Progressively movable holding device

A progressively movable holding device (2, 3) especially utilizable as tool or implement carrier (10) for treatment and/or inspection processes or workpieces (1) of larger or extended surfaces or of difficult access such as cast-iron pipes,

• having a number, adjustable to a predetermined processing length, of variably movable individual elements supported against the surface or contour of said workpiece (1),
• upon which elements both said holding device (2, 3) itself and said tool or implement carrier (10) are separately transportable by remote control to alternating working positions;
• wherein tightening elements (4, 12) actuatable by auxiliary energy provide for progressive movement from one working position to the next,
• and said tool carrier (10) is conveyable along said individual elements, characterized in that
• said individual elements consist of link plates (5, 6) retained together in releasable hinges and joined together to form two link chains (2, 3) at variable distance,
• said link plates (5, 6) are each separately held at a constant distance in respect to said workpiece,
• being themselves directly designed as double rails (26) for said tool or implement carrier (10) movable therealong and
• there being provided for progressive movement a partly transitory loosening and retightening of at least a few link plates (5, 6) by means of peripheral tightening elements (4, 32) actuatable by remote control.