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Патент USA US2408958

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Oct; 8, 1946.}
‘_
R. A. SCHAFER ‘ETA-L
.
2,403,957
REXOTB‘ CONTROL APPARATUS FOR “CHINE TOOLS
Filed Jan. 15, 1944
.
'
"'15 Sheets-Sheet 1
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oct- 8, 1946-
R. A. SCHAFER ETAL
‘
2,408,957
REMOTE CONTROLIAPPARQTUS FOR MACHINE TOOLS
Filed Jan. 15, 1944
‘15~Sheet$-Sheet'2 '
Oct. 8,1M.
R. A. SCHAFER TErAl.
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REMOTE CONTROL APPARATUS FOR “CHINE TOOLS
Filed Jan. 15', 1944
.
2,408,957
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15 Sheets-Sheet 3 _
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R. A. SCHAFER EI‘AL ’
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REMOTE CONTROL APPARATUS FOR MACH'INE TOOLS
‘ Filed Jan. 15. 1944
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REMOTE CONTROL APPARATUS FOR momma TOOLS
Filed Jan. 15,‘ 1944
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R. A. SCHAFER ETAL
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RE-IOTE CONTROL APPARATUS ‘FOR MACHINE TOOLS _
Filed Jan. 15, 1944
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Oct. 8, 1946.
R. A. SCHAFER ETAL
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REIOTE CONTROL APPARATUS FOR MACHINE TOOLS
Filed Jan. 15, 1944
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REMOTE CONTROL APPARATUS FOR MACHINE 'I'OQLS
Filed Jan, 15, 1944
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R. A, SCHAFER ETAL
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REIOTE CONTROL APPARATUS FOR MACHINE TOOLS
Filed Jan. 15, 1944 '
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R. A. SCHAFER EI'AL
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REMOTE comm}; APPARATUS FOR MACHINE TOOLS
Filed Jam; 15, 1944
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R. A'. SCHAFER EI'AL
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REMOTE CONTROL APPARATUS FOR MACHINE TOOLS
Filed Jan. 15, 1944
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Oct. 8, 1946.
R. A. SCHAFER EI'AL .
2,403,957.
REMOTE CONTROL APPARATUS FOR MACHINE TOOLS
Filed Jan. 15, 1944
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R. A. SCHAFER ETAL
REMOTE CONTROL APPARATUS FOR MACHINE TOOLS
Filed Jan. 15, 1944
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15 Sheets-Sheet '15
Patented Oct 8, 1946
» ‘ 2,408,957
1
UNITED STATES PATENT OFFICE
REMOTE
S
CHINIJTQOLS
.
ltobertA. Schafer and RalphBBodaLBichmond,
,
to National Automatic Tool
Company, Inc., Richmond, 1nd., a corporation
> Ind., assignors
of Indiana -
Application January 15, 1944,8erlal No. 518,366
.
(01. 121-45)
12 Claims.
1
,
Fig. 4 is a side eievational view of the assembly
Our invention relates generally to remotaicolh '
trol apparatus for machine tools, ‘and more par
showninFig.3;
\
'
-
_
Fig.5 is an enlarged‘ side elevational view of the
ticularly ‘to combined electrical and hydraulic
controls usable in conjunction with machine tools
hydraulic control panel;
Fig. 6 is a side elevational view of the hydraulic
to cause them to operate through cycles of pre
determined or selected character.
'
control panel assembly;
,
.
'
Fig. 7 is a bottom plan view of the hydraulic
control panel assembly, taken on the line 1-1
In the control of machine tool cycles’ by means
of a directional valve which in turn controls the
of Fig. 6;
' admission and discharge of hydraulic ?uid to the
.'
actuating cylinder of the tool, it is desirable to 10' Fig. 8 is a sectional'view, in part diagrammatic,
taken through the axis of the positioning motor,
initiate the control functions by means of elec
‘
substantially on the line 0-8 of F18. 6;
trical circuits and apparatus because of their
Fig. 9 is an enlarged plan ‘view of the position
greater ?exibility, higher speed of operation, and
because the control stations may be remotely posi
- tioned with respect to the hydraulic controls.
