Improvements in the Construction of Crankshafts.
Year: 1888

page_text: Date of Application, 21st Sept., 1888
Complete Specification Left, 18th June, 1889-Accepted, 24th Aug., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Construction of Crankshafts.
I, HENRY FOSTER of 92 Dilston Road, Newcastle-upon-Tyne in the County of the
same City, Engineer, do hereby declare the nature of this invention to be as
follows:-
In the construction of crankshafts according to this invention, I form the crank
pin together with its two crank arms in one piece of forged or cast steel, or other
suitable metal, as described in my previous specification, No. 941 of 1884; but in
order to obviate the use of keys for securing the crank arms to the body part of the
shaft, I form the ends of the shafts where they enter the crank arms partly concentric
and partly eccentric to the axis of the shaft of which they form a part.
I then bore the holes through the crank arms to correspond exactly with the ends
of the shafts so formed, and after heating the crank arms to a suitable temperature, I
shrink them on to the ends of the lengths of shaft forming the body of the crankshaft,
which, by virtue of their being made partly concentric, and partly eccentric to the
axis of the shaft where they enter the crank-arms; securely lock themselves against
turning, and render the use of keys for securing the crank arms to the body of the
shaft unnecessary.
The object of this Invention is to provide crank shafts so constructed, that the said
crankshafts may be more quickly manufactured, and at the same time be cheaper, and
more durable than those heretofore in use, and also to provide a means by which
crankshafts which have been fractured at the crank pin, or crank arms, can be
repaired and made in overy way suited for further use.
Dated thin 20th do
f Cantamban 1000
COMPLETE SPECIFICATION.
Improvements in the Construction of Crankshafts.
1, HENRY FOSTER, of 92 Dilston Road, Newcastle-upon-Tyne, in the County of the
same City, Engineer, 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 :—
In the Construction of Crank-shafts according to this invention, I form the Crank-
pin together with its two crank-arins in one piece of forged, or cast steel, or other
suitable metal, as described in my previous specification No. 941 of 1884; but in
order to obviate the use of keys for securing the Crank-arms to the body part of the
shaft, 1 form the ends of the shafts where they enter the Crank-arms, partly
concentric, and partly eccentric to the axis of the shaft of which they form a part.
1 then bore the holes through the Crank-arms to correspond exactly with the ends
of the shafts so formed, and after heating the Crank-arms to a suitable temperature, I
shrink them on to the ends of the lengths of shaft forining the body of the crankshaft,
which, by virtue of their being made partly concentric, and partly eccentric to the
axis of the shaft where they enter the crank-arms; securely lock themselves against
turning and render the use of keys for securing the crank-arms to the body of the
shaft unnecessary.
The object of this invention is to provide crankshafts so constructed, that the said
crank-shafts may be more quickly manufactured, and at the same time be cheaper and
more durable than those heretofore in use, and also to provide a means by which
crankshafts which have been fractured at the crank-pin or crank-arms, can be repaired
and made in every way suited for further use.

page_text: Having now explained the nature of my invention for "Improvements in the
construction of Crankshafts," I will now proceed to particularly describe in what
manner the same is to be carried into effect by the aid of the following drawings.
Fig. 1. shows a crankshaft constructed according to this invention, with the crank-
pin, A, together with the crank-arms, B, B, made in one piece, and having the
ends, D. E. of the shafts, C. C. at their junction with the crank-arms, made partly
concentric, and partly eccentric to the axis of the shaft C. C, of which they form a
part.
In the drawing the ends of the shafts C. C. at their junction with the Crank-
arms B. B. are shown concentric to the axis of the shaft CC for a portion of their
length at E. E. and eccentric to the axis of the shaft for the remaining portion of
their length D. D.,
The holes through the Crank-arms B. B. having been bored to correspond exactly
with the ends of the shafts at D. E. so formed; the Crank-arms B. B. are heated to a
suitable temperature, and contracted on to the ends D. E. of the lengths of shaft C. C.
forming the body of the Crankshaft, which by virtue of their being made partly
concentric, and partly eccentric to the axis of the shaft C. C, securely lock themselves
against turning and render the use of keys for securing the crank-arms to the body
of the shaft unnecessary.
Fig. 2. shows a crankshaft fractured at d, d; the arms and pin shown in dotted
lines having been cut away, and the ends D. E. of the shafts C. C. formed partly
concentric and partly eccentric to the axis of the shaft CC; the portions shown by
the dotted lines are replaced by another crank-pin, A, together with its two crank-
arms B. B. made in one piece, and having holes bored through them to correspond
with the ends of the shafts D. E. These crank-arms are then heated to a suitable
temperature, and contracted on to the ends of the lengths of shaft C. C. as previously
explained in the manufacture of new Crankshafts.
Fig. 3 shows a crankshaft similar to Fig. 2 after having been repaired and made
in every way suited for further use.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1st. The construction of crankshafts having the crank-pin, A, and Crank-arms B. B.
made in one piece; in combination with the ends of the shafts D. E. where they enter
the crank-arms B, B, made partly concentric, and partly eccentric to the axis of the
shaft C. C of which they form a part, substantially as herein set forth.
2nd. Repairing Crankshafts which have been overstrained or broken at the Crank-
arms, or crank-pin, by cutting off portions of the Crank-arms, and substituting other
Crank-pins together with their respective crank-arms made in one piece, and con-
tracting them on to the ends of the lengths of shaft, made partly concentric, and partly
eccentric to the axis of the shaft of which they form a part, substantially as herein
before set forth. .
Dated this 17th day of Tune 1000