Improvements in or relating to Automatic Point or Switch Apparatus for Railways.
Year: 1895

page_text: Date of Application, 28th Aug., 1895-Accepted, 28th Sept., 1895
COMPLETE SPECIFICATION.
Improvements in or relating to Automatic Point or Switch
Apparatus for Railways.
A communication from STEFAN VON GAJEWSKI, Gentleman, of Mosezinsky-
strasse 8, Dresden, A, and LEOPOLD BRAUN, Merchant, of Uhlandstrasse, 10,
Dresden, A, both in the Kingdom of Saxony, German Empire.
I, ALFRED JULIUS BOULT, of 323 High Holborn, in the County of Middlesex,
Chartered Patent Agent, 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 relates to automatic point or switch apparatus for railways,
which is particularly useful in its application to street tramways and which is
actuated by the wheels of the vehicles. In this Specification the invention is
described as applied to a tramway having grooved rails, premising bowever that the
invention is not limited to this particular example.
A plunger is placed in the groove of the rail in front of the points that is to say
in such a position that the car, approaching a 'facing' point, arrives at the plunger
before reaching the points. This plunger is operated by the car to work a ratchet-
and-pawi apparatus which in its turn sets in operation a device in operative
connection with the shift rail or tongue of the points.
The plunger is run over and depressed by each axle (or pair of wheels) of the
car, and thus is depressed twice by the wheels of each car, therefore care is taken
to arrange the mechanism so that the second depression is of no effect. To this
end, the movement of the ratchet and pawl apparatus is transmitted to the points
by a pair of geared wheels, whereof one, the driver, is only partially toothed, its
other part being toothless, that is to say it is in effect a toothed segment. When
the front-wheel of the car runs over and depresses the plunger, a toothed portion
of the periphery of the driver' engages with the teeth of the other gear wheel,
and causes it to rotate; whereas, when the rear-wheel of the car operates the
plunger the second wheel remains motionless, because, though the driver rotates,
that part of its periphery which now runs round in proximity to the driven wheel
is toothless and there is consequently no engagement between the pair of gear
wheels. In certain cases, as hereinafter explained, devices other than road wheels
may be employed on the car, to actuate the plunger.
$
On the accompanying drawings ;-
Fig. 1 represents a plan of the apparatus;
Fig. 2 a longitudinal vertical section of the same;
Fig. 3 shows, on an enlarged scale, a vertical cross section through the apparatus
in the plane in which the plunger is situated with view of the ratchet and pawl
apparatus;
Fig. 4 is a section of a combined ratchet wheel and toothed wheel forming a

page_text: branches s' and 82. By means of the switch-tongue Z, pivoted at, the car-wheels
may be directed or shunted into the groove s¹ or s² as desired.
The bolt I, projecting from the under side of the tongue Z, engages in the slotted
arm 2 of an angle- or bell-crank lever 2-2, which pivots on the fixed bolt 3 as
a fulcrum. The other bell-crank-lever arm 2ª is connected with a crank-disc 5 by
the rod 4.
A short distance in front of the point of the switch-tongue, is placed in the
groove of the tramway the head of a plunger 6 whereof the stem or rod passes
vertically down through tram-rail or frame of the switch-tongue.
A coiled spring 7 (Fig. 3) tends constantly to keep the plunger 6 at such a height
that it projects above the bottom of the tramway groove, so that it cannot fail to
be depressed by the flange of the car-wheels running over it.
This spring 7 might be replaced by a weight, which, in that event, would be
mounted on a lever connected with the stem of 6, in a manner which needs no
special explanation.
The
On the fulcrum 8 in the case G situated in the roadway below the rails, the
arm 9 is pivoted; it is jointed to the plunger 6 and works as a pusher arm.
pusher arm 9 as will be seen on inspection of Fig. 3, rests upon one of four studs
or pins 10 of the ratchet-wheel 11, which last is journalled in bearings in the
case G; when the plunger is depressed the ratchet-wheel is caused to rotate
through the distance of a quarter-revolution by the movement of the arm 9 by the
plunger 6, into the position shown by dotted lines in Fig. 3. The pins 10, however,
are not immovable in ratchet-wheel 11, but are mounted in such manner as admits
of their sliding axially, against the opposing pressure of springs 12 carried by the
wheel and bearing on the pins, in order that these pins may be thrust out of the
way of the ascending arm 9 in its ascent when the car-wheels have quitted
the plunger 6 and this latter is again raised by the reaction of the coiled spring 7;
this purpose is also contributed to, by giving to the heads of the studs oblique
surfaces, as shown in section, Fig. 4. In this way, every depression of the wheel-
key will cause the ratchet wheel to advance a quarter of a turn. An ordinary
pawl-catch 13 prevents its rotation in the wrong direction.
With this ratchet-wheel 11 the bevel-wheel 14 is closely and firmly connected;
they may, in fact, be made in one piece; the bevel-wheel 14 also gears with a
smaller bevel-wheel 15 of only half its diameter which is suitably mounted ou
a fixed pivot in the frame G. Upon the shaft of the bevel-wheel 15 is secured
the spur-wheel 16 so that the bevel-wheel and spur-wheel gear together. The
spur wheel 16 gears with a spur-wheel 17 keyed on the shaft of a crank-disc,
which shaft turns in a fixed bearing in the frame G.
Thus a quarter of a turn on the ratchet wheel produces a half-turn of wheels 15
and 16 which, if the pair of spur-wheels are toothed in the usual way will result
in half a revolution of the wheel 17 and the crank-lise 5. The crank-disc will
thus pass, in regular alternation from one dead-point into the other, and the
switch-tongue will be caused by the connecting-rod 4 and bell-crank lever 2, 2³ to
pass to and fro between its one extreme position and the other.
Now, however, the displacement of the plunger 6 by the second wheel of the
car must be neutralized in relation to the points.
For that purpose-as, indeed, has been already indicated in the introductory
part of this Specification-the wheel 16 is only dentated over
one half its
circumference, the other half having no teeth. Thus in each of the four phases
of rotation of the ratchet wheel the spur-wheel 16 is caused to turn round
another half-circle in advance in this manner, the driveu-wheel 17 finds its
teeth opposite the toothed portion of the circumference, in one of the phases of
rotation, and, in the next following phase, opposite the smooth, toothless half;
and while, at each phase the ratchet-wheel makes a quarter of a revolution, at
each alternate phase the crank disc remains unmoved in the position in which it
was kept by the previous phase.
It depends upon the ratio of the gearing chosen whether the driving wheel 16

