Patent Application
20150206678
The present disclosure relates to alarms, fault pressure switches and their components, and more particularly, to a pneumatic detector with an integrated electrical contact.
Pneumatic pressure detectors used for an overheat and/or fire alarm system may use a gas which expands when heated and, as a result, actuates an associated deformable diaphragm to close an electrical switch indicating an alarm condition. Typically, these systems either use multiple deformable diaphragm switches, and/or multiple pressure inputs to operate the system.
The present disclosure relates to an advanced pneumatic detector switch. The advanced pneumatic detector switch may comprise a gas-tight enclosure. The gas-tight enclosure may be coupled to an inlet for operable connection to a pressure side tube. The advanced pneumatic detector switch may comprise a deformable diaphragm coupled within the enclosure configured to make contact with an electrical contact surface in response to an increase in pressure within the gas tight enclosure communicated through pressure side tube. The electrical contact surface may be electrical contact surface coupled to an insulating material. The electrical contact surface may comprise a plated electrical contact surface. The electrical contact surface may pass through a gap coupling a gas-tight enclosure and a back pressure well. The electrical contact surface may be configured to create an electrical path from a deformable diaphragm to a contact side tube.
The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosure, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements.
The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and their best mode. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical changes may be made without departing from the spirit and scope of the disclosure. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step.
The present disclosure relates to the design of a pneumatic detector with an integrated electrical contact configured for use with alarms and fault pressure switches, such as a fire alarm system for an aircraft. Conventional systems use two separate switches and two separate diaphragms to indicate an alarm or fault condition. The pneumatic detection system is typically hermetic and contains a minimum normal pressure which is equivalent to the pressure where the surrounding environment is −65 F, and can set be as desired. This pressure is enough to deform a deformable diaphragm in the fault switch so it will create electrical continuity between the deformable diaphragm and a contact pin in response to an increase in pressure against the diaphragm. Thus, in response to the deformable diaphragm making contact with the contact pin an electrical circuit may be formed and an alarm may be triggered.
An advanced pneumatic detector (“APD”) may be a diaphragm type, pneumatically-powered gate valve actuator designed to operate a “fail-closed” or “fail-open” safety valve. The APD may be configured for thermal detection. APDs may be utilized in wellhead safety valve applications, flow lines, header valves and gathering lines. APDs may be utilized in casing relief valve and storage valve applications. APDs are lightweight, and are generally easy to maintain.
With continued reference to
The insulating material 10 may be configured to separate the retainers 11 and 12 from the contact side tube 13. The material of retainers 11 and 12 may be any suitable material, such as a molybdenum material. The insulating material 10 material may be any suitable material such as a ceramic material (e.g. alumina material). Prior to use in an APD, the contact side of the switch is evacuated the sealed. The switch is evacuated through the contact side tube 13.
According to various embodiments, and with reference to
A few benefits of this approach are to simplify the manufacturing process and improve the robustness of the switch by decreasing the number of failure points. For instance, failures modes include loss of hermeticity and variation of the switching pressure due to changes in the contact pin position. By integrating the contact pin assembly and the ceramic isolator, variations in the switching pressure due to contact pin migration are reduced and/or eliminated.
According to various embodiments, the advanced pneumatic detector alarm switch may comprise a single deformable diaphragm 9 rather than two separate deformable diaphragms to indicate an alarm or fault condition. The advanced pneumatic detector alarm switch may comprise a single pressure input to sense an alarm or fault condition.
Benefits, other advantages, and solutions to problems have been described herein with regard to specific embodiments. Furthermore, the connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and/or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may be present in a practical system. However, the benefits, advantages, solutions to problems, and any elements that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as critical, required, or essential features or elements of the disclosure. The scope of the disclosure is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.”
Systems, methods and apparatus are provided herein. In the detailed description herein, references to “various embodiments”, “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. After reading the description, it will be apparent to one skilled in the relevant art(s) how to implement the disclosure in alternative embodiments. Different cross-hatching is used throughout the figures to denote different parts but not necessarily to denote the same or different materials.
Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112(f), unless the element is expressly recited using the phrase “means for.” As used herein, the terms “comprises”, “comprising”, or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
