US2758675A - Floor leveler assembly for elevator cars - Google Patents

Description

Au@ 14, 1956 c. R. CALLAWAY 2,758,675

FLOOR LEVELER ASSEMBLY FOR ELEVATOR CARS Filed Nov. 16, A1953 4 Sheets-Sheet l T5 i '1:75 a

Aug. 14, 1956 c. R. CALLAWAY 2,758,675

FLOOR LEVELER ASSEMBLY FOR ELEVATOR CARS Filed Nov. 16, 195s 4 shee'ts-shet 2 INVENTOR.

E 4 @Y mmw Aug. 14, 1956 c. R. CALLAWAY 2,758,675

FLOOR LEVELER ASSEMBLY FOR ELEVATOR CARS Filed Nov. 16, 1955 4 Sheets-Sheet 3 La, EVIL .Down 3 IN VEN TOR. /OO A1A/Mm fm/4x 24 l @recare/x w/L of 4455A/ @umn/HY E E BY llg- 14, 1956 c. R. cALLAwAY FLOOR LEVELER ASSEMBLY FOR ELEVATOR CARS Filed NOV. 16,V 1955 4 Sheets-Sheet 4 INVENTOR. Uu miv/fief. Cm mmf EXECUTE/x,

W/L of: CLAES/c5 E. @umn/,4r @YM Lw ATTORNEY United States Patent FLOOR LEVELER ASSEMBLY FOR ELEVATOR CARS Clarence R. Callaway, deceased, late of Fort Myers, Fla., by Lillian MCE. Callaway, Fort Myers, Fla., assigner to Watson Elevator Company, Inc., New York, N. Y., a corporation of New York Application November 16, 1953, Serial No. 392,282

11 Claims. (Cl. 187-29) This invention relates to a floor leveler assembly for elevator cars and more particularly to an improved floor leveler assembly for elevator cars in which the dead zone may be regulated.

Elevator car drive systems provide an operating speed for driving the car between floors and leveling speeds for leveling the car at any particular oor. As the car approaches tioor level, the leveling system controls the drive speed to bring the car level with the oor. The leveling system may be a two-speed system which provides a high leveling speed and a low leveling speed. Therefore, the switch assembly of the leveling system must include an up high leveling speed position, an up low leveling speed position, an off position (when the car is level with the licor), a down low leveling speed position and a down high leveling speed position. Moreover, the switch must be arranged to be actuated to the respective positions in the proper order. That is, assuming the elevator car is approaching a floor in the up direction, the leveling control switch is closed to the up high leveling speed position when the car is a predetermined distance from iloor level. When the car has traveled a further distance, the switch is closed to the up low leveling speed position and when the car reaches the floor level, the switch occupies the off position. In the event the car overruns, the switch will first occupy the down low leveling speed position and should the car overcarry far enough, the switch closes to down high speed leveling position to bring the car back to floor level. It will be appreciated that some means responsive to the position of the car in the shaft must be provided to actuate the switch assembly.

Elevator car floor leveler assemblies of the prior art include, for example, a single leveling cam associated with each oor and a pair of cam follower arms adapted to be actuated by the respective cams when the elevator car approaches the corresponding floor levels. One of these cam follower arms cooperates with the leveling cam in the up direction of the car and the other in the down direction to actuate the leveling switch assembly. In these assemblies the space or distance between the point at which leveling in an up direction ends and the point at which leveling in a down direction begins is fixed. This distance is known in the art as the dead zone. The accuracy of leveling is a function of the ambit of the dead zone, and the extent of the dead Zone, in turn, is aV function of the low leveling speed, since this speed governs the car inertia during leveling. Ideally, there would be no dead zone, but since the low leveling speed must have some value, a dead Zone exists. In order that the accuracy of leveling and the tendency of the car to hunt at floor level in floor leveler assemblies of the prior art be controlled, the low leveling drive speed must be controlled, since the dead Zone is fixed. This close control over low leveling drive speed necessitates the use of an expensive and complicated variable voltage control system associated with the drive motor. This invention provides a oor leveler assembly in which the dead zone 'lice itself can be adjusted to control accuracy of leveling and tendency to hunt. As a result of this adjustment, a relatively inexpensive control system may be used to control the low leveling speed; that is, in this invention the accuracy of leveling is controlled by adjusting the dead zone itself rather than by varying the low leveling speed. Accordingly, a close control over low leveling drive speed is not necessary and a simpler and less expensive speed control may be employed for the drive. ln addition, since the zone may be adjusted, a higher low leveling speed may be employed and the elevator leveled more quickly. This is not possible where the dead zone is fixed. Of course, the adjustment of the dead zone is limited by the accuracy of leveling desired. Since the tendency of the car to hunt is a function of the car inertia which depends on the low leveling speed, this tendency also may be controlled.

