Improvements in Machines for Cutting Screws and Worms.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Machines for Cutting Screws and Worms.
I, HENRY LIEBERT, of Perseverance Works, Milnrow, in the County of
Lancaster, Engineer, do hereby declare the nature of this invention to be as
follows:
This invention has for its object the construction of a machine for cutting
screws and worms with square or similarly shaped threads, say from 3 to 1½ inches
in diameter by means of a milling tool instead of by the ordinary cutting tool
hitherto used.
According to one form of my invention employ upon one end of a bed, a
carriage in which is mounted a spindle having at its inner end a socket into which
one end of the screw or worm to be cut is secured, the other end being supported
by a pedestal fixed upon the respective end of the said bed adjacent to a headstock
which carries the milling tool. The said carriage is actuated along the said bed
by means of a guide screw mounted in front of the bed, whilst the spindle in
the said carriage is rotated by means of suitable gearing from the said guide
screw, change wheels being provided for cutting double, triple or quadruple
threads.
The said headstock consists principally of a slide rendered crosswise and rotary
aljustable upon the bed of the machine and having an upright on which is
rendered vertically adjustable a horizontal bracket in which is mounted tho
spindle carrying the milling tool and gearing by which the latter is rotated.
The said milling tool engages in a slot formed in the aforesaid pedestal which
serves as a guide for the same.
The wheel which imparts rotary motion to the spindle in the aforesaid carriage,
may be disconnected therefrom by the removal of a pin, so as to allow the said
spindle and the screw or worm to be cut to be rotated independently of the guide
screw when desired. The said headstock is rendered rotary adjustable so as to
allow of setting the milling tool to suit the various angles of the threads and
vertically and horizontally so as to accommodate same to the various diameters of
screws to be cut.
According to another form of my invention the screw to be cut may be arranged
to rotate only and the headstock which carries the milling tool made to travel
along the same, whilst according to a third form the screw to be cut may remain
stationary and the milling tool be caused to rotate around the same and be fed
longitudinally.
The machine may be provided with automatic knock-off and bevel wheel clutch
arrangement, for cutting right and left hand threads and with a quick return
motion where required as in ordinary screw cutting lathes.
noted this 12th day of April 1897
°
F. BOSSHARDT & Co.,
Agents to Applicant.

page_text: Improvements in Machines for Cutting Screws and Worms.
I, HENRY LIEBERT, of Perseverance Works, Milnrow, in the County of
Lancaster, 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 has for its object the construction of a machine for cutting screws
and worms with square or similarly shaped threads, say from 3/8 upwards in
diameter by means of a milling tool instead of by the ordinary lathe cutting tool
hitherto used.
And in order that my invention may be more fully understood I have caused
to be appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures, Fig. 1 being a front view, Figs. 2 & 3
views of the headstock and tail end of my improved screw and worm cutting
machine respectively. Fig. 4 is a plan of the headstock, Fig. 5 a cross section
at line A-A of Fig. 1 and Fig. 6 an enlarged view of a screw and milling tool
showing the position of the latter relative to the screw being cut.
In carrying out my invention and referring to the figures generally, according
to one form, I employ upon one end of a bed a, a carriage b in which is mounted
a spindle c having at its inner end a socket d, into which one end of the screw e
(or worm) to be cut is secured, the other end being supported by a pedestal f
fixed upon the respective end of the bed a adjacent to the headstock which latter
carries the milling tool g. The carriage b is actuated along the bed a by means
of a guide screw h mounted in front of the bed a, whilst the spindle c, d in the
said carriage is rotated by means of suitable gearing i, see Figs. 1 & 3, from
the guide screw h, change wheels being provided as usually in lathes for cutting
all pitches of double, triple or quadruple threads.
and
The said headstock consists principally of a slide k rendered adjustable upon
the bed a by the screwed spindle ¹, of a slide 7 rendered crosswise adjustable
upon the slide k, by the screwed spindle and of a bracket m adapted to swivel
and be locked in position by bolts m¹ upon the slide 7 and having an upright m²
on which is rendered vertically adjustable, by the screwed spindle n¹, a horizontal
bracket in which is mounted the spindle o carrying the milling tool
gearing by which the latter is rotated. The said gearing preferably consists of
a shaft pupon which are secured a speed pulley and spur wheel q, r respectively,
which latter by means of carrier wheels s is geared up with a spur pinion of on
the tool o. The pedestal f is formed with a slot f¹, see more particularly Fig. 5,
adapted to receive and allow the tool g of coming into contact with the screw
(or worm) to be cut.
The wheel which imparts rotary motion to the spindle c, d mounted in the
carriage b, may be disconnected therefrom by the removal of a pin ¹, so as to
allow the said spindle and the screw (or worm) to be cut, to be rotated indepen-
dently of the guide screw h when required. The said headstock is rendered
rotary adjustable so as to allow of setting the milling tool g to suit the various
angles and depths of threads, see Fig. 6, and vertically and horizontally so as
to accommodate same to the various diameters of screws (or worms) to be cut.
The machine described may be provided with an automatic knock-off and bevel
wheel clutch arrangement, as shown in Figs. 1 and 2, for cutting right and left
hand threads and with a quick return motion where required as in ordinary
screw cutting lathes.
According to another" form of my invention the screw (or worm) to be cut may
be arranged to rotate only and the headstock which carries the milling tool made

page_text: to travel along in a direction parallel with the axis of the screw (or worm) to be
cut or according to a third form the screw (or worm) to be cut may remain
entirely stationary and the milling tool be caused to rotate around the screw
(or worm) to be cut and be fed longitudinally at the same time, in other words
to travel around the screw (or worm) to be cut in a spiral path, the pitch of which
corresponds with that of the screw (or worm) to be cut.
When cutting very short screws (or worms) the pedestal f, f¹ may be dispensed
with as the spindle c, d itself will be able to give the required support.
By the method of and means hereinbefore described screws (and worms) can
be cut at a much quicker rate than hitherto by unskilled hands, the thread being
cut to its full depth in one operation of the milling tool.
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:-
1st. In a machine for cutting screws and the like of the kind hereinbefore
indicated, the use of a milling tool g for cutting screws or the like threads, which
tool is capable of adjustment in accordance with the pitch and depth of thread
and diameter of screw or the like to be cut, all substantially as set forth.
2nd. In machines for cutting screws and the like of the type specified in the
preceding claim, the employment of a pedestal in combination with the rotary
inilling tool g, the said pedestal being adapted to support the screw or the like
whilst being cut and the said tool to mill the thread into the same, all substan-
tially as set forth.
3rd. In a machine for cutting screws and the like of the type specified in the
preceding claims, the pedestal f formed with a slot f¹ adapted to receive the mill-
ing tool, all substantially as set forth.
4th. The general construction and combination of parts constituting my inven-
tion operating substantially as and for the purpose set forth.
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicants.