Year: 1888

page_text: 434
Screws
I, JOHN HASKINS LADD, of 116 Queen Victoria Street in the City of London,
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 relates to machines for rolling screw threads of the type in which
the formation of the threads is effected by the action of actively reciprocating dies
which roll the screw blanks over the faces of supporting dies, the opposed faces of the
said dies being provided with systems of parallel ribs, relatively inclined in opposite
directions
The said invention comprises two actively reciprocating dies moving in rectilinear
paths and operated by a common actuator in combination with two supporting dies
which are supported in the frame of the machine, and the faces of which are
appropriately ribbed, and are parallel with and in suitable proximity to, the planes of
motion of the faces of the actively-reciprocating dies, respectively
By means of independent feeding devices, screw-blanks are delivered respectively
in opposite positions to be acted upon by the two pairs of dies, so that at each
complete stroke of the common actuator, threads are formed upon two blanks
In the accompanying drawings I have shown how my said invention can be
conveniently and advantageously carried into practice
Figure 1 is a plan
Figure 2 is a side elevation, partly in section
Figure 3 is a vertical section on the line T, T, Figure 1
Figure 4 is a plan of the portion of the machine in which the dies are supported,
with the caps removed for the purpose of more clearly showing the supporting dies,
and the devices for supporting and operating them
Figure 5 is a transverse vertical section on the plane indicated by the dotted
TA

page_text: Figure o is a vertical section on the lines, & figure
Figure 7 is a plan of one of the supporting dies and one of the cams which operate
it, showing it in its extreme forward position, in which the finger upon its forward
end acts as a divider for dividing the lowermost blank from the column of blanks held
suspended by their heads in the ways, and also affording a top view of the adjacent
nctively-reciprocating die in the position which it occupies near the conclusion of that
one of its excursions in which it rolls the finished blank off from the rear end of the
supporting die
Figure 8 is a side elevation of the supporting die shown in Figure 7 and of the
carriage in which it is mounted, and of the cam for imparting endwise reciprocating
movements to the said carriage
Figure 9 is a vertical section on the line w, w, Figure 7
Figure 10 is a vertical section on the liner Figure 7, showing the cam for
operating the wedge by means of which the supporting die is wedged toward the
plane of motion of the adjacent actively-moving die
Figure 11 is a plan of the lower end of one of the ways showing the separator
finger on the end of one of the supporting dies in the position which it assumes in
relation to the ways when the cams which control the movements of the said supporting
die are in the positions in which they are represented, respectively, in Figures 7, 8, 9
and 10, also showing the end of the actively-moving die in the position which it
occupies immediately pieceding the commencement of that one of its movements
in which the blank at the end of the ways is moved against the face of the sup-
porting die
Figure 12 is a plan of one of the supporting dies, and the cams which operite it,
and of a portion of the adjacent, actively-moving die, which is represented as having
Just entered upon th it one of its movements during which the blank at the end of the
ways is carried by the deliverer into the position in which it is about to be caught
between the opposed fices of the two dies
Figure 18 is a side elevation of the supporting die and its carriage, showing the
position of the cam which operates it at the time when the parts are in the positions
in which they are shown in Figure 12
Figure 14 is a vertical section of the carriage-operating cam on the line Y, Y,
Figure 12
A
Figure 15 is a side elevation of one of the wedge-operating cams
Figure 16 is a vertical section on the line 'z, z Figure 12, showing in elevation the
deliverer and the mechanism for operating at in the positions they occupy (when the
deliverer is 'in the position in which it is represented in Figure 12
A is the frame of the machine A' is the bed
'Power to drive the machine is applied to the pulley a to the shaft of which is
affixed the pinion a¹, engaging with the toothed wheel afixed-to-the crank-shaft a³
By means of the mitre wheels or bevel wheels at and a power is transmitted to the
shaft a from which-by means of the mitre wheels or bevel wheels a' and sa³, power 1s
transmitted to the cam shaft B
'
'
The crank fixed to the crank shaft a³, is connected by the crank pinto³ to the
stem d, of the forked piece or connecting rod D
The two branches, d¹and, of the forked piece or connecting rod D, are preferably
inserted 'through 'holes in the cross-head D1, and the portions of them which are
inserted through the cross head are each preferably sorew threaded and provided with
nuts, e, e', and f, f¹, respectively At their opposite ends the branches d'and d are
pivoted respectively to the actively-reciprocating die-carriages bE and F, which are
seated upon the bed A', and are separated from each other by the vertical rib'G, and
are held in their appropriate positions by means of the cap G³, provided upon its
under side with 'the downwardly projecting pins 9, g, which enter the longitudinal
grooves g, g, formed in the tops of the die carriages(E and F, respectively It will
be seen that by means of the nuts e, el and if, f, the actively-reciprocating die-
carriages E and F can be independently adjusted endwise with relation to the crank
shaft a³
1

