Abstract:
A decompression block assembly for coupling a source of hydraulic pressure to a hydraulically operated attachment. The assembly includes a valve body defining first and second ports that are fluidly connected to first and second couplers that are connectable to hoses of the attachment. The valve body includes a shuttle chamber having an opposed valve seats and a valve element engageable with the valve seats depending on residual pressure in fluid passages. A release member is operable to connect the shuttle valve to a drain port to discharge residual pressure in one or both fluid passages communicating with the attachment. The release member, when operated, opens a check valve in order to discharge residual pressure.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 62/169,183, filed Jun. 1, 2015, the subject matter of which is incorporated herein in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to fluid coupling devices and, in particular, to a decompression block used with quick couplers to enhance the functionality of quick coupling hydraulic systems. 
       BACKGROUND OF THE INVENTION 
       [0003]    A trend in the construction industry has been to utilize smaller, more versatile machinery on the job-site. For example, mini-excavators and skid-steer loaders are often used to perform a variety of tasks. In many cases, a skid-steer loader or mini-excavator is equipped with an attachment for performing a particular task. Such attachments are typically powered by an auxiliary hydraulic circuit on the skid-steer loader or mini-excavator. 
         [0004]    Numerous attachments exist for performing a variety of tasks. For example, attachments exist for allowing a skid-steer loader to be used as a backhoe, an earth auger, an angle broom, a drop hammer, a snowplow, a brush saw, etc. These attachments typically are designed to be quickly connected and disconnected from the skid-steer loader or other machine by an operator on the job-site. The ability to quickly change attachments on the job-site makes these smaller machines more versatile than larger machines. 
         [0005]    Quick-disconnect couplers are often used to allow quick and convenient connection and disconnection of hydraulic lines of an attachment to the auxiliary hydraulic circuit of the machinery. These types of couplers also are often used on construction equipment or agricultural tractors for connecting auxiliary circuits that power work tools or pull behind implements. The couplers can be mounted at the end of piping, hoses or in manifolds in positions that are easily accessible to the operator when connecting an attachment. Generally the couplings are in close proximity to each other. 
         [0006]    In general, an operator manually connects the hydraulic lines of an attachment to the auxiliary hydraulic circuit of the machine. To form the connection, a plug-like coupler part and a socket like coupler part are customarily used to couple the supply/return lines. In many instances, the connection is made while internal hydraulic pressure exists in one or both of the lines to be connected. Such internal hydraulic pressure can be residual hydraulic pressure build up in the hydraulic circuit or may be due to pressure in an attachment due to thermal expansion. Regardless, hydraulic pressure in the circuit can make forming the connection more difficult, especially with standard quick-disconnect couplers. 
       Disclosure of the Invention 
       [0007]    The present invention provides a new and improved decompression coupling block which can be operated to release residual pressure in the hydraulic system to enable hydraulic attachment hose assemblies to be coupled and decoupled from the hydraulic system. The decompression coupling block includes a pair of hose couplers by which hose assemblies are releasably coupled to the block. The decompression block includes ports that communicate with associated couplers. As is conventional, the ports are connected to control valving, such as a directional valve forming part of the hydraulic system. The valving selectively applies fluid pressure to one or both ports which, in turn, communicate the fluid pressure to the couplers and to a hydraulically operated attachment that is connected to the decompression block by associated hose assemblies. 
         [0008]    According to the invention, the decompression block includes a shuttle valve that includes a pair of seats and a shuttle member located in a shuttle valve chamber. The shuttle valve member is engageable with one or the other seat. In the illustrated embodiment, the shuttle valve member comprises a ball. 
         [0009]    In the exemplary embodiment, one seat of the shuttle valve communicates, via a first branch passage, with a first fluid pressure port-to-coupler passage that fluidly connects a first port with an associated coupler. The other seat of the shuttle valve communicates, via a second branch passage, with a second fluid pressure port-to-coupler passage that connects a second port with an associated coupler. Fluid pressures in the first and second port/coupler passages communicated to the shuttle valve chamber via the first and second branch passages urge the shuttle member towards one of the seats, depending on the relative pressures between the first and second port-to-coupler passages. If, for example, the first branch passage has a higher pressure than the second branch passage, the shuttle member or ball will be urged towards the seat associated with the second branch passage and inhibit fluid pressure from flowing from the first branch passage to the second branch passage. 
         [0010]    The shuttle valve chamber communicates with a fluid pressure discharge valve via a branch return passage. In the illustrated embodiment the pressure discharge valve comprises check-like valve that includes a ball that is spring biased towards an associated seat. The seat communicates with a return passage or conduit such that when the ball is moved off its associated seat, fluid pressure in the shuttle valve chamber will be allowed to flow to the return passage or return conduit, which is typically connected to the tank of the hydraulic system. When the ball engages the seat the flow of fluid pressure from the shuttle valve chamber to the return passage/conduit is blocked. 
         [0011]    According to the invention, when hose assembles are to be connected to, or disconnected from, the decompression coupler block, residual fluid pressures in the block i.e. in the port-to-coupler passages are discharged to the tank by the manipulation of a pressure relief actuating member by an equipment operator. In the illustrated embodiment, the pressure relieving operating member is pin-like and is slidably held by the decompression coupling block. The operating pin includes a frustoconical or tapered surface which is engageable with the ball that forms part of the pressure discharge valve. 
         [0012]    In one embodiment, fluid pressure is relieved and discharged to the tank via the return passage/conduit by pulling the pressure relief operating pin which causes the frustoconical segment formed on the pin to engage and then raise a pressure discharge valve element off its seat and allow fluid pressure in the shuttle valve chamber to be discharged to the return conduit. In another embodiment, the pressure relief operating pin is pushed inwardly and it too includes a frustoconical surface or segment that engages and unseats the valve element when the pin is moved laterally allowing pressure in the shuttle valve chamber to be discharged to a return conduit. In both embodiments the pressure relief operating pin is biased toward a ball disengaged position by a suitable spring. In one embodiment, the valve element is a ball and in another embodiment, the valve element is a poppet. 
         [0013]    The present invention provides a hydraulic connection assembly or decompression control assembly that is positioned between an onboard hydraulic system of the vehicle and a hydraulically operated attachment. The disclosed assembly has a discharge control which discharges residual pressure when hose assemblies from the hydraulically operated attachment are connected to or disconnected from the vehicle mounted hydraulic system. The assembly includes a valve body that is attachable to the vehicle and which includes first and second hydraulic ports and at least one drain port that is connected to a return line that communicates with a hydraulic tank forming part of the vehicle hydraulic system. 
         [0014]    The valve further includes first and second hydraulic couplers that are connectable to first and second hydraulic lines extending from the hydraulically operated attachment. The valve body defines a first flow passage by which the first port is communicated with the first coupler and a second flow passage for communicating the second port with the second coupler. The valve body defines the drain passage communicating with the drain port. The assembly includes a shuttle valve chamber defining spaced apart, valve seats and a shuttle valve element located within the shuttle chamber engageable with the first or second valve seats. The first valve seat communicates with the first flow passage and the second valve seat communicates with the second flow passage. Under predetermined operating conditions, the shuttle chamber communicates with the drain passage. A spring biased check valve controls the communication of the shuttle chamber with the drain passage. A release member is operatively engageable with the spring biased check valve and when moved to a release position, unseats the check valve to allow the shuttle chamber to communicate with the drain passage. The shuttle valve element is engageable with the second seat when a fluid pressure in the first slow passage is greater than the fluid pressure in the second flow passage and the shuttle valve element is engageable with the first seat when a fluid pressure in the second flow passage is greater than a fluid pressure in the first flow passage. 
         [0015]    In one disclosed embodiment, the release member is pulled axially in order to cause the engagement of a tapered segment with the spring biased check valve eventually unseating the check valve to communicate residual pressure to the drain passage. In an alternate embodiment, the release member is pushed to move the member axially in order for a tapered segment forming part of the release member to engage and unseat the spring biased check valve. 
