Note: Descriptions are shown in the official language in which they were submitted.
WO 96/08341 ~ 9 ~ ~ PCT/US9S~11941
TORQUE TRANSFER DEVICE
FIELD OF THE INVENTION
This invention relates to a device for 1- dl ,~r. i"g torque by continuous loop
direct drive means which Ll a~ r~ torque from a first drive gear to a seco, Id drive
gear, and is particularly directed to a device for the L, dl ,~fer of relatively high torque
within a co-,rined space, or where the device is enclosed in a relatively small
5 housing.
BACKGROUND OF THE INVENTION
There are many devices which L,ar,s~er torque or (uLaLional velocity from
10 one point to another. Chains, belts and similar direct drive means lldn~r~;r
roLdlio"al movement from one gear or pulley or similar drive means to a second
or subsequent gear or pulley or similar driven means.
In some a~ lic~l;o,1s, it is desi,c,ble to L,d"srer relatively high torque from
one point to anuLl,er point or from one device to a"uLl,er device. In such
1~ arr'~ sns, space limitations may be a factor. The relativeJy high torque to be
Ll dl l~r~l ed may preclude the use of torque L, a"s~er devices which cannot handle
heavy duty loads while space dûes not permit the use of large devices.
An example of such space lil "iL~Liûns are torque L, c"~er devices which are
placed within e"closures. Examples of devices which L~ dl ,sr~r relatively high torque
2û are tools which are used to tighten f;~sLe"er~ by the ~" c~tion of torque. Engines
and ",oLor~ use torque Lldnsrt:r devices both o,~erdLionally such as calllsl
drives, and as power take off devices, such as chain drives on " ,otor-;ycles. High
torque and limited space is a factor in such devices.
~ Various wrenches, e,~L~"sions raLcl1eL~, ada,uters and power L, dl ,~r~r tools
25 and devices are ~iscloserl in the prior art. Similarly, camshafts and similar devices
are driven by the ~rplication of relatively high torque where space for the
WO96/08341 ~ 9 9 6 ~ PCT~S95111940
..
~pplic~l;on of the drive means is limited Problems are encountered with such
devices where the devices are enclosed in relatively small housings, or are
otherwise required to be relatively co",,l~aL:~ in comparison to the torque to be
L,dr,srer,ed. Co"l,llo,l problems experienced with the devices of the prior art
5 include friction and wear between the housing of the device and the drive means,
in~e~ te sLlenyLll of the drive means or gears, and inadequate or illl,uroper
ell~agelllellL of the drive means and the gears due to space lillliLdLiullS.
SUMMARY OFTHEPRESENTINVENTION
The present invention is a device which L, Cl l~r~r~ torque from one point to
a seco, Id remote point of the device. A drive means or drive tool inputs torqueinto the device at a first point, and the roLdLional movement, and torque, is taken,
15 or harvested, from the second rell,oLe point. Typically, the Llc"~rer of the ,uLaLio,I
by the tool will be along a path of travel which is not on the same axis as the
ruLdLiu,, of the drive tool.
The invention incorporates a direct drive means which connects a first drive
gear to a second drive gear. The first gear rotates as torque is a~u,ulied to the first
20 gear, and as the direct drive means is el ~yayed by the first gear, the direct drive
means engages the second drive gear, causing it to rotate.
The direct drive means is COI I IIJI ised of a pluralitv of links contlecLed to form
a continuous loop. Each link has an arcuate shape of con~LanL dia"lt:Ler which
cor,es~Jonds to the outer circumrerence of the drive gears. The links are joined25 end to end and pivot relative to each other. Each alL~rl ~dLin~J link has an orifice
which receives a tooth of the drive gear as the link rotates through the gears.
The use of links having an arcuate shape of co,lsLa"L diallleLer c~uses the
links to form a ,IJol Lion of a circle as the links rotate through the gears. This partially
circular shape corresponds to the circull,r~-e"ce of the drive gears, and e~L~u ds
30 from the circu~tellce of the drive gears. Particularly when the device is used in
WO g6/08341 21 9 ~ g ~ 3 P~/US95J11940
limited space, such as in a housing, the arcuate shape of the links allows the
device to fit within the limited space. Further, the use of links having an arcuate top
surface, with some links having a smooth top suRace, results in minimal frictionand wear if the direct drive means conLa~;, the housing. Other features of the
5 invention are ~ .arenl from the draw;r,y~ and the descf~ LiGns herein.
DESCRIPTION OF THE DRAWINGS OF THE PREFERRED EMBODIMENT
Figure 1 is a frontal view of a drive gear.
Figure 2 is a top plan view of a section of direct drive means showing
l I IcLin9 links, with an arrow indicating the inse, Lion of a pivot pin to jointhe links.
Figure 3 is a side view of the section of direct drive means of Fig. 2.
Figure 4 is a side view of a drive gear of Fig. 4, partially se~iliulled to
the teeth of the drive gear.
Figure 6 shows the drive means as it rotates through the drive gear,
with arrows indicating the direction of rol~lion.
Figure 6 is another view of the device as shown in Fig. ~.
Figure 7 is a view of the device positioned within a housing.
Figure 8 is a side view of the housing of Fig. 7 partially sectioned to
show the direct drive means.
Figure 9 is a partial view of the housing showing a drive gear posi~iolled
within the gear housing.
Figure 10 is another view of the device shown in Fig. 9.
wo 96108341 ~ 1 9 ~ 9 6 3 PCTIUS95111940
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention is characterized by a direct drive means which is r
driven by a first drive gear, or pulley, or similar roLdLiu,,al device, which, in turn,
5drives a second drive gear, a pulley, or a similar roLaLional device. The direct drive
means then Ll ~"~rer~ torque from a first ruLd~ y member to a second, or perhapssl Ihsegl lent, roLaLi"g " ,el, Iber.
Rer~,, i, ,g now to the drawing figures, Figure 2 shows a sectio" of the direct
drive means. Each alLer"~Ling Iink 2 of the direct drive means has an orifice 6
10therein which ,~ceives a tooth 10 of a drive gear 8 as the direct drive means
rotates through the drive gear. Each remaining link 4 has a smooth and closed
top surface 12.
The continuous direct drive means is formed by a series of allen~aling links
2 which are connected to one of each of the re",ai"i. ,g links 4 at each end, until
15a continuous loop of the required length is for",ec~. The links are pivotally
conlle~ted, so that the links pivot relative to each other. As shown in Figure 2,
each alLer"ali"g link has two arms 14 exLendiny from each end of the link. Each
re",ain;.,~ link has a protrusion 16 extending from each end of the link. The
protrusion is inserted ~eL~rccn the two arms, and the links are joined in a pivotal
rasl~io" by a connecting member which ailows the pivoting or limited roLaLiul, of the
links relative to each other. The conne~ti,lg member may be a pin 18 which is
i"sel led through the two arms and the protrusion to join the links. The pin maybe fixed in the two arms of the aller, l~ling link, with the remai"i"y link allowed to
rotate about the pin.
Each of the links has an arcuate shape of con~lc"l radius as shown in
Figure 3. Each of the links has the same radius, and is of app, c,xi" Idl~,ly the same
length and width. The links have a bullul " surface 20 of co n~l~l ll radius and a top
surface 22 of co":.lanl radius, which makes up the yenerally arcuate shape of the
links. For the purpose of this ~lisclosl~re~ the bulluril surface of the link is defined
21~963
WO 96/08341 PCT/US9S/11940
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as the suRace of the link which a~oi"s the drive gear, while the top surFace of the
link is o~J~osiLe the drive gear. When the links are viewed from the side, as in F1g.
3, the top surFace and bottom surface have a concentric, arcuate shape, which
may be rounded as the ends of the links are formed.
The links are pivotally joined end ~o end to form a continuous loop. The
end of the link is defined as the part of the link which is attached to or joins with
the next, or ad5~,ini"y, link. The continuous loop direct drive means rotates through
a first drive gear and a second drive gear. A drive gear 8 is shown in Figure 4.The drive gear has an outer circu""~re"ce 26. This outer circu",~re,~ce is of a
radius which is ye"erally the same as the radius of the bottom surface 20 of thelinks. The outer circu""e,~nce forms a circle. A plurality of teeth 10 e,~L~nds
radially from the drive gear, and more speci~ically, from the surface which forms
the outer circulll~ere"ce of the drive gear. The drive gear may have ~I~"yes 30
on one or both sides of the drive gear.
Typically, the drive gears will have a void 32 in the center which provides
a means by which the drive gear may be driven, and power may be taken from the
drive gear. The void may be provided in the drive gear for insertion of a drive
means to drive the drive gear, and a void may be provided on the r~",~ i"g drivegear for i"se, Liul, of a driven means, or power takeoff means.
Co"""o"ly, the ,~Jr~sellL invention will be used with hand tools or power
tools. Hand tools and power tools in use commonly use six point, or hexagonal,
engaye~ "ent means, or twelve point el ~yagel "enL means. Accwdi, Iyly, the device
as shown has three teeth exLendi"g from the drive gears 8,24. The teeth
cones~Jund to the flat spot in the void of the gear. Since each alL~InaLilly link of
the device has an orifice for receiving the teeth, the sum of the arc which forms the
buLlo", surface of six links joined Log~LI ,er will equal the outer circu"~rere"ce of the
drive gear. Stated otherwise, each link has a length along the arc which forms the
bottom surface which is approximately one sixth the outer circL"~ rence of the
drive gear. The length is approximate since the links are joined end to end, and
WO 96/08341 PCT/US95/11940
~1~9~
the buLLoi,, surface of the individual links may actually be somewhat longer than
one sixth of the outer circu",rerence of the drive gear.
In use, a gear is rotated by ap~lic~l;on of torque from another roLaLi"y
device, or drive means. The roL~Ling device could be any known tool, including
5 a w,encl1, ratchet, screwdriver, or a power tool, a motor, or a t,d"sr"issio,l, or
other device which will apply a rolaLional force to the gear. The rc,L&Lio,- of the
direct drive means by the first gear 23 causes rotation of the second gear 24. In
this " ,a"ner, torque is Ll dl ,:,ren ed to the second gear. Power take off means may
be supplied, and arp' c~tion means, such as a tool, a generator, a pump, or other
10 device which is ~ ted by the applicaLion of torque could be used. For the
purpose of increasing or dec, easil lg torque, or incr~asil ~y or decreasing rc.L~Lional
speed, gears of different effective diameters could be employed, if space permits.
As shown in Fig. 5, the direct drive means rotates through the gear, either
driving, or being driven by, the gear. Each of the alLel, la~ links engages one of
the teeth of the drive gear as the direct drive means rotates through the gear. The
bottom arcuate surface of the links contact the outer circl-" ,rere"ce of the drive
gear. The bottom arcuate surface of the links is approximaLely the same radius as
the radius of the surFace of outer circ- ~ "rere"ce of the drive gear. The direct drive
means engages the gear and enters the gear between the na"yes of the gear, if
20 flanges are used. Further, the for",dlion of the partially circular shape within the
gears by the links, which is an exL~ :"sio" of the radius of the gear, means that the
presence of the links within the gears sl,enyll,ens the gears and the device. This
feature is important since the ~.rese"ce of the void 32 weakens the gear. Very little
" ,aL~rial may be present between the void and the outer circ~l "r~re"ce of the gear
25 where hexagonal drives are used.
The device may be placed within a housing 36. The housing may be
~lar,gaLed. A longitudinally and cenLIdlly disposed wall 38 may be placed withinthe housing, if used, to separate the portions the drive means moving in opposite
directions as the gears rotate. The wall may have a lubricant or low r,i~iLio"al
WO 96/08341 2 1 9 9 g 6 ~ US9~/11940
quality, by the use of a rllaLerial such as teflon at the point of c~ ;L of the drive
means with the wall. The arcuate shape of the top surface of the links f~ es theroLdliufl of the device within the housing which will usually have an enla, ~ed gear
housing of co,ls1t",L radius on each end, as shown in Fig. 7.
The tolera"ces of the direct drive means are critical. Due to the large
number of links, small devidLions add up. An adju~L"~e"L means 40 may be
in~ e~ The adju~L,.~"L means allows one or both of the gears to be pushed
toward either end of the device to take up slack in the direct drive means as
needed. The adju~l" ,e, IL means may be connected to or extend from the wall 38.1û The adjusl",enL means may be secured as desired by a locking screw or other
locking means. A slot may be provided for the locking means to provide for
adju~ nL of the adjustment means.
The housing may be arcuate. An object of the ~rese"l invention is to
provide a device which will lra~,:,rer torque to a point where there is difflculty in
po~ilio"ing a drive. The use of various shapes including straight lines and arcs for
the housing furthers this object of the invention.
A primary goal of the ~JresenL invention is to provide a torque Lransrer device
which may be used in ~rplic~lior,s where a great amount of torque is to be
Il ~"sr~., ed, but oper~ u~ ,al space is limited. Accordingly, the configuration of the
2û direct drive means is critical to the invention and the use of the arcuate sl ,a,ued
individual links of collsLc,,L radius accol"plisl,es a goal of the invention. The
arcuate shaped links form a ~,a, Liz-l'y circular shape as they rotate through the
gears, Ll ,ereby " ,; ,i" ,i~i"g the space occupied when co" ,~Jare~ to other possible
configu,~aLiol,s. The arcuate top surfaces of the links have no e,~Lt:nsions or
2~ protrusions, and the shape of the top surface ",i"i",i~es friction in the event of
contact of the links with a housing or other env;ro"",e"L in which the device isused. While the device is very space erric,e"L, the structure of the links provides a
direct drive means which is extremely strong and c~r~l~'E of carrving high torque
loads, with minimal loss of energy due to friction.
WO 96tO8341 PCT/US95/11940
~1~9~3 ~
The best mode of using the device is as e~le"sio" for tools. A drive, such
as the drive of a ratchet or air wrench is inserted into the first drive gear 23. The
direct drive means t, ~,-srer:i torque to the second drive gear 24, and a socket or
other tool can be used to li~hL~I ~ or loosen a threaded fastener at a loc~tion which
5 is remoL~ from the w. ~, Ich. The device is particularly suited to such an application
since tools for torquing threaded fasteners must be able to handle high torque,
while the space in which such tools are used is frequently limited, meaning that the
tool must be as small as possib!Q. Other uses for the device are a,u~,are, IL from
the . ~ ,iQslJre of the device herein.
It is not ! ,ecess~. y that the drive gears rotate within the same plane. The
applicalioll of torque may be directed to position the device to rotate on a plane
which is perpendicular to, or otherwise dirrert:nl than, the plane within which the
first gear rotates. One or more idler gears could be used to facilitate such
.li, e.,Lional ul ,ar,!Je.
