CA1076844A - Power drive transmission assembly - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

This invention relates to a novel power drive assembly for use with a prime mover. The assembly comprises a rotatably supported first shaft and a rotatably supported second shaft spaced from the first shaft and parallel thereto. A pair of pulleys are provided and the lateral movement of the second half portion of the driving pulley relative to the first half portion is fixed by a manual control acting together with a feedback loop. This loop comprises a load sensor which senses the load on the prime mover and an automatic voltage level setting circuit. This circuit is coupled between the manual control and the power means that move the second half portion of the driving pulley. The output of the load sensor is coupled to an input of the voltage limiting circuit such that the maximum level of the voltage applied to the power means is fixed by the load sensor. If the load on the prime mover exceeds the set level, the voltage limiting circuit will reduce the voltage applied to the power means in response to the output of the load sensor to reduce the effective pitch diameter ratio between the driving and driven pulleys thereby preventing the load on the prime mover from exceeding the predetermined maximum load set by the load sensor. This device has overcome the problem of radial imbalance of the prior art and provides a greater improved and efficient assembly.

Description

1~768~
This is a divisional application of patent application serial number 239,932 filed on November 17, 1975.
BACKGROUND OF THE INVENTION
1. Field of the Invention :` _ Power drive transmission assembly.

2. Description of the Prior art In the past, various power operated assemblies have been proposed and used in an attempt to automatically control the pitch diameter ratios of a driving and driven pulley connected by a V-belt in accordance with the rate o~ rotation imposed on one of the pulleys. Such prior art devices have, in the main, utilized centrifugal means to attempt to accomplish this result, but such centrifugal means are effective in but a limited range, and have the disadvantage that they impart a radial imbalance to the system.
The primary purpose in devising the present invention is to supply a power drive transmission assembly which can be automatically or manually controlled to provide a desired pitch diameter ratio to the driving and driven pulleys engaged by an endless V-belt. This ratio is achieved by varying the pitch diame~er of the driving pulley only, and the `~
pitch diameter of the driven pulley automatically varying în accordance therewith due to the spring loaded structure of the driven pulley. The change of the effective pitch diameter of the driving pulley only is accomplished by moving a second portion thereof relative to a first portion, which increases or decreases the pitch diametler of the driving pulley. The pitch diameter of the _~-, .. ..... .. . . . . . . .

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drive~ pulley is also controlled bv the belt tension, and . the ma~nitude of the sprin~ loading on the second hal~
: portion of the driven pulley.
A major object of the present invention is to provide a power transmission assen~ly for a prime mover, suc~ as an internal combustion engine, which assembly may b~ so adjusted that a driving pulley, driven pulley and connecting.V-belt that for~ a part thereof are so con-: trolleG and so cooperate with power means and a sensing device that detect both the rate of rotation and the lat-eral position of a second movable half portion of theariving pulley relative to a half portion.that rotates in a fixed position on the-driving shaft, that the power means is energized to vary the lateral spacing bet~een the ~5 first and second half portions of the driving pulley that : a ~esired pitch diameter ra.io is achieved between the driving and driven pulleys. As the lateral spacing be-tween the first and second hal.f portions of the driving ; pulley is varied, the ter.sion on the V-belt is increased or decreased, and the effective diameter of the driven pulley is varied by laterall~7 moving a second spring loaded second portion thereof relative to a first portion of the ariven pulley that is rigidly secured to the driven shaft, with the ratio between the pitch diameter of the driving and driven pulleys when the invention is operating at all times has a desired relationship to the torque curve of the prime mover.
Another object of the invention is to supply a ..

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power transmission assembly that when in operation effects an infinite number of variations in the effective pitch diameter ratio of the driving and driven pulleys without loss of power, is at all times in radial balance, requires no radially movable parts or weights a~d in effect uni-formly shifting the pitch diameter ratio of the driving and driven pulleys without being dependent on the rate of rotation of the driving pulley.
A further object of the invention is to supply a power transmission assembly that is easily and con- ;
veniently adjusted to a particular torque curve of a particular engine or prime mover, and when so adjusted will continue to automatically have a desired relation_ ship to the torque curve of the engine as the driven pul-ley is subjecteddto varying loads.
Another object of the present invention is to supply a power drive transmission that has a broad capa- ' bility to accept a wide variation of~engine drive speeds, horse power, and torque output, and permit greater effi-ciency to be obtained from the engine inasmuch as the -power drive assembly does not require the capability to sense torque being applied to the driven pulley.
Yet another object oftthe invention is to fur-nish a power transmission assembly that permits upward and downward shifting of the pitch diameter ratios of the driving and driven pulleys without the driving force being disengaged therefrom.

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1 To this end, in one of its aspects, the invention provides a power drive assemhly for use in combination with a prime mover comprising:
a rotatably supported first shaft;
a rotatably supported second shaft spaced from said first shaft and parallel thereto;
a first pulley definecl by first and second halves, said first half being rigidly secured to said first shaft and said second half being slidably mounted on said first shaft but non-rotatable relative thereto;
a second pulley defined by first and second halves, said first half of said second pulley rigidly secured to said second shaft, and said second half of said second pulley slidably mounted on said second shaft and substantially non ~
rotatable relative thereto; `.
an endless V-belt associated with the first and second pulleys;
force exerting means that tends to maintain said .
second half of said second pulley~ in a position relative to said first half thereof such that the effective pitch diameter of said second pulley is maximum;
spring means that tends to move said second half of said first pulley to a predetermined maximum spacing : relative to said first half thereof; ~:
a first means operatively associated with said spring means for moving said second half of said first pulley relative - to said first half thereof when said first means is energized;
and . ;
a second means for energizing said first means in :
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1 accordance with a predetermined relationship thereby varying t~
effective pitch diameter ratio of said first pulley and said second pulley relative to the V-belt, wherein the second means comprises:
(i) a third means for pxoducing an output having variable magnitude, said output being coupled to and energizing said ~
first means; --(ii) a fourth means for sensing the load of said prime mover and g~nerating an output whose magnitude is related to the magnitude of said load; and (iii) a fifth means for fixing the maximum magnitude of -~
said output of said third means in response to the magnitude of said output from said fourth means whereby said maximum magnitude corresponds to a maximum preselected load on the prime mover with which it is in combination. : :
In another oi its aspects, the invention provides, in combination with a prime mover having a drive shaft to which rotational power is transmitted by said prime mover, a power . drive assembly operatively associated with said prime mover, 2~ said assembly comprising: - :
a rotatably supported driven shaft spaced from said driving shaft and parallel thereto;
: a driving pulley defined by first and second halves with said first half being rigidly secured to said driving shaft, and said second half being slidably mounted on said driving shaft, but non-rotatable relative thereto;
a driven pulley defined by first and second halves, said first half of said driven pulley rigidly secured to said driven ::
shaft, and said second half of said driven pulley slidably mounted on said driven shaft and substantially non-rotatable relative thereto;
an endless V-belt associated with the driving pulley ~ ~ ~b -~''., 10'7~Gi84~ and th~ driven pulley;
force exertiny means that tends to maintain said sccond halE of saicl driven pulley in a position relative to said first half thereof so that the effective pitch diameter of said driven pulley is a maximum;
spring means that tends to move said second half of said drivin~ pulley to a predetermined maximum spacing relative to said first half thereof;
a first means operatively associated with said spring means for moving said second half of said driving pulley relative to said first half thereof when said first means is energi2ed to vary the effective pitch diameter of said driving pulley;
a second means for energizing said first means in accordance with a predetermined relationship thereby varying the ' effective pitch diameter of said driving`pulley and said driven pulley relative to the V-belt, wherein the second means comprises:
ti) a third means for producing an output having variable magnitude, said output being coupled to and energizing said first 20 meanS;
(ii) a fourth means for sensing the load of said prime mover and generating an output whose magnitude is related to the magnitude of said load; and tiii) a fifth means for fixing the maximum magnitude of said output of said third means in response to the magnitude of said output from said fourth means whereby said maximum magnitude corresponds to a maximum preselected load on a prime mover with which it is in combination. `:

