Improvements in Machines for Rifling Gun Barrels.
Year: 1891

page_text: Date of Application, 13th Feb., 1891-Accepted. 16th May, 1891
COMPLETE SPECIFICATION.
Improvements in Machines for Rifling Gun Barrels.
We, THE PRATT AND WHITNEY COMPANY and CHARLES WILLIAM SPONSEE
both of No. 1 Flower Street, Hartford in the County of Hartford and State of
Connecticut, United States of America, Manufacturers, 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 automatically making the rifle-grooves of
gun-barrels, and has for its object to furnish improved and effective means for
operating the barrel and the rifle-tool, and for feeding said tool to the work.
In the drawings accompanying and forming a part of this Specification,
Fig. 1 is a plan view drawn on a small scale, of a rifling machine embodying my
invention.
Fig. 2 is a front or side elevation of the machine.
Fig. 3 is a plan view on an enlarged scale of the right-hand end of the machine,
showing that portion of the bed carrying the driving mechanism, the shipper
mechanism and the oil-pump.
Fig. 4 is a front elevation of the parts shown in Fig. 3, some details being broken
away, the more clearly to show the construction.
Fig. 5 is a longitudinal central vertical section of the carriage.
Fig. 6 is an end view of the carriage as seen from the right-hand in Fig. 1 and
showing a portion of the bed in section.
Fig. 7 is a plan view of a portion of the bed of the machine, with the parts com-
posing the barrel-carrying head in position thereon.
Fig. 8 is a longitudinal central vertical section of the parts shown in Fig. 7.
Fig. 9 shows a portion of the bed in section, and means for rotating the driving-
screw by hand; also an end elevation of the index-plate and accessory parts as
seen from the left-hand in Fig. 7, the outline of the framework of the head being
shown by broken lines.
Fig. 10 is a side view, and Fig. 11 an edge view, of the index-plate.
Figs. 12 and 13 are similar views of the ratchet-wheel for turning the index-plate
and spindle.
Figs. 14 and 15, 16 and 17, are similar views of the pawl-plate and the pinion-
plate, respectively.
Figs. 18, 19 and 20 are views, similar to Fig. 9, illustrative of the operation of the
index-plate and accessory parts used when four rifle-grooves are to be cut in a
barrel.
Figs. 21, 22 and 23 are three similar views illustrative of the operation of the
index-plate and accessory parts when constructed and arranged for making six
grooves in the gun-barrel.
Fig. 24 is a view of the rifling-rod, drawn to a small scale.
Figs. 25, 26 and 27 are views, drawn on a scale about full or natural size, of a
portion of the rifling-rod, shown partially in section, for illustrating the method of
feeding out the rifling-cutters.
Fig. 28 is a view of the rear end of the rifling-rod.
Fig. 29 is a plan view of one of the cutters.
Fig. 30 is a front-end view of the spindle-socket for holding the rifling-rod.
Fig. 31 is a plan view of a portion of the bed of the machine, showing the feed
mechanism in position thereon.
Fig. 32 is an end view. partially in section, of the feed mechanism as seen from

page_text: Fig. 33 is a side view of the feed-ratchet and the feed-screw, the ratchet being
shown in section.
Fig. 34 is a side view of the oil-pump with cover thereof removed.
Fig. 35 is an end view of the lock-nut and accessory parts for holding the
barrel.
CC
Similar characters designate like parts in all the figures.
The main frame or bed of the machine, which is designated in a general way by
the letter B, is somewhat similar in its general proportions to the beds of ordinary
engine lathes," being composed of the two vertical side walls c and d, connected
at the ends and in some parts of its length by the floor f, and being flanged at the
base and top of the side walls; the top flanges e and g form a table whereon to
assemble some of the details, and the inner edges of said flanges form the ways 61
and 62 whereon to clamp the barrel-carrying head and the feed mechanism, and
whereon the carriage is fitted to slide.
In the general views, Figs. 1 and 2, owing to the small scale on which the same
are drawn, some of the mechanisms are designated as a whole by a single letter, the
barrel-carrying head being designated by the letter H, the feed mechanism by the
letter F, and the carriage by the letter C; cach of these mechanisms being more
fully described in connection with separate and enlarged views thereof. The
principal operative part of the machine may be considered as carriage mechanism,
designated in Figs. 1 and 2 by the letter C, and shown on an enlarged scale in
Figs. 5 and 6. The carriage proper, 60, is fitted to slide on the aforesaid ways 61
and 62, being held thereto by the straps or gibs 63 and 64, said gibs being secured
to the under side of the carriage by screws in a well-known manner, as indicated by
dotted lines in Fig. 6. The half-nut 59 is fixed by screws to the under side of said
carriage 60, as indicated in said figs., and is adapted to mesh with the thread of the
carriage-driving-screw 11, which screw is supported in bearings 13 (Fig. 3) and 13'
(Fig. 8) on the frame of the machine. When said driving-screw is revolved in one
direction, it traverses the carriage towards the left-hand in Figs. 1, 2, 7 and 8; and
when reversed to run in the opposite direction, it traverses said carriage towards
the right-hand in said figs. The driving mechanism for actuating said screw is
shown in the general views, Figs. 1 and 2, and on an enlarged scale in Figs. 3 and 4,
and will next be described in detail. At the right-hand or rear end of the carriage-
driving screw 11, said screw has fixed thereto a gear, 10, which may be fastened in
place by an ordinary shaft-key (not shown) and the nut 12, in a well-known
manner. The driving-shaft 5 is located below the screw-shaft 11, its inner end
being carried in the bearing 6 (see Fig. 4) formed in the frame B, and its outer end
in the bearing 7 of the yoke or driving-shaft frame, K. Said driving-shaft has
fixed thereon the driving-gear 9, which meshes with and drives the aforesaid gear 10
of the screw-shaft. For actuating the shaft 5, said shaft is provided with a set of
driving-pulleys, consisting of the fixed pulley 3 and the loose pulleys 22 and 24,
carried on the shaft at the inner and outer sides, respectively, of said fixed pulley.
