US2639135A - Speed-controlled actuating device - Google Patents

Description

May 19,1953 H, E. s LQAN 25539135 SPEED-commun: ACTUATING D'Evrcf:

Find net. 1o, 195o 2 sheets-sheet 1 Patented May 19, 195.3

SPEED-CONTROLLED ACTUATING DEVICE Harry E. Sloan, Hartford, Conn., assigner to The Cushman lChuck Company, Hartford, Conn., a corporation of `Connecticut Application October 10, 1950, Serial No. 189,339

9 Claims.

The present invention relates in general to an automatic actuating-device and more especially to a speed-controlled actuating-device for automatically operating an electric switch or the like, of the type disclosed, but not claimed, in Patent No. 2,563,970, dated August 14, 1951.

An object of the invention is to provide a superior speed-controlled actuating-device.

A further object of the invention is to provide a superior speed-controlled actuating-device which is of simple, economical and dependable construction.

A still further object of the invention is to provide a superior speed-controlled actuatingdevice, the elements of which are so compactly arranged that the entire device occupies comparatively little space.

A still further object of the invention is to provide a superior speed-controlled actuatingdevice wherein centrifugal force is employed to activate the device from its normal position to its operating position and wherein gravitational force is employed to return the device from its operating position to its normal position.

Other objects and advantages will appear to those skilled in the art from the following, considered in conjunction with the accompanying drawings.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a vertical elevation in section of the speed-controlled device of this invention shown in its normal inoperative position;

Fig. 2 is a vertical side elevation in section of the speed-controlled actuating device on line 2-2 of Fig. 1;

Fig. 3 is a vertical elevation similar to Fig. 1, but showing the device in its operating position;

Fig. 4 is a plan elevation in section on line 4-4 of Fig. l;

Fig. 5 is a plan elevation in section on line 5--5 of Fig. 1;

Fig. 6 is an end elevation in section of the rotor and actuating-plate on line 6 6 of Figure 1;

Fig. 7 is a perspective view of the rotor of the speed-controlled actuating-device; and

Fig. 8 is a vertical elevation in section of another form which they device may assume in accordance with the present invention.

Referring to the drawings, the latter show two forms of the invention, each form being used for the purpose of automatically actuating an element which, in this instance, is a limit-switch, but it will be understood that either or both forms of the invention may have other applications and that modifications of the specific embodiments of the invention shown herein are contemplated and included within the scope of the appended claims.

The showing of Figs. 1 through 7 The automatic speed-controlled device shown in Figs. 1 through 7 comprises, in the main, a casing indicated generally at I0 consisting of a substantially cup-shaped base-member II having a cover-member I2 which, in turn, is provided with a cap I3, the cup-shaped base-member, cover-member and cap all being formed of a suitable material such as, for example, cast iron, steel or the equivalent.

The base-member Il is shown rlxedly mounted on a. frame-member I4 by means of a substantially-vertical sleeve-portion I5 oi' reduced cross section integral at its upper end with the bottom of the base-member, and provided at its lower end with a supporting-flange I6 which is adapted to be bolted or otherwise detachably secured to the frame-member I4.

Extending through the frame-member I4 and the flanged sleeve-portion I5 of the base-member into the bottom thereof, is an axial aperture I1 which is substantially concentric with the sleeve I5, the axial aperture II being provided at its upper end with a substantially concentric counterbore which constitutes a seat for supporting a ball bearing I9. A similar counterbore is provided in the axial aperture I'I at its intersection with the bottom face of the supporting-flange I6 for accommodating a ball bearing 2|, which is adapted to be secured therein between the bottom of the supporting-harige and the upper face ofthe frame-member I4 on which ythe supporting-flange is secured.

In general, the base-member II, cover-member I2 and cap I3 are substantially circular, as shown especially well in Figs. 4 and 5, the covermember I2 being detachably secured on the upper edge of the cup-shaped base-member by fastening-means such as, for example, machine bolts, to form therewith a substantially-closed chamber 23.

Formed on the cover is an integral upstanding eccentric-boss provided with a substantially-vertical internally-threaded aperture 24 extending therethrough and substantially in alignment with the axial aperture I'I of the base-member, the internally-threaded aperture 24 of the cover being provided adjacent its upper end with a substantially-concentric cylindrical restriction 25, which forms an annular downwardly-facing shoulder at the upper end of the internally threaded aperture 24. Threadedly secured in the lower portion of the latter is a spring-com pression adjusting-bushing 26, the upperend of which is adapted normally to be spaced below the aforesaid downwardly-facing shoulder of the restricted portion 25 of the aperture, so as to provide an annular upwardly-facing shoulder forv supporting the lower end oi a helical compression spring, as hereinafter described.

wardly-and-outwardly-sloping bottom Wall 54 of each roll-track is slightly less than the angle of inclination of the upwardly-and-outwardly-sloping frusto-conical surface 39 of the actuatingplate. Thus, the vertical spacing between the bottom wall 54 of each roll-track and the frustoconical surface of the actuating-plate increases from the inner end of each roll-track outwardly.

Thus, as the balls 56--56 roll up their respective inclined tracks outwardly of the rotor-head, the actuating-plate is permitted to drop downwardly relative to the rotor-head. On the other hand, as the balls roll inwardly down their respective inclined tracks, the balls serve to force the actuating-plate upwardly relative to the rotorhead.

As pointed out above, the roll-members shown in the present embodiment constitute balls, but it will be understood that the rolling-members may comprise cylindrical rollers, if desired, in which case, suitable tracks are provided in the rotor-head for guiding the radial movement of the cylindrical rollers. Moreover, although two rolling-members have been found to operate successfully, it is within the purview of the invention to use more than 'two balls or cylindrical rollers in the rotor-head for displacing the actuating-plate.

Operation of the showing of Figs. 1 through 7 inclusive The speed-controlled device disclosed in Figs. l through 7 is adapted to automatically operate the exemplary electric switch 23 housed within the cap I3 of the device for energizing and deenergizing an electric circuit. Assuming, then, that the switch 28 is so arranged that it is normally held open, then on releasing its button 29, the switch will be closed. Conversely, upon re-engaging the button 29, the switch will be automatically opened. The actuation of the switch is effected as follows. When the rotor is stationary, the device may be said to be in its normal position wherein the actuating-plate is held upwardly in its raised position with respect to the rotor-head by engagement of the balls 5B with the inner peripheral edge of the upwardly-andoutwardly-sloping frusto-conical surface 39 of the actuating-plate. The weight supported by the balls is that fractional part of the weight of the actuating-plate which is not carried by the counterpoising spring and is hereinafter referred to as the residual weight of the actuating-plate. The shank 4| of the actuating-plate is likewise in its raised position, whereby the head 4B of the stud 45 supports the arm 33 of the bell-crank lever in a substantially-horizontal position in which the actuating-pin 30 of the bell-crank lever engages the `button 29 of the switch to hold the latter open` Upon rotation of the drive-member 5l and the driven pinion 50, the rotor-head will be rotated rapidly, whereupon centrifugal forces are developed which roll the balls outwardly and upwardly in their respective inclined roll-tracks. As the balls move outwardly, the actuating-plate is gradually lowered from its normal raised position to its lowermost or operating position, due to the slope-differential between the bottom wall of each track and the frusto-conical surface 39 of the actuating-plate, the actuating-plate being held in its lowermost position against further descent when the collar 43 becomes seated on the upper stop surface of the eccentric-boss, as shown in Fig, 3. By adjustment of the. collar t3,r the actuating plate 35 may be adjusted vertically so that the :same is, in its lowermost position, spaced slightly from the balls 56 when the latter are at or adjacent the outer ends of their respective tracks. concurrently with the lowering of the actuating-plate 35, the head 46 of the stud 45 is loweredy to permit the horizontal arm 33 of the bell-crank lever to swing downwardly in a counterclockwise direction as viewed in Fig. l, and in so`doing withdraws its holding-pin 30 from engagement with the button 29 of the switch, so as to permit the latter to automatically close.

Upon disengaging the rotor drive-means, the rotor gradually comes to rest, during which interval the centrifugal forces which hold the balls at their outer extremities of their respective tracks gradually diminish until the balls are no longer held thereby at the outer extremities of their respective tracks. Since the actuatingplate 35 is supported clear of the balls in the manner hereinabove described, the balls are unrestrained and hence gravitational force acting on the ba-lls will cause the balls to start to roll back down their respective inclined tracks. After gaining some momentum, the balls will reengage the frusto-conical surface of the actuating-plate against which they exert a wedging action of sufiicient force to overcome the residual weight of the actuating-plate and lift it upwardly to its normal position. Thus, when the balls arrive at the inner ends of their respective inclined tracks, the actuating-plate is fully elevated relative to the rotor-head and the horizontal arm of the bell-crank lever swung upwardly in a clockwise `.direction to its normal substantially-horizontal position, wherein its holding-pin 30 engages the button 29 of the switch to hold the latter open.

As previously mentioned, the bushing 26 may axially be adjusted to vary the compression oi the spring 42 and thus permit ready ne adjustment of the counterbalance of the actuator plate 35. On the other hand, the collar 43 is axially adjustable to permit ready vertical adjustment of the actuator plate 35. Finally, the stud 45 is axially adjustable on the shank 4| of the actuator plate 35 so that the stud 45 may have its Vertical stroke in the same region relative to the electric switch 28 even if the actuator plate 35 is vertically adjusted.

The showing of Fig. 8

In the showing of Fig. 8, certain of the parts correspond to those previously described herein and such parts have reference characters applied thereto which correspond to those previously employed.

In the embodiment of the invention shown in Fig. 8, all parts of the device are substantially identical to those shown and described hereinabove, with the exception of the actuating-plate which is indicated by the reference character 35a and provided on its underside with an outwardly-and-downwardly--inclined frusto conical surface 39a. The upwardly-inclined bottom walls of the respective ball-tracks and the frustoconical surface 39a immediately thereabove thus converge toward the outer ends thereof.

In accordance with this construction, the normal position of the actuating-plate is its lowermost position with respect to the rotor-head, in which position the actuating-plate is restrained by engagement of its adjustable collar 43 with the upper stop face of the eccentric-boss of the cover. Since in this form of the invention 'the forces acting on the balls to return them to' 'their normal innermost positions are diminishassen-sa 7. ing as the balls: approach their innermostipositions, clearance is preferably provided between the frusto-conical surface of the actuating-plate and the balls, when the lattery are in their normal` inner positions by adjustmentl of the adjusting-nut L13, in the manner-hereinabove described. As the balls are moved outwardly radially, they overcome the residualk weight of: the actuatingplate and elevate the latter into` its., operating position, as .hereinafter described', in which position the balls willv support the residual. Weight of the actuating-plate.

Assuming the actuating-plate is: inv its lowermost or normal; position, theny the head1 of the adjustable stud at. the upper endof the shank of, the actuating-plate will be displacedv down.- wardly below the horizontal position ofthe arm 33.1,of the bellfcrank lever, whereby. the latter. isl

allowed to pivot counter-clockwise and-disengage its` holding-pinfromthe switch-actuating button, thereby permitting the switchto close.

When the rotor. isrotated; centrifugalY force will-carry the ballsoutwardly and upwardly along their respective inclined; tracks, thereby raising the actuating-plate relative tothe rotor-headdue to. theiwedging actionof the ballsas they. move outwardly between. the upwardly-inclined'. bottom.

walls of the tracks and-thedownwardly-inclined frusta-conical` surface of: the actuating-plate. This4 upward. movement. off the actuating-plate elevatcs the.: head: ofy the adjustable-screw. of the actuating.-piate` to; thereby pivot. the belli-cranklever clockwise. and; hence, move itsholding-.pin

intoengagement with the switch-button to vhold the switch. open.

Upon', reaching the outer ends of: their respec-v tive tracks, the balls are held from escapingtherefrom bythe yoke-members: fastenedV across the. ends thereof.;

As; explained above, as,V the balls arrive atthe outer ends of their respective tracks, the residual weight of' the. actuating-plate is carried' by the` Moreover, due to; the inclination of` theballs. lustconical; surface of ther actuating-plate at its points ofv engagement with the balls, they re*y sidualweieht-enforce of the-actuating-platetendsto cam1 the balls.,4 backand downwardlyl along their: respective tracksthus. augmenting gravitan tional forces acting on the balls.

