CA1148988A - Automatic coupling device to connect tractor and tractor-drawn means hydraulic systems - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An automatic coupling device to connect a tractor hydrau-lic system and a tractor-drawn device hydraulic system com-prising a panel secured on the tractor-drawn device and a body mounted on the tractor. The panel accommodates receiving unions with shut-off valves. The body has blind bores accom-modating hollow plungers each fitted with a shut-off valve at the end face operatively engaging the union. In each of the bores, the corresponding plunger defines a bottom chamber, the bottom chambers being intercommunicated. The hollow of one of the plungers communicates via an aperture in the side wall thereof with a pressure port, and the hollow of the other plunger, via a similar aperture in the side wall, with a drain port. In the device the pressure port and the drain port are provided in the body, the pressure port has a branch to the bottom chambers, and the aperture in the side wall of each of the plungers is disposed at the end face opposite to that operatively engaging the union. Such a structure of the device simplifies its construction and upgrades its dependability.

Description

The present invention relates to the field of agricul-tural engineering and is specifically concerned with automa-tic coupling devices for connecting the hydraulic system of a txactor with that of a tractor-drawn device.

The invention may be used to connect the hydraulic sys-tem of a tractor with the hydraulic dump cylinder of a dump trailer or with the actuating hydraulic cylinder of a self-contained loader on a trailer.

The invention may be employed to the best advantage to connect the hydraulic systems of a tractor and of a drill, a cultivator, or another hydraulically-operated agricultural machine.

The problem of a reliable automatic coupling of the tractor and a tractor-drawn device hydraulic system without complicating the construction of the coupling device remains yet to be adequately solved.

There has been proposed, for example, an automatic coup-ling device which has unions, provided with seals, to be brought into an operative engagement (USSR Inventor's Certi-ficate No. 178,251, Int. Cl .F 16L 37/04, published March 26, 1963).
This device has no shut-off members, in particular shut-off valves, in the unions and is thus not protected against fouling, which impairs its operational dependability.

The closest in the technical concept to the present invention is an automatic couplin~ device to connect the A tractor and tractor-drawn ~n~ hydraulic systems, disclos-ed, in the USSR Inventor's Certi~ica,te ~To. 580,993 (Int.C12 B60D 7/04, published January 25, 1977), which comprises a panel with receiving unions, mounted on the tractor-drawn Jc~;c~
~ , and a body wi-th hollow plungers movable in correspond-in~ bores in the'body mounted on the tractor. ~ach plunger partly extends out o~ the bore ln the body and~;de~ines by one o~ its end ~aces a bottom chamber~below the plunger~in the bore. ~he operatlvel~ en~aging end ~aces oY the hollow plungers and o~ the receiving unions are ~ibted with spring-loaded shut-o~ ball valves. The bobtom chambers are inter-.
oommunicated, and the hollow o~ each of the~plungers commu- --nicates via a union ln the side wall~o~ the plun~er portio~
extending out of the bore with the pres~ure or the drain line , o~ the bractor hgdraulic system, the bottom chambers perio-dioally oommunicating via the spring-loaded chec~ valve with ~ " , ; ~ ~ the holLow o~ one or another plungér. -;
The~ shut-o~ valves~provided in this deviGe~on the~
operablvely~engagLng end~;~faces~o~-the plungera and o~ the ; r~oeiviDg uDions~protecb bhe~device and bhe hydrsulic~sys-,t~e,'~m~from Pouling~ but~the~provision o~the;spring-loadèd - ~-valves~ sid~e~;bhe~plungers~ oo~plioates~-bhe G onstruo-~tion~o~the~d~evia~e~and~its operation? sinee;;bhe e~ort o~
"~ the oheoX valve~ springs ~mus~ be aocurately calibratea t~
c;o~nform ~witb the~wor~i~g pressure of the ~luid in'the hy-àulio~sysbem~ oreover~, an aociden~tal pressure drop;in . ~: , . ~ , ~ ., . . . . - . -8~
the hydraulic system due to a fluid leak through a check valve may cause the engaged parts of the device to disconnect from each other, which is particularly undesirable when the tractor hydraulic system is connected to that of a hoisting means. The above drawbacks greatly impair the operational dependability of the device.

