GB669387A - Improvements in and relating to soot blowers - Google Patents

Abstract

669,387. Sootblowers. BRITISH THOMSONHOUSTON CO., Ltd., and JEFFERSON, H. F. Aug. 27, 1948 [July 24, 1947], No. 19915/47. Class 99 (ii) In a sootblower of the retractable type the blower tube B is continuously rotated by an electric motor N and intermittently reciprocated to and from the operative position by a cam U driven by the motor through a clutch b, Fig. 2. The cam U is of cylindrical form freely mounted by a web U1 on a countershaft z driven by a gearwheel K by which the blower tube is rotated. The cam track U comprises a groove formed of half a right-hand helix continuous with half a left-hand helix. The groove is engaged by a roller V carried by a forked lever W which is pivoted on a support Y and engages a collar H on the blower tube. A long key J permits reciprocation of the blower tube through the fixed bearing of the gearwheel K. In the blowing position a cam D engages a tappet E to actuate a pilot valve of the valve (not shown) supplying steam to the nozzle A. The clutch comprises a flanged sleeve a which is fixed on the countershaft z and a spring-loaded slidable sleeve b having lugs c engaging slots in the cam U and a rod k slidable through the web U1. The rod k is connected by a link h to a pivoted lever e carrying a roller f which is actuated by a cam Z to declutch the cam U, the cam Z being controlled by pawl-and-ratchet mechanism from the gearwheel K. A pin l on the gearwheel actuates a lever m, linkage q<SP>1</SP>, and a pawl r engaging a ratchet-wheel Q free on the countershaft. A holding pawl (not shown) is provided. A lug R, on the ratchet engages a lug T on disc S which carries the cam Z and is also free on the countershaft. The lever m, pawl r, ratchet-wheel Q, and disc S are all loaded by springs (not shown), the disc being biased agaist a stop 52, Fig. 2. At the beginning of an operation the cam U is clutched as shown in Fig. 2 and makes a half revolution moving the blower tube to the blowing position. The roller f and cam Z then engage to declutch the cam U, and the blower tube rotates in the blowing position until continued actuation of the ratchet causes the roller f and cam Z to disengage. The blower tube is then withdrawn, and a rocking lever (not shown) actuated by a cam aa, Fig. 1, disengages the pawls, the disc S and ratchet returning to their initial positions.