CA1040523A - Wand operated venetian blind - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

The invention relates to a Venetian blind that is closed in either direction, i.e., by tilting the slats in either direction from their horizontal position, the slats being tilted by motion transmitted to them from a gear, the gear being rotated by a worm, and the worm being rotated by a manually rotated wand that is connected to the worm. The gear is a sector of less than 360° and is on the verge of rotating out of mesh with the worm upon the blind reaching its closed position in either direction, the gear retrogresses a little upon rotat-ing out of mesh with the worm. The point at which the gear rotates out of mesh with the worm is a little beyond the point at which the blind reaches its closed position and at least as far beyond such point as the retrogression of the gear upon rotating out of mesh with the worm, whereby the retrogression of the gear takes place entirely beyond the point at which the blind reaches its closed position and, thereby, the blind is protected against retrogressive opening movement. This arrange-ment is advantageous over the prior art in that it obviates the possibility of damage or adverse effect upon the blind due to continued turning by the operator, beyond the point where the blind is fully closed.

Description

s~7320 .

04~S~3 q?he pr~s~nt in~ention relat~s to Venetian blind~.
~ho s~at~ o~ a wand operat~d Venetian blind a:re ti~ted by manu~lly rotating a ~and~ al~o called ~ baton, The ~and~
rotati~ely dr1vos b~o worm o~ a worm and-~ssar til~er. Th~
5 worm rotate~ tho gsar and~ b~ ~uitable and known means" tho movemsnt o~ the gear i~ tr~nsmittad to ths ladders and rend~red e~c1;i~e to tilt the ~lat~ o~ the blind bg~ pulling up the rear ~idapiece~ Or the ladders while payi~8 out ths ~ront sidepieces9 or vice ~tr8a. -Continued t~lt~x~ o~ the slat~ clo~e3 the bl$nd to ita maximum normal ¢lo~ure~ ~he point o~ maximum rlormal oloslu~e~
in ths usu~l Venetlan blindOis reaohed b0~0re the ~dge o~ e~h ~l~t Would move agsin~t tho ~ao~ o~ an adJaoent ~lat~ the li~b cords inter~ere with ~uoh rull alosure exoept ~n the oase ~P
1~ a so-called ~ull olo~ure bl~nd 3uch as, ~or example~ blind disclosed ln U.S. Pat~n~ 3,170,505. When the polnt o~ n~clmum norm~l 01091~e h~L9 b~en rsach~d ths porson olo~in~ the blind ordln~rily halts hi~ rotabion o~ the wand. Xowe~ri a per~on ma~ ~all to timely halt ~1~ rotation o~ the wand; he may be inattent~v0, or he may ~%ppose th~t he oan olose th~ blind atill morfl by continued rotatlon o~ the wandO
When the point or maxim~n norm~l 0l09UI`e h~s bee~
reached, continued rotatlon o~ the wA~d oause~ overpull on khe ladd~rs; alld th~ overpull oan b~oome d~leterlo~ ln one or moro ways. ~ho o~erpull may ~amb th~ top slat ~ga~n~t the ~ -head o~ the blind~ ~1SOJ it may ~-use the top slAt to Xlip o~er or try toJ particularly in the oass o~ a narrow slat bl~nd. In tho oase Or the bl~nd o~ U~S~ P~ten~ 3~?~g~237J in wh~oh the top slat ooac~s ~lth a cord-loc~ actuator5 it i~
po~ble ~or ovorpull on the ladder~ to roul ~he oord lock.

