US 3371986 A
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G. G. BROWN DOOR AND SEALING ARRANGEMENT THEREFOR March 5, 1968 2 Sheets-Sheet 1 Filed Feb. 24, 1964 INVENTOR. GILBERT 6. BROWN (/iz XML ATTORNEY G. G. BROWN DOOR AND SEALING ARRANGEMENT THEREFOR March 5, 1968 2 Sheets-Sheet 2 Filed Feb. 24, 1964 FIG. 5
6. BROWN GILBERT ATTORNEY United States Patent Ofiice 3,371,986 DOOR AND SEALING ARRANGEMENT THEREFOR Gilbert G. Brown, Erie, Pa., assignor to American Sterilizer Company, Erie, Pa., a corporation of Pennsylvania Filed Feb. 24, 1964, Ser. No. 346,726 Claims. (CI. 2198) ABSTRACT OF THE DISCLOSURE The present invention relates to a sterilizing chamber having a surface around the door and an inflatable seal which is controlled by pressure within the chamber so that the seal will not be released nor will the door be opened until the pressure within the chamber has fallen below a predetermined value. The chamber is characterized by a double wall connected together by a member that defines the surface on which the inflatable seal rests.
This invention relates to doors and, more particularly, to doors in combination with pressure and/or vacuum vessels.
.The present invention discloses a door for use on any type of pressure or vacuum vessel such as dishwashers, sterilizers, sanitizers, and other devices which contain a pressure or vacuum. The edges of the door slide behind an overhang on the end plate of the vessel when closed in such manner that three of the doors edges are behind the overhang which is fastened securely to the end plate. When the seal is inflated and/ or the shell pressurized, the door will be forced against the overhang and prevent further lateral motion of the door.
The present invention also solves a problem of long standing in guillotine doors. An obvious mechanical weakness is inherent in a guillotine door. That is, the, unrestrained side of the door will tend to bulge when the shell is pressurized. This is overcome by welding a reinforcing bar to the unrestrained side. For example, in a specific use of the door, its size is 20" x 30" or six hundred square inches. The internal shell pressure is fifty pounds. This indicates that a total force of 30,000 pounds .is acting against the door which is restrained by the overhang on only three sides. Hence, the reinforcing bar on the restrained edge.
It should be of no significance whether the door is flat, dished, concave, or convex. This deals specifically with forces and bending of the door under pressure.
The door, maybe powered to open and close in any of several ways. For example, (a) an air or hydraulic, or air-draulictair over fluid) cylinder may supply the motive force. The door may be powered up, then down by gravity by simply bleeding air or oil from the cylinder. (-b)' The door may be moved by cables wound around a drum and powered by a motor. (0) A threaded rod may be revolved by a motor with a threaded nut fastened to the door, or therod may be threaded with both a left and right handedthread such as used by the level wind on a fishing reel. When the latter principle is used, the rod is revolved in one direction only and the nut engages the other thread at the end of each stroke.
' Presently constructed pressure vessels utilize a diaphragm arrangement for a coincidental locking method so that the door cannot be opened when the shell is pressurized. Pressure in the shell depresses the diaphragm by the unbalanced forces between internal shell pressure and atmosphere. A pin is forced into the door opening mechanism and prevents unauthorized door opening under pressure. This device is quite costly. The present invention discloses a novel method for accomplishing exactly the same results at a cost of approximately one percent of the cost of the diaphragm method. A small rectangular bar, for example, one-fourth inch square and one and one-half inches long is welded or cast in a horizontal mode on the front of the door, one bar at each side thereof. When the door is fully closed, the bars are positioned directly opposite a slot of somewhat larger dimensions. The pressurizing of the seal and/or the shell forces the door outward and the bars are captivated in the slot, preventing the door from opening until the shell and the seal are deflated.
A pressure interlock switch is used in the seal air inflation circuit and electrically tied in with the door actuating mechanism so that the door cannot be opened until the pressure in the seal is reduced to atmospheric. This is very important since, if the seal were inflated and the door powered open, the inflated seal would be sheared off or damaged when it passed the leading edge of the lower section of the opening in the shell. This also prevents the inadvertent opening of the door when the chamber is under pressure.
