Improvements in and relating to apparatus for testing lip seals

1,014,079. Testing lip seals. GEORGE ANGUS & CO. Ltd. Nov. 12, 1964 [Nov. 21, 1963], No. 45999/63. Heading F2B. In apparatus for testing the lip loading of lip seals and comprising a cylindrical surface member 1 diametrically split into halves 2, 3 mounted for relative movement perpendicularly to the split, the cylindrical surface of the member 1 corresponding in diameter to the surface to be sealed by a seal to be tested, actuating means for effecting and indicating the movement of the halves comprises a pneumatic load cell 16 having a thrust member movable by air at a controlled pressure, mechanical coupling means, e.g. a bell crank lever 8, for transmitting movement between thrust member and one half 3 of the member 1 and a pressure gauge connected to the cell to respond to air pressure change consequent on movement of the thrust member. In the arrangement shown in Fig. 1 for testing internal lip seals the member 1 is a hollow stub shaft mounted on a frame 4 the half 2 being fixed to the frame and the half 3 being movable on a guide 6. The lever 8 is pivoted at 7 and has an adjustable abutment 10 on one arm 9 that engages the movable half 3 while the other arm 11 bears against a boss 12 on the head 13 of a piston 14 slidable in a cylinder bore in the body 15 of the cell 16. A recess 17 surrounded by a flange 18 is formed in the top of the body 15 and compressed air which is supplied to the recess through a restrictor 23, passages 20 and duet 21 in the body can escape through the clearance 19 between the flange 18 and the head 13. The duct 21 is connected to a pressure gauge 22, Fig. 2 (not shown). According to the pressure of air supplied to the cell 16 the head 13 will stabilize at a given height and, in use, the pressure is adjusted so that the halves 2, 3 are separated by an amount to give an overall diameter, perpendicular to the split, equal to the nominal diameter of the part to be sealed by the seal 27 to be tested. The latter is then fitted on the member 1 and the resultant movement of the half 3 towards the half 2 decreases the clearance 19 with consequent increase in the air pressure which is indicated on the gauge as a measurement of the lip loading.