Load measuring arrangements for fork lift trucks or the like

• US 4,212,360 A
• Filed: 10/12/1978
• Issued: 07/15/1980
• Est. Priority Date: 10/20/1977
• Status: Expired due to Term

• Current Assignee: PYE Electronic Products Limited (Koninklijke Philips N.V.)
• Original Assignee: PYE Electronic Products Limited (Koninklijke Philips N.V.)
• Inventors: Chesher, Keith
• Primary Examiner(s): Miller, Jr., George H.
• Application Number:
  US05/950,659
• Time in Patent Office: 642 Days
• Field of Search: 177/139, 177/147, 177/211
• US Class Current: 177/139
• CPC Class Codes: G01G 19/083 lift truck scale
• CPC Class Codes: G01G 3/1406 combined with special measuring circuits

Abstract

A load weighing system for a fork lift truck uses load cell transducers to measure the compressive forces exerted between a supporting chain or chains which support(s) the load forks and an anchorage point for the chain(s).

Claims

1. An arrangement for measuring the weight of a load being carried by a fork lift truck or other load-handling device having a fork or other load engaging member mounted on a carriage supported and arranged for movement parallel to the axis of a substantially vertical mast of the device, which comprises at least one flexible carriage support member, one end of said support member being secured to a first anchor member fixed in relation to the mast and the other end of said support member being secured to a second anchor member fixed to the carriage, at least one anchor member having an opening therethrough;

a securing member associated with said one anchor member and having a central portion passing through the opening in said one anchor member, a first end portion adapted to be connected to one end of the flexible support member on one side of the anchor member, and a second end portion having a cross-section greater than that of the opening and positioned on the other side of the anchor member;

a load cell transducer located between said second end portion and said other side of the anchor member and responsive to measure the compressive forces exerted between the securing member and the anchor member; and

means responsive to the resulting load cell transducer measurement to provide an indication of the weight of the load being carried.

2. An arrangement according to claim 1, in which the load cell transducer comprises a generally cylindrical body having an axial bore and oppositely disposed end faces, the central portion of the securing member passing through the bore with one end face of the cylindrical body bearing against said other side of the anchor member and the other end face of the cylindrical body bearing against said second end portion of the securing member, and resistive strain-gauge elements affixed to the cylindrical body in such positions as to be responsive to compressive forces applied to the end faces of said body.

3. An arrangement according to claim 1 or 2, in which the securing member comprises an eye-bolt and nut assembly, the flexible support member being attached to the eye of the bolt, and the nut comprising said second end portion of the securing member.