IMPROVEMENTS IN THE MANUFACTURE OF DRILLS, RYMERS, SCREWING TAPS, AND OTHER SIMILAR ARTICLES
Year: 1877

page_text: LETTERS PATENT to Thomas Richards Harding and Thomas Walter Harding,
"
both of the Tower Works, Globe Road, Leeds, in the County of York, Hackle,
Card, Comb, & Steel Pin Manufacturers, for the Invention of IMPROVEMENTS
IN THE MANUFACTURE OF DRILLS, RYMERS, SCREWING TAPS, AND OTHER
SIMILAR ARTICLES.”
Sealed the 15th February 1878, and dated the 4th September 1877.
PROVISIONAL SPECIFICATION left by the said Thomas Richards Harding
and Thomas Walter Harding at the Office of the Commissioners of Patents on
the 4th September 1877.
THOMAS RICHARDS HARDING and THOMAS WALTER HARDING, both of the Tower
Works, Globe Road, Leeds, in the County of York, Hackle, Card, Comb, & Steel
Pin Manufacturers. "IMPROVEMENTS IN THE MANUFACTURE OF DRILLS, RYMERS,
SCREWING TAPS, AND OTHER SIMILAR ARTICLES."
Our Invention has reference to the manufacture of twist drills, which have
hitherto been made by cutting the twist grooves out of solid round bars.
Our improvements consist in rolling, forging, or drawing the steel to such sections
as that by twisting the bar, drills similar to the "Morse" twist drill will be
formed.
For the process of twisting, the bar or rod is passed through a die or dies and
feeding rollers, which deliver it to a twisting apparatus actuated by gearing, the
degree of twist being modified, according to circumstances, by a system of change
wheels. The twisted steel rods or bars are then cut to convenient lengths and
hardened, tempered and ground to standard or other sizes, pointed for use at one
or both ends.
In using the above drills they will be held in suitably formed sockets or grips.

page_text: By modifying the grinding the twisted rods or bars are made into Rymers, and
by cutting a thread upon them are thus made into screwing taps.
For some purposes the steel of this section may be used as drills, rymers, or taps,
without being twisted.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Richards Harding and Thomas Walter Harding in the Great
Seal Patent Office on the 1st March 1878.
THOMAS RICHARDS HARDING and THOMAS WALTER HARDING, both of the Tower
Works, Globe Road, Leeds, in the County of York, Hackle, Card, Comb, and Steel
Pin Manufacturers. "IMPROVEMENTS IN THE MANUFACTURE OF DRILLS, RYMERS,
SCREWING TAPS, AND OTHER SIMILAR ARTICLES."
Our Invention has for its object improvements in the manufacture of drills, rymers,
screwing taps, and other similar articles, which will be readily understood from the
following description thercof, reference being had to the accompanying Sheet of
Drawings, in which Fig. 1 shews a bar of steel rolled to such a section that when
twisted the cutting parts will be similar to those of the "Morse" twist drills.
Fig. 2 is a cross section of the bar, shewn in Fig. 1, which is found suitable for a
one inch drill; and Fig. 3 shews such a bar twisted, and ready for cutting up into
drills of required lengths, as shewn in Fig. 4. The steel being thus for the larger
sizes rolled, to the section desired, into bars of considerable length, or if for smaller
sizes, drawn to the section in coils of wire, is next twisted.
For the purpose of twisting the rolled or drawn bars or rods we use a slide lathe
with hollow spindle, and suitable socket or chuck to grip the bars or rods. Such
parts of an ordinary slide lathe as are necessary for explaining the process are shewn
in plan at Fig. 5, and in elevation at Fig. 6. The saddle A, with the standard B,
in which is fixed the die C, through which the bar or rod passes, and on which said
standard B are suitably mounted, the feed rollers D, D, taking into the rolled
or drawn grooves of the steel bar or rod which it is intended to twist. The said feed
rollers D, D, also form a sufficient holding apparatus to prevent the said steel bar or
rod from revolving during the operation of twisting.
When the bar or rod has been firmly gripped in the chuck E, and the lathe set in
motion so as to twist the bar or rod, the saddle A, with its guiding die C, and the
feeding rollers D, D, are at the same time moved away from the chuck or socket E
by means of the usual sliding medium attached to the lathe, which in this case is
the screw F, on which are the driving pulleys F1 and F". The speed of the saddle,
and therefore the amount of twist, are regulated by the system of change gearing
G at the end of the lathe. For some pitches the driving may take place by the
ordinary cone pulley in the lathe headstock. After twisting a convenient length of
the bar or rod the motion of the lathe is stopped, the grip of the chuck or socket E
on the bar or rod is released, the saddle is brought back to its first position
(pushing the twisted portion of the bar or rod through the chuck or socket E and
the hollow spindle of the lathe), the chuck or socket E is then made to take a fresh
grip of the bar or rod, and the twisting process is repeated, till the twisting of the
whole length of the bar or rod has been accomplished.

