US3674113A

US3674113A - Automatic elevator stopping apparatus

Info

Publication number: US3674113A
Application number: US19318A
Authority: US
Inventors: Sidney Richmon
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-13
Filing date: 1970-03-13
Publication date: 1972-07-04
Anticipated expiration: 1989-07-04
Also published as: GB1347273A

Abstract

Automatic elevator control signals are provided by a system of switches and wire mounted cams. A cable extends along the length of the elevator shaft and passes through a switch box mounted on the elevator. Mounted on the cable are a separate pair of bullet shaped cams for each floor serviced by the elevator. These campairs cooperate with a star switch mounted in the switch box; and, depending upon the direction of the elevator motion, the first cam in each pair turns the star switch one increment as the elevator approaches a floor. And the star switch provides elevator control circuits with floor registration and slowdown information. If the star switch gets out of step with the elevator''s location, a specially modified rack and pinion correct the position of the star switch when the elevator reaches either end of the shaft. Cams which are tapered at both ends are also mounted on either the bullet cam cable or a separate cable. These double-tapered cams cooperate with up and down leveling switches mounted in the switch box for providing leveling control.

Description

United States Patent Richmon [541 AUTOMATIC ELEVATOR STOPPING APPARATUS Sidney Richmon, 1202 Peachtree Blvd., Richmond, Va. 23226 [22] Filed: March 13,1970

1211 Appl. No.: 19,318

[72] Inventor:

[58] Field of Search ..l87/29; ZOO/61.13, 61.14, 79, 1 200/160; 340;l9;21

[ 56] References Cited UNITED STATES PATENTS 5/1960 Loughridge ..l87/29 Dickmann 187/29 Primary ExaminerT. E. Lynch 7 Assistant Examiner-W. E. Duncanson, Jr. Attorney-Griffin, Branigan and Kindness 51 July4, 1972 [57] ABSTRACT Automatic elevator control signals are provided by a system of switches and wire mounted cams. A cable extends along the length of the elevator shaft and passes through a switch box mounted on the elevator. Mounted on the cable are a separate pair of bullet shaped cams for each floor serviced by the elevator. These cam-pairs cooperate with a star switch mounted in the switch box; and, depending upon the direction of the elevator motion, the first cam in each pair turns the star switch one increment as the elevator approaches a floor. And the star switch provides elevator control circuits with floor registration and slowdown information. If the star switch gets out of step with the elevators location, a specially modified rack and pinion correct the position of the star switch when the elevator reaches either end of the shaft. Cams which are tapered at both ends are also mounted on either the bullet cam cable or a v separate cable. These double-tapered cams cooperate with up and down leveling switches mounted in the switch box for providing leveling control.

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v I It ATTORNEYS PATENTEDJU 4 I972 SHEET 3 BF 3 luvsu'ron SIDNEY RICHMON ATTORNEYS AUTOMATIC ELEVATOR STOPPING APPARATUS BACKGROUND OF THE INVENTION My invention relates to automatic control apparatus and particularly to elevator control systems used to control elevator location, elevator slowdown, and elevator leveling.

Three major types of signals are usually furnished to the automatic control circuits of elevators. They are: elevator location signals, slowdown signals, and leveling signals. When a passenger selects a particular floor, the elevator begins to move toward that floor. The elevator location signals provide information as to which floors are being passed by the elevator so that the automatic control circuits will know when the elevator approaches the floor at which it is to stop. As the elevator nears the designated floor, the slowdown signal tells the control circuits to start slowing the elevator. The leveling signals then tell the elevator the exact point at which it is to stop. The leveling signals also provide up and down correction signals.

The prior art has proposed various systems for providing some or all of the desired control signals. For example, the system described in U.S. Pat. No. 3,211,258 to G. Dickmann uses switches which are activated by the movement of cams mounted on the elevator cable past a fixed point in the elevator shaft. The cams contact switches and change each switch setting one increment for each cam contact. As the switch setting is changed, elevator location signals are given, thus signalling the control circuits the location of the elevator. While such a system is satisfactory in some elevator environments, it is not satisfactory in all such environments. For example, this system would be difficult to use with a building having more than three floors. Moreover, the switches are remote from the elevator. Hence, extensive control wiring is necessary, thereby making the system expensive to manufacture, install, and maintain.

One prior art device that provides all three of the above mentioned signals is described in 11.8. Pat. No. 2,938,603 to Loughridge. Loughridges system comprises six flat parallel tapes positioned along the elevator shaft wall. Cams are supported between the tapes. Thus five tracks are provided. Switches, mounted on the elevator, ride in the tracks and cooperate with the cams. For example, a star switch rides in one track wherein is positioned a cam for each floor, thus the star switch is turned once for each floor. The second track contains a plurality of down-stop cams, the third track contains a plurality of up-stop cams, the fourth track contains down-level cams and the fifth track contains re-level cams. A primary disadvantage with this system is that it requires five switches, one for each track, and five sets of cams, one for each track. Hence, in addition to the number of switches making this system expensive to manufacture, install, and maintain, a large switch box must be provided to contain the switches.

It is an object of this invention to provide a new and improved system for providing control signals.

