Improvements in Automatic Railroad-gates.
Year: 1895

page_text: Date of Application, 5th Jan., 1895--Accepted, 20th July, 1895
COMPLETE SPECIFICATION.
Improvements in Automatic Railroad-gates.
1, WILLIAM THOMAS CRAWFORD, of Tampa, in the County of Hillsborough,
and State of Florida, United States of America, Gentleman, 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 :-
The object, of my invention is to provide a simple mechanism which will be
operated with certainty by a passing train to close the gates as it approaches
the crossing and to open them again as the train moves away without sudden or
spasmodic action.
The invention will be fully understood upon reference to the accompanying
drawings, forming part of this Specification, in which :
Fig. 1 is a perspective view of a railway crossing to which the simplest form of
my invention is applied. Fig. 2 is a plan view showing a modification in the
working connections which may be utilized when the actuating mechanism which
receives the impact of the car wheels is located at a distance from the gates in
order to cause the lowering to take place a sufficient time before a fast train reaches
the crossing. In this view one of the two similar opposite ends of the actuating
mechanism is omitted.
Fig. 2 is a side elevation of the form of working connections used in Fig. 2.
Fig. 3 is a side elevation of the arrangement shown in Fig. 1.
Fig. 4 is an enlarged end elevation of one of the gate posts, one wall being
removed to disclose the parts within.
Fig. 5 is a detail view of one of the safety joints, which adapt the gates to open
outwardly and permit escape from within.
Fig. 6 is a detail view of the alarm actuating treadle.
Fig. 7 is a detail view of the clamp for attaching the tube or conduit through
which the flexible connections are led.
Fig. 8. is an enlarged detail view of the flag and gong operating connections.
Figs. 9 and 10 are enlarged perspective views of the locking devices at opposite
ends of the system and in different positions.
Fig. 11 is a detail view showing the cam in position not to be locked by
engagement with one of the pius.
Fig. 1 illustrates a form of my invention especially adapted for use at crossings
where trains pass at slow speeds.
1 represents the railway track formed of rails 2, on cross ties 3, and 4 a crossing
in said track, which may be built or laid upon the extended cross-ties 5.
6 represents a longitudinal rock-shaft mounted in bearings 7 alongside one rail
and provided with a radial fin 8, 8ª, extending from each end to the crossing, and
an intermediate crank 9 at the crossing. The radial fin 8, 8ª, is arranged spirally
for a distance from each end and for the remainder of the way is straight. It is
located in such position that the engine and car wheel flanges will engage and
depress the fin causing a slow rotary movement of the rock-shaft, and the spiral
portion 8 is arranged at such pitch that the rotary movement will be continued for
a quarter or half revolution. The rock shaft and its fins with the working con-
nections constitute the mechanism which operates the gates. The rock-shaft
extends on either side of the crossing a distance sufficient to insure the lowering
of the gates in ample time before the passing of the train. The rotation of the
shaft is accomplished by the complete traversing by the train of the spiral part of
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2

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the fin, and it is therefore obvious that by lengthening this part of the fin the
movement of the gates may be rendered as slow and gradual as desired. From the
end of the spiral portion 8 of the fin the straight portion 8", continues toward and
terminates at the crossing, and serves by receiving the wheel flanges to hold the
shaft in its rotated position and through the shaft to hold the gates in lowered
position. For slow speeds it may be found sufficient if the spiral portion 8 of the
flange extends for forty or fifty feet, and the straight portion continues fifty or sixty
feet to the crossing, but these dimensions may be changed as experience dictates.
10 represents four posts or standards upon which are pivoted vertically-swinging
gates 11 having counter balances 12, and 13 represents controlling shafts which
have cranks 14 and operating mechanism to be hereinafter described, located within
the posts.
15 are pitmen which connect the crank 9 with each of the cranks 14, and thereby
cause the shafts and 13 to rotate synchronously.
The parts are arranged as will hereinafter more fully appear, so that when a
train approaches from either direction the rock-shaft will be rotated a sufficient
part of a revolution to cause the gate axis to rotate a quarter revolution and bring
the gates from vertical to horizontal position. In order to hold the gates in such
position till the train passes when going at slow rates of speed the radial fins are
made to extend the whole length of the rod except the width of the street and
portions of the fins are made straight in order to hold the shaft without further
turning it. When the train has passed the gates resume a vertical position. The
break in the fin immediately at the crossing does not permit the gates to
return even though but an engine be passing because the latter is of sufficient length
to prevent all the wheels being out of engagement at one time.
is
In Fig. 2 is shown an arrangement adapted for use where trains pass at high rates
of speed and it is necessary to set the flanged rock-shaft off a great distance
from the crossing. It is similar in principle to that shown in Fig. 1 but the rock-
shaft is divided into two parts (one only being shown) located on opposite sides
of, and a sufficient distance from the crossing, and each having a crank 9. Motion
transmitted from each of the separate shafts by means of double bell-crank
levers 17 pivoted at 18, and having their middle arms 19 connected by pitmen 15
with cranks 9, while their two armis 20, 21, are connected in pairs by crossed
belts 22 In this form of apparatus, the gate-controlling shafts 13 pass under the
track and connect opposite gates in pairs. Upon these shafts 13 instead of the
cranks, are fixed pulleys 23 which receive belts 22. When the fin 8 at either end
receives the impact of the wheels the rock-shafts and bell-cranks are rocked,
being coupled together and the belt causes the pulleys 23 to rotate with their
shafts 13 so as to lower the gates. At the same time the locking device at the end
opposite the approach, automatically locks the gates in horizontal position, that at
the end of approach being prevented from operating as will hereinafter appear, and
the gates remain lowered till the train passes off, and releases the locking device at
the end of departure. This form may also be used for short connections if more
convenient as at curves.
p
The construction of the gates will be more fully understood upon reference to
Figs. 3, 4, and 5. The post 10 is a hollow box of sufficient size to accommodate
the flag alarm, and gate-operating mechanism, and in it are mounted the gate-axis 25
having pinion 26 and a sprocket wheel 27 connected with the pinion 26 by a
chain 28. The relative size of the pinion and the sprocket is such as to require.
but a slight movement of the latter in order to effect the lowering of the gates.
Within the gate posts or in one or two of them are also mounted the flag-shaft 30
having crank 31, the gong 39, the alarm-shaft 32, engaging clapper 33, and
having crank 34, which engages crank 31, and crank 35 which is connected by
pitman 38 with the crank 37 of the alarm-controlling shaft 36.
Each gate-arm is preferably formed at its inner end with a casting 40 which
carries the counterbalance 12, and in which is pivoted at 41 the arm 42. A
spring 43 coiled around opposite ends of the pivot 41 on the casting 40 is connected

