Patent Number: 062401548
Section: description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Using the drawings, the preferred embodiments of the present invention will now be explained. FIG. 2 illustrates a first embodiment of the present invention which is an augmented cooling system for a head lift rig (106). As in FIG. 1, the head lift rig (106) is cooled by a forced air system in which cooled air is forced under pressure into the head lift rig (106) through piping (107). The cooled air moves around and cools the Control Element Drive Mechanism (CEDM) (105) and is expelled through exhaust holes (102). However, as shown in FIG. 2, vents (201) are added to the pipes 107. At the top of each of these vents (201) is a self-actuated louver (202). Each of these louvers (202) includes a series of substantially flat, elongated slats arranged parallel to each other across the opening of the vent (201). Each of the slats is freely rotatable about an axis which runs length-wise along each slat. Consequently, the slats may rotate between a closed position in which they lay flat across the vent (201), their edges overlapping such that the vent (201) is blocked, and an open position in which the slats are disposed perpendicular to their closed position so as to allow air to freely exhaust from the vent (201). As the cooled air is forced through the pipes (107), pressure is created by the forced movement of the cooled air. The slats of the louvers (202) are shaped and weighted to respond to this pressure by remaining in the above-described "closed" position so long as the forced flow of cooled air creates pressure. However, if the flow of forced air through the pipes (107) is discontinued for any reason, the pressure caused by that flow will dissipate. When this occurs, the slats of the louvers (202) will, under the influence of gravity, swing into the open position, thereby allowing hot air from the head lift rig (106) to vent and cooler ambient air to enter the head lift rig (106). The cool ambient air may enter through the exhaust holes (102). Alternatively or additionally, a louver (203) may be incorporated into the head lift rig (106). This louver (203) operates in the same manner as the louvers (202), remaining closed so long as forced air is circulating and automatically opening when the pressure caused by such circulating air is removed. Preferably, additional louvers (204) are added to the chamber (103). These louvers may be self-actuated louvers as well, which remain closed so long as the flow of air is maintained. However, when allowed to fall open, the louvers (204) allow cooler ambient air to flow directly into the chamber (103). This air is then heated by the heat in the chamber (103) and rises to escape through louver (203) or the upper louvers (202). This circulation allows the heat in chamber (103) to be quickly dissipated. A second embodiment of the present invention is illustrated in FIG. 3. The system of FIG. 3 is similar to that of FIG. 2. However, instead of the louvers (202), flap valve louvers (301) are used to regulate the vents (201). The flap valve louvers (301) rotate between a first position (301A) and a second position (301B). During normal operation of the cooling system, refrigerated air is forced under pressure through the pipes (107) the pressure of this moving air forces the flap valve louvers (301) into the first position (301A) and holds the louvers (301) in this position. In the first position (301A), the louvers (301) block the vents (201). Should the flow of air be discontinued for any reason, there will be no pressure holding the flap valve louvers (301) in the first position (301A). Under the influence of gravity, the louvers (301) will then fall to the second position (301B). In the second position (301B), the louvers (301) allow hot air from the head lift rig (106) to exhaust out the vents (201) and cooler ambient air to enter the head lift rig (106). The cool ambient air may enter through the exhaust holes (102). As shown in FIG. 3, this embodiment of the invention may also include the louver (203) in the head lift rig (106). However, the louver (203) need not be used, leaving the flap valve louvers (301) to provide ventilation for the head lift rig (106). The preceding description has been presented only to illustrate and describe the invention. It is not intended to be exhaustive or to limit the invention to any precise form disclosed. Many modifications and variations are possible in light of the above teaching. The preferred embodiment was chosen and described in order to best explain the principles of the invention and its practical application. The preceding description is intended to enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims.