Patent Application
20240376686
The invention generally relates to couplings of the type used to mount detachable farm or construction implements on the free end of the arms of a prime mover vehicle such as a tractor, loader, or the like.
Loaders are powered vehicles running on wheels or tracks having hydraulically operated upper and lower pairs of arms extending from the front of the vehicle. Loader machines such as front-end loaders and tractor-loaders (each of which is sometimes referred to herein generally as a “loader”) often include a quick coupler operatively connected to the arms. The coupler is adapted to mate selectively and releasably with an implement for performing work, such as a construction attachment or agricultural attachment (e.g., a bucket, a boom, a fork attachment, a rake, or the like). Such coupler systems typically use a male master mounted on the upper and lower arms of the loader together with female coupler attachments affixed to an implement. The implement typically consists of a pair of upper hooks and lower protruding lugs. The upper hooks receive a generally horizontal male member on the coupler. The lower protruding lugs have slots or openings which are configured to receive movable locking wedges or pins combined with the coupler (as used herein “locking pins” shall include locking wedges and other suitably shaped locking members). The implement is secured or released by extension or retraction of hydraulically or manually actuated locking pins through the protruding lugs. To be properly connected, both upper hooks need to be fully around the upper horizontal bar member of the coupler and both locking pins need to be extended through the respective implement lugs of the implement. The coupler allows an operator of the loader to engage with and disengage from various implements as needed without exiting the operator's cab. Such couplers provide for improved machine productivity and operator convenience as compared conventional loaders that require the operator to exit the cab to connect and disconnect each implement. An exemplary coupler is disclosed in U.S. Pat. No. 4,708,579 (Baird et al.) issued on Nov. 24, 1987, the complete disclosure is hereby incorporated by this reference.
Prior couplers of the above type are disadvantageous in that there are no means of signaling the operator whether the locking pins are fully latched to the implement. In some cases, the coupling may approach the implement but, for one reason or another, the locking pins may not move fully into latching engagement with the implement. For example, the lug on the implement may be dirty or bent and therefore incapable of fully receiving the coupler's pin. Further, even if fully extended, the lug/pin engagement may occur at a location that is difficult for the operator to see from the cab. Accordingly, the operator must leave the prime mover vehicle and visually inspect the pins to make certain that the implement is securely attached. Still further, it is important to ensure the implement remains properly attached to the coupler during use. Damage to hydraulic lines, valves, and motors, leaking hydraulic fluid, and external forces acting on the locking pins during operation can all cause the locking pins to retract from an extended position to an unsafe position without warning to the operator.
There is therefore a need for an improved coupler which overcomes these and other drawbacks in the prior art.
One aspect of the present disclosure relates to a coupler assembly for coupling an implement to a prime mover vehicle. The coupler assembly includes a hydraulic system having a first fluid flow path and a second fluid flow path. The hydraulic system is configured to convey fluid under system pressure to a hydraulic cylinder for moving one or more locking pins between an extended position and a retracted position. A proximity sensor is in communication with the hydraulic system, the proximity sensor having an open position wherein system pressure is allowed to flow through the first fluid flow path toward the hydraulic cylinder and a closed position wherein fluid is prevented from flowing through the first fluid flow path toward the hydraulic cylinder. An indicator in communication with the hydraulic system through a third fluid flow path, the indicator is configured to indicate a first sign when system pressure is not received through the third fluid flow path and a second sign when system pressure is received through the third fluid flow path. The first sign is indicative of the locking pins not being in the extended position and the second sign is indicative of the locking pins being in the extended position.
