Patent GB-665095-A (GB)
Title: Improvements in or relating to rotary brushes
IPC: A46D1/00
Filed: 1947-07-28
Abstract: 665,095. Rotary brushes; treating bristles; grinding and polishing. OSBORN MANUFACTURING CO. July 28, 1947 [March 23, 1942], No. 20366/47. Drawings to Specification. Classes 19 and 60 In a rotary brush of the type comprising a brush back and brush material extending radially therefrom, the individual elements of the brush material have applied thereto a coating of a substantially non-drying material of such a nature that, during normal operation of the brush, said coating exhibits the characteristics of a highly viscous tacky fluid whereby the individual elements tend to adhere together, said elements nevertheless still retaining their ability to separate during normal operation in engagement with a work piece. The coating may be such that during normal operation of the brush the inner portions of the individual elements tend to adhere together whereby lateral compacting of the outer portions of the elements is minimised. The coating material must wet the bristles when initially applied and should preferably be readily removable from the work piece. Suitable treating agents include the various semi-drying oils such as soya bean oil and blown hemp seed oil both with and without the addition of alkyd resins or other resinous agents. Other specified treating materials include soya bean oil with addition of alkyd resins and tack additives such as a polymerised petroleum fraction, hemp seed oil or perilla oil and combinations of same as in the case of soya bean oil, castor oil especially that form which is petroleum fraction soluble and combinations of same as in the case of soya bean oil, menhaden oil, sulphonated oils, e.g. sulphonated castor oil and soaps especially those that have considerable tack such as zinc and iron soaps. The treating materials may be applied with a solvent which may later be removed by evaporation. Typical solvents are mixtures which consist of a petroleum fraction, alcohol and a minor amount of certain coal tar derivatives. The alkyd resins used above may be selected from the glycerine, phthalate condensation products. The brush material treated may be Tampico fibre, horse hair, twisted and braided cord, wire, or a mixture of wire and Tampico fibre or horse hair. Abrasive may be incorporated with the treating material but it is preferred to apply the abrasive to the rotating brush in paste or stick form after the application of the treating material, either manually or for example by means of an intermittent or continuous feeding device, or, when in liquid or powder form by drawing the abrasive from a container or hopper. Suitable abrasives for use with the previously coated brushes are emery, silica, silicon carbide, alumina in the form of a firm paste or in a semi-fluid form as by suspending it in such media as tallow, grease, oil, soap, or a soluble oil such as a sulphonated oil or glue. The brush material may be treated by mounting the rotary brush sections on a mandrel or spindle and immersing in a tank containing the treating material the sections being placed on the spindle with suitable spacers which allow the treating material to wet the brush fibres. The spindle and brushes may then be withdrawn above the level of the treating material and rotated to remove excess of the latter. The treatment may also be applied to helically wound brushes. The Specification as open to inspection under Sect. 91 includes mutton tallow as an example of the treating material. This subject-matter does not appear in the Specification as accepted.