Hoops for Locomotive and other Cranks.
Year: 1886

page_text: Hoops for Locomotive and other Cranks.
I WILLIAM DANIEL ALLEN, of the Bessemer Steel Works, Sheffield, in the
County of York, Steel Manufacturer, do hereby declare the nature of this invention
to be as follows:-
Hoops to be shrunk upon the webs of locomotive and other cranks for affording
additional strength and security have heretofore usually been made by bending a
bar of iron into a hoop having an internal form and dimensions approximating to
the external shape and size of the crank web for which the hoop has been designed
welding the two ends of the said bar together and afterwards slotting or tooling
the internal part of the hoop when necessary to make it fit the crank web.
Now my invention has for object to produce hoops for the purpose mentioned of
greater strength and with less labour than by the method above described for
which purpose according to my invention the hoop is made weldless by forging or
rolling after the manner practised in making steel railway wheel tyres, and is
subsequently by blocking, hammering stretching or stamping brought internally to
a shape corresponding to the external form of the web on which it is to fit so that
sufficient accuracy may be attained without slotting or tooling. A suitable metal
for the manufacture of hoops according to my invention for the purpose mentioned
is steel of a mild and ductile nature.

page_text: Hoops for Locomotive and other Cranks.
I, WILLIAM DANIEL ALLEN, of the Bessemer Steel Works, Sheffield, in the
County of York, Steel Manufacturer, do hereby declare the nature of this invention,
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Hoops to be shrunk upon the webs of locomotive and other cranks for affording
additional strength and security have heretofore usually been made by bending a
bar of iron into a hoop having an internal form and dimensions approximating to
the external shape and size of the crank web for which the hoop has been designed,
welding the two ends of the said bar together, and afterwards slotting or tooling
the internal part of the hoop when necessary to make it fit the crank web.
Now my invention has for object to produce hoops for the purpose mentioned of
greater strength and with less labour than by the method above described for
which purpose according to my invention the hoop is made weldless by forging or
rolling after the manner practised in making steel railway wheel tyres, and is
subsequently by blocking hammering stretching or stamping brought internally to
a shape corresponding to the external form of the web on which it is to fit so that
sufficient accuracy may be attained without slotting or tooling.
A suitable metal for the manufacture of hoops according to my invention for the
purpose mentioned is steel of a mild and ductile nature.
In carrying out this invention a hoop or ring is forged or rolled without a join
or weld to the intended section of the strengthening hoop, and it may be forged or
rolled, of a diameter that will allow of such amount of subsequent stretching in the
blocking process as may be deemed desirable. Then the said hoop or ring is
shaped either in a heated, or in a cool state, to fit the web of the crank for which
it is designed, by blocking, hammering, stretching or stamping, and the following
arrangement of apparatus, will be found efficient for the purpose.
Fig. 1 is a side elevation. Fig. 2 a plan, and Fig. 3, an end view of the
machine.
a is a hydraulic cylinder, b a ram working into the same, c c are projections or
bosses cast on the top of the cylinder, and on the top of the head of the ram, d d
are blocks, or stretchers that can be placed upon the projections, or bosses c, the
blocks or stretchers being therefore changeable, so that various sizes and forms, of
blocks or stretchers can be used on the same machine. e. e. are two screws,
passing through lugs cast on each side of the cylinder, and also passing through
lugs cast on each side of the head of the ram; these screws act as guides, and

page_text: is a
keep the cylinder and ram correctly in their relative positions, g g are nuts
whereby the extent of the traverse of the ram is regulated and defined.
screw used for forcing the ram back into the cylinder after each operation.
Enlarged views of a set of blocks or stretchers are given in Figs. 4 and 5. When
close together or nearly so these blocks admit of the rolled or forged hoops passing
over or around them, and when thrust asunder a given distance they assume the
form and size of the exterior of the web of the crank for which the hoops are
designed. On each side of the blocks or stretchers slides or loose sliding pieces
(shewn in dotted lines in Fig. 4) may be used so that as the blocks or stretchers
separate, the slides or loose sliding pieces cover the intervening space and maintain
the contour of the form entire.
In operating with such a machine, the blocks or stretchers are placed upon the
bosses c and the ram is forced into the cylinder by means of the screw h, until the
blocks are sufficiently close together to allow of the rolled or forged hoop or ring
passing over them; water under pressure is then admitted into the cylinder by the
pipe x, by which the ram is forced out until stopped by the nuts g. g.
The mechanical arrangement with hydraulic power as above described is found
to be simple and efficient, but it will be obvious that any suitable means for
forcing the blocks or stretchers apart may be used, and it will also be obvious that
the form, size, general arrangement, and construction of the blocks or stretchers
themselves, may be changed to suit the various forms of hoops required.
Figs. 6 and 7 shew an arrangement of block by the use of which the blocking or
stretching can be done by manual labor when it is found inconvenient to obtain or
to apply mechanical power although I do not consider this method so efficacious as
that previously described. The parallel part d' of the block is of the contour of
the crank web the rolled or forged hoop to be operated upon is whilst at a bright
heat roughly flattened into an elliptical form and whilst still hot and in the
expanded condition is at once placed on to the taper part of the block and driven
down on to the parallel part thereof; it may then be fullered or hammered round
where necessary in order to bring it as near to the form and size of the block as
practicable. In cooling it will contract tightly round the block and assume more
correctly its form. When cold it can be driven off by a tup or other means.
block is kept cool by a stream of water flowing into the recess k in the centre of it.
When the hoops are required to be more correct to form, and size, than those
made on the blocking and stretching system they can be stamped in suitable dies
of which a set is shewn in Figs. 8 and 9. m is the bottom part of the die having
in it a recess corresponding to an impression of one half of the exterior form of the
hoop to be produced; n is the top part of the die it is recessed in like manner, and
has a hole through it to permit of its passing over a centre block o. The lower
part of this block is shaped correctly to the form, and size of the crank web whilst
the upper part is slightly tapered.
The
In operating, the block is placed in the centre of the recess in the bottom part of
the die; the hoop to be operated on which should be red hot and bent roughly to
the elliptical form, is placed over the taper end of the block, the top part of the die
is then placed upon the hoop and forced down by any suitable means, such as by
blows from a steam hammer, or pressure from a hydraulic press, until the top and
bottom parts of the die meet; thus the hoop is driven down, fattened, and pressed
tightly around the block, and is made to correctly take (internally) the external
form and size of the block; whilst the exterior of the hoop is shaped in the
recesses of the die. Hoops intended to be stamped in dies, should be made some-
what wider when in the rolled or forged state, than they are required to be
when finished, and should be reduced to the required width in the stamping
operation. The form, size, and construction of the dies may be varied to suit the
various forms and sizes of hoops required. The dies will be found to stand best
when made of mild steel,

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what
I claim is
The manufacture of strengthening or safety hoops for locomotive and other
cranks made without a weld or join by forging or rolling weldless hoops or rings
and blocking hammering stretching or stamping them to fit the webs of the cranks
substantially in the manner herein set forth and described.
}