Year: 1897

page_text: I, THOMAS JAMES SLOAN; of 98, Avenue de St. Mande, Paris, France, Engineer,
do hereby declare the nature of this invention to be as follows:
This invention relates to a vertical machine for the manufacture of wood screws
which receives the blanks from the stamping machine and turns them out
completely finished.
The machine consists essentially of a series of mechanisms for performing
successively the following operations:-
(1) Turning the head, forming the nick, and removing the burrs;
(2) Pointing and threading the stems.
A characteristic feature of the machine is that the screw-threading tools which
are stationary and independent in their action, act successively upon each screw
produced, the first tool effecting the roughing and the last tool finishing, so that
should the work performed by one of the tools of the series be defective the defect
would be remedied by the succeeding tools and absolutely perfect screws would
be turned out.
The invention also comprises a distributor which takes the blanks from the
feed channel, presents them in succession to the different tools, and removes at
same time the screw which has been operated on. This distributor arm first
presents each blank to the tools for turning and nicking the head, these tools
essentially comprising two chucks or grippers mounted at 180° apart upon a
vertical shaft which are brought at the desired moment opposite the distributor
arm to deliver the screw thereto after it has been turned and nicked and to receive
the blank which it presents. The gripner which has received the blank turns the
head while the other gripper presents to the milling tool the blank whose head has
been turned. At a given moment the shaft which carries the grippers makes half
a revolution, the first gripner takes the place of the second so as to present to the
milling tool the blank whose head has been turned, and the second gripper returns
to the position of the first and subjects the head of the blank which it holds to a
second action of the head turning tool for removing the burrs produced by the
nicking tool. The blank is then again received by the distributor which conducta

page_text: it to the pointing and screw-threading tools. Every time that a gripper after
having completed half a revolution presents its blank to the action of the tool for
turning the head or removing the burrs it receives rotary motion and in order that
it may be set in motion without shock it is thrown into gear through the medium
of a spring cushioned toothed wheel.
The pointing and screw-threading tools comprise a certain number of
grippers movable about their axis; these grippers are arranged in a circle and the
whole may turn about a common axis so that each gripper will present the blank
This screw-
which it carries successively to the action of the different tools.
threading machine thus differs from those heretofore used in that each screw
made is acted on successively by all the tools of the series from the roughing to the
finishing tools. The distributor coming opposite to these tools takes from the
gripper which is opposite to it the screw which is completely finished and delivers
to this gripper the screw which it brings to it. This gripper presents successively
the screw which it has just received to the action of a special tool for pointing
and then to the action of screw threading tools, each tool continuing the work of
the preceding one. In this arrangement there are as many tools as grippers so
that each gripper is always opposite to the tool and when an operation is terminated
the combination of grippers makes only a fraction of a turn so that each gripper
presents its screw to the action of the following tool, the last tool performing the
finishing operation. The finished screw is carried away by the distributor arm
which throws it into a collecting trough.
The machine performs alone all the operations required in the manufacture of
screws, operations which have heretofore only been performed by means of several
apparatus. The invention therefore enables considerable economy to be effected in
respect of machinery and hand labour and moreover the production is very much
greater.
I have represented in the accompanying drawings an example of the
machine. Figure 1 is an elevation and Figure 2 is a plan of the machine.
Figure 3 is a horizontal section on line 1-2. Figure 4 is a plan of the driving
gear. Figures 5 6 7 are detail views shewing the distributor in elevation,
end view, and plan. Figure 8 is a vertical section of the gripper which holds the
blank during the turning and nicking of the head. Figure 9 is an underside plan
shewing the spring cushioned driving wheel of the gripper. Figures 10 and 11
shew in elevation and plan the device carrying the pinion which is thrown into
gear with the spring cushioned gripper wheel. Figure 12 is a vertical section of
one of the grippers for holding the screw during the threading and of the means
for imparting the two movements to these grippers. 'Figures 13, 14, and 15 are
detail views shewing in elevation, end view, and plan the screw pointing device.
Figure 16 is a plan of the principal parts for cutting the thread. Figure 17 is a
vertical section shewing the operating gear of the threading tool. Figure 18
shews the device for moving the tool in its horizontal plane. Figure 19 is a detail
view of the part whereby the tool is enabled to produce the conical form of the
screw point. Figure 20 shews the mechanism for operating the backstay in which
the screw is held during the threading. Figure 21 shews the mechanism for
operating the backstay in which the blank is held during the turning of the head.
Figure 22 is an elevation and cross-section of the end of the feed trough.
these figures the same reference letters and figures denote the same parts.
In
The various parts are driven from the main shaft a provided with fast and loose
pulleys. The shaft a drives, through a worm 6 and worm wheel c, a vertical
shaft d on which are keyed different cams for imparting the principal movements
to the different parts of the machine.
The feeding of the blanks is effected by a specially constructed distributing arm
consisting of a rod e at the extremity of which is jointed a finger e¹ held in position
by the action of a spring; this finger el is terminated by two small spring
grippers ee, each adapted to seize a screw. The arm e is mounted at the end of a
shaft capable of receiving two movements, rotary motion about its axis and

page_text: sliding motion in the direction of its length. These two movements are so
combined that the distributor may receive either a movement of rotation about the
axis for a forward or backward movement relatively to the machine so as to
perform the evolutions necessary for transporting the screws where required. The
movement of rotation is obtained by means of a toothed sector f¹ keyed on the
spindle and in gear with a rack 9 connected by a link with a lever g¹, to which
is jointed a rod whose extremity is acted on by a cam h keyed on the vertical
shaft d and whose various steps correspond to the different amplitudes of the
angular motions of the distributing arm e. The sliding motion is derived from a
lever arm i movable about a pivot 1 by the action of a cam j keyed on shaft d, this
lever à being connected by a link with the end of spindle f the connection of the
link with the spindle being effected by any coupling permitting free rotary motion
of the spindle.
