Flue shield

Abstract

A flue shield comprising a cylindrical body, a first portion and second portion connected at each end of the cylindrical body, each first portion and second portion comprising projections extending radially inward of the cylindrical body, the projections for each of the first portion and second portion being biased in a predetermined axial direction with respect to the cylindrical body, the projections pressingly engagable and slidingly engagable with a pipe, and the first portion and second portion each describing a bore having an inside diameter less than a cylindrical body diameter whereby a space is created between the pipe and the cylindrical body.

Description

FIELD OF THE INVENTION

The invention relates to a flue shield comprising a lanced support collar for sliding engagement with a flue pipe.

BACKGROUND OF THE INVENTION

In the art a vent or flue pipe is assembled up through roof trusses before the roof deck is installed. Although there may be adequate space between undecked trusses when the vent or flue is initially installed, it is not unusual for the decking to be later installed tightly around the vent or flue pipe without a minimum clear air space as required for fire safety. Correcting this situation requires a contractor to return to the job to cut a clearance hole in the roof decking around the vent or flue at significant additional expense.

Representative of the art is U.S. Pat. No. 6,997,801 to Green discloses a roofing vent that includes a base a duct extending from the base. The duct includes a first end attached to the base and a second end having a hood or cover over the second end. A collar having an aperture therethrough is mounted from the duct such that the duct extends through the aperture, with the collar is slideably supported along the duct and captured between the base and the hood or cover.

What is needed is a flue shield comprising a lanced support collar for sliding engagement with a flue pipe. The present invention meets this need.

SUMMARY OF THE INVENTION

The primary aspect of the invention is to provide a flue shield comprising a lanced support collar for sliding engagement with a flue pipe.

Other aspects of the invention will be pointed out or made obvious by the following description of the invention and the accompanying drawings.

The invention comprises a flue shield comprising a cylindrical body, a first portion and second portion connected at each end of the cylindrical body, each first portion and second portion comprising projections extending radially inward of the cylindrical body, the projections for each of the first portion and second portion being biased in a predetermined axial direction with respect to the cylindrical body, the projections pressingly engagable and slidingly engagable with a pipe, and the first portion and second portion each describing a bore having an inside diameter less than a cylindrical body diameter whereby a space is created between the pipe and the cylindrical body.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and form a part of the specification, illustrate preferred embodiments of the present invention, and together with a description, serve to explain the principles of the invention.

FIG. 1 is a side view of the flue shield.

FIG. 2 is a detail of a collar.

FIG. 3 is a detail of a collar.

FIG. 4 is an end view of the flue shield at 4-4 on FIG. 1.

FIG. 5 is a side view of the shield installed in a roof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a side view of the flue shield. Flue shield 10 comprises a cylindrical body 11. Cylindrical body 11 comprises metal or galvanized metal suitable for high temperature service.

Engaged with each end of body 11 are collars 12, 13. Each collar 12, 13 comprises a bore 30 into which a flue is inserted. Crimps, peens, tack welds or other suitable adhesive 122, 132 are applied to secure each collar 21, 13 to body 11.

Each collar 12, 13 further comprises a lanced portion 121, 131, respectively. Lanced portion 121, 131 comprises an annulus that projects inward of body 11 in a radial direction. A plurality of radially oriented, partial cuts 123, 133 are present in each portion 121, 131, see FIGS. 2, 3. The cuts create a plurality of adjacent projections or tabs 125, 135 that project radially inward of body 11.

Each portion 121, 131 is slightly bent so as to cause each to be flared or biased in a predetermined axial direction in body 11.

The inside diameter “ID” of each collar 12, 13 is slightly less than an outside diameter “OD” of a vent or flue pipe 400, see FIGS. 1 and 4. This dimensional feature, along with the tab bias, causes each collar to grip the flue or vent pipe. As the collar grips the flue or vent pipe each tab 125, 135 is flexed slightly to assure a good grip to prevent inadvertent movement of the shield during other construction activities that will occur near the flue or vent pipe. Namely, the projections are pressingly engagable and slidingly engagable with a vent pipe.

The flue shield creates and a gap or air space 200 between the body 11 and flue or vent pipe 400. Space 200 prevents contact of the hot flue pipe with roofing materials.

FIG. 2 is a detail of a collar. Radial cuts 123 are disposed on a substantially equal spacing about portion 121. Tabs 125 are flexible to accommodate engagement with a vent or flue pipe.

FIG. 3 is a detail of a collar. Radial cuts 133 are disposed on a substantially equal spacing about portion 131. Tabs 135 are flexible to accommodate engagement with a vent or flue pipe.

FIG. 4 is an end view of the flue shield at 4-4 on FIG. 1. Shield 10 is installed by sliding it down over a flue 400. Flue 400 will usually extend through roof trusses to a location coplanar with the roof decking. Collars 12, 13 center the shield and allow it to be pushed down the installed flue or pipe 400. The shield keeps the roof decking a minimum distance away from the vent or flue, thereby creating a cool air space 200 between the vent or flue pipe and the body 11, see FIG. 1. The shield does not interfere with other vent of flue parts that may eventually be installed and can be pushed farther down the flue or vent out of the way if necessary after the roof decking has been installed. The shield will stay in position on the flue or vent pipe due to the action of the flexed tabs 125, 135. Due to the predetermined orientation of tabs, 125, 135, the shield must be installed in a certain direction “D”. The shield will slide over the vent or flue pipe in direction “D”, but cannot be pulled back in the opposite direction. Direction “D” is opposite the direction of the bias of tabs 125, 135.

FIG. 5 is a side view of the shield installed in a roof. Shield 10 is shown in a coplanar position with respect to roof decking “R”. Shield 10 is slidingly installed by being pushed in direction “A” down pipe 400. Shield 10 may remain in place through construction completion or may be pushed below the roof line as needed.

Although forms of the invention have been described herein, it will be obvious to those skilled in the art that variations may be made in the construction and relation of parts without departing from the spirit and scope of the invention described herein.

Claims

1. A flue shield comprising:

a cylindrical body;

a first portion and second portion connected at each end of the cylindrical body;

each first portion and second portion comprising projections extending radially inward of the cylindrical body, the projections for each of the first portion and second portion being biased in a predetermined axial direction with respect to the cylindrical body, the projections pressingly engagable and slidingly engagable with a pipe; and

the first portion and second portion each describing a bore having an inside diameter less than a cylindrical body diameter whereby a space is created between the pipe and the cylindrical body.