US3034766A - Apparatus for installing lines through conduits - Google Patents

Description

y 1962 J. c. HAMRICK 3,034,766

APPARATUS FOR INSTALLING LINES THROUGH CONDUITS Filed Nov. 18, 1958 INVENTOR: IAMss c. HAMIZRK.

ATTORNEYS nited States atent Ofitice 3,034,766 Patented May 15, 1962 3,034,766 APPARATUS FOR INSTALLING LINES THROUGH CONDUITS James C. Hamrick, Charlotte, N.C., assignor to Jet Line Products, Inc., Charlotte, N.C., a corporation of North Carolina Filed Nov. 18, 1958, Ser. No. 774,617 1 Claim. (Cl. 254134.4)

This invention relates to an apparatus for installing a guide line through a conduit, thereby permitting the guide line to be utilized in subsequently drawing a relatively rigid line or similar elongated article through the conduit which, because of its particular physical characteristics, cannot be initially passed through the conduit without experiencing great difiiculty.

The present apparatus constitutes an improvement over the invention disclosed in co-pending United States patent application 674,930, filed July 29, 1957, now U.S. Patent 2,930,584, issued March 29, 1960, of which I am a joint inventor, and is complementary to the method and apparatus disclosed in my co-pending United States patent application, Serial Number 774,715, filted November 18, 1958.

The practice of passing a guide line through a conduit for subsequently drawing another line, cable, or the like through the conduit by attaching it to the guide line has heretofore been accomplished through the use of a rubber ball-like projectile to one end of which the guide line is attached. This rubber ball-like projectile has a diameter large enough to provide a seal with the bore-defining wall surface of the conduit through which the guide line is to be passed. The rubber ball-like projectile, drawing the guide line thereafter, is forced through the conduit by employing a separate source of pneumatic or hydraulic pressure. Under such a procedure, the operator must have an available source of pressure for forcing the rubber ball-like projectile through the conduit. This method is likely to be relatively slow and inefficient because an effective propelling pressure must be maintained behind the rubber ball-like projectile. This requirement cannot be efiiciently fulfilled if the conduit through which the guide line is to be passed is not leakproof. Moreover, the bore diameter of the conduit must be maintained substantially uniform throughout its length, while the rubber ball-like projectile must be of a specific size with respect to the bore diameter of each individual conduit for providing a seal between the projectile and the bore-defining wall surface of the conduit to prevent the escape of propelling pressure therebetween which could otherwise cause the projectile to fail in drawing the guide line through the conduit. Increased amounts of propelling pressure must be supplied where the conduit through which the guide line is to be passed is extremely long or possesses a number of angular bends therein, the aforesaid circumstances also adding to the complicated problem of maintaining a seal between the rubber ball-like projectile and the bore-defining wall surface of the conduit.

In my co-pending United States patent application, Serial Number 774,715, filed November 18, 1958, I have disclosed the concept of providing a line package attached to the trailing end of a self-propelled cartridge projectile utilizing a gaseous substance as a propellant, wherein the line package is drawn behind the projectile as it travels through the conduit, while the line unwinds from the line package in response to its movement through the conduit. The nature of this method is such that the line package utilized therewith can only be used for a single run through a conduit and must be discarded thereafter even though some of the line in the line package may remain unused after the line package has been drawn through the conduit by the projectile. Moreover, the line package for practical purposes has an elongated cylindrical shape, the length of which will not permit its use in conduits possessing relatively small bore diameters and exceptionally sharp angular bends therein. In the latter instance, the elongated line package will probably be unable to traverse a sharp angular bend in a small-bore conduit and is likely to become wedged in the conduit.

It is therefore the object of this invention to provide an improved apparatus for installing a guide line through a conduit, the improved apparatus including a cartridge projectile adapted to be fired into one end of the conduit by a hand tool or gun upon which a line can is releasably mounted, and the line can containing a dispensable supply of line attached to the trailing end of the cartridge piojectile. The line is pulled through the conduit by the cartridge projectile as it travels therethrough, being dispensed from the line can.

An object of the invention having been stated, other objects will appear as the description proceeds, when taken in connection with the accompanying drawings, in which FIGURE 1 is a side elevational view of the improved apparatus for installing a guide line through a conduit;

FIGURE 2 is an enlarged end elevational view of the line can and the mounting clip shown in FIGURE 1;

FIGURE 3 is a greatly reduced schematic side elevational view showing cartridge projectiles with attached guide lines fired into opposite ends of a conduit for entanglement of the lines within a medial portion of the bore thereof;

FIGURE 4 is an enlarged elevational View, illustrating the two cartridge projectiles and their respective attached lines approximating the relationship they will assume in the conduit shown in longitudinal section upon one line being grasped after the cartridge projectiles have been fired in the manner indicated in FIGURE 3; and

FIGURE 5 is an enlarged elevational view, similar to that shown in FIGURE 4, but illustrating the positions assumed by the two cartridge projectile and their attached lines upon one of the lines being pulled in the direction indicated by the arrows from a point located outside of one end of the conduit.