page_text: The continuous twisted bars or rods are then cut into suitable lengths, the most
suitable apparatus for the purpose being the same hollow spindle lathe already
referred to, and provided with a suitable cutting-off arrangement not shewn in the
Drawing.
Fig. 4 shews a length so cut as to form a point at each end, and these lengths
are then hardened and tempered, and ground up their whole length with emery or
other grinding wheels in the usual way, so as to make them quite true and of
standard size. The drills thus produced, twisted over their whole length, are next
sharpened at both ends for use.
The chuck or socket E may conveniently be constructed, as shewn in Figs. 7, 8,
and 9.
Fig. 7 is a longitudinal section; Fig. 8, a half end view and half cross section.
Fig. 9 shews the gripping jaws in detail and in section. H is the central part or
body of the chuck, which is split or forked at the part I to receive the gripping
jaws J, J. These jaws are made V form on their gripping surfaces; these V surfaces
are also shaped crosswise and angularly into leaves and spaces, which leaves and
spaces intersect and take into each other when the two jaws are made to approach
for gripping small diameters.
On the body of the chuck is formed a concentric projecting bearing at K, and
fixed on the end is a corresponding concentric bearing L. These two bearings
receive the part M, which revolves freely thereon, the inner surface of the said part
M from N to O is formed into two internal helically formed surfaces, which act on
the end of the gripping jaws, as shewn in Fig. 8, a spanner being applied to the
polygonal part M', when it is required to fix or release a bar or rod.
Another form of socket or chuck is shewn in longitudinal section at Fig. 10, in
half cross section and half end view at Fig. 11, and in part section at Fig. 12. The
front part P of this chuck is split or forked in a similar manner to the previously
described chuck for receiving the gripping jaws, which are formed in the same
manner as those in the last-described chuck; on the part P is mounted a bevel
wheel Q, which takes into and drives two bevel pinions R and S, which are fixed
respectively on the screws R¹ and S¹, the collars of which are recessed into and take
a bearing against the part T of the chuck. The movement of the jaws is effected
by means of a spanner applied to the polygonal part Q' of the bevel wheel Q,
thereby turning the screws R' and S¹, and moving the jaws in the desired direction
for gripping or releasing the bars or rods.
Either of these sockets or chucks is found convenient for holding our improved
drills when in use, as such drills require a chuck or socket of suitable length of
bearing to cover the void spaces incident to their twisted figures. By a modification
of the grinding the twisted bars or rods may be made into rymers, and by cutting
a thread upon them may thus be made into screwing taps. For some purposes the
steel of the previously described section may be used as drills, rymers, or taps,
without being twisted.
Having thus particularly described the nature of our said Invention, and the
manner of performing the same, we wish to state that we do not restrict ourselves to
the precise details delineated, as the same may obviously be modified without
departure from the distinctive characteristics of our Invention as herein set forth.
We are aware twist drills have been made, or proposed to be made, with cylindrical
or taper shanks at one end, the remainder of the tool being provided with spiral
grooves, either cut out of the solid steel by circular cutters, or formed out of the
bar by forging or hammering, and then twisting, to which, apart from our improve-
ments, we lay no claim, but what we believe to be novel and original, and
therefore claim as secured to us by the herein-before in part recited Letters
Patent, is,
1. The making of twist drills without shanks, from continuous bars or rods of
steel, rolled or drawn to suitable section, such drills being adapted for being pointed,
sharpened, and used at both ends, substantially as herein-before described with
reference to Figs. 1, 2, 3, and 4 of the accompanying Sheet of Drawings.

page_text: 2. Twisting the bars or rods by machinery, substantially as herein-before
described, with reference to Figs. 5 to 12 inclusive of the accompanying Sheet of
Drawings.
In witness whereof, I, the said Thomas Walter Harding, have hereunto set my
hand and seal, this Twenty-eighth day of February, in the year of our
Lord One thousand eight hundred and seventy-eight.
T. WALTER HARDING. (L.S.)