Improvements in Automatic Wood Screw Cutting Machines.
Year: 1895

page_text: Date of Application, 9th Oct., 1895-Accepted, 14th Mar., 1896
Improvements in Automatic Wood Screw Cutting Machines.
We, AUGUSTIN NIGGLI, of Bözingen, near Biel, and SERAPHIM LAMBERT of
'Grenchen, in the Canton of Solothurn in Switzerland, Manufacturers, 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:-
The invention described in the present Specification relates to an automatic
screw-cutting machine for wood screws, in which several of the appliances required
for cutting the screws, for instance the jaws and several cutting tools are fitted on
a so-called revolver in such a manner that several wood screws may be cut at a
time.
In the accompanying drawings such a screw-cutting machine is represented
in Fig. 1 to 14.
Fig. 1 is a horizontal longitudinal section.
Figs. 2 to 10 are cross-sectious on lines I-I to VIII-VIII of Fig. 1.
Fig. 11 is a plan view of a part of the machine.
Fig. 12 a vertical longitudinal section on lines IX-IX of Fig. 1.
Figs. 13 and 14 details of the machine on a somewhat larger scale.
The revolver, to which are attached the jaws which receive the screws that are
to be cut, as well as also the cutting tools, consists chiefly of the plates 1, 1ª, 1, 1º,
fitted on a hollow shaft. This revolver bears on the shaft 2, and is secured against
displacement in end direction. The shaft 2 bears on one side in the frame of the
machine and on the other side in the hollow part of shaft 3 and is also secured
against unintentional turning.
The jaws 4 for fixing the wood screws are of the usual construction. They are
turnable in the plates 1b and 1° of the revolver and may be opened and shut by
appropriate shifting of rods 5 which stand under spring pressure. The jaws 4 are
fitted on one side with the toothed pinions 6, which all gear together with a common
wheel 7. This wheel 7 receives motion from shaft 3, which latter is actuated from
shaft 12, by means of toothed wheels 8, 9, 10 and 11. The cutting tools 13 are
fastened movably to steel rods 14. The steel rods 14 bear turnably and movably
in plates 1 and 1b of the revolver and their position can be altered towards plate 1
by pins 15 inserted in plate 1 of the revolver and fixed to plate 16, the contrary
change of position can be obtained by springs 17.
The position of plate 16 can be changed by means of a slide 18 fitted around
shaft 3, and with the aid of a movable worm 19, which may move along a toothed
rod 20, when the worm 19 receives motion from shaft 12 through wheels 21, 22, 10
and 11.
To advance the cutters each time after cutting one thread for the distance of
another thread, the following construction is made: Each steel rod 14 has an
arm 23, to which a pin 24 is fixed which can be regulated, and which is pressed, by
a spring 25 fitted to the steel rod and the revolver, against a drum 26, fixed to
shaft 2 and provided with an uneven surface, in such a manner, that on turning
the revolver, pin 24 will slide over the drum-surface and turn the steel rod 14 in
this or that direction, that is to say, it will direct the cutter against the screw or
away from it according to whether pin 24 passes an elevation or a depression on the
surface of the drum 26.

page_text: There are provided on the drum surface as many elevations and depressions
respectively as cuts by the threading tool are required for finishing the screw.
The radial distances from the surface of the drum to the upper edge of the
elevation always amount to the depth of one thread.
During the cutting of the screw, pin 24 slides in the direction of the axis over
the corresponding elevation of the drum 26; these elevations are formed therefore
according to the shape of the screw.
The toothed rod 20 is fixed in a spring-actuated lever 27, and is kept in
connection with worm 19 by an excentric 28 which presses against lever 27 each
time until one thread has been cut, when the toothed rod will be released by a
backward movement of lever 27 occasioned by spring pressure. As soon as this
release has taken place, worm 19, slide 18, plate 16 and the steel rods 14 will be
turned back again by spring-pressure. To prevent this operation from being
carried out too suddenly, a rod 29, fitted to the slide 18 will touch with its
roller 30 a skew-surface 31 which is fitted to a movable spring actuated rod 32 and
which can be moved in one direction with its axis (see Fig. 2) by means of a spring
controlled by a cam 33; thus on moving the rod 32 the skew surface 31 will be
permitted to slide away from under the roller 30, and rod 29 with the slide 18 may
return slowly.
