IMPROVEMENTS IN THE CONSTRUCTION OF CHAIN PULLEYS
Year: 1871

page_text: LETTERS PATENT to James Henderson, of Leith, in the County of
Mid Lothian, North Britain, Engineer, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF CHAIN PULLEYS."
Sealed the 8th August 1871, and dated the 16th February 1871.
Office of the Commissioners of Patents, with his Petition, on the
16th February 1871.
I, JAMES HENDERSON, of Leith, in the County of Mid Lothian, North
Britain, Engineer, do hereby declare the nature of the said Invention for
“IMPROVEMENTS IN THE CONSTRUCTION OF CHAIN PULLEYS,” to be as follows,
that is to say :—
PROVISIONAL SPECIFICATION left by the said James Henderson at the
Office of the Commissioners of Patents, with his Petition, on the
16th February 1871.
I, JAMES HENDERSON, of Leith, in the County of Mid Lothian, North
Britain, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF CHAIN PULLEYS," to be as follows,
that is to say :—
This said Invention has reference to a new or improved mode and means
of giving greater holding or acting and bearing surface to the regular or

page_text: "pitched" indented and projecting parts of the receiving grooves o
perimeters of chain wheels, pulleys, barrels, drums, or cylinders, fo
their chains to act and rest on when used in the direct transmission o
motion, force, or power, as for pulley blocks, cranes, winches, wind
lasses, capstans, and other purposes, or otherwise, in the conducting o
motion and power, through transmitting or "messenger" chains and
pulleys, for such and other purposes, for all which such chains and
their indented wheels and perimeters are used either in the transmission
of power and motion from the former to the latter or the latter to the
former, and further for the ordinary constructions of chains in which the
links are linked through each other successively at right angles, so that
the alternate links lie with their flat sides and the others with their edges
on the perimeter of their grooves or recesses, and are generally by
preference formed of round sectional metal with semicircular ends,
although they may be made of other sections of metal and other forms
of links, and which said new or improved greater holding surface gives
the advantage of more steady action of the power and motion trans-
mitted and stronger and longer wearing power or durability of the acting
parts of both the chains and holding grooves of their wheels, and this
said new holding surface is considered by the Inventor to be equal to
about one-half of that obtained by the best forms of such holding surfaces
or recesses heretofore used, and may either be used by itself or in com-
bination with the ordinary holding surfaces, in which case it would add
nearly one half more effectual holding power thereto.
.
The nature of this said Invention or new or improved extra holding
surfaces substantially consists in forming regular or "pitched" recesses
and projections or teeth round the bearing and holding grooves, peri-
pheries, or perimeters of.the.said and such chain wheels or pulleys- or
"pitched" chain wheels..or pulleys, to fit. or suit and receive the edge
central links alternately disposed between, and, by preference, in addition
to the ordinary horizontally disposed links and their recesses and pro-
jections, and thus produce or form new "pitched" holding projections or
teeth standing up in the middle of and between the ends of the said
central vertical edge links from what is usually made, only a mere plain
groove to receive and guide the said row of alternate vertical links of the
chains on to their grooves and wheels, which projections acting on the
lower ends and edges of these said vertical links substantially form or

page_text: give the said new or extra holding surface, the tops of which projections
may be carried up to or past the centre of the links in the form of.
holding teeth or cogs when desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Henderson in the Great Seal Patent Office
on the 14th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
HENDERSON, of Leith, in the County of Mid Lothian, North Britain,
Engineer, send greeting.
-
WHEREAS Her most. Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of February, in the year.
of our Lord One thousand eight hundred and seventy-one, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs, and successors,
give and grant unto me, the said James Henderson, Her special licence
that I, the said James Henderson, my executors, administrators, and
assigns, or such others as I, the said James Henderson, my executors,
administrators, and 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
THE CONSTRUCTION OF CHAIN PULLEYS," upon the condition (amongst others)
that I, the said James Henderson, my executors or administrators,
by an instrument in writing under my, or their, or one of their hands
and seals, 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 James Henderson, 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 in writing, reference being had to the accompanying