page_text: at 45 to the inner end of the arm and keeps said arm normally straight with a
yielding pressure. The gate thus formed is mounted so that the arms break
outward though the shape of the castings is such as to resist bending inward.
With such construction, an animal being caught between the gates when they are
automatically lowered may readily escape. In thus forming the gates, the casting
forms a box in which the arms work, and the arm is provided with a cast metal
shoe 46 on its inner end which adapts the arm to work in the box-casting, and which
receives the wear.
The alarm is operated by the treadle 47 journaled on the side of one of the rails
and having a crank-arm 48 connected by wires 49 with a crank 50 on the alarm-
controlling shaft 36. The adjustment of these parts is such that each wheel
striking the pedal sends an impulse to shaft 36. By each impulse the alarm-shaft
is rocked causing the clapper to strike the bell and releasing and returning the
flag-shaft so that it falls and rises repeatedly. The crank 31 of the flag-shaft and
crank 34 of the alarm-shaft are connected by a flexible connection 34", and each
time the pedal rises, after being depressed by the wheel, and the shaft 36 and the
alarm-shaft return to normal position allowing the flag-shaft to fall back to
horizontal position. Repetition of this operation causes a vigorous ringing of the
bell and waving of the flag.
The connectors between the treadles 47 and cranks 50 are passed through
tubes 52 which are held to the side of the rail by clamps 53 as shown in Fig. 7.
This operation continues till the train reaches the gate motor where the gates are
lowered.
By referring to Fig. 8 it will be seen that the gear wheel 26 is provided with two
pins 26, and 26%, on one of its faces. The flag-shaft 30 has a setting arm 30",
which projects across the path of the pin 26, and the crank 34 of the alarm
shaft 32 projects across the path of pir. 26. When the gates are lowered, the
flag-shaft crank and the alarm-shaft crank are engaged by the respective pins and
forced to the position shown by dotted lines in Fig. 8. When the gates return,
the parts are released, but the alarm-crank engages behind and retains the flag-
shaft in normal position, until the parts are again released by the initial impulse
given by the next approaching train.
The locking devices which are located at the respective ends are precisely
similar in construction and each consists of a peculiarly-formed cam 55 on the end
of the flanged rock-shaft 6, and a transversely arranged rock-shaft 56 having
pins 57, 58, releasing treadle 59 and spiral spring 60, one end of which spiral
spring is fixed to the bearing 61 of the rock-shaft while the other one engages one
of the pins.
cam 55.
The pins are spaced apart both longitudinally and circumferentially on the rock-
shaft 56, the circumferential distance between them being sufficient to admit the
62 represents a notch in the cam into which the pin 58 may engage when
the cam passes between the pins to its lower limit of movement, and while the
pin 57 is therefore not engaging the cam; but when the pin 57 is first forced to a
position behind the cam, and the latter then moves to its lower limit, the location
of the pin 57 is such that it not only does not itself enter notch 62 but it also
keeps pin 58 from entering said notch. This locking device will operate to lock
the flanged rock-shaft only at the end where the train leaves, that locking device
at the approach end being prevented from taking effect as will now appear."
The two rock-shafts at opposite ends of the system are connected in such manner,
either by the rod being made continuous or by the connection between its parts
herein before referred to, that the flanges at opposite ends are always in the same
relative positions and move simultaneously when the wheels impinge on either. As
will be understood with reference to Figs. 9 and 10 when the train approaches the
end shown in Fig. 9, the first wheels strike the releasing treadle 59 so as to cause
the pin 57 to move on the inside of the cam 55 as shown in Fig. 11, and
immediately thereafter the impingement on the flange depresses. said cam to its
lower limit of movement. This lower limit of movement, however, is not, such as

