Note: Descriptions are shown in the official language in which they were submitted.
39~8
This invention relates to a spring cartridge
assembly particularly of the type for resiliently resisting
axial movement of an axial member with respect to the
assembly.
This is a division of copending Canadian
Application Serial No. 300,267, filed April 3, 1978.
In a large number of manufacturing processes
utilized in industries such as petrochemicals and food
processing, the move toward automation has resulted in the
necessity for applying motorized power sources to the com-
ponents of those manufacturing processes. One of the
largest and most critically needed areas of motorized
operation is in the opening and closing of valves such as
gate valves, butterfly valves, plug valves, and ball valves.
The prior art has provided motorized valve operators
which primarily utilize electric motors operating through
worm gear assemblies with gear reduction to move the gate
valve stem vertically and rotate the valve stems of butter-
fly and plug valves. The prior art motorized valves have
been further automated by the provision of torque sensitive
cut-off and reversing switches to shut the actuator motor
off before the valve is properly closed. In addition to the
automatic operation, a back-up system of manual operation
must be provided for the situation where a power loss or
motor failure has occurred.
The disadvantages suffered by the prior art valve
actuators arise in the structure of the two above-mentioned
features, the torque cut-off switch and the manual operation
feature. The prior art devices utilize a type of torque
sensing system such as a coil spring or Belleville springs
intercon~ected with the worm gear assembly such that when
the gate valve is closed and resistance to further movement
~9~:I48
begins to increase drastically, the spring system is com-
pressed to a point that a switch is actuated. This cuts
power to the actuator motor and the motor slows and stops.
The problem that arises with this type of system
is that a correct calculation of the closing torque that
will be obtained is not possible with any degree of accuracy
because of the high rotational inertia in the motor after
electric power is shut off. Thus, the only method of getting
the proper closing torque is through a trial and error
process on each individual motorized operator because of
the large number of variables involved, such as motor size,
motor speed, total rotational momentum, required seating
torque, gear reduction ratio, stem speed, gear masses, and
others. As a consequence of this inaccuracy, severe damage
can occur to the valve components from inadvertent over-
tightening.
A second disadvantage suffered by prior art devices
involves the provision for switching the actuator from
automatic to manual operation. These devices provide a
separate lever and gear assembly in the actuator. This
elaborate system begins with an external shifting lever
and includes several shafts and sliding gears for shifting
the mode of operation. Unfortunately, the mere inertia
and complexity of this system may prevent its successful
operation when it is needed the most. A small amount of
dirt, sludge, or corrosion can render the shifting mechanism
inoperable and the valve will not be operable until either
the motorized operation is restored or the actuator can be
disassembled and repaired. Also, the nature of the manual
lever system requires that the actuator be placed in an
easily accessible location.
According to the present invention there is
9~48
provided a spring cartridge assembly for resiliently
resisting axial movement of an axial member with respect
to the assembly, which spring cartridge assembly, when
used in a valve operator of the type descr:Lbed above
overcomes certain of the disadvantages. The spring
cartridge assembly includes a slidable base plate arranged
to receive an axial member in non-slidable connecting
relationship therewith and a slidable lower plate on the
base plate. Resilient biasing means is provided on the
lower plate, and a slidable upper plate is provided on
the resilient biasing means. A stationary top plate is
provided on the upper plate. Limiting means extends through
the top plate, the upper and lower plates, and is securely
attached to the base plate, the limiting means having abut-
ment means thereon arranged to abut the top plate. Second
limiting means extends through the base plate, the lower
plate and the upper plate and is securely attached to the
top plate, a second limiting means having abutment means
thereon for abutment with the base plate.
Brief Description of the Drawings. Figures lA
and lB illustrate a cross-sectional view of a first
embodiment of the invention.
Figure 2 is a partial cross-sectional axial view
taken at line 2-2 of Figure lA.
Figure 3 is an axial cross-sectional view taken
at line 3-3 of Figures lA and lB.
Figures 4A and 4B, Figure 4B appearing on the
same sheet of drawings as Figure 2, illustrate a partial
cross-sectional
~ 9~48
view of the invention of Figures lA and ls rotated approximately
90 therefrom.
Figures 5A and 5B illustrate a cross-sectional view of a
second embodiment of the invention.
Figure 6 is a partial axial view of the second embodiment
taken at line 6-6 in Figure 5A.
Figures 7A and 7B are detailed views of the tripping
mechanism of Figure 5B at line 7-7.
Description of the Preferred Embodiments. Referring now
to Figures lA and lB, which when connected at common break line a-a
form a cross-sectional illustration of the valve actuator mechanism
10. The actuator mechanism 10 has a stem assembly 11, a motor sec-
tion 12, a hand wheel assembly 13 and a spring cartridge assembly
14.
The electric motor assembly 12 has an outer housing 15
and a motor stator assembly 16. The stator assembly 16 is mounted
' in housing 15, and a rotor assembly 16a is mounted on a rotatable
shaft 17 which is carried by upper roller bearing 18 and lower rol-
ler bearing 19. The stator 16 encloses an annular space 20, and in
close proximity thereto is located a sliding sleeve 21 mounted in a
stationary electromagnetic shield sleeve 22. The sliding sleeve 21
is of a magnetic substance such as iron or steel and has threaded
therein a plurality of elongated stud members 23.
At the opposite ends of studs 23 is a stud plate 24 se-
curedly attached to the studs by threaded locknuts 25. A first sec-
tion of spreading rod 26 having a threaded end 26a extends through
hollow shaft member 17 and stud plate 24 and is tightly secured to
plate 24 by a pair of locking nut sets 27 and 28. A helical coil
spring 29 abuts stud plate 24 and an internal web surfac~ 30 of
housing 15. The action of coil spring 29 is to continuously bias
stud plate 24 downward thereby maintaining sliding rod 26 in its
lowermost position.
9~?48
At the upper end of housing 15 is an internal wall sec-
- tion 31 which provides support for bearing 18 and through which
projects the upper end of shaft 17. The projecting end of shaft 17
has a splined section 32 formed thereon and on which is slidingly
located a jaw clutch member 33. Jaw clutch 33 is securedly attached
to spreading rod 26 by means such as welding 34.
Sliding movement of the motor shaft 17 is prevented by
abutment of shoulder 17a with the inner race of bearing 18. Like-
wise, a shoulder 17b prevents movement of shaft 17 in the opposite
direction by abutment with the inner race of bearing 19. Spreading
rod section 26 may slide coaxially inside shaft 17.
The motor housing 15 is attached by means such as bolts
to an actuator gear housing 35 containing a second spreading rod 36
which is in coaxially aligned abutment with lower rod section 26.
Rod section 36 passes through a jaw clutch 37 held in web plate 38
in rotatable relationship therein by a ball bearing assembly 39.
The jaw clutch sleeve 37 has an upwardly extending shaft section 40
having a worm section which comprises a continuous helical tooth
40a formed on the outer surface thereof. A position switch gear
shaft 40c extends behind worm section 40a and has secured thereon
in engagement with worm 40a a position switch worm gear 40b (see
Fig. 4A). Rotation of shaft 40 rotates gear 40b and shaft 40c
which are operably connected to a position-limit switch ~not shown),
which switches are known in the art. This switch governs valve
travel in the opening and closing directions and regulates the po-
sition indicator lights. When a position-seated valve such as a
butterfly or plug valve is being operated, rather than a torque-
seated valve such as a gate valve, the position-limit switch is
advantagcous for shutting off the motor and reversingthedirection
of travel. Basically, the position-limiting switch tracks the
number of rotations of the shaft 40 and its direction of rotation
to monitor valve position.
~9~8
Above worm 40a, shaft 40 has short external splines 41
formed thereon. A helical worm 42 haviny internal splines 43 is
slidably located on the splined portion of shaft section 40. Worm
42 has a continuous helical tooth 42a located externally thereon.
Worm 42 is in engagement with a cylindrical, driven, worm gear
sleeve 44 which is located in sliding relationship around a stem 45.
Driven worm gear sleeve 44 has a plurality of longitudinal gear
teeth 44a formed on the external surface thereof and a pair of up-
wardly extending lugs 46 and 47 extending upward past the ends of
teeth 44a. The lugs are arranged to contact a pair of abutment
lugs 48 and 49 formed on stem 45.
The upper end of worm 42 extends into a spring cartridge
base 50 and has located thereon a ball bearing assembly 51 secured
by a threaded nut 52. Bearing assembly 51 allows rotation of
sleeve 42 within base member 50. The upper extended portion of
shaft 40 passes slidably through the sleeve of worm 42 and extends
upward in housing 35. A third spreading rod 53 extends through the
center of hollow member 40 protruding slightly past the upper end
thereof. A jaw clutch 54 is secured on the end of shaft 40 by means
such as a spline or keyway 55. The jaw clutch is retained by snap
rings 56 and 57.
A mating jaw clutch 58 is arranged in slidably abutting
relationship with clutch 54 such that engagement of the two clutch
members can be accomplished. Clutch member 58 is slidably and co-
axially located on a splined shaft 59 and a fourth spreading rod60 passes through the center of hollow shaft 59 extending into
abutting relationship with rod 53. Rod 60 has an enlarged head
section 61 at the lower end for abutment with rod 53. A retention
washer 62 is located above head 61 and in abutment therewith for
preventing rod 60 from sliding upward and out of shaft 59.
