GB1574284A

GB1574284A - Flexible hose

Info

Publication number: GB1574284A
Application number: GB3209/78A
Authority: GB
Original assignee: Dayco Corp
Current assignee: Day International Corp
Priority date: 1977-02-02
Filing date: 1978-01-26
Publication date: 1980-09-03
Also published as: DE2804251A1; FR2379746A1; CA1087532A; IT7819660A0; IT1092149B

Description

(54) IMPROVEMENTS IN AND RELATING TO FLEXIBLE HOSE (71) We, DAYCO CORPORATION, a corporation organised under the laws of the State of Delaware, United States of America, having its principal place of business at 333 West First Street, Dayton, Ohio 45402, United States of America, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: Flexible elastomeric smooth bore hose constructions or hoses are widely used throughout industry to convey various types of fluids. However, each application usually has the need for a particular type of hose construction. For example. in vacuum cleaning apparatus the need exists for a flexible vacuum hose which has a smooth inside surface free of inside convolutions to prevent air turbulance and the trapping and accumulation of dirt within the inside convolutions while having a convoluted outer portion which provides reinforcement for the hose and at the same time provides easier sliding of such hose over a floor or carpet.

Manv of the previously proposed vacuum hoses are made of helically wound strips to assure each of such hoses has optimum flexibility: however, inherentlv each hose made from such a helically wound strip has an inside surface which has numerous inside convolutions which cause turbulance and trap dirt as mentioned above. Others of previously proposed vacuum hoses enjoy a comparatively thick tube having a smooth bore; however. inherently a hose using a comparativelv thick tube has limited flexibility. Still pothers of previously proposed vacuum hoses are too expensive to gain wide usage. Accordingly, previously proposed vacuum hoses are deficient because of one or more of the abovementioned items.

According to one aspect of the invention there is provided a flexible hose having a reinforced convoluted outer surface, comprising a thermoplastics inner tube having a smooth bore and reinforcing means disposed in a helically coiled relation around said tube, said reinforcing means comprising a thermoplastics strip portion firmly "fused" as herein defined or adhered both to said inner tube and to a thermoplastics reinforcing member, each helical convolution of said reinforcing means being spaced on said inner tube such that it does not adhere to an adjoining reinforcing means.

The invention also includes a method of making a reinforced flexible outwardly smooth bore hose construction comprising the steps of: forming a thermoplastics inner tube having a smooth inside surface which defines said smooth bore, and disposing reinforcing means in helically coiled relation around and against said tube, said reinforcing means comprising a thermoplastics strip portion firmly "fused" as herein defined or adhered both to said inner tube and to a thermoplastics reinforcing member, each helical convolution of said reinforcing means being spaced on said inner tube such that it does not adhere to an adjoining reinforcing means, thereby to form a hose adapted to carry a fluid at a substantial differential pressure from ambient pressure.

The term "fused" used herein with reference to the strip portion includes the situation where the strip portion is made, or becomes integral with the reinforcing member.

Following is a description by way of example only with reference to the accompanying drawings of methods of carrying the invention into effect.

Figure 1 is a primarily schematic presentation illustrating the method of this invention which may be employed to make the hose construction of this invention.

Figure 2 is a fragmentary view with parts in elevation, and parts broken away of a generalized view of embodiments 3 and 4 of the hose construction of this invention made utilizing the method of Figure 1; Figure 3 is a fragmentary cross sectional view illustrating an exemplary embodiment of the hose construction of this invention; Figure 4 is a cross-sectional view illustrating a fragmentary portion of another exemplary embodiment of the hose construction of this invention.

Reference is now made to Figure 2 of the drawing which illustrates a generalized view of the embodiments of the hoses construction or hose of this invention. A hose is designated generally by the reference numeral 20 and such hose construction 20 may be made utilizing any suitable technique known in the art and preferably made utilizing the method illustrated in Figure 1 of the drawing and such method is designated generally by the reference numeral 21 in Figure 1. The hose construction 20 is a reinforced comparatively highly flexible hose construction which has a smooth bore and an outwardly convoluted configuration as indicated by the plurality of outwardly projecting convolutions 23.

The hose construction 20 is made primarily of one or more elastomeric materials and preferably entirely of thermoplastics materials and comprises a thermoplastics inner tube 24 having a smooth inside surface, which defines the smooth bore of the overall hose construction. The hose construction 20 also has reinforcing means designated generally by the reference numeral 25 disposed in helically coiled relation around and against the inner tube 24.

The inner tube 24 has a comparatively small wall thickness as compared with the inside diameter of the tube 24, which assures optimum flexibility for the overall hose construction. Further, the reinforcing means 25 enables carrying of fluid in the hose construction 20 without impairing the flexibilitv thereof vet at a substantial dif ferential pressure from ambient pressure.

Accordingly, the hose construction 20 is capable of carrying a fluid, such as air, under partial vacuum and is also capable of carrying a fluid under substantial pressure.

The fluid which may be contained or conveyed in hose construction 20 may be in the form of a gas, a liquid, or a combination of gas and liquid.

The reinforcing means 25 of the hose construction 20 is helically coiled around and against the outside surface of the tube 24, is so disposed as to assure that there is no inward bulging of the inner tube 24. It will be appreciated that the reinforcing means 25 define the outwardly convoluted configuration of the overall hose construction 20.

The hose construction 20 is preferably made employing the method 21 shown in Figure 1 which is a continuous process. In such a method or process a plurality of rectilinear mandrels, indicated schematically by arrows 43, of substantial length generally of the order of 50 feet, and more, are moved continuously through various stations. In particular, each mandrel 43 is moved through a crosshead extrusion apparatus 44 of known construction and operation where a thin-walled tube, also designated 24, is extruded therearound as a seamless tube to define a tube-covered mandrel 45.

The tube-covered mandrel 45 is suitably cooled in the area indicated at 46 and moved if desired into a thermoplastic covered wire coiling section 47 where the wire containing reinforcing member is pre-coiled in a helical configuration so that the inside diameter of the helical coil is substantially equal to the outside diameter 40 of the inner tube 24.

Any suitable apparatus known in the art may be employed for this purpose and such apparatus is employed to continuously apply the reinforcing member around the tubecovered mandrel 45 so that the wire containing reinforcing member is disposed against the outside surface of the tube 24.

The tube-covered mandrel 45 with the reinforcing member disposed therearound is then moved to a wrapping station 50 where the strip 33B or 67C is disposed therearound. Any suitable known apparatus may be used for this purpose. The resulting construction is, in essence, the hose construction 20 illustrated in Figure 3 and 4 and such construction emerges the wrapping station at 52.

The hose construction 20 is then moved into an oven 54 in a continuous manner to provide heat bonding or fusion of the strip 33 or 67C against such surface 32.

The now heat set hose construction is suitably cooled at a cooling station 55 to define the completed hose construction 20; and, the completed hose construction is of extended length over a plurality of mandrels whereby it is then cut at opposite ends of each mandrel 43 to define such hose construction 20 corresponding in length to its mandrel. Each mandrel 43 is then suitably removed from within its length of hose construction 20 using techniques which are known in the art and each of such removed mandrels is returned as indicated by the arrow 56 upstream of the extrusion apparatus 44 to repeat the formation of a hose construction 20 therearound in a continuous manner and as described above.

Specific exemplary embodiments of the hose construction of this invention are illustrated in Figures 3 and 4 of the drawings. The hose constructions are designated generally by the reference numerals 20B (Figure 3) and 20C (Figure 4) respectively; the designation B referring generally to Figure 3 and C to Figure 4.

The hose construction 20B has an inner tube 24B, reinforcing member 31B and strip 33B. The strip 33B thereof is in the form of a preformed strip which when viewed in cross section or from an end thereof has a roughly semicircular central portion 64B adjoined at opposite end edges thereof by outwardly tapering extensions 65B. The length of each extension is such that uncovered spaces 66B are defined between adjoining turns of the strip 33B.

Hose construction 20C of Figure 4 is also comprised of an inner tube 24C and has the reinforcing means 25C thereof in the form of a single strip member designated generally by the reference numeral 67C. The member 67C is helically wrapped around and against the inner tube 24C. The member 67C is defined by a rectangular strip portion 70C which has an enlarged substantially semicircular reinforcing portion 71C integral with the central portion thereof.

The member 67C is preferably made entirely of a thermoplastic material.

The strip portion 70C also has opposed end edges 72C and when the member 67C is helically wound around the inner tube 24C the end edges 72C of each helical turn of the strip portion 70C are disposed in abutting but not joined relation with adjoining end edges 72C of adjoining turns of such strip.