This invention also provides a simple means for adjusting the positions of the leveling cams along the leveling camshaft. This adjusting means securely fastens the cams to the shaft Without defacing, scoring or pitting the shaft. Since the shaft is not marked by the fastening means, extremely accurate adjustments of position are possible and the adjustment will not be thrown oi by an indentation which may have been made on the shaft during a prior adjustment.

One object of this invention is to provide an improved floor leveler assembly for elevator cars wherein the dead zone may be adjusted.

Another object of this invention is to provide an improved tloor leveler assembly for elevator cars which permits the car to be leveled in an up direction or down direction at a relatively high speed.

A further object of this invention is to provide an improved iloor leveler assembly for elevator cars including improved means for adjustably anchoring the leveling cams to the camshaft.

A still further object of this invention is to provide an improved floor leveler assembly for elevator cars wherein the accuracy of leveling and tendency of the elevator car to hunt may be controlled in a rapid, convenient and expeditious manner.

Other and further objects of this invention will appear from the following description.

ln general, this invention contemplates the provision of a framework having guide means and a pair of shafts thereon for supporting a carriage for movement up and down within the frame. Drive means actuated from the elevator car moves the carriage up and down along the guides and drives a camshaft supported by the frame. At spaced intervals along the framework corresponding to the iioors of the building in which the elevator operates, pairs of leveling cams are adjustably mounted on the camshaft. Each pair of leveling cams includes an up leveling cam and a down leveling cam. The carriage supports a pair of switch actuating cranks mounted on the respective shafts for rotation therewith and movement therealong. Each of the cranks carries a cam follower adapted to cooperate with one of the respective up or down cams corresponding to each of the floors. When the follower on a crank is engaged with its respective ca rn at a floor level, it rotates its associated shaft. The rotation of the shaft actuates the switch assembly controlling the drive motor to level the car at the floor corresponding to the cam engaged. ln addition, the present invention includes means for holding the switch actuating cranks to positions where their followers will not engage the cams when the car is between the floors. Selecting switches are provided for ile-energizing this holding means as a ioor level is approached. The use of a pair of switch actuating cranks and the adjustable mounting of the leveling cams permits the dead zone to be varied.

VIn the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals areusedto indicate like parts in the various views:

Figure l is a front view of the improved oor leveler assembly for elevator cars.

Figure 2 is a side view of the improved floor leveler assembly with one side removed, taken along the line 2-2 of Figure 1.

lFigure 3 1 is a sectional view on an enlarged scale of the improved oor leveler assembly taken along the line 3-v3`of Figure l. u

Figure 4 is ahfrontview with parts removed of the portion of the improved floor leveler assembly shown in Figure@ Figurevj is a top view on an enlarged scale ofthe improved oor leveler assembly taken alo-ng the line 5-5 of Figure l, with'parts removed.

. Figure 6 is a front view of the portion of theirnproved floor leveler assembly shown in Figure 5 and taken along the line 66 of Figure 5.

igure 7 is afragmentary perspective view showing the switch assembly of the improved floor leveler assembly.

A Figure 8 is a schematic view showingthe cam development'of a pair of leveling cams of the improved oor leveler assembly'.

FigureQis a fragmentary sectional view on an enlarged scale yofnaportion of the assembly shown in Figure 3with a part broken away to illustrate the means for mounting the leveling cams von the camshaft.

More" particularly referring n ow to the drawings, a framework, indicated generally by the reference character 1 0, includes a pair of sides 12 and 14 and a top`16 and is Kmounted on a pair of U-shaped standards 1 8. Within thleqfr'ame 10 adjacent lthe top and bottom' thereof, as viewed in Figures l and 2, a pair of flanged brackets 2Q and 22l are fixed between the sides by appropriate mean/Issuch as bolts 24. A pair of guide rails 26 and 28 are fixed at either end in brackets 2@ and 22 so as to extend therebetween. A carriage, indicated generally by referencel numeral I30, is mounted for movement yup and down along rails 26 and 2S and includes a back 32 having afpairNof ilanges 34 and 36 extending outwardly therefrom as viewed iny Figure 2.v A first pair of brackets 38 are mounted on liange 34 by appropriate means such as bolts 40,1I and avsecond pair of brackets 42 are mounted on flange 36 by bolts 44. As can be seen by reference to Figure 3, guide rod 26 passes through bushings 46 in left-hand1-bra'ckets38 and 42 and guide rod 28 passes4 bushings (16 inthe right- hand brackets 38 and 42 as viewed in lFigure l.

drum 48 drives a shaft 50 iixed in a bearing 52 in :sidez 14 ofthe frame 1th and is supported at points along its length byl bearing brackets 545 and 56 xed to theundersi'deof bracket 22 by appropriate means such asfvve'ljdii'ig.l DrumfSis driven by a cable 58 which is fixed to the elevator` car (not shown) and passed around thedrum 48 to provide a Vfriction drive. The left-hand shaftglrl as viewed in Figure 1 has a pinion 60 thereon which engages rwith and drives a gear62 fixed on ash'aftpjl rotatably mounted in bearings 66 and 68 in the sides"z12 and`1l4, respectively, of the frame 111. Gears @Hand 62 provide a reduction gear train so that a large motion ofthe car produces arelatively small proportionategmotion of the carriage 30.