A helical coil spring 63 is located in compression inside
a hollow recess 64 in shaft 59. Spring 63 provides a continual
6394~48
biasing ac~ion a~ainst shaft 59, pushing retainer 62 downward
against head 61 and tending to maintain rod 60 in its lowermost
position. A raised annular shoulder 65 is formed externally on
shaft 59 and seats in a recess 66 formed in the upper housing 67
to restrain shaft 59 from upward passage therethrough.
Actuator gear housing 35 has an upwardly extending spring
cartridge housing 77 formed integrally therewith. This housing is
joined at 68 to the upper wheel housing 67. Upper housing 67 is
secured to spring cartridge housing 77 by a number of threaded bolts
69 passing through openings 70 and threadedly engaging housing 77
in threads 71.
A manual operating wheel 72 is attached to shaft 59 and
prevented from rotating thereon by key means 73 fitting in corre-
sponding grooves formed in shaft 59 and the internal surface of
wheel hub 72a. A snap retainer ring 74 prevents wheel 72 from
sliding off of shaft 59. The upper end of shaft 59 extends through
the hub 72a of wheel 72 almost flush with the upper surface thereof.
Shaft 59 has an enlarged opening 75 formed at the upper end for re-
ceiving the upper end of rod 60 which contains a nut 76 threaded
thereon.
A spring loaded lockout mechanism 80 is provided with the
manual wheel assembly and consists of a sliding lock member 81 lo-
cated in hub 72 passing through an opening in the upper end of
shaft 59 and arranged to be projected inward below nut 76 to pre-
vent further downward movement of rod 60. An intermediate threadedsleeve 82 is threaded into hub 72a and contains a helical spring
83 compressed therein. Locking pin 81 is in abutment with spring
83 and has a reduced diameter pin shaft 84 extending outward through
threaded sleeve 82. A crossbar 85 is secured in narrow pin shaft
84 and has a thumb cap 86 located thereon. The intermediate sleeve
82 has a transverse groove 87 which allows the pin assembly to be
secured in its outward, nonlocking, retained position by pulling
~ 9~4~B
cap 86 to the riqht and rotating 90~ to seat crossbar 85 in groove
87. To return to locking action, crossbar 85, pin 81, and shaft 84
are released from groove 87 and allowed to slide radially inward,
whereupon it will automatically move into a locking position below
nut 76 when the nut has moved upward sufficiently to pass above
locking pin 81. Figure lA shows the mechanism in its automatic
locking setting. The locking mechanism may be neutralized by pull-
ing outward on cap 86, rotating 90 and reseating locking bar 85 in
groove 87.
A pair of spring compression plates 78 and 79 are loeated
inside cartridge housing 77. Lower plate 79 is slidably located
above cartridge base 50 on top of circular snap ring 88. Two sets
of helical compression sprin~s each comprising three equispaced
eoil springs are located between plates 78 and 79. The first set
of springs 89 are located around bolts 90 in encircling relation-
ship therewith. Each bolt 90 is located inside an enlarged bolt ~ -
head.opening 98 located in upper cartridge plate 125. Bolt 90
passes through a bolt passage 95 in the spring eompression plate 78
and extends downward inside eoil spring 89 and bolt liner 93. The
threaded end 91 of bolt 90 is threadedly engaged in spring eartridge
base 50. Bolt 90 passes through bolt passage 92 in-the lower com-
pression plate 79.
A seeond set of three helieal eoil eompression springs 103
is also located in eompression between upper and lower compression
plates 78 and 79 equispaced between each of the eoil springs 89. A
spring stud 101 passes eoaxially through eaeh eoil spring 103 and
is threadedly engaged at 106 in upper plate 125. A loeknut 107
further seeures stud 101 against movement with respeet to plate 125.
Stud 101 extends downward through a stud passage 105 formed in up-
per eompression plate 78, through the spring guide 104, through astud passage 102 formed in lower eompression plate 79 and into a
eylindrieal opening 99 formed in base 50. An enlarged eylindrieal
.
--8--
96;~i4'~
piston section 100 is formed on the lowcr end of stud 101
for sliding encJacJement in cylinder 99. Passage 102 is
insufficient to allow rnovement therethrou~h by piston 100.
The construction of each bolt and spring assembly of the
three member set is identical to that illustrated at 89
and 90. Likewise, the assembly of each stud and spring
assembly in the three member set is identical to that
disclosed at 101 and 103.
Upper plate 125 is tightly secured to the upper
portion of cartridge housing 77 by a plurality of bolts 109
passing through plate 125 and threadedly engaging in bore
108. The bolts 109 have enlarged heads 110 for abutment
with washers or directly with plate 125. An inwardly pro-
jecting annular shoulder 111 is formed inside on the wall of
housing 77 for receiving plate 125 in abutment therewith.
