Improvements in Machines for Making Screws, applicable also for Turning other Articles.
Year: 1893

page_text: Date of Application, 1st Aug., 1893-Accepted, 30th Dec., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by THE SINGER MANUFACTURING COMPANY,
of New York, in the United States of America, Sewing Machine Manu-
;
facturers.]
Improvements in Machines for Making Screws, applicable also for
Turning other Articles.
I, ALEXANDER ANDERSON. Manager of The Singer Manufacturing Company's
Works, Kilbowie, Dumbartonshire, do hereby declare the nature of this invention
and in what manner the same is to be performed, as communicated to me to be
particularly described and ascertained in and by the following statement :-
This invention, which has for its object the cutting of screws by machinery,
relates to apparatus whereby the different operations necessary for the cutting or
turning down of the stock threading the screw blanks and then severing the
threaded screws from the stock-bar or wire, are automatically performed.
The invention is illustrated on the accompanying drawings,
Figure 1 being a side elevation of a screw cutting machine embodying my
invention.
Figure 2 is a detail side view of the tool-carrying slide, and Figure 3 is an end
view thereof.
Figure 4 is a partial plan view to shew the driving mechanism for the spindles,
and Figure 5 is a partial end elevation shewing the same.
Figure 6 illustrates a slightly modified form of driving mechanism.
Figures 7 and 8 are details of the turret carrier and slide.
A denotes the frame-work of the machine and B the cam or tappet shaft thereof
journalled in suitable bearings formed in the said frame, said shaft being provided
with a driving worm wheel b meshing with a worm wheel c on a transverse driving
shaft c', the latter shaft being operated by a belt not shewn.
Mounted on the
shaft B are the cam or tappet wheels 1, 62, 63, 4, and 6 which are or may be of
ordinary construction and which operate the several mechanisms of the machine in
the usual way.
The frame A is furnished with posts or standards a in which. are journalled
the stock-carrying spindles D provided at their forward ends with clutch-heads d;
the said spindles also having the gears d' by which they are rotated and which are
both engaged by a driving gear e on a driving shaft E supported by suitable
brackets formed integral with or attached to the posts or standards a said
shait E having the fast pulleys and the intermediate loose pulley on which
latter the driving belts, which run in opposite directions (as is usual in this class
of machines) are alternately shifted by the belt shipper F operated from the camp
or tappet wheel on the shaft B.
The spindles D are provided at their rear ends with the grooved wheels
engaged by a post 9 on the slide G operated by tappets on the wheel b which
tappets engage the depending stud or projection gf on said slide, the longitudinal
movements of said spindles imparted thereto from said slide being for the purpose
of feeding forward the stock. The spindles D are also furnished with the grooved
wheels mounted on sleeves forming parts of said spindles in that they rotate
therewith said sleeves being longitudinally movable independently of the clutch-
carrying parts of the spindles for the purpose of clamping and releasing the
clutch jaws in the usual manner in machines of the class to which my invention
elates.
The grooved wheels are engaged by a post on a slide H having the
depending stud or pin operated by tappets on the wheel '. The slides G and H
are guided in suitable ways on a bar A' extending from the frame A and the

page_text: posts and hon said slides are steadied by braces g³ånd ³ respectivēly con-
necting the upper ends of said posts with said slides.
I is the cutting-tool carrying-slide mounted, to reciprocate cross wise of the
machine in suitable guide-ways on the frame A, said slide being operated by the
levers J receiving movements from the tappet wheel b. The slide I carries two
posts and on the former of which are mounted the cutting tools while the
post is herein shewn as being furnished with the projections 3 which form stops
to limit the forward feeding movements of the rods or wires from which the
screws are made but the said post i may also be provided with any suitable
cutting or knurling tools if desired.
K denotes a post or turret carrying the threading dies & and other tools the
said post or turret being mounted on a slide L arranged to move lengthwise of the
machine and having a depending pin or stud k¹ engaged by cams or tappets on
the wheel to operate said slide.
On the transverse driving shaft c¹ are two pulleys j one of which is keyed the
The cam 5 acts on the
other being loose but geared to a pinion on the shaft c
belt shipper m to shift the belt from the keyed to the loose pulley and the object
of this is to alter the speed from a fast drive when the turret K is to be revolved
to bring the required tool against the article being operated on to a slow drive
when the tool is operating on the article.
•
The turret K is revolved by the mechanism shewn by Figures 7 and 8, Figure 7
being an inverted plan of the sliding piece in which the turret is carried and
Figure 8 a plan of the slide.
An extension of the turret K is entered into an eye in the sliding piece K' and
on the underside of this extension a star wheel K is fixed. There is also fixed on
this extension between the star wheel K' and the base of the turret a disc.K'
having in it slots K into which enters a spring locking piece K provided with a
downwardly projecting pin K said locking piece being carried in a recess in the
sliding piece K¹ and acting to secure the turret in position after each partial
revolution. The action of this mechanism is as follows. When the sliding
piece K is being retracted the projecting pin K acts against the inclined edge of
a spring held stop K' secured on the slide K and so releases the locking piece K
from the turret and immediately thereafter the star wheel K comes in contact
with another stop K' also secured on the slide and thus revolves the turret.
By reference to Figures 4 and 5 it will be seen that the driving gear e is of such
size as to engage the gears d' on the spindles D so that said spindles are both caused
to rotate in the same direction as is necessary to cause the screw to be threaded
properly by the threading dies. Instead, however, of driving the duplex spindles
by the gear e which engages the gears on said spindles one spindle may be driven
from and be caused to rotate in the same direction as the other by the arrangement
of parts shewn in Figure 6 in which the upper spindle D is shewn as being
furnished with the driving pulleys e', the gears d' on said spindles being connected
by the intermediate gears d' which causes the lower spindle to rotate in the
same direction as the upper or driving spindle.
From the foregoing it will be apparent that by the use of my improvements I
an enabled to double the capacity of an automatic screw-cutting machine, as the
duplicate spindles, cutting tool and threading dies adapt the machine to make
two screws at one operation instead of a single screw as heretofore. I do not
however, wish to be understood as limiting my invention to the use of two similarly
rotating spindles with corresponding cutting tools and threading dies as by making
the other parts of the machine sufficiently strong three or more stock-carrying
spindles all geared to rotate in the same direction, may be employed in one machine
in combination with a similar number of cutting tools and threading dies, my
invention therefore comprising a plurality of these parts in a screw cutting
machine.
It will, of course, be understood that my improved double spindle machine may
be used for forming screw blanks (to be threaded, at a separate operation) if

page_text: desired, and in such case the turret or post carrying the threading dies may be
omitted or removed, or permitted to work idly; also, if desired, the machine may
be used for turning bowls or cam-rollers, or for other purposes; and in such case
instead of the threading dies on the post or turret K the latter will be supplied with
other suitable tools co-operating with the cutting tools on the transversely-movable
slide I. It will therefore be seen that parts of my invention may be employed
without using the entire machine organized as shewn in the drawings and as
hereinbefore described.
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 :-
In a screw-cutting machine the combination with the frame A, the shaft Band
the cam or tappet wheels carried by the latter of the stock-carrying spindles D
driving gearing for said spindles causing them to rotate in the same direction the
slides G and H connected with said spindles to move the same longitudinally the
transversely movable slide I, the posts i and mounted thereon, the cutting
tools carried by the said post the stops carried by the said posts ¹ the
levers J and tappet wheel & for operating said slide, the longitudinally movable
post or turret K, the threading dies k carried thereby, the slide L on which
said post or turret is mounted and the tappet wheel for operating said slide L.
Dated this 31st day of July 1893.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.