The steels 34, for turning the points of the screws are fixed to holders 35 which
are influenced by springs, and have bearing in plate 1 of the revolver. Each of
these holders 35 can be pushed at the moment, when the point of the screw is to be
cut, against the screw by a movable rod 36, having at its end a roller 37, and with
the aid of a disk 38 which has on its side a concentric cam surface on which the
roller slides.
The plate 38 is fixed loosely and turnably on the fixed shaft 2, and with the aid
of the toothed wheel 39 equally fixed loosely on shaft 2 it may receive its motion
from shaft 42 through toothed wheels 40 and 41. Shaft 42 is actuated by shaft 3
through wheels 45 and 43*, shaft 44, wheels 45 and 45, shaft 46 and wheels 47
and 48.
To give a secure support to the screws during the cutting, a turnable, spring
influenced collar plate 49 is provided, which may fit against the screw and partly
cover the same during the cutting. The collar plates 49 are turnable on pins 50,
which are fixed in plates 1 and 1° of the revolver and are pressed against the screw
by means of movable dogs 51. The dogs 51 bear movably in grooves on
the plates 1 and 1ª and their distance from the middle of the revolver may be
regulated by keys 53. The moving of the dogs 51 is done by means of a cam-
disk 54 fixed on the shaft 2, in the groove of which slide the pins 52 fixed to dogs 51,
whilst the revolver is turning.
The pressing of the collar plate against the screw is obtained by shifting the
dogs 51 against the jaws 4, whilst a contrary movement of the collar plates will
result on the withdrawal of dogs 51, occasioned by the springs.
With the present form of machine eight thread cuts are required for the complete
cutting of a screw therefore eight steps of the step-by-step motion will be necessary;
moreover the cutting of the screw point and the receiving and delivering of the cut
and uncut screws respectively will require more steps, thus 10 steps will be wanted
in all to cut a screw complete which ten steps will have to be executed during one
complete turning of the revolver.
This periodical turning of the revolver is produced by a rod 55, one end of which
engages in the recesses 56 on the circumference of the plate 1, whilst the other
end is connected with a lever 57 which can be actuated by the aid of an excentric 58
fitted on shaft 46. The free end of the rod 55 is constantly pressed by a spring 59
in the corresponding recess 56.
After a partial turn of the revolver has taken place, the latch 60, which fits into
an indent 61 on the circumference of the plate 1° will prevent it from any further
turning. The latch 60 is actuated by an excentric also fixed on the shalt 46.
As soon as the revolver has been fixed by the latch 60, the traction rod 55 is

page_text: shifted out of the recess 56 by a finger 63 and the excentric on shaft 46; and will
be brought into the next recess 56 of plate 1° by the lever 57 fixed on arm 65 and
the excentric 58.
movable spring-
The jaws 4 will be opened by an arm 66 which is fixed on
influenced shaft 67 (see Fig. 11) having an arm 70 provided with pin 68 and
roller 69 so that roller 69 with arm 70 and shaft 67 will be displaced at the right
moment in a horizontal direction by the graduated part of plate 28 fixed to shaft 44,
thus the arm 66 may exercise a sufficient pressure on the rod 5 of the jaw 4, to
open the same.
As the jaws will have to be opened after each th of a turn of the revolver
and the plate 28 makes one revolution at each 10th of a turn of the revolver; to
prevent a too early opening of the jaws, the arm 70 is conducted by pin 68 in a
groove 71 of wheel 72 in such a manner, that the roller 69 will have to come into
contact, at each 2nd revolution of the plate 28, with the graduated part of the
same and may therefore occasion a shifting of shaft 67 and of arm 66 respectively.
The wheel 72 receives its motion from shaft 46 with the aid of wheel 73 and
wheel 74.
The screw blanks are collected in the usual manner by a turnable plate 75 into
a channel 76, the lowest screw will fit into a groove 77 of a movable box 78
forming the termination of channel 76.
