The ornamental design for a keyboard for controlling machinetools, as shown and described.
FIG. 1 is a perspective view of a keyboard for controlling machine tools showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a left side elevational view thereof;
FIG. 4 is a right side elevational view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof; and,
FIG. 7 is a rear view thereof.
The broken line showing is included for the purpose of illustrating portions of the article and forms no part of the claimed design. The dot-dashed lines show unclaimed boundaries.