CA2035290A1 - Check-relief valve for a hydraulic circuit - Google Patents
Check-relief valve for a hydraulic circuitInfo
- Publication number
- CA2035290A1 CA2035290A1 CA 2035290 CA2035290A CA2035290A1 CA 2035290 A1 CA2035290 A1 CA 2035290A1 CA 2035290 CA2035290 CA 2035290 CA 2035290 A CA2035290 A CA 2035290A CA 2035290 A1 CA2035290 A1 CA 2035290A1
- Authority
- CA
- Canada
- Prior art keywords
- fluid
- valve
- port
- draper
- flow
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Fluid-Pressure Circuits (AREA)
- Check Valves (AREA)
Abstract
CHECK-RELIEF VALVE FOR A HYDRAULIC CIRCUIT
ABSTRACT OF THE DISCLOSURE
A check-relief valve for use in a hydraulic circuit comprises a channel through a valve body which is divided by a central annular restriction into two portions. On each side of the restrictor is provided a valve seat which cooperates with a spherical ball to close off flow in a direction toward the restriction. At the outer end of each portion of the channel is provided a perforated plate which prevents the ball from restricting flow when the ball is forced against the plate. Either the ball or the restrictor is formed of a resilient deformable material which can be deformed when the pressure in the fluid exceeds a predetermined maximum in which case the ball is forced through the restriction to the opposite portion of the channel. The check valve is used in a system of a swather for moving one of the draper assemblies longitudinally of the frame of the swather and simultaneously reversing the direction of rotation of the drive to the draper.
A check valve restricts the fluid flow to the drive motor for the rotation of the draper so that all of the fluid is available to move the draper and its support longitudinally of the frame until the draper reaches end stops whereupon the check valve releases by the deformation of the valve member to allow fluid to continue to flow through the drive motor to the draper rotation.
ABSTRACT OF THE DISCLOSURE
A check-relief valve for use in a hydraulic circuit comprises a channel through a valve body which is divided by a central annular restriction into two portions. On each side of the restrictor is provided a valve seat which cooperates with a spherical ball to close off flow in a direction toward the restriction. At the outer end of each portion of the channel is provided a perforated plate which prevents the ball from restricting flow when the ball is forced against the plate. Either the ball or the restrictor is formed of a resilient deformable material which can be deformed when the pressure in the fluid exceeds a predetermined maximum in which case the ball is forced through the restriction to the opposite portion of the channel. The check valve is used in a system of a swather for moving one of the draper assemblies longitudinally of the frame of the swather and simultaneously reversing the direction of rotation of the drive to the draper.
A check valve restricts the fluid flow to the drive motor for the rotation of the draper so that all of the fluid is available to move the draper and its support longitudinally of the frame until the draper reaches end stops whereupon the check valve releases by the deformation of the valve member to allow fluid to continue to flow through the drive motor to the draper rotation.
Description
CHE~K-RELIEF VALVE FOR A HYDRUALIC CIRCUIT_ This invention celates to a check-celief valve foc a hydcaulic ciccuit which is particulacly but not exclusively designed foc use in the headec of a swathec.
A swathec header includes a table on which is mounted a ficst dcapec and a second draper. Each draper includes a dcapec canvas in the focm of an endless loop and a plucality of support collecs for the canvas which form the loop into an uppec run and a lower run with one or moce of the collers being dciven to cause cotation of the rollec about its axis and thus movement of the upper run of the dcapec canvas in a cequiced dicection longitudinal of the headec.
Many such headecs are accanged so that they can opecate in diffecent modes. In a ficst mode the ficst and second dcapecs ace spcead apact so that the matecial is fed on each drapec towacd a centce opening defined between the dcapecs through which the material falls to focm the swathO
In an alternative mode, one of the dcapecs on a suitable support fcame including the collecs and the canvas is moved longitudinally of the table so that the opening between the dcapecs is closed and a furthec opening is formed at one end of the headec. In this mode, it is often desicable foc the opening to be moved from one end of the header to the other end of the headec and this is achieved by moving both dcapers on suitable support frames longitudinally of the table.
As well as the lateral or lineac movement of the dcapec assembly, it is of coucse also necessar~y when changing mode oc changing the position of the opening to change the direction of rotation of the rollers driving the drapers. soth the actuatoc foc moving the lateral movement of the dcapec support and the drive motor for cotating the rollecs are generally poweced hydraulically and it is most convenient to mount these devices in a single hydraulic circuit.
Fucthecmore it is highly desirable that a single valve be provided which changes from one mode to anothec mode oc changes the location of the draper and at the same time reverses the dicection of the cotation of the draper. This single valve avoids any possible confusion or misfunction of the device and simplifies the operation for the drivec.
The linear movement of the suppoct for the dcapec can be actuated by a piston and cylinder arrangement or alternatively it can be cafried out by a rotary motor togethac with a drive system which translates the rotary movement of the motor into linear movement of the support for example a lead screw arrangement.
, ~
~ 2 In one arcangement which has pceviously been used, the actuatoc for moving the longitudinal movement and the dcive motoc foc cotating the dcapec ace simply mounted in pacallel so that some of the fluid nocmally passing through the dcive motoc is bypassed into the actuator until the actuator moves the dcapec to an end stop at which time fucthec fluid thcough the actuatoc is halted causing the whole of the fluid to retucn to its noemal path thcough the drive motoc. This device has been found to opecate ceasonably satisfactocily but in some cases additional friction in the suppoct system cacrying the dcapec can restrict the movement of the suppoct so that the pacallel fluid system does not pcovide enough pcessuce at the actuatoc to complete the movement quickly and posi~ively. Fcee flow relief valves are available which can alleviate this pcoblem. Howevec these must be provided as a cooperating paic and in addition they ace celatively expensive.
SUMMARY OF THE INVENTION
It is one object of the pcesent invention, thecefoce, to pcovide a check-relief valve accangement foc a hydcaulic ciccuit which can be used in a symmetcical mannec to check flow thcough the device up to a pcedetermined maximum pcessuce following which the pcessure is celeased and flow allowed to continue with minimum restciction in the initially ?~ ~ ~
checked dicection.
According to the invention, therefore, thece i~
pcovided a check-celief valva foc use in a hydraulic circuit compcising a valve body defining a channel through which fluid can pass in either dicection between a ficst end and a second end of the channel, means for connection of the fiCS~ end of the channel to a first fluid line, means for connection of the second end of the channel to a second fluid line, means defining an annulac rest~iction membe~ within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a ficst valve seat defined on the restriction member on a side of the restriction member facing said ficst poction and adjacent said ficst end, a second valve seat defined on the restriction member on a side of the cestriction member facing said second portion and adjacent said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the ficst end towacd the second end and altecnatively with the second valve seat to halt flow of fluid in a di~ection from the second end toward the first end, means at the ficst and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the ~ 3 ~
first and second end cespectively, at least one of the cestriction membec and the valve member being focmed fcom a material which is deformable under pressuce from the fluid such that upon an increase in the fluid pcessure in the first portion above a pcedetermined pressure, the valve member is forced fLom the first valve seat throuyh the restriction member into the second portion and on an inccease in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat thcough the cestriction member into the first portion, whereby the valve opecates symmetrically to check flow of the fluid up to said predetermined pressure and then to release the flow aftec said predetecmined pcessuce is exceeded.
