Field of the Invention
The present invention relates to a mouthpiece valve for breathing equipment and more particularly to a mouthpiece valve which can be locked in a closed position prior to use and subsequently unlocked by a single motion of the user when the breathing equipment is to be used.
Background of the Invention
Mouthpiece valves for breathing equipment typically employ two pins directly connected to the valve disc. The valve disc is moved along the axis of the valve stem by the user's lips in order to open the valve. The two pins are in turn displaced by the movement of the valve disc. Such a mouthpiece valve is shown in U.S. Pat. No. 4,090,511. The disadvantage with this device is that there is no means of preventing premature movement of the pins and disc and thus the opening of the valve since the pins can be axially displaced at any time prior to the intended opening of the valve. The resultant unintended opening of the valve is particularly undesirable for two reasons. First, it is possible to expend an indeterminate portion of the air stored in the breathing equipment. Also, the user may be unaware of this escape because the valve disc may subsequently be returned to the closed position, thereby concealing the escape. The user would then have only a fraction of the anticipated capacity of the breathing equipment available for use. Secondly, if the mouthpiece valve is used in breathing equipment which is deployed underwater, when the valve disc moves water can flow through the valve into the breathing equipment. If the breathing equipment uses a chemical canister, this could render it unusable.
It would be desirable therefore to provide a mechanism for reliably locking the mouthpiece valve in the closed position during storage and transport so that the user can be assured that the first time valve is opened is when the user intentionally opens it during use. Furthermore, the locking means should be able to be quickly and easily unlocked, preferably in a single motion by the user, at the desired time when the breathing equipment is to be used.
Summary of the Invention
Generally the present invention relates to a mouthpiece valve for breathing equipment which is opened by a user with his lips by moving a flange member mounted on the mouthpiece. The flange member is connected to a valve stem which is in turn connected to a valve disc so that when the flange member is moved, the valve stem and valve disc move axially thereby opening the passageway to the breathing equipment. To prevent premature opening of the valve, movement of the valve stem is initially prevented by the placement of two tapered pins in a cover of the valve casing with their narrow ends abutting a connecting member connected to the valve stem. The pins are in turn secured by a safety bridge placed in contact with the wide end of the tapered pins. The safety bridge straddles a short length of cord by which cord a nose clip is connected to the cover of the mouthpiece valve, so that when the nose clip is put on by the user, the safety bridge is displaced by the cord, thereby allowing the tapered pins to fall free and enabling the valve stem and valve disc to move axially.
Other details, objects and advantages of the present invention will become readily apparent from the following description of a presently preferred embodiment thereof.
Brief Description of the Drawings
In the accompanying drawings, a preferred embodiment of the present invention is illustrated by way of example only, wherein:
FIG. 1 is a side view of the present invention, in elevation and with a portion of the valve casing cut away, and with the valve locked in the closed position;
FIG. 1a is a section taken parallel to the elevation of FIG. 1, and at the centerline of the present invention, with the valve locked in the closed position;
FIG. 1b is a section of the present invention taken perpendicular to those of FIGS. 1 and 1a, at the centerline of the invention;
FIG. 2 is a front view of the present invention shown in FIG. 1 showing the safety bridge positioned on the knob, the safety strip over the cap of one of the tapered pins and the nose clip disposed on a cord, which cord is inserted in a slot in the safety bridge;
FIG. 2a is a front view of the present invention with the safety bridge, tapered pins, safety strip, nose clip and cord all removed;
FIG. 3 shows the knob portion of the mouthpiece valve on which the slotted safety bridge is placed;
FIG. 4 shows one of the tapered pins; and
FIG. 5 shows the slotted safety bridge.
Description of the Preferred Embodiment
As shown in FIGS. 1, 1a and 1b, the mouthpiece valve comprises a valve casing 1, a cover 2 which closes the casing 1, two movable pins 3 extending outwardly from the casing 1 and mounted in the cover 2 for axial movement therein, and a connecting member 4 disposed within the cover 2 and at the end of the pins 3 and which is substantially perpendicular to and connects the two pins 3. The pins 3 each project into the interior of the valve casing 1. The mouthpiece valve further comprises a valve stem 5 disposed perpendicular to and concentrically with a valve disc 6 and parallel to and between the two moveable pins 3, with one end abutting the connecting member 4 and the other end abutting the valve disc 6, which valve disc 6 is loaded by a spring 10 and to which a resilient plate 11 is permanently attached. The resilient plate 11 is in contact with a valve seat 9 when the mouthpiece valve is in the closed position. A flange member 7 is permanently disposed on the ends of the moveable pins 3 which project from the valve casing 1 and travel axially (direction "A" in FIG. 1) along a cylindrical portion of the casing 1 which terminates in a mouthpiece 8.
When the mouthpiece valve is in the closed position, the valve seat 9 in the valve casing 1 is closed so that no air can pass from the breathing equipment (not shown) through tube 13 and access opening 12 and through the breathing valve, thereby preserving the supply of breathing air in the breathing equipment.
To keep the mouthpiece valve in the closed position until the user intends to open it, the valve disc 6 and resilient plate 11 must be locked to the valve seat 9 and the connecting member 4 must be locked to the pins 3 and flange member 7 in such a way that these components are prevented from moving axially (direction A in FIG. 1). To achieve this, two tapered pins 14 (see FIG. 4) are loosely inserted into cover 2 so as to abut connecting member 4 (see FIG. 1) and are secured by safety bridge 15 (see FIG. 5) whose central slotted recess 16 is placed on pin 18 of knob 19 (see FIG. 3) of cover 2 in such a way that the convex caps 20 formed on the wide end of tapered pins 14 are resiliently engaged by circular holes 17 of the safety bridge 15. To ensure that the mouthpiece valve has not been opened and the contents of the breathing equipment depleted, a seal in the form of a safety strip 21 (see FIG. 2) is stuck over one of the circular holes 17 of the safety bridge 15.
When the breathing equipment is put into operation it is necessary, preferably in one motion, to unlock the flange member 7 so that the valve disc 6 and resilient plate 11 can immediately be moved to the open position. To do this, the user puts on a nose clip 22, which is securely connected to the safety bridge 15 with a cord 23 disposed on the casing 1 and inserted into a slot 24 in the safety bridge 15 before the safety bridge is placed on the pin 18 of knob 19. In the process of putting on the nose clip, the safety bridge 15 is removed and the two tapered pins 14 are moved out of the locked position, breaking the safety strip 21. The tapered pins 14 fall out of the cover 2 and the flange member 7 can now freely be moved axially (in direction "A") by the user's lips, thereby opening the mouthpiece valve.
The advantage of this arrangement is that the mouthpiece valve reliably remains in a closed position while packed and not in use. Until the breathing equipment is put on, it cannot be unlocked and opened without the additional operation of putting on the nose clip 22. Advantageously, to ensure that the mouthpiece valve is automatically unlocked and put in the operating position when the nose clip 22 is put on, the length of the cord 23 securing the nose clip is such that the nose clip 22, hanging down from the back of the valve, is disposed in the angle of view of the wearer and below the safety bridge 15.
While a presently preferred embodiment of practicing the invention has been shown and described with particularity in connection with the accompanying drawings, the invention may otherwise be embodied within the scope of the following claims.