IMPROVEMENTS IN MACHINERY FOR SHAVING AND NICKING SCREWS
Year: 1876

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine, Lake, &
Co., Patent Agents, Southampton Buildings, London, for the Invention of
"IMPROVEMENTS IN MACHINERY FOR SHAVING AND NICKING SCREWS." A
communication from abroad by the American Screw Company (Incorporated)
of Providence, Rhode Island, United States of America.
aled the 5th December 1876, and dated the 16th October 1876.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 16th October 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR SHAVING
AND NICKING SCREWS." A communication from abroad by the American Screw
Company (Incorporated), of Providence, Rhode Island, United States of America.
In the manufacture of wood screws it is usual to shave and nick the screw upon
different sides of the same machine.
The principal part of my Invention relates to the nicking side of the machine,
and consists in a contrivance for preventing the chucks from wabbling, and for
securing uniformity in the depth of the nicks.
My Invention also consists in the employment in a shaving and nicking machine
of a device for ensuring greater regularity in the revolution of the chucks. As
usual in such machines there are two chucks, which revolve about a common
centre, and the screws are received and discharged on the shaving side of the
machine in the usual manner. The two operations are carried on simultaneously,
the time for nicking a screw being the same as that required for receiving, shaving
twice, and discharging, the order of operation being to shave, nick, and then shave
again.
I will now proceed to describe as much of the double machine as is necessary to

page_text: elevation of the same; Figure 5 is a sectional elevation through the line x, x,
Figures 1 and 2.
A is the frame or table of the said machine; B is the main shaft having bearings
under the said table; C is an upright shaft carrying the circular nicking saw a,
which is secured to its upper extremity by plates and a nut, as shown. The shaft C
is operated from the main shaft by the bevel gear wheels D' and B¹; D is a shaft
having bearings in two standards A1, A2, above the table in which it makes a half
revolution at a time by means herein-after described; E, E¹, are two yokes rigidly
secured to the shaft D, in the eyes of which are supported two chucks F and F for
holding the screw to be operated upon. The chucks have a slight longitudinal
motion through the eyes, but springs c, c, between the yoke E¹, and plates d, d,
secured to the rear ends of the chucks F and F¹ tend to keep the chucks drawn back
towards the rear ends of the machine, the backward movement being limited by
collars e, e; G is a cam shaft carrying two cams H and J, and geared to the main
shaft through an intermediate shaft G', both the cam shaft and the intermediate
shaft having bearings under the table; K is a bell-crank lever hung upon a
pin f in a projection under the table. A spring keeps one end of the bell-crank
lever K in contact with the cam H; its other end is connected by a link 7 with a
lever L rigidly secured to a rock shaft M, as shown; N and N1, are two jaws pivoted
to an arm O, which in turn is pivoted at g to a projection from the standard A¹.
The two jaws N and N¹ have independent pivots, the jaw N being pivoted below
the arm O at h, and the jaw N¹ above at h'. These jaws enclose the saw shaft C, and
have flanges or aprons to direct the course of the filings or dust falling from the
screws. In a slot at the outer end of each jaw a small tooth n is secured by a
plate o and set screw. These teeth n at proper times close upon the screw just
below the head, as shown in Figure 2. A spring p¹ tends to draw the jaw N¹ back
from the screw against the standard A', and in like manner a spring p tends to
draw the jaw N back from the screw towards a rocking lever M³, which is a fixed
projection, from the rock shaft M. This rock shaft M vibrates on two pins r, r,
which have bearings in a bent standard P screwed to the table as shown. In the
upper part of the standard P is a projection t, having in it a slot in which rests a
projection n' from the jaw N, the slot allowing the projection n' a movement when
the jaw N opens and shuts. Between the jaw N and the rocking lever M' is a
toggle which permits the rocking lever to operate upon the jaw at any position in
which the jaw may be placed, the aforesaid spring p keeping the toggle in place.
R is a curved lever also hung upon the pin f. To this lever is attached one end of
a rod u, having at its other end a wedge w, which works through the side of the
table, and through slots in the arms of a V shaped projection S on the side of the
table against a similar wedge on the lower end of an arm W swinging between the
arms of the shaped projection, and pivoted to the side of the table at w, as shown.
A boxed spring & keeps the faces of the two wedges in contact, and thus keeps the
curved lever R in contact with the cam J. The two arms O and W are connected by
means of a rod z, having on it two slides s¹ and s² so connected with the arms Ŏ
and W as to slide on the rod without binding. The rod z is screw threaded, as
shown, and set screws keep the slides 8 and in any required position.
The operation of the mechanism thus far described is as follows:-The cam H at
the proper time permits the jaw N to close upon the screw, when the cam J
coming into play through the aforesaid wedge and the arm W forces back the
pivoted arm O, thereby tightening and drawing back the jaws to force the screw
against and towards the centre of the revolving saw. This operation in the old
arrangement of these machines is attended with a serious difficulty. The teeth n
in drawing the screw towards the saw frequently slip upon the bevel of the screw
head and the screws are accordingly not carried a uniform distance forward, thus
causing a want of uniformity in the depth of the nicks. Yet it is desirable to
employ the teeth to draw the blank upon the saw when the nick is cut, for other-
wise much time is lost in receiving the blank and in discharging it from the chuck,
for where the teeth are not used the chuck must embrace within its grasp nearly

