IMPROVEMENTS IN LOCOMOTIVE ENGINES
Year: 1859

page_text: LETTERS PATENT to Thomas Aveling, of Rochester, in the County of Kent,
for the Invention of "IMPROVEMENTS IN LOCOMOTIVE ENGINES."
Sealed the 21st February 1860, and dated the 1st September 1859.
PROVISIONAL SPECIFICATION left by the said Thomas Aveling at the
Office of the Commissioners of Patents, with his Petition, on the 1st
September 1859.
I, THOMAS AVELING, of Rochester, in the County of Kent, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN LOCOMOTIVE ENGINES,"
to be as follows:-
This Invention relates to a peculiar construction and arrangement of
apparatus for giving more or less tension to an endless chain or chains when
used for transmitting motion to the driving wheels of locomotives, whether for
common roads, railways, or agricultural purposes. In carrying out this
Invention the endless chain is passed round a peg wheel connected with the
driving wheel or wheels, and over a small chain drum or pulley, which is
contained within a quadrant arm or lever, working freely at one end round
the main driving shaft of the engine, and having a slotted quadrant at the
other end, whereby it may be set in any desired position requisite for imparting
more or less tension to the chain by drawing the small chain drum or pulley
further from or nearer to the driving wheels. On the axis of the small chain
drum or pulley is a spur wheel which gears into a spur pinion keyed on to the
main driving shaft. This wheel is free to move in a circular direction round
the pinion when the quadrant arm is adjusted, without being disengaged there-

page_text: from, so that the motion will be transmitted from the pinion in whatever
position the quadrant may be. The fixing or setting of the quadrant in any
desired position is effected by bolts fixed in brackets attached to the side of
the boiler, and passing through the curved slot of the quadrant, which is
tightened by means of nuts.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Thomas Aveling in the Great Seal Patent Office on the 1st
March 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, J, THOMAS
AVELING, of Rochester, in the County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of September, in the year of our Lord
One thousand eight hundred and fifty-nine, in the twenty-third year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Thomas Aveling, Her special license that I, the said Thomas.
Aveling, my executors, administrators, and assigns, or such others as I, the
said Thomas Aveling, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
LOCOMOTIVE ENGINES," upon the condition (amongst others) that I, the said
Thomas Aveling, by an instrument in writing under my hand and seal, should
particularly describe and ascertain the nature of the said Invention, and in
what manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Aveling, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings and to the
letters and figures marked thereon, that is to say :-
of
My said Invention relates to certain peculiar constructions and arrangements
apparatus for giving more or less tension to an endless chain or chains when
used for transmitting motion to the driving wheels of locomotives, whether for:
common roads, railways, or for agricultural purposes.

page_text: According to one mode of carrying out this Invention the axis of the small
chain pulley, which transmits motion to the endless chain passed round a
larger chain wheel on the hind running axle of the engine, is capable of
lateral adjustment in a curved slot in the main supporting bracket, which
carries the plummer blocks of the engine shaft, the curve of this slot being
struck from the centre of the main shaft. By this means the spur wheel and
pinion employed for actuating the small chain pulley will not be affected by
the lateral adjustment of such pulley, but will remain in gear in whatever
position the axis of the pulley may be placed in its curved slot.
According to another modification the endless chain is passed round a chain
pulley connected with the driving wheel or wheels, and over a small chain.
drum or pulley as in the first arrangement, but the small pulley is contained
within a quadrant arm or lever working freely at one end round the main
driving shaft of the engine, and having a slotted quadrant at the other end,
whereby it may be set in any desired position requisite for imparting more or
less tension to the chain by drawing the small chain drum or pulley further
from or nearer to the driving wheels. On the axis of the small chain drum or
pulley is a spur wheel, which gears into a spur pinion keyed on to the main
driving shaft. This wheel is free to move in a circular direction round the
pinion, when the quadrant arm is adjusted without being disengaged there-
from, so that the motion will be transmitted from the pinion in whatever
position the quadrant may be. The fixing or setting of the quadrant in any
desired position is effected by bolts fixed in brackets attached to the side of
the boiler, and passing through the curved slot of the quadrant, which is
tightened by means of nuts.
Or, according to a third arrangement, the tightening of the endless chain
may be effected by adjusting the axle of the large running wheels laterally in
a horizontal slot in its bearings or supporting brackets. It is obvious, however,
that various other mechanical contrivances may be adopted for taking up the
slack of the endless chain, based upon the same principle, namely, the widening
the distance between the two centres round which the endless chaiu passes
without interfering with the action of the gearing which transmits motion to
the chain from the main engine shaft.
And in order that my said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose
I shall refer to the several Figures on the Sheets of Drawings hereunto
annexed, the same letters of reference indicating corresponding parts through-
out all the corresponding Figures.
Figure 1, on Sheet 1 of my Drawings. represents a side elevation of a

