Land vehicles: bodies and tops – Tops – Roof structure
Reexamination Certificate
2000-04-18
2001-10-30
Pape, Joseph D. (Department: 3612)
Land vehicles: bodies and tops
Tops
Roof structure
C296S102000, C296S208000, C296S210000, C296S190090
Reexamination Certificate
active
06309012
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a one piece plastic molded hollow roof for a vehicle cab and in particular to a roof having integrally molded and separated inlet and outlet air ducts within the hollow roof.
2. Description of Related Art
U.S. Pat. No. 5,690,549 discloses a roof for a vehicle cab that comprises a hollow plastic body molded in one piece and defining a cavity therein. The body includes an inner partition wall extending between the upper roof surface and the lower roof surface to define a well bounded by the partition wall. The partition wall separates the well from the cavity of the hollow body. The entire cavity within the hollow body serves as an inlet air duct having one or more inlets. A blower mounted in an aperture in the partition wall draws air into the cavity. The blower draws air into the well which houses a heater core and an air evaporator coil. From the well, the air is discharged downward, into the interior of the vehicle cab. This structure uses the entire cavity of the hollow roof as a single inlet air duct. The air outlets are limited to the well area and the well is limited to the regions in the roof having sufficient space to package the heater core and evaporator coil. These may not be optimum locations for the air outlets.
SUMMARY OF THE INVENTION
The present invention overcomes the above disadvantages by providing the one piece plastic molded hollow body roof with multiple interior cavities sealed from one another, forming at least one inlet air duct and at least one outlet air duct. The ducts are sealed from one another to prevent air from flowing between the ducts. By providing separate inlet air ducts and outlet air ducts, the location of the outlet openings is not dictated by the location of the chamber containing the heater core and evaporator coil. The outlet locations can be better optimized for operator comfort.
The roof is rotationally molded. A first charge of resin forms the outer solid surface layers of the hollow body. The solid surface layers generally in the form of upper and lower panels that are spaced from one another to create a single cavity within the hollow body. The upper and lower panels are widely spaced in regions of the roof that form the air ducts and are closely spaced in regions of the roof about the periphery of the air ducts. After the outer surface layer is molded, additional resin is dumped into the interior of the hollow body. This additional resin contains a foaming agent. During the rotational molding process, the second resin charge coats the interior of the outer solid surface layer. Once the second resin charge reaches a predetermined temperature, the foaming agent is activated, causing the resin to foam and expand. In those regions where the upper and lower panels are closely spaced, the foam will expand to completely fill the void between the solid surface layers, bonding the layers to one another. The foam structure seals the air ducts from one another.
The foam is preferably rigid to add strength to the plastic molded hollow body. The foam also provides acoustic and thermal insulation. Bonding the upper and lower panels to one another at numerous locations in the roof further strengthens the roof.
The roof of the present invention is formed with an open chamber, preferably open from above. The open chamber houses the heater core and evaporator coil. A blower is provided between the open chamber and each outlet duct. The blower forces air into the associated outlet air duct for discharge into the interior of the cab. The blowers produce a reduced pressure in the chamber, drawing air through the inlet air ducts into the open chamber. The inlet air ducts have air inlets located inside and/or outside of the cab for recirculating air or for drawing in fresh air from outside the cab. The open chamber allows the heater core, evaporator coil, blowers and other mechanical components to be easily mounted to the roof. After these components are installed, a cover is placed over the chamber opening to close the chamber.
Rotational molding with a foam core is the preferred method for making the roof of the present invention. The roof can by made by twin sheet thermoforming or by SMC panels molded together at seams about the inlet and outlet air ducts to seal the ducts from one another.
REFERENCES:
patent: 2817281 (1957-12-01), Schwan et al.
patent: 3532377 (1970-10-01), Grasseler
patent: 3841430 (1974-10-01), Babbitt, Jr. et al.
patent: 4088364 (1978-05-01), Termont
patent: 4097085 (1978-06-01), Nelson
patent: 4120527 (1978-10-01), Lawrence
patent: 4133574 (1979-01-01), Martin
patent: 4503749 (1985-03-01), Kuhn et al.
patent: 4658598 (1987-04-01), Schulz
patent: 4660462 (1987-04-01), Thompson et al.
patent: 4721031 (1988-01-01), Nakata et al.
patent: 4739853 (1988-04-01), Ogilvie
patent: 5690549 (1997-11-01), Webb et al.
patent: 5906411 (1999-05-01), Stauffer et al.
patent: 5921619 (1999-07-01), Cederberg et al.
Bartz Shawn Michael
Boyce Dean Arden
Fryk Bruce Kevin
Blankenship Greg
Deere & Company
Pape Joseph D.
LandOfFree
One piece molded roof for a vehicle cab does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with One piece molded roof for a vehicle cab, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and One piece molded roof for a vehicle cab will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2578788