Improvements in Machines for Forming Screw Threads on Bolts and Wood Screws.
Year: 1895

page_text: Date of Application, 1st July. 1895
Complete Specification Left, 31st Mar., 1896-Accepted, 1st Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in Machines for Forming Screw Threads on Bolts and
Wood Screws.
I, LÉON EDMOND MARIE ERNEST LEVENT, of Lovignier-Bavay, in the
Republic of France, Manufacturer, do hereby declare the nature of this invention
to be as follows :-
This invention relates to an improved screw cutting machine especially devised
for the hot screw cutting of bolts and wood screws for rails.
The machine is constructed vertically which arrangement allows of a great
economy of space, of workmanship and of motive power, while being at the same
time of great productive capacity.
Cast in one piece with the hollow frame of the machine are two bosses or
projections which are bored out in order to receive the driving boxes of three
vertical shafts and of three intermediate shafts imparting the movement to three
screw taps. The frame is provided with a large base allowing of fixing the same
firmly to the ground.
The movement is imparted to the machine by a horizontal shaft arranged at the
top of the frame and carrying a fly wheel, and two pulleys, one of which is fixed
and the other loose. Upon the inner extremity of the said shaft a bevel pinion is
mounted which actuates a bevel wheel firmly connected to a case having teeth
arranged internally and gearing with three pinions, imparting the movement to
three vertical shafts. Upon the lower extremity of these three shafts three inside
toothed muffles are keyed; into each of these muffles a driving pinion is encased
which is keyed upon the extremity of one of the intermediate shafts carrying the
screw taps. These pinions are maintained in contact with the teeth of the said
muffles by the aid of screw nuts screwed respectively upon the muffles.
This arrangement permits the shafts to be inclined during the rotary movement
and consequently allows the screw taps to approach and recede from each other.
Each of the screw taps is formed by a cylinder having such a screw thread as is
required to be imparted to the screw or bolt and stops following the conical shape
required by the boring threads.
The aforesaid bevel wheel connected with the case is keyed upon a central shaft
resting in a socket on the one hand and guided by a support jointed upon the top
of the machine frame. Upon this central shaft and above the upper support or
bearing a spur pinion is keyed which gears with a spur-wheel fixed upon a vertical
ebatt arranged on one side of the central shaft. This side shaft transmits its
movement to a movable muffle or clutch mounted upon the lower extremity of said
shaft. The toothed face of this muffle is thrown into gear by the movement of a
pedal with the toothed face of a cam running loosely upon the side shaft. The
movement of this cam ceases when the pedal is released and a stop with inclined
plane held by the cam has freed the driving muffle while imparting to the same a
downward movement. The cam then being left to itself is brought back to its
initial position by a rotary inverse motion imparted to it by a counter-weight
through the medium of a string in connection with a grooved pulley firmly
connected to the cam. The cam is thrown out of gear at the moment when the
screw or both is completely screw threaded; from this moment the counterweight
aforesaid which acts upon the cam by the medium of the pulley, acts also by the

page_text: aid of another pulley and connecting rods upon a hinged cup which then throws
back the finished screw or bolt upon an inclined plane which passes the same into
a receiving bag.
The extremity or nose of a vertical rod which serves to push the screw or bolt
between the screw taps presents a hollow of exactly the same diameter as the head
of the wood screw; the head of this latter once being placed into the nose the
guiding of the screw or bolt in its upward movement is extremely easy.
According to the diameters of the bolts or wood screws to be screw threaded it
is necessary to be able to regulate the withdrawal of the screw taps at the end of
the work. In order to obtain this result first an arrangement is made consisting of
rings with screw threaded rods, which by the aid of spiral springs and thumb
screws allow of constantly pressing the shafts of the screw-taps against small
connecting rods of the collar. The other arrangement consists in a small fly
wheel which allows of regulating the angular course which the cam is required to
impart to the collar. From this course depends the displacement of the small
connecting rods aforesaid and the final approach of the screw taps. One can thus
change very easily the screw cutting diameter according to the pieces to be
worked.
For operating the machine one first regulates the positions of the thumb screws
and of the fly wheel according to the diameter of the pieces to be worked. The
workman who is in a sitting position subsequently takes hold of the heated piece
to be worked with his right hand by the aid of pincers, and introduces said piece
into the nose or socket aforesaid and acts with the right foot upon the proper pedal;
the vertical rod rises and introduces the working piece between the guides as far as
they are required to be screw threaded. The workman subsequently acts with the
left foot upon another pedal whereupon the side muffle and the cam are thrown
into gear the cam actuates the collar as well as the small connecting rods which
act upon the guides or screw taps. As soon as the movement has commenced and
the working piece has been gripped by the guides the vertical rod is enabled to
fall back by releasing the pedal. Whilst the first working piece is thus being
automatically threaded, the workman places a second piece into the nose or socket
which is then passed to the screw tap as soon as the work of the preceding piece
has been finished.
At the same time when the screw cutting of one piece has been finished, the
movable cup which has passed the finished piece into the receiving bag rises whilst
the screw taps recede, in order to permit of the immediate introduction of another
working piece and so forth.
Data: 14
C
1005
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.
Improvements in Machines for Forming Screw Threads on Bolts and
Wood Screws.
I, LEON EDMOND MARIE ERNEST LEVENT, of Lovignier-Bavay, in the
Republic of France, Manufacturer, 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 important improvements in machines for screw threading
bolts and wood screws for rails, by the hot process.
The said invention is embodied in a vertical machine the arrangement of which
permits of greatly economizing space, workmanship and motive power, while its
productive capacity is very considerable.

page_text: The upper bevel wheel g is keyed upon a central shaft g², resting in a socket g³,
on the one-hand, and guided from above in a support g', connected to the top of
the frame a. Upon this shatt g2 and above the support is keyed a pinion h,
gearing with a wheel with angular teeth fixed upon a vertical shaft j placed at
the left side of the machine. This shaft transmits its movement to the movable
coupling box, which is mounted upon the lower extremity of the said shaft. The
toothed fare of this coupling box gears when actuated by the pedal k, with the
toothed face of a cam 1, loose upon the shaft j.
An abutment is fixed to the bottom surface of the cam and is of a sufficient
height to engage during the rotation of this cam, with the rod a of the fork which
controls the up and down movements of the clutch j, and the line which this
abutment describes during its action is an inclined plane or preferably a curve
such as represented in the drawing.
When, under these conditions, by the action of the foot upon the pedal k, the
clutch has entered with its teeth into engagement with those of the cam I, this
cam and its abutment commence to turn and the operator ceases to act upon the
pedal. At the moment, when the blank or bolt is completely screw threaded, the
abutment comes into contact with the rod a and forces the latter to descend, and
thereby the clutch j is instantly disengaged. The cam being then left to itself, is
together with its tappet returned to its initial position by a rotation in the
opposite direction communicated thereto by the counterweight p through the
medium of the cord p' and of the grooved pulley jointly acting with the cam.
This cam will thus execute, at each operation, exactly the same course because
it will always start from the same point and will be thrown out of gear at the same
place.
When the cam is disengaged the counterweight p which acts upon the cam
through the medium of the pulley ², also acts by the aid of the pulley, and the
connecting rods n and upon the hinged cup 2, which then throws the finished
piece upon the inclined plane Z which passes the same into an appropriate
receptacle.
The extremity or recessed head t¹ of the rod t which serves to push the blank
between the screwing rollers, has exactly the hollow shape of the head of the
blank when the head of this latter is once placed in the recessed head, the
guidance of the blank in the upward movement of the rod is extremely easy.
This movement is effected by the aid of a pedal 2 arranged in the axis of the
machine and sideways of the engaging pedal k.
According to the diameters of the blanks to be screw threaded, it is necessary
that the distance between the screwing rollers can be regulated. In order to
obtain this result, there is first a device arranged consisting of the rings rrr with
screw threaded rods which permit, by the aid of the spiral springs and of
the thumb nuts 222, of constantly forcing the shafts of the screwing rollers
against the small connecting rods sss of the collar S constantly bearing against
the cam by a spring y Figure 5.
The other arrangement consists of a small hand wheel which permits of
regulating the angular course, which the cam must impart to the collar S. Upon
this course depends the displacement of the small connecting rods and the definite
approachment of the screwing rollers. The working diameter of the screwing
rollers may thus be very easily changed according to the blanks to be worked
upon.
The operation is as follows
The positions of the thumb screws and of the hand wheel are first
adjusted according to the diameter of the blanks to be worked upon. Subsequently
the workman having taken his seat in front of the machine at the side of the fire,
where the blanks of the bolts or wood-screws or the like, are heated, he takes with
his right hand, by means of a pair of tongs, the heated blank and introduces the
same into the nose or recessed head t'. He then depresses with the right foot the
pedal 2; the rod is thus displaced from below upwardly and, while being

