IMPROVEMENTS IN LOOMS FOR WEAVING
Year: 1877

page_text: PROVISIONAL SPECIFICATION left by John Collins at the Office of the
Commissioners of Patents on the 28th June 1877.
JOHN COLLINS, of Glasgow, in the County of Lanark, North Britain, Machine
Maker. "IMPROVEMENTS IN LOOMS FOR WEAVING."
This Invention has reference to certain simple improvements in the construction
or arrangement of the actual shedding mechanism of power looms, for the weaving
of tarlatans and other fabrics in which the striped effects are produced by passing
different numbers and sizes of weft threads, or "shots," through the shed of the
warp, opened and held open by the heddle leaves actuated in a positive manner by
the said shedding mechanism, being also improvements upon the Invention for
which Royal Letters Patent were granted to the petitioner, bearing date the 29th
November 1876, and Numbered 4619, which simple improvements will enable this
class of looms fitted with them to weave and produce a greater variety of patterns
or ornamental effects than heretofore. And the nature and novelty of the Invention
consists in producing the shed of the heddle leaves by two oppositely set and acting
cams on one boss or eye revolving loosely between collars on the ordinary oscillating
shedding shaft, or it might be paced by a spring strap or lever, and turned in either
direction with the cams acting or rolling over antifriction pulleys in ordinary shed-
ding levers, directly connected to the heddle leaves above, which are thus actuated
or shed at each half turn of the cam boss in either direction. For thus turning the
cam boss it has two holes (or it might be projections) formed in it at exactly opposite
sides of the axis, opposite a single slightly round edged or ended pin in a longi-
tudinal shifting collar or clutch box, fitted with feather and groove to the oscil-
lating shedding shaft close to the cam boss, all so that when this clutch box (the
action of which is controlled by the new pattern mechanism of the said former
patented Invention) is shifted towards the cam boss, its pin (or it might be recessed
catch) engages into one or other of the catch holes of the cams so as to move them
a half turn with the oscillating shaft and its said clutch box, in whichever direction
the shaft may at the time be oscillated in the usual manner by a pinion on its one
end gearing into a corresponding toothed segment on the end of a rocking lever,
actuated by the crank shaft through a second motion shaft or wheel and eccentric,
so as to make an up or a down stroke, each revolution of the crank shaft and half
revolution of its own driving eccentric and wheel axis. But when this catch or

page_text: clutch box is pushed out of action by the pattern mechanism, the cam boss or box
stands still, and keeps the shed formed for as many picks or shots of weft as deter-
mined by the pattern chain and its mechanism before mentioned, to give the width
of cord desired, with 1, 2, 3, 4, 5, 6, or more shots of the weft, when the pattern
mechanism then brings the clutch into action again with the cam boss, and turns or
oscillates it half a revolution at each action to give the regular shedding motion to
inake plain cloth until another change and figured cord is required.
The essential improved effect obtained is, the giving of the shed to the heddles by
turning the cams half a revolution either backwards or forwards, according as the
single catch box is engaged, by the pattern mechanism, into one or other of the two
catches in the cams at either, the up or the down stroke of the segmental toothed
lever, all instead of the ordinary loose oscillating end or lateral shifting boss or
pulleys, with straps directly connected thereto. and to the heddle leaves for shedding
them, which did not give this power of shedding by a revolving motion in either
direction, but only that of the oscillating action backwards and forwards of the
actuating shaft, and therefore had to make the return stroke, and extra or odd pick
to take back or reverse the shed, which only gave 1, 3, or 5 picks, and so on in the
shed, while with this simple improvement the 2, 4, or 6 picks may also be given,
effecting the full sequence and all the variety of effects which could be desired.
It is preferred to form the cams with a slight hollow at the centre of their
extreme throw to rest steadily on the antifriction rollers of the shedding levers, to
insure their remaining steady in this central position, where they are set and left by
the catch box, but the catch, box might also be made to shift in a stationary or
holding pin or catch as it left the cams.