Referring now to Figure 2, an axial cross-sectional
view of the arrangement of bolts and studs described above in
the cartridge housing is illustrated. Each of the bolts and
studs 90 and 101 are located in an alternating circular pattern
as shown. The four bolts 69 securing the upper housing 67
to the cartridge housing 77 are shown in cross-section. The
four bolts 110 securing the upper plate 125 to the annular
shoulder 111 are shown spaced from bolts 69.
The above-described spring cartridge assembly is
also described and is claimed in copending divisional
application Serial No. 355,845, filed July 9, 1980.
Figure 3 illustrates a partial cross-section~l view
of the assembly taken at line 3-3 of Figures 1~ and lB. In
Figure 3 spreading rod 36, splined section 40 and worm ~2
are shown in axial cross-section. Also illustrated are
the driven gear sleeve ~ with gear teeth ~4a surrounding
valve stem ~5. Stem ~5 is mounted in roller bearincJs 126
9~'~8
and sleeve 44 is located in axial abutment with the inner
race 127a of roller assernbly 127.
Also in Figure 3, mieroswitch 116 is shown and a
second microswitch assembly 116' is drawn-in phantom.
Eaeh microswitch assembly is arranged to provide a sensing
and switching function in one direetion of movement of the
spring eartridge assembly. Thus, switeh 116 is in operating
engagement with wedge surface 113 and the second switeh 116'
will be contacted with a seeond wedge surfaee having a surfaee
tapered in the opposite direetion to surfaee 113.
Figures 4A and 4~, when joined at eommon line b-b,
comprise a eross-seetional illustration of the invention of
Figures lA and ls at a 90 orientation therefrom. The Figure
further illustrates the relation between the valve stem 45,
gear sleeve 44 and gear ring 44a. In this Figure, similar
numbers indicate similar strueture with respeet to Figures
lA through 3.
In typical operation, the valve actuator meehanism
10 is energized by supplying an electric power source to the
motor 12. As this power source energizes motor 12 an
electromagnetic field is generatea around the stator. This
strong magnetie field draws sleeve 21 into spaee 20 and into
eontaet with the stator. This in turn moves stud members 23
and stud plate 24 upward simultaneously therewith. This
movement of plate 24 slides spreading rods 26, 36, 53, and 60
upward. This serves to move jaw eluteh 33 into engagement with
eluteh 37 while simultaneously pushing jaw elutch 58 out of
engagement from jaw cluteh 54. This spaeing of the two pairs
of elutehes is sueh that elutehes is 58 and 54 will be com-
pletely disengaged before clutehes 33 and 37 begin engagement.
The above-described valve aetuator wherein means
is responsive to the internal magnetic field of the motor
-10--
- .~
~9~48
to engage the clutch is also described and is claimed in
copending,Canadian Divisional Application Serial No. 355,8~7,
filed July 9, 1980.
Likewise, with this shifting movement of the spreading
rods, the rotational force imparted by the motox assembly
12 is transferred to shaft 17 which in turn moves through
splines 32, the jaw clutch 33. Since clutches 33 and 37
are engaged, clutch 37 and the upward extending shaft 40,
which is an integral part thereof, also begin to rotate.
The rotation of shaft 40 operates through splines 41 and 43
to rotate worm 42. This in turn drives the driven gear ring
44 until the lugs 46 and ~7 impact the valve stem lugs 48
and 49 thereby imparting a sufficient hammer force to the stem
to begin movement of it in case it has become stuck or frozen by
corrosion or sediment.
The motor will continue to rotate the valve stem 45
through the aforementioned clutch and gearing system until
that point when the valve stem has reached the end of the
desired travel. At this point, the valve stem will begin
to tighten at a sharp rate and resistance to further rotation
will increase to the point that further rotation of shaft
37 will force the worm 42 to slide upward along shaft 40.
This movement will be transferred through the bearing
assembly 51 and into base 50 and spring compression plate 79.
Movement upward of these elements will serve to compress
the six helical springs 89 and 103. This compression will
occur against upper plate 78. Bolts 90 will move freely
upward through opening 98 and studs lOl will remain stationary
as the lower section lO0 thereof will be allowed to slide in
3~ opening 99 as base section 50 moves upward thereby. Movement
upward by plate 78 is prevented by abutment with upper plate
125 which is securely held against shoulder lll by bolts 109.
