Many manufacturers have produced a special renovator for cleaning stairs. This has nearly always taken the form of a bristle brush, approximately 4 in. square. When renovators are rigidly attached to their stems, this form of renovator is convenient and almost a necessity. However, when swivel joints are provided, the ordinary carpet or bare floor renovators are fully as convenient, and, being larger, are more rapid cleaners, and the stair renovator is unnecessary.
In isolated cases, where unusual cleaning is necessary, such as the removal of cork dust from the floors of a cork factory, picking up telegraph forms from the floors of stock exchanges, picking up wrapping papers in watch factories, etc., special forms of renovators, with large openings and large capacities for air exhaustion, become necessary. These appliances have generally taken the form similar to the carpet renovator, but with much wider slots, the forward edges of which are raised slightly above the surface of the floor when the renovator is in operation. These renovators, being of no use for any other purpose than that for which they are specially designed, and requiring quantities of air in excess of those usually provided for ordinary types of renovators, may be considered simply as special appliances and do not form a part of the outfit required to be furnished with an ordinary cleaning system.
Another class of cleaning which requires a special system and special appliances is the renovation of furs. Furs must never be brushed, as it tends to mat the hair and produce an effect opposite to renovation. The only agent suitable for renovating furs is compressed air and the form of renovator best suited for this work is a straight nozzle, flattened at the end with a slot approximately 4 in. long and not over ¹⁄₃₂ in. wide, from which the air escapes in a thin sheet. When held at such an angle that the air will impinge on the skin under the hair, a thorough renovation of the fur is possible.
For the renovation of pillows a hollow needle, with small openings along its sides, supplied with compressed air, produces the best results. The needle is thrust through the cover into the mass of feathers, the air tending to loosen up the matted feathers and to leave them in practically the same condition as when the pillow was first filled.
As the arrangement of the air removal system, to permit it being reversed from exhaustion to compression, complicates the outfit and adds to its first cost, and as cleaning of this character is required only at rare intervals, these renovators may also be considered as special and need not be included in the average equipment.
The author considers that the renovator equipment for a system in which from 20 to 30 cu. ft. of air per minute is exhausted for each renovator in operation, and which the author classes as a “small volume” system, should contain the following renovators in each “set” furnished:
One carpet renovator with cleaning slot ¹⁄₄ in. by 12 in. long.
One bare floor renovator 12 in. long, with curved felt-covered face.
One wall renovator 12 in. long, with cotton flannel and curved face.
One upholstery renovator with slot ¹⁄₄ in. by 4 in.