By' ' fßfeal.

April 23, 1940.
K_ RÖTHLER
2,197,831
MOUNTING OF BOILERS 0F ~MALLET LOCOMOTIVES
Filed June 25, 1938
I
3 Sheets-Sheet 1
1519.1
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IN" $1..
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By'
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fßfeal.
A//omey
April 23, 1940.
,
K. RÖTHLER
2,197,831
MOUNTING 0F BOILERS OF MALLET LOCOMOTIVES
Filed June 25. 1938
3 Sheets-Sheet 2
Inventor
El.'g. 5
,i H
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íìfâ?eax.
A Homey
April 23, 1940.
K. RÖTHLER 4
.
2,197,831
MOUNTING 0F BOILERS 0F MALLET LOCOMOTIVES
Filed June 25, 1958
_
5 Sheets-Sheet 3
g " /FE/ÉQLE
„j
4' @î By~
Afiornev
Patented Apr. 23, 194()y »
2,197,831 t
kUNITED , STATES PATENT OFFICE
.
2,197,831
I
MOUNTING oF BloILERs oF
ì
LoooMoTIvEs
MALLET
Karl Röthler, Kassel, Germany, assignor .to
Henschel & Sohn, Gesellschaft Vmit beschränk
ter Haftung', Kassel, Germany
Application June 25, 1938, Serial No. 215,865
'
In Germany June 26, «1937
f
-
7 Claims. (C1. 105,-1'117)l
The present invention relates to an improved
mounting of _ the boiler of a Mallet locomotive.
In connectionwith' Mallet locomotives, it is nec
v essary to provide on each side of the locomotive
two)or Imore independent groups of springs in
in which the springs areconnected by compensat
ing levers, each'group of springsA with' ,compen
sating levers `forming a >complete unit. In most
constructions 'of the Mallet locomotive, the lboiler
is supportedupon the front bogie by means of
one or two plane Atable supports and consequently
the iront and the rear truck or frames are -'al-
ways guided parallel to one another.l Lateral
displacement of the plane supports must in this
construction be avoided. The front bogie and
the'rear frames of the locomotive cannot in this
construction adapt themselves independently to
an uneven*y track, and unevenness of the track
must be taken up by variations in the elongations
20 of the various groups of springs,-these variations
being substantially equal to thevariations which
' would occur if all the groups of axles were mount
ed in a common frame.
With-a very long wheel base of a Mallet loco
.25 motive having a’considerable numberof driven
wheels >and with sharp curves in the line of the
track, veryk considerable relative inclinations oi
the -axles of the front bogie with regard tothe
axles of the rearvframe will occur, apart from
30 inclinations due to accidental unevenness of the
track. ‘- These relative inclinations lead to very
with a VMallet locomotive, it is important to sup
port the front part -`of the boiler by means of a
spherical or ball vbearing in the middle plane of
the frame of the vfront v.bogie and to arrange for
w
al1 the driven and running axles of the rear lframe ‘C’
to be connected on either side by a >left hand
and a right hand group'of springs, the springs
of each group being connected >by compensating
levers. Independently oi this arrangement the
'iront bogie‘ must again have a three-point sup- s
port, for instance by connecting'the’leading run
ning axles and the ñrst driven axles by means
of longitudinal and transverse levers and by two
lateral groups of springs ofthe following three
driven axles. rCurves in the track and accidental 15
unevenness will then not lead -to any substantial
variation of the spring tension and. the wheel
loads. There will, however, still remain the un
favourable inñuence ofthe lateral displacement
of' the front part of the boiler with regard to its
bogie occurring in curved portions of the track,
l, G
and it is necessary «to compensate or avoid the
’ effect of this lateral displacement upon the load
distribution by additional means. I
Fig. l is a section on line I-I oi Fig. 2,
Fig. 2 is a cross section on line II-II of Fig. l,
Figs. 3 to 5 are diagrams of boiler mountings,
Fig. 6 is a general View of the Whole locomotive.
Theoretically there are three possible ways of \ O
reducing the overstressing of the springs. These
-considerable over-loading or under-loading of the ways are diagrammatically indicated in Figs. 3,
Springs and the wheels at one or the ,other` side ‘l and 5, Figs. 3 and 4 showing vdiagrammatically
of the locomotivesyand have to be taken care v'known manners of mounting-the vboiler upon
35
of by special devices.
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the front bogie, and Fig. 5 showing diagram- .
