Year: 1885

page_text: PICCHIAL
We RONALD AUGUSTUS SCOTT, WALTER THOMAS GOOLDEN, and ALEXANDER
PELHAM TROTTER, all of 2 Victoria Mansions, Westminster, Electrical Engineers,
do hereby declare the nature of this invention to be as follows :—
This invention relates to electrical switch boards designed to facilitate the
connexion of dynamos or other sources of electricity with electrical circuits, the
object of the invention being to enable any or all the circuits coupled to the switch
board to be put in connexion with either of a number of dynamos, and to prevent
any circuit being put in connexion with more than one dynamo at a time. For
this purpose cach circuit has in it a pivotted arm or lever upon which is mounted
a sliding contact piece. Below the arm when in the working position, and at
right angles to it, there lie a number of metal bars, each of which forms one
terminal of a dynamo. The sliding contact piece can be moved along the arm into
positions corresponding with each of the bars, the exact points being marked, to
facilitate the operation, by notches or depressions which engage lightly with a
catch on the said piece. The bars may be spaced so far apart that even if the
sliding piece be not at the place marked out for it by the notch, it will not bridge
the distance between two bars, and thus become connected to both dynamos. Firm
contact between the bar and the sliding piece is secured by a spring hook which
automatically engages with the end of the arm when put into position or by a
lever or an eccentric which can be set to grip it. A rapid and complete break of
the connexion of the two parts is effected by a spring, which, as soon as the arm is
released, forces it away from the dynamo bar. This spring may act on an extension
of the arm near the pivot or directly on some other part of the arm. As a further
safeguard against accidental connexion of the circuit and one of the dynamo bars
and as a convenience in manipulation, it is preferred to arrange the arm in an
inclined position, so that the spring throws it past the vertical line, and gravity
carries it onward until it stands at right angles, or nearly so, to the switch board.
In addition to the bars which are connected each to a dynamo, it is convenient to
Drin Q27

page_text: have an insulated bar to which the sliding contact piece can be applied when the
corresponding circuit is out of action.
The connexion between the arm and the corresponding circuit is made through
a fusible bridge or safety fuse, mounted on the switch board. For extra security
and convenience in testing a second fuse may be placed at the other end of the
circuit where it is coupled to a bar which forms a common return lead to the whole
of the dynamos. This fuse and the bar are likewise mounted on the switch
board, which is of a non-conducting material, such for example as slate.
Any number of circuit arms and any number of dynamo bars may be combined
on one switch board.
We, RONALD AUGUSTUS SCOTT, WALTER THOMAS GOOLDEN, and ALEXANDER
PELHAM TROTTER, all of 2 Victoria Mansions, Westminster, Electrical Engineers,
do hereby declare the nature of this invention, and in what manner the same is 2
to be performed to be particularly described and ascertained in and by the
following statement:-
This invention relates to electrical switch boards designed to facilitate the
connexion of dynamos or other sources of electricity with electrical circuits, the
object of the invention being to enable any or all the circuits coupled to the switch 2
board to be put in connexion with either of a number of dynamos, and to prevent
any circuit being put in connexion with more than one dynamo at a time.
For this purpose each circuit has in it a pivotted arm or lever
which is
upon
mounted a sliding contact piece. Below the arm when in the working position,
and at right angles to it, there lie a number of metal bars, each of which forms one 3
terminal of a dynamo. The sliding contact piece can be moved along the arm into
positions corresponding with each of the bars, the exact points being marked, to
facilitate the operation, by notches or depressions which engage lightly with a
catch on the said piece. The bars may be spaced so far apart that even if
the sliding piece be not at the place, marked out for it by the notch, it will not 3
bridge the distance between two bars, and thus become connected to both dynamos.

