IMPROVEMENTS IN BRICK-MAKING MACHINES
Year: 1867

page_text: PROVISIONAL SPECIFICATION left by William Steven and Anselm
Robertson at the Office of the Commissioners of Patents, with their
Petition, on the 2nd July 1867.
We, WILLIAM STEVEN and ANSELM ROBERTSON, both of Glasgow, in the
County of Lanark, North Britain, do hereby declare the nature of our
said Invention for "IMPROVEMENTS IN BRICK-MAKING MACHINES," to be as
follows:-
This Invention relates to brick-making machines of the kind described in
the Specification of Letters Patent granted to Robert Cook and Andrew
Cunningham, and dated 22nd March, 1841 (No. 8897). In a machine of
the kind referred to the clay issues by one or more outlets from a pug-mill,
and there is in connection with each outlet a sliding frame formed with
moulds or mould openings, into which openings the clay has hitherto been
forced by a piston or plunger. When each mould has been thus filled with
clay it moves forward to a position wherein a second piston or plunger forces
the clay downwards through the sliding frame into a portable mould or box
in which it is removed from the machine.
One improvement consists in dispensing with the first pistons or plungers,
and thereby saving the gearing and power hitherto required to work them.
A cover of metal, wood, or other suitable material is placed over each pug-
mill outlet, and is shaped so as to lead or guide the issuing clay down into the
moulds or mould openings in the sliding frame; by these means the machine
is rendered more simpler and less likely to get out of order.
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page_text: A second improvement consists in actuating the remaining pistons or
plungers by means of weights in combination with levers, which levers have
their movements regulated by cams shaped with depressions to allow of the
descent of the weights at the proper times, and the inclined sides of which
depressions re-elevate them by a positive action.
Hitherto these pistons have been worked by the positive action of a cam or
crank, and when the movement has been obstructed by stones or otherwise
the machine has been broken; but with the improved arrangement when an
obstruction occurs it simply prevents the descent of the weight without
doing any injury. The pistons being already actuated by means of levers, the
weights have simply to be connected to the descending sides of those
levers. This improvement is, by preference, used in connection with a cam-
produced motion of the sliding frame such as is already in use in various brick
machines.
A third improvement consists in introducing a yielding appliance in the
driving arrangement, so that when from obstructions in the machine the
resistance becomes injuriously increased the parts will slip, and thereby save
the gearing for this purpose any known frictional coupling may be used,
the holding power of which can be adjusted. For example, a wheel of the
gearing may be loose on the shaft, and may be formed with an outer conical
surface fitting a corresponding surface on a pulley arranged to turn with the
shaft, such pulley being pressed into contact with the driving wheel by a lever
or levers weighted to the required extent; or the driving belt may be made
to pass round a tension pulley carried by a weighted lever, which will allow
the belt to slacken when the proper strain is exceeded.