US3744521A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directional control valve
Assignee: Parker Hannifin Corp
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Filing: 1971-12-13
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Granted: 1973-07-10
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Expires: 1991-12-13
Abstract
Abstract A four-way spool type valve assembly for controlling for example the boom actuating motor of a front end loader and the like characterized in that, when the spool is in power lower position, the return fluid from the motor is conducted to the return passage via a passage in one end portion of the spool and a restricted orifice which opens into the return passage. The valve assembly herein is further characterized in that, when the spool is in float position beyond the power lower position, the passage in said one end portion thereof yet communicates with the adjacent motor passage while additional passages axially adjacent the restricted orifice open into the return passage and in addition a passage in the other end portion of the spool intercommunicates both motor passages so that the boom may partake of rapid upward and downward float. A further characterizing feature of the valve assembly herein is that there is a make-up check valve to prevent motor cavitation as during rapid floating movements of the boom.
Inventors
- 👤 J Paul
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:55
CPC Classifications
F; F15; F15B; F15B13/00; F15B13/02; F15B13/04; Y; Y10; Y10T; Y10T137/00; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/8667; Y10T137/86694; Y10T137/86702
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
135 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage, and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage therein which in one operating position provides restricted communication between one motor passage and said return passage to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage.
Claim 2
Dependent Claim
135 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage, and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage therein which in one operating position provides restricted communication between one motor passage and said return passage to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage.
Claim 3
Dependent Claim
63 words
The valve assembly of claim 1 wherein said spool has additional passages communicating with said first passage through which fluid under pressure is conducted from said inlet passage to said one motor passage in another operating position of said spool and wherein said spool has a peripheral groove freely communicating said other motor passage with said return passage in said another operating position.
Claim 4
Dependent Claim
72 words
The valve assembly of claim 1 wherein said spool has a float position whereat a second passage in said spool communicates said motor passages with each other and whereat passages in said spool in addition to that which provides for such restricted flow of fluid from said one motor passage to said return passage provide free flow of fluid between said one motor passage and said rEturn passage in said float position.
Claim 5
Dependent Claim
248 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage, and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage therein which in one operating position provides restricted communication between one motor passage and said return passage to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in said spool communicates said motor passages with each other and whereat passages in said spool in addition to that which provides for such restricted flow of fluid from said one motor passage to said return passage provide free flow of fluid between said one motor passage and said return passage in said float position; and a make-up check valve in said housing operative to supply fluid from said return passage to a motor passage in the event of development of a negative pressure condition in said first and second passages and said motor passages when said spool is in said float position.
Claim 6
Dependent Claim
248 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage, and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage therein which in one operating position provides restricted communication between one motor passage and said return passage to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in said spool communicates said motor passages with each other and whereat passages in said spool in addition to that which provides for such restricted flow of fluid from said one motor passage to said return passage provide free flow of fluid between said one motor passage and said return passage in said float position; and a make-up check valve in said housing operative to supply fluid from said return passage to a motor passage in the event of development of a negative pressure condition in said first and second passages and said motor passages when said spool is in said float position.
Claim 7
Dependent Claim
238 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in the other end portion thereof opens into said other motor passage and opens to said one motor passage adjacent the opening of said first passage thereto, said spool having additional openings from said first passage into said return passage when said spool is in said float position to provide for free flow of fluid between said motor passages and said return passage for rapid float of the movable component of such fluid motor in opposite directions.
Claim 8
Dependent Claim
238 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in the other end portion thereof opens into said other motor passage and opens to said one motor passage adjacent the opening of said first passage thereto, said spool having additional openings from said first passage into said return passage when said spool is in said float position to provide for free flow of fluid between said motor passages and said return passage for rapid float of the movable component of such fluid motor in opposite directions.
Claim 9
Dependent Claim
33 words
The valve assembly of claim 5 wherein the fluid communication between said one motor passage and said return passage in said float position is through said restricted opening and through such additional openings.
Claim 10
Dependent Claim
271 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuatiOn of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in the other end portion thereof opens into said other motor passage and opens to said one motor passage adjacent the opening of said first passage thereto, said spool having additional openings from said first passage into said return passage when said spool is in said float position to provide for free flow of fluid between said motor passages and said return passage for rapid float of the movable component of such fluid motor in opposite directions; and a make-up check valve in said housing operative to supply fluid from said return passage to a motor passage in the event of development of negative pressure conditions in said motor passages.
Claim 11
Dependent Claim
271 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuatiOn of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said spool having a float position whereat a second passage in the other end portion thereof opens into said other motor passage and opens to said one motor passage adjacent the opening of said first passage thereto, said spool having additional openings from said first passage into said return passage when said spool is in said float position to provide for free flow of fluid between said motor passages and said return passage for rapid float of the movable component of such fluid motor in opposite directions; and a make-up check valve in said housing operative to supply fluid from said return passage to a motor passage in the event of development of negative pressure conditions in said motor passages.
Claim 12
Dependent Claim
180 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said first passage having additional openings adjacent to said restricted opening to freely communicate said one motor passage with said inlet passage in another operating position of said spool.
Claim 13
Dependent Claim
180 words
A valve assembly comprising a housing having a bore intersected axially therealong by an inlet passage, a return passage and a pair of motor passages respectively adapted for connection with a fluid pressure source, a tank, and a fluid motor; a valve spool reciprocable in said bore from a neutral position whereat communication of said motor passages with said inlet and return passages is blocked to operating positions whereat said inlet and return passages are selectively communicated with said motor passages to control actuation of such fluid motor; said spool having a first passage in one end portion thereof which opens into one motor passage and into said return passage with restricted communication from said passage into said return passage in one operating position of said spool to control the rate of actuation of such fluid motor by fluid under pressure conducted from said inlet passage to the other motor passage; said first passage having additional openings adjacent to said restricted opening to freely communicate said one motor passage with said inlet passage in another operating position of said spool.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |