Spring insert for cushioning insert
Patent 5335380 Issued on August 9, 1994. Estimated Expiration Date: 
November 3, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
November 3, 2012. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2897520 3261037 3262138 3276048 3280410 Fluid mattress Waterbed mattress with spring insert Patent #: 5060328 InventorApplicationNo. 970706 filed on 11/03/1992US Classes:5/255, Springs, nonspiral5/683, Hydraulic chambers267/122Diaphragm or bellowsExaminersPrimary: Grosz, AlexanderAttorney, Agent or FirmInternational ClassesA47C 023/04A47C 023/047 A47C 023/05 A47C 023/053 AbstractA spring insert for a waterbed mattress includes a plurality of spring bellows units arranged in upright relation within the mattress. Each bellows unit has a top wall and pleated sidewall which is collapsible from a normal expanded height to a shortened compressed height wherein the internal volume of the bellows unit is substantially reduced. Each bellows unit furthermore has a bleeder opening through one wall so that a compression load exerted on the bellows unit through the mattress top wall is resisted by both spring action and hydraulic action of the bellows units. The bellows units may be interconnected to form upper and lower sections arranged in stacked relation. Stacked pairs of upper and lower bellows units may be arranged in fluid communication to define joint hydraulic chambers. | |
