Improvements in Slack Adjusters for Brake Gears of Railway Rolling Stock.
Year: 1896

page_text: Date of Application, 29th July, 1896-Accepted, 3rd Oct., 1896
COMPLETE SPECIFICATION.
Improvements in Slack Adjusters for Brake Gears of Railway
Rolling Stock.
We FREDERICK WILLIAM SELLEY of Hurstville near Sydney in the Colony
of New South Wales Engineer and WILLIAM HOLMES NISBET of Martin Place
in the City of Sydney and said Colony of New South Wales, 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:-
This invention refers to the brake gears of all kinds of railway vehicles including
carriages waggons locomotives &c. in which gears the brake blocks are applied to
the wheels by the movement of a lever suspended under such vehicles and which
Baid lever is necessarily in connection by a beam or a truss with one set of blocks
and might be further connected by tie rod or tie rods to link or links and beam or
beans truss or trusses with other set or sets of brake blocks and this invention
relates to improvements in slack adjusters for such break gears so that any slack
in the connections resulting from wear of the brake blocks or otherwise will be
automatically adjusted or taken up and the gear be thus retained effective under
all ordinary circumstances.
Slack adjusters for break gears of railway rolling stock constructed according
to these présent improvements consist essentially first of a lever or crank or cord
or chain or arm and pulley connection to the actuating or brake lever adapted to
have motion imparted to it by movement of said lever. Secondly of a nut box or
bridle or holder articulated to the brake lever and supporting a screw connection
upon the end of the pull rod of the brake beam or truss. Thirdly of a rocking
pawl in connection with the mentioned lever or crank connection to the brake lever
and resiliently anchored to a rigid support on the mentioned nut box or bridle or
support or on the under framing of the vehicle and with its pawl in gear with a
ratchet on one factor of the mentioned screw connection of the brake beam or
truss. And though these four parts are thus set out as essential features of these
present improvements yet it is to be understood that for one or other or more of
them might be substituted mechanical equivalents whose duties or actions would
be the same or similar to the functions hereinafter fully.described and explained of
such essential parts.
But in order that this invention may be clearly understood reference will now be
made to the drawings herewith in which
Figure 1 is an outline sectional elevation of so much of a railway vehicle as is
necessary to show the arrangement and disposition of a brake having as part of its
genr or slack adjuster constructed according to these improvements.
Figure 2 is a side elevation Figure 3 an end elevation and Figure 4 a half plan
of a complete slack adjuster.
Figures 5 and 6 are side elevation and end elevation respectively of a modified
construction of such slack adjuster and Figures 7 8 and 9 are side and end elevations
and partial plan respectively of a further modified construction of same.
Figures 10 and 11 are side and end elevation respectively of a still further
modified construction of such slack adjuster having a cord or chain and pulley
connection with the brake lever. Figure 1 illustrates the brake gear of a railway
vehicle with the underframing and wheels simply indicated. The double brake
lever A is geared or connected to the piston rod of the cylinder of a pressure or

page_text: other brake. The suspension rods B carry the fulcrum pin A¹ of said lever A
whose lower ends have connections to the nut box or bridle C which carries female
screw or nut E taking on the screwed end of pull rod G of truss or beam and
adapted to be revolved by connections D and F. Each set of brake blocks H is
supported by hangers Hand tie rod H connects lever A to suspension lever H
connected to pull rod G* of the second truss or beam. The details of the parts
forming the slack adjuster will be now described with special reference to the other
figures of the drawing."
In the slack adjuster shown in Figures 23 and 4 the lower ends of double brake
lever A have each of them an 'outwardly pointing pin or pintle A which fits
orifices about midway of the length of the box C (on top of. which box there
might be a cover though none. is shown) which thus easures 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 A¹ of said lever A is a bell crank D whose upper
end takes on said fulcrum pin A', whose angle has as fulcram the pin C on box C,
and whose other end is linked by links D' to end F¹ of a double ended rocking
lever F whose other end F is connected by means of spring F to hook stanchion
or support F taking in socket C on box (or said end F might be resiliently
connected to the under framing of the vehicle). The boss E of this double ended
rorking lever rides upon journal E' on end of box or bridle C and takes against
loose washer E2 on nut or female screw E. The pawl Fx of said rocking lever
engages with ratchet E¹ of nut E which is screwed upon the pull rod G of truss
or beam and which passing through an aperture or orifice in the end of box C is
retained in place free to revolve by means of divided or split ring E' fitting behind
collar E and exceeding it and the orifice in diameter.
Now in operation the brake lever A moving on fulerum A' in suspension rods B]
in applying the brakes will if there be any slackness in the connections caused by]
wear of the brake blocks or otherwise so move the position of fulerum A', relative.
to nut box C and pin C as to give motion to bell crank D causing it by
means of links D' to rock the double ended pawl lever F against the resilient force
of spring F. The pawl Fx thus travels backwardly over one or more of the
teeth of ratchet Eso that when the brake is released said spring returning the
pawl lever F to its normál position said pawl F will partially revolve nut E on.
screw G of the pull rod G of truss or bean and so shortening the length of the
pull rod of said truss or beam from said nut and nut box C to the brake blocks
will adjust or take up the slack of the connections.
In the modified construction of this slack adjuster shown in Figures 5 and 6 the
rather lengthy nut box C is dispensed with thus obviating the addition of the pins.
or pintles A to the lower ends of the brake lever. For the box C is substituted a.
nut block or holder e carrying pins or pintles a' which take through the lever ends.
To the block or holder c is secured by screws c' a cheek piece carrying pine as fulcrum
for the bell crank D. The nut E has thereon ratchet E' and loose washer E and
the journal E of holder e supports double ended pawl lever F while said nut E.
passes right through block e and is secured therein by divided ring E under
collar E. The bell crank D does not take directly on fulcrum pin A' of brake.
lever A but is linked to it by link d and it has links (not shown) to end F of the
pawl lever and the end F' of said lever is resiliently attached by a spring or other-
wise to the under framing of the vehicle or to a rigid connection from nut block or
holder c.
The operation of the parts of this modified construction (Figures 5 and 6).
are exactly similar to those described in reference the similar parts referred to
in Figures 2, 3 and 4 and no further explanation of them can possibly be
needed.
The further modified construction of slack adjuster illustrated in Figures 7, 81
and 9 necessitates a forging of the end of the pull rod G of the brake truss or
beam with a longitudinal slot G through winch the connecting pin 24 of the,
double brake lever A passes and in which slot said pin may have free movement.

