Angled ductwork fittings, flexible fitting machine and methods of manufacture

Abstract

Machines and methods for making an angled ductwork fitting from a length of flexible spiral pipe, which may be flat oval, having two ends. A pair of end securing devices are attachable to respective ends of the length of flexible spiral metal pipe. A mechanism moves the end securing devices relative to each other through a range of movement to an end position which effects bending of the length of spiral metal pipe to a desired angled configuration. Another disclosed method employs a preformed inflatable bladder which, when inflated, assumes the shape of an elbow. The preformed inflatable bladder is inserted in collapsed form into a length of flexible spiral metal pipe, and thereafter inflated.

What is claimed is:  
     
         1 . A machine for making an angled ductwork fitting from a length of flexible spiral metal pipe having two ends, said machine comprising: 
 a pair of end securing devices attachable to respective ends of the length of flexible spiral metal pipe; and    a mechanism for moving said end securing devices relative to each other, while attached to the respective ends, through a range of movement to an end position which effects    bending of the length of spiral metal pipe to a desired angled configuration.    
     
     
         2 . The machine of    claim 1   , which further comprises an inner radius die positioned so as to contact a portion of the length of spiral metal pipe intermediate the two ends.  
     
     
         3 . The machine of    claim 1   , which further comprises: 
 an intermediate securing device attachable to a portion of the length of spiral metal pipe intermediate the two ends; and wherein    said mechanism for moving the end securing devices relative to each other in addition moves the intermediate securing device relative to at least one of the end securing devices.    
     
     
         4 . The machine of    claim 1   , wherein one of said end securing devices is attached to a fixed table, and the other of said end securing devices is attached to an articulating arm.  
     
     
         5 . The machine of    claim 4   , which further comprises an inner radius die positioned so as to contact a portion of the length of spiral metal pipe intermediate the two ends.  
     
     
         6 . The machine of    claim 1   , wherein said mechanism for moving said end securing devices relative to each other comprises: 
 a table to which one of said end securing devices is attached;    a movable element to which the other of said end securing devices is attached;    an arm attached to said movable element and extending past a pivot point; and    an actuator attached to said arm.    
     
     
         7 . The machine of    claim 6   , wherein the position of said pivot point is adjustable.  
     
     
         8 . The machine of    claim 1   , wherein said mechanism for moving said end securing devices relative to each other comprises an X and Y axes drive mechanism attached to one of said end securing devices.  
     
     
         9 . The machine of    claim 8   , which further comprises: 
 an intermediate securing device attachable to a portion of the length of spiral metal pipe intermediate the two ends; and    another X and Y axes drive mechanism attached to said intermediate securing device.    
     
     
         10 . A method for making an angled ductwork fitting, said method comprising: 
 providing a length of flexible spiral metal pipe having two ends;    employing a machine having a pair of end securing devices attachable to respective ends of the length of flexible spiral metal pipe, and a mechanism for moving the end securing devices relative to each other, to manipulate the length of flexible spiral metal pipe to a desired configuration.    
     
     
         11 . The method of    claim 10   , wherein said step of providing a length of flexible spiral metal pipe having two ends comprises providing a length of flat oval flexible spiral metal pipe.  
     
     
         12 . A method for making an angled ductwork fitting, said method comprising: 
 providing a length of flexible spiral metal pipe having two ends;    providing a preformed inflatable bladder which, when inflated, assumes the shape of an elbow;    inserting the preformed inflatable bladder in a collapsed form into the length of flexible spiral metal pipe; and    inflating the bladder.    
     
     
         13 . The method of    claim 12   , wherein said step of providing a length of flexible spiral metal pipe having two ends comprises providing a length of flat oval flexible spiral metal pipe.