~ 049~5Z3 In any cas~ excesslv3 oonti~u~d rotat~on o~ tho ~and ~ter the bl~nd has r~aehed it9 ma~imNm normal clo~ure can oau~e excesslve ten~ion to be exerted on ~idapie~ses of the ladder~
and/or o~ ~ho~e rung~ o~ the ladders which are draw~ng tho top slat ag~ln9t the bottom Or the head Gh~mnel~
The gear oP th~ tilter i~ a sector o~ le9s than 360 ~ogrees, ~hereby tho gear can run out ~ me~h with ths ~orm, AppliGant~ construction and arrangement are such thst~ wh~n maximum normal 0109ure 0~ the blind ha8 been reached~ the gear 1~ on the verg~ o~ running ou~ o~ me9h with the worm --meanln8 that 8mall additlonal mo~emsnt o~ thc ge~r would oaW e the gear to run ou~ Or mesh with the worm. Ab thi3 point the per~on clo~lng the blind would normally halt hls rot~tion o~ the wand, 8hould he ~ail to do 80, the gear will 1~ promptly run out o~ mo9h with the worm to ~u~p~nd biltlng aotion o~ the ~ilt~r bo~ore deleteriou~ o~erpull on the ladd~rs ha~ taken plaae~ Continued rotation Or th~ wand wlll then be i~er~eotiva~ and w~ll bo harml~ss aaoording~y.
Many~ psrhap~ mos~l Veneti~n blind~ are arranged to b~
clo9ed by tilbing the 81at9 ln either direotion, If the bllnd bs on~ whloh 1~ arranBed ~or 0109ure ln either direo~ion tho tilter ~ill provid0> as regards ~oh diractionO ~or the ~sar runnin~ out o~ mesh w~th the worm unle~s rotatlon o~ the wa~d i9 halt~d prompt~y upon the m~x~mum normRl clo9ure o~ :~

2~ ~he blind being reaohed~ Il bhe blind be one ~hioh ~8 .
arranged ~or olosure ~n one direotion only, the t~lter need provide~ a~ reg~rd~ that direotion only~ ~or the Be~r runnlng out Or mesh with ~he worm~ .
Th2 ~l~tg 0~ th9 b~ind are tilted to olosed position b~
pulling up either ths ~ront or the rear ~idep~eces ~ t~e ~3-~4~

S'~3 ladders, !rhe pull on the sidep~eces ~nean~ that thsrQ i~ baok pull by k~e 3idepisces ~hem~elves~ as~l thi~l back pull i~
rairl~ atrong a~ the blind appro~ohes maxi~ ormal 0103ure.
~he back p~ll i8 ~ran~mitted to the tiltor and b~aa~ the 5 ge~r retrogres~lvelg. q~he e~d ~ooth o:e th~ ge~r havi~g rur out o~ m~sh with the worm, and the thre~d of` tha wo~m ha~rlng ~lipped past the ~nd tooth~ the r~l;rogre~sive bia~ ~ the gear eauses the gear to retrogre~s a little ~-the r~trogrs~-~on belng Rrrestsd bg the end tooth o~ the gear ~ec~or ongag~ng the worm convclu~ion somewhat back of ths poink ~t whiah the tooth ran out o~ mesh with the worm, To pre~ent, or at lea~t limit~ retrogres~lon o~ the blind ~rom maximum norm~l olo~ure~ ~he polnt a~ ~hioh the go~r 1~ ~o run out o~
me~h with tho worm i8 plaoed 30mewhat be~ond th~ poSnt ~t 1~ ~hiah ma~lmum ~ormal olo~ure Or the blind i8 r~ached~ ~h~reby ~11 or some o~ the re~rogression o~ tha gear will h~ve tak~n plaoe be~ore the geQr has retrogres~od to the point at whi¢h maximum norm~l clo~ure o~ the blind was reaahed.
The invention i9 lllustrated, by wa~ o~ example in 2~ ths ao~ompan~ing drawing~ in whioh:
~ ig~ ~ 15 ~ largoly dlagrammatio rront alevat~o~ o~ a Vsnetia~ blind e~bodging th~ inventio~, the ~ront~ o~ the blind boin~ the ~ace thQt 18 toward tho room~
FiB. 2 i8 09gentially A ~ront elevation o~ a ~ragment of the head a~ tha blind~ on a larger s~ale~ a por~ion o~ ~ho ~ronb ~all Or the head ohann~l beinB broke~ out to roY~al the tiltsrj ~ 1~. 3 19 es~nt~ally a seotion Or the he~d~ ta~en ~nerall~ on the Dine 3~3 Or Flg, 2. ~ rragment ~r the ~~