<
Another very disturbingvinflue'nce is the fact
that on passing sharp curves of the track the
front part of the boiler will move very consider
ably laterally with'> regard to its front’ bogie, which
40 again influences in avery unfavourable manner
present invention.
`
Referring first to Fig. 3, it will'be seen that the
vboiler 2 is provided upon its under side with'
a Asemispherical pivot I which rests in a cor- »
the distribution’ of the load vupon the spring
Vrespondingly, shaped socket 3. The socket 3 `is
groups at the left and at the right side olf-the
locomotive,` either the one or the other grou
>slidable upon a'horizontal surface il of the yiront
becoming overloaded.
l45
matically the improved manner vaccording to the
.
I
These two main inñuences and the influence of
the unevenness rof the track frequently have a
cumulative’el’fect> and they produce very con
siderable variations in the individual spring and
wheel loads, which` may lead to derailment'of the
locomotive and fracture of springs.
_
In‘view of the above-mentioned unfavourable
influences, it is advisable to aim- in connection
bogie 5. Assuming the maximum displacement
of the socket 3 to be indicated bythe distance 6
and the portion of the weight ofthe boiler trans- :45
mitted by the pivot I -to Vbe indicated by theletter
W, then it will be seen that at the maximum lat-`
eral displacement of the boilerfwith regard to
the front bogie, the weight'W will no longer be
`distributed uniformly upon the .wheels at the
left hand side and those-at the rightfhand side,
but ywill be taken up chiefly by those atthe left
with a Mallet locomotive having a very long wheel
hand side. Consequently'the :springs interposed
base, at the obtention of a three-.point support.
Ini order to obtain ,such< a support,- ìn .connection
,between the 4wheels and the frame of the bogie '
»at .the left hand side will be over-.stressed and ,5v
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2,197,831
those at the right hand side will be under-stressed,
whilst the distribution of the load upon the axles
stressing of the springs amounting to about 52%.
of the rear frame will remain unaltered.
struction sho-wn in Fig. 4, the over-stressing and
under-stressing respectively of the wheels of the
rear frame will amount to about 16% and over
The
turning moment MOM increasing the stressing
at the outer side of the curve in the track will
With the same load and in the case of the con
be represented by MOM=W><6.
In the construction shown in Fig. y4,l the posi
tions of the semispherical pivot andthe slídable
stressing and under-stressing respectively of the
springs will amount to 22%.
socket are reversed, the pivot I’ being fixed to
the horizontal surface 4 of the bogie frame 5 and
the boiler 2 being provided upon its under sur
shown in Fig. 5 there Will be stress variations ,
face with a ñxed support 8 having a horizontal
surface 9 which slides upon the top of the socket
3’ co-operating with the semispherical pivot I’.
In this construction the weight WI of the front
part of the boiler taken up by the front bogie
will always act in the middle plane of the front
bogie and therefore, even when the front part
of the boiler is displaced with regard to the front
bogie by the maximum distance 6, the load will
be distributed equally upon the left hand and
right hand side springs and wheels. On the other
hand, there will be a turning moment
which tends to turn the front part of the boiler
to the outer side of the track. This turning
moment is taken up by the springs of the rear
frame, the outer springs and wheels of the rear
30 frame being over-stressed and the inner springs
and wheels being under-stressed.
.
To avoid the disadvantages of the construction
diagrammatically illustrated in Figs. 3 and 4, the
invention provides a construction diagrammati
35 cally indicated in Fig. 5.
v
In this construction, both the boiler 2 and the
frame 5 of the front bogie are provided with sub
stantially horizontal slide surfaces 9 and 4 re
spectively and between these surfaces there is
40 slidably mounted a ball joint consisting of a
spherical pin I’ and a corresponding socket 3’.
The movement of the ball joint I', 3’ relatively
to the horizontal guideways 9 and it is controlled
by a double-armed lever I0, I2, pivotally mounted
at II upon the socket 3’. v‘The upper end of the
lever arm I0 is vertically guided by means of a
slide I3 in a guideway I4 of theV boiler support 9,
whilst the lower end of the lever arm I2 is ver
,.tically guided by means of a slide block I5 in a
50 vertical guideway I6 of the bogie frame 5.l The
`effective arms of the lever I0, I2 are preferably
_so_chosen that upon lateral displacement of the
boiler with regard to the front bogie, the dis
tances of the middle planeY of the ball joint from
the middle plane of the bogie and the middle
plane of the boiler will be about equal. There
fore, the maximum displacement of the boiler
will be equal to sI-l-s2 and the disturbing mo
ments due to the displacement will be about
60 halved, the moment MOMI being equal to W><sI
and the moment MOM2 being equal to W><s2.
