Note: Descriptions are shown in the official language in which they were submitted.
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"Actuator device for_the displ~cement
of a mem~er,~and sli~l~gc~ doq
~quipped therew _h."
The present invention relates to a de~i~e ~or the
S di~placement of a ~en~ber, and in parlicul~r ~or the
displacement of a sliding lea~ ~etween its open and
- closed positions.
- ~he present invention likewise relates to doors
havin~ ~ sliding leaf or leaves equipped wi~h su~h a
device.
- - - In many applications, and in parti~ular in rail
: - or roa~ t~an6port vehicles, it is necessary t~ open or
-~ : -close a sliding door b~ a ~echanical means o-f small b~lk,
bearing in ~ind the available space, by exe~ting a
positive ~c~ion in order to ob~ain each of the configura-
tions, this beln~ for rea~ons of safety in operation. In
~u~h appl~c~ions, i~ is desired to avoi~ xotary motors,
in par-t~cu~r ele~triG motors, in favor of actua~ors, in
' part~ cular hydraulic or pneumatic actuators.
- 20 A device is known which is re~erred to as ~
- "rodless actuator'~, in which a flexible strap, passing
around two return p~lleys git~ated at the two ends o~ the
body of a double-acting actua~or, is fixed by its two
- . ~ ends to ~he two ends of the piston of the actuator. A
2S traveler mo~ing along the bod~ of the actu~tor is fixed
- to the strap between the two pulleys and trans~its the
motion to the memb~r to be displac~d. Rodless act~lators
have the advantage of ha~ing a ~elatively lon~ useful
~ravel r~lative to their lengthwise bulk.
30 Ne~ertheless, the travel is still substantially
less than the lengthwise ~ulk whereas, in the above-
mentioned- applications rela~ing to vehiclçs, it ig
- generally d~sirable ~or ~he motive device to be accom.
modated in the width of the aperture an~ ~o impar~ to the
35 leaf a travel subs~a~ially equal to said width.
. - Moreo~er) rodless ac~uator~ are cos~ly an~ pose
~ ~ifficu~t sealing pro~lems lia~l~ to entail maintenance
-- :opqr~tions and breakdo~ns.
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A doubl~-acting actuator has likewise been
proposed whose pis~on bears a rack enga~in~ with a pinion
having its axl~ solidly ~ixed to the axle of a drive
pulley of laryer diameter. ~he pulley driv~s a belt
connected to the lea~. An appropriate ~iametral ratio
between pinion and pulley make~ it possible to u~e
conventional actuator of ~elatively small s.ize compatible
with ~he available spa~e, while achieving sufficient
amplitude of displacement o~ the me~ber to be ~ontrolled.
Such a devicQ, howe~er, suf~ers fxom a double
disad~antage in that, fi~stly, it requires a relatively
~ostly rack-and-pinion syste~, ~nd secondly the drive
pulley m~y slip ~ela~ive to the ~elt an~ consequently
fail to transmit thereto the mo~ion created by the
a~uator, It is thus necessary to make special arrange-
~ent~ to avoid the abovementioned ~lippage, but with no
certainty of preventinq ~he lat~e~, which may be in~on-
venient ~o~ the point o~ view o~ safe~y in publi~
transport.
This device ha~ the further disadvanta~e ~hat,
when ~he ro~ of the a~tuator is in the projecting pos~-
tion, the rack passes beyond the drive p~lley, which
means that here again a lengthwise bulk has to be pxovid~
ed which is ~early g~ea~er than the useful txavel of the
de~ice.
Furt~ermore, F~-A-2,522,081 proposes in Figu~e S
a double~actin~ actuator ~aving a fixed apparat~s and a
mobile apparatus, the lat~er aGtuating a flexible strap
passing around two retu~n pulleys at the two ends of the
~vel Of a dog fixed to the st~ap in a re~ion extendin~
be~w~en khe two pulle~æ, said strap passinçl through two
tackle devices each o~ which is functionally arranged
bet~een one of the return pul leys and a respe~tiYe
at~achment end, these tackle devices each comprising a
tackle pulley whose axle is connected ~o th~ mobile
appar~tus of the actuator.
When the mobile apparatus moves, it entrains with
it the two tackle pulleys, one of whi~h pulls ~ length of
strap substan~ially equal to a multiple of the len~h of
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the displacement o~ ~he ~obile apparatus ~by virtue of
the ~ackle~, while the other tackle pulley relea~e~ the
same ~ultiple length o~ ~tr~p.