However, the hydraulic controls generally com
' prise closely ?tting valves, such as the directional
' ing motor assembly;
is
Fig. 10 is a side elevational view of the position
ing motor assembly, as viewed along the line’
lO-liiofFis. 7;
~
,
Fig. 11 is a sectional view, in part schematic,
valve, which require considerable power for their
through the control panel, showing the governor
operation, and it is therefore notfeasible, in gen‘
eral, to apply the necessary actuating forces to '20 and the adjustable aperture coarse and ?ne feed
the directional valve by electrical means.
Fig. 12 is a sectional view through the control
It is therefore one of the primary objects of
valves;
.
.
panel, showing the low pressure and high pre8- ,
our invention to provide an improved control ap
sure relief valves, and the low to high pressure
paratus for machine tools, which combines the
reliability and ruggedness of the hydraulic con 25 oil transfer check valve;
~ Figs. 13, 14, and 15 are sectional views through
trol with the ?exibility of electrical control ap
paratus, thereby to obtain an improved remotely ' the servo valve, taken on the lines I 3-43, |d-_-ll,
and "-15, respectively, of Fig. 17;
‘
controlled machine tool.
Fig. 16 is a fragmentary detail showing the con
A further object is to provide an improved sole
noid controlled positioning motor arranged, 30 nection between the positioning valve gear shaft
and the servo valve;
‘
'
4
through a servo valve mechanism, 'to control the
Fig. 17 isa sectional view through the control
position of the directional valve.
A further- object is to provide an improved elec- ' panel, taken through ‘the center .of the servo
troinagnetically controlled positioning motor.
valve mechanism;
mined operating cycle, or in which the apparatus
may be manually controlled from a remote sta-
electrical control circuits.
-
A further object is to provide an improved con 85 Fig. 18 is. a schematic diagram showing the relationship between the various portions of the
trol apparatus for machine tools, in which the ap
hydraulic control system; and ,
paratus may readily be set to effect a predeterl
tion.
.
.
A further’ object is to provide an improved
combined electrical and hydraulic control appa
ratus which is very ?exible and reliable, and
Fig. 19 is a schematic wiring diagram of the .
‘
-
General description -
Our invention is illustrated as applied to a
‘hydraulically operated vertical drill press which.
which may be manually controlled from a remote
as shown in Figs; 1 and 2, ‘comprises a vertical
description, reference being had to the accom
tion. A suitably counterbalanced tool carrying
head 24 is traversable on ways 28-integral with
the column 20. An adjustable knee 28 comprises
45 column 20 suitably secured to a base 22, which,
station.
as is customary, is bolted to the floor or founda
Other objects will appear from the following '
panying drawings, in which
v
,
a
Fig. 1 is a side elevational view of a vertical
drill press embodying the improved remote con 50 a work table 32 upon which a work piece 34 may
be secured in the usual manner. Above the head
trol apparatus of the invention;
N is a casing 25 for suitable change speed gear,
Fig. 2 is a front elevational view thereof;
ing which may be adjusted by a control arm 38.
' Fig. 3 is a front elevational view of the hy
One
or more tool carrying spindles '38 are secured
draulic reservoir, hydraulic control panel, and
to the head 24 by one or more adjustable arms
electric motor driven pump assembly;
'
2,408,957
3
40. The spindles are rotated by an electric
motor 42 having a suitable driving connection
with the spindles 3|! through the change speed
which conductors lead to the push button panel
,, gearing and through gearing and universal joint ,
_ connections contained within the head 24..
An actuating piston rod “has its upper end
secured to the head 24 by a‘bracket 48 and has
a piston 48 at its lower end, this piston being
r
ll and to the other electrical parts of the ma
chine tool. The valve bodies 25 and H2 are
preferably enclosed in a perforated sheet metal
5 housing I2lsecuredtothebodyll. .’
In general, the machine cycle is controlled by
the push buttons and limit switches operating
upon the solenoids III to H2. these solenoids
' reciprocable in a hydraulic actuating cylinder 48
controlling the position taken by a positioning
' which is rigidly secured to the‘ inside of the 10 motor "I (Fig. 18) and the positioning motor‘
column 20. A housing ll, containing limit
operating the directional valve I34 through a
switches, is mounted on the upper right-hand
servo valve Ill. '
,
'
side of the column 20. These limit switches are
The output of the low pressure pump 22 is con
provided with operating arms 32 carrying rollers
trolled by a low pressure relief valve mechanism '
I4 cooperable with dogs 58 adjustabiy secured 15 I8! and a check valve mechanism I40, while the
to a bracket 58, the bracket being carried by the
head 24. The rollers I4 of the limit switches
lie in different planes, as do the dogs It. so that
each one of the limit switches may be controlled
by a particular one of the dogs.
