US2811228A

US2811228A - Fly ball governor cable clamp

Info

Publication number: US2811228A
Application number: US565282A
Authority: US
Inventors: Joseph H Borden
Original assignee: Haughton Elevator and Machine Co
Current assignee: Schindler Haughton Elevator Corp
Priority date: 1956-02-13
Filing date: 1956-02-13
Publication date: 1957-10-29
Anticipated expiration: 1974-10-29

Description

Oct. 29, 1957 J. H. BORDEN FLY BALL GOVERNOR CABLE CLAMP 3 Sheets-Sheet 1 Filed Feb. 13. 1956 IN'VENTOR. JOSEPH H BURDEN A 7' T'OR/VEYS Oct. 29, 1957 BQRDEN 2,811,228

FLY BALL GOVERNOR CABLE CLAMP Filed Feb. 13, 1956 Y 3 Sheets-Sheet 2 IN V EN TOR.

JOSEPH H BORDE/V A TTORNE Y5 Oct. 29, 1957 J. H. BORDEN FLY BALL GOVERNOR CABLE CLAMP s Sheets-Sheet 3 Filed Feb. 13, 1956 INI'ENTOR. JOSEPH H BURDEN A T'TOR/VE Y5 United States Patent FLY BALL GOVERNOR CABLE CLAMP Joseph H. Borden, Toledo, Ohio, assignor to Haughton Elevator Company, Toledo, Ohio, a corporation of bio Application February 13, 1956, Serial No. 565,282

10 Claims. (Cl. 188-189) This invention relates to fly ball governor mechanism for use in elevator systems. Such fly ball governor mechanism usually is located at the top of each hoistway. it comprises a pulley over which passes the upper bight of a continuous cable, the lower bight of which passes under a cable tension sheave located in a pit at the bottom of the hoistway, and comprises also a fly ball governor geared to the pulley, a switch which is tripped when the fly ball attains a predetermined speed and a clamp which grips the cable when the fly ball has attained a still greater predetermined speed.

The cable is wound around a drum carried by the elevator car so that as long as the drum does not turn the speed of the fly ball governor is proportional to the speed of the car. Tripping the switch cuts off the power that is moving the elevator car and applies a brake, which may be the same brake that is employed to stop the car at landings. If the cars movement continues to accelerate when the power is cut off and the brake applied, as it might in case of failure of the hoisting and braking mechanisms, the clamp grips and securely holds the cable causing rotation of the drum around which the cable is wrapped, and which is carried by the car. Thus the drum is turned whenever the car moves while the cable is held by the clamp. Turning of the drum causes safety jaws to engage vertical guides along which the car normally rises and descends thereby bringing the car to a stop and holding it securely locked to the vertical guides.

It is an object of this invention to provide a clamp for fly ball governor cables which is capable of gripping cables of various thicknesses.

It is a further object of this invention to provide a fly ball governor clamp which will permit a new fly ball governor cable to run between its jaws with ample clearance but which nevertheless will seize the cable promptly and reliably even after the cable has been subjected to much use and wear by reason of which its thickness has been reduced.

It is a further object of the invention to provide a fly ball governor clamp which while it will reliably seize a fly ballgovernor cable nevertheless will permit the cable to be pulled therethrough by force so far below the breaking strength of the cable that the factor of safety is adequate.

And it is still a further object to provide a fly ball governor clamp the grip of which may be adjusted to comply with codes and regulations in jurisdictions throughout the United States.

Other objects and various advantages of the invention will be apparent from the following description illustrated by the accompanying drawings in which:

'-Fig. I is a front elevational view showing a fly ball governor mechanism incorporating the cable clamp of this invention, the cable clamp being shown in nonclamping condition;

{Fig.ll'is a plan view of the cableclamp per se, the cable clamp being shown in nonclamping condition;

Fig. 111 is a rear elevational view of the cable clamp per se, the cable clamp being shown in nonclampin'g' condition;

Fig. IV is a front elevational view of the cable clamp per se, the cable clamp being shown in clamping condition; and

Fig. V is a rear elevational view of the cable clamp per se, the cable clamp being shown in clamping condition.

