Flexible metal hose

Claim 2

Flexible metal hose of the type formed from a helically wound metal strip with the edges of adjacent convolutions interfolded, said convolutions having first surfaces which undergo significant sliding movement relative to second surfaces of adjacent convolutions when said hose is flexed; wherein the improvement comprises a plurality of shallow projections and recessions on said first and second surfaces of said convolutions, but not on the radially innermost surface of said hose, said projections slidably locating in said recessions, said recessions formed to allow said projections to slide freely therein generally parallel to the hose axis, said recessions formed to impede said projections from substantial sliding movement therein in directions not generally parallel to the hose axis.

Claim 3

Flexible metal hose as recited in claim 1 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 4

Flexible metal hose as recited in claim 2 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 5

Flexible metal hose as recited in claim 1 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 6

Flexible metal hose as recited in claim 1 wherein said projections are angularly spaced about one-fourteenth inch center to center.

Claim 7

Flexible metal hose as recited in claim 5 wherein said projections are less than about one twenty-eighth inch high and said recessions are less than about one twenty-eighth inch deep.

Claim 8

Flexible metal hose as recited in claim 1 wherein said recessions are angularly spaced about one-fourteenth inch center to center.

Claim 9

Flexible metal hose as recited in claim 7 wherein said projections are less than about one twenty-eighth inch high and said recessions are at least one twenty-eighth inch deep.

Claim 10

Flexible metal hose as recited in claim 1 wherein said metal strip is provided with a plastic coating.

Claim 11

Flexible metal hose of the type formed from a first helically wound metal strip having a first lateral edge and a second lateral edge, and a second helically wound metal strip with one lateral edge of adjacent convolutions of said second strip and said first lateral edge of said first metal strip interfolded, said second lateral edge of each convolution of said first strip overlapping a portion of each adjacent convolution of said first strip, said second strip having first and second generally parallel off-set surfaces, said first lateral edge of each convolution of said first strip located between said first surface of each convolution of said second strip and said second surface of each adjacent convolution of said second strip, the surface of said first lateral edge of said first strip undergoing significant sliding movement relative to one of said first and second surfaces of said second strip when said hose is flexed: wherein the improvement comprises a plurality of closely spaced shallow projections and recessions on said slidably engaging surfaces of said first and second strips, but not on the radially innermost surface of said hose, said projections slidably located in said recessions, said recessions formed to allow said projections to slide freely therein generally parallel to the hose axis, said recessions formed to impede said projections from substantial sliding movement therein in directions not generally parallel to the hose axis.

Claim 12

Flexible metal hose of the type formed from a first helically wound metal strip having a first lateral edge and a second lateral edge, and a second helically wound metal strip with one lateral edge of adjacent convolutions of said second strip and said first lateral edge of said first metal strip interfolded, said second lateral edge of each convolution of said first strip overlapping a portion of each adjacent convolution of said first strip, said second strip having first and second generally parallel off-set surfaces, said first lateral edge of each convolution of said first strip located between said first surface of each convolution of said second strip and said second surface of each adjacent convolution of said second strip, the surface of said first lateral edge of said first strip undergoing significant sliding movement relative to one of said first and second surfaces of said second strip when said hose is flexed: wherein the improvement comprises a plurality of closely spaced shallow projections and recessions on said slidably engaging surfaces of said first and second strips, but not on the radially innermost surface of said hose, said projections slidably located in said recessions, said recessions formed to allow said projections to slide freely therein generally parallel to the hose axis, said recessions formed to impede said projections from substantial sliding movement therein in directions not generally parallel to the hose axis.

Claim 13

Flexible metal hose as recited in claim 10 wherein said second lateral edge of said first metal strip extends on the radially inner side of said second metal strip to line the interior or said hose.

Claim 14

Flexible metal hose as recited in claim 11 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 15

Flexible metal hose as recited in claim 12 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to said hose axis.

Claim 16

Flexible metal hose as recited in claim 11 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 17

Flexible metal hose as recited in claim 10 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 18

Flexible metal hose as recited in claim 10 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 19

Flexible metal hose as recited in claim 16 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surfaces on which they are formed against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 20

Flexible metal hose as recited in claim 10 wherein said projections are angularly spaced about one-fourteenth inch center to center.

Claim 21

Flexible metal hose as recited in claim 18, wherein said projections are less than about one twenty-eighth inch high and said recessions are at least about one twenty-eighth deep.

Claim 22

Flexible metal hose as recited in claim 10 wherein said recessions are angularly spaced about one-fourteenth inch center to center.

Claim 23

Flexible metal hose as recited in claim 20 wherein said projections are less than about one twenty-eighth inch high and said recessions are at least one twenty-eighth inch deep.

Claim 24

Flexible metal hose as recited in claim 10 wherein said first and second metal strips are each provided with a plastic coating.

Claim 25

Flexible metal hose of the type formed from a helically wound metal strip,each convolution of said strip having in cross section a first free edge portion disposed generally parallel to the hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion generally parallel to said first free edge portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extEnding radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; each of said convolutions interfolded with an adjacent convolution, said first free edge of one convolution slidably received in said second channel of an adjacent convolution, adjacent surfaces of said free edge portions and medial portions slidably engaged, wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of said hose on at least two of said slidably engaged surfaces, said deformations including recessions on one of said surfaces and projections on the adjacent slidably engaged surface, said recessions formed to allow said projections to slide freely therein in directions generally parallel to the hose axis when said hose is flexed and to impede sliding movement in other directions, said narrow end portions being substantially free of said deformations

Claim 26

Flexible metal hose of the type formed from a helically wound metal strip,each convolution of said strip having in cross section a first free edge portion disposed generally parallel to the hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion generally parallel to said first free edge portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extEnding radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; each of said convolutions interfolded with an adjacent convolution, said first free edge of one convolution slidably received in said second channel of an adjacent convolution, adjacent surfaces of said free edge portions and medial portions slidably engaged, wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of said hose on at least two of said slidably engaged surfaces, said deformations including recessions on one of said surfaces and projections on the adjacent slidably engaged surface, said recessions formed to allow said projections to slide freely therein in directions generally parallel to the hose axis when said hose is flexed and to impede sliding movement in other directions, said narrow end portions being substantially free of said deformations

Claim 27

Flexible hose as recited in claim 23 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to said hose axis.

Claim 28

Flexible hose as recited in claim 24 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 29

Flexible hose as recited in claim 23 wherein said recessions are the opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about axis generally perpendicular to the plane of said hose axis.

Claim 30

Flexible metal hose as recited in claim 23 wherein said metal strip is provided with a plastic coating.

Claim 31

Flexible metal hose of the type formed from a first helically wound metal strip having a first lateral edge and a second lateral edge, and a second helically wound metal strip, each convolution of said second strip having in cross section a first free edge portion disposed generally parallel to said hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion generally parallel to said first free edge portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extending radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a second narrow end portion extending radially inwardly from the rear end of said second medial portion; and a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; said first lateral edge of each convolution of said first metal strip and one of said free edge portions of each convolution of said second metal strip slidably received in one of said channels of each adjacent convolution of said second metal strip, said second lateral edge of each convolution of said first metal strip overlapping a portion of an adjacent convolution wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of said hose on at least two of the slidably engaged surfaces, said deformations including recessions on one of said surfaces and projectioNs on the adjacent slidably engaged surfaces and projections on the adjacent slidably engaged surface, said recessions formed to allow said projections to slide freely therein in directions generally parallel to the hose axis when said hose is flexed and to impede sliding movement therein in other directions, said narrow end portions being substantially free of said deformations.

Claim 32

Flexible metal hose of the type formed from a first helically wound metal strip having a first lateral edge and a second lateral edge, and a second helically wound metal strip, each convolution of said second strip having in cross section a first free edge portion disposed generally parallel to said hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion generally parallel to said first free edge portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extending radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a second narrow end portion extending radially inwardly from the rear end of said second medial portion; and a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; said first lateral edge of each convolution of said first metal strip and one of said free edge portions of each convolution of said second metal strip slidably received in one of said channels of each adjacent convolution of said second metal strip, said second lateral edge of each convolution of said first metal strip overlapping a portion of an adjacent convolution wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of said hose on at least two of the slidably engaged surfaces, said deformations including recessions on one of said surfaces and projectioNs on the adjacent slidably engaged surfaces and projections on the adjacent slidably engaged surface, said recessions formed to allow said projections to slide freely therein in directions generally parallel to the hose axis when said hose is flexed and to impede sliding movement therein in other directions, said narrow end portions being substantially free of said deformations.

Claim 33

Flexible hose as recited in claim 28 wherein said projections are spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 34

Flexible hose as recited in claim 29 wherein said recessions are opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 35

Flexible hose as recited in claim 28 wherein said recessions are opposed concave surfaces of spaced ribs elongated generally in the axial direction serving to reinforce the surface on which said ribs are located against bending about an axis generally perpendicular to the plane of hose axis.

Claim 36

Flexible metal hose as recited in claim 28 wherein said first and second metal strips are each provided with a plastic coating.

Claim 37

Flexible metal hose of the type formed from a helically wound metal strip with the edges of adjacent convolutions each folded reversely and interconnected so that at said interconnection the wall of said hose is comprised of at least four layers of said metal strip, said layers undergoing significant sliding movement relative to one another when said hose is flexed, wherein the improvement comprises corrugations formed in the two outermost layers at said interconnection, but not in the innermost layer, said corrugations comprising a plurality of minute angularly spaced ridges and grooves, said ridges on one of said layers slidably located in said grooves on another of said layers, said ridges and grooves extending generally parallel to said hose axis to permit said layers to slide over each other in a direction generally parallel to said hose axis while tending to impede said layers from sliding over each other in directions transverse to said hose axis.

Claim 38

Flexible metal hose of the type formed from a helically wound metal strip with the edges of adjacent convolutions each folded reversely and interconnected so that at said interconnection the wall of said hose is comprised of at least four layers of said metal strip, said layers undergoing significant sliding movement relative to one another when said hose is flexed, wherein the improvement comprises corrugations formed in the two outermost layers at said interconnection, but not in the innermost layer, said corrugations comprising a plurality of minute angularly spaced ridges and grooves, said ridges on one of said layers slidably located in said grooves on another of said layers, said ridges and grooves extending generally parallel to said hose axis to permit said layers to slide over each other in a direction generally parallel to said hose axis while tending to impede said layers from sliding over each other in directions transverse to said hose axis.

Claim 39

A flexible metal hose of the type formed from a helically wound strip of metal which in cross-section has two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, and the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, adjacent surfaces of said body and hook portions undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of circumferentially spaced shallow deformations along substantially the entire extent of two of said slidingly engaged surfaces, but not on the radially innermost longitudinal body portion, said deformations comprising alternating projections and recessions, said projections on one convolution slidably located in the recessions on the deformed slidably engaging portion of the next convolution, said recessions formed to permit said projections to slide therein a direction generally parallel to the hose axis and to impede sliding movement in other directions, so that while the hose walls are deformed to prevent sliding in non-axial directions, the radially inner surface of the radially innermost body portion of each convolution describes a smooth cylindrical surface of uniform circular cross-section.

Claim 40

A flexible metal hose of the type formed from a helically wound strip of metal which in cross-section has two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, and the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, adjacent surfaces of said body and hook portions undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of circumferentially spaced shallow deformations along substantially the entire extent of two of said slidingly engaged surfaces, but not on the radially innermost longitudinal body portion, said deformations comprising alternating projections and recessions, said projections on one convolution slidably located in the recessions on the deformed slidably engaging portion of the next convolution, said recessions formed to permit said projections to slide therein a direction generally parallel to the hose axis and to impede sliding movement in other directions, so that while the hose walls are deformed to prevent sliding in non-axial directions, the radially inner surface of the radially innermost body portion of each convolution describes a smooth cylindrical surface of uniform circular cross-section.

Claim 41

A flexible metal hose of the type having first and second helically wound metal strips, said first metaL strip in cross-section having two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, and said second metal strip in cross-section having two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, said second strip having its web engaging the web of said first strip and the front longitudinal edge of said second strip being arranged between the body portion of one convolution and the rear hook portion on the rear edge of the preceding convolution, and the rear longitudinal edge of said second strip being arranged between the inner side of the rear body portion of the respective first strip convolution and the rear edge of the preceding second strip convolution and also engaging with the inner side of the rear part of the next following convolution of the second strip, adjacent surfaces of said first and second strips undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of closely spaced shallow deformations along substantially the entire extent of two of said slidably engaged surfaces of said first and second strips, but not on the radially innermost longitudinal body portion of said second strip, said deformations comprising alternating projections and recessions, said projections on one convolution slidably locating in the recessions on the deformed slidably engaging portion of the next convolution, said recessions formed to permit said projections to slide freely therein in a direction generally parallel to the hose axis and to impede sliding movement in other directions, so that while the hose walls are deformed to prevent the convolutions from sliding against one another in non-axial directions, the radially inner surface of the radially innermost body portion of each convolution of said second strip describes a smooth cylindrical surface of uniform circular cross-section.

Claim 42

A flexible metal hose of the type having first and second helically wound metal strips, said first metaL strip in cross-section having two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, and said second metal strip in cross-section having two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, said second strip having its web engaging the web of said first strip and the front longitudinal edge of said second strip being arranged between the body portion of one convolution and the rear hook portion on the rear edge of the preceding convolution, and the rear longitudinal edge of said second strip being arranged between the inner side of the rear body portion of the respective first strip convolution and the rear edge of the preceding second strip convolution and also engaging with the inner side of the rear part of the next following convolution of the second strip, adjacent surfaces of said first and second strips undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of closely spaced shallow deformations along substantially the entire extent of two of said slidably engaged surfaces of said first and second strips, but not on the radially innermost longitudinal body portion of said second strip, said deformations comprising alternating projections and recessions, said projections on one convolution slidably locating in the recessions on the deformed slidably engaging portion of the next convolution, said recessions formed to permit said projections to slide freely therein in a direction generally parallel to the hose axis and to impede sliding movement in other directions, so that while the hose walls are deformed to prevent the convolutions from sliding against one another in non-axial directions, the radially inner surface of the radially innermost body portion of each convolution of said second strip describes a smooth cylindrical surface of uniform circular cross-section.

Claim 43

Flexible metal hose of the type formed from a helically wound metal strip, each convolution of said strip having in cross-section a first free edge portion disposed generally parallel to the hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extending radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a narrow end portion extending radially inwardly from the rear end of said second medial portion; and a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; each of said convolutions interfolded with an adjacent convolution, said first free edge of one convolution slidably received in said second channel of an adjacent convolution with adjacent surfaces of said free edge portions and medial portions slidably engaged, said hose in cross-section being substantially cylindrical, said first and second medial portions respectively forming the radially innermost and radially outermost substantially cylindrical surfaces of said hose, wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of the hose on two of said slidably engaged sUrfaces, said deformations including recessions on one of said surfaces and projections on the adjacent slidably engaged surface, said recessions formed to permit said projections to slide freely therein in directions generally parallel to the hose axis and to impede sliding movement in other directions.

Claim 44

Flexible metal hose of the type formed from a helically wound metal strip, each convolution of said strip having in cross-section a first free edge portion disposed generally parallel to the hose axis; a first narrow end portion extending radially inwardly from the forward end of said first edge portion; a first medial portion extending rearwardly from the radially inner end of said first narrow end portion and spaced therefrom to form a rearwardly opening first channel; a narrow connecting portion extending radially outwardly from the rear end of said first medial portion; a second medial portion extending rearwardly from the radially outer end of said narrow connecting portion to lie generally parallel to the hose axis; a narrow end portion extending radially inwardly from the rear end of said second medial portion; and a second free edge portion extending forward from the radially outer end of said second end portion to form a forward opening second channel; each of said convolutions interfolded with an adjacent convolution, said first free edge of one convolution slidably received in said second channel of an adjacent convolution with adjacent surfaces of said free edge portions and medial portions slidably engaged, said hose in cross-section being substantially cylindrical, said first and second medial portions respectively forming the radially innermost and radially outermost substantially cylindrical surfaces of said hose, wherein the improvement comprises a plurality of small circumferentially arranged deformations disposed throughout the length of the hose on two of said slidably engaged sUrfaces, said deformations including recessions on one of said surfaces and projections on the adjacent slidably engaged surface, said recessions formed to permit said projections to slide freely therein in directions generally parallel to the hose axis and to impede sliding movement in other directions.

Claim 45

Flexible metal hose as defined in claim 36 wherein said deformations are comprised of rows of alternating projections and recessions, said projections and recessions being narrow and elongated generally in the axial direction so that they serve to reinforce the surface on which they are formed against bending about an axis generally perpendicular to the plane of said hose axis.

Claim 46

Flexible metal hose as defined in claim 37 wherein said deformations are located only on said second medial portion and said first free edge portion.

Claim 47

A flexible metal hose of the type formed from a helically wound strip of metal which in cross-section has two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, and the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, adjacent surfaces of said body and hook portions undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of small circumferentially arranged deformations on two of said slidingly engaged surfaces, said deformations including recessions on one of said surfaces and projections on the other of said surfaces, said recessions formed to permit said projections to slide freely therein in directions generally parallel to the hose axis and to impede sliding movement in other directions, said projections and recessions being of a height and depth respectively less than about twice the thickness of said metal strip.

Claim 48

A flexible metal hose of the type formed from a helically wound strip of metal which in cross-section has two substantially parallel longitudinal body portions, the opposing inner edges of which are off-set from each other and connected by a web portion, the outer longitudinal edges of said strip being bent reversely along opposite sides of said body portions to form hook portions, and the hook portion on one edge of one convolution interlocking with the hook portion on the opposite edge of the next convolution, adjacent surfaces of said body and hook portions undergoing substantial sliding movement relative to one another in a direction parallel to the hose axis when said hose is flexed, wherein the improvement comprises a plurality of small circumferentially arranged deformations on two of said slidingly engaged surfaces, said deformations including recessions on one of said surfaces and projections on the other of said surfaces, said recessions formed to permit said projections to slide freely therein in directions generally parallel to the hose axis and to impede sliding movement in other directions, said projections and recessions being of a height and depth respectively less than about twice the thickness of said metal strip.