‘
output of the high pressure pump ‘II is controlled
.by a high pressure‘relief valve mechanism I42.
The rate of traverse of the head is controlled by
the metering of the oil discharged from the lower ‘ -
20 end of the actuating cylinder 42, this metering
A push button station,‘comprising a panel 60,
is suitably supported by an electrical conduit 6|
which is secured to the base 22, the panel having
nine push buttons 62 to "Ill, inclusive, located for
convenient accessibility by the machine oper 25
ator. The machine cycles are controlled by these
push buttons and by the limit switches operated
by the arms 52..
The electrical control circuits operate throuih
being effected through a governor valve mecha
nism I 44, an adjustable coarse feed valve mech
anism I“, and an adjustable ?ne feed valve
‘mechanismv I42.
'
The valve mechanisms I24, I", III, III, I42,
I44, I46, and I4! are generally similar to the
corresponding mechanisms disclosed in our co
pending application, ‘Serial No. 339,476, ?led June
8, 1940, which has matured into P tent No. 2,
an intermediate hydraulic traverse control unit 30 377,720, to which reference may be
for most
contained in a reservoir ‘I2, which is secured to
of the details of their construction and oper
the base 22 .by bolts 14.‘ This unit includes an
ation. As shown in Fig. 18, these valve mech
electric motor ‘It driving a high pressure low
volume pump ‘it and a low pressure high volume
' anisms are connected in hydraulic circuits dif
fering in somerespects from those shown in the
pump II through a ?exible ‘coupling 82, these 35 aforesaid application, and such di?'erences will
pumps being located below the level of the oil
be hereinafter pointed out in detail.
within the reservoir 12, and having their outlets
connected by suitable conduits to a valve body
II. ‘The inlets of these pumps are connected
To facilitate following the various hydraulic’
circuits, all passageways, conduits, ports, and the
like, which are in communicati
with each other
_ by suitable conduits with strainers 8‘ located near 40 at all times, sothat irrespectiv of the phase of’
thebottom of the reservoir or sump. The reser
the operating cycle oil could flow from one to
voir may be drained by removal of a drain plug
82.
‘
' An oil level gauge 90 and an oil pressure gauge
another, will be given the same reference char
acters, followed by decimals to distinguish indi
vidual parts. Thus,,for example, when it is stated
II are mounted near the top of the reservoir 45 that oil under pressure flows into a conduit bear
‘I2. ‘Servicing and installation of the unit is ac
complished by removal of a cover 92 forming the.
ing a certain reference character, it w?l be under
stood that oil in all‘ parts bearing that reference
major portion or the rear wall of the reservoir - character, followed by am decimal fraction, will
be likewise under pressure. similarly, all pes
A valve panel 84 constitutes part of the valve 50 sageways, etc., through which oil is at all times
body II and forms a portion of the side wall of
free to discharge to the sump or reservoir, will
the reservoir. Upon this panel are mounted the
be followed by the letter "8," which'should be
various control valves, conveniently accessible to
interpreted to mean, "from which the oil may
the machine operator.
‘
flow freely to the sump.”
As shown to a larger scale in Fig. 5, these
‘5
Solenoid controlled positioning motor
controls comprise a ?ne feed valve adjusting nut
II, a coarse feed yalve vadjusting nut ll, a check
‘ The solenoid controlled positioning motor In,
‘ valve retaining plug I00, a low pressure relief‘
best shown in Figs. 6, 'I, 8, 10, and i8, is supplied
valve adjustment cap nut‘ I I2, and a high pres
with oil from the low pressure pump ll through
sure relief valve adjustment cap nut I04. A servo go a‘conduit Ill (Fig. 18). a branch IIIJ 'of‘which
valve position indicator I” is ‘visible through a
extends through thevalve- body ll by passageways
,
IBM and IIOJ, the passageway IIIJ being in
Secured to the valve body 8| by cap screws
registry with apassageway "4.4 in theposition
III is a positioning motor body III with which .-ing motor body II2. rrom'passageway Ill.4 oil
are assembled ?ve solenoids III, II‘, III, II‘, 66 may ?ow through either of two branch passage
transparent plastic protection cap I”.