page_text: The pull rod of the truss or beam however terminates with a screw G' which
takes into female screw or nut E having ratchet E. Loose washer E passes through
the end of a bridle or holder and is held.to said. bridle or holder by dividing ring E
behind collar E. The bridle or holder has sides or cheeks I extending back-.
wardly to pin 24 which pin passes through both cheeks as through lever A. To
one side of the lever A is an arm or lever extension IP connected by links 2D to
the end F of a double ended pawl lever Fon journal E of said bridle or holder I°.
The other end F' of said lever is resiliently connected by spring F to stanchion
hook or support F taking in socket 2 of bridle or holder (or may be resiliently
connected to the underframing of the vehicle). It is to be seen that in place of
the arm 1 there might be used in this arrangement, Figures 7 and 8 a bell crank
supported by a bracket supported by the bridle or holder and operated by the lever A
in manner described in reference to Figures 2, 3 and 4.
In operation when the brakes are applied and there is any undue slackness in
the connections the alteration of the relative positions of lever A and bridle or
holder Ic causes arm or lever connection I" to move end F of double ended pawl
lever F and the pawl Fx to travel back round ratchet E' so that when the lever
recovers its normal position the spring F will bring the bridle or holder I to its
normal position during which movement the nut will be partially revolved and the
slack of the connections.adjusted.
The still further modified construction of slack adjuster shown in Figures 10
and 11 has instead of the bell crank lever or arm lever connection between the
brake lever and the nut box or holder a cord or chain D* having one end attached
to lever A say on end of fulcrum pin A¹ passing over a pulley d¹ on arm or
bracket C on box C and its other end attached to end F1 of the pawl lever. In
all other respects the slack adjuster is identical with that described with reference
to Figures 2, 3 and 4 and its respective parts bear corresponding letters to those
stated in such description.
In operation in consequence of the alteration of relative positions of lever A
and nut box or holder C the cord or chain DX performs exactly similar functions
to those of bell-crank D and links D' of Figures 2, 3, and 4. It will be easily
seen that in all cases instead of end G' of the pull rod of the brake truss or
beam being a male screw working in the female screw or nut E that the screw
connection might be reversed and the end G' bear a female screw and the pawl F*
gear into the ratchet head of a male screw or both taking into said last mentioned
female screw.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :
First. In brake gears of railway rolling stock the combination and arrangement
with a brake truss or beam and an actuating or brake lever fulcrumed in a suspension
link of a nut box or bridle or suport for a screw connection between the pull rod
of said brake truss or beam and said nut box or bridle or support articulated to
said lever a rocking pawl resiliently anchored to a rigid support and adapted by
means of a ratchet to revolve one factor of said screw connection and lever cranks
arms and links or chains or ropes and pulleys conuecting said lever to said rocking
pawl so that upon the applying and releasing of the brakes the alterations of the
relative positions or angular set of said lever and the said articulated nut box bridle
or holder will cause said pawl and ratchet by partially revolving the one factor of
the screw connection to shorten the length of the pull rod of the said brake truss.
or heam substantially as herein described and explained.
Second. The particular combination and arrangement of mechanical parts all
together forming an improved slack adjuster for brake gears substantially as
herein described and explained and as illustrated in Figures 2, 3 and 4 of the
drawings.
Third. The particular combination and arrangement of mechanical parts all

page_text: together forming an improved slack adjuster for brake gears substantially as
herein described and explained and as illustrated in Figures 5 and 6 of the
drawings.
Fourth. The particular combination and arrangement of mechanical parts all
together forming an improved slack adjuster for brake gears substantially as
herein described and explained and as illustrated in Figures 7, 8, and 9 of the
drawings.
Fifth. The particular combination and arrangement of inechanical parts all
together forming an improved slack adjuster for brake gears substantially as
berein described and explained and as illustrated in Figures 10 and 11 of the
drawings.
Dated this Nineteenth day of June One thousand eight hundred and
Dinely-STAT
F. W. SELLEY.
WM. H. NISBET.
Wallace Fairweather,
Chartered Patent Agent,
62 St. Vincent Street, Glasgow, Agent for the Applicants.