Airlock Construction

Abstract

An airlock housing having opposed doors with a normally closed locking device cooperable with one door, the locking device being operable to open position through an actuating arm cooperable with the opposite door when the opposite door is moved to closed position.

Description

BACKGROUND OF THE INVENTION

The present invention relates to an airlock construction and more particularly to a sequential closure arrangement for opposed doors of an airlock compartment. Airlocks are utilized in various environmental air control situations to interconnect the interior of a compartment or room with the exterior of such compartment or room. Access to an airlock is usually provided by doors at either end with an interlock system to prevent the doors from being opened at the same time.

Various airlock constructions have been utilized in the past to provide such a door interlock system. For the most part, these past constructions have proven complex and expensive in erection and maintenance, requiring a multitude of parts and a series of operations without necessarily ensuring efficient positive action.

SUMMARY OF THE INVENTION

The present invention provides a new and useful airlock construction which is straightforward and efficient in construction and operation, requiring a minimum of parts and providing efficient positive action of the locking arrangement with a minimum of effort.

Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.

More particularly, the present invention provides an improved airlock construction comprising: an airlock housing having opposed door openings at opposite extremities of the housing; opposed doors pivotally mounted on the housing in cooperative relation with the door openings; door latch strike means fixed to one of the door; door latch means pivotally mounted to engage the strike means to lock the one door when the one door is in closed position; actuating rod means connected at one end to the door latch means; spring means cooperating with the actuating rod means to urge the actuating rod means in a first direction to pivot the door latch means into locked position with the strike means; the actuating rod means being sized to extend through the opposite door opening when the door latch means is in locked position with the door strike to be engaged by the opposite door when the opposite door is moved to closed position to urge the actuating rod means in an opposite direction against the spring means to pivot the door latch means into unlocked position with the door strike means. In addition, the present invention provides an arrangement wherein the actuating rod means is sized to extend through one of the doors to indicate the relative position of the opposite door.

It is to be understood that various changes can be made in the arrangement form and construction of the apparatus disclosed herein without departing from the scope or spirit of the present invention.

Referring to the drawing which discloses one advantageous embodiment of the present invention:

FIG. 1 is a broken plan view of a portion of the ceiling of an airlock housing which incorporates the improved airlock construction of the present invention, the door latch being shown in closed position;

FIG. 2 is a side elevational view of the door latch portion of the apparatus of FIG. 1; and,

FIG. 3 is a plan view of a portion of the apparatus of FIG. 1 disclosing the door latch in open position.

As can be seen in FIG. 1 airlock housing 2 is disclosed, having opposed door openings 3 and 4 at opposite extremities of housing 2. Pivotally mounted on housing 2 in a suitable manner (not disclosed) to cooperate with opposed door openings 3 and 4 respectively are opposed doors 6 and 7.

Fixed to the one door 6 is door latch strike 8, a suitable spacer bar 9 extending between door latch strike 8 and the inner face of door 6. Adapted to cooperate with door latch strike 8 is a door latch 11. Latch 11 can be in the form of an angle pivotally mounted at its apex to arm 12 extending normally from support block 13 which in turn is fixed to housing 2. A suitable slot 14 is provided in door latch 11, the slot 14 engaging with door latch strike 8 when the door latch 11 is pivoted to closed position.

An actuating rod member 16 which extends the length of housing 2, is connected at one end to door latch 11. Advantageously, this connection is accomplished by threading one end of actuating rod 16 as at 17, the threaded end of the actuating rod engaging in internal threads of rod adjusting block 18 which in turn is mounted on door latch 11. It is to be understood that the connection of actuating rod 16 to door latch 11 is accomplished with sufficient tolerance to accommodate for the swinging movement of the door latch about pivot arm 12 without effecting any linear movement of actuating rod 16.

In accordance with the present invention, actuating rod 16 is sized in length so that the opposite end 19 thereof passes through the opposite door opening 4 when the door latch 11 is in locked position with door latch strike 8 to be engaged by opposite door 7 when opposite door 7 is moved to closed position. This causes actuating rod 16 to be moved in an opposite direction to pivot the door latch 11 into unlocked position relative door strike 8.

As will be noted in FIG. 1, spring 21 in the form of a helical coil is disposed within guide member 22 to cooperate with actuating rod 16. Guide member 22 which can be in the form of a U-shaped saddle has its base leg fixed to housing 2. Opposed apertures are provided in the opposed side legs of guide 22, the rod member extending therethrough. The spring member which, as aforementioned, is in the form of a helical coil is positioned between the opposed legs of the guide member 22. A suitable stop 24 is provided on the actuating rod member to be engaged by an extremity of the helical coil. Accordingly, when door 7 is in open position, spring 21 urges actuating rod 16 in such a direction as to cause door latch 11 to engage in locking position with door latch strike means 8 to lock door 6.

Still another feature of the present invention is the provision of guide 26 in the form of a tubular member fixed to housing 2 with its longitudinal axis in alignment with the longitudinal axis of actuating rod 16 to slidably receive an extremity thereof. An aperture 27 is provided in door 6 of housing 2 to be in communication with tubular member 26. The actuating rod 16 is sized to extend through aperture 27 when opposite door 7 is moved to closed position to indicate this fact to someone on the other side of door 6. It is to be understood that sufficient clearance is provided between the aperture 27 and rod 26 to permit free movement of door 6. It also is to be understood that a suitable spring (not shown) can be utilized in tubular member 26 is so desired.

In a typical operation an electrical interlock (not disclosed) can be provided to permit door 7 to be opened. When open, door latch 11 engages with strike 8 to lock door 6. The entrance door 7 must be closed before door 6 can be opened. When door 7 is so closed, the end of actuating rod member 16 projecting through aperture 27 can be readily visible to someone on the other side of door 6. Suitable provisions (not shown) can be made to ensure by electrical interlock that door 6 be closed before allowing the cycle to be repeated.

Claims

The invention claimed is:

1. An improved airlock construction comprising: an airlock housing having opposed door openings at opposite extremities of said housing; opposed doors pivotally mounted on said housing in cooperative relation with said door openings; door latch strike means fixed to one of said doors; door latch means pivotally mounted to engage said strike means to lock said one door when said one door is in closed position; actuating rod means connected at one end to said door latch means; spring means cooperating with said actuating rod means to urge said actuating rod means in a first direction to pivot said door latch means into locked position with said strike means; said actuating rod means being sized to extend through said opposite door opening when said door latch means is in locked position with said door strike means to be engaged by said opposite door when said opposite door is moved to closed position to urge said actuating rod means in an opposite direction against said spring means to pivot said door latch means into unlocked position with said door strike means.

2. The apparatus of claim 1, said door latch means being pivotally mounted to said housing and guide means for said actuating rod means, said guide means being mounted to said housing to guide said rod means in lineal movement along its longitudinal axis.

3. The apparatus of claim 2, said spring means being in the form of a helical coil disposed within said guide means to cooperate with said actuating rod means.

4. The apparatus of claim 2, said guide means including an open end tubular member fixed to said housing with its longitudinal axis aligned with the longitudinal axis of said actuating rod member to slidably receive an extremity thereof; one of said doors having an aperture therein in communication with said tubular member; said actuating rod means being sized to extend through said aperture when said opposite door has been moved to closed position to so indicate this fact.

5. The apparatus of claim 2, said guide means being in the form of a U-shaped saddle with its base leg fixed to said housing and having opposed apertures in opposed side legs through which said actuating rod means extends; said spring means being in the form of a helical coil disposed between said opposed side legs; said actuating rod means having a stop extending therefrom to be engaged by said helical coil.