Power is supplied to the driving-shaft 5 from a main-shaft (not shown) by means of
the two belts 2 and 4, one of which is 66
an open "belt and the other a "crossed'
belt, and which are guided to run on the said loose pulleys 22 and 24, respectively,
when the machine is idle. When the carriage C is required to be driven in one
direction, one of said belts is shifted onto the fixed pulley 3; and when said carriage
is required to be reversely operated, the other of said belts is shifted onto said fixed
pulley. As a means for operating said belts, a belt-shifting mechanism is provided,
which, in its preferred form, is constructed and arranged as follows:
"
The position of the shipper mechanisms, when the machine is at rest, is shown in
Figs. 3 and 4.
The screw 11 being right-handed, and the belts 2 and 4 being run
in the direction of the arrows shown thereon, the belt 4 will be the driving-belt for
running the carriage C forward, or toward the left-hand; while the belt 2 will be
the returning belt, for drawing back the carriage toward the right-hand. Of
course, the loose pulleys 22 and 24 revolve in the direction of the respective belts
thereon. A shipper-rod, 23, is carried in suitable bearings, as 25, fixed on the

page_text: At
main-bed, see Figs. 1 and 2. As a means for operating this rod by hand, it has
rack-teeth, 26, engaging the teeth cut in the inner segmental end of the shipper
handle 27, which is pivoted at 28 to a bracket, 29, that is fixed to the bed B.
its right-hand end, the shipper-rod has a rack, 30, (which may be connected
thereto by means of the nut 31,) which rack is fitted to slide in the rack-box 32,
and has rack-teeth formed in one side thereof to engage the teeth of the shipper-
pinion 33. In Fig. 3 the covers of the rack-box and of the shipper-cam box are
removed to more clearly show the disposition of the various parts; in Fig. 4 said
covers are shown secured in place. Said shipper-pinion 33 is carried by the shipper-
pinion shaft or stud 34, to which it is or may be fixed by a key not shown; said
shaft being fitted to freely turn in a lower bearing at 35 in the rack-box 32, and an
upper bearing at 36 in the cover, 37, of said rack-box. A segment, 38, designated
as the shipper segment, is also carried by the shaft 34 and is fixed thereto by means
of a key not shown; the teeth of said segment engage rack-teeth that are formed
in one side of the shipper-cam 39, as more clearly shown in Fig. 3. Said shipper-
cam 39 is fitted to slide in the shipper-cam box 40, which is fixed on the bed of the
machine at the right-hand end thereof; said cam has two cam-grooves, 41 and 42,
wherein engage, respectively, the shipper-cam pins, 43 and 44, of the respective
shipper-rods 45 and 50, which are fitted to slide in bearings formed therefor in the
cam-box 40, and are provided with the shippers, 46 and 51, that are clamped to the
rods by the clamp-screws 47 and 52, respectively. For preventing rotation in their
bearings of said shipper-rods 45 and 50, their respective pins 43 and 44 pass through
slots 48 and 49, respectively, in the bottom of the cam-box 40. As shown in
Figs. 3 and 4, the shipper 46 engages the belt 2, and the shipper 51 the belt 4.
The organization of this belt-shipping mechanism is such, as will be seen from
Figs. 1 and 3, that when the carriage C moves toward the right-hand and strikes
the stop 111 fixed on said rod 23, it acts through said rod and the connecting gearing
and the cam 39, to first shift the belt 2 from the pulley 3 onto the loose pulley 22, and
immediately thereafter (by reason of the form and arrangement of the grooves 41
and 42) to shift the belt 4 from the loose pulley 24 onto the pulley 3, thus reversing
the motion of the screw-shaft 11 and of the carriage C. When the carriage has
run in the opposite direction sufficiently far, it strikes the similar stop 113, and thus
reversely operates the rod 23 to re-shift the belts to again reverse the motion of
the carriage. The stops 111 and 113 are, of course, adjustable lengthwise of the
rod 23. The bed 60 has formed thereon, or fixed thereto, the lugs or ears 110
and 112, the former to engage the adjustable shipper-rod stops 111 and 113, and
the latter to engage the indexing-cam-rod stops 114 and 115, (see Figs. 1, 2
and 6).
The carriage-actuating screw 11 is, in practice, threaded only a portion of its
length, the remaining portion being continued, of reduced diameter, to connect with
the devices for actuating said screw-shaft by hand. This arrangement is shown in
Figs. 8 and 9. On the left-hand end of said shaft 11, and adjacent to the bearing 13',
there is a mitre-gear, 14, (fixed to said screw-shaft by the pin 15, or otherwise,) for
meshing with the mitre-gear 16, which is shown in dotted lines in Fig. 8, and in
section in Fig. 9. Said gear 16 is suitably fixed to the inner end of the shaft 17,
as illustrated in Fig. 9, wherein the said gear 14 is shown in dotted lines. Said
crank-shaft 17 is or may be carried in a bushing. 19, which is fitted into a bore in
the bed B and secured by screws, as 20. By means of this gearing and a hand-
crank applied to the squared head 21 of the shaft 17, the carriage-screw 11 may be
readily revolved by hand, to bring the carriage to an exact position when adjusting
the machine ready for using.
To prevent any undue deflection of the screw-shaft 11, one or more shaft-
bearings, 18, are fixed to the bed B under said shaft by screws, as shown in Figs. 1
and 6; said bearings are, of course, fitted to the outside diameter of the threaded
part of the said screw-shaft.
