Improvements in the Method of Making and Adjusting Chains and Apparatus used therein.
Year: 1895

page_text: Date of Application, 7th Jan., 1895--Accepted, 9th Feb., 1895
COMPLETE SPECIFICATION.
Improvements in the Method of Making and Adjusting Chains and
Apparatus used therein.
I HEINRICH GÖRKE of Grüne near Tserlohn Westfalia, Mechanical Engineer
lo 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:-
This invention relates to a new manner of welding together the single links of
chains and adjusting them at the same time so that the pitch of all the links will
be absolutely the same and that also their width will be equal and that the welded
part will be quite round and as true in shape as the other parts of the link. Chains
used for pulley blocks, for cranes and the like which run over toothed or grooved
pulleys must have links of absolutely equal length whether they serve for carrying
loads or for transmitting power and in the first case, where it often happens, that
the load hangs down for a considerable length, it is a condition that the chain does
not twist but hangs absolutely straight, so that in winding it up the load will not
be turned about.
There are two methods in use, by which the adjusting and finishing of chains
for pulley blocks, for transmitting of power, where the chains run over a toothed
and grooved pulley, is done. According to the one into each link, having been
welded to the chain, is driven a mandrel X like that shown in Fig. 9 of the
annexed drawing, the link being supported by a suitable anvil. Now if the wire
of which the links are made were of equal thickness throughout and the weldings
absolutely equal this method might satisfy, but such is not the case, such chains
twist and the pitch of the links varies.
The other method is similar to the first one: All the links having been welded
and joined together a mandrel of the shape shown by Fig. 10 of the drawing is
driven into the open space of a link between this link and the two joined thereto
previously, and thus the said link is adjusted and all the others in the same manner.
But this method also does not give complete satisfaction for the same reasons and
in a length of a yard a twist of 90 degrees takes place, wheu the chain hangs free;
this is principally due to the incomplete roundness of the links at the welding
place.
Now by my new process I am enabled to produce chains of almost absolute
perfection with regard adjustment, equality of pitch and roundness of the weld.
I proceed as follows and I thereby use the tools shown by Figs. 1 to 8 of the
drawing, in which :
Figures 1 and 2 are front views of the top and bottom die respectively; Figure 3
is a top view of the latter; Figures 4 and 5 are vertical sections of Figs. 1 and 2
along line II and Figures 6, 7 and 8 show the use and working of the dies.
The upper die used in my process consists of a piece of steel which can be put
into the ram of a steam or other hammer, or fixed to the spindle of a press. The
lower surface of this die is provided with a half circular groove A corresponding
to the shape of a chain link and the part in the centre of this groove forms a
recess or cavity B tapering a little towards the top. The bottom die, which is fixed
to the anvil or to the table of a press is in the main of similar shape as the upper
die; it has a half circular groove C. forming the counter part of the groove A, so
that both, when put together form a closed groove of circular section of the shape
of the link. The central part between the groove is surmounted by a piece or

page_text: mandrel D fitting exactly into the cavity B of the upper die. The piece D is of
such shape, that there where it meets the groove C or rises out of it, it corresponds
exactly to the shape of the free space of the inner circumference of a chain link
with one link connected there to; its back side is half round convex ; its front side
is concave and of such shape that a link standing vertically to the link lying in
the groove C will just fit into the concave. Figures 6, 7 and 8 will help to
explain this.
One die is fixed to the anvil and the other to the ram of a hammer or the table
and spindle respectively of a press, so that when their faces touch each other the
grooves and the mandrel and cavity exactly fit. Now in carrying out my process,
in welding and adjusting the chain links, I proceed as follows:
it
The link F (Fig. 6-8), which has been joined to the last link of a chain E
and provisionally welded is made white hot; it is then put over the mandrel D,
the welding part opposite the link E; the upper die is then thrown down upon
with a firm and quick blow, so that the link F is driven down along the mandrel D
into the groove C and both dies touch each other on their faces as shown by
Fig. 8. I thus obtain not only a perfect welding but also a true circular shape of
the welded part, and the length and width of the link must correspond exactly to
the shape of the dies.
These dimensions being always the same, the chain must of course be equal
in all its parts; the pitch is absolutely the same throughout and the rounding of
the welded part of the links forms a true circle.
Therefore a chain made by the use of my tools and according to my method will
not twist and its links will always fit nicely to the teeth of the chain wheel.
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:
A method or process in making and adjusting chains by which a perfectly
uniform pitch of all the links and equality of the shape of the same is obtained
which consists in that, that the last link joined to the chain, and which had been
provisionally welded, is made white hot and is then put with the welded part at
the end side upon a die having a half circular groove of the shape of the link and
a mandrel in the centre filling out the hollow space between the said link and the
one joined thereto previously; a counter or upper die having a groove corre-
sponding to the said groove in the lower die and a cavity corresponding to the
mandrel of the lower die being driven firmly down upon the link on the first die,
forcing it thus to adopt the exact shape of the mould formed by both dies when
they touch each other.
Dated 100th day of December 1901
HEINRICH GÖRKE,
Per Karl J. Mayer,
Agent.