Erect tube bending mandrel

Claim 2

A tube bending mandrel comprising a series of flexibly interconnected mandrel units arranged end to end, each mandrel unit having a one-piece link, the link having a generally cylindrical socket female portion adjacent one end, said cylindrical socket having a transverse cross-section which is greater than a semi-circle but less than a circle, and a generally cylindrical male portion at the other end received in the female portion of the next adjacent link whereby a succession of the links are flexibly attached together, said link having a longitudinal axis extending from said one end to said other end and said male and female portions having parallel longitudinal axes which lie substantially normal to the longitudinal axis of the link, and an outer ring fastened to its associated link portion so as to retain the male portion of the next adjacent link in the socket of the associated link while permitting freedom of pivotal movement of each link relative to the next adjacent link in a single plane.

Claim 3

The tube bending mandrel of claim 1 wherein the longitudinal axis of the female portion is spaced inwardly from the one end of the associated link a distance which is less than the radius of the socket so that the female portion has an opening in the one end through which the attached link can protrude, said opening having a width which is smaller than the diameter of the generally cylindrical male portion.

Claim 4

The tube bending mandrel of claim 2 wherein the link portions of the mandrel are attached together so that the longitudinal axes of the substantially cylindrical socket female portion and the cylindrically shaped male portion are vertical and the socket of each link opens through the top of the link so that the male portion of an adjacent link can be inserted into the socket female portion through the opening in the top of the link and retained therein by the outer ring.

Claim 5

The tube bending mandrel of claim 3 further including a circular spacer slug abutting against the top of said male portion so as to be disposed between the top of the male portion and the outer ring.

Claim 6

The tube bending mandrel of claim 2 wherein the one end of said lInk is flattened and the socket opening therein is U-shaped with a width less than the diameter of the socket.

Claim 7

The tube bending mandrel of claim 1 further including a ball detent assembly having a compression spring disposed in a bore in the cylindrically shaped male portion and a detent ball biased outwardly by the spring so that the ball will drop into a depression in the socket female portion wall when the associated attached links are axially aligned.

Claim 8

A tube bending mandrel comprising in combination a straight mandrel section including a socket portion of substantially cylindrical configuration at one end and a series of flexibly interconnected mandrel units disposed in end-to-end relation with respect to one another and with respect to the end of the straight mandrel section, each of said flexibly interconnected mandrel units including an outer ring member and a one-piece inner connecting link, each connecting link including a socket portion of substantially cylindrical configuration adjacent one end with a transverse cross-section which is greater than a semi-circle but less than a circle and a generally cylindrical bulb portion at the other end adapted to seat in the socket portion of an adjacent link or in the socket portion of the straight mandrel section, the outer ring member of each unit being attachable to the associated link so as to retain the bulb portion of the adjacent link in the socket of the associated link in a manner such that the links will be free to pivot in a single plane.

Claim 9

A tube bending mandrel comprising in combination a straight mandrel section including a socket portion of substantially cylindrical configuration at one end and a series of flexibly interconnected mandrel units disposed in end-to-end relation with respect to one another and with respect to the end of the straight mandrel section, each of said flexibly interconnected mandrel units including an outer ring member and a one-piece inner connecting link, each connecting link including a socket portion of substantially cylindrical configuration adjacent one end with a transverse cross-section which is greater than a semi-circle but less than a circle and a generally cylindrical bulb portion at the other end adapted to seat in the socket portion of an adjacent link or in the socket portion of the straight mandrel section, the outer ring member of each unit being attachable to the associated link so as to retain the bulb portion of the adjacent link in the socket of the associated link in a manner such that the links will be free to pivot in a single plane.

Claim 10

The tube bending mandrel of claim 7 wherein the socket portion of the straight mandrel section is in a removable insert which can be fixedly secured in a recess in a bar portion of the straight mandrel section.

Claim 11

The tube bending mandrel of claim 7 wherein the longitudinal axis of the substantially cylindrical socket is spaced from the one end of the associated link a distance which is less than the radius of the socket so that the socket has an opening in the one end through which the attached link can protrude.

Claim 12

The tube bending mandrel of claim 9 wherein the link portions of the mandrel are attached together so that the longitudinal axes of the substantially cylindrical socket and the cylindrically shaped bulb are vertical and the socket opens through the top of the link so that the bulb of an adjacent link can be inserted into the socket through the opening in the top of the link and retained therein by the outer ring.

Claim 13

The tube bending mandrel of claim 7 further including a ball detent assembly having a compression spring disposed in a bore in the cylindrically shaped bulb and a detent ball biased outwardly by the spring so that the ball will drop into a depression in the socket wall when the associated attached links are axially aligned.

Claim 14

A tube bending mandrel comprising in combination a straight mandrel section having a recess in one end, an insert adapted to be fixedly secured in said recess so as to have an exposed end with an opening therein, the insert having a generally cylindrically shaped socket communicating with said opening, said socket having a vertical longitudinal axis, a series of flexibly interconnected mandrel units disposed in end-to-end relation with respect to one another and with respect to the end of the straight mandrel section, each of said flexibly interconnected mandrel units including an outer ring member and an inner one-piece connecting link, each connecting link including a socket portion of substantially cylindrical configuration adjacent one end, said cylindrical socket portion having a transverse cross-section which is greater than a semi-circle but less than a circle, and a generally cylindrical bulb portion at the other end adapted to pivotally seat in the socket portion of an adjacent link or in the socket of the straight mandrel section, the longitudinal axes of the socket portion and the bulb portion both being spaced from the one end of the associated link a distance which is less than the radius of The socket portion so that the socket portion has an opening in the one end through which the attached link can protrude, the outer ring member of each unit being attachable to the associated link so as to retain the bulb portion of the adjacent link in the socket of the associated link in a manner such that the links will be free to pivot in a single horizontal plane, and a spacer abutting against the upper end of said bulb portion of each link so as to be disposed between the bulb portion and the outer ring such that linear movement of the bulb portion in the socket portion will be prevented.

Claim 15

A tube bending mandrel comprising in combination a straight mandrel section having a recess in one end, an insert adapted to be fixedly secured in said recess so as to have an exposed end with an opening therein, the insert having a generally cylindrically shaped socket communicating with said opening, said socket having a vertical longitudinal axis, a series of flexibly interconnected mandrel units disposed in end-to-end relation with respect to one another and with respect to the end of the straight mandrel section, each of said flexibly interconnected mandrel units including an outer ring member and an inner one-piece connecting link, each connecting link including a socket portion of substantially cylindrical configuration adjacent one end, said cylindrical socket portion having a transverse cross-section which is greater than a semi-circle but less than a circle, and a generally cylindrical bulb portion at the other end adapted to pivotally seat in the socket portion of an adjacent link or in the socket of the straight mandrel section, the longitudinal axes of the socket portion and the bulb portion both being spaced from the one end of the associated link a distance which is less than the radius of The socket portion so that the socket portion has an opening in the one end through which the attached link can protrude, the outer ring member of each unit being attachable to the associated link so as to retain the bulb portion of the adjacent link in the socket of the associated link in a manner such that the links will be free to pivot in a single horizontal plane, and a spacer abutting against the upper end of said bulb portion of each link so as to be disposed between the bulb portion and the outer ring such that linear movement of the bulb portion in the socket portion will be prevented.