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-5~

11)4~5Z3 l~ddor-and-slat a~3emb1~ i~ lndlc~tod includi~ a ~r~gm~nk 0~ B l~t oord, Th~ blind iq ~ully open, the ~lat~ belng horizontal~ i.e. untllted.
Fi~ 4 i~ the sam~ as Fig. 3 but with the blind and t~lter ~t the poinb o~ maximum normal olo~ure with ~h~ ~lats tilted forwardly, l.e~ tilted with ~he ~ro~t edge~ Or th~
31at~ dspre~3ed~
Fig~ 5 is ~he 3am~ a~ Fig~ 3 but with the blind a~d tilter at ~he polnt Or maximum norm~l closure ~ith the ~lats tilted rearwardly, i.e~ tilted with th~ rear edge~ o~ the slats depre~ sed .
The drawi~g ~hows the presently pro~err~d embodiment o~
tho invention~ i.e~ the bes~ mode thu~ rar contomplated o~
o~rr~ing out tho inven~lon. Exoep~ a~ m~y ba otherwi~e lndioated, the descriptlo~ herelnart~r re~ers on~y to the particular smbodiment o~ the in~ention that i9 sho~n ln the dra~ing, ~everthele~s~ the disclosure is by ~ay of illus~
tration and example; the olaim~ ombraoe other embodiment~ ~
o~ th~ invention~ : :
Except ~or the t~lter and the ooordlnation o~ the tilter with khe ladders~ both Or whioh will be de3crib~d and explnin~
~d laterJ the blind m~y be a wand operated Yenetl~n blind o~
suikable known ~on~truction and ~rran~ementJ ~or ~xample, th~
oonstrustion and arraneement dlsolos~d in t~e U.S. patent e~ ;
~orent~en et ~1 3~425~47g 19su~d Fsbruary 4D 1969. ~h~ known oon~truction and arran8ement th~ i8 disclosed in the pre~e~
application i~ the constructlon and ~rrangement Or the blind o~ that patentO
~ ladder~and-~lat a3sembl~ that i3 d~signated ~
whole by 15 i8 po~ition~d bsneath a head whioh i9 de3ign~tod ,.. ... . . . , . . . `,. ,. .. , . . .. ;.. . .. , .. . . ~ ;;

104~S23 a~ a whole by 16~ m e ladd~r~and~ t ~s~embly include~ 8 s9rie~ 0~ 91at9 ~7 that ar~ ~upported and arti¢ul~t~d together ln known manner by two or more ladders 1~. Eaoh ladder 18 ha~ a Pront ~idepie~e 18a and ~ rear ~idepiece 18b, the ~wo ~idep~eoe~ being interconne¢ted by v~rtically-~pao0d cro~s- :
pieces or rungs ~ôc on which the slat~ 17 re~t, The l~dder shown i5 0~ the ~trin3~l type~ the sidep~oes 18~ and 18b being braided cords and each ¢ro~splece l~Q belng a plural~t~
Or ~ilaments whlch may b~ braided or twisted int~ one or more strands~.
The head 16 ¢on~ists primarily o~ a sheet-steel ohannel 20 and the me¢hanism that i9 oontalned therelnO ~he ohannel 20 has a ~ront wall ~Oa~ ~ r~ar wall 20b and ~ bot~m wall 202. A~ong the upper ed~s o~ the ~ront and rear wall3 20~
1~ and 20b there are long~udinally-extendlng ~langeY 20d wh~oh ~re ~olded lnwardly and downwardly. The bottom wall 20c 18 piero~d in known m~nner (not shown) ~or pa~sage lnto the oh~nnel 20 o~ eaah sidep~ec0 18a and lôb Or the ladders and ~ .
o~¢h ll~t cord 22 (one ~ho~n~.
~he Venetian blind~ designated a3 a ~hole by 14 in F18~ 1~ i3 ~hown diagr~mm~tlaall~ a~ bein8 mounted in oon~entional manner with~ a windo~ opaning. The head 16 o~
~h~ blind i8 mounted on co~vent~on~l ln~tallation braokets one atkaohed ~o each o~ ~he ~amb~ 6 o~ the ~indow openlng.
~ha ~o~ o~ ~he ~lndow op~nlng ~9 indioated at 7 a~d ~he sill at 6.
~he construc~lon~ arra~gament and operation o~ the tilker ~ill now be d~cribed. The tilter~ ~hieh i9 de~ na~ed as a whole by 40~ 1 w lude~ a hou~lng bhat i8 mounted in the head ehannel 20~ Journalled within ~he housin5 the~e i~