It is also an object of this invention to provide a new and improved system for providing automatic elevator control signals.

It is a further object of this invention to provide an automatic elevator control signal mechanism which is structurally uncomplicated and easily installed.

It is yet another object to provide a structure which permits a single set of cams to initiate floor designation signals and both up and down" slowdown signals.

SUMMARY OF THE INVENTION In accordance with principles as applied to the illustrated embodiment, of my invention, both elevator location and slowdown signals are provided by a unique switch cooperating with a special set of cams. Two cams are provided for each floor, and mounted on a single wire so that the first cam contacts the switch before the elevator arrives at the floor and the second cam contacts the switch after the elevator passes the floor. The cams and switch are so constructed that the first cam always activates the switch but the second does not regardless of whether the elevator is traveling up or down. The switch signals inform the control circuits that the elevator is approaching a certain floor, thus, the control circuits know the location of the elevator and have time to slow the elevator if it is to stop at that floor.

In accordance with a further principle of my invention, unique cylindrical cams are mounted on the same wire. These cams cooperate with specially constructed switches to provide leveling signals. An alternative embodiment of my invention, employs two wires and two sets of cams, each set mounted respectively on one of the wires. In either event, one set of cams is bullet shaped and cooperates with the elevator mounted star switch to provide both floor registration and slowdown signals. The back end of every second bullet shaped cam in either movement direction turns the star switch one increment, while the intermediate cams pass through arms of the star switch without causing switch movement. This latter effect is due to the unusual shape of the cams and the unique construction of the star switch arms.

A preferred embodiment of my invention also includes an automatic correction device to correct the position of the star switch each time the elevator arrivesat the top or the bottom of the elevator shaft. This is helpful if the star switch fails to turn upon contacting a proper cam or in the event the star switch is inadvertently turned during an inspection operation. In addition, a second unique set of cams provides leveling signals by cooperating with two switches mounted on the elevator. More specifically, the elevator is leveled by finding the position at which the switches are located respectively above and below one of the leveling cams.

Although this invention is described in the context of an elevator control, it is to be understood that the invention can be used to automatically control the slowing, stopping and positioning of any moving device. For example, it can be used to control the movement of cars used to carry customers through a Fun House. Another application is controlling the movement of a conveyor belt.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects, features and advantages of the invention will become more apparent from the following, more particular, description of a preferred embodiment of the invention illustrated in the accompanying drawings. The drawings are not necessarily to scale. Instead emphasis is placed upon illustrating the principles of the invention in clear form.

FIG. 1 is a cutaway perspective of a switch box with switches mounted therein and earns passing therethrough;

FIG. la is a schematic illustration of an elevator in a shaft;

FIG. 2 is a schematic block diagram of components involved in automatically controlling the elevator;

FIG. 3 is a fragmentary view of a modification of the device shown in FIG. 1;

FIG. 4 is a close up view of a bullet shaped cam on a wire;

FIG. 5 is a close up view of one-half of an arm of a star switch;

FIGS. 6, 7 and 8 are close up views of a bullet shaped cam cooperating with an arm of a star switch at different time intervals;

FIG. 9 is a pictorial view of a switch box partially broken away to show an elevator locator correction device;

FIG. 10 is a pictorial view of a modified rack used in the correction deice of FIG. 9;

FIG. 11 is a pictorial view of a pinion used in the correction device of FIG. 9;

FIG. 12 is a sectional view of the pinion taken along the lines 12-12 in FIG. 11;

FIG. 13 is a sectional view of the pinion taken along the lines 13-13 in FIG. 11.

FIG. 14 is a fragmentary view of the rack and pinion of the correction device to illustrate their coactive relationship within the switch box of FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, in FIGS. 1 and 1a an elevator 2 is moved up and down past floors 3 in a shaft 4 by means of a cable driven by a motor 8. A switch box is fixedly attached to the elevator; and wires 12 and 13 (which may be, for example, music wire having a 0.040 inch diameter) extend from the top of the elevator shaft to the bottom and pass through apertures 16 in the top and bottom of the switch box. A plurality of bullet shaped cams 18 (A, B, C, etc.) are attached to wire 12 and a plurality of leveling cams 20 are attached to wire 13. All of the cams must be durable and I have found bronze to be a suitable material. In a preferred embodiment of the invention bullet shaped cams 18 are 1 inch long and five-sixteenths inch in diameter. In addition, the apertures 16 into the control box 10 are funnel shaped at both ends so that they do not obstruct the entry and exit of the

cams

18 and 20. Moreover, best results have been obtained when the outside diameters of the openings at both ends are at least as large as twice the diameter of the cams to ensure that the blunt ends of the bullet shaped cams 18 do not snag.

A star switch, generally designated by the numeral 22, has electrical contacts, not shown, and comprises a cylindrical disc 24, two arm assemblies 26 and a nut and bolt assembly 28 to hold the disc and arm assemblies together. The material used for the disc 24 is not critical, however, it can be turned more easily if it is formed of a light weight material. I have found a strong plastic to be a suitable material and include circular apertures 30 to reduce weight.