page_text: The actively-reciprocating die E' is mounted upon the carriage E, and operates in
conjunction with the supporting die H mounted upon the carriage H and the actively
reciprocating die F is mounted upon the carriage F, and operates in conjunction
with the supporting die I, mounted upon the carriage Ii
The die carriages H₁ and I are pressed laterally away from each other by means
of the expanding spiral springs J shown in Figures 1 and 4, and also by means of
the expanding spiral springs J¹ shown in Figure 5, which latter, as will be seen,
exert their outward thrust upon pins h and 1, which are respectively inserted into and
project downward from the supporting die carriages H¹ and I'
H
ge
Appropriate to and fro end wise movements are imparted to the carriage H³, for the
purpose of effecting the successive feeding of the blanks, and the successive dischai,
of the finished screws, by means of the cam H³, the periphery of which bears upon
the antifriction roller h¹, pivoted to the carriage
The rear end of the carriage H₁ terminates in a loop or ring H', which loosely
encloses the hub K' of the cam H' The hub K¹ is provided with a notch K', for
engaging at the proper time the rib , projecting radially inward from the inner side
of the loop or ring, the object of such engagement being to steady the movement
of the carriage H¹ when the parts are in the position in which they are represented
in Figure 8, in which, as will be seen, the apex of the cam H is bearing upon the
anti-friction roller h¹
Similarly, the carriage I¹ is provided with an antifriction roller ², affording a bearing
for the cam k, the hub of which is loosely enclosed in the loop or ring and is
provided with a notch similar to the notch K³, for engaging a rib upon the inner side
of the loop or ring, which rib is similar to the rib ³, shown in Figure 8
The machine is preferably so constructed that the actively reciprocating dies make
several to and fro movements, and hence roll the screw blanks successively several
times to and fro over the surfaces of the supporting dies, in order to fully form the
threads upon them During the greater part of this operation, the faces of the
supporting dies are made to gradually approach the planes of motion of the faces
of the actively-reciprocating dies This is effected by means of the cams L, 1, acting
respectively upon the wedges L³, 1 These wedges are moved end wise in one
direction by their cams, and in the opposite direction, when their cams permit it, by
their reciprocating springs I³, 1ª
Provision is made for laterally adjusting the supporting die I by means of the
horizontal set screws M inserted through the bracket A', and bearing upon their inner
ends upon the gib m which affords the support for the diagonal side of the wedge A
Upon releasing the set screws M, the carriage I', wedge l, and gib m are permitted
As owing
to move outwardly under the influence of the expanding springs Jand J¹
to the counter-shaft a" and the mitre wheels or bevil wheels a' and as it is inconvenient
to employ horizontal set-screws to effect the lateral adjustment of the carriage H' of
the die H, the expedient is adopted which is illustrated in Figure 6, in which, as will
be seen, the gib n, which affords support for the diagonal side of the wedge L, is
tapering in cross section, and so placed that its inclined side bears upon the inclined
side of the wedge bolts N By raising the wedge bolts N, the gib n, wedge L, and
carriage H', and die H, are forced toward the centre of the machine, while when the
wedge bolts N, are dropped down, the said parts are free to move laterally outward,
in obedience to the thrust of the springs J and J
The die carriages H₁ and I are each provided with a retracting spring, one of
which H, is shown in Figure 3 and, as will be seen is attached at one end to the
frame of the machine, and at the opposite end to the pin projecting downward from
the said carriage H¹ The machine is provided with two chutes or ways, one chute
or way O, for feeding screw-blanks to the dies E' and H, and the other chute or way P,
for feeding blanks to the dies F¹ and I
The mode of operating the deliverers Q for delivering the blanks successively from
the ends of the ways into positions to be seized by the dies, respectively, is substan-
tially the same as that illustrated in Letters Patent No. 1575 A D 1887, granted to
HA Harvey for Improvement in machine for rolling screws, dated February 11887,

