US3667345A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air shut-off torque responsive control valve unit for pneumatically powered tools
Assignee: Chicago Pneumatic Tool Co LLC
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Filing: 1970-08-19
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Granted: 1972-06-06
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Expires: 1990-08-19
Abstract
Abstract A completely assembled air shut-off control valve unit illustrated as fitted in a bore of a pneumatically powered nut runner in the path of air flow between the throttle valve and the motor. The unit is of capsule form defined by means of a shell in which the various components are confined. A cap closes over an open end of the shell through which end the various components may be withdrawn. The valve is of a piston and rod form having a spring load in association with an adjusting screw and travel nut means for adjusting the load of the spring upon the valve. Structural design of the valve, together with a valve guide serve to effect pneumatic balancing of the valve and consequent reduced friction in its movement.
Inventors
- 👤 Raymond J Schaedler
- 👤 Lester A Amtsberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 03:02
CPC Classifications
B; B25; B25B; B25B23/00; B25B23/14; B25B23/145
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
346 words
In a nut running tool including a housing fitted with a throttle valve and containing an air-driven motor, wherein the throttle valve connects by means of a pressure air feed passage with a side wall area of a bore in the housing and the bore connects by means of an outlet passage through its side wall area with the motor; a pressure responsive air shut-off control valve unit comprising a capsule closed at both ends removably inserted in the bore and defining within the interior of the capsule a piston chamber having an inlet port registered with the feed passage and an outlet port registered with the outlet passage so as to provide through the chamber a pressure air flow passage between the throttle valve and the motor, a piston valve slidable axially within the chamber from a normally open position clear of the outlet and inlet ports to a position closed only over the outlet port, stop means within the chamber having cooperation with the piston valve to limit the latter from moving beyond its closed position, the inlet port having a location at which it is at all times not subject to being closed by the piston valve, a restricted passage through the piston valve communicating the piston chamber at an inner end of the piston valve with a clearance defined in the piston chamber at the rear end of the piston valve, the area of the piston valve over its rear end being greater than that over its inner end, the piston valve having a tendency under pressure of inlet air developing in the clearance to slide to its closed position, and a spring within the chamber normally biasing the piston valve to its open position exerting a load upon the piston valve predetermining the degree of air pressure required to develop in the clearance to overcome the spring load; wherein the piston valve has a axially depending stem, and a valve guide slidably arranged within the capsule has an axial bore the wall of which provides a bearing surface for the stem.
Claim 2
Dependent Claim
346 words
In a nut running tool including a housing fitted with a throttle valve and containing an air-driven motor, wherein the throttle valve connects by means of a pressure air feed passage with a side wall area of a bore in the housing and the bore connects by means of an outlet passage through its side wall area with the motor; a pressure responsive air shut-off control valve unit comprising a capsule closed at both ends removably inserted in the bore and defining within the interior of the capsule a piston chamber having an inlet port registered with the feed passage and an outlet port registered with the outlet passage so as to provide through the chamber a pressure air flow passage between the throttle valve and the motor, a piston valve slidable axially within the chamber from a normally open position clear of the outlet and inlet ports to a position closed only over the outlet port, stop means within the chamber having cooperation with the piston valve to limit the latter from moving beyond its closed position, the inlet port having a location at which it is at all times not subject to being closed by the piston valve, a restricted passage through the piston valve communicating the piston chamber at an inner end of the piston valve with a clearance defined in the piston chamber at the rear end of the piston valve, the area of the piston valve over its rear end being greater than that over its inner end, the piston valve having a tendency under pressure of inlet air developing in the clearance to slide to its closed position, and a spring within the chamber normally biasing the piston valve to its open position exerting a load upon the piston valve predetermining the degree of air pressure required to develop in the clearance to overcome the spring load; wherein the piston valve has a axially depending stem, and a valve guide slidably arranged within the capsule has an axial bore the wall of which provides a bearing surface for the stem.
Claim 3
Dependent Claim
67 words
In a nut running tool as in claim 1, wherein a load spring encircles the stem, one end of the spring being in abutment with the inner end of the valve, the other end abutting the guide, and adjusting means is provided within the capsule for adjustably sliding the guide axially relative to the spring so as to vary the load of the spring upon the valve.
Claim 4
Dependent Claim
57 words
In a nut running tool as in claim 2, wherein the adjusting means includes a travel nut lying in abutment with an end of the guide having axial movement within the capsule but restrained against relative rotation, and manipulative screw means is provided for causing axial travel of the nut relative to the end of the guide.
Claim 5
Dependent Claim
29 words
In a nut running tool as in claim 3, wherein the screw means includes a head having a screwdriver slot externally exposed through an axial opening in the cap.
