Crane or similar manipulating apparatus with integrated assembly for overcoming each dead position between primary and secondary part of its operational arm

A crane apparatus, comprising:

• a rigid bearing framework, which is adapted for attachment to a chassis and is furnished with at least two telescopic supporting legs;
• an approximately vertically arranged and rigid bearing mast, which is in a area of its first end portion connected with said bearing framework, while in an area of its second end portion an operational arm is attached in a first pivot point, in which the operational arm is pivotable around a horizontal axis, wherein
• the operational arm includes a rigid primary part a rigid primary part first end portion of which is in the first pivot point pivotally around the horizontal axis attached to the rigid bearing mast, while its rigid primary part second end portion is in a second pivot point pivotally around the horizontal axis connected with a rigid secondary part first end portion of a rigid secondary part, to a rigid secondary part second end portion of which a gripping assembly of a crane;
• wherein the rigid secondary part of the operational arm is in the second pivot point pivotable relative to the rigid primary part via a first hydraulic cylinder with a first piston that is attached to the rigid primary part of the operational arm, while each residual part of the first hydraulic cylinder is attached to the rigid secondary part of the operational arm;
• wherein the operational arm is pivotal relative to the rigid bearing mast via a second hydraulic cylinder with a second piston that is attached to the rigid bearing mast, while each residual part of the second hydraulic cylinder is attached to the rigid primary part of the operational arm,
• wherein the rigid secondary part is in an area of the second pivot point, pivotal around the horizontal axis, and connected with the rigid primary part of the operational arm via a dead position overcoming assembly, wherein the dead position overcoming assembly includes a rotational driving subsystem as well as of a mechanism for attachment of the first hydraulic cylinder for pivoting relative to the rigid secondary part of the operational arm, and which is attachable to rigid secondary part of the operational arm,
• wherein the rotational driving subsystem is in the area of the second pivot point for pivoting of the rigid secondary part of the operational arm relative to the rigid primary part, and wherein the rotational driving subsystem includes a casing, which is firmly and with the possibility of transferring a torque connected with the rigid secondary part of the operational arm, and represents a casing of a hydraulic cylinder with hydraulic connectors, which are in a horizontal direction spaced apart from each other, as well as of a central part, which is with the possibility of transmission of torque around the horizontal axis through the second pivot point between the rigid primary part and the rigid secondary part of the operational arm connected with the rigid primary part of the operational arm and represents a piston of the hydraulic cylinder, which is movable along the horizontal axis of the second pivot point, and wherein the casing and the central part are conceived as parts of a clutch, so that the casing is furnished with first protrusions, which are in a circumferential direction equidistantly spaced apart from each other and each is furnished with two axially outward first converging slopes, and the central part is furnished with second protrusions, which are in a circumferential direction equidistantly spaced apart from each other and protrude towards first protrusions on the casing, and each is also furnished with two axially outwards second converging slopes, wherein each of the second protrusions on the central part is formed complementary with each gap between each two neighboring first protrusions on the casing, and wherein a second inclination of the second converging slopes on each second protrusion on the central part corresponds to a first inclination of the first converging slopes on each first protrusion on the casing such that the first hydraulic cylinder for pivoting the rigid secondary part relatively to the rigid primary part of the operational arm is temporarily deactivated due to a mutual engagement of the first second protrusions on the casing as well as on the central part, and each displacement of the central part in an axial direction of the casing along the horizontal axis within the second pivot point results in a synchronous rotation of the central part relative to the casing, and wherein a mechanism on which the first hydraulic cylinder for pivoting the rigid secondary part relative to the rigid primary part of the operational arm is attached, is conceived as a crank mechanism that includes an L-shaped lever, a shorter arm of which is on a free end portion pivotal around the horizontal axis attached to a rigid primary part of the operational arm adjacent to the second pivot point between the rigid primary part and the rigid secondary part of the operational arm, and a longer arm is pivotal around the horizontal axis attached to the rigid secondary part of the operational arm at a distance apart from the second pivot point, and in a coinciding area of the shorter and longer arm said the first hydraulic cylinder for pivoting the rigid secondary part relative to the rigid primary part of the operational arm is pivotal around the horizontal axis and attached via a first one part, while a second part of the first hydraulic cylinder is pivotal around the horizontal axis attached to the rigid primary part of the operational arm.