A; pair of sprockets '70 and 72 are keyed to shaft 64 adjacent the respective sides 12 and 14 of the frame 10; A second pair of sprockets 74' and 76 are mounted, respectively, onstubv shafts 78 and Si), rotatably mounted in; bearings SZand 84 in the sides 12 and 14. One' end ofthe pitch' chain 86 associated with drive sprocket "itl is fixed by appropriate means such as a fitting 88 to flange-T361 of carriage 30. Chain 86 passes downwardly, as viewed inl-ligure l, around'drive sprocket 70,'upward`ly around idler sp'ocket 75l and thence downwardly to a fitting@ by means 0f which.. it is fixed to, flange 34-01. carriage 30. Similarly, pitch chain 92 associated with drive sprocket 72 is lxed to flange 36 adjacent the righthand side as viewed in Figure 1 by a fitting 94 and passes downwardly around sprocket 72, upwardly around idler sprocket 76 and down to a fitting 96 on flange 34 of carriagel 30. Irthwill beappreciated that drum 4,8, driven by cable 58, provides a means, through gears 60 and 62, shaft64 and drive sprockets '70 and 72, for moving the carriage .3U-up and Idown'along guides 26' and23 to"levels" corresponding' with theactual floor levels in the elevator shaft' and at speeds proportional to the speed of travel of the elevator car. y

As'l can be seen by reference to Figures l, 4 and 6, a pair of shafts 9S and 100 are rotatably mounted in bearings 102 and 10dA in bracket 22 and extend upwardly through bushings 166 and 10S in brackets 42 and 38, respectively, and through bearings 1111 and 112 ink bracket 20. It will beappreciated that shaftsy 98 and 1110 provide means 4additional to guide rails 26 and 28 for guiding carriage 30 in its movement up and downin the frame 10..,

Shaft 50 carries a bevel gear 114 adjacent its midpoint which drives a bevel gear 116 fixed on'the end of a cam'- shaft 118 rotatably mounted in a bearing`12 in bracket 22 and extending upwardly past carriage 30 to a suspension bearing 122' in bracket 21B. At each level' along the frame 10 in a vertical direction as viewed in Figure 1 corresponding to a floor level in the elevator shaft, an up helical levelingcam 124 and a down helical leveling' cam 126 are mounted on shaft 118 and driven thereby.

Referring now to Figures 3 and 4, collars or sleeves- 128 and 131) are mounted within carriage 30, respectively, by any convenient means, on shafts 9S' and 100 for rotation therewith andjrnovement therealong. For example, shafts 9S and 11161 may be provided with a polygonal cross section, as shown. Sleeve 128 has anv up switch actuating crank 132 formed thereon which' carries a cam follower 134 by means of a pin 136. Similarly, sleeve has a down switch actuating crank 138 formed thereon carrying a cam follower 141i by means of a pin 142; The arrangement is .such that followers 134 and 140 cooperat'e'with the respective up and down: leveling cams 124 and 126 of a particular floor when carriage 30'is at a level corresponding with the door level.

It will be seen that each of the cams 124iand 126v has a.V high speed' leveling portion 1421, a low speed leveling portion 146, and an off or stop portion 148 formed thereon and is secured to camshaft 118 by a special pin or stud Asl can bel seen by reference to Figures 3 and 9, each ofthe pins 150 has an arcuate depression 152' .in' thev direction of its length which coincides with the surface of shaft 118' when' the cam is in position on the shaft. Each of the pins 151B is inserted in abore 154 in the cam' before the cam is placed on the shaft so that its surface 152 coincides with the surface of the holeformed' in the center of the cam. One end of pin 151)v is threaded1 and extends' outwardly beyond a' boss 156 formed on the cam and is adapted to` receivev a nut 158'. It will be appreciated that when nut 158v is tightened, the' cam will be rmly held in position along the shaft by thel engagement of surface 152v with the shaft surface' and the wed'gingaction. Since there is a large area of contact between surface 152 and the shaft, no highly localized force is applied to the shaft which might damage it.

