IMPROVEMENTS IN SEWING MACHINES
Year: 1878

page_text: 2 :
LETTERS PATENT to Martin Benson, of No. 9, Southampton Buildings, London,
for the Invention of "IMPROVEMENTS IN SEWING MACHINES." A communi-
cation from abroad by Duncan H. Campbell, of Pawtucket, in the County of
Providence, State of Rhode Island, United States of North America.
Sealed the 9th August 1878, and dated the 4th May 1878.
COMPLETE SPECIFICATION filed by the said Martin Benson at the Office of
the Commissioners of Patents on the 4th May 1878.
MARTIN BENSON, of No. 9, Southampton Buildings, London.
"IMPROVEMENTS
IN SEWING MACHINES." A communication from abroad by Duncan H. Campbell,
of Pawtucket, in the County of Providence, State of Rhode Island, United States
of North America.
:
My said improvements have been applied by me to machines for sewing with
waxed thread, and they will be described as embodied in a lock-stitch machine of
the wax-thread class, having an hooked needle, and an awl.
The main features of my Invention consist in a novel construction of the shuttle,
its race and its carrier, and in such a combination of these parts with a crochet or
hook needle, that the shuttle in passing through the loop subjects the waxed thread
to a minimum of frictional contact with the shuttle.
The shuttle is novel in its construction in that it has its point in line with its
longitudinal centre, has a longitudinal score, preferably V shaped, in each of its sides,
and a longitudinally slotted web at its under side, whereby when a shuttle enters a
loop, previously mainly drawn down by the needle, it spreads the loop equally on
both sides, and passes through it in contact therewith at four separate points, one on
each side of the shuttle, and one on each side of the slotted web, and the V shaped
recesses being occupied by correspondingly shaped ways in the shuttle race, the
shuttle is enabled to draw downward such additional thread as may be requisite to
afford its passage.

page_text: The shuttle race is novel in its construction, in that it supports the shuttle inde-
pendently of the carrier, by means of inwardly projecting ways, preferably V shaped
in section, which occupy.similar longitudinal recesses in the shuttle, and which are
broken away on each side adjacent to the middle of the race opposite the path of
the needle. The shuttle race being thus broken away affords a free space for each
side of the loop during the passage of the shuttle, and the projecting ways limit the
shuttle to a longitudinal movement.
For removing the shuttle from the race a portion of one of its projecting ways is
provided with means whereby it may be retired out of engagement with the shuttle.
The shuttle carrier is unlike any previously known to me, in that while it loosely
engages with the heel and shoulders of the shuttle, it does not support said shuttle
or exercise any control over it whatever, except to move it to and fro by abutting
with its heel and shoulders; and said carrier is novel in its construction, in that it
has two oppositely located fingers or projections for contact with the opposite
shoulders of the shuttle.
These several novel features constitute separate portions of my Invention, but I
also claim the novel combination with suitable "feeding" and thread-delivering
mechanism of a hook needle, a centrally-pointed shuttle, supported within the
shuttle race on ways broken away adjacent to the needle, and a shuttle carrier
which surrounds the shuttle longitudinally and laterally, and loosely engages with
its heels and shoulders. I have embodied these novel features in a machine having an
awl which punctures the material on the work plate, and also performs the
feeding" function. The feeding may, however, be accomplished by a complex
movement of the needle as heretofore, or by any other known mechanism for per-
forming that service.
"
In my new machine I also employ certain novel mechanism in connection with
delivering the thread to the needle, but any well-known thread delivery mechanism
may be employed in the combination specified. As it is desirable that the shuttle
should be well tapered at its front, and as the shuttle enters the loop before the
needle has passed fully below the shuttle, I provide an upwardly projecting stop,
centrally located within the race, which when the shuttle advances occupies the
groove between the webs of the shuttle on its under side, and prevents the lower
end of the loop from moving forward with the shuttle; and my Invention further
consists in the combination with a hook needle of a shuttle, provided on its under
side with longitudinal webe separated by a groove and an upwardly projecting stop
within the shuttle race which occupies the groove in the shuttle in its passage over
said stop.