The distributing arm being in the position shewn in Figure 6 first receives a
forward movement so as to seize by its leading grippere the blank which is con-
tained in the notched part of the feed trough k, Figure 22. The distributor arm
then retires backwards and turns through about 90° from right to left in order to
place itself opposite the tools for turning and nicking the head. This combination
of tools comprises two grippers as follows:-Each gripper comprises, as shewn
in Figure 8, a tubular casing m within which is mounted a system of jointed
levers n' n terminating in gripping jaws n³ n. Upon the casing m is a sliding
collar o carrying at its upper part a pair of friction rollers p and constantly
pressed upwards by a spring a whereby the rollers are pressed against the ends
of the upper members of the gripper levers whereby the gripping jaws are closed
together. The opening motion of the jaws is effected by the descent of rod r carry-
ing a crosshead's guided. by slots in tube m and which in descending bears upon
the collar o and pressing between the two upper members of the gripper forces
them apart. Each gripper receives rotary motion about its axis through the
medium of a spring cushioned toothed wheel t whereby shock is avoided on its
being thrown into gear. The grippers are mounted on the gripper carrier u in
which they can turn freely, the gripper carrier being fixed upon a vertical shaft v
turning in bearings in the frame. By the revolution of the shaft the grippers ¹ 18
are presented in turn opposite the distributor arm e to receive therefrom a blank of
which the head is immediately turned by the cutter w against which it is revolved
by the rotary motion of the gripper about its axis.
At a given moment the shaft v makes half a turn about its axis and again stops
so that the gripper has taken the place of the gripper in order to receive a
blank and turn the head whilst the gripper presents the head already turned to a
milling tool x which cuts the nick. The shaft v then again makes a half turn and
stops, whereupon the gripper 2 presents its blank to the milling tool a whilst the
gripper brings back the notched head of the blank which it holds and again
turns it in contact with the cutter w to remove the burrs, after which it delivers it
up to the distributing arm, receives another blank, and so on for each gripper.
The intermittent rotation of the vertical shaft is obtained by means of a slot
wheel y keyed on that shaft and actuated by a disc z keyed on the vertical shaft d
and carrying a pin and friction roller ¹ which at each revolution engages in one
of the slots of the wheel y and gives it half a turn. In order to securely retain
the grippers during the turning and nicking of the heads, the gripper carrier u
has two diametrically opposite notches u with which alternately engages the end
of a lever 1, the lever being retracted when the shaft v is to be turned under the
operation of a cam 2 on shaft d. The rotary motion of the grippers each
about its own axis is produced as follows: -Each gripper is provided with a
toothed wheel which comes into gear with an intermediate wheel t¹ actuated by
a wheel keyed on a shaft 3 receiving motion from the driving shaft a through
which is mounted
the medium of bevel gear 3, 4. The intermediate wheel
upon a support movable about the axis 3 is brought up to the toothed wheel t by
the action of a spring 5 and a hook 6 forming part of a lever 7 which is actuated

page_text: by a pawl presented by the lever 1. When the shaft v is to make its half revolution,
the pawl 1 on being disengaged from the notch u¹ oscillates the lever 7 and the
hook 6 is retracted at the moment of throwing out of gear. On the other hand at
the moment of throwing into gear, as soon as the pawl 1 is engaged in its notch the
lever 7 is oscillated in the opposite direction under the action of its spring and
the hook engages with the stud carrying the wheel t¹. In order to avoid all
shock when, after the half revolution of the shaft v, the wheel t is thrown into gear
with wheel the toothed wheel t is mounted loose on the casing of the gripper and
is supported by a collar m¹ fast thereon the wheel t transmitting rotary motion to
the gripper through the medium of a spring abutting on the one hand against_a
lug m³ on the collar m' and on the other hand against a lug t on the wheel t. In
order to avoid all binding of the spring the latter is made in sections connected by
movable guide blocks 8, as shewn in Figure 9. The opening and closing of the
grippers is effected at the proper moments by the action of a tappet 9 on the
spindle this tappet being formed by the extremity of a lever movable about
the axis 10 and actuated by a cam 11 keyed on the shaft d.
When the screw blank is engaged between the jaws of one or other of the
grippers it is acted on by a pusher 12 which brings its head opposite to the
cutter w.
This pusher 12 is mounted, by a jointed connection, upon a support 13
clamped at the proper height upon a vertical rod 14 whose up and down movements
at the proper times are determined by the action of a cam 15 mounted on the
shaft d. The screw blank is held up against the cutter w during the turning of
the head, by a support 16 movable about an axis 17 and whose forward and back-
ward motions are produced by a wedge 18 mounted upon the support 13. The
contour of the cam 15 is such that when the screw blank is engaged between the
jaws of the gripper 1 or 2 the rod 14 receives an upward motion. In this move-
ment the wedge 18 escapes the part 16 which under the action of its spring brings
the pusher 12 into line with the axis of the gripper and the pusher then comes
into contact with the head of the screw and raises it to the height of the gripper.
The rod 14 is then moved downwards which has for effect to cause the wedge 18
to bring the part 16 against the stem of the screw blank in order to support the
latter whilst the head is turned.
