This disclosure describes an expandable cover system which includes a work base and a plurality of inverted U-shaped frames which are supported on the base. Each of the frames have adequate sheet means to cover the frames in a waterproof manner. The frames are of different sizes so that they can nest, one inside of the other. The largest frame is fixed to the base at one end thereof, and the others are supported on two lines of rollers which are positioned under the legs of each of the frames so that they can be moved in a line perpendicular to the plane of each of the frames. There are projections on the inside and outside of each of the frames so that they can interact with corresponding projections on the adjacent frames so that when the inner frame is pulled longitudinally it will successively pull with it, the adjacent frame, then the next adjacent frame and so on. Conversely, when the smaller frame is pushed toward the stationary one the intermediate frames will successively be carried by the smallest one, riding on the rollers, until they are all nested inside of the stationary frame. A traversing means, such as a pair of longitudinal screws with nut means attached to the legs of the smallest frame are provided. These are arranged adjacent and parallel to the lines of rollers, so that the inner frame can be moved from the nest position to an extended position, carrying with it each of the intermediate frames until the group is fully extended. There are guide slots on the base so that the frames are guided laterally as they move longitudinally.

A traversing strut and housing system for securing and housing a helicopter aboard a ship. One or more telescoping housing sections are mounted on and movable along a track extending outward from a fixed section. A traverse strut assembly which permits only lateral movement is attached to the end movable section and secures the helicopter to the housing. Once thus secured, the helicopter is rotated to a preferred orientation then moved into its stored position.

An arrangement of tensile elements and rollers provides support for an extensible part against forces occurring in two directions perpendicular to the extension direction in which the extensible part is carried by a carrying part of conforming geometry. Two wire ropes form the tensile elements. First ends of each rope are attached to the top corners of one end of the carrying part and second ends of each rope are attached to the opposite bottom corners of the other end of the carrying part. The ropes extend in the extension direction from their carrying part attachments to the extensible part. At the extensible part, the ropes are passed over pulleys in two directions substantially transverse of the extension direction.

A telescopic device with two telescopic members (1, 2) comprises a control means with a flexible transmission element (4) for bringing the telescopic members in relative movement. The transmission element (10) is in engagement with a driving wheel (5), which is fixed relative to one (1) of the telescopic members in that the driving wheel is journalled at a base part (3) attached to said one telescopic member and from which the transmission element extends in a loop, which is arranged about a diverting wheel (8) arranged within a space limited by the telescopic members. The diverting wheel (8) is likewise fastened relative to the first telescopic member (1). The second telescopic member (2) is connected to a part (10) of the transmission element which extends between the driving member (5) and the diverting member (8), whereby thus a rotation of the driving member in a first direction causes contraction of the telescopic members while a rotation of the driving wheel in a second direction causes extension of the telescopic members.

A telescopic mast having a plurality of elements comprising the mast wherein the elements are slidably arranged in relation to each other, together with cables for the erection of the mast, wherein the cables are before the erection of the mast connected to all of the elements and the erection of the mast is carried out by a successive sliding of each element on the element therebelow, further including provision for separating the cables of each element after the end of the hoisting operation of that element.