US3435917A - Top of car selector for use in an elevator control system - Google Patents

Description

April ,1 s. A.-HORNUNG ET AL 3,435,917

TOP OF CAR SELECTOR FOR USE IN AN ELEVATOR CONTROL SYSTEM Filed May 4, 1965 Sheet of 2 sascroe 2 CAR I N VENTORS, STEPHEN 4. HOP/WING B Y 8067 E Y REED A r runners.

s. A. HORNUNG ET AL 3,435,917

April 1, 1969 TOP OF CAR SELECTOR FOR USE IN AN ELEVATOR CONTROL SYSTEM Filed May 4, 1965 Sheet ,3 of2 m a y 6 United States Patent 0 3,435,917 TOP OF CAR SELECTOR FOR USE EN AN ELEVATQR CONTROL SYSTEM Stephen A. Hornung, Louisville, and Buckley Reed, Valley Station, Ky., assignors to K. M. White Company, Louisville, Ky., a corporation of Kentucky Filed May 4, 1965, Ser. No. 453,108 Int. Cl. B66b 1/00 U.S. Cl. 187-29 15 Claims ABSTRACT OF THE DISCLOSURE A selector apparatus for an elevator control system mounted on the top of the elevator car and includes an elevator displacement-related carriage having first and second mutually perpendicular rows of circuit controlling elements which are advanced and retrograded, within a frame, dependent upon the movement of the car. The first set of circuit controlling elements is engaged by angularly displacing cams responsive to the movement of the car, and the second set of circuit controlling elements is linearly related to associated circuit control means. The high differential in car movement response between the first and second associated sets of circuit controlling elements and control means permits the same instrumentality to control car speed and dead-zone levelling.

This invention relates to elevator control circuits generally and in particular to an improved selector apparatus for, inter alia, indicating the car position to cooperating control and logic circuits and supervising speed reduction switching, dead zone leveling and elevator car door openmg.

Conventional selectors take many forms and because of their diverse functions, tend to be large, complicated devices which have heretofore been disposed in or adjacent the shaft, sometimes necessitating magnetic units, vanes, brackets or tapes in the shaftway to accommodate the various functions. Needless to say, this complexity and location of conventional selectors have proved an impediment to maintenance and consequently a serious drawback.

Where attempts have been made to simplify such devices and reduce their size, considerations such as: the number of functions to be supervised; the desired leveling ratio vis-a-vis speed reduction initiation; and the difficulty in eliminating backlash upon car reversal have inhibited progress.

Accordingly, it is the object of this invention to pror vide a selector which is simple in construction, small in size and which may be mounted on top of the car with which it is associated.

It is another object of this invention to provide a selector which includes an inherent low leveling ratio and which by virtue of suitable common leveling and deceleration drives, minimizes backlash.

It is a further object of this invention toprovide a selector of suflicient flexibility to adapt to the desired leveling and deceleration differental, the spacing between landings, the hoist and descent speeds, the landing approach speed, and the leveling speeds of new and existing systems.

Briefly, the invention is predicated upon the division of the selector into two mutually perpendicular advancing planes; the deceleration control lying in a first plane and the leveling control in a second. The advancement of the planes is directly driven in response to the movement of the car and cooperating members are disposed in the path of the respective planes for sequential engagement. By directly driving one set of cooperating members angularly for successive engagement with the leveling controls (in one plane) as they advance, a high differential in leveling and deceleration is achieved. By using reasonably good tolerance direct drives throughout, backlash through play and friction loss is minimized.

The above mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will best be understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a simplified plan view showing the installation of the selector according to the invention;

FIG. 2 is a bottom view of a selector according to the invention;

FIG. 3 is a sectional view taken along lines 33 of FIG. 2; and

FIG. 4 is a detailed perspective of the selector carriage.

Inasmuch as the inventive concept is limited to the selector itself and not the attendant control, relay, or logic circuitry, the description will, for brevity, be confined to this mechanism. It is to be understood, however, that the novel selector, like conventional ones, cooperates with a large amount of adjunct equipment, indicating or supervising the functions allocated to it.

It is to be further understood that it is this adjunct equipment which finally controls the operation of the elevator car. Since this control is unchanged by the invention, it will be described only briefly where necessary for an understanding of the invention.

The cooperation of the selector mechanically with the elevator car and shaftway is illustrated in FIG. 1. The elevator car 10 is raised and lowered in the conventional manner by means of hoist cables 12, coupled to a counterweight overlying a traction sheave, the latter being driven by a hoist motor (not shown). The hoist cables are coupled to the car via the cross head 14. Disposed in front of the cross head, and preferably bolted thereto or to the car roof with suitable supports is the selector 20. A drum portion of the selector is shown at the right. This is the sheave 21, a helically grooved cylinder around which the selector cable 23 is wrapped.