According to a second aspect of the invention, thecefore, thece is provided a hydraulic fluid circuit compcising a soucce of pcessurized hydraulic fluid, a fluid return sump, a ficst fluid line, a second fluid line, a flow control valve opecable to move from the ficst condition in which the soucce is connected to the ficst line and the sump is : 20 connected to the second line to a second condition to which the source is connected to the second line and the sump is connected to the first line, a first actuator having a first fluid poct and a second fluid port and cesponsive to fluid flow 6~ 73 fcom the first poct to the second poct to cause a first action and to fluid flow from the second port to the first poct to cause a second action, a second actuatoc having a first fluid port and a second fluid port and cesponsive to fluid flow from the first poct to the second port to cause a first action and to fluid flow from the second port to the first poct to cause a second action, said first fluid line being connected to said ficst port of the first actuator and to the first pOft of the second actuator, said second fluid line being connected to said second poct of the first actuator and ~o the second poct of the second actuator, and a check-relief valve mounted so as to act upon fluid flow through the first actuatoc, said check-relief valve comprising a valve body defining a channel thfough which fluid can pass in eithec direction between a first end and a second end of the channel, means connecting said ficst, means defining an annulac cestriction membec within the channel Sl through which the fluid can pass and dividing the channel into a first portion and a second portion, a ficst valve seat defined on the restriction member on a side of the cestriction membec facing said ficst portion and said first end, a second valve seat defined on the restciction membec on a side of the restriction membec facing said second poc~ion and said second end, a valve membec mounted within and movable within the channel and ghaped to coope~ate wi~h the ficst valve seat to halt flow of fluid in a direction from the first end towacd the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the ficst and second end respectively, at least one of the restriction member and the valve member being formed from a material which is defocmable under pressure from the ~luid such ~ha~ upon an increase in the fluid pcessure in the first port1on above a predetermined pcessu~e, the valve member is forced from the first valve seat through the restriction member into the second poction and on an inccease in fluid pcessure in the second portion above a .
predetermined pressure the valve member is forced fcom the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid through said first-actuator up to said predetermined pcessure and then to release the flow after ~aid predetermined pressuce is exceeded.
Such a device can therefore be used for example in the header constcuction described above to restrict the flow through the drive motor for a period of time sufficient to '~ ~3 ~
`
allow the ac~uator to move the suppoct to the ~equiced end stop following which the inccease of pcessuce caused by the halting of the fluid through the actuator causes the check-valve to release to the celief position so that the fluid can then continue to flow thcough the motoc to drive the draper in the requiced direction.
Accocding to a third aspect of the invention, therefoce, thece is provided a header foc a swather compcising a frame, a first drapec mounted on the frame having support rollec means, hydraulic drive means for driving said collec means and an endless dcapec canvas wrapped acound said collec means foc movement of an upper run of the canvas longitudinally of the frame, suppoct means mounting the first draper on the frame foc movement of the ficst drapec including the collec means and canvas thereof longitudinally of the frame, from a ficst position of the first drapeL in which a space is pcovided at one end of the first dcapec for deposit of ccop material therethcough to a second position of the first draper in which a space is provided at an opposed end of the first drapec foc discharge at an opposed end of the first draper, the hydcaulic dcive means of the ficst drapec being acranged to drive the ficst dcapec alternatively in clockwise and countecclockwise dicections, hydcaulic actuatoc means foc moving said support ~. ' . ' .
.
t,~
means and said firs~ d~aper altecnatively in one direction from the first position to the second position and in the opposed dicection from the second position to the ficst po ition, single valve means operab.e manually to causa both actuation of said hydcaulic actuatoc means and said hydcaulic drive means to cause movement of said suppoct means and said ficst draper in a cequired dicection and cotation of the first dcaper in a cequiced dicection and a hydcaulic circuit contcolled by said single valve means for supplying fluid to said hydraulic dcive means and to said hydraulic actuatoc mean~, said hydraulic ciccuit comprising a source of pcessurized hydraulic fluid, a fluid retucn sump, a first fluid and a second fluid line, said single valve means being constituted by a flow contcol valve operable to move from a first condition in which the source i5 connected to the ficst line and the sump is connected to the second line to a second condition in which the source is connected to the second line and the sump is connected to the ficst line, the hydcaulic actuatoc means having a ficst fluid poct and a second fluid poct and ~esponsive to fluid flow fcom the first fluid port to the second fluid poct to cause driving of said support means and said ficst dcaper in said one dicection and to fluid flow from the second port to the first port to cause driving of said suppo~t means and said first `` _ g _ . . .
draper in the opposed direction, said hydcaulic drive means having a first fluid port and a second fluid port and respon3ive to fluid flow from the first fluid port to the second fluid port to cause rotakion of the first draper in a first direction and to fluid flow fcom the second fluid port to the first fluid port to cause rotation of the first draper in an opposed direction, said first fluid line being connected to said first port of said hydraulic ac~uator means and to said first port of said hydraulic drive means, said second fluid line being connected to said second port of the nydraulic actuato~ means and to the second poct of the hydraulic drive means, and a check-relief valve mounted so as to act upon fluid flow through the hydraulic dcive means and first and second stop means for halting movement of said ~upport means and said first dcaper on ceaching said first and second positions respectively, said check-relief valve comprising a valve body defining a channel thcough which fluid can pass in sither direction between a first end and a second end of the channel, means connecting said first line through said check relief valve, means defining an annular restriction member within the channel th~ough which the fluid can pass and dividing the channel into a first portion and a second portion, a firs~
valve seat defined on the restriction member on a side of the .
S~
cestriction member facing said ficst portion and said first end, a second valve seat defined on the cestriction member on a side of the restriction membec facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the firSt valve seat to halt flow of fluid in a dicection from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve membec bein~ formed from a material which is deformable under pressure from the fluid such that upon an inccease in the fluid pressure in the first ; portion above a predetecmined pressure, the valve membec isfocced from the first valve seat through the restriction member into the second poction and on an increase in fluid pressure in the second portion above a predete~mined pressure the valve member is forced from the qecond valve seat through the cestriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid thcough the hydraulic drive means until the suport means and the first draper ace moved to one of said stop means and then to release the flow to allow dciving of the first drapec in a cequired direction.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates aa this specification p~oceeds, the invention is herein described by reference to the accompanying drawings forming a part he~eof, which includes a descciption of the best mode known to the applicant and of the preferred typical embodiment of the pcinciples of the present invention, in which:
DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross-sectional view through a check-relief valve according to the present invention.
