Towing apparatus

Claim 2

A crane including an elongated boom; a main pivot at the front end of said boom; power operated means connected to said boom for raising the rear end thereof about said main pivot as a center; a tow bar assembly including an elongated boom extension, an elongated cross-bar, and swivel means connecting said crossbar at its mid-region to one end of said boom extension and generally at right angles with respect thereto; said tow bar assembly being movable to an operating position wherein the other end of said boom extension is at the rear end of said boom and said done end of said boom extension is positioned below and to the rear of said other end; with said tow bar assembly in said operating position the longitudinal axis of said boom extension being transverse to the longitudinal axis of said boom; said tow bar assembly being movable from said operating position to a retracted position wherein said longitudinal axes are generally parallel and said other end is a substantial distance forward of the rear end of said boom.

Claim 3

A crane as set forth in claim 1, in which said boom and said boom extension are in telescoping relationship when said tow bar assembly is in said retracted position.

Claim 4

A crane as set forth in claim 2, also including a spring connected to said boom extension and urging said tow bar assembly toward said retracted position.

Claim 5

A crane as set forth in claim 3, in which the strength and line of action of said spring are such that said spring is ineffective to move said tow bar assembly from said operating position.

Claim 6

A crane as set forth in claim 4, in which the strength and line of action of said spring are such that said spring is effective to move said tow bar assembly to said retracted position when said boom extension is moved to a position generally in axial alignment with the rear end portion of said boom.

Claim 7

A crane as set forth in claim 5, in which the spring is also effective to move said tow bar assembly to said retracted position when the other end of said boom extension is moved to a predetermined position above and in front of said rear end.

Claim 8

A crane as set forth in claim 1, in which there is a first element at the other end of the boom extension and a second element at the rear end of the boom; with said tow bar assembly in said operating position said first element operatively engaging said second element to cooperate therewith in constituting a horizontal pivot means about which said tow bar assembly is movable relative to said boom.

Claim 9

A crane as set forth in claim 1, in which said boom extension is telescoped within said boom when said tow bar assembly is in said retracted position; said boom being a tubular member having a rear cutaway portion providing a narrow channel having an open top; said open top permitting said other end of said boom extension to be moved to a position above said boom to facilitate movement of said tow bar assembly between said operating and retracted positions.

Claim 10

A crane including an elongated boom; a main pivot at the front end of said boom; power operated means connected to said boom for raising the rear end thereof about said main pivot as a center; a tow bar assembly including an elongated boom extension, an elongated cross-bar, and swivel means connecting said cross-bar at its mid-region to one end of said boom extension and generally at right angles with respect thereto; said tow bar assembly being movable to an operating position wherein the other end of said boom extension is at the rear end of said boom and said one end of said boom extension is positioned below and to the rear of said other end; said tow bar assembly being movable from said operating position to a retracted position wherein saId other end is a substantial distance forward of the rear end of said boom; said boom and said boom extension being in telescoping relationship when said tow bar assembly is in said retracted position; a spring connected to said boom extension and urging said tow bar assembly toward said retracted position; said spring being of such strength and having its line of action so positioned that said spring is ineffective to move said tow bar assembly from said operating position.

Claim 11

A crane including an elongated boom; a main pivot at the front end of said boom; power operated means connected to said boom for raising the rear end thereof about said main pivot as a center; a tow bar assembly including an elongated boom extension, an elongated cross-bar, and swivel means connecting said cross-bar at its mid-region to one end of said boom extension and generally at right angles with respect thereto; said tow bar assembly being movable to an operating position wherein the other end of said boom extension is at the rear end of said boom and said one end of said boom extension is positioned below and to the rear of said other end; said tow bar assembly being movable from said operating position to a retracted position wherein saId other end is a substantial distance forward of the rear end of said boom; said boom and said boom extension being in telescoping relationship when said tow bar assembly is in said retracted position; a spring connected to said boom extension and urging said tow bar assembly toward said retracted position; said spring being of such strength and having its line of action so positioned that said spring is ineffective to move said tow bar assembly from said operating position.

Claim 12

A crane as set forth in claim 9, in which the strength and line of action of said spring are such that said spring is effective to move said tow bar assembly to said retracted position when said boom extension is moved to a position generally in axial alignment with the rear end portion of said boom.

Claim 13

A crane as set forth in claim 10, in which the spring is also effective to move said tow bar assembly to said retracted position when the other end of said boom extension is moved to a predetermined position above and in front of said rear end.

Claim 14

A crane including an elongated boom; a main pivot at the front end of said boom; power operated means connected to said boom for raising the rear end thereof about said main pivot as a center; a tow bar assembly including an elongated boom extension, an elongated cross-bar, and swivel means connecting said cross-bar at its mid-region to one end of said boom extension and generally at right angles with respect thereto; said tow bar assembly being movable to an operating position wherein the other end of said boom extension is at the rear end of said boom and said one end of said boom extension is positioned below and to the rear of said other end; said tow bar assembly being movable from said operating position to a retracted position wherein said other end is a substantial distance forward of the rear end of said boom; said boom extension being telescoped within said boom when said tow bar assembly is in said retracted position; said boom being a tubular member having a rear cutaway portion providing a narrow channel having an open top; said open top permitting said other end of said boom extension to be moved to a position above said boom to facilitate movement of said tow bar assembly between said operating and retracted positions.

Claim 15

A crane including an elongated boom; a main pivot at the front end of said boom; power operated means connected to said boom for raising the rear end thereof about said main pivot as a center; a tow bar assembly including an elongated boom extension, an elongated cross-bar, and swivel means connecting said cross-bar at its mid-region to one end of said boom extension and generally at right angles with respect thereto; said tow bar assembly being movable to an operating position wherein the other end of said boom extension is at the rear end of said boom and said one end of said boom extension is positioned below and to the rear of said other end; said tow bar assembly being movable from said operating position to a retracted position wherein said other end is a substantial distance forward of the rear end of said boom; said boom extension being telescoped within said boom when said tow bar assembly is in said retracted position; said boom being a tubular member having a rear cutaway portion providing a narrow channel having an open top; said open top permitting said other end of said boom extension to be moved to a position above said boom to facilitate movement of said tow bar assembly between said operating and retracted positions.

Claim 16

A crane as set forth in claim 1 also including a generally horizontal base including spaced elongated side members extending generally parallel to the plane of movement for said boom; said main pivot being positioned at the front of said base; said base also including a transverse member positioned rearward of said main pivot; said power operated means connected between said transverse member and a point on said boom positioned to the rear of said transverse member; said cross-bar being positionable below said base by lowering the rear end of said boom.

Claim 17

A crane as set forth in claim 13 in which there are stabilizing members extending from opposite sides of said boom and connected to said base at the front thereof.