--11--
. '
~9~i48
It should be noted that, as previously mentioned,
clutches 58 and 5~ are completely disengaged before any
engagement of clutch 33 and 37 are achieved. This serves
to disengage the manual valve opening mechanism consisting
of the hand wheel 72 and a splined shaft 59 which is contin-
uously engaged in clutch 58. Upward movement of the four
spreading rods serves to push the retention washer 62 upward
by means of abutment with head 61. The snap ring 112 and
the recessed shoulder above washer 62 in clutch 58 serve to
retain the washer tightly in the central opening of clutch
58. Thus, when head 61 is pushed upward by rod 53 this moves
clutch 58 upward through abutment with washer 62.
Clutch 58 is provided with internal splines 58a
which mate with external splines 59a on spline shaft 59. This
splined arrangement allows sliding movement of clutch 58
on shaft 59 but locks them together against any rotational
movement therebetween.
Upon reaching the proper seating or opening torque,
the wedge surface 113 will have moved under the contact
button 118 a sufficient amount to compress it into housing
117 thereby actuating a microswitch located at 116. This
is connected with the power source to motor assembly 12 and,
upon compression of button 118 a predetermined distance by
surface 113, power will be disconnected from the electric
motor. When this occurs, the magnetic field in the stator
assembly will dissipate instantaneously and sleeve 21 will
no longer be held therein. Springs 29 will thus be able to
force plate 24 back downward which in turn pulls spreading
rod 26 downward and simultaneously disengages clutch 33 from
clutch 37.
The rotational inertia remaining in the heavy motor
assembly will thus be allowed to dissipate in a free wheeling
-12-
9~48
manner and will not react on the gear assembly to further
increase the tiyhteniny torque on the valve stem. This
instantaneous mechanical disconnect of the motor thus allows
the person operating the valving system to earefully present
the desired seatiny torque without having to account for the
additional torque added by the rotational inertia of the
driving motor.
When the actuator has moved the valve stem to the
end of its travel, for example, when closing the valve, and
the switeh system 116 has disconnected the motor, both
mechanically and electrically, a secona eireuit may be
provided in switch 116 to reverse the direction of rotation
of the electric motor for the next power eyele. Thus, when
the operating personnel wish to open the valve again, the
power is merely reeonnected to the electrie motor and the
valve will be actuated in the opposite direetion. Alternately,
a switching cireuit may be provided having markings thereon
related to opening or closing, thus allowing operating per-
sonnel to seleet the direetion of travel for the valve.
In any ease, upon diseonneetion of the motor from
the aetuating gears and elutches, the manual operating system
is automatically reengaged in the aetuating system. This
oeeurs through the spring aetion of eoil spring 63 whieh
expands against washer 62 and slides eluteh 58 baek downward
into engagement with clutch S4. Thus, should the power fail
or the motor become inoperable, it will automatically discon-
nect the aetuating mechanism from the motor drive end of the
assembly and engage the hand operated meehanism at the
opposite end of the assembly.
- 30 The valve actuator ineluding the manual operator
means operably connectable to the worm gear means is also
deseribed and is elaimed in above-identified application
~39~ 8
Serial No 300,267, filed April 3, 1978.
The hand wheel 72 may be locked out of operation
through the activation of the lockout arrangement 81. The
cap 86 is rotated until the crossbar 85 is in the position
shown in Figure lA, thus allowing spring 83 to move member
81 radially inward against nut 76. When power is applied to
motor assembly 12, the action of the spreading rods upward
will slide nut 76 above member 81 allowing it to move in
further against rod 60 below nut 76. Thus, the manual
operating wheel will be locked out regardless of whether the
electrical drive system is operable or not. The manual
system may be reengaged any time the power is off by pulling
outward on cap 86 and rotating it 90 to seat crossbar 85
in the upper groove 87. This maintains member 81 in a
position clear of nut 76.
When the valve actuating mechanism is reversed to
move the valve stem in the opposite direction as mentioned
above by either of the alternate methods, the electric power
will be restored to the motor 12 which will then be rotating
in the opposite direction from that previously described.
The magnetic field will again be instantaneously generated
around stator 16 and in space 20 which will pull sleeve 21
against the stator, moving the spreading rods upward,
disengaging clutches 58 and 54, and shortly thereafter
reengaging clutch 37 with clutch 33. The rotational force
of the motor will then be imparted to the worm 42 which will
in turn drive gear 44. Lugs 47 will rotate until they contact
stem lugs 49 and impart an initial hammer blow to free the
stem if stuck or frozen. Movement of the valve stem will then
commence. The motor will drive through the gearing assembly
until the valve stem reaches the end of its travel whereupon
gear ring 4~ will slow and eventually stop, thereby causing
~9~48
worm 42 to advance clownward pulling its associated intercon-
nected assemblics with it.
