Improvements in Advancing Devices or Poppets for Boring Bars, also Applicable to other Machine Tools.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Advancing Devices or Poppets for Boring Bars,
also Applicable to other Machine Tools.
A communication from abroad by FREDERICK WINSLOW TAYLOR, residing at the
corner of Locust and Magnolia Avenues, in the City of Philadelphia, State of
Pennsylvania, United States of America, Mechanical Engineer.
1, PHILIP MIDDLETON JUSTICE of 55 and 56 Chancery Lane, in the County of
Middlesex, Fellow of the Institute of Patent Agents 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 relaies especially to that class of poppets or tail-stocks" which
are used upon lathes of considerable size to advance a boring bar into the axis of a
piece of revolving work such as a cannon; but it being also well adapted as a poppet
for use in combination with lathe carriages, slide rests, planer crossheads, upright
drills &c., it is hereinafter particularly described in conjunction with the adjustable
tail-stock of an engine lathe as illustrative, rather than as limitative, of its use and
scope. The chief object of the present invention is to deliver an advancing tendency
to a boring bar by a hydraulic mechanism or ram and also to prohibit or control the
rate of advance which the thrust of such hydraulic ram or rams may tend to deliver
upon the boring bar by a releasing" or let off mechanism, the two parts of the
device, viz. the advancing and releasing portions being preferably arranged cor-
centrically around and in common alignment with the axis of tho bar which they
control.
"
Another object is to so contrive the mechanism that by taking one or more holds
upon the bar its advance is kept up and continued through a range of action greater
than that of the working stroke of the hydraulic ram or rams which urge it.
Reference being now had to the accompanying drawings forming part of this
specification in which similar letters of reference indicate corresponding parts
throughout the several figures, they will be found to illustrate the invention as
follows, to wit:
Figure 1 is a side elevation of an engine lathe equipped with a back-rest and the
improved boring bar poppet mechanism shown in the act of feeding an endwise
sliding boring bar into the axis of a piece of work chucked to the live head of the
lathe.
Figure 2 is an elevation of a longitudinal median section of the poppet mechanism
shown in Figure 1. the foot or supporting part being broken away.
Figure 2 is a similar sectional elevation of a modification of the structure shown in
Figure 2.
Figures 3 and 4 are front and rear views respectively of the poppet head shown in
above enumerated figures, the line a, a, Figure 1, denoting the plane of cross-
section of Figure 3, and the line y, y, denoting that on which the section of Figure 4
was made.
Figures 5 and 6 are respectively side view and end elevation of a modification; the
latter partially in cross section by a plane passed immediately behind the ram
cylinders which are here of a multiple sort in a modified arrangement.
In the figures, A represents the live head of an engine lathe; the shears, C, of
which are equipped with ordinary prismatic guide rails c c (Figures. 1 and 3) and
carry a back rest or boring collar D:-The work E, carried by a chuck a finding a
concentric bearing in the collar d of this rest D, presents its free or muzzle end e, to
the boring bar F. And this bar F, preferably enveloped in a concentric sleeve, as
the bushing H shown in Figures 2 and 4, issues from the muzzle or front end of the
ubular or hollow poppet slide G; the whole lying concentrically disposed to and in

page_text: the prolongation of the axis of the mandrel d'. The slide G finds an abutment for its
muzzle against the adjoining face of the chuck flange or collar H' of the
hushing H, the radial screws 9, 9, 9, of which serve to grip and fix at any desired
portion of its length the shank of said centrally disposed boring bar F, which bar is
also preferably so fitted to this. bushing that, without loss. of alignment, it can slide
freely end wise through the same. So too, the circular neck orifices B2 B3 of the
poppet head housing B and their packing glands 1 1 (see Figures 2 and 2ª adjustably
bolted to the froilt and rear of said housing by the bolts and fittell closely about
the front and reliced 'tail G and G², respectively, of this slide) serve to keep it and