The cutter w is fixed in a holder w¹ movable about an axis wa so as to advance
the cutting tool against the head of the screw blank at the beginning of the opera-
tion and retract it when the operation is completed, the movement of this tool
carrier being produced by a lever 19 actuated by a cam 20 keyed on the shaft d.
The cutting of the notch is effected at the moment when the screw blank, after
having had its head turned, is brought by the half revolution of the shaft v to the
diametrically opposite point, this operation being performed during the turning of
the head of the next succeeding blank. The milling tool for cutting the notch
For
is mounted on a horizontal axis a actuated by a pinion and worm ³ from a
vertical shaft a driven from the main shaft a through bevel gear. The hori-
zontal shaft ¹ turns in bearings carried by a bracket 7 movable about an axis
and at the moment when the notch is to be cut the whole system is raised by
turning about the axis and lowered again as soon as the notch is cut.
this purpose a thrust rod 21 abuts against an arm of the bracket 7 the rod being
mounted on the end of a lever 22 actuated by a cam 23 keyed on the shaft d, the
length of the rod 21 being capable of adjustment so as to regulate the depth of the
notch. The screw blank after being notched is then again presented, after half a
revolution of the shaft v, to the action of the cutter as above stated, this operation
being analogous to that of turning and having merely for object to remove the
burrs caused by the milling tool.
The screw blank having had its head turned and notched is then re-taken by
the distributing arm e. The latter having come opposite the screw after its move-
ment of rotation through about 90° receives a forward movement the finger el
meeting a fixed abutment 24 is obliged to make a circuit so that it will be caused to
take hold of the turned and notched blank by means of its rear nipper e³. The

page_text: distributor then descends slightly and moves backwards so as to present to the jaws of
or the screw which it carries in its front nipper 3. After having delivered
this blank the distributor is rotated through about 180° and brings the blank
which has had its head turned and notched up to the pointing and screw-threading
tools. This combination of mechanism comprises a certain number of grippers
which hold the screws during the work and impart to them rapid rotary motion
about their axes and which successively bring the screws opposite to different
cutting tools. Each gripper is constructed, as shewn in Figure 12, of a hollow
mandrel within which is a vertically movable rod 25 constantly pressed upward by
a spiral spring and terminating in a head having a pair of slots 26 in which engage
when the rod is moved downwards two lugs 27 carried by the lever arms 28 of the
gripper which carry the gripper jaws 29 adapted to retain the head of the screw
blank. In their normal position these two jaws are constantly pressed together by
the action of the spring acting on rod 25 but when the latter is moved downwards
the slots 26 in which engage the lugs 27 produce the opening motion of the jaws.
The type of machine represented in the drawing is provided with six such
grippers but it is to be understood that this number may be varied according to
circumstances. These six grippers are arranged in a circle on a gripper carrier 30
capable of rotating freely about a central support 31 and receiving intermittent
angular motion so as to carry each gripper from one tool to the next, the extent of
this angular motion in the present case being therefore one-sixth of a revolution.
For this purpose it is provided with a toothed wheel 32 in gear with a pinion 33
keyed on a vertical shaft 34 having at its lower end a slot wheel 35 in the slots of
which engages at each revolution of shaft d a stud and friction roller 36 on
the underside of the disc z. After each angular motion the parts are retained in the
position to which they are moved by a pawl 37 which is caused to engage at the
exact moment with one of the teeth of the wheel 32 the pawl being retracted
during the angular motion, the movement of the pawl 37 being produced by a
bell crank lever 38 acted on by a cam 39 keyed on the shaft d. The opening
motion of each gripper is produced at the proper moment by a tappet 40 which is
caused to depress the stem 25 by the action of a cam 41 keyed on the shaft d.
Each gripper also receives rapid rotary motion about its axis and for this purpose
each mandrel is provided at its upper end with a pinion 42 all these pinions being
in gear with the wheel 43 keyed on the vertical shaft 44 which passes through the
central support 31 on which the gripper carrier 30 turns, this shaft 44 being
driven from the main shaft a through bevel gear 45, 46. Opposite to the first gripper
of the series, that is to say the one in front of which the distributor e has been
brought, is situated the tool for pointing the screw. This tool consists of a cutter 47
(Figures 14, 15) held in a tool carrier 48 provided with a small annular back-
stay 49 in which the blank is supported during the pointing. This tool holder
receives an upward vertical motion at the moment of commencing the operation
and returns to its initial position as soon as its action is completed. For this
purpose it is carried by a small vertical shaft 50 against the lower end of which
abuts a lifting rod 51 jointed to a lever 52 actuated by a cam 53 keyed on the
shaft d. The tool holder 48 also receives at a given moment a slight angular
motion so as to be retracted and make room for the distributor. To this end the
shaft 50 is provided with a finger 54 which in its downward movement meets an
incline 55 against which it is pressed by the action of a spring, the finger in slid-
ing along this inclined plane communicating to the shaft 50 the required angular
motion.
Opposite to each of the other grippers is mounted a screw cutting tool, each of
these tools being identical in construction and so regulated that each continues the
work of the preceding one.
Each screw-threading tool must perform the following operations:-Pass
several times along the part of the shank to be theaded; be retracted after each
passage in order to turn without touching the screw to the commencement
of the thread; make a deeper cut at each passage; cut during one and the same

page_text: passage gradually deeper in order to give the required slightly conical form and
sharp point to the screw.
The tool 56 which is a sort of graver is fixed in a holder 57 mounted on a tubular
spindle 58 receiving a relatively slow downward motion during the screw-thread-
ing operation and an upward or return motion to return the tool to its
initial position. All the tool carriers 57 receive the same movement at the same
time and all of the spindles 58 being actuated in their downward movement by
a ring 59 connected by rods 60 to a crosshead 61 forming a sort of footstep bearing
in which turns the lower end of a shaft 62. This shaft is connected by a sliding
key 63 with a corresponding groove in the hub 64 of the bevel wheel 45 and at
its lower end provided with a leading screw 65 with which is capable of being
geared at a given moment a segmental nut 66 which is moved to and fro in order
to be put in or out of engagement with the screw 65 by a cam 67 on the shaft 68,
driven through wheel 69 and pinion 70 which is in one with the bevel wheel 45.
The hub 64 thus turns the shaft 62 which when the screw is engaged by the nut 66
is forced to move downwards carrying with it the ring 59 and consequently all
the tool carriers 57. As soon as the nut 66 is disengaged from the screw 65 the
two holders are raised by spiral springs 71 contained in the tubular spindles 58
the whole being retained on its ascent by cam 72 keyed on the shaft 68 against
which bears roller 73 carried by a lower ring 61. Each tool thus receives a down-
ward movement and passes several times, three for example, along the part of the
screw-stem to be threaded. Before commencing its downward motion each tool
should be applied against the screw to be threaded and for this purpose at the
beginning of the operation each tool holder 57 is pressed forward by a lever 74
against the extremity of which bears an inclined plane 75 carried by a rod 76.
When the rods 76 receive an upward movement the tool carriers 57 move toward
the screws to be threaded and on the other hand when the rods descend the tool
carriers are retracted. Furthermore at each fresh cut the rods 76 rise higher so
as to force the tool to make a deeper cut. These different upward and downward
movements of the rods 76 are produced as follows:-The lower ends of all the
rods 76 bear upon a ring 77 connectel by rods 78 to a hub 79 under which engages
the forked end of a lever 80 actuated by a cam 81 keyed on shaft d. In order to
cause the tool to make a gradually deepening cut so as to give the screw its conical
form, the lever arm 74 carries a cam-like piece 82 of the formn shewn in Figure 19,
against which bears the tool carrier 57 in its descent. The screw is supported
during the action of the threading tool by a backstay 83 which is movable about a
pivot 84 and bears against the screw at the commencement of each threading
operation, its motion being produced by a rod 85 which is recessed at its upper
part to allow the blank to be retracted. Each rod 85 is guided by two collars and
is pressed by a spring against a ring 86 receiving vertical motion; this ring is
carried by a rod 87 guided at its lower part which is actuated through a lever 88
from a cam 89 on the shaft d. The screw-threading tools being thus arranged
there are always six screws being operated on at a time, one being pointed and five
being threaded. Each screw is acted on successively by these six tools (of which
the first three are rough threading tools and the rest finishing) and when the screw
is finished it is retaken from the jaws of the gripper by which it has been held
during all these operations, by the distributor e.
The distributor after having placed between the jaws of the gripper the screw
to be threaded which it brings to it in its rear nipper e³ is slightly retracted and
turns in the reverse direction through about 45° so as to cause the completely
finished screw to be taken by its front nipper which transfers it to a collecting
channel 90 by a slight retracting motion of the distributor which disengages the
screw from the nipper e³ and allows it to fall into the channel 90. The distributor
continues then to turn in the same direction and comes opposite to the feed
channel k; it again moves forward, takes from there another screw blank, and
the same operations are repeated, and so on.
The general operation of the machine may be summed up as follows:-The

page_text: distributor takes with its forward nipper e a screw blank, then after making a
slight backward movement it turns through about 90° in order to come opposite
the tools for turning and nicking the head, it then moves forward in order to seize
with its rear nipper e³ the screw blank of which the head has been turned and,
nicked, and then it gives up to the gripper 11 or 12 the screw which it brought. The
distributor after a slight backward movement then turns through about 180° in
the opposite direction so as to come opposite to the threading tools. It then seizes
by a forward movement with its front nipper the finished screw held in the
jaws 29 which are opposite to it, then after having slightly moved downwards it
continues to advance and rises slightly so as to engage between the same jaws the
screw blank to be threaded which it holds in its rear nipper . The distributor
then turns backward through about 45° and engages the finished screw in the
collecting channel 90, and then by a slight backward movement the nipper e abandons
this screw which falls into the channel 90, the distributor e then completing its
evolution so as to again come opposite to the feed channel k, to which it again
advances in order to take from there a fresh screw blank, and so on. During the
movements of this distributor there are always eight screws in work, one having its
head turned, a second being nicked, a third being pointed, and five others being
threaded. To each revolution of the distributor correspond a half revolution of
the grippers and an angular motion of one-sixth of a turn of the gripper
carrier 30.
Dated this 27th J
100%
I, THOMAS JAMES SLOAN, of 98, Avenue de St. Mande, Paris, France, Engineer,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
This invention relates to a vertical machine for the manufacture of wood screws
which receives the blanks from the stamping machine and turns them out
completely finished.
The machine consists essentially of a series of mechanisms for performing
successively the following operations:-
-
(1) Turning the head, forming the nick, and removing the burrs;
(2) Pointing and threading the stems.
A characteristic feature of the machine is that the screw-threading tools which
are stationary and independent in their action, act successively upon each screw
produced, the first tool effecting the roughing and the last tool finishing, so that
should the work performed by one of the tools of the series be defective the defect
would be remedied by the succeeding tools and absolutely perfect screws would
be turned out.
