Description:1 Title of invention
Mechanical stay mechanism for aircraft panel.
2 Field of invention
The present invention relates to aircraft structural engineering in general and more particularly to construction and operation of daily inspection panels of an aircraft. The present invention is an embodiment to the service panel of aircraft structure where the aircraft service panels are frequently accessed, operated and maintained during aircraft inspection or servicing on day to day basis or accessed, operated and maintained during aircraft servicing on need basis. The aircraft service panels form the part of aircraft structure that provide access to aircraft servicing accessories.
3 Background of invention
A typical aircraft is provided with the aircraft service panels that needs to be designed to have features like ease of accessibility, good maintainability, and high reliability. Most of these aircraft service panels accessed during daily inspection are provided on the aircraft structure that generally have hinged covers with quick release fasteners.
In some of the conventional aircraft, few service panels which are required to be serviced by ground support equipment (GSE) house line replaceable units, adaptors and other accessories that needs to be accessed after each sortie and shall cater to spring loaded hinge mechanism which continuously “stays” in open position after opening the service panel. However, due to the frequent operation of the above panel, the effectiveness of the spring hinge gradually decreases leading to sagging of the panel over the period of time which ultimately causes safety issues and also inhibit coupling or mating of ground support equipment (GSE) adaptor. These aircraft service panels are designed with spring hinge-trigger lock mechanism for quick opening and closing of the panel. Spring hinge failure in these aircraft panels may lead to safety and maintainability issues. Consequently, leading to additional cost due to the replacement of spring hinge and also resulting in increased aircraft down time.
In the prior art pertaining to aircraft panel system, a spring hinge mechanism was used. The drawbacks of the prior art include:
a. it has limited life cycle;
b. it does not ensure the mechanical integrity of the panel for the full life cycle of the aircraft;
c. sagging of the panel due to the weakening of the spring hinge which leads to partial access to line replaceable units, thereby, hindering complete access and poor aircraft maintenance;
d. checking of hinge and trigger locks each time increases inspection time before each sortie. Degradation in effectiveness of spring action is difficult to quantify during daily inspections and is predominantly subjective, leading to high vulnerability; and
e. the overall reliability of spring hinged mechanism is low.
4 Summary of the present invention
The primary objective of the present invention is to provide a reliable, durable, efficient, and simple mechanical stay mechanism for aircraft service panels so as to enable ease of access and maintenance. In cases of small aircraft panels, with more space required for adaptor interface, it is difficult to integrate elaborate stay mechanism due to space constraints.
The present invention uses link rod stay mechanism, which is hinged at bracket-spring hinge and positioned at the edge member location in the open position of the panel. It ensures that the panel opens at desired angle of opening (90deg) consistently without sagging of the panel and would not compromise safety and accessibility. This mechanism does not occupy any space in the system maintenance area. The mechanical stay mechanism for aircraft service panels is mainly comprising of a panel (104) that is having two trigger locks (105) and a piano hinge (106) along with a link rod mechanism (100). This mechanical stay mechanism is simple to operate. The aforementioned elements of the invention aid in clear and consistent access with the help of simple link rod mechanism. This improves the overall maintainability and reliability of the panels. Safety aspects in flight operation is completely mitigated in this scheme.
5 Brief description of drawings
Fig.1 illustrates a closed position of aircraft service panel (104) with typical mechanical link rod mechanism (100) placed at identified location and mainly comprising of link rod (101), hinge bracket (102) secured to piano hinge(106) of panel (104) assembly.
Fig.2, illustrates an open position of aircraft service panel (104) with typical mechanical link rod mechanism (100) placed at identified location and mainly comprising of link rod (101), hinge bracket (102) secured to piano hinge(106) of panel (104) assembly.
Fig.3, illustrates the sectional view of the panel (104) assembly in open position.
6 Detailed description of invention
An aircraft structure is provided with a plurality of service panel (104) assemblies on predetermined locations of aircraft structure. These panels are used for accessing of aircraft line replaceable units, adaptors for ground support equipment, and other accessories that are required for aircraft servicing and periodic inspection. The present invention is a mechanical stay mechanism (100) which is embodied to the aircraft service panel (104). The elements of the mechanical stay mechanism (100) mainly comprises of: a link rod (101), a hinge bracket (102), and a spring clip (103) mounted in inner surface of the aircraft panel(104) along with a piano hinge(106). The aircraft panel (104) also consists of a plurality of trigger locks (105) positioned at suitable locations. Refer, Fig.1.
