The ornamental design for a horizontalbeam, as shown and described.
FIG. 1 is a front perspective view of a horizontal beam showing the claimed design;
FIG. 2 is a rear perspective view of a horizontal beam showing the claimed design;
FIG. 3 is rear elevation view of a horizontal beam showing the claimed design;
FIG. 4 is front elevation view of a horizontal beam showing the claimed design;
FIG. 5 is left side elevation view of a horizontal beam showing the claimed design;
FIG. 6 is a right side elevation view of a horizontal beam showing the claimed design;
FIG. 7 is a top plan view of a horizontal beam showing the claimed design; and,
FIG. 8 is a bottom plan view of a horizontal beam showing the claimed design.
The dot-dot-dash broken line(s) define the bounds of the claimed design and form no part thereof.
The horizontal beam is shown with a symbolic break in its length. The appearance of any portion of the article between the break lines forms no part of the claimed design.