Tow bar apparatus

Claim 2

A crane including an elongated boom; a main pivot at the front end of said boom; a power operated device connected to said boom from below for raising the rear end thereof; a tow bar assembly including an elongated boom extension and an elongated cross-bar; said boom extension connected at one end thereof to said rear end of said boom to be raised by said power operated device as the latter raises said boom; with said tow bar assembly in a working position said boom extension having its other end positioned below and to the rear of said one end; swivel means connecting said cross-bar at its mid-region to said other end of said boom extension and generally at right angles with respect thereto; 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 device 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; stabilizing members extending from opposite sides of said boom and connected to said base at the front thereof.

Claim 3

A crane including an elongated boom; a main pivot at the front end of said boom; a power operated device connected to said boom from below for raising the rear end thereof; a tow bar assembly including an elongated boom extension and an elongated cross-bar; said boom extension connected at one end thereof to said rear end of said boom to be raised by said power operated device as the latter raises said boom; with said tow bar assembly in a working position said boom extension having its other end positioned below and to the rear of said one end; swivel means connecting said cross-bar at its mid-region to said other end of said boom extension and generally at right angles with respect thereto; 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 device 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; stabilizing members extending from opposite sides of said boom and connected to said base at the front thereof.

Claim 4

A crane including an elongated boom; a main pivot at the front end of said boom; a power operated device connected to said boom from below for raising the rear end thereof; a tow bar assembly including an elongated boom extension and an elongated cross-bar; said boom extension connected at one end thereof to said rear end of said boom to be raised by said power operated device as the latter raises said boom; with said tow bar assembly in a working position said boom extension having its other end positioned below and to the rear of said one end; swivel means connecting said cross-bar at its mid-region to said other end of said boom extension and generally at right angles with respect thereto; 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 device 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; stabilizing members extending from opposite sides of said boom and connected to said base at the front thereof.

Claim 5

A crane as set forth in claim 1, in which said swivel means comprises a device supporting said cross-bar from a point therebelow.

Claim 6

A crane as set forth in claim 1, in which said boom, said boom extension, and said cross-bar are each constructed of tubular elements.

Claim 7

A crane as set forth in claim 1 also including a safety device connected to said boom tO limit lowering thereof in the event there is a malfunction of the power operated device.

Claim 8

A crane as set forth in claim 4 in which the safety device comprises first and second telescoping elements, one connected to said boom and the other connected to said base, a retractable locking member carried by one of said elements and biased to be engageably by locking formations of the other of said elements as said boom is being lowered, thereby limiting lowering movement of said boom unless said locking member is retracted.

Claim 9

A crane as set forth in claim 1 in which the power operated device comprises fluid cylinder means.

Claim 10

A crane including an elongated boom; a main pivot at the front end of said boom; a power operated device connected to said boom from below and comprising the sole means for raising said boom and elements secured to the rear end of said boom for raising the rear end thereof; a tow bar assembly including an elongated boom extension and an elongated cross-bar; said boom extension connected at one end thereof to said rear end of said boom to be raised by said power operated device as the latter raises said boom; with said tow bar assembly in a working position said boom extension having its other end positioned below and to the rear of said one end; swivel means connecting said cross-bar at its mid-region to said other end of said boom extension and generally at right angles with respect thereto; a pivot means connecting said one end of said boom extension directly to said rear end of said boom, said pivot means and said main pivot being parallel to each other and generally parallel to said cross-bar; said tow bar assembly being movable about said pivot means as a center to a storage position, wherein said boom extension overlies said boom, with said other end of said boom extension being forward of said rear end of said boom, and with both said boom and said boom extension being lowered to generally horizontal positions; 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 device 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.

Claim 11

A crane including an elongated boom; a main pivot at the front end of said boom; a power operated device connected to said boom from below and comprising the sole means for raising said boom and elements secured to the rear end of said boom for raising the rear end thereof; a tow bar assembly including an elongated boom extension and an elongated cross-bar; said boom extension connected at one end thereof to said rear end of said boom to be raised by said power operated device as the latter raises said boom; with said tow bar assembly in a working position said boom extension having its other end positioned below and to the rear of said one end; swivel means connecting said cross-bar at its mid-region to said other end of said boom extension and generally at right angles with respect thereto; a pivot means connecting said one end of said boom extension directly to said rear end of said boom, said pivot means and said main pivot being parallel to each other and generally parallel to said cross-bar; said tow bar assembly being movable about said pivot means as a center to a storage position, wherein said boom extension overlies said boom, with said other end of said boom extension being forward of said rear end of said boom, and with both said boom and said boom extension being lowered to generally horizontal positions; 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 device 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.