CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS TO BE USED IN CONNECTION WITH LOOMS FOR WEAVING
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Mould and Thomas Grimshaw
at the Office of the Commissioners of Patents on the 26th May 1882.
WILLIAM MOULD and THOMAS GRIMSHAW both of Preston in the County of
Lancaster CERTAIN IMPROVEMENTS IN MACHINERY OR APPARATUS TO BE USED
IN CONNECTION WITH LOOMS FOR WEAVING
Our Invention relates to an arrangement of mechanism to be used in connection
with looms for weaving and is designed to simplify the construction of the
complicated Dobby at present in use.
Our Invention consists of a suitable frame-work resting upon standards a
convenient height above the top of the loom. At each end of the frame-work
passes a horizontal rocking shaft supported in the front and back part of the
framing. Each of these shafts is provided with two arms keyed or secured thereto
and working close to the inner parts of the front and back part of the frame. On
the upper ends of these fast arms is bolted a flat plate or knife which rocks with
the shaft. Upon these shafts and between the aforesaid arms are fitted a suitable
number of loose bell-crank levers, the upper portion of each of which corresponds
in shape with the fast arms, and is always in a position similar thereto excepting
when acted upon by a catch hereinafter referred to. These loose bell-crank levers
are held in position by a projecting part from the underside of the boss which
rests against the cross rail of the framework. The other or lower arms of these
bell-crank levers are inclined downwards towards the centre of the apparatus
and their lengths vary, according to the amount of lift required for the "shed" of
the corresponding healds; the levers (one on each shaft) which are connected to
the same healds being of course equal in length.
At the end of the upper arm of each of these bell-crank levers is a button-headed
stud to receive a catch which is booked at one end and suitably slotted a short
distance from the other end, the slotted part engaging with the button-headed
stud.
This catch bears upon the above named flat plate or knife when in its ordinary
position, the hooked end engaging therewith, but when the upper end is depressed
by a peg on a pattern-barrel, on a sway-beam above, this hook is lifted (the stud
on the loose lever acting as a pivot) so as to allow the plate to move as it is rocked

page_text: without carrying the catch with it, thus leaving the loose bell-crank lever at rest.
But if the end of the catch is not depressed by the pattern-barrel the catch is
carried away by the plate, or knife, and brings the upper end of its loose bell-crank
lever with it. The other end of this lever is connected to its opposite lever and to
a central vertical slide by means of a suitable bar, and this slide being conveniently
attached by cords or other equivalent means to the top and bottom of one of the
healds the latter is raised and lowered as the plate or knife rocks.
It will be evident from the above description that there is a series of central
vertical slides each connected to a heald and to a bar linked at either end to a
bell-crank lever on each of the rocking shafts.