There thus takes place, between the two return
S pulleyst a displacement o~ th~ strap, anclcQn~equently of
the dog, whlc~ is equal to ~ multiple of the tra~el of
the mobile apparatus of the actuator. No slipping is
possible, since the displacement of the strap is a
necessa~y consequence of the relative displac~men~ of the
axles of t~e ~arious pulleys of the device. ~or~overt ~nd
for the same reasons, if the actuator i~ of the double-
~c~ing t~pe, or is of the single-acting and spring-return
type, the deviGe transmits ~he ac~ion of the actuator in
both directions of mo~e~ent of its mobile apparatus.
The a~ove device makes it possible ~o avoid the
sealing problems specific to ~he ~Irodless actuator~" but
provides virtually no improvement in the matter of bulk,
eithex rel~ive to the rodless actua~o.rs or even relative
to the rack-type actuators, slnce it is necessary to
~0 provide for the cleardnce o~ the tackle p~lley at each
end o~ the body of ~he actuator.
The ob~ect of the present invention i~ thus to
provide a very simple, reliable, compact and economical
d~vice for the displacement o~ a member.
~he present invention relates to ~ device for the
d~splacement of a ~ember between two predet~rmined
positions b~ means of an actuator having a fixed
apparatus and a mobile app~ra~us, the latter actuating a
flexible strap surroundin~ two return pulleys at the two
ends of the travel of ~ dog ~ixed to ~he strap in a
region extending be~ween the two pulle~s, t~e said str~p
passing throu~h two tackle de~ices, each of which is
functionally arranged ~e~ween one of the return pulleys
and a r~spective attachment end of t~e strap, these
tackle devices ea~h comprising a tackle pull~y whose axle
is connected to ~he mobile apparatus of the actuator,
wh~rein the fixe~ apparatus of the actuat~r comprises a
bo~y having two coaxial cylin~ers separated ~y a parti-
~ion, and the mo~ile apparatus ~ompxises two pistons
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~ach disposed in one of the cylinders, wherein at lea-~t
one of the pistons defines, between itself and the
partition, a variable-vol~e working chamber, the two
pistons being conne~ted to each o~her by a rod pas~ing
S through the partition in a sealing manner, each o~ the
tackle pulleys being connected to a face of a respective
piston, which face is opposi~e the partition, and where-
in, at each end o~ the travel of the mobile app~xatus,
one of ~he tack~e pulleys is engaged in the corresponding
cyli~der.
By ~omparison with known devices, the device
according to the invention possesses sub~tantial
advantages, and in particula~ a very significant reduc-
tion in longitudinal bulk, be~ause;
- the mobile apparatus, bearing on t~o pistons,
is perfectly g~ided by virtue of its structure and in
its positions alon~ the fixed apparatus, and pistons o~
a roduced axial dimension ~y be used without riskin~ any
~ilting and jammin~ effect:
- the penetxation of the t~ckle pull~ys into the
body of the actuator, at the end o~ travel, a~lows the
pulleys to be pl~ced very close to the piston~ and thus
allows the axial hulk of t~e device to be g~ea~l~ reduced
relative to that o~ FR-A-2,522,081.
According to a pa~ticular e~bodi~ent o~ the
invention, the device is a de~ice comprising at leas~
four return pulleys, around which the strap describes a
tra~e~tory corresponding to a closed loop supplemented by
a half~loop so tha~, in any posi~ion of the mobile
apparatus, the~e are two strands moving in the s~me
di~ection and connected b~ a strand ~oving in the opposi-
te dire~tion, and wherein a do~ is provid~d on each of
the two strands of the loop.
~ccor~ing to a second aspect of ~he in~ention,
the sliding-leaf dQor is a door wherein the l~af is
connected to the dog of a device in ac~ordance wi~h the
fir~t aspect.
Accordiny to a third aspect of the invention, the
door ha~ing two lea~es sli~in~ in opposi~e ~irections i~
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a door wherein each leaf is connected ~o one of the dogs
of the abovementione~ particular emb~dimen~ o~ the de~ice
accoxding to th~ invention.
Oth0r features and advantages oi' the invention
will become apparent in the cour~e of the description of
~ariou~ examples o~ embodiment ~hich will now be ~iven in
a nonllmiting manner.
