US 3097288 A
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July 9, 1963 R. B. DUNLAP FLEXIBLE CONDUCTOR CABLE Filed Jan. 27, 1960 ,IIIIIIIIIII INVENTOR.
gwwaxw 3,097,288 Patented July 9, 1963 3,097,288 FLEXIBLE CONDUCTOR CABLE Robert B. Dunlap, Medway, Mass, assignor to Jacob S. Kamborian, West Newton, Mass. Filed Jan. 27, 1960, Ser. No. 5,043 11 Claims. (Cl. 219-39) This invention relates to flexible conductors for transmitting fluid from one point to another, and more especially to a heated conductor for transmitting liquid adhesive from a heated conductor to an applicator such as a nozzle.
The principal objects of the invention are to provide a conductor in which the adhesive may be kept hot as it passes therethrough; to provide a conductor with means for heating the adhesive directly, thereby to make the most eflicient use of the heat; to provide a conductor in which there is a minimum heat loss; to provide a conductor which is flexible enough so that it can be manipulated easily to facilitate delivery of the adhesive to the work to which it is to be applied; and to provide a conductor so constructed that it will not be collapsed or damaged by such movement. Other objects are to provide a conductor which is durable and perfectly safe to use.
As herein illustrated, the conductor comprises a flexible Teflon tube, a pair of rigid ferrules having threaded portions for screw-threaded engagement with a container and nozzle respectively, a slender tip for interengagement with the ends of the tube, and means for securing the ends of the tube to the tips. Each ferrule contains a radial threaded opening through its wall, within which there is screwed an insulator sleeve which supports a conductor element with one end internally of the ferrule and the other externally thereof. A conductor wire is stretched lengthwise of the tube between the inner ends of the conductor elements and the outer portion of the tube between the conductor elements is covered with means for resisting heat loss and damage, including a flexible armor sleeve surrounding the Teflon tube, insul ation covering the armor and a braided glass fabric sleeve covering the insulation.
The invention will now be described in greater detail with reference to the accompanying drawings wherein:
FIG. 1 is an elevation of a length of flexible conductor connected to its ends respectively to a container and a nozzle and broken away intermediate its ends; and
FIG. 2 is a diametrical longitudinal section of the conductor at one end.
The conductor 10, herein shown, is intended to transmit fluid from a container 12 to a nozzle 14 and to keep the fluid hot during transmission. As constructed, the conductor has an inner Teflon tube 16, at the ends of which there are rigid ferrules 18, each of which has a threaded portion 20 for screw-threaded engagement with the receptacle 12 and nozzle 14 respectively, and a slender tapered tip 22 for interengagement with an end of the Teflon tube. A Teflon tube is preferred because it is highly resistant to heat and is very flexible. It is to be understood, however, that the tube maybe made of other materials having the desired properties of heat resistance and resistance to corrosion.
Each ferrule has a threaded opening 24 in its wall into which is screwed an insulator sleeve 26. Preferably the wall of the tip, adjacent the threaded portion, is thickened radially to provide an external boss 25 for receiving the opening 24. The sleeve 26 is internally threaded to receive a threaded metal conductor element 28 which may be adjusted therein, so that its inner end is disposed within the tip and its outer end exteriorly thereof. A metal lock nut 30 is applied to the outer end of the conductor element to fix it in place and also to secure a conductor wire w thereto. A Nichrome wire, which is helically wound, is stretched axially within the Teflon tube with its ends anchored to the inner ends of the conductor elements 28. Except for its ends the Nichrorne wire is otherwise unsupported and, as thus situated, lies centrally of the stream of adhesive flowing through the tube, so that it supplies its heat directly to the adhesive in the most eflicient fashion. Moreover, since it has no contact with the tube, except when the conductor is sharply bent, there is a minimum heat loss to the tube by direct conductance thereto. To prevent contact of the conductor wire with the tips, an insulator 34 is disposed inside of each tip.
Between the bosses 25 there is means for securing the ends of the Teflon tube to the ferrule and means for preventing loss of heat and damage to the conductor wire by internal pressure, or by moving it about, and damage to the Teflon tube by too sharp bending. The securing means comprises collars 36 forced onto the portions of the Teflon tube within which the tips are located so as to constrict the ends of the Teflon tube on the tips. If desired, the external surfaces of the tips may be threaded to improve the seal between the surfaces and the tube. Shoulders 38 are provided near the ends of the Teflon tube and the collars are forced into the shoulders so as to force the latter into firm engagement with the bosses 25. As previously stated, the tips 22 are tapered to prevent sharp contact with the inside of the Teflon tube and hence to minimize wear at these points.
To prevent expansion of the Teflon tube, due to internal pressure, stretching of the Teflon tube due to pulling too hard axially thereof and of bending the Teflon tube too sharply, an armor sleeve iii is placed about it. This armor sleeve is of the kind conventionally known as BX cable used to cover electric wires and has interlocking helical coils which permit flexing but prevent stretching and/or bending at too sharp an angle. The cable is preferably metal but maybe a tough hard plastic. The ends of the armor sleeve are fastened to the collars 36 by solder 42 or other suitable means.
To prevent loss of heat, insulation 44 is placed about the armor sleeve and this consists of a spirally wound tape made of polyurethane foam. The insulation is not durable enough for handling and, because of its porous character, would take up foreign matter, hence a tough protective sleeve 46 of braided glass yarn is applied to the external surface of the insulation.
It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.
1. A flexible conductor for transmitting fluid from a container to a nozzle, comprising a Teflon tube, a pair of metal ferrules having threaded portions for screwthreaded engagement with a container and a nozzle respectively, and slender tips for interengagement with the ends of the Teflon tube, a conductor element extending through a wall of each ferrule into the interior of the tip, means insulating the conductor elements from the ferrules, a conductor wire stretched axially within the tube with its ends anchored to the inner ends of the conductor elements, and means surrounding the tube between the conductors for resisting heat loss and damage, including metal collars securing the ends of the tube to the tips of the ferrule-s, a flexible armor sleeve surrounding the Teflon tube, means securing the ends of the tube to the tips of the ferrules, means securing the ends of the armor sleeve to the collars, insulation surrounding the armor sleeve and a braided cover encasing the insulator sleeve.
2. A flexible conductor for transmitting fluid from a container to a nozzle, comprising a Teflon tube, a pair of brass ferrules having threaded portions for screwth-readed engagement with a container and a nozzle respectively, and slender tips for interengagement with the ends of the tubes, and each having a radial threaded opening through its Wall, an insulator sleeve screwed into the threaded opening, a conductor element supported in the sleeve with one end disposed Within the tip and the other exteriorly thereof, a helically wound Nichrorne wire stretched axially, internally of the tube, with its ends anchored to the inner ends of the conductor elements, and means surrounding the tube between the conductor elements for resisting heat loss and damage, including metal collars securing the ends of the tube to the tips, a flexible metal armor cable surrounding the Teflon tube, said armor cable being soldered at its ends to the collars, a polyurethane foam insulation wrapped about the armor cable, and a braided glass sleeve covering the insulation.
3. A conductor according to claim 1, wherein each ferrule contains an internal insulator through which the conductor element extends to the interior of the ferrule and by which the ends of the conductor wire are insulated from the ferrules.
4. A conductor according to claim 1, wherein the tip of each ferrule tapers toward its extremity.
5. A conductor according to claim 1, wherein the conductor wire is unsupported intermediate its ends.
6. A conductor according to claim 1, wherein the external surfaces of the tips are threaded.
7. A conductor according to claim 1, wherein the forrules have external bosses and the ends of the tube are forced into firm engagement with them by the collars.
8. A flexible heated conduit comprising: a tube of flexible material; a ferrule having a hollow tip positioned in an end of the tube; a radially outwardly extending boss on said tip; a shoulder on said end of the tube abutting against the boss; a hollow'collar" embracing the tube end and ferrule tip for constricting the tube end on the ferrule, said collar abutting against said shoulder whereby the shoulder is interposed between the boss and the coll ar; an electrically conductive element extending radially through the boss; an electrioally conductive Wire extending axially through the tube and connected at one end to said element; and a sleeve of rigid material placed about the tube and having an end abutting against and connected to said collar.
9. The conduit according to claim 8 wherein thermally insulative material is placed about the sleeve.
10. The conduit according to claim 8 further comprising: an electrically insulative sleeve fitted in said boss,
said element extending through said sleeve.
11. The conduit according to claim 10 further comprising: an electrically insulative member disposed inside the tip and embracing the wire.
References Cited in the file of this patent UNITED STATES PATENTS