System for indicating stop levels for an elevator

A system for indicating the stop levels for an elevator car in a hoist shaft so as to transmit signals to the elevator machinery when a selected stop level is approached. Vertically aligned pins are provided projecting from the wall of the hoist shaft; at least one pin being provided for each stop level. The pins extend into the path of the arms of the a cross, fixed to one end of a shaft journaled in a box which is attached to the outside wall of the elevator car and cause the cross and shaft to rotate a quarter turn each time one of the arms of the cross engages one of the pins. The other end of the shaft carries a pinion gear which engages a movable rack connected to a linearly movable slide mounted on the elevator car. One end of the slide ends in a stairstep-like configuration, each step serving to actuate one microswitch in a transverse row of microswitches as the slide moves. The slide is advanced one step, corresponding to one story, for each quarter of a complete revolution by the cross when the elevator car is traveling through the hoist shaft. Thus, when each floor level is reached, the corresponding microswitch will be closed by the slide to transmit a signal to the elevator machinery.

The present invention is a system for indicating stop levels for an 
elevator. 
Story selectors for elevators usually indicate the position of the elevator 
car in the hoist shaft by means of a counting apparatus, preferably 
located in the elevator car, which is advanced or retreated in pace with 
the story or stop levels passed by the elevator car. The count of the 
counting apparatus indicates the story at which the elevator car is at the 
moment. In elevators of the rack-and-pinion type the counting apparatus is 
advanced by a gear wheel engaging the rack. The more stories and/or the 
greater the height of the elevator, the more complicated such a counting 
apparatus will become so that, for a great number of stories or a 
considerable elevator height, it will be difficult to produce a counting 
apparatus operating with the accuracy desired. The gear wheel, having a 
diameter restricted by spatial considerations, basically has to complete 
one revolution during the travel of the elevator car from the lowest to 
the highest story. This means, obviously, an angular or peripherical 
distance on the wheel for each stop level, which is decreased for an 
increased elevator height and, thus, a correspondingly reduced accuracy in 
the stop location of the elevator car. This disadvantage--as well as 
others--is overcome by the invention in that the elevator car has a 
control element including a number of uniformly spaced arms extending into 
the hoist shaft, said control element being rigidly mounted on a 
horizontal center shaft which is journally mounted on the elevator car and 
being arranged, when rotating, to advance a member movably mounted on the 
elevator car for a consecutive operation of a set of switches, and that 
vertically aligned projections are provided in the hoist shaft to extend 
into the rotary path of the arms of the control element, at least one 
projection being provided for each stop level preferably two projections 
are provided for each stop location--the lower projection for the 
ascending movement of the elevator and the higher projection for the 
descending movement of the elevator--so that, when the elevator car is 
moving in the shaft, the control element is actuated by each projection to 
be advanced one arm pitch, i.e., an angle corresponding to the angle 
defined by adjacent arms, and, in its turn, displace said member so as to 
consecutively operate the switches for indicating the stop level at which 
the elevator car is located. By "indicating" is to be understood, in this 
connection, an indication of the location of the elevator car on one hand, 
and an indication to the drive machinery for the elevator on the other 
hand.