The invention also comprises a distributor which takes the blanks from the
feed channel, presents them in succession to the different tools, and removes at
same time the screw which has been operated on. This distributor arm first
presents each blank to the tools for turning and nicking the head, these tools
essentially comprising two chucks or grippers mounted at 180° apart upon a
vertical shaft which are brought at the desired moment opposite the distributor
arm to deliver the screw thereto after it has been turned and nicked and to receive
the blank which it presents. The gripper which has received the blank turns the

page_text: head while the other gripper presents to the milling tool the blank whose head has
been turned. At a given moment the shaft which carries the grippers makes half
a revolution, the first gripper takes the place of the second so as to present to the
milling tool the blank whose head has been turned, and the second gripper returns
to the position of the first and subjects the head of the blank which it holds to a
second action of the head turning tool for removing the burrs produced by the
nicking tool. The blank is then again received by the distributor which conducts
it to the pointing and screw-threading tools. Every time that a gripper after
having completed half a revolution presents its blank to the action of the tool for
turning the head or removing the burrs it receives rotary motion and in order that
it may be set in motion without shock it is thrown into gear through the medium
of a spring cushioned toothed wheel.
The pointing and screw-threading tools comprise a certain number of chucks or
grippers movable about their axis; these grippers are arranged in a circle and the
whole may turn about a common axis so that each gripper will present the blank
which it carries successively to the action of the different tools.
This screw-
threading machine thus differs from those heretofore used in that each screw
made is acted on successively by all the tools of the series from the roughing to the
finishing tools. The distributor coming opposite to these tools takes from the
gripper which is opposite to it the screw which is completely finished and delivers
to this gripper the screw which it brings to it. This gripper presents successively
the screw which it has just received to the action of a special tool for pointing
and then to the action of screw-threading tools, each tool continuing the work of
the preceding one. In this arrangement there are as many tools as grippers so
that each gripper is always opposite to the tool and when an operation is terminated
the combination of grippers makes only a fraction of a turn so that each gripper
presents its screw to the action of the following tool, the last tool performing the
finishing operation. The finished screw is carried away by the distributor arm
which throws it into a collecting trough.
The machine performs alone all the operations required in the manufacture of
screws, operations which have heretofore only been performed by means of several
apparatus. The invention therefore enables considerable economy to be effected in
respect of machinery and hand labour and moreover the production is very much
greater.
I have represented an example of the machine in the drawings accompanying my
Provisional Specification. Figure 1 is an elevation and Figure 2 is a plan of the
machine. Figure 3 is a horizontal section on line 1-2. Figure 4 is a plan of the
driving gear. Figures 5 6 7 are detail views shewing the distributor in elevation,
end view, and plan. Figure 8 is a vertical section of the gripper which holds the
blank during the turning and nicking of the head. Figure 9 is an underside plan
shewing the spring cushioned driving wheel of the gripper. Figures 10 and 11
shew in elevation and plan the device carrying the pinion which is thrown into
gear with the spring cushioned gripper wheel. Figure 12 is a vertical section of
one of the grippers for holding the screw during the threading and of the means
for imparting the two movements to these grippers. Figures 13, 14, and 15 are
detail views shewing in elevation, end view, and plan the screw pointing device.
Figure 16 is a plan of the principal parts for cutting the thread. Figure 17 is a
vertical section shewing the operating gear of the threading tool. Figure 18
shews the device for moving the tool in its horizontal plane. Figure 19 is a detail
view of the part whereby the tool is enabled to produce the conical form of the
screw point. Figure 20 shews the mechanism for operating the backstay in which
the screw is held during the threading. Figure 21 shews the mechanism for
operating the backstay in which the blank is held during the turning of the head.
Figure 22 is an elevation and cross-section of the end of the feed trough.
these figures the same reference letters and figures denote the same parts.
In
The various parts are driven from the main shaft a provided with fast and loose
pulleys. The shaft a drives through a worm 6 and worm wheel c, a vertical

page_text: shaft d on which are keyed different cams for imparting the principal movements
to the different parts of the machine.
The feeding of the blanks is effected by a specially constructed distributing arm
consisting of a rod e at the extremity of which is jointed a finger e¹ held in position
by the action of a spring; this finger e¹ is terminated by two small spring
grippers e, e³, each adapted to seize a screw. The arm e is mounted at the end of a
shaft capable of receiving two movements, rotary motion about its axis and
sliding motion in the direction of its length. These two movements are so
combined that the distributor may receive either a movement of rotation about the
axis for a forward or backward movement relatively to the machine so as to
perform the evolutions necessary for transporting the screws where required. The
movement of rotation is obtained by means of a toothed sector f¹ keyed on the
spindle and in gear with a rack 9 connected by a link with a lever g¹, to which
is jointed a rod 9 whose extremity is acted on by a cam h keyed on the vertical
shaft d and whose various steps correspond to the different amplitudes of the
angular motions of the distributing arm e. The sliding motion is derived from a
lever arm i movable about a pivot by the action of a cam j keyed on shaft d, this
lever i being connected by a link 23 with the end of spindle f the connection of the
link with the spindle being effected by any coupling permitting free rotary motion
of the spindle.
