Air-powered system for routing a pulling cord through a conduit

A system for routing a pulling cord endwise through a cylindrical conduit having an inner diameter for purposes of securing the pulling cord to an item desired to be pulled through the cylindrical conduit with the pulling cord, the system comprising:

• an elongated carriage capable of being advanced along the length of the cylindrical conduit for carrying the pulling cord along the length of the cylindrical conduit as the elongated carriage is advanced therealong wherein the elongated carriage includes a disc-shaped head having a cross section which is sized to substantially span the interior of the cylindrical conduit through which the pulling cord is desired to be carried and has a circular and forwardly-directed face having an outer diameter which is within about one-half inches less than the inner diameter of the conduit through which the elongated carriage is desired to be moved, and the elongated carriage further includes an elongated stem portion which is joined to the disc-shaped head for trailing the disc-shaped head of the elongated carriage through the conduit as the elongated carriage is moved through the conduit, the disc-shaped head having a forwardly-directed face and an opposite rearwardly-directed face, and the elongated stem portion being joined to the disc-shaped head so that the elongated stem portion extends rearwardly of and is arranged substantially normal to the rearwardly-directed face of the disc-shaped head, and wherein the elongated carriage is comrised of a relatively hard and inflexible plastic material which prevents the formation of an air seal between the elongated carriage and the inner surface of the conduit;
• and
• means for delivering air, under pressure, into the conduit so that by securing the pulling cord to the elongated carriage, inserting the elongated carriage head-first into the conduit and then delivering air, under pressure, against the rearwardly-directed face of the disc-shaped head, the elongated carriage is moved along the length of the conduit with the pulling cord.

A system for routing a pulling cord endwise through a cylindrical conduit having an inner diameter for purposes of securing the pulling cord to an item desired to be pulled through the conduit with the pulling cord, the system comprising:

• an elongated carriage capable of being advanced along the length of the cylindrical conduit and for carrying the pulling cord as the elongated carriage is advanced along the length of the cylindrical conduit wherein the elongated carriage includes a disc-shaped head having a cross section which is sized to substantially span the interior of the cylindrical conduit through which the pulling cord is desired to be carried and an elongated stem portion which is joined to the disc-shaped head for trailing the disc-shaped head of the elongated carriage through the conduit as the elongated carriage is advanced through the conduit, the disc-shaped head having a circular and forwardly-directed face and an opposite circular and rearwardly-directed face, wherein the forwardly-directed face of the disc-shaped head has an outer diameter which is within about one-half inches less than the inner diameter of the conduit through which the elongated carriage is desired to be advanced and wherein the elongated stem portion is joined to the disc-shaped head at about the center of the rearwardly-face thereof so that the elongated stem portion is arranged substantially normal to and extends rearwardly of the rearwardly-directed face of the disc-shaped head, and wherein the elongated carriage is comrised of a relatively hard and inflexible plastic material which prevents the formation of an air seal between the elongated carriage and the inner surface of the conduit and is devoid of a conduit-engaging skirt portion for extending along the inner surface of the conduit, and
• means for delivering air, under pressure, into the conduit so that by securing the pulling cord to the elongated stem portion of the elongated carriage, inserting the elongated carriage head-first into the conduit and then delivering air, under pressure, into the conduit so that the rearwardly-directed face of the disc-shaped head is exposed to the delivered air, the elongated carriage is advanced along the length of the conduit with the pulling cord.