As heretofore constructed a thread eye and a thread arm have been so combined
that the thread is delivered to the hook of the needle in the form of a bight, and
although these elements are employed by me, they operate in my machine in a novel
manner in that they are so constructed and combined with the presser foot, that in
proportion as the latter is located above the work plate by the thickness of the
material on the plate, the operation on the thread arm will vary as to the length of
the thread drawn down by it for presentation to the hooked needle, in other words,
the thread eye and thread arm so co-operate that the quantity of thread drawn
down and presented to the needle will be automatically varied in accordance to the
thickness of the material which is being stitched, and in this connection my
Invention further consists in the combination with a hooked needle and presser foot
a thread eye and a vibrating thread arm, which is connected with and controlled
by the presser foot.
of
;
This portion of my Invention is not limited to a shuttle machine, nor to one
in which a separate awl is employed, because it is applicable to any machine in
which the hook needle is used.
For the purpose of securing the return movement of the thread arm without
liability of abrading the standing thread of the loop as it is being drawn down by
the needle, my thread arm is jointed and provided with a spring, so that it is rigid

page_text: when moving forward, and flexible when moving backward, and this novelty in
construction constitutes another portion of my Invention.
.
In my improved machine the thread eye is also controlled as to the extent of its
vibratory movement by the presser foot, and by having both the thread eye and thread
arm thus controlled, it assures the presentation to the needle of the thread, which
extends from the eye to the arm at a point always about midway between the eye
and the arm, whether they be widely separated and at their extremes of move-
ment or otherwise, thereby enabling the needle to pass downward without causing
the thread to slip in the hook; and my Invention further consists in the combina-
tion with a hook needle of a vibrating thread eye, which is varied with relation to
the extent of its vibratory movement by the location of the presser foot with relation
to the work plate.
In wax-thread machines it is not new to impart a positive lift to the presser foot
during the feeding movement, but I have devised a novel combination of mechanism
which is of special value in machines in which the feeding is effected by the lateral
movement of a vertically reciprocating awl, which co-operates with a vertically
reciprocating needle, these being located respectively above and below the work
plate; said combination consists in a cam on the main shaft, a rod connecting with
said cam, a horizontal spring lever, and a self-adjusting spring clamp, which
engages with the bar or holder of the presser foot with uniformity, whether
the presser foot be at the lowest point or at its highest, or at any intermediate
point.
As heretofore constructed lock-stitch wax-thread machines have been provided
with mechanism for positively controlling the surplus thread of a loop after the
passage of the shuttle, but I have devised a simple and effective "take-up," which is
operated from the main shaft, and is capable of varied adjustment, so as to locate
the junction of the two threads at any desired point within a single thickness of
material, or at any desired point between the upper and lower surfaces of a pile
composed of several layers of leather, or other material capable of being stitched.
This portion of my Invention consists in the combination of suitable tension devices
which will properly deliver thread to the needle for the formation of a loop with a
lever provided with a thread wheel, and an operating lever which is positively
vibrated at intervals by its connection with the main shaft, and which engages
with the thread wheel lever for forcibly vibrating it sufficiently to take up the
surplus thread after the passage of the shuttle and tighten the stitch. For variably
limiting the movement of the thread wheel lever my Invention further consists in
the combination with said lever of an adjustable abutment.
For attaining a heavy strain on the "take-up," when using heavy thread on thick
work, I employ a tension wheel which will freely deliver thread (when the thread
wheel lever is not under the control of the operating lever), and combine therewith
a brake which is operated by the thread itself whenever the thread-wheel lever is
driven downward by its operating lever.
For the purpose of smoothly delivering the thread to the needle, I provide in the
head of the machine a tube, which extends from top to bottom thereof, nearly in
line with the path of the needle, and which is exposed to the heating apparatus ;
and such thread tube within the head of a sewing machine, and exposed to the
heating apparatus, constitutes another feature of my Invention.
For affording great strength and securing durability to the feeding mechanism,
whereby the awl is moved laterally to and fro, my Invention further consists in a
solid head, channeled at top and bottom, in combination with the awl bar slide,.
which is mounted therein, and provided with upper and lower guides occupying
respectively the upper and lower channels in the head.
To more particularly describe my Invention I will refer to the accompanying
Drawings,
Die 1 is a naromactive viene of
nabing embodying my Invention
:

page_text: Fig. 2 is an elevation thereof, with the side of the frame removed for exposing
the main shaft.
Fig. 3 is a sectional view of the head of the machine, the feed slide, and presser
foot holder.
Fig. 4 is a perspective view of the head of the machine, broken from the main
frame, and without the feed slide.
Fig. 5 is a perspective view of the feed slide detached.
Fig. 6 represents the relative positions to each other of the thread eye and
thread arm when the needle is at its lowest position, its path being indicated by
dotted lines.
Fig. 7 represents the thread arm and thread eye in the positions occupied by them
just prior to the descent of the needle with the thread in its hook.
1
Fig. 8 represents the shuttle race in top view.
Fig. 9 represents in perspective the shuttle carrier.
Fig. 10 represents the shuttle in perspective.
Fig. 11 represents the shuttle enlarged and in longitudinal central section.
Fig. 12 represents the shuttle and the carrier in lateral section, as if mounted on
the ways of the shuttle race.
The main shaft is shown at A, provided in the side of the balance wheel a with
a cam groove for operating the tension devices and the feed motion; a side grooved
cam a¹ for operating the awl bar, the thread eye, and the thread arm; a cam a' for
lifting the presser foot during the feeding movement; an edged grooved cam a³
for operating the shuttle, and a side grooved cam a' for operating the hooked
needle.
B denotes the hooked needle which is vertically reciprocated in a slide as usual
beneath the work plate by means of the connection of its holder with the cam a*,
substantially as heretofore. Its cam is so shaped that the needle is moved fully
upward, thence fully downward below the point of the shuttle, thence slightly
upward, and then rests until the next movement.
C denotes the shuttle race which extends transversely across the machine. A
work plate bas heretofore is located over the centre thereof, is provided with a
needle slot, and a screw by which it is secured in position. Two sliding plates b¹
cover the remainder of the race and render it accessible from above. The race on
each side is provided with a projecting way or spline c, which in section is prefer-
ably V shaped, and at a central point each way is removed as at c¹; one portion of
said way c is fitted to slide laterally within a recess, and is provided with cam slots
which are occupied by pins on the sliding rod c³, so that by pulling said rod
outward longitudinally, said portion of the way c is withdrawn into its recess
and forced outward by the return movement of said rod, thereby affording a means
for removing the shuttle from the race as will hereafter be described.
The splines or ways c are secured to the frame of the machine by means of slots
and screws, which admit of adjustment, so as to permit the accurate location of the
shuttle with relation to the needle, and also so as to provide for compensating for
wear from time to time.
At one end of the race, opposite the movable way and below it, is a shuttle
table c, on which the shuttle may rest while being inserted into working position,
and which prevents it from falling when the movable way spline is retired.
The needle bar post is provided with an upwardly projecting stop c, which is
located in front of the hook side of the needle, and occupies a central position in
the shuttle race, as seen in Fig. 8.
D denotes the shuttle carrier, it is in this instance grooved on each side
longitudinally for engaging with the splines or ways c before described. It is
rectangular in form, and encloses the shuttle on each side and at both ends, but it
in no manner supports the shuttle. It abuts with the heel of the shuttle, has two-
oppositely located fingers or projections d...which laterally engage, loosely with the

page_text: shoulders of the shuttle, so that the carrier will be capable of a slight longitudinal
movement without moving the shuttle. The shape of its cam a² is such that the
carrier is moved forward abreast of the needle, then rests, then moves to end
of its stroke, then slightly reciprocates for easing the loop over the rear end of the
shuttle, and then retrurns, substantially as heretofore.
I sometimes mount, this carrier independently of the splines or ways in the
shuttle race by providing independent slides or supports therefor, and this relieves the
ways c from any wear other than that incident to the movement of the shuttle
thereon. E denotes the shuttle, it is hollow, has a detachable heel or cover secured
by a spring, and a perforated tension web on top, substantially as heretofore. It is
also provided on each side with a longitudinal score or groove e for receiving the
ways or splines c in the shuttle race. These scores correspond in form with the
form of the shuttle race splines, and are preferably V shaped. The point of the
shuttle is in line with its longitudinal centre, and preferably slightly below the
lateral centre thereof, as shewn. It has on its under side two webs e', which
extend from the point to the heel of the shuttle, and are separated by a space,
groove, or channel e, which is wider than the diameter of the needle employed
therewith.
