Improvements in Slack Adjusters for Brake Gears of Railway
Year: 1897

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Date of Application, 4th Aug., 1897-Accepted, 25th Sept., 1897
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COMPLETE SPECIFICATION.'
Improvements in Slack Adjusters for Brake Gears of Railway'
Rolling Stock.
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248.
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We FREDERICK WILLIAM SELLEY of Enmore, near Sydney, in the Colóny of
New South Wales, Engineer, and WILLIAM HOLMES NISBET, of Martin' Place,
Sydney,. aforesaid, 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
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This invention relates particularly to certain. improvements in this kind of
slack adjusters for brake gears of railway rolling stock for and in respect of which
the present inventors obtained Letters Patent in Great Britain which...are
dated the 29th day of July One thousand eight hundred and ninety-six. and
Numbered 16793.
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These present improvements consist firstly in combining together as one integer
the pawl actuating rocking lever and a cover or box for the pawl and for the
ratchet nut on the pull-rod screw connection, secondly in the particular combina-
t.or of said rocking lever pawl and ratchet nut with the pull-rod screw and with
the nut box or bridle; thirdly in the substitution for the fixed fulcrum or pivot
for the bell crank lever or adjusting lever of an adjustable pivot or fulcrum whose
distance from the nut box or bridle may be altered or adjusted quickly and easily
so that the slack adjuster may be made to standard sizes and adjusted to suit
different brakes; fourthly in the substitution for a fixed attachment on the rocking
lever for the links or cord from the bell crank or actuating lever of an adjustable
attachment whose distance from the centre may be quickly and easily altered so
as to facilitate such adjustment as before mentioned to different brakes; fifthly
in the combination and arrangement with the combined lever and pawl box and
a cover therefor of a trying pintle or pin on the pawl; and sixthly in the peculiar
combination or joint connection of the screw pull-rod with the brake truss or
beam so that said truss or beam will centrally articulate and so adapt itself
as to give equal pressure on either side of the vehicle no matter to what extent
the brake blocks may be worn.
But in order that this invention may be clearly understood reference will now
be made to the drawings herewith in which Figure 1 is a side elevation and
Figure 2 an end elevation of a brake gear slack adjuster constructed according
to these present improvements Figure 3 is a view of part of Figure 2 with the
cover of the rocking lever pawl box removed. Figure 4 is a partial sectional
elevation of the rocking lever pawl box on the line a a Figure 3, Figure 5 is a
plan of this slack adjuster and Figure 6 is a central horizontal section of same.
The various parts and their functions will be now pointed out with the aid of
distinguishing letters as set out in the former patent referred to and then those
parts which form these present improvements will be farther described. The
double brake-lever A is geared or connected to the piston-rod of the cylinder