Claim 6
Dependent Claim
94 words
In a nut running tool as in claim 1, wherein the piston valve is defined by means of a cylindrical head mounted axially to an end of the stem, the piston chamber providing a bearing surface for the periphery of the head, the head being provided with a plurality of parallel channels extending fully about its periphery, which channels are subject to being filled with bleed pressure air from the piston chamber about the periphery of the head, the air upon filling the channels serving to exert axially directed balancing forces upon the head.
Claim 7
Dependent Claim
40 words
In a nut running tool as in claim 5, wherein the pressure air carries an oil lubricant, and the channels serve as collectors for some of the lubricant so as to provide lubricant uniformly about the periphery of the head.
Claim 8
Dependent Claim
272 words
In a tool including a piston valve chamber having a side inlet connectible with a source of pressure air and having a side outlet spaced axially rearwardly of the inlet connectible with an air driven load, a piston valve pneumatically slidable axially in the chamber to open and closed positions relative to the outlet, stop means preventing the valve from moving sufficiently to close over the inlet, spring means normally biasing the valve to its open position and determining the degree of air pressure required to develop over the rear face of the valve to force the valve to its closed position, the rear face of the valve being of greater area than its forward face and exposed to a clearance rearwardly of the valve, a restricted orifice through the valve communicating the chamber area forwardly of the valve at all times with the clearance, and the outlet being of greaTer cross sectional area than the orifice, the valve being responsive to development through the orifice of a predetermined air pressure in the clearance as a consequence of a predetermined back pressure created by the air driven load to slide to closed position over the outlet against the resistance of the spring, and the orifice continuing after the valve has moved to its closed position to communicate inlet air entering the chamber with the clearance; wherein the valve has a plurality of spaced parallel channels about its periphery into which air entering the piston valve chamber is adapted to bleed, the bleed air upon filling the channels serving to provide pneumatically balancing axially directed air pressure about the periphery of the valve.
Claim 9
Dependent Claim
272 words
In a tool including a piston valve chamber having a side inlet connectible with a source of pressure air and having a side outlet spaced axially rearwardly of the inlet connectible with an air driven load, a piston valve pneumatically slidable axially in the chamber to open and closed positions relative to the outlet, stop means preventing the valve from moving sufficiently to close over the inlet, spring means normally biasing the valve to its open position and determining the degree of air pressure required to develop over the rear face of the valve to force the valve to its closed position, the rear face of the valve being of greater area than its forward face and exposed to a clearance rearwardly of the valve, a restricted orifice through the valve communicating the chamber area forwardly of the valve at all times with the clearance, and the outlet being of greaTer cross sectional area than the orifice, the valve being responsive to development through the orifice of a predetermined air pressure in the clearance as a consequence of a predetermined back pressure created by the air driven load to slide to closed position over the outlet against the resistance of the spring, and the orifice continuing after the valve has moved to its closed position to communicate inlet air entering the chamber with the clearance; wherein the valve has a plurality of spaced parallel channels about its periphery into which air entering the piston valve chamber is adapted to bleed, the bleed air upon filling the channels serving to provide pneumatically balancing axially directed air pressure about the periphery of the valve.
Claim 10
Dependent Claim
173 words
In a nut running tool including a housing, an air driven motor, a port in the housing connected with the motor, a slide valve movable axially in the housing relative to the port upon application of pneumatic pressure to one end of the valve, a spring at the opposite end of the valve normally biasing the valve to an open condition relative to the port and determining the value of pneumatic pressure required to be applied to the valve to move it to its closed condition over the port, a slide member, the spring being compressed between one end of the slide member and the valve, and adjusting means for adjustably sliding the slide member axially relative to the spring; wherein the adjusting means includes a travel nut lying in abutment with an opposite end of the slide member having axial movement within the housing but restrained against relative rotation, and manipulative screw means is provided for causing axial travel of the nut relative to the said opposite end of the slide member.
Claim 11
Dependent Claim
173 words
In a nut running tool including a housing, an air driven motor, a port in the housing connected with the motor, a slide valve movable axially in the housing relative to the port upon application of pneumatic pressure to one end of the valve, a spring at the opposite end of the valve normally biasing the valve to an open condition relative to the port and determining the value of pneumatic pressure required to be applied to the valve to move it to its closed condition over the port, a slide member, the spring being compressed between one end of the slide member and the valve, and adjusting means for adjustably sliding the slide member axially relative to the spring; wherein the adjusting means includes a travel nut lying in abutment with an opposite end of the slide member having axial movement within the housing but restrained against relative rotation, and manipulative screw means is provided for causing axial travel of the nut relative to the said opposite end of the slide member.
Claim 12
Dependent Claim
28 words
In a nut running tool as in claim 8, wherein the screw means includes a head having a screwdriver slot externally exposed through an opening in the housing.
References Cited (Backward Citations)
US3373824A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-06 | 1975-12-06 | 1976-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-06 | 1979-12-06 | 1980-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-06 | 1983-12-06 | 1984-06-06 | $7700.00 | Window Closed / Lapsed |