| 摘要 |
773,296. Pipe couplings. HOOVER, Ltd. Sept. 21, 1955 [Oct. 11, 1954], No. 27016/55. Class 99(1) A telescopic tube assembly,' particularly adapted for connection between a suction cleaner and a dusting tool, . comprises an inner tube 10 provided with a longitudinally extending flute or flat 20 which is engaged by a guide block 40 carried by the outer tube 11 to prevent a relative rotation between the tubes, a latching means 26 carried by the outer tube being adapted to engage one. or more projections 32, 33 on the flute or flat 20 to latch the tubes against relative longitudinal movement. The outer tube 11 is provided at one end with a pin 18 for engagement in a fitting on the suction cleaner and the inner tube 10 is provided with a leafspring latch 14 for retaining in a slot 13 a pin of a cleaning tool fitted in the tube 10, a sealing ring 15 contacting the outer surface of the tool fitting to form a seal. A second sealing ring 22 carried in a recess in the endof the tube 10 forms a seal between the tubes 10, 11. The latching means 26, Fig. 2, comprises a spring band riveted at one side 28 to the outer tube and provided at the other side with a latching portion 30 which projects through a slot 29 in the outer tube 11 and has a hole 31 to receive the latching projections 32, 33, to latch the two tubes in an extended position and retracted position respectively, the latching band having at the sides of the hole 31 ramps 34, 35. to enable it to ride up over the pins 32, 33. The latching band is disengaged from the projections 32, 33, by pressing in the sides 38 of the band. The guide means, comprises a block 40 positioned in a recess 25 in the tube 11 and provided with a flat face 41, Fig. 3, engaging the flat 20 on the tube 10, a hooked spring 46 riveted to the block engaging a locating slot in the recess 25 to hold the block in its correct position. A recess 48 in the block 40 allows the projection 32 to pass therethrough when the tubes are extended. For assembly of the block 40, the tube 10 is first rotated to bring the flat 20 opposite a slot 50 through which the block 40 is inserted, the tube 10 being then rotated to carry round the block 40 to its correct position in which the spring 46 snaps into its locating slot. |