page_text: locomotive agricultural or farm engine, capable of being used also as a traction
engine, with one modification of my improvements applied thereto; Figures 2
and 8, on Sheet 2, are enlarged details of the gearing and mode of adjust-
ment; and Figure 4 on the same Sheet is a side elevation of a boiler fitted
with another modification of adjusting apparatus.
In Figure 1, A is the boiler of the locomotive or traction engine, supported
on the two pairs of running wheels B and B'. The hind axle has secured
firmly to it a large notched chain wheel C, round which is passed an endless
driving chain D, also passed round the small notched chain pulley or peg
wheel E, shewn also in the detail, Figure 2. This latter chain pulley has a
long boss F cast upon it, which boss turns freely on the stud shaft G, and is
secured to the spur wheel H on the same shaft by being inserted into the boss
of that wheel, and secured therein by keys, so that the spur wheel and chain
wheel will turn together, but may be detached from each other when either of
them becomes worn and requires renewing. The stud shaft G is provided with
a large collar I, which bears against the front face of the bracket K, and a
second but loose collar L is applied behind the bracket, so as to bear against
the back face thereof. This loose collar is keyed up tight by a jib and cutter
passed through the stud in the usual well-known manner. The opening in
the bracket, through which the stud shaft passes, is in the form of a curved
slot, the curve of which is struck from the centre of the main driving shaft M
above. N is an adjusting screw working through a tapped boss O, in the
side or edge of the bracket, and bearing at its inner end against the side of the
stud shaft. By turning this screw in the proper direction, it is obvious that
the stud shaft may be slid laterally in its curved slot. The spur wheel H
receives motion from the spur pinion P, which slides laterally, by. means
of a groove and feather on the end of the main driving shaft, but always
revolves with that shaft. The object of this lateral adjustment of the pinion P
is to throw it in or out of gear with the spur wheel H, so that when the engine
is not required to travel, the locomotive gear may be thrown out of action, and
the engine worked simply as an ordinary farm engine. The pinion P may be.
brought in or out of gear with the spur wheel H by sliding it along the main
shaft and securing it in a proper position thereon by the set screw Q, or the
same may be accomplished by a clutch lever or other convenient contrivance.
One side of the engine only is provided with gearing for driving the bind axle,
and either one or both of the wheels may be driven from the axle by means of
clutches or other suitable engaging and disengaging apparatus.
In Figure 1 I have shewn the running wheel as being connected to the
large chain pulley by means of a bolt 6 passed through a segmental bar c,

page_text: secured to the arms of one of the main running wheels; by removing this bolt
the running wheel will be disconnected from the large chain wheel. A suitable
disconnecting apparatus is also applied to the opposite running wheel, so that
either one or both wheels may be rotated or not, as desired, which is a great
advantage in turning sharp curves. As the curved slots in the brackets K are
struck from the centre of the main shaft, it follows that the stud shaft may be
adjusted laterally to any desired amount, so as to tighten up the driving chain
without interfering with the gearing together of the spur wheel Hand
pinion P. T is the steam cylinder of the engine; and U is a water tank
placed behind the fire-box. The top plate or cover of this tank serves to
carry the fuel, there being a raised side fitted round it for that purpose); this
top plate answers also as a foot plate for the engine driver. V, V, are pro-
jections made of Tangle iron in the form of clips, which embrace the felloes
of the driving wheels, and are secured firmly in their places by nuts, as shewn,
or in any convenient manner; these projections are intended to be used on
soft ground, for the purpose of increasing the bite of the driving wheels, and
may be readily applied or removed at pleasure.
In the modification shewn at Figure 4, the endless driving chain D is
passed round the chain pulley C, connected, as in the previous modification,
to the driving wheels; it is also passed over the small chain pulley E, carried
by. the quadrant arm or lever e, which works freely at one end round the main
driving shaft M of the engine, and having a slotted quadrant f formed at its
other end, by which it may be set in any desired position for increasing the
tension of the chain by the bolts g, g, fixed in brackets attached to the side of
the boiler, these bolts, passing through the curved slot of the quadrant, and
being tightened therein by means of nuts, as shewn. By suitably adjusting
the lever e, it is obvious that the small chain pulley E may be moved further.
from or nearer to the chain wheel C, and that consequently any desired amount
of tension may be thereby imparted to the endless driving chain. The small
chain pulley has secured to it a spur wheel H, which gears into a corresponding
spur pinion P, carried by the main driving shaft of the engine. It will be
obvious, on referring to the Drawing, that in whatever position the quadrant
lever may be fixed, the spur wheel H and pinion P will always remain in gear
with each other, and transmit the requisite motion to the endless driving chain
and driving wheels. Suitable well-known appliances may also be here
adopted for throwing the pinion P in or out of gear with the spur wheel H,
so that the engine may be used as a traction or locomotive engine, or as a
stationary portable engine, as required. The chain which I prefer to use for
the purpose herein-before mentioned consists of an alternate pair of flat links

page_text: and a single hollow link, the single link being of the full width of the opening
between the flat links.
Figures 5 and 6 represent respectively a side elevation and plan of a portion
or length of chain constructed after the manner above described.
the flat links, and 6, 6, the single hollow links.
Although I have only described and illustrated my tension apparatus as
applied to the taking up of the slack in the endless driving chains employed
in transmitting motion to the driving wheels of locomotive or traction engines,
it will be obvious to the practical man that the same apparatus may be
advantageously applied in many cases to the tightening of driving belts or
bands usually employed in transmitting motion to machinery.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that what I consider to be novel and
original, and therefore claim as the Invention secured to me by the herein-
before in part recited Letters Patent, is-
First, the general constructions and arrangements of locomotive or traction
engines, as herein-before described.
Second, the peculiar constructions and arrangements of apparatus for
tightening or taking up the slack of endless chains employed in rotating the
running wheels of locomotive or traction engines, as herein-before described.
In witness whereof, I, the said Thomas Aveling, have to this my
Specification set my hand and seal, this Twenty-seventh day of
February, One thousand eight hundred and sixty.
THOP. AVELING. (L.S.)