Tube bender

Claim 2

A tube bender comprising: a mandrel having an axis and a segmentally annular, radially outwardly opening tube receiving groove concentric to said axis, said groove defining a bend-start point and a center plane perpendicular to the mandrel axis; a hook immovably fixedly associated with said mandrel and defining a recess opening generally parallel to said axis at a position rearwardly of said bend-start point for receiving the tube in a bend-start position and limiting the movement of the tube away from said mandrel rearwardly of the bend-start point and restraining the tube against axial movement in said mandrel groove; shoe means; and means connecting said shoe means to said mandrel for swinging movement of said shoe means about said axis to bend the tube arcuately into said annular groove forwardly from said bend-start point, said connecting means being constructed to space said shoe means away from the mandrel adjacent said bend-start point in a tube loading disposition providing clearance between said shoe means and said mandrel to receive the tube freely between said mandrel, hook, and shoe means.

Claim 3

The tube bender of claim 1 wherein said hook comprises an element secured to the mandrel.

Claim 4

The tube bender of claim 1 wherein said shoe connecting means defines means for limiting the lateral movement of the tube parallel to said axis to guide the tube substantially into axial alignment with said center plane of the groove.

Claim 5

The tube bender of claim 1 wherein said hook further comprises means for limiting the rearward movement of the connecting means to a position wherein said shoe means carried thereby is spaced substantially radially outwardly from said bend-start position.

Claim 6

The tube bender of claim 1 wherein said shoe means is swingably mounted on said connecting means and said hook further comprises means for limiting the rearward swing of said shoe means relative to said connecting means when said connecting means is disposed adjacent said bend-start point.

Claim 7

The tube bender of claim 1 wherein said mandrel and hook define interlocking shoulders effectively positively positioning said hook in a preselected tube hooking position.

Claim 8

The tube bender of claim 1 including means fixedly securing the hook to the mandrel to open accurately parallel to said axis.

Claim 9

The tube bender of claim 1 wherein said hook defines a rearward biting edge fixedly positioned relativE to said axis to effectively positively lock the tube against forward axial displacement during a bending thereof by said shoe means.

Claim 10

The tube bender of claim 8 wherein said biting edge comprises an acute angle corner.

Claim 11

The tube bender of claim 1 wherein said connecting means includes friction holding means for frictionally retaining the shoe means in a plurality of different positions relative to the mandrel.

Claim 12

The tube bender of claim 10 wherein said connecting means comprises a link and pivot means pivotally connecting the link to the mandrel and the link to the shoe means, and said friction holding means comprises spring washers carried by said pivot means.

Claim 13

A tube bender comprising: a mandrel having an axis and a segmentally annular, radially outwardly opening tube receiving groove concentric to said axis, said groove defining a bend-start point and a center plane perpendicular to the mandrel axis; a hook fixedly associated with said mandrel and defining a recess opening generally parallel to said axis at a position rearwardly of said bend-start point for receiving the tube in a bend-start position and limiting the movement of the tube away from said mandrel rearwardly of said bend-start point and restraining the tube against axial movement in said mandrel groove; shoe means; and means connecting said shoe means to said mandrel for swinging movement of said shoe means about said axis to bend the tube arcuately into said annular groove forwardly from said bend-start point, said connecting means being constructed to space said shoe means away from the mandrel adjacent said bend-start point in a tube loading disposition providing clearance between said shoe means and said mandrel to receive the tube freely therebetween, said mandrel being provided with a recessed portion extending rearwardly from said start point permitting a tube to be bent to be moved laterally into said recessed portion while extending in a direction parallel to said axis to a first position wherein the axis of the tube lies in said center plane of said groove and at an acute angle to a line from said axis to said bend-start point and to be subsequently moved transversely to said axis to a second position with the tube axis lying in said plane perpendicularly to said line at said start point.

Claim 14

A tube bender comprising: a mandrel having an axis and a segmentally annular, radially outwardly opening tube receiving groove concentric to said axis, said groove defining a bend-start point and a center plane perpendicular to the mandrel axis; a hook fixedly associated with said mandrel and defining a recess opening generally parallel to said axis at a position rearwardly of said bend-start point for receiving the tube in a bend-start position and limiting the movement of the tube away from said mandrel rearwardly of said bend-start point and restraining the tube against axial movement in said mandrel groove; shoe means; and means connecting said shoe means to said mandrel for swinging movement of said shoe means about said axis to bend the tube arcuately into said annular groove forwardly from said bend-start point, said connecting means being constructed to space said shoe means away from the mandrel adjacent said bend-start point in a tube loading disposition providing clearance between said shoe means and said mandrel to receive the tube freely therebetween, said mandrel being provided with a recessed portion extending rearwardly from said start point permitting a tube to be bent to be moved laterally into said recessed portion while extending in a direction parallel to said axis to a first position wherein the axis of the tube lies in said center plane of said groove and at an acute angle to a line from said axis to said bend-start point and to be subsequently moved transversely to said axis to a second position with the tube axis lying in said plane perpendicularly to said line at said start point.

Claim 15

The tube bender of claim 12 wherein said connecting means is arranged to swing the shoe means against the tube and cause the tube to move from said first position to said second position as a result of said shoe means being swung to adjacent said bend-start point.

Claim 16

The tube bender of claim 13 wherein said shoe connecting means is constructed to permit said shoe to abut the tube in said first position and to urge the tube to said second position as an incident of movement of said shoe from said tube loading position to a bend-start position wherein said shoe abuts the surface of the tube radially outwardly of said bend-start point.

Claim 17

The tube bender of claim 13 wherein said recessed portion is defined by a planar outer surface of the mandrel extending at a preselected angle to said line from said mandrel axis to said bend-start point and parallel to said mandrel axis.