US2584500A - Closure mechanism for pressure vessels - Google Patents

Description

Feb. 5, 1952 A. o. RloRDAN 2,584,500

CLOSURE MECHANISM FOR PRESSURE VESSELS /7 Train/Ens Feb. 5, 1952 A. o. RloRDAN 2,584,500

CLOSURE MECHANISM FOR PRESSURE VESSELS Filed May 29, 194s 2 SHEETS- SHEET 2 #Wa/ME75.

Patented Feb. 5, 1952 CLOSURE MECHANISM FOR PRESSURE l VESSELS' Albert 0. Riordan, Saginaw, Mich.; assignor to Baker Perkins Inc., Sa

tion of New York ginaw, Mich., a corpora- Appiication May 29, 194s, serial No. 30,129

rThis inventionrelatesto pressurevessels and, in particular, refers to the closure mechanism thereof.

An object of the invention is to Yeliminate the .danger or possibility of violent'and uncontrolled movement ofthe cover mechanism due to internalpressure during the opening of the vessel. Another object is to provide a hydraulic piston .and cylinder mechanism for controlling the opening of the c over,l so that forces tending to open' .the cover are absorbed by the pressure of vtrapped liquid in one end of the cylinder.

Another object. is to provide a hydraulically controlled closuremechanism of the type described in which a short stroke piston and cylinfderunit may be employed toeffect full opening movements and in which at the samek time the ,imposition of excessive hydraulic pressures on the cylinder and piston unit is avoided.

A furtherobject isI to provide a self-aligning .and rmly seating cover device. Broadly speaking the. present invention comprises a cover mechanism in combination with a hydraulic lpiston and cylinder unit so connected lvessel exerts 'a force tending to open the cover andthisiorce is absorbed bylcontrolling the rate ,of exhaust of iiuid from said other `end of the cylinder. It. `will be apparentthat with such an arrangement, if the cover and cylinder were drectly connected and .axially aligned, it would be 4.necessary to have a cylinder of` relatively large 7 diameter to avoid excessive pressures; lwithin the cylinder due to the tendency of the cover. to. open, and itwould also .be necessary to .employ a long .ylnder to. produce the necessary total cover movement. If the cover is simply pivoted to the vessel and the cylinder connected to the cover near th e pivot point, a shorter piston could be used, but the internal pressure tending to open the cover would create a force which would be multiplied by the lever advantage and result in the imposition of an'exce'ssive force on the cylinder and piston unit. If, on the other hand, the l'piston and cylinder unit is connected to a pivoted cover` at-a point remote fromlthe pivot point,

Swhile the forces on' the unit will vbe'reduceda 'cylinder of objectionable length would be rerquired. A 1

Theabove diiculties are overcome in accordance-'with the present invention byproviding a pivotal `connection between the cover and the iaclaim's. (ci. ass-74.5

vessel', connecting/a relatively short piston and cylinder unit to the connecting meansor cover adjacent to the pivotpoint and providing means independent of the piston and cylinder unit for absorbing at least a portion of the force exerted bythe pressure `within the vessel during initial opening movements of the cover. In the preierred mechanism illustrated and described herein, the cover is pivoted to a fulcrum bar, and means are provided to permit pivotal upward movement of the bar rst about one end and then about the other. The piston and cylinder unit is connected to the bar adjacent the second pivot point and the mechanism is so arranged that initial opening movements occur automaticallyby pivotal movement of the bar about the rstpivot point. As a result the loads imposed von the piston and cylinder unit during the initial opening movement are low and yet a short cylinder will sunice to complete the opening movement.

The principles of the invention will become more clearly evident upon consideration of -the accompanying drawings which illustrate a preferred form of the invention, and in which:

Figure 1 is a side elevation, partly in section, of a pressure vessel embodying aclosure mechanism according to the principles of the present invention; Fig. 2 is a partial 'front view of the apparatus shown in Fig. l;

Fig. 3 is a plan View of the apparatus shown in Fig. 1;

Fig. 4 is a somewhat diagrammatic side elevationwith parts removed and broken away and parts in section.. showing the closure mechanism in closedposition; n y Fig. 5 is a View similar to that of Fig. 4 showing the closure mechanism inthe initial or rst stage of opening; and

Fig. 6 is a view similar to that of Figs. 4 and 5 .showing the closure mechanism in the fully opened position.

Referring to the drawings, the pressure vessel l is xedly connected to a-frame 2 'and has an opening 3 which is shown as being tapered and rectangular but obviously may be of any desired shape and form. Y

A cover 5 is suitably adapted to seal the opening 3 and preferably has a pair of oppositely directed transverse. trunnions .'l by means of which it is pivotally and slidably mounted in longitudinal -slots 9 in the parallel, longitudinal arms il. There are desirably two o f the arms li, though clearly loncor more than two may be used; and since they carry the cover 5, they may be used to coact with suitable locking means to at least partially latch the closure mechanism to the vessel I.

