One-piece molded chasis having openings and rib minimizing deformation during cooling

A chassis made by the process of:

• molding a material selected from the group consisting of a thermoplastic resin and a thermosetting resin in a cavity mold, the cavity mold having a mold cavity with cavity wall surfaces for forming a bottom plane and at least three side planes joined at an angle, so as to produce a one-piece molded thermoplastic or thermosetting resin body comprising a one-piece molded thermoplastic or thermosetting resin body comprising a bottom plane, at least three side planes, each said plane having an in-plane area, junction portions joining said bottom plane and said side plane with each other, and ribs integrally molded as one piece with said bottom plane and said side plane extending from said in-plane area of said bottom plane, through said junction portion and to said in-plane area of said side plane, wherein at least one of said bottom plane and said side plane has an opening portion therein located between said ribs at least adjacent to and along said junction portion, said opening portion having a length along said junction portion at least 5/10 the length of said junction portion;
• and
• cooling said one-piece molded thermoplastic or thermosetting resin body while minimizing differences in the cooling rate at different parts of said one-piece body, wherein said opening portion defines a means for preventing angular deformation of said resin body between said bottom plane and said side plane from said angle by minimizing differences in the cooling rate at different parts adjacent to said junction portion in said one-piece body.

A chassis made by the process of:

• molding a material selected from the group consisting of a thermoplastic resin and a thermosetting resin in a cavity mold, the cavity mold having a mold cavity with cavity wall surfaces for forming a bottom plane and at least three side planes joined at an angle, so as to produce a one-piece molded thermoplastic or thermosetting resin body comprising a bottom member extending in a bottom plane, at least three side members extending in respective side planes, junction portions joining said bottom member and said side members with each other, and ribs integrally molded as one piece with said bottom member and at least one of said side members extending from said bottom plane of said bottom member, through said junction portion, and to said side plane of the at least one of said side members, wherein at least one of said bottom member and the at least one of said side members has an opening portion therein, located between said ribs at least adjacent to and along said junction portion, said opening portion having a length along said junction portion at least 5/10 the length of said junction portion;
• and
• cooling said one-piece molded thermoplastic or thermosetting resin body while minimizing differences in the cooling rate at different parts of said one-piece body, wherein said opening portion defines a means for preventing angular deformation of said resin body between said bottom plane and said side plane from said angle by minimizing differences in the cooling rate at different parts adjacent to said junction portion in said one-piece body.