Year: 1888

page_text: Fig. 2 is a detached view of the rocking-bar.
Fig. 3 is a top view of a single-lever switch embodying this improvement.
In Fig. 1 which represents a switch operated by a pair of toggle-joints such as is
described in the specification to Letters Patent No. 2758 of 1887 dated February 22nd
1887, A is one of the fixed and B one of the movable rails.
The switch-bar a is pivoted to the movable rail B and is operated by the co-acting
movement of the pair of toggle-arms bb, c e, which are pivoted at opposite ends to
some stationary part d and at their adjacent ends pivoted together to an ear piece el
which forms part of the frame or box e. The lever operates the toggle-arms in the
manner described in the specification hereinbefore referred to moving the box e and
with it the switch-bar a to the right, by doubling the arms 6 6 and straightening the
arms c c', and thereby locking the switch whenever either pair of arms forms a straight
line.
T
The switch-bar a which is a continuous rod, passes through the two ends of the
box e by holes corresponding to its size. Within the box e the switch-bar a is of
smaller size than at either end; shoulders a¹ and a being thus formed in it, against
which shoulders rest at each end a-collar i connected with and forming one piece with
the sleeve. Between the two collars i, and supported upon the sleeves i¹, rests the
compressible coiled-spring y. The opening in the collar i and sleeve through which
the switch-bar a passes, is the size of the contracted part of the switch-bar, so that the
collars and sleeve are left free to move. inward upon it, but not outward. The collars
and sleeves can also move inward within the box e, but are pressed against the
respective ends of the box by the coiled spring.
The operation of the parts so far described, is not different in principle from that of
an ordinary spring switch; when the switch is shifted by the operator moving the
lever (and there is no obstruction), the spring g keeps the collars i pressed against the
ends of the box and the box and switch bar are moved over together. If a train
passes upon the open switch and partially shifts it, the shoulder a' nearest the rails
presses against its adjacent collar and moving it within the box, compresses the
spring without moving the box e or the toggle-arms; and when the train has passed,
the recoil of the spring returns the parts to their former position. When the switch
is in the opposite position the shoulder a¹¹ acts upon its adjacent collar i in like manner.
The present improvement consists essentially in the addition of the rocking bar h
pivoted to the box e at el. It is so fitted and pivoted. to e beneath the toggle-arms,
that the action of straightening the arms presses the shoulder h¹ (Fig. 2) down in
front of the collar i, at the same time releasing the shoulder h" from connection with
the other collar.
While the shoulder h¹ bears against the collar i in the position shown in Fig. 1,
there is a positive connection of parts from the hand of the operator to the movable
rail; viz.,, c, h, i, a and B. When, therefore, there is any obstruction between
A and B, the operator cannot move the switch, and if the obstruction is only slight,
preventing complete action of the switch but allowing of some action, this also is
revealed by his not being able to make the complete movement of his lever. In other
words, the rocking-bar h locks the collar i to the box e, so that the switch cannot give
upon its spring in that direction. The other ond, however, is open as before, and
when the rail B is moved by the passing of a train, the shoulder a¹ acts upon the
collar and the spring g is compressed as before described, the collar being free to
pass under that end of h. When the switch has been shifted into the opposite position,
and at the end of such movement has been rocked so as to release one collar and
engage the other; precisely similar conditions exist. The connection between the
switch-house and rails is positive, and the switch may still yield for the passing of a
train, all motions being reversed.
The rocking motion of h may be made slight without impairing its efficiency as a
lock. The best form is to cause the toggle-joints to pass slightly beyond the straight
line, and have b¹ and c¹ begin to act upon h just as they reach the straight
line. In such case there will be no break in the positiveness of action until after the
switch has been completely shifted. The rocking-bar h may be so pivoted that one

