IMPROVEMENTS IN THE CONSTRUCTION OF PULLEYS OR DRUMS
Year: 1885

page_text: "
I ARTHUR BRAMHAM PERKINS of The Forge Thornton Road, Bradford in the
County of York, Ironmaster, do hereby declare the nature of my invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF PULLEYS OR DRUMS and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
My invention relates to improvements in that class of pulleys or drums in which
the boss is made of cast or wrought iron, and the spokes are attached thereto by
rivets or bolts.
To carry out my invention I make the boss of the pulley or drum with two
similar flanges connected by a neck and bored out to the required size to receive
the shaft. A series of rectangular recesses are formed in the outer sides of the
flanges of the boss and radially round the outer edge of each flange; the said
recesses are for the purpose of receiving the ends of the spokes which when placed
in the recesses are held in position by rivets or bolts passing through the flange.
The spokes are made by preference of D sectioued iron which is cut off into the
required lengths, and one or more hole or holes is or are punched or drilled near
each end, through which hole the bolt or rivet is afterwards passed for the purpose
of securing the spokes to the boss; near the centre of the cut off length one or
more hole or holes is or are formed through which the rivets are passed for securing
the rim to the spokes.
The length of iron having holes formed therein as described is then held by the
centre in a vice or bending machine and the two ends are bent at right angles (or
nearly so) to the short centre portion of the bar so as to give the spoke the form of
the letter U. The two ends of the bar are placed in the recesses in each side of
the boss hereinbefore described, and are secured therein by rivets or bolts which
pass through the holes made for that purpose near the ends of the bar and through
each flange of the boss. The narrow central portion of the bar which connects the
two limbs of the U is secured to the rim of the pulley or drum by rivets passed
through the two holes hereinbefore referred to.
Any required number of such spokes can be used in the construction of a pulley
or drum, provision being made for securing the ends of the spokes by forming the
necessary number of rectangular recesses arranged radially around the outer side
of the flanges of the boss as described.

page_text: When the arms or spokes have been rivetted. to the boss the framework thus
formed is supported upon cones fitted upon a mandril, which cones when caused to
approach one another by nuts screwed upon the mandril hold the boss in such a
manner that the framework can be caused to revolve truly. The framework is
then turned round slowly so that each of the outer portions of the spokes
alternately come in contact with an emery wheel or grindstone, whereby the outer
circumference of the spokes is finished truly to the required size, and distance from
the centre. For convex rimmed pulleys or drums a radial motion is given to the
framework during the operation of grinding, in a direction across the curved ends
of the spokes upon which the rim is to be fitted by which radial motion the required
are shaped form is given to the outer ends of the spokes or arms to allow them to
fit inside the curved rim.
When the spokes have been secured to the boss, and the rim has been rivetted
to the spokes, the superfluous projecting portion of the rivets is dressed off level
with the surface of the rim of the pulley or drum by means of an emery wheel or
grindstone against which the pulley or drum is pressed, and traversed in a line
exactly corresponding with the curved surface of the pulley or drum when finished.
During this grinding operation the pulley is firmly supported by a mandril upon
which are placed two cones the apices of which enter the hole in the boss and which
cones are adjusted by nuts working upon the mandril.
When it is required to construct the pulley or drum in halves, lugs are cast upon
the neck of the boss which connects the two flanges, and one or more bolts which
pass through these two lugs hold together the two halves of the boss and the two
halves of the rim are held together by plates and bolts in the usual manner.
I apply the construction of the spokes and boss herein described to pulleys or
drums of the formed referred to in the specification of Letters Patent granted to
Henry Simon and myself and dated the 6th day of February 1884 and numbered
2853; and also to the grooved pulleys for rope driving described in the specification
of Letters Patent granted to me, and dated the sixteenth day of February 1884
and numbered 3443.
By the method of construction herein described I am enabled to produce stronger
pulleys and drums (with the same weight of material) than those constructed with
round spokes; as the greatest strength of the material lies in the same direction as
the working strain; and I am also enabled to make and fix the spokes more
accurately than by the method hitherto in use, consisting in heating the boss and,
while hot, putting in the spokes, after which they require to be set and adjusted.
The hold of the spokes upon the rim is firmer, and better distributed than heretofore,
as each spoke has two points of attachment to the rim instead of one.
The whole process of construction is cheaper and simpler and the pulleys or
drums firmer and stronger than those hitherto in use.
In order to enable my improvements to be fully understood, I will proceed to
describe the same by reference to the accompanying drawings in which, Figure 1
represents a side elevation of a pulley or drum constructed according to my
improved method; figure 2 is a sectional elevation of the same; figure 3 is an
elevation of the boss of the same shewing the recesses for the reception of the ends
of the spokes, and the method of bolting together, the two halves of the boss;
figure 4 is a sectional elevation of the boss of the same; figure 5 represents a
length of D sectioned bar, with holes near the end and near the centre for the
purpose described; figure 6 represents a cross section of the bar; figure 7 represents
the form into which the lengths of bar are bent preparatory to being secured to the
boss. Similar letters in each figure of the drawing refer to similar parts. The
boss of the pulley or drum is represented at A, and the shaft at B. Each of the
arms or spokes C is fitted into recesses formed in the outer side of the flanges of
the boss and is secured in position by rivets or bolts.
The rim D is attached to the spokes by rivets F; in figure 5 a bar of iron is
shewn cut off to the required length and a hole H is shewn formed near each end,
for the purpose of receiving the rivets to secure the spokes to the boss; one or

page_text: more holes J, are formed near the centre, for the purpose of receiving the rivets to
secure the spokes to the rim; the bar is then bent into the form shewn at figure 7,
when it is ready to be fixed to the boss and to the rim in the manner described.
Gare the bolts for securing together the two parts of a pulley or drum formed
in halves of my improved construction.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. The construction of pulleys or drums with bosses recessed as described for the
reception of the ends of the spokes, such recesses being formed for the firmer
holding of the spokes in the manner described.
2. The construction of the spokes of pulleys and drums in the manner described
and the method of attaching such spokes to the boss and to the rim substantially
as set forth.
3. The combination of the spokes boss and rim in the construction of pulleys or
drums all substantially as described and represented in the accompanying drawings
or any mere modification thereof.
4. The combination of the boss and spokes herein described and represented
with a rim of a double pulley or drum made according to the specification of letters
patent granted to Henry Simon and myself dated the sixth day of February 1884
and numbered 2853.
5. The combination of the boss and spokes herein described and represented
with rims of rope driving pulleys made according to the specification of letters
patent granted to me dated the sixteenth day of February 1884 and numbered
3443.
1