FIG. 1 is a front elevational view of a first embodiment;

FIG. 2 is a rear elevational view of the first embodiment;

FIG. 3 is a top plan view of the first embodiment;

FIG. 4 is a bottom plan view of the first embodiment;

FIG. 5 is a left side elevational view of the first embodiment;

FIG. 6 is a right side elevational view of the first embodiment;

FIG. 7 is a cross-sectional view of the first embodiment along line 7--7 of FIG. 1;

FIG. 8 is a perspective view of the first embodiment;

FIG. 9 is a front elevational view of a second embodiment;

FIG. 10 is a rear elevational view of the second embodiment;

FIG. 11 is a top plan view of the second embodiment;

FIG. 12 is a bottom plan view of the second embodiment;

FIG. 13 is a left side elevational view of the second embodiment;

FIG. 14 is a right side elevational view of the second embodiment;

FIG. 15 is a cross-sectional view of the second embodiment along line 15--15 of FIG. 9; and,

FIG. 16 is a perspective view of the second embodiment.

FIGS. 9, 11 and 16 have a control panel with a display screen at the left-hand side thereof.

FIGS. 7 and 15 omit an internal mechanism.