page_text: excepting, however, that in the present case the whole operation of separating the
lowermost blank, and of delivering it to the dies, is performed with great rapidity,
and to prevent the blank which is being fed from being thrown by the deliverer too
far beyond the end of the actively-reciprocating die, the face of the carriage upon
which the actively-reciprocating die is mounted is provided with a laterally projecting
shoulder or laterally projecting pins, either of which expedients serve as a stop against
which the body of the blank bears, when the parts are in the positions in which they
are represented in Figures 11 and 12
In the drawings the stop R is represented as applied to the carriage E, of the
actively reciprocating die El
It will be understood of course that a similar stop is applied to the carriage F, of
the actively reciprocating die F¹
One of the important and novel features of the present machine consists in the
employment of cams for controlling the end wise movement of the supporting dies,
which are independent of the cams for controlling the Interal movements of those
dies It hence follows that a large range of endwise movement is permitted to the
supporting dies, without any of the increased friction which would be due to the
accompanying lateral movement of those dies if such movement occurred coincidently
with, and in proportion to, the end wise movement, as in the case of the machine
shown in Letters Patent No 157587 heroinbefore referred to
Another peculiar feature of the present machine, by which a product of very great
smoothness is obtained, consists in arresting the lateral movement of the supporting
die for a sensible period prior to the discharge from the dies of the finished screw
This is conveniently accomplished by making a suitable portion of the cams Land
concentric, the concentric portion of the cam being that which is of the largest radius,
as shown in Figures 10 and 15
It thus follows that the endwise movement of the wedge ceases as soon as its
operating cam has completed a prescribed portion of its revolution, and hence during
the remainder of the revolution of the operating cam the supporting die ceases to
move, or only moves very slowly toward the plane of motion of the actively recipro-
cating die
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
-
First In a machine for rolling screw threads, two screw-blank foeding chutes or
ways and deliverers, and two pairs of suitibly ribbed dies, each pai consisting of an
actively reciprocating die and supporting die, in combination with actuating
mechanism comprising a crank and forked piece or connecting rod for imparting
motion to the sud actively reciprocating dies, substantially as and for the purpose
set forth
Second In a machine for rolling screw threads of the type in which an actively
reciprocating die is employed to roll the screw blank over the face of a supporting
die, and in which the said supporting die has prescribed endwise movements for
effecting the feeding of the blanks to the dies and the discharge of the finished screws
therefrom, and, during the operation of rolling the thread upon each blank, also has a
lateral movement toward the plane of movement of the actively reciprocating die the
combination, of a cim for effecting such end wise movements of the said supporting
die and an independent cam for instituting such lateral movement of the said supporting
die-substantially as and for the purpose above specified
Third The combination in a double michine for rolling screw threads, of two
actively-reciprocating dies which are independently adjustable with relation to the
mechanism which actuates them, two supporting dios supported in the firme of the
machine, and two cams for imparting prescribed endwise motions to the said supporting
dies substantially as set forth
Fourth Inchine for rolling screw-threads of the type herein shown, in which
an actively reciprocating die and a supporting die are employed, a cam for imparting

page_text: a prescribed range of endwise movement to the said supporting die, a wedge inter-
posed between the carriage upon which the said supporting die is mounted a laterally
adjustable gib affording the bearing for the diagonal side of the said wedge, and a
cam for imparting a prescribed end wise movement to the said wedge, substantially as
described
Fifth In a machine for rolling screw threads of the type in which an actively
reciprocating die and a supporting die are employed the combination of supporting
H$
die H, mounted upon a carriage H¹ having affixed to its rear end a loop or ring
provided with a rib h³ for imparting a prescribed range of endwise movement to the
carriage H, and a notched hub K¹, provided with the notch K, for steadying the
carriage H at the end of the said movement, substantially as set forth
Sixth In a machine for rolling screw threads of the type in which an actively
reciprocating die and a supporting die are employed, the stop R, affixed to and
projecting from the face of the actively reciprocating die carriage at an appropriate
distance from the die mounted thereon, as and for the purpose above specified
Seventh The combination of the supporting die carriages H¹ and I', with the
expanding springs J, J', for holding the die carriages against the side bearings upon
which they slide, substantially as described
Eighth The combination of the cam-shaft B, the cams H2 and k, mounted thereon
the supporting die carriage H¹ and I', with the chutes or ways, O and P, and the
spring check slides Q operated by the die carriages H¹ and I respectively, substantially
as described
Ninth The improved machine for rolling screw threads constructed substantially
as described with reference to Figures 1 to 16 of the accompanying drawing
1000
HASELTINE LAKE & Co,
45, Southampton Buildings, London,
Agents for the Applicant