GB826588A - Apparatus for determining the dust content of flowing gases - Google Patents

Abstract

826,588. Tachidometers. BOSCH G.m.b.H., R. Dec. 19, 1957 [Dec. 22, 1956], No. 39499/57. Class 97(3) [Also in Group XXVIII] - A tachidometer for determining the soot content of exhaust gases of diesel engines, comprises a sampler with an inlet adapted for insertion into an exhaust pipe and connected by a pipe to a pump the piston of which is movable by a spring from an inner to an outer position to draw the gas into the working chamber of the pump and through a filter. The piston is held in its inner position and released therefrom by manual means. As shown, the tachidometer comprises a sampler formed by tube sections 3, 4 between which is a space 5 into which flow gases in an exhaust pipe 1, the sections 3, 4 being held therein by spring stirrups 9, 13. The gas in space 5 flows through bores 6 in section 4 and via a pipe 8 to a pump which is held on the exhaust pipe by spring clips 75. Pipe 8 terminates in a removable cover 16 of the pump, this cap carrying a triangular plate 28, which distributes the incoming gas evenly. Between the cover 16 and a cap 17 are clamped a filter disc 30 and sealing ring 31. Within the pump casing 25 a piston rod 37 is axially movable, this rod terminating at its upper end in a piston,. formed by discs 33, 34 and sealing ring 35, and at its lower end in a cap 69 between which and a bush 41 carried by an end cap 42 of casing 25 is a spring 72. This end cap 42 accommodates a member 48 which slides on the bush 41 and has inner annular grooves of different diameters, these grooves co-operating with ball bearings 45 mounted in bores in bush 41. A bellows 50 is disposed between member 48 and a member 58 fixed to the casing 25 and an air line passes through member 48 to a bulb 64. When in its inner position, to which it is pushed manually against spring 72, the piston rod is held against the force of spring 72 by the engagement of balls 45 in an annular groove 47 of the rod 37, these balls being held in this position by the member 48 which is pressed by springs 57 against deflated bellows 50 and has its inner groove of smaller diameter opposite the balls. By squeezing bulb 64, the bellows 50 expands and thus lowers slidable member 48 against springs 57 to release balls 45 from the groove 47 whereupon spring 72 forces the piston downwardly and gas is drawn into the casing 25, the air in casing 25 between the piston and member 58 flowing out of holes 73. In another embodiment, the piston rod is held in its inner position by a spring-urged plunger which is moved by a Bowden cable to release the piston rod.