Every time an uncut screw has to be directed into a jaw, holding a cut screw
ready, the box 78 will be shifted in an inward direction and the screw lying in
groove 77 will be gripped by the carrier 79, which is fixed on an arm 80, turnable
and movable in a vertical direction; and will be conducted thereby into the
corresponding jaws. The ready cut screw in the same jaws will be gripped by the
discharger 79 and taken out of the jaw as soon as the corresponding collar
plates have made their retrograde movement; after this the carrier 79 will release
the uncut screw to the empty jaws, and the arm 80 will return to its previous
position with the ready-cut screw, which will be dropped in a groove on the way.
The arm 80 is fixed to a turnable and movable shaft 81 and receives its above-
described motion from an arm 82 fixed on the shaft 81 the free end of which arm
slides alternately on two cam plates 83 and 84 fitted together, turning in inverse
directions, making an unequal number of revolutions and fitted with cam surfaces.
The outer plate 83 receives its motion from the wheel 72, whilst the inner plate 84
is actuated by the shaft 44. The arm 82 is pressed constantly against the plates 83
and 84 by a spring 85 influencing the shaft 81. The box 78 is moved backwards
and forwards by the lever 86 the traction rod 87 and arm 89, fixed on shaft 88,
which latter receives its motion from arm 90 fixed on this same shaft and with the
aid of cam plate 91 fitted to the toothed wheel 72. By a spring 92 actuating the
shaft 88, the arm 90 is continually pressed against the circumference of the cam
plate 91.
The working of the machine is as follows:-
The
The upper carrier fitted on the arm 80 takes an uncut screw blank from the
groove 77 of the inwardly shifted box 78, and brings the same before the jaws
containing a ready cat screw, then these jaws open, the lower discharger takes the
ready cut screw from the jaws, after which the upper carrier delivers the uncut
screw to the now empty jaws and the arm 80 returns to its previous position. The
revolver makes now 1th of its complete revolution, during this turning the collar
plate moves against the screw held in the jaws and fits against the same.
steel for turning the points moves against the screw, turns the point, and regains
its former position. The revolver now turns another tenth part. When this turn
is nearly completed the cutting tool moves against the screw and begins to form
the first thread. As soon as this thread has been cut the revolver will turn another
tenth part, during which the cutting tool, influenced by springs, will return to its
former position and make a second cut, and so forth, until the revolver will have
completed 18ths of its revolution. During the last 10th of the revolution, the
collar plate will be returned to its former position by the action of springs.

page_text: As several screws may be cut at the same time with this machine, its efficiency
is considerably greater than that of any other machine in use until now, and it may
be augmented still further by increasing the number of jaws and cutting tools.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
.claim is :
1. An automatic revolver wood screw cutting machine, consisting of a turnable
and fixed revolver having several fittings for fixing the screws and several cutting
tools for cutting and turning the points for same; which are fitted in such a manner,
that several screws may be cut at the same time; the jaws for fixing the screws
having toothed pinions geared with one common wheel, substantially as described
and shown in the drawings.
2. On the screw cutting machine as described in Claim 1, a fixed drum, provided
with elevations and depressions, in connection with turnable, movable, spring
actuated rods holding the cutters; for the purpose of advancing the cutters for
the depth of one cut towards the screw that is to be cut, the radial distance from
the surface of the drum to the top point of the adjacent elevations being in each
case equivalent to the depth of one cut; these elevations to be formed according
to the particular shape of the screw, as described and shown in the drawings.
3. In the machine described in Claims 1 and 2, a turnable plate 38, provided
with a concentric cam surface; in combination with a movable spring actuated
rod (36) for the purpose of forcing the point cutting steels (34) against the screw,
substantially as described and shown in the drawings.
4. In the screw cutting machine described in Claim 3 a worm (19) adapted to be
moved along a fixed toothed rod (20) in connection with a slide (18) and plate (16)
fitted with pins (15) for the purpose of moving the steel rods (14) and cutters (13)
respectively along the screws, substantially as described and shown in the
drawings.
Dated this 9th day of October 1895.
HERBERT HADDAN & Co.,
18 Buckingham Street, Strand, W.C., Agents to the Applicants.