IMPROVE- MENTS IN MACHINES TO BE USED IN THE MANUFACTURE OF WOOD-SCREWS
Year: 1883

page_text: LETTERS PATENT to Henry Harris Lake of the firm of Haseltine Lake & C°
Patent Agents, Southampton Buildings London for an Invention of "IMPROVE-
MENTS IN MACHINES TO BE USED IN THE MANUFACTURE OF WOOD-SCREWS
Communicated to him from abroad by Hayward Augustus Harvey of Orange,
"
COMPLETE SPECIFICATION filed by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 11th June 1883.
"
HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co, Patent Agents
Southampton Buildings, London, 'IMPROVEMENTS IN MACHINES TO BE USED IN
THE MANUFACTURE OF WOOD-SCREWS" Communicated to me from abroad by
Hayward Augustus Harvey, of Orange, New Jersey, United States of America,
Mechanical Engineer,
This invention relates to machines for forming the thread on wood-screws, and
more particularly to that class of screw-threading machines in which the thread is
formed by causing the blank to be rolled along the curved face of a stationary die,
having suitably inclined ribs, by the action upon it of a cylindrical rotating die
having corresponding oppositely inclined ribs formed upon its face; and the said
invention consists essentially in giving to the stationary die the capacity of
yielding in a direction perpendicular to the axis of the rotating die.
The desirability of giving to the stationary die this yielding capacity arises from
the fact, that the ordinary iron wire of commerce is now drawn in such extreme
lengths that the opposite ends of a coil exhibit considerable differences in diameter.
By making the concave faced die yielding and supporting it by powerful springs, I
am enabled to roll screw-threads upon blanks of varying sizes without crushing the
larger blanks and without the clogging of the machine, which has heretofore
sometimes been caused by the presence of an unusually large blank.
In the accompanying drawing
Figure 1 is a top view showing one of the cylindrical rotating dies and the
concave faced yielding die, constructed according to this invention.
Figure 2. is a vertical section on the line x, x Figure 1
I have not deemed it necessary to show, in the drawing more than a pair of the
dies employed, as the machine for rolling screw-blanks is fully described in the
Specification of former Letters Patent dated 20th June AD 1879 N° 2465
According to this invention the rotating cylindrical die A is affixed to the upper
end of the vertical shaft A¹, in the same horizontal plane, with the usual concave-
faced die B.

page_text: 1
The concave-faced die B rests upon the horizontal bed or table C, and is tapped
in the centre of its convex side to receive the check bolt D, the shank of which is
inserted through the concave flange, E, which is cast upon, or otherwise fastened to,
the bed or table upon which the concave die rests
The object of the bolt D is to limit the range of movement of the die B toward
the rotating die. The position of the die B, with relation to the rotating die, is
determined by means of the adjusting screws F' and F¹, for which holes are tapped
horizontally through the flange E in directions which are radial in relation to the
rotating cylindrical die.
The inner ends of these screws bear upon the convex sides of stiff curved spring-
plates G and G¹, the ends of which bear respectively either upon the convex face of
the die B, or, if desired, upon other curved spring-plates g, g', interposed between
the convex face of the die B and the spring-plates G, G¹
By turning in the adjusting screws F, F, the die B may be moved toward the
rotating die, until the under side of the head of the screw-bolt D impinges against
the exterior face of the flange E
The machine is operated in the same manner as the machine described in the
said former specification with respect to the method of feeding the blanks to it, and
the operations which it performs on the blanks, but by means of the present
invention the dies are adapted to roll screw threads upon blanks which may vary
sensibly in diameter. To that end I make the springs which I have described
sufficiently stiff to hold the curved die firmly enough to enable the ribs upon its
face to impress the grooves of the desired depths in the body of the blank, while at
the same tinie, if a large blank should get into the machine, the springs will yield
slightly, and thus the large blank will go through the machine, and have the
thread formed upon its body, without either being crushed or stopping the
machine
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 screw-threading machine in which a blank is caused, by the action of
a rotating cylindrical die, to roll across the concave face of a stationary die,
mechanism substantially such as described, whereby the concave die is enabled to
yield in a plane perpendicular to the axis of rotation of the rotating cylindrical die,
as, and for the purpose, set forth
Second, In combination with the rotating cylindrical die A, and the concave-
faced die B having the capacity of horizontal movement toward and from the
rotating die, the adjusting screws F and F¹, inserted horizontally through the
flange E, and suitably curved spring-plates interposed between the ends of the
adjusting screws F and F and the convex face of the die B, as, and for the
purpose, set forth.
Third, The concave-faced die B, provided with the check-screw D loosely
inserted through a suitable perforation in the flange E, in combination with the
adjusting screws F and F¹ and the springs interposed between the inner ends of
the said adjusting screws and the concave faced die, as, and for the purpose, set
forth.
In witness whereof I the said Henry Harris Lake, have hereunto set my hand
and seal this Eleventh day of June in the year of our Lord One thousand eight
hundred and sights three