ACTUATOR FOR AIDING HITCHING OF AN IMPLEMENT TO A TRACTOR

ACTUATEUR FACILITANT L'ATTELAGE D'UN OUTIL A UN TRACTEUR

English Abstract

The present invention relates to an actuator device
for aiding the hitching of an implement (1) to the three-
point linkage of a tractor (2) or similar pulling vehicle.
According to the invention, the actuator device comprises
a double-acting hydraulic cylinder (5), which is mountable
between two pulling links (3) of the tractor's three-point
linkage for controlled adjustment of the mutual distance
between the pulling links (3), and said hydraulic cylinder
(5) is connectable to a two-way directional control valve
bank (4) of the hydraulic system of the tractor. To avoid
mechanical overload of the pulling links (3), the cylinder
(5) is manufactured with a piston clearance providing an
internal bypass flow path.

French Abstract

Dispositif actuateur facilitant l'attelage d'un outil (1) au système d'attelage trois points d'un tracteur (2) ou d'un véhicule analogue. Ce dispositif actuateur comporte un vérin hydraulique à double effet (5) monté entre deux bielles (3) du système d'attelage trois points du tracteur, et destiné à régler la distance comprise entre les bielles de traction (3), ledit vérin hydraulique (5) étant raccordé à un groupe de vannes de distribution à deux voies (4) du système hydraulique du tracteur. Dans le but d'éviter toute surcharge mécanique des bielles de traction (3), le piston du vérin (5) est installé avec un certain jeu radial formant un passage interne de dérivation.

Claims

Claims:
1. An actuator device for aiding hitching of an implement
(1) to a three-point linkage of a tractor (2) or similar
pulling vehicle by means of a hydraulic cylinder system for
controlled adjustment of the mutual distance between the
pulling links (3 ), characterized in that a double-acting
seal-less hydraulic cylinder-piston device (5) is connected
to a two-way directional control valve bank (4) of the
hydraulic system of the tractor and mounted transversally
between two pulling links (3) of the tractor's three-point
linkage.
2. An actuator device as defined in claim 1, characterized
in that the hydraulic cylinder (5) is provided with a
clearance of approx. 0.1 to 0.2 mm between the cylinder
inner wall and the piston.
3. An actuator device as defined in claim 1, characterized
in that the hydraulic cylinder-piston device (5) is
detachably connected to the pulling links (3) of the
tractor (2) by means of quick-release joints mounted to the
ends of said pulling links (3).

Description

4~ 7 ~38-- r ~, I / r ~ n7e,~ C~
~CTUATOR FOR AIDINO nl.. OF AN IMPL~ T TO A TR~CTOR
~he pre~i~nt invention rela~l3~ to an ~ctuato~ Lnt~nde~ to
a~d hltohing o An ~ ~rl ~ l~ tC a ~ 9 p~lnt llnkns~l~ of a
traotor cr ~imll~r pullinc ~ehLcLe ~y m~n3 of a hydr~ulic
cyl~nd~r y~;tl~m ~or controlled ~a~u3~ment of the mutual
di~t~nc~ tw~n the pullin~ llnk~.
With th~ gr~t~r 3~ze and ~7c~ght of modern equipment, th~
u~ oving of ~ractor3 c~ weLl ~as i ~pL~ n~ haY baco~e ~ces-
alvely ~ t~id. Con~equ~ntly, s~roper loo~tion o th~
tr~otor ~nd th~ ~ual l~ltching o~ th~ implnm~nt ~ullins
llnk~5ie c~n ke an ~ ,L~ .~ly dlfficult and ev~r. potentl~lly
cl2hsr~rous operation, wh:ich ,..o, e:OV~L illi tim~-~onsuminSI.
~5
In D~ 1 557 84~ ~here ~s ~l~clo~ed an a~L~r-v- ~ ~or
~Idln~ to coup~e cn ~ t to the pulling llnkY o~ c
tr~ctor. ~h~ known 4_~.CI15,~ compri~es two ~lr.gle stroke
cyiinde~s, ~}~ch couplod between the frame OI' th~ trac~or
2~ and on~ ~ulling link. Irl orter to adm~ t ~ lat~r^l m ~ "t
o~ th~ pullln~ lir~ks wlt:h u~ n~ed mutual d$3t~nce when
th~ flu$d connsc:t~on o~ th- cylinders to ~ hy~rAulic pump
and a return plpe i~ int~3rrupt-d there i~ 8 iluld connec~
ti~n ~ntwean th~ two cylind~rs. This known a~
2s requlre!s at l~a~t t~o s~p~r~5t~ lve~ ~o ~e controlled
lnd~vidually, two ~t~ion~rily nwunted hydr~ulio cylin~r~
~nd ~ nyln~ ho~e3, re~ultlng ln ~ rel~tlvely
complic~te~ con~tructlon.
30 It 1~ ~n o~eot of th~3 ~r~lsnt in~ention to uv-.~ . s ~uoh
pro~lems and to obt~in a mor~ ~implifi~d nnd sconomio
con~ruction by virtue ~ an aatu~tor devi~- b~lng oharac-
t~rlzod ln ~hat a doubla~-~ctln~ s~ hydraulic
~ylin~ r-piaton devic~ 13 ~v~ .d to a two-way direc-
35 tional con~rol v~l~7n ban~ o~ the hy~rnulic ~y~te~ of thetractor and l~wunted LL~ VQL~a11Y ~tween two pulling llnks
o~ the t~actor ' ~ three-p~ nt link~g~ .
AMENDED SHE~