As will appear from the lateral section, Fig. 12, the shuttle while passing through
a loop engages therewith only at the two sides and at the edge of each web, thus
but slightly exposing the loop to abrasion. The shuttle when in the race within
the carrier is supported wholly by the splines c, and the carrier has an abutting con-
tact at the rear, and also on each side of the shoulder of the shuttle. The stop c
before described occupies a portion of the path of the shuttle in that it projects
upward within the groove between the webs, when the shuttle enters the loop is
drawn down by the needle and released therefrom; the shuttle then moves forward,
and this stop by engaging with the under side of the loop prevents it from being
moved forward with the shuttle. The shuttle is easily removed from the race after
pulling the sliding rod c, which retires one portion of the spline c into its recess.
F denotes the head of the machine, which contains the presser foot holder,
feed slide, and the awl holder. It is cast solidly with the neck, is channeled at top
and bottom, as at f, for the reception of the guide plates f' of the feeding slide Ġ,
in which the awl g and its holder g is mounted.
The feeding movement is effected by the awl as heretofore, in a manner well
known, and when it moves upward after punching and moving the fabric or
leather is exactly in line with the path of the needle. The presser foot H is as
usual provided with a holder h, which has slide bearings in the head F; and the
upper and lower guides fl of the feeding slide are slotted, so as to afford spaces for
the holder. The presser foot is provided with the usual spring h¹, and the usual
cam lever h² for lifting and retaining it preparatory to receiving work on the table.
The presser foot is lifted at each feeding movement of the slide by means of a cam a³
on the main shaft, the vertical rod h³ provided with a screw thread and thumb
screw at its top for adjustment, a horizontal spring lever h* and a lever clamp h³,
which encircles the presser foot holder h. The lever clamp is composed of a band
or sleeve, which loosely encircles the holder h or spiral spring h', which, when the
presser foot is not lifted, forces the sleeve downward on the holder in contact with
the adjacent surface of the feed guide slide f¹. The clamp lever he is pivoted to
the sleeve ho, and is provided at its inner end with a cam-shaped surface, which
causes it to firmly engage with the presser foot holder only when the cam on the
main shaft operates thereon through the rod and horizontal spring lever h, and
when the lifting pressure is removed from the clamp lever 8 the spiral spring h' is
free to maintain the lever he and sleeve at the lowest possible position in contact
with the upper surface of the guide plate ƒ³.
The feeding slide G is reciprocated to and fro for imparting to the awl g the
lateral motion by which the material is moved for stitching by means of the rock
shaft I, which is actuated from the main shaft by means of the cam groove in

page_text: wheel a.
At the outer end of the shaft I is a grooved arm g² having an adjustable
ping, which is provided with a lever and occupies the groove in the arm, and also
a vertical slot g₁ in the feeding slide G. By adjusting the pin g³ with relation to
the axis of the rock shaft in the groove of the arm g³ and in the slot g' the extent
of movement of the feed slide may be varied substantially as heretofore. The awl
holder g is reciprocated vertically by an arm g on the sleeve I mounted on the
rock shaft I and a connecting link, as heretofore. This rock shaft sleeve I¹ is
actuated by the cam a¹ on the main shaft.
The machine is provided with the usual wax cup heated by suitable means, and the
thread passes from the spool through the wax, and thence to the tension mechanism
as heretofore. The thread in its delivery to the needle is subjected to the action of
the ordinary tension wheel i, which is as heretofore provide with a compressing spring
and adjusting screw. The thread is passed usually once around said tension wheel,
and thence over a small pulley k, thence beneath a shielded wheel k¹ mounted in the
arm of a thread wheel lever 1, thence upward over a shielded wheel k², and thence
downward within a tube m enclosed within the head F, and therein subjected to
heat as shewn in Fig. 3.
For light sewing, the thread pulley k being quite small affords sufficient resistance
against undue draft of thread from the spool, when the thread wheel lever is
depressed, but when intended for heavy sewing, I employ the brake n, which is in
the form of a lever centrally pivoted, as the pulley k mounted in one end thereof,
and has its opposite end arranged to engage frictionally with the thread on the
tension wheel i, whenever the thread wheel lever is depressed for drawing up the
surplus thead, requisite for affording a passage for the shuttle through the loop.
