CERTAIN IMPROVEMENTS IN MECHANISM TO DECREASE, FRICTION IN PROPELLING MACHINERY, AND TO COMPENSATE FOR THE WEAR THEREOF, AND TO STRENGTHEN THE DRIVING PARTE
Year: 1853

page_text: LETTERS PATENT to Elias. Robison Handcock, of 58, Pall Mall,
in the City of Westminster, for the Invention of "CERTAIN
IMPROVEMENTS IN MECHANISM TO DECREASE, FRICTION IN PROPELLING
MACHINERY, AND TO COMPENSATE FOR THE WEAR THEREOF, AND TO
STRENGTHEN THE DRIVING PARTE."
Sealed the 30th December 1853, and dated the 30th June 1858.
PROVISIONAL SPECIFICATION left by the said Elias Robison
Handcock at the Office of the Commissioners of Patents, with his
Petition, on the 30th June 1853.
I, ELIAS ROBISON HANDCOCK, 58, Pall Mall, London, do hereby
declare the nature of the said Invention for for "CERTAIN IMPROVEMENTS
IN MECHANISM TO DECREASE FRICTION IN PROPELLING MACHINERY, AND TO
COMPENSATE FOR THE WEAR THEREOF; AND TO STRENGTHEN THE DRIVING
PARTS," to be as follows:-
My improvements consist in placing the teeth of wheels at such
distances and at such an angle as will prevent the back lash so preju-
dicial in cog, spur, and other wheels of the same description, now
generally used in machinery, especially for driving the screw in steam
vessels, and also in increasing the strength of the teeth, and in providing

page_text: the means of compensating for any wear which may occur, by means
of inserting pieces of steel, gun metal, or other hard substance in that
part of the tooth most liable to it, which pieces may be removed or
replaced, if necessary, as occasion may require by enabling them to
slide in in a dove-tail manner, as seen in Fig. 5, or inserted in a bed,
left for the purpose in the teeth, and kept in their places by means of a
countersunk screw, as seem in the rubbing parts of each tooth in
Figures 1, 2, 3, 4.
Fig. 1, shows two corresponding wheels in contact at the point of
greatest power.
Fig. 2, shows the position of two wheels when the tooth of one
wheel is is half way removed from that of the corresponding tooth of
the opposite wheel.
Fig. 3, shows the multaplying motion, and the means of giving
double velocity to one wheel.
Fig. 4, shows the multaplying motion. The teeth of one half the
thickness of each wheel being reversal.
Fig. 5, shows how a piece of hard metal may be inserted into the
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Elias Robison Handcock in the Great Seal
Patent Office, on the 30th December 1859.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
ELIAS ROBISON HANDCOCK, of 58, Pall Mall, in the City of West-
minster, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of June, in the year of
our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto the said Elias Robison Handcock Her:
special licence that 1, the said Elias Robison Handcock, my exccutors,
administrators, and assigns, or such others as I, the said Elias Robison
Handcock, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times

page_text: 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 "CERTAIN IMPROVEMENTS IN MECHANISM TO DECREASE FRICTION IN
PROPELLING MACHINERY, AND TO COMPENSATE FOR THE WEAR THEREOF, AND
TO STRENGTHEN THE DRIVING PARTS," upon the condition (amongst others)
that I, the said Elias Robison Handcock, 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 immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Elias Robison Handcock, 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 bad to the Draw-
ings hereunto annexed, that is to say:
Figure 1, shews the construction of a wheel and pinion, and the
formation of the required angles and circles, and also the necessary
section of the circle describing the face of the teeth, by means of which
a rolling instead of a rubbing motion is attained; also shows the
distance from point to point and from base to base of cach tooth. On
the accuracy of this construction depends the snooth working of the
wheel, obviating the injurious effects of wheels working at different
velocities, and enabling the teeth of the wheel and pinion (or the teeth
of different sized wheels acting together) to be constantly kept in con-
tact without any blow or noise. For this purpose the angles B, and C,
should correspond with the angles F, and G, and the angles at D, and
E, should correspond with the angles II, and I, and the triangle A, B,
C, should correspond with the triangle K, F, G; taking the angle K,
as the centre, and I, or G, as the distance, the sides of the triangle will
form radii of the same circle, or that in taking the angle F, as the
centre, and G, as the distance, the line F, G, will form the radius of a
circle; and, in like manner, the triangle A, B, C, of the large wheel
may be proved to correspond with the triangle K, F, G, of the
pinion.