Another aspect of the present disclosure relates to a coupler assembly configured to selectively couple a work implement to a prime mover vehicle. The coupler assembly includes a hydraulic system configured to convey hydraulic fluid under system pressure from a hydraulic motor or other source to move one or more locking pins between an extended position where the locking pins are received by openings or lugs in the work implement to secure the coupler assembly to the implement, and a retracted position wherein the locking pins are retracted from the openings or lugs to allow the implement to be removed from the coupler assembly. The hydraulic system of the coupler assembly is configured to be combined with and operated by the hydraulic system of a prime mover vehicle. In some embodiments the locking pins are the rod of a hydraulic cylinder. In other embodiments the locking pins are actuated by the rod of a hydraulic cylinder. The coupler assembly further includes one or more proximity sensors configured to determine whether the implement is seated properly with the coupler assembly. The proximity sensors are in communication with the coupler's hydraulic system and only allow the flow of hydraulic fluid through the system toward the locking pins when the implement is determined to be properly seated with the coupler. The coupler assembly further includes an indicator in communication with the coupler's hydraulic system. The indicator may be a visual indicator configured to visually indicate a first sign and a second sign. The first sign is indicative of the implement not being properly attached to the coupler and the second sign is indicative of the implement being properly attached to the coupler. In some embodiments the indicator physically moves between a first position to indicate the first sign and a second position to indicate the second sign, and is biased in the first position by a biasing member such as a spring. The indicator is biased in the first position and is only moved to the second position if certain conditions are met. In some embodiments, in order for the indicator to be moved to the second position signaling a proper attachment, the proximity sensor(s) must be actuated to allow fluid to flow through the hydraulic system to the locking pins and the locking pins must be fully extended. In some embodiment, if these conditions are met, then hydraulic fluid is conveyed through a fluid flow path to the indicator at a high enough system pressure to overcome the biasing force keeping the indicator in the first position, thereby moving the indicator to the second position. In other embodiments other conditions are also required to convey enough hydraulic pressure to move the indicator to the second position.
Another aspect of the present disclosure relates to a hydraulic system associated with a coupler assembly configured to selectively attach to a work implement. The hydraulic system associated with a coupler assembly is configured to be combined with and operated by the hydraulic system of a prime mover vehicle. The hydraulic system of the coupler assembly is configured to convey system pressure from the hydraulic system of a prime mover vehicle to move one or more locking pins between an extended position where the locking pins are received by openings or lugs in the work implement to secure the coupler assembly to the implement, and a retracted position wherein the locking pins are retracted from the openings or lugs to allow the implement to be removed from the coupler assembly. The hydraulic system of the coupler assembly includes one or more proximity sensors configured to determine whether the implement is seated properly with the coupler assembly. The proximity sensors are in communication with the coupler's hydraulic system and only allow the flow of hydraulic fluid through the system toward the locking pins when the implement is determined to be properly seated with the coupler. Each proximity sensor includes a permissive control valve that, in some embodiments, is plunger operated such that the implement provides force against the plunger when the implement is properly seated against the coupler. The permissive control valve is biased in a first position wherein fluid is not allowed to move through the hydraulic system toward the one or more locking pins. The force from the properly seated implement actuates the plunger to move the permissive control valve into a second position where hydraulic fluid is allowed to move in the hydraulic system toward the one or more locking pins. The hydraulic system of the coupler assembly further includes a fluid pathway from the one or more locking pins to an indicator, which may be a visual indicator, configured to move between a first position having a first sign or signal and a second position having a second sign or signal. The first position is indicative of the implement not being properly attached to the coupler and the second position is indicative of the implement being properly attached to the coupler. The indicator is biased in the first position by a biasing member such as a spring and is only moved to the second position if certain conditions are met which allow hydraulic system pressure to overcome the biasing force thereby moving the indicator to the second position indicating proper attachment with the implement. In some embodiments, in order for the indicator to be moved to the second position signaling a proper attachment, the proximity sensors must be actuated to allow fluid to flow through the hydraulic system to the locking pins and the locking pins must be extended, which opens a fluid pathway allowing system pressure to flow to the indicator. In other embodiments other conditions are also required to provide enough hydraulic pressure to move the indicator to the second position.
Another aspect of the present disclosure relates to a method for determining a state of a coupler assembly. The method includes providing a coupler assembly having a hydraulic system, as described above, the coupler assembly configured to be selectively attached to an implement. Connecting the hydraulic system of the coupler to the hydraulic system of the prime mover vehicle and attempting to attach the implement to the coupler. Actuating system pressure to move the locking pins to the extended position. In the event the implement is properly seated with the coupler, the proximity sensors allowing fluid to flow through the hydraulic system toward the locking pins thereby meeting a first condition. In the event the implement is not properly seated with the coupler, the proximity sensors preventing fluid from flowing through the hydraulic system toward the locking pins and the indicator remaining in the first position without meeting the first condition. Upon meeting the first condition, fluid pressure is conveyed through the system to extend the locking pins to the extended position. In the event the locking pins extend to the extended position, a second condition is met and hydraulic system pressure overcomes the biasing force keeping the indicator in the first position thereby moving the indicator to the second position indicating the implement has been properly attached to the coupler assembly. In the event the locking pins do not extend to the extended position, the second condition is not met and the indicator remains in the first position. Actuating system pressure to move the locking pins to the retracted position thereby causing the biasing force of the indicator to be greater than retraction system pressure so the indicator returns to the first position.