These moments are taken up by the springs of
the front frame and by the springs of the rear
bogie respectively.
It will thus be seen- that by the improved ar
-rangement there will be reduced over-stressing or
overloading at the outer side of the curve and
also reduced under-stressing at the inner side
of the curve as compared with those occurring
70 in the construction indicated in Figs. 3 and 4.
Assuming the load of the boiler taken up by
the front bogie to be say 23,500 kg. calculations
>and tests have shown that in the construction
laccording to Fig. 3 there ~will be over-stressing of
75 the wheels Vamounting to about 28% and over
In the construction according to theinvention
.both in the front bogie and in the rear frame, and
those in the front bogie will amount to about
15.3% as regards the wheels and about 28.4% of
the springs. In the rear frame, stress variation
of the Wheels will be ’7.3% and that of the springs
10%. Itwill thus be seen that by the improved
constructions, the stress variations are main
tained within permissible limits and will avoid
any possibility of accidents when passing over
sharp
curves.
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l
Another feature of the invention consists in 20
providing _veryjsimple means .for returningv auto
matically the boiler to its normal positionwhen
the locomotive has'passed a curve. -This is, ac
cording tothe invention, attained by suitably
shaping the surface upon which the'ball joint g
slides upon the front bogie.l `
f
` f
A constructional example of the invention is
indicated in the drawings in Figs. 1, _2 and 6. » Y
Referring ñrst toiFig. 6, a indicates `>the* boiler
which is in manner known perse supported upon 30
a front bogie' b' -and a rear frame 5i, lwhich `are
coupled together as-'usual by a vrod-X. The front
bogie has four driven wheel pairsl driven `by an
engine k and a runningwheel pair rm whichis
not driven, whilst the rear frame has four> driven 35
wheel pairs Z and two pairs of non-driven vrunning
wheels m. The spring suspension of ¿the front
`bogie is indicated by the letters an and o whilst
the spring suspension ofthe rear frame is _indi
cated by the letter p. 4In .both the bogie `and
the _frame the individual'sp'rings' are connected
by levers to form a complete :unit on either side
of the frame. The boiler ¿tv rests upon the rear
bogiei at threepoints A, B,-B, the point A being
vin the middle plane of the boiler` and the points
B being on either side of the middle plane.Í,¿The
as
front part of >thç-i-boìler rest'sfat> C’upon thefront
bogie, this support being the >subject lof lthe in
vention` and‘shown in details> in Figs. 1, 2l and 5.
Referring to Figs. 1 and 2 which show in detail
the front support of-¿the boilerfagindicates the
boiler and b the vframe ofïthe front ybogie. ,To the
under side ofthe boiler is ñXed a support c havf-`
¿ing a plane under surface.¿,n'I'he bogiemfranìe Ab
is provided with an upper surfaced, and between
the under surfaceof the supporto and thesur
Ñface vdy of the bogie there isuslidably mounted a
ball joint consisting of anruppïerlpivoted member
e having a semispherlcal bearing surfaceresting
in a corresponding semispherical `s_urvfacewof a .60
socket member-f. To the socket_member'_ye -are
pivoted
armed leversg
at intermediate
and h respectively
pointsQ’ which
and Q’f
_in the
normal position of the boiler are located’in the
' Amidaie plane of-„the boiler andthe bogie., >'The
upper end of each lever is forke_d,qthe,forked por
tions being pivotally connected at Pto blocks
slidably mounted in vertical guid'e'w'ays formedin
the boiler support c.Y The lower vends of -'the'le~
vers are also pivotally vconnecte'd'at Rin any suit
able manner to similar' blocks slidably mounted
in vertical guideways'forme'd inthe bogie frame b.
The positions of the-‘pivots- of thev levers andthe
lengths of >the arms 'are so‘cho'sen that during
lateral- 'displacement' of f the »boilerl with regard to rur
3
-,the ¿front bogie, the middle plane _ _of the, ball ljoint
2. In «a’Mallet locomotive. of the type wherein
remains ,approximately atl equal distances, from
_themiddleplane o_f the .bogie ‘frame andthe- mid.