Each arm assembly 26 is in the form of a flat pin wheel having six arms 34. The arm assemblies 26 are positioned on both sides of the disc 24 so that the related arms 34 are positioned opposite one another. The arms 34 must be strong and durable and, in the preferred embodiment, are made of spring steel.

The disc 24 has a ridge 32 formed around the outer perimeter on both sides. The ridge is cut away at points such as 35 where the arms 34 extend beyond the perimeter of the disc. In this way, the ridge both prevents rotation of the arm relative to the disc and the wire 12 from getting caught or wedged between the arms and the disc. The distance between arms 34 (which distance is also the thickness of the disc) is determined by the size of the cams 18, which in a preferred embodiment, is five thirty-seconds of an inch.

A guide block 36 is fixedly attached to the switch box 10 in such a position that it holds the wire 12 and bullet shaped cams 18 between the arms 34. The guide block 36 has a width slightly less than the distance between arms 34, so that the arms can pass on either side of the guide block.

An up leveling switch 38 and a down leveling switch 40, cooperate with leveling cams such as 20 mounted on wire 13 to provide up and down leveling'signals. These are two-position switches which are ON when they are in contact with a leveling cam 20 and OFF when not in contact with the leveling cam. As illustrated in FIG. 1, the leveling earns 20 are generally torpedo shaped, i.e., cylinders with bullet shaped noses on either ends.

Turning now to the operation of the system shown in FIG. 1, and assuming that the elevator is traveling down; as the switch box moves down,

wires

12 and 13 and all of the attached

cams

18 and 20 pass through apertures 16 from the bottom to top of the switch box. A pair of bullet shaped cams l8 and a single leveling cam 20 exists for each floor. Bullet shaped

cams

18A and 18B are a pair which represent one floor and, as illustrated in FIG. 1 have their pointed ends directed toward one another. As the switch box moves down, the upper bullet shaped cam 18A passes through lower opening 16 and its blunt end 21 makes contact with a pair of points 27 formed in one pair of adjacent arms 34. The points 27 are formed just outwardly of the places where the arms exit from the disc 24.

The specific cooperation between the arms 34 and the bullet shaped cams 18 will be more fully explained hereinafter. In any case, the blunt end 21 of the upper bullet shaped cam 18A causes one of the arm pairs and thereby the star switch 22 to be turned one 60 increment one-sixth of 360 in a clockwise direction. This action causes a signal to be generated indicating that the elevator is approaching a particular floor. When this same pair of arms 34 comes in contact with the lower bullet shaped cam 18B, as the elevator continues to decend, the star switch does not turn further because the arms 34 are opened by the pointed end 19 and pass over the lower bullet shaped cam 18B. In addition, the friction between the lower bullet shaped cam 18B and the arms 34 is insufficient to overcome the internal friction of the star switch 22.

From the foregoing description, it will be understood that the star switch 22 turns only once for each floor, although it passes two cams. It will also be understood that when the elevator has been traveling up instead of down the star switch 22 is turned one increment in the opposite direction (counter clockwise) by the blunt end 21 of the lower bullet shaped cam 18B. Similarly, during upward travel the star switch is not turned by the pointed end of the upper bullet shaped cam 18A.

The elevator is actually at a particular floor level when a particular arm 34 is positioned midway between a given pair of bullet shaped cams 18, as shown in FIG. 1. Assume now that the elevator is commanded to stop at a particular floor and is moving down. As the elevator travels down, the blunt end 21 of the upper bullet shaped cam 18A (which in this case is related to the particular floor) turns the star switch 22 one 60 increment in the clockwise direction. The star switch now registers that it is approaching the desired floor. Because the star switch is turned and a suitable signal generated before the elevator actually reaches the desired floor, the control circuits have sufficient time to command the elevator to slow down. It is at this point that the level switches 38 and 40 come into play. In this respect, lower level switch 40 rides up on leveling cam 20 for the desired floor and creates asignal which commands the elevator to continue to move down. When the leveling cam 20 has cleared lower level switch 40 and comes in contact with upper leveling switch 38 the elevator is commanded to stop and move up. This procedure is repeated until neither leveling

switch

38 or 40 contacts the leveling cam 20 and each is positioned at opposite ends of the leveling cam.

It can, therefore, be understood by those skilled in the art that the system of switches and cams described above provides elevator location, slowdown and leveling signals.

FIG. 2 schematically illustrates an electrical control system suitable for use with a preferred embodiment of the invention; however, it should be noted that a particular electrical control system is not critical to my invention.

