IMPROVED DEVICES FOR COMMUNICATING VARIABLE SPEED TO MACHINES
Year: 1885

page_text: We ALEXANDER EASTON Muslin Manufacturer and SAMUEL M°GAW Mechanic
both of Madeira Court Glasgow & JOHN MOUNTGOMERIE COLLINS Machinist of
45 Bartholomew Street Glasgow, do hereby declare the nature of our invention
for "IMPROVED DEVICES FOR COMMUNICATING VARIABLE SPEED TO
MACHINES" to be as follows:-
SEWING
In large factories where engine power is employed for driving sewing machines
the individual machines are brought into operation as required by the worker by
bringing into contact discs or wheels on a main driving shaft and on the machine.
By this means a uniform speed only is obtainable or if the speed be varied such
variation must be effected by varying the friction between the driving discs or
wheels a method which is objectionable because of its uncertainty of action and
the danger resulting from heating of the frictional surfaces. The object of our
invention is to provide for driving sewing machines from a main shaft at variable
speeds but with a positive gripping action between the driver and the driven wheel
or disc. To that end we interpose between the surfaces of the driving disc or wheel
and that which is driven a friction wheel or pulley which may be traversed between
these surfaces and transmit a high or low speed according to the velocity of the
discs or wheels at the point where the friction wheel is in contact. In one modifi-
cation a driving disc on the main shaft acts through an intermediate friction pulley
on a disc on the counter-shaft of the machine the axes of the shafts being parallel.
The intermediate pulley is carried by a spindle which is free to traverse radially
between the discs and when at a position near the axis of the driver and removed
from the axis of the driver wheel it communicates a comparatively slow speed to
the disc on the machine shaft but when shifted nearer to the periphery of the
driver it communicates a much higher speed to the driven disc. The pulley is
traversed by means of a forked lever or other device which may be actuated by a
treadle or handle under control of the worker.
One of the discs is made movable towards or from the other to bring the driving
surfaces into or out of contact and such disc is operated by a treadle or handle in
the usual way.
In lieu of (lises, cones or wheels may form the driving surfaces between which the
friction pulley may be gripped and traversed.

page_text: Improved Devices for Communicating Variable Speed to Sewing
Machines.
We, ALEXANDER EASTON, Muslin Manufacturer and SAMUEL MCGAW, Mechanic
both of Madeira Court, Glasgow, and JOHN MONTGOMERIE COLLINS, Machinist, of
45 Bartholomew Street, Glasgow, Lanarkshire, do hereby declare the nature of our
invention, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement in writing, reference
being had to the accompanying Drawings and to the letters and Figures marked
thereon; that is to say:-
In large factories where engine power is employed for driving sewing machines
the individual machines are brought into operation as required by the worker by
bringing into contact discs or wheels on a main driving shaft and on the machine.
By this means a uniform speed only is obtainable, or if the speed be varied such
variation must be effected by varying the friction between the driving discs or
wheels on the same axis, a method which is objectionable because of its uncertainty
of action, and the danger resulting from heating of the frictional surfaces, besides
the extra wear on the driving bands. The object of our invention is to provide. for
the driving of sewing machines, from a main shaft, at variable speeds, but with a
positive gripping action between the driver and the driven wheel or disc. To that
end we, by our improvements, interpose between the surfaces of the driving disc or
wheel and that which is driven, a transmitting friction wheel or pulley, which may
be traversed radially between their surfaces, and transmits a high or low speed
according to the difference of the circumference at the parts of the discs or wheels
where the friction wheel is in contact with them.
In order that the full nature and novelty of our said Invention, and the mode of
putting the same into effect or practice may be properly understood, we shall now
proceed to describe the several illustrative Figures on the sheet of Drawings which
we have hereunto appended for that purpose, the same reference letters indicating
the same parts in all the Figures where shown.
Figures 1, 2, and 3 are a transverse vertical section, a side elevation, and a plan,
(with a part of the upper wood work as broken away to show the new speed
driving gearing more clearly) all respectively and corresponding to each other, of
a part of a double sewing machine table A, A, carried on iron and wood frames or
standards AA". On the opposite sides of this table a row of sewing machines B, B¹
would be mounted at proper distances apart for the operators to get room to work
and control the action of their respective machines. In these illustrations only one
of the set of sewing machines on each side of the table are shown, having the main
driving shaft C carried in adjustable bearing standards C¹, secured to and projecting
up from the floor under the centre of the table A, A¹, and shown as driven by fast
and loose pulleys C, Cu, at the extreme end of the shaft and table, all so far in a
usual manner-But showing two applications of our improved differential driving
friction speed gearing, one driving each of the sewing machines B and B' on opposite
sides A and A¹ of the table.

