GB167869A - New or improved apparatus for demonstrating and testing different classes of fits of engaging parts of machines and other engineering constructions - Google Patents

Abstract

167,869. Thomson, H. J. May 20,1920. Testing mental aptitudes. - Apparatus for demonstrating and testing different classes of fits used in mechanical appliances comprises a conical plug fitting within an outside member formed with a hole of the same taper and means for varying the clearance between the members by relative axial movement, the class of fit being estimated by " feel " upon rocking one member relative to the other while resting against adjustably set stops. The plug 1 is shorter than the outside member 4 and is carried on shaft extensions 2, 3. Sleeves 5, 6 are adapted to form stops which may be set to particular limits. In practice, the shafts 2, 3 together with the sleeves 5, 6, which are split, are mounted in standards 7, 8. The sleeves are provided with graduations as shown, and the stops are set to allow axial movement corresponding to clearances at the high and low limits, whereupon the sleeves and shafts are clamped at 9, 10, and the type of " clearance " fit may be demonstrated by the play of the cone 4 upon the plug 1. For demonstrating " obstruction " fits, in which the plug grips in the hole, the stops 5, 6 may be made to screw on the shafts 2, 3 so that considerable thrust can be put on the cone 4 by the stop 5, and this ,thrust subsequently released by the stop 6. A lever arm on the cone 4 acting against a spring would then show the torque required to rotate it. To measure the film thicknesses of various lubricants, the amount of longitudinal movement of the cone 4 from full clearance to full engagement without clearance is compared first when the cone surfaces are dry and then when lubricated.