IMPROVEMENT IN PICKER MOTIONS FOR LOOMS
Year: 1888

page_text: Date of Application, 19th June, 1888
Specification Accepted, 20th July, 1888
[Communicated from abroad by HENRY SAWYER, Millowner and Manufacturer, of
Boston, Massachusetts, and ROSWELL S. DOUGLASS, Gentleman, of Plymouth,
Massachusetts, both in the United States of America.]
I, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery Lane,
London, in the County of Middlesex, Patent Agents, do hereby declare the nature of
the invention for IMPROVEMENT IN PICKER MOTIONS FOR LOOMS and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:—
This invention is an improvement in looms and has relation particularly to certain
improvements in picker motions or means for communicating motion from the driving
mechanism of the loom to the shuttle through the medium of the picker staffs. In
In carrying out this invention two disks are provided which have each a V shaped
projection, the two projections extending inward toward each other, when placed in
position for use, forming, together with the disks, cam wheels to act alternately upon
certain levers hereinafter to be described. These cam wheels are fixed at proper
points to the driving shaft with their V shaped cams bearing certain relation to each
other so that the proper interval of time will be given between the throws of the
picker staffs.
Pivoted to fixed portions of the frame of the loom are lever arms, partly straight and
partly curved, which move about their axes or fulcrums in a horizontal plane and lie
with their straight portions normally close to the inner surfaces of the said disks.
The straight portions of said lever arms are engaged at points forward of the shaft.
which carries the cam disks and between said shaft and the strap ends of the levers,
by the cam points or projections, and after contact at said points the cam projections
are allowed to pass the curved portions of said levers, unobstructed, between said
driving shaft and the fulcrums or the pivoted ends of the said levers. The forward
ends of the levers are connected to the picker staffs on each side of the loom by
flexible straps.

page_text: The picker staffs, in practice have their bottom ends connected by springs in the
usual manner which will keep their upper ends out from the center of the loom
normally. During the revolution of the cam holding shaft the cams act upon the
lever aris described and thus move the picker staffs to throw the shuttle.
In the drawing Fig. 1 is a plan view, partly in section, of part of a loom showing
the improvements.
Fig. 2 is a vertical sectional view of the same.
Fig. 3 is an edge elevation of the cam wheels.
Similar letters of reference indicate like parts in all of the figures.
Referring to the drawing B is the driving shaft properly journalled in the frame of
the loom, upon which are fixed the disks A provided with the inwardly projecting
V shaped cam points F. C, C are the lever arms pivoted to the rear portion of the
frame of the loom and curved or bent laterally in rear of the shaft B, as at 9, so that
the cam points may pass said levers unobstructed on the side of the cam shaft. The
arms C, C, at their rear ends have eyes d through which pass bolts d' which secure
said levers to the frame of the loom and answer the purpose of pivots or fulcrums for
the said arms.
At the opposite ends of the levers C, C are loops E which receive the straps C¹, the
latter of which are secured also to the picker staffs N.
The picker staffs N are of the usual form pivoted at the base of the frame of the
loom and rising to the shuttle race. The cam points of the disks are formed with
easings which merge into the inner faces of the disks and preclude the possibility
of shock between said parts and the levers C. The levers C, at their points of contact
may be provided with anti-friction rollers h, but these are not essential. The lever
arms are placed in horizontal planes close to the cam carrying shaft.
The construction and arrangement of the picker motion has merit over any devices
of this kind of which I have a knowledge in the following particulars, viz.:
First the points of contact between the cams and the levers are forward of the
driving shaft and near the strap ends of said levers so that the benefit of a long
leverage of the levér-arms with short radii-for the disks is secured.
Second: the lever arins being placed so as to contact with the inner surfaces of the
disks, the change from the plane surfaces of said disks and the cam points is easy,
gradual and without lost motion.
Third: the lever arms being almost in a horizontal plane with the driving shaft
force that would be expended in lifting the said arms is avoided.
Fourth the lever arms bearing against the disks at all times the action between
the said disks and levers will be prompt and steady and there can be no‘lost motion‘to
the picker staffs.
:0
Fifth the motion of the lever arms being in a horizontal plane, and the said levers
being close to the driving shaft but little space is required for the device, consequently
it is easily adaptable to any of the ordinary looms now in use.
Sixth: from the nature of the cam points with reference to the disks, said points
are treadily interchangeable with others of larger or smaller size when more or less
'throw to the picker sticks is required.
Seventh: the cam points being eased to the flat surfaces of the diskst the movement
against said: points is smooth and without check and practically noiseless.
'
I am aware of English patent No. 12,979 (old law) which shows and describes
a roller fixed on an arm carried by a rotating shaft and having working in connection
with said troller a lever provided with an offset which normally sets vertically below
the axis of the roller carrying shaft. The roller contacts with the lever or its offset
primarily between the driving shaft and the fulcrum of said lever and ceases its
contact at a point immediately below said shaft. Such contact between the roller and
the laterally moveable lever requires more power to effect a given force than would be
the case were the power exerted forward of the driving shaft and between said shaft
and the moving end of the lever as it is in my arrangement. And not only does not
the roller in said English patent contact forward of the driving shaft but with its
arrangement it is quite impossible for the lever and roller to have such contact.

page_text: It is to be born in mind that this device gives the contact in a horizontal plane with
reference to the driving shaft while said English patent gives the contact in a vertical
plane with reference to the driving shaft.
Then again, the English patent shows the lever inclining inward toward the plane
of movement of the roller which increases the resistance to be overcome by the power
over and above what would be offered were the said lever parallel to the said plane of
movement.
In this device the lever is not only at right angles to the driving shaft but it
is parallel with the plane of the cam disks.
There is also an advantage to this device, over the construction of the English
patent referred to, in that the movement of the lever laterally is guided and steadied
by its contact with the said disk, an advantage impossible to said English patent.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is :
The combination with the cam shaft and the cam disks on said shaft provided with
laterally projecting V shaped cams, of picking levers pivoted at the rear of said cam
shaft and bent or curved at the rear of the said shaft to permit unobstructed passage
of the cam projections, the cam projections engaging with said levers at points
in front of the cain shafts and between the said shaft and the forward ends of the said
levers, as described, the picker staffs and straps connecting the said staffs with the
front ends of the said levers, as and for the purpose set forth.
Dated this 19th day of June 1888.
ALLISON BROS.,
Agents for the Applicant.