Abstract: A tamper-proof device is provided for lockingly attaching a piece of equipment such as a TV set or a microwave oven to a support base. It has a pair of rigid plates that are respectively connected to the piece of equipment and the support base. One of the plates is surrounded by a flange which defines a closed area in which wedges are located to hook both plates together. The two plates are rigidly connected to each other by a screwable bolt that can be reached with a screw driver through a coaxial opening provided in the flange. A sleeve extends in between the head of the bolt and the opening. This sleeve can be closed by key-operated lock in order to prevent access to the bolt. The lock is free to rotate within the sleeve even when its latch is locked in outward position. Such prevents a theft from breaking the latch by forcing the lock into rotation in a cantilever fashion.

Abstract: A chair assembly for use in a vehicle such as a locomotive, having a height adjustable base which is free of any wobble and shaking motion, whether being raised, lowered or in use by a driver. The chair also has lateral movement capacity as well as fore-aft or side-aft movement relative to the base. A footrest adjustable by the feet of the driver is further provided.

Abstract: The horn housing may comprise an inner metal shell in the shape of a hexagonal box open at one end fitting into a similarly shaped outer dense solid box similarly open at one end. Space between the inner and the outer boxes being filled by a low density sound absorbing filler, and the inner box being connected to the outer box by vibration absorbing bolts. The outer box is mounted to a structure by vibration absorbing mounting brackets. When a high decibel horn or siren is mounted in the inner box to directed sound through the opening, most of the sound propagating sideways towards the structure is absorbed by the housing increasing the comfort level of passengers or crew inside the structure.