and ill (see Figs. 8, 7, 9, and 10). _ The solenoids
ways IIIJand IIIJ (Fig. 8). ‘The passageways
III to I II are energized through conductors I24
IIIJ and "0.8- communicate respectively with \
(a representative pair. of which are shown in Fig.
the ends of a cylinder I42, the ends of which are
"7), which are connected to plugs I24 threaded . closed by gasketed caps I“, III, through meter- '
in a wall I28 of the valve body ll, these plugs / 70 in: ports III, III formed in these caps. Within the cylinder I52 a positioning motor piston III
. insulating the circuits fromone another and from
the valve body II. Suitable conductors are con
is freely reciprocable, this piston having heads at
nected to theouter ends of the plugs I24 and
th ends thereof and having a rack I“ formed
are led through a hooded electrical conduit I28
termediate the heads. The rack Ill meshes
, which'is connected to a junction .box I20 from 75 width a pinion I02", which isnon-rotatably secured
2,408,957 .
to a stub shaft I84 (Fig. 1'!) mounted for free
rotation in bearing bushings I86 and I81. The
positioning motor body H2 is aligned with the
valve body 85 by means of an alignment sleeve I68.
' ‘ The shaft I84 is provided with a tang I18 ?tting
in a slot I12 formed in the lower end of a servo
valve I14 (Fig. 16) so that this servo valve will
be angularly positioned by the positioning motor.
The piston I58 has its position determined by .
the operation of solenoids II5’to II9. As best 10
8 shown in Figs. 8 and 9, the “coarse feed" solenoid
I I 8 has a plunger I16 which is suitably connected
to a pilot valve I18. The pilot valve I18 normally
cuts of! a passageway I888 from a passageway
. I82 having ports I82.I and I82.2 leading into the
cylinder I52. The pilot valve I18 has a reduced '
determined by its engagement
6
with the cap I55,
while when pilot valve 2I2 is opened, the piston _
I58 will move to its lower limit of stroke-deter
mined by its engagement with the cap I54. In
the somewhat diagrammatic view of Fig. 8, the
various positions assumed by the pilot valve con
nected to gear I62 are indicated by legends co
operating‘ with the pointer I86 shown in dotted
lines.
-
>
From the foregoing, it will be clear that the
servo valve I14 will assume acertain definite po
sition, depending upon which of the solenoids I I5
to .I I8 is energized. 'I'hev electrical circuits for
energizing these solenoids, as will appear here
matter, are so arranged that only one solenoid is
energized at a time.
diameter extension I84 to which a spring seat
' Servo valve mechanism
washer I86 is secured, a coil spring I88 being
compressed between the washer I86 and a coun
The servo valve mechanism, as best shown in
terbored spring seat shoulder I98, thereby nor 20 Figs. 13 to 18, comprises the servo valve I14 which
, operates in a complementary servo valve follower
mally to hold the pilot valve I18 in its closed posi
sleeve 2I8, the latter being rotatable in a closely
tion.‘ A similarly constructed pilot- valve I92 is
?tting bore 228 formed in the valve body 85. The
_ operable upon energization of‘ its “?ne feed’?
follower sleeve 2I8 has a pinion 222 formed in
solenoid II1 to open communication between a
tegrally therewith meshing with a rack 224
branched passageway I94 and a passageway I96S,
the passageway I94 having ports I94.I and I94.2 - formed on the annularly- grooved piston valve 226
opening into the cylinder I52.
-
of the directional valve mechanism I34.
A similar pilot valve I98 operated by the “stop"
solenoid II9 isvadapted to control the discharge
'
I
A ?ange 2I9 on the servo valve I14 has a plu
rality of notches 2'2I formed in its peripheryfor
from a branched passageway 288 to a discharge 30 cooperation with a spring ball detent 223, where
by the valve is held against accidental rotation
passageway 2828, the passageway 288 having ports
due to vibration or other minorv disturbances.
