Propeller assembly pitch change apparatus
First Claim
1. A pitch change apparatus for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly, the apparatus comprising:
- a unison ring which is coaxial with the propeller assembly, the unison ring being movable to drive respective mechanisms for varying the pitch of the blades, anda plurality of pitch lock assemblies circumferentially distributed around the unison ring;
wherein each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades, the pitch lock assembly moving from the free to the locked state when the assembly receives a signal to lock the blades.
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Accused Products
Abstract
A pitch change apparatus is provided for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly. The apparatus has a unison ring which is coaxial with the propeller assembly. The unison ring is movable to drive respective mechanisms for varying the pitch of the blades. The apparatus further has a plurality of pitch lock assemblies circumferentially distributed around the unison ring. Each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades. The pitch lock assembly moves from the free to the locked state when the assembly receives a signal to lock the blades.
9 Citations
20 Claims
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1. A pitch change apparatus for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly, the apparatus comprising:
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a unison ring which is coaxial with the propeller assembly, the unison ring being movable to drive respective mechanisms for varying the pitch of the blades, and a plurality of pitch lock assemblies circumferentially distributed around the unison ring; wherein each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades, the pitch lock assembly moving from the free to the locked state when the assembly receives a signal to lock the blades. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 20)
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9. A pitch change apparatus for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly, the apparatus comprising:
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a drive element movable to drive respective mechanisms for varying the pitch of the blades, and a plurality of pitch lock assemblies, each pitch lock assembly having a free state which allows movement of the drive element and a locked state which limits movement of the drive element and thus limits variation of the pitch of the blades, the pitch lock assembly moving from the free to the locked state when the assembly receives a signal to lock the blades; wherein each pitch lock assembly has a respective connection member which joins the pitch lock assembly to the drive element, the connection members allowing a predetermined amount of movement of the drive element relative to the connection members, the predetermined amount of movement corresponding to a predetermined amount of variation in the pitch of the blades, so that, in the free state, the pitch lock assemblies allow movement of the connection members and hence allow movement of the drive element, and, in the locked state, the pitch lock assemblies prevent movement of the connection members relative to the pitch lock assemblies and hence limit the drive element to the predetermined amount of movement.
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10. A pitch change apparatus for a propeller assembly having a row of propeller blades which rotate around an axis of the assembly, the apparatus comprising:
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a unison ring which is coaxial with the propeller assembly, the unison ring being movable to drive respective mechanisms for varying the pitch of the blades, and a plurality of pitch lock assemblies circumferentially distributed around the unison ring; wherein each pitch lock assembly has a free state which allows movement of the unison ring and a locked state which prevents or limits movement of the unison ring and thus prevents or limits variation of the pitch of the blades, the pitch lock assembly moving from the free to the locked state when the assembly receives a signal to lock the blades, wherein each pitch lock assembly has a respective connection member which joins the pitch lock assembly to the unison ring so that, in the free state, the pitch lock assemblies allow movement of the connection members and hence allow movement of the unison ring, and wherein, in the locked state, the pitch lock assemblies prevent movement of the connection members relative to the pitch lock assemblies and hence prevent or limit movement of the unison ring. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification