Improvements in Station or Street Indicators for Tramways, Railways, and Public Vehicles, applicable also for Advertising and the like.
Year: 1896

page_text: Date of Application, 5th May, 1895-Accepted, 18th July, 1896
COMPLETE SPECIFICATION.
Improvements in Station or Street Indicators for Tramways,
Railways, and Public Vehicles, applicable also for Advertising
and the like.
A communication by FRIEDRICH ZILLGER, of Bockenheim, near Frankfort-on-
the-Main, in the Empire. of Germany, Engineer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M:I.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 322 High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this 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 has for its object an apparatus to indicate to the public travelling
in tramcars, omnibuses or public vehicles the names of the streets through which
the vehicle is passing. The apparatus is operated by turning the thumb piece, knob.
or handle of a switch specially constructed and arranged for the purpose, the
operation being effected by the driver, conductor or the like.
The apparatus is shown in various sections and views in Figures 1-8 of the
accompanying drawings.
。
In order to prevent the warping of wood having any deleterious effect whatever
on the apparatus, it is constructed with an iron bed plate on which are screwed two
stands or supports e and e' which carry bearings for a shaft b. Two discs c and c¹
are fastened on this shaft 6 between the bearings and are provided with holes fnear
their periphery in which the name plates are revolubly mounted between the discs
or cheeks c and c. The front and rear faces of these name plates & may, according
to requirements, be provided with street names, advertisements or the like. Two
ratchet wheels g and gl are arranged on the shaft b outside the supports e and el,
with which ratchet wheels two armaturo pawls and engage, by means of which,..
movement of the drum kis produced through the action of two electro-magnets.
The armature h is pivotally mounted at above an electro-magnet i and is
retained by means of a spring y in the desired position on the interruption of the
current, u is a contact stop for the armature h, Figure 9. The mechanism
arranged on the same ratchet wheel g opposite the armature à consists of an
automatic pawl device r, which, at each rotation, automatically adjusts itself on a
tooth of said wheel by means of a spring z and thereby stops any backward rotation.
The armature pawl is pivotally mounted at w to engage against the second ratchet
wheel g' in front of the electro-magnet m, and, by means of the spring r, is always
kept in engagement with the ratchet wheel g¹ during interruption of the current.
This pawl prevents any rotation in the direction of the arrow.
The action of the electro-magnets on the armatures and h to produce movement
of the drum k is regulated in the following manner :-
The necessary current for the electro-magnets is drawn from a battery o and
conveyed to the clamp springs, I, II, III and IV of a commutator or switch in such
a way that the positive current is conveyed through the coils of the electro-
magnets m. i to the clamp springs II and IV, and the negative current direct to the
clamp springs I and III. The commutator, which consists of vulcanite, (that is to
Bay of a non-conducting material) is penetrated by contacts x, y, and x', y'. The

page_text: clamp springs I II III IV rub on the surface of the vulcanite cylinder, so that on
rotating the latter by the knob q, the clamp springs III and IV make contact with
the contact surfaces a y, by which means the circuit is closed through the electro-
magnet m. The electro-magnet m, thus excited, attracts the armature pawl and
releases the drum k for the forward direction. If the commutator or switch
be then further turned, the electro-magnet i operates in a similar way a short time
after the other magnet depending on the extent to which the contact surfaces a y₁
are opposed or displaced on the periphery of the vulcanite cylinder relatively to the
contact surfaces or y, Figure 5. In this position, both electro-magnets receive
current, the armature remains therefore still attracted and the electro-magnet i
by attracting the armature h, produces a rotation of the drum k to the extent of one
tooth. This rotation is sufficient to cause the upper name plate d to swing away
from the edge of the bar n of the exposing aperture. A further rotation of the
drum k is impossible because the armature h has only sufficient power of movement
to effect the rotation of the drum to the extent of one tooth, and because, during
the rotation of the knob g of the commutator or switch, the current for the electro-
magnet m is cut off so that the armature l again comes into engagement with the
ratchet wheel and thereby prevents the drum k from rotating further.
In order however to yield a greater security as regards the fixing of the drum k,
au automatic stopping or pawl device v is employed in addition to the two armature
pawls and h which pawl is held in engagement with the ratchet wheel g simply
by means of a springz and thus prevents a backward rotation of the drum.
If the commutator or switch be moved further, the drum k will be rotated at
each contact of the contact surfaces with the clamp springs of the armature h or 1,
and thus a fresh name plate will become visible. Figures 5-7 show the commutator
or switch disconnected.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
A station or street indicator applicable also for advertising and the like in which
the movement forward and stopping of the drum (k) carrying the name plates (d)
is effected by electro-magnetic means characterised by the combined action of two
ratchet wheels gand g' having opposed teeth and provided with two pawls (hand 1)
each operated by a separate electro-magnet (i and m) excited on the movement of
a switch in such a way that first one pawl is raised and then the other actuated to
produce a partial rotation of the indicating drum, the drum being then fixed in both
directions by means of both pawls substantially as described.
Dated this 4th day of May 1896.
WM. P. THOMPSON & Co.,
Agents.