IMPROVEMENTS IN COUPLINGS FOR RAILWAY CARRIAGES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the
Office of the Commissioners of Patents, with his Petition, on the
28th November 1870.-A communication from abroad by Richard
Campion and James W. Thomson, junior, both of Camden, New
Jersey, and John H. Michener and Samuel L. Ward, both of
Philadelphia, Pennsylvania, all in the United States of America.
I, WILLIAM ROBERT LAKE, of the "International Patent Office,"
Southampton Buildings, London, Consulting Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN COUPLINGS FOR
RAILWAY CARRIAGES," a communication, to be as follows:-
This Invention relates to that class of couplings in which the coupling
link is automatically inserted and locked in the drawhead by means of
a swinging pawl or latch which yields in one direction to admit the link,
but is unyielding in the other direction in order to retain the link in
the drawhead.
The object of the first part of the said Invention is to lift the pawl
readily to uncouple the carriages and to hold it up out of the drawhead

page_text: when required, and it consists in a novel method of combining with the
drawhead a vertically swinging locking pawl, and an oval ring attached
to the pawl in such manner that the ring forms a handle by which to
lift the pawl, and also when the pawl is raised serves as a stop to hold
it up; by passing the longer side of the ellipse of the ring over the pawl
and then turning the ring half round its shorter axis comes beneath the
pawl but above the drawhead and keeps the pawl from descending.
The object of the second part of the said Invention is to prevent strain
on the pivot of the pawl, and it consists in a novel method of combining
with the drawhead a pawl swinging vertically on a pivot in the said
drawhead, the hole through the pawl in which the pivot pin fits being
made eccentric to and larger than the pivot when the pawl is down so
as to allow the pawl to abut against the drawhead itself, and thus relieve
the pivots of strain.
The said Invention further consists in a novel method of forming the
recesses above-mentioned by securing a pin or stud of hard metal in the
drawhead to form the partition between the two recesses. The drawhead
is made of any suitable exterior form, and may have lugs on its upper
surface to form bearings for the pivot of the pawl, and it has a flaring
throat. At the back of this throat are two recesses, the lower recess
being in some cases deeper than the upper one, but it is preferable for
reasons herein-after given to make them of equal depth, and in all cases
each of them should be in height somewhat more than the diameter of
the link to be used. These recesses may be formed either by making
the back of the throat deeper below than above a projecting point at a
the back of the throat, or by curving the back of the throat into two
nearly semicircular divisions. It is preferable to insert or cast in at
this point a pin or stud of steel or other metal, in either case the space
between the projecting point and the bottom of the throat and between
the said projecting point and the top of the throat being somewhat
greater in height than the diameter of the link, and of sufficient depth
for the point to overlap the end of the link, and hold it in a horizontal
position in the lower recess. A vertical longitudinal slot is made
through the top of the drawhead and through the lugs. In the bottom
of the drawhead is a curved depression shorter than the slot through 3
the top. A pin or bolt is passed through holes provided in the lugs on
top of the drawhead and crosses the slot, passing through and serving as

page_text: a pivot for the pawl. The pawl is so shaped that when in position it
presents at its front upper edge a bearing against the front end of the
slot, in which slot it is pivotted upon the bolt which passes through a
hole in the front upper end or shoulder of the pawl. From this bearing
edge the pawl curves upward and backward sufficiently to admit of its
turning freely on its pivot against the face of the slot. It then extends
back a distance greater than half the length of the said slot, the
distance to which it thus extends back being more or less beyond the
middle of the length of the slot, according to the amount of lost
motion which it is desired to take up. It then turns downward in a
straight line at its back edge to a point near the floor of the drawhead
where it curves downward and forward along the recess or curved
depression to the front end or face of this recess, and from this point it
rises with the front edge or face of the recess, and gradually curves
forward to the bottom of the slot, thus completing its outline. This
pawl is of such thickness as to ensure ample strength, and is adapted
to swing freely in the slot and recess upon its pivot. The hole in the
pawl through which the bolt passes is elongated, so that the pawl has
some play upon its pivot lengthwise of the slot. An oval ring is
attached in any suitable manner to the top of the pawl and rests upon
the drawhead when the pawl is in position. This ring serves to lift
the pawl in uncoupling the carriages, and when it is desired the pawl
may be raised until its lower end comes outside of the drawhead, the
ring is then passed lengthwise over the base of the pawl, and then
turned so as to bring it crosswise of the slot and under the pawl, thus
shortening the axis of the ring parallel with the pawl, so that the pawl
will rest upon and be supported by the ring. Of the two recesses in
the drawhead the lower one serves to hold the link (which is pressed
back into the recess) by one end horizontal or nearly so, insuring the
entrance of the other end of the link into the drawhead of the approach-
ing carriage when the drawheads of the two carriages are in about the
same horizontal plane, and the outer end of the link thus held will also
rise to any height required in coupling a lower to a higher drawhead.
The upper recess is called into requisition in coupling carriages whose
drawheads are in planes so different that their throats do not come nearly
opposite each other, in which case one end of the link being in the upper
recess of the higher drawhead, the deflection of its outer end would be
such that it would enter the drawhead of the lower carriage, and effect

page_text: the coupling. The two recesses are preferably made of equal depth, so
that in all cases the depth of the throats and recesses in the two draw-
heads which come together, being greater than the length of the link
the drawheads will cover the link entirely before they come together,
and thus prevent any jamming or crushing of the links.