US3945299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Linear positioning apparatus
Assignee: Albany International Industries Inc
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Filing: 1974-06-24
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Granted: 1976-03-23
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Expires: 1994-06-24
Abstract
Abstract A positioning apparatus includes a master hydraulic positioning cylinder having a relatively long stroke capability and a train of additively connected, short-stroke pneumatic control cylinders for controlling the length of stroke of the master cylinder and thus the positioning of a variable-position tool such as a band saw. One end of the cylinder train is connected by a feedback rod to an extensible portion of the master cylinder. A connecting rod connects the opposite end of the train directly to the spool of a three-position servo valve which controls the flow of hydraulic fluid to and from opposite sides of the master cylinder. When air pressure is admitted to a selected side of a selected control cylinder, at least a portion of the train shifts initially in a direction to move the servo valve to an operating position to begin stroking the master cylinder in a desired direction. Stroking movement of the master cylinder is transmitted through the feedback rod to the train to stroke the selected control cylinder until its piston bottoms out, after which continued stroking of the master cylinder shifts the train to close the servo valve and stop the master cylinder when it has stroked through a distance corresponding to the full stroke of the selected control cylinder. The cylinder train includes a pair of "lost motion" cylinders enabling movement of the train beyond the limits of movement of the servo valve. This lost motion of the train activates a high-speed valve in the hydraulic circuit to stroke the master cylinder at high speed and a "final set" cylinder in the train to ensure that final stroking of the master cylinder to a selected setting always occurs from the same direction to eliminate setting errors from lost motion in the system. A lockout valve in the hydraulic system overrides the servo and high-speed valves when the controlled tool is in an operating condition to block flow to the master cylinder and prevent possible damage to the tool or positioning apparatus.
Inventors
- 👤 Rene E. Fritz
- 👤 Ted C. Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 15:30
CPC Classifications
F; F15; F15B; F15B11/00; F15B11/16; F15B11/18; Y; Y10; Y10T; Y10T83/00; Y10T83/768; Y10T83/7755; Y10T83/7763; Y10T83/7776; Y10T83/778; Y10T83/869; Y10T83/8696; Y10T83/87
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
330 words
In a positioning apparatus having a large-stroke fluid-operated, double-acting master cylinder means for controlling the position of a variable position controlled device, a train of smaller-stroke fluid-operated control cylinder means additively interconnected and mounted for axial linear movement, means for selectively extending and retracting selected individual control cylinder means to determine the total length of said train, and servo valve means for controlling the flow of pressure fluid to and from said master cylinder means, characterized by: said train of control cylinder means including a series of double-acting control cylinder means each normally biased by internal fluid pressure in either one of its two bottomed positions and each being selectively movable independently of the others under internal fluid pressure to the other of its two bottomed positions, one end of said cylinder train being rigidly connected by feedback means to a means positionable by said master cylinder means and the other end of said cylinder train being mechanically connected to said servo valve means for controlling the operating positions thereof such that admission of pressure fluid to one side of a selected said control cylinder means in sequence (1) first causes said selected control cylinder means to begin stroking toward the opposite side thereof by moving at least a portion of said train in one direction to shift said servo valve means to an operating position to begin stroking said master cylinder means, (2) then causes said selected control cylinder means to continue stroking toward said opposite side to a bottomed position as induced by continued stroking of said master cylinder means acting through said feedback means and (3) finally causes said train to shift said servo valve in an opposite direction to a neutral position through continued stroking of said master cylinder means acting through said feedback means to block flow to and from said master cylinder means whereby said master cylinder means is stroked through a distance corresponding to the full stroke of said selected control cylinder means.
Claim 2
Dependent Claim
330 words
In a positioning apparatus having a large-stroke fluid-operated, double-acting master cylinder means for controlling the position of a variable position controlled device, a train of smaller-stroke fluid-operated control cylinder means additively interconnected and mounted for axial linear movement, means for selectively extending and retracting selected individual control cylinder means to determine the total length of said train, and servo valve means for controlling the flow of pressure fluid to and from said master cylinder means, characterized by: said train of control cylinder means including a series of double-acting control cylinder means each normally biased by internal fluid pressure in either one of its two bottomed positions and each being selectively movable independently of the others under internal fluid pressure to the other of its two bottomed positions, one end of said cylinder train being rigidly connected by feedback means to a means positionable by said master cylinder means and the other end of said cylinder train being mechanically connected to said servo valve means for controlling the operating positions thereof such that admission of pressure fluid to one side of a selected said control cylinder means in sequence (1) first causes said selected control cylinder means to begin stroking toward the opposite side thereof by moving at least a portion of said train in one direction to shift said servo valve means to an operating position to begin stroking said master cylinder means, (2) then causes said selected control cylinder means to continue stroking toward said opposite side to a bottomed position as induced by continued stroking of said master cylinder means acting through said feedback means and (3) finally causes said train to shift said servo valve in an opposite direction to a neutral position through continued stroking of said master cylinder means acting through said feedback means to block flow to and from said master cylinder means whereby said master cylinder means is stroked through a distance corresponding to the full stroke of said selected control cylinder means.
Claim 3
Dependent Claim
78 words
Apparatus according to claim 1 wherein said servo valve means comprises a three-position spool valve including a centered said neutral position and two said operating positions including a first operating position on one side of said neutral position for directing flow to one side of said master cylinder means to extend said master cylinder means and a second operating position for directing flow to the opposite side of said master cylinder means to retract said master cylinder means.
Claim 4
Dependent Claim
60 words
Apparatus according to claim 2 including connecting rod means directly interconnecting one control cylinder means at said other end of said train and said spool valve such that movement of at least a portion of said train including said one control cylinder means in opposite directions causes a corresponding shifting of said spool valve between its neutral and operating positions.
Claim 5
Dependent Claim
58 words
Apparatus according to claim 3 including stop means positioned along said connecting rod means for limiting travel of said spool valve in opposite directions from said neutral position to said operating positions, and said cylinder train including lost motion means for enabling movement of said train in opposite directions beyond the limits of travel of said spool valve.
Claim 6
Dependent Claim
41 words
Apparatus according to claim 4 wherein said lost motion means comprises a pair of air-operated cylinder means in said cylinder train operable under an air pressure less than the operating fluid pressure of the remaining control cylinder means in said train.
Claim 7
Dependent Claim
65 words
Apparatus according to claim 1 wherein said control cylinder means of said cylinder train are air-operated, a pair of adjacent said control cylinder means being single-acting with one of said pair being air-biased to an extended condition and the other of said pair being air-biased to a retracted condition by air pressure less than the operating air pressure of the remaining said control cylinder means.
Claim 8
Dependent Claim
69 words
Apparatus according to claim 6 wherein said train of control cylinder means includes a final set cylinder means operable to cause said master cylinder means to stroke to its final setting from the same direction during both extension and retraction of said master cylinder means, said final set cylinder means being operable in response to bodily shifting movement of said pair of single-acting control cylinder means in one direction.
Claim 9
Dependent Claim
94 words
Apparatus according to claim 6 including a series of air control valves for controlling the supply of air under operating pressure to said control cylinder means, and air supply and exhaust manifold means leading to and from said air valves, said air valves being connected in parallel to an air supply and including a first pressure regulator means for controlling the operating air pressure to said double-acting control cylinder means and a second pressure regulator in series with said first pressure regulator for controlling the air pressure to said pair of single-acting cylinder means.
Claim 10
Dependent Claim
86 words
Apparatus according to claim 1 wherein said means for selectively extending and retracting includes a series of air control valves for controlling a supply of air under operating pressure to said control cylinder means, at least some of said air valves each including an air supply line leading to said valve and an air exhaust line leading from said valve, said air exhaust line including a variable flow control means for regulating the rate of flow of exhaust air from an associated said control cylinder means.
Claim 11
Dependent Claim
106 words
Apparatus according to claim 1 including high-speed valve means connected in parallel with said servo valve means for increasing the rate of flow of pressure fluid to and from said master cylinder means to increase the stroking speed thereof, said high-speed valve means normally being positioned to block fluid flow therethrough to and from said master cylinder means but being movable to an operating position upon a predetermined shifting movement of a portion of said cylinder train in either direction to direct flow therethrough during and in the same directional mode as the flow through said servo valve means to and from said set cylinder means.
Claim 12
Dependent Claim
87 words
Apparatus according to claim 10 wherein said cylinder train is operable upon a first predetermined movement in either direction to shift said servo valve means to an operating position to stroke said master cylinder means at a low speed and is operable upon a second predetermined movement greater than said first movement in the same said direction to shift said high-speed valve means to an operating position corresponding to said operating position of said servo valve means to stroke said master cylinder means at a high speed.