The distributing arm being in the position shewn in Figure 6 first receives a
forward movement so as to seize by its leading gripper e³ the blank which is con-
tained in the notched part of the feed trough k, Figure 22. The distributor arm
then retires backwards and turns through about 900 from right to left in order to
place itself opposite the tools for turning and nicking the head. This combination
of tools comprises two grippers 11, 18, as follows:-Each gripper comprises, as shewn
in Figure 8, a tubular casing m within which is mounted a system of jointed
levers n¹, n³, terminating in gripping jaws n³ n. Upon the casing m is a sliding
collar o carrying at its upper part a pair of friction rollers p and constantly
pressed upwards by a spring 9 whereby the rollers p are pressed against the ends
of the upper members of the gripper levers whereby the gripping jaws are closed
together. The opening motion of the jaws is effected by the descent of rod r carry-
ing a crosshead's guided by slots in tube m and which in descending bears upon
the collar o and pressing between the two upper members of the gripper forces
them apart. Each gripper receives rotary motion about its axis through the
medium of a spring cushioned toothed wheel whereby shock is avoided on its
being thrown into gear. The grippers are mounted on the gripper carrier u in
which they can turn freely, the gripper carrier being fixed upon a vertical shaft v
turning in bearings in the frame. By the revolution of the shaft v the grippers 11 12
are presented in turn opposite the distributor arm e to receive therefrom a blank of
which the head is immediately turned by the cutter w against which it is revolved
by the rotary motion of the gripper about its axis.
2:
At a given moment the shaft v makes half a turn about its axis and again stops
so that the gripper has taken the place of the gripper 11 in order to receive a
blank and turn the head whilst the gripper A presents the head already turned to a
milling tool which cuts the nick. The shaft then again makes a half turn and
stops, whereupon the gripper 2 presents its blank to the milling tool whilst the
gripper brings back the notched head of the blank which it holds and again
turns it in contact with the cutter w to remove the burrs, after which it delivers it
up to the distributing arm, receives another blank, and so on for each gripper.
The intermittent rotation of the vertical shaft is obtained by means of a slot
wheel y keyed on that shaft and actuated by a disc z keyed on the vertical shaft d
and carrying a pin and friction roller 2 which at each revolution engages in one
of the slots of the wheel y and gives it half a turn. In order to securely retain
the grippers during the turning and nicking of the heads, the gripper carrier u
has two diametrically opposite notches u¹ with which alternately engages the end
of a lever 1, the lever being retracted when the shaft is to be turned under the
operation of a cam 2 on shaft d. The rotary motion of the grippers 11, 18, each

page_text: about its own axis is produced as follows:-Each gripper is provided with a
toothed wheelt which comes into gear with an intermediate wheel t¹ actuated by
a wheel keyed on a shaft receiving motion from the driving shaft a through
the medium of bevel gear 3, 4. The intermediate wheel t¹ which is mounted
upon a support movable about the axis t³ is brought up to the toothed wheel t by
the action of a spring 5 and a hook 6 forming part of a lever 7 which is actuated
by a pawl presented by the lever 1. When the shaft v is to make its half revolution,
the pawl 1 on being disengaged from the notch u¹ oscillates the lever 7 and the
hook 6 is retracted at the moment of throwing out of gear. On the other hand at
the moment of throwing into gear, as soon as the pawl 1 is engaged in its notch the
lever 7 is oscillated in the opposite direction under the action of its spring and
the hook 6 engages with the stud carrying the wheel t. In order to avoid all
shock when, after the half revolution of the shaft v, the wheel is thrown into gear
with wheel t¹ the toothed wheel is mounted loose on the casing of the gripper and
is supported by a collar m¹ fast thereon, the wheel & transmitting rotary motion to
the gripper through the medium of a spring abutting on the one hand against
a lug m³ on the collar m¹ and on the other hand against a lug on the wheel t. In
order to avoid all binding of the spring the latter is made in sections connected by
movable guide blocks 8 as shewn in Figure 9. The opening and closing of the
grippers is effected at the proper moments by the action of a tappet 9 on the
spindle this tappet being formed by the extremity of a lever movable about
the axis 10 and actuated by a cam 11 keyed on the shaft d.
When the screw blank is engaged between the jaws of one or other of the
grippers it is acted on by a pusher 12 which brings its head opposite to the
cutter w. This pusher 12 is mounted, by a jointed connection, upon a support 13
clamped at the proper height upon a vertical rod 14 whose up and down movements
at the proper times are determined by the action of a cam 15 mounted on the
shaft d. The screw blank is held up against the cutter w during the turning of
the head, by a support 16 movable about an axis 17 and whose forward and back-
ward motions are produced by a wedge 18 mounted upon the support 13. The
contour of the cam 15 is such that when the screw blank is engaged between the
jaws of the gripper 1 or 12 the rod 14 receives an upward motion. In this move-
ment the wedge 18 escapes the part 16 which under the action of its spring brings
the pusher 12 into line with the axis of the gripper and the pusher then comes
into contact with the head of the screw and raises it to the height of the cutter.
The rod 14 is then moved downwards which has for effect to cause the wedge 18
to bring the part 16 against the stem of the screw blank in order to support the
latter whilst the head is turned.
The cutter 2 is fixed in a holder w¹ movable about an axis w so as to advance
the cutting tool against the head of the screw blank at the beginning of the opera-
tion and retract it when the operation is completed, the movement of this tool
carrier being produced by a lever 19 actuated by a cam 20 keyed on the shaft d.
The cutting of the notch is effected at the moment when the screw blank, after
having had its head turned, is brought by the half revolution of the shaft v to the
diametrically opposite point, this operation being performed during the turning of
the head of the next succeeding blank. The milling tool x for cutting the notch
is mounted on a horizontal axis a actuated by a pinion 23 and worm 23 from a
vertical shaft a driven from the main shaft a through bevel gear 5, . The hori-
zontal shaft a turns in bearings carried by a bracket a movable about an axis
and at the moment when the notch is to be cut the whole system is raised by
turning about the axis 28 and lowered again as soon as the notch is cut. For
this purpose a thrust rod 21 abuts against an arm of the bracket 7 the rod being
mounted on the end of a lever 22 actuated by a cam 23 keyed on the shaft d, the
length of the rod 21 being capable of adjustment so as to regulate the depth of the
notch. The screw blank after being notched is then again presented, after half a
revolution of the shaft v, to the action of the cutter as above stated, this operation
being analogous to that of turning and having merely for object to remove the
burrs caused by the milling tool.