page_text: A communication from abroad by ROBERT H. ISBELL, of the City, County, and State
of New York, United States of America, Manufacturer.
1, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane in the County of
Middlesex Fellow of the Institute of Patent Agents do hereby declare the nature of
this invention and in what mannor the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to spring-switches for railways, i.e., to that class of split-
switch in which the movable rails or points are so arranged in connection with a
spring, that the wheels of a passing train approaching an open switch can themselves
shift the points, while the spring returns them to the former position after the passage.
It consists in general of the addition to such a switch, of a rocking-bar which auto-
matically connects the operative parts together in positive connection, in the direction
in which the switch may be shifted by the operator, and at the same time leaves it
free to yield upon the spring in the other direction for the passage of a train; and its
object is to reveal the presence of any obstruction between the movable and fixed rails
by preventing the switchman's operating the switch. Heretofore the trouble has been
in spring switches, that the spring has in effect constituted a component part of the
switch bar, the movement of the rails in either direction depending upon the strength
of the spring alone; and consequently that the operator might move the switch-bar,
and thus (as he thought) throw over the switch, without, in reality, doing anything
but compress the spring. This would occur whenever there was any obstruction
between the rails sufficient to overcome the resistance of the spring. So also he
might move the rails a part of the distance, compressing the spring for the remainder,
and thus leave the switch partly open. The spring switch when operated in the night
time, or from a pointsman's box, thus introduces an element of danger not present in
one operating through positive connections. But with the present improvement
applied to such a switch, while the spring still serves its purpose of allowing a train
to shift it and of returning the rails after the train has passed, the system of
connections extending from the hand of the switchman to the movable rails is positivo
in action in either position of the switch, and any obstruction is instantly revealed by
their not acting, or acting with difficulty.
In the accompanying drawings forming part of this specification:
--
Fig. 1 is a top view partly in section of a switch operated by double toggle-joints
embodying the invention.

page_text: shoulder (¹) does not release its collar 1 until the other shoulder (4¹¹) engages with
the other collar.
In Figure 3 the principle is the same, with some modification of parts. The bar j
connecting the movable rails has affixed to it a frame k, through which at each end
pass the sleeves n' forming part of the collar n. The switch-rod m, by which the
switch is operated, passes through the sleeves and collars, whose motion upon m is
limited outwardly by the nuts m¹.. The coiled spring p bears against the collars n, and
presses them against the ends of the frame k. The rocking-bar o is pivoted to the bar j
and acts in the same manner as described above, locking the two collars alternately to
the frame k, and thus accomplishing the same purpose as in Fig. 1.
Various methods may be adopted to turn e upon its pivot, after each shifting of the
switch, so as to release and lock the collars alternately. In the method shown ris a
pin projecting upward from some stationary part, and adapted to move in the opening
or slot o' in the rocking-bar o. During most of the time while the switch is passing
from one position to the opposite, the bar o retains its position relative to k, the pin
merely traversing its slot, but when very near the end of the slot, when the switch
has been virtually shifted, the pin strikes the upper part of the slot, and acting as a
cam thereby reverses the position of bar o. By regulating the length of the cam
part of the slot o¹, and the distance of such slot from the pivot, the relative quickness
with which the bar o is turned upon its pivot, may be varied.
This improvement in spring switches is especially adapted for the use in those
operated by double toggle-joints as shown in Fig 1. No additional part is there needed
to perform the rocking. The part which shifts and locks the switch also turns the
bar h upon its pivot, and with an action which is sure. A further difference between
the forms shown in Figs. 1 and 3 is that in Fig. 1 during the passing of a train the
bar remains stationary, but in Fig. 3 the bar o passes over and returns with j.
The parts described as collars (e.g., the part i in Fig. 1) need not necessarily tako
that form, nor necessarily be movable upon the switch-bar (a). Thus i, instead of a
collar movable inward upon a, may be a pin affixed to a, and moving through an
appropriate opening in the frame e, a being of the same size throughout. Or, again,
the collar i may be a part of a, thus forming a shoulder thereon, the opening in small e
being large enough to admit it, the essential idea being the locking of the switch-bar
to the frame in one direction while it is free in the other, such constructions would
serve that purpose. The pin would merely be an equivalent for the combination of
the collar and the shoulder upon the switch-bar. When shifted by a train passing
over, the pin would pass with the switch-bar cut through the opening in e, the spring
being compressed between the ends of e and the other corresponding pin upon the
switch-bar.
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 mo
by my foreign correspondent, I declare that what I claim is :-
1. In a railway switch, the combination of a compressible spring lying within a
frame; a switch-bar adapted to compress the spring against the frame by movement
in either direction; a rocking-bar pivoted to the frame, and adapted to alternately lock
the switch-bar to such frame in each direction, while leaving it free in the other; and
means for rocking such bar upon its pivot at the end of each shifting of the switch.
2. In a switch operated by double toggle-joints, the combination of arms bb, c c',
and the rocking-bar h, both pivoted to e¹; with the frame e, containing and supporting
the collars i, switch-bar a, and spring g.
Dated this fith day of March 1888