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Патент USA US3080900

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March 12, 1963
Filed April 2, 1959
Patented Mar. 12, 1963
sealed between the opposing ?anged portions 10c of hous
3 089,890
ing members 10a and 10b while the periphery of a cen
Donald M. Papa, Milwaukee, ‘Wis, assignor to Cutler
Inc, Milwaukee, Wis, a corporation of Del
Filed Apr. 2, 1959, Ser. No. $03,763
1 Ciairn. (till. 137-484)
tral opening 14a therethrough is, as best shown in FIG. 3,
, compressively sealed between an annular ?ange 12a on
5 pushrod 12 and the diaphragm follower 16.
As best illustrated in FIG. 3, the pushrod 12 is sub
stantially cylindrical in shape and may be machined from
a single piece of stock. A stepped body portion 12a
This invention relates to pressure responsive operators
comprising a portion 12b and an annular ?ange 12c is
and more particularly to those for use in the vacuum
10 integrally formed intermediate the ends of the pushrod
Pressure responsive operators designed foruse in the
vacuum range of pressure commonly employ two dia
phragms, a main diaphragm for transmitting movement
12. The diaphragm follower 16 which comprises a ?at,
rigid disk overlying a greater portion of diaphragm 14 is
permanently secured at its center to pushrod 12. As
shown in FIG. 3,,the inner peripheral wall of the cen
to an operating rod and a second diaphragm to afford a
trally located opening 164: in the diaphragm follower 16
?exible seal about an opening in the vacuum chamber as 15 surrounds the portion 1212 on the pushrod 12. The
the operating rod moves inwardly and outwardly thereof.
diaphragm 14 and diaphragm follower 16 are compres
Therefore, a principal object, of this invention is to
provide an improved pressure responsive controller
wherein the necessity of providing a second diaphragm
sively held between the annular ?ange 12c and the out
wardly ?ared portion 1211 of the portion 12b. The ?ar
20 ing operation is completed subsequent to assembly of the
to seal the vacuum chamber is eliminated. ~
diaphragm 14 and diaphragm follower 16 on the pushrod
ks.\ A further object is to provide a controller of the afore
12 and may be accomplished by ring staking or peening‘
said character in which the vacuum chamber may be
over the upper surface of the portion 12b.
evacuated through a pushrod element penetrating said
Toroids or O-rings 26 and 28 are preferably formed
vacuum chamber.
Another object is to provide a pressure responsive con
trol device which is characterized by simplicity of design,
low cost of manufacture, and extended operational life.
Other objects and advantages of the invention will
hereinafter appear.
In the drawings:
FIGURE 1 is a top plan view of an electric switch
controller constructed in accordance with, my invention;
FIG. 2 is an elevational view partly in section taken
along lines 2——-2 of FIG. 1 and further schematically
illustratingan attached switch mechanism; and
25 of a resilient material, such as neoprene or Buna N syn~
thetic rubber, and may be lubricated with pneumatic
The annular grooves 12d and 12:: which are
oppositely located outwardly of the midpoint of the push
rod along its longitudinal axis accommodate the toroids
30 26 and 28 and prevent their displacement upon longi
tudinal movement of the pushrod 12 within ?tting 20
and bearing 18, When the above described parts are
properly assembled as shown in FIG. 2, the grooved
portions 120! and 12a of pushrod 12 which carry the
35 toroids 26 and 28 are disposed within the aligned open
ings 18b and Ztlb of the bearing 18 and the ?tting 20,
FIG. 3 is an enlarged sectional view of a subassembly
respectively. The toroids are of such dimension to pro
shown in FIG. 2.
vide a sliding seal between the pushrod and the walls of
As best illustrated in PEG. 2, the operator device com
openings 13b and 2% as the pushrod 12 reciprocates
prises a diaphragm housing 19, a pushrod 12, a ?exible
within said openings.
