Improvements in Screw-machines.
Year: 1899

page_text: COMPLETE SPECIFICATION.
Improvements in Screw-machines.
I, GEORGE EARL RANDLES, of 76, Hopkins Street, in the City of Hartford,
County of Hartford, and State of Connecticut, United States of America, Manu-
facturer, do hereby declare the nature of my 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 relates to screw-machines, and more especially to means for
automatically regulating the length of a thread to be cut independently of the
mechanism which drives or feeds the turret or other carrier for the threading-
tool, and to a device for holding said threading-tool.
My invention includes as one of its features means for regulating or determining
the length of thread to be cut. The means for controlling the length of thread
is preferably adjustable and is usually carried by the holder for the screw-threading
or other tool, by reason of which the amount of thread to be cut can be readily and
quickly varied without adjusting any parts of the feed or driving mechanism for said
carrier, this last-mentioned operation ordinarily consuming considerable time
and necessitating great care in this class of apparatus as now constructed.
My invention includes as another of its features a holder for a tool, such as a
screw-threading die or tap, consisting of two sections one of which is usually
reciprocative and oppositely rotative relatively to the other, and a stop located
to arrest the motion of said reciprocative and oppositely-rotative section at a
predetermined point.
In screw-machines the work is usually fixed against longitudinal movement
during the formation of a thread, and the holder, which carries the die or tap,
is advanced either to form an external or internal thread; and the tool in my
improved machine is held by the holder just specified, the two parts of which,
for convenience in distinguishing them, being denoted, respectively, by the terms
fixed and movable members. The movable member of the holder, which directly
carries the threading-tool, usually has a perforation or recess adapted to receive
a projection or pin carried by the fixed member, which slides in said recess; and
in practice I prefer to employ a series of such recesses and a corresponding
series of projections or pine.
In the drawings accompanying and forming part of this specification, Figure 1
is a side elevation of a screw-machine of known construction provided with my
improvements. Figs. 2, 3, and 4 are sectional side elevations of the holder for
the screw or other tool, on an enlarged scale, and show the movable member
thereof in three of its positions during the formation of a thread; and said
figures illustrate a turret by dotted lines. Fig. 5 is a cross-sectional view taken
in line 55, Fig. 3, looking in the direction of the arrow a; and Fig. 6 is a
similar view looking in the direction of the arrow b.
Similar characters designate like parts in all the figures of the drawings.
The framework for sustaining the several parts of the machine is illustrated
as consisting of a main frame A and an auxiliary frame B, the latter directly
supporting the driving-shafts, feed mechanism, &c.

page_text: In a general way the construction and operation of the machine illustrated
are in many respects similar to those of automatic screw-machines now in use;
and said machine embodies the usual cam-shaft 2, carrying a series of cam-
drivers for operating the different tools and other parts of the machine; a work-
spindle, as 3; a turret-slide, as 4, carrying a turret 5, which is equipped with
the usual tools for operating upon the blank; and a chuck 5¹ for holding the
work to be operated upon.
"
The mechanism for reciprocating the turret-slide 4, and consequently the
turret 5, and for also rotating said turret to bring the successive tools thereof
into position for operation upon the blank, is designated in a general way by F;
and the mechanism for driving and for also reversing the rotation of the work-
spindle 3 is designated by), and includes a series of pulleys 6, 7, and 8, the
belts of which and the belt-shipping mechanism are not shown.
My.invention includes as one of its features a holder for a tool, said holder
being clamped. in the turret 5 and being designated by H and adapted to hold
a tool, as T, which is. represented. in the present case as a die for cutting an
external thread; although it is obvious that a tap or other metal-working tool
could be secured in the holder.
6
"
The holder H usually embodies two disks 10 and 12, the two parts being denoted,
respectively, for convenience, as the "fixed" and the movable members of
the device, and the part 10 having a shank or stem 13, which fits into a socket 14
in the turret 5 and is held therein in the usual manner, and the part 12 having
an elongated shank 121, which slides in the bore 12", formed centrally in the
part 10 and extending through the stem 13 of said part 10. The section 12
of the tool-holder is mounted for reciprocative and oppositely-rotative move-
ment relatively to its companion, and one of said members is provided with means
for regulating automatically the amount of forward movement of the movable
member and thereby determining the length of thread to be cut.
The means illustrated for controlling the forward stroke of the movable holder-
section 12 is illustrated consisting of a series of projections or pins, which may
be of any number, (four being illustrated herein and designated, respectively,
by 15, 16, 17, and 18.) Said pins are shown as carried by the fixed member 10
of the holder, although this disposition may be reversed without departing from
the spirit of the invention; and said pins are adapted to enter a corresponding
series of perforations or recesses, as 15¹, 161, 171, and 18', which are formed in
the member. 12, as represented in Fig. 2.
In Fig. 2 the die or tool T is represented as operating upon the work, which
is rotating in the direction of the arrow, and the outer ends of the several pins
are shown as disposed in the co-operating recesses in the member 10, by reason
of which the work or blank, as it rotates, will tend to rotate the said member 12;
but the pins being rigid on the member 10, which, it will be understood, is
fixed against rotative movement, the rotation of the member 12 is thereby
prevented, and it naturally follows that the advance of said member 12 is caused
by the thread being cut on the blank. The forward movement continues until
the pins are clear of their recesses, as represented in Fig. 3, by reason of which
the part 12 is free to rotate, and the further advance of said part 12 cannot
occur.
It will be understood from the foregoing description that the pins 15, 16, 17,
and 18 control the operation of the tool, and for the purpose of cutting threads of
different lengths without the necessity of manipulating the driving mechanism F
I prefer to make the pins adjustable, they being adapted to move longitudinally
through a series of holes extending through the part 10, as indicated in Fig. 2.
Each of the pins has a thread, as 19, adapted to be engaged by the corresponding
thread of the internally-threaded collars 20 and 21, rotatively supported upon
the fixed member 10. Said collars serve to move all of the pins simultaneously,
one of them being adapted to move said pins forward, and the other backward,
while that collar which is not employed for feeding the pins is carried with them

