FIG. 26. ANOTHER TYPE OF BARE FLOOR RENOVATOR.
This form of renovator, while more efficient than the oscillating floor type, still had its faults in that it had a tendency to push the dirt along the floor in front of it, much the same as the floor brush from which it was copied was designed to do. Also, there was too much tendency for the air to pass into the body of the renovator without coming into intimate contact with the surface to be cleaned. While this type of floor renovator or a slight modification thereof is still in use by several manufacturers today, it never has and never will be an effective bare floor cleaner.
A modification of this type of bare floor renovator, in which the bristles have been shortened and made thicker, the skirting or flaps placed on the outside and the stem provided with a swivel joint, is shown in [Fig. 26]. Such an arrangement is an improvement over the former type as, owing to its wider and shorter mass of bristles, there is less tendency for the air to pass into the body of the renovator without coming into intimate contact with the surface cleaned. It is still prone to push its dirt before it and is far from being a perfect bare floor cleaner.
FIG. 27. BARE FLOOR RENOVATOR WITH FELT CLEANING SURFACE.
The next modification in the bare floor renovator was the abandoning of the bristle brush in favor of a cleaning surface composed of felt as shown in [Fig. 27]. In this form of renovator the air entering the body of the same must pass either between the felt and the surface cleaned or through the felt itself, and this air quantity is small. Since this renovator has a wider cleaning slot than the Type A carpet renovator, and, as it is used with the same vacuum producer, hose and pipe lines, a considerable degree of vacuum will be produced under same, especially when operated on polished floors, where the conditions are nearly the same as we observed with Type A carpet renovator operated on linoleum. With the wider slot, the effort to move these renovators becomes too great for easy operation. This trouble can be overcome by using a soft grade of felt which permits sufficient air to pass through its open pores to reduce the vacuum under same and permit easy operation. Unfortunately, this felt is subject to rapid wear when operated on surfaces as hard as floors and its use has been abandoned in favor of a harder felt. Openings are left in the felt to permit the passage of sufficient air to reduce the vacuum in the renovator to working limits. These slots have taken many forms. In one form the felt was placed in alternate X and diamond shapes, glued to the face with small open spaces between them, as illustrated in [Fig. 28]. However, as these small pieces must be held in place by glue, they are easily broken loose and the efficiency of the renovator impaired.
FIG. 28. BARE FLOOR RENOVATOR WITH UNUSUAL FORM OF SLOT.
Another method, which has now become standard, is to open the ends of the renovator sufficiently to permit easy operation. This method produces high velocities at these end openings which are very effective in cleaning close to walls and in corners, where large quantities of dust always lodge and are removed with difficulty without these open slots.