~ n the attached drawings:
- Fig~re 1 is a diagran~atic elevation of a
sliding-lea~ door of a railroad vehicle fitted with a
device a~cording to the inven~ion, shown with cu~ away
and in par~ial section, the door being in th~ closed
position;
- ~igure 2 is ~ diagrammatic view in longitudinal
se~tion, on a larger scale, of the device in Figure l;
- Figure 3 is a view analogous to Fig~re 2, but
shown in a position corresponding to the open position o~
th~ door
- Figure 4 is a pa~tlal section ~f an al~ernative
en~odim~n~ comprising~ for e~h tackle de~ice, a second
tackle pulley pern~i~ting greater amplification oE
~otion;
- Figure 5 is a ~iagran~atic section of anotheL
alte~native embodiment of the device according to ~he
invention, ~ith a partial view of a door having two
leaves sliding in the opposite direction.
A de~ice 1 according to the invention is shown
in Fi~ures 1 to 3. T~e device 1 is installed above the
sliding leaf 2 o~ a door 3 givin~ ~ccess to a railroad
vehicle, in order to aotu~te this leaf, b~ mean~ o a
double-acting actua~o~ 4, between a position of closu~e
of a passage surrounded by the frame o~ the doo~ 3 an~ a
position o opening o~ thi~ passage.
The door ~ is a doo~ having a single sliding
leaf, o~ a t~pe known per se, which it is unnecessa~y ~O
describe in detail. In the upper part of the door, in the
~icinity o~ the lea~ing ed~e (~elative to ~he direction
of closure)~ is fi~ed a bxacket 5 provided wi~h a s~ating
~o r~ceive ~he end o~ ~ do~ 7, the bracke~ S and the dog
7 being solidly fixed to each other relative to move-
ments which are parallel
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to that of the leaf 2. ~he do~ 7 is fixed at an appro~
priate point of an actuation region 'la of ~ ~lexible
strap 9. In the ~egion 9a, the strap ~ moves in ;it~ own
lQnyth by th~ func~ioning of the device 1 and may adopt
S two positions 7a, 7b, respectlvely corresponding to the
closu~e and ~o the opening of ~he leaf 2 ~s~e Figu~es 2
and 3). In the example shown, the door is of the type
having a simply sliding leaf (~hat is to say tha~ the
leaf mo~es in it~ own plane) but t~e invention is
llkewise applicabl~ ~o doors having a leaf of the so-
ca~led com~lned type, in which the leaf undergoes,
at the ~tart of the opening movement and at the end o~
the closing movement, an ex~r~c~ion move~nt an~ an
insertion movemen~, respe~tively, relative to the ~ram~
o~ the door. In thi~ case the dog 7, instead ~ being
coupled directly to the leaf, would for ex~mple ~e
couplod to a trolley, rela-tive to ~hic~ the leaf executes
its movements of, re~pecti~el~, extraction and inser~ion.
In ~he example shown in.Pi~ure 1, the ~uide means
or the lea~, which may for example comprise rollers
fixed to the leaf and sliding in rails solidly fixed to
the frame of the door, ha~e been omi~ted, the device
according to the invention providiny only the ~riving and
not the ~uiding oE the leaf.
A fixed apparatus 11 o the double^-~cting
act~tor 4 co~prises a body 1~ fixed to the ~ame of the
doo~ 3 by means of assemblies 19, 21 forming collars.
~he body }3 ~e~ines within itself two cylinde~s
lS (soe ~igure 2) wh1~h hav~ the same axi~, parallel tO
the di~e~ion of ~he .sl~din~ of ~he leaf, and the same
diameter and are ~eparate~ in a sealing manner by a fixed
median partition 27. In each cylinder 15, a ~ariable-
volume cha~bex 23 is defined between the partition 27 an~
a respective piston 29 which is reciprocally movabl~ in
t~e cylin~ex 15. The ~wo pistons ~9 and an axial rod 32
connecting ~he latter form a mobile apparatus 31 which
moves as a single unit within the body 11 of ~he ac~uator
4. The rod 32 passes through the partition 27 in a
sealing manner relative to the press~re difference ~hich
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may exist, in operation, between the two chambe~ 23, as
will be understood in due ~ourse. The chambers 23 ~ay be
sclec~ively co~nected by lines 33 to a compressor 34 or
to the atmosphere 35 by means of a distxibu~ox 30, in a
~anner such that one of the chambers 23 eva~uates to the
atmosphere 35 when the other fills un~er the action of
the compressor 34 Iwhich ~ay be a pressure ~ource of the
vehicle) or conversely.
~he oute~ surfaces of the pi3tons :29 ~oppo~ite to
the partition ~7) each hear a block 41 supportlng a
tackle pulle~ 37. Under these conditions, the axle~ of
the two pulleys 37 axe solidly fi~ed to the ~obi~e
apparatus 31 of th~d actuator 4.