The present invention provides an automatic coupling de- -vice which, owing to a separate fluid feed into the bottom chamber and into the plunger hollow, ensures a reliable con-nection of the tractor and a tractor-drawn device hydraulic system.

The present invention thus provides an automatic coupling device which ensures a reliable connection of the tractor and a tractor-drawn device hydraulic system.

The present invention also simplifies the construction of the device.
According to the present invention an automatic coupling device to connect the tractor and a tractor-drawn device hydraulic system which comprises, on the tractor-drawn device, a panel accommodating receiving unions with shut-off valves, and on the tractor, a body with hollow plungers each fitted with a shut-off valve at the end face to be brought into an operative engagement with a union, each movable in the cor-responding blind bore in the body, and each defining a bottom chamber in the bore below the plunger, the bottom chambers being intercommunicated, the hollow 11~L8988 o~ one of the plunger communicating via an aperture in the side wall thereo~ with a pressure port, a~d the hollow o~
the other plunger, al50 via an aperture in the ~ide wall A thereoi', with a drain port, ~oor~n0 to--t~lo invo-~tion, the preqsure port and the drain port àre provided in the body, the pressure port has a branch to the bottom chambers, and the aperture in the side wall i~ in each o~ the plun~ers disposed at the end ~ace opposite to that brought into the operative engagement with the union.
A separate ~luld ~eed into the bottom chamber an~
into the plunger hollows through a branohed port provided in the body obviates the need ~or check valve~ in the plung-ers, which complicate the device and impair its dependabi~
: lity.
In a modl~ioabion of the aubo~atic coupling device, : ~ the drain port provided Ln the body also has a branch to the bottom chambers, each branch communioating with the chamb-ers via an inbermediate chamber containing~a ball to alter- :
nately block the~branches. : ~ ~
Such a modi~ioation~provides a symmetrical conneotion o~the~dev1oe;~to~the~:pressure line. ;; ~ ; :
æ`~ In'another modification, a spr-n~- oaded valve is~L~
t~e'rp~osed~between t~e pressure port in the body and the~pres-s:~';e~port branoh,~;and~a:~spring-loaded rod is built into the body~;parallel~to the plungers axe9; the rod parbly e~tends~
` ~o ~ the~body, passing~through the pressure port, and carries~:aD the~pr;essure port a thrusb member~which perio-~8~38 dically interacts with the spring-loaded valve, the effort of whose spring is less than that of the thrust member spring.

This modification of the device is most expedient when the tractor hydraulic system is connected with that of a hoisting means, i.e. when more stringent safety precautions should be observed, since the provision of the valve, as mentioned above, prevents a self-disconnection of the tractor and tractor-drawn device hydraulic svstems.
The invention will now be explained by a description of particular embodiments thereof with reference to the accom-panying drawings, in which:

lS Fig. 1 is a diagrammatic view of the automatic coupling device of the invention with the automatic coupler between the tractor and the tractor-drawn device disengaged;

Fig. 2 shows the same as in Fig. 1, but with the automa-tic coupler between the tractor and the tractor-drawn device engaged;

Fig. 3 is a diagrammatic view of a modification of the coupling device of the invention with a branch in the body from the drain port, in the inoperative position;

Fig. 4 shows the same as in Fig. 3, but in the working position;

Fig. 5 is a diagrammatic view of a modification of the coupling device of the invention with a controlled valve, in the initial position;

Fig. 6 is a fragmentary view of the coupling device of Fig. 5 at the moment of fluid feed from the pressure line;

~, - 5 -' - ' ' -~1~8988 Fig. 7 shows the same as in Fig. 5, but in the work-ing position; and ~ ig. 8 shows the same as in FiK. 5, but at the moment o~ disen~agement o~ the automatic coupler between the tract-~ v;c e, A or and the tractor-drawn~ane and fluid feed into the top chamber.
Referring to Figs 1, 2, an automatic coupling device ~ ~ :
to connect the hydraulic s~stems o~ a tractor 1 and o~ a '' ~I ~v ~
tractor-drawn~e~ 2 compr~ises a panel 3 mounted on a lock -~
4,o~ an automatic~ coupler o~ the tractor-drawn means 2 aud a body 5 mounted on a ~ating part 6:o~ the auto~atic coupler lock 4, secured t:o the,tractor 1. ~he panel 3 is via li~nes 7 connected to the hydraulic system o~ the tractor-drawn Jc~
mo4~4, and the body 5, via a pre~sure line 8 and ~ drain line :
~9, to the hydraull¢ sgstem o~ the tractor 1. ~ ~
he panel ~ incorporates built-in réceiving unions,10 ~:
g. 3) ~itbed with ~hut-o~f ball valves:ll. ~o;~allow ~or :manu~acturing:inaccuracies and misalignment o~'~the two parts ~ .
o~ :the;~devioe~,~the~ receiving unions 10 are secured in the:pa-,nel~3~by~means~of re`sillent bushings 12:. The lines 7~are con- .
t:o~the~:u~io~s.10.~
he-~bo~y.,5,~haa~:at:1easb~twc blind cylindrical~bores o~dating,~hollow;~plungers 14.~:Each plunger 14 definos: ~ i ', ~ m~`ohambe~r~l5~:1n the oorresponding bore;13, the bot-,",.'.,~1.~'~ ~ chambers~l5 being~lntero~ommunicated. The end faces o~
; .~he ~ r~ bo~b:e~brQu~ht into an operative engage-~`'`' ~ 7 ',' ~ me~t~:`wIth the~rèspeoti:ve unions lO~oarry shut-of~ ball 11~8~88 valves 16. The body 5 has a pressure port 17 and a drain port 18 for connection -with the respective lines 8, 9 o~
the hydraulic system o~ the tractor 1.
The side wall oi' each o~ tLl~ ~lungers 14 has, at -the plun~er end ~ace opposite to that tv be brought i~to the operative en~agement with the union 10, an aper~ture 19 to cor~rllunicate the hollows o~ the plungers via the ports 17, 18 with the lines 8, 9.
A branch 20 lrom the pressure port 17 to the inter-communicating bo-ttom chambers 15 is also provided in the body 5.
In a modi~ication o~ the coupling device (Figs ~, 4), the drain port 18 has a branch 21 to the bottom chambers 15 in order to provide a symmetrical connection o~ the device to the pressure line 8. Both branche3, 20 and 21, communi-cate with the bottom chambers 15 via an intermediate chamber 22 which houses a ball 2~ to alternately block the branches 20 and 21.
This provision greatly simpli~ies operatio~ o~ the de-vice and enhances ibs operational dependability.
: ~ In another modi~ication o~ the coupling device, a spring-loaded valve 24 (Flgs 5-8) is interposed between the pres-sure port 17.in the body 5 and the branch 20 o~ the port 17, and a spring-loaded rod 25 is built i~to the body 5 paral-lel to the a~es o~ the plun~ers 14; the rod 25 passes thra-::
~: ugh the pressure port 17, and a portion o~ the rod 25 ex-tends out o~ the body 5. In the pressure port 17, the rod . . ~ . , .
-- ~ . . .
. , ~ , , .
, , . , ~ ::

25 carries a thru~t member 26 which periodically interact9 with the spring-loaded valvc 24; the effort o~ a 3pring 27 of the-valve 24 must be le~s than tbat of spring 28 o~ the thrust piece 26.
~ his modification prevents a sel~-disconnection of tho bydraulic ~ystems o~ tbe tractor 1 and of the tractor-drawn means 2 in the evont of an accidental fluid pre~ure drop.
~ o-return the plungers 14 to tbe initial po~ition, t~e automatic coupling devico maD, for example, incorporate springs 29 (~ig8 3, 4) each of which i9 mount~d into one of the r0~pectivo plungHrs 14 and fi~ed bg one cnd in tbe body 5 with the aid of a stud 30, and by the oth~r ond, in thc bead of the plunger 14, or be provided with top chamber~
31 (~ig8 5, 7) disposed above th~ pluneers 14 and ¢ommuni-cating witb bhe drain port 18.
, ~ t ~ ho-p~opDaod-automati~ cDupling dovico fun¢tion~ as follow~.
The tractDr 1 ia brougbt in rovorso to tbo tractor-~ ,ce, drawn m an~--2 placod o~ ~ leYol ground. ~he tWD automatic aoupler part~ 4, 6 (soe Figs 1, 2) engagc oach othor, with tbe rosult tbat tbe pan~l 3 and tb~ bodg 5 o~ the dovico aw dispo~ed in thc prodetermined spaced coaxial relabionship bo ~acb othor. ~D couple thom, tbo driver o~ the tracbor 1 turn~
~n tho b~draulic ~gstom pre~suro line, and fluid i9 via - - , .
tbc prcssuro port 17 and tbe brancb 20 (9ee Fig. 3~ admitt-ed intD bho interconnectin~ bottom chamber~ 15.
In the modificabion with tbe i~bormediate chamber 22 and the brancb 20, bbo b~ll 23 blocks either the branch 20 or the branch 21, deponding on into whicb of tbe port~, 17 Dr 18, ':
. . ~ . .

119~8~88 fluid i8 de,livered. ~rom the intermodiato chamber 22, fluid ~l~w3 intD t~e bottom cham~ër9 15.
~ he f-luid pressure causes the plungers 14 (see ~ig.4) to move in the bores l~ in the body 5 until their valves 16 operativel~ engage the valves 11 o~ the receiving unions 10. Having come into the operative engagement, the valves 16, 11 open one a~other, and the aPertures 19 in the side wallæ o~ the plun~ers regi~ter with the pressure port 17 and the drain po~t 18. Fluid from the pressure line 8 passes via the pressure port 17, the aperture l9 in the slde wall o~
one of the plungers 14, the hollow o~ the lattor, and the corresponding Open val~ves l6, 11 into the hydraulic system of the tractor-drawn~.~t~ 2.
~ o di~connect the h~draulic systems of the~tractor and the tractor-drawn~c*p~ the driver~simply turns of~
the ~luid pre~sure~in the pre~sure line~, and the plunger~
14 under th~ acbion o~ the ~pring~ 29 return to th~ initial pos1tion, iorcing ~lula out o~ the bottom chamber 15.
; In another~modi~ioation o~ the automatio coupling de-vioe, at the moment when the~automatic coupler engages,~bhe ~ -rod 25~(se~e Fig.~5),~lntsractlng b~ its~extsndin~ portion ~ ;
wlth~the pansl 3~,~movss Jointly with bhe tnrust member 26 do~n~snd thus~releasss the valve 24, which comes~to the~
l~positIon. Whe~ f-luid i9 f~ed~into ~the~pre~s~ure porb hei 1 ~d~pre~su e ~G: scs~th `vqlvs 24 to op~n,~and~
`lu~ d~is~via;the~branoh~20~admitted~;~into the botbom chamb-ers 15~ses ~ig. 6)~ following~ hiob~the operation o~ ths~
~ ics~proossd~ l;n~bhe~ame manner~as described above.
Af-ter~th9~plu~ger~14 havs come into the operativs ~8~88 ' -10-engag~ement with the receiving unions 10 and the side aper-tures o~,-the plun~jers have registered with -the pressure port 17 and the drain port 1~, the fluid pIessure in all the ports, branche~, and chambers equalize~, and the valve 24 closes (returns to the ini~ial position as shown in ~i~. 7).
In,the event o~ an acciden~al ~luid pressure drop, the c'losed valve 24 prevents ~luid ~rom passing out o~ the bottom chambers 15 and thereby precludes a sel~-disconnection o~
the hgdraulic systems of the tractor 1 and the tractor-draw~
n~ ue~*~ 2. This ~eature is of particular importance when the tractor hydraulic system 19 oonnecbed with that o~, ~or ex- :
ample, a ~el~-contained loader of a trailer.
Used,~luid from the hydràulio system o~ the tractor-drawn mean~ pa~ses via another receiving union 10 in the pa-nel 3, ~he~corre~pondi~g plunger 14, and further into the drain : : ~ port~18. , ; Disconneotion o the hyd~raulic systems o~ the tractor -'~
df ~ V, ~ .
and~bhe tractor-draw~ ~h~t~is acoomplished semi-automatlcal~ly. ~' For ~this:purpose,:bhe aubomatic coupler parts are disengaged?
whiGh;:relea6es,th6 end of the rod 25;~aoted upon by the:spring, t,h.e-~;r:od~25~ move~:up~,;and~the thrust~ ember 26 `opens the~ . ' valvè-~24.:~hereupon~, bhe pressure::~,line 8 is connected to ~ ~:
bh~`drai~n~porb~18.o~ bhe~devlc;e,~-~6nd~fluid flows~into the top~ohambers~31:~t:o~Qrce,th6,p1un~er6~ 14 to the initial po-,ibio,n~ 1uid~:rom thé~bottom~chamb6r6 15 ~ree1D ~low6 via th~branch:~20,: the~op~n:val've~24,,and the~pre:69ùre~ port 17 : ' e~e:Fig.:~8~. I:t~;~will~be, apparent t~ab the plungers 14 may ~1~8988 also be returned to the initial position in the same manner as in the preceding modification. ~ .

: -:

, :
, , : 20 .

:, :~ . . ' : :' ' '': -'' '' ' ~, - ;',': :~' -, -: . , -: :. ' ,

Claims (4)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An automatic coupling device for connecting a hy-draulic system of a tractor and a hydraulic system of a tractor-drawn device comprising a panel secured on said tractor-drawn device receiving unions accommodated in said panel and con-nected with said hydraulic system of said tractor-drawn device, first shut-off valves built into said receiving unions for con-trolling fluid flow through said receiving unions, a body se-cured on said tractor, hollow plungers movably mounted in blind bores in said body, the number of said plungers being equal to that of said receiving unions and said plungers having first end faces movable into positions operatively engaging said re-ceiving unions, second shut-off valves disposed in the plungers at the first end faces operatively engaging said unions, bottom chambers defined by said hollow plungers in each of said bores, said bottom chambers intercommunicating with each other; a pres-sure port provided in the body for connection to the tractor hydraulic system; a branch provided in said body and extending from said pressure port to said bottom chambers, for furnishing fluid under pressure to said bottom chambers, such fluid moving said hollow plungers with respect to said body so that said first end faces enter said receiving unions and said second shut-off valves engage said first shut-off valves whereby said shut-off valves are moved to establish fluid communication between said receiving unions and said plungers; a drain port provided in said body for connection to said hydraulic system of said trac-tor; and apertures provided in the side wall of each of said plungers at the end faces opposite to those operatively engaging said unions for communicating the hollows of said plungers with respective ones of said pressure and said drain ports.

2. An automatic coupling device as defined in claim 1, having a branch provided in said body from said drain port to said bottom chambers, an intermediate chamber provided in said body and communicated with said branches and said bottom cham-bers, and a member housing in said intermediate chamber for alternately blocking the branches.

3. An automatic coupling device as defined in claim 1, having a spring-loaded valve disposed in said body between said pressure port and its branch; a spring-loaded rod built into said body so that it is disposed parallel to the axes of said plungers, passes through said pressure port, and partly extends out of said body; a spring-loaded thrust member disposed in said pressure port on said rod and periodically interacting with said spring-loaded valve, the force of the valve spring being less than that of the thrust member spring.

4. An automatic coupling device for connecting a first hydraulic system to a second hydraulic system, said coupling de-vice comprising: a panel connectable in a fixed position to a structure supporting the second hydraulic system; receiving unions accommodated in said panel in fluid communication with said second hydraulic system; first shut-off valve means accom-modated in said receiving means for controlling fluid flow through said receiving units, said first shut-off valve means being mov-able between blocking positions blocking fluid flow through said receiving unions and non-blocking positions permitting fluid flow; means for urging said first shut-off valve means into said blocking positions; a body connectable in a fixed position to structure supporting the first hydraulic system and having blind bores; hollow plungers movably mounted in said blind bores, said hollow plungers being movable into extended positions in which first end faces thereof are received in said receiving unions; second shut-off valve means accommodated in said first end faces for controlling fluid flow through said first end faces, said first and second shut-off valve means being movable by each other so as to permit fluid flow between said hollow plungers and said receiving unions; interconnected bottom chambers defined in said body between second end faces of said hollow chambers and bottoms of said blind bores; a pressure port pro-vided in said body connectable to said first hydraulic system for establishing communication between one of said blind bores and said first hydraulic system, the plunger disposed in said one blind bore having an aperture in a side wall thereof for communicating the interior of said plunger with said first hy-draulic system; a passage formed in said body for establishing fluid communication between said bottom chambers and said pres-sure port so that pressure from said first hydraulic system is fed into said bottom chambers to move said hollow plungers into said extended positions; and a drain port provided in said body connectable to said first hydraulic system for establising fluid communication between a second of said blind bores and said first hydraulic system, the plunger disposed in said second blind bore having an aperture in a side wall thereof for communicating the interior thereof with said first hydraulic system.