288.l and 288.2 leading into the cylinder I52, ,
A pilot valve 284 is operable by the “forward”
The indicator or pointer I86 is securedto the end
of the servo valve I14 and cooperates with suit
able legends on a panel face sheet 225. The'servo
valve is held in place by a retainer 228 having an
solenoid M5 to control the?ow from a passage
way 286, having port 286.I leading into the cyl
inder I52, to a discharge passageway 2I8S.
A pilot valve 2 I 2, when operated by its "reverse."
oil seal 233.
,
'
I
r
I
'
solenoid I I8, opens communication between a pas
sageway 2I4, having a port 2I4.I leading into the
The follower sleeve 2I8 has a central external
- I52, and that when any one of the pilot valves
' piston 226 is connected by passagewayv 221.I with
groove I58.8 and communicating ports I58._9
cylinder I52, with a discharge passageway 2I6S. 40 (Figs. 14 and 1'1), whereby oil from the'low pres
sure pump 88 is continuously supplied to an an
From the foregoing, it will appear that oil under
low pressure is continuously supplied through the ’ nular chamber I58.I8. The right-hand end 221
(Fig. 18) of the bore 228 for the directional valve
metering ports I56, I51 to the ends of the cylinder
I18, I92, I96, 284, or 2I2, is opened, the motor 45 annular groove 221.2 (Fig. 17) surrounding the
piston I56 will be moved to a position such that ~
servo valve follower sleeve 2I8. .As‘best shown
it substantially cuts oil the ports associated with
the open pilot valve. For example, if the pilot
valve I18 is opened, with the piston I58 in the
in Fig. 13, the annular groove 221.2 has a pair of
diametrically‘ opposite ports 221.3 which, upon
relative movement of the servo valve I14 and'its -
. position in which it is shown in Fig. 8, the oil 50 follower sleeve 2I8, may communicate with pas
sageways I58.I I or passageways 23 IS which com
entering the metering port I56 will exert a pres
municate with a central bore 2328 through suit
sure on the adjacent head of the piston I58 to
able ports, depending upon the direction of'rel- I
move the latter upwardly (Fig. 8), whereas the
oil passing through the metering port I51 will
discharge freely through the port I82.2 and pas 55
ative rotation.
sageways I82 and I885 to the sump, However,
as the piston I58 moves upwardly, it will cut oil
the port I82.2 and thereafter the pressure on the
municates through passageway 234.I with annu- ~
,
In a similar manner (Fig. 18), the left-hand
end 234 of the directional valve cylinder 228 com
lar groove 234.2. As best shown in Figs. 15 and
17, the follower sleeve 2I8 has a pair of ports' ‘
opposite ends or the piston I58 will equalize and
hold the piston in this position.
60 234.3, which upon relative movement of the sleeve
In the event that the piston should travel up
wardly beyond the position at which it cuts off
both ports I82.I and I82.2, the uncovering of port
and servo valve I14, are adapted to communi
‘ cate either with passageways I58. I 2V or with spaces
2368 which communicate freely with the cen-;
tral passageway 2328, depending upon the di
lower end of the cylinder I52 and therefore the 65 rection of relative rotation. Passageways I58.II'
and I58.I2 communicate with the annular cham
piston I52 will move downwardly until the port
I82.I is again covered.
When the positioning motor piston I58 rotates
In a similar way, when the pilot valve I92 is
the servo valve I14 clockwise with respect to its
opened, the piston I58 will be forced to the posi
, tion in which it is shown in Fig. 8, covering both 70 sleeve 2I8, the ports 221.9 will communicate with
the space 23IS, thus permitting oil to flow to the
ports NH and I84.2. When the pilot valve I88
sump from the space 221 at the right-hand’ of
is opened, the piston I58 will be moved to a posi
the directional valve 226. ‘At the same time,‘the
tion in which it covers both ports MM and 288.2.
spaces I58.I2 (Fig. 15) are brought into com
When the pilot valve 284 is opened, the piston
I58 will be moved to the‘ upper hmit of its stroke, 75 munication with the ports 234.3 and thus voil un-_
I82.I will permit a reduction in pressure at the -
ber
I58.I8.
'
.
'
‘
2,408,957
Y
7
8
der pressure may flow from the low pressure
A check valve 212, normally held closed by
pump_44 through the conduits I40 and I44.I,
through passageway "0.2, ports I503, and pas
sageways ISILIII and vI4II.I2, to ports 234.2, an
nular groove 234.2, and passageway 234.I, to the
left-hand end 234 of the directional valve cylin
a spring 214 seated against a guide plug I04, is
adapted to open to permit ?ow of oil from the
sway I44.I4, that is, from the low pressure
pump, to the passageway 244 whenever the pres
sure'in the latter passageway drops appreciably
der. The directional valve 226 is thus moved to
the right (Fig. 18), but due to its driving con
nection provided by the rack 224 and pinion 222,
usually occur during the rapid forward or rapid
below that in the passageway "4.", as will ,
reverse traverse portions of the operating cycle.
the servo valve sleeve 2|! is rotated clockwise
onlyuntil the ports 221.3 and 224.4 are again
’ covered by the servo valve I14. Upon counter
Thus, the output of both pumps is utilized during
those portions of the operating cycle which do not
require high pressure in the actuating cylin
clockwise rotation of the servo valve I14, the
sleeve 2" and the directional valve 224 are con
strained to follow the movement of the servo
' der 44.
Difec?dndl valve
The directional valve :20 which has been pre
viously referred to, controls the operating cycle
valve in a similar manner. It will thus be seen
that the servo valve mechanism I24 serves as a
power ampli?er to cause movement of the di
rectional valve 224 in a direction and to an ex
of the machine by determining the ?ow of oil to ‘
and from the opposite ends of the actuating cyl
tent determined by the movement of the position 2.0 inder 44 and by rendering e?ective the connec
ing motor piston I44.
.
tion of the lower end of the actuating cylinder
44 to the governor valve I44 and to the adjust
Low pressure relief valve
able coarse feed control valve I44, the ?ne feed
The discharge conduit IIII (Fig. 1.8) is con
adjustable control mechanism I 44, or the sump
nected to a passageway I50." (Fig. 12) which 25 during the appropriate portions of the operat
leads to a chamber I40.“ of the low pressure re_
' ing cycle of the machine.
lief valve mechanism I24. This mechanism is.
generally similar to that disclosed in our afore
said application, and comprises a hollow piston
The normal operating cycle of the machine is
as follows: rapid forward (downward), coarse.
. feed forward, ?ne feed forward, rapid reverse to
valve member 234 which operates against a com
30
pression coil spring 224, the upper end of which
seats against a bushing 24!! threaded in the body
44. The oil under pressure is admitted to the
the original starting position, and stop; In Fig.
18, the directional valve 224 is shown in ?ne feed
position. In this position the high pressure
pump 14 feeds through conduit 244.2 to annulus
lower end surface of the valve member 244
244.4 which is in free communication with 'an
through a port 242. This oil under pressure is 35 nulus 214, which is in direct communication with
also admitted to space 244 in'the interior of the
the upper end of the cylinder 44 through conduit
valve member 244 through a metering ori?ce 244.
214.l. The piston 44 is therefore forced down
The oil pressure within the space 244 is ex
wardly and the oil beneath the piston is forced
erted upon, a pilot relief valve 244 held in closed
through passageway 214 to the governor valve
position by a compression coil spring 240, the de 40 mechanism “'4 and hence successively through
gree of compression of which may be varied by _
adjustment of a set screw 242 over which the
the coarse feed valve I44 and ?ne feed valve I 44,
since the branch passageway 214.l leading to an
cap nut M2 is threaded. Thus, when the valve
nular groove 214.2 is blocked by a land of the di-.
244 is moved to open position to uncover its ports rectional valve 224, and because the annular
244, the pressure within the space 244 is relieved‘
groove 244.2 is similarly blocked.
and the piston valve member 244 can then move
The directional valve 224 is similar to that die
to the right (Fig. 12) to permit relief of the low
closed in our aforesaid application, except that
pressure pump through a port 2448. The force
it is provided with a central drilled passageway
exerted by the spring 244 is, however, su?lcient
240 which has a port 244.IB communicating with
to maintain a substantial~ pressure in the cham 60 the sump through a passageway 244.28. The
ber "4J4. This is necessary since the passage
outer end of the passageway 244 is plugged, while.
way Illl.4 (Fig. 8—through which oil is supplied
the inner end has a port 244.2 which‘may com
for the operation of the positioning motor) is in
municate with a port 244.I communicating with
direct communication-with the chamber I50.I4.
the space 244 through a passageway 244.2. By
Thus the back pressure on the outlet of the low
virtue of this hydraulic connection, the pressure
pressure pump is at all times maintained at a
in the space 244 isrelieved during the ?ne feed
suf?ciently high value to assure rapid operation
of the positioning motor.