These drawings and the following description are exemplary only and are not intended to impose limitations on the scope of the invention.

The mechanism is mounted upon a base 1, integral with which is a frame 2 shaped substantiallylike an A, at the apex of which are hearings in which are journalled a vertical shaft 3 and a horizontal shaft 4.

The vertical shaft 3 carries a pair of links 5 and 6 to which are pivoted the stems 7 and 8 of a pair of fly balls 9 and 10. The stems 7 and 8 of the fly balls 9 and 10 act upon a push rod 11 that is slidably mounted in an axial bore in the vertical shaft 3. Interposed between the upper end of the vertical shaft 3 and a nut 12 on the push rod 11 is an expansive spring 13 that is prestressed to hold the fly balls 9 and 10 from swinging outwardly until the vertical shaft 3 reaches a predetermined rotational speed, and that yieldably resists downward movement of the push rod 11 as the fly balls then swing outwardly under the influence of centrifugal force.

Fixed upon the vertical shaft 3 is a driven bevel gear 14 that meshes with a driving bevel gear 15 which is fixed upon the horizontal shaft 4. Also fixed upon the horizontal shaft 4 is a pulley 16 over which passes the upper bight of a cable 17.

The fly ball mechanism is located at the top of an elevator hoistway within which an elevator car ascends and descends along stationary vertical guides. The car is raised and lowered by motor operated hoist mechanism of any preferred type and is provided with braking mechanism of any preferred type. The car also carries a drum which is normally frictionally held against turning but when turned causes safety jaws to engage the aforementioned guides and prevent the elevator from falling or descending at excessive speed in event of failure of the hoist mechanism to function properly. The apparatus mentioned in this paragraph is well known in various modifications, any of which may be employed in elevator systems equipped with the fly ball governor cable clamp of this invention. Therefore no such hoistway, guides, car, hoist mechanism, braking mechanism, drum or safety jaw, is described in this specification or illustrated by the accompanying drawings.

The cable 17 is continuous. Its lower bight takes around a tension sheave (not shown) located in a pit at the bottom of the hoistway and one of its vertical stretches passes around the normally nonturning drum carried by the elevator car. Hence whenever the car goes up or down while the cable 17 is free the pulley i6 and the fly balls 9 and 10 rotate with a rotational speed proportional tothe vertical speed of the car.

The nut 12 preferably is adjusted to a position on the push rod 11 in which the expansive spring 13is sufliciently pretensioned to hold the fly balls 9 and 10 from swinging outwardly so long as the vertical speed of the car does not exceed a predetermined limit, which may be prescribed by code or regulation or by accepted engineering practice. When such limit is exceeded the fly balls 9 and 10 swing outwardly forcing the push rod downwardly. The first increment of downward movement of the push rod 11 opens a switch which shuts off the motor. that operates the hoist mechanism and applies the braking mechanism.

Further downward movement of the push rod 11 actuates means to restrain the cable 17 and thus cause the drum carried by the car to turn and force safety jaws into engagement with the stationary vertical guides whereby the car is infallibly stopped.

The apparatus so far described is known and it therefore has been described only generally so that the instant invention and its incorporation with the known apparatus can be readily understood.

Rigidly fixed to the base 1 are upstanding'uniquelyshaped plates 19. The plates 19 are spaced at a distance apart somewhat greater than the width of the rim of the pulley 16, and they constitute a fulcrum stand to which each of four

parallel links

21, 22, 23 and 24 is pivoted at one end. The other ends of the

parallel links

21, 22, 23 and 24 are pivoted to a clamping jaw 25, which thus is prevented from tilting as it moves up and down. The upper end of the clamping jaw moves in an are about the axis on which the

upper links

21 and 23 are pivoted to the plates 19 while the lower end of the clamping jaw 25 moves in an are about the axis on which the

lower links

22 and 24 are pivoted to the plates 19, the face of the clamping jaw 25 being kept vertical during the movement.

Sunk into its vertical face the clamping jaw 25 has a vertical groove 26 which registers with a vertical groove 27 sunk into the vertical face of a matching jaw 28, and the cable 17 runs between the grooves. The matching jaw 28 is connected at its lower end to the clamping jaw 25 by a pair of bell crank levers 29 and 30 which are fulcrumed upon coincident axes upon the clamping jaw 25 and have

short arms

31 and 32 pivoted upon coincident axes to the matching jaw 28.

The matching jaw 28 is further connected to the clamping jaw 25 by a pair of

check links

33 and 34 which are functionally parallel to the bell

crank lever arms

31 and 32 and which maintain the face of the matching jaw 28 parallel to the face of the clamping jaw 25.

The bell crank levers 29 and 30 have long arms 35 and 36 which are pivoted on coincident axes to a block 39 that is mounted for limitedsliding movement upon a pair of upright bolts 37 and 38 which are fastened at their lower ends to the base 1. Interposed between the base 1 and the block 39 are helical

expansive springs

40 and 41 which urge the block 39 upwardly, the

springs

40 and 41 being'preloaded to such a degree that they hold the block 39 against the heads of the bolts 37 and 38 with a definite force equal to a prescribed fraction (e. g. one fifth) of the breaking strength of the cable 17 which may have a breaking strength of some ten thousand pounds. The block 39 thus constitutes a yieldably mounted anchorage for the longer arms 35 and 36 of the bell crank levers 29 and 30.

Erected upon the base 1 is a bracket 42 to which is pivoted one corner of a three cornered member 43 to another corner of which is pivoted one end of a link 44 the other end of which is pivoted to the lower end of the clamping jaw 25.

So long as the three cornered member 43 is held in the position in which it is shown in Fig. III the link 44 holds the clamping jaw 25 in the elevated position in which it is shown in Figs. I and III. With the clamping jaw 25 held in the elevated position in which it is shown in Figs. I and III the bell crank levers 29 and 30 hold the matching jaw 28 away from the clamping jaw 25 so that the cable 17 can move freely between the jaws.

A third corner of the three cornered member 43 is connected to the bracket 42 by linkage consisting of a short link 45 having an overbalancing weight 46 fixed thereto, the short link 45 being pivoted to one end of a longer link 47 the other end of which is pivoted to the three cornered member 43. The chain of

linkage

44, 43, 47 and 45 being behind other parts of the mechanism is most clearly shown in theplan view, Fig. '11, and

the rear elevational views, III and V, of the cable clamp per se. When the linkage is in the folded condition in which it is shown in Fig. III, the point of articulation between the short link 45 and the longer link 47 is above a plane passing through the axes on which the linkage is pivoted to the bracket 42 and to the three cornered member 43. Hence, the action of gravity on the clamping jaw 25 and the parts connected thereto, including the link 44 and the three cornered member 43, tends to swing the short link 45 about the pivot connecting the short link to the bracket 42 in a direction that is counterclockwise as viewed in Fig. III. Such counterclockwise movement of the short link 45 is prevented by engagement of a finger 48 upon the longer link 47 (see Figs. II and Ill). The overbalancing weight 46 assists in keeping the finger 48 reliably in engagement with the longer link 47 and in preventing the finger from bouncing away from the longer link.

Should the speed of a descending elevator car and the consequent speed of the cable 17, the pulley 16 and the fly balls 9 and '10 become greater than the speed at which the centrifugal action of the fly balls causes the push rod 11 to open the switch which shuts off the hoisting motor and applies the brake, the push rod 11 will descend further. Further descent of the push rod 11 amounting to a small fraction of an inch brings the lower end of the push rod 11 into engagement with the longer link 47, which as shown in Fig. II is so formed that a portion thereof lies in the path of the lower end of the push rod, and still further descent of a small fraction of an inch pushes the longer link 47 downwardly-thus moving the short link 45 in a clockwise direction until its point of articulation with the longer link 47 is-pushedbelowthe plane that passes through the axes upon which the linkage is pivoted to the bracket-42 and the three cornered member 43. There upon the action of gravity upon the clamping jaw 25, the matching jaw28, the bell crank levers 29 and 30, the parallel links 23 and '24 and other parts swing the mech anism downwardly until the jaws come into gripping engagement-with the cable -17.

The downward pull on the cable 17 after frictional engagement of the

jaws

25 and 28 therewith, has a servo action which augments the-force with which the jaws engage the cable. This servo effect increases until the downward pull on thecable 17 is sufiicient to compress the

springs

40 and 41 whereupon theblock 39 and the ends of the'bell crank

levers

29 and 30 which are attachedthereto move downwardly. The force with which the clamps resist downward movement of the cable is thuslimited to the force required to compress the

springs

40 and 41, leaving the clamps to resist the pull of the cable to-an, extent amply sufiicient to turn the drum carried by theelevator car and cause the safety jaws to engage the verticaljguidesalong the hoistway and bring the downward-movement of the car to a safe stop. This feature of the device which limits the clamping eflect of the

jaws

25 and 28 and permits the cable 17 to slip therebetween with an adequate factor of safety insures against breakage of the cable 17 which otherwise might disastrously disable the entire safety mechanism.

To reset the device into the condition in which it is shown in Figs. I and III it is only necessary to return the short link andits overbalancing weight 46 counterclockwise, as viewed inFig. 1V, until the finger 48 again engages the longerjlink .47.

With the device thus resetthe jaws have ample clearance, e. 'g.'% on both sides of the cable before stretchingandrwear'tend to reducetheidiameter of the cable. The clamp constructed in accordance with this invention, which provides proper clearance for a new cable, will grip the cable on occasion with the same efficacy after the size of the cable has been reduced by stretching and wear. A clamp which, for example, is operative with a hi cable is operative as well'with a%;" cable. By relatively simple adjustment of the initial height of the pushrod 11, of initial tension of the spring 13 and initial loading of the

springs

40 and 41 the fly ball governor cable clamp of this invention may be made to function in accordance with requirements of codes and regulations throughout the United States and in accordance with the best engineering practices.

The device as above described and as illustrated in the drawings is susceptible to variations within the spirit and scope of the subjoined claims.

Having described the invention, I claim:

1. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising pairs of relatively long parallel links each pivoted at one of its ends to saidframe and at the other of its ends to said clamping jaws, a pair of bell crank levers having relatively long arms connecting said clamping jaw to said anchor and relatively short arms connecting said clamping jaw to said matching jaw, a pair of relatively short links also connecting said clamping jaw to said matching jaw, said relatively short links being parallel to said relatively short arms of said bell crank levers, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable.

2, In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising pairs of relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaws, a pair of bell crank levers having relatively long arms conmeeting said clamping jaw to said anchor and relatively short arms connecting said clamping jaw to said matching jaw, a pair of relatively short links also connecting said clamping jaw to said matching jaw, said relatively short links being parallel to said relatively short arms of said bell crank levers, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable, said trigger mechanism consisting of linkage folded into nonreleasing condition, an element operatively connected to said cable to cause said linkage to unfold into releasing condition and means for adjusting said element to act upon said link age when the speed of said cable exceeds prescribed limit.

3. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said 6 releasable means comprising pairs of relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaws, a pair of bell crank levers having relatively long arms connecting said clamping jaw to said anchor and relatively shortarms connecting said clamping jaw to said matching jaw, a pair of relatively short links also connecting said clamping jaw to said matching jaw, said relatively short links being parallel to said relatively short arms of said bell crank levers, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable, said prestressed yieldable means for mounting said anchor upon said frame being yieldable to when said cable pulls upon said jaws with a force in excess of a prescribed limit.