Áthe boilcreis supported upon-,a ,iront bogie >and
dle plane of «theboilen -~In some `cases,however,
ci the dimensions of -thelever „arms andthe posi,
ytionswof the pivots maybe chosen, in_.such a man,
` ner asto-obtaina .d_iiîerentproportionbetween
.the said distances.
.
. .
.
- In atrack curve,_ the >direction of_.,tli_e longi
lo" tudinal middleaxis of the frontybogie is displaced
withrespect to that of theboilerpthetwo@ axes
vformi,ng-an` angle between them. ` Now, itis ,obj
' ,vicusythatthe further @particular- point 0n _cnc
._arear; frame, the combination of; a boiler ;,_al front
bogie; a». gllideway. `iixed tothe under «side of' the
boiler; ,a guideway upon the bogie; a ball joint
slidable between said two guideways;-and-means
_for controlling themovementof i said ball joint
_due to lateral displacement of the .boilerwith re
gard to ythcbogie to maintain a definite propor
tion between thedistancesiof said ball joint from
vthe middle plane ofthe boiler and the bogie, said
ball joint comprising a semispherical socket mem
ber and a semispherical pivot member, said sock
axisnorflimby of the displacement, angle _iszjfrqni _ et member `being slidable uponthe guideway upon
the bogieand said pivot member. being slidable
vits distance from apointon the _othervv lirnbpr _upon the vguideway iixed to the boiler_
axis located at an equalgdistance from. the said
.apex pointA
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._3. ¿In la Malletk locomotive of the >,type wherein
the boiler is ,supported upona front bogie and a
rear frame, the combination of: a boiler; a front
._ The levers `g-_and It `are _located _at d_iiîerentv
distances, from the apex of the angle'` formed by ' bogie; means forsupporting said ¿boiler on said
the _relative _displacement of the middle-axes _ojf_ front, bogie, >said means comprising..a_pguideway
the front bogie and the boiler. Consequently,
whenxthe-fvehícle Atraverses a curve,.each leverv
_fixed to the under side ,of the boiler; -aguideway
is displaced to a different extent.
The lever h
`said two guideways; saidpballfjoint.comprising a
located closer to the apex point has a shorter
socket member slidable upon one of said guide->
ways and a -ball', in said socket, and slidable upon
path and thus the smaller displacement,ïwhil_st
‘ the lever g, located further forwardly of the Ve
upon the bogie; and a ball jointlocated .between
the other guideway; 'and' means for controlling
hicle, undergoes the greaterv displacement.. On ‘ the movement-of said ball joint due to lateral dis
the other hand, however, the intermediate pivot
placement of the boiler with regard to the bogie
30 points Q’ and Q",of the levers g and h, should,
to maintain a definite proportion between the
30' l
yon account ofthe parallel guiding of the ball. distances of said ball joint from the middle plane
joint, constantly carry out displacements of equal. ` of the boiler and the bogie, said guideway upon
sizes. ' The axes of rotation of the levers g and- h
the bogie rising laterally from its centre to its
always lie parallel to the axis of the front bogie
ends.
`
Sii b. In'order, therefore, that the ball socket f shall
4. In a Mallet locomotive of the type wherein 35A
be guided parallel to itself and to the centre of - the boiler is supported upon a front bogie and a
the bogie b, different lever transmissions are rear frame, the combination of: a boiler; a front
necessary. As can be seen from Figure 1, this is'A . bogie; means for supporting said boiler on said
achieved in the example described, by making`~the front bogie, -said means comprising a guideway
40 two levers g and h of the same overall length, but
fixed to the under side of the boiler; a guideway 40
locating the intermediate points Q' and Q" in upon the bogie; and a ball joint located between
such positions therealong‘ that the proportion of ' saidtwo guideways; said ball-joint comprising a
the lengths of the arms PQ'; Q’R ‘and PQ”; socket member slidable upon one of> said guide
Q”R are different. In order to'provide for au
ways and a ball, in said socket, and slidable upon
tomatic return of the parts c, e, f, d into the the other guideway; and means for controlling 45
' initial position after the `train has passed over a
curve in the track, the bearing surfaces ,of the
socket f 'are made wedge shaped. This construc
tion is extremely compact, which is a very> con
siderable advantage in view'of the'small avail
able space.
u
the movement of said ball joint due to lateral
displacement of the boiler with regard to the
bogie to maintain a deñnite proportion between
the distances of said ball joint from the middle
plane of the boiler and the bogie, said means for
controlling the movement of the ball joint com
It will be understood that other means may y prising leverseach pivoted at an intermediate
be' provided vfor positively controlling the relative pointalong the length thereof to the ball joint
` movement of the parts. For instance, instead and operatively connected at the ends thereof to
55
of guiding the upper ends of the levers in verti
the -boiler and the bogie respectively.
cal guideways, links might be used, and the levers
5. In a Mallet locomotive of the type wherein
might, for instance, be replaced by toothed racks the boiler is supported upon a front bogie and
a rear frame the combination of: a boiler; a front ,
. and wheels.
I claim:
_
Y
1. In a Mallet locomotive of the type wherein
the boiler is supported upon a front'bogie and
a rear frame the combination of: a boiler; a
iront bogie; means for supporting said .boiler on
said front bogie, said means comprising a guide
way ñxed to the under side of the boiler; a guide
way uponthe bogie; and a balll joint located be
tween said two -guideways; said ball-joint com
prising ‘a socket member slidable upon one of
said guideways and a ball, in said socket, and
70
slidable upon the other guidewaypand means for
controlling the movement of said ball joint due
_ to lateral displacement ofthe boiler with regard
to the bogie to maintain a definite proportion'be
tween the distances of-said ball joint from 4the
75 middle plane of the -boilerand the bogie.
bogie; means for supporting said boileron said 60
front bogie, said means comprisinga guideway
ñxed to the under side of the boiler; va guideway
upon the bogie; and a ball joint located between
said two guideways; said ball-joint comprising
a socket 'member slidable upon one of said guide 65
ways and a ball,‘in said socket, and slidable upon
the other guideway; and means for controlling
the movement of said ball joint due tolateral dis
placement of the boiler with regard to the bogie
to maintain a definite proportion between the w
distances of said ball joint from the middleplane
of the boiler and the bogie, said controlling means ,
comprising levers each pivoted at an interme
diate point along the length> thereof to the ball 7,5 .
joint; vertical gi'xideways for theends of said le
vers provided upo?rthe boiler andthe'bogie'? and
4slide blocks pivoted to the upper 'ends'of the
lever, Vsaid blocks sliding‘in the 'vertical guideways
on the boiler and slide` blocks 'pivoted to ¿fthe
lower ends of said levers, said blocks' sliding Yin
the
guideways on the bogie.
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v
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6. In a Mallet locomotive of the'typ'ewherein
the boiler is supported upon a front bogie and a
rear frame, the combination of :"aboiler; a front
10 bogie;- means for supporting lsaid boiler on said
front bogie, `said means comprising'a ‘gui'deway
fixed tothe underside of the boiler; a guideway
upon the bogie; and a ball joint vlocated between
the :boiler is supported‘upon affront bogie and 'à
rear frame, the combination ofi abfoiler;- a front
bogie; means for supporting said"boi1er‘- on‘said
front bogie, said means comprising a guideway
fixed to the under side of 'the boiler; a guideway 5
upon the bogie; and a ball joint located between I
said two guideways; »said ball-joint comprising ak
socket member slidable upon one of'saidÍ guide
ways and a balLin said socket, >and slidable upon
the other guideway; and means .for controlling-
the movement of said ball jointdue to'late?al
displacement of the boiler with` regard* tothe
bogie to maintain a definite proportion between
said: two guideways; said ball-joint comprising a v the distances of said ball joint from 'the'middle’
plane of the boiler and the bogie, said means-for
ways and a ball, infsaid socket, and lslidable'upoen controlling» the movement of Vthe’ball joint'cor'ni
the other guideway; and means‘for controlling prising levers, each pivotedat an intermediate
the movement of said ball joint'due to vlateral >point along the length thereof to the ball Ajoint
displacement of îtloe~ boiler with regard to- the and operatively connected at the ends thereof
20 bogie to maintain a deñnite proportion between to the boiler and the bogie respectively, the Aral 20
the distances of said ball joint from the middle tio of the eiîe‘ctive arm lengths of the levers be
` '
' __ \ ff
plane of theboiler and the bugie; ysaid proportion in_g different'.
15 socket member slidable >upon one of said guide
being substantially 1:1.-
v
ï
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7,; 11n* a Mallet locomotive of the "type wherein ,
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KARL ROTHLER.
,