Tube forming machine

Abstract

A machine or device for forming tubes or the like includes one or more cables or other elongated flexible members. An expanding forming device is positioned at an end of the cables, and the cables are inserted into a tube that is to be formed. The expanding device expands outwardly, and tension is placed on the cables to pull the cables through the tubes. This causes the tubes to be permanently deformed outwardly to a larger outer diameter.

What is claimed is: 
     
         1 . A tube forming apparatus, comprising:
 a support structure;   a winding member rotatably mounted to the support structure;   at least one elongated flexible member that winds onto the winding member, the elongated flexible member having an end that moves towards the winding member upon rotation of the winding member;   a powered actuator operably connected to the winding member such that actuation of the powered actuator causes the winding member to rotate and wind the at least one elongated flexible member onto the winding member;   an expandable forming tool connected to the end of the at least one elongated flexible member, the expandable forming tool having outer forming surfaces that can be selectively shifted outwardly from an insertion configuration to a forming configuration, and wherein:   the end of the elongated flexible member and the expandable forming tool can be inserted into an elongated metal tube in the insertion configuration, followed by shifting the outer forming surfaces outwardly, followed by actuation of the powered actuator to rotate the winding member to pull the expandable forming tool back through the metal tube, such that the tube is deformed outwardly due to contact between the outer forming surfaces of the expandable forming tool and inner surfaces of the tube.   
     
     
         2 . The tube forming apparatus of  claim 1 , wherein:
 the expandable forming tool comprises an outer member, wherein the outer forming surfaces are disposed on the outer member; and wherein:   the expandable forming tool further comprises an inner member at least partially disposed in the outer member, and wherein the inner member is configured to engage the outer member and shift the outer forming surfaces outwardly.   
     
     
         3 . The tube forming apparatus of  claim 2 , wherein:
 the outer member includes a plurality of flexible fingers, wherein the outer forming surfaces are disposed on the fingers.   
     
     
         4 . The tube forming apparatus of  claim 3 , wherein:
 the outer member includes a base portion, and the fingers extend from the base portion.   
     
     
         5 . The tube forming apparatus of  claim 2 , wherein:
 the inner member comprises a mandrel having an inner end and an outer end that is enlarged relative to the inner end, the inner member further comprising a tapered transition portion extending between the inner end and the outer end.   
     
     
         6 . The tube forming apparatus of  claim 5 , wherein:
 the tapered transition portion has a generally conical outer surface.   
     
     
         7 . The tube forming apparatus of  claim 6 , wherein:
 the outer member includes inner surface portions that engage the conical outer surface of the inner member.   
     
     
         8 . The tube forming apparatus of  claim 7 , wherein:
 the inner surface portions of the outer member are generally conical and slidably engage the generally conical outer surface of the inner member as the inner member is shifted axially relative to the outer member.   
     
     
         9 . The tube forming apparatus of  claim 2 , wherein:
 the outer member defines a bore extending axially through the outer member;   the inner member is movably disposed in the bore, the inner member including a tapered outer surface that engages the outer member and moves the outer forming surfaces outwardly upon shifting of the outer member relative to the inner member in a first direction; and including:   a resilient member biasing the outer member in the first direction relative to the inner member.   
     
     
         10 . The tube forming apparatus of  claim 1 , wherein:
 the elongated flexible member comprises a cable.   
     
     
         11 . The tube forming apparatus of  claim 10 , wherein:
 the cable includes an inner strand and an outer casing, wherein the inner strand is movably disposed in the outer casing; and wherein:   the inner strand and the outer casing are operably connected to the expandable forming tool such that shifting of the inner strand relative to the outer sheath causes the outer forming surfaces of the expandable forming tool to shift outwardly.   
     
     
         12 . The tube forming apparatus of  claim 11 , wherein:
 the winding member comprises a pulley disposed on the shaft for rotation relative to the shaft; and including:   a shaft rotatably mounted to the support structure;   a lost motion device including a tensioning member that is fixed to the shaft, wherein the tensioning member permits rotation of the winding member in first and second opposite directions relative to the shaft for a predefined rotational distance, after which the pulley rotates with the shaft; and wherein:   the tensioning member is connected to the inner strand and the outer casing is connected to the pulley such that rotation of the pulley relative to the shaft shifts the inner strand relative to the outer casing to thereby selectively shift the outer forming surfaces inwardly and outwardly.   
     
