Coupling for fire hose with built-in communication cable

Abstract: The present invention which relates to a coupling for a fire hose with built-in communication cable includes an inner cylinder, with identical shape for the male and female units, in which a hose with built-in communication cable is fitted in the base end part and an annular conductor, to which is applied electrical insulation and water-proofing, is provided on the opening face on its tip, and an outer cylinder engaged idly with the outer periphery of the inner cylinder, and provided with at least one set of an engaging claw part serving as male side and an open­ ing window serving as female side, on the same face as that of the opening end of the inner cylinder, to improve the linking operability between the hoses. On the other hand, when couplings are fitted to the respective ends of the hoses, the communication cable is interposed between the jacket part and the protective cushion of the hose so as to protect it from being broken, and is tightened.

Description: FIELD OF THE INVENTION AND RELATED ART STATEMENT : The present invention relates to a coupling for fire hose with built-in communication cable. In fire fighting with a fire-fighting vehicle or the like, it is necessary to control the rate of water discharge depending upon the conditions at the scene of the fire. Because of this, what is usually done is to control the pressure of water supplied to the fire hose by adjusting the opening of the throttle valve of the engine or to control the rate of supplied water by opening or closing the discharge valve, based on information on the fire condition given to the personnel on the fire engine by means of radio communication or a liaison fire man. However, in a fire, it is general that the total number of fire hoses in use amounts to a large number because a plurality of fire hoses are connected to about four discharge ports provided for one fire engine. In particular, it is usual that there are gathered several or ten odd fire engines on the scene of the fire, each of them using fire hoses as described in the above. Accordingly, due to radio interference or insufficient number of available fighting personnel, it used to be difficult to transmit information that corresponds to the conditions of the fire scene necessary for adjusting the pressure or flow rate of supplied water, to persons stationed at the fire engine. Further, in the case of controlling the rate of water discharge by exclusively adjusting the rotation speed of the engine while leaving the valves of all of the discharge ports, flow rate of supplied water from each of the discharge ports is uniform, so that it was not possible to control the rate of supplied water in response to a detailed situation of the fire scene aimed at by each of the discharge ports. Under these circumstances, there was proposed in the past a coupling structure in which a connecting terminal for communication cable is arranged on each of the opposing faces of couplings with built-in communication cable that are to be mutually connected, by interposing a pressure-sensitive conductor whose resistance in the axial direction alone can be varied by the axial compression of the coupling between the connecting terminals (Japanese Patent Provisional Publication, No. 62-27972 (No. 27972/1987)). Such a hose has an advantage that it can import the conditions of the fire scene by means of a communication cable. In addition, there was disclosed a device in which a cable is incorporated in the axial direction of a ring-shaped insulating body in place of the pressure-sensitive conductor in the above system (Japanese Utility Model Provisional Publication, No. 63-103087 (No. 103087/1988) and Japanese Utility Model Application, No. 62-50735 (No. 50735/1987)). However, the pressure-sensitive conductor requires more cost and time for its manufacture, and moreover, the accuracy of change in the resistance obtained falls short of one's expectation. In addition, in the type with built-in cable, it tends to cause defective contact due to bending of the wire caused by the tightening of the coupling. Further, there used to be a difficulty that it leads to a delay in starting the fire fighting activity because of the time it requires for completing the connection of the couplings that have identical shape for both of the male and female parts. On the other hand, the prior art fire hose is connected to the coupling by inserting an end of the hose to a hose connecting part having saw-tooth engaging peripheral grooves, and binding it with a fastening piece. However, there was a problem that with such a connection structure it is not sufficient to prevent leakage of water. In view of this, the present applicants proposed previously a connective for fire hose which enables secure engaging of a fire hose with a coupling as well as prevention of leakage (Japanese Utility Model Publications, No. 58-28625 (No. 28625/1983) and No. 58-28626 (No. 28626/1983)). However, when the above-mentioned connective device is applied to the fire hose with built-in communication cable, there was created a new difficulty that the communication cable built in the hose was broken as a result of tightening with a tightening piece. OBJECT AND SUMMARY OF THE INVENTION : The present invention has been contrived to solve the above-mentioned tasks, and, therefore, it is an object of the present invention to provide a coupling for fire hose with built-in communication cable which facilitates the hose connection work and enables to obtain a sure electrical connection as well as a water-tight construction. According to the present invention a coupling for a fire hose with built-in communication cable consists of two fittings, each of said fittings