Note: Descriptions are shown in the official language in which they were submitted.
2~525~
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Th~ pres~nt invention rel~es to indexing ` ~. .
drive~ or in~ermi~tent mv~ion ~echanisms and, mo~e
paFticularly, to indexin~ dri~s having an inter-
~it~ently driven output sha~ ~hich intersec~s the
inp~t sha~ at An angl~
~A~KGROU~_OF ~HE I~vEN~I~N .;
Indexing drives ~or impar~ing in~ermit~ent .' ~. ;
motion have existed in the prl~r art. On~ ~uch
1~ classic device i~ ~nown as the ~eneVa ~echanism.
witn the G~neva meahanism, aonstant rota~ion o~ an
input sha~t is ~onverted to intermitten~ an~ular
rotation 0~ an ou~pu~ s~f~ which is parallel to the . . -
~nput ~.ha~ h~ Gen~Ya ~echani~m typi~ally ha~ a .
5ingle pin, ~ar~ie~ by ~he inpUt sha~t, ~hi~h m~ves
into and out o~ a series o~ s~raigh~ radial slots in
~h~ p~riph~ry o~ a di~k on the outpU~ shaft. The pin
: engages one o~ the slots in the disX as the input
sha~t ro~ates, a~elera~ing and then ~acelerating the
outpu~ shaft ~om and ~k to a res~ po~ition while -~
rokating i~ through an angle o~, for example, l~o ~:;
degrees or le~
~: '. . ' .
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2 ~ ~ 5 2 ~
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~he Geneva mecharlism has many limitations.
~he limi~tions are dis~ussQd, fo~ ex~rQple, in IJ. S .
Patent 3,4~3,4~5, whi~h is dirQcted ~c~ward an :~
impro~rement in int:e~mitt~nt ~otion de ri~es . R
fur~her improvement is disclose~ in U.S. Pa~ent -~
3, ~35, ~3 . These improvement devices employ a pair
o~ pin~ ~nd pair~ o$~ corre~p~ncling slo~s. ~ne 4:E the ~.
pins and one slot of e~çh pair ~ooperil~es to :
acc:elera~e the o~tput shaft ~rom re~t to a maximum
ang~lar 1~rRl~city and ~he other one o~ the pin~ and
the other slot o~ each pair cooperates to dec:el~rate
thç ou~put sha:~ b~clc to res~ or zero angular
~relooity. ~hese im~roved devi~es ~ollgh~: to overcome - .
some of the disadv~nt~ges o~ ~he earlier Gen~va and
~5 other ~ypee o~ ind~xing me~hahisms, parti¢ularly th~
a~rupk chdng~s in ac:celeration of the ou~put sh~ts
suc:h as occ:u~ in the C-eneV~ mechanism upon eng~gement
and di~engage~ent o~ a radia~ slot on the ou~put
sha~t by the pin on ~he lnput shaf~ ~n the devices
of ~he ~Pove~identi~ied U.S. patents, the p~ir o~
pin~ on the driving sh~f~ e~age a oorresponding pair
of sl~t~ on ~ne dxiven or ou~put ~ha~t, each af which `~
.. ..
h~ An opposi~e c~rve that determines the output ~
. .
sh~t' motion, ~hus providing ~reater flexibility
than ~lth a single ~lo~ of the ~nventional Geneva
meoh~nism b~ allowi~g s~aping Or the ~lots. Tha
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2 ~ ~ 5 ~
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devices of the a~ove-men~ioned paten~ empla~
airaular ~lots. -;~
Providing an imp~oved in~exing mech~nism i~
a right angle d~ive has p~ssented grea~r d~ iaulty. ;.
one su~h d~vice i~ disclo~ed in ~.~. Pat~nt Na.
3,583,~58. ~hat device seeks ~o ~olve on~ of ~he
pr~lems ~ound in prior ~echanism~ ~y elimin~ting khe
a~rupt a~celera~ion from, and deceleration ~o, z~xo
~ngular velaci~y by pxovidin~ a hemispheric~l slot~ed ~.~,",.'~
ou~put member in ~hich a pin on ~he inp~t or dri~ing .~
elemen~ eng~ges the 514k o~ the output or driven .; .
element thr~ugh a ~ull 180 degree~. In the device .:;
d~s~ribed in p~tent 3,583,~58, the pin enters the ;~
slot ~angen~ to ~e 510~ dire~tio~ in order to - -
~5 provi~e 5mooth begin~in~ and ending accelerati~on at
~h~ rest positi~n. Wi~h ~uch a devioe, the
hemi~pherical sur~e terminates in a planar edge
WhiCh lies in ~ di~meter plane ~r~u~h the ~e~ter of
the hemispher~, the plane ~eing at right angle~ to
the outpu~ axi~ o~ ro~ati~n and ca~taining ~he input
~xi6 ~ ro~ation. q~he motion o:E th~ o~tput ~lement
wi~h suc~h a d~vice i~; deqqribed therein as o~erwise
~orr~ponding to that or~ ~ tr~ ional Genev~
mech~ni~m.
~5 ~h~ traditional ~ene~ m~ohani~m produces
an ou~pu~ motion which has two a~di~ional unde~irable
~qa~r@~. ~h~ Geneva m~ohanis~ has a ~lati~ely high
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- - 2 ~ 5 5 2 ~
maximum ac:celeration ~nd maximum dec~ler~tion, ~nd ~ -,
ad~itionall~ p~oduce~ a r~pid tra~ition from ;~
~c~lera~ion ~o de!lc:eleration at the maxim~n angul~r
velocit:y poin~ . ~his i~parts a rapi~ a~c:~le.~a~ion ~ ~ ;
~hange ra~e, o~ Jer~, to the ou~pu~ sha~t. ~he jerk
is in the f~rm of a su~den torque ~eversal. ~hiS may
be rep~sented ~y an equ2tion o~ mo~iQn in whic~ the
t~ird ~eriv~ti~e of tha angle o~ the aUtput shai~t ~ or
~he rate o~ oha~ge of the angular acceleration of the
output sha~t, i~ not zero, hut rather is a high
neyativ~ nu~ber a~ ~he poi~t o~ maxim~m ~u~pu~
an~u~ax velocity. Such motion ch~racteristic~ impart
si~ni~ia~nt s~re~ ~o the outpu~ drive ~rain and to
o~ t being handled, processed or ~ovçd hy ~he ~ ~-
driven app~ra~us, ~s w~ll ag we~ ~o the me~hanism ~.
it~el$. .-
Device~ of ~e priv~ art hav~ no~ provided
the non-planar indexi~g me~hanism, that is one in
whi~h ~he input and output sha~ are not parallel, ~ :
which is aapa~le o~ ov~rcomin~ high a~celeration, and
o~er~omi"g ~ hi~h rate o~ changs ~ accel~ration,
p~r~icularly a~ ~aximum velooi~y and a~ tr~nsition
points in the in~ermittent drive cyole where
mechanical qompon~n~ ~ake and br~ak a~n~act. ~h~
~5 pr.ior ar~ has ~uxther ~ailed ~n pr~vide an indexing ;~
~echani~m ~hich ha~ a~ceptable ~h~racteris~ics which :t`:
ar~ g~ner~lly adap~a~le ~o deviaes in which a driving
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2~2~
and a driven ~ha~ interse~-~ a~ an angle ~ha~ may be
o~her th~n ~o de~ees.
~ a prim~ry ob~ec~ive o~ the present
invention ~o provide an indexing m~hani~m for : -
intermit~ently dxiving an outpu~ sh~f~ t~lat .. :
inter~e~t an lnput shaf~ at ~omB angl~, and whiçh
dri~es the output shaft in A smooth and acceptabl~
manner. Ik i ~ more par~iaular objeoti~ of th~
pre~Rnt in~ntion to proYide such an ind~xin~
meahanism th~t ~s ¢apable o~ imparting intermit~ent
motion ~c the outp~t ~ha~t with the aapahili~y of
~pti~izing pe~k angular acceler~tion, of pro~idin~
c4ntin~ous an~ular ac~ele~ation that is pre~er~bly
1~ æ~ro at aritical points in the dri~e cycle, and o~
providinq a aontin~ou~ ra~e o~ change o~ angular
.ac~eler~ion ~hat is in some em~odiments al~o
pr~era}~ zero at c~itiaal points in the cycle.
Ac~ording to the prinoiple~ o~ the pr~sen~
i~vention, ~h2re is provided an indexing me~hanism
~or inter~i~ten~ly drivins an ou~put ~h~ft h~ving an
axi~; that ir~terseats tha~ o~ the inpllt s}~a~t at a :
point, ~o as to p~o~ride de~ir~d ac~ele~a~ion
char~terlstics. In the p~e~er~ed e~nbodiment, the
m~hanism opera~e~ to 5~1tOOt~lly ~c~eler~te the oUtpllt
~ha~ ~r~m zero an~ular velacity to a maximum ang~llar
velocity and th~n to smoo~hly deaelerate the ou~put ~-
sha~t b~c~ to zero ~ngular vel4~1ty.
Acaording to the presen~ in~ention, an
indexing meahani~m is previded withl a driving element
which is mounted on the lnput shaft and ~ driven
~l~ment moun~ed on ~he ou~p~t sha~ o~h o~ the
elewen~ are preferably f~rm~d with corresponding ~:
spherical sur~ace~ that are 410sely spa~ed and both ~ -
~en~ered about the point of inter~ec~ion o~ the two
axes.
In certain ~reEerred embodlments, one o~
the elem~n~s inaludes a se~ o~ dxive pins, pre~e~ably
two in number, and prefeFabl~ on the driving element, ;~
whi~h move~ th~rewith in a plan~ perpendi~ular to the ::
~5 element'x axis and ~n a cir~le on the surface of the
sphere. The other ele~ent, pre~erably ~he ~riven ;
e~ement, contains ch~nnels whi~h h~ve ~ammin~
sur~a~es that ~ooperate with the pins and a~e
in~ermittently eng~ged there~y ~ drive the driven ~
elem~nt about ~h~ out~t axis. The channe}s are ~ .
pre~erably in the form o~ slots in the sur~a~e of the :
~le~en~ ~nd ~ave radial wa~ls which ~orm ~m~ing
surfaces th~t c~n be engaged ~y ~he pins.
In accordance with the pref~r~ed em~odiment
o~ ~he i~v~ntion, the ~amming surfac~g of the
ch~nnels ~e shap~d in su~h a way ~s to determine the
relation~hip of the ~otion of the outpu~ ~haf~ to the
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input ~h~f~. The channels or slot~ are in two
se~tion~, one o$~ whic:h is enga~eabl~ y a pin or~ ~he ~ j.
othe~ element to ~moothly and con~ inuou~ly aocelerate ~-
t~e ou~put sha~ ~rom zero ang~lar velocity to a
~aximu~ angular ~eloci~y while the oth~r i~ -
engageable ~ a pin on the qther ele~ent to :~ .
dec~lerat~ ~he output sha~t from ~he maxim~m ~ngular
ve}oGity ~ a zero angul~r velQ~i~y. -~
In c~rtain eml~odiment:~ o~ the pre~nt
inventiGn, ~he indexi~g meahaniæm dri~es the output
~ha~t to a ~aximum an~ul~ veloçity and then
im~ediately returns it ~o a zero angular veloci~y
after a ~ractional ~otation of the ou~pu~ sha~t
t~rough some in~egr~l seg~ent of ~he complete circle ;~
~uah a~ 1/3~ 1/4 0~ lf5 the rota~ion. With such -~
embodiments, the slo~s, or other t~pe of channels
with ¢amming sur~aces, a~e employed in ~, 4 or 5 -~
pair~ re~peativ~ly, one slot of each pair is ,;~
positioned to enyage a di~ferent one of A pair of
pin~ on th~ o~her elemen~, which is prefera~ly the .~
driving el~nent. In ~he alte~native , a aon~inuous ; ~ ~;
slot having ~o c:amming segmen~ ~nay appear on the
driving element ~o engage 3 t 4 o~ 5 pins on the -
drlver~ element. In su~h an em:t~o~imen~ in whiah the
~5 610t: iS loca~ed on ~h~ driving element, one seotion
of the ~lo~ is shaped to aocelera~e the output shaft, ;:
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while ano~her section of the slot i5 ghaped ~0 -
d~c~lerate the ~utpu~ shaf~
I~ certain other emho~iments of the pre~ent
invention, an index.ing me~hanism i~ p~ovided ~or
drivin~ an output shAft in such a w~y ~nat it ~ ~:
aa~elerake ~om ~ zero ~n~ular veloalt~ to a ~aximu~
ang~l~r velocity, then continues t~ rot~e at a
aonstan~ ~aximum ~nyular veloci~y, and then
da~elerat~s ~a~k to zero angular velocity. Wi~ s~ch ::
an em~odimenk, a~ditlonal dri~e mq~ns is provided,
su~h as mating ~e~r~ on tha driving and driven
element~ on th~ lnput and output sha~ts, which :
intermittently engage, as the ac~elerating pin and ;~
sha~ disengag~ ter th~ ou~put sha~t has been
dr~ven ~o its maximu~ angular velocit~, to continue
rotati~n o~ ~he output sha~t through ~n angle at -~
fi~ed ~n~ul~r ~elooity~ Then, a~ ~he d~ele~ating
p~ n and ~lot engage to ~egin de~eleration of ~he
output ~haft ~ac:k ~o zero veloclty, the additional
drive m~an~ di~eng~ge. Su~h embo~imen~ are
p~rtiaularly use~ul ~o~ moYing the outp~t shaft
through large fraational angles, or through an~les of
a ~ull rotation or more, such as ~, 1 1/2, or 2
rot~tions o~ the output ~ha~
~5 Aacordin~ to aert~in embodiments of the ~ , :
present inv~ntion, ~arious speci~ic shapes of the -~
ah~nnel ~lls or camming sur~aces are provided. ;~
, . . .
2~52~4
Pre~era~ly, t~e slo~ or chanr~els are c:-lr~ed in ~uc~ a
wa~ tha~ the pins en~age ~hç channel~i with the pi~s :
moving into and ou~ o~ the ~ilo~ he slots are
our~d, p~eferably in a ~iral~ whi~h ha~; its cen~er --
on the surfae o~ the sphe~e ou~;icle O;e the circle o~
ro~ation o~ the pin~ on the input æha~ lemen~
Pra~era~ly, th~ oirole is tangent to the cirale o~
rotation o~ thç ~iving pins z,~ the p~in~ of initial
nr ~inal enga~emenk o~ a pin with the corres~oncling
510~ a~ zero out;put velocity. Accordlngly, ~he .
center o~ the ;:i~cle on which the slo~ s is in a
plan~ which qontains the lnput axi~, and the point o~ .
contac~ of the pin with the slot At the zero QU'tpUt;
sha~t velo~it~r conta~t point, inc:luding the cen~er of
1~ the slot~ ircl~ The radlus o~ the slo~ curvatu~e
arc on ~he sur~ace of the sphere i~ op~imized, eit-her :.
empiriaally or by computa~ion a~ set for~h herei~
The ~ele~tinn o~ slo~ radius preqisely loa~tes the
:, .
center o$ k~e 910~ c~urY~ a~ a pc~in~ on the sur~a~Ç of
~o the ou~put dri~ elemen~. Preferably, the ~ ~ ~
acaelera~ion and decel~ra~ion slo~s are symmetrical ~:
about a plane ~hrough ~he ~en~er o~ ~h~ o~put sha~t
angle o~ incremental rotation. Such lo~ curva~ure
impar~ a &mooth transition fr~ ma~imum a~eleration
qr decRleration ~s the output sha~t accelera~es to, :
or de~el~rates from, m~ximum anyul~r veloci~y. ;~
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~he location of the cen~er ~f the slot ~-
aurvature cirt:~e el~ewhere c~n provide ~or ~ æero ~ - :
rate o~ ~han~ acc~leration at other points su~h
a~ ~t ~he tran~ition points to ~nd ~rom zero angular
veloai~y. gimilarly, as with other embodlmentS o~
the invention, the ~lot curv~re may a0~ume ~ ~urve ~ ;
~hi~h i~ o~h~r than a ~iroular a~, which can ~e made
to exhibi~ a ~m40th rate o~ change of a~eleration at
va~ioU& points, or t~ optimize the acceleration ~y,
~or exa~ple, minimizin~ the maximum ac~eleration. A
~mooth rate of ah~nge to and from z~ro rate o~ change :~ .
of ~cc~leration approaching the maximum v~lo~i~y is ~ . :
prnvided ~n ~he pre~rred embodiment to prevent
i~pa~ting r~pid t~que reversal, or other rapid rate
}5 o~ change of a~c~leration, or jer}~, to ~he ou~pu~
sha~, partiaularly with the embn~lments ~hat employ
~he constant velocity drive maans o~ gear drive
~etween ~he input and ou~put elements.
~he pre~et invention has the advan~ges o~
~0 pro~idin~ an ind~xing device which f~nc~ions at
various angle~ o~ relationship between the input and
ou~put sha~ts a~d which is ¢apable of impar~ing a
driving relationship to the lnput and output shaf~s
tb provid~ various desired ~unc~ions of ang~lar
veloci~y, aoceleration or rate 4f change o~ ; -
aa~lara~io~ in r~latiPn to the input ~n~ular
v~l~city.
,,.~.
2 ~ ~ ~ 2 ~
~ hese and o~er ob~ec~ives an~ adv~nt~geS
o~ the presenk in~en~.ton will be mo~e ~eadil~
app~rent f~om the ~qllo~in~ d~ailed desaription of
~he dra~in~ ln which~
Fig. l i a pe~p~tive vie~ of an indexing
~ech~nis~ a~ordin~ to the p~inciple~ o~ ~he present
i~vention in ~ rig~t angle ~0~ ~our stop em~dim~nt~ ~.
Fig. 2 i~ a view simila~ to Fl~. 1 o~ ~he ; `
lo ~ame embodiment illustra~lng the ou~put shaft in the
ro~ating condition,
~ ig. 3 is ~ ~ross-sec~ional vie~ alorlg the
line 3-3 of Flg. 1. ..