Thus, downward movement of sleeve ~2 acting through
nut 52 moves bearing assembly 51 and base plate 50 downward
therewith. The lower compression plate 79 is held against
downward movement by its abutment with piston ends 100 on
studs 101. Studs 101 are prevented from downward movement
by their threaded engagement with plate 125 and by the
presence of locknuts 107. Downward movement of cartridge
base 50 also caused downward movement of upper plate 78
through the action of bolts 90 which are threaded into plate 50
and in abutment with upper plate 78. Thus, since lower platç
79 is refrained from moving downward but upper plate 78
is brought down by the action of bolts 90, a compression of
the six helical springs 89 and 103 between the two compression
plates is achieved. The compression of the six springs tends
to absorb shock from the bearing components and from the
valve stem reaching its end of travel. The springs also tend
to retard the downward movement of sleeve 42.
Upon reaching a certain amount of downward movement,
the cammed surface having an opposite slope to that of
surface 113 engages the complimentary microswitch 116' which
is similar in operation to switch 116 except it operates for
movement of the valve actuator in the opposite direction.
When the cartridge assembly has moved downward sufficiently - -
to activate switch 116', power to the motor assembly 12 will
be disconnected and the magnetic field generated therein will
simultaneously be dissipated allowing spring 29 to move
plate 24 downward, disengaging clutches 33 and 37 and
reengaging the rmanual actuating mechanism as previously
described.
~ djustment of the closing or openincJ torque desired may
~ ~V9~4~
be obtained to a fine degree by the adjustment of switches
116 and 116'. This adjustment is provided by rotating threaded
sleeve 115 having internal and external threads thereon.
Rotation of switch box 116 is prevented by the securing
arrangement 119 and 120. Rotation of housing 117 is prevented
by being securedly attached to switch housing 116. A radial
rotation arm 115a is formed on sleeve 115 so that sleeve 115
may be rotated clockwise or counterclockwise to move housing
117 and contact button 118 inward or outward with respect
to wedge surface 113. A threaded lock screw 121 is engaged
in the outer radial end of arm 115a and a flat circular
calibration ring 122 is provided around the periphery of the
arc created by rotation of arm 115a and sleeve llS. A number
of setting holes 124 are drilled in the flat calibration
ring 122 which allow screw 121 to be threaded thereinto to
lock sleeve 115 in the desired position. The torque settings
associated with each position 124 may be enscribed on ring 122
which settings may be calculated or determined by experimental
methods. Likewise, a similar structure is provided for switch
assembly 116' for operation of the valve stem in the opposite
direction .
The advantages of the above described embodiment are
numerous and are obvious in light of the description thereof.
One of the main advantages is the elimination of a complex
parallel gearing and lever system for disengaging the electric
motor and engaging the manual hand wheel. In the present
invention, the hand wheel and the motorized system are in the
same coaxial gear train. Likewise, no manual changeover from
the motor to the hand wheel is required. When power is lost
or motor failure occurs, the motor is automatically disconnected
and the hand wheel is automatically engaged. Thus, the
elimination of the separate shifting mechanism found in the
prior devices.
-16-
~ 9~4B
A second major advantage is the elimination of the
valve overtightening which occurs in the prior art devices
from the dissipation of the rotational inertia of the drive
motor. The prior art devices utilize electric disconnect
of the motor but dissipate the rotational energy in the
tightening operation. There is provided simultaneous
electric and mechanical disconnection of the motor to prevent
any of the rotational inertia of the motor from entering the
tightening sequence after the preselected torque has been
achieved. This results in the ability to obtain a very
accurate and precise torque in the closing and opening of
the valve.
A third advantage is found in the spreading rod
principle which is a fail-safe design arranged to prevent
simultaneous engagement of the actuator motor and the manual
operation system. The total combined length of the spreading
rods is just sufficient to prevent simultaneous engagement of
clutches 33 and 37 and clutches 58 and 8~.
Likewise, a feature is provided whereby the manual
operating system may be placed on automatic lockout for
- lockout at any time power is restored to the motor. The dis-
engagement of the hand wheel will activate the lockout pin and
the hand wheel will not be reengageable until the lockout
has been manually reset to allow hand wheel operation.
Another advantage of this invention is the provision
of a multitude of coil springs 89 and 103 to replace the
fatigue-prone Belleville spring systems of the prior art
devices. The multitude of helical springs also is advantageous
over those prior art devices which utilize a single large coil
spring which itself is subject to failure. The provision of a
number of springs allows operation of the assembly even though
one or more of the springs may have failed.
~17-
1)9~48
The disclosed embodiment also allows the retention
of the conventional worm gear operation on the valve stem which
is a gear reducing mechanism and which also is a self locking
gearing system
.
-18-
~39~4 ~
.
preventing loosening or backing off of the valve after it has moved
into the opening or closed position.
