Abstract: A device is provided for lifting and lowering objects to and from a deployed tree stand by an occupant of the tree stand. The device has a clamp connectable to a rigid support member of the stand, a threaded shaft connected to the clamp, a reel mounted on the shaft, and a threaded knob also mounted on the shaft, the knob having an inner portion with a contacting surface which comes into contact with a mating contact surface of the reel upon turning of the knob by the occupant. Upon making contact, the reel is slowed down and may be stopped by braking action. This enables control over movement, which may be stopped and restarted, as well as slowed down at any location.

Abstract: A clogged filter detection system has an optical transmitter (32) aligned to pass light through an air filter (14) of an HVAC air flow plenum, a receiver (34) including a sensor and positioned to receive the transmitted light (48) directly or from a reflector (42), a processing assembly (35) receiving signals from the sensor and communicating a visual (104) or audible (106) indication when an accumulated level of obscuration exceeds a predetermined level and a component support structure. The support structure uses a “U” or “L” shaped bracket (60,63) attached to peripheral structure of a filter receptacle frame (12) and one or more side plates (24,26) of the bracket are connected to an arm (74,76) on which components are carried. The transmitter (32) and receiver (34) may be located on opposite sides of the filter (14) or on the same side, with a retroreflector (46) on the other side. The processing assembly includes a microprocessor (94) and related devices.