Improved Machinery for Cutting Threads in Screw Blanks.
Year: 1892

page_text: Date of Application, 20th Dec., 1892-Accepted, 13th May, 1893
COMPLETE SPECIFICATION.
Improved Machinery for Cutting Threads in Screw Blanks.
I, MAX KUGEL of Werdohl, Westphalia, but at present residing at
No. 22, Southampton Buildings, Chancery Lane, in the Administrative County
of London, Manufacturer, 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 relates to improvements in machinery for cutting threads in screw
blanks and the object of it to cut the threads by means of a rotary cutter.
In carrying the invention into effect, the blank is rotated, and the rotary cutter
traversed along it at a rate equal to the pitch of the screw. The distance of the,
cutter from the blank determines the depth of the thread. The point of the screw
is produced by advancing the cutter up to the axis of the blank, when the aforesaid
distance ceases to exist and vanishes. The advantage of the invention is that the
thread can be cut at one operation.
In order that my invention and the means by which it is to be carried into
practical effect may be thoroughly understood, I will describe it and them in'detail;
referring in so doing to the accompanying figures which are to be taken as part of
this Specification. Only as much of the screw inaking machine as is affected by
the present invention,is illustrated. The omitted mechanisms are of the usual
construction.
Fig. 1 is a part plan of a screw making machine to which my invention has been
applied.
Fig. 2 is a sectional elevation taken on the line 2-2 of Figure 1.
a is a bar of the frame of the machine, and is as much of it as is concerned by
the present invention.
bis the driving pulley. It is fast on the outer end of the shaft c. The latter
passes through and has its bearing in a sleeve e which is held to the bar a in the
proper position for that purpose, by two collars e', e both fast to the sleeve but
standing, respectively, on opposite sides of the bar a and close up to it. The sleeve
is capable therefore of only a rotary motion in the said bar.
fis the traverser for both the cutter carriage e and the arm m of the steady rest L.
This arm stands up from and is made fast to the traverser. The latter is traversed
through the cutting traverse by the traverser rod i which is made fast to it. It
receives its motion from some suitable member of the driving mechanism and is
returned by the resilience of a coiled spring which is held in the necessary position
for that purpose between the bar a and the traverser f by a rod g around which it
18 coiled. This rod is made fast by one end to the bar a. Its opposite one projects
through the traverser.
h is a pair of nippers adapted to hold the blank; parallel with the axis of the
shaft c. This blank is shewn as a nearly finished screw. I is the steady rest. It is
adjustable on the end of the arm m.
is the cutter carriage. It is a ring surrounding the sleeve e along which it
must move to and fro, and about which it must be moved with a reciprocating
motion through the required arc.
It receives the necessary linear motion along the sleeve e by the engagement of
the nose of the traverser f in the arc shaped recess e' in its adjacent face. The
excess circular length of the recess over the depth of the face of the nose f³ is to
permit of the reciprocating motion of the carrier about the sleeve. This recipro-
cating motion is imparted by the revolving shaft p through the following devices.
p¹ is a disc fast upon the said shaft. It has a cam groove p* cut in its face. 9³ is
an arm engaging, by means of a stud q¹ on one end of it, in the groove p³, and made

page_text: fast by its opposite end to an arm o¹ which stands up in an adjacent and parallel
plane from the collar e. The arm o¹ is fast to the sleeve and therefore its motion
is communicated to the latter. is a feather engaging in both the adjacent faces
of the sleeve e and of the cutter carriage e². o is an arm. standing up from the
cutter carriage in the same way as the arm o¹ stands up from the sleeve. The
two arms are parallel with each other. The arm o terminates in an eye n², and
the arm o¹ in a second one n³. The eyes n³, n³ are provided with thimbles nº, n
which are free to rotate therein respectively about their respective axes but are
incapable of any other motion in the said eyes. The thimble n is made fast to the
pinion d'. The latter meshes with the gear wheel d which is fast on the driving
shaft c.
n is the cutter. It is held to the cutter bar n' by the screw n². This
cutter bar is polygonal in cross section in order that the motion of the pinion d'
may be communicated through it to the cutter. It can move linearly in either
direction through both the thimbles.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. Mechanism for cutting threads in metal screw blanks by means of a rotary
cutter.
.2. The general construction of the mechanism for actuating a rotary cutter so aв 2
to cut the thread in a metal screw blank as described with reference to the
accompanying figures.
Dated this 20th day of December 1892.
PHILLIPS & LEIGH,
22, Southampton Buildings, Chancery Lane, W.C.,
Agents for the Applicant.