page_text: Referring to these Figures and to the arrangement and combination of our
improvement shown for working each sewing machine, a driving disc a is secured
opposite each sewing machine on the main shaft C, and acts through an inter-
mediate transmitting friction pulley b, upon the face of the driven disc c secured
on the band driving counter-shaft c¹ of each sewing machine B or B¹, the axes of
the shaft C and c¹ being parallel and in the same horizontal plane. The inter-
mediate pulley b is mounted to revolve loose on its carrying guide spindle b¹, on
which it is traversed radially between the discs a and c, all mounted so that when
the pulley b is at a position near the axis C of the driver a and removed further
from the axis of the driven wheel c, it communicates a comparatively slow speed
to the discs c on the counter shaft c¹ and to the machine shaft B*; but when the
pulley b is shifted nearer to the periphery of the driver a it communicates a much
higher speed to the driven disc c and to the machine. The pulley b is traversed on
its guide spindle b' by means of its grooved boss and a forked lever rod 6ª actuated
by the arm bu of the treadle b³ preferably of the operators right foot, but it might
be other equivalent connections under the control of the foot or knee.
One of the discs a or c is made movable towards or from the other to bring their
driving surfaces into or out of frictional driving contact, with the transmitting
pulley b between them; and this moving disc is operated by a second treadle e for
this new purpose, much in a usual way.
In this arrangement the inner end of the carrying guide spindle 6, of the
pulley b, is secured loose by a gland 6 over the main shaft C, and has its outer
end carried and guided in a lateral slot in the top of an adjustable standand
secured to the floor z, a stop coller 65 preventing the treadle from bringing the
pulley too far out. The counter-shaft c¹, of the disc c is carried so as to shift a
little on end in its bearings c" in the top of its supporting bracket standard c², and
it is drawn forward towards its driving pulley by the knee of the rod d, actuated
by the slotted gab d" and the crank on the spindle ³, carried in the bearing
bracket d' secured to the floor close to the second treadle foot plate e which by a
pin e in its front end works in a slotted lever secured on the outer end of the
spindle so as to actuate this, which thus draws forward the counter-shaft c¹ and
its disc c as stated. Each disc c of the counter-shafts c, has a groove f cut in its
outer periphery, so that by a band f', passed over this and carried up (through a
bole in the table) and passed over the grooved band pulley f2 of the driving spindle
and hand wheel B2 of the sewing machine will actuate this, all as indicated by the
arrows in Figure 1, which show the direction of motion of all the driving parts
from the main shaft C; and it will be seen that all the machines B on the one
side A of the table have to be driven by open bands f¹ while the machines B¹ on
the other side A¹ require their bands f" to be crossed. The working faces of the
friction driving discs a and c are preferred to be angled inwards, like beveled
wheels, to a point on their axes approaching the point where the axis of the
pulley b intercepts the axes of the discs, as this construction gives each disc a
conical rolling and gripping surface for itself on the pulley b, which gives a freer
shifting and driving action with less friction than if the faces of the discs were
made flat and the pulley parallel working between them. The left foot treadle
plate e when pressed down shifts forward the disc c into working action and when
slightly released enables the right foot treadle plate to shift the pulley b to give
either a slow or quick speed to the counter-shaft c' and to the sewing machine
through the band f¹ all in a positive manner without slip or friction of the driving
parts and bands, and as herein before explained. When the machine has to be
stopped, this is done instantaneously by raising the left foot treadle, when a spiral
or other spring g which is attached to the lower part of the standard c and to the
bar d, draws the bar back, so that a brake block g¹, secured on it, comes against
the face of the disc c and presses it back out of action, with a large collar behind,
up against a leather collar g² on its neck bearing, so as to stop the motion of the
disc c and the sewing machine smoothly and at once without shock. In bringing
the disc c into action again the foot on the treadle e, by a slight play, first takes

page_text: the brake g¹ out of action before the knee arm d¹ of the rod d comes into action to
press the back end of the spindle c' forward as before explained.
In lieu of discs, friction cones, or parellel wheels, or rollers may form the driving
surfaces between which the friction pulley 6 may be gripped and traversed.
Figures 4 and 5 show an end elevation and a plan of an illustration or application
of these friction wheels to drive a counter-shaft cat right angles to the driving
shaft C, where the driving cord pulley f, requires to drive sewing machine spindles
at right angles to those shown in Figures 1 to 3. In this arrangement the counter-
shaft c is mounted in bearings in the top of two vertical arms of a rocking frame h,
and has a parallel friction surface driven wheel or roller c on it opposite the driving
face of the disc a with the loose revolving reciprocating pulley 6 mounted and
traversed between them on its guide-carrying spindle b¹, all as described in reference
to the former Figures 1 to 3. The grooved pulley f, for driving the band f¹ of the
sewing machine in this case is mounted on the overhanging end of the counter-
shaft brought forward for the purpose in a vertical plane with the pulley on the
spindle of the sewing machine above, not shown in these Figures 4 and 5. The
left foot treadle plate e in this arrangement actuates the bent horizontal lever ¹ of
the rocking frame h to bring the roller c into proper working action on the pulley b
and disc a, and when the treadle plate e is released a spring g, attached to the
rocking frame and to the fixed standard of a brake block g¹, brings the roller
wheel c back against the brake block and stops its motion at once. Instead of the
roller wheel being made parallel as shown it might be made conical or tapered as
dotted in on Figure 5.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
First. The arrangement and combination of the parts of a positive driving
differential speed and stop brake driving friction gear for sewing machines,
substantially as herein described, and shown in the accompanying Drawings.
Second. In friction driving gear for sewing machines, the combination of two
disc wheels or cones with transmitting pulley reciprocated between them so as to
approach the periphery of the one disc as it approaches the smaller circumference
of the other, substantially as and for the purposes herein described, and as shown
in the accompanying Drawings.
Third. In friction driving gear for sewing machines, the traversing of a loose
transmitting pulley, between the differential driving and driven surface of such
gear, by one treadle motion, in addition to the usual treadle motion for shifting the
driving disc, substantially as, and for the purposes described, and as shown in the
accompanying Drawings.