CERTAIN IMPROVEMENTS IN CHAINS APPLICABLE TO THE TRANSMISSION OF MOTIVE POWER, KNOWN AS PITCH CHAINS, AND TO THE WHEELS OR PULLEYS ON WHICH THEY WORK, APPLICABLE TO VELOCIPEDES, HOISTING MACHINES, TOP ACTION ExanATIN AND OTHED MECHANICAL PURPOSES
Year: 1881

page_text: LETTERS PATENT to John Icely Warman, of the Firm of Warman, Laxon, and
Aslatt, of Coventry, in the County of Warwick, for an Invention of "CERTAIN
IMPROVEMENTS IN CHAINS APPLICABLE TO THE TRANSMISSION OF MOTIVE
POWER, KNOWN AS PITCH CHAINS, AND TO THE WHEELS OR PULLEYS ON
WHICH THEY WORK, APPLICABLE TO VELOCIPEDES, HOISTING MACHINES,
TOP ACTION ExanATIN AND OTHED MECHANICAL PURPOSES"
PROVISIONAL SPECIFICATION left by the said John Icely Warman at the
Office of the Commissioners of Patents on the 25th August 1881.
JOHN ICELY WARMAN, of the Firm of Warman, Laxon, and Aslatt, of Coventry,
in the County of Warwick. "CERTAIN IMPROVEMENTS IN CHAINS APPLICABLE
TO THE TRANSMISSION OF MOTIVE POWER, KNOWN AS PITCH CHAINS, AND TO
THE WHEELS OR PULLEYS ON WHICH THEY WORK, APPLICABLE TO VELOCIPEDES,
HOISTING MACHINES, TRACTION ENGINES, AND OTHER MECHANICAL PURPOSES."
The chain consists in its most usual form of one central flat link shaped to fit
the periphery of the wheel acting with it rectangular in cross-section, having the
long side of the rectangle at right angles to the axis of the wheel on which the
chain works, and necessarily at right angles to the axis of the pins connecting the
links with each other; alternating with two links, also rectangular in cross section,
and disposed in a similar manner; at each end of each link is a circular hole in
which the connecting pin fits. The flat link first described comes between the two
other side links at each end, and they are connected by the pins before mentioned,
thus forming a continued chain of one and two links alternately and of any required
length; the chains may also be made of two and three links alternately, or any
other suitable combination. To prevent the strain due to the tension on the chain
coming on to the connecting pins, each of the central flat links has a circular boss
or projection surrounding the hole at each end; these bosses fit into corresponding
recesses in the side links, the ends of which are provided with longer bosses for
the purpose of engaging with the wheel afterwards to be described; the recesses in
the side links are on the inner side, that is, the side nearest to the longitudinal

page_text: centre of the chain, and the bosses to engage with the wheel are on the outside.
By means of the bosses on the outer links the motion is transferred from the wheel
to the chain, or vice versa, and by means of the bosses on the inner or central links
the power is transmitted directly from one set of links to the next, altogether
avoiding any shearing strain on the connecting pins, the office of which is merely
to hold the links together sideways. These connecting pins are fastened to the
links by rivetting over, or by any other suitable method.
In another modification the chain is made as above described, but the boss at
each end of each outer link, instead of bearing directly on the wheel hereafter
described, has a slating turned upon it with a check or raised projection left on the
inner part. On this seating a roller revolves which engages with the projections
on the wheel described below; each of these rollers is secured in its place by a
washer and a pin, or by the rivetting over of the connecting pins of the chain, or
in any other suitable manner, the latter being the plan usually adopted.
The wheel which either imparts its motion to the pitch chain (before described)
has its circumference. of a channel form in transverse section, or it may be other-
wise described as a flat band wheel with a projection flange on each side. On each
of these projecting flanges or channel sides occurs a series of notches equadistant
around the circumference, and the same distance apart from centre to centre as are
the connecting pins in the claim.
The cotton part of each of these notches, that is to say, the part that is nearest
to the centre of the wheel, is semicircular, and the upper part is widened out and
rounded off with an easy curve to meet the outer circumference of the wheel. The
notches in each flange are exactly in line with each other. In action the bosses on
the outer links of the pitch chain engage into the notches or recesses in the flanges
of the wheel, and thus impart motion to the wheel or receive motion from it,
according to whether the pitch chain is the driver and the wheel the follower, or
vice versa.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Icley Warman in the Great Seal Patent Office on the
24th February 1882.
JOHN ICELY WARMAN, of the Firm of Warman, Laxon, and Aslatt, of Coventry,
in the County of Warwick. *" IMPROVEMENTS IN CHAINS APPLICABLE TO THE
TRANSMISSION OF MOTIVE POWER, KNOWN AS PITCH CHAINS, AND TO THE WHEELS
OR PULLEYS ON WHICH THEY WORK, APPLICABLE TO VELOCIPEDES, HOISTING
MACHINES, TRACTION ENGINES, AND OTHER MECHANICAL PURPOSES."
In endless or other chains as at present made such as are used for the purpose of
driving or transmitting motion either from prime movers to machines or from one
part of a machine to another, there is very generally a large amount of needless
friction between the working parts, and an absence of neatness and compactness in
design, and also of strength, the strain when the chain is in motion usually
coming on the connecting pins. The wheels also which act upon the chain are
frequently not of the best form for the purpose, either as regards appearance,
ease, and certainty in working or durability. To remedy these defects is the object
and purpose of this my said Invention.
Certain improvements in chains applicable to the transmission of motive power,
known as pitch chains, and to the wheels or pulleys on which they work,
applicable to velocipedes, hoisting machines, traction engines, and other mechanical
purposes.
In the first manner of carrying out my Invention, so far as regards the chain,
there are, reckoning in the direction of the length of the chain, alternately two
links and one. The links are formed of flat metal plates placed edgeways to the
chain wheel, and curved to fit its rim. The single link is double the thickness of
either of the two links either before or behind it, thus equalising the strength of
the different parts of the chain. The single link, wherever it occurs, is on the
centre line of the chain, and is henceforth called the central link, and the thin links
are called the side links. Each side link from centre to centre of boss is the same
length as each centre link. On each side of either end of the link is formed a
circular projecting boss, and through the centre of each of these bosses is drilled a
cylindrical hole having its axis coincident with the axis of the boss. On each end
of each of the side links, but at one side only, is a circular boss, larger than the
before described boss on the central link. In each of the bosses on these side links
is formed a cylindrical recess into which one of the bosses of the central links fits
and works. The remaining portions of the bosses on the side links have cylindrical
holes drilled through, one to each, iu a similar manner to those in the central links
already described, and the outer end of this hole is by preference countersunk.
When the chain is built up in the manner described by fitting the bosses on the
central links into the recesses on the side links, pins are put through the central
holes, one to each, and the ends rivetted or otherwise fastened. By making the
chain in the manner above described, and using it in combination with the chain
wheel next to be described, a very firm and secure hold of the chain is obtained,
and all strain on the central pin connecting the links is avoided, this pin merely
serving to keep the links together laterally. The chain wheel which I use, in
combination with the chain already described, has a hub and arms of any usual
and suitable construction, my Invention having reference to the shape of the rim.
In cross section the rim is of a trough section, or to use a term well understood by
engineers, it is double shrouded. Equidistant around the circumference of the
wheel is a series of pairs of notches, two notches, one in each shroud, being opposite

page_text: to each other and forming a pair. The bottom of each notch, that is, the part
nearest to the centro of the wheel, is in the form of the arc of a circle, very nearly
a semicircle, and the upper part of each notch is widened out. The "pitch" or
distance from centre to centre of each notch, measured as a chord of an arc, passing
through the centres of the link bosses when the chain is in position on the wheel,
is exactly the same.distance as that from centre to centre of the bosses on the chain
links. The notches in the rim of the chain wheel are of such a depth that when
the bosses of the side links of the chain rest on the bottoms of the notches, the
edges of the links themselves shall rest fairly on that part of the rim of the wheel
which lies between the shrouds.
In the second manner of carrying my Invention into effect the general con-
struction of the chain is the same as that previously described, only that instead
of each link in the chain being of equal length the central links are very much
shorter than the side links, and when the chain is put together it is flush or nearly
so on the outsides, and the bosses on the side links, instead of projecting outwards
as in the first arrangement, project inwards towards each other, and meet on the
centre line of the chain.
To suit this second form of chain the chain wheel has a series of teeth round the
rim instead of notched shrouds. When the wheel revolves these teeth fall into
gear successively with the bosses on the links of the chain in the same manner to
the sides of the notches in the first arrangement..
In the third manner of carrying my Invention into effect the links are of equal
length and equal thickness, of similar shape in side view, and of equal strength,
but instead of there being alternately two links and one link in the chain, as in the
first and second methods, there are two outer links and then two inner links, then
two outer links again, and so on. The method of connecting the links together is
by means of large recessed bosses on the inner links, and smaller projecting bosses
on the outer links fitting into them, with a small circular hole going right through
each set of bosses, and a pin with the ends rivetted over, as before described for
the first method. In a chain of this form the outer sides are nearly flush, and the
bosses on the inner links project towards each other and meet on the centre line of.
the chain.
The chain wheel which I use in this third method of carrying my Invention into
effect is very similar to that used for the second method, that is to say, there are
teeth all round the circumference which engage with the bosses on the chain
links, but in this third method the teeth are spaced so as to suit the equal length
of chain links instead of the alternate long and short ones, as in the second
method.
I will also describe another form of chain which may be used with the first
form of wheel. In this method of carrying out my Invention I make each link of
my chain alike with a circular boss partly cut away on the inner end, and recessed
for the reception of a cylindrical bush having a small hole through its centre
axially. The working strain is transmitted in this case through the bush, and the
pin which is put through the centre of each boss serves to keep the parts together
laterally as in the former methods.
In another form of chain which may be used with the first form of chain, there
is alternately one thick central link and two thin side links, and the general
construction of this chain resembles that described under the first method. With
a view however of diminishing friction, each boss which projects outwards is
previded with a "tumbler" or external bushing which can revolve on it, and which
is provented from coming off by having a washer, and the ends of the pin rivetted,
or by any other convenient appliance.
I do not limit myself to chains consisting of single links or alternately one and
two links, but by modifications easily made, and which do not affect the essential
part of my Invention, I make chains with two or more rows of links, or with
alternately two and three, three and four, or other suitable numbers of links, the
wheels being made to correspond in each case either by using three or more

page_text: Fig. 21 is a view of details of links and rollers for same.
In the first method shown in Figs. 1 to 5, a, a, are the rims of the wheel;
b, b, the notches in same; c, c, the rounded bottoms of the notches; d, d, the side
or outer links; d', d, the bosses on same; d³, d², recesses in same; d³, d, the holes
for the pins; d, d, pins; e, e, the central links; e¹, e', the bosses on same; e³, e³,
the holes for pins.
In the second method shown by Figs. 6 and 7, and 13 to 15, f is the rim of
wheel; f¹, f', the teeth; g, g, the outer links of chain; g¹, g¹, the bosses on same;
g, g, recesses in bosses; g³, g³, holes for pins; h, h, the inner links; h¹, h', bosses
on same; h2, h3, holes for pins; h³, h³, pins.
In the third method, shown by Figs. 8 to 12, f is the rim of the wheel; f', f¹, the
teeth; j,j, the outer links of chain; 1,, the bosses on same; *,, the holes for
pins in same; k, k, the inner links; ke', k', the bosses; k², k², the recesses; k³, k³, the
holes for pins; k^, ^, the pins.
In Figs. 16, 17, and 18, 1, 1, are the links; ", ', the bosses; 13, 13, the recesses;
,, the bushes; 1, 4, the holes for pins; 1, 15, the pins.
In Figs. 19 to 21, m, m, are the inner links; m², m³, the bosses; m², the pin
holes; n, n, the outer links; o, o, the rollers.; p, p, the washers; and q, q, the pins
rivetted at the ends.
Having now described my Invention, and the manner in which the same is or
may be carried into effect, I do not limit myself to the exact shape or configuration
of the parts as herein described, but I may make any alteration which may be a .

page_text: -
mere modification thereof. What I claim as novel, original, and useful, and desire
to be secured to me by the herein before in part recited Letters Patent are,-
First. The construction and arrangement of a driving chain with links having
bosses, and the wheel to suit the same, as described as my first method.
Second. The construction and arrangement of a chain as described as my second
method.
Third. The construction and arrangement of a chain as described as my
method.
third
Fourth. The construction of different forms of chains for the wheels previously
described, as the one with similar links and the one with rollers.
Fifth, and Lastly. The combination of parts of chains and chain wheels, substan-
tially as and for the purposes herein before described and set forth, or any mere
modifications thereof.
In witness whereof, I, the said John Icely Warman, have hereunto set my
hand and seal, this Twenty third day of February, in the year of our Lord
One thousand eight hundred and eighty two.