Figure 2 is a schematic illustration of a hydraulic circuit incorpocating a check-relief valve accoLding to the present invention.
Figure 3 is a plan view of the header of a swathec.
Figure 4 is a schematic illustcation of the drive system of the swathec heade~ of Figure 3 incorpocating the ci~cuit of Figure 2 and the check-celief valve of Figure 1.
Figure 5 is a schematic illustration of an c~
alternative ciccuit and drive system for the header of Figure In the drawings like characters of reference indicate cocresponding pac~ in the diffecent figuce3.
DETAILED DESCRIPTION
The check-valve is shown in Figu~e l and compcise~ a valve body 10 having a cylindcical channel ll thecethrough with a centcal cestcictoc membec 12 and channel ends 13 and 14. The channel ends are acranged oc coupling two hydraulic line~ by coupling means (not shown). setween the channel end and the respective coupling 13, 14 is provided a ; perforated end plate 15 in the focm of a cicculac disc inserted into the body and maintained in location at the cespective ends of the channel ll.
The cestciction membec 12 is genecally annular in shape and has a first valve seat 16 on one side and a second valve seat 17 on the othec side with each valve seat facing the cespective end 13, 14 of the channel. Within the channel is mounted a fceely movable valve membe~ in the form of a ball 18 focmed of a cesiliently deocmably matecial such as urethane.
The valve body is formed of a suitable ~igid matecial such as steel. The diameter of the spherical valve membec 18 is slightly gceatec than the inside diametec of the ce tciction 2~3~
member 12 so that the ball is nocmally prevented from passing thcough the rest~iction member.
In operation, with the ball on the left hand side of the restriction member tha~ is in the portion of the channel adjacent the end 13, fluid is fcee to flow in the direction from the end 14 toward the end 13 since the valve membec will then move toward the end plate 15 and cannot interfere with the flow in view of the large diameter of the disc and the plurality of holes through the disc. On reversal of flow, however, so that the fluid flow~ from the end 13 towacd the end 14, the ball moves onto the valve seat 16 and cooperates therewith to close off further flow of fluid in that direction~
The diametec of the ball is chosen however in comparison with the diameter of the restriction member so tha~
when the fluid exceeds a predetecmined pressure, the ball is focced through the annular restriction into the poction of the chamber on the right hand side of the restriction. This i~
achieved by deforming the ball sufficiently so that it is reduced in diamete~ to that of the restriction and then is forced through the restriction to the other side of the restriction. The ball is formed of a material which then is sufficiently elastic to revert to its oriyinal spherical shape and the original diametec. As the ball moves into the right ~ ~ 3 3 2~'~
hand portion of the channel, flow in that direction then carries the ball to the end disc 15 where there i5 no valve seat so that the fluid can con~inue to flow in that dicection.
As the acrangement is entirely symmetcical/ the same operation will take place with the ball in the right hand poction of the channel but in this case flow will be halted and then released in the direction from the end 14 toward the end 13.
The check valve is used most effectively in the circuit shown in Figure 2. In this ciccuit check-relief valve is shown at 10. There is provided in the ciccuit a pump 20 and a sump 21 for return of the preasurized fluid. The four way valve 22 is provided for coupling the fluid from the pump along a line 23 and the fluid to the sump along a line 24. The valve 22 enables the line 23 and the line 24 to be coupled to one of a ficst line 25 and a second line 26 downstream of the valve 22. Depending upon the position of the valve 22, therefore, the line 23 is coupled to the line 25 oc is coupled to the line 26.
The circuit furthe~ includes a first motor 27 and a second motor 28. The motor constitutes one example of a device which can utilize the hydcaulic fluid pressuce and is of a type in which fluid flow in one direction from a port 27A to ~3~?~
a port 27B cau~es a first ac~ion and flow in the opposite dicection causes a second action. In this cas~ using the example of the motor, the first action ia rotation in one direction and the second action is rotation in the opposite direction. The motor 28 also includes ports 28A and 28B and operates in the same manner. The line 25 is coupled to each of the ports 27A and 28A in parallel. The line 26 is coupled to each of the po~ts 27B and 28B in pacallel. The check valve 10 is positioned in series with one of the motors oc actuators 27 and 28 and in the example shown is in the line to the first port 27A of the first motor 27.
In operation of the device, therefore, when the fouc way valve is positioned as shown in Figure 2, fluid from the pump is applied to the ports 27A and 28A of the motors 27 and 28. This requires fluid to flow through the check valve to the port 27A. As the ball 18 is on the upstream side of the restriction 12, it will be pushed against the valve seat and will halt further flow of fluid to the motor 27. All of the flow is therefore bypassed to the motor 28. The motor 28 as described in relation to Figure 3 includes end stops which halt its motion after a predete~mined period of time. Once the motion of the motor 28 is halted, the pressure behind the ball 18 rises rapidly and forces the ball through the restriction as pfeviously described. The motor 27 is then free ~o run.
When the valve 22 is switched to the oppo ite direction, the same process in reverse occurs in that the valve 10 halts flow of fluid through the motor 27 until the motoc 28 ceaches its end stop following which the increase in pressure focces the ball back through the rest~iction to the initial position.
Turning now to Figure 3 the CiLCUit is shown in conjunction with the header 30 of a swather. The header ` 10 includes a frame 31 with a sickle knife schematically indicated at 33 on a front edge of the table.
Mounted onto the frame is a fir~t conveyoc assembly 34 and a qecond conveyor assembly 35. Each conveyor assembly includes a draper canvas 36 shown in Figure 4 and a pair of rollers 37 and 38 acound which the canvas is wrapped as an endless loop so that the canvas can move with an upper run of the canvas moving longitudinally of the frame in a direction controlled by the direction of rotation o~ the driven roller 37.
Each conveyor assembly is supported in the frame by a rail 40 at the rear edge of the frame and rail 39 at the front edge o~ the frame behind the sickle knife and is movable on the rails 39 and 40 longitudinally of the frame from a first position as shown in which the ficst d~ape~ is at the end of the frame 31 where it is halted by end stops 42 to a second position in which the draper moves toward the second draper 35 to a position where it i9 halted by end stops 43. A~ shown in Figure 4, the movement is obtained by a sprocket 45 driven by the motor 28 operating on a roller chain 46 attached to either end of the conveyo~ assembly to form a rack. Rotation of the first dcapec and particularly the roller 37 is obtained from the motor 27.
As previously explained in the preamble, the : driver can operate the single valve 22 to supply fluid to the ports 27A and 23A of the motocs 27 and 28 respectively. The check valve 10 will act to halt the flow to the motor 27 while all of the fluid is bypassed to the motor 28 until the motor 28 moves the draper to the second position where it will engage the end stops 43. Once the end stops are engaged, the motor 28 can move no further and the full pressuce of the fluid is applied to the check valve 10 thus forcing the ball to the second position and allowing fluid to continue to flow to the motor 27 acting to drive the draper in the required direction.
