Abstract Apparatus for making flexible tubing with annular corrugations and uniform wall thickness. The apparatus includes a tubular cylindrical mandrel adapted to receive a sleeve of extruded rubber, and an axially extensible external form adapted to be received over the mandrel and sleeve. The form includes a plurality of axially spaced disk-like elements, each having a circular opening coaxial with the respective circular openings of the other elements, and a plurality of resilient extensible helical springs spaced about the axis of the openings. Each spring is connected to each disk-like element to support the elements in uniformly spaced parallel relation to one another to accommodate generally uniform increase in the axial spacing between said elements when the springs are axially extended. The mandrel has radial ports so that the sleeve may be expanded by internal pressure to make a preliminary impression in the uncured rubber caused by the edges of the circular openings of the disklike elements.
In an apparatus for making flexible tubing having annular corrugations, said apparatus including a mandrel adapted to receive an extruded sleeve of uncured rubber thereover and means for radially expanding said sleeve by fluid pressure when received on said mandrel, the improvement which comprises an axially extensible external form adapted to be disposed over said mandrel and sleeve and comprising a plurality of axially spaced unitary disk-like elements, each having an opening defined by a continuous inner edge of the element and coaxial with the respective openings of the other elements, and a plurality of axially extensible helical springs symmetrically spaced about and spaced radially from the axis of the mandrel and extending parallel to the axis of the mandrel and constituting the sole connection between said disk-like elements, each spring being connected to each disk-like element to support said disk-like elements in spaced parallel relation to one another and to accommodate generally uniform increase in the axial spacing between said disk-like elements when said springs are axially extended whereby said disk-like elements cause preliminary annular impressions in the uncured rubber sleeve when said sleeve is radially expanded.
Claim 2
Dependent Claim
188 words
In an apparatus for making flexible tubing having annular corrugations, said apparatus including a mandrel adapted to receive an extruded sleeve of uncured rubber thereover and means for radially expanding said sleeve by fluid pressure when received on said mandrel, the improvement which comprises an axially extensible external form adapted to be disposed over said mandrel and sleeve and comprising a plurality of axially spaced unitary disk-like elements, each having an opening defined by a continuous inner edge of the element and coaxial with the respective openings of the other elements, and a plurality of axially extensible helical springs symmetrically spaced about and spaced radially from the axis of the mandrel and extending parallel to the axis of the mandrel and constituting the sole connection between said disk-like elements, each spring being connected to each disk-like element to support said disk-like elements in spaced parallel relation to one another and to accommodate generally uniform increase in the axial spacing between said disk-like elements when said springs are axially extended whereby said disk-like elements cause preliminary annular impressions in the uncured rubber sleeve when said sleeve is radially expanded.
Claim 3
Dependent Claim
11 words
Apparatus as defined in claim 1 wherein said openings are circular.
Claim 4
Dependent Claim
12 words
Apparatus as defined in claim 1 comprising two of said helical springs.
Claim 5
Dependent Claim
30 words
Apparatus as defined in claim 1 wherein at least two convolutions of each of said springs are located between the connections of said spring to adjacent pairs of disk-like elements.
Claim 6
Dependent Claim
19 words
Apparatus as defined in claim 1 wherein said springs are attached to the outer edges of said disk-like elements.