IMPROVEMENTS IN THE MANUFACTURE OF BISCUITS AND IN THE MEANS OR MECHANISM EMPLOYED THEREFOR.”
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by William Gray and Alfred Harvey at
the Office of the Commissioners of Patents on the 5th February 1877.
WILLIAM GRAY, of the Firm of "Gray, Dunn, & Company," Bread and Biscuit
Manufacturers, of the City of Glasgow, North Britain, and ALFRED HARVEY, Fore-
man to the said Firm. "IMPROVEMENTS IN THE MANUFACTURE OF BISCUITS AND
IN THE MEANS OR MECHANISM EMPLOYED THEREFOR.”
This Invention has reference to the manufacture of the class of biscuits known
as "drop biscuits" or small cakes, which are generally of a rich, soft, spongy, or
crisp nature, and made from such moist, soft, or sticky dough that they cannot. be
quickly or easily separated into the small portions necessary, as the other tougher
doughs and biscuits generally are by knives or stampers, but has to be dropped
from a spoon, or the spout of a dish, or that of a close pressure bag, and usually by
hand, in the small regular quantities on to sheets or trays, all ready for being sub-
sequently baked in the oven into the said biscuits or small cakes.
And further, this Invention has special reference to new or improved means or
arrangements of mechanism for automatically depositing the said soft dough for this
class of biscuits in the required and nearly uniform quantities on to portable trays
or sheets of paper, or it might be traversing webs of these, ready for being baked
in the regular or automatic traversing biscuit oven instead of the ordinary baking
oven; all in a far more regular and expeditious manner, with a great saving of
labour as compared with the modes and means heretofore employed in the manu-
facture of the said biscuits.
The nature and novelty of the Invention consist all substantially as follows:-
In having an endless travelling web passing over rollers and guides carried between
and in bearing bushes in two main side frames, secured together at the proper
width apart by transverse stays or frames, with the web at a convenient height
for laying on the trays or sheets of paper at the one end of the machine and lifting
them away at the other or delivery end.
The main driving, roller of the said endless web is actuated intermittently by a
ratchet wheel and pawl lever, or friction feed wheel, mounted on its spindle at one
end, the latter reciprocated by a connecting rod, attached at its other or back end
to a shifting eccentric pin in a slide crank or disc fixed on one end of the first
motion transverse revolving shaft, also carried in bush bearings in the two side
frames, and actuated by a cone pulley, or fast and loose pulley on its other end, by
a belt passed over them from any convenient motive or counter shaft, which would

page_text: give the differences of speed to suit the size or kind of biscuits being made, all so
far fitted and driven substantially as other motive biscuit-making machines and
their rolled sheet dough-carrying webs are.
By the improvements of this Invention a shallow horizontal plunger compressing
chamber is mounted to, and nearly the whole width between, the side frames, a little
above the middle of the top of the travelling web, and having its pressing plunger
worked or reciprocated longitudinally by a rod or rods out through its open back
end, either direct from the said first motion revolving shaft actuating the endless
web, or through a countershaft or rocking levers and rods. This compressing
chamber is preferably fitted with a close sliding lid across nearly the whole of its
top side, with a deep vertical or angled hopper, wide above and contracted below
to receive the soft mixed dough, as before stated, and convey it through the said
lid into the compressing chamber in front of the plunger at its back stroke, but a
little behind it when at the extreme front part of its stroke, regulated by the
shifting cover, or by the stroke of the pressing plunger or its acting rods.
The front of the compressing chamber is closed in by a close end right across
fitted with a number of round tapered tubes or nozzles, each attached at its back
end by a short piece of vulcanized india-rubber tube, or an open projecting "bizzle"
or branch formed or secured at suitable intervals apart across the front, close end,
or face of the compressing chamber. The india-rubber joints (or it might be other
joints) allow the front or open ends of the whole row of these nozzles to have a
short downward and upward motion given to them by a bar attached to the whole,
and links attached to it and to rocking levers actuated froin the rocking shaft or
cross head moving the pressing plunger, all so that each time the plunger comes
forward it presses an equal quantity of the soft dough out through each of the
whole row of nozzles, which are at this time pressed down against a tray below
them carried on the intermittent travelling web, so as to deposit all the quantities
or drops of dough on to the tray; then the nozzles are raised off the tray just as
the plunger recedes on its back stroke, and allows the travelling web to carry the
trays sufficiently forward to allow room for depositing the next row of drops or
sections of dough in like manner as the pressing plunger comes forward, carrying
with it a fresh quantity of dough into the close front end.
Another improvement consists in fitting an automatic or positively moved air
valve to open inwards to the front close part of the compressing chamber (at the
inner or back end of the delivery tubes or nozzles) at the time the piston begins to
move backwards, and by thus equalizing the pressure on both ends of the nozzles,
the suction or vacuum, which would otherwise (without this valve) draw back a
great part of the dough pressed out, is prevented. This valve is preferred to be
fitted as a long narrow clack valve across the wholo width of the front close end of
the chamber immediately over the back end of the tubes of the nozzles, so as to
admit the air thereto but instantly close up against the top to prevent the escape
of dough on the forward pressure stroke of the plunger.
When the dough is desired to be laid in elongated sections for "lady finger," or
other long or curved fancy biscuits, either the travelling web or the set of nozzles
would have a short corresponding longitudinal or curved motion given to them while
the latter were dropping the dough on the sheets of paper or trays, the feed motion
of the travelling web being regulated accordingly to move while the dough was
being dropped or deposited.