The strip portion 70C and thus member 67C is bonded against the outside surface 32C of the tube 24C by heat fusion or adhesive means as shown at 73C. It will be appreciated that the enlarged semi-circular bead portions 71C of the member 67C when helically wound around the inner tube 24C define the outer reinforcing convolutions of the hose construction 20C.

The hose construction 20B is shown employing an associated reinforcing member 31B which has a central metal wire with a thermoplastic sleeve therearound. The wire may be simply a reinforcing wire or such wire may be in the form of an electrical conductor which may be used with a ground wire. not shown, and for a purpose which is well known in the art. Also, instead of having a single wire disposed helically around the inner tube a plurality of insulating sleeve covered electrical wires (such as two wires) may be helically disposed in position around the associated inner tube for the purpose of carrying electricity as well as providing reinforcement and as is well known in the art. The electrical wires are also helically wrapped with an outer strip or tape to arrive at a hose construction similar to the hose construction 20B.

The strip disposed around the reinforcing members 31B may also be in the form of a thermoplastic strip which may also be bonded in position by heat fusion or suitable adhesive means.

Each exemplary hose construction disclosed herein has optimum flexibility, has a smooth inside surface free of inward convolutions or bulges, and has an inner tube of minimum wall thickness for optimum flexibility yet because of the utilization of a helically coiled reinforcing means disposed around the inner tube each of such hose constructions is capable of containing and conveying fluid either under partial vacuum or under substantial pressure. In addition, the outwardly projecting convolutions of each hose construction provide spaced corrugations enabling sliding of each hose construction over any surface with minimum friction and wear.

Reference has been made in this disclosure to the utilization of a thermoplastic material to define each inner tube, each sleeve disposed around each wire of each reinforcing member, and the reinforcing means 67C of the hose construction 20C; and, it is to be understood that any suitable thermoplastic material known in the art may be used for this purpose.

WHAT WE CLAIM IS: 1. A flexible hose having a reinforced convoluted outer surface, comprising a thermoplastics inner tube having a smooth bore and reinforcing means disposed in a helically coiled relation around said tube, said reinforcing means comprising a thermoplastics strip portion firmly "fused" as herein defined or adhered both to said inner tube and to a thermoplastics reinforcing member, each helical convolution of said reinforcing means being spaced on said inner tube such that it does not adhere to an adjoining reinforcing means.

2. A hose as claimed in claim 1 wherein said reinforcing means is made entirely of a thermoplastics material and has a portion of enlarged thickness and defining an outwardly convoluted reinforcing bead.

3. A hose according to claim 1 wherein said reinforcing member comprises an outer portion made of a thermoplastics material and an inner metallic portion.

4. A hose according to any preceding claim wherein the thickness of the wall of the inner tube is substantially equal to the maximum thickness of said reinforcing member.

5. A hose according to any one of the preceding claims wherein the thermoplastics strip portion is adhered to said tube by an adhesive layer.

6. A hose according to any one of claims 1 to 4 wherein the stip portion is fused to said tube by suitable heat treatment.