page_text: of a pressure or other brake. The suspension-rods B carry the fulcrum-pin A¹ of
said lever A whose lower ends have connection to the nut box or bridle C which
carries female screw or nut E adapted to be revolved as hereinafter described.
This nut box or bridle receives the screwed end G¹ of pull rod G which has rain
and dust cover G and is articulated to the end or bight of the brake truss or
beam J. The lower ends of double brake lever A have each of them an out-
wardly-pointing pin or pintle A, which fits orifices about midway of the length
of the box C, which thus insures that said box C partakes of the same motion as
the lower part of said lever A. Connected to said box C and to the fulcrum-pin A
of said lever A is a bell-crank 1) whose upper end is slotted and takes on said
fulcrum-pin A', whose angle has a fulcrum on the pin C supported by box C and
whose other end is linked by links D to end F¹ of a double-ended rocking lever
whose other end 1 is connected by means of spring F to hook stanchion or
support taking in socket (3 on box C (or said end F might be resiliently
connected to the underframing of the vehicle). The boss F of this double-ended
rocking lever rides in or on journal E on end of box or bridle C and it is
enlarged and forms a cavity or pawl box G³ the nut or female screw E which is
screwed upon the pull-rod G of the brake truss or beam J is retained in place in
nut box or bridle C free to revolve by means of journal E and screw uut E'
fitting behind said journal. The pawl F is carried by said lever F in the pawl
box G3 and engages with ratchet E around the nut E. Now in operation the
brake lever A moving on fulcrum A¹ in suspension rods B in applying the brake
will, if there be any slackness in the connections caused by wear of the brake-
blocks or otherwise, so move the position of fulcrum A' relative to nut box C and
pin C as to give motion to bell crank lever I causing it by means of links D' to
rock the double ended rocking lever F against the resilient force of spring F.
The pawl F is thus caused to travel backwardly over one or more of the teeth
of ratchet E¹ so that when the brake is released said spring Freturning the
lever to its normal position, said pawl F will partially revolve nut E on the
screw of the pull-rod G and so shortening the length of the pull-rod will adjust
or take up the slack of the connections.
It will be seen that the lever F is constructed integral with the pawl box G³
which has circular periphery and which has a cover G said latter being kept in
position by split pins Go through lugs or pintles G³ and having a slot G7 through
which protrudes a handle or pin F from the pawl F* so that the pawl may be
tested and be actuated by hand when desired. The said pawl 1 is carried by
said box G3 on pin or stud G*.
The ratchet nut E¹ passes through the head of box or bridle C screwing on
screw of rod G and it is kept in position by nut E on its end. The box Ga
fits over the end of bridle C with a lap as at G8 for keeping out dust and is also
held in its position by the screwing up of the nut E*.
The fulcrum or più C¹ is carried on the end of screw C³ which passes through
two female screws in lugs A and has a jamb nut A so that upon loosening said
nut A and revolving the screw the position of said fulcrum or pin C¹ would
be adjusted as desired.
The links D have slotted parts 13 which will pass through the jaws of the
attachments while the other parts will not and thus these links are secured against
danger of being misplaced or lost. The attachment H takes through a slot in the
end F of the rocking lever pawl box and is adjustable by reason of the corrugated
surface into which a rib or ribs on its washer H' may be tightly fastened by
screw nut H³ said corrugations and the rib or ribs might of course be on the jaw
side of the attachment instead of on the nut side.
The pull rod G is articulated to the brake truss J by a joint pin J'. The rod G
terminates in a knuckle joint on pin J¹ to a yoke J2 which takes around the bight
or angle J of the beam or truss connection J to the brake blocks which angle-
piece J is fastened by pin J3 by its tail Jo through the yoke J. It will be seen
that the articulation and specially having the two joint pins will allow the beam

page_text: or truss J to adapt itself to any inequalities of its resistance when the brake is
applied.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
First. In brake gear slack adjusters of the class set forth a pawl actuating
rocking lever containing or made integral with a pawl cover or box substantially
as herein described and explained and as illustrated in the drawings.
Second. In brake gear slack adjusters of the class set forth the particular
combination and arrangement with the nut box or bridle of the rocking lever
the pawl and the ratchet nut for the purposes and in the manner substantially
as herein described and explained and as illustrated in the drawings and more
particularly in Figure 4 thereof.
Third. In brake gear slack adjusters of the class set forth an adjustable pivot
or fulcrum for the bell crank or actuating lever for the purposes set forth
substantially as herein described and explained and as illustrated in the drawings.
Fourth. In brake gear slack adjusters of the class set forth an adjustable
attachment or rocking lever connection for the purposes set forth substantially as
herein described and explained and as illustrated in the drawings.
Fifth. In brake gear slack adjusters of the class set forth the combination with
a pawl box and its cover of a handle or pin on the pawl protruding through said
cover for the purposes set forth substantially as herein described and explained
and as illustrated in the drawings.
Sixth. In brake gear slack adjusters of the class set forth pull rod articulated
to a triangular brake beam or truss for the purposes set forth substantially as
herein described and explained and as illustrated in the drawings.
Seventh. In brake gear slack adjusters of the class set forth the combination
and arrangement with the pull rod having a knuckle joint and of a yoke taking
over or around the bight of the brake beam or truss and being fastened thereto
substantially as herein described and explained and as illustrated in the drawings.
Dated this Seventeenth day of June One thousand eight hundred and
ninety-seven.
BUTOR
F. W. SELLEY.
WM. H. NISBET.
Wallace Fairweather,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.