A pressure switch relates the internal shell pressure to atmospheric and is electrically tied in with the door opening mechanism so that the switch cannot be actuated until the internal shell pressure is within four ounces of atmospheric. The door could move vertically, latera ly, or horizontally within the scope of the present invention.
As a matter of convenience the word sterilizer or washer sterilizer is sometimes used herein. It is understood that these words contemplate all pressure vessels wherein a guillotine door can be used to advantage.
It is accordingly an object of the present invention to provide an improved door.
Another object of the invention is to provide a door and sealing means in combination therewith which is simple in construction, economical to manufacture, and simple and eflicient to use.
Still another object of the invention is to provide an improved inflatable seal in combination with a door.
It is another object of the invention to provide an improved guillotine type door. I
A further object of the invention is to provide an improved locking mechanism for a guillotine type door.
Still a further object of the invention is to provide an improved safety mechanism for a guillotine door.
With the above and other objects in view, the present invention consists of the combination and arrangement of parts hereinafter more fully described, iilust-rated in the accompanying drawing and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and minor details of construction without departing from the spirit or sacrificing any of the advantages of the invention.
In the drawing:
FIG. 1 is an isometric view of a washer sterilizer with the improved door installed therein;
FIG. 2 is a cross sectional view taken on line 2-2 of FIG. 1;
FIG. 3 is an enlarged cross sectional view similar to FIG. 2 of the door;
Patented Mar. 5, 1968 FIG. 4 is a side cross sectional view of the door; and
FIG. 5 is a view of the door taken from inside the washer sterilizer looking out.
Now with more particular reference to the drawing a washer sterilizer 16 is shown having legs 36 and a guillotine type door 14 for closing the door opening of the Washer sterilizer. The washer sterilizer may be of any general type of autoclave such as shown, for example, in Patent 3,086,263. Such a sterilizer is usually made with double wall shells such as walls 18 and 19 and may be joined by a connecting member, such as member 27, having an exposed front surface 27a extending around the fdoor opening. An L-shaped flange 17 could be welded to the side of the washer sterilizer at each sideof the door and another flange 15 above the door as shown. The channels formed by flange 17 define two generally parallel, opposed channels,
one at each side of the door, the channels opening toward each other, through which the door 14 could slide up and down. The channel formed by flange 15 across the top of the door opening downward forms a channel in which the top of the door is restrained. The door can be moved by any suitable moving means, for example, the cylinder 40 having the piston rod 41 extending therefrom which will move the door up and down. The flanges 17 will overlie the sides of the door to limit its outward movement, yet allow it to move freely between the flange 17 and the surface 27a. These flanges 17 must be welded to the washer sterilizer securely enough to withstand the internal pressure which would ordinarily be impressed inside the washer sterilizer against the inside surface of the door 14, in addition to any force applied by the inflatable seal 22. The
upper edge of the door will slide under flange 17 when the door is in closed position.
The door 14 has an inwardly facing groove formed in its surface which extends entirely around the door adjacent its outer edge which receives the inflatable seal 22. The inflatable seal is generally rectangular in cross section and fits into the rectangular groove 12. The groove 12 will be slightly deeper than the uninflated depth of the inflatable seal 22 so that the seal will collapse and be entirely inside the groove when uninflated and, therefore, it will not interfere with the movement of the door.
The part of the seal 22 adjacent the chamber will generally define a half cylinder when expanded and unrestrained. When the door is closed, the seal will engage surface 27 and the cylindrical surface will be distorted to the shape shown in phantom lines at 28.
Beads 43 are formed along each of the sides of groove 12 and they extend into it and overlie the bottom thereof. The seal 22 has two grooves, one on each side of it that extend entirely around the gasket. The part of the seal 22 that is received in groove 12 has an outside surface that is an intaglio of the inside surface of groove 12. Beads 43 are received in the two grooves in seal 22. These beads thus overlie the part of the seal 22 that is received in groove 12 and hold it firmly against removal therefrom.