One further advantage of the present invention is the
ease with which the spring cartridge assembly may be removed for
repair or replacement with springs of different spring force con-
stants. The spring cartridge assembly may be removed by disassembl-
ing the bolts 69,90 and 110.
Referring now to Figures 5A through 7B, an alternate em-
bodiment of the invention is disclosed. Figures 5A and 5B, when
joined at common break line c-c, illustrate a cross-sectional view
of a valve actuator mechanism 200 which does not utilize the auto-
matic switching feature from motorized operation to manual operation
on power loss or motor failure. The actuating mechanism 200 in-
stead utilizes a switching feature that is hand-engaged rather than
automatically engaged as in mechanism 10. In mechanism 200, many
of the same components are utilized from the actuator 10 and these
components are numbered identically to the correspondina components
in Figures lA through 4B.
In this invention, a standard electric motor 212 is uti-
lized which does not feature the magnetic engagement operation as
utilized in the first embodiment. The motor 21Z has a stator as-
sembly 213 secured inside the motor housing 212a. A rotor assembly
214 is secured on a rotating shaft 214a which is supported by ball
bearings 215 set in web structure 216. The upper end 214b of shaft
214a has external splines 214c located thereon which are engaged in
the internal splines of jaw clutch 217. A raiséd shoulder section
214d is formed on shaft 214a below spline section 214c. ~his shoul-
der receives a retention disc 218 having a stepped outer perimeter
218a. A coil spring 219 encircles the lower end of jaw clutch 217
and engages in the stepped perimeter 218a of disc 218. Spring 219
is in compression and tends to bias jaw clutch 217 to slide upward
on splines 214c.
--`19--
9~
A mating jaw clutch 37 is located above clutch 217 in a
position to be engaged therewith. Clutch 37 has an upper extending
hollow shaft section 40 as described in the previous embodiment. A
lower spreading rod 220 is located in the central passage of clutch
37 and extends downwardly therefrom to an enlarged abutment disc
221 formed at the lower end of rod 220. Clutch 37 is rotatably
secured in web plate 38 by ball bearing assembly 39.
The valve stem 45 and the driven worm gear ring 44 having
' lugs 47 thereon are similar in construction to the corresponding
10 elements o the previous embodiment. A position-limit switch (not
shown) is connected via shaft 40c and worm gear 40b (not shown) to
a limit switch worm section 40a formed on shaft 40 as described in
the previous embodiment. Operation of this switch is also the same
as in the first embodiment. Likewise, spline section 40 and worm
lS 42 are similarly constructed.
A number of flat spacer discs 36a are located on top of
rod 220 and carry a second rod 222. Rod 222 extends upward above
the upper end of shaft 40. A jaw clutch 223 is securedly held on
shaft 40 by means such as snap rings. A keyway 224 locks jaw clutch
20 on shaft 40 against rotation thereon. A mating jaw clutch 225 is
located directly above clutch 223 and is similarly secured to the
hand wheel shaft 226 by keyway 227 and upper and lower snap rings.
Hand wheel shaft 226 is slidably and rotatably mounted in
upper housing 228. A manual hand wheel 229 having a reenforced hub `
25 section 230 is secured on the upper end of shaft 226 by snap rings
and rotation thereon is prevented by a keyway 231. A peripheral
groove 232 is formed in shaft 226 for receiving a spring loaded de-
tent button 233. A pair of microswitches 116 and 116' for sensing
the opening and closing torque in the valve stem are provided as
; 30 described in the previous embodiment.
A pair of locking plungers 234 and 235 are located in
threaded openings in the wall 35a of the actuator housing. Each
-20--
9~8
locking plunger is located radially outward from jaw clutch 217.
Jaw clutch 217 has formed in the outer wall hereof a stepped perim-
eter section 217a. Each lockiny plunger utilizes a generally cy-
lindrical housing 234a with a threaded section 234b. The plunger
body is hollow and contains a plunger rod 236 which has an abutment
shoulder 236a thereon for preventing the rod from sliding out of the
end of housing 234a. A coil spring 237 is located in compression
behind shoulder 236a and in abutment with threaded plug 238 which
is threaded into section 234b of the plunger housing. Plug 238 has
a bore passage therethrough for slidably engaging rod 236.
Figures 7A and 7B more particularly illustrate the struc-
ture of the two locking plungers 234 and 235. ~igure 7B is a cross-
sectional view of jaw clutch 217 illustrating the peripheral step
section 217a. It can be seen that stepped section 217a contains a
pair of diametrically opposed cammed shoulders 217b having an outer
diameter identical to the outermost diameter of jaw clutch 217.
Thus, when jaw clutch 217 is pushed downward against spring 219,
at least one of the locking plungers 234 or 235 will engage in
stepped shoulder 217a thereby locking jaw clutch 217 in its dis-
engaged downward position.
