Improvements in Machines for Screwing and Cutting Pipes, Rods, and the like.
Year: 1890

page_text: Date of Application, 1st Oct., 1890-Accepted, 28th Mar., 1891
COMPLETE SPECIFICATION.
Improvements in Machines for Screwing and Cutting Pipes, Rods,
and the like.
I, AUGUST GÖBEL, of Ems, in the German Empire, 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 will be best understood by reference to the accompanying drawings
in which Fig. 1 is a longitudinal vertical section, Fig. 2 an end elevation and
Figs. 3 and 4 details of a screwing machine constructed according to this invention.
Upon the hollow shaft z of the support A is carried a head-stock b. consisting of
two cylinders of unequal width and adapted to be turned by means of a worm
wheel integral with one of them under the action of the worm s, rotated by the
adjustable crank or handle a. The head-stock carries a cutter-head k of
known construction capable of displacement in the direction of its axis but the
independent rotation of which is prevented by two stops e, working in slots
provided for the purpose in the head-stock. The cutter-head k is thus only
permitted to revolve with the head-stock while it may be shifted backwards or
forwards.
To facilitate the initial cut of the screw-thread the checks of the cutter-head are
partially bevelled inwardly.
On the side of the support A opposite to that where the head-stock b is situated
is arranged the automatic centering holder or clamp constructed as follows:-
:-
A ring carrying a screw-spindle t is fitted for longitudinal adjustment within
a V-shaped piece or jaw d the front ends of which are cut off at an angle of
120°. The inner side of the said ring opposite to that supporting the spindle t
is formed with two inclined faces so that a cylinder or pipe inserted into the
ring comes in contact with the inner edge of the ring at two points and also with
the two inclined faces of the jaw d.
As the spindle t is provided with a screw-thread as aforesaid and owing to the
action of the nut m bearing against the jaw d the gripping faces of both the
ring and the jaw d may be caused to move towards each other with sufficient
power to clamp and hold the cylinder or pipe inserted between them.
The nut m being screw threaded externally is adapted to move up and down
within the bracket n mounted on the support A; but the pitch of the outer screw
thread of this nut being smaller by half than that of the spindlet the motion of
the jaw d and the ring against each other is such that any circles which may be
inscribed in the space open between the contact surfaces will all have one common
centre. If therefore this centre be so adjusted as to be in a line with the axis of
the shaft, it will be seen that all cylinders or pipes inserted into the clamping
device will be locked in a position concentric with the head. The nut m is
provided with a grooved projection whereby it is fitted to the jaw d and is
besides held in position by pins so as to participate in any backward motion.
A lateral displacement of the pipe-clamping device is prevented by the ribs
of the support A while the plate o prevents displacement in the direction of the
axis of the machine.
There is further inserted into the head-stock a device for cutting off lengths
of pipes or bars secured in place by means of two screws so that it partakes of
the rotary motion of the said head-stock. This device consists of a piece fin
which is adjustably arranged a slide h held in place by a plate g. To this slide h
are attached small cutters or knives c and it is reciprocated by the screw i
operated by means of the star wheel l.
In the lower portion of the support A is provided a pin o so arranged that

page_text: when it bears on the rib of the support (on the right of the drawing) on one end
its opposite or forward end engages with the star-wheel while when it bears
on the rib on the left the star wheel passes its forward end without engaging
with it.
As the stock revolves the cutter of the pipe or bar-dividing-device will
surround the pipe or bar introduced into the stock and when the pin o is so
adjusted as to engage the star wheel the desired portion of tube is cut off. Three
screws y arranged at equal distances around the circle serve as an additional
locking-device for the pipe to be cut in this manner. In order to ensure the
desired pressure of the cutter-head k upon the tube to be provided with a screw
thread by an arrangement which will not be in the way in the subsequent operations
of cutting off a portion of tube or bar and removing the cutter-head k, the
following device has been constructed.
To the foot-plate carrying the support A is fixed a bracket p to which is
pivotted the pressure lever u. This lever bears on the eccentric portion of the
pivot which when rotated by means of the handle causes the lever u along
with the cross piece 7 and the cutter-head to move in the direction of the
support A. When in order to cut a pipe or bar into lengths it is desired to
move the cutter-head the hand lever w with its pivote is withdrawn from the
bracket sufficiently to enable the lever u to be turned back as required.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. A device for cutting screw threads on pipes or bars and also cutting them
into lengths in which a head stock & carrying the cutter-head k and the automatic
device for cutting off portions of pipe is caused by means of a hand-crank and a
screw gear to turn upon a hollow shaft forming part of the main support A;
the blank to be operated upon being held in position concentrically with the stock b
by a clamping device provided upon the support A and consisting of a piece n
provided with inner and outer screw threads a movable ring r and a bent piece or
jaw d the whole substantially as described.
2. In a machine for providing gas-pipes and the like with screw threads as
characterized in Claim 1, the device whereby the cutter-head k is caused to bear with
the desired amount of pressure upon the blank and consisting in a pressure lever u
operated by the eccentric portion of a spindle v turned by means of a handle w
so as to swing round a pivot while its free end acts upon the cutter-head by
means of a cross-piece q substantially as described and illustrated in the accom-
panying drawings.
Dated this 1st day of October 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.