U"~ o~ L . 3~ ga ll~ 4~ 7~8~- ~CT/Fi95 i~035
I Th~ Swe~l-h Patent omeo
o PCT 11 . n~lAppl~c~on ¦ t 4
1~ ~18143~
Wlth th~ hel~ of the ~ctuatcr devlce ;~ccordinSI to th~3
lnventlon, hltchlng o~ th~ 1 1~ t c~n b~ c~rrl~d out
wlthout th~ n~d ~or t~ drlv~r to lu~v~ the c~bln ~or
hitchlnq, s~ince tha ~unc ticn o~ thQ hydr~ullc cyllr~der czm
5 b~ controll~d ~y th~ contrcl 113vor~ o~ thl~ tr~ctor's
hydr~ullc ~yst~m~ wh~ ch ~re lc ca~eld lrl th~ tractor c~bin
~h3 ne~ lQrs hydr~ulic cylinder-pi~ton d~vice prevQnts
effectivQly excennive lo~d on the pullin~F links ~nd it
permit~ ~ ~lontlnS~ 1 of thff pulling li~k~ durlng thQ
1C timQ th~a hydr~ulic cylind~r i- not i5 po~r-d
It has ~ n ~shown that a pref~red ~ n of cle~r~nc6
l~tw~eln th~ cylind-r lnn~r Prell ~nd th~ plston i~ ~pprox
0 10 to 0 20 mm
Fur~hor ch~racterlstic~ of thc preqent Lnventlon
~pe~r ~om the qnt~l on~d clslms
... .. .., ... . . ~ . . . .. -
C~wing to the Rimpl~ con;~truction of the ~ctuat~r a~vice
2~ ~ccording to the invQntLon, the devicQ i~ ~n' 1 y dur~ble
and reli~bl~ lr U8~.
.
AMEN~IEP 'SI IEEI

2;L8~3~
WO 95/20311 - r~
The inventlon will now be (~ r~ hed in greater detail with
L~Le~ oe to the appended drawings, in which:
Figure 1 is a peLx~ Llve vlew of an a~;LuaLu~ device
- s according to the invention mounted to a tr2ctor; and
Figure 2 is a top view of the a~,LuaLuL device illustrated
in Fig. 1 with an ~ t hitched to the pulling links.
to With reference to Fig. 1, the actuator device according to
the invention for aiding the hitching of an 1 ,1~ L 1 to
the three-point linkage of a tractor 2 or similar pulling
vehicle comprises a double-acting hydraullc cylinder 5,
which is mountable between two pulling links 3 of the
15 three-point linkage of the tractor 2 for controlled
adjustment of the mutual distance between the pulling
links, which hydraulic cylinder is culllleuLable to a two-way
directional control valve bank 4 of the tractor ' s hydraulic
system .
To perform its function, the hydraulic cylinder 5 is
mounted between the two parallel pulling links 3 of the
tractor 2 so that its cylinder portion 5a is connected to
one pulling link 3, while its piston rod 5b is connected to
2s the opposlte pulling link 3. The hydraulic cylinder 5 is
adapted to be powered by the conventional hydraulic system
of the tractor via two hydraulic oil hoses 6 connected to a
two-way directional control valve bank 4 of said hydraulic
system, said hoses 6 advt,L~ y~uu8ly being attached to said
30 control valve bank 4 by means of quick-release uun..eu L
6a. By vlrtue of this alL~ t, the operation of the
hydraulic cylinder 5 can then be controlled by control
levers located in the tractor cabin 7 of the tractor as a
standard a~ f P~ y of the tractor.
3s
To achieve a L:unL7LLuuL~on which is r-x~r-l ly simple and
safe in use, the hydraulic cylinder 5 is advcl-.Lc.y~uusly

