Directional control valve

Claim 2

A directional control valve comprising a main housing having first and second bores each intersected axially therealong by inlet, motor, and return passages respectively adapted fOr connection with a pump, a fluid motor, and a tank, and having a bypass also intersecting said bores communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; said return passage being common to said bores and including a portion extending generally parallel to said bores between such one face and said second bore; a spool reciprocable in each bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having a pair of openings in such one end face which communicate with said portion of said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor, and return passages of which said auxiliary bypass and return passages register respectively with said opening and said pair of openings in such one end face of said main housing; said auxiliary return passage having a pair of branches registering with said pair of openings and a connecting portion into which said auxiliary bypass passage opens downstream of said auxiliary housing bore; an auxiliary spool reciprocable in said auxiliary housing bore from a neutral position whereat said auxiliary bypass passage is open to said connecting portion and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or one of said auxiliary return passage branches, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage connecting portion whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said pair of openings in said main housing when said spools are in neutral position.

Claim 3

The directional control valve of claim 1 wherein said auxiliary housing is clamped between said main housing and a cap member by fastening means engaged with said cap member and said main housing, said cap member and auxiliary housing defining therebetween said connecting portion which intercommunicates the downstream portion of the auxiliary bypass passage with said auxiliary return passage branches.

Claim 4

The directional control valve of claim 1 wherein said main housing has therein a flow control valve which provides a flow control orifice in said bypass passage downstream of said first bore; said flow control valve having a movable flow control member which communicates said bypass passage with said return passage to divert excess flow to said return passage.

Claim 5

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operAting positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a relief valve therein which is operative to communicate said inlet passage with said return passage when said inlet passage pressure exceeds a predetermined value during the time that said spool is in said one operating position; said relief valve having plunger means exposed to fluid pressure in said bypass passage downstream of said spool when said auxiliary spool is in said one operating position effective to increase the effective seat area of said relief valve thus to relieve pressure in said inlet passage at less than such predetermined value.

Claim 6

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operAting positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a relief valve therein which is operative to communicate said inlet passage with said return passage when said inlet passage pressure exceeds a predetermined value during the time that said spool is in said one operating position; said relief valve having plunger means exposed to fluid pressure in said bypass passage downstream of said spool when said auxiliary spool is in said one operating position effective to increase the effective seat area of said relief valve thus to relieve pressure in said inlet passage at less than such predetermined value.

Claim 7

The directional control valve of claim 4 wherein said relief valve is of the pilot operated type in which the pilot relief valve member engages a seat of prescribed area; and wherein said plunger means has a seat of larger area which engages said pilot relief valve member and moves it away from the seat of such prescribed smaller area.

Claim 8

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a second bore therein and having a second spool reciprocable in said second bore to control actuation of a second fluid motor; said second bore being intersected axially therealong by said bypass passage and by said inlet and return passages and by a motor passage adapted for connection to such second motor; said second spool being reciprocable in said second bore from a neutral position whereat said bypass passage is open and whereat communication between said motor passage and said inlet and return passages is blocked to operating positions whereat said motor passage thereof is selectively communicated with said inlet passage or said return passage, said second spool in one of said operating positions blocking said bypass passage for buildup of pressure in said inlet passage for flow to said motor passage; said main housing having a flow control valve therein defining a flow control orifice in said bypass passage between said main housing spool bores and comprising a movable flow control valve member which opens communication between said bypass passage and said return passage to divert excess flow to said return passage when said main housing spools are in neutral position thus to control flow of fluid to said auxiliary valve.

Claim 9

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a second bore therein and having a second spool reciprocable in said second bore to control actuation of a second fluid motor; said second bore being intersected axially therealong by said bypass passage and by said inlet and return passages and by a motor passage adapted for connection to such second motor; said second spool being reciprocable in said second bore from a neutral position whereat said bypass passage is open and whereat communication between said motor passage and said inlet and return passages is blocked to operating positions whereat said motor passage thereof is selectively communicated with said inlet passage or said return passage, said second spool in one of said operating positions blocking said bypass passage for buildup of pressure in said inlet passage for flow to said motor passage; said main housing having a flow control valve therein defining a flow control orifice in said bypass passage between said main housing spool bores and comprising a movable flow control valve member which opens communication between said bypass passage and said return passage to divert excess flow to said return passage when said main housing spools are in neutral position thus to control flow of fluid to said auxiliary valve.

Claim 10

The directional control valve of claim 6 wherein said main housing has another flow control valve therein providing a flow control orifice in the inlet passage to said second spool and comprising a movable flow control member which opens communication between said inlet passage and said return passage to divert excess flow to said return passage.

Claim 11

The directional control valve of claim 1 wherein said motor passage intersecting said first bore in the other of said operating positions is communicated with said return passage via two separate paths of flow including a groove in said spool and openings in said spool and a load check valve within said spool; said spool in said first bore being of the three-way type for actuating a single acting fluid motor whereby fluid is rapidly exhausted from such single acting motor under conditions of a small load thereon.

Claim 12

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a second bore therein and having a second spool reciprocable in said second bore to control actuation of a second fluid motor; said second bore being intersected axially therealong by said bypass passage and by said inlet and return passages and by a motor passage adapted for connection to such second motor; said second spool being reciprocable in said second bore from a neutral position whereat said bypass passage is open and whereat communication between said motor passage and said inlet and return passages is blocked to operating positions whereat said motor passage thereof is selectively communicated with said inlet passage or said return passage, said second spool in one of said operating positions blocking said bypass passage for buildup of pressure in said inlet passage for flow to said motor passage; said second spool having therein a pressure actuated plunger valve which is exposed to pressure in said inlet passage to block return flow through said motor passage to said return passage except when said inlet pressure is of prescribed minimum value thus to prevent cavitation of a double acting fluid motor connected to said second spool.

Claim 13

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage, said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said main housing having a second bore therein and having a second spool reciprocable in said second bore to control actuation of a second fluid motor; said second bore being intersected axially therealong by said bypass passage and by said inlet and return passages and by a motor passage adapted for connection to such second motor; said second spool being reciprocable in said second bore from a neutral position whereat said bypass passage is open and whereat communication between said motor passage and said inlet and return passages is blocked to operating positions whereat said motor passage thereof is selectively communicated with said inlet passage or said return passage, said second spool in one of said operating positions blocking said bypass passage for buildup of pressure in said inlet passage for flow to said motor passage; said second spool having therein a pressure actuated plunger valve which is exposed to pressure in said inlet passage to block return flow through said motor passage to said return passage except when said inlet pressure is of prescribed minimum value thus to prevent cavitation of a double acting fluid motor connected to said second spool.

Claim 14

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said Auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage; said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said spools having switches associated therewith to energize a pump drive motor upon actuation of either spool from neutral position to an operating position.

Claim 15

A directional control valve comprising a main housing having a bore therein intersected axially therealong by inlet, motor, and return passages respectively adapted for connection with a pump, a fluid motor, and a tank, and having a bypass passage also intersecting said bore communicating at one end with said inlet passage and terminating at the other end in an opening in one face of said main housing; a spool reciprocable in said bore from a neutral position whereat said bypass passage is open to said inlet passage and whereat communication of said motor passage with said inlet and return passages is blocked to operating positions whereat said motor passage is selectively communicated with said inlet passage or return passage thus to control actuation of such fluid motor; said spool, when in one operating position communicating said inlet and motor passages with each other, being operative to close said bypass passage; said main housing having another opening in such one end face which communicates with said return passage; an auxiliary valve having a housing secured to such one end face of said main housing and having therein a bore intersected axially therealong by auxiliary bypass, motor and return passages of which said auxiliary bypass and return passages register respectively with said opening and said another opening in such one end face of said main housing; an auxiliary spool reciprocable in said Auxiliary housing from a neutral position whereat said auxiliary bypass passage is open and whereat communication of said auxiliary motor passage with said auxiliary bypass and return passages is blocked to operating positions whereat said auxiliary motor passage is selectively communicated with said auxiliary bypass passage or said auxiliary return passage; said auxiliary spool in one of said operating positions being operative to close said auxiliary bypass passage for flow of pressure fluid in said auxiliary bypass passage upstream of said auxiliary spool bore to said auxiliary motor passage, the downstream portion of said auxiliary bypass passage being communicated with said auxiliary return passage whereby said bypass passages in said main housing and in said auxiliary housing are open to said main housing return passage via said another opening in said main housing when said spools are in neutral position; said spools having switches associated therewith to energize a pump drive motor upon actuation of either spool from neutral position to an operating position.

Claim 16

The directional control valve of claim 1 wherein said spool in said first bore in said main housing is of three-way type to control actuation of a single acting motor; and wherein said bypass passage remains open in the other operating position whereby said auxiliary valve may receive fluid under pressure from said bypass passage upon movement of said auxiliary spool to said one operating position.

Claim 17

The directional control valve of claim 2 wherein a duplicate auxiliary valve is interposed between said cap member and said auxiliary housing with registering bypass passage and return passage branches therethrough.

Claim 18

The directional control valve of claim 1 wherein said opening is disposed between said pair of openings and is constituted by a sleeve which extends through said portion of said main housing return passage to define the portion of said main housing bypass passage downstream of said second bore.