page_text: Drawings, and to the letters and figures marked thereon, that is
to say :-
My said Invention has reference to a new or improved mođe and
means of giving greater holding or acting and bearing surface to the
regular or "pitched" indented and projecting parts of the receiving
grooves or perimeter of chain wheels, pulleys, barrels, drums, or cylinders,
for their chains to act and rest on when used in the direct transmission
of motion, force, or power, as for pulley blocks, cranes, winches, wind-
lasses, capstans, and other purposes, or otherwise, and the conducting of
motion and power through transmitting or messenger chains and pulleys
for such and other purposes, for all which such chains and their indented
wheels and perimeters are used, either in the transmission of power and
motion from the former to the latter, or the latter to the former, on land
or on ship board; and in all cases where the ordinary constructions of
chains are used with their links connected to or linked through each
other transversely and successively at right angles, so that the alternate
links lie with their flat sides, and the intermediate or other links lie with
their edges on their respective and corresponding grooves or recesses
formed in the perimeter of the particular chain wheel, pulley, drum, or
barrel on which the said chains work, and which are generally by
preference formed of round sectional iron or other metal with semi-
circular ends, although they may be made of other sectional forms of
metal, and of various forms and sizes of links, and which said new or
improved greater holding-surface thus given to the acting perimeter and
chain gives the advantages of more steady action of the power and
motion transmitted, with a consequently stronger and longer wearing
power or durability of the said acting parts, both of the said chains and
holding grooves, and this new. holding surface I consider would be
equal to about one-half of that obtained by the best forms of such
holding surfaces or recesses heretofore in use, and it may either be used
by itself or in combination with the ordinary holding surfaces, in which
latter case it would add nearly one-half more effective holding surface
thereto.
The nature of this my said Invention or the new or improved extra
holding surface substantially consists in forming regular or pitched
recesses and projections or teeth round the bearing and holding grooves,
novinhomies or perimeters of the said and such chain wheels or pulleys or

page_text: pitched chain wheels or pulleys, drums, or barrels, to fit or suit and
receive the edge central vertical links alternately disposed between, and
by preference in addition to the ordinary horizontally disposed links and
their recesses and projections, and thus produce or form a half more new
"pitched" holding projections or teeth standing up in the middle of
and between the ends of the said central vertical edge links, from what
is usually made only a mere plain groove to receive and guide the said
row of alternate vertical links of the chains on to their grooves and
wheels; these new projections acting on the lower ends and edges of
these said vertical links substantially form or give the said new or extra
holding surface, and the tops of which projections may be carried up to
or past the centre of the links in the form of holding teeth or cogs when
desired.
Having thus described the nature of my said Invention, I will
proceed to describe the manner of performing the same by describing
the several Figures on the Sheet of Drawings which I have hereunto
appended for the purpose of showing the best modes and means I am at
present aware of for so carrying out my said Invention into effect or
practice, the same reference letters indicating the same or like parts in
all the Figures.
---
Figure 1 is a sectional elevation taken on the line 1- 1 in Figure 3,
and Figure 2 is a plan corresponding to Figure 1, while Figures 3, 4,
and 5, are transverse sections taken on the lines 2---2, 3- - - 3, and
4---4, respectively in Figure 1, all of a part of the rim of an ordinary
simple form of "pitch" or griping chain pulley or wheel, such as used
on the first motion or actuating shaft or spindle of travelling and other
cranes, crabs, and winches, and of hoists of various kinds, and of pulley
blocks for actuating these by their chains, having the "pitched" or
regular sized links set at right angles to each other, and by motive or
manual power (according as the chains are so primarily actuated), all
sufficient to show my new or improved holding recesses and projections
for receiving and catching the central edge link applied to or formed on
such chain, pulleys, or wheels, and marked and indicated in the several
Figures by the letters A, A³, respectively.
Figures 6, 7, 8, 9, and 10, are a similar sectional elevation, plan,
and three transverse sections to that shown in Figures 1 to 5, all
respectively and of a like chain wheel or pulley, illustrating a slightly

page_text: different modification of my improvements or Invention, in which the
new acting teeth are made longer, and marked or indicated by A³ in
these Figures.
Figure 11 is an edge elevation, and Figure 12 is a sectional elevation
taken on the line 1. 1, in and at right angles to Figure 11, of a
differential two grooved chain wheel or pulley complete for hoisting chain
blocks or other purposes, with the chain shown in red lines passed over
one of the pulley rims, constructed in accordance with the modification
of the improvements shown in Figures 6 to 10, and sufficient to
show the manner of applying and performing my said Invention or
improvements.
Figures 13, 14, 15, 16, and 17, show sectional elevations of a part of
the ordinary and four other forms and constructions of chains (as a, b,)
having their alternate links (as 6) horizontal or parallel, and their
intermediate links (as a) jointed or linked into the others vertically or
at right angles respectively to the axis of the wheel or pulley as they
pass over the holding recesses and projections of its perimeter, being
sufficient to show the character or various forms and constructions of
chains my said improvements are applicable for, whatever may be the
section of the iron or form of links, so long as they are linked at right
angles into each other.
Referring to the modification of my said Invention and improvements
shown in Figures 1 to 10, it will be seen that the chain a, b, here shown,
is of an ordinary construction, formed of a round section of malleable
iron, with oblong semicircular ended links (as also shown in the detached
view Figure 13) the alternate links marked a thereof, which in passing
over the pulley always lie at right angles to its axis and to their inter-
mediate links b, I term the vertical links, and the others or intermediate
links marked b, which while the chain is passing over the pulley, always
lie parallel to its axis, and at right angles to the links a, I term the
horizontal links. And it will be seen that the horizontal links b
pass in
the usual manner into and round the ordinary receiving recesses B, and
holding projections B¹ "pitched " and formed all round the outer
perimeter or groove C, as the outer working and griping surface of these
and such like chains and chain pulleys or wheels D, as heretofore
constructed.

