US2008741A - Seal for closures - Google Patents

Description

July 23 1935 J. R. ALLAN 2,008,741

SEAL FOR CLOSURES Filed Feb. 5, 1932 2 Sheets-Sheet 1 onHuHHHHHHInIlHHHHnHHHUJlHhha, www .\\\\|.h"..PlhlnluniluvnhhvuHMHJJJ rw. n Il ..\||l|||\|||\l!.t\|||u||i @9021 oooo 6 0@ L d# QW.; wm ww @mi I v I O O O n u July 23, 1935.

J. R. ALLAN SEAL FOR CLOSURES med Feb. s, 1932 2 Sheets-Sheet 2 l MN.

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Patented July 23, 1935 UNITED STATES PATENT GFFICE 2 Claims.

This invention relates to a seal for closures.

More particularly, it relates to an air seal particularly designed for use with the doors, turntables and other closures of sand blast rooms and equipment.

The principal object of the invention is to construct a seal for closures which is substantially air, dust anddirt tight and which is dependable and serviceable in operation.

Another object is to provide an air and dust tight seal which is actuated or placed inoperative relation after a closure is in place in its supporting frame and which is removed from engagement before the closure is removed.

Another important object of the invention is to provide a control means which permits the actuation of the sealing means only when the closures are in closed position.

Another object is to provide in a room or compartment particularly designed for sand blasting, a control for the sand blast air of such a nature that the sand blast can be operated only when the doors and other closures, which are provided with the seals embodying the invention, are in closed position with therseals extended into operative position.

The objects of the invention are accomplishedV by the provision of pneumatic tubes secured to the closure or to the frame which surrounds the closure. The tubes may be tted in suitably formed recesses. The tubes are extensible through the open side of the recesses whereby When inflated they engage the adjacent wall and form a substantially air tight seal. The air pressure for inflating the tubes is supplied from the same air line which is utilized for supplying air for sand blasting equipment. Valves are positioned inthe main air supply line ahead of the branches running to the pneumatic tubes and to the sand blast equipment. These valves are positioned and constructed to be operated by closing the doors and or turntables of the sand blast chamber whereby air cannot be .supplied until the doors and or turntables are closed. A 3-Way valve is positioned in the main line between thek safety valves operated by the closing of the doors and the branches leading to the pneumatic tubes and to the sand blast equipment. This valve is manually operable to cut off the main air supply and tobleed the air from the pneumatic seals, whereby the doors may be opened. It is then impossible, even by actuation of the S-way valve, tovsupply air to either the pneumatic tubes or the sand blast equipment until the doors are again closed.

In the drawings:

Figure 1 shows a wall of a sand blast room or chamber containingl an opening around which a frame work is constructed;

Figure 2 isa sectional View taken on the line 2-2 of Figure 1, showing in addition, in a somewhat diagrammatic manner, the air supply and distribution means for operating the pneumatic seals and the sand blast equipment to be utilized;

Figure 3 is an enlarged sectional View, showing one means for mounting the pneumatic door seals embodying the inventiornthe dotted position showing the tube inflated in its sealing position; and Y Figure 4 is an enlarged sectional View showing a modification of the means for mounting a pneumatic seal of the invention.

Doors I0, carried on hinges II attached to the framework of the main wall, are swingable to open and close the opening therein. These doors may be of any conventional construction, usually being built up of metal plates properly reinforced with angle bars.

As shown in Figure 3, angle bars I2 secured around the plates forming the door, are spaced from the outer edges thereof to provide for mounting the pneumatic tube. A metallic bar I3 substantially circular in cross section, is positioned` in the recess formed by the angle bar I2, the main plate of the door I il, and an angle bar i4 which is a part of the frame surrounding the doors. The member I3 is cut away for substantially 90 of its circumference on the side adjacent the bar I4. A heavy Walled rubber tube I5 is mounted Within the member I3. Said tube, in uninflated condition, has an external diameter substantially the same as the internal diameter of the member I3. The walls of the tube are sumciently thick to hold the tube in substantially circular position when it is vnot inilated and when the interior of the tube is in communication with atmospheric pressure. It will be noted that a substantial clearance is provided between the angle bar I4 and the adjacent wall of the tube I5 when the tube is not inflated. An inflation tube I6 extends through the tube I5, through the member I3, and through the angle bar I2. The modification shown in Figure 4 is substantially the same as that shown in Figure 3. The angle bar I 2 has an extension Il which is substantially parallel to the main plate of the door it). A shaped, Wooden member I8 is iitted into the recess formed bythe door I0, the angle bar I2', and the extension I1. Said member has a bore formed therein substantially circular in cross section, being open on the side adjacent the frame `bar I4. The tube I9, fitted in the member IS, is of the same construction as the tube I5, previously described.- An inflation tube I6 extends through the bar I2 and the member I8, into the tube I9 for inflation thereof.

As shown in Figure 2, the doors, as illustrated,

are so constructed that they come together at theV center. Latch bars 20, pivoted on one door at vertically spaced positions, are connected to gether by an operating bar 2 I. As shown in Figure 2, one of the latch bars 2i! is rigidly secured to a pin 22, which extends through the door. An operating arm 23 is rigidly secured to the pin 22 inside the door, whereby the latch bars may be lifted to open the doors from either within or without the sand blast chamber. The latch bars 20 extend from the door on which they are pivoted, over the edge of the other door. Latches 2Q are provided on said second door with which the bars 2G are engaged when the member 2l is opH era-ted to lock the doors.

A main air supply line 25, as diagrammatically shown in Figure 2, extends into the sand blast room for supplying air under pressure, both for operating the pneumatic seais and for operating sand blast equipment. Tivo exactly similar valves 26 are positioned in series in theair supply line 25. Each valve consists oi the main outer casing and a piston 2l mounted orreciprocation therein. The piston has a connecting rod 23 which extends through the main valve casing and is provided with an engaging head 29, positioned where it will be engaged by closing movement of the door behind which it is positioned. A spring 30, seated against the valve casing and'against a stop place on the connecting rod 23, resiliently urges the connecting rod into an extended position. The piston on said rod is so positioned that When the connecting rod is in extended position the piston will close thevalve against the flow of air. A S-Way valve 3l is positioned in the main air supply line 25 beyond the valves 2S. This valve may be of any conventional construction, having three series of huid communication as illustrated by the pipes 32, 33 and t4. The valve is so constructed and operated that air flow may be provided for from the pipe 32 to the pipe 33 or from the pipe 33 to the pipe 34. Beyond the bypass valve 3l a B-way connection 36 is provided by which the air pressure from the pipe 33 is' communicated at all times to a conduit 37 and a conduit 38. The conduit Si is connected to a valve 39, which is in turn connected to a conduit 4U, which delivers to the sand blast equipment to be utilized. The conduit 38 is connected by a 3-way connecting member il to conduits 52 and 43. These conduits, as well as the other conduits illustrated, are flexible, that is, they may be constructed of conventional high pressure rubber tubing. The conduits /iZ and i3 are connected to the inflation tubes I6.

In operating the seals, as described above, and the air supply system associated. therewith, air is supplied to the line 25 under a suitable regulated pressure. Assuming that the doors are in open position and that all arrangements have been made within the sand blast chamber for performing blasting Work, the operator enters the compartment, closes the doors il? and locks them in closed position by operation of the control handle 23. W hen the doors swing into closed position their inner sides engage the connecting rods 23 and open the valves 26 to the flow of air therethrough. The 3-way valve 3l is then operated to permit air fiow from the pipe 32 to the pipe 33. Air pressure is then transmitted through the conduit 38 and the conduits l2 and d3 to the pneumatic tubes l5. Said tubes upon inilation are extended to the conduit line position shown in Figures 3 and 4, whereby a substantially air and dust tight air seal having an appreciable contact area, is obtained. The operator may then by acrtuation of the valve 39, supply air to his sand blast equipment.

When the work within the sand blast chamber has been nished, the operator may either turn oi the valve 3s first or he may merely actuate the `eway valve 3i. When the valve 3i is operated to cut ofi the supply of air pressure and to put the pipe 3S in communication with the blow off pipe 353, air pressure is relieved from the Vpneumatic tubes i5, and they take their cylindrical shape in spaced position away from the contacting Walls. The doors may then be unlatched and opened.

It will be noted that in the particular embodiment ofthe invention illustrated, the tivo adjacent tubes at the center where the two doors come together, engage each other upon inflation. This is a particular feature of the construction, as the same principle may be utilized wherever a plurality of closure members are utilized or any reason. As shown in Figure l, the corners of the doors are rounded to permit the use oi relatively long radius curves on theY elbows necessary in the pneumatic tubes. It has been found that the long radius curves at the corners permit a construction by which a better it may be obtained. The only requirement is that the frame around the doors or closure members, have an abutting surface adjacent the` pneumatic tubes of the same general shape and in slightly spaced relation thereto to prevent any binding or rubbing action when the closures are placed into or removed from position.

lt is to be understood that applicanthas shown and described only certain preferred embodiments of his improved pneumatic seal and that he claims as his invention all modications falling within the scope oi the appended claims.

What is claimed is:

1. A pneumatic seal for sand blast rooms and equipment comprising, in combination With a wall having an opening formed therein and a frame surrounding said opening, a door hinged to said frame and swingable to a closed position against the frame, thereby substantially closing said opening, an endless resilient tube surrounding the door and secured thereto, said tube being positioned between a portion of the door and a portion of the frame, means to inflate said tube whereby it is extended into contact with the frame, thereby forming a substantially air and dust tight seal, means operative to permit the inflation of said tube only whentheA door is in closed position, and further means operatively interlocked with the door to operate the sand blast equipment only when air is supplied to the sealing tube.

2. A pneumatic seal for sand blast rooms and equipment comprising, in combination with a wall having an opening formed therein and a frame surrounding said opening, a door hinged to said frame and swingable to a closed position against the frame, thereby substantially closing said opening, an endless resilient tube surrounding the door and secured thereto, said tube being positioned between a portion of the door and a portion of the frame and being tree from contact with the frame during swinging of the door, means to inflate said tube whereby it is extended into contact with the frame, thereby forming a substantially air and dust tight seal, means operative to permit the inflation of said tube only when the door is in closed position, and further means operatively interloclred with the door to operate the sand blast equipment only when air is supplied to the sealing tube.

JAMES R. ALLAN.

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