~6_ .. . , . ~ ., ,. ~ , - , 1~4~5Z3 doubls threa~ ~orm 41 and a gaar 420 ~he ~orm i~ m~ld0d in one pleco wi~h a ~h~t 45 that proJ~cts as sho~n through an op~nin~ 20~ in the head ~annel, ~h~ch ope~ing i8 ~pread over an area that in¢ludes th~ ~un¢ture o~ the ~ront wall 5 20a and the bottom wall 20c, Hanging down ln ~ront oP the l~dder-and~lat assembly 1~ )J ~nd ~uitably conne¢ted to ~he worm ~ha~t 45~ there i~ a ~Qn~ 38 which i~ manuall~
rota~ed to rotat~vely drivs the worm 41-~he wand 38 Qnd ita connection tQ sh~t 45 m~ be aa in U.~. Patent 3~425~479. Except ~or the gear 42~ t~ coordina~
ti~n Or the gear 42 ~ith the worm 41 sn~ the coordi~ation o~
tho gear 42 with the l~dders ~8~ the tilter 40 and its mountine in the head ohan~ol 20 are the ~ame a~ ln U,.S.
Paben~ 3,425~479. Fig~ 3 shows the r~l~tion~hip between the 15 worm 1~1 and l;he gear 1~2 when the gear '~g in mld positio~,~9" hal~-way between its llmlt o~ rotati~n ~lockurlse and itd limlt o~ rotation ount~r-clockwi~. lL9 a Dlatter of m~chaIlioal oonveniancs in the partioular tilt~r, Q radius o~ ~:
~e gear 42 doe~n~t ~n~ers~¢t the worm hal~way between the 20 ends o~ th~ worm 41 bu~ lnterseGt~ the ~orm nearer the top end o~ ~he worm, ;ear 42 1~ a seotor o~ le~ then 360 de~ree~9 the . .
partioular gear shown bsing a ~eator which i8 8/13 Or 36~ ~
dagrees. The gear 1~ driven b~ the worm; and rotation o~ th0 ~ ::
g~ar in ei~er dircct~on 1~ limited b~ the ~ ooth o~ the ~:
gear s~ctor boing brought to th~ worm and then pu~hed as ~Pr as the ~orm can push ~t. F~g. 4 shows the relatlonship between the worm 41 a~ the gear 42 when the gear i~ on th~ :
ve~ge o~ run~ing out ~ me~h wlth khe worm b~ olockwi~e ~o rotab~o~ Fig~ ~ shows the relRtionship between the ~a~m 41 q7~