page_text: Firm contact between the bar and the sliding piece is secured by a spring hook
which automatically engages with the end of the arm when put into position or by
a lever or an eccentric which can be set to grip it. A rapid and complete break of
the connexion of the two parts is effected by a spring which as soon as the arm is
released, forces it away from the dynamo bar. This spring may act on an extension
of the arm near the pivot or directly on some other part of the arm. As a further
safeguard against accidental connexion of the circuit and one of the dynamo bars
and as a convenience in manipulation, it is preferred to arrange the arm in an
inclined position, so that the spring throws it past the vertical line, and gravity
carries it onward until it stands at right angles, or nearly so, to the switch board.
The connexion between the arm and the corresponding circuit is made through a
fusible bridge or safety fuse, mounted on the switch board.
For extra security and convenience in testing, a second fuse may be placed at
the other end of the circuit where it is coupled to a bar which forms a common
return lead to the whole of the dynamos. This fuse and the bar are likewise
mounted on the switch board, which is of a non-conducting material, such for
example as slate.
Any number of circuit arms and any number of dynamo bars may be combined
on one switch board.
Referring to the accompanying sheet of drawings, Fig. 1 is a front view of a
switch board arranged according to this invention, and Fig. 2 is a corresponding
side or edge view of the same. The base board A is formed of a non-conducting
material, such as timber or slate, upon it there are mounted a number of arms or
levers B B, each of which forms one terminal of an electric circuit.
Each arm B'is pivotted in a bracket O fixed to the base A and provided with a
terminal D. Upon the arm there runs a sliding contact piece E, provided with a
non-conducting handle E¹ by which it can be moved backwards and forwards when
desired. The slider carries a spring catch which engages with notches FF in
order that it may be readily adjusted in position. In Fig. 1 the sliders E are
shown moved to the right of the bars H.
The slider is an easy fit on the arm or lever, and a light spring G is placed
between the two to maintain them in good electrical contact and to prevent jarring.
The lower part of the slider is provided with a contact piece Q composed of several
thin sheets of copper which render it flexible or spring like and thus ensure good
contact with the dynamo bar H below it. The arm or lever B is constantly
pressed by a spring I so arranged as to cause it. to rise and rotate about its pivot,
as soon as the catch J is released by pressure on the insulated knob J. Å stop
bar K prevents the arm being pressed down too far in making contact.
The cross bars H H each form or are connected to one of the terminals of a
dynamo, and are so situated that any of the sliding contact pieces E E can be
applied to any of the cross bars. The other terminals of the dynamos are all
connected to the bar M.
The circuits commence at the terminals D D and pass through safety fuses to the
terminals D¹ D¹ from which they branch off.
At their other extremities they come to the terminals N N and pass through
safety fuses to the bar M.
00 are the safety fuses between the terminals D and D¹. PP are similar fuses
between the terminals N N and the dynamo bar M there being thus a double set
of safety fuses in each circuit. The terminals D¹ and N are the terminals of the
external circuits. By removing the fuses O and P testing of the external circuits
may be effected without disturbing any other connections or stopping the dynamo
machine or machines.
R is a sparking piece secured to each slider; it is of such length as to be in
contact with the dynamo bar before and after the contact piece Q has made or
broken contact with the said bar. In this way the sparking piece will take the
spark produced at the making and breaking of the circuit and thus preserve the
main contact surface between the dynamo bar and the contact piece Q.

page_text: The switch board is placed, by preference in a sloping or inclined position, so
that when one of the knobs J₁ is pressed the corresponding arm will rise smartly
into such attitude that its return is prevented by gravity. The extent of its swing
is regulated by the stop O. When contact is to be made between one of the
circuits and one of the dynamos the corresponding slider is adjusted to the proper
notch and the arm pressed down until caught by the catch. This immediately
slips over its extremity and secures it, so that the slider and the bar are in firm
contact. This catch thus constitutes an automatic locking device to hold the arm.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
1. A switch board comprising a series of bars each of which is one terminal of a
dynamo, and a series of levers each of which is one terminal of a circuit the said
levers being over and at right angles to the said bars and each lever being
provided with a sliding contact piece and being arranged in such a manner that
when liberated from the locking device it rises automatically to such a distance
that not only is the circuit broken between the sliding piece and the bar, but the
two are so far removed that it is not possible for an arc to be established between
them substantially as described.
2. In a switch board, providing an automatic locking device which on the contact
piece being pressed into position secures it there, substantially as described.
3. In a switch board the use of a double set of safety fuses in each circuit
substantially as hereinabove described for the purpose specified.
4. The bereinabove described switch board.