In FIG. 2, the numeral 42 designates a star switch assembly and the numeral 44 designates a leveling switch assembly. For illustrative purposes, these assemblies are shown as separate blocks but in fact they both are located inside the switch box 10, as illustrated in FIG. 1. The star switch assembly 42 contains an elevator locator 46 which puts out a signal on one of a plurality of elevator location lines 48 adepending on which floor the elevator is approaching. For example, when the basement floors bullet shaped cam turns the star switch 22 one increment, the elevator locator 46 applies a signal to elevator location line 48a. When the star switch 22 is turned one more increment to the first floor by a bullet shaped cam 18, the elevator locator applies a signal to 48b and so forth through the six arm positions. The is, as previously stated, because the star switch 22 only has six arms, it is only useable in the herein described embodiment to locate the elevator with respect to six floors. The elevator locator lines 48 a-f are connected to one input of six two-input AND gates 50 a-f, and to the combining and control circuits S7. Separately connected to the other inputs of the AND gates 50 a-f are floor selector lines 54 which receive signals from a floor selector 52 located either in the elevator or at the various floors. The floor selector is also connected between the switch box 10 and the rod 74. In this respect, the two rods are affixed to the rack which is held in a central location within the tube 80 by

springs

88 and 90 as illustrated. In this manner, downward motion of rod 74, caused by its engagement with breakaway bracket 76, urges rack 84 downwardly against the bias of spring 90. Similarly, when the elevator is at the bottom of the elevator shaft, a second bracket.( not shown) urges rod 86 upwardly to move rack 84 against the bias of spring 88.

A specially modified pinion 92 (FIG. 11) is affixed to the shaft assembly 28 which extends outwardly along this axis of the star switch 22 and is journaled in bearings 91. In a preferred embodiment, the pinion is of a standard 24 pitch type and located so as to coact with corresponding 24 pitch teeth on the rack 84. Two of the pinion s teeth, 96 and 98, are only half as wide across their faces as the remainder of the pinions teeth. In this regard, one of the half-face-width teeth 96 is on the outer side of the pinion in FIG. 9; and the other of the pinions half-face-width teeth 98 is on the inner side of the pinion, but spaced from the other half-face-width tooth by a full sized tooth 100. In this manner, the pinion only has four full-face width teeth and two half-face-width teeth. Moreover, these teeth are arranged so that the outer side of the pinion, has five teeth with a space 102 therebetween; and the inner side of the pinion has, five teeth with a space 104 therebetween.

The rack 84 has no full-face-width teeth. Instead, it has only a first set of half-face width teeth 106 which are located at one comer of the rack and coact with the outer five teeth on the pinion. Similarly, half-face-width teeth 108 are located on the other corner of the rack 84 so as to coact with the inner five half-face-width teeth of the pinion. It should also be noted that the rack has a space 110 that is void of any teeth at all. When the rack is in its central or neutral position, this space 110 is aligned with a cut-away portion 112 of the tube 80 in FIG. 9-- directly under the pinion 92 in FIG. 14.

In operation, the pinion is affixed with respect to the rack so that, when the elevator is at the upper end of the shaft and the star switch is properly positioned, the space or gap 102 in the outer side of the pinion 92 is adjacent portion 114 of the space 110 on the rack 84 (FIG. 10). Hence, downward motion of the rod 74 urges the rack 84 downwardly but causes no rotation of the pinion, because the racks teeth 106 pass under the gap 102 in the outside of the pinion. If, however, the star wheel 22 has for some reason failed to turn upon contact with a proper bullet-shaped cam, one of the pinions outer teeth is located in the space 114 when the elevator reaches the upper end of the shaft. Consequently, in this event, downward motion of the rack 84 by the rod 74 causes the pinion 92 to be rotated until its space 102 is adjacent the racks teeth 106, at which time the star switch is again properly positioned.

The automatic correction device works in a similar manner when the elevator travels to the lower end of the elevator shaft. In this instance, however, when the star switch is properly positioned it is the space 104 on the inside of the pinion that is over portion 116 of the racks blank space 110. Similarly, it is the rack's teeth 108 that rotate the pinion and star wheel into their proper positions when the star switch is in an incorrect position as the elevator approaches the lower end of the shaft. Thus, if the star switch is in some manner placed into an improper position, it is corrected into a proper position whenever the elevator reaches its terminal points. That is, either one end of the elevator shaft or the other.

Under normal operation, the elevator slows to a near stop before the rod 74 strikes the breakaway angle bracket 76 so that the impact between the rod 74 and the breakaway angle bracket 76 is not very large. However, on occasion, the elevator goes to the attic (for repairs, for example) and, passes the top floor at a higher speed. In this event, a breakaway hinge 77 rotates when there is a sudden impact between the rod 74 and the breakaway bracket 76, thus, allowing the switch box 10 to continue moving upwardly without damaging either the bracket 76 or the reset mechanism. Also, there is a dashpot 87 connected between the rod 74 and the switch box 10 to prevent sudden motion of the rack 84. In this regard, the rack is prevented by the dashpot 87 from moving suddenly downwardly, for example, so as to cause the pinion 92 to spin freely. Similar events occur when the elevator travels below the first floor to the celler of a building. Hence, although not specifically illustrated, similar structure is also located below the switch box 10.

It will be appreciated by those skilled in the art that although the invention has been illustrated in connection with an elevator which travels only six floors, the structures capacity can be modified to handle more or less floors by merely using more or less bullet-shaped cams on the wires and changing the number of star switch arms accordingly.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art and others that various changes in form and detail may be made therein without departing from the scope of the invention. For example, the switching could be accomplished electronically rather than mechanically.

