Patent Publication Number: US-3875640-A

Title: Brush assembly tool

Description:
United States Patent Perrin et al. Apr. 8, 1975 BRUSH ASSEMBLY TOOL 3.001.271 9/!961 Perrin 1. 29/283 7 2 [76] Inventors: Joe F. Perrin; Henry K. Perrin. both 3319325 5/l96 Nessamar et 9/235 0f Box Hume 78634 Primary Examiner-Al Lawrence Smith [22] Filed: Nov. 26, 1973 Assistant Examiner-Harold P. Smith, .Ir. [2&#39;] P I NO 418 938 Attorney, Agent, or Firm-Ted D. Lee; Donald R.  
 p Comuzzi [52] US. Cl. 29/205 R; 29/283 7 [51] Int. Cl B25b 27/14 [5 l ABSTRACT: [58] Field M Search 29/205 R, 235, 239. 2531 A dev1ce for spreadmg field housmg brushes by shdmg 29/283. 219/238 239 the brushes over the device thereby wedging the brushes apart and while spread apart slipping the [56] References Cited brushes into position on commutator of the armature UNITED STATES PATENTS a 2.261.015 10/1941 Brody 219/238 3 Claims. 8 Drawing Figures BRUSH ASSEMBLY TOOL BACKGROUND OF THE INVENTION The present invention relates to a device for spreading field housing brushes over the armature when assembling a motor, and more particularly relates to a tool that can be positioned on the end of an armature shaft so that the housing containing the field housing brushes can be slid into position around the commutaor of the armature and the tool subsequently removed. The tool spreads the brushes by sliding the brushes along planes that extend outward onto a conical shaped body with each plane receiving a separate brush.  
 BRIEF DESCRIPTION OF THE PRIOR ART The present invention is an improvement over U.S. Pat. No. 3,00l,27l issued on Sept. 26, l96l to Joe F. Perrin.  
  Many types of expansion devices have been used in the past to expand various components by the use of a sloping surface. A wedge is probably the simplest of such devices. The task of expanding two objects is relatively simple when the two objects are close to each )ther and the direction of expansion is not critical with the only requirement being that the two objects be separated by a greater distance than presently exist. However, as a number of objects need to be expanded relative to each other at the same time, in a given manner, and in a given direction, the problem becomes somewhat more complicated. Various special tools have been designed in the past for the expansion ofa number of objects at the same time.  
  The above mentioned reference does show a device somewhat similar to the present invention that can spread at least four field housing brushes when assembling the housing over the armature of a motor. However, the cited reference has a Z-shaped upper surface with tapered receiving grooves extending in a screw type of fashion down the surface of a cone. This cited reference, though workable, is somewhat more difficult to initially position when sliding the field housing brushes into place. The cited reference which is the closest known art, when taken in combination with other known or existing art, does not have the simplicity and total utility as the present design.  
 SUMMARY OF THE INVENTION The present invention provides the simplest possible device for spreading field housing brushes by simply cutting planes through a cone. The field housing brushes are easily positioned with respect to the brush assembly and positioning tool of the present invention and slid into place. Also a tapered recess is provided to accommodate shafts of an armature that may be of varying diameter.  
  It is therefore an object of this invention to provide an improved brush assembly and positioning tool for spreading field housing brushes for positioning over a motor armature. The brush assembly and positioning tool is mounted on the shaft of the armature and spreads the brushes to the proper position as the motor housing is moved axially over the armature.  
 BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention can be obtained when viewing the below mentioned drawings with the following description.  
 FIG. 1 is an elevated view of the present invention.  
 FIG. 2 is a side view of FIG. 1.  
 FIG. 3 is another side view of FIG. 1.  
  FIG. 4 is a cross sectional view of FIG. 1 along lines 44.  
 FIG. 5 is an isometric view of the present invention.  
  FIG. 6 is an exploded isometric view showing how the brush asembly tool sets on a motor armature shaft.  
  FIG. 7 is an isometric view illustrating initial contact between the brush assembly and positioning tool and the field housing brushes.  
  FIG. 8 is an isometric view illustrating the final position of the field housing brushes on the commutator of the armature.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1-5 the present invention consists of a single body of a basically conical shape with various planes having been cut through the cone. Consider FIGS. 1-5 as a group when reading the following description. The brush assembly and positioning tool 10 has a conical surface 12 and a base 14 that is substantially circular in shape. Two planes are cut through the conical surface 12 of the brush assembly and positioning tool 10 to form large sliding surfaces 16 and 18. The large. sliding surfaces 16 and 18 are slopes that are reversed with respect to each other on opposing sides of the brush assembly and positioning tool 10. Both planes that form large sliding surfaces 16 and 18 intersect the brush assembly and positioning tool below the apex of the conical surface 12 and extend downward and outward so that the large sliding surface 16 and 18 does not cut the base 14 so that the field housing brushes will slide onto the commutator.  
  Two other planes also intersect the brush assembly tool, in the manner previously described, to form small sliding surfaces 20 and 22. Small sliding surfaces 20 and 22 are also reversed sloped, but they would intersect the conical surface 12 if extended closer to the apex than the previously described planes. Also the planes forming small sliding surfaces 20 and 22 which are extending downward and outward in the brush assembly and positioning tool 10 and leave the conical surface 12 at a distance further away from the base 14 than do large sliding surfaces 16 and 18. The reason for having the large surfaces 16 aand l8 and the small surfaces 20 and 22 is because the brushes 50 and 56 collapse further than the brushes S2 and 54. The larger the surfaces 16 and 18 are, the less force will be exerted upon the brushes 50 and 56.  
  A fifth plane is cut above the base 14, but parallel thereto, and below the apex of the conical surface 12. This fifth plane intersects the four previously mentioned planes for forming large sliding surfaces 16 and 18 and small sliding surfaces 20 and 22 to form an upper rectangular surface 24. The small sliding surfaces 20 and 22 are perpendicular. to the large sliding surfaces 16 and 18.  
  The brush assembly and positioning tool 10 also has a recess 26 cut in the base 14. The recess 26 which is of a diameter slightly less than the diameter of the base 14 has a gradually inward tapered surface 28 around the outermost edge adjacent the base 14. Thereafter. the recess 26 has a sharp inwardly tapered surface 30 to substantially reduce the diameter of recess 26. Finally, recess 26 has another gradual inwardly tapered surface 32 within the innermost part of the recess. The gradually inwardly tapered surface 32 comes to an upper point 34 that may be the apex of a cone, portion of a sphere, flat surface or other suitable termination. The entire recess 26 is located along the axis of the conical surface 12 with the axis of the recess 26 being the same as the axis of the conical surface 12.  
  Referring now to FIG. 6 of the drawings, the brush assembly and positioning tool are fitted over the shaft 36 of armature 38. The armature 38 has a surface 40 against which field housing brushes may rub. If the brush assembly and positioning tool 10 is made of a suitable size and shape, the shaft 36 will fit snugly against gradual inwardly tapered surface 32. The base has a diameter equal to or greater than the diameter of rubbing surface 40. The large portion 42 is a spacer on the end of the shaft 36 which can be enclosed in large diameter surface 28 of the recess 26. The spacer 42 is normally made of a suitable substance such as leather.  
  To understand the operation of the present invention, view FIGS. 7 and 8 in combination when reading the following description. After the brush assembly and positioning tool 10 is fitting on the shaft 36 of armature 38, a field housing 44 that contains two pairs 46 and 48 of field housing brushes 50, 52, 54 and S6 is slid over the armature 38 with the axis of brush assembly and positioning tool 10, armature 38 and field housing 44 being in line for proper assembly. Field housing brushes 52 and 54 of pairs 46 and 48, respectively, are a further distance from the axis than brushes 50 and 56. Therefore. field housing brushes 54 and 52 should be positioned so that they contact small sliding surfaces and 22. Field housing brushes 50 and 56, which are located closer to the axis of the field housing 44 than the other brushes in their respective pair, will contact the large sliding surfaces 16 and 18. Now the field housing 44 is moved along the axis toward armature 38 and the brushes 50, 52, 54 and 56 are extended away from the axis of the brush assembly and positioning tool 10 by sliding along their respective sliding surfaces 16, 20, 22 or 18, and along the conical surface 12 for a final positioning on rubbing surface 40 of the armature 38. The force of springs 58 and 60 of field housing 44 hold the brushes 50, 52, 54 and 56 against the rubbing surface 40. It is the force of the springs 58 and 60 that must be overcome when assembling the field housing ofa motor over an armature. Without the brush assembly and positioning tool 10 it would be necessary to move all the brushes 50, 52, 54 and 56 against the force of their springs 58 and 60 while moving the field housing 44 axially along armature 38. Such an assembly without the brush assembly and positioning tool 10 can be very cumbersome, time consuming and even require two people. The present invention provides a rapid and easy method of assembling a field housing over the armature.  
  The foregoing described brush assembly and positioning tool 10 can be manufactured from any relatively solid material such as steel, iron, aluminum, plastic, wood or other rigid material that can withstand small amounts of shock.  
 What is claimed is:  
  l. A device for spreading field housing brushes over the commutator ofa starter motor including a generally conical body having a substantially circular base with a recess therein, a plurality of surfaces on said conical body comprising two first surfaces defined by planes being cut through the conical body starting below the apex and extending downward and outward without cutting said circular base so that the brushes will extend over the commutator, said planes having first reversed slope with respect to each other to expand said field housing brushes to said circular base, said reversed slopes forming sliding surfaces for expanding the innermost field housing brushes which are normally the insulated brushes, said circular base being as large as an armature commutator against which the field housing brushes normally rub so that said device may be mounted on the end of an armature with said device expanding the field housing brushes by spreading the brushes outward and onto the commutator as a field housing is moved axially into position over said device, said device further including two second surfaces defined by said planes, said second surfaces having second reverse slopes substantially perpendicular to said first reverse slopes, said second reverse slopes expand the outermost field housing brushes, a rectangular upper surface defined by a plane generally parallel to said base cut through the conical body below the apex to form said rectangular upper surface where it intersects said first and second surfaces, said rectangular upper surface being of such a shape to allow easy positioning of the field housing brushes on sliding surfaces formed by said first and second reverse slopes.  
  2. The device for spreading field housing brushes as given in claim 1 wherein said recess is tapered to receive armature shafts of varying diameters.  
  3. The device for spreading field housing brushes as recited in claim 2 wherein said recess further includes a plurality of tapers with the outermost taper being gradual for spacers of large diameters, a rapid inward taper, and another gradual taper on the innermost por-&#39;