Improvements relating to Archimedean Drill Stocks.
Year: 1899

page_text: Date of Application, 2nd June, 1899-Accepted, 8th July, 1899
COMPLETE SPECIFICATION.
Improvements relating to Archimedean Drill Stocks.
We, HOBBIES LIMITED, of 12, Paternoster Square, in the City of London, and
HERBERT JEWSON, of East Dereham, in the County of Norfolk, 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:-
This invention relates to Archimedean drill stocks of the kind having nuts
thereon so constructed as to rotate the drill stock in one direction only, the return
stroke of the nut being inoperative on the helical stem of the drill stock.
The object of this invention is to produce nuts of the character above indicated
which can be rapidly produced and are strong and comparatively cheap to make.
In the accompanying drawings Fig. 1 is an elevation of an Archimedean drill
stock fitted with a nut constructed according to our invention; Fig. 2 is part
of same showing the nut in its inoperative position; Figs. 3 to 6 are enlarged
detail views; Fig. 3 is an under plan of the clutch or pawl; Fig. 4 is a section
on the line of Fig. 3; Fig. 5 is a plan of the lower or toothed or notched part
of the nut, and Fig. 6 is a section on the line y y of Fig. 5. The same letters
of reference where they occur are used to denote the same or corresponding parts
in all the figures.
The nut is formed of two reversely disposed collars or dished parts A & B
stamped or pressed from sheet steel or other suitable material, having each a
central hole large enough to pass over the helical stem C without rotating it,
and connected together by suitable pieces D.
The lower part B is, by suitable dies or otherwise, formed with a series of
notches or teeth barranged in a circle and each having a square shoulder 62 at
one end and tapering off at the other, each shoulder being adjacent to the tapered
end of the contiguous notch or tooth (see Figs. 5 & 6).
The clutch piece E shown in Figs. 3 & 4 is similarly provided with a series of
notches or teeth e' corresponding in size and position to those on the lower part B
of the nut. This clutch piece E has a four sided aperture e adapted to engage
the convolutions of the helical stem C and cause same to rotate when passed
thereover in a longitudinal direction. This clutch piece is placed between the
two parts A and B of the nut with its teeth or notches e pointing downwards
toward those on the lower part B of the nut as shown in Fig. 2, and the parts
A & B are then connected by means of the pieces D which are brazed, soldered
or otherwise rigidly fastened to the parts A & B, and the complete nut so made
is threaded on the helical stem in the ordinary manner.
When the nut is traversed along the stem towards the drill in the direction
shown by the arrows in Fig. 1 the teeth e¹ on the clutch piece E engage the
oppositely disposed teeth 61 on the part 13 of the nut and the clutch E, being held
fast thereby, rotates the stem C. When the nut is traversed in the direction
shown by the arrows in Fig. 2, the teeth on the clutch ride on and pass over the
teeth on the nut without rotating the drill stem.

page_text: It is obvious that, as the upper part A of the nut acts as a simple cover plate
to keep the clutch piece E in position, its shape is not material but we prefer to
make it of the shape shown as thereby the completed nut offers a convenient grip
to the operator. Also that the toothed part B may be the upper part and the
cover part A the lower part of the nut if so desired.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same iš to be performed we declare that what
we claim is:-
--
(1) An Archimedean drill stock nut comprising a part having shouldered
notches or teeth formed in a circle on the face thereof by stamping or pressing,
a correspondingly formed clutch reversely disposed, and a cover plate secured to
the notched part of the nut in any suitable manner so as to enclose the clutch
between the two parts of the nut with its teeth or notches towards those on the
nut substantially as and for the purpose herein before described and illustrated
in the accompanying drawings.
(2) An Archimedean drill stock nut comprising a toothed part and a toothed
clutch having the teeth formed by stamping or pressing from the flat, and a
cover plate to keep the clutch in position to engage the toothed part substantially
as and for the purpose hereinbefore set forth and illustrated in the accompanying
drawings.
Dated FIFIS CL
Or June 1899.
F. W. GOLBY,
36, Chancery Lane, London, W.C.,
Patent Agent for the Applicants.