Joint compensator

A joint compensator for compensating for the weight of a first joint and at least one subsequent joint, the first joint to be supported above the at least one subsequent joint, the joint compensator comprising

• a body interconnectible between the first joint and a moving apparatus,
• the body including supporting apparatus for supporting the first joint above the at least one subsequent joint and for providing support of the first joint as it moves with respect to the at least one subsequent joint, the supporting apparatus compensating for weight of the first joint as it moves,
• the support apparatus for alternately supporting the first joint and then the at least one subsequent joint, the support apparatus initially adjustable to compensate for the weight of the first joint so that the support apparatus is also thereby adjusted to compensate for weight of the at least one subsequent joint,
• the support apparatus comprising a movable piston movably mounted in a hollow cylinder with a first spring cushion means for cushioning the piston on a first side of the piston and a second spring cushioning means for cushioning the piston on a second side of the piston, the piston connected to a piston rod part of which projects from the cylinder for interconnection to a joint to be supported by the joint compensator,
• control apparatus for selectively controlling the first spring cushion means and the second spring cushion means,
• the first spring cushion means comprising an amount of gas, the second spring cushion means comprising an amount of gas, and the control apparatus further comprising
• a valving system and a fluid flow line system interconnecting the first spring cushion means, the second spring cushion means and a source of gas under pressure from which flows gas for the first spring cushion means and the second spring cushion means so that the joint compensator continuously compensates for weight of a joint connected thereto.

A joint compensator for compensating for the weight of a first joint and at least one subsequent joint, the first joint to be supported above the at least one subsequent joint, the first joint to be supported above the at least one subsequent joint, the joint compensator comprising

• a body interconnectible between the first joint and a moving apparatus,
• the body including supporting apparatus for supporting the first joint above the at least one subsequent joint and for providing support of the first joint as it moves with respect to the at least one subsequent joint, the supporting apparatus compensating for weight of the first joint as it moves,
• the support apparatus for alternately supporting the first joint and then the at least one subsequent joint, the support apparatus initially adjustable to compensate for the weight of the first joint so that the support apparatus is also thereby adjusted to compensate for weight of the at least one subsequent joint,
• the support apparatus comprising a movable piston movably mounted in a hollow cylinder with a first spring cushion means for cushioning the piston on a first side of the piston and a second spring cushioning means for cushioning the piston on a second side of the piston, wherein the first spring cushion means is at least one constant force spring, and wherein the second spring cushion means is at least one constant force spring, and
• control apparatus for selectively controlling the first spring cushion means and the second spring cushion means so that the joint compensator continuously compensates for weight of a joint connected thereto.