The invention generally relates to a coupler assembly 10 having a hydraulic system 50 configured to actuate an indicator 16 upon the occurrence of certain conditions. The hydraulic system 50 of the coupler assembly 10 is configured to be fluidly connected to and operated by the hydraulic system of a prime mover vehicle 13. The hydraulic system 50 of the coupler assembly 10 is configured to convey a fluid, which may be a hydraulic fluid, from the hydraulic system of the prime mover vehicle 13 to a hydraulic cylinder 19 and other system components described herein. The fluid is conveyed into the hydraulic system 50 of the coupler assembly 10 under system pressure and is conveyed back to the hydraulic system of the prime mover vehicle 13 under return system pressure. The hydraulic system described herein will primarily relate to the hydraulic system 50 of the coupler assembly 10. Further, reference is primarily made to “hydraulic” fluid, however, any other suitable fluid may be used with the system.
The coupler assembly 10 further includes a hydraulic system 50 configured to move the one or more locking pins 18 between an extended position where the locking pins 18 are received by the openings or lugs 25 in the work implement 11 to secure the coupler 10 to the implement 11, and a retracted position wherein the locking pins 18 are retracted from the openings or lugs 25 to allow the implement 11 to be removed from the coupler 10. In the embodiments shown in
The coupler assembly further includes one or more proximity sensors 14 configured to determine whether the implement 11 is in a seated position or a non-seated position relative to the coupler 10. Positioning the implement 11 with the coupler assembly 10 in the seated position may include ensuring the implement 11 is within a predetermined distance from a predetermined area of the coupler assembly 10. It may also include ensuring the implement 11 aligns with the coupler assembly 10 at a predetermined angle. It may also include ensuring the rear face of the implement 11 is aligned in planer parallel with the front face of the coupler assembly 10. In some embodiments proper seating will not occur unless all of the hooks 31 on the implement properly engaged the cross horizontal member 21 on the coupler assembly 10. As described below in more detail, the proximity sensors 14 are in communication with the coupler assembly's 10 hydraulic system 50 and only allow the flow of hydraulic fluid through the system toward the locking pins 18 when the implement 11 is determined to be properly seated with the coupler 10. Each proximity sensor 14 includes a permissive control valve 33 having an open position and a closed position. In the open position hydraulic fluid is allowed to flow in a first direction toward the locking pins 18 and also in a second direction towards the hydraulic supply/reserve tank 22. In the closed position hydraulic fluid is prevented from flowing in the first direction toward the locking pins 18, but is still allowed to flow in the second direction toward the tank 22. The permissive control valve 33 is biased in the closed position so that hydraulic fluid can only pass through toward the locking pins 18 if the proximity sensors 14 detect that the implement 11 is properly seated with the coupler assembly 10. In some embodiments, two proximity sensors 14 are in communication with the hydraulic system 50 in series so that both sensors 14 must be in their open position in order for system pressure to flow toward the cylinder 19.
The proximity sensors 14 help determine whether the implement 11 is property seated against the coupler 10. The proximity sensors 14 may detect the proper seating of the implement 11 and operate the permissive control valve 33 mechanically or electrically. In some embodiments the proximity sensors 14 operate mechanically by physically actuating a plunger 15 that is movable between an extended position and a retracted position and is biased in the extended position. In the extended position the permissive control valve 33 is in its closed position wherein a check valve 24 prevents hydraulic fluid from flowing into the system (toward the locking pins 18), but still allows fluid to flow out of the system toward the tank 22. In the retracted position the permissive control valve 33 is in its open position allowing fluid to flow both into the system toward the locking pins 18 and out of the system toward tank 22. In use, the implement 11 provides force against the plunger 15 when property seated against the coupler assembly 10 to move the plunger 15 to the retracted position. Movement of the plunger 15 to the retracted position opens the permissive control valve 33 to allow hydraulic fluid to flow toward the cylinder 19 for moving the locking pins 18 to the extended position. In other embodiments electrical components may determine proper seating and open the permissive control valve 33 to allow hydraulic fluid to flow toward the locking pins 18.
