Improvements in Automatically Rotating Boring and other Tools.
Year: 1890

page_text: Date of Application, 20th Oct., 1890-Accepted, 22nd Nov., 1890
COMPLETE SPECIFICATION.
[Communicated from abroad by EMIL VON BÜHLER, of 105, Urbanstrasse, Berlin,
Germany, Merchant.]
Improvements in Automatically Rotating Boring and other Tools.
I, HUGH DONALD FITZPATRICK of 70 Wellington Street, Glasgow, Lanarkshire,
Registered Patent Agent, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement :-
This invention relates to tools, such as tools for boring or drilling holes, which
require a partial or total turning movement to be given to them when being operated
and it has for its object to produce such turning or rotating movement in a simple
and efficient manner.
The invention is specially designed for up and down moving tools, although it may
be applied to horizontally moving tools.
The manner of up and down motion, the motive power and the tool itself may be of
any kind and as these are not the subject of the invention they are not described
herein.
On the annexed drawings
Fig. 1 shows the new contrivance, by way of example as applied to a pneumatic
borer which is partly shown in the view.
Fig. 2 is a part vertical section of the tool on a line at right angles to Fig. 1
Fig. 3 is a view looking up from the bottom of the tool.
I will now proceed to describe the invention, reference being had to the drawings
annexed.
To the sole plate A, two brackets a, a' are firmly screwed in position and in these
brackets rest the contracted or neck parts b, 6' of the pneumatic toolcase B. The upper
and lower ends of the tool case B bear on friction balls C carried in the brackets.
Over the neck 6 of the tool case B is pushed or fitted a cylindrical shell D which is
free to turn round on the neck 6 and in the bracket c screwed to the sole plate A. The
shell D has on it a ratchet wheel D' which is caught by a pawl d (Fig. 3) acting under
pressure from a plate or other spring e. The spring pawl d is pinned to the lower
bracket c in the manner shown so that the ratchet wheel D' and shell D is only allowed
to revolve in one direction, being prevented from turning back by the pawl d catching
in the ratchet teeth. There is also made in the shell D an oblique slot F (Fig. 1)
through which projects a pin f fixed in the tool shaft E.
An exactly similar shell, D2, to the shell D is or may be fitted on the upper end or
neck of the case B.
First the tool-shaft E is moved so that the pawld will catch firmly in the ratchet D
and the shell D is consequently held fast. If then the tool shaft E is moved down-
wards the pin f will slide along the oblique slot F, as the oblique slot will prevent the
perpendicular movement, and consequently the shaft meets the work with a boring or
turning movement. If then the tool shaft E is raised again the pin f will move
towards the upper oblique side of the slot F and will turn the shell as the turning
movement is in the same direction as the pawl d points and therefore the pawl will not
oppose the turning but will allow the ratchet D¹ to revolve freely. During this
turning movement of the shell D the tool holder remains in its position. At the
following moving down of the tool holder the pin f is inclined to turn the shell D in
the reverse way, which as previously described is prevented by the pawl d catching in
the teeth of the ratchet D, so that the shell D is fixed and consequently a further
turning of the tool holder with the tool will take place.
Every down movement of the tool holder therefore as will be seen produces a slight

page_text: turning so that the tool makes, step by step, a full turn round and bores in the work
a round hole.
In this way the tool meets the work with a turning motion; but, if it is desired to
do the boring with vertical thrusts, it is only. necessary to fit the ratchet wheel and
pawl in the reverse way, then the turning of the tool will take place at the raising
and the turning of the shell at the lowering.
It is evident that the motive mechanism for the tool holder is unimportant. If desired,
however, similar mechanism to that used for spring hammers may be applied in this
case or any other suitable mechanism may be used.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is-
A contrivance for automatically turning or rotating tools, characterised by the use of
a shell D turnable in one direction which is fitted over the tool shaft E and has an
oblique slot F in it in which a pin, fitted on the shaft E, works, substantially as herein-
before described with reference to the drawings annexed.
Dated 171 1
H. D. FITZPATRICK.