Improved Roller Press for Ramming Sand Moulds.
Year: 1899

page_text: Date of Application, 29th Aug., 1899-Accepted, 28th Oct., 1899
COMPLETE SPECIFICATION.
Improved Roller Press for Ramming Sand Moulds.
I, OTTOCAR LINDEMANN, of No. 53, Victoria Street, in the County of London,
do hereby declare the nature of this invention (as communicated to me from
abroad by Ernest Korting, of No. 2, Allee Strasse, Hanover, Germany) and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:
This invention consists in a construction of roller press for ramming sand
moulds wherein a roller is caused to roll over a plate or device which is inter-
posed between it and the sand in the mould, such plate or device being dis-
connected from the roller and capable of yielding to its pressure which it trans-
mits to the sand. This plate is made of such a form that the pressure exercised
thereby upon different parts of the sand can be made to vary at will indepen-
dently of the weight and pressure of the roller, and without injuriously shifting
the sand from one part of the mould box to another, such as would be unavoid-
able if the rolling were to be effected without the interposition of the plate or
device. The said rolling process with a yielding intermediate device of suit-
able construction affords all the advantages of ramming with vertical pressure
and in addition it affords the convenience of enabling the pressure to be varied
at different parts of the pattern, by suitably forming the plate or device at such
points.
The yielding property of the plate or device can be effected in various ways.
For example, it may be constructed as a flexible or jointed band, or as a curved
rocking plate in the hollow of which the roller is made to roll. The pressure
of the roller at any particular point is dependent in the first mentioned case
upon the flexibility of the band or the length of the jointed parts, and in the
latter case upon the curve of the plate, the pressure being the greater the more
flexible is the band and the shorter the jointed lengths, and the smaller the
radius of the curvature of the plate. If the pattern has special projections or
recesses, these may be allowed for by providing corresponding recesses or pro-
jections on the interposed device, in order to obtain the proper compression of
the sand at those parts such pressure being also regulated by the repeated roll-
ing backwards and forwards of the roller.
A great advantage of the method of operating consists in the ease with which
the roller is worked as this rolls almost without resistance upon the interposed
plate or device, while if it were rolled directly on the sand it would be moved
with difficulty.
The motion is rendered still easier if at each end thereof an elastic stop be
provided, so that on striking against these it is at once caused to commence its
backward motion.
On the accompanying drawing are shewn various forms of the interposed
device in connection with the roller.
Figs. 1, 1 and 1° shew a longitudinal section, cross section and plan of a
mould box in which are patterns between which are spaces a, and over which
the sand is introduced. Upon this is placed the interposed device a formed
of a series of jointed plates on which are formed projections & corresponding