Referring more specifically to the drawings, in FIG- URE 1, there is illustrated a hand tool or gun 10 having a barrel 11, the gun 10 preferably being of the same type disclosed in my co-pending United States patent application, Serial Number 774,715, filed November 18, 1958. A line can 20 is releasably mounted on the barrel ll of the gun 10 by suitable means, such as a resilient spring clip 21 having oppositely disposed U-shaped portions for releasable reception of the barrel l1 and line can 20 respectively. The line can 20 comprises a cylindrical opentopped container 22 in which is coiled a supply of flexible, pliable line L. The open top of the cylindrical container 22 is closed by a cover or lid 23 having a central aperture 24 therein through which one end portion of the line L within the container 22 is passed for a purpose to be subsequently described. The annular lid portion immediately surrounding the aperture 24 juts outwardly from the remainder of lid 23 providing a radially inwardly tapering entrance mouth 25 for the aperture 24 which decreases the frictional drag of the line L on the lid portion surrounding the aperture 24 to facilitate the dispensing of line L therethrough. The lid 23 also preferably includes punched-out tabs 26. The lid or cover 23 may be attached to the cylindrical container 22 in any suitable manner, such as the threaded engagement shown. To prevent the opposite end of the line L from being drawn away from the line can 20, it may be trapped between the lid 23 and the edge of the cylindrical container 22 receiving the lid 23.

A launching attachment 30 is releasably secured to the forward end of the barrel 11 of gun 1d, the launching attachment 30 comprising an elongated barrel member 31. The barrel member 31 is provided with a longitudinal bore extending therethrough for reception of a cartridge projectile 32 therein. As in the launching attachment disclosed in my co-pending United States patent application, Serial Number 774,715, means in the form of a leaf spring 40 is secured at one end to the external surface of the barrel member 31 by a screw S. The other end of leaf spring 40 has a projection or lug 41 thereon extending inwardly within the longitudinal bore of the barrel member 31 through an aperture provided in the wall of the barrel member 31 for releasably and resiliently retaining the cartridge projectile 32 within the barrel member 31 preparatory to the firing of gun for launching the cartridge projectile 32.

When the line can 20 is not in use, the end portion of the line L extending therefrom is tucked beneath the tabs 26 formed in the lid 23 to prevent the unwinding of the line L within the cylindrical container 22. To prepare for launching the cartridge projectile 32, the end portion of the line L which is passed through the aperture 24 in the lid 23 of line can 20 is disengaged from the tabs 26 and attached to the rear end portion of the cartridge projectile 32 by suitable means, such as a split ring circlet 44- to which the line L is tied, as shown in FIGURES 4 and 5.

The cartridge projectile 32 contains a gaseous propellant substance, such as compressed carbon dioxide. Upon the rear end of the cartridge projectile 32 being punctured by the firing of the hand tool or gun 10, the cartridge projectile 32 is thrust forwardly away from the launching attachment 30 by the escape of gas from its rear end.

As shown in FIGURE 3, upon inserting the launching attachment 30 of the hand tool or gun 10 within one end of a conduit C with a cartridge projectile 32 loaded within the launching attachment 30 and having the end of line L extending from the line can 20 attached thereto, the subsequent firing of the gun 10 projects the cartridge projectile 32 forwardly through the conduit C, the cartridge projectile 32 drawing the line L from the line can 20 thereafter. The line L is coiled in line can 20 to unwind from a longitudinal axis thereof outwardly, such an arrangement reducing the frictional drag of the line L against the cylindrical container 22.

It is contemplated that the present apparatus is especially adapted for use where the conduit C is relatively long and/or of small bore diameter. It is impractical to use a cartridge projectile containing a sufficient volume of gaseous propellant substance therein for traversing the complete length of a conduit where the conduit is so long as to require a rather bulky cartridge projectile. Therefore, in using the present apparatus according to one method, the gaseous propellant is allowed to be completely exhausted from the cartridge projectile 32, whereupon the forward thrust developed by the cartridge projectile 32 will diminish and the cartridge projectile 32 will eventually stop. As illustrated in FIGURE 3, the cartridge projectile 32 fired from the right-hand end of the conduit C has come to rest within a medial portion of the bore of conduit C, it being noted that the cartridge projectile 32 is disposed beyond the middle of conduit C and closer to its left-hand end. A second cartridge projectile 32 is then loaded into the launching attachment 3% of the gun 10 for projection through the opposite or left-hand end of the conduit C. If the same gun It) is to be used, the end of the line L protruding from the right-hand end of the conduit C is appropriately secured to some point outside of the conduit C was sufficient slack therein to enable the line L to extend completely through conduit C, thereby permitting the use of the same line can 20 and the supply of line therein in firing the second cartridge projectile 32 into the opposite end of conduit C. As before, the line is attached to the rear end of the cartridge projectile 32' by a circlet 44. For purposes of clarity, the line attached to cartridge projectile 32 will be designated L.