comprising: an inner cylinder, having a base end part fitted with a fire hose with built-in communication cable and annular sealing material for insulating and water-proofing the opening end face of said inner cylinder, an annular conductor connected to said communication cable an outer cylinder freely engaged with and held captive by an outer peripheral surface of said inner cylinder, said outer cylinder having an opening end surface corresponding to the opening end face of said inner cylinder; whereat said outer cylinder is provided with at least one pair of engaging projections which are arranged along the circumferential direction of said opening end surface of said outer cylinder and which form a male part, while opening windows in the outer cylinder form a female part; characterized in that the two fittings are of identical shape, the end face of said annular sealing material is formed as an inclined surface that protrudes out of said inner cylinder end face in a direction from an outer side of said inner cylinder towards an inner side of said inner cylinder, a groove is defined on the inner peripheral surface of each outer cylinder by a flange whose thickness increases along the circumferential direction from the opening windows such that when two outer cylinders are turned with respect to each other by being assembled so as to cause the flange of one outer cylinder to be engaged with the engaging projections of the other outer cylinder said outer cylinders can be brought into contact with each other, thereby bringing said annular sealing materials on said respective inner cylinder into a pressurized contact, while said annular conductors on said respective inner cylinders are brought into electrical contact. According to the invention the groove part on an outer cylinder is formed in such a way that when two outer cylinders are assembled with the engaging claw part on the partner outer cylinder is engaged with the groove and the two outer cylinders are turned relatively with each other, the two outer cylinders can be tightenend or loosened. By so doing, it becomes possible to bring the sealing materials on the respective inner cylinders into a pressurized contact. To explain the operation of the above device, two inner cylinders are matched mutually, and the outer cylinders are combined so as to bring the claw part and the opening window coincident with each other. Next, by relatively turning the outer cylinders one against the other, the claw part on one of the outer cylinders moves along the groove part of the partner outer cylinder, bringing the respective inner cylinders into pressurized contact. In this manner, annular conductors are provided on the respective end faces of the inner cylinders are mutually pressure contacted, establishing an electrical connection. As described in the above, according to the coupling for fire hose with built-in communication cable of the present invention (1), partner couplings are of the same shape, each having both of the male and female parts. Therefore, the work for connecting the couplings requires no need for taking the sense of each of the couplings into account, so that the operability can be enhanced. BRIEF DESCRIPTION OF THE DRAWINGS : FIGS. 1(A) and 1(B) through FIG. 3 show the coupling for fire hose with built-in communication cable in accordance with the present invention, wherein FIG. 1(A) and FIG. 2 show longitudinal sectional diagrams, FIG. 1(B) shows a right elevation of FIG. 1(A), and FIG. 3 is a perspective view of FIG. 2. FIG. 4 is a perspective view showing the outer cylinder of FIG. 3, FIG. 5 is an enlarged sectional diagram of a part of FIG. 1, FIG. 6(A) is a longitudinal sectional diagram of the hose with built-in communication cable, FIG. 6(B) is a sectional diagram as taken in the plane of the line A-A of FIG. 6(A), and FIG. 7 is a conceptual diagram for the cable. DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS : Referring to the drawings, the present invention will now be described in detail. In FIGS. 1(A) and 1(B) to FIG. 4, l is a coupling which links two fire hoses with built-in communication cable, where the male and female units are constructed by coupling fittings 3₁ and 3₂. Each of the metal fittings 3₁ and 3₂ consists of an inner cylinder 5 in which an annular conductor 4 is provided on the opening end face on its one end and a hose with built-in communication cable is arranged, and an outer cylinder 6 engaged with the inner cylinder 5 and has a connection part. The inner cylinder 5 has a recessed groove 7 formed along circumferential direction on its opening end face, with an annular sealing member 8 inserted within the recessed groove 7. The sealing member 8 is so formed as to project its inner diameter side toward the axis of the hose with respect to the outer diameter side, with the inner diameter side protruding from the end face of the inner cylinder. On the outer circumferential side of the sealing member 8 there is fitted integrally an annular electrical conductor 4 with one of its peripheries bent along the end face on the outer diameter side of the sealing member 8. The annular conductor 4 is made, in this case, of a metallic wire mesh with the mesh so arranged as to intersect obliquely the axial direction of the inner cylinder 5 in order to permit its elongation or contraction in the axial direction. Here, after the wire mesh is wound in a cylindrical form, the inner peripheral side and the outer peripheral side are surrounded by a sealing member. On the inner surface of the recessed groove 7 a sliding conductor 9 that makes contact with the annular conductor 4 is provided as shown in FIG. 5, and the sliding conductor 9 is connected to a lead line 9a which is provided penetrating through a flange