Screw Machines.
Year: 1891

page_text: Date of Application, 24th Feb., 1891-Accepted, 28th Mar., 1891
COMPLETE DE MOITIATION.
Screw Machines.
1. CHRISTOPHER MINER SPENCER, of the City of Hartford, in the County of
Hartford and State of Connecticut, United States of America, Machinist, 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:-
My invention relates to improvements in machines for making screws automati-
cally, and the objects of my improvement are to make screws directly from a coil of
wire; to simplify the construction of the machine, and to increase its efficiency
especially with reference to requiring but little attention from an attendant and to
rapidity of producing screws.
In the accompanying drawings:
Figure 1 is a perspective view of my machine.
Figure 2 is a front elevation of the same.
Figure 3 is a rear elevation thereof with parts of the bed sectioned and broken
away.
Figure 4 is a vertical section of the bed and shaft on line - of Fig. 2, the
parts on the left of said line being shown in side elevation.
Figures 5 and 6 are developed plan views of two cam wheels.
Figure 7 is an enlarged plan view of one end of the machine.
Figure 8 is a vertical section on line y-y of Fig. 7.
Figure 9 is a detached front elevation showing a portion of the feed, the same
being on a still larger scale.
Figure 10 is a vertical section on line 2-2 of Fig. 9.
Figure 11 is a perspective view of supplementary carriage.
Figure 12 is a perspective view of one of the boxes or bearings for the shafts of
the feed rollers.
Figure 13 is a partial central vertical section and partial elevation, illustrating
more particularly the head of the lower lathe spindle and its connections..
Figure 14 is a transverse vertical section of said head on the line w-w of
Fig. 13.
Figure 15.is an end view of the same with the tool carriage moved into a different
position.
Figure 16 is a plan view of said head with the tool carriage in the same position
as in Fig. 14.
Figure 17 is a detached plan view of a portion of said head, and-
Figure 18 is a front elevation with parts broken away of portions of the lathe
spindles in a modified form, said figure being on the same scale as Figs. 7 and 8.
A designates the bed or table upon which the uprights B, B, that support the
second bed C, are mounted. In suitable bearings in the uprights B B the cam
shaft D is supported, said shaft bearing cam wheels E, F, and cam G.
The shaft
is driven by means of the pulley H and connecting back gearing 18 the same as
that on an ordinary engine lathe which is too well known to be described.
One end of the bed C (the left hand end in Fig. 2) is provided with ways within
which the principal carriage 19 reciprocates from right to left. A friction roller 69
is mounted on a stud on the lower side of said carriage for being engaged by the
cams of the cam wheel E. The inner end of said principal carriage has rigidly
connected to it an upright 20 the same being provided with vertical ways shown
most clearly in plan view, Fig. 7, within which ways is a vertical slide 21 having a
pin 36 that rests upon the edge of the cam G. A supplementary carriage a is
rigidly connected to said slide so that it has an up and down movement inpependent
D1121

page_text: "
of the principal carriage, while at the same time it moves horizontally with said
carriage. To the rear side of the supplementary carriage, I attach straightening
rollers. 22, 23, the same being grooved at their periphery and mounted on suitable
shafts with the axis of the upper rollers in different vertical planes from that of the
lower ones, the rollers being set near enough to each other so that a wire passing
between them will be straightened. Different sizes of rollers may be applied for
different sizes of wire. By the side of these straightening rollers the feed rollers 24
are mounted. These rollers are mounted on suitable shafts 25 and held upon the
shafts by nuts 70. The shafts are received in boxes or bearings 26 which have
ledges or flanges 27 at one end for sliding in the vertical ways 28, Figs. 10 and 11
"of the supplementary carriage a. These boxes are secured within their carriage by
nuts 29 while the shafts are secured within their boxes by nuts 30. The shaft for
the upper roller has rigidly secured to it a ratchet wheel 31, and loosely secured so
as to oscillate thereon a lever 32. This lever has mounted upon it a pawl 67 for
engaging the ratchet wheel 31 and a spring 68, see Fig. 9, for pressing the pawl
against said wheel all of any ordinary construction. The supplementary carriage a
is provided with set screws 33 for bearing upon the boxes 26 and adjusting the feed
rollers toward each other and holding them in place when adjusted, the nuts 29
being loosened prior to adjustment and retightened after adjustment. The outer
end of the lever 32 is, or may be, slotted longitudinally for purposes of adjustment
and within' said slot the upper end of the link 34 is secured, while its lower end is
pivotally connected to the bed C. The connection of the upper end of the link
with the lever 32, when adjustable therein, may be that of the ordinary slot and bolt
connection, too common in all classes of machinery to require a detailed description.
If desired the bed C may be provided with several screw holes as shown at 35 in
Fig. 2, for pivotally connecting the lower end of this link at different points.
The opposite end of the bed C is provided with uprights 37 which may be cast
integral with said bed. Within these uprights there is a series of spindles 38, 39,
and 40, the same bearing at their inner ends any desired tool. As shown the upper
one provided with a cutter head 41 for carrying turning tools for turning down
the body of the screw, the middle spindle 39 is provided with a head 42 carrying a
threading die and the lower spindle 40 with a head 43 that carries a tool for turning
off the head of the screw, and another for cutting the screw from the wire or stock.
The heads 41 and 42 are or may be of any ordinary construction and hence require
no detailed description.. In some cases the lower spindle 40 may be provided with
ha head and cutting tool of ordinary construction, but when it is provided with a head
having a tool for turning the screw head and another for cutting off the stock it is
made as follows; the head 43 is best illustrated in Figs. 13 to 17. It is slotted
longitudinally on its underside for the reception of the sliding cam 44 as shown
most clearly in Fig. 15, and it is slotted transversely on its upper side to receive the
sliding tool carriage 45. Said sliding tool carriage is provided with a cutting
tool 47 on the upper side of its centre and at its opposite end with a cutting off
tool 48, on the reverse side of its centre. The sliding cam 44 is provided with an
oblique slot 49 whose edges form the cams and through which slot a screw 50
passes into the body of the sliding tool carriage 45. This sliding cam is provided
with a grooved collar 51 which encircles the spindle 40 and a shipping fork 52 is
secured to the sliding shaft 53 mounted to slide in the uprights 37, said shaft being
provided with a downward projection 54 for engaging the cams of the cam pulley F.
Said head is also provided with a central bushing or socket 46 to support the work
therein.
!!
1
The spindles 38 and 40 are intended to be driven by means of suitable belts
running over the pulleys 55 and the spindle 39 which has a slight longitudinal
motion in its bearings is driven by means of the double-faced friction pulley 56
which bears against opposing conical pulleys 57 on the shafts 38 and 40 in a manner
.hereafter described.
+
The cam wheel Eis provided with cams 58, 59 and 60 for operating the shipper
of the sliding tool carriage, and the cam wheel E is provided with cams 61, 62, 63,

page_text: 4, 65, and 66 for reciprocating the carriage 19. I prefer to form these cams of
eparate pieces screwed to the periphery of the pulleys so that different cams may
e applied to the same pulleys for different purposes when desired.
The machine is supplied with wire b from a suitable coil arranged near the
machine so that the wire may be drawn therefrom as it passes between the
straightening and feeding rollers. If the coil is set up edgewise the slight bend in
the wire as it is uncoiled will be straightened between the straightening rollers by
pressure upon opposite sides in the bottom of the grooves therein. The feeding.
and straightening rollers bear upon the stock or wire with sufficient friction to hold
the same against rotation during the several operations performed thereon. The
cam Gacting on the pin 36 of the slide 21 raises and lowers said slide, together
with the supplementary carriage a. When this carriage is being lowered the link 34
pushes the outer end of the lever 32 upwardly and carries its pawl 67 upwards, the
spring 68 permitting said pawl to yield and wipe the teeth of the ratchet when it
slips over in thus being drawn back. Upon the upward movement of the carriage a
the point of the pawl engages a shoulder in the ratchet wheel so that when the
lever 32 swings under the action of the link 34 as the supplementary carriage rises,
the ratchet wheel and feed roller shaft with which it is connected are revolved a.
part of a revolution thereby turning the upper feed roller to feed the wire forward
a given distance, the lower feed roller turning with the upper one by friction as in
ordinary feed rollers of this class. The cam G has three concentric peripheral
faces and when it is on the highest one of these faces the wire b in the feed rollers
is elevated into a position in alignment with the spindle 38. The cam 61 is now
engaged by a friction roller 69 which is mounted upon the underside of the principal
carriage 19, so as to force said carriage against the head 41 in the spindle 38,
whereby said head turns off a portion of the rod to the proper size for the body of
the screw.
The cam 62 then engages said roller 69 and withdraws the stock from
the head 41 of the spindle 38. The cam G then comes into position where the
pin 36 of the vertical slide 21 rests upon the middle concentric face so as to bring
the rod in alignment with the thread cutting spindle 39. The cam 63 now moves
the carriage 19 and the rod into the threading die when one side of the friction
pulley 56 will be pressed against the conical pulley 57 of the spindle 38 to drive the
spindle 39 in the proper direction to cut the thread. The cam 64 next engages the
roller 69 to withdraw the carriage and rod, thereby pulling the friction pulley 56
out of contact with the pulley 57 of the shaft 38 and bringing it into contact with
the pulley 57 on the spindle 40 so as to revolve the spindle 39 in the opposite
direction and unscrew the threading die. The cam G moves on so that the pin 36
of the slide 21 rests upon the lowest concentric face of said cam and the cam 65 on
the cam wheel E moves the carriage and rod again forward to present it to the
head 43 of the spindle 40. The pin 54 on the sliding shaft 53 is engaged by the
cam 58 to move the sliding tool carriage 45 in a direction to carry the tool 47
The cam 59 next engages the
against the work to turn the head of the screw.
pin 54 and operates the shipper 52 to move the sliding cam 44 in the reverse
direction, thereby moving the sliding tool carriage 45 in the direction to withdraw
the cutting tool 47 and bring the cutting-off tool 48 into action to completely sever
the screw thus turned and threaded from the rod. The cam 60 next operates the
shipper to move the sliding tool carriage 45 partly back again far enough so that
its point will be clear of the rod as it is again fed into the socket or bushing 46 for
repeating the operations before described. Immediately after the screw has been
thus cut off the pin 36 on the cam G is carried from the lowest to the highest of its
peripheral concentric faces to again bring the wire in the supplementary carriage in
alignment with the upper spindle for repeating the operations before described, the
feed being operated to throw the stock forward during the upward movement of
the slide 21.
In Fig. 18 1 have shown a modification of the driving mechanism for the threading
spindle 39, which in combination with the other spindles I consider the equivalent

