Abstract: A speculum for dilating a body cavity includes a base and a number of arms pivotably attached to the base. There is an actuator movably attached to the base for causing each of the arms to move relative to each other from a closed position to an opened position so that a body cavity can be smoothly opened after the arms have been inserted into the body cavity.

Abstract: A speculum for dilating a body cavity includes a base and a number of arms pivotably attached to the base. There is an actuator movably attached to the base for causing each of the arms to move relative to each other from a closed position to an opened position so that a body cavity can be smoothly opened after the arms have been inserted into the body cavity.

Abstract: An air tight shutter is provided having a set of pre-made bifold doors in conjunction with a frame wherein the shutters are manufactured to have tight tongue-in-groove reception area not only with respect to the bifold doors but also with respect to the bifold doors and frame. A burglar proof latch mechanism is provided such that a ball crank is turned by means of a handle thereby withdrawing elongated rod-like members from the frame section which then permits the bifold doors to open, or in the alternative, the ball crank is turned in the opposite direction causing the elongated members to penetrate an aperture in the frame and thereby lock the shutters in place. An assembly method for producing the shutter is also disclosed, along with the machinery particularly adapted for said assembly method. The machinery disclosed achieves the close tolerance required in assemblying of the shutter.