The carriage mechanism, C, in the preferred form thereof shown in the drawings,
is constructed and arranged as follows: The carriage frame 60 is fitted to slide on

page_text: The two
the ways or guides, 61 and 62, of the main-bed B, and is provided, as herein before
mentioned, with the gibs 63 and 64, for holding the carriage to its ways.
uprights or heads, 65 and 66, on the bed 60, are provided with removable bearings,
as 67 and 68, held in place by the usual caps, as 69 and 70, for the rifling spindle 71,
see Fig. 5. Two pinions, 72 and 73, are fitted to said spindle, being fixed thereto
by shaft-keys; a collar or flange 74, and the nut 75, hold the spindle and the pinions
thereon in place longitudinally. Said pinions 72 and 73 engage a rack that is
preferably made in two parts for the purpose of adjustment to prevent back-lash or
play the part 76 of said rack is fixed to the rack-slide by screws as 78, and the
teeth thereof mesh with the teeth of the pinion 72; the part 79 of said rack is
closely fitted to slide in said slide 77, and is adjusted longitudinally of the part 76,
by means of a screw, (not shown,) in a well-known manner. A bracket or rack-
carrying frame, 80, is secured to the carriage-frame 60 by screws as shown, and
carries said rack-slide 77; said bracket being supplied with a gib, 81, for holding
the rack-slide in place. The rack-slide 77 is bored to receive a stud 82, which is
also fitted to turn closely in the traverse-bar slide or block 83, thus pivotally con-
necting said slides. The slide 83 has usually a loose part or gib, 84, (shown in end
view in Fig. 6.) provided with a screw, 85, for adjusting the said slide in a well-
known manner to maintain a close fit between the ways, 86, of the traverse-bar 87.
The said traverse-bar is pivotally supported on the stud 88, which is fixed by a
nut, 89, in the traverse-bar bracket 90; said bar is provided for the purpose of
regulating the degree of the taper, or "twist," of the rifle-grooves being formed in
the gun-barrel, and is therefore made adjustable. To this end, two brackets or
segments, 91 and 92, are suitably fixed to the main-bed by screws as shown in the
general views, Figs. 1 and 2, and have T-shaped grooves, as 93 and 94, for
receiving the T-heads of the clamp-bolts 95 and 96; which bolts are provided with
nuts as shown, to clamp the traverse-bar 87 in any required position. A backward
and forward movement being imparted to the carriage by means of the hereinbefore
described screw-shaft and driving mechanism, and the bar 87 being set inclined as
indicated in Fig. 1, said bar traverses the carriage-slide 77 to and fro crosswise of
the machine, during the carriage movement.
The carriage-spindle 71 is fitted to carry the rifling-rod, as follows, reference
being had especially to Fig. 5 and to Figs. 24 to 30, inclusive. The rifling-rod is
designated in a general way by 100, and has a shank, 102, Figs. 24 and 28, fitting
into the bore, 101, of said spindle. Said shank has formed thereon arms or
lugs, 103, which fit into the corresponding notches, 104, that are formed in the
front end of the spindle 71. See Figs. 24, 28 and 30. The shank of the rod 100
having been placed in the bore, 101, of the spindle 71, with the arms 103 of said
shank fitting into the notches 104, the lock-nut, 105, is screwed onto the spindle 71,
thereby forcing the shank 102 tightly into the socket 101; the check-nut 106,
Fig. 24, is then screwed up against the said lock-nut, thus securely holding the
rifling-rod in place. The lock-nut 105 usually has notches, 107, Fig. 5, formed in
the front thereof to allow of the free passage of the arms, 103, of the rifling-rod
shank 102. To remove the rifling-rod from the spindle, the check-nut 106 is first
loosened and then the lock-nut 105 turned back until the shank 102 is loosened and
the notches 107 stand in alignment with the arms 103, when the rod may be
removed, said arms passing through said notches.
Figs. 25 to 27, inclusive, illustrate the mode of carrying the rifling-cutters in the
rifling-rod, and the method of feeding out the said tools or cutters. The
cutters, 108, usually two in number as shown in the drawings, are inserted in
mortises formed in the rod 100; said rod is bored for a portion of its length to
receive the feed-pin or wedge 109, which is flattened and tapered for a portion of
its length on two sides thereof to form a thin wedge by means of which the cutters
are forced out. When the machine is prepared for use, said wedge or feed-pin is
drawn out, as in Fig. 25, to allow the cutters 108 108 to pass freely through the
gun-barrel. At the left-hand end of the machine there is a feed-screw, 212, which
is turned (by means hereinafter described) toward the right-hand a small distance

page_text: at each stroke of the rod 100. When the rod approaches the feed-screw, as in
Fig. 25, the pin 109 strikes the face, 2121, of said screw as in Fig. 26, the wedge
being thus driven farther in between the cutters 108 108, as indicated by the
lines ab, which lines are nearest together in Fig. 25, farther apart in Fig. 26, and
still farther apart in Fig. 27, where two feeding operations are supposed to have
been performed. The cutters 108 are or may be of the usual description, being
shown in plan view in Fig. 29, and each having several inclined cutting teeth,
as 99, adapted to form the required rifle-grooves by successive cuts.
The barrel-carrying mechanism, which is designated by H in Figs. 1 and 2, is
more fully shown in Figs. 7 and 8, while some details are further shown in Figs. 9
to 23, inclusive. This division of the machine has a supplemental bed, 120, which
rests on the ways 61 and 62 of the main-bed, and is fixed thereto by screws as
shown in Fig. 7. A part of said bed 120, designated by 121, Fig. 9, supports the
indexing-cam box, 122, which with its cover 123, is or may be secured to said
part 121 by screws as shown. The indexing-cam, 124, is fitted to slide in the said
box 122, and has fixed to one end thereof the cam-rod 125; which rod is fitted to
slide in bearings, 126 and 127, that are fixed to the main-bed B, as shown in Fig. 1.
Said cam 124 has a cam-groove, 128, formed therein; in this groove works the
cam-pin, 129, that is fixed in the indexing-rack segment 130, which is pivoted
at 131 in an opening or mortise, 132, formed in the said part 121 to receive said
segmental gear, together with the rack 133, with which said segment meshes. Two
bearing uprights, 135 and 136, rise from the bed 120, and two spindle-bearings, 137
and 138, are fitted in said uprights respectively, being held in place by the usual
caps, 139 and 140. The tubular barrel-carrying spindle 141 is journaled in said
bearings, and is held in place longitudinally by its flanges 142 and 143, that are
formed on said spindle on either side of the box 138.
For holding the barrel, G, to be rifled, said spindle is provided at its front end
with a lock-nut, 185, fitting a screw-thread formed on the spindle, after the manner
of holding ordinary lathe-chucks. A bushing, 180, is bored to receive the enlarged
end or breech, 181, of the barrel G, and a nut, 182, is bored to fit the part 183 of
said barrel and to screw into the said bushing 180, thus firmly securing said
bushing to the breech of the barrel. The bushing 180 has formed on the front end
thereof the lugs or projections 184, to fit the corresponding notches formed in the
spindle 141, similar to the notches 104 in the rod-carrying spindle 71. The lock-
nut 185 is screwed onto the spindle to engage the front side of said projections 184,
and thus hold the above-described parts firmly in place. Notches, as 186, are
formed in the lock-nut, so that the barrel G, with the bushing 180 fixed thereon,
may be removed from the spindle 141 without entirely removing the said lock-nut,
in a manner essentially the same as above described for removing the rifling-rod
from its spindle. A collet or thimble, 187, whose outer end, 188, is bored to fit the
taper of the barrel G, and which is preferably cylindrical in form, is fitted to slide
closely in the bore of the spindle 141; it is usually split in one or more places, as
at 189, for the purpose of providing a slight degree of elasticity. After the barrel
is fixed in the spindle, the collet 187 is slid into the spindle 141 until the end 188
of the collet "brings up" firmly on the tapered part of the barrel, as indicated in
Fig. 8, thereby accurately centering the same relatively to the spindle.
For intermittently revolving the spindle 141 and the barrel, spindle-actuating
devices are provided as follows: A pinion, 144, is fitted to turn freely on the
spindle, the teeth thereof meshing with the teeth of a rack, 133, which is fitted to
slide on and crosswise of the carriage; a disk, 145, is fixed to the hub, 146, of said
pinion by suitable means, as key 147. The plate 145 carries a pawl-plate, 148,
which is adjustably fixed thereon or thereto by a stud, 116, and nut, 118; said
plate 148 having a series of holes, 156, 157, and 158, therefor. Said pawl-plate
carries pivotally supported thereon at 149, (see Figs. 9, 14 and 15,) an index or cam
pawl, 150, and at 151 a ratchet-pawl, 152; a stop-pin, 153, is fixed in the plate 148
to limit the movement of the pawl 150, as best shown in Fig. 14. A spring, 154,
(shown in dotted lines in Fig. 9,) may be provided to actuate the said pawls. By:

page_text: shifting the bolt 116 from one to another of the holes 156, 157, and 158, the
positions of the plates 145 and 148 may be adjusted relative to each other to suit
different kinds of rifling.
For firmly retaining the spindle 141 in its several positions while making the
cuts, it is furnished with an index-plate, 159, which is shown fixed thereto by a
key 160. The spindle-actuating ratchet-wheel 161 is fitted onto the hub, 162, of
the said index-plate, being usually fixed thereto by a key, 163. As is best shown
in Figs. 10 and 11, the said index-plate or cam-plate, 159, has formed thereon
or fixed thereto two similarly-shaped cams 164 and 165, which we denominate
the feed-cams, and which operate the feed mechanism in a manner hereinafter
fully described, through a lever, 166, that is carried by a stud, 167, fixed in the
upright 136 of the bed 120. See Figs. 7 and 9. The cap 140 has formed
integral therewith a bracket, 168, in which is fitted to slide vertically the lock-
bolt 169, for locking the index-plate; said bracket is furnished with a wedge-
shaped gib, as 170, Fig. 7, for taking up the wear of the bolt; which bolt is
provided with a bolt-actuating pin, 171. The bracket 168 has an opening formed
therein, in which is inserted a spring, 172, and a pin or bolt, 173, that operate
through the pin 171 to hold the point 174 of the lock-bolt 169 normally in
engagement with one of the index-notches, 179, of the index-plate 159, as is best
shown in Fig. 8. On the forward movement of the disk 148, the cam-end, 150¹,
of the pawl 150 first lifts the bolt 169 (through the pin 171 thereof) out of
engagement with the index-notch, as 179, and next, the pawl 152 engages one
of the teeth of the ratchet 161, thus turning forward the spindle 141, together
with the several parts carried thereby, until the next index-notch, as 179', comes
to the lock-bolt. During the early part of that forward movement, the cam 150¹
passes from under said pin 171, and thereby allows the spring 172 to throw
down the bolt onto the periphery of the index-plate, in readiness to engage the
next approaching index-notch, as 1791, Figs. 9 and 10. These several successive
operations are illustrated in Figs. 18, 19 and 20, respectively. In Fig. 18 the
pawl 150 is carried forward sufficiently far to have lifted the bolt 169 out of
engagement with the notch 179. In Fig. 19 the index-plate has been turned
forward one full space, and the bolt has descended again into the notch 179¹
Fig. 20 illustrates the return movement of the pawl-carrying plate 148, and
shows the lifting-pawl 150, with the cam 150¹ thereof, returning over the bolt-
pin 171 in a well-known manner; said cam projecting on one side of the arm of
the pawl 150, to provide for that return movement.
