Abstract: A self-erecting crane including a mast mounted on a rotating platform and supporting a boom is configurable between a transport configuration and a working configuration. The mast supports a hitch element suitable for being coupled on a fifth wheel provided on a rear platform of a tractor truck, the hitch element being located in a front hitch area of the mast which is dimensioned to come above the rear platform. The self-erecting crane also includes a mooring system located on the front hitch area and a removable ballasting element. In the transport configuration, the removable ballasting element is configured to be temporarily moored on the mast by the mooring system so that the removable ballasting element is located under the mast in the front hitch area. In the working configuration, the removable ballasting element is mounted on the rotating platform.

Abstract: This defining method comprises the steps of: —simulating a crane comprising: i) a boom made up of elements and ii) a lifting member that is able to move along the boom, —selecting several elements to be tested, maximum stresses, and several ranges along the boom, and —carrying out the following analysis steps of: •choosing a theoretical load, •calculating stresses brought about by the theoretical load in each element to be tested, •comparing these stresses with maximum stresses, •increasing or decreasing the theoretical load depending on whether stresses are less than or greater than the maximum stresses, •repeating the calculating step and the comparison step and the step of increasing or decreasing until the maximum theoretical load is found, and •recording i) the range and ii) the maximum theoretical load.

Abstract: A self-erecting crane including a mast mounted on a rotating platform and supporting a boom is configurable between a transport configuration and a working configuration. The mast supports a hitch element suitable for being coupled on a fifth wheel provided on a rear platform of a tractor truck, the hitch element being located in a front hitch area of the mast which is dimensioned to come above the rear platform. The self-erecting crane also includes a mooring system located on the front hitch area and a removable ballasting element. In the transport configuration, the removable ballasting element is configured to be temporarily moored on the mast by the mooring system so that the removable ballasting element is located under the mast in the front hitch area. In the working configuration, the removable ballasting element is mounted on the rotating platform.

Abstract: This automatic unfolding and folding tower crane comprises a mast and a jib which are movable between an operation configuration and a transport configuration. The mast has a first mast section (2.1) and a second mast section (2.2). The jib has a first jib section (4.1) and a second (4.2) jib section. The first jib section (4.1) has an upper limit (4.11) and a lower limit (4.12) defining a height (H4.1) of the first jib section (4.1). The first mast section (2.1) is rotatably connected to the first jib section (4.1) about a hinge axis (Y24). The jib direction (X4) is shifted with respect to the mast direction (Z2) parallel to the hinge axis (Y24). A distance between the hinge axis (Y24) and the lower limit (4.12) is greater than 75% of the height (H4.1) of the first jib section (4.1).

Abstract: This defining method (100) comprises the steps of: —simulating a crane comprising: i) a boom made up of elements and ii) a lifting member that is able to move along the boom, —selecting several elements to be tested, maximum stresses, and several ranges along the boom, and —carrying out the following analysis steps of: •choosing a theoretical load, •calculating stresses brought about by the theoretical load in each element to be tested, •comparing these stresses with maximum stresses, •increasing or decreasing the theoretical load depending on whether stresses are less than or greater than the maximum stresses, •repeating the calculating step and the comparison step and the step of increasing or decreasing until the maximum theoretical load is found, and •recording i) the range and ii) the maximum theoretical load.

Abstract: This automatic unfolding and folding tower crane comprises a mast and a jib which are movable between an operation configuration and a transport configuration. The mast has a first mast section (2.1) and a second mast section (2.2). The jib has a first jib section (4.1) and a second (4.2) jib section. The first jib section (4.1) has an upper limit (4.11) and a lower limit (4.12) defining a height (H4.1) of the first jib section (4.1). The first mast section (2.1) is rotatably connected to the first jib section (4.1) about a hinge axis (Y24). The jib direction (X4) is shifted with respect to the mast direction (Z2) parallel to the hinge axis (Y24). A distance between the hinge axis (Y24) and the lower limit (4.12) is greater than 75% of the height (H4.1) of the first jib section (4.1).

Abstract: An optical switch comprising a base (1) having a light path (4, 5) passing therethrough, a guide slot (6) intersecting said path, a moving shutter (24) displaceable at least partially inside said guide slot (6) between a position where it allows light to pass along said path and a position where it interrupts said passage, and a return spring (22) for the shutter, the switch being characterized in that said shutter (24) and said spring (22) constitute portions of a deformable blade (2), the spring (22) being fixed at one of its ends to the base, and the moving portion of said blade having a surface (21) which is large enough to be capable of responding to magnetic attraction exerted against the action of said spring.