An Improved Metal Expanding Boring Bit.
Year: 1894

page_text: Date of Application, 7th Aug., 18°4
Complete Specification Laft 71h
1005
.
Date of Application, 7th Aug., 1804
Complete Specification Left, 7th May, 1895 Accepted, 22nd June, 1895
PROVISIONAL SPECIFICATION.
An Improved Metal Expanding Boring Bit.
DAVID HONEYWOOD 7 Rosenau Road, Battersea Park London, Engineer
and ERNEST LYNNSTEAD AUSTIN 69 St. Thomas Road, Finsbury Park London,
Engineer, do hereby declare the nature of this invention to be as follows:-
Our invention consists of a turned steel bar of various sizes & lengths consistent
with capacity required & bored up in centre to receive internal expander. The
said internal expander is operated by means of milled collars fitting screwed
portion of said bar & the said milled collars are graduated to shew grade of
expansion. Internal expander is provided with two spiral grooves on the end
giving it a rotary motion by means of two steel slides held and operated by two
plain collars (also working on the above mentioned steel bar) & said slides work
through longitudinal slots running through centre of bar or parallel expander with
taper slots as may be required, a sliding motion is also given to last named expander
by the milled collars above mentioned by reason of a pin which in passing through
centre of parallel expander is brought into contact with the collars above mentioned.
The expauder requiring a rotary motion is provided with a series of eccentric
grooves corresponding with equal number of slots running through cutter end of
bar such slots to receive steel cutters. Both slots & cutters are bevelled on the
ends at suitable angles. To insure contact between cutters & expander a variable
pressure is imparted to said cutters by means of a spiral spring thus keeping same
firmly in position.
Dated this Fourth day of August 1894.
DAVID HONEYWOOD.
ERNEST L. AUSTIN.
RACORA BIG DUTING DIL.
We, DAVID HONEYWOOD of 7 Rosenau Road Battersea Park London, S. W.,
Engineer and ERNEST LYNNSTEAD AUSTIN of 69 St. Thomas Road Finsbury
Park London, N., 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 aud by the following statement :-
Our invention consists of an improved metal expanding boring bit and in order
that it may be fully understood we will now proceed to describe same with the aid
of the accompanying sheet of drawings, in which, Figure 1 is a longitudinal
sectional elevation of an expanding boring bit constructed in accordance with our
invention. Figure 2 a transverse section on line 1. 1. of Figure 1. Figure 3
a transverse section on line 2. 2. of Figure 1, Figure 4 a modification for effecting
the expanding of cutters or imparting the necessary rotary movement to the internal
expander; Figure 5 a cutter as used in the expanding boring bit illustrated in
Figures 1, 2, and 3, Figure 6 an expanding boring bit particularly adapted for
small work, Figure 7 a transverse section on line 3. 3. of Figure 6, Figure 8 an
[Price 8d1