When it is requiced by the operator to move the draper to the outer end as shown, a valve 22 is moved to the opposite position to transmit fluid to the ports 27B and 28B
~r~
.
which again causes the valve 10 to halt the flow of fluid through the motor 27 until the motoc 28 feaches the end stop.
It will be appa~ent that the flow of fluid thcough the motor 27 is thus automatically controlled in direction to drive the draper in the required direction depending upon its position.
In an alternative arcangement qhown in Figure 5 the motor 28, sprocket 45 and chain 46 are replaced by a piston cylinder acrangement 50 of a double acting nature which will carry out the same function.
In this embodiment, a pi ton 51 is mounted in a cylindec 52 and is movable longitudinally carrying piston rods f 53 which ace coupled to the conveyor assembly 34 by a coupling assembly (not shown). A channel for flow of fluid through the piston 51 is provided to allow the cylinder 52 to act a~ a conduit to the drive motor 27 previously desccibed. The check-relief valve 10 is mounted in the channel through the piston so as to restrict the flow to cause movement of the piston until the end stop is reached whereupon flow to the motor 27 is continued by actuation of the valve 10 as previously described.
Since various modifications can be made in my invention as heceinabove desccibed, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, i~
is intended that all matter contained in the accompanying specification shall be interpreted as illustcative only and not in a limiting sen~e.
. ~
A swathec header includes a table on which is mounted a ficst dcapec and a second draper. Each draper includes a dcapec canvas in the focm of an endless loop and a plucality of support collecs for the canvas which form the loop into an uppec run and a lower run with one or moce of the collers being dciven to cause cotation of the rollec about its axis and thus movement of the upper run of the dcapec canvas in a cequiced dicection longitudinal of the headec.
Many such headecs are accanged so that they can opecate in diffecent modes. In a ficst mode the ficst and second dcapecs ace spcead apact so that the matecial is fed on each drapec towacd a centce opening defined between the dcapecs through which the material falls to focm the swathO
In an alternative mode, one of the dcapecs on a suitable support fcame including the collecs and the canvas is moved longitudinally of the table so that the opening between the dcapecs is closed and a furthec opening is formed at one end of the headec. In this mode, it is often desicable foc the opening to be moved from one end of the header to the other end of the headec and this is achieved by moving both dcapers on suitable support frames longitudinally of the table.
As well as the lateral or lineac movement of the dcapec assembly, it is of coucse also necessar~y when changing mode oc changing the position of the opening to change the direction of rotation of the rollers driving the drapers. soth the actuatoc foc moving the lateral movement of the dcapec support and the drive motor for cotating the rollecs are generally poweced hydraulically and it is most convenient to mount these devices in a single hydraulic circuit.
Fucthecmore it is highly desirable that a single valve be provided which changes from one mode to anothec mode oc changes the location of the draper and at the same time reverses the dicection of the cotation of the draper. This single valve avoids any possible confusion or misfunction of the device and simplifies the operation for the drivec.
The linear movement of the suppoct for the dcapec can be actuated by a piston and cylinder arrangement or alternatively it can be cafried out by a rotary motor togethac with a drive system which translates the rotary movement of the motor into linear movement of the support for example a lead screw arrangement.
, ~
~ 2 In one arcangement which has pceviously been used, the actuatoc for moving the longitudinal movement and the dcive motoc foc cotating the dcapec ace simply mounted in pacallel so that some of the fluid nocmally passing through the dcive motoc is bypassed into the actuator until the actuator moves the dcapec to an end stop at which time fucthec fluid thcough the actuatoc is halted causing the whole of the fluid to retucn to its noemal path thcough the drive motoc. This device has been found to opecate ceasonably satisfactocily but in some cases additional friction in the suppoct system cacrying the dcapec can restrict the movement of the suppoct so that the pacallel fluid system does not pcovide enough pcessuce at the actuatoc to complete the movement quickly and posi~ively. Fcee flow relief valves are available which can alleviate this pcoblem. Howevec these must be provided as a cooperating paic and in addition they ace celatively expensive.
SUMMARY OF THE INVENTION
It is one object of the pcesent invention, thecefoce, to pcovide a check-relief valve accangement foc a hydcaulic ciccuit which can be used in a symmetcical mannec to check flow thcough the device up to a pcedetermined maximum pcessuce following which the pcessure is celeased and flow allowed to continue with minimum restciction in the initially ?~ ~ ~
checked dicection.
According to the invention, therefore, thece i~
pcovided a check-celief valva foc use in a hydraulic circuit compcising a valve body defining a channel through which fluid can pass in either dicection between a ficst end and a second end of the channel, means for connection of the fiCS~ end of the channel to a first fluid line, means for connection of the second end of the channel to a second fluid line, means defining an annulac rest~iction membe~ within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a ficst valve seat defined on the restriction member on a side of the restriction member facing said ficst poction and adjacent said ficst end, a second valve seat defined on the restriction member on a side of the cestriction member facing said second portion and adjacent said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the ficst end towacd the second end and altecnatively with the second valve seat to halt flow of fluid in a di~ection from the second end toward the first end, means at the ficst and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the ~ 3 ~
first and second end cespectively, at least one of the cestriction membec and the valve member being focmed fcom a material which is deformable under pressuce from the fluid such that upon an increase in the fluid pcessure in the first portion above a pcedetermined pressure, the valve member is forced fLom the first valve seat throuyh the restriction member into the second portion and on an inccease in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat thcough the cestriction member into the first portion, whereby the valve opecates symmetrically to check flow of the fluid up to said predetermined pressure and then to release the flow aftec said predetecmined pcessuce is exceeded.
According to a second aspect of the invention, thecefore, thece is provided a hydraulic fluid circuit compcising a soucce of pcessurized hydraulic fluid, a fluid return sump, a ficst fluid line, a second fluid line, a flow control valve opecable to move from the ficst condition in which the soucce is connected to the ficst line and the sump is : 20 connected to the second line to a second condition to which the source is connected to the second line and the sump is connected to the first line, a first actuator having a first fluid poct and a second fluid port and cesponsive to fluid flow 6~ 73 fcom the first poct to the second poct to cause a first action and to fluid flow from the second port to the first poct to cause a second action, a second actuatoc having a first fluid port and a second fluid port and cesponsive to fluid flow from the first poct to the second port to cause a first action and to fluid flow from the second port to the first poct to cause a second action, said first fluid line being connected to said ficst port of the first actuator and to the first pOft of the second actuator, said second fluid line being connected to said second poct of the first actuator and ~o the second poct of the second actuator, and a check-relief valve mounted so as to act upon fluid flow through the first actuatoc, said check-relief valve comprising a valve body defining a channel thfough which fluid can pass in eithec direction between a first end and a second end of the channel, means connecting said ficst, means defining an annulac cestriction membec within the channel Sl through which the fluid can pass and dividing the channel into a first portion and a second portion, a ficst valve seat defined on the restriction member on a side of the cestriction membec facing said ficst portion and said first end, a second valve seat defined on the restciction membec on a side of the restriction membec facing said second poc~ion and said second end, a valve membec mounted within and movable within the channel and ghaped to coope~ate wi~h the ficst valve seat to halt flow of fluid in a direction from the first end towacd the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the ficst and second end respectively, at least one of the restriction member and the valve member being formed from a material which is defocmable under pressure from the ~luid such ~ha~ upon an increase in the fluid pcessure in the first port1on above a predetermined pcessu~e, the valve member is forced from the first valve seat through the restriction member into the second poction and on an inccease in fluid pcessure in the second portion above a .
predetermined pressure the valve member is forced fcom the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid through said first-actuator up to said predetermined pcessure and then to release the flow after ~aid predetermined pressuce is exceeded.
Such a device can therefore be used for example in the header constcuction described above to restrict the flow through the drive motor for a period of time sufficient to '~ ~3 ~
`
allow the ac~uator to move the suppoct to the ~equiced end stop following which the inccease of pcessuce caused by the halting of the fluid through the actuator causes the check-valve to release to the celief position so that the fluid can then continue to flow thcough the motoc to drive the draper in the requiced direction.
Accocding to a third aspect of the invention, therefoce, thece is provided a header foc a swather compcising a frame, a first drapec mounted on the frame having support rollec means, hydraulic drive means for driving said collec means and an endless dcapec canvas wrapped acound said collec means foc movement of an upper run of the canvas longitudinally of the frame, suppoct means mounting the first draper on the frame foc movement of the ficst drapec including the collec means and canvas thereof longitudinally of the frame, from a ficst position of the first drapeL in which a space is pcovided at one end of the first dcapec for deposit of ccop material therethcough to a second position of the first draper in which a space is provided at an opposed end of the first drapec foc discharge at an opposed end of the first draper, the hydcaulic dcive means of the ficst drapec being acranged to drive the ficst dcapec alternatively in clockwise and countecclockwise dicections, hydcaulic actuatoc means foc moving said support ~. ' . ' .
.
t,~
means and said firs~ d~aper altecnatively in one direction from the first position to the second position and in the opposed dicection from the second position to the ficst po ition, single valve means operab.e manually to causa both actuation of said hydcaulic actuatoc means and said hydcaulic drive means to cause movement of said suppoct means and said ficst draper in a cequired dicection and cotation of the first dcaper in a cequiced dicection and a hydcaulic circuit contcolled by said single valve means for supplying fluid to said hydraulic dcive means and to said hydraulic actuatoc mean~, said hydraulic ciccuit comprising a source of pcessurized hydraulic fluid, a fluid retucn sump, a first fluid and a second fluid line, said single valve means being constituted by a flow contcol valve operable to move from a first condition in which the source i5 connected to the ficst line and the sump is connected to the second line to a second condition in which the source is connected to the second line and the sump is connected to the ficst line, the hydcaulic actuatoc means having a ficst fluid poct and a second fluid poct and ~esponsive to fluid flow fcom the first fluid port to the second fluid poct to cause driving of said support means and said ficst dcaper in said one dicection and to fluid flow from the second port to the first port to cause driving of said suppo~t means and said first `` _ g _ . . .
draper in the opposed direction, said hydcaulic drive means having a first fluid port and a second fluid port and respon3ive to fluid flow from the first fluid port to the second fluid port to cause rotakion of the first draper in a first direction and to fluid flow fcom the second fluid port to the first fluid port to cause rotation of the first draper in an opposed direction, said first fluid line being connected to said first port of said hydraulic ac~uator means and to said first port of said hydraulic drive means, said second fluid line being connected to said second port of the nydraulic actuato~ means and to the second poct of the hydraulic drive means, and a check-relief valve mounted so as to act upon fluid flow through the hydraulic dcive means and first and second stop means for halting movement of said ~upport means and said first dcaper on ceaching said first and second positions respectively, said check-relief valve comprising a valve body defining a channel thcough which fluid can pass in sither direction between a first end and a second end of the channel, means connecting said first line through said check relief valve, means defining an annular restriction member within the channel th~ough which the fluid can pass and dividing the channel into a first portion and a second portion, a firs~
valve seat defined on the restriction member on a side of the .
S~
cestriction member facing said ficst portion and said first end, a second valve seat defined on the cestriction member on a side of the restriction membec facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the firSt valve seat to halt flow of fluid in a dicection from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve membec bein~ formed from a material which is deformable under pressure from the fluid such that upon an inccease in the fluid pressure in the first ; portion above a predetecmined pressure, the valve membec isfocced from the first valve seat through the restriction member into the second poction and on an increase in fluid pressure in the second portion above a predete~mined pressure the valve member is forced from the qecond valve seat through the cestriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid thcough the hydraulic drive means until the suport means and the first draper ace moved to one of said stop means and then to release the flow to allow dciving of the first drapec in a cequired direction.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates aa this specification p~oceeds, the invention is herein described by reference to the accompanying drawings forming a part he~eof, which includes a descciption of the best mode known to the applicant and of the preferred typical embodiment of the pcinciples of the present invention, in which:
DESCRIPTION OF THE DRAWINGS
Figure 1 is a cross-sectional view through a check-relief valve according to the present invention.
Figure 2 is a schematic illustration of a hydraulic circuit incorpocating a check-relief valve accoLding to the present invention.
Figure 3 is a plan view of the header of a swathec.
Figure 4 is a schematic illustcation of the drive system of the swathec heade~ of Figure 3 incorpocating the ci~cuit of Figure 2 and the check-celief valve of Figure 1.
Figure 5 is a schematic illustration of an c~
alternative ciccuit and drive system for the header of Figure In the drawings like characters of reference indicate cocresponding pac~ in the diffecent figuce3.
DETAILED DESCRIPTION
The check-valve is shown in Figu~e l and compcise~ a valve body 10 having a cylindcical channel ll thecethrough with a centcal cestcictoc membec 12 and channel ends 13 and 14. The channel ends are acranged oc coupling two hydraulic line~ by coupling means (not shown). setween the channel end and the respective coupling 13, 14 is provided a ; perforated end plate 15 in the focm of a cicculac disc inserted into the body and maintained in location at the cespective ends of the channel ll.
The cestciction membec 12 is genecally annular in shape and has a first valve seat 16 on one side and a second valve seat 17 on the othec side with each valve seat facing the cespective end 13, 14 of the channel. Within the channel is mounted a fceely movable valve membe~ in the form of a ball 18 focmed of a cesiliently deocmably matecial such as urethane.
