Improvements in Tapping and Studding Machines.
Year: 1890

page_text: Date of Application, 29th Jan., 1890
Complete Specification Left, 17th Oct., 1890-Accepted, 22nd Nov., 1890
PROVISIONAL SPECIFICATION.
Improvements in Tapping and Studding Machines.
I, GEORGE WILLIAM ELLIOTT of 160 Shirebrook Road, Heeley, Sheffield, Mining
and Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
The object of this invention is to produce a machine to be used in connection with
a drilling machine or other driving medium, for tapping holes in metals, and screwing
therein studs or bolts, and for other purposes to which it is applicable, whereby the
force transmitted from the drilling machine, or other driving medium, can be
regulated so as not to exceed that which is necessary to do the work, and when any
excessive resistance is met with, or the tap, or stud, has been driven to the bottom of
the hole, there is not sufficient force transmitted to injure the tap, or machine.
Hitherto such machines have been constructed for this purpose, depending upon
the compression of a spring, or springs in connection with inclined surfaces, for
regulating the force transmitted.
By this invention a much cheaper and more durable machine is constructed.
This is effected by making the machine in two parts, one part a spindle, attached to
a drilling machine or other driving medium, and coupled to the other part, which
holds the tap, or stud, by an adjustable frictional coupling, by which means the forco
transmitted from the driving medium may be regulated to rotate the tap, or stud,
without danger of breakage or damage to either, or to the machine.
The spindle is made with a head, or collar, on the opposite end to that attached to
the driving medium, and fitted on the spindle is a drum, bossed-disc, or bush, capablo
of sliding freely upon it in the direction of its lengih, and of being rotated by it.
The other part of the machine is made in a tabular form, one end to carry the tap,
or stud, and the other fitted with the adjustable frictional arrangement which embraces
the drum, bossed-disc, or bush on the spindle, and the centre tubular part large enough
to admit the head or collar on the end of the spindle. A spiral spring encircling the
spindle is placed inside the tubular part, one end abutting against the head of the
spindle, and the other against the lower end of the drum, bassed-dise, or bush, and is
compressed sufficiently to support the weight of the machine, with the exception of
the spindle, and is long enough to be compressed sufficiently to allow that part of the
machine which it supports, to be drawn down by the tap, or stud, until it has reached
the bottom of its hole.
This spring may be dispensed with and a set screw or other device employed to
secure the machine at any desired position on its spindle, when not in use.
Dated this 28th day of January 1890.
GEORGE WILLIAM ELLIOTT.
COMPLETE SPECIFICATION.
Improvements in Tapping and Studding Machines.
I, GEORGE WILLIAM ELLIOTT of 160 Shirebrook Road, Heeley, Sheffield, Mining
and Mechanical Engineer 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 object of this invention is to produce a machine to be used in connection with
a drilling machine, or other driving medium, for tapping holes in metals and screwing
therein studs, or bolts, and for other purposes to which it is applicable, whereby the
force transmitted from the drilling machine or other driving medium can be regulated

page_text: so as not to exceed that which is necessary to do the work, and when any excessive
resistance is met with or the tap or stud has been driven to the bottom of the hole,
there is not sufficient force transmitted to injure the tap or the machine.
To render the mode of carrying out this invention clearly understood, two sheets of
drawings are annexed in which like letters refer to like parts in each figure.
Fig. 1 is a longitudinal section of the machine.
Fig. 2 is a plan of Fig. 1.
Fig. 3 is a longitudinal section of the machine constructed in a different manner
to that shown in Fig. 1.
Fig. 4 is a plan of Fig. 3.
One part of the machine, the spindle a, Figs. 1, 2, is made with a head or collar b,
and fitted on the spindle a, is a bush c, capable of sliding freely upon it in the direction
of its length, and being rotated by it by means of a feather d, or otherwise.
The other part of the machine e, is made in a tubular form, one end f, to carry the
tap at g, and the other made to clip the bush c, and formed with a slit i, down one
side as far as necessary to allow the top part of the tubular pari e, to spring, and be
compressed by the bolt h, which passes through the end of the tubular part e, and a
groove made in the bush c.
By this means a clamp is formed to clip the bush c, and the bolt h, is the means of
adjusting the amount of friction, or driving force transmitted from the part of the
machine a, which is driven by the power used, to the other part e, which carries the
tap at g.
The centre of the tubular part e, is made large enough at k, to admit the head or
collar b, and a set screw or a lever and spring n, employed to keep the part e, carrying
the tap at g, in position when the tap is out of its hole.
Figs. 3, 4, show a machine arranged with a bossed-disc c, instead of a bush as
shown in Figs. 1, 2, driven by the spindle a, to transmit the driving force to the
tubular part e, by being clamped between the part e, and the cap o, which is pressed
on to it by the bolts h h.
In this arrangement is shown a spiral spring 1, encircling the spindle a, within the
chamberk, one end bearing against the lower end of the bossed-disc c, and the other
against the bottom of the chamber k.
The spring 1, is compressed sufficiently to support the weight of the part e, of the
machine, and is long enough to allow that part to be drawn down, together with the
bossed-disc c, on the spindle a, by the tap at g, as it is screwed into its hole, until it
reaches the bottom, the spring 1, being compressed as the tap at g, progresses into
its hole.
The tap may be attached to either end of the machine, and the power applied to
the other.
Having now particularly described and ascertained the nature of muy said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;
1. Constructing tapping machines with the driving force transmitted to the part
holding the tap by a plain frictional coupling capable of adjustment for the purpose,
and in the manner substantially as herein set forth and illustrated.
Dated this 16th day of October 1890.
G. W. ELLIOTT.