It will be clear from an examination of- Figuresv 3 and' 4' that cams 124 and 126' aremounted onsh'aft 118 in reverse order thatv is, while' the cams are identical, one of a pair of adjacent cams is in upside=down relation to the other. Each of the cams has a projection 161i upstanding from one side and a threaded hole 162' in its rim. Hole 162 receives a set screw 164. The set screw 164 of one of apair of adjacent cams bears Iagainst the' projection 1611 of the' other cam. The relative'y radial' positions of the cams with respect to each other may be adjusted, after nuts 158 have been loosened, by loosening the set screw 164 or" one of the cams of a pair and tightening the set screw of the other of the pair of cams.

Referring now to Figures 5 to 7, each of the shafts 98 and 100 has a portion 166 and 168 extending upwardly from the respective bearings 110 and 112 in bracket 20, on which is mounted a lower contact arm 170 by its hub 172 and xed for rotation therewith by a screw 174 bearing on the respective shaft. Hub 172 has a radial ange 175 formed thereon to which is attached by appropriate means such as screws 178 a plate 176. Plate 176 has a bolt 180 extending through its end opposite ange 175. Bolt 180 carries a high leveling speed Contact 182 on its end and a spring 184 is disposed about the bolt and extends between contact 182 and plate 176, as can be seen in Figures 5 and 7. Lower contact arm 170 exten-ds upwardly in the direction ot the shaft with which it is associated and has a pin 186 formed adjacent its upper end.

Magnet levers, indicated generally by the reference character 188, are formed each with a hub 190, a bifurcated end 192, tangential flange 194, and an arm 196 at its end opposite the bifurcated end. A pair of magnet levers 188 are mounted by means of their hubs 190 on the respective portions 166 and 168 of shafts 98 and 100 immediately above hubs 172.

An upper contact arm 198 is mounted above each of the magnet levers 188 by a hub 200, which has a radial bracket 202 formed thereon. This bracket carries a plate 204 by means of screws 206. A low leveling speed contact 208 is mounted on a bolt 210 passing through the end of plate 204. A spring 212 is disposed about the bolt between the contact 208 and the surface of plate 204. Hub 200 also has an angle bracket 214 formed on its periphery which carries a stop screw 216.

A hinge 218, formed of suitable insulating material, is fixed to ange 194 of each of the magnet levers by screws 220 and carries contactors 222 and 224 adapted to engage, respectively, the low leveling speed contact 208 and the high leveling speed contact 182, Screws 223 mount contactors 222 and 224 on hinge 218 and carry lugs 225 which provide the proper electrical connections to the elevator drive motor control circuits (not shown). To provide an engagement between lower contact arm 170 and magnet lever 188, a bolt 226 passes through an opening 228 in arm 170 and through a second opening 230 in arm 196. This bolt carries a spring 232 arranged to bear between a washer 234 retained on bolt 226 by a nut 236 and the surface of arm 196 to provide a resilient seat for the high speed contacts when made. ln addition, arm 196 carries a stop screw 238 for engagement with arm 170. A spring 240 carried by pin 186 on .arm 170 bears against arm 198 to provide a resilient seat for the low speed contacts when made. One of the screws 178 and 206 on each of the respective anges 175 and 202 carries a spacer 207 to limit the movement of contactors 222 and 224 relative to their respective contacts 182 and 208.

A housing 242 is mounted on the bracket by any convenient means such as bolts 244 and encloses an electromagnet coil winding 246. As can be seen by reference to Figure 5, a pair of armatures 248 are disposed within coil 246 for sliding movement. Each of the armatures 248 carries for movement therewith a rod 250 secured to a reduced end portion 264 o-f the armature. A coil spring 272 disposed within coil 246 between armatures 248 urges the armatures out of the housing. Collars 266 made of suitable material, such as brass, are secured to housing 242 to prevent magnetic sealing of the armatures 248. To provide a resilient driving connection between armatures 248 and the switch contact arm assembly, each of the armature rods 250 carries a spring 258, a pair of washers 254 and 261, a sleeve 252, and a nut 262 threaded on the end of rod 250 to hold the parts in place. The actual connection between rod 250 and the contact arm assembly is provided by magnet lever 188, the bifurcated end 192 of which is arranged over the rod 250 between the washers 254 and 261. lt will be appreciated that spring 258 bears between a ange 260 formed on the reduced end portion 264 of armature 248 and washer 254. It is to be noted further that the bifurcated end 192 is formed with arcuate sides so that it may roll between the washers 254 and 261 when the lever 188 rotates. Accordingly as one of the armatures moves inwardly or outwardly with respect to the coil 246, washers 254 and 261 move end 192 so that the lever arm 188 is pivoted about its associated shaft. Threaded rods 274 are screwed into the collars 266 at the respective ends of housing 242 and carry washers 276 and nuts 278 near their other ends. Bifurcated end 192 oit lever 188 also embraces this rod which thus provides a stop to limit the pivotal movement of lever 188 under the action of its associated armature 248. The spring 258 provides a resilient connection between an armature and its magnet lever 188.

lt is to be noted that to avoid confusion, the switch actuating assembly illustrated in Figures 5 and 6 has been described with reference to only one side thereof. While the parts are identical on either side, it Will be appreciated that the right-hand switches, as viewed in Figure 5, operate the down leveling switches and those on the left-hand side, the up leveling switches.