104~SZ3 and the B~a~ 42 livh0n the ~ear i8 Otl the verge o~ r~ning out of mesh with the ~orm b~ oount0r-olookwise rotat~or~0 Tho construot~on ar~ arrangemexlt o~ the blind o~
Patent 3,425,479 is used in ~he pre~ent in~ltanos to transmit the m~ement o~ bhe gear 42 to the ladders 1~ and ronder the ~ nt Or tho ge~r e~ect~ve to tilt the slats 17 by pulllng up the rront sldep~eoais 18a while paging out ~e rear ~id~plsc0s 18b or vlcie ~ersa, ~g in the bllnd o~ ~.S.
~tent 39425,479, the gear 42 i3 ooaxial wlth a st3el tllt -~
rod 24 o~ D-shaped cro~s ~ectlon~ whlch rod i8 al90 oalled a D rod. The rod 24 makes a sliding ~it with a D~shaped holo 24~ in the hub Or tho gear 42J and the rod extend~ aorossi the tops Or the ladder~ 15, At the ladder~ the til~ rod 21~ .-.
oarrie~ drun~ (nob shown) to which th~ sid~pleoes l~a and 15 18b Or tho ladder~ are 3uitablg attaahed, e.g~ a~ di~closed in U.S~ Patent 3~425~479.
~ n increment o~ angular movement o¢ the Be~r 42 doa~n~t erreot a particular lnor~m~nt Or tllting mo~ment o~ the ~lat~ ~7 regardlass Or the mean~ by whioh the mo~ement o~
th~ eoar i~ tr~nsmitted to the clst~ or regar~le~s o~ the widbh o~ the 31a~c. What an inorcmen~ of ~ngular movemont o~ the ~ear 42 doo~ do ~3 to o~ct a ~lke inorem~t Or ~ngular mov0m~nt o~ the tllt rod 24 and ths ~run~ that are ~ounted thereon and ~o ~hioh the ladder sid~pieGe~ 18a and 2~ 18~ are ~ttached. How muoh th~ sidepieces Or the ladders ~re ral~ed or lowered b~ a glven increment o~ angular ~o~ement ~ the drum~ ~ill be eoYe~ned by th0 radiu~ o~ the drum~0 ~nd ho~ much the ~lats are tl~d by a partlcular Sncrem~n~
of up anâ do~?n mo~omen~ o~ the sid~pleces 18a and 18b ~rill ~0 be e.~ecte~ b~ tho distance ~e~een th~ b~o siaepiece~ Or ~, . . ' '-: , . , :,.

~9--~4~1523 a laddcr ~hieh~ in turn~ is go~ern~d b~ ~he width o~ th~
slats~ ~he net re~ult i~ that the ~ear s~otor 42 should be ooordi~ated with the slats for th~ particular b~ind in ~hich the tllt~r i9 to be u3ad.
In tha blind ~ U.S. Pate~k 3~425,459 the drum~ to whlch ~he laddor~ are ~ttaeh~d ar~ in m~d positlon~ and the slat~
are untilted as shown ln Fi~, 3 o~ the pressnt application, whon the rl~t of th~ ~-rod 24 i~ hori~ontal and i9 at the top~ ~ith the gear ~eCtQr 42 in the mid rokative positlo~
~0 ~ho~n ln Fig. 3J the n~oe3~ary rotat~e lndexing o~ ~he ~-hole 24~ i~ the hub o~ the eear ~2 can be e~tablished~
the holo 24t ~ill be rotativel~ indsxed ~o plac~ the flat o~ the hole 24~ horizontal and on top when the drun3 are .. ..
in mid po~ition and the ~lat~ are untilted. ~hen the teeth . . .
Or the gear sector 42 oan be layed out. Tho oir¢ular pitoh ~:
of the teeth and the number on ea¢h side o~ the mid point a~e ~ele¢ted to have the gear on the v~rg~ of runnlng out Or m3sh with the ~orm wh~n the 31at8 ~7 have been tilted ~o bhe po~nt Or maximum norm~,l olo~ure o~ the blind~
In the pre~ent oase the gear ha9 eight teeth snd th~ :
eighb keebh take up 8 h3 ~ th~ o~roumrerenoe o~ ~he goar 42. Tha numbcr o~ teeth being e~en~ khe ~eotor ha~ a ¢en~er p~ir Or teeth ratb,er tha,n a oenter tooth. I~ Fig~ 3 the ~ eenter pair o~ teeth o~ the gear 42 13 in, mesh with the ~orm 41. Prooeedi~g counter-olock~i~e ~rom the center palr o~ beeth~ the ~e~itor 18 pro~ded wlth ~hr~e teeth ~he end tooth Or which i9 ~ooth tl~ ~roc~edlng clookwiss ~rom the ~enter pair o~ teeth th~ g~ar ~eetor 42 lg provided ~ith three teebh the end too~h Or which i8 ti2e Rot~bing ~h3 wan~

.. ~9~

~10- :

~ 5Z 3 ln tho direotion of the arrow in F~e. 4, the end to~th tl i8 brought to the ~orm 41 and i~ on the verg0 o~ running out o~ m~sh wi~h the worm ~hen the blind has b~en brou~h~ to it~
maximum ~orm~l cl~ure by tilting the ~lat~3 forwardly; this i8 8hown in ~ig. 4~ Rotatlng ~he wand ln khe direction o~
the arro~ in Fig. 5~ the end tooth t2 i9 brought to the worm 41 and i8 on the Yerge Or ru~ning out Or m~sh with the ~orm when the bllnd has been broughb to its mR~mum normal clo~ure by tiltlng the slats rearwardl~; this iq shown i~
Flg- 5~
Onco m~ximum normal clo~ure h~s ~esn reached in either dlrectlon, bhe ~ear 42 wlll run out Or m~sh ~ith bho worm 41 unless rotabion Or the w~nd 38 19 halted promptly, .~owe~er~
R llttle addltional rotation o~ the ~ear 42 ~g rsquired ~o cause the gear to run out o~ ~sh with tho worm, When the 8ea~ doos run out e~ m~h with the wor~, the gear will retrogre~ a littl~ a~ ha~ been explained. ~ut unle~a the -~
rstr4gress~0n bri~g~ the g~ar ~arther b~ck ~han the point ~t which ma~imum n4rmal 0109Ure ~a~ reached, bhcre will b~
no retrogre~sion o~ th~ blind ~rom maximum normal closure~
The retrogre~aion o~ the blind ~rom maximum normal clo8u~e i9 llnited accordingly and may be oomplet~l~ ob~iated~
Pre~a~ably ea~h end too~h ~l and t2 i po~itioned to keep the ge~r ln mesh ~ith the ~orm 41 untll tha angle by ~hlch the gear has passed the point at which maxlmum norm~l clo~ure ~as reached i3 at lea~t as gre~t as the m~ximum ~n8le o~ retrogrea~ion o~ the ~ear ~hen the g~ar runs o~lt o~ mesh ~lth the worm~ Thi3 in~ure~ that there ~lll be no rotrogre~s~on o~ the blind ~rom m~xfmum normal 4109Ure w~en the Bear runs out of meah ~ith th~ worm~

....

.. : , ~ . . , ~ 4 ~ 5 Z3 It ~111 bs s0en that the blind i3 ~utomatically prot0~ted ag~in~t the po~9i~11ity 0~ deleteriou~ overpull - :
on the ladders by oontinued rotation of ~h~ wand a~ter maximu~ norn~l closure ha~ ~een reaohed~ Xt ~ill al~o be seen that re$rogre~ion o~ the blind rrom n~ximu~ normal ~ .
closure i9 limited and~ pre~erably, obviated.
In the blind of u.æ . ~atent 2 ~174, 991~ the ~eQr Gan rwn out o~ ~e~h with ~ho ~orm at times. Th~ worm 13 ~otated ~ :
by ~ ~ord~driven pulley and the gear i8 to ~un out o~ me~h w~th the worm o~ly when aooumul~t0d ~lippage o~ the ~ord on the pulley-i~ to be correot~d~
" :,..-"'

Claims

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

1. A Venetian blind that is closed in either direc-tion, i.e., by tilting the slats in either direction from their horizontal position, the slats being tilted by motion transmit-ted to them from a gear, the gear being rotated by a worm, and the worm being rotated by a manually rotated wand that is con-nected to the worm - wherein the improvement comprises:
the gear is a sector of less than 360° and is on the verge of rotating out of mesh with the worm upon the blind reaching its closed position in either direction, the gear retrogresses a little upon rotating out of mesh with the worm, and the point at which the gear rotates out of mesh with the worm is a little beyond the point at which the blind reaches its closed position and at least as far beyond such point as the retrogression of the gear upon rotating out of mesh with the worm, whereby the retrogression of the gear takes place entirely beyond the point at which the blind reaches its closed position and, thereby, the blind is protected against retrogressive opening movement.