page_text: displaced, introduces the blank between the screwing rollers to the extent
required for screw threading. As soon as this lifting movement is completed,
the workman depresses with the left foot the pedal k; the engagement of the
coupling box and of the cam takes place; the cam commencing to rotate, carries
along with it the collar, and then the small connecting rods sss act immediately
upon the screwing rollers. When the movement commences, these screwing rollers
seize the blank and the rod t can be allowed to fall back by releasing the first
pedal t2.
While the blank, introduced between the screwing rollers without any supervision
on the part of the workman is being screw threaded, the workman places another
blank into the nose or recessed head t' of the rod t, and this latter conveys it to the
screwing rollers as soon as the work of the preceding blank is finished. At the
same time, when the threading of one biank is finished, the movable cup ², which
has conveyed this finished piece into the receptacle, rises while the screwing roliers
recede from one another, in order to allow of the immediate introduction of a fresh
blank and so on.
This work which is effected while the workman is sitting dowu evidently does
not necessitate the exercise of power and a child would be sufficient to perform this
action.
To these advantages must be added that the machine being constructed vertical,
does not occupy more space than an ordinary chasing machine; the same requires
less power than a simple cold screw-cutting machine; its productive capacity is
considerable, owing to the slight amount of movement to be executed by the
workman. In fact in all existing hot screw-cutting machines of horizontal
construction, the workman stands up, a stoker passes on to him the heated blank;
he takes hold of it by the nid of a pair of tongs which he holds in his right hand,
introduces the same by a driving motion with his left hand between the screwing
taps or rollers, waits until the operation is finished, in order to subsequently take
hold again of the finished piece and to throw it on the heap; and not until then
does he commence on the next blank.
In using my vertical machine, almost all these manipulations are obviated: the
workman in a sitting position takes hold of the heated piece, places the same into
the nose or recessed head of the vertical rod t, lifts this rod by exerting a pressure
with his foot upon the pedal t2; the blank is then seized and screw threaded by the
screwing rollers, which have been set in action by the secoud pedal k. The vertical
rod t falls back and receives another blank to be screw threaded, which is
immediately substituted for the finished piece thrown out automatically by the
machine.
It will be understood that I may make such modifications as practice may
suggest, as regards the whole as well as the detail arrangement of my machine.
Although three screwing rollers are quite sufficient, I may employ a greater
number. I may also arrange quite differently the actuating movements of the
cam and the approaching movements of the screw taps, either by placing the cam
itself on the same central shaft as the collar, carrying the small connecting rods,
or in any other manner. I may also change the device which permits of the
simultaneous rotation and approachment of the screw taps.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A vertical machine for screw threading bolts and wood screws for rails, by
the hot process, in which machine a horizontal motor shaft arranged at the top of
the machine frame, transmits its rotary movement, by the intermission of vertical
shafts and of internally toothed muffles, to three or more pendulous shafts or
spindles carrying screwing rollers or taps, so as to enable these shafts or spindles
to be inclined during the rotary movement and consequently to enable the screwing
rollers to be approached or receded, substantially as described.

page_text: 2. In a vertical machine for screw threading bolts and wood screws by the hot
process in combination with the pendulous shafts or spindles carrying the screwing
rollers, a collar embracing these different shafts or spindles, and to which collar
small connecting rods are coupled, one extremity of which is guided in radial
grooves, so that to a partial rotation of the collar in the desired direction
corresponds the direct pressure of the connecting rods upon the pendulous shafts
and consequently the approach of the screwing rollers, substantially as described.
3. The actuating mechanism of the collar which carries the small connecting
rods, acting upon the screwing rollers, this mechanism comprising a cam held
constantly in contact with an arm of the collar and causing its angular displacement
when the said cam is turned; this cam being loosely mounted upon a vertical
shaft actuated by a continuous rotary movement but being carried along by this
shaft, when the workman acts upon a pedal, which causes a movable muffle,
mounted upon the shaft, to gear with the toothed bottom face of this cam,
substantially as described.
4. The automatic cam stopping and returning device comprising an abutment
with an inclined plane or with a curved face, carried by the cam and which throws
the driving clutch out of gear at the desired moment by acting in a downward
direction upon the rod of the fork which actuates this clutch; and a counterweight
located in the frame which acts upon a rope or cord fixed with one end to a pulley
jointly acting with the cam, and which returns this cam to its initial position as
soon as the disengagement has been effected by the abutment, substantially as
described.
5. The mechanism serving to pass the blanks between the screwing rollers,
comprising a rod, terminating in a nose or recessed head, the hollow of which has
the shape of the head of these blanks, and which rod in its rising and descending
movements is controlled and actuated by a pedal and system of levers, substantially
as described.
6. The device for transporting the screw threaded blanks, this device comprising
a movable cup, driven by the intermission of a pulley and of levers, by the
counterweight of the engaging cam, substantially as described.
7. A vertical machine for carrying out the process of screw threading bolts and
wood screws for rails, consisting in the combination and arrangement of the
different devices or mechanisms herein before described.
Dated this 31st day of March 1896.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.