' The bottom of the door has reinforcing angle 40' across it welded thereto which acts as a beam to prevent the door from buckling when the chamber is under pressure.
In use, when the seal is deflated, the door will have a clearance between the door and the surface 27a so that the door can move toward the surface 27a and lug 41 can move out of notch 42. The door can then be moved freely to open and closed positions by means of a cylinder 40. When the door is in closed position, the hydraulic fluid or air or some other suitable medium can be injected into the hollow 24 of the inflatable seal. This will expand it and it will tend to assume the position indicated vat 48. This will expand the seal 22 and cause it to engage the surface 27a, forcing the door out into engagement with the flange 17, and, thereby, forming a pressure proof seal. between the surface 27a and the door. Lugs 41 will be located in notches 42 and the door will thus be held closed.
'41'will beput in shear and hold the door closed.
The control circuit shown is exemplary of a pressure actuated circuit which can be used to insure that the door is not accidentally opened while the chamber is under pressure. The valve 44 is a pressure actuated four-way valve having a floating spool. The spool floats so that it Will not allow the door to close if pressure fails as would be the case if valve spool were spring loaded. When the pressure is present inside the chamber, the valve will be held in position to keep a pressure on the space below the piston in cylinder '40. When the pressure in the chamber is reduced, the .valve will connect the top of the cylinder to pressure and bleed the pressure from below-the cylinder. Thus, by opening valve 45, the door will be opened. The movement-up and down of the cylinder itself can be controlled by valves 45 and 46 either manually or by remote control. This same pressure invalve 44 can be referenced to line 47 which will connect to the source of pressure to the insideof seal 22. Thus, the door 'cannot move downward so long as the seal 22 is inflated, because of the interlock, until .such time as, the interlock is closed and it points the spool to move laterally. Obviously, an electric switch mechanism could be substituted for the valve The foregoing specification sets forth the invention in its preferred practical forms but the structure shown is capable of modification within a range of equivalents without departing from the invention which is to be understood is broadly novel as is commensurate with the appended claims. I
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. In combination, a chamber and a door, said chamber having a lateral opening therein providing a door opening,
a vertically disposed flange fixed to said chamber along each side of said door defining a channel along each side of said door opening,
said channels facing each other,
said flange across the top of said door fixed to said chamber and defining a channel opening,
said door having its lateral edges slidably "received in said vertically disposed channels, the top edge of said door being slidable into said'downwardlychannel opening, i
means to move said door to open and to closed position,
an inflatable sealing member onfthe inner side of said door on the surface thereof adjacent said chamber and disposed adjacent the outer edges of said door and around said opening,
a lug on's aid door slidable under'saidvertically disposed flanges, and I 'an opening in each said vertically disposed flange receiving said lugs whensai-d'door is closed position and forced outwardly when said seal is inflated,"
said seal making sealing engagement with said chamber around s'aid door. i I i 2. The combination recited in claim 1 wherein said chamber has relatively thick walls comprising an inside shell and an outside shell connected by a connecting member generally parallel to saiddoor, and said door seal makes sealing engagementwith outwardly disposed surface disposed on said connecting member.' V I v 3. The combination recited in claim 1 wherein said groove has an inwardly extending head like flange on each side thereof engaging grooves :in ,said
, sealing member whereby said sealing member is held in saidgroove.
4. The combination recited in claim 1 wherein a member defining a downwardly facing channel is disposed above said opening and attached to said chamher and the top of saiddoor slides into said channel 5 6 when said door is in closed position whereby the top References Cited of said door is prevented from buckling by said rnem- UNITED STATES PATENTS bers defining said channel. 5. The combination recited in claim 4 wherein a rein- 2,358,344 9/1944 Meyer 2198 X forcing beam member is fixed to the bottom of said door 5 2,507,360 5/1950 Wi k 49 477 X and extends from side to side whereby the bottom edge of said door is reinforced against buckling. JAMES H. TAYMAN, JR., Primary Examiner.