Lift truck carriage

• US 5,217,343 A
• Filed: 12/04/1992
• Issued: 06/08/1993
• Est. Priority Date: 04/24/1991
• Status: Expired due to Fees

• Current Assignee: Superior Fabrication Co. LLC
• Original Assignee: Swingshift Manufacturing Incorporated
• Inventors: Johnson, Alan, Bostad, Wayne, Frison, Emmett
• Primary Examiner(s): Huppert, Michael S.
• Assistant Examiner(s): KEENAN, JAMES W
• Application Number:
  US07/985,743
• Time in Patent Office: 186 Days
• Field of Search: 414/607, 414/631, 414/659, 414/663, 414/667, 414/671
• US Class Current: 414/667
• CPC Class Codes: B66F 9/148 Whole unit including fork support moves sideways

Abstract

A lifting mechanism for a fork lift truck wherein a side shifting carriage is slidably supported on horizontal bearing bars that are directly attached to the upright of the lift truck. Lifting bars secure the bearing bars together and carry load roller bearings supported in the guide slots of the uprights. A hydraulic motor anchored to the bearing bar assembly at one end and the carriage at the other controls horizontal sliding of the carriage relative to the bearing bars. The interfitting arrangement of the bearing bars in the carriage reduces the load moment arm, reduces the weight requirement, and provides the operator with greater visibility as compared to prior side shift carriage mounts.

Claims

1. In a lifting truck for lifting and moving heavy items, said lifting truck including power means for raising and lowering a lifting mechanism, and a pair of uprights for guiding the lifting mechanism in a vertical path, said lifting mechanism comprising;

horizontally disposed upper and lower bearing bars having front and back sides and top and bottom edges, and guide means secured to the back side of said bearing bars and mounted to said uprights for mounting and guiding the upper and lower bearing bars on the lifting truck uprights immediately adjacent to and forward of the uprights;

a carriage including upper and lower horizontally disposed carriage bars and vertically disposed interconnecting web portions therebetween, said carriage constructed to have sufficient strength and rigidity to support the load of said heavy items, said upper and lower carriage bars configured to have body portions adjacent to and forward of the front sides of the upper and lower bearing bars respectively, and top and bottom flanges that extend over the top edges and under the bottom edges of the upper and lower bearing bars respectively, said top edge of said upper bearing bar and said bottom edge of said lower bearing bar configured to form rails, and said top flange of said upper carriage bar and said bottom flange of said lower carriage bar configured to form tracks that substantially envelope said rails, said carriage adapted to shift relative to said uprights with the carriage bars sliding along said bearing bars whereby the tracks and rails provide the bearing surfaces, said configured carriage bars providing a nesting relationship with said bearing bars for maintaining sufficient strength and rigidity to support heavy loads, and whereby the combined front-to-back spacing of the carriage bars and bearing bars forward of the uprights is substantially the same as that of the carriage bars alone, and said upper bearing and carriage bars are vertically spaced from said lower bearing and carriage bars to provide a viewing window for the fork lift operator; and

motor means connected between the bearing bars and the carriage for controlled side shifting of the carriage relative to the bearing bars.

2. A lifting mechanism as defined in claim 1 wherein said guide means comprises a pair of spaced apart vertically disposed lifting bars, said uprights having elongated guide slots and said lifting bars including guide members projected into the guide slots for guided movement of the lifting bars along the length of the uprights;

said lifting bars having portions protruded forward of a forward edge of the uprights and said bearing bars attached to said protruded portions to be raised and lowered along the forward edge of the uprights; and

powered lifting means for raising and lowering the lifting bars, bearing bars, and carriage relative to the uprights.

3. A lifting mechanism as defined in claim 2 wherein a pair of forks are removably and adjustably secured to the carriage.

4. A lifting mechanism as defined in claim 3 wherein the carriage is provided with a window opening between the carriage bars through which an operator of the lift truck can observe the forks.

5. A lifting mechanism as defined in claim 4 wherein a top edge is defined by said window opening and the motor means is a hydraulic motor disposed adjacent the upper bearing bar, said motor connected between a lifting bar and the carriage and located at the top edge of the window of the carriage and substantially out of the view of the operator viewing the forks.

6. A lifting mechanism as defined in claim 1 wherein a low friction channel member is positioned between the configured edges of the bearing bars and the tracks of the carriage.