page_text: s they move, and is then turned backward to serve as a check-nut firmly to hold
aid pins in their adjusted positions.
The threaded pins 15, 16, 17, and 18 are held against turning by a series of
tey's, as 24.
1
After the pins have passed out of the recesses the reversing mechanism starts
and reversely rotates the chuck-spindle and the member 12, and in connection
with the pins I prefer to provide a series of stops, as 25 and 26. While one
of these stops will serve the purpose I prefer to employ two, as I thereby secure a
more stable structure. The stops 25 and 26 are yieldingly mounted and are
lisposed in suitably-formed diametrically-opposite sockets in the member 12,
and they project normally beyond the inner face of said member.
On the advance or forward rotation of the member 12 the stops will strike the
fixed pins when the latter are withdrawn from the recesses, and will be forced into
their seats by said pins, whereby said member may freely rotate; but on the
reversal of the rotation of said member the heads of the stops will strike two of
the pins and thereby arrest further rotative movement of the member 12. This
being the case, said member 12 will be forced toward the member 10 by the
threaded work as it withdraws from the die, and the pins 15, 16, 17 and 18 will
enter the recesses 15¹, &c., as indicated in Fig. 4, until the parts 10 and 12 come
into contact.
The stops 25 and 26 are preferably spring-actuated, and each of them consists
of a pin longitudinally slidable in a socket in the part 12, said pins having
enlarged heads, as 25 and 261, extending normally beyond the inner face of
the part 12, and each of them being beveled, as at 30. The two stops are held
in their outer positions by coiled springs as 31 and 32, disposed in the hollow
shanks 33 and 34 of said stops and bearing against the part 12 and the stops,
respectively, and are held against rotation and also in their seats by the screws 35
and 36, carried by the part 12, the inner ends of which are disposed in longi-
tudinal slots, as 35 and 36¹ in the hollow shanks of the two stops. When the
pins 15, 16, 17, and 18 are clear of the recesses 151, 161, 171, and 18¹ in the
part 12, as represented in Fig. 3, the beveled ends 30 of the stops will impinge
against the ends of said pins as the part 12 rotates, thereby forcing the stops
into their seats and permitting such rotation until the reversing mechanism
operates, when the projecting portions of the two stops will strike said pins,
which instantly prevents further rotation of the part 12, and consequently causes
the rearward feed of said part, as the work rotates, in the direction of the arrow
in Fig. 4.
The tool T is usually held in the part 12 by the set-screw 40, although other
means can be utilized for this purpose.
Means are employed for holding the two sections of the holder H normally in
contact, and said means is represented as consisting of the coiled spring 45,
bearing against the shoulder 46 on the part 10, and also against the collar 47 on
the end of the stem 121, said collar being fixed in place by the pin 48. When
the part 12 has advanced in the manner herein before specified, the spring is
5 compressed and relaxes on the opposite movement of said part 10, but its only
purpose is to hold the two parts in contact except when a thread is being cut.
0
The invention is not limited to the particular features of construction herein-
before described, as many changes may be adopted by persons conversant with
this class of apparatus without departing from the scope thereof.
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:
1. A tool-holder consisting of two members, one of which is reciprocative
and rotative relatively to the other, one of said members having a pin and the
55 other a stop independently mounted for yielding movement and adapted to be
engaged by said pin.