T~o return pulleys ~4 rotate a~out axle~ 49 which
ar~ fixed relative to the fixed ap~aratus of the
actuator, the two axles 49 being substantially parallel
an~ situated, in operation, in a plane substan~ially
p~rallol to th~ di~ec~ion of the sliding of the le~. The
retu~n pulleys 44 are ~a~h s.ituated at one o~ the end~ of
the device, beyond one of th~ respective ends of the body
13.
~he region 9a of the strap 9 extends between the
two return p~lleys 44.
On either side of ~he region 9a, the strap 9
compri~es two tackle regions gb which each extend between
the associated ~eturn pultey 44 and a r~spec~i~e attach-
~ent end gc. E~ch tackl~ region ~b passes a~ound the
nea~est tackle pulley 37, thus adopting a U-shap~d
configuration openin~ towards the outside of the body 13.
The two ends 9c are i~ed to two lu~s 45 whi~h are fixed
relative to the ixed appara~us ll o~ the actuator 4 and
sit~ated subs~antially at the ends of the devi~e.
~he mo~e o~ operation of the de~ice is as
follows:
3S ~t may be assumed that ~he door 2 is in the
closed position, as shown in Figlres 1 and 2, and ~hat
the dog 7 is in its seating situated in the brac~et 5,
occupyin~ the position 7a (Figure 2). The ri~ht-hand
pulley 37 is en~a~ed in the corresponding cylin~ex 15. To
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open the leaf, the left-hand chamber 23 is connected to
the compressor 34 and, simulkaneously~ the other cham~er
23 is connected to the a~mosphere 35.
Under these conditions, the volume o~ the fir~t
chamber 23 increases, that is to say ~hat the mobile
apparatu~ 31 of ~he act~ator ~oves toward the leSt i~
Figure 2. The right-hand pulley 37 moves away towar~ the
interior o~ the bod~ 13, relative to the corresponding
p~lley 44 and lug 45, this pulley 3~ penetra~ing into the
adjacen~ c~llnder 15. ~h~ effec~ of this, foL each of the
strand.~ 52 and S3 of the associated region 9b, is an
increase in len~th which i~ substantially equal to the
txavel performed by the mobile appar~us, and this
absorpt.ion of s~rap by the right-hand tackle device thus
lS has to be compen~ated by a displacement of the region 9a
bearin~ the dog 7, this displacement ~eing equal ~ the
sum of the increases in len~th of ~he strands 52 ~nd 53,
thus e~ual to twice the travel performed by the mobile
apparatus 11. This displacemen-t of the re~ion 9a in i~s
2Q own length to~ard the righ~-hand ~ackle device is
permitted by the left-hand tackle device since each of
the two strands of the reqion 9b are reduced in length
by an amGunt su~stantially equal to the travel per~o~med
by ~he mobile apparatus 31.
~5 Finally, the dog 7 passes from the position 7a
to the position 7br shown in ~x4ken lines, correspondin~
to the opening of the door 2, with a distance L bet~een
the initial and final positio~s of the dog 7 which is
equ~l to twice the total d.L~placement of the mo~ile
apparatus of the ac~uator, an~ substan~ial~y e~ual ~o ~he
length of the body 13 of tho actuator 4.
In other words, the effect o~tained is an
amplification of mo~ion by a factor of 2.
In or~er to pass fro~ the open position oP the
~eaf 2, w~ich is sho~n in Fi~ure 3, ~o the closed p~si-
tion, an analogous but s~nmetrical pro~eduxe is adopted,
~hat is to say that the ri~ht-hand chamber 23 i5
conne~ted to the compressor 34 ~nd the left-han~ chambex
to the atmosphere 3~. This causes the displacement o~ the
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dog from the position 7b to the position 7~, and conse-
quently the closure of the lea 2. Ry virtue o~ it~ two
plstons 29, rigidly conne~ted ~o each other, the mobile
apparatus 31 i~ very well guide~ within the body even if
5 the pi~ons are axially very-thin. This enables the axial
length of the actuator to be further reduced.
In the alternative embodiment of th~ inven-tion ~o
which Piguxe 4 ~elates, each tackle device comprise~ a
second tackle pulley 39 having a fixed axle 43, around
which tackle pulley the str~nd 9b passes between the
~obile tackle pulley 37 and the attachment end 9c which
i~ directed toward the mobile apparatu~ and fi~ed to a
hook S7 carried b~ ~he ~especti~e piston 2g alongside the
block 41.