For purposes of clarity, in the showing of Figure 5 the upper contact arm 198 and its associated structure has not been shown on the shaft portion 166 on the lefthand side of the figure. Similarly, the radial flange 17E7 of the lower contact arm and its associated structure has not been shown on portion 168 of shaft 100 in the right-hand side of Figure 5.

Referring now to Figures 2 and 3, a rst pair of angle brackets 296 and 298 are iixed to the respective frame sides 12 and 14 adjacent the top 16 by bolts 300, and a second pair of angle brackets 302 and 304 are attached to the respective sides 12 and 14 near the bottoms thereof by bolts 306. A floor selecting switch supporting panel 280 having longitudinal slots 282 is supported between brackets 296 and 298 and brackets 302 and 304 by bolts 308. A floor selecting switch having a contact 'I linger 285 is arranged in each of the slots 282 at a height along the panel corresponding to the elevator shaft level at which leveling in an up or dow-n direction at a particular floor is to beg-in. The back 32 of carrier 30 has slots 286 formed therein in which are fixed brackets 292 by means of bolts 294. Switch actuating rollers 288, corresponding respectively to selecting switches 284 are carried by pins 290 in brackets 292. As the carriage 30 is traveled up and down along frame 10, an actuating roller 288 will engage a linger 285 of one of the selecting switches as iloor level is approached by the car to initiate leveling by de-enerrgizing coil 246 to allow the leveling switch assembly to function. The point at which leveling commences can be adjusted by moving switches 284 up or down in slots 282 or moving brackets 292 up or down in slots 286.

In use, when the car is in its normal running position between floors, the elevator motor drives the car at normal operating speed, and coil 246 is energized to draw armatures 248 into the coil. When the armatures 248 are drawn in, the associated rods 250 are drawn in, and through the medium of nuts 262, spacers 252 and washers 254 and 261 rotate magnet levers 188. Referring, for example, to the left-hand lever 188 in Figure 5, the lever will be rotated in a clockwise direction when its associated piston 248 is drawn into coil 246. This is the position illustrated in the left-hand side of Figure 5. Referring now to the right-hand lever 188 in Figure 5, it will be rotated in a counterclockwise direction when its armature 248 is drawn into the coil 246. As will be clear from an examination of Figures 5 and 7, when the right-hand levei T88 vis rotated in a countercloekwise direction, stop 23s en '-156 yengages arm im to rotate hub 172 and thereby shaft 180 `in ya counterclockwise direction. Since swith actuating crank iss `is fixed on Shaft tot, it will be rotated to a position where it cannot engagea cam 126. rFhis :posit-ion is indicated by the line x Vin Figure 3. Similarly, switchactuating crank 132 will be rotated to a corresponding position where it cannot engage a cam 124 when coil w246 is energized. This is the lnor'iiial position `of the Vcranks when the car is running between oors at normal operating speed.

The distance between stop 238 and arm 178 is such that when coil 2'4'6 Vis energiie'd to Adraw in armature 248, hinge 2118 is rotated through a ksmall angle before stop 23'8frotates arm 170. Therefore, contacts 224-moveaway from contact 182 and the high leveling speed switch is open. Likewise, hinge 218 rotates through a further angle before arm l178 l'rotates arm '-188 and its associated Contact 288 through the medi-urn of pin 186 and spring 240so Athat low leveling s'p'eed contacts 222 and 288 are open. That is, inthe normal ruiming position of the car neither the high vnor the low leveling speed contacts are closed and cranks 132 and 138 are in positions where they `cannot 'engage their associated cams.

As the car approaches a particular floor, one of the switch actuating rollers 288 on housing 30 engages the finger 285 of a selecting switch 284'corresponding to the floor being approached. The switch 284 de-energizes the coil 246 allowing armatures 248 to move outwardly from their 'normal `running positions. Since coil 246 is deenergi-zed, the respective up and down leveling armatures 2'48 will be moved outwardly of the coil 246 by the action of spring 272 to rotate their associated magnet levers 188. When the armatures 248 are thus moved outwardly under the action of spring 272, levers 188 will rotate in directions to move hinges 218 toward both the high vand low leveling speed contacts. It is to be noted that the relative radial positions of flanges 175 and 282 carrying the respective high and low speed contacts 182 and 288 are adjusted by screw 174 and springs 232 and 240 so that if both anges were fixed, the high speed contacts would irst be engaged. As a hinge 218 moves toward its associated contacts, lever 188 tries to rotate the lower contact arm 170 carrying the high speed leveling contact 182 by means of spring 232 and bolt 226. The arrangement is such that if arm 176 were free to move, spring `232 would prevent the engagement or" high speed contacts 224 and 182. lf, however, the lower contact armis held, as by the engagement of its associated switch actnating crank cam follower 134 or 141i with the high speed portion 144 of a respective leveling cam 124 or 126, hinge 218 will move to engage high speed contacts 224 and y182. The movement of hinge 218 will stop, and upper low speed contacts 222 and 288 will not be engaged because of the radial position of ange 282. Spring 232 provides a resilient seat for contacts 224 and 182 by y"absorbing the additional force exerted by magnet lever 4188. l

If the ylower `contact arm A178 is free to move, the high speed contacts cannot make a circuit, and the hinge 218 continues to move toward low speed contact 288. lf during this continued movement of hinge 218, the associated switch actuating crank cam follower 134 or le@ does not engage a low leveling speed cam surface 146, the -lower Contact arm 178 continues to move and engages screw'216 to drive the upper contact arm hub 288 so that the'low leveling speed contacts 222 and 288 do not close. If, however, after arm 170 engages screw 226, it is prevented Vfrom further movement by the engagement of its associated switch actuating crank cam follower 134.- or 140 with a low leveling speed cam surface M6, hinge 218 will move against the action of spring 232 toclose the low Vleveling speed contacts 222 and 288. it will be appreciated that spring 248provides `a resilient seat for the-'lowleveting speed contacts by vabsorbing the torce exerted by hinge 218 on the contacts owing to the contiued yi-'n'oveme'lit of armature V248 outwardly of housing 246 after contact is made. The gap between s't'op 216 and Contact arm 17 tl 'is adjusted so that the high speed `contacts do not lengage when the low speed contacts are -e'ngag'ed. It will be appreciated that if a follower 134 or does lnot engage an associated cam, both its high and low yleveling speed contacts will be open.

The corresponding parts for the up and down leveling systems operate in the same manner but are, lof course, rotated in the opposite directions. It will be appreciated that if either the up or down switch actuating crank cam follower engages the up or down leveling cam at vthe floor level, its corresponding switch assembly `may not be per'- mitted to complete the cycle Outlined above. That is, the surface contours of cams 124 and 126 may -p'r'event 'the armature 248 corresponding to either the up or down switch assembly from being pushed to the limit of its outward movement from coil 246 under the action of spring 272. Considering the right-hand lever 188 as it rotates in a clockwise direction, its arm 196 bears on spring 232 to rotate arm around shaft 180 also in a clockwise direction by means of bolt 226. After a short distance, arm 170 engages stop screw 216 and rotates arm 214 clockwise.

Assuming the car is going down and approaching the third oor, the camshaft `118 will be rotated counterclockwise or in `the direction of the 4arrow in Figure 8, and the selecting switch 284 c-orresponding to the down direction at the third door is actua-ted to render the leveling switch assembly operative by de-ener-gizing c'oil 246. If the relative positions of the followers are those indicated by reference character A in Figure 8, the up follower .134 will not be engaged by the portion 146 of the up leveling cam .124, `but the down follower 140 will be in a position to engage the Vhigh leveling `speed portion l144 of the down leveling cam 126. This high speed level lposition will permit the right-hand armature 248 of yFigure y5 to rotate its associated lever 188 to a position where lthe high level speed contact 208 is engaged, as explained hereinbefore. As the car moves downwardly still further, the followers will occupy relative positions such as indicated by reference character B in Figure 8. `In this position follower 134 `still ywill no't engage its cam 1124, but Afollower 140 moves onto the `low speed portion 146 of its cam, and only the down low level speed contacts `182 are closed. It is to be noted that as long las follower 134 cannot engage its cam, Vits switches will be open, as explained hereinbefo're. When the car moves further, the relative positions "of the followers will be that indicated at C in Figure 8. In this position the elevator is level and followers 134 and 140 engage the-off positions 148 of their respective cams and `will be in the position indicated by c in Figure 3. The arrangement isP such that when the lfollowers are permitted by cams 124 and '126 to occupy this posi-tion, arms 17 0 .and 198 lare rotated by lever 188 in the manner described to positions where both the high and the low level speed switches will be open. When the followers are in this position, the arrangement is such that plate 204 makes a greater angle with the plane passing through shafts 98 and 100 than does plate 176.

ShouldH the car overcarry a slight amount, the followers4 will occupy positions D of Figure 8 so that fol- .f lower 140 will not engage its cam but the up follower 134 will engage the low level portion 146 of cam 124. This position of follower 134 permits its armature 248, which is the left-hand armature as viewedin Figure 5 to move the associated magnet lever 188 to a position where the low speed leveling switch is closed in the manner set forth above. This will move the elevator up to the'desired level. Shouldthe car overcarry still further, the down follower 140 will not eng-age its cam, but the up follower 1- 34 engage the high 'speed-portion '144 of vup cam 124. This 'will permit lever 188 to rotate avsaefrs 9 further to close the high speed contact 224 and 182 on the left-hand side of Figure 5. The elevator will move up at its high leveling speed until the low speed level 146 of the cam is reached and thereafter at low speed until the elevator settles at the floor level.

The tendency of the car to hunt at a particular oor level is controlled by adjusting the low leveling speed which, as explained hereinbefore, -is a function of Ithe extent of the dead zone. In leveling systems of .the prior art, the :tendency could yonly be controlled by means of expensive speed control systems. This invention provides a means by which the dead zone itself can be adjusted to minimize hunting.

In leveling, when the car is moving in the up direction and approaching a particular floor level, the camshaft 118 rotates in a clockwise direction, and leveling is accomplished in the same manner by the up leveling switch actuating crank 132 and its associated switch assembly.

When bot-h the followers 134 and 140 are in a position corresponding to C in Figure 8, they will be in position corresponding to c in Figure 3, high and low speed leveling switches are open and the car is level. When follower 134 is in position D in Figure 8, it will be in position d in Figure 3, follower 140 will not engage its cam, and the car is driven at low leveling speed in the up direction. When follower 134 is in position E in Figure 8, it will be in position e in Figure 3, follower 140 does not engage its cam, and the car is driven at high leveling speed in the up direction. Similarly, positions A and B of follower 140 in Figure 8 correspond to positions a and b in Figure 3. As explained hereinbefore, when the car is in the normal running position between floors, coil 246 is energized and followers 134 and 140 will be held in a position x in Figure 3 by coil 246 and armatures 248. In order that pairs `of cams may be arranged to accommodate various floor levels, some means must be provided for adjusting the positions of the cams axially along the camshaft .118. In addition, in -order that the dead zone may be regulated, means must be provided for permitting radial adjustment of the cams around shaft 118. Pins `150 which x the cams in position on the shaft 118 may be loosened by unscrewing nuts 158 to permit these adjustments. That is, after loosening of the nuts `1'58 a pair of cams may be slid axially along the shaft 118 to a position corresponding to a floor level. If the nuts 1-58 of a pair of cams have been loosened, the relative radial positions of the cams around the shaft 118 may be adjusted to vary the dead z-one by loosening a set screw 164 on one of a pair of cams and tightening the set screw 164 of the other cam of the pair. When the desired relative radial position has been arrived at by such adjustments the nuts 158 may again be tightened to cause the pins 150 to hold the cams in position on the shaft. This relative radial adjustment of a pair of cams provides a c-onvenient means by which ythe dead zone at la particular oor may be regulated. The dead zone is a function of the point at which a follower engages its respective cam. Therefore, the ambit of the dead zone may be varied by moving a pair of cams radially relative to one another so that each cam engages its follower a-t an earlier or later time, depending upon the direction of the adjustment. If the adjustment is such that each follower engages its respective cam at an earlier time the ambit of the dead zone is increased. It will be appreciated that the angle between the respective surfaces 148 of the up and down leveling cams of a pair is a convenient measure of the dead zone. The greater the angle between these surfaces, the larger the dead zone. If the angle is decreased the dead zone is decreased while if the angle is increased the dead zone is correspondingly increased. This adjustment permits the use of a relatively inexpensive low leveling speed control, since the dead zone is normally a function of this speed. Should the low leveling speed be too great, the dead zone can be increased by increasing the angle between the respective surfaces 148 of a pair of leveling cams at a door. Likewise, the dead zone could be decreased in the event that the low leveling speed was too low. It is to be understood, of course, that the accuracy of leveling is a function of the size of .the dead zone. In addition to providing -a means for adjusting the `dead zone as the low leveling speed varies, the present invent-ion provides a means `for increasing the accuracy of leveling for a particular low leveling speed.

Thus it will be seen that the objects of this invention have been accomplished. A leveling assembly for elevator cars has been provided in which the dead zone may be controlled. This permits adjustment of the dead zone as the low leveling speed varies and eliminates the necessity for an expensive speed control system. In addition, it provides means for adjusting the dead zone for a predetermined low leveling speed to minimize hunting. Further, this invention provides a means by which any of the leveling cams may be adjusted in position along the shaft with great accuracy without damaging the shaft and provides means for adjusting the relative radial positions of a pair of cams associated with a particular oor level.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated .by and is within the scope of the claims. It is further obvious that various changes may be made in details within the scope of the claims without departing from the spirit of the invention. It is therefore to be understood that the invention is not to be limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

l. A floor leveler assembly for elevator cars including in combination a frame, guide means on said frame, a carriage mounted for movement along said guide means, a camshaft rotatably carried by said frame, an up leveling cam mounted on said camshaft, a down leveling cam mounted on said camshaft, `a pair of cam followers c-arried by said carriage for engagement with the respective up and down leveling cams, an up leveling switch assembly and a down leveling switch assembly mounted .on said frame, means actuated by respective cam followers for operating said up and down leveling switch assemblies and drive means for rotating said camshaft and mov-ing said carriage along said guide means whereby said followers engage their respective cams to actuate said leveling switches.