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_mmary of the Invention The power drive transmission assembly is used in conjunction with a prime mover, such as an internal combustion engine or electric motor, that has a known torque curve. The engine is provided with a driving pulley that includes a first half portion that rotates in a fixed position relative to the drive shaft of the ~ engine. The driving pulley includes a second half por-; tion that may move laterally to the first half portion on the driven shaft. Power means are provided that ef-fect controlled lateral movement of the second half por-tion of the driving pulley relative to the first half portion thereof.
The driving pulley is engaged by an endless ~-belt, which belt also engages a driven pulley that is subject to a load of varying magnitude. The driven pulley includes a first half portion that rotates in a fixed position on the driven shaft, and a second half portion that is spring loaded and at all times tends to move toward the first half po~tion of the driven pulley.

The power driven transmission assembly includes an endless rotatable surface that rotates with the driv-ing pulley. The endless surface has a sequence of spaced ;~
light~--reflecting surfaces of generally triangular shape thereon that are constantly scanned by a photoelectric device. The light reflecting surfaces are of such shape that when scanned by the photoelectric device first and second electric signals are generated that in magnitude are related to the rate at which the driving pulley ~ .

1~ ;8~4 rotates and ~he position of the second l~alf portion o t~e pulley.
The first ancl second signals are continuouslv compared bSr electronic means thclt at all ti~es tend to ~aintain them in balance by actuatinq the power means ~o move tne second portion O,c the drivins pulley later-ally relative to the first half portions thereof. Such movemen~ of the second half portion OL the ariving pulley changes the effective pitch diameter of the driving pulley, lQ and tne magnitude of the tension exerted on the belt. This change in tension on the belt results in the ef~ective pitch dia~ter of the driven pulley c'nanging due to var-iation in ~he lateral force iMposed on the spring loaded second half portion of the driven pulley. Thus, the - 15 power drive trans~ission assembl~ constantly changes the ~-ratio of t:~e effective pitch diameters of the driving and driven pulleys to maintairl the first and second elec-tric signals in balance. The spacing and configuration of the lightreflecting surfaces is so chos~n that the first and second signals are in balance when the enginè ~;
is operating to produce torque on the driven pulley that has a desired relationship to the torque curve. The - `
light reflecting surfaces will normally be so chosen that the first and second signals are in balance when the en-gine is producing less than the maxi~um torque possible through the driving pulley, for otherwise it would not be possible to accelerate the engine to drive the driving pulley at a ~reater rate o~ rotation.

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The po~ier drive transmission assemDly of the present invention has the aclvantaaes over prior art. de-vices of this nature in tha. the invention provides:
1. Greater variation in effective pitch ~iameter ratios ket~7een the driving and driven pulleys;
2. Broader capabilit:y of accepting wide varia-tions of engine drive speed, horsepower and tor~ue out-put;

3. Greater erficiency in that the invention does not require the capability to sense torclue applied to the driven shaft;

4. Automatic or manual up or down shirting or the effec-tive pitch diameter ratios withou, disen-gaging the drive forcei

5. Is at all ti~.es in balance in that there is no radially movable parts.

6. Can be made to follow an electronically generated shiftincJ pattern.
In another embodi~.ent the objects of the pre~
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sent invention are accomplished with the unique com-bination similar to that previously described. In the second embodiment the lateral movement of the second half portion of the driving pulle~ relative to the first half :
portion is fixed by a manual control acting together with a feed~ack loop. The feedbac}; loop comprises a load sensor which senses the load on the prime mover and a automatic voltage level settins circuit. The au-tomatic voltase level setting circuit is cou~le~ ~et~leen the man-.. . . . . .. .. ..

'76844 ual control and thQ power m~ans that ~ove the second halfpor-tion of the drivincJ pulle~. The ou.put of the load sensor is coupled to an input of t~e voltage limiting circuit such tnat the maximum level o~ the voltagQ ap- :
plied to the po~er means is fixed by t;le load sensor.
In the second embodiment the prime mover ro-.ates at a constant rotational speed and the ef~ective pitch dia~.eter ratio between the driving and driven pul-leys is primarily set by the ~.anual control. Accordingly, lQ even though tne prime mover is operating at a constant rotational speed, the output rotational speed from the .- transmission assembly may increase or d~crease in response to the manual control so long as the lo~d on the prime mover does not exceed some predetermined set level. If the load on the prime mover exceeds the set level, the voltage li~itin~ circuit ~,ill reduce the voltage appliQd ~o the po~er means in respons~e to the outpu. of the load sensor to reduce the effective pitch diameter ratio be- :
tween the driving and driven pulleys thereby preventing ~he load on the prime mover from exceedin~ the predeter-mined maximum load set by the load sensor.
In another embodiment OI the present invention~ :
the objects are accomplished by a.unique com~ination sim-ilar to that previously described except that the drivincJ
pulley and driven pulley are interchanged in position~ In other words, the drivin~ ~ulley is utili~ed as the driven pulley and the driven pulley is utilized as .h~ drivini~
pulley. In the third embodiment, the pri~e ~over is of . ~ . . i ~76~3~4 t~e t~pe w~lose rota~ional s~eed varies over ~.~,ide ranqes and it is d_sirable that the output o~' the potler trans-mission be a constant rotational speed. In this embod~'-ment the ~osition or the second hal- portion of the driving pulley is controlle{l b~ a feedback loop. ~he feedback loop comprises a sensor which senses the ro-tational speed of the driven pulley and supplies an out-put to a comparator means which compares the output or the speed sensor with some reference signal w'nich is 1'~ related.to the desired rotational speed of the driven pulley. Tlle comparator circuit generates a signal to vary the effective pitch diameter ratio between the driv-ing and driven pulle~ which is applied to the power means on the driven pulley so that the output signal from the : 1~ spee~ sensor is e~ual to the reference sisnal.

Brief DescriPtion o' the ~ral?inqs ' `
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The above-mentioned and other features and ob-jects of the present invention will become more apparen~
by reference to the follo~.^.ing description taken in conjunc-tion with the accompanying dra~Yings, t~7herein like reference - numerals denote like elements, and in which: .
Figure 1 is a perspective view o* an internal combustion engine in driving arrangement t7ith the power drive transmission assembly.
2~ ure 2 is a lonqitudinal cross sectional view of a power drive transmission assembly, Figure 3 is a fragmentar~ cross sectional vie;,-; of d portion of the asse~ly ~:itllin tlle oval defined by .~ .