page_text: 2. A tool-holder consisting of two members, one of which is reciprocative
and rotative relatively to the other, one of said members having a pin and the
other a yielding stop beveled at its working end and adapted to be engaged by
said pin.
3. A tool-holder consisting of two members, one of which is reciprocative
and rotative relatively to the other, one of said members having an adjustable
pin and the other a stop independently mounted for yielding movement and
adapted to be engaged by said pin.
4. A tool-holder consisting of two members, one of which is reciprocative
and rotative relatively to the other, one of said members having a threaded pin
and also having a nut adapted to engage the thread on said pin whereby to adjust
the same, and the other member having a stop adapted to be engaged by said
pin.
5. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other, of a threaded pin carried
by one of said members and adapted to fit in a recess or perforation of the other
member; a nut for adjusting said pin; and a stop on the other member adapted
to be engaged by said pin.
6. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other and is provided with a series
of recesses or perforations, of a series of pins carried by one of said members and
adapted to fit in said recesses or perforations; means for simultaneously adjusting
said pins; and a series of stops on one of the members adapted to be engaged
by said pins.
7. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other, of a piu carried by one of said
members and adapted to fit in a recess or perforation of the other member; means
for adjusting said pin; and a stop on the other member adapted to be engaged
by said pin.
8. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other, of a threaded pin carried by
one of said members; nuts for engaging the thread of said pin; and a stop
carried by the other member and adapted to be engaged by the pin.
9. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other, said member having a recess
or perforation, of a yielding stop adjacent to said recess or perforation; and a
pin carried by the other member and adapted to enter the recess or perforation
and also to engage said stop, substantially as and for the purpose specified.
10. The combination, with a tool-holder comprising two members one of which
is reciprocative and rotative relatively to the other and is recessed or perforated,
of a projection carried by one of said members; a yielding stop mounted on the
other member and adapted to be engaged by said perforation; and a spring for
normally holding the two members in contact.
11. The combination, with a tool-holder comprising two members, one of said
members having a socket, of a stem carried by the other member and fitting in
said socket; a projection carried by one member and adapted to fit in a recess
of the other member; a yielding stop adapted to be engaged by the projection;
and a spring bearing against a collar on the stem and serving normally to hold
the two members in contact.
12. A tool-holder comprising two members, one of which is reciprocative and
rotative relatively to the other, one of said members having a pin and the other
a yielding stop adapted to he engaged by said pin; and means carried by the
member which supports said stop for holding the latter against rotation.
13. The combination, with a tool-holder comprising two members, one of which
is reciprocative and rotative relatively to the other, one of said members having a
socket, of a yielding stop having a slotted shank fitted in said socket; a pin on

page_text: the other member adapted to engage said stop; and a device entering the slot
of said shank for preventing the stop from turning.
14. The combination, with a reciprocative slide and with means for actuating
said slide, of a tool-holder mounted on the slide; means comprising two members,
one of which is reciprocative and rotative relatively to the other and is adapted
to carry a screw-cutting tool, one of said members being provided with a series
of recesses or perforations; a series of pins carried by one member and adapted
to fit in recesses or perforations of the other member; means for adjusting said
pins; a series of stops on one of the members adapted.to be engaged by said
pins; a chuck-spindle; and means including reversing mechanism for operating
said spindle, substantially as and for the purpose specified.
15. The combination, with the turret-slide of a lathe, of a turret carried by the
slide; a chuck-spindle; means including reversing mechanism for operating said
spindle; a tool-holder consisting of two members, one of which is reciprocative
and rotative relatively to the other, carried by the turret; a pin or projection
carried by one member and entering a recess or perforation in the other member;
means for adjusting said pin; and a stop for engaging said pin when the latter
is withdrawn from said recess or perforation, substantially as and for the purpose
specified.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.