Abstract: A foldable hoist, fall-arrest and recovery system to be used in connection with a rectangular manhole guard having vertical posts at four corners of the guard including an upper structure having four elongated support members forming a pyramid shaped structure with the base of each of the support members being securely mounted to the top of a post on the manhole guard and the other ends of the support members being pivotally connected to an apex so that the upper structure can be folded for storage and shipment when disconnected from the base and means connected at the apex for raising and lowering workers and/or cargo into and out of the manhole or for arresting the fall or recovering a worker.

Abstract: An assembly for directing air to a desired location for use as an air blower, carpet drier or the like. An air blower component in a preferred embodiment includes an outlet having attachment means engageable with a separate component such as a ducting housing or carpet drier attachment, through engageable lugs.

Abstract: A gas-fired construction heater which meets the applicable ANSI Standard and operates to supply heated air separately from products of combustion. The products of combustion are permitted to contain no more than a specified percent of carbon monoxide when uncontrolled heater operating conditions are within predetermined ranges. The uncontrolled operating conditions include variations in input rate and supply voltage. A combustion chamber produces the products of combustion and has primary and secondary combustion zones. A heat exchanger receives the products of combustion and transfers heat therefrom to fresh air to be heated. The chamber and the heat exchanger define a tertiary combustion zone. Inlets supply a separate natural combustion draft to each of the primary and tertiary combustion zones. The inlets include a first and a third fixed-area inlet for respectively supplying the separate natural drafts to the primary and tertiary combustion zones.

Abstract: A hub for providing an articulating interconnection between the ends of tent frame struts, comprising a base member and a cap member rotatably interconnected by a common axis of rotation to form an encasement having a plurality of interior cavities equally spaced radially from the common axis, a like plurality of elongated windows each having top and side framing portions and a sill, each in communication with one of the cavities, a like plurality of radial slots in the base member in respective communication with one of the said windows and a like plurality of sockets, each having a spherical terminating end portion and disposed in each of said cavities.

Abstract: A self supporting collapsible tent structure having a tension bearing polygonal shaped floor member defining a first tent level, a plurality of hub members each carrying a plurality of sockets which are pivotal about axes which are co-planer and are interrelated one to the other as the sides of polygon, a series of said hub members disposed in a plane at a second tent level which is spaced apart from said first tent level and whose sockets are pivotal in a first direction, and additional series of said hub members disposed in a plane at a third tent level which is spaced apart from said second tent level and whose sockets are pivotal in a second direction, opposite to the said first direction, a single, apex forming hub member disposed at a fourth tent level and whose sockets are pivotal in said first direction, a first plurality of compression rods, the ends of which are seated in the said sockets of the hub members in slightly curved polygonal planes defined and bounded by the rod members and a second plura

Abstract: A tenting structure with two angularly related sidewalls forming a roof and having at least one collapsible frame for externally supporting each of the sidewalls and where the frame includes a hub radially carrying a plurality of flexible struts whose distal ends are secured in external pockets positioned around the edges of each of the sidewalls and where the frame is sized and dimensioned in respect to the sidewalls that the frame members take on a compression induced dish shaped outward bow. The hub includes a plurality of pivotal strut mounting sockets which rotate about their pivotal axis to a discrete splayed position and to a definitive stowed position.