Method and means of treating synthetic fibers of brushes
United States Patent Ripstein Apr. 15, 1975 [54] METHOD AND MEANS OF TREATING 3,191,478 6/1965 Peterson 300/17 X S H C FIBERS OF BRUSHES 3,325,845 6/1967 Sawkiw 300/21 X [76] Inventor: Max Aronowicz Ripstein,  
 Cuauhtemoc 60-304, Mexico, D.F., Mexico [22] Filed: Nov. 6, 1973 21 Appl. No.2 413,337  
 [52] US. Cl. 300/21; 300/1; 300/17 [51] Int. Cl A46d 1/05 [58] Field of Search 300/1, 17, 18,21  
 [56] References Cited UNITED STATES PATENTS 2,812,530 11/1957 Whitcsel 300/21 X Primary Examiner-Granville Y. Custer, Jr. Attorney, Agent, or Firm-Karl W. Flocks [57] ABSTRACT A method of treating bristles of brushes made of synthetic fibers by beating them below their free ends at a speed to cause fibrilation of the ends due to a whip action which explodes or bursts the bristles at their end portions.  
 5 Claims, 3 Drawing Figures METHOD AND MEANS OF TREATING SYNTHETIC FIBERS OF BRUSHES BACKGROUND OF THE INVENTION The present invention refers to the manufacture of brushes and particularly the flagging of the bristles on such brushes.  
  Paint brushes of animal bristles have certain qualities which allow better holding of the paint and spreading of the paint smoothly over a surface. Much of this quality is due to the subdivision of the bristle ends into socalled flags.  
  An attempt has been made in the prior art to duplicate this structure on paint brushes and also on brushes for other uses having bristles of synthetic fibers. This has been done by abrasive means applied against the bristle ends with certain disadvantages inherent with such a method. One such disadvantage is the wearing away of portions of the bristles which can cause uneven lengths. Also end shapes are changed by such abrasion.  
 SUMMARY OF THE INVENTION The method of the present invention and the means to accomplish it forms brush end portions with flags thereon on synthetic bristles without incurring the disadvantages of the prior art and with greater uniformity of bristle lengths and a resulting smoother set of brush bristles.  
  Basically. in the present invention the bristles of a brush are subjected to a beating action below their ends which causes a vibrating action or whipping motion at a speed to cause the ends to explode or burst into numerous separate ends on each bristle.  
  The brushes may then be passed through a comb to clean the burrs formed by the exploding end portions of the bristles.  
  The means to perform the beating action includes a rotating crossbar situated below the bristle&#39;s free ends and caused to rotate fast enough to cause the whipping action but less than the speed at which the bristles would burn.  
 BRIEF DESCRIPTION OF THE DRAWINGS The above and other advantages of the invention will become apparent upon full consideration of the following description and accompanying drawings in which:  
  FIG. 1 is a partial perspective view illustrating apparatus performing the method of the present invention;  
  FIG. 2 is an enlarged view of a brush subjected to the method of FIG. 1 showing the affected portion of the brush; and  
  FIG. 3 is a further enlarged view ofa single bristle of the brush of FIG. 2.  
 DESCRIPTION OF A PREFERRED EMBODIMENT Referring first to FIG. 1, there is shown a conveyor moving in the direction shown by arrow 11 and carrying brushes l2 thereon. Conveyor 10 may be of any convenient type for moving brushes 12 in the direction shown. Brushes I2 are shown as paint brushes but such procedure may also be applied to other types of brushes having bristles of synthetic fibers where such ends as are formed by the present method and apparatus are desired.  
  Brushes 12 are moved against rotating crossbars 13 which are rotated in a direction shown by arrow 14. This direction of rotation is not necessarily critical since the crossbars are situated so as to strike the bristles approximately one-third of the distance from their free ends. Since contact would not ordinarily be made with the bristle ends. either direction of rotation should 5 suffice.  
  The crossbars 13 are rotated at a high speed sufficient to cause a whipping action of sufficient force to explode the free ends of the bristles. Also the speed must not be so great as to cause a burning and welding 0 action of the bristles. Such a desired speed has been found to be within a range of 700 to 2440 revolutions per second for synthetic fibers such as those ordinarily used with paint brushes.  
  After such beating action by crossbars 13 the brush as shown in FIG. 2 has uniform flagging of the bristles with each bristle 15 having a flagged portion 16 extending from its free end as shown in FIG. 3.  
  Due to the exploding action of bristles 15 some burrs may be formed remaining on or between bristles 15. These are removed by passage of the bristles through the teeth of comb I7 placed in the path of bristles 15 on brushes I2. Since this method is not one of abrasion of the ends. the rotating crossbars 13 may be removed from the path of brushes I2 after completing their action.  
  After undergoing this procedure the brushes have retained their shape and have an increased softness and easier passage over the surface being painted.  
  It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.  
 What is claimed is:  
 l. A method of treating bristles of brushes comprising the steps of moving the brushes against a crossbar with the crossbar contacting the bristles approximately one-third of the distance from their free ends, and rotating the crossbar with a beating action against said bristles at a speed of 700 to 2440 RPS to cause a whipping action and exploding of the end portions of said bristles. 2. The method of treating bristles according to claim 4 1 further characterized by combing the bristles after the exploding of the end portions. 3. Apparatus for treating bristles of brushes to cause flagging of the end portions comprising a beating station,  
 means to move the brushes to said beating station, beating means to strike the bristles at a high speed to cause a whipping action and explode the end portions of the bristles. said beating means being located at said beating station to contact the bristles away from their free ends, said beating means comprising a dull crossbar and means to rotate said crossbar at said high speed comprising 700 to 2440 RPS. 60 4. Apparatus in accordance with claim 3, further characterized by combing means at a subsequent station from said beating station. located to comb the bristles. 5. Apparatus in accordance with claim 3, further characterized by said crossbar contacting the bristles approximately one-third of the distance from their free ends. :k