In Figure 7A the means for disengaging the locking plungers
is illustrated. This consists of a small offset 239 between the
plunger rods of the two locking plungers 234 and 235. This offset
occurs in the axial direction corresponding to the longitudinal axis
of shaft 214 and rod 220. Thus, after the jaw clutch 217 has been
manually disconnected from clutch 37 by moving it backwards until
locking plungers 234 or 235 engage shoulder 217a, jaw clutch 217
will remain locked down until power is restored to motor 212. Upon
restoring power to the motor, jaw clutch 217 will begin to rotate
with rotation of the motor. At this time, the plunger rod 236 of
the left-most locking plunger 234 will be compressed by engaging
one of the cam shoulders 217b. Upon reaching the outermost
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9~148
diameter on shoulder 217b, the locking action of plunger 234 will
be neutralized and jaw clutch 217 will shift to the right by an
amount equivalent to the offset 239. At this point, the jaw clutch
will be engaged with locking plunger 235 and plunger 234 will no
longer be able to reengage in stepped section 217a.
Upon an additional 90 rotation of jaw clutch 217, plunger
235 will engage a cammed shoulder 217b and will be compressed until
it reaches the outermost pexiphery of a cammed shoulder, and the
jaw clutch will be completely released to move upward and reengage
clutch 37. The spring action of coil spring 219 automatically
assures that this action will occur in all instances when the
electric motor is restarted unless one of the operating personnel
is still engaging the hand wheel and maintaining it pushed inward
in the mechanism. The results of the hand wheel being engaged and
power being supplied to the electric motor will still not create a
dangerous situation since the length of spreading rods 220 and 222
has b.een adjusted precisely by the addition of spacer discs 36a to
prevent simultaneous engagement of clutch 225 with 223 and clutch
37 with clutch 217.
The reengagement of power to motor 212 while the hand
wheel is being held in place will merely allow the motor to rotate
freely without engaging the actuating gear mechanism. When manual
operation has been completed, releasing hand pressure on wheel 229
will allow spring 219 to move jaw clutch 217 against end 221 of
spreading rod 220. This abutment will move rods 220 and 222 upward
against shaft 226 tending to bias it outwards from housing 228.
Spring detent button 33 will be compressed radially outward from
groove 232 by this upward pressure and hand wheel 229 will be moved
outward disengaging clutch 225 from clutch 223.
Any time power failure occurs or motor 212 quits running
for any reason, the manual engagement may be accomplished merely
by pushing downward on hand wheel 229 until detent button 233
11~39~L8
engages groove 232 indicating by a snapping fcel and sound
tha~ the manual systcm is engaged. This will prcss down on
spreading rods 222 and 220 moving jaw clutch 217 do~nward
on splines 214b until one or more of the locking plungers
234 engage shoulder 217a and lock jaw clutch 217 in its
disengaged position. The hand wheel is then in a position
tl-rough engagement of the upper jaw clutches to rotate worm
sleeve 42 to drive valve stem 45 by means gear ring 44.
Operation of the torque control assembly com-
prising the six helical springs and their associated studsand bolts with switches 116 and 116' is identical to the
operation of the identical components as described with
respect to the first embodiment.
The above-described locking system is also
described and claimed in copending divisional applications
Serial Nos. 355,848 and 355,849, filed July 9, 1980 -
Thus, the advantages of the second embodimentinclude the elimination of the need for an independent gear
and lever assembly for switching from manual to motorized ~;~
operation. A second advantage lies in the spreading rod
principle which prevents simultaneous engagement of the
; motorized gearing with the manual gearing.
This invention is particularly suited in nuclear
plants and critical areas where speed of stem travel is very
important. The use of this invention allows use of high
speed motors to achieve a high stem speed for rapid valve
operation.
Other advantages include those found in the previous
embodiment such as easy removal of the spring cartridge
assembly for maintenance or changing of spring constants.
Likewise, this embodimcnt offcrs the advantage of precise
control of predetermined valve seating torque.
9~4gl
Although certain preferred embod:iments of the
invention have been herein described in order to provide
an understanding of the general principles of the invention,
it will be appreciated that various changes and innovations
can be effected in the described valve actuator mechanism
without departing from these principles. For example,
whereas six helical compression springs are utilized in the
spring cartridge assembly, it is clear that other numbers
and other types of springs might be utilized. Also, it is
apparent that different types of sensing switches could
be substituted for the spring button microswitches 116.
Other changes would be apparent to one skilled in the art
and therefore the invention is declared to cover all changes
and modifications of the specific examples of the invention
herein disclosed for purposes of illustration which do not
constitute departures from the spirit and scope of the
invention.
~ ' .,.
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