7. A hose according to any one of the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. generally by the reference numerals 20B (Figure 3) and 20C (Figure 4) respectively; the designation B referring generally to Figure 3 and C to Figure 4. The hose construction 20B has an inner tube 24B, reinforcing member 31B and strip 33B. The strip 33B thereof is in the form of a preformed strip which when viewed in cross section or from an end thereof has a roughly semicircular central portion 64B adjoined at opposite end edges thereof by outwardly tapering extensions 65B. The length of each extension is such that uncovered spaces 66B are defined between adjoining turns of the strip 33B. Hose construction 20C of Figure 4 is also comprised of an inner tube 24C and has the reinforcing means 25C thereof in the form of a single strip member designated generally by the reference numeral 67C. The member 67C is helically wrapped around and against the inner tube 24C. The member 67C is defined by a rectangular strip portion 70C which has an enlarged substantially semicircular reinforcing portion 71C integral with the central portion thereof. The member 67C is preferably made entirely of a thermoplastic material. The strip portion 70C also has opposed end edges 72C and when the member 67C is helically wound around the inner tube 24C the end edges 72C of each helical turn of the strip portion 70C are disposed in abutting but not joined relation with adjoining end edges 72C of adjoining turns of such strip. The strip portion 70C and thus member 67C is bonded against the outside surface 32C of the tube 24C by heat fusion or adhesive means as shown at 73C. It will be appreciated that the enlarged semi-circular bead portions 71C of the member 67C when helically wound around the inner tube 24C define the outer reinforcing convolutions of the hose construction 20C. The hose construction 20B is shown employing an associated reinforcing member 31B which has a central metal wire with a thermoplastic sleeve therearound. The wire may be simply a reinforcing wire or such wire may be in the form of an electrical conductor which may be used with a ground wire. not shown, and for a purpose which is well known in the art. Also, instead of having a single wire disposed helically around the inner tube a plurality of insulating sleeve covered electrical wires (such as two wires) may be helically disposed in position around the associated inner tube for the purpose of carrying electricity as well as providing reinforcement and as is well known in the art. The electrical wires are also helically wrapped with an outer strip or tape to arrive at a hose construction similar to the hose construction 20B. The strip disposed around the reinforcing members 31B may also be in the form of a thermoplastic strip which may also be bonded in position by heat fusion or suitable adhesive means. Each exemplary hose construction disclosed herein has optimum flexibility, has a smooth inside surface free of inward convolutions or bulges, and has an inner tube of minimum wall thickness for optimum flexibility yet because of the utilization of a helically coiled reinforcing means disposed around the inner tube each of such hose constructions is capable of containing and conveying fluid either under partial vacuum or under substantial pressure. In addition, the outwardly projecting convolutions of each hose construction provide spaced corrugations enabling sliding of each hose construction over any surface with minimum friction and wear. Reference has been made in this disclosure to the utilization of a thermoplastic material to define each inner tube, each sleeve disposed around each wire of each reinforcing member, and the reinforcing means 67C of the hose construction 20C; and, it is to be understood that any suitable thermoplastic material known in the art may be used for this purpose. WHAT WE CLAIM IS:

1. A flexible hose having a reinforced convoluted outer surface, comprising a thermoplastics inner tube having a smooth bore and reinforcing means disposed in a helically coiled relation around said tube, said reinforcing means comprising a thermoplastics strip portion firmly "fused" as herein defined or adhered both to said inner tube and to a thermoplastics reinforcing member, each helical convolution of said reinforcing means being spaced on said inner tube such that it does not adhere to an adjoining reinforcing means.

7. A hose according to any one of the

preceding claims wherein the thermoplastics reinforcing member is separately fused or adhered to said inner tube.

8. A hose according to any one of claims 3 to 7 wherein said strip is in the form of a thermoplastics tape.

9. A hose as claimed in any one of claims 3 to 8 wherein said strip is in the form of a preformed thermo-plastics strip having a substantially semi-circular cross sectional figuration adjoined at opposite edges thereof by outwardly tapering extensions.

10. A hose as claimed in claim 1 and substantially as herein described with reference to and as illustrated in Figures 1, 2, 3 and 4 of the accompanying drawings.

11. A method of making a reinforced flexible outwardly convoluted smooth bore hose construction comprising the steps of: forming a thermoplastics inner tube having a smooth inside surface which defines said smooth bore, and disposing reinforcing means in helically coiled relation around and against said tube, said reinforcing means comprising a thermoplastics strip portion firmly "fused" as herein defined or adhered both to said inner tube and to a thermoplastics reinforcing member, each helical convolution of said reinforcing means being spaced on said inner tube such that it does not adhere to an adjoining reinforcing means, thereby to form a hose adapted to carry a fluid at a substantial differential pressure from ambient pressure.

12. A method as claimed in claim 11 in which said disposing step comprises disposing reinforcing means in the form of a strip made entirely of thermoplastics material and having a portion of enlarged thickness defining an outwardly convoluted reinforcing bead.

13. A method as claimed in claim 12 and comprising the further step of adhesively bonding said strip against said tube.

14. A method as claimed in any one of claims 11 to 13 wherein said disposing step comprises helically coiling the reinforcing member around and against said tube, said reinforcing member having an outer portion comprising said portion made of a thermoplastics material, and helically wrapping said strip around said member to hold said member against said tube.

15. A method as claimed in claim 14 in which said helically coiling step comprises precoiling said member so that it has an inside diameter substantially equal to an outside diameter of said tube.

16. A method as claimed in claim 15 and comprising the further step of heat treating said formed hose.

17. A method as claimed in claim 11 and substantially as herein described with reference to the accompanying drawings.