An adjustable chock is provided with a first component having screw threads, a second component having screw threads cooperating with the screw threads of the first component and having a lower bearing surface, and with a bearing element provided with a lower bearing surface in contact with an upper bearing surface of the first component, and with an upper bearing surface. At least one of the lower bearing surface of the second component and the upper bearing surface of the bearing element is provided with a coating having a coefficient friction higher than that of the associated bearing surface.

An aircraft assembly including a wing component and an engine mounting pylon component. The wing component has three fastening locations arranged in a triangle and a plane. The engine mounting pylon component is connected to the wing component by three tension fasteners, wherein each of the tension fasteners passes through a different one of the fastening locations. The wing component comprises three first spherical surfaces positioned such that the center of each first spherical surface is at a different one of the fastening locations. The engine mounting pylon component comprises three second spherical surfaces having equal and opposite curvature to the first spherical surfaces. Each of the second spherical surfaces is in contact with a different one of the first spherical surfaces.

An aircraft assembly including a wing component and an engine mounting pylon component. The wing component has three fastening locations arranged in a triangle and a plane. The engine mounting pylon component is connected to the wing component by three tension fasteners, wherein each of the tension fasteners passes through a different one of the fastening locations. The wing component comprises three first spherical surfaces positioned such that the center of each first spherical surface is at a different one of the fastening locations. The engine mounting pylon component comprises three second spherical surfaces having equal and opposite curvature to the first spherical surfaces. Each of the second spherical surfaces is in contact with a different one of the first spherical surfaces.

A kit includes an adjustable chock provided with a first component having screw threads and with a second component having screw threads cooperating with the screw threads of the first component and having a lower bearing surface, and with a bearing element provided with a lower bearing surface in contact with an upper bearing surface of the first component, and with an upper bearing surface. The kit further includes at least one friction ring adapted to be mounted against the lower bearing surface of the second component or against the upper bearing surface of the bearing element.

A locking device adapted to lock a shell to an installation body includes a thread connection member extending through a connecting hole in the shell and engaging a threaded hole in the installation body, a sealing ring sleeved on the thread connection member and adapted to be pressed on an installation surface of the shell to seal the connecting hole of the shell, and a gasket sleeved on the thread connection member and adapted to be pressed between the thread connection member and the sealing ring to prevent the thread connection member from being loosened. The gasket has a pair of stopping arms. An angle defined between the stopping arms is greater than 0 degrees and less than 180 degrees. A pair of top ends of the stopping arms are adapted to simultaneously abut against an outer wall of the shell to prevent the gasket from rotating with the thread connection member.

A locking device adapted to lock a shell to an installation body includes a thread connection member extending through a connecting hole in the shell and engaging a threaded hole in the installation body, a sealing ring sleeved on the thread connection member and adapted to be pressed on an installation surface of the shell to seal the connecting hole of the shell, and a gasket sleeved on the thread connection member and adapted to be pressed between the thread connection member and the sealing ring to prevent the thread connection member from being loosened. The gasket has a pair of stopping arms. An angle defined between the stopping arms is greater than 0 degrees and less than 180 degrees. A pair of top ends of the stopping arms are adapted to simultaneously abut against an outer wall of the shell to prevent the gasket from rotating with the thread connection member.

A precision adjustment fastener mechanism comprises a base, a platform, and a locking push-pull fastener assembly. The base has a first aperture and the platform has a second aperture. The fastener assembly is disposed within the second aperture. The fastener assembly comprises a clamping fastener having a portion positioned in the first aperture, a sleeve having a third aperture extending along an axis of the sleeve. The clamping fastener is positioned within the third aperture. The sleeve comprises a first portion moveable relative to a second portion along the axis. The first portion and the second portion each comprise outer threads. An axial displacement portion separates the first and second portions and transmits a torque between the first and second portions. The axial displacement portion facilitates movement of the first and second portions to bind threads of the first and second portions with the threads of the platform.

An assembly is disclosed including a first component, a second component, and a spacer component. The first component has a first interface surface. The second component has a second interface surface with a curvature different to the curvature of the first interface surface. The second component is connected to the first component such that the second interface surfaces faces the first interface surface. The spacer component is disposed between the first interface surface and the second interface surface and is configured to be pivotable relative to the first interface surface.

A fastening system has two fastening elements for mounting a bracket of a rail system of an elevator installation. The fastening elements each have a clamping plate having a through-hole and a receiving sleeve receiving an anchor bolt. The receiving sleeves each have a through-opening for the anchor bolt and an angularly movable ball joint is formed between the clamping plate and the receiving sleeve.

Herein disclosed is a fall-proof component for a screw, comprising: a first structure configured to act on a portion of the screw to stop the screw; and a second structure configured to be fitted and latched onto a part which is to be fixed by the screw; wherein the first structure and the second structure cooperate with each other to prevent the screw from falling and the fall-proof component is configured to be adapted to be disposed adjacent to a head of the screw in a fitted status. Also disclosed are a corresponding fall-proof screw assembly, a corresponding fall-proof screw-nut assembly, a corresponding part suitable for the fall-proof screw assembly, a corresponding combination structure and a corresponding assembly. According to the disclosure, the fall-proof component has a simple structure and a low cost and can be reusable.