Improvements in Crank-plate Mechanisms.
Year: 1891

page_text: Date of Application, 12th Feb., 1891
Complete Specification Left, 11th Nov., 1891-Accepted, 12th Dec. 1891
PROVISIONAL SPECIFICATION.
Improvements in Crank-plate Mechanisms.
I, ERNST HAMMESFAHR, of No. 7 Foche, Solingen, Prussia, in the German
Empire, Manufacturer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to a construction of crank-plates in which the crank pin,
instead of being rigidly fixed, is free to partake of a sliding motion thereon, so that
when the pin has been brought round by the crank-plate to a certain point of the
revolution, the crank pin is free to slide thereon in obedience to gravity or to a
pull exerted upon it by a tool weight or other object attached directly or
indirectly thereto, until by the continued rotation of the crank plate the abut-
ment thereof is again brought against the crank pin so as to impart motion
thereto.
The crank plate and its pin may be variously constructed for this purpose, thus
the path on which the pin slides may either consist of a groove or slot in the plate
in which the base of the pin is situated, or it may be a raised rib on the face of the
plate, over which the base of the pin slides, the rib being either of dovetail or
undercut cross section, over which the base of the pin fits with a corresponding
dovetail or under cut slot.
In the first case the pin is carried round by the end face of the groove or slot
bearing against it, and in the second case an abutment is provided at the end of the
rib against which the pin bears. The said path, whether of the one or the other
form, may either be circular and concentric with the shaft of the crank-plate, or it
may
be of elliptical or other shape deviating more or less from the circle. The
action will in every case be such, that the abutment of the groove or rib will carry
the crank pin round in a circular path until a point is reached in which the line of
pull exerted by the tool or other object connected to the pin commences to be
directed forward, away from the abutment, whereupon such pull will cause the pin
to be drawn along its path, away from the crank pin until either the pull of the
tool or other object ceases, or such pull is checked by the pin coming in contact
with an abutment at the other end of the path, when the pin and tool &c. will remain
stationary until the crank plate, in following up again, brings its acting abutment to
bear against the pin, so as to repeat the above operation.
As before stated the tool &c. may either be connected directly or by a
connecting rod or link to the crank pin, or it may be connected thereto by a
cord chain or band passing over a guide pulley or by a combination of rods
and levers.
Dated this 19th dow of Feb-101
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Crank-plate Mechanisms.
I, ERNST HAMMESFAHR, of No. 7 Foche, Solingen, Prussia, in the German
Empire, 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 :-
My invention relates to a construction of crank-plates in which the crank pin,
instead of being rigidly fixed, is free to partake of a sliding motion thereon, so that
when the pin has been brought round by the crank plate to a certain point of the

page_text: revolution, the crank pin is free to slide thereon in obedience to gravity or to a pull
exerted upon it by a tool, weight, or other object attached directly or indirectly
thereto, until by the continued rotation of the crank plate the abutment thereof is
again brought against the crank-pin so as to impart motion thereto:
The crank plate and its.pin. may be variously constructed for this purpose, thus
the path on which the pin slides may either consist of a groove or slot in the plate
in which the base of the pin is situated, or it may be a raised rib on the face of the
plate, over which the base of the pin slides, the rib being either of dovetail. or
undercut cross section, over which the base of the pin fits with. a corresponding
dovetail on undercut slot.
In the first case the pin is carried round by the end face of the groove or slot
bearing against it, and in the second case an abutment is provided at the end of the
rib against which the pin bears. The said path, whether of the one or the other form,
may either be circular and concentric with the shaft of the crank-plate, or it may be
of elliptical or other shape deviating more or less from the circle. The action will.
in every case be such that the abutment of the groove or rib will carry the crank
pin round in. a circular path until a point is reached in which the line of pull exerted
by the tool or other object connected to the pin commences to be directed forward,,
away from the abutment, whereupon such pull will cause the pin to be drawn along
its path, away from the crank pin until either the pull of the tool or other object
ceases, or such pull is checked by the pin coming in contact with an abutment- at
the other end of the path, when the pin and tool &c. will remain stationary until the.
. crank. plate, in following up again, brings its acting abutment to bear against the
pin, so as to repeat the above operation.
As before stated the tool &c. may either be connected directly or by a
connecting rod or link to the crank pin, or it may be connected. thereto, by
a cord chain or band passing over a guide or by a combination of rods and.
levers.
The accompanying drawing shews various arrangements of my above described
invention..
In the construction shewn at Fig. 1, the crank plate a receiving rotary motion
from a shaft on which it is fixed, has a circular groove or sunk path b in which
is a sliding block, carrying a crank pin c. The crank plate is in this case assumed
to be applied to the working of an ordinary drop hammer.
For this purpose a rod or coupling link e is connected to the crank pin, the
other, end of which is attached to the strap or cord from which the hammer block is
suspended. On the rotation of the plate a in the direction of the arrow, the crank.
pin will be carried along with it by the abutment d at the end of the groove,,
from, the position, at I to the position at II as indicated by dotted lines, thereby
raising the hammer block connected thereto from the lowest to the highest position.
When arrived at the position II it will be seen that the stop d is now in such a
position relatively to the vertically downward pull exerted by the hammer-block.
upon the crank pin, that it no longer supports the pin against. such pull. and
consequently, the latter draws the pin away from the stop, causing it to pass
rapidly down in the groove in following the drop of the hammer block, which is
thus enabled to effect its blow with the full force. At the same time, as the crank
plate continues to revolve, the stop d quickly follows up the crank pin and when
arrived at the position I it again effects the raising of the crank pin and hammer
block as before, the speed of the crank plate being by preference so adjusted that
the hammer. block is rapidly raised off the object operated upon after the blow has
been effected.
Instead of arranging the crank plate directly over the hammer block as at Fig. 1,
it may be arranged at the side thereof either above or below the same,, Fig. 2
shews such an arrangement where the crank plate a is carried on the floor, the
crank pin c being connected to the hammer block by a strap or cord gepassing.
over a pulley f.
Fig. 3 shews in front view, plan and cross section, a construction in which the

page_text: crank plate a has a raised undercut circular path 6' on which moves a corre-
spondingly formed slide with the crank pin c. A raised stop d' is provided for the
abutment of the slide.
Instead of making the path for the crank pin circular, it may be formed elliptical
or of other suitably curved shape that will allow of the before described action of
the crank pin. Figs. 4 and 5 shew by way of example two such forms. In these
cases, owing to the non-circular form of the path, the latter begins to raise the
hammer block immediately after this has effected the blow, which is of advantage
in forging operations.
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 crank plate a having a circular or curved path 6 or 6' in or on which a loose
crank pin cor e' is free to slide, the crank pin being carried round with the
crank plate by means of a stop or abutment during one part of its revolution,
while during another part of the revolution it is caused by gravity or by a
pull operated upon it, to slide loose in or on the said path, away from the said
abutment.
Dated this 11th day of November 1891.
ABEL & IMRAY,
Agents for the Applicant..