page_text: nas one or more toothed sectors, and correspondingly one or several toothless
sectors.
If, for instance, the ratchet-wheel were only required to move over one-eighth of
a revolution at a time the ratio of transmission would need to be 1:4; then the
periphery of the driving-wheel 16 would comprise, alternately, two toothed and two
plain quarters, diametrically opposed to each other.
The spur-gear pair of wheels 16-17 might however be suppressed, if the bevel-
wheel 15 were fixed on the shaft of the crank-disc, and the companion bevel-wheel 14,
were, as described only toothed in alternate parts.
Thus far the apparatus has been described on the assumption that the cars, in
regular succession require to travel, alternately, on either branch, i.e. one car
by and the next by 2. Each car will then properly adjust for itself the switch
which its predecessor had left in a false position as regards it successor-though
suitable for itself.
But for the case, when two cars in succession require to travel in the same direction,
and not in opposite directions, the auxiliary appliance, previously mentioned, and
now about to be described, comes into operation; and its use is further recommended,
in reference to the possibility of accidental or deliberate and intentional displacement
of the switch-tongue.
This auxiliary apparatus is applied directly to the car itself, and, as a general
rule, indeed, at both ends of the car, over the right-hand rail.
One modification (or form of application) is shown on the car illustrated in Fig. 5,
and also in detail in Figs. 6 and 7.
It consists, as will be seen, of a frame 18 with two rollers 19, which latter are
competent to run in the bottom of the tramway-groove and depress the plunger 6.
The frame 18 is suitably adapted to slide vertically in the guide-bars 20 attached
to the car. A spring 21 (Fig. 5) tends constantly to keep the apparatus well-raised
and pendent over the tram-rail. But, despite the opposing pressure of the spring 21,
the frame 18 may be depressed by the lever 22 and treadle 23, when operated by
the foot of the driver of the tramcar.
This movement of the frame may also be brought about by other kinematic
means, e.g. a hand-lever, a screw, etc. Thus, depressed by the tramcar driver, and
running along in the bottom of the groove, the auxiliary appliance described acts
exactly like a car preceding the one to which it is attached each of the two
rollers depresses the key, and the first one at once changes over the switch-tongue,
which, as has been seen, is not reversed by the action of the second roller, which
remains of none effect. The switch-tongue, now correctly placed for the approaching
car and which would only be shifted over into the wrong position by the action of
the car-wheels-is set wrong purposely by means of the auxiliary appliance, so
that it may be set right again. By means of this auxiliary appliance, the action of
the apparatus is modified as desired.
Many variations are, of course, admissible in the constructive details, without
departure from the essential principles and scope of the invention.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondents, and in what manner the
same is to be performed, 1 declare that what I claim is ;-
1. An automatic switch-apparatus for railways or street tramways, wherein the
forward axle of each car effects the change in the point while the second axle or
pair of wheels remains without any action thereon characterised by a plunger (6)
actuating a ratchet and pawl mechanism which transmits movement to lever and
connecting-rod gearing controlling the switch and that by means of a pair of
wheels (16-17) whereof the driving wheel is partly dentated and partly plain or
devoid of teeth so that when the ratchet-wheel is caused to rotate step by step one
such movement operates the connecting-rod by means of the dentated part of the
periphery of the intermediate driving-wheel and thus shifts the switch-tongue
over while the text following motion of the driving-wheel leaves the crank-slide

page_text: at rest and effects no such change because the corresponding part of its periphery
is plain, and does not engage with the motor-wheel of the crank-slide.
2. In combination with the switch-controlling apparatus described in Claim 1
an auxiliary device applied on the car for shifting the point over and consisting of
a frame located in the same vertical plane as the groove of the tram-rail and
carrying two rollers (19) the whole reciprocating in the vertical plane whereby
when required the said rollers are lowered so as to act upon the wheel-key like a
pair of car-wheels whereby an intermediate shifting over of the point restores it to
its original position.
3. The combination and arrangement of parts constituting a complete point-
apparatus substantially as and for the purpose described and illustrated in
Figures 1 2 3 and 4 or Figures 1 to 7 of the accompanying drawings.
Dated this 28th day of August 1895
BOULT & WADE,
Agents for the Applicant.