Method for manufacturing school bus seat with energy absorber and using same

• US 8,647,544 B2
• Filed: 02/22/2008
• Issued: 02/11/2014
• Est. Priority Date: 09/30/2004
• Status: Expired due to Fees

• Current Assignee: Selwyn Arthur Burch
• Original Assignee: Selwyn Arthur Burch
• Inventors: Burch, Selwyn Arthur
• Primary Examiner(s): HAUTH, GALEN H
• Application Number:
  US12/035,767
• Publication Number:
  US 20080143157A1
• Time in Patent Office: 2,181 Days
• Field of Search: 264/46.6, 297/452.59, 297/452.6, 297/452.61
• US Class Current: 264/46.6
• CPC Class Codes: B29C 44/1228 Joining preformed parts by the expanding material
• CPC Class Codes: B29C 44/146 Shaping the lining before foaming
• CPC Class Codes: B60N 2/015 Attaching seats directly to vehicle chassis
• CPC Class Codes: B60N 2/242 Bus seats
• CPC Class Codes: B60N 2/4214 longitudinal
• CPC Class Codes: B60N 2/42709 involving residual deformation or fracture of the structure
• CPC Class Codes: B60N 2/42745 of the back-rest B60N2/433 takes precedence; higher part of the back-rest moving together with the headrest B60N2/888
• CPC Class Codes: B60N 2/682 Joining means

Abstract

A method and an apparatus for manufacturing an envelope style bus seat back cushion includes the steps of opening a hinged mold and then spraying the cavity of the mold with an elastomeric skin. The hinged mold includes first and second sides having a cavity in each of the sides. The cavities of the mold combine to form a mold cavity. The sides of the mold include interengaging faces, ridges and recesses. The faces, ridges and recesses interengage to seal the mold. Once the first and second sides of the hinged mold are closed and intermate, the steps of injecting a urethane foam into the mold cavity of the closed hinged mold are inserting, quickly, a center core insert into the mold cavity of the closed hinged mold; curing the urethane foam; removing the center core insert from the mold cavity; opening the first and second sides of the mold cavity; and, removing and demolding the envelope style bus seat back cushion from the mold.

Claims

1. A method for manufacturing an envelope style bus seat back cushion comprising the steps of:

injecting urethane foam into an envelope style bus seat back cushion mold, said mold having a core to form said envelope style bus seat back cushion, said envelope style bus seat back cushion includes;

a front portion and a rear portion;

said front portion and said rear portion are connected by a joining portion;

said front portion, said rear portion, and said joining portion include a closed upper portion;

an open lower portion; and

an intermediate portion;

said front portion, said rear portion, and said joining portion form said closed upper portion;

said open lower portion includes an aperture therein in communication with a pocket formed in said intermediate portion; and

said pocket has sides and a bottom reciprocally shaped to slide over a seat back;

extracting said envelope style bus seat back cushion urethane foam from said mold;

overspraying said envelope style bus seat back cushion urethane foam externally from said mold with an elastomeric skin to a desired thickness.

2. A method for manufacturing an envelope style bus seat back cushion, comprising the steps of:

opening a hinged mold, said hinged mold having first and second sides having a cavity in each of said sides, said sides include interengaging faces, ridges and recesses;

spraying said cavities of said first and second sides of said hinged mold with an elastomer skin;

closing said hinged mold and sealing said interengaging faces, ridges and recesses of said hinged mold and forming a mold cavity;

injecting a urethane foam into said mold cavity of said closed hinged mold;

inserting, quickly, a center core insert into said mold cavity of said closed hinged mold after injecting said urethane foam into said mold cavity of said closed hinged mold;

curing said urethane foam;

removing said center core insert from said mold cavity;

said steps of injecting urethane foam, inserting a center core insert, curing said urethane foam, and removing said center core insert form said envelope style bus seat back cushion;

opening said first and second sides of said mold cavity; and

,

removing and demolding said envelope style bus seat back cushion from said mold.

3. A method for manufacturing an envelope style bus seat back cushion as claimed in claim 2, further comprising the steps of:

guiding said center core insert into said mold cavity.

4. A method for manufacturing an envelope style bus seat back cushion as claimed in claim 3, further comprising the steps of:

restraining said center core insert within said mold cavity.

5. A method for manufacturing an envelope style bus seat back cushion as claimed in claim 3, further comprising the steps of:

attaching, releasably, Velcro to said center core insert;

interengaging said Velcro and said urethane foam, said Velcro remaining in engagement with said urethane foam when said center core insert is removed from said mold cavity.

6. A method of manufacturing an envelope style bus seat as claimed in claim 4 wherein said elastomer skin includes a first polyol and a first isocyanate and further comprising the steps of:

mixing said first polyol and said first isocyanate at 102 index to form said elastomer skin;

spraying said elastomer skin into and onto said cavity of said hinged mold;

coating said cavity of said hinged mold until said elastomer skin has a thickness of approximately 0.9 mm;

mixing a urethane including a second polyol and a second isocyanate to form said urethane;

injecting said urethane into said mold at a temperature in the range of 90-140°

F.;

adhering said urethane to said center core insert and said elastomer skin on said mold;

removing said urethane from said mold within a demold time of 3-4 minutes, said urethane having a molded density in the range of 2.5-4.0 lbs./ft 3.

7. A method of manufacturing an envelope style bus seat cushion as claimed in claim 6 wherein said first polyol has a water content of less than or equal to 0.05%, a viscosity of approximately 1100 centipoise and a specific gravity of approximately 1.033 at 25°

C.; and

, said first isocyanate has a viscosity of approximately 700 centipoise and a specific gravity of approximately 1.212 at 25°

C.;

mixing said first polyol and said first isocyanate together at a ratio of 100 parts by weight first polyol to 45.5 parts by weight isocyanate to form said elastomer skin;

said elastomer skin having a thickness in the range of 0.9-1.2 mm, a density of approximately 1.03 g/cm3, a Shore A Hardness of 58, a tensile strength of 1001 psi, an elongation of 263%, a tear strength of 93 lb/in, and a puncture resistance of 271 ppi; and

,

said urethane includes said second polyol and said second isocyanate;

said second polyol having a viscosity of approximately 1275 centipoise at 77°

F. and said second isocyanate having a viscosity of approximately 33 centipoise at 77°

F. and said urethane has a free rise density of 3.10 lbs./ft³.

8. A method of manufacturing an envelope style bus seat cushion as claimed in claim 7 wherein said second polyol and said second isocyanate are mixed in a ratio of 100 parts by weight said second polyol to 48 parts by weight of said second isocyanate.

9. A method for manufacturing an envelope style bus seat back cushion comprising the steps of:

opening an envelope style bus seat back cushion mold;

spraying an elastomeric polymer on the surface of said open envelope style bus seat back cushion mold to a predetermined thickness before closing said mold and injecting urethane foam therein;

closing said mold;

injecting urethane foam into said closed mold, said mold having a core to form said envelope style bus seat back cushion, said envelope style bus seat back cushion includes;

a front portion and a rear portion;

said front portion and said rear portion are connected by a joining portion;

said front portion, said rear portion, and said joining portion include a closed upper portion;

an open lower portion; and

an intermediate portion;

said front portion, said rear portion, and said joining portion form said upper closed portion;

said lower open portion includes an aperture therein in communication with a pocket formed in said intermediate portion; and

, said pocket has sides and a bottom reciprocally shaped to slide over a seat back;

curing said envelope style bus seat back cushion urethane foam and adhering said elastomeric polymer sprayed on said surface of said mold to said urethane foam forming an elastomeric skin thereon;

extracting said cured envelope style bus seat back cushion urethane foam with said elastomeric skin formed thereon from said mold;

overspraying said elastomeric skin on said cured envelope style bus seat back cushion urethane foam externally from said mold with an additional layer of elastomeric skin to a desired thickness; and

,

removing said core from said cured envelope style bus seat back cushion urethane foam after said step of overspraying said elastomeric skin on said cured envelope style bus seat back cushion urethane foam externally from said mold with an additional layer of elastomeric skin to a desired thickness.

10. A method for manufacturing an envelope style bus seat back cushion comprising the steps of:

spraying an elastomeric polymer on the surface of an open envelope style bus seat back cushion mold to a predetermined thickness before closing said mold;

injecting urethane foam into said envelope style bus seat back cushion mold, said mold having a core to form said envelope style bus seat back cushion, said envelope style bus seat back cushion includes;

a front portion and a rear portion;

said front portion and said rear portion are connected by a joining portion;

said front portion, said rear portion, and said joining portion include a closed upper portion;

an open lower portion; and

an intermediate portion;

said front portion, said rear portion, and said joining portion form said closed upper portion;

said open lower portion includes an aperture therein in communication with a pocket formed in said intermediate portion; and

said pocket has sides and a bottom reciprocally shaped to slide over a seat back;

transferring said elastomeric polymer from said surface of said open envelope style bus seat back cushion mold to said urethane foam forming an elastomeric skin thereon;

extracting said envelope style bus seat back cushion urethane foam having said elastomeric skin thereon from said mold;

overspraying said envelope style bus seat back cushion urethane foam having said elastomeric skin thereon externally from said mold with an additional elastomeric skin to a desired thickness.