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phantom line in Figure 2 and identified by the numeral 3, and illustrating the positioning of the patterned light reflecting surface on~a part of the driving pulley.
Figure 4 is a top plan view of a sheet having patterned light reflecting strips defined thereon, with each strip being adapted for use on the ~assembly to achieve a particular power output that is related to the torque curve of the engine.
Figure 5 in diagram form illustrates in con=
10 junction with an endless V-be-lt the effective pitch dia-meter ratios that may be achieved between a driving and ;
driven pulley.
Figure 6 is a top plan view illustrating the lateral shifting of portions of the driving and driven pulleys.
Figure 7 is a simplified top plan view of`~a~ th~ ;
second form of the invention.
Figure 8 discloses plotted curves -that illus-trate the po~er output of the invention relative to the 20 toraue curve.
Figure 9 is a diagram illustrating the elec- ;
~ trical circuit used on the invention.
- Figure 10 is a top plan view of a third form of the invention.
Figure 11 is an enlarged fragmentary cross-sectional view of the third form of the invention.
Figure 12 is a perspective view of the two of the components used in the third form of the invention.
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1Figure 13 is a block diagram of a second embodiment of the invention wherein the prime mover is a source of constant rotational speed.
Figure 14 is a third embodiment of the present invention wherein an output of constant rotational speed is desired.
Figure 15 is a top plan view of a sheet having a pattern of light reflecting strips defined thereon.
Figure 16 is a cross-sectional schematic view of one ~O embodiment of a linear actuator.
Figure 17 is a simplified view taken along the lines 17-17 of Figure 16.
Description of the Preferred Embodiment An internal combustion engine C has a first form of power drive transmission assembly D operatively associated therewith as shown in Figure 1. Engine C and assembly D are illustrated in Figure 1 as supported on a base frame 10, which when the invention is used may be a part of a vehicle chassis not shown.
~OEnglne C as illustrated in Figure 1 includes a drive shaft. In Figure 2 a drive shaft 12 is illustrated that has a driving pulley F mounted thereon, and this pulley is capable of driving an endless V-belt 14. Driving pulley F
is of split structure and includes a first half F - 1 that is by a key 16 rigidly secured to drive shaft 12. Drive shaft 12 has a first grooved wheel 18 rigidly secured thereto. The first pulley half F - 1 is formed with an outwardly tapering interior first face 20 as may best be seen in Figure 2.
Belt 14 has oppositely disposed side walls 22 that .

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taper inwardly toward one another at substantially -the same angle as that of the first face 20.
First pulley half F-l as shown in Figure 2 includes a cylindrical first hub 24, with the first hub extending outwardly away from the first surface 20.
First pulley F also includes a second half F-2, which second half includes a second cylindrical hub 26 in which a longitudinal bore 28 is formed. The bore 28 is slidably engaged by first hub 24. A key 30 is secured to first hub 24 and slidably engages an interior groove 32 in second hub 26 to prevent the first and second pulley halves F-l and F-2 rotating relative to one another as shown in Figure 2. First half F-2 has an outwardly tapering interior face 34, that tapers at substantially the same angle as one of the belt side walls 22. The first and second faces 20 and 34 taper outwardly away from one another as shown in Figure 2.
Bore 28 on the inner end thereof develops into a re-cess 36 that is partially defined by a ring shaped body shoulder 38. A snap ring 40 is mounted in a circumferentially extending groove 42 formed on the outer surface of first hub 24. The snap ring 42 serves as a stop when contacted by body shoulder 42 to limit the inward movement of second pulley half F-2 relative to first half F-l. It should be understood that the assembly ~' of Figure 2 may be employed with an assembly such as shown in Figure 1 or other assemblies. The common numbering and lettering between of Figure 1 and 2 is onlyssuggestive of one possible form of cooperation.
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A housiny G is secured to engine C by bolts 44 or o~her suitable fasteninc~ means. }lousing G has an outwardly disposed open end that is normally closed by a firs-t plate 46 that is removably secured -thereto by bolts 48. First pla-~e 46 has an opening 50 tnerein. A slo-t 52 is formed in the side of housing G as shown in Figure 1. A second pla-te 54 is provided that is disposed outwardly from first plate 46 and is removably secured thereto by screws 57.
Returning to Figure 2, the outer end of a second hub 26 has a circular member 56 secured thereto by screws 58. A bore 60 is formed in the center of member 56.
A rigid cylindrical shell 62 having an outwardly extending flange 64 engages opening 50 and is gripped between first and second plates 46 and 5~ when screws 57 are tightened lS as shown in Figure 1. A block 66 is slidably supported in ; - cylinder 62, with the block having a pin 68 that extends outwardly therefrom to slidably engage a longitudinal slot 70 formed in the shell. A ball bearing assembly 72 ``
is disposed between member 56 and block 66. In Pigure 2 it will be seen that a compressed helical spring 74 is disposed in the open portion of the bore 28 and is in abutting contact with second pulley half F-2 and member 56~ ;~
Spring 74 at all times tends to move second pulley half F-2 away from first pulley half ~
- A threaded rod 76 is rotatably supported in ;
a fixed longi-tudinal position in second plate 54 as shown in Figure 2, and rotatably engages a tapped bore 78 formecl in block 66. A grooved wheel 80 is secured ' .. . .

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to the OUL~:arCi1Y projecting end ol rod 76 to per~it the rotation thereof. Rotation of the rod 76 moves bloc~; :
66, rinc; sha~e~ men~er 56, bclll bearillcJ asse~ly 72 and secona pulley half F-2 as a unit toward or ~ay from first pulley half F-l dependent upon the direction of rotation OL the rod 76. ;
~n endless belt 82 as mav be seen in Figure .
1 engages grooved wheel 80, with the belt extending: ::
to a groovea wheel 84 on the drive shaft of a reversible electric motor 86, which motor is supported in a fixea position relative to housing G by conventional I.teans (not sho-~m). The motor 86, belt 82, grooved wheels 80 and 84 together with tllreacled rod ?6 and block 66 serve as a linear actuator to move the second pulley half F-2 laterally relative to first pulley half F-l, The ~eans ~y w.hich the motor 86 is electricaliy ener-gized ~ill be explained later in detail.
~ The bàse 10 has bracket means~86 of conven-tional struc.ure secured thereto as ~ay be seen in ~ig- :
.` 20 ure 1, which bracket means rotatably su~port a trans- .`
versely d~sposed driven shaft 88. A dri~ren pulley ~ is ~ounted on shaft 88 as shown in Fi~ures 1 ancl 2, and is ; - ~ngaged by belt 14.
The driven pulley H inclucles a first half portion ~I-l that is rigicllv secured to driven s.haft :, ~
: 88 by a key 90. Key 90 enga~es a longitudinal slot 92 . in driven shaft 88 and a slot ga formeci on the interior ,~' . . .......
~ OL a cyli~drical hub 96 that projects Erom first half H-l ~

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. "' ~ ' ~768~4 as shown in Fi~ure ~. The driven pu112'~ includes a second half ~1-2 tha. has a cvlindrical shell 9~ pro-jecting therefrom that is slidably mounted on a hub 96.
A ~ey lO0 en~a~es aligned longitudinal grooves lO2 and maintains t'ne first and seco~d halves E1-l and 11~2 in non-rotatable relaiionship relative to one another as . sho~7n in Figure 2.
: A compressed helical spring 104 encircles hub 98 and is in abutting contact with second half ~.-2 and . :~
l~ a retainer 106 that is held in a fixed position relative to driven shaft 88 by a resilient clip 108. The clip 108 engages a circumferential groove llO form.ed in the free end portion of hub 96 as may be seen in Figure 2.
- W11en the secon~ half F-2 moves transversely l~ relative to the sècond.half ~'-l, the tension and lateral force exerted by the belt la is varied to overcome the ~orce exerted b~ the spr ng lO4, with the effective ~ pitch diameter ratio bet7een t`ne driving pulley F and :~ driven pulley H varying bet~7een the extremes shown in ~.
2~ Pigure 5. It ~ ll be particularly noted that the por-tions of the driving and driven pulleys F and ~! engaged ..
- by belt 14 at all times remain axially aligned for as shown in Figure 6, when the belt l4 ~oves from a posi- -tion sho-~in i~ solid line to one shown in phantom line the lateral shifting of tne second movable halves F-2 :~ and H-2 is in the same direclion. Thus, there is no .; tendenc~ for belt l~ to become disengaged from the driving and driven pulleys as the e.fec~ive pitch ra~ios thereof is varied. ~;

