A GESELLSCHAFT QUALI NIE DIEUITTUATION Improvements in Crank Shafts.
Year: 1898

page_text: Date of Application, 9th Nov., 1898-Accepted, 17th Dec., 1898
A
communication
GESELLSCHAFT
QUALI NIE DIEUITTUATION
Improvements in Crank Shafts.
by THE GESELLSCHAFT FÜR
MIT
AUTOMOBILWAGENBAU,
BESCHRÄNKTER HAFTUNG, of Nuremberg, in the
Empire of Germany, Manufacturers.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, G, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, 118, New Street, Birmingham, in the County of War-
wick, and 322, High Holborn, in the County of Middlesex, Civil 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 motors having a great number of revolutions of the main shaft, it is advan-
tageous to give the crank pins a hardened wearing-surface in order to reduce the
wear of the same to the smallest extent. As the said shaft as a
rule is pro-
vided with bends at right angles it is obvious in order to allow of the pressure
exerted on the crank pins being distributed on two journals (a and b) in such a
way as to favourably load the shaft, that the hardening of the pins can only be
undertaken with considerable difficulty on account of the possibility of warping
the shafts and thereby altering the axial position of the shaft ends or journals.
This invention which is shown in vertical section in Figure 1 of the accom-
panying drawings, has for its object to remove this drawback and to form such a
shaft of separate parts in such a manner as to obtain a completely solid connection
between the hardened crank pins 1 and the two sections 2 and 3 of the shaft, which
must lie axially to one another and parallel with the pin 1. The pin 1 is prefer-
ably formed in one piece with the arm 5 and when turned down is hardened and
ground along the full extent of its wearing surface. The tapered end e is then
fitted in the other part of the crank which has remained soft and which is bored
exactly parallel to the crank pin and the connection between the section of the
shaft 2 and the arm 5 is effected by means of wedges and screws. The cast iron
flywheel 4 is employed as means of connection between the pin 1 and the section 3
of the shaft.
The main difficulty consists in keying the wheel sufficiently firmly on the taper-
ing end e of the pin 1. In rapid running machines, more particularly in four-
stroke explosion motors the direct attachment in the cast iron body is never
sufficient. The pin, even where a wedge and screwing are both employed, soon
becomes loose so that by mutual warping of the sections 2 and 3 of the shaft, the
machine may come to a standstill. In order to remove this drawback the con-
nection with the flywheel takes place according to the present invention in the
following manner: —
A steel bush 6 is let into the body of the wheel at the point of attachment and is
firmly keyed thereto. This bush is very suitable by reason of its somewhat con-
siderable diameter for receiving the high pressure or strain without damage to the

page_text: fastening, and to convey the same to the boring in the much softer cast iron and it
is also itself owing to its greater hardness better suited to render possible a secure
holding of the end of the pin e in its tapering bore. The advantage which thus
arises out of the use of the above mentioned inserted bush and the previously
described connection of the hardened crank pin with the section 2 of the shaft
consists in that it is possible to make a crank shaft bent at right angles with a
hardened crank-pin between the bend in simultaneous combination with a cast
flywheel in several parts as a solid whole.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondents, I declare that what I claim is:-
1. In the formation of a crank shaft in several parts, a hardened crank pin (1)
on an arm (5) being connected by means of this arm with one section (2) of the
shaft and then by its tapering end (e) being let into the flywheel (4) of the other
section (3) of the shaft, substantially as hereinbefore set forth.
2. In a crank shaft such as described, the use of a steel bush (6) let into the
flywheel (4) for the purpose of obtaining a durable connection of the tapered-
crank-pin end (e) with the flywheel, substantially as described.
Dated this 8th day of November 1898.
WM. P. THOMPSON & Co.,
Agents.