Control valve means for fluid motors

Claim 2

Valve instrumentalities for governing operation of a fluid motor, characterized by: A. a control valve having a pair of service passages for connection with the opposite sides of a fluid motor, and a valve element movable through a number of metering positions to full flow operating positions concurrently communicating either of the service passages with pressure fluid supply means and the other service passage with fluid return means in the valve, from a hold position closing off said service passages from the fluid supply and return means; B. a pressure reducing valve mechanism for each service passage, having a passageway through which exhaust fluid from the governed motor flows to the fluid return means through the associated service passage in one of said full flow operating positions of the valve element, and a pressure responsive valve member actuatable in a passageway resticting direction whenever the pressure of exhaust fluid in the associated service passage is caused to exceed that of fluid in the return means by a substantially small amount as a result of the valve element occupying one of said metering position, to thereby maintain the pressure of exhaust fluid in the associated service passage at a substantially uniformly low value above that of fluid in the return means; C. and means cooperable with each pressure reducing valve mechanism and rendered operative in response to pressure of fluid in said pressure fluid supply means for effecting flow of such supply fluid through the associated service passage to the governed motor substantially without interference from said pressure reducing valve mechanism.

Claim 3

The combination of claim 1, wherein said last named means comprises a chamber communicated with the pressure fluid supply passage means, and a plunger which is connected with said valve member and which operates in said chamber to be held by pressure of supply fluid therein in a position blocking movement of said valve member toward a passageway restricting position.

Claim 4

a valve member actuatable in one direction to restrict flow of motor exhaust fluid through said passageway,

Claim 5

a valve member actuatable in one direction to restrict flow of motor exhaust fluid through said passageway,

Claim 6

and a spring to yieldingly urge the valve mmber toward an inactive position affording substantially free flow of motor exhaust fluid through said passageway; B. means rendered operative in response to the rise in service passage pressure produced by movement of the control valve element to one of its said exhaust flow metering positions for effecting actuation of the pressure reducing valve member in the flow restricting direction an extent depending upon the magnitude of the pressure present in the service passage; C. and means rendered operative in response to the pressure of supply fluid flowing to the service passage in said first position of the control valve element, for effecting flow of such supply fluid through said passageway and to the governed motor substantially without interference from the pressure reducing valve member.

Claim 7

and a spring to yieldingly urge the valve mmber toward an inactive position affording substantially free flow of motor exhaust fluid through said passageway; B. means rendered operative in response to the rise in service passage pressure produced by movement of the control valve element to one of its said exhaust flow metering positions for effecting actuation of the pressure reducing valve member in the flow restricting direction an extent depending upon the magnitude of the pressure present in the service passage; C. and means rendered operative in response to the pressure of supply fluid flowing to the service passage in said first position of the control valve element, for effecting flow of such supply fluid through said passageway and to the governed motor substantially without interference from the pressure reducing valve member.

Claim 8

In combination with a control valve for a fluid motor, having a valve element movable to a first position to communicate a service passage with supply passage means, and movable to a second position to provide for flow of motor exhaust fluid through the service passage to return passage means, said control valve element being movable through a range of metering positions short of said second position thereof to provide for restricted flow of motor exhaust fluid from the service passage to the return passage means in an amount which increases as the valve element approaches its said second position: A. a pressure reducing valve mechanism having

Claim 9

In combination with a control valve for a fluid motor, having a valve element movable to a first position to communicate a service passage with supply passage means, and movable to a second position to provide for flow of motor exhaust fluid through the service passage to return passage means, said control valve element being movable through a range of metering positions short of said second position thereof to provide for restricted flow of motor exhaust fluid from the service passage to the return passage means in an amount which increases as the valve element approaches its said second position: A. a pressure reducing valve mechanism having

Claim 10

The combination of claim 3, further characterized by: A. said control valve element being movable to a load holding third position to close off the service passage from the fluid supply and return passage means; B. and said pressure reducing valve mechanism also being operable to maintain the pressure in the service passage at said low value in said load holding position of the valve element.

Claim 11

The combination of claim 3, wherein said last named means comprises: A. means connected with the service passage providing a bypass around the pressure reducing valve mechanism, through which pressure fluid can flow to the governed motor in said first position of the valve element; B. and a check valve in said bypass to block reverse flow of fluid through the bypass.

Claim 12

Valve instrumentalities for governing flow of pressure fluid to and from a fluid motor via a service line connectable therewith, characterized by: A. a directional control valve having fluid supply and return passage means, a service passage for connection with the service line to form a part thereof, and a valve element movable from a hold position to first and second operating positions to respectively communicate the service passage with the fuild supply and return passage means, said valve element being movable through a range of metering positions to provide for return flow of motor exhaust fluid from the service passage to the return passage means in an amount which increases with movement of the valve element toward said second position thereof and reaches maximum thereat; B. a pressure reducing valve mechanism having a valve member to regulate flow of motor exhaust fluid through the service line to the service passage, said valve member being urged by a spring toward a normally inactive position but being actuatable out of said position in a direction to restrict return flow of motor exhaust fluid through said service line to the service passage under force exerted on the valve member counter to the force of its spring; C. means for monitoring the pressure of fluid present in the service passage and rendered operative by the valve element in said metering positions thereof to translate said monitoring pressure into said actuating force on the valve member whenever said monitored pressure rises to a predetermined value above that of fluid in the return passage means; D. and means rendered operative by supply fluid pressure, in said first operating position of the valve element, for assuring substantially free flow of pressure fluid through the service line to a fluid motor connected therewith.

Claim 13

Valve instrumentalities for governing flow of pressure fluid to and from a fluid motor via a service line connectable therewith, characterized by: A. a directional control valve having fluid supply and return passage means, a service passage for connection with the service line to form a part thereof, and a valve element movable from a hold position to first and second operating positions to respectively communicate the service passage with the fuild supply and return passage means, said valve element being movable through a range of metering positions to provide for return flow of motor exhaust fluid from the service passage to the return passage means in an amount which increases with movement of the valve element toward said second position thereof and reaches maximum thereat; B. a pressure reducing valve mechanism having a valve member to regulate flow of motor exhaust fluid through the service line to the service passage, said valve member being urged by a spring toward a normally inactive position but being actuatable out of said position in a direction to restrict return flow of motor exhaust fluid through said service line to the service passage under force exerted on the valve member counter to the force of its spring; C. means for monitoring the pressure of fluid present in the service passage and rendered operative by the valve element in said metering positions thereof to translate said monitoring pressure into said actuating force on the valve member whenever said monitored pressure rises to a predetermined value above that of fluid in the return passage means; D. and means rendered operative by supply fluid pressure, in said first operating position of the valve element, for assuring substantially free flow of pressure fluid through the service line to a fluid motor connected therewith.

Claim 14

The valve instrumentalities of claim 6 wherein said last named means comprises: A. means defining a piston connected with said valve member and which can be held by fluid pressure force in a position blocking movement of the valve member toward its active position; B. and means for translating pressure of supply fluid into said force on the piston.

Claim 15

The valve instrumentalities of claim 6, wherein wherein said last named means comprises: A. a passage connecting with the service passage and through which supply fluid can flow in bypass relation to said valve member in said first operation position of the control valve element; B. and a check valve in said bypass passage to block flow of exhaust fluid therethrough to the return means in said second operating position of the control valve element.

Claim 16

The valVe instrumentalities of claim 6, further characterized by: A. said pressure reducing valve mechanism comprising a pair of chambers, one of which is communicated with said service passage to be pressurized by motor exhaust fluid therein; B. said valve member having portions disposed in said chambers, and being movable toward an active position restricting said passageway in response to pressure of motor exhaust fluid in said one chamber; C. and means venting the other of said chambers.

Claim 17

The combination of claim 9, wherein said last named means comprises a vent line at all times connecting said other chamber with pressure fluid supply passage means in the control valve.

Claim 18

The combination of claim 9, wherein said venting means communicates with the pressure fluid supply passage means in tne control valve.

Claim 19

The combination of claim 9, wherein said venting means comprises a duct at all times communicated with the fluid return means.

Claim 20

The combination of claim 9, wherein said venting means comprises a duct which communicates with the pressure fluid supply passage means in the control valve and further comprises a passage in the control valve element effective only in the hold position thereof to communicate the pressure fluid supply passage with the fluid return means.

Claim 21

The combination of claim 9, wherein said venting means comprises a duct communicating said other chamber with the pressure fluid supply passage means, and wherein passage means in the control valve element communicates the pressure fluid supply passage means with the return means in the hold position of the valve element.