diaphragm 14, a diaphragm follower 16, an annular bear
As shown in FIG. 2, a reduced end portion 12]‘ of
ing bushing 18 and a ?tting 20. Also shown in FIG. 2
pushrod 12 extends upwardly into inter?tting engage
are portions of one form of switch mechanism 30 suit
ment with a central opening 34a in the spring gland 34 of
ably constructed'for operation by my pressure responsive
the switch mechanism 30.
operator. The cooperation of certain parts of the switch
As best illustrated in FIG. 3, cylindrical bore 12g ex~
mechanism 30 and the operator will be hereinafter de 45 tends coaxially through the pushrod 12 from the lower
scribed in detail.
end wall 12m thereof to a point intermediate the an
The housing 10 comprises two symmetrically formed,
shallow, bell-shaped members Ida and itlb. The latter
are preferably formed of a metal such as steel or alu
nular recess 12d and the annular shoulder 12b. Inter
secting the innermost extreme of bore 12 is an aperture
‘12k which extends transversely through pushrod 12 and
minum. The ?anged peripheral portions 10c of mem 50 opens into chamber lilh. It will be understood that the
bers 10a and 1011 are provided with radially spaced
longitudinal bore 12g and the transverse aperture 12k
apertures 10d, best shown in FIG. 1, which are alined to
provide an airtight connection between the interior bore
receive threaded screws 22. Additional apertures lite
Ztic of ?tting 2t) and the sealed chamber 10h.
and 10]‘ are provided in housing members 18a and 10b,
An essential feature of this invention is the elimina
respectively. Apertures ltle are open to the atmosphere,
tion of all exterior connections to the vacuum chamber
while apertures 10]‘ are alined with like dimensioned
14th. As shown this result is achieved by providing a
apertures 32a in switch frame 32 to accommodate
passageway through the pushrod 12 itself which func
threaded fasteners 24 which secure the housing 10 to the
tions as a vacuum connectionto the vacuum chamber
switch frame 32. Housing member 10a is provided with
a central circular opening 10]" for receiving a reduced
In operation the interior bore Ztic of ?tting 20 is con
portion Zita of ?tting 20. The bushing 18 has a reduced
nectcd to a vessel, pipeline or other enclosure in which a
portion 18a which projects outwardly of housing 10
pressure less than atmospheric is to be created and main
through a central opening 10k in member liib. Fitting
tained by a vacuum producing device. As a vacuum is
2t) and bushing 18 are preferably brazed to their respec
created in the interior bore 200 of ?tting 29, the pressure
tive housing members 10a and 10b to provide an airtight 65 in chamber 16h acting upon diaphragm 14 is reduced to
seal therebetween.
less than atmospheric. As shown previously, the cham
As shown in FIG. 2, diaphragm 14, which is circular
ber ltlg opens to atmosphere through the apertures 10a
and formed of a suitable resilient material, extends trans
in housing member 10a; therefore, the underside of the
versely of the assembled housing 10 bisecting the same
?exible diaphragm 14 is continuously subjected to atmos
into an upper chamber 10h and a lower chamber 103..
pheric pressure. The resulting pressure differential on
The outer periphery of diaphragm 14 is compressively
opposite sides of the-diaphragm 14 tends to ?ex the latter
Although my invention is particularly suitedfor ‘opera
upwardiy. ' The diaphragm iollowerle'is urged upwardly
‘by the underlying diaphrgam 14 thereby transmitting a‘
'force upwardly throughpushrod 12 and spring gland 34
against the downward bias of compression spring 36 of
tron as a vacuum sensing control device,.from the. fore~
going description it will be apparent to one skilled in the '
7 art that this device is likewise adapted for'operation as a
positive pressure actuated controller.‘ Furthermore, while '
the switch mechanism 3%. ; As the pressure differential
the embodiment hereinde-scribed in detail suggests that
acting upon diaphragm iii-overcomes this downwardbias
of spring vlid, the ‘pushr‘od ~12. carries the spring gland 34
, - the controller is particularlywell suitedto actuate an elec~
[ tric switching mechanism, it is'papparent that my invention
out of engagement with an underlying ‘portion 33a of the
lever 25% which extends transversely of the switch housing ' , will perform varioustmechanical as well as electrical con-'
32, thereby permitting lever 38 to pivot in a counterclock 10 trol functions ‘in response to, a predetermined pressure
wise direction about a pivot member 40' in response to the
biasing action of spring 42. As lever ?s'pivots in'the
manner just described, an insulating contact actuator bar
as intoycir-cuit completing engagement with stationary.
contacts 48.