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

1. A system for automatically controlling the motion of a body moving in either direction along a track past a plurality of stations including end stations and at least one intermediate station so as to position said body at selected such stations comprising:

a plurality of control cams arranged in a line there being at least two control cams for each of said intermediate stations and at least one control cam for each of said end stations, said control cams being formed such that some of said control cams actuate a switch means while other of said control cams do not actuate said switch means when said body travels in one direction along said track and the reverse is true when said body travels in the other direction along said track;

switch means arranged to be selectively actuated by said plurality of control'cams when there is relative motion between said switch means and said plurality of control cams in a direction along said linear arrangement of control cams said selective actuation depending upon the direction of relative movement; and,

motion means for moving said plurality of control cams and said switch means relative to one another in a direction along said linear arrangement of control cams at a velocity proportional to the velocity that said body moves along said track whereby said switch means is actuated by said plurality of control cams so as to provide information as to the location of said body along said track.

2. A control system as claimed in claim 1 wherein said plurality of control cams are mounted on a cable, said cable being mounted so that said plurality of control cams selectively activate said switch means when there is relative motion between said switch means and said plurality of control cams.

3. A control system as claimed in claim 1 wherein:

said track is an elevator shaft;

said stations are floors;

said control cams are arranged in a line along said elevator shaft;

said switch means is fixedly attached to said elevator; and

said motion means is an elevator lift motor which moves the elevator up and down.

4. A control system as in claim 3 wherein cooperation between said switch means and said control cams provides sufficient information for determining the floor at which said elevator is located and for determining the slowing point at which said elevator should slow down to stop at a selected floor.

5. A control system as claimed in claim 4 wherein:

said switch means includes a flexible arm for contacting said control cams; and,

connected via control lines 56 a-f to a combining and control circuit 57. The outputs of the AND gates 50 a-f are commonly connected to the combining and control circuit 57. The up and down leveling

switches

38 and 40 are also connected to the combining and control circuit 57. The combining and control circuit 57, in turn, is connected to the motor 59 which controls the movement of the elevator.

In operation, when someone, either on a floor or in the elevator, selects a floor by pressing a button 55 of the floor selector 52, a command signal is relayed to the combining and control circuit 57 via one of the control lines 56 a-f. The combining and control circuit 57 compares this command signal with a signal from one of lines 48 a-f representing the present location of the elevator and directs the motor 56 to either: (1) move the elevator up if the selected floor is above the present location; (2) move the elevator down if the floor selected is below the present location, or (3) open the elevator door if the selected floor is at the present location. The 'floor selector 52 also sends a continuous signal to one of the AND gates along one of the floor selector lines 54 a-f.

As the elevator moves toward a selected floor, the star switch 22 cooperates with the bullet shaped cams 18 in the manner previously described. In response to the movement of the star switch 22, the elevator locator sequentially applies signals to the floor register lines 48 a-f as each floor is approached. At some point, one of the AND gates 50 a-f receives two signals, one from the floor selector and one from the elevator locator. At this point the particular AND gate applies a signal to the combining and control circuit 57. For example, if the second floor is selected by placing a signal on floor selector line 54c, when the elevator approaches the second floor, a signal is placed on elevator locator line 480 and AND gate 500 applies a signal to the combining and control circuit 57. This latter signal tells the combining and control circuit to start slowing the elevator. At this point, either switch 38 or 40, depending on whether the elevator is traveling up or down, comes in contact with the second floor leveling cam 20 and applies a signal to the combining and control circuit 57 via '"either line 58a or 58b, as the case may be. The combining and control circuit 57 uses the signals from lines 58a and 58b to command the motor to level the elevator so that the

switches

38 and 40 are respectively located above and below the leveling cam 20. In this respect, the combining and control circuit 57 is formed such that it disregards signals from leveling

switches

38 and 40 until a signal is received from one of the AND gates 50 a-f.

It will be appreciated by those skilled in the art that the electrical circuits represented by the boxes in FIG. 2 can be structured in any one of many conventional manners. Hence, it is not necessary to more fully describe them here. In addition, it should be noted that the arrangement of the circuits as shown in FIG. 2 is only one such arrangement in which the claimed invention can be used.

A modification of the above described system is shown in FIG. 3 wherein both the bullet cams 18 and the leveling cams 20 are mounted on the same line 59. The modification device functions substantially the same as the system shown in FIG. 1, that is the bullet shaped cam 18 cooperate with a star switch (not shown in FIG. 3) to provide floor registration information to the control circuits and the leveling cams coordinate with leveling

switches

38 and 40 to provide leveling information to the control circuits. Neither type cam interfers with the operation of the other. The leveling cams 20 do not trip the star switch because the leveling are tapered at both ends and, therefore, slide between the star arms 34. The bullet cams 18 do activate the leveling switches 38 and 40 so that signals are sent to the combining and control circuit 57 but this does not confuse the system because the combining and control circuit 57 disregards leveling signals until a signal is received from one of the AND gates 50 aas explained above.

FIG. 4 is an enlarged view of a preferred embodiment of a bullet shaped cam 18. As therein illustrated the pointed end 19 forms a 30 angle, or a angle with the cams axis, and a bore 64 of approximately 0.050 inch in diameter, runs longitudinally through the center. An attaching screw 62 passes through the side of the bullet shaped cam to the bore 64 and affixes the bullet shaped cam to the wire 12. The blunt end 21 of the, bullet shaped earns 18 is recessed at 66, as shown in FIG. 4. The angle of the recess is preferably, approximately 5 (for illustration the angle has been exaggerated in FIG. 4). The purpose of the recess 66 is to ensure that, upon making contact with the points 27 on the arms 34, the points do not ride over the cams but rather are held in contact with the blunt end 21.

FIG. 5 shows one side of an arm 34. As previously described the arms each have points 27. In addition, each arm has safety tabs 68. The points 27 are formed on either edge of the arms and, preferably, make angles of 45 with the arm, in the regions illustrated in FIG. 5. The points 27 are bent along the crease lines 70 in FIG. 5, away from the other half of the particular arm pair (not shown in FIG. 5). The safety tabs 68 are located on the other side of the points from the disc, as illustrated in FIG. 1, and are bent along the crease lines 72, in FIG. 5, also away from the other half of its related arms 34. The reason for these bends can best be seen by reference to FIG. 1. In this respect, as the star switch 22 turns, the opposing arms 34 pass on either side of the non operating bullet shaped earns 18 and the guide block 36. Because the safety tabs 68 and the points 27 are bent, as explained above, so that they flare away from the guide and the bullet shaped cams, these elements tend to be funneled between the opposing arms. In addition, by bending the points 27 away from the bullet shaped cams, wear is reduced on both the bullet shaped cams and the arms.

FIG. 6 illustrates a bullet shaped cam 18 as it makes contact with the point 27 of an arm 34. It should be noted that the point 27 is held in the recess 66, hence, when bending the points 27 along the crease 70, in the manner previously described, care must be taken that the distance between the points of opposing arms is not greater than the diameter of a bullet shaped cam 18. Otherwise, the points may not be caught in the recess 66.

FIG. 7 is sequentially related to FIG. 6 and shows arm 34 after a bullet shaped cam 18 has contacted it. Once a bullet shaped cam rotates the star switch 30, a biasing spring (not shown) causes the star switch to complete the 60 turn. Thus the am 34 is caused to separate from the operative bullet shaped cam 18. In this manner, wear to both elements is prevented. There are many ways in which the biasing spring arrangement can be attached to the star switch 22 to provide the desired movement. An example of one such way is shown in FIG. 11 of US. Pat. No. 2,938,602 to Loughridge, previously referred to. In the structure of the instant invention, however, if the biasing spring fails to flip" the star switch 22 and thereby rotate arm 34, the arm s safety tab 68 is left in the path of the bullet shaped cam 18 in the position illustrated in FIG. 8. As can be seen, point A on the safety tab 68 then contacts the blunt end 21 of the bullet cam 18 and the arm 34 is rotated the complete 60.

As noted above, the star switch might occasionally fail to turn in response to contact with one of the proper bullet shaped cams. In other instances, the star switch is inadvertently turned during manual operation of the elevator such as during an inspection operation. In these cases, therefore, it is desirable to have an automatic correction device to correct the position of the star switch each time the elevator arrives at the top or bottom of the elevator shaft. In this respect, FIG. 9 illustrates the switch box 10 as it arrives at the top of the elevator shaft so that a rod 74 strikes a breakaway angle bracket 76 which is affixed to the wall of the elevator shaft and extends outwardly into the path of the rod 74. The rod 74 extends into an opening 78 in one end of a brass tube 80 which has a hollow square cross-section and is affixed to one side of the control box 10, as illustrated in FIG. 9.

As shown in FIG. 14, a specially structured rack 84 (FIG. 10) is located within the square tube 80 between the rod 74 on one end and a similar rod 86 on the other. A dashpot 87 is said control cams have tapered ends and blunt ends; whereby the switch arm will flex without actuating said switch upon contacting a tapered end of said control cams but will actuate said switch means upon contacting a blunt end of said control cams.

6. A control system as claimed in claim wherein said switch means includes a switch which is rotatable about an axis and has a plurality of arms, each arm comprising parallel flexible members; and, wherein said plurality of control cams are mounted on a cable.

7. A control system as claimed in claim 6 wherein said control cams having tapered ends are cylindrical in shape.

8. A control system as claimed in claim 7 wherein:

said blunt ends of said control cams are recessed; and,

said parallel members of said arms have protrusions which are positioned on said parallel members so that they engage said recessed blunt ends of said control cams upon initial contact of said arms with said blunt ends of the control cams.

9. A control system as claimed in claim 8 wherein:

said switch means rotates in definite increments; and,

each said parallel flexible member of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned on said members that said blunt end of a control cam makes initial contact with said initial contact protrusion and secondary contact with said safety protrusion to ensure that said switch rotates the desired increment.

10. A control system as claimed in claim 9 and further including a guide means for guiding said linear arrangement of control cams between the parallel flexible members of said switch arms.

11. A control system as claimed in claim 10 wherein each of said control cams have one blunt end and one tapered end.

12. A control system as claimed in claim 10 wherein said guide means is a block positioned so that said parallel flexible members of each arm pass on either side of said block as said switch rotates.