One way in which this may be accomplished is by providing the forward end of each arm II with a surface I3 adapted to lockingly engage a notch I5 in a pin I1 which is rigidly afxed to the Vessel I at the forward edge of opening 3. To facilitate engagement and disengagement of the pins I1 and arms I I, the coactive locking surfaces I5 and I 3 thereof may be made plane and parallel to the plane of the opening 3'. The forward under side of each arm II is preferably rounded, as shown at I8, for a purpose Which will become evident hereinafter in connection with the description of the preferred opening movement of the arms I I.

The arms II are preferably rigidly joined by a transverse cross bar I9 which is located near the rearof the arms II and on the opposite side of ythe opening 3 from the latch means I1.

Means may be provided, if desired, for preventing substantial tilting or swinging of the cover 5 on its trunnions 1 when it is opened. A preferred arrangement for accomplishing this includes a llongitudinal rod 2I which is fixed to the cross bar I9. The forward end of the rod ZI is loosely carried 1n a recess 23 that is formed in a lug 25 on the cover 5 and which is disposed so as to be more or less normal to the plane of the arms II.

vTilting of the cover 5 is therefore limited by the edges of the recess 23 striking the fixed rod 2l. The rod 2I desirably carries a fixed, adjustable spring spacer 21 and a spring 28 which is compressed between the spacer and the rear of the lug 25. The spring 28 vtherefore acts to yieldably force the cover 5 and trunnions 1 forwardly in the slots 9 in arms I I.

The arms I I are actuated by means which ca-use va slight initial opening of the cover 5 before dis- .connection of the locking means. With the particular locking means already shown, i. e., the

fixed pins I1 for locking only the forward side of the closure mechanism it is desirable that the actuating means coact therewith to rst pivot the arms on their rounded forward ends I8 so as to crack open the cover 5 and permit pressure equalization and then longitudinally move the arms I I to the rear until the surfaces I3 and the notches I5 are out of engagement and the cover .5 is free to lne-swung clear of the opening 3 in any suitable manner, preferably by pivotal move- ,ment in a longitudinal plane-normal to the opening. To accomplish these functions, a suitable construction comprises downwardly curved end portions 29 on the arms II to the rear of bar i9 which are movably connected between and to the .legs 3I'of the bifurcated brackets 33 that are aflixed to an upper portion of the frame2.

`The legs 3I have vertically disposed cam slots 31 .to which the arm end portions 29 are at least.

ythe arms II. The portion 31h, however, diverges rearwardly andv therefore provides a Vcamming action to force the pins 39 and thus the arms I I to the rear for the purpose ofdisengaging the arms from the locking means or pins I1.

A hydraulic cylinder 4I is employed for mov.

'brackets 33 so as to reduce the required stroke.

This connection may be on either the forward or rear side of the brackets 33 but is preferably forward and to the central portion of the arm I9 as shown at 49. Pressure fluid from a suitable source (not shown) may flow to or from the underside of the piston 45 by means of the port 5I and to or from the top side of the piston 45 by means of the port 53.

The removal of the cover 5 from the opening 3 may be thought of as comprising two distinct stages, viz., 1) the pressure equalization and unlocking stage and (2) the cover withdrawal stage. In the preferred construction that has been illustrated, stage (1) may be vfurther considered ascomprising rst a stage of pressure equalization followed by a subsequent `stage wherein the locking means is completely disengaged.

In the closed position, the cover 5 is locked to the pressure vessel I, in the preferred construction shown, by the combined action of two means. The rst of these comprises the pins I1 which act on the forward ends I3 of the arms I I and the other comprises the cylinder 4|, the upper end of which is filled with liquid which is prevented from escaping by any suitable means. For example. the ports 5I and53 may be connected by a reversing valve to the outlet and inlet respectively of a positive displacement pump. If desired, a relief valve may be provided to prevent exhaust of liquid from the upper end of the cylinder until a predetermined pressure is built up. In the first stage Vof opening, liquid is admitted to port 5I and allowed to escape at a controlled rate. from port 53. This permits the piston 45 and rod 41 to move upwardly at a controlled rate and they, acting through the connection 49 and arm I9, permit the arms II to move upwardly. Since, however, the 'forward ends of the arms II are xedly held by the pins I1 against movement away from the opening 3, the force applied to these arms by 4the hydraulic cylinder 4I causes them to pivot or rock on their rounded ends I8, the cam slot portions 31a providing nointerference to the corresponding motion of the pins 39. AThus, though Suu naked by the pins n and the cylinder 4| against violent movement, the rea-r side of the cover 5 is withdrawn slightly from the opening 3 as shown at 55 in Fig. 5. Pressure fluid flows through the cracked opening 55 and substantial lpressure equalization occurs, the degree of pressure equalization being a function of the particular operating conditions and the rate of move- Vment of piston 45.` By proper design of the ap- Vso that they are forced rearwardly. This motion is relative to the cover 5 because of the elongated slots 9, By the time the pins 39 reach the tops of the slots 31, the surfaces I3 are withdrawn from the notches I5 and the locking means are disengaged. Stage (l) is thus completed and the The cylinder is pivotally con- `4ernaartoe lcover 51s free tof-bei swung clearo'fthe opening 3 in any. tiesiredv manner'.