In FIGS. 1 and 2 there is shown an elongated box 1 which, normally in a 
standing position, is fixed externally to the wall of the elevator car 
(compare also with FIG. 7 where the elevator car K is shown in the hoist 
shaft S). An indicator panel 2 is provided internally of the wall of the 
elevator car opposite to the box 1 and presents, in the example shown, 
sixteen markings numbered 1 through 16 corresponding to the number of 
stories present. A lamp indicator of the conventional type may be used. 
Parallel bars 3 are, for the standing position of the box, mounted in 
pairs horizontally in the upper half of the box for carrying microswitches 
4, one for each of the bottom and top stories and two for each 
intermediate story. The microswitches are distributed in four parallel 
rows, each row but one having eight switches, and sequentially numbered 1 
through 30, i.e. corresponding to the sixteen stories assumed 
(1+2.times.14 +1). 
From the box 1 there extends, according to FIG. 2, into the hoist shaft a 
pulsator, generally designated with 5, the components of which are shown 
in FIGS. 3 and 4. In these Figures there is shown a member 6 in the shape 
of a cross having four arms 7 and being fixed to a center shaft 8 mounted 
for rotation in bearing brackets 9 which, by means of screws 10 and nuts 
11, fix a snap-detent housing 12 to the box wall (see FIG. 2). 
In the center of the housing 12 the shaft 8 supports a cam disk 13. The cam 
disk has the general shape of a cushion having concave sides, the corners 
of the cushion slidably engaging the inside of a circular recess 14 in the 
housing into which recess two diametrically opposite bores open. In each 
of the bores a sleeve 15 is slidably mounted the inner end of which 
supports a roll 16. By means of a compression spring 17 the roll is urged 
against the cam disk 13 and forces it to a stable position with the roll 
resting in the lowest point in a concave portion of the cam disk, as shown 
in the Figure. It is apparent from the Figure that the cross 6, when 
rotated through an angle exceeding 45.degree. snaps into a distinct 
position, exactly corresponding to a quarter of a complete revolution. 
The shaft 8 of the cross 6 carries at its end projecting into the box 1 a 
pinion gear 18. This pinion, as shown in FIG. 2, engages a rack portion 19 
of a slide 21 mounted on rolls 20. The slide is shown separately in FIGS. 
5 and 6. In these Figures the rolls 20 as well as the rack portion 19 are 
again to be found. One end of the slide is, in the example described, 
stepwise reduced in eight steps 22 corresponding to the previously 
mentioned eight microswitches 4 in each row, as shown in FIG. 1. The 
coordination of slide steps and microswitches is indicated by steps 22 in 
dashed lines in FIG. 1 where the highest step faces the switch No. 1 and 
the lowest faces the switch No. 8 in the first (lowest) row. 
Finally, there project, as shown in FIG. 7, from a wall in the hoist shaft 
S, vertically aligned pins T, one--or preferably (as shown) two adjacent 
pins--for each step level P.sub.n, P.sub.n+1 and so on having their ends 
extending into the rotary path of the cross 6 of the pulsator 5. 
The microswitches are connected through a relay system to the drive 
machinery of the elevator for controlling the travel of the elevator car. 
This system will not be described in this connection as it may be a purely 
conventional one. However, the arrangement of the invention including 
studs in the hoist shaft for driving a pulsator for operation of 
microswitches may replace prior art systems designed for the same purpose. 
For example, the system of the invention may replace a prior art system 
based on permanent magnets positioned at different levels in the shaft and 
laterally displaced with respect to each other, each of said magnets being 
vertically aligned with a different magnetic switch in the elevator car 
for operation of the same. Thus, the number of selectively operative 
permanent magnets--and consequently the number of stories traversed by the 
elevator--necessarily is restricted by the width of the shaft. With the 
invention such geometrical restriction is overcome, as is clear from the 
following description of the operation. The greatest advantage, however, 
is that the height of the elevator--or number of stories traversed by the 
elevator--is of no importance to the accuracy of halting at the stop 
levels. 
It is assumed that the elevator car K in FIG. 7 is ascending in the hoist 
shaft S and has arrived to the position indicated by full lines, i.e. with 
the bottom of the elevator car approaching the destination stop level 
P.sub.n, say P.sub.6. During the travel five stop levels have been passed, 
and for each stop level the shaft pins associated with that level have 
rotated the cross 6 of the pulsator 5 a quarter of a complete revolution, 
each time advancing the stepped slide one step. This means that the slide 
already has consecutively closed the microswitches Nos.1-8 in the first or 
lowest row (the right one in FIG. 1) and then, by its highest step, has 
started to close the switch No. 9 in the second row. Up to this point the 
stop level indicators for floors Nos. 1-5 have been passed and the 
elevator machinery is still driving the elevator car upwards. In the 
elevator car position shown the cross is just about to rotate one more 
quarter of a revolution as a result of the engagement of one of the cross 
arms with the lower of the pins T so that the second highest step of the 
slide closes the switch No. 10, at which time the braking of the elevator 
car may be triggered (in the same manner as utilized in prior art systems 
whereby the elevator car will be able to stop exactly at the stop location 
for the sixth floor P.sub.6. The conditions will be reversed when the 
elevator car is descending and approaches the stop level P.sub.n, again 
level P.sub.6, from above (dash-and-dot-line position). The slide is 
retracted stepwise from the switches allowing these to resiliently return 
to their original opened position. The marking for the stop level 
P.sub.n+1, i.e. the 7th floor, has just been passed, and the braking of 
the cage can be started after the upper one of the pair of pins T has 
rotated the cross of the pulsator and the switch No. 11 has opened. 
From the foregoing description it is apparent that the system of the 
invention can be used with an arbitrarily great number of stories while 
maintaining the same accuracy in the indication of each story and, 
consequently, also securing accuracy in the movement of the elevator car. 
The number of stories is only limited by the size of the box. 
Many different modifications of the embodiment shown and described are 
within the scope of the invention, especially as regards the form of the 
pulsator and the slide as well as the positioning of the switches. Thus, 
the cross-shaped member shown could be replaced by a rotary element having 
fewer, as well as more, than four arms in combination with a corresponding 
modification of the snap-detent mechanism for forcing said element to a 
well-defined position after it has been rotated past an unstable point. 
The step or "staircase" configuration of the end of the slide could 
basically be replaced by an inclined straight line, even if steps are to 
be preferred on account of the more distinct actuation of the switches. 
Alternatively, the slide could be formed with its end line perpendicular 
to the longitudinal axis of the slide, and the microswitches could be 
consecutively displaced in the direction of the axis of the slide. The 
only essential criterion is that an angle always be formed between the 
general transverse extension of the slide end and the line of 
microswitches. These switches may, moreover, be replaced by other 
circuit-making and -breaking means for mechanical, magnetical or 
electrical actuation, for example, by gap-contacts which can be bridged by 
the slide.