13. A control system as claimed in claim 10 wherein said control system further comprises a leveling means for providing one signal signifying that said elevator is located on one side of a selected floor and another signal signifying that said elevator is located on the other side of said selected floor; whereby, sufficient information is provided to correct the position of said elevator to correspond with the position of said floor and finally stop said elevator at said floor.

14. A system as claimed in claim 13 wherein said leveling means comprises:

cylindrical leveling cams being tapered at both ends arranged linearly along said elevator shaft, at least one for each floor;

two leveling switches, spaced at least one leveling cam length apart, fixedly attached to said elevator;

said leveling switches and leveling cams being so arranged relative one to the other that a cam is positioned between said switches when said moving body is at a floor and motion of the elevator in either direction from a floor brings one of said switches in contact with a tapered end of the cam.

15. A control system as claimed in claim 14 wherein said leveling cams are linearly arranged along the same line as said control cams.

16. A control system as claimed in claim 13 wherein is further included a correction means for correcting an improper position of said switch means.

17. A control system as claimed in claim 16 wherein said correction means includes a correction actuating means fixedly located at an end of the normal operating range of said elevator.

18. A control system as claimed in claim 16 wherein said correction means further includes:

a pinion gear having at least one tooth partially cutaway connected to said rotatable switch means; and,

a linkage means providing linkage between said actuating means and said pinion gear.

19. A control system as claimed in claim 6 wherein is further included a correction means for correcting an improper position of said switch means.

20. A control system as claimed in claim 19 wherein said correction means includes a correction actuating means fixedly located at an end of the normal operating range of said elevator.

21. A control system as claimed in claim 20 wherein said correction means further includes:

a linkage means for providing linkage between said actuating means and said pinion gear.

22. A control system as claimed in claim 4 wherein said control system further comprises a leveling means which includes:

cylindrical leveling cams being tapered at both ends and arranged linearly along said elevator shaft, at least one for each floor;

two leveling switches, spaced at least one leveling cam length apart and fixedly attached to said elevator;

said leveling switches and said leveling cams being so arranged relative one to the other that a cam is positioned between said switches when said elevator is at a floor but motion of the elevator in either direction from a floor brings one of said switches in contact with a tapered end of the cam.

23. A control system as claimed in claim 22 wherein said leveling cams are linearly arranged along the same line as said control cams.

24. A control system as claimed in claim 22 wherein is further included a correction means for correcting an improper position of said switch means.

25. A control system as claimed in claim 24 wherein said correction means includes a correction actuating means fixedly located at an end of the normal operating range of said elevator.

26. A control system as claimed in claim 25 wherein said correction means further includes:

a pinion gear having at least one tooth partially cut away connected to said rotatable switch means; and,

27. A switch and cam system of the type in which a switch is actuated by contact with cams comprising:

cams arranged in a line;

a rotatable switch having a plurality of flexible arms, each arm comprising parallel flexible members;

moving means for causing relative movement between the cams and said rotatable switch in a direction along the line of said cams; whereby said switch arms sequentially contact said cams and thereby cause said switch to rotate.

28. A switch and cam system as claimed in claim 27 wherein said cams have tapered ends and blunt ends, whereby said switch arms will flex without rotating said switch upon contacting a tapered end of said cams but will rotate said switch upon contacting a blunt end of said cams.

29. A switch and cam system as claimed in claim 28 wherein said cams having tapered ends are cylindrical in shape.

30. A switch and cam system as claimed in claim 29 wherein:

said blunt ends of said cams are recessed; and,

said parallel flexible members of said arms have protrusions which are positioned on said arm members so that they engage said recessed blunt ends of said cams upon initial contact of said arms with the blunt ends of said cams.

31. A switch and cam system as claimed in claim 30 wherein:

said switch rotates in definite increments; and,

said parallel flexible members of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned on said members that said blunt ends of said cams make initial contact with said initial contact protrusion and secondary contact with said safety protrusions to ensure that said switch rotates the desired increment.

32. A switch and cam system as claimed in claim 31 and further including a guide means for guiding said line of cams between the parallel flexible members of said rotating switch.

33. A switch and cam system as claimed in claim 32 wherein said guide means is a block positioned so that said parallel flexible members of each arm pass on either side of said block as said rotatable switch rotates.

34. A switch and cam system as claimed in claim 27 wherein:

said cams have blunt ends which are recessed; and,

said parallel flexible members of said arms have protrusions which are positioned on said arm members so that they engage said recessed blunt ends of said cams upon initial contact of said arms with said blunt ends of said cams.

35. A switch and cam system as claimed in claim 34 wherein:

said switch rotates in definite increments; and,

said parallel flexible members of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned on said members that said blunt ends of said cams make initial contact with said initial contact protrusions and secondary contact with said safety protrusions to ensure that said switch rotates the desired increment.