page_text: the whole screw blank up to the head instead of a small portion near the end for
the point. This difficulty, according to my Invention, is overcome, by lengthening
the rod z and pivoting it at z¹ to an arm Z which is pivoted at 2 to the standard A³.
To the arm Z is secured by set screws a plate Y somewhat cam shaped, and
capable of such adjustment as to receive the plates d, d, when the chucks F and F¹
are revolved about the shaft D. Consequently when the rod z carried forward by
mechanism previously described, thereby causing the teeth to close upon and draw
forward the blank, the plate Y pushes forward the chuck in which a screw is held
at the point by the ordinary contrivance, and in connection with the teeth, which
no longer have the liability to slip, forces the screw head an exact distance into or
upon the saw, and the combined action of the plate and the teeth keep the chuck
and blank from wabbling.
It now only remains to describe the device for ensuring regularity and exactness
in the revolution of the chucks. Hitherto their revolution has been made or con-
trolled by ratchets and springs. In place of such uncertain devices I have substituted
gearing applied and operated as follows:-V is a gear wheel upon the cam shaft G;
T is a gear wheel running on a fixed shaft B2 projecting from the table, as shown.
It has two sets of teeth, or rather some of its teeth are longer than others, as shown.
All the teeth take into the teeth of the gear wheel V, whereby the gear wheel T is in
constant revolution. The long teeth which are together, and all of which are seen
in Figure 1, take also at intervals into the teeth of a cog wheel D2 upon the shaft D.
The long teeth on gear wheel T are sufficient in number to cause the shaft D to
make exactly a half revolution at every revolution of the wheel T. C¹ is a four-
sided plate on the shaft D just outside the cog wheel D². Its edges are concaved to
fit upon a part of the periphery of the gear wheel T, which is without teeth, as"
shown in Figure 4, a portion of said periphery being cut away to permit the
plate C to make a half revolution when the shaft D does the same.
Having thus fully described the said Invention, as communicated to me by my
foreign correspondents, and the manner of performing the same, I wish it under-
stood that I claim,-
First. In a shaving and nicking machine the plate Y operated in combination
with the teeth n by the mechanisin above described for the purpose specified.
Second. In combination with the chuck shaft of a shaving and nicking machine
the aforesaid gearing, consisting of a wheel T, cog wheel D2, and plate C₁, arranged
and operated from the main shaft, as above described.
Third. In a shaving and nicking machine, constructed as shewn in the accom-
panying Drawing, the aforesaid improvements, or either of them, arranged and
operating in combination with the other parts of the said machine, as above set
forth and for the purposes specified.
In witness whereof, I, the said William Robert Lake, have hereunto set
my hand and seal, this Sixteenth day of October in the year of our Lord
One thousand eight hundred and seventy-six.
WM. ROBT. LAKE. (L.S.)