         [0016]    In a third embodiment, the release member is rotated about an axis in order to unseat the spring biased check valve. In this embodiment, the release member includes a segment having flat and an arcuate portion. When the flat is aligned with the spring biased check valve, the valve element forming part of the check valve is allowed to engage its associated seat. When the release member is rotated, the arcuate portion engages the check valve, causing it to disengage its seat and allowing residual fluid pressure to be discharged into the drain passage. 
         [0017]    Additional features of the invention will become apparent and a fuller understanding obtained by reading the following detailed description made in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0018]      FIG. 1  is a schematic representation of a hydraulic system which includes a decompression coupler block constructed in accordance with a preferred embodiment of the invention; 
           [0019]      FIGS. 2A and 2B  are front and rear perspective views of a decompression coupling block constructed in accordance with one embodiment of the invention; 
           [0020]      FIG. 3  is a front perspective view of a decompression coupling block constructed in accordance with another embodiment of the invention; 
           [0021]      FIG. 4  is a front perspective view of a decompression coupling block constructed in accordance with another embodiment of the invention; 
           [0022]      FIG. 5  is a sectional view of the decompression coupling blocks shown in  FIGS. 2A, 3 and 4 ; 
           [0023]      FIG. 5A  is a top view of the sectioned decompression coupling block shown in  FIG. 5 ; 
           [0024]      FIG. 6A  is a sectional view of the decompression coupling block shown in  FIG. 2A ; 
           [0025]      FIG. 6B  is a sectional view of the decompression coupling block shown in  FIG. 3 ; 
           [0026]      FIG. 6C  is a sectional view of the decompression coupling block shown in  FIG. 4 ; 
           [0027]      FIG. 7A  illustrates, schematically, the decompression coupling block shown in  FIG. 2A ; 
           [0028]      FIG. 7B  illustrates, schematically, the decompression coupling block shown in  FIG. 3 ; 
           [0029]      FIGS. 8A and 8B  are additional partially sectional views of the decompression coupling block shown in  FIG. 2A ; 
           [0030]      FIG. 9A  is an enlarged, partially fragmentary view of the decompression coupling block shown in  FIG. 8A ; and, 
           [0031]      FIG. 9B  is a partial fragmentary view showing another embodiment of a valve element forming part of the decompression block. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]    Referring now to the drawings in detail, and initially to  FIG. 1 , an exemplary hydraulic circuit  10  generally comprises a pump  14 , a coupler assembly  16 , and an attachment  22 . In the illustrated embodiment, which is particularly suited for use in a mini-excavator, skid-steer loader, or similar type of machinery, there is a directional control valve  26  that directs pressurized fluid from the pump  14 , which draws fluid from a tank  28 , to either hydraulic line  30   a  or  30   b  depending on the desired direction of operation of the attachment  22 . Hydraulic lines  30   a  and  30   b  are connected to the coupler system  16  which includes a decompression block  18 , constructed in accordance with the present invention. More particularly, the lines  30   a  and  30   b  are connected to block ports  34   a  and  34   b , respectively. Block ports  34   a  and  34   b  are connected internally via the block  18  to block couplers  38   a  and  38   b , respectively. 
         [0033]    In the illustrated embodiment, the coupler  38   a  is a male fitting and coupler  38   b  is a female fitting, this being in accordance with conventional practice. Companion or mating attachment couplers  42   a  and  42   b  connect hydraulic lines  46   a  and  46   b  of the attachment  22  to the block couplers  38   a  and  38   b . A motor case drain port  50  in the block  18  is connected internally with a motor case drain line coupler  54 . The motor case drain line coupler  54  is coupled to a mating motor case drain line coupler  55  and motor case drain line  56 . 
         [0034]    The motor case drain port  50  is connected to the tank  28  via line  58 . As will be described in further detail herein, the motor case drain port  50  also is connected internally with the coupler ports  34   a  and  34   b  and couplers  38   a  and  38   b  for releasing pressure from the system  10 . 
