IMPROVEMENTS IN MACHINERY FOR SHAVING, POINTING, AND FORMING THE THREAD ON WOOD 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, POINTING, AND FORMING THE
THREAD ON WOOD SCREWS." A communication from abroad by Charles D.
Rogers, of Providence, Rhode Island, United States of America.
Sealed the 7th July 1876, and dated the 19th May 1870.
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 19th May 1876.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "IMPROVEMENTS IN MACHINERY FOR SHAVING,
POINTING, AND FORMING THE THREAD ON WOOD SCREWS." A communication
from abroad by Charles D. Rogers, of Providence, Rhode Island, United States of
America.
This Invention comprises the employment of a multiple tool in each or cither of
the operations of shaving, pointing, and "threading," (or forming the thread of)
screws in machines in which a single tool has been used heretofore; in devices for
bringing the different cutting parts of the multiple tool into operation successively
as they may be required with especial reference to the continued use and adjust-
ment of the tool as it wears away, and in a contrivance whereby the times at which
the different cutting parts of the tool are brought into operation may be determined
automatically.
"
It is well known that in shaving, pointing or threading" screw blanks, the
tools employed for those operations become dull after operating upon a small
number of blanks, and that there is great loss of time and skilled labor in changing
the blunt tool for a sharp tool and in adjusting the new tool for further work.
The object of iny Invention is to remedy this difficulty, and for that purpose I have
so cut teeth in circular steel plates that each tooth when brought up to the blank
by partially revolving the plate shall present to the blank the same cutting edge
or edges presented by the ordinary single tool; and I have also devised mechanism
which may be embodied in the ordinary shaving, pointing, or threading machine,
for successively presenting the different teeth of the plate to the blank with
sufficient exactness and at the required times.
In the accompanying Drawings I have shown the several multiple tools for
respectively shaving, pointing, and "threading," or forming the thread of the screw
and the mechanical devices for operating and adjusting such tools as embodied in
a "threading" machine.

page_text: Figure 1 is a plan of the said "threading" machine; Figure 2 is a front eleva-
tion; and Figure 3 is an inverted plan of the same.
Figures 4 and 5 are vertical sections on the dotted lines in Figures 1 and 2.
Figure 6 is a section through a clutch and cam, herein-after more particularly
described.
Figure 7 is a plan, and Figure 8 is an elevation of a swinging arm and double
cam.
Figures 9 and 10 are a plan and section of a multiple shaving tool.
Figures 11 and 12 are similar views of a multiple pointer.
Figures 13 and 14 are similar views of a inultiple threader.
A is the frame of the machine; B is the spindle provided with any ordinary
means of holding the screw blank; C is the cam shaft driven from the spindle, as
shown and carrying the principal cam D; E is the tool post, having all the motions
of the tool post in ordinary threading machines. Its motion to give the lead to
the screw is derived from a lift on the side of the cam D acting upon the end of
a rocking shaft e to which the tool post is rigidly connected, and which rocks and
slides in bearings projecting from the table or frame, a spring s attached to the
frame and to a rigid elbow projection e¹ from the tool post keeping the end of the
rock shaft e in contact with the cam. The rocking of the tool post forward to carry
the tool forward towards the axis of the blank is governed by a small cam F under
the table which is revolved by a ratchet frigidly attached to it, and a pawl b
attached to a sliding bar G, which in turn is operated by a wedge-shaped projection
on the periphery of the cam D and a spring. As the cam F revolves it gradually
raises a bar H lying on the table, which bar in turn lifts a former I; the former I
in turn lifting the elbow projection e¹. A spring s¹ draws back the tool post when
the cam permits.
When this Invention is applied to a shaving or a pointing machine the mechanism
for giving the lead to the screw is omitted, and the cam Facts directly upon the
elbow projection e¹.
In the threaded mechanism the upper surface of the former I is so shaped as to
cause the point of the screw to be threaded, the end of the elbow projection el
traveling along that surface. The tool is released from the blank between the
successive cuts by means of a projection on the lower side of the former I and a
projection on the upper side of the bar H, and a sliding motion is given to the
har H. When the projections are disengaged the spring & draws back the tool
from the blank; when they are engaged the tool post and tool are directly under
the control of the cam F. The bar H gets its sliding motion from a lever H¹ to
which it is pivoted at h, and which in turn is pivoted to the table and is vibrated
once in every revolution of the cam D by having a projection from it enter a
depression in the side of the can, the said projection being constantly held up
against the side of the cam D by a spring attached to the bar H and the table;
J is a rest for the blank and is rigidly attached to a rock shaft j. A spring coiled
around the shaft keeps the rest back from the blank. The rest is held up to the
blank by means of a pink screwed into an arm clamped to the rock shaft j so as
to form an elbow, the lower end of the pin & resting upon the upper surface of a
ratchet L under the table, revolved by means of a pawl , the pawl being operated
by a sliding bar having a pin engaging with two projections on one side of the
can D. There is a depression in the upper surface of the ratchet L into which the
pin enters once in every revolution of the ratchet, remaining there during a
partial revolution of cam D to permit the rest J to fall back from the blank. Thus
far, with the exception of the multiple tools as units, I have merely described
ordinary screw machinery to which this Invention is applicable.
I will now procced to describe the manner in which I have applied the said
Invention upon such machines,-

page_text: Pis a multiple tool secured by a set screw to a shaft 2, which revolves in
bearings in the tool post E; M is an index wheel, having projections or teeth
corresponding in number and position to the teeth of the multiple tool. The index
wheel is mounted on the same shaft as the multiple tool, being keyed thereto; and
it is obvious that by turning the index wheel one tooth forward and locking it by
any ordinary means the multiple tool will be turned one tooth forward, and a new
tooth will be presented to the screw blank ready to operate upon it; and this
operation may be continued by any operative of ordinary skill until all the teeth of
the tool have been used to such an extent as to require sharpening. As the teeth
rapidly wear away in use, however, it is desirable to have in the machine some
contrivance for bringing a repaired tool up to its work, or for adjusting the tool
whatever may be its diameter. Such a contrivance consists of a quadrant plate N,
loose upon shaft p and secured to the tool post by a set screw working in a slot
in the quadrant; a vibrating arm m pivoted, as shown, with an attached pawl n;
a locking pawl o pivoted to the quadrant at o¹, and having pivoted to it a wedge-
shaped piece a with a notch into which the projecting end of the vibrating arm m
enters, two pins and, and two springs as shown. A partial revolution of the tool is
made by raising the vibrating arm m; this movement causes the pawl n to enter
between two teeth of the index wheel M, and at the same time the inner end of the
vibrating arm m enters the notch of the wedge-shaped piece a and pulls that piece
down, thus disengaging the tooth of the locking pawl o from the teeth of the index
wheel and allowing the pawl n to move the index wheel forward. The wedge-
shaped piece a is held against the pin by a spring as shown, and finally releases
the arm m from the notch when the tooth of the locking pawl o flies back between
the teeth of the index wheel. The vibrating arm m is then permitted to fall back
upon the pin, the spring bringing its attached pawl n back with it.
As the mechanisin for revolving and locking the tool above described (more
especially the locking device) is secured to the quadrant, it follows that by changing
the position of the quadrant on the tool post by means of the set screw and slot
before referred to, the tool may be adjusted to any required position; and further,
that the adjustment having been made for one tooth of the tool it is made for all
the teeth.
It remains to describe an automatic device for operating the vibrating arm m.
This arm is automatically pulled down by force of a spring S². It is lifted by
aT shaped bar R working up and down in a socket in the table, the bar R being
lifted by an arm & clamped to a rocking shaft T under the table, the arm t being
kept away from the bar R by force of a spring coiled on a shaft, except when the
shaft is rocked by a pinion t', operated by a rack w, when the latter descends; the
rack w being in turn caused to descend at required intervals by a cam W loose
upon the spindle, and having a slot in its side to receive the pin v of a spring
clutch V keyed to the spindle.
Y is a swinging arm pivoted to the frame, as shown. It is pulled down at the
proper intervals by a rod c, whose lower end is attached to a swinging lever g
pivoted below the table, and operated by a projection upon the lower side of the
ratchet wheel L, the means for turning which have already been described. The
swinging arm Y has on one side a projection y, serving as a double cam for a
purpose next to be described.
The spring clutch V has a spring pin v, one-half of the end of which bears against
the face of the cam W, or when the pin is unlocked enters the slot in the said cam
while the other half of the end is uncovered, or when the pin is unlocked presses
against the side of the double cam 3. The spring clutch pin v for most of the time
is held in place by a second pin, also having a spring coiled around it, which
pin in turn, from time to time, is drawn out to release the clutch pin by a third
pin rigidly secured to it at right angles and working in a slot in the clutch V, as
shown, this third pin being moved in the slot by striking the cam-shaped
periphery of the double cam y when the arnı Y is drawn down. The operation of
the clutch is accordingly as follows:-At intervals determined by the projection

page_text: on the lower face of the ratchet L the swinging arm Y falls and the cam on the
periphery of the double cam y inoves the pin in its slot, thereby releasing the
clutch pin which enters in part the slot of cam W; but while the clutch Y and
cam W are making a revolution together the pin v strikes the cum on the side of
the double cam y, and is gradually drawn back into its recess in the clutch V, thus
disengaging the clutch V and cam W.
The armi Y is raised by a spring coiled around the rod c. As above stated the
rack w is caused to descend by the cam W acting upon its upper end. When
released from the cam it rises by the force of the aforesaid spring coiled on the
rocking shaft T.
When the vibrating lever m is not operated automatically it should be provided
with a suitable handle.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim,-
First. In a machine for shaving, pointing, and forming the thread of screws a
multiple tool mounted on the tool post, and so governed by a locking index wheel
that by turning forward and locking the said index wheel a new tooth may be
presented to a revolving blank and caused to operate upon it as above described.
Second. In a machine for shaving, pointing, and forming the thread of screws,
a multiple tool having bearings in the tool post in combination with an index
wheel and mechanism for making and preserving the adjustment, whatever may be
the diameter of the tool, as above described.
Third. In a machine for shaving, pointing, and forming the thread of screws a
multiple tool revolved and adjusted as above described, in combination with
mechanism as specified for controlling the revolution of the said tool automatically.
Fourth. In a machine for shaving, pointing, and forming the thread of wood
screws, the parts forming my improvements as above specified, applied and
operating in combination with the other parts of the said machine as shown in the
accompanying Drawings, and as above set forth.
In witness whereof, I, the said William Robert Lake, have hereunto set my
hand and seal, this Nineteenth day of May, in the year of our Lord Onc
thousand eight hundred and seventy-six.
Witness,
JA. EDWARDS,
8, Southampton Buildings,
London.
W. ROBT. LAKE. (L.S.)