MENTS IN LOOMS FOR WEAVING
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Henry Lea at the Office of the
Commissioners of Patents, with his Petition, on the 1st May 1866.
I, HENRY LEA, of Birmingham, in the County of Warwick, Mechanical
Engineer, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN LOOMS FOR WEAVING," to be as follows:-
The object of my Invention is to effect an economy in the expenditure of
compressed air when used for propelling the shuttles of looms. I make the
shuttle box parallel inside, and of such a size that it fits the shuttle closely but
freely; I also make the shuttle box of such a length that after the volume of
compressed air required for the propulsion of the shuttle has been admitted
immediately behind the said shuttle such volume of air shall by its expansion
within the box continue to accelerate the velocity of the shuttle, and I
prefer that the shuttle box should be of such a length that the pressure of the
air propelling the shuttle should fall to that of the external atmosphere by the
time the shuttle has left the mouth of the shuttle box. In order to cause the
shuttle to enter truly and freely into a shuttle box so closely fitting the shuttle,
I place at the mouth of the shuttle box two guides, one of which is fixed
truly in line with one internal side of the shuttle box, and the other guide is
so hinged and pressed by a spring as, firstly, to compel the shuttle to slide truly
against the opposite fixed guide, and therefore to enter truly into the shuttle
box; secondly, by its friction to bring the shuttle to rest in its proper
position in the shuttle box; and, thirdly, to prevent the rebound of the shuttle
from the box. I withdraw the hinged guide by a cam at the proper time, so

page_text: as to permit the free exit of the shuttle when propelled by the compressed air.
I work the valve which admits the air to the shuttle box in the following
manner, by which method of working the volume of air so admitted may be
determined with exactitude and certainty and unnecessary waste prevented.
I provide a revolving cam upon or near the shuttle box, which cam compresses
a spring, and this spring upon being released by the cam strikes through the
medium of a small hammer or otherwise the end of the valve spindle, thereby
opening the valve for an instant against the pressure of the confined air and
admitting the required volume of the compressed air to the shuttle box. The
volume of air may be varied by altering the set or strength of the spring by a
set screw. I also
I also provide a small valve in the side or top or bottom of the
shuttle box and near its closed end, and I cause the said valve to open at the
proper moment, so as to prevent the air within the shuttle box being an
obstacle to the ingress of the shuttle when driven from the opposite box, and
I cause the valve to reclose air-tight during the egress of the shuttle. The
cam for effecting this is fixed upon the shaft which carries the two.cams
previously referred to. I prefer to make on each cam three rises or swells,
and to cause the cam shaft to rotate by means of a lever and pall driving
tooth by 'tooth a ratchet wheel of six teeth fixed upon the cam shaft. The
lever being attached by a rod to the frame of the loom will be caused to
vibrate by the action of the lathe or sley beam carrying the shuttle box and
cam shaft, and as the ratchet wheel has six teeth, while the cams have only
three, each cam will act upon its respective valve or spring once only for
every two teeth propelled by the ratchet lever, thus securing the alternate
action of each shuttle box in unison with the vibrations of the lathe or sley
beam. Other numbers than three and six may be used for the rises or swells
on the cams and ratchet wheel respectively, such, for example, as 'two and
four, or four and eight, the object being that each cam shall act once only
for each two revolutions of the crank shaft which works the lathe or
sley beam.