초록 ▼

An apparatus includes a valve body defining a chamber located on an axis. The chamber has axially upper and lower ends. The chamber further has upper and lower orifices located at the upper and lower ends through which air can exit the chamber. An upper plug is configured, in a closed position, to c

An apparatus includes a valve body defining a chamber located on an axis. The chamber has axially upper and lower ends. The chamber further has upper and lower orifices located at the upper and lower ends through which air can exit the chamber. An upper plug is configured, in a closed position, to close the upper orifice. A lower plug is configured, in a closed position, to close the lower orifice. A spring is compressed between the plugs so as to elastically urge the plugs axially apart and into their respective closed positions. A plug displacement device is configured to displace the upper plug from its closed position against bias of the spring into an open position, and to displace the lower plug from its closed position against the bias of the spring into an open position.

대표청구항 ▼

The invention claimed is: 1. An apparatus comprising: a valve body including a chamber, located on an axis, having axially upper and lower ends and upper and lower orifices located at the upper and lower ends through which air can exit the chamber; an upper plug configured, in a closed position, to

The invention claimed is: 1. An apparatus comprising: a valve body including a chamber, located on an axis, having axially upper and lower ends and upper and lower orifices located at the upper and lower ends through which air can exit the chamber; an upper plug configured, in a closed position, to close the upper orifice; a lower plug configured, in a closed position, to close the lower orifice; a spring compressed between the plugs so as to elastically urge the plugs axially apart and into their respective closed positions; and a plug displacement device configured to displace the upper plug from its closed position against bias of the spring into an open position, and to displace the lower plug from its closed position against the bias of the spring into an open position; wherein the plug displacement device comprises a valve stem extending axially through both orifices and having upper and lower abutment surfaces, the upper abutment surface being located above the upper plug and configured to push the upper plug downward into its open position, and the lower abutment surface being located below the lower plug and configured to push the lower plug upward into its open position; and both abutment surfaces simultaneously abut their respective plugs when the plugs are in their closed positions, such that the biasing of both plugs into their closed positions by the spring biases the stem into a neutral position. 2. The apparatus of claim 1 wherein the stem is closely received by the upper and lower plugs so as to keep the plugs aligned with their respective orifices as the plugs slide axially between their open and closed positions. 3. The apparatus of claim 1 wherein the stem extends axially through the spring. 4. The apparatus of claim 1 wherein the stem has a projecting section that projects upward from the valve body and by which the stem can be pushed downward to push the upper plug into its open position and pulled upward to push the lower plug into its open position. 5. An apparatus comprising: a valve body including a central chamber, located on an axis, having axially upper and lower ends and upper and lower orifices located at the upper and lower ends through which air can exit the central chamber; an upper plug configured, in a closed position, to close the upper orifice; a lower plug configured, in a closed position, to close the lower orifice; a spring compressed between the plugs so as to elastically urge the plugs axially apart and into their respective closed positions; and a plug displacement device configured to displace the upper plug from its closed position against bias of the spring into an open position, and to displace the lower plug from its closed position against the bias of the spring into an open position; wherein the valve body further includes an upper chamber extending upward from the upper orifice, a lower chamber extending downward from the lower orifice, proximal and distal upper ports open to the upper chamber, and proximal and distal lower ports open to the lower chamber, each proximal port being axially closer to the central chamber than the corresponding distal port; the plug displacement device comprises a valve stem extending through both orifices, and the valve has a neutral condition in which the stem is in a neutral position, both plugs are in their closed positions, the upper ports communicate with each other through the upper chamber, and the lower ports communicate with each other through the lower chamber; and the valve is shiftable from the neutral condition into a first open condition, by lowering the stem, in which the upper plug is in its open position, the lower plug is in its closed position, the distal upper port is blocked by the stem, the proximal upper port communicates with the central chamber, and the lower ports communicate with each other through the lower chamber. 6. The apparatus of claim 5 wherein the valve is shiftable from the neutral condition into a second open condition, by raising the stem, in which the upper plug is in its closed position, the lower plug is in its open position, the upper ports communicate with each other through the upper chamber, the proximal lower port communicates with the central chamber, and the distal lower port is isolated from the proximal lower port and the central chamber by the stem. 7. An apparatus comprising: a valve body including a central chamber, located on an axis, having axially upper and lower ends and upper and lower orifices located at the upper and lower ends though which air can exit the central chamber; an upper plug configured, in a closed position, to close the upper orifice; a lower plug configured, in a closed position, to close the lower orifice; a spring compressed between the plugs so as to elastically urge the plugs axially apart and into their respective closed positions; and a plug displacement device configured to displace the upper plug from its closed position against bias of the spring into an open position, and to displace the lower plug from its closed position against the bias of the spring into an open position; wherein the valve body further includes an upper chamber extending upward from the upper orifice, a lower chamber extending downward from the lower orifice, proximal and distal upper ports open to the upper chamber, and proximal and distal lower ports open to the lower chamber, each proximal port being axially closer to the central chamber than the corresponding distal port; the plug displacement device comprises a valve stem extending though both orifices, and the valve has a neutral condition in which the stem is in a neutral position, both plugs are in their closed positions, the upper ports communicate with each other through the upper chamber, and the lower ports communicate with each other though the lower chamber; the valve is shiftable from the neutral condition into a first open condition, by lowering the stem, in which the upper plug is in its open position, the lower plug is in its closed position, the distal upper port is blocked by the stem, the proximal upper port communicates with the central chamber, and the lower ports communicate with each other though the lower chamber; and the valve is shiftable from the neutral condition into a second open condition, by raising the stem, in which the upper plug is in its closed position, the lower plug is in its open position, the upper ports communicate with each other through the upper chamber, the proximal lower port communicates with the central chamber, and the distal lower port is isolated from the proximal lower port and the central chamber by the stem; and further including a tool housing, an air inlet nozzle, a bi-directional air motor, an output shaft, and a vent to the atmosphere all interconnected as parts of a unitary handheld tool, wherein the motor has first and second inlets through which air is directed to power the motor to drive the shaft respectively in forward and reverse directions, the valve body further has an inlet port open to the central chamber and connected to the nozzle, the upper and lower proximal ports are respectively connected to the first and second motor inlets, and the distal ports are connected to the vent. 8. An apparatus comprising: a valve body including a chamber, located on an axis, having axially upper and lower ends and upper and lower orifices located at the upper and lower ends through which air can exit the chamber; an upper plug configured, in a closed position, to close the upper orifice; a lower plug configured, in a closed position, to close the lower orifice; a spring compressed between the plugs so as to elastically urge the plugs axially apart and into their respective closed positions; and a plug displacement device configured to displace the upper plug from its closed position against bias of the spring into an open position, and to displace the lower plug from its closed position against the bias of the spring into an open position; wherein the valve body includes an inlet port communicating with the chamber, and the apparatus further includes a sleeve sealed about the valve body both above and below the inlet port and rotatable about the axis relative to the valve body, and an inlet nozzle that projects radially outward from the sleeve and communicates with the inlet port through the sleeve. 9. An apparatus comprising: a valve body located on an axis and defining an axially extending channel that includes an axially upper chamber, an axially lower chamber, a central chamber located between the upper and lower chambers, and further defining an upper outlet port open to the upper chamber, a lower outlet port open to the lower chamber, and an inlet port open to the central chamber; and a valve stem extending axially in the channel and shiftable between a neutral position for isolating both outlet ports from the inlet port, a lower position below the neutral position for communicating the upper outlet port with the inlet port, and an upper position above the neutral position for communicating the lower outlet port with the inlet port, without blocking the inlet port in any of the three positions; wherein said upper outlet port is a first upper outlet port, and said lower outlet port is a first lower outlet port, and further comprising a second upper outlet port open to the upper chamber and spaced above the first upper outlet port, and further comprising a second lower outlet port open to the lower chamber and spaced below the first lower outlet port; the body and the stem are together configured such that, when the stem is in the neutral position, the upper outlet ports communicate with each other but not with the inlet port, and the lower outlet ports communicate with each other but not with the inlet port; when the stem is in the lower position, the second upper outlet port is blocked by the stem, the first upper outlet port communicates with the inlet port, and the lower outlet ports communicate with each other but not with the inlet port; and when the stem is in the upper position, the upper outlet ports communicate with each other but not with the inlet port, the first lower outlet port communicates with the inlet port, and the second lower outlet port is isolated from the inlet port by the stem.