Claims

1. A system for automatically controlling the motion of a body moving in either direction along a track past a plurality of stations including end stations and at least one intermediate station so as to position said body at selected such stations comprising: a plurality of control cams arranged in a line there being at least two control cams for each of said intermediate stations and at least one control cam for each of said end stations, said control cams being formed such that some of said control cams actuate a switch means while other of said control cams do not actuate said switch means when said body travels in one direction along said track and the reverse is true when said body travels in the other direction along said track; switch means arranged to be selectively actuated by said plurality of control cams when there is relative motion between said switch means and said plurality of control cams in a direction along said linear arrangement of control cams said selective actuation depending upon the direction of relative movement; and, motion means for moving said plurality of control cams and said switch means relative to one another in a direction along said linear arrangement of control cams at a velocity proportional to the velocity that said body moves along said track whereby said switch means is actuated by said plurality of control cams so as to provide information as to the location of said body along said track.

3. A control system as claimed in claim 1 wherein: said track is an elevator shaft; said stations are floors; said control cams are arranged in a line along said elevator shaft; said switch means is fixedly attached to said elevator; and said motion means is an elevator lift motor which moves the elevator up and down.

5. A control system as claimed in claim 4 wherein: said switch means includes a flexible arm for contacting said control cams; and, said control cams have tapered ends and blunt ends; whereby the switch arm will flex without actuating said switch upon contacting a tapered end of said control cams but will actuate said switch means upon contacting a blunt end of said control cams.

6. A control system as claimed in claim 5 wherein said switch means includes a switch which is rotatable about an axis and has a plurality of arms, each arm comprising parallel flexible members; and, wherein said plurality of control cams are mounted on a cable.

8. A control system aS claimed in claim 7 wherein: said blunt ends of said control cams are recessed; and, said parallel members of said arms have protrusions which are positioned on said parallel members so that they engage said recessed blunt ends of said control cams upon initial contact of said arms with said blunt ends of the control cams.

9. A control system as claimed in claim 8 wherein: said switch means rotates in definite increments; and, each said parallel flexible member of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned on said members that said blunt end of a control cam makes initial contact with said initial contact protrusion and secondary contact with said safety protrusion to ensure that said switch rotates the desired increment.

14. A system as claimed in claim 13 wherein said leveling means comprises: cylindrical leveling cams being tapered at both ends arranged linearly along said elevator shaft, at least one for each floor; two leveling switches, spaced at least one leveling cam length apart, fixedly attached to said elevator; said leveling switches and leveling cams being so arranged relative one to the other that a cam is positioned between said switches when said moving body is at a floor and motion of the elevator in either direction from a floor brings one of said switches in contact with a tapered end of the cam.

18. A control system as claimed in claim 16 wherein said correction means further includes: a pinion gear having at least one tooth partially cutaway connected to said rotatable switch means; and, a linkage means providing linkage between said actuating means and said pinion gear.

21. A control system as claimed in claim 20 wherein said correction means further includes: a pinion gear having at least one tooth partially cutaway connected to said rotatable switch means; and, a linkage means for providing linkage between said actuating means and said pinion gear.

22. A control system as claimed in claim 4 wherein said control system further comprises a leveling means which includes: cylindrical leveling cams being tapered at botH ends and arranged linearly along said elevator shaft, at least one for each floor; two leveling switches, spaced at least one leveling cam length apart and fixedly attached to said elevator; said leveling switches and said leveling cams being so arranged relative one to the other that a cam is positioned between said switches when said elevator is at a floor but motion of the elevator in either direction from a floor brings one of said switches in contact with a tapered end of the cam.

26. A control system as claimed in claim 25 wherein said correction means further includes: a pinion gear having at least one tooth partially cut away connected to said rotatable switch means; and, a linkage means for providing linkage between said actuating means and said pinion gear.

27. A switch and cam system of the type in which a switch is actuated by contact with cams comprising: cams arranged in a line; a rotatable switch having a plurality of flexible arms, each arm comprising parallel flexible members; moving means for causing relative movement between the cams and said rotatable switch in a direction along the line of said cams; whereby said switch arms sequentially contact said cams and thereby cause said switch to rotate.

30. A switch and cam system as claimed in claim 29 wherein: said blunt ends of said cams are recessed; and, said parallel flexible members of said arms have protrusions which are positioned on said arm members so that they engage said recessed blunt ends of said cams upon initial contact of said arms with the blunt ends of said cams.

31. A switch and cam system as claimed in claim 30 wherein: said switch rotates in definite increments; and, said parallel flexible members of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned on said members that said blunt ends of said cams make initial contact with said initial contact protrusion and secondary contact with said safety protrusions to ensure that said switch rotates the desired increment.

34. A switch and cam system as claimed in claim 27 wherein: said cams have blunt ends which are recessed; and, said parallel flexible members of said arms have protrusions which are positioned on said arm members so that they engage said recessed blunt ends of said cams upon initial contact of said arms with said blunt ends of said cams.

35. A switch and cam system as claimed in claim 34 wherein: said switch rotates in definite increments; and, said parallel flexible members of said switch arms have both an initial contact protrusion and a safety contact protrusion, said protrusions being so positioned oN said members that said blunt ends of said cams make initial contact with said initial contact protrusions and secondary contact with said safety protrusions to ensure that said switch rotates the desired increment.