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1~7~8~4 Referring to Fiyure 1 a ~rooved wheel 18 (such as sho~n in Figure 2) engacJes an endless belt 112 tha.
drives a ~rooved wheel 114 secured to a rotatable shaft 116 of an electrical generator 118. The generator 118 is secured to a bracket 120 that is affixed to the engine C by conventional means such as bolts 122 or the like.
Driven shaft 88 as may be seen in Figure 1 has a power take off sprocket 124 mounted thereon that is engaged by a lin~ belt 126 that delivers rotational power from engine C to a desired source.
The torque curve ~ ol engine C is shown in - Figure 8 in solid line. The torque that is desired to be delivered by the driven shaft 88 from enyine C through transmission ~ b~ varying the pitch diameter ratios OL
of the driving and driven pullevs F and H is in~icated by the torque curve K in Figure 1.
~orsepower is a product of torque and rota- ~-:~ .
`; tion speed, and the horsepo.~7er at any given r.p.m. will vary directly with the torque~ By selectively varying the pitch diameter ratios ol the driving and driven pul-. .. ~ j , . .
- leys F and H the torque curve I~ in the region thereof be-tween 5500 and 10,500 r.p.m. as shown in Figure 8 can be ~` made substanti211y 1at.
The transmission ~ in co~bination with the 25 automatic sensing device L noS~ to be described permits -the power output on the driven sha~t B8 to ~ollow the torgue curve J to a desired degree, and obtain usable .. . .. .

J . ~
.. , - . - .. . . -. :. :. : - , .. :.

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po~;~r at the driven shaft in a more erficient manner than by manually var~ing ,he pitch dia~et2r ratios of the drivinc~ ~nd ~riven pulley~ F and ~I.
sheet M of plia`~le ma,erial, such as paper or the like is provided that has a number of strips to M-4 inclusi~-e defined iherQon. ~ach strip M-l to M-4 has a sequence ol triangular shaped light d~flecting areas N-l, N-2, ~J-3 and N-4 defined thereon and these areas being separated by darX non-light rellecting tri-angular areas O-l, O-2, ~-3 and 0-4. The triangular areas ~-1 to ~-4 and O-l and 0-4 are of different con-figuration an~ t7idths for reasons tnc~t will later be ;~;
explained.
- One oE the strips M-l to M-4 has light re~lect-~1~ ing an~ non-liaht reflectina areas of an appropriate con-; figuration for engine C and is mounted on thè hub 26 as shown in Figure 2 to encircle the same. `~
The desired strip M-l to M-4 is removably held in the encircling ~osition on hub 26 by conventional means `- 2~ ~not shown) sucn as an adhesive or the like.
A source of electric energy is provided, sucn - as a storage battery ~not shown) which is charged when engine C is o~erating by the generator 118 Electric energy is delivered from generator 118 to the source 2~ through conduc-tors 130 shown in Figure 1. The source of electric energy supplies electric po-,,er V to a num~
ber of terminals that are identi~ied in Figure 9 by t'ne letter P.

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~ 76~4 - A light emittin~ diode 132 is providec~ ~hat direc.s a ~eam of li~nt 13~ on the strip M--l as it ro-tates Wi ~h hub 26 as sho~n in ~'iyure 9. The diode 132 is supported by a bracket 136 from shell 62 as sho~n in Figure 2. A beam of light 134' is reflected fro~ the areas N-l as tlley rotate to a transistor U that is elec-trically c~ductive only when the beam impinges thereon.
One terminal of light emitting diod.~ 132 is connec ed to a terminal P by a conductor Q and the other 10 terminal by a conductor R to ground S. ~ preamplifier : .
138, Schmidt trigger 140, monostable multivibrator 142 . . and low pass filter 144 are connected by conductor 146, 148 and 150 as shown in ~igure 9. Transistor U, pre-: amplifier 138, Schmidt trigger 140, monostable multi- -.
vibra.or 142 and low pass filter 144 each have one ter- .;
minal P.and the other terminal by a conductor R to .. ~ ground S. ~.
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The beam o~ light 134' is intermittent and as it intermittently renders transistor U electrically .

conductive causes the latter to deliver a pulsating ; voltage. V to preamplifier 138. The frequency of the . -, .: :
~:~ pulses of voltage V is related to the rate o~ rotation , of the driving pulley F, and the time duration of each i~ pulse is relat~d to the time it ta~es for each light : ~.
.... ..
.;I 25 reflecting area N-l to rotate past the beam 134. mhe i time it takes for each light re-Elec~ing àrea N-l to rotate past the beam 134 is related to ~he position o~

the second half F-2 of driving pulley F relative to the , ...

~ _3 first half F-l thereof, for the light reflecting areas N_l move laterally concurrently with the second half.
The pattern of the voltage V as it is altered by the elements 138, 140, 142 and 144 is shown plotted ; against magnitude and time in small graphs adjacent the elements in Figure 9~ and the low pass filter de-livering a relatively constant voltage B that in magni-tude is related to the rate at which the driving pulley F rotates. Voltage B is delivered to a conductor 148.
A second low pass filter 154, inverter 156, summer 158 and power buffer 160 are connected by conduc-tors 162, 164 and 166 as shown in Figure 9, with each of `
the above identified elements being connected to termin--`~ als P and ground S by conductors Q and R.
Conductor 148 has a junction point 148a there-1 in from which a conductor 162 delivers electric energy `, in the squared voltage pattern ~' to the second low pass ~` filter 154. Inverter 156 delivers a voltage A to sum-mer 158 that is related to the i:ime it takes for a light , 20 reflecting area N_l to move past beam 134 which in turn is related to the transverse positioning of the second half F-2 of driving pulley F relative to the first half thereof.
Power buffer 160 has a conductor 168 extending therefrom to a linear actuator X which when actuated is capable of transversely moving second half F-2 of driving pulley F relative to first half F~l to vary the pitch diameter of the driving pulley. The linear actuator -19- ~

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1~'7~84~ ~
May be ei.her the ~irst for~ X-l thereof sho~.m in Figure 2 or a secon~ form ,~-2 illus,rated in Pigure 7 an~ la~er to be described.
The voltages A and B due to inverter 156 are oS di-ferent polarities. 'When voltages A and B are egual they cancel one anotrer and po~.~er buffer 160 is not actuated to energize the linear actuator X. The motive power in actuator X-l is the reversible motor 86.
~Jhen voltages A and B are not equal power buffer 160 -; 10 causes a flo~7 of electric current to motor 86 through ~- conductor 168 in a direction to cause the motor to ro-;~ tate threaded rod 76 in a direction to VarY the pitch dia~
meter of the driving pulley F until A and B are again e~ual.
The width of the lig~t reflecting areas N-l is ',` 15 so cho~en that the torque J o~ the driven shaft 88 will ~ have a desired relationship to the torque ~ of engine ,~ C. For instance, the sesm2nt K-l o~ torque curve T;
`` as sho-.,n in ~igure 8 ma~ be so selected that the e~fec- -`. tive pitch di~eter of drivins and driven pulleys F and ' '`
'' 20 H is 8 to 1, w~ile the segment ~-2 may have a pitch dia~
meter of 2 to 1. In all instances it is d,esirable that ,~' torque curve K be some;7hat less than torque curve J to permit acceleration of the engine C. ' .

