One corner cleaner.
One radiator tool.
At least one hat brush with each system.
The number of sets of renovators to be furnished should naturally be at least equal to the number of sweepers which the plant will handle, and in all buildings, except residences, there should be one set of renovators for each floor of the building. This will be ample, except in exceedingly large buildings.
The wearing face of any renovator should never be made of soft metal, such as brass or aluminum, as the action of the dust passing the face of the renovator, where the velocity is always the highest in the system, will roughen these parts and cause undue wear on the surfaces cleaned. Stamped steel is undoubtedly the best material for wearing surface and cast-iron ranks next. These are the only materials which should be permitted.
CHAPTER V.
Stems and Handles.
Having discussed the various forms of renovators in detail, the next appliance to be taken up is the connection between the renovator and the cleaning hose, this being the next portion of the apparatus forming a conduit for the dust-laden air on its way from the renovator to the atmosphere on the exhaust side of the vacuum producer.
In order that the renovator may be moved about on the surfaces to be cleaned, a rigid handle must be provided and, in order that these various surfaces may be reached while the operator remains in a standing position, it is necessary that this handle be of considerable, as well as variable, length. Also, a passage for the dust-laden air must be provided in connection with this handle. These conditions are best met by a metal tube, which the author terms the stem.
These stems have been made of various metals, that first used being drawn brass, probably because it is best suited to be nickel plated. On the earlier systems they were almost invariably made of No. 16-gauge tubing, ⁷⁄₈-in. outside diameter, and were bent at their upper end through an angle of nearly 135° in order that the hose would hang from the stem vertically downward, when the stem was held at an angle with the floor of 45°.
The lower ends of these stems were rigidly attached to the renovator in such a manner as to assume the above-mentioned angle with the floor when the renovator was in the proper position for cleaning. In order to bring the curved portion of the stem hand high, the stem was made approximately 5 ft. long.