High pressure relief valve and check valve
phase of the cycle of operation, thereby permit
ting the valve 244 to open under lower pressure,
that is, whenever the pressure of the .011 de
60 livered by the low pressure pump 44 is lu?icient
The high pressure relief valve mechanism I42
to move the valve 224 against the force of its
is generally similar to the low' pressure relief
spring 244.v The power required to"operate the
valve mechanism, and operates in a similar man
low pressure pump is thus reduced during the
ner. The discharge of the high pressure pump
fine feed operation. During other portions of
14 is supplied _to a passageway 244 from which it 65 the operating cycle, the port 244.I is blocked by
'?ows through ports 244.I,--and a metering port
one of'the lands of the "directional valve 224 so
241 in a valve 244 and into a chamber 244. The
that the low pressure pump 44 operates against
valve is held in closed position by a spring 242 and
its normal pressure determined by the degree of
the pressure in the chamber 240 is relieved by a
compression of the spring 244 (Fig. 12).
'
pilot relief valve 244 held in closed position 'by 70
a relatively strong compression coil spring 244,
governor and feed valve mechanism: 7
the force applied by the latter beingvariable by
means of an adjusting screw 244 threaded in a ,
bushing 210. The adjusting screw 244 is cov
ered by the cap nut I44.
,
,
‘The’ governor valve mechanism I44 shown in‘
Figs. 11 and 18, comprises a valve sleeve 242 in
which ‘a valve member 244 having a piston head
15 "4 is reciprocable. the valve having milled ports
2,408,987
.
>'
91
'
cross sectional area as the valve 294~is moved to
the left or to the right (Fig. 11) by the oil pres- -
pump motor and starting controls 902 to lines LI ,
sure exerted upon its piston portion 288 in op
position to the force of a spring 290. After pass
ing through the ports 288 the oil ?ows through a
passageway 292 and thence through the valve
port 294 of the adjustable coarse feed valve mech
anism I48.
L2, and L9, the circuit to line LI including the‘
winding of overload relay 9I0. Similarly, the
energization of relay 908 connects the head motor‘
and starting controls 904 with lines LI, L2, and‘
L9, the connection to line LI being through the _,
'
From this valve the oil discharges through a 10
passageway 288 to the line feed adjustable aper
ture valve 298. The position of the coarse feed
aperture valve 294 is adjusted by means of the
knob 98, while the position of the ?ne feed-aper
ture valve 298 is adjusted by means of its knob 15
98, suitable graduations =being marked on the.
sheet 225 (Fig. 5) to indicate the feed rates to
which these valves are adjusted.
'
The oil, ‘after flowing through the adjustable
aperture of the fine feed valve aperture 298, (Fig.
11) is discharged to the sump through its central
bore and passageway 3008. ~ A passageway 298.I
10
ton 98, windings of relays 909 and 909, and the
switches of overload relays 9I0 and 9i I, to line
Ll. Energization of the relay 908 connects the
289 which provide apertures of greater or lesser
winding of overload relay 9i I.- The energization
of these relays 808 and 908, through closure of
switches 3I2- and 9I3, also completes a holding
circuit for these relays; this holding circuit in
cluding the stop switch 85, so that whenever the
stop switch is operated, the relays 908' and 908
will be deenergized and the current supply to the
pump and head motors cut off.
.
In setting‘ up the machine, manual operation
will ordinarily be required to enable the operator
to make the adjustments of the positions of the
20
dogs 58 to accord with the piece of work to be
_ machined. To accomplish this; the operator
connects the passageway 298‘ with an annulus
298.2 (Fig. 18) of the directional valve, this an
shifts the manual control switch 88 from the full
- line to the dotted line position shown in Fig. 19, '
thereby closing switch M4 and opening switch
nulus being uncovered during the. coarse feed, 25 9I8. Closure of switch 9" connects conductor
so that during this portion of the cycle the aper- '
M8 to the line L9 and thereby energizes control
ture valve 294 provides the only restriction for
relay‘CR2, the latter thereby opening switches
the escape of oil from the lower end of the actu
,9I8 to 329. The opening of these switches ef- '
ating cylinder 48.