Preferably, the cable is coupled to the sheave in a nonfriction dependent manner for positive nonslip response of the selector to the movement of the car. This is accomplished by constituting the cable in two parts. The first cable portion is fastened to the base of the shaft and starting at the middle of the sheave, it is wrapped clockwise to the right end where it passes through an aperture and is fixedly joined to the sheave periphery. The second portion is fixedly joined at a sheave aperture at the left and from there is wrapped clockwise to the right. At the approximate middle (leaving suitable space) the second portion leaves the sheave tangentially and is afiixed to the shaft roof. Consequently, car movement in either direction rotates the sheave and simultaneously plays out one cable portion and rewinds the second; the two cable tangents moving to the left for one direction of car movement and to the right for the other direction. Suitable tensioning is provided :by springs in series with the cable at the top or bottom of the shaft (not shown).

The electrical connections from the selector terminal block (to be described) emerge in a cable 28 which is led to the control equipment in a similar manner to that conventionally employed for the normal car located controls (e.g., floor push buttons, emergency stop, etc.).

The internal mechanisms of the selector will be described with reference to the remaining figures. Since the selector may be broken down into mechanical and electrical substructures, each will be described in turn and the cooperative relationship described subsequently.

The selector frame comprises four corner struts 40-43, secured at their respective ends to side plates 45 and 46. The sheave 21 is fixedly mounted upon rotatable shaft 47 journaled in bushings 49 and 50 afiixed to the respective side plates. A dust cover, removed for clarity, surrounds the frame and is afiixed thereto in the conventional manner. Parallel and adjacent the shaft 49 is a worm 52, the respective ends of which are similarly journaled in bushings 53 and 54. Cams 63 and 67 are spaced along shaft 47 for rotation therewith. These are split cams adjustable in position and attitude by the associated tightening bolts (denoted by the prime of the corresponding cam designation).

Fixedly mounted on both the worm 52 and shaft 47 are the juxtaposed sprocket wheels 55 and 56, each engaged for common drive by the chain 58. While belt and gear mesh drives are also capable of employment, the former has the disadvantage of slippage, While the latter is quite inflexible in its adaptability to various speed differentials without using specially designed and machined gears. Needless to say, it is a matter of choice whether the worm or shaft is to be directly connected to the sheave. Riding the worm 52 is carriage 30 engaging the thread thereof by nut 31. Stabilization of the carriage is afforded by the cooperation of the low friction Teflon blocks 32 and 33 (mounted on the carriage side members 34 and 35 respectively) with the rectangular guide 60 mounted in end piece sockets 61 and '62. For convenience in illustrating the worm, the guide is shown fragmented and the right end socket omitted from FIG. 2.

As a consequence of the foregoing, rotation of the sheave in the direction of the arrow (in response to a downward car movement) will move the carriage to the left and the cams clockwise (in FIG. 3). Upward car motion will reverse each of the foregoing.

Disposed above and slightly offset from the worm 52 is an array of contacts constituted in three rows 70, 71 and 72. These contacts are disposed upon an insulated network comprising four linear insulators 7376, held in parallel by spacer assemblies 77 and 78, and in position, relative the worm, by end piece sockets 79 and 80.

The rows of contacts 70 and 71 are identical, each consisting of pins adjustably mounted (by virtue of the nuts 70 and 71). These rows control the deceleration function; one row for upward and one for downward car movement. Since the speed reduction is the same regardless of the floor, the pins are coupled in series by resilient helical wires 80 and 81 (to allow for adjustment). There are N-l pins per row; where N equals the number of landings.

The third contact row 72 consists of linear segments each designating the location of the car in the shaft for controlling indicator lights, landing displays, and car sequency logic circuits. There are N of such contacts.

The output leads from the three rows are coupled (two from the first two rows and N from the third row) to the terminal block 82 mounted upon a support 83 (shown fragmented) seated in end piece sockets 84 and 85. The output lead from this terminal block is that designated 28 in FIG. 1.

Turning now to FIG. 4, the cooperation of the carriage mounted elements with the contact rows and cams will now be described. The carriage mounted electrical elements are confined in two distinct planes. The first is cantilevered to the right and comprises three resilient wiping contacts or brushes 36, 37 and 38 adjustably mounted, for example, by nuts and lock washers 36', 37' and 38, upon an insulator assembly 39 similar to that bearing the row contacts 70, 71 and 72.

The second set of carriage mounted elements are in a plane perpendicular to the first and are borne by a carriage affixed (e.g., by brackets) arcuate shaped member conforming roughly in shape to the cam surfaces which will be engaged. Switches 91, 92 and 93 are equispaced along the arc and are adapted by means of cam followers 91', 92' and 93' to be closed by the cams. This latter group of switches controls the dead zone leveling functions; the two outer switches controlling respectively up and down car leveling. The intermediate switch 92 may be relegated to controlling car door opening relays or high speed leveling.