page_text: The screw blank having had its head turned and notched is then re-taken by
the distributing arm e. The latter having come opposite the screw after its move-
ment of rotation through about 90° receives a forward movement, the finger e¹
meeting a fixed abutment 24 is obliged to make a circuit so that it will be caused to
take hold of the turned and notched blank by means of its rear nipper e³. The
distributor then descends slightly and moves backwards so as to present to the jaws
of or the screw blank which it carries in its front nipper e² After having delivered
this blank the distributor is rotated through about 180° and brings the blank
which has had its head turned and notched up to the pointing and screw-threading
tools. This combination of mechanism comprises a certain number of grippers
which hold the screws during the work and impart to them rapid rotary motion
about their axes and which successively bring the screws opposite to the different
cutting tools.
Each gripper is constructed as shewn in Figure 12, of a hollow
mandrel within which is a vertically movable rod 25 constantly pressed upward by
a spiral spring and terminating in a head having a pair of slots 26 in which engage
when the rod is moved downwards two lugs 27 carried by the lever arms 28 of the
gripper which carry the gripper jaws 29 adapted to retain the head of the screw
blank. In their normal position these two jaws are constantly pressed together by
the action of the spring acting on rod 25 but when the latter is moved downwards
the slots 26 in which engage the lugs 27 produce the opening motion of the jaws.
The type of machine represented in the drawing is provided with six such
grippers but it is to be understood that this number may be varied according to
circumstances. These six grippers are arranged in a circle on a gripper carrier 30
capable of rotating freely about a central support 31 and receiving intermittent
angular motion so as to carry each gripper from one tool to the next, the extent of
this angular motion in the present case being therefore one-sixth of a revolution.
For this purpose it is provided with a toothed wheel 32 in gear with a pinion 33
keyed on a vertical shaft 34 having at its lower end a slot wheel 35 in the slots of
which engages
at each revolution of shaft d a stud and friction roller 36 on
the underside of the disc z. After each angular motion the parts are retained in the
position to which they are moved by a pawl 37 which is caused to engage at the
exact moment with one of the teeth of the wheel 32 the pawl being retracted
during the angular motion, the movement of the pawl 37 being produced by a
bell crank lever 38 acted on by a cam 39 keyed on the shaft d. The opening
inotion of each gripper is produced at the proper moment by a tappet 40 which is
caused to depress the stem 25 by the action of a cam 41 keyed on the shaft d.
Each gripper also receives rapid rotary motion about its axis and for this purpose
each mandrel is provided at its upper end with a pinion 42 all these pinions being
in gear with the wheel 43 keyed on the vertical shaft 44 which passes through the
central support 31 on which the gripper carrier 30 turns, this shaft 44 being
driven from the main shaft a through bevel gear 45, 46. Opposite to the first gripper
of the series, that is to say the one in front of which the distributor e has been
brought, is situated the tool for pointing the screw. This tool consists of a cutter 47
(Figures 14, 15) held in a tool carrier 48 provided with a small annular back-
stay 49 in which the blank is supported during the pointing. This tool holder
receives an upward vertical motion at the moment of commencing the operation
and returns to its initial position as soon as its action is completed. For this
purpose it is carried by a small vertical shaft 50 against the lower end of which
abuts a lifting rod 51 jointed to a lever 52 actuated by a cam 53 keyed on the
shaft d. The tool holder 48 also receives at a given moment a slight angular
motion so as to be retracted and make room for the distributor. To this end the
shaft 50 is provided with a finger 54 which in its downward movement meets an
incline 55 against which it is pressed by the action of a spring, the finger in slid-
ing along this inclined plane communicating to the shaft 50 the required angular
motion.
Opposite to each of the other grippers is mounted a screw cutting tool, each of
these tools being identical in construction and so regulated that each continues the
work of the preceding one.

page_text: Each screw-threading tool must perform the following operations:-Pass
several times along the part of the shank to be threaded; be retracted after each
passage in order to turn without touching the screw to the commencement
of the thread; make a deeper cut at each passage; cut during one and the same
passage gradually deeper in order to give the required slightly conical form and
sharp point to the graver.
The tool 56 which is a sort of graver is fixed in a holder 57 mounted on a tubular
spindle 58 receiving a relatively slow downward motion during the screw-thread-
ing operation and a quick upward or return motion to return the tool to its
initial position. All the tool carriers 57 receive the same movement at the same
time and all of the spindles 58, being actuated in their downward movement by
a ring 59 connected by rods 60 to a crosshead 61 forming a sort of footstep bearing
in which turns the lower end of a shaft 62. This shaft is connected by a sliding
key 63 with a corresponding groove in the hub 64 of the bevel wheel 45 and
it is also provided with a leading screw 65 with which is capable of being
geared at a given moment a segmental nut 66 which is moved to and fro in order
to be put in or out of engagement with the screw 65 by a cam 67 on the shaft 68.
driven through wheel 69 and pinion 70 which is in one with the bevel wheel 45.