.
v
disables the- automatic control. circuits
The operation of the governor valve mechanism . fectively
and prevents power from the manual control cir-I
I44 and the two adjustable aperture valve mech
cuits feeding back to the automatic control cir
anisms I48 and I48 in conjunction with the op
cuits. The relay CR2 will remain energized as _
eration of the directional valve229, is similar to
long’as the switch 88 is in manual position.
the operation of the corresponding parts disclosed
When the machine is thus conditioned for
35
in greater detail in the aforesaid oopending ap
manual operation, the operator can'_ jog the
head in rapid forward,.coarse feed, ?ne feed,
‘or rapid traverse. by,.depressing the desired
280.9. 280s, and 280.IS in the directional valve '
manual control push buttons 88, 81, ‘I0, or 94.
228 which connect the pilot valve chamber. 244
When none of'these' push buttons is depressed,_
of the low pressure relief valve to the sump dur 40 a series circuit, including all of these push
ing the coarse and fine feed positions. The di
buttons in their upper (Fig. 19) positions, and
rectional valve 228 differs slightly also in that it
a conductor 924, is completed to energize the
is arranged to block the port. 244.I when the valve
plication, Serial No. 339,476. The only substan-‘
tial difference resides in the provision of the ports
is in stop position.
I
'
stop solenoid II8.- Since this is the normal con-'
45 dition of these four'push buttons, the stop sole
noid I I9 will normally be energized whenever the
~ Elect'rica‘l' control circuits and operation
switch 99 is moved to manual control position.
It has previously been pointed out how the ’ The directional valve 229 is therefore maintained
operation of the positioning valve, through the
in stop position.
pilot valve mechanism, controls the position of 50 ' When, for example, the operator depresses the
the directional valve. If it were not for the sub
forward push button 89, a circuit from conductor
stantial force required for shifting the direc
9I8 to line Li is completed through aconductor
ticnal valve, the latter could have been mechani
cally operated by the positioning motor.
The
929 and forward solenoid II8.
This solenoid,
through energization of its pilot valve associated
automatic cycle, as well as the manual control 55‘ with the positioning motor I92, will operate
of the machine tool head, is determined initially
by the electrical controls'and circuits‘ shown in
Fig. 19.
‘ .
,
In Fig. 19, the solenoids iii to H8 are repre
sented as coils bearingcorresponding reference
characters. The purpose of the electrical con
trol circuits is to cause energization of these sole
noids in a predetermined sequence for the auto
through the servo valve mechanism I99 to move
the'directional valve 228 to “forward" position.
The head will continue in rapid forward traverse
J as long as the push button 89 is held depressed.
' this push button is released, the ‘circuit
60 when
through the stop solenoid I I8 is immediately com
pleted, this resulting in the'shifting of’ the direc
tional valve 228 fromits rapid “forward” to its
matic cycle, and to permit individual energiza
“stop” position. The depression of the push but
tion of these solenoids when the motion -of the 65 tons 91, ‘I0, and 94 will, in a similar manner, cause
head is to be manually controlled.
,
the energization or the coarse feed solenoid “9,
The pump motor and starting controls are indi
the line feed solenoid Ill, and the reverse sole
cated by a block 302, while the head motor and
its starting controls are indicated by a block 994.
Energizing current for these motors and their
noid H9, respectively‘, to cause corresponding
movement of the head.
,
‘
For automatic‘ operation of the head. the se
controls is provided through line conductors LI, 70 lector switch 88 is moved to automatic (full line)
L2, and L3. To start these motors ‘for either an
position, thus opening switch 9 I 4 to disconnect ,
automatic operation or a 'manualoperation, the
conductor 9l8 from line L9 andclosing switch 9I8
start push button 82 is depressed. ‘This operation
to connect conductor 929 to the line L9, the sup
connects line L9 witha jumper connection 909 ' 75 ply of current to the conductor 929 being effec
and completes a circuit through stop push but
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