IMPROVEMENTS IN PITCH CHAINS OR CHAINS FOR WORKING UPON وا CHAIN WHEELS
Year: 1882

page_text: LETTERS PATENT to Sydney Pitt of Sutton in the County of Surrey for an
Invention of "IMPROVEMENTS IN PITCH CHAINS OR CHAINS FOR WORKING UPON
وا
CHAIN WHEELS A communication to him from abroad by James Mapes Dodge
of Chicago United States of America.
PROVISIONAL SPECIFICATION left by the said Sydney Pitt at the Office of
the Commissioners of Patents on the 5th September 1882.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN PITCH
CHAINS OR CHAINS FOR WORKING UPON CHAIN WHEELS" [A communication to him
from abroad by James Mapes Dodge of Chicago United States of America. ]
This invention has for its object improvements in pitch chains or chains for
working upon chain wheels.
The chains are made with oval links and blocks of cast iron or malleable cast iron
are inserted into the links.
When the blocks are in place the links of the chain no longer come into contact
the one with the other but they bear upon these blocks which are interposed between
the links at their ends.
Each block has two semicircular grooves in planes at right angles and in these
grooves the ends of the links lie.
Thus broad bearing surfaces are provided for the links upon the blocks and upon
these surfaces movement of the links takes place as the chain passes around the
wheel.
The exterior of the block is adapted to enter a V form groove or recess in the
periphery of the wheel.
The dimensions of the blocks are such that when turned to a suitable position
they can be readily inserted into the links but they cannot escape from between
them when the chain is in its working position.
Where it is required that there should be attachments to the chain lugs
are provided upon the blocks and to these the attachments may be bolted or
rivetted.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Sydney Pitt in the Great Seal Patent Office on the 3rd
March 1883.
SYDNEY PITT of Sutton in the County of Surrey "IMPROVEMENTS IN PITCH
CHAINS OR CHAINS FOR WORKING UPON CHAIN WHEELS."-(A communication to me
from abroad by James Mapes Dodge of Chicago United States of America)
This invention has for its object improvements in pitch chains for working upon
chain wheels.
Previous to this invention chain cables have been used to a greater or less extent
in connection with wheels having their peripheries formed to effect an interlocking
with the links of such cables; but it has been found impracticable to run such cables
with much success on such wheels, mainly on account of the inadequacy of the
bearing-surfaces afforded (by the links of such cables) to the sprockets or other
interlocking devices on the periphery of the wheel, and, furthermore, on account of
the liability of the links to get misplaced relatively to the wheels interlocking
devices, and thus render impossible a proper engagement of the cable with the
sprockets or other engaging or interlocking portions of the wheel's periphery. It
has also been common to use chain cables (more or less) in the construction of
elevators and conveyors; but their use has not, so far as is known, been attended
.with much practical success in this connection, on account not only of the difficulties
just mentioned of perfectly running such cables on the engaging peripheries of
chain-wheels, but, furthermore, because of the liability of the cable to twist, and
thus to cause not only a derangement of the chain relatively to the wheel's periphery,
but also a displacement of buckets in the case of elevators, or of the flights in the
case of conveyors.
It is proposed by this invention to overcome all these difficulties in and objections
to the use of chain cables as drive chains or cables for elevator, conveyer, and other
purposes, whether run on sprocket-wheels or wheels with other interlocking devices;
and to this end the invention consists in the use, in combination with a chain cable,
of blocks or bearing and retaining devices made preferably of some cast metal or
material well adapted to stand friction and wear on cast-iron wheels, and adapted to
afford good bearing-surfaces for the sprockets or other interlocking devices of the
wheel's periphery to engage with, and also adapted to retain the links of the cable in
proper relative position with each other and with the wheel, and thus render the
cable incapable of twisting, all as will be hereinafter more fully explained.
To enable those skilled in the art to which the invention relates to fully understand
and practice the same I will now proceed to further describe the same, referring by
letters to the accompanying drawings, forming part of this specification, and in
which I have illustrated the said invention as carried into effect in a form under
which it has so far been successfully practiced.
Figure 1 is a plain view of part of a chain cable designed for use merely as a
drive-chain. Figure 2 is a side view of the same. Figure 3 is a perspective view
of the bearing and retaining block. Figure 4 is a view similar to that seen at
Figure 1, but showing the bearing and retaining block formed with or supplemented
with a carrier attachment adapted to support a conveyer-flight. Figure 5 is a cross
section at xx, Figure 4, looking in the direction indicated by the arrow. Figure 6
is a perspective view of the attachment-block (seen at Figure 5) detached from the
chain links. Figure 7 is a plan view of the contrivance seen at Figure 1, but
showing one of the links removed from its working relative position with the
bearing-block, in order to permit the removal of said block; and Figure 8 is a