The gun 10 is again fired to launch the cartridge projectile 32 through the conduit C from the left-hand end thereof, as shown in phantom lines in FIGURE 3. The cartridge projectile 32 is provided with sufiicient forward thrust to travel past the location of the cartridge projectile 32. The lines L and L attached to the respective cartridge projectiles 32 and 32' inevitably become entangled, as illustrated in FIGURE 4. The operator then grasps the end of either line L or L which protrudes from a respective end of the conduit C and pulls against this line in a direction outwardly of the end of the conduit C.

In FIGURES 4 and 5, the line L is being pulled in the direction indicated by the arrows, which results in the cartridge projectile 32 being drawn against the cartridge projectile 32 and the lines L and L becoming securely ensnarled. Thus, as the operator withdraws line L from the conduit C, line L is drawn through the remaining portion of the conduit C which it has not traversed. Continued withdrawal of the line L moves the entangled cartridge projectiles 32 and 32' toward the lefthand end of the conduit C where they can be grasped by the operator to complete the installation of the line L through the conduit C, whereupon line L may serve as a guide line for subsequently drawing a relatively rigid line or similar article through the conduit C.

Although the use of a single hand tool in firing cartridge projectiles through opposite ends of a conduit has been described, it is contemplated that separate guns may be provided for each end of the conduit C in which case, the cartridge projectiles 32 and 32 may be launched into opposite ends of the conduit C simultaneously by separate operators.

While to outward appearances, the ensnarling of the cartridge projectiles 32 and 32' together with their attached lines L and L would appear to be largely a matter of chance resulting in a rather inefficient method of installing a line through a conduit, it has been established that the necessary entangled condition of the cartridge projectiles 32 and 32 and their attached lines L and L occurs almost without fail. Through the use of the method employing the apparatus embodying the present invention, a guide line may be passed completely through a conduit which ordinarily defies attempts to accomplish this feat through conventional procedures.

I have therefore disclosed an improved apparatus for passing a guide line through a conduit wherein the guide line is to be used for subsequently drawing a rigid line, cable, or the like through the conduit. The improved apparatus may be used in a method which relies upon the firing of cartridge projectiles having lines attached thereto through opposite ends of the conduit so that the cartridge projectiles and their attached lines may become ensnarled, whereupon one of the lines may be withdrawn from the conduit to draw the other line through the portion of the conduit which it did not initially traverse.

The apparatus which includes a hand tool or gun upon which a line can containing a dispensable supply of line is releasably mounted and a cartridge projectile having one end of the line attached thereto can also be employed to install a guide line completely through a conduit by firing a single cartridge projectile through the conduit where the length of the conduit will permit this. In contrast to the line package disclosed in my co-pending United States patent application, Serial Number 774,715, which may be used only once in passing a guide line through a conduit, the line can 20 may be used repeatedly until its supply of line L is exhausted.

In the drawings and specification there has been set forth a preferred embodiment of the invention and, al-

though specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claim.

I claim:

In combination, a hand tool for installing a line through a conduit, said hand tool including a barrel containing a cartridge projectile, a line can, means releasably mounting said line can on said barrel, said means comprising a first pair of interconnected resilient arms defining a substantially U-sha-ped upper portion clampingly gripping the line can, a second pair of interconnected resilient arms defining a substantially U-shaped lower portion connected to said U-shaped upper portion in oppositely disposed relation thereto, and spring fingers integral with the 1,,

lower ends of said second pair of arms, said spring fingers extending upwardly between said second pair of arms in spaced underlying relation thereto and clampingly gripping said barrel therebetween within said U-shaped lower portion, said line can comprising a cylindrical container 20 holding a coiled line supply and a lid closing said cylindrical container, said lid being provided with a central aperture, an outwardly jutting radially inwardly tapered entrance mouth on said lid surrounding said aperture, one end of the line from said coiled line supply being disposed adjacent the longitudinal axis of said cylindrical container, said one end of line being guided by said entrance mouth through the aperture in said lid and attached to said cartridge projectile, and tab means struck out of said lid for reception of said one end of line therebehind to prevent said line supply from unwinding.

References Cited in the file of this patent UNITED STATES PATENTS 526,141 Bloomer Sept. 18, 1894 2,069,276 Ryan Feb. 2, 1937 2,490,032 Cunningham Dec. 6, 1949 2,515,953 Dufresne July 18, 1950 2,966,337 Knapp Dec. 27, 1960 FOREIGN PATENTS 41,895 Denmark Mar. 12, 1930

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