US1912668A - Speed responsive appliance - Google Patents

Description

June 6, V1933. R. c. sYLvANDr-:R ET Al. 1,912,568

SPEED RESPONSIVE APPLIANCE Fi1=d May l5, 1950 2 Sheets-Sheet l @mman v June 6, 1933- R. c. sYLvANDER ET Al. 1,912,668

SPEED RESPONSIVE APPLIANCE Filed May 15, 1930 2 Sheets-Sheet 2 N lily/aziona Foy .Sylvazaler Patented June 6, 1933 PATENTOFFICE y nos C.` ,sirLv-ANnia. aNnlrmnortrr BECK, l or enrnenonr, CONNECTICUT, i AssicNoas `Iro "CoNsomDAmEnAskHCRorr HANCOCK COMPANY, or NEW raak, N.`Y., A CORPORA- ma QF DELAWARE i. y "SFPD BEsrfoNsrvE APPLIANCE j y' application mea may 15, 1930. serial No. 452,691.

l This invention relates to speed responsive devices, and moreparticularlyto speed responsive devices M actuatedby Y centrifugal movement of a rotating: mass. "i While in its l broaderaspects theinventionis applicable to instrument.

and useful in4 speed responsive devices or apparatus having f other purposes,its'most appropriate application `is Vfound in ,speed regulating and measuring 1 instruments, `for example, instruments fknovvn as tachometers, and thelinvention isbhere-inafter described, byz Way ,of example, asfemblodied in` `such an n lThe primaryrequisite in all such, devices or instruments is that they shall respond with accuracy and delicacy to `variations in speed,

i butit is iurtheraobvious thatsuch devices,

tobe of commercial and practical value, must be `strong;rugged, durable, and ofsimple construction,` and` such that manufacturing cost andupkeep shall be 10W.'` i

In the attainment of the aboveand other desirable characteristics, the present :invention providest a construction-` in which the, number of. pivoted joints (which always tend to Wear and produce lost motion with resulting inaccuracy)` is substantially reduced as compared With` usual instruments `of this type; it `provides for transmitting motion ofthe actuatingcentrifugal mass toa movably responsive part (for example an index` cooperatingvvitlra graduateddial) in response to successiveequal increments `or decrements of speed in l such a vvay1 that? for each equal increment or decrement ot'speed the responsivepart shall move a,unitormfdistance;` `it further `providesfior transmitting `motion 'from the Centrifugalmass to the responsive partjor member `bygme'ans which is adapted to absorb and substantially eliminate vibrations or oscillations of small amplitudethereby reducing Wearand increasing thezaccuracy ofoperation; and `itlurther provides means for limiting the movementlof the centrifugal mass `to avoid damage `through ^overspeed, or

, oscillation at-lovv speeds `when the mass is rotatedin a substantially vertical plane.

Other objects and advantages of the invention will appear from the folloivingexplanation,` a 1 specific instance of the` invention shovvn, by way of exampleF only, in the accompanying drawings.` In the drawings:

Fig. lisa frontelevation, partly in section,

of speed-responsive mechanism embodying the invention; l i

i FigQ is a` front elevation, to larger scale, of the rotating Weight-driving member and centrifugally actuated Weights associated therewith;` l

f Fig. 3 is a bottom view, partlyin section, of the rotating Weight-driving memberland the Weights;

Fig. 3a is an elevationiof the centrifugally actuated` Weights and reciprocating head, showlng their respective positions at different velocities; A 1 i Fig. 4 is a plan View of the speed responsive device of Fig. l, showing the means for transmittingmovement `from the rotating and reciprocating upper head of the device to asutv able motion-responsive mechanism;

Fig 5 isa Ifragmentary front elevation illustrating'the application of the invention to an "instrument comprising a dial, motion-responsive means in theform of an indicating pointer, Aindeznor needle to which motion is transmitted, by means comprising a segment gear, from the upper rotating andT recipro-` cating head of the speed-responsive mechanism i of Fig.` 1.;

Fig 6 is a section on `the line 6-`6 ofFig. 5,and .my g

Fig. 'Tis a section on the line 7 --7 of Fig. 5. The illustrated embodiment of the invention comprises a rotating weight-driving member 11 which is carriedby a-rotaryshaft 12 turning in ballbearings 13 and 14, supported by a suitable framework-17 The rotating Weight-driving member 11 carries a movable mass, (here shownas comprising the tvvo pivoted weights 20 and 21), movable inwardly andfoutwardly to rotate in various orbital` paths determined by the effect of centrifugal force.` l We prefer to connect the'two Weights pivotally4 to the rotating Weight` driving member,"preferab1y adjacent tothe lower ends'of theweights, as shown in Figs.v land2;Y The weight-driving `member 11 preferably extends but slightly to either side of its axis of rotation and is bifurca'ted, as shown in Fig. 3, to provide recesses 22 and 23 for receiving the weights 20 and 21 which normally extend therefrom generally parallel to the axis of rotation of the weight-driving member. The weight-driving member 11 preferably is located quite close to the bearing 14, as shownZ in Fig; 1`so as'to diminish overhang and attendant likelihood of vibration.

Referring to the right-hand side of Fig. 8, the weight-driving memberhas spacedr arms 27 and 28 through which a pin 29 is secured. The weight 21 shown in Fig. 3 has a transverse bore of larger diameter than pin 29. Bushings 30 and31 are fitted intoI opposite ends of the bore, and these bushings have heads disposed between the opposed arms 27 and 28 respectively and the weight 21. In this vway lost motion, both axially and laterally of the bearing pin 29, is preventedand the weight is constrained to' pure rotation with respect tothe pin, so that the path of the weights is determined solely by the speed of rotation of the weight-driving member (with its attendant centrifugal effect) and theeffect of a suitable resilient member opposing the outward movement of the weights as hereinafter described.

3 In order to limit the outward movement of the weights under the action ofcentrifugal force, we provide the shorter part of each ofthe weights, that is the part depending below the pivot pin `29 in the illustrated embodiment, with a short extension indicated at 35 in Figs. 1, 2 and 3, and provide a suitable stop', preferably associated with the member 11 and conveniently in the form of a washer 37 joined to the weight-driving member 11 in any suitable manner and disposed in the inward path of these short extensions '35 of th-e weights. In this way outward movement ofthe longer upper part of the Weight is checked bv the engagement of the short extension 35 with this wash-er 37.

IVhen a. centrifugally actuated speed responsive device is disposed with its axis of rotation in a horizontal plane, or other than a. vertical position, the effect of gravity upon the rotating weights at low speeds of rotation is likely to cause undesirable'oscillations of the weights and .consequently of the indicating or' motion-responsive mechanism connected thereto. Accordingly, we provide means for checking the movement of the weights toward their axis of rotation at low. speeds thus to prevent these undesirable oscillations. In the illustrated embodiment we have disposed the inner upper edges 40 and 41 of the two recessed sides ofthe weightydriving member -11 in theppathof the inward movement of the upper longer portions of the weights, as shown in Fig. 2, so as to check movement when the weights toward the axis of rotation of the device is disposed horizontally.

To utilize the centrifugal movement of the weights, and in the present embodiment to facilitate transmitting a desired component of the centrifugallyinduced movement of the 4weights to a motion responsive part, we provide a head, indicated .generally at 50 (Fig. 1),"(this head in this instance constituting an intermediate or primary responsive part). A spindle 15 of reduced diameter is slidably mounted within the spindle 15a which is rigidly secured in any suitable manner to the Weight driving member 11, the spindles 15 and 15a being coaxial with the bearings 13-14 and the ball bearing member 16 in which the upper end of the spindle 15 is journaled. The head.50 is fast to spindle 15 which has a free axial movement in bearing 16 and in a bearing 16a disposed within the spindle 15. lDownward movement of this reciprocating head member 50 and spindle 15 is opposed by suitable means, for example a calibratedv coil spring 51 disposed between the weight-driving member 11 and the movable head member 50. This spring also exerts an upward thrust against the movable head member 50 which, through connections about tobe described opposes the outward swinging of the weights 20 and 21.

We prefer to reduce as much as possible the number of pivotal joints and connections between the weights and parts moved thereby in order to reduce wear of parts and consequent inaccuracy of operation. To this end we prefer to connect the weights to the movable head member 50 by flexible Ytension members 52 (Fig. 1) which may be, for example,.thin pieces of metal, referred to hereinafter vas flexible strips. These flexible strips by reason of their iiexibility, may be rigidly attached at their ends to the weights 20 and 21, and to the movable head member 50, without the use of pivotal connections. As shown in Fig. 1, the flexible strips are rigidly clamped `to the weights adjacent to the pivotal'axes thereof by washers 55 suitably held against the strips by screws 56, and at theiropposite ends to the movable head member 50 in a similar manner by members 60, which may serve also to guide the iexible strip as hereinafter explained. In this wav the use of pivotal connections between the weights and the movable head operated thereby is avoided.

In a deviceof this kind, wherein the motion of a weight in one direction is transmitted to a reciprocating or sliding head member restrained to motion in a non-parallel direction, the tension member (herein the flexible strip) connecting the weight and the reciprocating head necessarily moves through various .angular positions with respect to its connected weight and v reciprocating l head. Since the flexible stripis rigidly aiiixed at its opposite ends to thefiweight and to :the reciprocating head,it is desirable, in order )to prevent abrupt `flexure and straining of the Jstrip at `theserpoints` of connection, Sto' provide suitable strip-guiding surfaces, on the weight and reciprocating head, respectively, to cause the opposite ends of the stripto conform `to gentle curves `rather than abrupt bends. To this end we prefer to provide the centrifugally actuated Weights withcam faces which contactfwith the "flexible strips, each cam `face being, at least in part, in the `form, of a `curve of sufficient radius topreventabrupt bends in the `"flexiblestrips. As shown in F ig. l, the upper and outercam surfaces of the; two Vweights 2() and 2lfc-u`rve inwardly as indicated atf59so as tofcontact progressively with the associated flexible strips upon voutward movement "of i the weights. In like manner we prefer to provide the two upper strip-guiding members 60 (which "preferably form apart of the `refunction of the variable ygmgle inclination `of the connecting member.I` Furthermore," a

weight pivoted" adj acent4 .one end, in Ithe present embodiment of the invention opposed directly by ,afspring4 is `not moved through equal` radial distances lby equal 11noreasesin the velocity of the rotating-weightdriving member. However, `by employing a flexible strip for connectingthe centrifuga-lly actuated weight andthe movable member, and by suitablydesigninglboth strip-guiding surfaceswhich progressively `Contact with the Vflexible `strip and` using a` `spring having a known; constant, it is possibleto modify the force-transmitting i action of the flexible strip to attain `any `desired `differentialTratijo `between theiincrements of `increase of. velocity of therotating weight-driving member andthe increments of linear movement of the head4 5() or of any motion resp onsivemember ordevice carried or movable thereby. f i i. i.

In the illustrated embodiment of the invention, motion-responsivev mechanism, described hereinafter, intheform of a movable `index needle (which here-constitutes the ultimate responsive part), and-its driving gearing, `is connected to and actuated by theireciprocating head 50.` Sincesiit is desirable iny speedindicatingxapparatus that the; index` needle shallrcooperate with evenly spacedagrladuations :on an 4indicating.dial or chart, and further since gearing conveniently interposed be-` tween theindicating pointer and the reciprocatingfhead usually exercises but little correctiveleffect upon the motion transmitted tothepointer,` We deem itadvantageous-'to` dispose" the curved strip guiding surfaces in "such" a way asto `obtain substantially equal "differential incrementsof movement 4of the "head 50for equal differential changes in roitary velocity ofthe weight-driving4 member a l-Iowever, since it is `desirablefor the purpose. of preventing abruptlfiexure of the flexibleJ strip, as :explained above, `to employ curved strip-guiding surfaces at both ends vcV of thelstrips, we preferably use these two curved strip-guiding surfaces (herein shown i as the curved` surfaces 59 and 60) for conaction in modifying the force-trans-` :mittmg` effect ofstlie flexible strip 52. As

shown in Fig. 3a, thestrip-guiding surfaces 59 and 60 are suitably curved and disposed with respect tothe normal `angularity of the flexible strips 52 and to the pivotal axes 29 of the weights to provide, within the range of movement'of thepivoted'weights, equal movementof` the reciprocating head 50 for equal increases Vor decreases in speed yof the rotating-weight-carrying member.` At zero velocity the weights 20-21 andhead 50 are in the position indicated at VO and shown by full lines;- when the shaft l2 is rotated at a` speed of 1000 r. plm., for example, theweights 20--21 under the action of centrifugal force swing outwardly to force the head member '50 downwardly against thespring 51 into some suchposition, indicated at Vl for ex- Vample, and at aspeed of 2000r. p. m. the

weights and head areforcedinto a further position indicated, for example at V2, thus`effectingjequal linear movements ofthe head memberfor equal changesin thespeed `ofthe rotating shaft and `uf'eight driving member.

Referring tofFigs. 5 and 6 which illustrate the invention as embodied inan instrument having a graduated dial and'index needle, the

instrumentcomprises a `siiitable casing 70 provided with a glass front 7l and mounted uponthe upper extremity ofthe frame 17.

A dial 72 is disposed behindthe glass cover 7l, and an index `needle 73moves over suitable` graduations Pilmarlred onthe dial and preferably equally spaced to correspond to equal changes in speed of the rota-ry weightdriving member ll, or shaft l2. The needle T23-.maybe actuated by usual gage movement parts, for example, an index staff 90 carrying a small pinion gear wheel `91 `which meshes with a sector `gear 7 ipivoted at 76to any suitable `fixed `part of the `mechanism such as the V-shaped frame member 78.*An arm `77 connected vtoth'e sector gear 75, has-ran elongate slot-"79 which 'receivesfan adjustable, but normallyfxedbloclrSl. .(Fig. 17!) i In thek present embodiment of the invention we provide a fiat spring 8O secured at one end by a sere-w 80L (Fig. 7) to the arm 77 and block 81, and at its opposite end termi- Y nating in a knob-like part 83 which is disposed in any annulargroove defined by spaced `fianges 84 and v85 carried by the rotating and reciprocating head 50. The arm 77 and ythe lhead 50, it will be noted, are capable of movement in parallel planes, in the present instance, vertical. The spring 80 vis capable of fleXure in a vertical direction in the position lof Fig. 6 and provides a considerable .an'iplit-ude of flexible movement without undue friction with the reciprocating head. Rapid up anddown movements ofthe reciprocating head 50 are effectively damped by the resiliency lof this connection, and only the continued and major movements of the .reciprocating head are transmitted through. the spring 8() to the slotted arm 77 of the motion-.responsive mechanism. This arrangement, wherein a resilientY connection is employed between the reciprocating head and the motion-responsive mechanism, renders :unnecessary the. use of the conventional flywheel arrangement for damping the changes in rotary velocity of the weight-carrying `member .'11 or spindle 12, and likewise eliminates the torsional strains, the attendant friction, and the likelihood of injurious wear -of parts caused by the use of a flywheel.

Inlthe use of the complete device explained vherein as an instance of our invention, the spindle 12 lmay be connected 'toany rotating part. of which it is desired to lmeasure the velocity. Rotation of the spindle 12 and .hence of the weight-'driving member llsets up a centrifugal fo-rce upon the weights 20 and 21 which together with the resilient force of the spring 51 determinesthe orbital path of the weights 2O and 21 at any given instant in their rotation. Changes in velocity of the spindle 12 and rotary weightcarrying member 11 bring about changes in the orbital path offthe weights 20and 21, components of the movement ofthe Weights 20 and 21 being transmitted through the flexible strips 52, suitably modified by the curved strip-guiding surfaces 15, to the reciprocating head 50. From thence motion is transmitted through the resilient dalnping and connecting member 80 to the motionresponsive mechanism including the pointer v73 which, as explained above, may move over evenly spaced graduations to indicate the velocity of the moving part to` which Jthe device is connected. Y

Thefmechanism vherein described is adapted for use in recording tachometers, double dial tachometers or combination recording and indicating t'achometers.

It should be understood that the present disclosure vis for the 4purpose of illustration only andthat various changes in shape, proportion, and arrangement of parts, as well as the substitution of equivalent elements for those herein shown and described, may be made Without departing from the spirit and scope of the invention as set forth in the `appended claims.

NVe-claim:

1. 'A device of the class described comprising driving and driven members rotatable about the same a-Xis and relatively mov- '15 able along said axis toward and away from eachother, one of said members having a .part constructed and arranged torevolve in orbital paths ldetermined by centrifugal force, means for yieldingly opposing relative movement of said members vtoward each other, a flexible strip connecting the revolving part with the other of said members to efl'ect relative movement .between said members in response to changes 'in the orbital 85 path of said revolving part, an indicator having an actuating arm movable in a path substantially parallel tosaid axis, and resilient means for transmitting relative movement between said members to said arm, said means being capable of absorbing vibration setup .in said members.

2. A device of the class described comprising means movable in response to centrifugal force along a substantially rectilinear path, means for yieldingly opposing such movement, an indicator having an actuating arm movable in a path substantially parallel to the `path of movement of the responsive means,and resilient means for absorbing oscillations set up by said responsive means and for Vtransmitting movement thereof to said arm. Y

3. A device'of the class described-comprising a rotary member having a .pivotally mounted'weightl constructed and arranged to revolve kin orbital paths determined by centrifugal force, a responsive member movable toward and away from said rotary member along its axis of rotation, means for yieldingly opposing movement of said responsive member Atoward said rotary member, means connectingsaid weight and responsive member for actuating the latter in response to, changes yin lthe orbital path of the former, indicating :mechanism having an actuating member adjacent tofthe path ofmovement of said responsive member, and a resilient connection between said :responsive member and `said -actuating ymember for transmitting movement of the former to the latter, said '120 connection being capable of'absorbing vibrations set up in said responsive member.