The link rod (101) is a simple mechanical component with circular end for locking the panel (104) and also it provides the stiffness for the panel (104) assembly. The hinge bracket (102) is a housing for securing the link rod (101) in the spring clip (103) which is located in the hinge bracket (102). It also provides the rigidity for the panel (104) assembly in open position. The spring clip (103) is made up of a spring material and it is riveted with the hinge bracket (102). It is used for locking the panel (104) assembly with the link rod (101) at the hinge bracket (102) housing.
This typical panel (104) is provided with the two trigger locks (105) and the piano hinge (106) along with the link rod mechanism (100). The link rod (101) is secured with fasteners in the panel (104) at closed position. The hinge bracket (102) housing is fastened with fixed structure. The operator needs to un-toggle the trigger locks (105) for unlocking the panel (104) from the closed position. The panel (104) can be opened through hinged axis in the piano hinges (106) which is attaching both the fixed and removable part of the panel (104). When the panel (104) is opened to completely about 90deg, the link rod (101) will slide in to the spring clip (103) and gets mechanically locked at the hinge bracket housing and the panel(104) stays in the open position without any additional aid. With the above steps, the panel (104) assembly can be secured at open position for the inspection of aircraft systems and maintenance activities.
After completion of aircraft servicing or inspection activities, the panel (104) is pushed downwards by the operator, manually, to unlock the link rod (101) from the spring clip (103) at the hinge bracket (102) location. Finally, the panel (104) assembly should be closed with the trigger locks (105). This entire process will ensure the locking and unlocking of the panel (104) assembly by a single operator. The invention is self-sufficient and can be used for ground maintenance and inspection checks. This mechanical stay mechanism for aircraft panel ensures the secured and reliable operation of the aircraft panel (104) without any additional aid and can be operated by a single operator. This mechanism also enables easy method for accessing the aircraft maintenance components and with better reliability.

7 Drawing Numerals:
Sl.No. Description
100 Mechanical stay mechanism
101 Link rod
102 Hinge bracket
103 Spring clip
104 Panel
105 Trigger lock
106 Piano hinge , Claims:We claim:
1. A mechanical stay mechanism(100) for aircraft panel, embodied to the aircraft service panel (104) on the structure of the aircraft, the panel (104) is provided with a piano hinge (106) and a plurality of trigger locks (105), characterized in that, the stay mechanism (100) comprises:
? a hinge bracket(102) secured to the piano hinge(106) of the panel (104) ;
? a spring clip(103) housed within the hinge bracket (102); and
? a link rod(101) with a circular end for locking, such that, the link rod(101) is secured with fasteners to the panel(104), the hinge bracket (102) houses the spring clip(103) fastened to fixed structure of panel(104), the link rod(101) slides into the spring clip(103) and gets mechanically locked and stays in that position for open condition of the panel (104) that the panel (104) is opened through the hinged axis of the piano hinge (106) by operating the trigger locks (105), and the aircraft service panel(104) is pushed downwards manually to close the panel (104) such that the link rod (101) gets unlocked from the spring clip(103) at the hinge bracket (102) location.
2. The mechanical stay mechanism(100) for aircraft panel, as claimed in claim 1, wherein, when the panel (104) is opened to completely about 90 deg, the link rod (101) slides in to the spring clip (103) and gets mechanically locked at the hinge bracket housing and the panel(104) stays in the open position without any additional aid, thereby, the panel (104) assembly is secured at open position for the inspection of aircraft systems and maintenance activities.
3. The mechanical stay mechanism(100) for aircraft panel, as claimed in claims 1-2, wherein, after completion of the aircraft servicing or inspection activities, the panel (104) is pushed downwards by the operator, manually, to unlock the link rod (101) from the spring clip (103) at the hinge bracket (102) location, the panel (104) assembly is closed with the trigger locks (105), thereby, the mechanism (100) ensures the locking and unlocking of the panel (104) assembly by a single operator.