2. A door leveler assembly for elevator cars as in claim 1 including means for rendering said leveling switch assemblies inoperative, switch means for controlling the operation of said last-mentioned means and means carried by said carriage for actuating said switch means.

3. A oor leveler assembly for elevator cars as in claim l wherein each :of said leveling cams includes a high speed portion and a low speed portion and an off portion and each of said leveling switch assemblies includes a high speed switch and a low speed switch, the respective portions of said cams arranged to operate the corresponding switches when engaged by said followers, the arrangement being such that both of said switches are open when said followers simultaneously engage the off portions of their respective cams.

4. A floor leveler assembly for elevator cars as in claim l including means for adjustably mounting said cams on said camshaft for rotation therewith.

5. A oor leveler assembly for elevator cars as in claim 1 including means for adjustably mounting said cams on said camshaft for rotation therewith, said last-mentioned means comprising a stud having an arcuate depression along its length adapted to register with the surface of said camshaft.

6. A -oor leveler assembly for elevator cars as in claim 1 including means for adjusting the relative radial positions of said cams.

agessve 1l Whereinisaid means actuated byy thefcam followers incliid'es-a"l air-ofishaft'sandswitch actuating-cranksmounn edi'r focirotation* with' and movement alongf thev respe'etivev 8:'- Aflo'orleveler assembly f0r= elevatorJ cars incliidingl iri-c'o'mbinaltion' ai frame, guide meansl onsaidf'rame, a

carriage` mounted for movement? alongw said frame; a'.- ca'msh'aft-E rotatably carried-*by said frame,1pairs=0f1carnsf mounted on said camshaft for rotation therewith at`linter'y valseorresp'ondingto'the distanee between oor levels, eaelsi'; o'f'saidpa'irs of Vcan'is'includin'gl an up levelingf cam' anda downV leveling cam, apair ofL cam'- followersl car riet by' saidl carriage' and' adapted" to engage 'withk respec+ tivelp an'd-downr` leveling Cams of afpair. of eamsvvhen# said? carriage isat a'1position'-onthe guide means corresponding to thelffio'orv levell of al particular pair ot cams,

an" up leveling-switch assembly and a down levelinglswitch:

thef operationl of saidilast-mentionedv means, each'- of'saidl switcii'es'- being mounted' on` said frame atl a` level; corre.- spondingtoY a floor level and a plurality of switch*` actuating means carried by said carriage, each of said-actuatingf means being-` associated with a respective control swi't'cli 10': A loor levelerL assembly: for elevator` cars"A includ#- ing'ini combination ai frame; guide means'Y on) saidframe;4 aca-rri'a'ge mounted for: movement f along said guide means,v aieamsh'aft carriedirotatably bysaidframe, respective'upf and down leveling camstixedy on'` said camshaft, azpa-irvI of1 control shafts. carried byV the frame, a pair.y off cam followers supported by. saidv carriage and: mounted. on. respective control shafts for movement therealong.-4 and" fori-rotation therewith each ofsaid followersA associatedi with: a; respective leveling cam; a: pair' of high leveling-vspeed contact arms mounted oni thev respective' control shafts for lrotation therewith,y a'pair. of low leveling'speed- Contact arms mounted on respective control shaftsfor'k rotationI relative` thereto; means carrying high and. low leveling contactors monnted'oneach control shaftnmeans associated with said arms and said carrying rneanspro-F viding` an: interengagementtherebetween whereby saidl contacts-and lcontactors associated with the respective com trol shaftsiareV sequentially engaged as said shaftsy rotate and! drivel means for.V4 moving said.y carriage; along-i-` said` guide means and rotatingy saidcamshaft.

lll. A floor leveler assembly for elevator cars as inl claim l0 including means for moving said` contactors" topositions: where they cannot engage saidI Contact: arms; said lastementionedmeans including a coil' andr apair of'` opposed armatures, each of saidf armatures' having meanslthcreon for engagement with said carry-ing means.

References-Cittadini the ie of this-'patent UNITED STATES PATENTS 2,195,084 Eklund Mar. 26, 119210 2,221,395 Dunn NOV.. l2, 19.40 2,611,451 Larson Sept. 23, 1952l

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