Abstract: A compact forced air heater comprises a combustion chamber mounted in a housing, a burner module mounted across a back open end of the combustion chamber adjacent a back wall of the housing for producing heated air in the combustion chamber, an air intake in a front wall of the housing, and a high speed (3000 rpm) forced air blower mounted between the combustion chamber and the housing front end wall. The burner module includes a flameholder plate having a central primary air hole and circular rows of staggered secondary air holes surrounding the primary air hole. A flamespreader plate is mounted on the flameholder plate opposite the primary air hole, and an elongated right-angle burner tube, having a flattened locating-and-orienting end and at least one burner orifice in a sidewall of the tube, is located on an opposite side of the flameholder plate with the burner orifice aligned with the primary air hole and the flamespreader plate. An ignitor and a thermocouple are also mounted on the flameholder plate.

Abstract: A releasable latching device (32) for a portable circular power saw (10) includes a pivotable latch member (32) for releasably latching or locking a guard member (22) for a rotary saw blade (20) in a guarding position, to preclude serious injury to an operator during use of the saw. The latch member (34) includes a hook (44) engagable in a first retaining notch (46) or a second retaining notch (50) in a hub (48) of the guard member (22) for this purpose, depending upon whether the saw (10) is being used to make a straight cut or a 45.degree. cut. The latch member (34) is retained in a latching positon by a spring biased push rod (52) and is moved to an unlatching position by operation of the push rod.

Abstract: A forced air heater (10) includes a removable burner module (26) in which all of the burner components are mounted on a common support plate (42) to facilitate mounting of the burner module in the heater and removal of the burner module from the heater for servicing. An elongated burner tube (46) has a closed flattened end (50) receivable in a location-and-orienting bracket (76) to locate a single burner orifice (52) in a sidewall of the tube in proper position with respect to a pancake flame-spreader plate (78). A gas valve (44) and ignition device (58) also form part of the burner module 26. A combustion chamber (24) is of essentially box-shaped construction, with one open end (36), and includes an inclined baffle plate (40) which enhances mixing of combustion products and intake air in the chamber. A forced air blower (28) is mounted adjacent a heated air discharge opening (36b) of the combustion chamber (24).