The valve body is formed of a suitable ~igid matecial such as steel. The diameter of the spherical valve membec 18 is slightly gceatec than the inside diametec of the ce tciction 2~3~
member 12 so that the ball is nocmally prevented from passing thcough the rest~iction member.
In operation, with the ball on the left hand side of the restriction member tha~ is in the portion of the channel adjacent the end 13, fluid is fcee to flow in the direction from the end 14 toward the end 13 since the valve membec will then move toward the end plate 15 and cannot interfere with the flow in view of the large diameter of the disc and the plurality of holes through the disc. On reversal of flow, however, so that the fluid flow~ from the end 13 towacd the end 14, the ball moves onto the valve seat 16 and cooperates therewith to close off further flow of fluid in that direction~
The diametec of the ball is chosen however in comparison with the diameter of the restriction member so tha~
when the fluid exceeds a predetecmined pressure, the ball is focced through the annular restriction into the poction of the chamber on the right hand side of the restriction. This i~
achieved by deforming the ball sufficiently so that it is reduced in diamete~ to that of the restriction and then is forced through the restriction to the other side of the restriction. The ball is formed of a material which then is sufficiently elastic to revert to its oriyinal spherical shape and the original diametec. As the ball moves into the right ~ ~ 3 3 2~'~
hand portion of the channel, flow in that direction then carries the ball to the end disc 15 where there i5 no valve seat so that the fluid can con~inue to flow in that dicection.
As the acrangement is entirely symmetcical/ the same operation will take place with the ball in the right hand poction of the channel but in this case flow will be halted and then released in the direction from the end 14 toward the end 13.
The check valve is used most effectively in the circuit shown in Figure 2. In this ciccuit check-relief valve is shown at 10. There is provided in the ciccuit a pump 20 and a sump 21 for return of the preasurized fluid. The four way valve 22 is provided for coupling the fluid from the pump along a line 23 and the fluid to the sump along a line 24. The valve 22 enables the line 23 and the line 24 to be coupled to one of a ficst line 25 and a second line 26 downstream of the valve 22. Depending upon the position of the valve 22, therefore, the line 23 is coupled to the line 25 oc is coupled to the line 26.
The circuit furthe~ includes a first motor 27 and a second motor 28. The motor constitutes one example of a device which can utilize the hydcaulic fluid pressuce and is of a type in which fluid flow in one direction from a port 27A to ~3~?~
a port 27B cau~es a first ac~ion and flow in the opposite dicection causes a second action. In this cas~ using the example of the motor, the first action ia rotation in one direction and the second action is rotation in the opposite direction. The motor 28 also includes ports 28A and 28B and operates in the same manner. The line 25 is coupled to each of the ports 27A and 28A in parallel. The line 26 is coupled to each of the po~ts 27B and 28B in pacallel. The check valve 10 is positioned in series with one of the motors oc actuators 27 and 28 and in the example shown is in the line to the first port 27A of the first motor 27.
In operation of the device, therefore, when the fouc way valve is positioned as shown in Figure 2, fluid from the pump is applied to the ports 27A and 28A of the motors 27 and 28. This requires fluid to flow through the check valve to the port 27A. As the ball 18 is on the upstream side of the restriction 12, it will be pushed against the valve seat and will halt further flow of fluid to the motor 27. All of the flow is therefore bypassed to the motor 28. The motor 28 as described in relation to Figure 3 includes end stops which halt its motion after a predete~mined period of time. Once the motion of the motor 28 is halted, the pressure behind the ball 18 rises rapidly and forces the ball through the restriction as pfeviously described. The motor 27 is then free ~o run.
When the valve 22 is switched to the oppo ite direction, the same process in reverse occurs in that the valve 10 halts flow of fluid through the motor 27 until the motoc 28 ceaches its end stop following which the increase in pressure focces the ball back through the rest~iction to the initial position.
Turning now to Figure 3 the CiLCUit is shown in conjunction with the header 30 of a swather. The header ` 10 includes a frame 31 with a sickle knife schematically indicated at 33 on a front edge of the table.
Mounted onto the frame is a fir~t conveyoc assembly 34 and a qecond conveyor assembly 35. Each conveyor assembly includes a draper canvas 36 shown in Figure 4 and a pair of rollers 37 and 38 acound which the canvas is wrapped as an endless loop so that the canvas can move with an upper run of the canvas moving longitudinally of the frame in a direction controlled by the direction of rotation o~ the driven roller 37.
Each conveyor assembly is supported in the frame by a rail 40 at the rear edge of the frame and rail 39 at the front edge o~ the frame behind the sickle knife and is movable on the rails 39 and 40 longitudinally of the frame from a first position as shown in which the ficst d~ape~ is at the end of the frame 31 where it is halted by end stops 42 to a second position in which the draper moves toward the second draper 35 to a position where it i9 halted by end stops 43. A~ shown in Figure 4, the movement is obtained by a sprocket 45 driven by the motor 28 operating on a roller chain 46 attached to either end of the conveyo~ assembly to form a rack. Rotation of the first dcapec and particularly the roller 37 is obtained from the motor 27.
As previously explained in the preamble, the : driver can operate the single valve 22 to supply fluid to the ports 27A and 23A of the motocs 27 and 28 respectively. The check valve 10 will act to halt the flow to the motor 27 while all of the fluid is bypassed to the motor 28 until the motor 28 moves the draper to the second position where it will engage the end stops 43. Once the end stops are engaged, the motor 28 can move no further and the full pressuce of the fluid is applied to the check valve 10 thus forcing the ball to the second position and allowing fluid to continue to flow to the motor 27 acting to drive the draper in the required direction.
When it is requiced by the operator to move the draper to the outer end as shown, a valve 22 is moved to the opposite position to transmit fluid to the ports 27B and 28B
~r~
.
which again causes the valve 10 to halt the flow of fluid through the motor 27 until the motoc 28 feaches the end stop.
It will be appa~ent that the flow of fluid thcough the motor 27 is thus automatically controlled in direction to drive the draper in the required direction depending upon its position.
In an alternative arcangement qhown in Figure 5 the motor 28, sprocket 45 and chain 46 are replaced by a piston cylinder acrangement 50 of a double acting nature which will carry out the same function.
In this embodiment, a pi ton 51 is mounted in a cylindec 52 and is movable longitudinally carrying piston rods f 53 which ace coupled to the conveyor assembly 34 by a coupling assembly (not shown). A channel for flow of fluid through the piston 51 is provided to allow the cylinder 52 to act a~ a conduit to the drive motor 27 previously desccibed. The check-relief valve 10 is mounted in the channel through the piston so as to restrict the flow to cause movement of the piston until the end stop is reached whereupon flow to the motor 27 is continued by actuation of the valve 10 as previously described.
Since various modifications can be made in my invention as heceinabove desccibed, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, i~
is intended that all matter contained in the accompanying specification shall be interpreted as illustcative only and not in a limiting sen~e.