W0 95/20311 ~ 1 8 ~ ~ 3 4 ~ rL ~ .
manufaetured with an approx. O.lO - 0.20 mm clearance
between the eylinder inner wall and the piston without
using any seal to bridge the clearance. Then, the piston
can be advc,-l cy~ously manufactured from a bearing alloy.
5 This CL L Clly. l. ensures that the piston inherently
provides a bypass ehannel for a eertain amount of hydraulie
oil thus preventing exeessive load on the pulling links 3
notwithstanding the direct connection of the hydraulic
cylinder to the tractor ' s hydraulic system without using
lo any pressure reducing means . Such an aL L Cll~ . also
permits floating movement of the pulling links 3 during the
time the hydraulic cylinder 5 is not powered.
The mounting of the hydraulic cylinder can be '1f~rl so
15 as to cause minimal disturbance to the use of the power
take-off shaft of the tr~ctor.
By providing the pulling links 3 of the tractor 2 with
cluick-release ~oints, the hydraulic eylinder S ean be made
20 easily detachable and transferrable to another tractor 2
having compatible cylinder end ~oints.
With Lt:feL~~ to Fig. 2, the function of the actuator
device according to the inventlon is as follows. To hitch
2s an i, l~ t 1 to the three-point linkage of a tractor 2,
the tractor 2 is initially Lt!v~:L:~ed in front of the
, l ~ t l and the pulling hole 8 of one pulling link 3 of
the tractor linkage is aligned with the compatible pulling
pin 9 of the im;ll~ t. I~ext, the hydraulic cylinder 5 is
30 activated by operating t~le control lever of the control
valve bank 4 so that the hydraulic cylinder 5 is powered to
actuate the pulling links 3 with a pulling force. Then, the
pulling link 3 is moved toward the pulling pin 9 of the
~mrl t l so as to locate the pin through the pulling
35 hole 8 of the pulling lir~k 3. With the pulling pin 9 now
engaged in the pulling hc~le 8, the pulling links 3 of the
tractor are lifted at a moderate force by operating another

Wo 9S/20311 ;~ ~ 8 1 ~ 3 ~ r~llr~
control lever of the tractor hydraulic system until the
frlction of the pin in the hole ls sl~ff~t~1t~nt to keep the
pulling pin 9 of the ~ l~ L in place in the pulling hole
8 during the ~ubseyuellt hitching step of the 1 l~ L.
5 Tn this step, the hydraulic cylinder 5 is controlled to
zctuate in the opposite direction so that the pulling links
3 are forced to away from each other. Next, the pulling
hole 8 of the opposite side pulling link 3 is aligned in
front of the mating pulling pin 9 of the 1, l~ L, after
10 which the hydraulic cylinder 5 is powered to actuate a
pulling force between the links. Then, the opposite side
link 3 is moved toward the pulling pin 9 of the ~ mrl L
so as to locate the pin through the pulling hole 8 of the
pulling link 3. After the hitching of the 1, l L is
15 saiely and easily ~t ~ Rhe~l in the above-described
manner, the driver can leave the cabin 7 and secure the
t by inserting securing pins into holes drilled to
the ends of the pulling pins 9 of the ~ mrl t .
20 To prevent undesirable lateral swing of the pulling links
3, both sides of the tractor 2 can be provided with
conventional lateral ~ L limiters 10 adapted between
the tractor chassis ~md said pulling link 3.
By virtue of the invention, the unhitching of the ~mrl L
l from the pulling links 3 of the tractor i8 made e~Ll~ ly
8imple. After the securing pins are removed from the ends
of the pulling pins 9, the pulling pins 9 can be released
from the pulling links 3 by controlling the hydraulic
30 cylinder 5 to push the pulling links apart from each other.

Representative Drawing