Fro~ the foregoing discussion, it is apparent .' 2~ to one skllle~ in the art that an electric motor could "' ~:
be substituted for internal com~ustion engine and that an~ sensor or com~ination OLC sensors which s~nse .he ro-tational speed. of the prime mover and tne position of -2~- `

~76844 the second half portion of the driving pulley c~n be substituted for t'ne light be~m sensor cescribed herein t~itllout departln~ from th~ spirit ancl ~sco?e of the pre-sent invention. ~^;ithin this class of sensors or combin-~tions of sensors lalls such devices as magnetic sensors, ~umatic sensors, hydraulic sensors and a sensor as simple as a cam follo~rer coupled to the~ iper o' a linear resistor.
In Figure 7 a second form of the invention is shown in which the second form X-2 o~ the linear actuator is used. Elements in the second form of the invention that are co~mon to the first form are identi-fiea in Figure 7 by the same numQrals and letters previous-ly used ~ut with primes being added ther~Qto.
In the second form of the invention as shown in ~igure 7 plate 46' has a first hydraulic cylinaer 200 extending ou,wardly therefrom in ~hich a piston 202 is slidably mounted that has a recessed inner portion 204 ` :: :
on which the ball bearin~ assem~ly 72' is mounted, with one race of the asse~lv secured to hub 26'. Hydraulic fluid Y may be discharged into and out of first cylinder : :
200 througn a passage 206.
Passage 206 is in co~unication with the outer interior portion of a second hydraulic cylinder 208 tnat projects from plate 46'~ A second piston 210 is slidablv mounted in second c~linder 208. Cecond piston 210 has a ta~pe~ cavity 212 t`nerein that is en~aged by a ~ :
threaded shaft 214 that is driv~n by a reversibl2 elec- :.

~ 2 ~ .; .r. . ~

~ ~44 tric motor 215~ ~lec,ric m-,tor 216 rotates threaded shaft 21~l when the r~lotor is suppli~d ~ith electric power throu~h cond~ctor 16S and a cond~lctor R in the ~anner pxeviously describec' in connection wi~e the first form of the inven-tion.
When the motor 21S is actuated by electric power received from power buffer 160, the threaded shaft 214 is - rotated to move second piston 210, with hydraulic fluid Y
~` being forced into first cylinder 200 to move first piston 202 and second pulley half F'-2 relative to the first pulley half Fl-l until the pitch ratios of the drivin~ ;
and driven pulleys F' and H' is such that volta~es P and ~ ;~
B are equal. The above described operation ~ill continue intermittently as the load on drivenjshaft 38' varies, and -` 15 as a result the torque delivored by driven shaft 88' will ~;
ollo-~ the curve K illustraled in Figure B. Spring 74' ; ;~
tends at all timos to move second half F'-2 away from first half F'-l.
, ::
- In Figures 10 to 12 inclusive a third form o-E
tneinvention is sho~n on ~"hich a third form X-3 of the linear actuator is used. Elements in the third form of the invention that are common to the first form are identifie in Figures 10 to 12 by the samP numerals and letters previous-ly used but with double primes being added thereto.
2~ In the third form of the invention as illus-trated in Fisures 10 to 12 a bracket 300 secured to Eirst plate 46" by bolts 302 serves as a fi~ed mounting 'or the outer c~lindrical por,ion 304 of a hysteresis brake , : .

3L~'768~

306. The nys-teresis bra~;e -llustra~ed is manuLacture~
con~nerciall~r b ti-le ~ele~and Division. ~merican Precision Industries, Inc., ~Aast ~urora, ~ew ~;or}~ and serves as ..
the third form of linear ac~uator x-3.
Bra)~e 306 has coils 308 in portion 304 that may be electricall;. energized through conductors 168, Q and R.
rake 306 has a rotatable inner portion 310. Inner por-tion 310 is rotatably supported in outer por~ion 30~ b~
`- a pair of spaced ball bearing assemblies 312. The inner - 10 portion 310 has a nut 314 on the outer end thereof that en~ages a threaded rod 316 ~hat extends through a longi-tudinal bore 318 in the inner portion. Threaded. rod 316 on a first end 316a thereof has a slot 320 therein of rec~
tangular transverse cross-section that is remo-~rably en-1~ gaged ~y an elongate cross-mem~er 322 that is secured to circular mem~er 56" by a pin 324. Inner portion 310 has a c`rcular recess 326 therein that is engaged by a snap ring 328 that bears against the ball bearing assembly 312 nearest to circular member 56". Snap ring 328 limits the 23 outward movement of inner portion 310 relative to outer portion 304 as ma~ be seen in Figure 10. Nut 314 is secured to inner portion 310 by conventional means (not ; shown).
When coils 308 are not electricall~ energi2ed ~ .
cross mem~er 322 as it rota~es causes concurrent rotation of inner portion 310, threaded rod 316 and nut 314 as a unit. Uyon coils 3Q8 bein~ electrically energized by a :~
signal received b~ the third for~ X-3 of tne linear ac-16~4 tuator through conductor 168 the innQr portion 310 is stopped from rotating, but the -threaded rod 316 con-tinues to rotate relative to the inner portion and nut 314. Rotation of threaded rod 316 relative to inner portion 310 results in lateram movement of second half .: ;;
F"-2 to first half F"-l of driving pulley F" to vary the effective pitch diameter thereof as previously de-scribed in connection with the first form of the inven-tion. :;
The use and operation of the invention has been described previously in detail and need not be repeated.
Furthermore, it should be apparent that linear actuator X may be implemented in severl other ways, such " as, but not limited to a hydraulic or eddy current brake with_ out departing from the spirit and scope of the invention. ;~

l~ Referring to Figure 13, shown therein is another il embodiment of the present invention. Elements in this , . .~
embodiment of the present invention that are common to `
the other embodiments are identified in Figure 1~ by the same reference numerals.
Referrin~ to Figure 14~ the embodiment shown thère~ includes-a"prime~mover r~epresehted by elect~ric m~or~400 having a drive shaft 12. Driving pulley F ;
which is substantially the same as the driving pulley F ~j `
previously described is mounted on drive shaft 12.
Driving pulley F is coupled to driven pu~ley H by V- -belt 14. Driven pulley H is substantially the same as the driven pulley H previously described. Linear actu-; 24_ -,,.,-':
'' ~76~3~4 ator X is su~stantially the same as ~-1 through X-3 previousl~,~ described is cc~upled tc) seco~d pulley half F-2 of driving pulle;~ F. Po,ition sensor 402 senses the position of second pulle~ F-2 and the output of position sensor 4C2 is coupled to an input of compc.rator driver 404. ~he output o~ compara~or driver circuit 404 is - coupled to linear actuator ~
Electric motor 400 is po~7ered by a source of direct current represented b~ battery 406. Resistor 408 ` `
13 is coupled between the negative terminal of battery 406 and ground~ The terminal formed b~ the negative termin-~. :
al of batter~ 406 and one end of resistor 408 is coupledto an input of voltage limiting circuit ~10 and the out-put of voltage limiting circuit 410 is coupled to an in~
3 put of corrparator driver circuit 404.
Variable resistor 4'12 is coupled bett.e2n a minus source of direct current voltage represented by -~ a ~Vs and ground and the wiper of variable resistor 412 ~ -is cou~led to an input of voltage li~iting circuit 410 ` 20 Pedal 414 is mechanicall~J coupled to the wiper of variable resistor 412 such that depressing pedal 414 causes the ~;
wiper of variable r~sistor 412 to move such that the voltage between the wiper and ground increases in mag-` nitude toward -Vs~ -23 Th~ voltage limiter circuit 410 comprises two operational ampliriers 416 and 418. ~esistor 420 is coupled Detween the input Oc o~erational amplifier 416 and the connection rormecl ~ the negati~e terminal of , .
~, . . .