. ~
Claims
CLAIMS:
(1) A check-relief valve for use in a hydraulic circuit comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means for connection of the first end of the channel to a first fluid line, means for connection of the second end of the channel to a second fluid line, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and adjacent said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and adjacent said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid up to said predetermined pressure and then to release the flow after said predetermined pressure is exceeded.
(2) The check-relief valve according to Claim 1 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(3) The check-relief valve according to Claim 1 wherein one of the restriction member and the valve member are formed from urethane.
(4) The check-relief valve according to Claim 1 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(5) A hydraulic fluid circuit comprising a source of pressurized hydraulic fluid, a fluid return sump, a first fluid line, a second fluid line, a flow control valve operable to move from the first condition in which the source is connected to the first line and the sump is connected to the second line to a second condition to which the source is connected to the second line and the sump is connected to the first line, a first actuator having a first fluid port and a second fluid port and responsive to fluid flow from the first port to the second port to cause a first action and to fluid flow from the second port to the first port to cause a second action, a second actuator having a first fluid port and a second fluid port and responsive to fluid flow from the first port to the second port to cause a first action and to fluid flow from the second port to the first port to cause a second action, said first fluid line being connected to said first port of the first actuator and to the first port of the second actuator, said second fluid line being connected to said second port of the first actuator and to the second port of the second actuator, and a check-relief valve mounted so as to act upon fluid flow through the first actuator, said check-relief valve comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means connecting said first line through said check-relief valve, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid through said first-actuator up to said predetermined pressure and then to release the flow after said predetermined pressure is exceeded.
(6) The hydraulic circuit according to Claim 5 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(7) The hydraulic circuit according to Claim 5 wherein one of the restriction member and the valve member are formed form urethane.
(8) The hydraulic circuit according to Claim 5 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(9) A header for a swather comprising a frame, a first draper mounted on the frame having support roller means, hydraulic drive means for driving said roller means and an endless draper canvas wrapped around said roller means for movement of an upper run of the canvas longitudinally of the frame, support means mounting the first draper on the frame for movement of the first draper including the roller means and canvas thereof longitudinally of the frame, from a first position of the first draper in which a space is provided at one end of the first draper for deposit of crop material therethrough to a second position of the first draper in which a space is provided at an opposed end of the first draper for discharge at an opposed end of the first draper, the hydraulic drive means of the first draper being arranged to drive the first draper alternatively in clockwise and counterclockwise directions, hydraulic actuator means for moving said support means and said first draper alternatively in one direction from the first position to the second position and in the opposed direction from the second position to the first position, single valve means operable manually to cause both actuation of said hydraulic actuator means and said hydraulic drive means to cause movement of said support means and said first draper in a required direction and rotation of the first draper in a required direction and a hydraulic circuit controlled by said single valve means for supplying fluid to said hydraulic drive means and to said hydraulic actuator means, said hydraulic circuit comprising a source of pressurized hydraulic fluid, a fluid return sump, a first fluid and a second fluid line, said single valve means being constituted by a flow control valve operable to move from a first condition in which the source is connected to the first line and the sump is connected to the second line to a second condition in which the source is connected to the second line and the sump is connected to the first line, the hydraulic actuator means having a first fluid port and a second fluid port and responsive to fluid flow from the first fluid port to the second fluid port to cause driving of said support means and said first draper in said one direction and to fluid flow from the second port to the first port to cause driving of said support means and said first draper in the opposed direction, said hydraulic drive means having a first fluid port and a second fluid port and responsive to fluid flow from the first fluid port to the second fluid port to cause rotation of the first draper in a first direction and to fluid flow from the second fluid port to the first fluid port to cause rotation of the first draper in an opposed direction, said first fluid line being connected to said first port of said hydraulic actuator means and to said first port of said hydraulic drive means, said second fluid line being connected to said second port of the hydraulic actuator means and to the second port of the hydraulic drive means, and a check-relief valve mounted so as to act upon fluid flow through the hydraulic drive means, and first and second stop means for halting movement of said support means and said first draper on reaching said first and second positions respectively, said check-relief valve comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means connecting said first line through said check-relief valve, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion,; whereby the valve operates symmetrically to check flow of the fluid through the hydraulic drive means until the suport means and the first draper are moved to one of said stop means and then to release the flow to allow driving of the first draper in a required direction.
(10) The header according to Claim 9 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(11) The header according to Claim 9 wherein one of the restriction member and the valve member are formed from urethane.
(12) The header according to Claim 9 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(13) The header according to Claim 9 wherein the hydraulic drive means comprises a rotary drive motor and the hydraulic actuator comprises a rotary drive motor and means for converting rotary movement thereof into a linear movement of said support means and said first draper.
(1) A check-relief valve for use in a hydraulic circuit comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means for connection of the first end of the channel to a first fluid line, means for connection of the second end of the channel to a second fluid line, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and adjacent said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and adjacent said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid up to said predetermined pressure and then to release the flow after said predetermined pressure is exceeded.
(2) The check-relief valve according to Claim 1 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(3) The check-relief valve according to Claim 1 wherein one of the restriction member and the valve member are formed from urethane.
(4) The check-relief valve according to Claim 1 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(5) A hydraulic fluid circuit comprising a source of pressurized hydraulic fluid, a fluid return sump, a first fluid line, a second fluid line, a flow control valve operable to move from the first condition in which the source is connected to the first line and the sump is connected to the second line to a second condition to which the source is connected to the second line and the sump is connected to the first line, a first actuator having a first fluid port and a second fluid port and responsive to fluid flow from the first port to the second port to cause a first action and to fluid flow from the second port to the first port to cause a second action, a second actuator having a first fluid port and a second fluid port and responsive to fluid flow from the first port to the second port to cause a first action and to fluid flow from the second port to the first port to cause a second action, said first fluid line being connected to said first port of the first actuator and to the first port of the second actuator, said second fluid line being connected to said second port of the first actuator and to the second port of the second actuator, and a check-relief valve mounted so as to act upon fluid flow through the first actuator, said check-relief valve comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means connecting said first line through said check-relief valve, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion, whereby the valve operates symmetrically to check flow of the fluid through said first-actuator up to said predetermined pressure and then to release the flow after said predetermined pressure is exceeded.
(6) The hydraulic circuit according to Claim 5 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(7) The hydraulic circuit according to Claim 5 wherein one of the restriction member and the valve member are formed form urethane.