Thus, when the'. rotor slowsv downand the centrifugal force acting to hold the balls at the outer ends of their respective tracksy is diminv ished, a point will be reached at whichthecen-f trifugal forces are less than the combined forces.`

plate act simultaneously on the balls toy causethelatter to roll down their inclined tracks, this; action may occur while. the rotor-head is still rotating at an appreciable speed suchas, for example, substantially 20 revolutions per minute.

On returning toits normal lowermost. positiony with respect to. the rotor-head, the actuatingf plate carries they head of its adjustable-screw below. the horizontal plane of the armv 3 3 ofthe bellf-cranklever., whereupon theibell-crank leverpivots connterclockwise, therebyv disengaging, the switchfbuttonand allowing they switch to.` close.;

The. speed=contro1led actuatingrdevice.- is, thus..

seen to embody relatively few moving parts, all* of' which are of durable, dependableand inexpensive construction and assembled ina compact manner to provide a device which occupies comparatively little space. Moreover, thedevice is characterized by its novel construction and ar-Y rangement of elements whereby centrifugal forces serve to actuate the device from itsvnormal position to its operative position, Whilegravitational forcesv return the elementsof the device to their normal inoperativepositions.

The invention maybe carried outl in other speciiic ways than those herein set forth without departing from the spirit and essential' characteristics of the invention, and the present em-l bodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and

all changes. coming within. the meaning andv equivalency range of the appended'claims are in-y tended. to be embraced therein.

I claim:

l. A speed-responsive device, comprising a driver mounted for rotation abouta substantially vertical axis and provided in its top with iden@ tical, substantially radiallyy extending guideways terminating at their inner ends short of` the rotary axis of said driver andr having inwardly and downwardly inclined bottoms, respectively; identicalv balls received with arolling nt in saidA guideways, respectively, and. normally gravitating toward the respective inner ends thereof, said balls projecting above their respectiveguideways in any positions therein; a follower disc disposed above said: driver incoaxial alignment therewith and being axiallymovable, said dischaving a bottom surface` riding on` said balls and forming with the inclined bottoms. ofthe adjacent guideways identical. angles, respectively, sothat said disc is raised and: lowered onmovement of said ballsin oppositedirections, respec-` tively, in their respective g-uideways and' will. hinder. gravitationalr inward! movement of said. balls in their respective guideways; and spring means partly counterbalancing said disc tov perimit said balls, despite the residual. weight of said disc thereon, to gravitate toward ther inner ends of their' respective guideways. as saidk driver comes to rest.

2. A speed@responsive` device, comprising a driver mounted for rotation-about a substantially vertical axis and provided in its top` with identical, substantially radially extending.. guideways terminating at their inner ends short of the rotary. axis of said 'driver and: having inwardly andA downwardly inclined bottoms, respectively; identical balls received with a rolling iit in` said4 guideways, respectively,and normally. gravitatingf toward. the respective inner ends thereof, said balls projecting above their respective guideways in any positions therein; a follower disc disposed above said driver in coaxial alignment therewith and being axially movable, said disc having a bottom surrace riding on said balls and being of such invertedconical shape that the same ormswith the inclined bottom of each guideway an acute angle pointing inwardly toward the rotary axis of said dr-iver, solthat said disc is raised and lowered on inward' and centrifugal.utwardmovements, respectively, of said. balls in their respective guideways; and: spring means counterbalancing said disc sufficiently, to; permit said balls to gravitate toward the inner ends of theirrespective guideways and rza.ise.-sao`ly disc as; said driver comes to rest;

3; A., speed-responsive, deviner comprising a.

driver mounted for rotation about a substantially vertical axis and provided in its top with identical, substantially radially extending guideways terminating at their inner ends short of the rotary axis of said driver and having inwardly and downwardly inclined bottoms, respectively; identical balls received with a rolling t in said guideways, respectively, and normally gravitating toward the respective inner ends thereof, said balls projecting above their respective guideways in any positions therein; a follower disc disposed above said driver in coaxial alignment therewith and having an upwardly extending coaxial shank; a xed bushing through which said shank extends and in which it is guided for axial movement, said disc having a bottom surface riding on said balls and forming with the inclined bottoms of the adjacent guideways identical angles, respectively, so that said disc is raised and lowered on movement of said balls in opposite directions, respectively, in their respective guideways and will hinder gravitational inward movement of said balls in their respective guideways; a collar on said shank above said bushing; and a helical compression spring surrounding said shank and interposed between said collar and bushing, said spring partly counteibalancing said disc to permit said balls, despite the residual weight of said disc thereon, to gravitate toward the inner ends of their respective guideways as said driver comes to rest, and said collar is adjustable on said shank to permit axial adjustment of said disc.

4. A speed-responsive device as set forth in claim 3, further comprising an actuator stud threadedly received in the upper end of said shank so as to be axially adjustable thereon.

5. A speed-responsive device, comprising a driver mounted for rotation about a substantially vertical axis and provided in its top with identical, substantially radially extending guideways terminating at their inner ends short of the rotary axis of said driver and having inwardly and downwardly inclined bottoms, respectively; I

identical balls received with a rolling t in said guideways, respectively, and normally gravitating toward the respective inner ends thereof, said balls projecting above their respective guideways in any positions therein; a follower disc disposed above said driver in coaxial alignment therewith and being axially movable, said disc having an upwardly extending coaxial shank and a bottom surface riding on said balls and being of such inverted conical shape that the same forms with the inclined bottom of each guideway an acute angle pointing inwardly toward the rotary axis of said driver so that said disc is raised and lowered on inward and centrifugal outward movements, respectively, of said balls in their respective guideways; a bushing through which said shank extends and in which it is guided for axial movement; a collar on said shank above said bushing; a stop above said bushing on which said collar will become seated on descent of said disc into a lowermost position in which the same will clear said balls only when the latter are substantially at the outer ends of their respective guideways; and a helical compression spring surrounding said shank and interposed between said bushing and collar, said spring being adapted to counterbalance said disc sufficiently to permit said balls to gravitate toward the inner ends of their respective guideways and raise said disc when said driver is substantially at rest,

6. A speed-responsive device as set forth in claim 5, in which said bushing is axially adjustable to vary the compression of said spring.

7. A speed-responsive device as set forth in claim 5, in which said collar is adjustable on said shank to permit axial adjustment of said disc.

8. A speed-responsive device as set forth in claim 5, in which said bushing is axially adjustable to vary the compression of said spring, and said collar is adjustable on said shank to permit axial adjustment of said disc.

9. A speed-responsive device, comprising a driver mounted for rotation about a substantially vertical axis and provided in its top with identical, substantially radially extending guideways terminating at their inner ends short of the rotary axis of said driver and having inwardly and downwardly inclined bottoms, respectively; identical balls received with a rolling iit in said guideways, respectively, and normally gravitating toward the respective inner ends thereof, said balls projecting above their respective guideways in any positions therein; a follower disc disposed above said driver in coaxial alignment therewith and being axially movable, said disc having an upwardly extending coaxial shank element and a bottom surface riding on said balls and being of such inverted conical shape that the same forms with the inclined bottom of each guideway an acute angle pointing inwardly toward the rotary axis of said driver so that said disc is raised and lowered on inward and centrifugal outward movements, respectively, of said balls in their respective guideways; a bushing through which said shank elements extends and in which it is guided for axial movement; an actuator stud element threadedly received in the upper end of said shank element so as to be axially adjustable thereon; a collar axially adjustable on one of Said elements above said bushing; a stop above said bushing on which said collar will become seated on descent of said disc into a lowermost position in which the same will clear said balls only when the latter are substantially at the outer ends of their respective guideways; and a helical cornpression spring surrounding said shank and interposed between said bushing and collar, said spring being adapted to counterbalance said disc sufficiently to permit said balls to gravitate toward the inner ends of their respective guideways and raise said disc when said driver is substantially at rest.

HARRY E. SLOAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re, 13,650 Morrison Nov. 18, 1913 270,546 Hunt Jan. 9, 1883 330,328 Hodges Nov. 10, 1885 721,846 Watson Mar. 3, 1903 1,252,769 Bently Jan. 8, 1918 1,575,747 Farmer Mar. 9, 1926 1,925,484 Eastman Sept. 5, 1933 2,088,427 Maurer July 27, 1937 2,146,046 Bancroft Feb. 7, 1939 2,268,230 Warner Dec. 30, 1941 2,364,116 Whitehead Dec. 5, 1944 2,454,902 Warren Nov. 30, 1948 2,533,231 Drake et al Dec. 12, 1950 2,563,970 Sloan et al. Aug. 14, 1951

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