~g. ~ is a cr~s-seetional view along the
line 4-~ of Fig. 2. - .;-
Fig. 5 is ~ fragmen~ry view part~ally in i~
cro~-sec~lon alon~ the line 5-5 of Fi~
Fig. ~ i~ the per~pec~ive view similar to .
Fig~ 1 of an alte~na~ive e~bodiment o~ an in~exing -~
2~ mech~nism, acqording ~ the present inven~ion, in
which the output i~ lnte~mittently acoeleratçd to a
c:on3~an~ veloc:ity ~ whiah i~ is sustained and t~en
~le~elerated to ze~o velo~:ity produc~ g ~ complete 360
degree revolution O:e the outp~t shaft~
Fig. 7 is ~ view ~imil~r t~ Fig.
~ rating the sam~ embodiment in a position in
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20~5~
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which the o~tput shaft i~ moving at cons~n~
v~lo~i~y.
Fig. 8 ~s a oros~-sec:tional view Along ~h~
line 8-~ ~f Fi~. Ç.
Fig. 9 is a cross-sectional view Along the .
line 9-9 of Fig~ 7. ~ .
Fi~ is a diagram ilJustrating the ;
~ec~me~ric rela~ione~hips of th~ m~chanis~
Fig. 1~
Referring to ~ig. 1, an indexing mechanism
11 ac~ord~ing to one embodimen~ o~ the preserlt ' :~;
invention i~ illustra~ed. The mec:hanism 11 inc:ludes
a rigi~l frame 12 havlng rot~tal:~ly supported therein ; ~.
an inpllt ~haf~ 14, mo~nt~d in a ~earing 1~ ~F~g~. 3
and 4) ~ so as to be ro~atable about an aXis of ; . ;~.
rotation 1~. An output shaf~ 1~ is also ro~tal~ly
suppo~t~d to the frame l~. The ou~put shaft l~ is
~nount~d in a b~aring l~ and hA~ ~n aXi~ of rotation
20 WhiÇh in~er~ec~ the input axis 16 a~ an
interseation point 25~
,.
l~he mRahar~;i sm ~l, in the illustra~:ed
embodimen~ o~ the pre~ent inven~ion, operates to
tr~nslate a c:onstant an~lar rotation of the input
~ba~ ~4 to int~nitterlt angular rc~tation of the
OUtptlt ~ha~t 18. ~Ln ~his i~ ;tra~ed en~odi~nent, ~he ~::
~u~put sh~ft is in~er~it~ently a ::celer~ted from a
:.
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2~5~4
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zero ang~lla~:~ velocity up . o a maximllm ~ngular ~
~ln~i~y an~ th~n inunediately dec~q~ ated ~ak to
ze~o v~locity, ~ h the entire motion carryin~ the .-
4utput ~;haf~ thro~gh a ~P degree ar4 of rotatior
Thus, the ou~put shaf~ 18 in this em~odimen~ has fc~tlr
an~ ar rest positic:n~ at so de~ree .interv~ls around ~ -
the o~tput axis 2 0 .
Th~ s~a~t~ 14 and 18 have mo~n~ed a~ the
ends th~:reo~ intermitkent dri~re el~ments ~2 and 24,
re~pç~tively. The element 2~ is a driving element
which i5 rigidly moun~ed to the end of the input
sha~t 1~ to rotake l;:onskantly therewith. ~he el.ement ;.:
24 is a driven elem~nt which is rigidly m~nted a~
t;he end of th~ output ~ha~t ~ to rotate th~rewith. . ~ ~;
~5 The output el~ment Z4 iS r~tated by ~e driven
e.lement 22 in~ermittently upon engZZ~yement thereby.
Th~ ~lements 2~ and 24 make conta~ g en~agemen~ on
the sur~c~ o~ a sphere, whlch m~y be viewed as an ;
l~na~in~ry mathematical sur~ace S, as illus~r~ted in
ao Fig. lo, ~ cen~ered abo~t an inter~;ection poin~ c o~
.: .: . . ,::
th~ axe~ l~ and ~0, whlch represents the cen~er or
irltexse~tion point 2~ of ~igs. 1-5.
As illu~tr~ted in Fig. ~, the ~Irivir~g `
: . .~- i
ele~ent 22 has ~n inte~nal ~oncave spherical surface .
Z5 ~6 csorr~s~pondin~ t4 and sligh~ly larger ~h~n ~le
~ur~ace S. S~milarly, the dri~ren e~lement Z4 h~g ~n
ex~e~nal convex ~phe~ al sur~ace 2~ c~rrespondir~g to
2~2~
- ~4 -
and sli~htly smaller than the s-lrf~e S. Thus
con~igured, the sphericz~l surf~ce ~ of the driven
eletnent 24 li.~s on the spher~ with;n the sphere ~ ~:
aontaining the ~urface 26 of the driving elemen~ 2Z~
with the Rur~a~e~ 26 and 2~ spa~ed a slnall distance
apart with the surface of the ~:phere 5 therebet~een.
~he mechani~ c~n be ~on~ructed wi~h ~he
spheri~al surfaces ~ and 2a o~ the elemen~s 22 and -~
24 reversed such that the driven elemen~ 24 surrounds
1~ the drivin~ element ~2, ~owever, the pre~erred
embodi~ent is that de~cribed and ill~stra~ed.