page_text: to permit the pin 57 to engage in the notch 62 and neither pin therefore engages
the cam in such manner as to prevent the ready return of the rock-shaft by the
counter-balance weights of the gates but while the locking device at the end of
approach is prevented from operating, that located at the end of departure does
operate until the train passes away because at said end of departure the pins are
not previously moved and as the cam 55 is depressed it passes between said pins so
that as soon as the notch 62 coincides with the pin 58 as shown in Fig. 10, said pin
engages in the notch and prevents the cam returning.
The gates are thereby locked in lowered position and remain so until the train
passes the crossing and the last wheel of the train reaches the releasing treadle 59
at the end of departure. As this takes place the treadle is depressed sufficiently
to release pin 58 from notch 62 but no farther, and the cam together with the
rock-shaft is freed and returned to normal position by the effect of the counter-
balance on the gates. From the foregoing it will be seen that precisely the same
device is used at either end that the system may be approached in either direction
and that the locking only takes place at the end where the train leaves the
system.
It will be seen that the gates are positively operated by a slow and gradual
movement notwithstanding the rapidity at which the train passes, and that they are
released together with the operating mechanism when the train is passed and
automatically assume their normal positions.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is
1. The combination of a counterbalanced arm adapted when free to occupy a
normal position, actuating devices located on each side of the arm and operatively
connected together and to the said arm, a locking mechanism for each arm actuating
device normally occupying an operative position, and a trip for each locking
mechanism so disposed that the approaching train will operate the trip on the
approach prior to operating the said arm actuating device and throw the lock
connected therewith out of operative relation, the arm actuating mechanism when
operated being held by the lock at the departure side, and the trip at the latter side
being operated by the departing train to release the said arm actuating devices,
substantially as described.
2. The combination of a supporting post, counterbalanced vertically-swinging
gate-arms having spring-joints, a bell, a movable flag-staff, operating devices within
the post for the gate-arm, the flag-staff and the bell, a spirally flanged rock-shaft
journaled along one of the track-rails, connections between the rock-shaft and the
gate-operating devices within the post, a pedal located beside the track beyond the
rock-shaft, and flexible connections from the pedal to the bell and Hag-operating
devices, all substantially as shown.
3. The combination with gate arms arranged to return automatically to their
open position, of a spirally flanged crank-shaft at each side of the crossing,
connecting mechanism between the crank-shafts whereby they are compelled always
to move together, an automatic locking-device at the outer end of each shaft
consisting of a grooved and notched cam-wheel 55, thereon, together with a
transverse rock-shaft 56, having pins 57, and 58 to engage said cam-wheel, and a
returning spring 60, and a relieving arm on shaft 56, by which the pins are released
from the cams as the train is departing, substantially as shown.
4. The combination of the two flanged crank-shafts, the notched and grooved
cam wheels on the outer ends of said shafts, the two transverse rock-shafts provided
with pins for engaging the cam-wheels, the relieving arms, and the lever and cable
connections uniting the two sets of devices to each other and to the guard devices
at the crossing, substantially as shown.
5. The combination of movable arms pivoted on suitable standards, a flag-staff,
flag-operating mechanism located in said standards, apparatus located on the track

page_text: for operating the arms from a distance, and track irons more remote from the
crossing for actuating the flag-operating mechanism, all substantially as shown.
6. The combination of the gate arms, the flanged crank-shafts located at a
distance from the crossing, one on each side thereof, working connections between
said shafts whereby they move in unison, cams on the outer ends of said shafts,
rock-shafts located transversely between the rails having pins for engaging the
cams, springs on the latter shafts, and bearings therefor, all substantially as
shown.
7. The combination of the pedal 47, the crank-shaft 36 oscillated thereby, the
flag shaft 30 the double crank-shaft 32, the connections between the cranks of the
said three shafts whereby the oscillations of shaft 36 are transmitted to the flag,
the arm 30, projecting from the flag-staff, the wheel on the gate shaft and the two
pins 26, and 26, projecting therefrom, substantially as shown.
8. A gate arm, consisting of an inner pivoted and weighted section 40 having
ears at its outer end, an outer section 42 pivoted between said cars, and a spring
loop 43 bearing against the inner end of arm 42 and having its ends coiled around
the ends of pivot 41 whereby the two arms are normally held in line with each
other, all substantially as shown.
Dated this 5th day of January 1805
BOULT & WADE,
Agents for the Applicant.