Dual Control Dead Man System
AssigneeGraco Minnesota Inc.
InventorKeith Eliason
Life of this patent
Estimating the term…
Abstract
A dual control shut off system, such as a dead man system for a blasting system, blasting equipment, or other equipment having both pneumatic and electric safety control circuits, may include an electric dead man's switch or a pneumatic dead man's switch. An embodiment of the dual control dead man system is for wet abrasive blasting systems used for cleaning, preparing surfaces, removing coatings, and/or other abrasive blasting operations. Embodiments of the dual control shut off system provide the ability to conveniently switch between an electric and pneumatic shut off system.
Claims12
A safety shut-off system capable of being controlled by either an electric dead man's switch or a pneumatic dead man's switch, comprising:
- a relay valve, wherein the relay valve capable of switching from a venting position to an operating position, wherein in the operating position the pressurized gas port is in fluid communication with the control circuit inlet/outlet;
- a pneumatic dead man's switch capable of being connected to the relay valve and engagement of the pneumatically operated dead man's switch shifts the relay valve from its venting position to its operating position;
- and
- an electrically operated dead man's switch capable of being connected to a solenoid of the relay valve and engagement of the electrically operated dead man's switch shifts the relay valve from its venting position to its operating position.
A blast system, comprising:
- a slurry piping system, wherein the slurry piping system comprises a slurry shut off valve;
- a pressurized gas piping system;
- a relay valve connected to a source of pressurized gas and a control circuit, wherein the control circuit is connected to slurry shut off valve;
- an pneumatic dead man's switch capable of being connected to the relay valve and engagement of the pneumatically operated dead man's switch shifts the relay valve to its operating position;
- and
- an electrically operated dead man's switch capable of being connected to a solenoid of the relay valve and engagement of the electrically operated dead man's switch shifts the relay valve to its operating position.
Dependencies are inferred from the claim text.