4. A device of the 4class described comprising a reciprocating head, centrifugally actuated rotary mea-ns for reciprocating said i12 head'in accordance with changes in rotary velocity of said means, indicating mechanism having an actuating member movable in a path .adjacent to the path of movement of said head, and a spring connected to said '130 `head and actuating member to transmit Vof said head, a spring connected at one end to said actuating member, and means carried by the other end of said spring `for engaging Vthe groove in said head, whereby to transmit movement of said head to said actuating member.

6. A device of the class described comprising a" rotary member having a pivotally mounted weight constructed and arranged to `revolve in orbital paths in accordance with the centrifugal force acting thereon, a rotating and reciprocating head coaxial with said rotary member and having a peripherall groove concentric with its axis oflrotation,

a flexible `strip connectingA said,` weight and head,said.weight having a curved surface of varying radius positionedprogressively to Contact with said flexible strip to effect reciprocating movement of saidliead` inresponse to variations in rotary velocity of said rotarymember, means for yielding opposing movement of said headtoward said rotary member, indicating mechanism having `of said head to said actuating arm.

an actuating arm movable ina path substantially parallel to the path of movement of said head, a spring connected at one end to said arm, and means carried by the other end of said spring for engaging the groove in said head, whereby to transmit movement 7. In a tachometer of the class thecombination of means movable along a substantially rectilinearpath in accordance with dilerent speedsof rotation 4of a driving member, anindicating mechanism havt to the pathv of movement of said Vrotating ing an actuating member movable ina path adjacent to said means, and resilient means for transmitting movement from said movablemeans to said actuating member-while absorbing any vibrations set upin the former. y

` 8. `In a tachometer of the class described, the combination of a rotating member constructed and arranged to move axiallyin accordance with its'speed of rotation, an indi` eating mechanism having an actuating member movable in a path substantially parallel member, and a resilient connection between said rotating member and actuating member for transmitting axial movement of the former to the latter while` absorbing any vibrationsset upinthe former.` .Y f i 9. In a tachometer of the class described, driving` and driven members ,rotatable about the same axis and @relatively movable` along said axis toward and away from .each other, one ofi-said members `having a pivotally mounted part constructedand arranged toirevolve `irrorbital paths determined by centrifugal force, means `for yieldingly opposing relative movementeo saidmembers toward eachiy other, a flexible strip connecting t saidlpivotally; mounted `part with `the :other of said -memb'ersto effect, relative movement 'between said lmembersin response to varia.-

tions in the orbital path of" the former and guidemeans `associated ,with said members having surfacesgshaped land arranged progressively to contact with said llexible strip to eliect equal `changes in relative movement between said members for equal changes in their speed of rotation. i

` 10. In a tachometer of the class described, i

a rotary member having a weight constructed and arranged to revolve in orbital paths determined by centrifugal force, a responsive member movable toward and away from means for yieldingly opposing movement of said responsive member toward said rotary member, a` flexible `strip connecting said weight and responsive member to effect movement of the latter in Vresponse to changes in the orbital path of the former, and guide means associated with said weight and resaid rotary member along its axis of rotation, v

sponsive member having cooperating guide surfaces shaped and arranged progressively to Contact with said flexible strip to eilect equal changes in the movement of said responsive member for equal changes in the speed of rotation of said rotary member.

11. In a tachometer of the class described,

a rotary member having a pivotally mount-` described, Y

ed weight constructed and arranged to revolve in orbital paths determined by centrifugal force, a rotating and reciprocating head movable toward and away from said rotary member along its axis of rotation, means for yieldingly opposing movement of said head toward said rotary member, and means for transmitting movement of said weight to said head in accordance with changes in the orbital path of said weight, said means comprising a ilexible strip connected to said weight and head, and strip guidingmeans constructed and arranged progressively to contactrwith a greater length of said flexible strip as said weight revolves in progressively larger orbits to effect equal changes in `movement of said head for equal changes in speed of said rotary member.

12. In a tachometer of the class described, Y

driving and driven members rotatable about the same axis and relatively movable along said axistoward and away from each other,

one of said members having a part construct` ed and arranged to revolve in orbital paths determined by centrifugal force, means for yielding'ly opposing relative movement of said members toward eachl other, and mea-ns for transmitting movement of the revolving part to the other of said members, said means comprising a flexible member Connected to said part and to the other of saidpmembers, and' guiding means constructed and arranged progressively to Contact Withfsaid flexible member to effect equal changes in relative movement between said members: for equal changes in their' speed of rotation. 1

Signed by us at Bridgeport, Connecticut, this 9th day of May, 1930. f

" v ROY C. SYLVANDER.'

RUDOLF BECK.

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