Year: 1886

page_text: Date of Application, 23rd Dec., 1886
Complete Left, 23rd Sept., 1887
Complete Accepted, 25th Oct., 1887
I, WILLIAM PUTNAM, of the Darlington Forge Company, Limited, of Darlington,
in the County of Durham, Engineer and Forge Master, do hereby declare the
nature of this invention to be as follows:-
It is well known that the cranks and crank shafts of certain classes of steam
engines are exposed to strains of an abnormal character, in addition to those arising
from the performance of their legitimate work. This is especially the case with
regard to marine and locomotive engines, and they arise, in great part from the
varying forces to which they are subjected, and the consequent distortion of the axial
lines of such engines.
The unequal wearing of brasses, heating and other causes, also tend to throw
additional work upon the crank or cranks employed. These strains accumulating at
the pin, as being farthest from the axial line of the main shaft, cause a bending or
flexure of the webs in opposite directions: at each extremity of the stroke: which
frequently lead to a break down.
My invention consists in building up one or both webs of a crank, of laminated
plates, so that strains (of the above nature) imposed upon the same, are met by far
greater elasticity than is possible with the ordinary system of making the said webs ;
with the further advantage, that should the strains upon the crank become excessive:
due warning is given by the buckling of one or more of the plates; and the necessary
precautions can be taken to avoid disaster.
The plates forming the web are mounted upon, and secured to, both shaft and pin,
in any known way; but I may bore the holes in the web taper, and form the ends of
the shaft and pin in a corresponding manner; and securely attach them together.
It will be evident that the cranks of other classes of engines than those named may
be constructed according to my invention; and also that this invention may be
applied to cranks or crank shafts already made, by making the necessary alterations.
It is further to be understood that I do not limit myself to the number or thickness
of the plates which comprise the web or webs employed, as these will necessarily vary
with the dimensions of the crank and the work to be performed; nor to the material,
Ι may use either iron or steel plates, or a combination of the same.
as
Datod this 2nd day of Dasambar 1996
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Construction of Cranks and Crank Shafts.
I WILLIAM PUTNAM of the Darlington Forge Company, Limited, of Darlington
in the County of Durham, Engineer and Forge Master, 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 :-
It is well known that the cranks and crank shafts of certain classes of steam engines
are exposed to strains of an abnormal character in addition to those arising from the
performance of their legitimate work.
This is especially the case with regard to marine and locomotive engines, and they
arise, in great part from the varying forces to which they are subjected and the
consequent distortion of the axial lines of such engines.
The unequal wearing of brassos, heating, and other causes, also tend to throw
additional work upon the crank or cranks employed. These strains accumulating at
the pin, as being farthest from the axial line of the main shaft, causo a bending or
flexure of the webs in opposite directions at each extremity of the stroke: which
frequently lead to a breakdown.
:
My Invention consists in building up one or both webs of a crank of laminated
plates so that strains (of the above nature), imposed upon the same are met by far
greater elasticity than is possible with the ordinary systein of making the said webs;
with the further advantage that should the strains upon the crank become excessive,
due warning is given by the buckling of one or more of the plates; and the necessary
precautions can be taken to avoid disaster.
The plates forming the web are mounted upon, and secured to both shaft and pin,
in any known way but I may bore the holes in the web tapor, and form the
ends of the shaft and pin in a corresponding manner; and securely attach them
together.
It will be evident that the cranks of other classes of engines than those named
may be constructed according to my invention, and also that this invention may be
applied to cranks or crank shafts already made by making the necessary alterations.
It is further to be understood that I do not limit myself to the number or thickness
of the plates which comprise the web or webs employed, as these will necessarily vary
with the dimensions of the crank and the work to be performed; nor to the material,
as I may use either iron or steel plates, or a combination of the same; or any other
suitable metal or alloy. The plates need not be all of the same thickness.
Fig. 1 is an elevation, with one web in section, and Fig. 2 an end view of the
web. The web, made up of laminated plates, is indicated by a, the crank pin b, and
the shaft by c.

page_text: 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. A crank or crank shaft constructed substantially in the manner and for the
purpose described and illustrated.
2. A web or webs built up of plates substantially in the manner and for the
purpose specified.
3. A flexible crank or crank shaft comprising a crank pin, a shaft or shafts, and a
web or webs, the said parts being securely or rigidly attached to each other;
substantially as described.
;
4. A crank web constructed of two or more layers or plates, combined with a shaft
and pin the said web being adapted to buckle or bend when the strain becomes
excessive; substantially as described.
FAIRFAX & WETTER,
433, Strand, London,
Agents for the Applicant.