     
         13 . The tube forming apparatus of  claims 12 , wherein:
 the pulley includes spaced apart stop surfaces;   the tensioning member comprises a tension arm disposed between the stop surfaces and defining a gap relative to at least one of the stop surfaces.   
     
     
         14 . A tube forming apparatus, comprising:
 at least one elongated flexible member;   a powered device operably connected to the elongated flexible member, wherein the powered device includes a pull member that is operably connected to the elongated flexible member and a powered actuator that is operably connected to the pull member such that actuation of the powered actuator causes the pull member to pull on the elongated flexible member; and   a forming tool connected to the elongated flexible member, the forming tool having outer forming surfaces configured to slidably engage an inner surface of a side wall of a tube to thereby expand the tube outwardly to increase an outer dimension of a tube as the forming tool is pulled through the tube.   
     
     
         15 . The tube forming apparatus of  claim 14 , wherein:
 the outer forming surfaces of the forming tool can be shifted outwardly to increase a size of the forming tool.   
     
     
         16 . The tube forming apparatus of  claim 15 , wherein:
 the forming tool includes an outer member having a bore therethrough, and an inner member movably disposed in the bore, the inner member having an engagement surface that engages the outer member upon movement of the inner member relative to the outer member to shift the outer forming surfaces outwardly, and wherein the inner member is connected to the elongated flexible member such that tension on the elongated flexible member causes the inner member to shift relative to the outer member and thereby shift the outer forming surfaces outwardly.   
     
     
         17 . The tube forming apparatus of  claim 14 , wherein:
 the pull member comprises a pulley, and the powered actuator comprises an electric motor that rotates the pulley and causes the elongated flexible member to wind onto the pulley.   
     
     
         18 . The tube forming apparatus of  claim 14 , wherein:
 the elongated flexible member defines an end;   the forming tool is detachable connected to the end of the elongated flexible member, the forming tool comprising a rigid, non-expandable member having smoothly curved outer forming surfaces.   
     
     
         19 . The tube forming apparatus of  claim 18 , wherein:
 the outer forming surfaces are approximately spherical.   
     
     
         20 . A method of expanding a tube, the method comprising:
 providing an elongated metal tube having an open end and inner and outer surfaces defining inner and outer diameters, respectively;   providing a powered machine including a powered actuator and an elongated flexible member that can be pulled upon actuator of the powered actuator, the powered machine including an expandable forming tool connected to the elongated flexible member, the expandable forming tool having outer forming surfaces that can be shifted outwardly from a first configuration to a second configuration;   inserting the expandable forming tool into the open end of the elongated metal tube;   pushing the elongated flexible member to move the expandable forming tool in the tube in a first direction;   causing the expandable forming tool to shift from the first configuration to the second configuration, wherein the outer forming surfaces define an outer dimension that is transverse to a length of the tube, and wherein the outer dimension is greater than the inner diameter of the tube;   deforming the elongated metal tube to increase the diameter of the elongated metal tube by pulling the expandable forming tool back through the elongated metal tube in a second direction that is substantially opposite the first direction with the outer forming surfaces pushing outwardly on the inner surface of the elongated metal tube.   
     
     
         21 . The method of  claim 20 , wherein:
 the outer forming surfaces slidably engage the inner surface of the elongated metal tube as the expandable forming tool is pulled in the second direction.   
     
     
         22 . The method of  claim 20 , wherein:
 the elongated metal tube has a hairpin shape and includes a pair of generally parallel linear sections that are joined by a curved portion; and including:   providing a plurality of plate members, each having at least two openings therethrough;   positioning the elongated tube such that the linear sections extend through the two openings prior to pulling the expandable forming tool through the tube in the second direction.   
     
     
         23 . The method of  claim 20 , wherein:
 the expandable forming tool includes an outer member and an inner member that movably engages the outer member; and including:   shifting the inner member relative to the outer member to thereby shift the outer forming surfaces from the first configuration to the second configuration.   
     
     
         24 . The method of  claim 20 , wherein:
 the elongated metal tube is substantially linear with opposite ends that are open; and including:   providing a plurality of plate members, each having at least one opening therethrough;   positioning the elongated metal tube in the openings prior to pulling the expandable forming tool back through the elongated metal tube in the second direction.