part 5a of the inner cylinder 5. The lead line 9a is connected to the positive side 10a of a cable 10 of the hose 2 with built-in communication cable fitted on the outer peripheral surface of the inner cylinder 5. The negative side 10b of the cable 10 is connected to the inner cylinder 5 by means of soldering or the like. On the other hand, the outer cylinder 6 is fitted freely detachably to the inner cylinder 5, and is locked to the flange part 5a of the inner cylinder 5 to prevent dropping-off. The outer cylinder 6 consists of a small diameter part 6a which engages with the inner cylinder 5, and a large diameter part 6b which is provided with a pair of flanges 11 extending toward the cylindrical axis in a symmetrical manner, opening parts 12 formed with a predetermined spacing between the flanges 11, and a pair of engaging projections 13. The flange 11 is formed projecting for a predetermined length along the periphery from the inner peripheral face of the opening end of the large diameter part 6b. It is formed so as to increase the thickness gradually for a predetermined length from the opening part 12 along the circumferential direction of the outer cylinder. The engaging projection 13 is formed on the end face of the outer cylinder 6, projecting for a predetermined width toward the axial direction, and on its outer surface side there is formed a recessed part 14 that engages with the flange 11. The hose 2 with built-in communication cable as described in the above is formed by pasting a resin or rubber lining tube on the inner surface of the hose jacket as shown in FIGS. 6(A) and 6(B), with a cable 10 being disposed between the hose jacket 15 and the lining tube 16. The cable 10 is made, for example, by winding a copper wire 17 helically around a polyester resin core line 18, giving a coating 19 of polyvinyl chloride material, and further, winding a copper wire 20 helically over the coating 19, and giving a polyvinyl chloride coating 21 to form a coaxial cable, as shown in FIG. 7. The cable 10 is designed not to be broken even when it is elongated more (20%) than the elongation expected of the water pressure on the hose. It should be noted that use may also be made of a parallel bioxial type cable instead of the cable 10. Now, assembling of couplings with the above-mentioned constitution will be described in what follows. The coupling fittings 3₁ and 3₂ assembled by matching the engaging projection 13 of one 3₁ of the coupling fittings with the opening part 12 of the other coupling fitting 3₂, and matching the engaging projection 13 of the other coupling fitting 3₂ with the opening part 12 of one of the coupling fitting 3₁. When the outer cylinders 6 of the coupling fittings 3₁ and 3₂ in this state are turned relatively in the mutually opposing directions, assemblage is completed with the engagement of the engaging projections 13 with the respective flanges 11. With the above motion, the inner cylinders 5 and the outer cylinders 6 are brought closer to each other as the coupling fittings 3₁ and 3₂ are turned since the thickness of the flanges 11 of the engaging projections 13 is increased gradually along the circumferential direction of the outer cylinder. In this way, both sealing members 8 are mutually pressure contacted, bringing both annular conductors 4 into contact and estblishing an electrical connection between the cables 10 of hoses 2 with built-in communication cable.

Claims: A coupling (1) for a fire hose with built-in communication cable (10), consisting of two fittings (3₁,3₂) each of said fittings comprising: an inner cylinder (5), having a base end part fitted with a fire hose (2) with build-in communication cable (10), and annular sealing material (8) for insulating and water-proofing the opening end face of said inner cylinder (5), an annular conductor (4) connected to said communication cable (10); an outer cylinder (6) freely engaged with and held captive by an outer peripheral surface of said inner cylinder (5), said outer cylinder (6) having an opening end surface corresponding to the opening end face of said inner cylinder (5); whereat said outer cylinder (6) is provided with at least one pair of engaging projections (13) which are arranged along the circumferential direction of said opening end surface of said outer cylinder (6) and which form a male part, while opening windows (12) in the outer cylinder (6) form a female part; characterized in that the two fittings (3₁,3₂) are of identical shape, the end face of said annular sealing material (8) is formed as an inclined surface that protrudes out of said inner cylinder end face in a direction from an outer side of said inner cylinder (5) towards an inner side of said inner cylinder (5), a groove (12a) is defined on the inner peripheral surface of each outer cylinder (6) by a flange (11) whose thickness increases along the circumferential direction from the opening windows (12) such that when two outer cylinders (6) are turned with respect to each other by being assembled so as to cause the flange (11) of one outer cylinder (6) to be engaged with the engaging projections (13) of the other outer cylinder (6), said outer cylinders (6) can be brought into contact with each other, thereby bringing said annular sealing materials (8) on said respective inner cylinder (5) into a pressurized contact, while said annular conductors (4) on said respective inner cylinders (5) are brought into electrical contact.

Inventors: KANDA TOHEI, MIZUGUCHI HIROMI, NAITO OSAMU, OZAKI SEIJI, SHINOZAKI SHIGESAKU, KANDA, TOHEI, MIZUGUCHI, HIROMI, NAITO, OSAMU, OZAKI, SEIJI, SHINOZAKI, SHIGESAKU
Applicants: TEIKOKU SEN I CO LTD, TEIKOKU SEN-I CO., LTD.
Application year: 1989
Main classification: H01R13
IPC codes: F16L11, F16L37, F16L25, H01R13