The hub 64 thus turns the shaft 62 which when the screw is engaged by the nut 66
is forced to move downwards carrying with it the ring 59 and consequently all
the tool carriers 57. As soon as the nut 66 is disengaged from the screw 65 the
two holders are raised by spiral springs 71 contained in the tubular spindles 58
the whole being retained on its ascent by cam 72 keyed on the shaft 68 against
which bears roller 73 carried by a lower ring 61. Each tool thus receives a down-
ward movement and passes several times, three for example, along the part of the
screw-stem to be threaded. Before commencing its downward motion each tool
should be applied against the screw to be threaded and for this purpose at the
beginning of the operation each tool holder 57 is pressed forward by a lever 74
against the extremity of which bears an inclined plane 75 carried by a rod 76.
When the rods 76 receive an upward movement the tool carriers 57 move toward
the screws to be threaded and on the other hand when the rods descend the tool
carriers are retracted. Furthermore at each fresh cut the rods 76 rise higher so
as to force the tool to make a deeper cut. These different upward and downward
movements of the rods 76 are produced as follows: The lower ends of all the
rods 76 bear upon a ring 77 connectel by rods 78 to a hub 79 under which engages
the forked end of a lever 80 actuated by a cam 81 keyed on shaft d. In order to
cause the tool to make a gradually deepening cut so as to give the screw its conical
form, the lever arm 74 carries a cam-like piece 82 of the form shewn in Figure 19,
against which bears the tool carrier 57 in its descent. The screw is supported
during the action of the threading tool by a backstay 83 which is movable about a
pivot 84 and bears against the screw at the commencement of each threading
operation, its motion being produced by a rod 85 which is recessed at its upper
part to allow the blank to be retracted. Each rod 85 is guided by two collars and
is pressed by a spring against a ring 86 receiving vertical motion; this ring is
carried by a rod 87 guided at its lower part which is actuated through a lever 88
from a cam 89 on the shaft d. The screw-threading tools being thus arranged
there are always six screws being operated on at a time, one being pointed and five
being threaded. Each screw is acted on successively by these six tools (of which
the first three are rough threading tools and the rest finishing) and when the screw
is finished it is retaken from the jaws of the gripper by which it has been held
during all these operations, by the distributor e.
The distributor after having placed between the jaws of the gripper the screw
to be threaded which it brings to it in its rear nipper e³ is slightly retracted and
turns in the reverse direction through about 450 so as to cause the completely
finished screw to be taken by its front nipper e³ which transfers it to a collecting
channel 90 by a slight retracting motion of the distributor which disengages the
screw from the nipper e³ and allows it to fall into the channel 90. The distributor
then continues to turn in the same direction and comes opposite to the feed

page_text: channel k; it again moves forward, takes therefrom another screw blank, and
the same operations are repeated, and so on.
The general operation of the machine may be summed up as follows:―The
distributor takes with its forward nipper es a screw blank, then after making a
slight backward movement it turns through about 90° in order to come opposite
the tools for turning and nicking the head, it then moves forward in order to seize
with its rear nipper e³ the screw blank of which the head has been turned and
nicked, and then it gives up to the gripper or the screw which it brought. The
distributor after a slight backward movement then turns through about 180° in
the opposite direction so as to come opposite to the threading tools. It then seizes
by a forward movement with its front nipper the finished screw held in the
jaws 29 which are opposite to it, then after having slightly moved downwards it
continues to advance and rises slightly so as to engage between the same jaws the
screw blank to be threaded which it holds in its rear nipper e³. The distributor
then turns backward through about 45° and engages the finished screw in the
collecting channel 90 and then by a slight backward movement the nipper e³ abandons
this screw which falls into the channel 90, the distributor e then completing its
evolution so as to again come opposite to the feed channel k, to which it again
advances in order to take therefrom a fresh screw blank, and so on. During the
movements of this distributor there are always eight screws in work, one having its
head turned, a second being nicked, a third being pointed. and five others being
threaded. To each revolution of the distributor corresponds a half revolution of
the grippers 1 1 and an angular motion of one-sixth of a turn of the gripper
carrier 30.
Having now particularly described and ascertained the nature of the said in-
vertion and in what manner the same is to be performed I declare that what I
claim is:-
1. The herein described vertical machine for making wood screws, consisting in
the combination of:-
--
(a) a distributing arm taking each blank from a feed channel, conducting
it to the different mechanisms of the machine, and delivering it to a
collecting channel;
(b) the group of mechanisms for turning and nicking the head of the screw
and removing burrs;
(c) the group of mechanisms for pointing the screw and cutting the thread;
(a) the collecting channel receiving the finished screws.
2. In the machine herein specified the distributor, consisting essentially in a
lever arm terminated by a double nipper and mounted on a horizontal shaft
receiving a twofold motion viz.:-rotary motion about its axis and longitudinal
motion in the direction of its axis substantially as described with reference to
Figures 5, 6, and 7.
3. In the machine herein specified, the chucks or grippers and their operating
mechanism whereby the screw blanks are held during the turning and nicking of
the head, and the combination therewith of the spring-cushioned gear wheel
whereby rotary motion is imparted to the nippers and the mechanism for holding
in gear the pinion by which this wheel is driven as described.
4. In the herein described machine the construction of the chucks or grippers
and their operating mechanism by which the screws are held during the operation
of threading substantially as described in reference to Figure 12.
5. In the machine herein specified, the screw-pointing mechanism substantially
as described with reference to Figures 13, 14, and 15.
6. In the machine herein specified the rotary chucks or grippers which present
successively each screw to the action of the screw-threading tools which are
stationary and independent of each other so that the first act as roughing and the
last as finishing tools, the work of each tool being thus rectified by those which
follow.

page_text: 7. In the herein described machine the mechanism for operating the screw-
threading tool and the backstay for supporting the screw during the work substan-
tially as described with reference to Figures 16 to 20.
Dated this 24th day of December 1897.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.