The driving elemen~ ~2 h~s mounted ~hereon,
ea~h at the same radius ~r~m the inp~t shaf~ 1~, a
pai~ o~ drive pins 32 ~nd 34. ~h~ pin 32 and 34 are
1~ ln the ~orm o~ aylindrical rollers rota~a~ly mounted
to ~he sur~a~e ~6 ~nd having aXe~ 36 an~ 38,
re~pe~tively lying on radii o~ the sphere, which ~;
inters~c~ the inter~ection poin~ ~ at thç ~enter of
~he sphere $. Re~erri~g join~l~ to ~igs . 1 and 1~
0 a~ the inpu~ sh~t 14 rota~es a~out the inpu~ axis
16, the pins 32 ~nd 34 rota~e al~o aroun~ the input
aXis 16 ~;uch that t~eir axe~s 36 ~nd 38 intersec~ the
sur~c~ a~ th~ ~pher~ ~ along a circle T a~ s~o~n ill ~
Fi~ . lO O ~ ~-
In the sur~ace 28 of the driven element 24 .:
a~e four pairs of catn~ e surfaces o~ channels in ; . ;~:
the rorm o~ cuF~red slots 40, the palFs o~ whic:h 41,
" ~ ~
2~25~ ::
42, 43, an~ ~4, ~re sp~,ce~ at gO de~ree in~rements
around th~e output axi~ 20. The pAir~ o$ slo~s 40 a~e
identioal, and eaoh include~ an accLele~ation ~lo~ 40a
and a ~eceleration ~lo~ ~0~ In ~h,e e~bodiments
~hown, th~ o~ ~a~h pair ~r~ ~ymme~ri~al about
an interse~ting plane, though they need not be
~ymmetri~al in all emhodiments o~ the in~ention~ Th~
~lots 40 ar~L so positloned su~h that, when the inpu~
sh~t 14 anLd drive ele~ent 2~ a~e rotatin~ ln the ~
direction illwstrated ~y th2 arroW 45 in ~ 1, the .~ .
dri~e pin 32 seq~entially enga~es the ac~elerating ; .:
~lot~ 40a to ~ccele~ate the ou~put sh~f~ rom zero . ~.
ang~lar ro~ional veloaity ko the m~imum ro~a~ional ~ ;
velocity whi~e ~he drive pin 34 alternately en~age~
~he deoeleration ~Ob to deaelerate ~e outpu~ sha~t
~8 ~rom a =aXimum an~ular rotational velo~it~ to zero .- -
rotational velocity.
~iq~. 1 and 3 illustra~ the me~hanism 11 -~ -
With the outpUt sha~ 18 ~t re~t or at ~ero angu1ar
~0 ro~tlon. As the input sha~ 14 rotates in ~he :~
direc~ion o~ th~ arrow 45 ~hrough the position shown
in Fig. 1, tha pins 3~ and 34 a~e o~ o~ driving
eng~gement with ~he ~lots 40. To hold the ou~pu~ ;
sha~t 18 ~t rest when the pins 32 and 34 are not ln `~
eng~ç~n~ with any of ~he slots 40, a set o~ lockin~
pin~ 48 is pxovide~, $ou~ in number, which are spaaed
a~ egu~l 90 de~ee int~rvals abo~ the ou~put ~xis 20
~ ~.":
t~ ?~
and proje~i~ radially from the slurPaae 28 o~ e
dri~ren element 24, eac.~ pin 48 position~d o~ ~h~
biseating plane of one o~ the ~lot pin:; 40. Th~i~;e
pins a~ al~o in th~ ~orm of cylinclrical rollers on ;
aXe~ whiah inter~ect the inter6ection point ~ a.t ~he
asnter o~ the phere S in tha diagram of Fig. 1~
When th~ out:put element 24 is in the position shown
in Figs. l and 3, two adjac:ent one3; nse the rollers 48 ;
a~e in enga~ement with the driving element 2~ on ~he
input ~h~ 14 ~ res~ing again~t ~n anrlul~r re~ainin~
sllr~aae 49 ~n the dx~iving element ~2. A5 suoh, this ~ ~s.
pair o~ tha roller~ 4h holds t}~e oUtpll~ element 2~ :
agains~ ro~atl~n on the ~haf~ 1~ Wi~h the slot pair :
41 aligrled i~ the path o:e rota~inn of acceler~ing
rolle~ 32. The sur~ac~E: 4~ ~orms a ring aX~ollt the
axis 1~ which }~as an openin~ or notch 50 ~herein
whioh allo~Ts one o~ the pinC ~8 (in Pig. l, t~e one
,. ~ .
of the pins ~B whi~h is centered between ~he ~l~ts of
the pair ~1) to move ~hrough t:he ring af ~he surfac~e
4~ whenever eith~3r o~ the pins 32 or 34 is in drivin~ `
engag~ment ~ith one o~ the slo~ 40 of the ~lriven . ~:
ele~nent 2~, S@~a, for ex~mple, the depic~ion of the
pir~/slot rel~tionship in Fig. 5. ;~
: `
A~ shown in l~igs. ~, 4 and 5, one of the :
2~ pin~ 4 i~ sho~dn in the notch 50 of the ring ~ as :~
pins 32 ~nd 34 a~e in ~ri~ing en~g~men~ with the
slot~ 40a ~nd 40b, r~spect:ively, o~ the 810t pair 41. .
.~
20~2~ -
-- 17 - - .
~he position ~hown in Fi~s, 2, 4 ~nd 5 is the
position of maxlmu~ angular rota~ion and ~elocity 4
the output sha~t 1~, wlth th~ no~h ~0 and a roller
48 lyiI~g in ~hæ plane of the axe~ 16 and 1~ with the ~; -
pin~ 32 and 34 ~paaed e~ally on o~po~it63 side~ o~
that plane. Xt i~ in ~his positiun th~t ~rivin~
enga~em~.nt with the 510t p~ir 41 is s~ift~d from ; .-
aon~ac~ of ~he ~c~elera~ing pin 32 wi~h the
aoc~lerating slot 4~a to o~ntact O-e the decelerating ..
lo p~n 34 wi~h th2 de~ele~atin~ slot 40~. The magnitude
of the maximu~ angul~r ~elocity of t~e ou~pu~ shaf~
l~ which is achieved at th~ point illustrated in
Figs. z, 4 3nd 5 aan ~ bet~er understood by ;.
~e~erenoe to Fig. 10.
In Fig. lO, ~he axis 16 input s~t 14 ~ `~
int2rsect~ the axi~ 20 output shaft 18 at ~e c~n~er . ~.
C o~ the spher~ S as desari~ed a~ove~ ~he input axis
1~ interseats the surface S o~ the sphere a~ a point
while tha output sha~ 18 int~r~ects the s~rf~c~ 5
~0 ~at poin~ herçon. Th~ sur:eac:ç S of ~he sphere ;~ :
inter~ s the plane whiah c:ontains tb6: axes ~6 ~nd
18 at a circ~ h~ oircle T, whiah :ls a circle on
wh~ ah t:118 pin~ 32 ~ncl ~4 travel as ~he inpu~ shaft 16
rota~es~ int~r~ec~ the cirale U at a poirlt F. The
ma~ num angular ~r~locity of the outpUt shaft 18 will,
~cc~r~lingly, equa~ the pro~uQt of an~ular ~re~ocity of
-- 2 ~
- 18 -
the inp-lt ~haft ~ and the ratio of th~ ara ~ to the
~rc B~ in Fi~. 10.
Controlling ~he a~celeration and
d~3celeratiorl betw~en ~ero and maximlLl~ angular
v~loci~y on ~e oUtpllt shaft i~ act~ mplished ~y th
6hape o~ t~e ~lots 40. The slots 40~ or other :: ~x
c:hannel-like s~ruc~ures o~ ~he sur~a~e 2~ of the
dri~ven elenlen~ 2~, are bounded ~y ca~ning sllr~ac~s 55
which en~age the surface of the pin~ 3~ or 34 to :
impart the, driving motion ~rom ~he input elemen~ ~2
~o the olltpUt element ~4. The separate acceleration
and ~eoelerati.on ~lotæ on the ~pheric~ sur~ace o~
c~ne Of the elem~nts 22 or ~4 ~ ac~cording to the ; ~ ` : ~`.'
pre~ent ir~vention, providç~ the capahility Of .
~o~trollin~ th~ velocity accolerati~n an~l jerk
~har~ateri l;ias ~ccording to the requireme~s of the .
appl i¢atic~n .
Fo~ ex~mple l in certain applica~ions, it
may be d~sirable ~hat, upon appr~aohing maxin~um
~0 angular veloci~y~ the accel~ration smoo~hly and
contin~ou~ly decrease, bu~ with both the --
a~celerati~n, and in some ~ases ~lsu the rate o~
change of accel~ration, ~eing zero at ~he poin~ o~
tra~ition ~o maximum ~nqular velo¢ity, when d~i~ing .
~on~ct ~etween the a~ele~ting pin 32 and the
: a¢cels~ating 510t 40a, for example, i~ b~oken.
5i~ilarly, such conditions may also be ~e~ir~d upun
'.` `.'-"~`.
, ~ .' `"`': ~ ' .
-` 2 ~ ~ 5 ~
-- 1 g -- :
the ~ontact or engagemen~ bçtween the deoeleratiny
pin 3~ and th~ decelerating slb~ 40~ wh~n ~eqinnin~
to de~lerate ~rom ~aximum angular ~eloclty.
Preferahly, ~or smoo~h ~ran~ition i~
des~ed to and ~rom ze~o veloai~y, the slots are
t~ngent to the cirale T at th~ point of ini~ial
con~ct ~e~w~en th~ pin 32 ~nd the slat ~Oa, ~hi~h
occ~rs at the point illu~tra~ed as point D in Fig.
~he determination o~ the poin~ in the cy~le
. . ~ . . ~, .
at which zero accelexa~ion and rate of ch~n~e ~f ~ :;
a~cel~ration ~ay be achie~ed, ~or example, ~a~ be
acoomplished ~y optimizin~ the value of P with a 810t ~:
~Oa ~hich li~s on the circumferenae of a circle V
that is ~angent to the circl~ ~ at poin~ D ~nd ha~ a
oenter whiah lies in th~ plane of the input axis 16
through t~e point ~, ~8 ~ for example, point ~ i n Fig. .
lo~ Such a ~irale ~ will have a r~di~s P about point .
E. It should ~e not~d that p~in~ ~ is ~ixed with :~
2~ re~pect to the surfa~e Z~ o~ th~ dri~in~ elemen~ 22
~nd ~ota~es ~here~ith, w~ile poin~ ~ i5 fixed with
respeat to the surfaa~ Z8 of th~ driven element 24 - ~ -
~nd ro~ates the~ewith. A~ordingly, a~ the two
sph~ri~l sur~aces 26 and 28 ro~ate, four ar~s remain ;~`-
~5 con~tant, the arcs A~, AP, ~E, ~nd EP~ ~he ~o~ement
be~we~n the respe~tive ~omponents is thus that .. ~
b-tween the pin 3~ with respect to ~he slot 40a, as ~- -
. . . . .
- '`, ...
'"';'`,''..`'.",.'
' ~. ,' `~ :'
2~2~ ~
~ ~o --
the point ~ rotat.e ~bout ~he outpu~ aXis 20, ~nd as
point P rotateC a~c~t the input axis 1~. ~he ~ . -a
dec~lera~ion slot o,Ob wo~ld ~e ~onfigur~d
s~nm~triaally ~o provi~le ju~t ~he reverse, with the
loq~ion of it aenter E lying in 1:he pl~ne o~ ~he ~;
poin~ D ~t ~rhioh ~e pin 3~ disen~Ages the slo~ 40b.
~oc:ation o~ th~ point E and ~h~3 length ~f ~he arc 13
o~ slo~ radius, whic:h l~est E~rovides ze~o a~celer~on ~ .
and j er~c upon transiti4n ~o and ~rom maxi~um velo~:ity ~;
~n be det~ ed by ~he compu~er program con~aine~
in Appendix A here~o, written in ~ roso:~9 Q~ k
Ba~ ver~ion 4.5, or th~t cont~ined in AppendiX B,
t~ri~ten in C language. .
Another eln~3odiment OI the invention i5
illu~trated in Figs. ~ ~. This embodi~nent is similar
to thal; of Figs. 1-5, but has pxotri~ion for
additic~nal dr~ vin~ en~a~ nent be~ween ~he driving and
d~iven el~3ments to drive the output sha~t at constant :
ve1oclt~ a~ter the ~cc:elerating pin disengages the
a~c:el~rating 510t and }:~efore ~he deceler~ting pin
engage~ the deoele~a~ g slo~
In khe emb~diment~ of Figs. 6-9 ~n indexing
device 60 i~; provided wherein ~h~ r~llers 32~ anà 34a ~-~
a~ ~pa~ed ~n the driving elemen~ 22a, which is . -.
: . . - , ., .,: . . .
~uppor~ed on ~he end o~ input sha~t 1~, to engage : -
r~spective ~ccel~ration and dec:elera~ion slo~s ~
and ~lb provi~ed in the output element ~4a, which is
~.... ..
2 ~ ~ 5 2 5 ~
- 21
~upported on ~h~ ou~pu~ s~aft l~a. ~he sh~f~ 14a ~ -~
and 18a are respec~iYely supported in ~rings 15a
and l~a to frame 12a. ~3 wi~h the emhodi~ent
illustrated in Figs 1-5, in the embodiment ~-~
s ill~s~rated in ~ . 6~~ e a~e~ l~a and 20a o~ the
shafts 14a and l~a interseot ~t righ~ angle~ at a
~ent~r poin~ a5a~ which i~ analugous to point 25 in
the embo~iments of Figs 1-5 and t~ poin~ ~ in
Fig. lD.
~0 The ~o~s 61a ~nd ~lb correspond in
funation ko ~he ~lo~ 40a and 40b of Figs. 1-5. The .
slot~ 61a and 61b ~re di~ferently spa~ed ~han the
slo~ ~Oa ~nd 40b to allow for constant veloçity .;
rotation a~e~ ~cceleration ~hrough enga~emen~ of ~he
p~n 32a wi~h slot 61a and be~ore deceleratio~ ~y
~nga~e~ent o~ the pin 34a in the slot 61b. T~e - :
oon~tan~ velocity is ~aintai~ed by a bevel driving .-
~ear Ge~ment 71 on driving element 22a positioned to
int~rmitte~tly enga~e a mating bevel driven gear 72 ~ i~
on the ele~en~ 24a. The lenyth of the ~rc o~ the
driving ~ear s~g~e~t 71 and the ge~r r~tio ~et~een
th~ ge~r~ 71 ~nd 7~ may ~e s~le~ed ~t any value ` . . ;. . ~ .
deslred ~or the constant velo~l y ro~a~ion angle of
~he outp~t sha~t 18a.
The slots ~la and 61P may be, howe~er, of a
di~feren~ optimal shape than the ~hape pre~er~ed for - -:
~he embodiments of ~igs. 1-5. Pre~erably, for the -~
2 ~ 4
-- 2 2 ~
embodime.nts of Fi~s. ~-~, the ~loks are also cirçular
~nd s}~aped by sele~tin~ ~ sl41; ~adiu~ either
empirically or ~y solu~ion o~ the equ~tion~ as ~et
¦ for~h in khe p~o~ram of ~he attaahed appendix, ~o
pr~vide ze~o acceleration and jerk, or ra~e of change
of ~ccel~ration at the point~ ~here the mating ge~rs
71 and 72 make and ~reak engaging ~Pnta~t ~i~h eaoh
other.
~he output element 2~a ~ur~her iB provided
with a pair o~ lo~kin~ rolle~s 48a which, ~s ~i~h the
~ollers 48 o~ the em~odiment o~ Flgs. 1-5, function ~
to lock the output element 2~a and thus the o~tp~t
shaft lBa a~inst rokati~n durin~ ~he zer~ motion ~;~
portion o~ th~ in~exing ~ycle, be~a~e acc~lera~ion
~rom zero b~ eng~g~ment of the ac~elerati~n lo~ ~la -.~
b~ the ac~ler~tion pin 60a, and a~ter disenga~ment - .. ; .
o~ the decelera~ion slo~ 61b b~ the deceler~ion pin .:~
60h. The loc~ing mo~ion of ~n~ pins ~a is achieved
by ~he loakin~ ring segment 49a on the ~ri~i~g : :
element ~a, Whi~h parkially surrounds the inpu~ ~`
shaf~ ~4~. The rinq _egmen~ 49a, ~s with the ring ~
o~ Fig~ 1-5, is provlded wi~h a no~h 50a to releaae
the pin 4~ ~nd al~ow the outp~t el~men~ ~4a a~d ---
o~tput sh~t z~a ~o rotat~ ~h~n being driven by the . --
eith~ ~he ge~r 71 or pins 32~ ~d 3~a o~ the input - -
elem~t 2~a~
2 ~ ~ 5 ~
- ~ 3
'rhe pr~.ferred ind~xing mech~nism ~y be
con~idere~ a~ a 4-bar l inka~e lald out o~ a ~phe~
The ~o-lr link~, or o~n~tant arc length~;, are khe ~o~r
aras A~, Al:~, BE and I~ esaribed i~bove in conneatinn
with Fig. 1~. ~he design in~tolv~s spherioal
trigonometry. Th~ ar~ AB and Al~ ~ill be givf~n
value~, an~l tho arcs BE and DE m~y he deri~/~d ;~
:,i~::
empirically or loy the compu~er program o~ the
appendi~. The ~rariables representing ~he link~ ~nd
in~tlal angles whiah ~onstl~u~e ~he de~ign p~rame~rs
are, ~ith rePerenae ~o F~g. 10, a~ ~ollo~
SA = Shaf~ Angle link (arc: p~B) . ~ :.
- ~ .
~ - ~ri~te l inX ( aro AD)
P = Slot C~rvature link (ara DE) -
~5 n = Follower link ~arc BE) ~ -
Ini~ia~ Prive angl~ ( ~pherical triangle BAD) ~:
,B = Initial Driven angle ~ spherical ~riangle
~BI~
In Fig~ 10, aras ~A, C~, CD and CE are
equal. All links are loc~ated on tl~e ~ur~ce o~ a
~phere~ ~ith aon~t~n~ radius. ~r~e initial angle~ a `
and ~ are the angl~ at ~he! poin~s w~ere ~he
correspon;ling pins and ~ilots mak~ o~ brea~ contact at `
~er~ an~ular v~l~ci~y. ~. .
Desi~n con~idera~ions allow the use of what .
~nay be ~alle~ the "gearle~s~ (Fi~s. 1-~) and ~he
"gea~red~ igs~ 6-~) em~odimen~s, wi~h the gez~red `; ~`
., , ., .. :
:,,. . . : . . ~ . .
. ~ ~ . .: . : ~ . - . . :
2~52~
_ ~4 _ :
em}~o~im~nt ltilizing bevel ge~ring For ~ const~nt . - .
ve}oaity por~ion o~ the in~X pe~iod ~ The ~xes o~
th~ drive roller~; 32 or 34, locateA at: point D,
~hoUld pasE; thro-lgh the cerl~r o~ th~ ph~xe loc:Ated
a~ pvint
~ h2 ~Ige~rles~l sy~te~ ha~ ~ f ixe~ L~ and
relation~hip depending Q~l the illtermittent or ou~put
a~c seleot~d. Gptimi~ation D~ rho yives kinem~ic
values o~ ~ero a~elera~i4n ancl the lo~e~ j erk
~0 ~pulse) ~t mid-mo~ion, or maximum veloci~y, whel~e . ~ :~
tor~que reversal o~urs, This systqJn is pre~e~red ~or .
~rac:tiQn~1 output inAexing ~ 1 . e ., ~ -stop , 4-~:top , 5~ . '-
stop, etc,~. Wit~ tha "geared" system ~notion
5ele~tion is dependent on peak (te~nin~l) veloci~y or
gear ra~io, wher~ th~ solution provi~le~ the initial . :
v~lue o~ hs ini~al val~le o~t ~j ~ and rho give
kir~em~1;ic ~ralues of zero ~cc:ele~ation and ~er~ rate .- --
o~ ch~nqe of t cceleration or ~erk (puls~ fo~ smoo~h " . ^
tranttttti~ion into the "gearedl' ~constant ~eloity)
20 portion of ~he index pe~iod, q~this system is usefu1 ; . :.~or 50me ~racstional ou~put inde~inS~ and is pre:~erred -
for multi-revolution OlltpUt indexing ~ i . e ., 1 ....
r2~1ution, 1 1/2 revolution, ~ re~olution, etc~
O~her ~r~riahles used in the compu~er ~ -
.,. .:.
2~ progra~n o~ the appendix a~e as foll~ws: : .
~E~r~INaB = ,B- = Angle ~etween arcs BD and ~E ~ ~
: , . .:.
-,:
2 ~ ~ ~ 2 ~
- 25 ~
8A -- sha~t ~ngle or an~le between CA and CB,
e.g., ~/~ for a ~o c~egree me::hanis~n, whiqh iB a
c:on~tant
~el~aD ~ S - drive link nr ~rc~ length b~tween
dri~re pln and input axi~
~ho = P = 510t ~urva~r~ linl~ or slot aur~e
radiu~ arc len~th $r4~ E t~o D wheln pin i~ in 510t, ; .. ~ --
which i6 a oonstant
~oE~leg ~ n 5 arc BE ~etween OUt~ xi~ and ;
1~ ~ente~ oî slot curYature ci~le, whic~h is ~ çonstant .:
T~ rA ~ ar~gle between ~ and ~ in~ermit~ent
output ~notion)
BEq!A3 = ~E~A ; . .~ .
~I!A0 = BEq!A3 or q!~TA at p~int of initial ~or ;~
~in~l) contac~ a~ the acçeleratirlg ~or the
decelerating) drive pin n~er~ (or lea~te4 ) a slot ; ;.
~de~ined a~ the initial conditiorl poirlt)
CAPA~P~A = angle be~ween AD ~nd ~B ( cons~nt
input moki4n) ~:
; : 20 I~.~PHA0 =~ CAPl~IIP}~ at poirlt of initial c~ondition
poin~
lo~yi~ = deltaD + r~o at ini~ial ::onclition
point
~;~NAO = a.ngle be~ween AV ~nd E~D at initial
Z5 condi~ion point
: ~ , ' ~'''~.
,;
::,
2~2~
- 26 - - :
The obj~ctive of t~e op~imization which i~
accompli~hed by the program is to ~ol~e for A~H~
~TA0, ~h~ and topl~y.
one spe~i~ic solu~ion of a yearles~
e~odiment ill~tr~ted in Figs. 1-5, i~ a -Eour Stop ; .;
dri~ for produ~ing sa~ o~ output !sha~t ~otatian ~or ~.
~ Of inpu~ s~a~ ro~ation, wi~h th~ o~tput shaft
rest ~or 270i of inp~t sha~t rotation. For such an
embodim~nt, the de~ign having p~rame~er~ will ha~e
the ~ollowin~ value~ ~or both ~he acceler~tion slo~s
and the deceleration slots, wi~h the slots b~in~
m~ r~or ima~es o~ each other in a ~isecting plane
t~ro~gh th6l ~utput axis s ~ ....
SA = 90 ~ ~ ~
~5 a - 22.5~ !,'".,'.'-.. '~,''.
- ~2.$~
P = ~6 . 948
r~ -- 3 2 . 5 8 5
one ~pecif i~ solution of ~ geared ~ . .
em~odi~ent illu~tra~d in ~iys . 6-9, is a ane half
revolut~o~ index~ng ~e~h~nism which produces 180~ of
ou~ut sha~ rotati~n ~or 2~0 of input shaft `- -
rotation, with the output shaft at rest ~or 130 of
z~ ~he rota~i~n of the inpu~ shaf~. Fo~ such a geared
de~ign, the para~eter ~alues are as ~ollows~
.....
SA = ~
,: -: :-
2~2~
-- 2 7 :
~= 38.172~ ~-
,~ = 2 5 . 913 7
~ ~ 38.1738~
P = irjl. ~37~
n~ 31~.17
Gear ra~io = 1 to ~
Drlving ge~r arc ~ Tot~l ou~pu~ angle
çar ratio)
+ 44 = 130.~
While only pre~er~ed. ernihodimenk~ of the
invsntion ~re de~cri~ed, pere;ong skilled in the ark
to which it applie~ ~ill rEa~lily app~eciat~ ch~nges ~.
and modific~ions which may loe matle without depa~tir~y ;~
~rom the spirit o~ ~he inven~ion. Therefor, the
limitatinns h~rein are irlt~nded only t;4 be ~hose ~at `'
~or~h in the claim~
. , ,;,.. "~ ,.
, .. .. .
~,'."'.,. ~.
. ''.'. '~
- . .
.~
. '~- . ",.