‘ As the pressure differential a‘cting‘upon diaphragm 14 ,
decreases to a predetermined value, the biasing action of '
spring 36 forces the'spring gland 34 downwardly into en
gagement, with the aforementioned transverse portion 38a
of lever ‘38 thereby pivoting theleverj?t’s in a clockwise
direction and causing the contactor 46 to disengage from
contacts 45.
to t e atmosphere ‘and a second chamber open to the at;
dal, gaskets vseatedin annular recesses in, said pushrod, a
diaphrag. i follower disk ‘substantially overlying said dia
phragm in said ?rst chamber and movable therewith, said
25 dish being rigidly attached at its center point to saidfp'ush
switch isprovided ‘by empioying 'a‘sliding seal between’
rod, a ?tting attached jexteriorly of. said second chamber, "
a vacuum’ connection between said ?tting and said ?rst
~ chamber provided by a longitudinal bore intersected by a
. transverse aperture in said pushrod, said bore communi
eating with said ?tting and said aperture communicating
with said ?rst chamber.
the upper surface ofthe ?ared portion 12a of the pushrod
12 and the lower surface 18c of the bearing 18. This
‘distance is ,such'that the aforedescribed, sliding seal be
tween the pushrod l2 and the‘bearing 1'3 and ?tting 20
is maintained when the pushrod is moved to its upper
'Refcrences?ited. in the ?le of this patent
i a switching function. "While/one. form of such a switch
mechanism-has been shown partially in diagrammatic
form in FIG. '2, the structural details “of an electric switch
rnechanisrnwell suited for operation in response tomy
controlling device is disclosed in U.S. Patent No.‘
2,78 1,431.,
Sanford et al. _;_.._Q_.‘._.._. Mar. 19, 1935' ' r
Newton ..... ___ ________ _..-Jan. 26, 196-7
2,438,723. 7 ‘setter ______________ __~Mar.'30,,194'8
7 Pauly _______ __'_______ _, May 22, :1951
The "afored'escribed embodiment of my invention may
be used with many known forms of switching mechanisms
to translate the vertical displacement of the pushrod into
diaphragm housing comprising mating, bell-shaped mem
bers, a ?exibie diaphragm having its outer periphery
secured between the vmatingsuriaces of saidbell-shaped
membersto'divide said housing into a ?rst chamber sealed
f mosphere, apushrod iaxiallygpenetratinglthe end walls of
said housing andysaid diaphragmsealing means between
‘the housing 15th of the vacuum chamber itih and the push
rod 12, thereby making it unnecessary to ‘provide an addi
' tional diaphragm as a seal between the driving element of
the controller and the switchmechanism housing 32.
' ‘Therefore, the vertical displacement of the pushrod 12
is limited to the normal distance shownin FIG. 2 between
said pushrod ‘and said end walls comprising resilient toroi
~ Another distinict advantage of. the disclosed vacuum
In a pressure-responsive operator,- in ‘combination, a
44 attached to the lever 38 moves its associated ‘contractor
‘2,655,573. 1 Szwargulskitet al.,__~'__'_'__ Oct. 1-3, 1953
VonWeise ______ __‘___,___ Dec. 29, 1,953
‘Wirth ____ _'___,_ _______ .__ Oct.'l6, 1956
Seljosv ___"_‘_‘__'_..__ '
__.-_..'~Mar. 4, 1958
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