Method of producing a main frame for a shipping container
AssigneeNam Lee Industries (PTE) Ltd.
InventorsKin S. Yong, Fa S. Hsu
Life of this patent
Estimating the term…
Abstract
Shipping container carrying cargoes requiring temperature control and/or ventilation require a main frame capable of housing a refrigeration unit. Hitherto, main frames have been constructed by welding the component parts together which is extremely time consuming. The present invention provides a method for producing a main frame in which a recessed portion for housing the refrigeration unit is deep drawn while a force is simultaneously applied to maintain a substantially constant thickness of the main frame.
Claims4
A method for making a main frame for a shipping container of substantially uniform thickness and having a single integral recess from a single rectangular sheet of metal having a center line defining a first side and second side comprising the steps of:
- a) applying a compressive force directed along a plane defined by the sheet at the first side of the sheet;
- and
- b) simultaneously applying a deep drawing force directed substantially perpendicular to the plane of the sheet thereby forming the single recess, said deep drawing force applied separately from said compressive force, at the second side of the sheet and off-center relative to said center line so that only the single deep drawn recess is formed in the sheet;
- and
- c) adapting said main frame for attachment to said shipping container and further adapting said main frame to house a refrigeration unit to refrigerate said shipping container.
Dependencies are inferred from the claim text.