Year: 1893

page_text: Date of Application, 4th Oct., 1893-Accepted, 4th Nov.. 1893
We, CHARLES RISBEE IORNS of Altrincham, Cheshire, Engineer, and
GEORGE RICHARDS & Co. LIMITED of Broadheath, Cheshire, Engineers 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 :-
.
In the drawings,
Fig. 1 shows a side view of the machine in section.
Fig. 2 a cross section of same.
Fig. 3 shows in section, a modification of the reversing mechanism.
The same letters refer to the same parts in each figure.
"A" is the frame of the machine, which may be of any ordinary design. B is
the revolving spindle for carrying the tap. C & D are bevel gears running loose
in the bearings of "A." E is a toothed clutch working on a sliding key, so as to
transmit the rotation of either the gear C or the gear D (whichever it is temporarily
engaged to) to the tap spindle B, and thus reverse its motion. F is a bevel pinion
driven by the cone G. As the bevel gears C & D are driven from the opposite
sides of the pinion F, it will be seen that C & D will run in opposite directions.
His a hand lever for starting the tap into its work. I is a counterweight for
balancing the spindle, and also for causing the spindle to rise to its top position
after the tapping of the hole is completed. K is an adjustable stop for regulating
the depth the tap has to go into the hole. L is a lever provided with catch M
and wedge N. It swivels on the pin N¹, and the amount of its swivel is controlled
by the stops QQ, which catch the portion of the lever marked L'. The wedge
point N presses on the sliding wedge point O in lever P, which is provided with a
spring which keeps the two wedges in contact and is strong enough, when the thin
edge of N is made to slide past the thin edge of O, to produce a motion by sliding
the lower side of O up the upper side of N, or vice versa. After N has reached the
limit of its travel, by the lever L¹ coming in contact with the stops QQ, motion is
produced in P from the fulcrum R, by the spring pushing out the wedge point O
against the now fixed wedge point N. The motion thus produced is transmitted by
the link S to the lever T, and thus to the clutch E, which reverses the rotation
of the machine in the direction required.
To operate the machine, the work is placed on any convenient form of bench or
table; the tap which is of the form commonly used in tapping machines, is fixed
in the spindle B. The stop K is fixed to reverse the rotation when the required
depth is reached. The operator then introduces the tap into the hole to be
threaded by the lever H; the tap obtains a lead, and draws the spindle down until
the stop K strikes the end of lever L, which moves the wedge point N past the
wedge point O, and instantly reverses the tap as before described; the tap now
running in the opposite direction, withdraws itself from the hole, and as soon as it.
is clear, the weight I raises the spindle to its original position. The operator now
reverses the machine back to the first direction, by forcing the stop K past the
lever point M, which then stands clear, and allows the repetition of the whole
operation.
Fig. 3 shows a modification of the machine for use when the work is to be tapped
automatically.
X is a hardened threaded bush fixed in the spindle B by any suitable means.
W is a lever with a suitable hardened nut to work into thread X. X and the nut
in W are made so as to be easily changed, so as to allow of various numbers of
threads to be tapped.

page_text: V is a connecting link to transmit the motion of the lever T caused by the
stop K (Fig. 1) reversing the machine, and throwing the nut either into or
out of gear.
The object of the combination is to give an automatic feed to
the tap, together with a quick return of the spindle when the tap is clear of
the hole.
It is evident that the same mechanism can be applied to drilling machines, the
stop being then set, so as to be operated on by the descent to the proper point
of the feeding screw of the drilling spindle, which will cause the reversal of the
rotation, and the ascent of the drill as above described.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what we
claim is ;-
1. An automatically reversing machine for tapping metals to a precise depth, the
power required for feeding the tap being obtained from the lead of the tap in the
hole which is being tapped, substantially as described.
2. A combination driving and reversing gear, very accurate and certain in action,
enabling blind holes to be tapped without endangering the life of the tap, sub-
stantially as described.
3. An automatically reversing drilling machine for drilling metal to a precise
depth, substantially as described.
Dated this 3rd day of October 1893.
October 1893.
CHARLES RISBEE IORNS.
For GEO. RICHARDS & CO., LIMITED,
B. C. TILGHMAN, Director.