A New Arrangement of Toggle Jointed Levers for Imparting a Double Pressing Motion for Use in Moulding and Pressing Bricks, Briquettes, Tiles, Fuel Blocks, and other Articles.
Year: 1888

page_text: Date of Application, 17th May, 1888
Specification Accepted, 22nd June, 1888
A New Arrangement of Toggle Jointed Levers for Imparting a
Double Pressing Motion for Use in Moulding and Pressing Bricks,
Briquettes, Tiles, Fuel Blocks, and other Articles.
We, THOMAS CONSTANTINE FAWCETT, of the Whitehouse Engineering Works,
Leeds, in the County of York, Engineer, and JAMES DAWSON FAWCETT, of the same
place, Manager, 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 :-
Our invention has reference to a prior Patent granted to the said T. C. Fawcett,
bearing date the 29th day of March 1887, No. 4634, which invention consisted in the
employment of toggle jointed levers, so constructed and arranged that for one revɔ-
lution of a crank shaft, the toggle jointed levers would give a double pressing or
squeezing action upon a brick or other article placed underneath, such double pressing
motion being given through the medium of a connecting rod, which, when the toggle
jointed levers assumed a vertical line, gave one pressure upon the brick or other article,
but as the connecting rod was arranged to take the toggle jointed levers beyond a
vertical line, the pressure was removed, but on the return of the levers to a vertical
line the bricks received a second pressure, both of which pressures were given by one
revolution of the crank shaft.
So far as giving a double pressing motion for one revolution of the crank shaft, they
were successfully accomplished, but in practice we have found that the second beat or
squeeze did not materially affect the brick, as the under face of the pressing plate did
not descend any further for the second squeeze than for the first; it is now our inten-
tion to arrange and combine the toggle jointed levers in such a manner that the second
pressure is greater than the first, and this arises in consequence of the pressing plate
for the second squeeze descending slightly further than during the first squeeze, which
is accomplished by means of a peculiar shaped link or knuckle joint, formed on or
attached to one end of the connecting rod and working in combination with the
levers.
In order that our invention may be better understood, we will now make reference
to the accompanying sheet of Drawings, wherein Fig. 1 is an elevation of a set of toggle

page_text: jointed levers and knuckle joint, with connecting rod and crank for operating same,
arranged according to our invention, wherein A is a crank, and B a connecting rod
attached thereto, driven from any convenient source. At the end of the connecting
rod B is a link or double knuckle joint C, made with two recesses, as the Drawing
illustrates, the upper one receiving the end of the upper toggle lever D, which is
fastened to a fixed part of the machine E, the lower recess of the knuckle receiving the
end of the lower toggle lever F, which carries the pressing plate G. In Fig. 1 the full
line of the Drawing shews the toggles and pressing plate at their highest point, whilst the
dotted lines indicate the position of the toggles when the pressing plate is making its first
squeeze upon the brick or other article under operation. It will be observed on looking at
the dotted lines in Fig. 1 that the centres a and b of the levers are not directly over
each other, but on the crank moving upward from e to d, the connecting rod will be
carried further outward, as shewn in full line Fig. 2, in doing which, the pressure of
the pressing plate will be removed from the brick, but as the crank continues its
upward movement from d to e the toggle levers will assume a straight line as shewn in
dotted line Fig. 2, consequently the distance between the centres f and g in Fig. 2
will be greater than the distance and i shewn in Fig. 1, therefore the pressing plate
during this movement will make a further descent than during the first pressure, con-
sequently the brick under operation will get a double squeeze of unequal pressure, and
this arises in consequence of the recesses in the knuckle taking the toggle levers into
different vertical positions during the sweep of the crank.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is :-
In toggle jointed levers for imparting a double pressure, the combination there-
with of a knuckle or link, whereby the said levers descend further during the second
squeeze than during the first, all arranged and operated in manner substantially as herein
described and illustrated.