~7~8~4 batter~ 406 and one end of resistor 408. Capacitor 422 is coupled between the in~u~ and output of ampli~ier 416.
~7ariable resistor 424 is coupled ~ett~Jeen a positive source of direct current voltage re~resented by ~VL and ground.
Resistor 426 is coupled be.~een the wiper o~ variable re-sistor 424 and the input or operational amplifier 416.
Tne anode o~ diod~ 428 and the cathode of diode 430 are coupled to the output of amplifier 416~ The cathode of diode 428 and the anode ol diode 430 are coupled re-spectively to one end ol resistor 432 and ground. Theother end of resistor 432 is connected to the input of operational amplifier 418. The two ends o~ resistor 434 are coupled between the inpu~ of amplifier 418 and the wiper of variable resis.or 412 and resistor 436 is coupled between the input and output of amplifier 418. The out-put of amplifier 418 is coupled to an input of comparator driver circuit 404.
In practice, position sensor 402 can be su~-stan~ally the same as automatic sensing device L. Also, com~arator driver circuit 404 can be substantially the same as that portion of electronic circuit of Figure 9 comprising the series connection of preamp 138, S~hmidt trigger 140, low pass filter 154, inverter circuit 156, summer 158, ana power.bufer 160 except that the output 25 of voltage limiter circuit 410 is applied to an input of summer 158 on conductor 152.
~`or the sake o~ illustration, assume that the ; :~
outpu. rotational speed of electric motor 400 is a con-. .

10~34~

stClll L and that the s~riper CO~tdct o~ varidble re~istor 424 is set such that Lhe ~oltage bet~7een the wiper contact a,nd ground is some positive value corresponding to a pre-determined maximu~ load condit,ion. ~urther, assume that 3 pedal 414 is in a position such that the resistance be-tween the wiper arm of variable resistor 412 and sround is substantially 0 thereby making the input ~o amplirier 418 substantially 0 volts. If pedal ~14 is depressed, the wiper arm of variable resis~or 412 is moved such ;;
that the voltage increases in a negative direction from 0 toward -Vs thereby causing the voltage at the input of operational amplifier 418 to increase in the negative direction. As the input voltage of amplifier 418 in-~ creases in the negative direc8ion the outpu. voltage ', 15 of amplifier 418 increases in the positive direction ' and is coupled to the input of co~parator driver circuit '~
404. Com~arator driver cir.cuit ao4 compares the signal from position sensor 402 with the ou~put of amplifier : 418 and if there is a difference applies a signal to ,, 20 linear actuator X to move second pullev half F-2 relative '''' to first pulle~ half F-l until the difference bet~eèn the two signals is substantially 0. Accordingly, the e~fective ~; pitch diameter ratio between the driving and driven pulley ,, is varied and tne load on electric motor a~o increases.
~s the load on electric motor 400 increases, tne current supplied to electric motor ~00 b~ batLery 406 increases thereb~ increasins the voltage drop across resistor ~08 in a negative direction. So long as tr.e 10'7~8~
voltage drop across resistor ~08 is smaller in Dlagnitude than the positive voltage set by variable resistor 424, the output voltage Or the integrator _ormed by ampli-fier 416 and feedbac~ capacitor 422 increases in a neg-ative direction. So long as the output voltage of ampli-fier 416 is a negative, diode 428 is reverse biased ef-fectiv~l~ isolating the input of amplifier 41B from the output of am~lifier 416. Accordingl~, so long as the output of ampliCier 416 is negative, the output of am-~lifier 418 will vary directly in proportion to move-ment O,c pedal 414. To prevent the output of amplifier 416 fro~ ~ecoming too negative, diode 430 coupled between the ou'put and ground holds the output voltage at a minus one d~iode drop.
l~en t~e load current throu~h resistor 408 reaches a point such that t~ne~ voltage drop across resis-tor 408 ~ecomes greater than the voltage set on variable ~ resistor 424, tne inpu, voltage on amplifier 416 becomes `~ increasingly more negative thereb~ causing the ouput o~

~`` 20 am~ ier 416 to integrate toward a positive voltage.
' ~. :' ' The increasing positive voltage at the output of ampli-fier 41~ i~ reflected at the input of amplifier 418 ~`
`~ where it is additively com~ined with the negative vol-tage co-responaing to the voltage drop between the wiper 2, of variable resistor 412 an~ ground. Accordingly, the negative voltage ap~earin~ at the input of amplifier 418 ceases to continue to increase in the negative direction and the output voltage of amplifier 418 ceases to increase ~76~344 in the positive direction as pedal 414 is depressed. ~ur-thermore, so long as the loa~ on electric motor ~00 is in excess of some preselecte~ ~aluc-, the output voltage of am~lifier 418 will ~ecrease, thereby causing linear actu-ator ~ to move the second pulley half F-2 relative to first pulley half P-l to reduce the load on electric ~otor 400 thereby reducing the voltage drop across resistor ~08 un-til the drop across resistor 408 e~uals the voltaae pre-set on variable resistor 424. When t~e voltage across resistor 408 and tne voltage preset on variable resistor r 424 are equal, the input voltage on amplifier 426 is sub-stantially 0 and the integrator formed by amplifier 416 and capacitor 422 will cease to integrate up i~ a positive ~irection and hold the output voltage at some constant -; .
15 positive value~ Similarl~r, if the load on electric motor 400 drops below the preset load, tne output voltage of a~plifier 416 will integra~e do-,~nward until it becomes a negative value again there~y allowlng the output of - ampliSier 418 to be directly responsive to movements in pedal 414.
~ s previously stated, it should be apparent to one s~illed in the art that the function of position sensor 402 can be performed by severaL different types of sensors wi.thout departing from the spirit an~ scope of the invention. Furthermore, the description of cir-cuits which ~ill perform the comparator function and t~e voltage limiting function are meant to be purely illus-trative and not de~erminative oS the invention. Also ..... . . . . ~ ~ ~

the load on electric mo~or 400 can be sensed by any number of current sensors available in the art.
~;:

1~7684~
Referrin~ to Figure 14, sho~n therein is another embodiment of the present invention. Ele~ents - in this embodiment of the present invention that are co.mmon to the other embodiments are identified in Figure 14 by the same reference numerals.
Referring to Figure 14, the em~oaiment shown therein includes a prime mover 450 havin~ a drive shaft 12. Driving pulley F:~ wnich is substantially the same as the driven pulley H previously described is mounted on drive shaft 1~. Driving pulley~ is coupled to driven ~ ~-pulleyHF by V-belt 462. Driven pulley ~F i5 substantially the same as the driving pulle~ F prevlously described.
Linear actuator X substantially the same as the linear .1 actuators Xl through X3 previously described is coupled .
to second pulley half F2 of driven pulleyHF. Speed sensor 452 is coupled to driven pulley~ and the output of speed sensor 452 is cou?led to an input of comparator circuit ,~ 456. Reference level source 454 is coupled to another in-put of comparator circuit 456 and the output of comparator ~-circuit 456 is coupled to the input of linear actuator X.

In practice, spe~d sensor 452 can be substantiall~ ;
~he same as automatic sensind device ~ except that the dark nonre~lecting areas may be of constant longitudinal width a5 .
shown in Figure 15 instead of being triangular It is understo that the particular pattern shown is a simplified schematic -~form and other forms and shapes may be desirable. Also, compar, circuit 456 can be substantially the same as that portion ~-of the electronic circuit of Figure 9 comprising the series - ( - ' ' . ', connection of preamp 138, Sch~id. trigger lao~ monosLable multivibrator 142, low pass filter 1~4, su~er 158 and power buffcr 160 except that reference le-~rel 454 is a~-pliea to the summ~r on conduc.or 164 Furthermore, the ~ j~
reference level 454 can co~prise a source of direct cur-ren~ voltage represented by battery 460 coupled to a rheostat ~58 In operation, driving shaft 12 is rotated by -~
prime mover 450 For the sake of illustration assume that the output rotational speed of prime mover 450 is - not a constant and varies over some range The varying rotational rate of prime ~over 450 is transmitted via shaft 12, driving pulley FH and V-belt 462 to driven pulley HF Tne rotational speed of driven pulley HF is sensed by speea sensor 452 which generates an output to comparator circuit 456. Comparator circuit 45~ comparès the output from speed sensor 452 with a reference level 454 If the output from speed sensor 452 and the reference level are not equal, comparator circuit 456 delivers an output to energize aatuator X to move the second half F-2 o~ driven pulley HF to ~ary the effective pitch diameter ratios o~
the d~iving and driven pulleys at FH and HF until the out-put of speed sensor 452 and the reference le~ei are e~ual Accordingly, so long as the output from speed sensor 452 ~5 and the reference level 454 are equal, the speed of ro-tation of driven pulley HF is a constant irregardless of the c~anges in rotational speed of the driving pulley F~ ;
~.

- , ' , .-1~76~44 A s~ecific embodiment of the linear actuator that may be employed with the system of Figure 9 is snown in Figures 16 and 17 showing a housing 500 ~hich encloses ; the pulley 502 comprising a movable pulley half 504 and a fixed pulley half 506. The -fixed pulley half 506 is mounted to be driven directly by the output 542 of the prime mover (e g., output of the internal combustion engine, electric :;.
; motor, etc.). The fixed pulley half 506 is thus fixed , longitudinally with respect to movable pulley half 504 :, -which is adapted to slide longitudinally (arrows 508) with respect to fixed pulley half 506. The fixed pulley half 506 contains a bearing insert 510 fixedly secured in an opening 512 in movable pulley half 504. The bearing 510 ~ has a configuration as shown in Figure 17 comprising a ; 15 plurality of splinelike me~bers which slidingly engage a ` mating hu~ 514) which hub portion has a matching male cross-section to matchingly engage the bearing 510. Thus, ;` it can be seen that the vable pulley half 504 is free ; to slide in the direction of arrows 508 via bearing 51~ on the mating spline members 514 of the fixed half of the pulley 506.
The movable pulley half 504 has an internal lip , 515 against which the bearing 510 abuts ~he lip 515 also receives a washer 516 which washer is adap~ed to slidingly fit within the bore 517 of movable pulley half 504_ The washer 516 extends beyond lip 515 to engage the end of bearing 514 in fixed pulley half 506. The coil spring 518 a~uts the surface of the washer 516 and extends from the ,' . ~

107~8gL4 washer 516 to plate 528 ~hich is secured to one end of the movable pulley half ~04 by fastening means 523.
It can be seen that movement of the movable pulley hal~
504 in the direction of arrows 508 toward the ~ixed pulley half 506 will result in the spring 518 bein~ compressed between washer 516 (fixed by the end o~ spline 514) and ; plate 528 (which moves wi~h movable pulley half 504).
The plate 528 has ixed therein a circulating ballnut 522 which is a standard commercially available co~ponent. The ballnut 522 receives lead screw 520 .. which is securea to disc 534 which.in turn is rotatably . mounted in rotary bearing 536 by ~astening means 538 . (schematically shown). The lead screw 520 is also ro~atably mounted at its end 548 in an opening 546 in the end of fastening means 540. The as-tening means 540 secures the fixed half o~ the pulley 506 of the prime mover ou~put shaft as schema-tically indi.cated as 542. Thus,;it can be seen that lead screw 520 is mounted for rotation so that it can rotate at the same speed as ballnut 522 and movable -~
pulley hal~ 504 which rotate as a unit or lead screw 520 may rotate at a diIferent speed with respect to said ballnut and movable pulley hal~ 504. When a differential in speed exists between the lead screw and the movable half of pulley 504, the ballnut will be displaced along the lead screw resulting in the movement of movable half pulley 504 and the compression o~ spring 518.
The disc 534 which is secured to lead screw 520 orms part o~ an eddy curren. brake 530. The eddy current brake includes a plurality o~ coils 532 spaced around disc 534.

....

1~7689L4 Thus, the coils of eddy curr~nt brake 530 ~ay be energized to effect the ~orce supplied to the disc 534 which in turn ; places a variable force on the lead screw that determines ~:
the speed of the lead scre~7 with respect to ballnut 522 S A light and dar~ area sleeve 525 is mounted on the movable pulley half 504 and fixed thereon by snap ring 526, The light and dar~ area sleeve has been previously describea in connection with Figures 4 and 9. The light and dark areas on sleeve 525 cooperate with light sensor 52g and 1~ electronic assembly 531 to provide position and RP~
informatlon as to movable pulley half 504.
In s~mary, the above described linear actuator~
operates to change the pitch of the pulley by movement of -~
- the movable pulley half 504 with respect to the fixed 15. half 506. This movement is accomplished by the relative speed of the lead screw 520 with respect to the ballnut ~.
..
522 and movable pulley half 504 which rotates as a unit. ;~
The speed of the lead screw is determined by the eddy current brake 530 as controlled by the electronics hereinabove explained with the speed and positional :
information of the movable half 504 determined by the .
light sensor 529 and electronics 531 as explained in :. ;
detail above. .`
- One additional specific novel aspect of the~
above-described embodLment is the configuration of the spline 514 and the mating bearing 510 shown in detàil .
in Figure 17. It should be noted that the portions 511 of spline s:haft 514 contact the belt 550. The configuration - :.

- ~.. - '1 ~. . ,

7~8~4 of portions 511 are such as to ca~lse minimum ~ear ol ihe belt 550. In addi-tion, these spline members contac-t and drive the bearin~ of movable half 504 of the pulley.
The depLh of grooves 513 are less than -three-eighths of an inch and preferably the wall 519 is approximately one-quarter of an inch. This minimizes metal removal while maintaining the strength of the shaft and bearing.
Both the configuration and the fact that there are pluralities of such spline members enables the movable half 504 to be efficiently and effectively drive by spline 51~. Thus, the spline and bearing members present an additional novel aspect of this invention In all cases, it is understood that the above-described embodiments are merely illustrative of but a small number of the many possible specific embodiments which can-represent application of the principles of the present invention. Numerous and varied other arrangements can be readily devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention.

. - i

Claims (20)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A power drive assembly for use in combination with a prime mover comprising:
a rotatably supported first shaft;
a rotatably supported second shaft spaced from said first shaft and parallel thereto;
a first pulley defined by first and second halves, said first half being rigidly secured to said first shaft and said second half being slidably mounted on said first shaft but non-rotatable relative thereto;
a second pulley defined by first and second halves, said first half of said second pulley rigidly secured to said second shaft, and said second half of said second pulley slidably mounted on said second shaft and substantially non-rotatable relative thereto;
an endless V-belt associated with the first and second pulleys;
force exerting means that tends to maintain said second half of said second pulley in a position relative to said first half thereof such that the effective pitch diameter of said second pulley is maximum;
spring means that tends to move said second half of said first pulley to a predetermined maximum spacing relative to said first half thereof;
a first means operatively associated with said spring means for moving said second half of said first pulley relative to said first half thereof when said first means is energized; and a second means for energizing said first means in accordance with a predetermined relationship thereby varying the
1. Claim 1 continued:
   effective pitch diameter ratio of said first pulley and said second pulley relative to the V-belt, wherein the second means comprises:
   (i) a third means for producing an output having variable magnitude, said output being coupled to and energizing said first means;
   (ii) a fourth means for sensing the load of said prime mover and generating an output whose magnitude is related to the magnitude of said load; and (iii) a fifth means for fixing the maximum magnitude of said output of said third means in response to the magnitude of said output from said fourth means whereby said maximum magnitude corresponds to a maximum preselected load on the prime mover with which it is in combination.
2. 2. An assembly as claimed in claim 1 in which said force exerting means is a compressed helical spring that encircles said second shaft, with said spring having first and second ends, with said first end being in a fixed position relative to said shaft and said second end being in force exerting contact with said half of said second pulley.
   
   3. An assembly as claimed in claim 1 in which the first means comprises:
   a reversible electric motor;
   a threaded rod rotated by said motor;
   first and second hydraulic fluid containing cylinders that occupy fixed positions relative to said prime mover, said cylinder including first end portions connected by a fluid passage;
   first and second pistons slidably and sealably
3. Claim 3 continued:
   mounted in said first and second cylinders with said second piston having a tapped bore therein that threadably engages with said threaded rod; and bearing means disposed between said first piston and said second half of said first pulley for moving said second half of said first pulley relative to said first half thereof to vary the pitch diameter of said driving pulley when hydraulic fluid flows into and out of said cylinder through said fluid passage due to the electric motor being energized to move said second piston in said cylinder to vary the quantity of said hydraulic fluid in said first cylinder.
4. 4. An assembly as claimed in claim 1 in which said first means comprises:
   a threaded rod that extends outwardly from said second half of said first pulley and rotates concurrently therewith;
   a hysteresis brake that includes a stationary outer portion containing electrical coils and an inner portion that rotates freely relative to said outer portion except when said coils are electrically energized, said inner portion having a longitudinal bore therein through which said threaded rod extends;
   and a nut on said inner portion that is longitudinally aligned with said bore and engaged by said rod, with said rod rotating relative to said nut when said coils are energized to stop the rotation of said inner portion, and said second half of said first pulley being moved laterally relative to said first half as a result thereof.
5. 5. A power drive assembly as claimed in claim 1 wherein said prime mover is an electric motor.
6. 6. A power drive assembly as claimed in claim 5 wherein said fourth means comprises a current sensor.
7. 7. A power drive assembly as claimed in claim 6 wherein said third means comprises a manually controlled rheostat coupled in parallel with a source of direct current voltage.
   
   8. In combination with a prime mover having a drive shaft to which rotational power is transmitted by said prime mover, a power drive assembly operatively associated with said prime mover, said assembly comprising:
   a rotatably supported driven shaft spaced from said driving shaft and parallel thereto;
   a driving pulley defined by first and second halves with said first half being rigidly secured to said driving shaft, and said second half being slidably mounted on said driving shaft, but non-rotatable relative thereto;
   a driven pulley defined by first and second halves, said first half of said driven pulley rigidly secured to said driven shaft, and said second half of said driven pulley slidably mounted on said driven shaft and substantially nonrotatable relative thereto;
   an endless V-belt associated with the driving pulley and the driven pulley;
   force exerting means that tends to maintain said second half of said driven pulley in a position relative to said first half thereof so that the effective pitch diameter of said driven pulley is a maximum;
   spring means that tends to move said second half of said driving pulley to a predetermined maximum spacing relative to said first half thereof;
   a first means operatively associated with said
8. Claim 8 continued:
   spring means for moving said second half of said driving pulley relative to said first half thereof when said first means is energized to vary the effective pitch diameter of said driving pulley;
   a second means for energizing said first means in accordance with a predetermined relationship thereby varying the effective pitch diameter of said driving pulley and said driven pulley relative to the V-belt, wherein the second means comprises:
   (i) a third means for producing an output having variable magnitude, said output being coupled to and energizing said first means;
   (ii) a fourth means for sensing the load of said prime mover and generating an output whose magnitude is related to the magnitude of said load; and (iii) a fifth means for fixing the maximum magnitude of said output of said third means in response to the magnitude of said output from said fourth means whereby said maximum magnitude corresponds to a maximum preselected load on a prime mover with which it is in combination.
9. 9. An assembly as claimed in claim 8 wherein said prime mover is an electric motor.
10. 10. An assembly as claimed in claim 9 wherein said fourth means is a current sensor.
11. 11. An assembly as claimed in claim 8 wherein said third means comprises an adjustable rheostat in parallel with a source of direct current voltage.
12. 12. An assembly as claimed in claim 11 further comprising:
    fifth means for sensing the relative position of said second half of said driving pulley to said first half, said fifth means generating a fifth output whose magnitude is related to said relative position; and sixth means for comparing the difference in the magni-tudes of said fifth output and said output of said second means and generating a sixth output to energize said first means to move said second half of said driving pulley relative to said first half to vary the effective pitch diameters of said driving and driven pulleys until said fifth output and said output of said second means are equal whereupon the load upon said electric motor does not exceed a maximum preselected value.
13. 13. An assembly as claimed in claim 1 wherein the first half of the first pulley has a plurality of spline members in sliding and driving relationship with the belt, the portion of the spline members which are in contact with the belt having a smooth configuration.
14. 14. An assembly as claimed in claim 13 wherein said second shaft includes a lead screw and said positioning means includes a ballnut member fixed with respect to said second half and rotatably mounted on said lead screw for longitudinal movement.
15. 15. An assembly as claimed in claim 14 wherein an electrically energized brake means is mounted in cooperative relationship with respect to said second shaft to apply a force there to be con-trolled by an electrical signal.
16. 16. An assembly as claimed in claim 15 wherein said brake means is an eddy current brake having a disc mounted on said second shaft.
17. 17. An assembly as claimed in claim 13 including a spring means that tends to move said second half of said first pulley to a predetermined spacing relative to said first half thereof.
18. 18. An assembly as claimed in claim 13 wherein said second shaft includes a lead screw and said positioning means includes a ballnut member fixed with respect to said second half and rotatably mounted on said lead screw for longitudinal movement.
19. 19. An assembly as claimed in claim 18 wherein an electrically energized brake means is mounted in cooperative relationship with respect to said second shaft to apply a force there to be controlled by an electrical signal.
20. 20. An assembly as claimed in claim 19 wherein said brake means is an eddy current brake having a disc mounted on said second shaft.