page_text: similar view to Figure 7, but showing the bearing-block moved or slipped round
into a position to permit its easy separation from the chain.
In the several figures the same part, wherever shown, will be found designated
by the same reference letter.
A and B represent two links of an ordinary chain cable, and C is a cast metal
block, preferably of malleable iron, of such conformation (as shown, for instance)
that it embraces the adjacent end portions of two links laterally in its grooves b b
(which lie in planes transverse to each other) and at the same time affords a pintle-
like bearing-surface about equal in diameter to the width of the opening or space
between the side bars of a link for each link to articulate or turn on, and also
affords proper bearing-surfaces for the sprockets or other projections of the chain-
wheel to work against. The pintle-like portions referred to are seen at c, and the
portions of surfaces which serve for the wheel's sprockets to work against I have
marked d.
By reference now to Figure 1 it will be observed that if a contrivance such as
there shown (in top view) be run over the periphery of a wheel from which
project sprockets, (as for instance, illustrated by the dotted lines at said figure)
the said sprockets will take their bearing upon and will get an ample bearing at
the portions d, while the portions c of the cast-iron blocks will bear sidewise
against the sprockets of the wheel, thus avoiding any wear of the side bars of the
link A on the sides of the sprockets; and it will be understood that under the
conditions just explained the links arranged in vertical planes as, for instance,
the links B-will be free to turn or move articulately about one of each of the
cast-iron blocks pintle-like portions as illustrated by the dotted lines at Figure 2.
On the other hand, if the chain be carried around a chain-wheel having a vertical
axis, then the other horizontally arranged links (as, for instance, A) can turn in
either direction about the other one of each of the cast-iron blocks pintle-like
portions, as illustrated by the arrows at Figure 1.
To separate the block from the links of the chain it is only necessary to
manipulate the parts in a simple manner-as, for instance, is illustrated at
Figure 7 and 8, where one of the links is shown as having been moved out of
engagement with and away from the block, and the block then turned to a relative
position with the other link, in which it is plain to be seen, said block may be
moved away from said link. Of course, to re-engage the parts or re-arrange the
links and block in their working relative positions it is only necessary to reverse
the order of the just mentioned movements of the parts.
A great advantage is gained by the use of the separate bearing-blocks on the
score alone of thus providing a chain-cable with surfaces for engagement with a
chain-wheel which not only are of a better shape than any bearing-surface
which it is possible to get on the links of such a cable, but may be composed of a
material or quality of metal very much better adapted to stand the wear and
friction incident, to the action of the sprockets of the usual cast-iron chain-wheels
than any materal or metal of which chain cables either are made or can well be
manufactured.
It will be seen that not only is every part of the links of the cable protected
from wear and tear on the chain-wheels by the use of the malleable cast-iron blocks
in the manner shown, but that the wear and strain on the links are less than if
they engaged directly with each other at their enchained ends, (without the inter-
position of the pintle-like portions of the cast-inetal blocks,) mainly because of the
greater diameter of the said pintle-like portions; and secondarily, because of the
link coming into contact with the surface of a material, against which it will work
with less wear than against one similar in kind to itself.
The adjacent ends of the links are held, it will be seen, in a given relationship
laterally with each other and with the interposed block, so that there cannot
possibly occur to the cable (while under tension or in a working condition) any of
that twisting of the cable (or that oscillation of the links about an axial line
coincident with a line running lengthwise through the centre of the cable) which

page_text: is inevitable in chain cables in which the links are articulated one directly on the
other, as usual prior to this invention, and the chain with its block is necessarily
retained in a given and proper relationship with the peripheral devices of the
wheel on which it is run. This perfect avoidance of any such twisting of the
cable and retention of the working parts of the chain and wheel in proper relation-
ship enable the cable to be used with perfect success for all sorts of elevator and
conveyer purposes, since the chain is thus rendered capable of carrying and
maintaining always in perfect line and proper position any buckets, flights, or other
attachments which may be applied to it.
A chain cable made according to this invention may, for instance, have the
blocks formed or provided with carried attachments-such as seen at I Figures 4,
5 and 6-adapted to carry the flights of a conveyer, which may be required to
move all in a given position and with perfect regularity.
Of course, any and all sorts of attachments may be combined with the improved
cable either by direct connection in the blocks or with the links A or B, because in
neither case can any conveyor or elevator device applied to the cable become
disarranged relatively to anything with which it should maintain a given relationship
by any twisting action of the cable.
The precise form of block shown, as well as that of the links illustrated, may of
course be departed from without departing from the invention so long as the
blocks and links be made and combined so as to effect the essential results
explained, and, as already indicated, the cable may be adapted for and may be
used with a wheel having other engaging devices than the usual sprockets.
What I claim as new, and desire to secure by Letters Patent, is :-
First. In a chain cable, the combination, with the links of blocks interposed
between the adjacent end portions of the links, the said blocks being adapted to
afford bearing or working surfaces for the actions of the engaging devices of a chain
wheel substantially as set forth.
Second. In combination with the links of a chain cable, blocks interposed
between the adjacent ends of the links and provided with grooves which afford
pintle-like bearings for the said link ends, substantially as set forth.
Third. In combination with two enchained links, a block having grooves arranged
transversely to each other and operating to prevent any twisting movement of
said liuks relatively, substantially as set forth.
In witness whereof 1 the said Sydney Pitt have hereunto set my hand and
seal this fifteenth day of February in the year of our Lord One thousand
eight hundred and eighty three.