IMPROVEMENTS IN RAMMING APPARATUS FOR ASPHALT PAVEMENT, ETC
Year: 1881

page_text: "
LETTERS PATENT to Hugo Knoblauch, of the Firm of Knoblauch & Co.,
No. 17, Charlotten Strasse, in the City of Berlin and German Empire, for an
Invention of IMPROVEMENTS IN RAMMING APPARATUS FOR ASPHALT
PAVEMENT, ETC." A communication by Professor E. Dietrich, of the City of
Berlin aforesaid.
PROVISIONAL SPECIFICATION left by the said Hugo Knoblauch at the
Office of the Commissioners of Patents on the 27th August 1881.
HUGO KNOBLAUCH, of the Firm of Knoblauch & Co., No. 17, Charlotten
Strasse, in the City of Berlin and German Empire. "IMPROVEMENTS IN RAMMING
APPARATUS FOR ASPHALT PAVEMENT, ETC." A communication from Professor
E. Dietrich, of the City of Berlin aforesaid.
This Invention relates to improvements in the existing method of making
asphalt streets or pavements by compressing bituminous asphalt powder.
At present the powder is ramined by hand with iron rammers of a given or
constant weight and ramming-surface, which render light blows necessary at the
beginning of the work, whereas heavy ones are required later, which depend on the
height the rammers are lifted from the ground. The inequalities in the compression
produced according to this said process cause the formation of hollow places when
traffic passes over the surface, and result from the unequal force exerted by the
workman in ramming the material.
Besides this, the effect of the separate blows is by the process at present customary
limited to the power a man is capable of exerting.
A greater compression than is now obtained is desirable in order to effect an
increased density of the top surface, and to prevent as far as possible the
formation of hollows when the road or pavement becomes subjected to traffic.
For this purpose a stamping or ramming machine is employed, which is worked
by a crank and fly-wheel or other motive power of requisite strength. A number
of rammers are lifted by means of toothed wheels or by means of suitable pins,
Price Gd1

page_text: projections, or cams. The said rammers or ramming-blocks are then allowed to fall
from a given height upon the surface of the asphalt.
The under surface of the said rammers or ramming-blocks are rounded at the
edges, and these surfaces are arranged to so overlap one another that in performing
the operation of ramming no strip of unrammed asphalt can occur and no portion
of the surface can escape being rammed. In order to prevent unnecessary friction
between the teeth of the wheels and those of the racks a lug is attached to the
side of the wheel, which serves to raise the rack so that the teeth of the same come
into gearing with the teeth of the wheel.
In order to avoid any compression of the asphalt surface by the actual weight of
the apparatus, the same is placed on a carriage which is provided with small
wheels, two of which said wheels run on the finished part of the asphalt pavement
near the kerbstone, the wheels on the opposite side of the apparatus run on the
lath or boarding or other boundary piece at the extreme side of the asphalt to be
operated on.
The wheels are so attached to the carriage that the same can be rolled or moved
in any desired direction, and can be stood as near as possible to the kerbstone,
the wheels being fixed during the operation.of ramming in order to prevent the
carriage from slipping.
The workman engaged at the crank can stand on the asphalt or on a foot-board
which could be attached to the carriage and made to move with the same.
In
order to prevent the gearing upon which the weight of the rammers rest from
being injured by. the said rammers tipping or slipping, the motion of the apparatus
along the carriage must only be performed when all the rammers or ramming
blocks are raised out of contact with the ground. In order to effect this an
excentric is attached to one of the lifting or driving axles and connected to a
slotted lever; to the lower end of which said slotted lever a pawl is attached which
gears into a rack on the carriage and thus forces the apparatus along the carriage.
By means of a suitable arrangement of a double pawl which is attached to the
said slotted lever, the said pawl can work in either one or the other of two parellel
racks so that the apparatus can be moved in either direction on the framework of
the carriage. The slotted lever connection also enables the feed to be regulated so
that the movement of the apparatus along the carriage can be increased or
-diminished-without-altering the number of revolutions of the driving axle.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Hugo Knoblauch in the Great Scal Patent Office on the
22nd February 1882.
HUGO KNOBLAUCH, of the Firm of Knoblauch & Co., No. 17, Charlotten
Strasse, in the City of Berlin and German Empire. "IMPROVEMENTS IN RAMMING
APPARATUS FOR ASPHALT PAVEMENTS." A communication from Professor.
E. Dietrich, of the City of Berlin aforesaid.
This Invention relates to improvements in the customary manner of making
asphalt streets or pavements by compressing bituminous powder.
The powder is distributed upon a concrete foundation, and at present is rammed
by hand power by means of heavy iron rammers, and in order to prevent the
powder sticking to the cold iron the rammers are, previous to the operation and
sometimes during the same, warmed by means of coke fires.
Those places which happen to receive an extra quantity of the plastic asphalt
powder appear afterwards, when rammed to the same density as the other parts of
the pavement, as elevations or hillocks, and the evenness of the pavement or street
is only to be obtained by renewed ramming of such said parts. On the other hand one
incautious blow would ram down another portion which was perhaps provided with
the proper quantity of asphalt powder, and the hollow places thus formed had to be
rendered as far as possible invisible either by additional ramming of the surrounding
parts or by filling up the said hollow places with extra material. Experience has
shewn that all stamped asphalt streets are compressed during the first years in
which they are subjected to traffic, such said compression however depending on.
the original degree of density which the mass received; in consequence of which
the upper surface of the asphalt wears into grooves or hollows, those parts which
had received too much compression remaining as elevations or hillocks.
However the more irregular an asphalt street is the greater is the wear and tear
of the same, and consequently the cost of maintenance is increased. Such asphalt
streets have also to be made with greater incline in order that the rain water can
easily run off; this of course increases the danger of horses slipping sideways.
Besides this the degree of compression obtainable by hand power depends upon
the capability of one workman, while on the other hand with a machine increased
compression can be obtained by applying additional weight to the rammers, or by
raising the same a greater height, thus enabling an enormously increased density to
be given to the asphalt, enabling it to withstand the after compression when
subjected to traffic.
A thoroughly equable compression of the asphalt powder is attained by employing
my said apparatus, as all parts of the street or pavement receive the same number
of blows, and all the rammers fall from the same elevation, which is of course not
possible with hand rammers. The apparatus thus discovers all portions which have
received an unequal quantity of asphalt powder, and consequently compels the
workmen to distribute the powder equally. Before the commencement of the
ramming the powder is subjected to the pressure of a slightly heated hand roller.
The apparatus is so constructed that the stroke of the rammers can be adjusted
according to the temperature of the day or. heaviness of the traffic for which the
street is destined.
In order to avoid any compression of the asphalt surface by the actual weight of
the apparatus, the same is placed on a carriage about 23 feet long, which is provided
with four small wheels or rollers. The carriage can be rolled or moved in any
desired direction, and can be either placed across the street or in the direction of

page_text: the same.
The rammers b, which can be arranged in two or more rows, are so
situated towards one another, i.e., their lower surfaces are arranged to so overlap
one another, that in performing the operation of ramming no strip of unrammed
asphalt can occur, and no portion of the surface can escape being rammed. The
rammers are raised by racks which gear in wheels partly provided with teeth, or
the said rammers can be raised by means of suitable pins, projections, or cams.
In order to prevent unnecessary friction between the teeth of the wheels and those
of the racks, a lug is attached to the sides of the wheels which serve to raise the
racks, so that the teeth of the same come into correct gearing with those of the
wheels. In order to prevent the rammers from becoming heated, and the con-
sequent necessity of exchanging them, they are provided with a base or foot of
hard wood or other suitable materially, which is conically formed and firmly screwed
to the said rammers. These said bases or feet are covered with thin sheet steel.
The steel and wood being very bad conductors of heat, and the circumstance that
the rammers are raised immediately after falling by means of lugs attached to the
toothed wheels, admit of the employment of unwarmed rammers.
The wheels which raise the rammers are put into operation by means of a crank
and flywheel, or by means of some suitable motor or engine such as gas motor,
compressed air, other suitable means.
When worked by hand-power the workinen stand on a suitable foot-board d
which is attached to the carriage a.
The sliding of the apparatus upon the long carriage a is automatic, and is
executed by means of an excentric f, angle-lever g, and rack e, which latter is
attached to the carriage a. This sliding motion however can only take place
when all the rammers or ramming-blocks are raised out of contact with the ground
or pavement.
In order to avoid excessive concussion of the concrete foundation the rammers
are not permitted to fall all at once, but fall one after the other in rapid succession,
and are also raised one after the other in order to employ an equal amount of
force.
The apparatus can be used for making new streets or pavements, and also for
repairing and maintaining existing pavements. In the latter case after the place
to be repaired has become warm either by the warm temperature of a summer's
day-or-by-artificial_means, the elevations of the undulating surface are levelled by
subjecting them to additional compression.
For the convenient transport of the apparatus ordinary cart axles & wheels
can be attached underneath the girders of the long carriage.
Having now described my said Invention, and the manner in which the same
is to be carried into effect, I desire it to be understood that the parts of my Inven-
tion can be modified without departing from the tenor of my Invention, but what
I claim and desire to have secured by Letters Patent is,-
In a ramming apparatus for asphalt pavements and similar purposes---
1. Arranging the rammers in such a manner that when the apparatus is moved
forward in performing the operation of ramming the surfaces covered by the
blows slightly overlap one another in order to attain an equal amount of ramming
for the whole surface, substantially as described in the foregoing Specification and
shewn in the accompanying Drawings.
2. The arrangement of the ramming apparatus with foot-board d on a long
carriage a in order to avoid subjecting the unfinished part of the asphalt to undue
compression, substantially as described in the foregoing Specification and shewn in
the accompanying Drawings.
3. The intermittant and automatic sliding motion of the apparatus in order to
attain a regular advance of the same, but only when all the rammers are out of
contact with the ground or pavement, substantially as described in the foregoing
Specification and shewn in the accompanying Drawings.
4. Instantaneously raising the raminers directly after the fall by means of lugs
attached to the toothed wheels, and providing the bases of the rammers with a foot

page_text: of hard wood or other suitable material covered with sheet steel so as to be able
to operate with cold rammer, substantially as described in the foregoing Specification
and shewn in the accompanying Drawings.
In witness whereof, I, the said Hugo Knoblauch, have hereunto set my
hand and seal, this Twenty seventh day of January, in the year of our
Lord One thousand eight hundred and eighty two.
Witnesses,
GUSTAV EHLEN,
JOHN O. TONKIN.
HUGO KNOBLAUCH. (L.S.)