The ornamental design for a clampingassembly, as shown and described.
FIG. 1 is a top right isometric view of a clamping assembly;
FIG. 2 is a top right isometric view of a clamping assembly;
FIG. 3 is a front elevation view of a clamping assembly;
FIG. 4 is a rear elevation view of a clamping assembly;
FIG. 5 is a right elevation view of a clamping assembly;
FIG. 6 is a left elevation view of a clamping assembly;
FIG. 7 is a top plan view of a clamping assembly; and,
FIG. 8 is a bottom plan view of a clamping assembly.
The broken lines showing portions of the design in all figures is included for the purpose of illustrating environment and unclaimed features and forms not part of the claimed design.