page_text: It is shown in this Figure that the angles B, and C, forming the base
of the triangle A, B, C, touch the periphery of the circle describing
the diameter of the wheel; and the legs A, C, and A, B,-when produced,
form tangents to a circle drawn round a centre M, which circle will
vary according to the different dimensions of the wheels; while, on the
contrary, in constructing the pinion as laid down in Figure 1, the
angles F, G, formning the base of tlie triangle K, F, G, toner the circle
forming the periphery of the wheel, while the legs K, F, and K, G,
radiate from the centre.
This Figure also shows the construction of the back of the teeth by
the circles N, N, giving the proper section L, L, to form the face of
the tooth.
Figure 2, shows a wheel and pinion constructed according to the
required angles and circles.
Figure 3, shows the incans by which reverse motion is attained. In
this Figure two wheels are coupled together, the teeth of one wheel
being in a reverse position to that of the other, and so arranged that
when one wheel is acting the other is thrown out of gear and becomes
completely disengaged, and does not in any manner interfere with the
wheels which are propelling. These double wheels may be fastened
firmly together or may be cast together in one piece, and from the great
strength of the teeth, and the additional support given by the double
wheel, there need not be more thickness of metal than in a single cog
wheel of the ordinary construction. This reverse motion is peculiarly
applicable to the screw in steam vessels, in consequence of the absence
of vibration, and the impossibility of back lash occasioned by one tooth
while disengaging coming in contact with and striking the succeeding
one reversely, and from the facility of muffling the teeth to prevent
noise by facing the front of the teeth of one or both wheels with wood,
which can be removed at pleasure. It is also peculiarly applicable to
large and cumbrous machinery.
Figure 4, shows the angle necessary to construct two wheels of cqual
diameters. The legs of both the triangles X, Z, and W, and O, R,
and V, radiate respectively from the centre of the wheels. It also
shows the position of the teeth-whion half the stroke is completed, and
also the circle (S, S,) necessary to describe the face of the tooth; ant

page_text: it further slicw's the method of facing the teeth with wood, hard metal,
or other substance.
Figure 5, shows the position of the teeth when half the stroke is
completed.
Figure 6, shows another method of facing the teeth, a slot being cut
in the face of the tooth in a dove-tailed manner.
I wish to remark, that the number of the teeth may vary for parti-
cular purposes, but the number of the teeth in the pinion should, if
possible, be confined to eight, as that number will be found the most
advantageous; and, indeed, any pinion with less than eight teeth will
not be found to act smoothly or without noise.
The depth of the teeth of the pinion (in Figure 1,) is one eighth of
its diameter, and each tooth bears the same proportion from point to
point to the circumference as the depth of the tooth to the diameter;
and if the wheel be properly made one tooth will not disengage before
the succeeding one comes into action.
It will be observed that each tooth travels only the length of one
half its face, securing all the advantage of a short tooth with all the
strength of a deep one.
It often occurs that the common cog wheel is stripped of the teeth
by the sudden stoppage of the machinery; this is obviated by the great
strength of the teeth of the wheel, which is constructed' with little
trouble and expense.
As a general rule, tlie. circle determining the section forming the
face of the tooth should be equal in diameter to a radius of the pinion,
or the smaller of two wheels acting together.
This form of tooth may advantageously be employed in bevel wheels,
Having now described the nature of my Invention, and how the
same is to be performed, I have to remark that I do not claim all the
parts constituting my improved tooth wheel (as wheels with teeth of
various forms have long been known and used); but I do claim the
peculiar formation of the teeth, as shewn in the Drawings hereunto
annexed, and the arrangement by which only one tooth of each wheel

page_text: can come in contact during a portion of the stroke, as in Figure 4, and
never more than four teeth, being two of each wheel, during the other
part of the stroke, as in Figure 5, thereby considerably reducing fric-
tion, and preventing back lash by one tooth striking the succeeding
one with a reverse action, which disengaging itself, and in securing a
rolling instead of a rubbing motion along the whole face of the
tooth.
I also claim the peculiar manner of compensating for wear, as shewn
in Figure 4, T, and also in Figure 6, by inserting or affixing pieces of
hard metal or other substances on the face of the tooth, and of muflling
the teeth, as shown in the same Figure, and preventing vibration or noise
by facing the teeth of one or both wheels with wood, having for sup-
port such a body of metal as will prevent all likelihood of the teeth
breaking or being stripped in working.
I also claim the peculiar manner of obtaining a reverse action, where
such is desirable, as in the case of the screw for steam vessels, so as to
enable the vessel to go astern, by attaching two sets of wheels together,
the teeth of one set being in a reverse position to that of the other, and
so arranging them, as in Figure 3, that one set of wheels when acting
will be thrown out of gear and become quite detached, while the other
set is in action.
In witness whereof, I, the snid Elias Robison Handcock, have
hereunto set my hand and scal, this Twenty-ninth day of
December, One thousand eight hundred and fifty-three.
E. R. HANDCOCK (LS)