Y-Connection for Flexible Conduit

In ductwork it is often necessary to connect a thin-wall metal tubular conduit into a main conduit at an acute angle to make what is commonly referred to as a Y-connection. Several devices have been proposed for making such a connection when the main conduit is relatively rigid such as those disclosed in patents to: Cornell U.S. Pat. No. 1,908,821; Jones U.S. Pat. No. 3,406,988; and Plauka et al., U.S. Pat. No. 3,873,391. The Cornell patent teaches the use of a rigid saddle, that is arranged to overlie the hole in the main conduit, with the branch conduit disposed over a sleeve integrally formed on the saddle; the Jones patent discloses the use of a flexible sleeve to make the connection; and the patent to Plauka et al. concerns a method of connecting the branch conduit to the main conduit without using any auxiliary connector members. Another way of making this connection involves a plurality of tabs extending from the lower end of the branch conduit that are arranged to project through the hole in the main conduit and be bent back to hold the branch conduit on the main conduit. The prior art concerning Y-connections for a flexible main conduit is very limited. To applicants knowledge, only one patent is directed to such a device and that is the patent to MacDonald U.S. Pat. No. 3,120,965 which discloses apparatus for making a Y-connection, at the point not over a hole in the main conduit, but where two flexible metal conduits are joined. Again, this disclosure concerns the use of a saddle adapted to be disposed on the outside of the two pipes.

Accordingly, it is an object of the present invention to provide an improved Y-connection for a conduit. A further object is to provide apparatus for making a Y-connection over a hole in a thin-wall flexible metal conduit.

A Y-connection comprises an inner shoe adapted to be disposed internally of a flexible main conduit around a hole cut therein to provide a backing member around the hole, an outer saddle disposed over the hole and having an aperture in alignment with the aperture in the inner shoe and with the hole in the main conduit, a branch conduit connected to the saddle, and means for fastening the saddle and the inner shoe together with the flexible main conduit sandwiched therebetween. The inner shoe is provided with means for holding it in place while the saddle is being positioned, and the branch conduit also has means for holding it in position on the saddle while means for making a more secure joint between these members is being applied at the junction between the members.

FIG. 1 is a side elevation of the Y-connection of the present invention, partly broken away and partly in section.

FIG. 2 is a diagrammatic exploded perspective of the connection of FIG. 1.

FIG. 3 is a section taken along lines 3--3 of FIG. 1.

In FIG. 1 the reference numeral 10 indicates a thin-wall metal main conduit which has a plurality of grooves or corrugations 11 extending around its periphery to provide the conduit with a degree of flexibility. A hole 12 (FIG. 2) is cut through the wall of the main conduit. The connection of the present invention includes an inner shoe 14, a saddle 16 and a short section of a branch conduit 18. The inner shoe 14 is a thin sheet metal member which is provided with a hole 20 that has substantially the same configuration as the hole in the conduit. The hole 20 is so cut in the shoe that a plurality of tabs 22 are left to project into the opening. To lock the inner shoe to the main conduit, the shoe is placed against the inner wall of the conduit with the hole 20 in the shoe in alignment with the hole 12 in the conduit, and then the tabs 22 are bent to extend through the hole 12 and then are pressed back against the outer face of the conduit as seen in FIG. 1.

The saddle 16 (FIG. 2) is a thin sheet metal member having a hole 23 therethrough, which corresponds substantially to the holes 12 and 20 in configuration. Both the shoe 14 and the saddle 16 are dimensioned to extend around about 160.degree. of the periphery of the conduit 10.

The section of the branch conduit 18 is cut off at an angle such that, when it is connected to main conduit 10, the desired angle "A" (FIG. 1) between the conduits 10 and 18 is obtained. The branch conduit 18 is attached to the saddle 16 before the saddle is connected to conduit 10, at a time when the saddle has been bent to a curvature corresponding to the curvature of the outer surface of conduit 10. According, the angled cut at the end of the conduit 18 must be curved along its sides, as indicated at 18a (FIG. 2) so that the edge of the conduit will lie close to the curved edge around the hole 23 in the saddle.

The branch conduit 18 is secured on the saddle 16 by tabs 24 (FIG. 3) that extend outwardly from the lower curved edge of the conduit 18. To make this connection the saddle 16 is held in its final curved position, and the conduit 18 is moved endwise toward the hole 24 in the saddle so that its end extends into the opening 23. The tabs 24 are inserted into the hole and then bent outwardly to lie flat against the inner surface of the saddle around the hole 23. Rivets 24a or spot welds or other suitable means firmly secure the tabs to the saddle.

After the branch conduit 18 is locked on the saddle 16, a suitable sealant 26, such as a silicon sealant in heavy paste-like form, is spread over the joint between the outside surface of the saddle around the opening 23 and the lower outer surface of the conduit 18. Also, sealant is spread over the joint between the inner surface of the saddle 16 around the hole 23 and the lower end of the conduit 18.

It will be understood that the configuration of the openings in the conduit 10, in the shoe 14 and in the saddle 16 will vary from round to oval depending upon the desired angle of intersection between the two conduits.

After the inner shoe 14 has been locked to the inner surface of conduit 10 and the branch conduit 18 is sealed to the saddle 16, the saddle 16 is positioned over the hole 12 in conduit 10, as indicated in FIG. 2, and secured thereto by sheet metal screws 30.

It will be noted that in the completely assembled condition, the tabs 22 of the inner shoe 14 and the tabs 24 of the saddle 16 are disposed between the inner surface of the saddle 16 and the outer surface of the conduit 10. Thus the tabs 22 of the inner shoe 14 do not interpenetrate into the saddle 16 and the tabs 24 of the saddle 16 do not interpenetrate into the inner shoe 14. These may partially overlie each other or they may be located so that they interdigitate and do not overlie each other. For example, the six tabs 22 of the inner shoe may be positioned on the longitudinal centerline X--X of the hole 20 and at 45 degrees relative to the centerline; and the positions of the tabs 24 of the branch conduit relative to the longitudinal centerline Y--Y of the hole in the saddle 16 can then be selected so that the two sets of tabs do not interfere with each other.