US 5,174,708 AGranted

Boom mounted multiple stage freight lift apparatus

AssigneeYellow Freight System, Inc.

InventorsCarl J. Ruder, Ronald J. Haney

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Abstract

A freight manipulation includes a tracked chassis with an articulated cantilever boom extending therefrom which is capable of swinging about a horizontal tilt axis. A tool carriage, mounted at the end of the boom by a multiple stage lift mast, has a pair of freight engaging tools thereon. the telescoping mast includes an upper frame connected to the boom for pivoting about a vertical axis, a middle frame, and a lower frame having the tool carriage slidably mounted thereon. A pair of secondary lift cylinders are connected between the upper and middle frames. A pair of secondary lift chains are connected between the upper and lower frames and engage pulleys on the middle frame such that as the secondary cylinders extend or retract to respectively lower or raise the middle frame, the lower frame is lowered or raised relative to the middle frame. A primary lift cylinder is connected to the lower frame, and a pair of primary lift chains engaging pulleys on a ram of the primary cylinder are connected between the lower frame and the tool carriage whereby the tool carriage is lowered or raised as the primary cylinder is respectively extended or retracted.

Claims5

Dependent claims

A lift mechanism for transferring articles between a first location within an elongated interior of an article transporting vehicle and a second location external to said first location, said mechanism comprising:

(a) manipulator chassis means including mobile ground engaging means;
(b) an elongated boom pivotally connected to said chassis means to enable pivoting relative to said chassis means, said boom being spaced vertically from said ground engaging means and having a boom end;
(c) manipulator motor means drivingly engaged between said chassis means and said ground engaging means and operable to propel said chassis means on a support surface of said chassis means;
and
(d) a lift apparatus including:
(1) extendible mast means pivotally connected to said boom end to enable pivoting said mast means about a substantially vertical axis;
(2) pivot motor means connected between said boom and said mast means and operable to pivot said mast means about said vertical axis;
(3) a tool carriage movably mounted on said mast means and operable to move vertically relative to said mast means;
(4) a pair of fork tines operatively connected to said tool carriage, said fork tines being adapted to engage an article to enable lifting thereof by said lift apparatus;
(5) tilt means operatively engaged between said fork tines and said lift carriages and operable to tilt said fork tines relative to said lift carriage;
and
(6) lateral shift means operatively engaged between said fork tines and said lift carriage and operable to shift said fork tines laterally of said lift carriage.

9 more elements

Dependencies are inferred from the claim text.