As generally described above, in some embodiments the plunger 15 is positioned to physically engage a portion of the implement 11 when the implement is properly seated against the coupler assembly 10. In some embodiments, the plunger 15 is positioned to extend outward from the front portion of the coupler assembly 10 so that a rearward portion of the implement 11 engages the plunger 15 when property seated against the face of the coupler assembly 10. Multiple plungers 15 may be positioned at different locations on the coupler assembly 10 to help ensure multiple portions of the implement 11 are property seated with the coupler assembly 10.
The coupler assembly 10 further includes an indicator 16 in communication with the coupler assembly's hydraulic system 50. In some embodiments the indicator 16 is configured to visually indicate a first sign 32 to the operator and a second sign 34 to the operator. The first sign 32 is indicative of the implement 11 not being properly attached to the coupler assembly 10 and the second sign 34 is indicative of the implement 11 being properly attached to the coupler assembly 11. In some embodiments the indicator 16 is a visual indicator which provides an electronic sign or signal, such as a colored light or textual message, to communicate the first sign 32 and the second sign 34. In some embodiments the indicator 16 is a visual indicator which is member such as a flag, bladder, balloon, or pin which physically moves between a first position to indicate the first sign 32 and a second position to indicate the second sign 34. The member may have colors or shapes which help the operator identify whether the indicator is communicating the first sign 32 or the second sign 34. In embodiments where the indicator 16 is a bladder or balloon, when the predetermined conditions are met for a proper connection between the coupler 10 and the implement 11, hydraulic fluid flows into the bladder or balloon causing movement or inflation that is visible to the operator. In some embodiments the indicator 16 is an audio indicator configured to provide a noise to indicate a first sign 32 and/or the second sign 34 to the operator. In some embodiments the indicator 16 is configured to provide other sensory stimuli to the operator to indicate a first sign 32 and/or the second sign 34, such as a vibrating steering wheel, seat, or joystick.
In
Generally,
To relieve pressure from the cylinder 19 and unlock the position of the locking pins 18, pilot lines 27, 29 when pressurized, convey pressure to unseat the check valve 30, 28 on the return pressure (vent) side of the system allowing fluid to return to the tank 22. Fluid only passes through pilot lines 27, 29 when the operator actuates either extension or retraction to unseat the check valve 30, 28 on the opposite (return pressure) hydraulic line P1, P2. The pilot lines 27, 29 will not unseat the check valves 30, 28 without action by the operator. System pressure through line P1 extends the locking pins 18 outward toward the extended position (if the proper conditions described herein are met). Line P3 connects the hydraulic cylinder 19 and the indicator 16. Line P3 is in fluid communication with the hydraulic cylinder 19 through junction ports 46 so that system pressure through line P1 enters line P3 only after the locking pins 18 have moved to their extended position. Once the pistons 48 of each locking pin 18 extend past their respective junction ports 46 (from a first side of the junction port 46 to a second side of the junction port 46) to line P3, then system pressure travels through line P3 and moves the indicator 16 against the biasing force provided by the biasing member 44 from the first position showing the first sign 32 to the second position showing the second sign 34. The indicator 16 moves to indicate the second sign 34 because the hydraulic system pressure through line P3 is greater than the biasing force acting on the indicator 16.
A pressure relief valve 38 helps to ensure the indicator 16 does not remain in the second position (continue to show the second sign 34) during retraction when system pressure is introduced into line P2 and line P1 is vented to tank 22. The pressure relief valve 38 has an open position and a closed position and is biased in the closed position. In the open position, the pressure relief valve 38 allows fluid to pass from line P2 to line P1 along line 42, then back to tank 22. The pressure necessary to overcome the biasing force and move the pressure relief valve 38 to the open position is less than the pressure necessary to move/keep the indicator 16 in the second position. Therefore, when P2 is pressurized and P1 is vented, pressure in P3 never reaches full system pressure, but is relieved at the relief set point pressure of relief valve 38, which, in turn, keeps P3 pressure less than needed to move the indicator 16 to the second position.
Having thus described the invention in connection with the preferred embodiments thereof, it will be evident to those skilled in the art that various revisions can be made to the preferred embodiments described herein without departing from the spirit and scope of the invention. It is my intention, however, that all such revisions and modifications that are evident to those skilled in the art will be included with in the scope of the following claims.