The output leads from the brush and switch groups are led similarly to those of the contact rows, with proper dressing to allow for movement, to the terminal block 82.

For the purposes of clarity, and to provide a better understanding of the foregoing, a brief example of selector operation will be described with reference to FIGS. 2 and 3. It will be assumed that the car shaft includes six landings and the car is approaching the lowest of these.

Rotation of the various selector components is that shown by the arrows; the carriage moving to the left. When brush 38 engages the final pin contact in row 70, the deceleration relays will be energized via the terminal block 82 and the electrical cable 28 to this equipment, and the cars downward speed reduced. Substantially simultaneously, the segment in row 72 will have engaged the associated brush 36, thus indicating the car position for logic and indicating function relays.

When the car has proceeded into the dead zone leveling area, cam 63 will engage the first switch 93, and the car, via associated controls, will be subjected to leveling speed and braking controls until the cam rides off the associated cam follower of this switch. At this point the cam sits solely on cam follower 92' of switch 92. Boolean logic circuits, cooperating with switch 92 may control the door opening function. That is, when switch 92 and not 91 or 93 is closed, the door may open. If the oar overshoots the landing, switch 91 will be energized and the car leveled upwardly. Needless to say, the switch spacing depends upon the logic employed and any combination of switch closures may serve the same purpose.

At this juncture, it may be noted that the arcuate shaped member is slightly angled off true perpendicular. This is a desirable feature, and the size of the angle is dependent upon the pitch of the worm and the differential between worm and cam speeds, ensuring that the cams will strike the switches in their arranged order and not for example strike the middle switch first.

From the foregoing, it may be seen that by adjusting the cams longitudinally and angularly, precise levelling may be simply obtained, and that because of the selectors location on the top of the car, this adjustment may be easily made. Further, by suitable adjustment of the contact rows 70-72 in conjunction with the carriage mounted brushes 36-38, points of deceleration may be precisely controlled.

It may also be seen that the depicted arrangement provides a desirable large differential in the ratio of deceleration and leveling controls by virtue of the advancing carriage (via-a-vis the row contacts) and the angularly displacing cams. Moreover, this ratio is easily adaptable to the conversion of existing equipment by virtue of the flexibility afforded by varying the ratio of the diameters of the sprocket wheels.

Thus, for example, assuming a three to one ratio in sprocket diameters (the worm having the smaller sprocket), a one ft. diameter sheave, and a worm pitch of approximately .4 inch, a 60 ft. shaft may be represented by approximately 2 ft. of worm; each inch of worm representing approximately 2 ft. of shaft. Each degree of angular displacement of the cams will therefore represent approximately .1 inch of shaft.

Greater shaft lengths require an increase in only the longitudinal dimension of the selector; as 'a consequence, a nonexponential increase in volume accompanies larger selectors. If desired, where limited by space, rather than increasing the longitudinal dimension of the selector, the worm pitch may be decreased within practical limits.

While in the foregoing the carriage mounted elements have been described as mounted in two perpendicular planes, the arrangement may also be envisaged as three substantially mutually perpendicular lines, the two groups of carriage elements (i.e., the switches and brushes) lying along two of such lines and the worm axis representing the third perpendicular line. The phrase substantially perpendicular is employed to allow for the angular displacement of the arcuate member, as well as deviation from the ideal line by the brushes 36-38. This latter line may be visualized as an average bisecting the insulator supports in a direction normal to their length.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of my invention as set forth in the objects thereof and in the accompanying claims. For example, while only leveling, deceleration, car position indicating, and car door opening functions have been described, other functions may be embraced by the invention, as will be appreciated by those skilled in the art. It will also be appreciated that whereas the carriage mounted cantilevered elements have been described as brushes, and the rows as consisting of pin and segment contacts, these two groups may also cooperate in any other well known manner to close or open corresponding circuits. For example, the carriage mounted brushes may be replaced by cams and the pin and segment contact elements replaced by switches (or vice versa to efiect the same result).

I claim:

1. In an elevator control system, the improvement consisting of a selector apparatus adapted to be mounted on the top of a car and comprising: a. frame; a carriage having first and second substantially mutually perpendicular rows of circuit controlling elements mounted thereon; means responsive to the movement of an elevator car for advancing and retrograding said carriage within said frame in a direction perpendicular to a plane defined by said first and second substantially mutually perpendicular rows of current controlling elements; a plurality of parallel rows of circuit control means, mounted within said frame along the travel of said carriage for successive engagement by said first row of carriage mounted elements; a plurality of cams mounted in tandem within said frame along the travel of said carriage; and means responsive to the movement of the elevator car for rotating said cams in common for successive engagement by each cam of each element on said second carriage mounted row.

2. The improvement claimed in claim 1, in which at least two elements in said first row of carriage mounted elements and at least two of said parallel rows of circuit control means by cooperative engagement control the speed reduction of said car as it approaches a landing from respectively above and below, and in which at least two elements in said second row of carriage mounted elements are switches for controlling the dead zone leveling of said elevator car.

3. The improvement claimed in claim 2 in which at least one of said carriage mounted elements in said first row comprises a brush contact, and in which one of said parallel rows of circuit control means comprises spaced contact segments; the cooperative engagement of said brush contact successively with said segment contacts indicating electrically the location of said car.

4. The improvement claimed in claim 2 in which said second row of carriage mounted elements comprises a third switch disposed intermediate said two dead zone leveling switches for controlling the opening of the elevator car doors, the spacing of said switches being sufiicient to allow said cams to engage only one switch at a time.

5. The improvement claimed in claim 2 in which said cams rotate N revolutions for each successive cooperative engagement of said first row of carriage mounted elements with said parallel rows of circuit control means, where N is greater than one.

6. The improvement claimed in claim 2 in which both said means responsive to the movement of an elevator include in common: a sheave rotatably mounted in said frame; and a cable wrapped around said sheave and fastened to the respective ends of the elevator shaft.

7. In an elevator control system, the improvement consisting of selector apparatus adapted to be mounted on the top of the car and comprising; a frame; a worm rotatably mounted in said frame; a carriage riding said worm and having first and second rows of circuit controlling elements mounted thereon substantially mutually perpendicular to each other and the axis of said worm; a plurality of parallel rows of circuit control means, mounted within said frame along the travel of said carriage for successive engagement by said first row of carriage mounted elements; a shaft rotatably mounted in said frame parallel said worm; a plurality of cams spaced along said shaft for sequential engagement with said second row of carriage mounted elements, each cam for successively engaging each element in said second row; means coupling said worm and shaft for the common driving thereof; and means responsive to the movement of the elevator car for driving said coupling means.

8. The improvement claimed in claim 7 in which said movement responsive means comprises a sheave rotatably mounted in said frame, and a cable wrapped around said slfieafttve and fastened to the respective ends of the elevator s a 9. The improvement claimed in claim 8 in which said means coupling the worm and shaft comprise a pair of sprockets respectively mounted thereon, and a chain meshing said sprockets.

10. The improvement claimed in claim 9 in which said 8:116:16 is directly connected to one of said worm and said s a 11. The improvement claimed in claim 7 in which at least two elements in said first row of carriage mounted elements and at least two of said parallel rows of circuit control means by cooperative engagement control the speed reduction of said car as it approaches a landing from respectively above and below, and in which at least two elements in said second row of carriage mounted elements are switches for controlling the dead zone levelmg of said elevator car.

12. The improvement claimed in claim 11 in which at least one of said carriage mounted elements in said first row comprises a brush contact, and in which one of sa d parallel rows of circuit control means comprises spaced contact segments; the cooperative engagement of said brush contact successively with said contact segments indicating electrically the location of said car.

13. The improvement claimed in claim 11 in which said second row of carriage mounted elements comprises a third switch disposed intermediate said two dead zone leveling switches for controlling the opening of the elevator car doors, the spacing of said switches being sufiicient to allow said cams to engage only one switch at a time.

14. The improyement claimed in claim 11 in which said switches are mounted along an are, said are being slightly displaced from perpendicularity with said worm for equalizing the successive engagement of said cams.

15. In an elevator control system, the improvement consisting of selector apparatus adapted to be mounted on the top of the car and comprising a frame; a worm rotatably mounted in said frame; a carriage riding said worm and having a first row of contacts substantially traverse to the direction of displacement of said carriage; a plurality of cooperating function contacts mounted within said frame in a plurality of rows for sequential engagement by said carriage mounted contacts; a shaft rotatably mounted in said frame parallel said worm; a plurality of cams spaced along said shaft; a plurality of dead zone leveling switches mounted on said carriage in an arcuate row substantially perpendicular to both said carriage mounted contacts and the axis of said worm for sequential engagement with said cams, each cam engaging each switch in sequence; a sheave mounted on said frame; a cable Wrapped around said sheave and fastened at the respective ends of the elevator shaft for rotating said sheave in response to movement of the car, and transmission means coupling the sheave, said shaft, and said worm.

References Cited UNITED STATES PATENTS Hughes et a1.

0 ORIS L. RADER, Primary Examiner. T. E. LYNCH, Assistant Examiner.

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