4. In a safety device having acable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed ing said clamping jaw to said anchor and relatively short arms connecting said clamping jaw to said matching jaw, 21 pair of relatively short links also connecting said clamping jaw to said matching jaw, said relatively short links being parallel to said relatively short arms of said bell crank levers, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable, said trigger mechanism consisting of linkage foldedinto nonreleasing condition, an element operatively connected to said cable to cause said linkage to unfold into releasing condition and means for adjusting said element to act upon said linkage when the speed of said cable exceed-s prescribed limit, said prestressed yieldable means for mounting said anchor upon said frame being yieldable to when said cable pulls upon said jaws with a force in excess of a prescribed limit.

5. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaw, a bell crank lever having a relatively long arm connecting said clamping jaw to said frame and a relatively short arm connecting said clamping jaw to said matching jaw, a relatively short link also connecting said clamping jaw to said matching jaw, said relatively short link being parallel to the relatively short arm of said bell crank lever.

6. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagementwith said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaw, a bell crank lever having a relatively long arm connecting said clamping jaw to said frame and a relatively short arm connecting said clamping jaw to said matching jaw, a relatively short link also connecting said clamping jaw to said matching jaw, said relatively short link being parallel to the relatively short arm of said bell crank lever, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable.

7. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaw, a bell crank lever having a relatively long arm connecting said clamping jaw to said frame and a relatively short arm connecting said clamping jaw to said matching jaw, a relatively short link also connecting said clamping jaw to said matching jaw, said relatively short link being parallel to the relatively short arm of said bell crank lever, and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable, said trigger mechanismconsisting of linkage folded into nonreleasing condition, an element operatively connected to said cable to cause said cable to unfold into releasing condition and means for adjusting said element to act upon said linkage when the speed of said cable exceeds a prescribed limit.

8. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said prestressed yieldable means for mounting said anchor uponsaid frame yielding to permit said cable to be pulled through said jaws when the pull of said cable or said jaws exceeds prescribed limit.

9. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping said car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame and releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said cable or, when released, moving said jaws into clamping engagement with said cable, said releasable means comprising relatively long parallel links each pivoted at one of its ends to said frame and at the other of its ends to said clamping jaw, a bell crank lever having a relatively long arm connecting said clamping jaw to said anchor and a relatively short arm connecting said clamping jaw to said matching jaw, said prestressed yieldable means for mounting said anchor upon said frame being yieldable to permit said cable to pull through said jaws when the pull of said cable exceeds a prescribed limit.

10. In a safety device having a cable movable with speed corresponding to the speed of an elevator car which car is equipped with means for stopping such car when movement of said cable is restrained, the combination of a stationary frame, a bell crank lever anchor, prestressed yieldable means for mounting said anchor upon said frame, a clamping jaw and a matching jaw between which said cable extends, releasable means for keeping said jaws in vertical parallelism while either holding said jaws out of engagement with said jaws or, when released, moving said jaws into clamping engagement with said cable, a bell crank lever having a relatively long arm connecting said clamping jaw to said anchor and a relatively short arm connecting said clamping jaw to said matching jaw and trigger mechanism actuated when the speed of said cable exceeds a predetermined limit to release said releasable means to move said jaws into clamping engagement with said cable, said prestressed yieldable means for mounting said anchor upon said frame yielding to permit said cable to be pulled through said jaws when the pull on said cable exceeds a prescribed limit.

References Cited in the file of this patent UNITED STATES PATENTS 463,935 Blackburn Nov. 24, 1891 1,534,291 MacAskill Apr. 21, 1925 1,934,508 McCormick Nov. 7, 1933 1,976,495 Halfvarson Oct. 9, 1934