(8) The hydraulic circuit according to Claim 5 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(9) A header for a swather comprising a frame, a first draper mounted on the frame having support roller means, hydraulic drive means for driving said roller means and an endless draper canvas wrapped around said roller means for movement of an upper run of the canvas longitudinally of the frame, support means mounting the first draper on the frame for movement of the first draper including the roller means and canvas thereof longitudinally of the frame, from a first position of the first draper in which a space is provided at one end of the first draper for deposit of crop material therethrough to a second position of the first draper in which a space is provided at an opposed end of the first draper for discharge at an opposed end of the first draper, the hydraulic drive means of the first draper being arranged to drive the first draper alternatively in clockwise and counterclockwise directions, hydraulic actuator means for moving said support means and said first draper alternatively in one direction from the first position to the second position and in the opposed direction from the second position to the first position, single valve means operable manually to cause both actuation of said hydraulic actuator means and said hydraulic drive means to cause movement of said support means and said first draper in a required direction and rotation of the first draper in a required direction and a hydraulic circuit controlled by said single valve means for supplying fluid to said hydraulic drive means and to said hydraulic actuator means, said hydraulic circuit comprising a source of pressurized hydraulic fluid, a fluid return sump, a first fluid and a second fluid line, said single valve means being constituted by a flow control valve operable to move from a first condition in which the source is connected to the first line and the sump is connected to the second line to a second condition in which the source is connected to the second line and the sump is connected to the first line, the hydraulic actuator means having a first fluid port and a second fluid port and responsive to fluid flow from the first fluid port to the second fluid port to cause driving of said support means and said first draper in said one direction and to fluid flow from the second port to the first port to cause driving of said support means and said first draper in the opposed direction, said hydraulic drive means having a first fluid port and a second fluid port and responsive to fluid flow from the first fluid port to the second fluid port to cause rotation of the first draper in a first direction and to fluid flow from the second fluid port to the first fluid port to cause rotation of the first draper in an opposed direction, said first fluid line being connected to said first port of said hydraulic actuator means and to said first port of said hydraulic drive means, said second fluid line being connected to said second port of the hydraulic actuator means and to the second port of the hydraulic drive means, and a check-relief valve mounted so as to act upon fluid flow through the hydraulic drive means, and first and second stop means for halting movement of said support means and said first draper on reaching said first and second positions respectively, said check-relief valve comprising a valve body defining a channel through which fluid can pass in either direction between a first end and a second end of the channel, means connecting said first line through said check-relief valve, means defining an annular restriction member within the channel through which the fluid can pass and dividing the channel into a first portion and a second portion, a first valve seat defined on the restriction member on a side of the restriction member facing said first portion and said first end, a second valve seat defined on the restriction member on a side of the restriction member facing said second portion and said second end, a valve member mounted within and movable within the channel and shaped to cooperate with the first valve seat to halt flow of fluid in a direction from the first end toward the second end and alternatively with the second valve seat to halt flow of fluid in a direction from the second end toward the first end, means at the first and second ends respectively shaped such that, when engaged by the valve member, fluid can bypass the valve member to escape from the first and second end respectively, at least one of the restriction member and the valve member being formed from a material which is deformable under pressure from the fluid such that upon an increase in the fluid pressure in the first portion above a predetermined pressure, the valve member is forced from the first valve seat through the restriction member into the second portion and on an increase in fluid pressure in the second portion above a predetermined pressure the valve member is forced from the second valve seat through the restriction member into the first portion,; whereby the valve operates symmetrically to check flow of the fluid through the hydraulic drive means until the suport means and the first draper are moved to one of said stop means and then to release the flow to allow driving of the first draper in a required direction.
(10) The header according to Claim 9 wherein the valve member comprises a spherical ball which is formed from a material which is deformable.
(11) The header according to Claim 9 wherein one of the restriction member and the valve member are formed from urethane.
(12) The header according to Claim 9 wherein said means at the first end comprises a first perforated disc and the means at the second end comprises a second perforated disc, each of said discs presenting to the valve member a substantially flat surface which is perforated to allow passage of fluid therethrough.
(13) The header according to Claim 9 wherein the hydraulic drive means comprises a rotary drive motor and the hydraulic actuator comprises a rotary drive motor and means for converting rotary movement thereof into a linear movement of said support means and said first draper.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2035290 CA2035290A1 (en) | 1991-01-30 | 1991-01-30 | Check-relief valve for a hydraulic circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2035290 CA2035290A1 (en) | 1991-01-30 | 1991-01-30 | Check-relief valve for a hydraulic circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2035290A1 true CA2035290A1 (en) | 1992-07-31 |
Family
ID=4146910
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2035290 Abandoned CA2035290A1 (en) | 1991-01-30 | 1991-01-30 | Check-relief valve for a hydraulic circuit |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2035290A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109463130A (en) * | 2018-11-23 | 2019-03-15 | 南县伟业机械制造有限公司 | A kind of hydraulic transmission of underwater cutter |
-
1991
- 1991-01-30 CA CA 2035290 patent/CA2035290A1/en not_active Abandoned
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109463130A (en) * | 2018-11-23 | 2019-03-15 | 南县伟业机械制造有限公司 | A kind of hydraulic transmission of underwater cutter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5086613A (en) | Check-relief valve for a hydraulic circuit | |
| US5791128A (en) | Reversible hydraulic drive apparatus | |
| US7464525B2 (en) | Intake conveyor mechanism control for an agricultural working machine | |
| US5287794A (en) | Hydraulic motor with inlet fluid supplemented by fluid from contracting chamber | |
| US20030015405A1 (en) | Conveyor chain tension adjusting device | |
| EP0366815A4 (en) | Hydraulic drive unit for construction machinery | |
| CZ112297A3 (en) | Hydraulic driving system for a press | |
| US20030221548A1 (en) | Electrohydraulic lifting control device for industrial trucks | |
| US4164119A (en) | Hydraulic pump unloading system | |
| US5220790A (en) | Assembly of a pressurized fluid motor with multiple cubic capacities and a brake associated therewith | |
| CA2199156A1 (en) | Fluid Delivery System with Mounting Linkage | |
| KR0184127B1 (en) | Reciprocating floor conveyor and floor member | |
| KR20050096909A (en) | Control of a hydrostatic gearbox | |
| CA2035290A1 (en) | Check-relief valve for a hydraulic circuit | |
| RU2001107062A (en) | Hydraulic driven agricultural machine pick-up | |
| US3750406A (en) | Servo-control device for varying the delivery and direction of distribution of a variable delivery pump | |
| US4032003A (en) | Hydrostatic conveyor drive | |
| EP0537349A4 (en) | Hydraulic drive system in civil engineering-construction machine. | |
| US20230192053A1 (en) | Hydraulic system for a brake release device, brake release device with such a hydraulic system and brake system | |
| DE19517334C2 (en) | Swash plate compressor with variable delivery rate | |
| US6311489B1 (en) | Regulating device for an adjustable hydraulic pump with several consumers | |
| WO1987004987A1 (en) | Adjusting and recoil mechanism | |
| EP0010699B1 (en) | Fluid motor control circuit with fast-acting quick-drop valve | |
| KR102652658B1 (en) | Combine | |
| US4514134A (en) | Double sidewinder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |