Apparatus for and Method of Manufacturing Helically Wound Structures

Abstract

An apparatus ( 50 ) for and method of manufacturing helically wound tubular structures ( 116 ) includes a rotating faceplate ( 74 ) upon which are mounted a plurality of diameter defining rollers ( 78 ) which, in operation, cause a strip material ( 80 ) to be plastically deformed into a helical winding which may be lain down in abutting or self-overlapping relationship to form said tubular structure ( 116 ).

1 . An apparatus for manufacturing a tubular structure of helically wound strip comprising:
 a faceplate, mounted for rotation about a longitudinal axis;   a drive mechanism, for driving the faceplate in a first direction about said longitudinal axis; and   diameter defining rollers, mounted on said faceplate for causing the strip material to bend to a predetermined diameter prior to being formed into a tubular structure.   
   
   
       2 . An apparatus as claimed in  claim 1  including an assembly of shaping rollers, mounted for rotation with said faceplate and for forming a cross-sectional profile on strip material prior to it being formed to a pre-determined diameter. 
   
   
       3 . An apparatus as claimed in  claim 1  in which one or more of said shaping rollers are driven rollers. 
   
   
       4 . An apparatus as claimed in  claim 2  in which the diameter defining rollers include three mutually confronting rollers, one of which is adjustable relative to the other two so as to cause any strip material passing between said rollers to adopt a radius of curvature defined by the positional relationship between said rollers. 
   
   
       5 . An apparatus as claimed in  claim 1  in which said diameter defining rollers include a pair of pinch rollers rotatable about their own longitudinal axes and between which a strip of material may pass and a ring roller which is adjustable relative to a first pinch roller by rotation about the axis of the second. 
   
   
       6 . An apparatus as claimed in  claim 5  and including an actuator connected to said ring roller for effecting adjustment relative to said second pinch roller. 
   
   
       7 . An apparatus as claimed in  claim 1  including a reaction roller against which forming forces exerted on any strip as it is caused to adopt a radius of curvature by the ring roller will be reacted. 
   
   
       8 . An apparatus as claimed in  claim 7  and including a second actuator for causing the axial position of the reaction roller to be varied relative to a pinch roller. 
   
   
       9 . An apparatus as claimed in  claim 1  in including an actuator for effecting axial adjustment of one of said pinch rollers relative to the other. 
   
   
       10 . An apparatus as claimed in  claim 1  including drive means for driving one or more of said diameter defining rollers. 
   
   
       11 . An apparatus as claimed in  claim 5  including an actuator connected to said ring roller for effecting adjustment relative to said second pinch roller and including a computer coupled to said actuator or actuators for controlling the positional relationship of the roller or rollers. 
   
   
       12 . An apparatus as claimed in  claim 5  including an actuator connected to said ring roller for effecting adjustment relative to said second pinch roller and including an actuator connected to said ring roller for effecting adjustment relative to said second pinch roller and further including a computer coupled to said actuator or actuators for controlling the positional relationship of the roller or rollers further in which said computer comprises a computer programmed to control said roller or rollers in accordance with a predetermined programme. 
   
   
       13 . An apparatus as claimed in  claim 1  and including a first gearing assembly mounted on said faceplate and driven from a fixed gear arranged coaxially with said faceplate and in which said first gearing assembly is engaged with said diameter defining rollers for driving said diameter defining rollers. 
   
   
       14 . An apparatus as claimed in  claim 13  and further including a second gearing assembly mounted on said faceplate and driven from a fixed gear arranged coaxially with said faceplate and in which said second gearing assembly is engaged with said forming rollers for driving said rollers 
   
   
       15 . An apparatus as claimed in  claim 1  and including a main drive member for driving said faceplate in said first direction. 
   
   
       16 . An apparatus as claimed in  claim 15  in which said main drive member comprises a driven gear engaged with a corresponding gear portion on said faceplate. 
   
   
       17 . An apparatus as claimed in  claim 1  and further including a stock support for supporting a supply of stock of strip material for being formed into a tubular structure. 
   
   
       18 . An apparatus as claimed in  claim 17  in which said stock support comprises a circumferentially extending cassette extending around said faceplate on an outer diameter thereof. 
   
   
       19 . An apparatus as claimed in  claim 17  in which said stock support comprises a circumferentially extending cassette extending around said faceplate on an outer diameter thereof and in which said cassette comprises a plurality of support rollers circumferentially spaced around the longitudinal axis and which cooperate with a portion of a supply of strip stock and allow said stock to rotate about said axis. 
   
   
       20 . An apparatus as claimed in  claim 17  in which said stock support comprises a circumferentially extending cassette extending around said faceplate on an outer diameter thereof, in which said cassette comprises a plurality of support rollers circumferentially spaced around the longitudinal axis and which cooperate with a portion of a supply of strip stock and allow said stock to rotate about said axis in which said support rollers are mounted for rotation about a spindle secured to a non rotating portion of said assembly. 
   
   
       21 . An apparatus as claimed in  claim 1  in which the forming rollers are staggered along said longitudinal axis and in which the axis of rotation of said rollers relative to said axis varies in accordance with the spiral angle of the strip as it passes from a supply thereof to said diameter defining rollers. 
   
   
       22 . An apparatus as claimed in  claim 1  including a first strip supply guide roller for guiding a supply of strip material from a store thereof to said forming rollers. 
   
   
       23 . An apparatus as claimed in  claim 1  including a second strip supply roller for guiding a supply of formed strip from said diameter defining rollers to an inner diameter at which a tubular member is to be formed. 
   
   
       24 . An apparatus as claimed in  claim 1  including an adhesive applicator for applying an adhesive onto at least a portion of any strip after it passes through said diameter forming rollers. 
   
   
       25 . An apparatus as claimed in  claim 24  in which said adhesive applicator comprises an adhesive storing cassette for storing a roll of adhesive strip. 
   
   
       26 . An apparatus as claimed in  claim 24  in which said adhesive applicator comprises an adhesive storing cassette for storing a roll of adhesive strip and in which said adhesive storing cassette includes a spindle mounted on said faceplate for rotation therewith and around which a supply of adhesive strip may be positioned and rotate upon application of said adhesive strip to said tubular structure forming strip. 
   
   
       27 . An apparatus as claimed in  claim 24  in which said adhesive applicator comprises an adhesive storing cassette for storing a roll of adhesive strip and the apparatus further comprises a backing removing mechanism for removing any protective backing on said adhesive strip prior to said adhesive strip being applied to the tubular structure forming strip. 
   
   
       28 . An apparatus as claimed in  claim 1  in which the faceplate includes a central hole for receiving a core liner onto which said tubular forming strip may be wound to form a final tubular structure. 
   
   
       29 . An apparatus as claimed in  claim 28  including a central support trunion having a hollow centre which defines said central hole for receiving said core liner. 
   
   
       30 . An apparatus as claimed in  claim 28  including a central support trunion having a hollow centre which defines said central hole for receiving said core liner and in which said support trunion is non rotating and includes a gear thereon which forms said fixed gear from which said rollers are driven. 
   
   
       31 . An apparatus as claimed in  claim 28  in which said apparatus includes a support trunion and said faceplate is mounted for rotation on the said support trunion. 
   
   
       32 . An apparatus as claimed in  claim 1  in which said faceplate includes a receiving station for receiving a supply of flat strip material to be formed into a tubular structure. 
   
   
       33 . An apparatus as claimed in  claim 32  in which said receiving station comprises a ring having a diameter corresponding to the diameter of the cassette, thereby to facilitate transfer of strip material therebetween upon depletion of material from said cassette. 
   
   
       34 . An apparatus as claimed in  claim 32  and including supply means for supplying strip material to said receiving station as said station rotates, thereby to wind said strip material onto said receiving station in advance of material on said cassette being depleted. 
   
   
       35 . (canceled) 
   
   
       36 . A tubular structure made on an apparatus as claimed in  claim 1 . 
   
   
       37 . A method of manufacturing a tubular structure comprising the steps of:
 bending a strip of material into a helical form by plastic deformation thereof; and winding said bent strip in a self overlapping manner into a tubular structure; wherein the strip is bent into said helical form with a radius of curvature less than the final radius of the structure to be formed.   
   
   
       38 . A method as claimed in  claim 36  and including the step of passing said strip through a pair of pinch rollers and a ring roller adjustable relative to one of said pinch rollers such as to cause said strip to adopt said desired radius of curvature. 
   
   
       39 . A method as claimed in  claim 36  and including the step of passing the strip through a pair of pinched rollers, the axis of rotation of which are displaced relative to each other such as to cause said strip to adopt a bend along its length thereby to impart a sideways bend into said strip and create a strip having one edge longer than the other. 
   
   
       40 . A method as claimed in  claim 36  and including the step of applying an adhesive to portions of said strip which will be overlapping when formed into a tubular structure. 
   
   
       41 . A method as claimed in  claim 36  in which the adhesive is applied by applying the adhesive as a strip of adhesive to said strip of material. 
   
   
       42 . A method as claimed in  claim 39  and including the step of protecting said strip of adhesive by applying a protective coating to at least one surface thereof and removing said protective coating prior to applying said adhesive onto said strip which forms said tubular structure. 
   
   
       43 . A method as claimed in  claim 36  and including the step of providing a tubular core and winding said strip onto said core so as to produce a tubular structure having an inner core and an outer casing of helically wound material. 
   
   
       44 . A method as claimed in  claim 42  and including the step of forming said tubular core by roll forming a strip of material along its length and seam welding abutting longitudinal edges. 
   
   
       45 . A method as claimed in  claim 42  including the step of forming said tubular core as a series of discrete lengths of tube and assembling them into a continuous or near continuous length prior to winding said strip material onto said core. 
   
   
       46 . A method as claimed in  claim 42  including the step of forming said tubular core as a length of extruded pipe of a plastics material. 
   
   
       47 . A method as claimed in  claim 42  including the step of providing the core as discrete lengths of ceramic tube. 
   
   
       48 . A tubular structure manufactured according to the method of  claim 36 . 
   
   
       49 . (canceled) 
   
   
       50 . (canceled)