Improved Construction of Crank Plate for Working Percussion Tools.
Year: 1892

page_text: Date of Application, 23rd Mar., 1892
Complete Specification Left, 21st Dec., 1392-Accepted, 4th Feb., 1893
:
PROVISIONAL SPECIFICATION.
Improved Construction of Crank Plate for Working Percussion
Tools.
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 an improved construction of revolving crank plate for
working percussion tools, such as drop hammers, stamps, pile drivers &c. wherein
the crank pin is carried by a block that can slide in a curved or straight groove or
upon a curved or straight rib formed in or upon the crank plate, the crank pin
being either connected directly with the percussion tool or indirectly by means of
bands, cord chains, rods &c. in which latter case it can be situated at a distance
from the point where the tool operates, the cord band or chain being led over guide
pullies.
On the rotation of the crank plate, the crank pin and block will be carried along
with it by bearing against a stop at the one end of the slot or rib, until it arrives
at that point of the revolution where it loses the support of the stop, whereupon the
pull exerted by the tool will cause the crank pin to slide rapidly to the other end
of the slot or 'rib and thus allow the tool to operate with percussive action. The
slot or rib is made of such a length that the crank pin cannot arrive at the other
end thereof until the tool has exerted its full percussive action.
The crank plate in continuing to rotate while such accelerated motion of the
crank pin is taking place, causes the first named end of the slot or rib to overtake
the crank pin again when the tool has completed its action, and again raises these
parts for repeated action. For heavy tools, there may be two such slotted crank
plates placed opposite each other, with a crank pin common to both, carried by
two blocks sliding respectively in the slot or on the rib of each plate.
Dated this 23rd day of March 1892.
ABEL & IMRAY,'
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improved Construction of Crank Plate for Working Percussion
Tools.
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 an improved construction of revolving crank plate for
working percussion tools, such as drop hammers, stamps, pile drivers &c. wherein
the crank pin is carried by a block that can slide in a curved or straight groove or
upon a curved or straight rib formed in or upon the crank plate, the crank pin
being either connected directly with the percussion tool or indirectly by means of
bands, cords, chains, rods &c. in which latter case it can be situated at a distance
from the point where the tool operates, the cord, band or chain being led over guide
pullies.
On the rotation of the crank plate, the crank pin and block will be carried along
with it by bearing against a stop at the one end of the slot or rib, until it arrives
at that point of the revolution where it loses the support of the stop, whereupon
071

page_text: the pull exerted by the tool will cause the crank pin to slide rapidly to the other
end of the slot or rib and thus allow the tool to operate with percussive action.
The slot or rib is made of such a length that the crank pin cannot arrive at the
other end thereof until the tool has exerted its full percussive action.
On the accompanying drawings,
Figs. 1 and 2 shew apparatus constructed according to my said invention in
which the crank pin works in a curved concentric slot of the crank plate, the load
being connected directly to the crank pin at Fig. 1 while at Fig. 2 it is connected
thereto by a cord or chain led over a guide roller.
Fig. 3 shews an arrangement in which the slot in the crank plate is formed
straight.
A is the crank plate, B a slot in which slides a 'block carrying the crank pin C,
which is carried along by the one end of the slot as the disc A rotates, so as to
operate as a fixed crank pin during about three fourths of the revolution, and
thereby to raise the load through the distance I II, equal to double the distance of
the crank pin from the centre of the shaft. After the crank pin, on the continued
motion of the crank plate, has passed a certain distance beyond the line III it
will be drawn along the slot B by the pull of the load exerted thereon, such motion
taking place at a speed greater than the rotation of the crank plate, and approxi-
mating to that of a free falling body.
The slot B is for this purpose made of such a length that its leading end b
will not be reached by the block of the crank pin in its rapid motion, and will
consequently not impede the desired percussive action. After this has taken place,
the following end of the slot will overtake the block again and will carry up
the crank pin as before. The straight slot B Fig. 3 can be arranged in any
desired position as may be best suited for the free descent of the crank pin; the
action is otherwise just the same as above described, the sliding block C being
carried up from I to II in the direction of the arrow by the end of the slot, on
the rotation of the disc, and then allowed to fall freely in the slot.
Fig. 4 shows an arrangement of two crank discs A A' with two identical
slots B B and two blocks C C carrying the crank pin between them.
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 having a straight or curved slot or equivalent path in or on which
can slide a block carrying a crank pin connected to the load or tool to be raised,
the slot or path being of such a length that after the block has been carried by the
one end thereof through about three fourths of a revolution, the block can slide
more or less freely along such slot or path without reaching the other end thereof,
substantially as described.
Dated this 21st day of December 1892.
ABEL & IMRAY,
Agents for the Applicant."