In Figs. 21, 22 and 23 are shown successive operations of the ratchet mechanism
when constructed and arranged for dividing the revolution into six divisions.
According to this modification, the index-plate 159 has six notches, and the
ratchet 161 has a corresponding number of teeth, as indicated by the dotted lines.
In this arrangement, the ratchet-plate 148 is shifted on the dial 145 until the pin 116
passes through the hole 158, thus setting the ratchet-plate backward, (toward the
left-hand in Figs. 9, 21, 22 and 23,) by a distance equal to the difference between
one-sixth of a revolution and one-fourth of a revolution, this position being indicated
in Fig. 21. In the operation of the machine when thus adjusted, the ratchet-
plate 148 moves forward nearly one-sixth of a revolution before beginning to turn
the ratchet-wheel 161, this movement being begun when the parts are in the
position shown in Fig. 22, and completed when the parts reach the position shown
in Fig. 23. On the return movement of the ratchet-plate, the movement of the
pawl 150 is the same as described in connection with the preceding figs. The
intermediate pin-hole 157 (see Fig. 16) is for use when the barrel to be rifled is to
have five rifle-grooves made therein. By means of this system of adjustment, the
machine may be adapted for use in the rifling of different kinds of gun-barrels,
without altering the above-described mechanism for actuating the pinion 144.
The feed mechanism, which is designated by F in Figs. 1 and 2, constitutes a
principal feature of my invention, and is most fully shown in Figs. 31 and 32;
reference being had, also, to Figs. 9, 10 and 11, Figs. 18, 19 and 20, and Figs. 24

page_text: to 27, inclusive. The supplemental bed-plate, 195, is adjustably fixed to the main-
bed B near the left-hand end thereof, and carries the principal parts of the feed
mechanism. Said bed-plate 195 is clamped by straps 196, and bolts 197, to the
ways 61 and 62 of said main-bed. The feed-slide 198 is fitted to slide on the bed-
plate 195, longitudinally of said ways 61 62, being held in place by the guides 199
and 200 formed on the bed-plate, and the guide-straps 201 and 202, which are
secured to the said guides by screws as shown in the drawings. Said feed-slide 198
is bored to receive the reduced part, 203, of the rod 23 (Figs. 1, 2 & 7) which
passes freely through the said slide and whose outer end is supported by a
bearing, 204, on the bed 195. A. slide-retracting spring, 205, is carried by the
said rod between the slide 198 and said bearing 204. A stop-pin, 206, fitting in
the slot 207, is provided for the purpose of limiting the sliding movement of the
slide 198, due to said spring. The feed-screw carrier, 208, is pivotally supported
between the arms 191 and 192 of the slide 198 by means of a pivot-pin, 209. The
feed-screw ratchet 210 has a hub or sleeve, 211, journaled in said carrier, and
screw-threaded to receive the feed-screw 212; which screw, as shown in the
drawings, has a left-hand thread. The revolving feed-screw-nut is held in place
longitudinally of the carrier by a nut or collar, as 213, in the usual manner.
The
pin-driving feed-screw 212 is usually furnished with stop-nuts, 214 and 215, for
limiting the working stroke thereof. A stud, 216, is fixed in the carrier 208, and
engages the forked end 219 of the arm 217, which arm is fixed to the outer end
of the screw 212 by means of a pin 218, for the purpose of preventing the feed-
screw from rotating. The purpose for which the feed-screw is carried by the
laterally-shiftable carrier 208, is to permit said screw to be thrown out of its
normal or working position forward of the rifling-rod, and thus provide for
removal of said rod, and of the gun-barrel, without obstruction. The carrier
being pivoted as set forth, it may be swung into the position indicated by dotted
lines in Fig. 32. For limiting its downward movement when shifted into its
working position, said carrier has a stop-arm 237, which is fitted to bear against
a lug, 236, that is formed on the slide 198. For locking said carrier 208 in its
normal position as shown by solid lines in Fig. 32, a lock-bolt, 238, is provided,
which is operated by means of a spring, (not shown,) and with a knob, 239,
whereby to withdraw the same; this bolt locks the said carrier in position by
engaging under the arm 237, as indicated in dotted lines in Fig. 32. When
about to remove the gun-barrel from the barrel-carrying spindle, the feed-screw
is first shifted out of its normal position as set forth, after which the lock-nut 185
may be loosened and the barrel taken out.
«
On the rod 203, an adjustable stop-collar, 240, (Fig. 1) is secured by a clamp-
screw, for the purpose of pushing back or retreating" the slide 198 when the
carriage C reaches a certain predetermined point. This important function of the
machine is for the purpose of controlling accurately the feeding in of the wedge 109,
notwithstanding there may be a variability in the stroke of the carriage C; for,
as will be readily understood, the stroke of said carriage is necessarily slightly
variable, owing to the well-known variable action of the carriage-driving mechanism,
which, though of slight amount, is still sufficient in practice to prevent satisfactory
operation of the cutters.
The apparatus for feeding forward the feed-screw 212 comprises actuating
mechanism carried on the head H, and a reciprocating pawl connected to be
operated by said mechanism. The feed-pawl 223 (see Figs. 31 and 32) is pivotally
supported at 224 in the upper end of the pawl-slide or plunger 222 which is
carried in the bracket 220, which is set on the bed-plate 195 and fixed thereto.
A reciprocating movement being given at the proper time to said plunger 222,
the pawl 223 is thereby caused to feed forward the ratchet-wheel 210 one or more
notches at a time, as may be required. The upper end of the plunger 222 is
larger than the lower part thereof (see Fig. 32) and a spring, 225, contained in
the bore of said bracket, bears against the shoulder of the plunger for actuating
the pawl to operate said ratchet-wheel 210; by this means, it will be. observed,

page_text: said wheel is forwardly actuated by the force of the spring. For limiting the
working stroke of the pawl, said plunger 222 is provided at its lower end with
the check-nuts 226 and 227, as will be fully understood from the drawings. The
plunger is drawn back by means of the arms 233, which bear against the pro-
jecting ends of a pin, 235, which passes through slots (not shown) formed in a
well-known manner in the sides of the plunger-case 221, and passes through the
plunger; said arms bearing against the forward side of said pin, the downward
motion of the arms retracts the plunger, while the upward motion thereof simply
permits the forward movement of the plunger, without compelling such movement.
The rocker-arm 233 is carried by the rock-shaft 228, which is supported at one
end in the bearing 230 fixed to the bed B, (see Figs. 1 and 31,) and at the other
end in the similar bearing 229 fixed to the bed B adjacent to the frame 120,
(Fig. 8) that carries the hereinbefore-described spindle 141. Said rock-shaft 228
is held in place longitudinally by a collar 232 fixed thereto on one side of the
bearing 229, and by an arm, 231, fixed thereto on the other side of said bearing,
as best shown in Figs. 7 and 9. The arm 231 bears on the outer end of a
lever 166, which is pivoted to a stud, 167, fixed in the head of frame 120, and
whose inner end is shaped to bear against the cams 164 and 165 as these revolve
with the spindle 141. As shown in Figs. 9 and 10, the index-plate 159 carries
two said cams which are substantially alike, while the index has four divisions.
This arrangement results in operating the feed mechanism once for each two
strokes of the carriage C, the barrel being rotated through one of the index-plate
divisions for each movement of said carriage. It will be obvious that the lever 166
may be dispensed with, provided the arm 231 be lengthened sufficiently to be
operated by said feed-cams 164 and 165; the purpose of said lever is to reverse
the motion and to reduce the size of the parts, also to secure what is deemed in
some respects to be a preferable arrangement of the mechanism. When the
machine is in operation and the cam 164, for instance, acts upon the lever 166 to
turn the rock-shaft 228 to draw back the plunger 222, the pawl 223 passes over
the notches of the ratchet-wheel 210; and on the reverse movement of said shaft,
the spring 225 acting through said plunger and the pawl 223, feeds forward said
ratchet. This operation goes on until the check-nut 214 comes against the end of
the ratchet-wheel-hub; and since the ratchet-wheel cannot be turned farther, the
plunger, on being drawn back as set forth, is retained there by the pawl 223
engaging in the notches of said wheel 210, thus stopping the feeding operation.
The arm 233 being, as hereinbefore stated forward of the pin 235, it cannot act
directly to feed said ratchet-wheel. This mechanism furnishes a very convenient
and effective means for feeding said wheel, and one which is safe in practice,
since when the feed-screw reaches its limit, the feeding mechanism becomes
inoperative.
For oiling the rifling-cutters, we use an apparatus which is constructed and
arranged as follows: An oil-tank, T, a portion of which is shown in dotted lines
in Fig. 6, is fixed to the underside of the bed B near the right-hand end thereof. An
oil-pump, P, of a well-known type, (shown in plan view in Figs. 1 and 3, and in
side view, with the cover removed, in Fig. 34,) is fixed to the main-bed of the
machine. This pump is of the well-known "geared" variety, and consists of the
usual pump-frame, 245, having a driving-shaft, 246, journaled therein, to which is
fixed the driving gear, 247, that meshes with and drives the similar driven
gear, 248; the gear 248 is carried by a stud 249, which is journaled in the pump-
frame as shown. Said pump is driven by means of a belt (not shown) running on
a driving-pulley, 250, fixed in the driving-shaft 246. A suitable pipe connection
is had with the oil-tank by means of the ordinary pipes and pipe-joints, designated
by 251, through which the oil is drawn from said tank into said pump; the oil is
then forced by the said pump-gears through the large conveyor-pipe 252, which is
suitably connected to the pump as shown. A small sliding conveyor-pipe, 253,
is 66 telescoped into the horizontal pipe 252, and from said smaller pipe rise the
oil-spouts, 254 and 255; said pipes and spouts being supported by the pipe-

page_text: supporting clamps, 256 and 257, respectively, which are adjustably secured to one
of the ways of the bed B by clamp-screws, as indicated in the drawings. See
Figs. 1, 2, 3, 4, 7 and 8.
The general operation of the machine is as follows: In preparing to use the
machine, the operator shifts the feed-screw out of its normal position as indicated
by dotted lines in Fig. 32. Next, the rifle-barrel G is properly placed, as herein-
before described, in the barrel-carrying spindle 141 of the head H, and the
traverse-bar 87 is set at an angle corresponding to the required twist of the rifle-
grooves to be made. The rifle-cutters and the feed-pin 109 are properly placed,
as indicated in Fig. 25, in the rifling-rod 100; which rod is then properly fixed,
as hereinbefore described, in the rod-carrying spindle 71 of the carriage C. The
pin-driving feed-screw is now shifted into its working position (shown in solid lines
in Fig. 32) and (the pawl 223 being lifted by hand) the ratchet-wheel 210 turned
back until said screw is retreated so that on the first working stroke of the rod 100
the feed-pin 109 will only come to the face 2121 of said screw, without being
thereby driven into the rifling-rod. The pawl 223 is then dropped into engagement
with the ratchet 210, and the adjusting-nuts 226 and 227, on the plunger 222, are
set for limiting the feed-pawl movement to the desired number of ratchet-wheel
notches. Next, the stop 240 on the rod 203 is set for retreating the feed-slide 198
when the feed-pin 109 comes to the face 2121 of the feed-screw 212; so that, as
hereinbefore set forth, any excess of the normal stroke of the carriage will drive
back the feed-slide and the feed-screw thereon so as to prevent over-feeding the
rifling-cutters 108 on the contacting of the said pin 109 and the face 212. The
stops 111 and 113 are suitably fixed on the shipper-rod 23 to reverse the motion
of the screw-shaft 11 when the carriage reaches the ends of its proper stroke,
which stroke is made to correspond with the length of the barrel being rifled;
also, the stops 114 and 115 are properly placed on the rod 125 for actuating, as
hereinbefore described, (and at the ends of the carriage movement,) the index
mechanism for revolving the gun-barrel. The machine being now started up, the
carriage C has given thereto, by means of the driving mechanism therefor, a
reciprocating movement limited by the position of the aforesaid stops 111 and 113,
and at the completion of each forward stroke of the carriage by means of the stops
and connecting mechanism described. The spindle 141, carrying the barrel
therein, is turned forward through the space of one division of the index-plate 159.
The time, however, of said rotating movement may be shifted to the other end
of the working stroke of the carriage by reversing the construction of the
groove 128 in the slide 124 (see Fig. 7) in a well-known manner. The feed-
cams 164 and 165 being only half the number of the index-plate divisions, the
cutters are fed out only at each alternate forward stroke of the carriage; so that
said cutters make one cut on their forward stroke and one on their return stroke,
the said two cuts being in successive rifle-grooves. At each forward stroke of the
carriage toward the left-hand in Figs. 1 and 2, the feed-pin comes, as before
stated, to the feed-screw 212; and whenever said screw is advanced toward the
right-hand, said pin will thereby be driven between the rifling-cutters, and these
cutters thereby fed outward for taking a deeper cut. The operation of the
machine being continued as here described until the feed-screw stop-nut 214 is
brought against the hub or collar 213, the feeding forward of said feed-screw is
thereby, as herein before set forth, stopped, thus finishing the feeding out of the
rifling-cutters. This operation being completed, the operator stops the machine
by means of the handle 27, whereby he shifts the shipper-rod 23 to bring the belts 2
and 4 onto the loose pulleys 22 and 24, respectively, as indicated in Figs. 3
and 4; and if at that moment the carriage C has not withdrawn the rifling-rod
from the barrel G, the operator, placing an ordinary crank on the squared stem 21
of the shaft 17, turns the screw-shaft 11 to run the carriage to the desired position.
This being done, the feed-screw is shifted out of its normal position, as herein-
before stated, the lock-nut 185 is loosened and the barrel G removed; after which
another barrel is put in place, the feed-pin 109 withdrawn from its position in
B

page_text: Fig. 27 to that shown in Fig. 25, the feed-screw 212 again retreated, and the
machine otherwise made ready as hereinbefore described for further operation.
In operating the machine, the oil-spouts 254 and 255 are set to deliver oil unto
the cutters as they emerge at either end of the rifle-barrel; so that for each cut the
rifling-cutters are first thoroughly lubricated. During the operation of the machine,
the carriage C traverses to and fro through nearly the same stroke each time it
goes forward; but as before mentioned, said stroke is unavoidably slightly variable.
This variation is fully overcome so far as to avoid defective cutter-feeding due
thereto, by means of the rod operated from said carriage and carrying a stop, as 240,
set for retreating the feed-screw and its carrier when the carriage goes beyond its
normal movement. By means of this retreating feed-screw, the highest efficiency
and perfection of operation is readily attainable, and the most serious drawbacks of
the old kind of rifling-machines effectually overcome.
By means of my improved mechanism for rifling-machines, I am enabled to use
for operating the rifling-rod a driving mechanism substantially as herein described,
having a reversible screw-shaft for imparting the reciprocating movement to the
carriage whereby a uniform velocity of movement is obtained throughout the stroke
of the rifling-rod, thereby securing uniformity of cutting action throughout the
length of the rifling-groove. It is well known to men skilled in this art that a
variable cutting speed also varies the action of the cutters, so that it is difficult to
produce perfect work when the carriage is driven (as it generally is in the old kinds
of rifling-machines) by a crank and connecting-rod; it being remembered, of
course, that the crank and connecting-rod for driving the rifling-machine carriage
have heretofore been used chiefly on account of the limitations of the old kinds of
pin-driving feed mechanism.
It will, of course, be understood that many of the minor details of construction
shown in the drawings are old and well-known, and are therefore not to be regarded
as limitations of my invention, being adopted for use in my improved rifling-
machine because the value thereof as machine elements is established by practice.
Of this nature is the apparatus, for instance, intermediate to the rod 23 and to the
shipper-rods 45 and 50; this shipper-actuated mechanism being substantially the
same as that heretofore used for reversing the movement of metal-planers and
machines of like character.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :-
1. In a rifling-machine, the combination with the barrel-carrying spindle, and
with the carriage having a rifling-rod carrying rifling-cutters and a feed-pin for
said cutters, of feed mechanism located for driving said pin and constructed
and connected to be retreated on the movement of the rifling-rod beyond its normal
forward stroke.
2. In a rifling-machine, the combination with the reciprocating rifling-rod having
cutters and a feed-pin substantially as described, of a pin-driving feed mechanism
having a feed-slide connected to be retreated on the movement of the rifling-rod
beyond its normal forward stroke.
3. In a rifling-machine, the combination with the reciprocating rifling-rod having
cutters and a feed-pin substantially as described, of a pin-driving feed-screw carried
by a carrier constructed and connected to be retreated on the movement of the
rifling-rod beyond its normal forward stroke.
4. In a rifling-machine, the combination with the reciprocating rifling-rod having
a feed-pin projecting from the forward end thereof, of the feed-screw carried by a
slide movable longitudinally of the machine, said slide being constructed substantially
as described to be retreated on the movement of the rifling-rod beyond its normal
forward stroke.
5. In a rifling-machine, the combination with the slide carrying the pin-driving
feed-screw, of a stop limiting the movement of said slide toward the rifling-rod, and

page_text: a spring normally holding the slide to said stop, whereby the slide is permitted to
retreat as set forth, and the feed-pin is actuated by said spring through the slide
and feed-screw.
6. In a rifling-machine, the combination with the feed-slide, of the feed-screw
carrier shiftable thereon and carrying the feed-screw, and means locking and
unlocking said carrier, whereby the feed-screw may be shifted out of its working
position, substantially as set forth.
7. In a rifling-machine, the combination with the carriage having a rifling-rod
substantially as described, provided with a feed-pin, of means for carrying the rifle-
barrel, the feed-slide carrying feed mechanism substantially as described, and a
rod carrying adjustable stops intermediate to the carriage and feed-slide, whereby
the feed-slide may be retreated on the movement of the carriage beyond its normal
forward stroke.
8. In a rifling-machine, the combination with the feed-slide carrying a feed-screw,
of means substantially as described for actuating said feed-slide to retreat the feed-
screw, a ratchet-wheel operating the feed-screw, the pawl located for engaging the
ratchet-wheel during the retreating movement of the feed-screw, and means for
actuating said pawl.
9. In a rifling-machine, the combination in the feed apparatus thereof, of a
supplementary bed adjustable longitudinally of the machine, the feed-slide supported
on said bed for retreating movement, a feed-screw carried on said slide, and a feed-
screw-actuating pawl carried by pawl-actuating means substantially as described
supported on said bed.
10. In a rifling-machine, the combination with the barrel-carrying spindle, of
means substantially as described for intermittently rotating said spindle, the carriage
and the cutter-provided rifling-rod carried thereby, said rod having a feed-pin for
feeding out the cutters, a feed-screw located in the path of said feed-pin, a ratchet
and pawl for engaging the feed-screw, one or more feed-cams carried on the barrel-
carrying spindle, and connections actuating the feed-screw-ratchet from said
cams, whereby the feed-screw is advanced toward the carriage on the rotation
of the spindle.
11. In a rifling-machine, the combination with a barrel-carrying spindle, of a
disk arranged to have a rotary-reciprocating movement on said spindle, an index-
plate fixed on the spindle, a ratchet-wheel fixed on the spindle, a lock-bolt for said
plate, means rotating said disk through a fixed arc, and a ratchet-plate carrying
one pawl for revolving said spindle and a cam-pawl for lifting said bolt, said
cam-plate being constructed for attachment to the rotary-reciprocating disk
in successive positions corresponding to different numbers of divisions in the
index-plate.
12. In a rifling-machine, the combination with the barrel-carrying spindle, of
the pinion 144 and means for imparting a rotary-reciprocating motion to the said
pinion through a fixed arc, the ratchet-wheel and index-plate fixed on said spindle,
the lock-bolt engaging the index-plate, a spring normally holding the lock-bolt in
engagement with the index-plate, and pawls substantially as described adjustably
fixed on said pinion and arranged to first lift the lock-bolt and then engage the
ratchet-wheel for turning the spindle.
13. In a rifling-machine, the combination with the barrel-carrying spindle, and
with means substantially as described for locking the barrel in said spindle, the bore
of the spindle being larger than the diameter of the barrel, of the thimble 187
fitted to slide in the spindle and to engage the barrel by the tapering part thereof
as set forth.
14. In a rifling-machine, the combination with the barrel-carrying spindle, and
with the pinion adapted to run thereon and provided with spindle-actuating pawls,
of the index-plate and ratchet-wheel fixed on the spindle and adapted substantially
as described to be actuated by said pawls, the rack 133, the cam-slide 124 arranged
to slide lengthwise of the spindle and crosswise of the rack, said slide having therein

page_text: a cam-groove, and means substantially as described actuating said pinion from said
cam-groove through said rack.
15. In a rifling-machine, the combination with the carriage having the rifling-rod
provided with cutters and a feed-pin, of the barrel-carrying spindle located forward
of the carriage and having means for holding the barrel to be rifled, the cam-slide
connected substantially as described for intermittently actuating said spindle,
connections actuating said cam-slide from the carriage as the carriage approaches
the ends of its stroke, feed-cams carried. on the spindle, feed apparatus located
forward of the barrel-carrying spindle in position for contacting with the feed-pin
at the forward end of the carriage movement, a ratchet and pawl for operating the
feed-screw toward the carriage, and the rock-shaft connected substantially as
described to be actuated from said feed-cams on the spindle and to actuate said
pawl, whereby the feed-screw is advanced by connections from the carriage through
the barrel-carrying mechanism.
16. In a rifling-machine, the combination with a main-bed and with driving
mechanism at one end thereof, of the carriage actuated from said mechanism to
have a reciprocating movement on the main-bed, barrel-carrying mechanism forward
of the carriage, means rotating the barrel-carrying spindle of said mechanism
through connections with the carriage, feed mechanism forward of the barrel-
carrying mechanism and having the feed-screw supported on a retreating slide,
and a reciprocating rod connected to be actuated from the carriage and to
actuate the reversing apparatus of the driving mechanism, said rod having a stop
located thereon to retreat the feed-slide when the carriage goes beyond its normal
forward stroke.
17. In a rifling-machine, the combination with a feed-screw substantially as
described, and with a ratchet-wheel arranged for advancing said screw, of the
adjustable stop on the screw for limiting its advancing movement by engaging said
ratchet-wheel, the plunger having a pawl engaging said ratchet-wheel, a spring
arranged to actuate the plunger for turning said wheel, said plunger being provided
with a stop for limiting its forward movement, and a reciprocating arm connected
and arranged to retract the plunger.
Dated this 11th day of February 1891.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.