The brake is provided with a lateral pin by which it can be rendered inoperative
for light sewing if desired, and thereby permit the pulley k in itself to operate as a
check on the tension as before described. The thread wheel lever is depressed at
the proper moment by its operating lever O, which is pivoted to the frame of the
machine and is provided with the adjustable finger plate 0¹ which engages when
moving downward with the upper side of the thread wheel lever.
The operating lever is actuated by means of a lever mounted on the rear end of
the rock shaft I, which is in turn connected by a rod o² to a vibrating arm o³
pivoted to the rear side of the machine frame, and provided with a stud and roller
which occupies the cam groove in the side of the balance wheel a.
The thread wheel lever has a vertical pivoted arm, at the end of which the
shielded thread wheel is mounted. A slotted guide is occupied by the axis of the
thread wheel on lever l, and secures to it a truly vertical movement. Below the free
end of lever l, I provide therefor a cushioned abutment p, which consists of a
screw housed in a lateral stud projecting from the frame of the machine.
The head of the screw is recessed for receiving a cushion of leather or rubber, and
the lower end of the screw is squared so that it may be rotated by means of a
wrench for accurately adjusting it, and precisely limiting the extent of the downward
movement of the thread wheel lever.
The thread wheel lever has sometimes been so constructed by me that its upward
movement is relied upon to take up the thread, and this involves merely a modifi-
cation in the construction and arrangement of its operative mechanism without
departing from my Invention. K denotes the thread eye through which the
thread passes from above on its way to the needle. A wire guide as at`q is inter-
posed between the lower end of the tube m in the head, and thread eye, as is
common in sewing machines. This thread eye is mounted on a vertical shaft,
which has at its upper end an arm q', and this in turn is connected by a link q²,
with the lower arm of a bell-crank lever r which is pivoted to the end of a straight
lever 8, which in turn is pivoted to the frame of the machine, and connected at its
opposite end with the presser foot holder h. The bell-crank lever is slotted
vertically for the reception of the end of an arm r, on the sleeve I¹, on rock
shaft I.

page_text: The movement of the rock shaft causes the bell-crauk lever to vibrate on its
pivot to and fro, and impart to the thread eye a vibratory movement in the arc of
a circle. When the presser foot is raised, it causes the farther end of the straight
lever s to be depressed, and this virtually increases the throw of the thread
eye K.
.
I sometimes provide the bell-crank lever with a spring for securing its return
movement, but have in other cases relied upon the arm r¹ on the rock shaft to effect
that movement.
L denotes the thread arm. It is sometimes made by me to move in the arc of a
circle, but in this instance it is arranged to move in a right line to and fro, and is
so formed that its shank passes above the thread eye and its tip below it. It is
rigidly but adjustably inounted by means of a sleeve and a set screw on a down-
wardly projecting stud which is rigidly connected with a sliding bar t provided
with guides in the frame of the machine. At the rear end of the sliding bartis a
lateral pin which occupies a vertical slot t' in the lower end of the bell-crank lever r,
from which it derives its movements.
When the awl is nearly elevated, the thread eye stands at the rear, and the thread
arm in from of tlie needle slot, as shewn in Fig. 6; but when the needle comes up-
ward, the eye and arm approach and pass each other, the eye swinging round and
delivering the thread to the hook of the needle, the thread arm meantime with its
recessed tip u engages with the thread and draws it downward by a rearward move-
ment, as indicated in Fig. 7, after which they both resume their original positions.
The thread arm in its backward movement passes across the path of the
needle which is occupied by the standing thread of the loop, and in order that
it shall pass the thread without undue abrasion, the tip u is stop jointed, and
provided with a back spring which renders the thread arm rigid when moving
backward with the thread, and flexible when returning, so that it may readily
pass the standing thread.
It will be seen that the thread eye and the thread arm (both being operated through
the bell-crank lever r) will be variably moved according to the degree which the
presser foot is elevated, and that therefor the quantity of thread measured off and
presented to the needle will always be proportionate to the thickness of material to
be stitched; it is not always necessary that the movement of the thread eye be varied
provided the thread arm be thus operated, and in such case I provide a separate
arm on the sleeve I', and a separate pendent lever disconnected from the feed bar
holder which will impart to the thread arm a non-variable swinging movement
around the needle.
In stitching thin material I am enabled to attain very satisfactory results without
using the thread arm, and when not desired it can be readily removed.
Having in connection with the detailed description fully set forth the functions
and operation of the several parts, the operation of a machine as a whole will be
readily understood.
I employ usually one main heating lamp M with branch tubes, one of which
terininates beneath the wax cup, and the other at w, within the head F,
which thoroughly heats the tube m and the thread therein, as seen in Fig. 3;
another lamp M₁ is also located below the shuttle race for heating the wax
thread cup within the shuttle, and sometimes a third lamp is employed, located
beneath the wax cup.
L
Any suitable heating apparatus may be employed without in any manner effecting
my Invention.
-
In practice with my machine there is no liability of the undue accumulation of
wax either on the shuttle or in the race, and it will be seen that the thread at no
point is unnecessarily subjected to abrasion.
It is to be distinctly understood that I do not limit my Invention to the precise
construction and arrangement of the several parts, as I am aware from actual

page_text: .
experience that considerable variations may be made with approximately desirable
results without departing from my Invention.
Having now described the construction and manner of working my said Invention,
what I claim is,―
1st. A sewing machine shuttle having its points in line with its longitudinal
centre, a longitudinal recess at each side, and two longitudinal webs separated by a
space or channel, substantially as described.
2nd. A shuttle race having an inwardly projecting shuttle, supporting way, or
spline on each side thereof, which is broken away on each side at or near the middle
of the race, substantially as described.
3rd. A shuttle race having inwardly projecting shuttle supporting ways or splines,
a portion of which is movable, substantially as described, for the removal and
insertion of the shuttle, as set forth.
4th. A rectangular shuttle carrier mounted on ways or splines within the shuttle
race, and having two oppositely located fingers for engaging laterally with opposite
shoulders of the shuttle, substantially as described, whereby said carrier may control
a shuttle in its longitudinal movements, without affording any support therefor, as
set forth..
5th. The combination with suitable "feeding" and thread delivering mechanism
of a hooked needle, a centrally pointed shuttle supported within the race by
splines or ways which are broken away adjacent to the needle, and a shuttle
carrier which surrounds the shuttle longitudinally and laterally, and loosely engages
with its heel and shoulders, as set forth.
6th. The combination with a hook needle of a shuttle having a longitudinal
groove on its under side, and a projecting stop centrally located in the race in
front of the hook side of the needle, substantially as described, for preventing a loop
entered by a shuttle from being moved forward, as set forth.
7th. The combination with a hook needle and presser foot of a thread eye and a
vibrating thread arm which is connected to and controlled as to the extent of its
movement by the presser foot, substantially as described.
-
8th. A thread arm having a jointed spring tip which renders the arm rigid when
carrying thread, and flexible when returning past the standing thread of a loop,
substantially as described.
9th. The combination with a hook needle and presser foot of a vibrating thread
eye (for delivering thread to the needle), which is varied with relation to the extent
of its vibratory movement by the location of the presser foot with relation to the
work plate, substantially as described.
'
10th. The combination with the presser foot, its holder, and the main shaft of a
cam on said shaft, a rod connecting with said cam, a horizontal spring lever, and a
self-adjusting spring clamp which uniformliy engages with the holder, and lifts the
presser foot, regardless of the varied thickness of material beneath the foot, sub-
stantially as described.
•
11th. The combination in a sewing machine, with suitable tension devices which
will properly permit the delivery of thread to a needle for forming a loop, of a
thread wheel lever, and an operating lever, which positively vibrates the thread
wheel lever at intervals, for forcibly taking up the slack thread and tightening the
stitches, substantially as described.
12th. The combination with a positively vibrated thread wheel lever of an
adjustable abutment, which limits the movement of said lever, substantially as
described.
13th. The combination with a spring tension wheel and a vibrating thread wheel
lever of a break which is operated by the thread and thread wheel lever, substan-
tially as described.
14th. In a wax thread machine, a vertical thread tube located within the head
of the machine, and exposed to the heating apparatus, substantially as described,
whereby the thread as it is moved to and fro within the tube by the action of the
needle and take-up is maintained in a well heated condition, as set forth.
:

page_text: 15th. A feeding slide provided with upper and lower guide plates, in combina-
tin with a machine head which is channeled at top and bottom for the reception of
the guide plates of the slide, substantially as described.
.
In witness whereof, I, the said Martin Benson, have hereunto set my hand and
seal, this Third day of April, in the year of our Lord 1878.
MARTIN DENSON Gol