431,852. Soot blowers. BABCOCK & WILCOX, Ltd., Babcock House, Farringdon Street, London.-(Assignees of Snow, N. L.; New Canaan, Connecticut, and Thomas, W. P. ; Highland Park, Brelsford, H. E. ; Birmingham, Howse, C. L. ; Detroit, and Bowers, F. ; Detroit, all in Michigan, both in U.S.A.) Oct. 16, 1933, No. 28629. Convention date, Dec. 27, 1932. [Class 99 (ii)] [See also Group XXVI] In a soot blower for a fluid heater comprising a nozzled blower tube 25 to which cleaning fluid is supplied from a goose-neck 31, the blower tube is journalled in the said goose-neck and is rotated by a pinion 35 which engages a gear 34 thereon and is itself rotated by a pair of pawls 56. Each of the two pawls is pivotally mounted in a slotted yoke 54 of a piston 51, reciprocably mounted in a cylinder 50 of a housing 46, and engages the teeth 48 of a ratchet wheel 47 secured to the shaft 45 of the pinion 35. The two pistons 51 are actuated by fluid under pressure, e.g. steam, which is supplied by a pipe 62 and is controlled by valves 64, and they are so arranged as to act alternately, that is when one of them is working the other is exhausting. The valves 64 are each provided with a passage 65 and ports 66 to permit passage of steam from the pipe 62 to the corresponding cylinder 50 when the valve is in the position shown in Fig. 2 and with channels 68<a> to permit exhaust of the steam from the cylinder to the housing 46 when it is moved to the left, the steam pressure tending normally to maintain it in the former position. Movement of the valves to the left is effected alternately by bellcrank levers 68 pivoted in the housing 46 and in engagement respectively each with a cam track 49 on one of the ratchet wheels 48. In operation, steam will flow to one of the cylinders 50, and acting on the head 52 of the piston therein will force the piston to the right and cause its pawl 56 to rotate the ratchet 47 and pinion 35 ; simultaneously the other piston is returned by a spring 70 interposed between the rear head 53 thereof and the right-hand end of its cylinder, the corresponding pawl riding freely over its ratchet wheel. When the piston reaches the end of its stroke the cam 49 will actuate the lever 68 and shift the valve 64 to the left to permit return of the piston, and at the same time the other lever 68 is freed to permit its valve to move to the right and admit steam to the second cylinder. Reciprocation of the pistons may be retarded by liquid disposed in the spaces between the heads 53 thereof and the ends of the cylinders, these spaces communicating with each other by a valve-controlled passage 72, and means such as a whistle 80 and visible or audible means 86 may be provided for indicating operation of the blower. The supply of cleaning fluid is controlled by a valve 33 which is located in the goose-neck 31 and is actuated by a cam 36 on the gear 34 through a pivoted lever 37. Fig. 6 shows a device for controlling the retardation of the pistons, namely, a ratchet wheel 212 fixed on the shaft 45 and escapement mechanism comprising an adjustable pendulum 214 provided with pawls 216 adapted to engage said ratchet wheel. The Specification as open to inspection under Sect. 91 describes also several modified constructions of engines for rotating the blower tube. In one form, Fig. 6 (Cancelled), an engine with a single piston 105, the axis of which is parallel to the blower tube 25, is employed, the piston rod 99 rocking a member 97 provided with a head 100 which rotates a wheel 102, fixed to the blower tube, by engagement with pins 101 thereon and also actuates the valve mechanism 107 of the engine. In a modification, Fig. 9 (Cancelled), rotation of the blower tube is effected by a double - acting piston 125, teeth 129 on the piston rod 128 engaging teeth 130 on a gear 131 which meshes with a gear 141. The gears 131, 141 are loosely mounted on shafts 132, 140 respectively and are provided with pawls 135, 142 engaging ratchets 134, 143 fixed on said shafts to rotate same, the shafts having pinions 136, 144 in engagement with a gear 37<b> on the blower tube 25b. Alternatively, Fig. 11 (Cancelled), a piston 150 reciprocates a yoke 153 provided with pawls 155 on its arms which engage, as shown, opposite sides of a ratchet wheel 154 on the blower tube 25<a>. In a further modification, Fig. 12 (Cancelled), the blower tube is rotated by a wobble plate or inclined disc 164 which is fixed to a shaft 163 and is rotated by pistons 166 adapted to be projected from their cylinders 165 by fluid under pressure, e.g. steam, a head 161 locating the cylinders being provided with passages 167, 168 respectively and a valve integral with the shaft 163 for admitting and exhausting steam successively to and from the said cylinders. Rotation of the shaft may be retarded by a plurality of spring-pressed pistons 180 which are located in cylinders 182 constituting a chamber for liquid. Fig. 14 (Cancelled) shows a construction of rotary engine employing a cylindrical casing with a steam inlet and outlet 201, 202 respectively and housing a drum 204 which is mounted on an eccentric shaft 203 and is provided in its periphery with slots or recesses 205 locating loosely mounted rollers 206. In a still further modification, Fig. 19 (Cancelled), a rotor 241 provided with pivoted wings 248 co-operating with springs 250 is mounted for rotation within a housing 240 having a thickened portion 243 with a steam inlet and outlet 244, 245 respectively as shown. Means are also described for controlling the supply of steam to the abovedescribed engines. This subject-matter does not appear in the Specification as accepted.