         [0035]    In operation, the pump  14  provides pressurized fluid from the tank  28  to the directional control valve  26 . Depending on the desired direction of operation, the directional control valve  26  directs the pressurized fluid to either hydraulic line  30   a  or  30   b . By directing the fluid to one or the other of the hydraulic lines  30   a  and  30   b  the direction of operation of the attachment  22  can be reversed. Thus, either hydraulic line  30   a  or  30   b  can supply fluid to the attachment  22  while the other hydraulic line not supplying fluid acts as a return line to return the fluid to the tank  28 . The motor case drain is provided for use with auxiliary equipment that require a low pressure return, such as for draining fluid from a motor case in the auxiliary equipment. However, as will become apparent from the following description, the motor case drain port  50  and line  58  serve a further function of providing a low pressure return path to the tank  28  for fluid bled from the high pressure flow lines by means of the herein described decompression valving and associated circuit constructed in accordance with a preferred embodiment of the invention. 
         [0036]    As previously mentioned, a common practice is to use a variety of interchangeable attachments  22  with an auxiliary hydraulic system  10  of a skid-steer loader or similar type of machinery. Thus, the coupler block  18  of the hydraulic system  10 , which functions as a coupling system, provides a convenient interface for changing attachments  22  by providing a single location for connecting and disconnecting the hydraulic lines of the attachment  22  to the auxiliary hydraulic system  10 . Residual pressure, however, often remains in the system  10  after an attachment  22  is operated, and this can make it difficult to disconnect and/or connect the attachment  22 . In addition spillage of hydraulic oil can also occur, which is undesirable. Further, thermal pressure buildup in the attachment  22  and/or auxiliary hydraulic system  10  can be an impediment to connecting an attachment  22 . 
         [0037]      FIGS. 2A, 2B, 3 and 4  illustrate three preferred embodiments of a decompression coupling block constructed in accordance with a preferred embodiment of the invention. The embodiment of the decompression coupler block  18  shown in  FIG. 2  includes a pressure release member  100  which is pulled in order to release residual pressure within the coupling block  18 . In the embodiment of the coupling block  18 ′ shown in  FIG. 3 , a pressure release member  100 ′ is pushed in order to release residual pressure within the decompression block. In the embodiment shown in  FIG. 4 , a pressure release member  100 ″ is rotated. 
         [0038]    To simplify the description, components common to all three embodiments will be given the same reference character. As seen in  FIG. 2A , the decompression block  18  includes quick coupling fittings  38   a ,  38   b  by which the hoses of an associated attachment  22  ( FIG. 1 ) are attached to the coupling block  18 . In the illustrated embodiment the fitting  38   a  is a male fitting and the fitting  38   b  is a female fitting. The couplers may be of various configurations that are known in the art. 
         [0039]    The view shown in  FIG. 2B  is applicable to all three embodiments. As seen in  FIG. 2B , the decompression block  18  (in all three embodiments) includes fluid pressure ports  34   a ,  34   b  which are suitably connected to the directional valve  26  shown in  FIG. 1  or other suitable component of the hydraulic system  10 . Fluid pressure communicated to the ports  34   a ,  34   b  are communicated to the associated couplers  38   a ,  38   b  (shown in  FIG. 2 ) and to hose assemblies attached to the couplers. In general, rigid piping such as metal conduits are connected to the ports  34   a ,  34   b  and, as seen in  FIG. 1 , are connected to a hydraulic control device such as a directional valve  26 . 
         [0040]    According to the invention, prior to coupling a hose assembly to the decompression block  18  or decoupling a hose from the compression block  18 , residual pressure within the decompression block is released and discharged to the drain conduit  58 , which is shown in  FIG. 1 . With the disclosed decompression block, uncontrolled release or leakage of hydraulic fluid is substantially reduced or inhibited. 