page_text: elevation of the internal expander and Figure 9 a cutter as used in the expanding
boring bit illustrated in Figures 6 and 7.
Similar letters of reference relate to like parts of the drawings.
Referring to Figures 1, 2 and 3 the construction of the bar is as follows:---The
turned steel bar A, which may be of various sizes and lengths as required, is bored
up its centre or made hollow at B to receive the internal expander C which is
operated by means of the milled collars or nuts D, D' as hereinafter described.
The bored or hollow end B of the bar A is effectually closed by a hollow left-handed
screw plug B which serves as a bearing for the end of the internal expander C
which is reduced in diameter at C' for that purpose. The internal expander C
is provided with eccentric or cam shaped grooves or flutes E corresponding in
number with the slots F in the cutter bar A and upon the surfaces of these
grooves or flutes E bed or rest the cutters E' thereby forming a support for entire
length of cutter as shown in Figures 1 and 2. The opposite end of the internal
expander C is provided with two spiral grooves or guides G, G¹ for obtaining the
rotary motion which is effected by means of two steel slides or keys H, H' which
are actuated by the loose collars I through the studs or pins J, Jor any suitable
equivalent; these loose collars are kept in position by the screwed collars or
nuts D, D, and the slides or keys H, H¹ pass through and travel along the
longitudinal slots L, L' in the bar A which are preferably opposite to one another.
The cutters El are bevilled or tapered off at their ends E, E at suitable angles
so as to fit in the undercut surfaces A' and 12 of the bar A and the loose collar I¹
respectively. The latter collar I', at its opposite end, is pressed up to its work by
means of the spring M and milled collar or nut N whereby a variable pressure is
imparted to the cutters E¹ which ensures contact with the bearing surface of the
grooves or flutes E and keeps them firmly in position. This pressure may be varied
by the nut N. To extract the cutters E¹ it will merely be necessary to slacken the
milled collar or nut N thereby allowing freedom to the loose collar and spring M,
to be moved back and the cutters E' withdrawn.
It will now be understood that to effect the expanding of the cutters E¹ it will
merely be necessary to slacken the milled collar or nut D tighten D¹ thereby
forcing the pins J, J' carrying with them their keys or slides H, H' in the direction
of the plain arrow thus imparting a rotary motion to the internal expander C by
reason of its grooves G, G thereby turning it in the direction of the feathered
arrow (see Figures 1 and 2) consequently raising the cutters E¹ by bringing an
outer surface of the eccentric or cam shaped part of the expander C, or a surface
further away from the centre, to take the thrust of the cutter. It will be obvious
that this adjustment can be accurately and readily effected with the aid of the
graduated scale marked on the collar I."
We have found that the means illustrated in Figure 4 for effecting the expanding
of the cutters E' or imparting the rotary motion to the internal expanders C is
convenient and facilitates manufacture. In this case we are able to do with one
collar I, on which the graduated scale is inscribed and we cut on the one end
thereof the slots 13 which form recesses for the pins J, J' which are somewhat
differently shaped to those above described, for in the circular pin there necessarily
exists a certain amount of looseness or play. This defect is obviated by the
application of the angular surfaces I', and J' coming in contact with each
other.
For the purpose of boring small holes we illustrate in Figures 6, 7, 8 and 9
a modification in which we dispense with the fluted or grooved internal expander
and substitute therefor the parallel expander C which fits and is free to be moved
lengthwise in the bore or hollow part B of the cutter bar A. This parallel
expander C is provided with taper slots E which form a convenient surface E' for
the tapered end E' of the cutter E¹ to bed or rest upon, and is thereby made into
a triangular section (where the cutters E' bed) as shown in Figure 7 which is
a section of the expanding boring bit taken on line 3. 3. of Figure 6.
We preferably support the opposite ends E of the cutters E¹ on the conical

page_text: end E of the expander which is tapered to the end, at an equal angle to that
of the surface E so as to ensure the cutters being parallel. The end of the
bore or hollow part B is effectually closed dust-proof by means of the plug B.
To impart the necessary sliding motion to the internal parallel expander C, it
is provided with the pin J passing through its centre and extending on both
sides through slots L, 'L' in the cutter bar A and is brought into contact with the
loose collars I which are actuated by the milled collars or nuts D, D¹ on the
screwed portion of the cutter bar A. It will thus be understood that by
slackening the milled collar or nut D and tightening the milled collar or
nut D' the cutter E' will be expanded as shown in dotted lines in Figure 6.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
First. A metal expanding boring bit with an internal expander provided with
eccentric or cam shaped grooves or flutes forming a support for entire length
of cutter and having imparted thereto a rotary motion from the outside of cutter
bar to expand cutters substantially as described and illustrated in Figures 1 and 2
of the drawings.
Second. In a metal expanding boring bit of the kind forming the first claiming
clause hereof, the internal expander having spiral grooves G, G for imparting the
rotary motion, slides or keys H, H', and studs or pins J, J operated by the index
collar or collars I through the milled collars or nuts D, D' substantially as described
and illustrated in Figures 1, 2, 3, and 4 of the drawings.
Third. A metal expanding boring bit with a parallel internal expander provided
with tapered slots or conical parts for supporting and expanding the cutters by a
sliding motion imparted from the outside of cutter bar substantially as described and
illustrated in Figures 6, 7 and 8 of the drawings.
Fourth. In an expanding boring bit wherein the cutters E' are held in position
from the outside on to the eccentric grooves or cam shaped surfaces E provided
on the internal expander, the undercut parts or recesses A¹ in the cutter bar A at
the ends of the slots F and the loose collar I with its undercut edge I'
between which the cutters E¹ are securely held in place by means of the
spring M; the amount of pressure being regulated by the milled collar or nut N
and thereby obtaining a variable pressure necessary for expanding the cutters E¹
substantially as described and illustrated in the drawings.
D. HONEY WOOD,
E. L. AUSTIN,
7, Rosenau Road, Battersea Park, S. W., Applicants.