or other vehicles, in which a separate autoniatic circuit breaker
is associated with each controller, the two circuit breakers being connected in the
circuit in parallel. It is the purpose of the invention to provide, for two circuit
breakers thus situated, a single interchangeable handle which can be removed only
when the circuit breaker is open, so that the motorinan in going from one end of
the car to the other must remove the handle and. thus open the circuit at one
end before he can close the circuit breaker at the other end; to operate the
controller.
The accompanying drawings show a form in which my invention may be embodied.
Therein
Fig. 1 is a front elevation of a suitable circuit breaker;
Fig. 2 is a view of the handle and its receiving part, the latter being shown in
section, and the handle in side elevation;
Fig. 3 is a view of the same parts similarly shown; with the handle inserted
and turned through 180°;
Fig. 4 is a plan view of the parts shown in Fig. 3, partly broken away;
Figs. 5 and 6 are details; and
Fig. 7 is a car equipped with two circuit breakers in parallel, having an
interchangeable handle.
B is the handle provided with the collar B forming a cylindrical portion which
steadies the handle in the socket. A tapered cut-away portion C is also provided,
and upon a cylindrical extension, of which this tapered cut-away portion forms a
part, is a pin D. The socket E has a cylindrical boro E registering with the
portion B of the handle. The extended cylindrical portion of the handle passes
through a fixed collar E, which is secured in place by screws e. This collar, best
seen in Fig. 6, is cut through on its lower portion with a slot E³, the edges of
which are rounded slightly to permit the free passage through it of the pin D,
upon the handle. A Dutch E is provided in the upper part of the collar.
Connected with the socket is a lug Gmounted upon a bearing piece and retained
in the socket by a slot G through which a pin is passed. The socket forms an
integral part of the yoke E', and the lug rotates in the socket, as will be seen in
Fig. 4. In the rotating stud is a slot G', and the pin F, pressed outward by
its spring, passes through the end of this bearing piece. In the end of the bearing
piece the slot G forms a seat for the extension C from the handle, and a spring
controlled piu F is seated in the slot G¹.
The arts having been thus described, the method of operation is as follows:
The handle B is inserted in the socket, the tapered extension passing through the

page_text: collar E, and the pin D passing through the slot at the lower part of the collar.
In so doing, the tapered extension presses back the pin F' (the office of which is
to throw the hardle out when pressure upon it is released and to keep the pin D in
the notch E), and also presses upward the pin or tumbler F from the slot G
The handlo B is then twisted about its axis until the pin D drops into the
notch E of the collar E', as shown in Fig. 3. This twisting disengages the
lug G from the part H of the frame of the apparatus, and the handle may then be
depressed to close the circuit by the bridging piece M of the circuit breaker shown
in Fig. 1.
When it is desired to remove the handle, the operation just described is reversed,
and the spring pin F' forces the handle from its seat; but it is manifest that this
can only be accomplished when the circuit is open, inasmuch as the rotation of the
lug G will be prevented by the part II of the frame, unless the handle is in its upper
position in which the circuit is open.
.
In the automatic circuit breaker shown in the drawing, M' is a base or frame
which supports the various parts of the circuit breakers. N is a magnet coil in
the main circuit. The main electrodes or terminals of the conductor from the
negative brush of the generator and the line, are connected at k, k' respectively
and they are adapted to be bridged by a piece or pieces M, preferably made up of
a number of enperposed pieces of elastic and highly conducting metal carried on a
rod R and secured thereto by clamps or nuts, as shown.
The main current enters by a suitable conductor, not shown, adjacent to the
coil N, traverses the latter, passes by a suitable conductor, not shown, to the
terminal k, by the bridge M, to terminal A, and out by a conductor, not shown, to
the omnibus bar or external circnit.
The armature P of the coil N is supported at one end upon the pivot p, and at
its other end by a spring Z, whoso power or attractive force may be adjusted by a
nut. On the pivot p is also fulcrummed a detent lever L, whose outer end is
notched and engages with the edge of a lug (not shown) when the circuit is closed
by the bridge piece M against the action of a spring Z2, which latter acts to open
the circuit when, the lever L is released from engagement with the lug by the
automatic action of the coil N on an excess of current in the circuit, or by manual
operation of the handle V.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to bo performed as communicated to me
from abroad I declare that what I claim is :-
1. A plurality of automatic circuit-breakers, and an interchangeable handle
therefor, removable only when the circuit is open.
2. An electrically propelled vehicle, a pair of automatic circuit breakers thereon
connected in parallel, and an interchangeable handle for the two devices, removable
only when the circuit is open.
3. An automatic circuit breaker constructed to be locked when in open position,
in combination with a handle adapted to interlock therewith and removable only
when the circuit breaker is in open position.
4. The combination with an automatic circuit breaker of a rotary locking device
serving to lock the circuit breaker when in open position.
5. The combination with the haudle of an automatic circuit breaker, of a rotary
locking device, which locks the circuit breaker when in open position, and a spring
actuated device which disengages the circuit breaking handle when the circuit
breaker is in 'open position.
6. An automatic circuit breaker having a rotary handle, socket and locking
device which locks the circuit breaker when in open position, in combination with
a removable handle which interlocks with the rotary socket and is removable
therefrom only when the circuit breaker is in open position.
7. An automatic circuit breaker having a rotary handle, socket and locking device
which locks the circuit breaker when in open position, spring-actuated means for

page_text: holding the circuit breaker handle in place when the handle is in operative position,
and spring actunted means for removing the handle when the circuit breaker is in
open position, in combination with said removable haudle which interlocks with the
rotary socket and is removable therefrom only when the circuit breaker is in open
position.
16 21st day of April 1896.
For the Applicant,
J. C. CHAPMAN,
70 Chancery Lane, London, W.C., Chartered Patent Agent.