page_text: •
of that first described. The spindle 39 is provided with a gear wheel 71 which
engages gear wheels 72 on the spindles 38 and 40 said wheels being rigidly secured
to loose sliding sleeves and beveled at their ends so as to form friction chucks 73
for engaging hollow conical faces on said spindles, that on the spindle 38 being
formed in one side of the pulley 55, and that on the spindle 40 in one side of a rigid
collar 74. The operation is substantially the same as that of the spindles before
described.
When the spindle 39 is pushed inwardly it is revolved in a direction to
cut the thread by means of the friction clutch on the upper spindle 38 and when it
is pulled out it is revolved in the reverse direction by means of the friction clutch
on the lower spindle 40.
I am aware that the stock has been held stationarily while a tool for operating
thereon was revolved when only one operation was repeatedly performed on the rod
or blank. My machine differs from such machines because I hold a continuous rod
or wire against rotation and present it successively to a series of revolving tools
before cutting work therefrom into the desired length.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what 1
claim is :-
:-
1. The combination of a series of revolving spindles, devices for holding a con-
tinuous rod or wire against rotation, and a carriage upon which said devices are
mounted for presenting said rod or wire successively to said spindles, substantially
as described and for the purpose specified.
2. The combination of a series of revolving spindles, devices for holding the work,
a reciprocating slide or carriage upon which said devices are mounted moving in the
same plane as the axis of the several spindles, and a cam G having concentric faces
corresponding to the positions of said spindles for moving said slide and successively
stopping it with the work in alignment with the respective spindles, substantially as
described and for the purpose specified.
3. The combination of a series of revolving spindles, a principal carriage 19
moving longitudinally to and from said spindles, a supplementary carriage having
work holding devices and mounted on said principal carriage to move transversely
to said spindles, and mechanism for reciprocating said carriage, substantially as
described and for the purpose specified.
4. The combination of a series of revolving spindles, a principal carriage, a
supplementary carriage reciprocating thereon, the cam wheel for reciprocating said
principal carriage having cams corresponding to the respective spindles, and the
cam for the supplementary carriage having steps and concentric faces corre-
sponding to the positions of said spindles, substantially as described and for the
purpose specified.
5. The combination of a reciprocating carriage, the feed rollers mounted thereon,
mechanism for reciprocating said carriage, the lever 32 having ratchet and pawl
for moving the feed rollers and the link 34 pivotally secured to said lever and the
bed of the machine, substantially as described and for the purpose specified.
6. The combination of a series of revolving spindles, a reciprocating carriage
moving transversely to said spindles, with the straightening rollers and feed mounted
on said carriage, substantially as described and for the purpose specified.
7. The combination of the spindles 38, 40, the spindle 39 arranged between them
and having a degree of longitudinal movement, a driving wheel on said spindle and
frictional devices on opposite sides of said driving wheel for connecting it with
either spindle for revolving in different directions, substantially as described and
for the purpose specified.
8. The combination of the spindle 40, head 43, the tool carriage 45 sliding
transversely in said head, the cam 44 moving longitudinally in said head, and
mechanism for operating said cam, substantially as described and for the purpose
specified.

page_text: 9. The combination of the spindle 40, head 43, sliding tool carriage 45, cam 44
having shipping sleeve 51, the shipping fork 52, shaft 53 having projection 54, and
the cam wheel F, substantially as described and for the purpose specified.
10. The combination of a series of spindles the head 43 on one of said spindles,
having sliding tool carriage and cam, the shaft D, cam wheel F, mechanism
operatively connecting said cam wheel and cam of the sliding tool carriage in the
head 43 the principal and supplemental carriages bearing work holding devices, the
cam wheel E and cam G substantially as described and for the purpose specified.
Dated this 28th day of January 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.