I~ will be understood -that, in this manner, any
displacement of the mobile app~rat~s, for ~xample towaxd
the left ~Figure 4), increases by an equivalen~ amount
the length o~ each vf the thxee st~ands 61, 63, 65 o the
right-hand region 9b and r~duces by an eguivalent amoun~
each of the thxee strand~ of the lef~-hand region ~b, so
that the travel o~ the dog 7 is triple that of t~e mohile
apparatus 31.
The above alternative embodiment ~akes it readily
possible to obtain a displacement o~ the sliding lea~ 2
2S which is subtantiall~ gre~ter than the len~th of the
associated a~tuator 4. Such an altexnative embodiment ma~
adv~ntageously be employed whene~er ~he availRble spa~e
i~ stri~tly limited to the width of ~he doo~.
The alternative ernbodiment as shown
diagr~mmatically in Figure 5 relates to a door havin~ two
leaves sliding in opposite di~e~tions, the po~ition shown
corresponding to the opening of the two leaves.
The desc~ip~ion ~ill be li~ited ~o an indi~ation
of ~he di~erences as compared with ~he embodiment in
~i~u~e l.
T~e two single return pulley~ 44 in Fi~ures 1 to
3 are replaced by two dou~le pulleys 54 mounted on ~he
fixed axle~ 49. The flexible s~rap ~ is guided over the
pulleys 54 in a manner ~u~h that its region o fixed
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qeometry comprises a supplementary loop 9e, 9f in
addition to the half~loop ~a in Figuxe~ 1 to 3, the
length of the s~rap 9 being increased a~ a conseque~ce.
The strand 9a moves, a~ previou~ly, ;.n ~h~ opposite
S direction to the mobile appa~atus, the strand 9f moves in
the sam~ direction as the strand 9a, w:hile the return
strand 9e move8 in the same direction as ~he mobile ~;
apparatus 31. . :
T~-o dogs 7 and 8 are provided, each fixed to one
of ~he leaves. ~he dog 7 is, moreover, ~ixe~ ~o the
strand 9a, as previously, while the dog 8 is flxe~ to the
strand 9e. The references 7a and 8a de~ignate the posi-
~ions of ~he dogs 7 and 8 when the leaves are open, and
the references 7b and 8b desi~nate the positions of ~he
lS dogs 7 and $ when the leaves are closed~ Fro~ thei~
re~pective leav~s, th~ dogs 7 and 8 are angled towards
each other in a manner such that the respective ~ravels
o~ th~ir poin~s of att~chmen~ ~o the strand~ 9a and 9e r
~espe~ti~ely, are superposed. In other words, ~he posi-
~0 tions 7a and 7b of the dog 7 are ~ubstantially opposl~eto the po~itions 8b and 8a, respectively, oE the doq 8,
which minimises the bulk of the device in th~ direction :
of the width of the opening.
Th~ mode of operation is identical to that in the . :~
2$ em~odiment o~ Figure 2, though with the difference ~hat,
for a displacement d o~ the mobile appa~atus in a
specific di~ection corresponding, for example, to the
closing of the ~oor, the two panels move in opposite
directions, each by 2d. In total, for the above displ~ce-
men~ ~, the f~e~ passage closes by the distance ~.
~ he present inven~ion makes it possi~le toproduce an actuator-based device for displacing a member
between two specific positions by a po~itive action in
both directi~ns, this device having the ad~antage~ of
being of reduced ~imensions, of simple construction and
o~ reliable operation.
In pa~ticular, it is possible to install wi~hin
a very limited space, such ~s that which may ~e aYailable
in a collective mean~ of transport, a device for
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operating a ~liding door having a coefficient of amplifi-
cation of the mo~ion of the piston of the actuator which
is at least equal to ahou~ two, this device moreover
being of very great relia~ility.
~he in~ention is not, o~ course, restricted to
the examp].e~ of embodiment which have just been
described, and numerous ~odiiications may be made ther~to
without depar~ing ~rom the scop~ of the present
invention.
Thu~, the number of ~ackle pulleys ~or each
~ackle device cou}d be greater than two, as a function of
the diamete~ of the pis~ons and o~ ~he amplification of
motion e~visaged.
~oxeover, the number of return pulleys eould be
increased to take into account the ~elative disposition
of the actuator and of the door, possibly impo~ed by
cono~miny to the space availa~le.
~he ~tuator could posse~s a mobile body and a
fixed pistvn, the body bearing, on an outer la~exal wall,
two blocks for the two mobile tackle pulleys.
It would thus also be pos~ible to pro~ide for the
actuator to be of a conventional type wi~h ~ixed body and
mobile pistcn of the rod type, the ro~ bearing, outside
the bod~, the two mobile tackle pulleys of ~he ~wo tackle
devices.
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