In the construction. illustrated,v the @second vor cover withdrawalstage' is preferably; a continualtiorrof the movementalready started by the arms' ll.` The pins 39. being seated inthe upper portion of the slotsl 31:"prov'ide convenient fulcrumsrfor the arms l Il so that further upward motioniofgthe" dicatedV in Fig. 6.Y Sincethe rod 4111s connected to: the `arms ll near thepointsiof pivot,'-a relatively` short piston stroke,` or "lengths, 'of cylinder piston rod el pivotsthe .arms [tand swings thecover upwardly and clearl of the'opening 3..iasrin-- 4l, is. required to causethe` rather substantiall f movement necessary to' completely/withdraw theA lcover 5 from the vicinity ofthezopennig;

In closing, a pressure differentialapplied to the topf sidey of the piston `45V by meansofth ports 5l and 53 to provide avdownwardfforce on In addition, the centerof gravity,

the rods I I. of the cover 5. and. arms `I itis forward ofthe 4rod 41 so that they tend to: pivot about vpins 4.9,. which holds the'pins't in the upper `ends ofithepam slots. 3T until the cover 5 is seated. Further downward force on the arms Il. Vcauses thepins 3-9- to slide forwardly and downwardly: inicanrf-slotxp'ortions 31h. Thisslides thefarms H forwardly untilthe surfaces I3 thereof arefin full `locking engageinent with the notches l5. in .the pins'll. At this point the notches l5 become the pivotpointsand additional downwardv movement of the arms lvforces the cover 5 firmly upon-its seat.

It'will be noted that duringthe opening and closing of the cover 5, ythe'rod 2l,- which. has its forward end disposed in recess 23, limits the degree of pivotal",movementofv the coverv with respectto the armsv I l. Hence inclosing, .the-cover 5 automatically aligns itself' with the opening 3.,v

In the open position, the spring 28` acting on lug means. slidably .connecting the vremote end Vof the 'armirto .the braoketin said slot, andmeans piv- `otally connected to the. arm'. at a; point between the. arm connections withthe cover andv bracket for' applying force thereto substantially normal to the plane ofthe opening, said. cam slot being` shapedso thatlthe Alower portion is substantially normal to the plane of the opening and the. upper portion .diverges from: a: normal to the plane of the opening, whereby longitudinal movement ofthe arm away from the latch's effected only in. the upper portion.

" 2. In a pressure vessel having an opening, the combinationk of a cover torl the opening; an .arm carrying the. cover, locking means coactivewith said arm 'to'lock the coveriin closed position, said locking means` being: engageable and-disengageable by longitudinal translation of the arm, means for movingsaid arm in a direction to open and close the opening, and cam means connected to the armand designed tot eecft longitudinal translation of the arm during such opening and 'closing movement, such that the'arm is engaged V'with the locking: means during the initial stage `movement relative thereto, a' fixed wlatch `for engaging one-'ofsaid ymembers to prevent-r removal ofthe `cover from the'opening'ysaid `latclrbeing disengaged by longitudinal movement of the member, and means'f'or forcing said arm toward or away from the opening to apply orfremove the 25forces the cover trunnionsV T- against-the for-5I ward ends of the'slots 9 so as to yieldably prevent swinging of the cover even-'within Athe limits of the recess 23. y I

After the cover is fully closed, if it is not desired to rely upon the trapped liquid in cylinder 4I to keep the cover closed, additional meansA may be provided to.latchtheright-hand endsfof the bars in their lower positions.

As hereinbefore indicated, the various func,-

tions andl combinations thereof of the preferred',

construction selected to illustrate the principles of this invention may bey obtained by structure other than that shown in the drawing. `vJt'hile' the invention is particularly suited to hydraulically operated covers, it will'bel apparent that.

many of the advantages of theiinvention willybe realized if a hand wheel and screw are substituted for the piston and cylinder unit.

What is claimed is: ,l

1. In a pressure vessel having an opening, the combination of a cover for the opening, a locking pin on one side of the opening having an under,- cut notch therein substantially parallel to `the plane of the opening, an arm above said opening substantially parallel to the plane thereof and having one end remote fromthe opening and the other adjacent the opening, the end of the arm adjacent the opening being adapted to lockingly engage the notch, said cover being piyot.m ally connected at substantially its transverse ,axis to the arm in such manner as to be also capable of limited longitudinal movement relative to'the arm, a fixed bracket adjacent the said remote end of the arm having a cam slot which is subr stantially normal to the plane of the opening,

cover, said cam slot beingshaped so that it imparts a predetermined longitudinal; movement to 'the arm during opening and closingY movement thereof such that the latch is'engaged during the -initial stage 'of' removal ofthe. cover and thereafter isV disengagedv during further. removal of the cover.

4. In a pressure vessel having an opening, the combination of means providing a fixed cam slot which'is longitudinally spaced from said opening,l an arm `overhanging the 'opening which is pivotally and slidably mounted in the cam slot.

.a cover connected to said arm so as to be capable 'of movement therewith and of pivotal and sliding movement relativegthereto, a fixed' latch for engaging saidl arm to prevent removal of the cover from the opening, said latch' being disengaged-by'long'itudinal movement of the arm, and

7nal arms on either side of said opening, having elongated longitudinal slots in which said trunnions are mounted whereby said arms slidably and pivotally carry the cover, xed locking pins adjacent the forward edge of the opening having downwardly disposed locking surfaces, said arm having forward ends adapted. to slidably engage :the locking surfaces whereby said locking pins prevent substantial upward or opening movement of the arms and cover, and means providing xed cam slots for each arm to the rear of the opening, said arms being slidably mounted in said slots so that their longitudinal movement is governed thereby, said cam slotsbeing shaped so that the initial opening of the cover occurs before the arms are slidably moved out of engagement with the locking pins. v

6. In a pressure vessel having an opening, a closure mechanism including a cover for said opening and means for moving saidcover into and out of engagement with the opening; said mechanism being capable of linear and pivotal movement, locking means adapted to engage the closure mechanism to lock the cover in closed position; said locking means and closure mechanism being constructed and arranged so thatthey are engaged and disengaged by linear movement of the closure mechanism, and a guide member connected to the closure mechanism for controlling the linear movement thereof, said guide member being operative on the closure mechanism so that the cover is slightly open before sufcient linear movement occurs to disengage the locking means and closure mechanism.

7. In a pressure vessel having an opening, the combination of a cover for said opening, an arm,

`a pin and cam slot connection between one end of the arm and said vessel, said cover being connected to the arm intermediate the-ends of the arm, the other end of the arm having a locking surface, a fixed locking member adapted to engage said surface to prevent opening movement of that end of the arm, said arm being movable 'to engage and disengage the locking surface and locking member, means lfor moving the arm toward and away from the opening, said means being connected to the arm at a point between the arms connection with the cover and the pin and slot, said cam slot guiding movement of the arm Ato engage and disengage the locking surface and member and being shaped so that initial opening of the cover occurs before the arm is moved to( 45 the opening, said locking means being capable- 55 of permitting limited pivotal movementof the opposite end of the armaway from the opening,

4.means connecting the opposite end of the arm to the vessel for pivotal movement about said opposite end in a direction away from the opening and also for limited movementof said opposite end of the arm outwardly from the opening .incident to a pivotal movement of the arm about the end of the arm engaged by the locking means, power-operated means -for opening said cover connected to said arm at the opposite side of said opening. at a point spaced toward the opening from the axis of-pivotal movement of said arm about said'opposite end of the arm, and means eifectiveupon actuation of said power means in a direction to move said opposite end of the arm away from the opening for moving said arm in a direction parallel to said opening to disengage "said locking means after said opposite end of the "arm has moved away from the opening suiciently to elect an initial opening movement o f -combination of a cover for said opening, an arm carrying said cover, means pivotally connecting one end of the arm to the vessel, means for moving said arm about said end as a pivotal axis,

vmeans for disconnecting said pivotal connection,

means providing a fulcrum contacted by a portion 'of the armv remote from said one end when `said pivotal connection is disconnected, and

means for moving said arm about said fulcrum.

' i I ALBERT O. RIORDAN.

y REFERENCES CITED The following references are of record in the le of this patent: Y

UNITED STATES 15ATEN'r-s Number Name Date 1,127,278 Rachals Feb. 2, 1915 1,230,316 Napier June 19, 1917 1,276,191 Dittman et al. Aug. 20, 1918 1,990,300 Miller Feb. 5, 1935 Nyden Apr.*l6, 1940

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