Claim 13
Dependent Claim
103 words
Apparatus according to claim 10 wherein said high-speed valve means is normally biased to a neutral flow-blocking position and is electrically operated for movement to either one of two positions for directing flow to the opposite sides of said master cylinder means, a pair of electrical limit switch means for operating said high-speed valve means, and switch-actuating means carried by said cylinder train for operating one of said pair of limit switch means upon said predetermined movement of said train in one direction and for operating the other of said pair of limit switch means upon said predetermined movement in the opposite direction.
Claim 14
Dependent Claim
113 words
Apparatus according to claim 10 connecting rod means interconnecting said other end of said cylinder train and said servo valve means, stop means limiting travel of said connecting rod means in opposite directions through a limited distance sufficient only to move said servo valve means from its neutral position to an operating position, said cylinder train including lost motion means enabling movement of said train in opposite directions through a distance greater than said limited distance, and valve-operating means associated with said cylinder train and operable upon predetermined movement of said train in opposite directions through a distance greater than said limited distance to move said high-speed valve means to an operating position.
Claim 15
Dependent Claim
82 words
Apparatus according to claim 13 wherein said lost motion means includes a pair of single-acting cylinder means in said cylinder train, said pair of cylinder means being subjected to a continual fluid pressure substantially less than the fluid-operating pressure of the remainder of said control cylinder means in said train, one of said pair of cylinder means being normally maintained in an extended condition and the other of said cylinder means normally being maintained in a retracted condition by said continual pressure.
Claim 16
Dependent Claim
21 words
Apparatus according to claim 14 wherein said pair of single-acting cylinder means are positioned at said other end of said train.
Claim 17
Dependent Claim
15 words
Apparatus according to claim 14 wherein said cylinder means of said pair have equal strokes.
Claim 18
Dependent Claim
40 words
Apparatus according to claim 14 wherein said valve-operating means includes limit switch means in a fixed position adjacent said train and limit switch-actuating means carried by a portion of said train movable relative to said pair of single-acting cylinder means.
Claim 19
Dependent Claim
54 words
Apparatus according to claim 10 including final set means including one of said control cylinder means for controlling the operation of said master cylinder means such that both extension and retraction of said master cylinder means through a selected distance occurs with a final stroking of said master cylinder means from the same direction.
Claim 20
Dependent Claim
33 words
Apparatus according to claim 1 including lockout means operable independently of said servo valve means to prevent stroking of said master cylinder means in response to a predetermined condition of said controlled device.
Claim 21
Dependent Claim
65 words
Apparatus according to claim 19 wherein said lockout means comprises a lockout valve means in a fluid passage means between said source of pressure fluid and said master cylinder means, said lockout valve means being normally positioned to permit fluid flow between said source and said master cylinder means but being movable to a position to block said flow in response to said predetermined condition.
Claim 22
Dependent Claim
30 words
Apparatus according to claim 20 wherein said lockout valve means is electrically operated and is in a fluid passage means between said servo valve means and said master cylinder means.
Claim 23
Dependent Claim
44 words
Apparatus according to claim 10 including lockout valve means positioned for blocking fluid flow between said master cylinder means and said servo and high-speed valve means to prevent stroking of said master cylinder means in response to a predetermined condition of said controlled device.
Claim 24
Dependent Claim
47 words
Apparatus according to claim 1 including final set means for controlling the operation of said master cylinder means such that extension and retraction of said master cylinder means to a final setting always occurs with a final stroking of said master cylinder means from only one direction.
Claim 25
Dependent Claim
80 words
Apparatus according to claim 23 wherein said final set means includes a final set control cylinder means in said cylinder train, said final set control cylinder means being operable upon a stroking of said master cylinder means in a selected direction opposite the said one direction of final set to cause an initial overstroking of said master cylinder means in said selected direction followed by a final stroking of said set cylinder means in said one direction of final set.
Claim 26
Dependent Claim
75 words
Apparatus according to claim 24 including final set cylinder-operating means including final set air valve means normally positioned to maintain said final set cylinder means in one of its two fully stroked conditions, and valve-actuating means operable upon a shifting movement of said cylinder train in said direction of final set to reposition said final set valve to stroke said final set cylinder means to its other said fully stroked condition to cause said overstroking.
References Cited (Backward Citations)
US3011740A
Cited
US2846982A
Cited
US2886010A
Cited
US3183785A
Cited
US3307584A
Cited
US3361034A
Cited
US3534679A
Cited
US3722365A
Cited
US3641877A
Cited
US3635020A
Cited
US3763744A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |