Directional control valve and valve assembly in an asphalt distributor
US6499670B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1999 |
| Grant date | Dec 31, 2002 |
| Priority date | — |
| Expiry date | Feb 23, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/86919
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A directional control valve having three positions controls the direction of flow through an asphalt distributor. The directional control valve is interposed between a pump and a feed line assembly to a spray bar. The directional control valve has a first position in which flow is recirculated through the pump, a second position in which flow is delivered to the spray bar and a third position providing for handspray and transfer operations. A pressure relief valve is provided for controlling return flow of asphalt from the spray bar to the tank. The pressure relief valve is open in spray bar circulation mode and is closed during a spraying mode. According to the preferred embodiment the directional valve and pressure relief valve are contained within a modular control valve assembly. The directional control valve eliminates the need to reverse the flow in one of the individual feed lines and feed line assembly connecting the modular control valve assembly to the spray bar. The feed line assembly includes a delivery and return line running coaxial or otherwise adjacent for heat transfer therebetween. The directional control valve reduces the quantity and lengths of exposed valving a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.