page_text: The new or improved griping surface forming the novelty of my said
Invention is formed and effected by making "pitched" recesses A (in
the lower and central part of the said ordinary griping groove B, B¹, C,
at the proper. intervals all round between the projections B¹) to receive
and hold the alternate vertical links a of the chain (on edge) with
projections A¹ between them, which catch and hold the ends of these
links a (at their ends) when the chain a, b, is pulled or the pulley D is
turned in either direction (all instead of merely having a plain annular
groove for guiding the links a, as heretofore). These new projections A¹
in the application shown in Figures 1 to 5, only extend up to the level
or plane of the ordinary recesses B; but in Figures 6 to 10 they project
somewhat higher in the form of central cogs or teeth marked A³, so as to
pass up the centre of each horizontal link b, and catch or bear against
the two adjacent ends of the vertical links a quite up to their centre,
as thus, as stated, act in either direction, sufficient play being left in
the length of the chambers or recesses A to allow the links a to enter
freely and bear on the bottom, so that the whole of the links of the
chain sustain the strain and wearing effect in passing over the pulley.
And it will be seen that the new recesses and projections A, A³, or A, A³,
add nearly a half more acting or traction and wearing surface to these
and such like chains and chain pulleys so constructed over those as
heretofore constructed.
The complete chain pulley D, D¹, shown detached in Figures 11
and 12, has the projecting teeth A³ shown and described in reference
to Figures 6 to 10, and will illustrate and show their application to and
round the whole working perimeter of the chain pulley or wheel, and
the entering and passing off of the chain therefrom at a tangent, so that
the projections A³ roll or glide easily in and out of the spaces between
the links a and the centre of the links b, and with the least possible
friction.
It will be obvious that although the most common construction of
chain has been shown in the several applications of my said improve-
ments described, that other sections and forms or constructions of links
and chains may be used so long as they have intermediate vertical links
(as a), and the lower or inner half of these are made to enter recesses
formed for them in the centre of the holding groove or perimeter O of the
chain pulley or wheel D, so as thus to carry out my said improvements.

page_text: At Figures 14 to 17 is shown a few of the many other obvious forms
of chains with their links at right angles to which my said improvements
can be applied to suit, having semicircular, segmental, angular, and
square ends, and made with square or other sections of iron.
Although these new or improved holding recesses and projections
A, A', and A' have been shown and described as used in combination
with and as giving an additional holding surface and effect to the
ordinary recesses B and projections B³, yet still it is to be understood
that they may also be used without the latter when desired (in the same
manner as these have been used heretofore without the new ones) by
having a plain annular groove only for the horizontal links 6 to rest on
and pass over, although this might not give quite so much holding
surface as that attained by the ordinary mode of holding the links b
heretofore.
Although the new or improved holding chambers or recesses A and
projections A¹ and A² have only been shown and described in reference
to single and double annular chain griping grooved pulleys or wheels
D and D¹, yet still it is to be understood that any desired number of
these griping grooves C, C¹, with the new holding surfaces A, A¹, or
A, A', may be formed side by side round the same chain pulley, wheel, 2
drum or barrel made of a plain cylindrical form, or of a differential or
conoidal form, and having the said new holding recessed chain grooves
(as C, C',) either formed annularly or helically round their circumference
or perimeter, either for transmitting motion and power by the chains to
these or from them to the chains, all otherwise (than as I have herein 2
specially distinguished and described) substantially in the same manner
and for the same purposes that the ordinary chain holding grooves have
been applied.
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that what 3
I claim is, the forming of new or improved "pitched" recesses and
projecting parts or holding surfaces A, A', and A', in and on the lower
central part of annularly or helically formed grooves C round chain
wheels, pulleys, drums, or barrels for receiving and holding the vertical
or edge links a, of chains having their connecting links at right angles 3
to the others, and for transmitting motion and power through these for
the various purposes they are used on land or on board of ship by

page_text: manual or motive power, all substantially as herein described and shown
in the accompanying Drawings.
In witness whereof, I, the said James Henderson, have hereunto
set my hand and seal, this Tenth day of August, in the year of
our Lord One thousand eight hundred and seventy-one.
Witness,
GEO. G. THOMSON,
Agent,
20, Buchanan Street,
Glasgow.
JAS. HENDERSON.
(L.S.)