the parts it carries 'not only in its aforesaid alignment with great steadiness and
accuracy, but also to allow it to reciprocate longitudinally with tight joints through
the housing necks aforesaid, the length of the slide stroke being approximately the
length of the internal cylindrical cavity B of the housing aforesaid. The flange or
annular surface between the front and rear extensions of the slide G forms in the
preferred single ram cylinder form (illustrated in Figures 1 to 4 inclusive) the piston
area, upon which the water or other equivalent liquid when introduced under pressure
by any suitable supply and escape conduits, such as the pipes 23 screwed into the
holes (Figure 1) communicating with the cylindrical cavity B₁acts to urge the
slide G as a ram plunger outwards from the body of B towards the work.E. With
the poppet's slide bar & the bar F, either directly, as shown in Figure 2 or mediately
as through the tubular bushing H, also receives a tendency to similarly advance
toward the work upon the actuation due to the introduction of water &c. under
pressure to the ram cylinder. But this tendency to advance under such hydraulic
pressure in the endwise sliding parts of the above described device is preferably either
prohibited or controlled at such rate as may be desired by means of the screw-threaded
tail either of said bushing, or of the slide bar itself; for it is evident that the
bushing may be made integral with or as a fixed part of the slide bar instead of
being detached therefrom, in which case the screw-threaded tail H2 of the bushing
would be part of the slide bar. And also in either of these cases should this bar be
cylindrical and
a screw and nut with a suitable abutment for the latter be employed
as the let-off or releasing mechanism of the device, it is further evidently necessary to
spline the slide bar so as to prevent rotary motion. Such device is illustrated in the
figures by the slot fashioned longitudinally in the body of the bushing and the
key seated in the collar J¹ (see Figures 1 and 4) so that the bushing H, which
otherwise passes freely endwise through the collar, is prevented from rotating on its
axis. The collar J, which affords the abutment for the nut, being preferably
fashioned integral with a casing J, is secured by the latter's being abutted and fixed
as by screws to an annular shoulder j upon the rear of the housing B (see
Figure 1) for by this means the collar and casing form a concentric cap to the rear
of stuffing box and re-act to the strains which the advancing tendency of the ram
aforesaid transmits through the various sliding parts to the nut L, which nut
corresponds to and engages with the screw on the tail of the bushing or slide bar
proper. The device is ibus rendered self-contained and the nut L, when stationary,
delivers such strains as may be occasioned by pressure upon the ram piston through
the parts JJ to the shoulder j and thereby the housing B absorbs them and the
whole remains motionless. While should the nut L be rotated in an unscrewing
direction or run towards the tail of the bushing or slide bar (that is toward ³
Figure 2) it naturally acts to release and permit the aforesaid advancing tendency to
develop into an actual advance of the slide bar G, and with it the parts H H and F
which are fed toward the work.
:-
Now these conditions of the releasing nut L are conveniently regulated as follows:-
The screw H2 which is preforably of rapid pitch and slotted lengthwise as above
described for the sake of preventing rotary motion in it by means of a spline, carries
the. nut in such position that it is not only hanked against the rear of the abutment
collar J, but also so that such nut which is fashioned upon its outer periphery as a
worm wheel shall carry the teeth i thereof in proper engagement with the threads of
a tangent ser wk, which screw is journalled transversely to the axis of said nut L in

page_text: a suitable position as by the bracket bearings K K, for by this device the spindle ¹ of
the tangent screw affords, as by the crank hand wheel 2 a convenient means for
setting the releasing mechanism in motion, as well as an automatic hold fast preventive
of the releasing nut's rotation should the crank hand wheel k² or any other operating
mechanism with which the tangent screw is equipped be disconnected or left by the
operator at any desired adjustment along the threaded portion of the sliding member
upon which the nut is engaged.