         [0041]      FIG. 7A  illustrates, schematically, the operation of the pressure relief/discharge function. The decompression block  18  includes a shuttle valve  120 , which includes a pair of opposed valve seats  124   a ,  124   b . A shuttle ball  126  is engageable with either seat. The seat  124   a  communicates with the fluid pressure in a passage  130  which communicates the port  34   a  with the upper coupler  38   a  (as viewed in  FIG. 7 ) via a branch passage  132 . The seat  124   b  communicates the fluid pressure in a passage  140 , which communicates the port  34   a  with the lower coupler  38   b  (as viewed in  FIG. 7A ) via branch flow passage  142 . The shuttle valve  120  includes a chamber  144  which communicates with a spring biased ball valve  150  via discharge passage  152 . As seen best in  FIGS. 8A and 8B , the ball valve  150  includes a ball  150   a  that is urged towards an associated seat  150   b  by a compression spring  151 . As seen in  FIG. 7A , the pressure relief operating member  100  is transversely movable and slidably received within the decompression block  18 . When the member  100  is pulled by the pull-ring  154 , a distal end of the member  100 , which includes a frustoconical or tapered section  156  engages the ball  150   a  and pushes it off its seat  150   b , thereby relieving any pressure in the branch passage  152 . The seat  150   b  of the ball valve  150  communicates with connected internal discharge passages or return passages  158 ,  158   a  which allows any fluid discharged through the ball valve  150  to return to the tank  28  via return passage  158   a  which communicates with the return line  58 . 
         [0042]    The shuttle valve  120  operates to block the flow of fluid pressure from one coupler to another. In particular, if the upper coupler passage  130  has a residual pressure that is higher than the residual pressure in the lower coupler passage  140 , the ball  126  will be urged towards the right (as viewed in  FIG. 5A ) and engage the seat  124   b , thus blocking flow to the lower coupler passage  140 . When the release member  100  is pulled, thereby unseating the ball valve  150   a  from its associated seat  150   b , any fluid pressure in the fluid passage  130  and the branch passage  132  will be discharged to the drain conduit  58  ( FIG. 1 ). If, after discharging pressure from the upper coupler passage  130 , a residual pressure exists in the lower coupler passage  140 , this residual pressure will shift the ball  126  valve towards the left, thereby causing the ball  126  to engage the seat  124   a  and the residual pressure in the branch conduit  142  will be discharged through the ball valve  150  to the return conduit  58 . 
         [0043]      FIGS. 5 and 5A  illustrate the mechanical details of the components shown schematically in  FIG. 7A . As seen in these Figures, the shuttle chamber  144  is formed by a drilled passage indicated generally by the reference character  151 . The drilled passage  151  is a multi-step bore, one of the steps defining the seat  124   b  that is engageable by the ball valve  120 . The seat  124   a  is formed by a threaded insert  153  which is threaded into a threaded segment of the bore  151  and which includes an O-ring  155  which seal the insert  153  to the valve body. The chamber  144  is defined by a bore segment that extends between the seats  124   a ,  124   b . The passages  132 ,  142 , which communicate with the respective seats  124   a ,  124   b  are formed by drill passages shown in  FIG. 5  which include intersecting drilled passages  132 ,  132   a  and intersecting drill passages  142 ,  142   a , as seen best in  FIG. 5 . Suitable plugs  157  are used to close and seal the drilled passages. As seen best in  FIG. 5A , an internal passage (not shown) in the insert  153  communicates with the passage  132   a  via a cross-drilled passage  132   b . When the ball  126  is not engaging the seat  124   a , the chamber  144  communicates with the passage  132   a  via the internal passage in the insert  153  and the cross passage  132   b.    
         [0044]      FIGS. 8A and 8B  are additional sectional views of the decompression block and illustrate the details of the pressure release member  100  and associated components that it interacts with. As seen in these two Figures, the release member  100  is slidably mounted within a multi-step bore  159  machined into the valve body. A seen in  FIG. 8A , a spring  160  biases the release member  100  towards the left, as viewed in  FIG. 8A . The release member  100  includes a tapered or frustoconical segment  156 . The ball valve  150 , which was described previously, includes a check ball  150   a  which is engageable with the seat  150   b . A peripheral segment of the ball  150   a  extends into the bore  159  so that when the release member is pulled to the right, the tapered segment  156  eventually engages the ball periphery and pushes it downwardly (as viewed in  FIG. 8A ) thus causing it to disengage its associated seat  150   b  (the disengaged position is shown in  FIG. 9A ). When the check ball  150  disengages its seat, it communicates the return passage  152  with a region  159   a  of the bore  159  which, in turn, communicates with the return passage  158   a  (shown in  FIG. 7A ). When the pull ring  154  is released, the spring  160  returns the release member to the position shown in  FIG. 8A  at which the ball  150   a  engages its associated seat  150   b . In the preferred embodiment, grooves  179  in the release member ( FIGS. 8A and 9A ) facilitate the communication of the region  159   a  with the return passage  158   a.    
         [0045]    The alternate embodiments of the decompression block shown in  FIG. 3  and  FIG. 4  operate in a similar fashion. In the embodiment shown in  FIG. 3 , the pressure relief operating member  100 ′ is pushed and moved inwardly with respect to the decompression block  18 . The release member  100 ′ has an end portion  154   a  that extends outside the valve body ( FIG. 6B ). As seen best in  FIGS. 6B and 7B , the operating member  100 ′ includes a tapered or frustoconical, camming surface  156 ′ which engages and unseats the ball valve  150   a  when the operating member  100 ′ is moved towards the left as viewed in  FIG. 7B . In both embodiments, the shuttle valve  120  operates to communicate the coupler passage with the higher pressure to the discharge passage  158  when the ball  150   a  is unseated. 
         [0046]      FIGS. 4 and 6C  illustrate the third alternate embodiment for the invention. In this embodiment, an operating member  100 ″ is rotated by an operating lever  154 ′ in order to release the residual pressure. As seen best in  FIG. 6C , the operating member  100 ″ includes a segment  156 ′″ which includes a flat  167 . As seen in  FIG. 6C , with the flat  167  in the illustrated position, the ball  150   a  is disengaged by the operating member and is allowed to engage its associated seat  150 B (shown best in  FIG. 8A ). By rotating the operating member  100 ′″ using the associated lever  154 ′, the ball  150   a  is unseated as the flat moves out of its position shown in  FIG. 6C  and a circular or arcuate portion of the operating member  100 ″ engages the ball  150   a , thus pushing it off its seat  151   b . After the residual pressure is released, the operating lever  154 ′ is rotated counterclockwise so that the flat  167  is the position shown in  FIG. 6C , at which the ball  150   a  is allowed to reengage its associated seat  150   b . The present invention also contemplates the use of a suitable spring, such as a torsion spring to cause the operating member  100 ″ to return to its normal operating position shown in  FIG. 6C  whenever the lever  154 ′ is released. 
         [0047]      FIGS. 8A, 8B and 9A  show additional details of the pull-type pressure relief member  100 . As seen best in  FIG. 8A , the plunger  100  is spring biased towards the left as viewed in  FIG. 8A . To release residual pressure within the decompression block, the pull-ring  154  attached to the release pin  100  is pulled and when sufficient force is applied to the pull ring to overcome the spring force applied by the spring  160 , the release pin  100  moves rightwardly causing the tapered surface  156  to engage and unseat the spring biased check ball  150   a . Unseating the check ball  150   a  allows fluid pressure to be discharged into the region  159   a  surrounding the frustoconical segment of the release pin member  100 , which communicates with the discharge passage  158  (the passage  158  can be seen in  FIG. 8B  and is shown schematically in  FIGS. 7A and 7B ). 
         [0048]      FIG. 9B  discloses information regarding an alternate embodiment of the invention. In particular, the embodiments shown in  FIGS. 6A, 6B and 6C  include a ball  150 A as the valve element for controlling the discharge of fluid to the return port  50  (via the return passages  158 ,  158   a ).  FIG. 9B  illustrates a poppet  150   a ′ that may be substituted for the ball  150   a . Those skilled in the art will recognize that to substitute the poppet  150   a ′ for the ball  150   a , slight modifications will have to be made to the valve  150  so that the poppet  150   a ′ is reciprocally movable towards and away from an associated seat similar to the seat  150   b . In addition, the poppet  150   a ′ would be spring biased towards engagement with its associated seat. When seated, a top surface  173  of the poppet  150   a ′ be engageable by the tapered surface  156  when the pin  100  is moved to the right, as viewed in  FIG. 8A . 
         [0049]    Although the invention has been described with a certain degree of particularity, it should be understood that those skilled in the art can make various changes to it without departing from the spirit or scope of the invention as hereinafter claimed.