Moreover in cases where means for forcibly exhausting the liquid introduced in the
cavity B' do not exist the nut L and screw H are in themselves readily available as
the device for withdrawing the protruded portions of the sliding members G H and
whatever bar F &c. they may have secured to them. But of course to this end the
fluid in the cylinder B' must not only be released from pressure, but allowed to
escape as by the conduit 63. Otherwise by permitting the fluid &c. to escape from the
cavity B¹ the pressure of the air upon the muzzle area of the ram plunger or piston
rod may be called upon to act to force the sliding parts home after any protrusion of
them, the nut L being then merely run along the tail upon which it is threaded at a
proper pace to permit of the consequent retreat.
The slide bar G may be, as is evidently the case in ordinary lathe poppets, prismatic
instead of cylindrical (see G100 Figures 5 and 6 wherein it is illustrated as of square
cross section :) and it may be equipped with a releasing device differing from that
already shown without departing from the purview of the present Invention. That
is to say, it may be equipped with longitudinally disposed rack work F20 and a spur
and tangent wheel train F3 F40 F50 rotatably journalled in a suitable housing formed
by an extension B8 of the main poppet housing B. The crank handle or other means
of actuating and controlling such releasing train (see Figure 6) may be fixed to
the spur wheel shaft and serve to control the slide bar in releasing, restraining or
retreating the mechanism.
In addition to the above forms which are substantially enveloping as well as
concentric, or at least radially disposed about the general mass of the poppet housing
proper, the position of the forcing ram may be varied and as shown in the last two
figures, it may be multiple instead of single, the general construction illustrated in
Figures 1 and 2 is however preferred.
So Figs. 5 and 6 display still further modifications without departing from the
typical radial disposition; for, in addition to a square slide-bar G100, which, in point of
fact, is a self-acting spline to prevent rotation, and its rack and pinion-releasing gear
as above identified, three cylinders Bare here shown-fashioned integral from a
single poppet-head housing B: and the whole disposed concentrically and at equal
angular divergences (120°) about the slide-bar guide axis thereof, which latter is a
mere prismatic envelope, B200, to the aforesaid square bar G100. The abutment
member, H, in this case, being formed both integral and terminal upon the slide"
bar G100, has in its muzzle end G200 a hollow conical cavity for a drill or centre
socket seat; in which the boring bar F or other appropriate tool having a similar
conical shank, F10, fits and chucks itself in a well-understood manner. The
conduits, 263, are here, as more specifically shown in Figure 2, presumably in
connection with the several ram-cylinders' respective cavities; indicated by broken
outlines; and their plunger-rams Gare provided with proper pistons, as g½ for
receiving the pressure both front and rear, and are divested of rearward extensions,
for the slide bar G100 is now sufficiently guided to be independent of them by its
envelope B200 aforesaid.
'
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
First. The combination of the poppet housing with an interguided reciprocative
slide bar adapted to carry a boring-bar or equivalent instrument, and a hydraulic ram
or rams operative to exert a pressure upon said slide bar and tend to advance it ; and
a hold-back screw or nut or equivalent mechanism operative to prohibit or control the

page_text: thrusting tendencies of said advancing mechanism, substantially as and for the
purposes herein before described.
Second. The combination of the poppet housing with an inter-guided reciprocative
slide bar adapted to carry a boring-bar or equivalent instrument; a radially sym-
metrically, and concentrically-disposed elide bar advancing-mechanism consisting
of a hydraulic ram or rams; and a holi-back screw and nut or equivalent releasing
mechanism operative to prohibit or control the thrusting tendencies of said advancing
mechanism, substantially as and for the purposes hereinbefore described.
Third. The combination of the poppet housing with an inter-guided reciprocative
slide bar adapted to carry a bushing or chuck, operative to grasp a boring-bar or
equivalent instrument at any desired portion along its shank; a concentric slide-bar
advancing-mechanism attached to said poppet and consisting of a hydraulic ram or
rams; and a hold-back screw and nut or equivalent releasing-mechanism also sub-
stantially concentric to slide bar and operative to prohibit or control the thrusting
tendencies of said advancing mechanism, substantially as and for the purposes
herein before described.
Dated this 5th day of June 1890
PHILIP M. JUSTICE..