US1997681A - Cable equalizer - Google Patents

Description

April 16, 1935. J. DUNLOP CABLE EQUALI ZER Filed Jan. 14, 1933 2 Sheets-Sheet 1 INVENTOR Patented Apr. 16, 1935 UNITED STATES PATENT OFFICE CABLE EQUALIZER Application January 14, 1933, Serial No. 651,685

9 Claims.

My invention relates to cable equalizers and more particularly to equalizers for the hoisting cables employed in operating elevator cars in their hatchways.

In elevators in which the car is suspended by a plurality of hoisting cables or ropes, considerable difficulty has been experienced in maintaining the cables in such condition that each one carries an equal proportion of the load provided by the car and its counterweight. causes of this difliculty are the tendency of the cables to stretch unequally under load, the differential in diameter of the cable grooves in the hoisting drum arising from mechanical imperfections or wear, and differences in the diameters of the cables themselves. Although: elevator cables are very carefully constructed at present, it is still impossible to so make them that they will not stretch in service or have some slight difference in diameter. Furthermore, as the use of the cables continues, their diameter may change by reason of wear. The grooves in the cable drum are usually almost perfectly constructed, but they also tend to wear unevenly in long continued service.

One of the objects of my invention is to provide an equalizer for so connecting the hoisting cables to the car and its counterweight that each cable will carry an equal share of the total load and to automatically maintain such equal distribution of the load, even though the cables change in length by reason of stretching, or the diameters of, the cables or the cable grooves change by reason oi wear.

Another object is to provide an equalizing means that willeffect an even distribution of the load on the cables under all conditions without moving the cables out of their axial alignment.

A further object is to provide an equalizer of high mechanical eiiiciency in which the cable drawbars shall have comparatively short strokes, and in which the drop of the car to the stops provided on the equalizer, in the event of a cable breaking, shall be as short as possible.

A still further object is to provide an equalizer which will permit such an arrangement of the hoisting cables that they become, in effect, ap- 0 proximately one continuous cable laced from the car and over the hoisting drum to the counterweight.

It 'is also an object ,ofmy invention to provide an equalizer that is simple and inexpensive to manufacture and maintain in operation, and

The usual which shall not catch and hold dirt or grit in its working parts.

Other objects will, in part, be obvious, and will, in part, appear hereinafter in the following description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a view in perspective of an elevator provided with equalizers constructed in accordance with my invention;

Fig. 2 is a diagrammatic representation of the cables and equalizers laid out in a plane;

. Fig. 3 is a view representing a vertical section of one side of one of the equalizing units embodied in Fig. l; i

Fig. 4 is a sectionalview taken on the line IV-IV of Fig. '3;

Fig. 5 is a top plan view of the equalizing unit shown in Fig. 3, with the top mounting plate removed to permit a view of the interior of the device; and

Fig. 6 is a diagrammatic representation of the system of roping the hoisting cables employed for the elevator illustrated in Fig. 1.

Referring more particularly to Fig. 1, I have illustrated an elevator car C as suspended by a plurality of hoisting cables Ca that pass over a hoisting drum D to a counterweight Cw, the drum being provided with suitable grooves G for the cables. The car may be called a service load and the counterweight a counter-balancing load.

The car C comprises a cab l disposed in a sling comprising a pair of upright members 2 and 3 that are connected at their upper ends bya pair of channel members 4. The hoisting cables Ca are connected to the car C through a plurality of 35 drawbars or thimble rods 5 (see Fig. 2) the cables being attached to the upper ends of the drawbars in the usual manner-- s In order that the load of the car upon the cables may be evenly distributed among the cables, the lower ends of the drawbars 5 are connected to the car by means of my improved equalizing means comprising a plurality of equalizing units I mounted on the underside of an adjusting plate 8, which, in turn, is secured to the underside of a 45 mounting plate 9 attached to the underside of the channel members 4. r

The counterweight Cw comprises aplurality of weights I!) mounted in a counterweight sling H constructed in the usual manner. The cables Ca are connected to the counterweight through a plurality of drawbars l2 that are similar to the drawbars 5 connecting the cables to the car.

In order that the load of the counterweight Cw may be equally distributed among the hoisting cables, and also in order that the hoisting cables may automatically adjust themselves to any change in their lengths and to differences in their diameter and differences in the diameters of the hoisting drum grooves, the lower ends of the drawbars |2 are connected to the counterweight sling II by an equalizing means I4. The equaliz ing means l4 comprises a pair of equalizing units l5 attached to the underside of an adjusting plate l5 mounted on the underside of the top portion of the counterweight sling.

Referring now to Figs. 3, 4 and 5, each of the equalizing units 1 attached to the car comprise a hollow rectangular housing 20, in which a pair of equalizing bars 2| and 22 are disposed to slide upwardly and downwardly. The cooperating sides of the housing and the bars are constructed in planes parallel to the longitudinal axes of the bars for the purpose of preventing lateral movement of the bars while permitting their longitudinal movement. The adjacent inner faces 24 and 25 of the bars are beveled upwardly for cooperative engagement with an equalizing roller or equalizing member 26 so disposed as to prevent simultaneous upward movement of the bars.

The equalizingroller 26 is rotatably and movably suspended in its position between the adjacent beveled faces of the bars by a shaft 21 the ends of which are supported in a pair of side straps 2B and 29 which swing from a large shaft 30 set in the side walls of the housing. A wheel 3| is rotatably mounted between the upper ends of the straps 28 and 29 on the shaft 80. The size and position of the wheel 30 are such that its periphery may be engaged by the periphery of the roller 26 and thereby provides an antifriction track upon which the roller may rotate and revolve in accordance with the forces exerted upon it by the beveled faces of the equalizing bars.

In order that the bars 2| and 22 may move easily, a plurality of anti-friction elements comprising a plurality of bearing rollers 33 are disposed between the rear sides of the bars and the cooperating Walls of the housing. The bearing rollers 33 for the bar 2| are mounted in a roller cage 34 by means of a plurality of pins 35. A small projection 36 at the top of the roller cage extends over the top of the bar 2| to prevent the cage and rollers from dropping downwardly when the apparatus is in use. A depression 31 is provided in the upper part of the bar 2| to receive the projection 36 when the bar 2| moves upwardly where it engages the top plate 3. The roller cage for the bar 22 is similar to that just described for the bar 2|.

As shown, the bars 2| and 22 are provided with holes 38, through which the drawbars 5a. and 5b may be inserted and locked by a plurality of nuts 38 for the purpose of connecting the cables to the bars.

In assembling the equalizing units for use in an elevator, it has been found advisable to firmly secure them to the underside of the supporting plate 8, as by means of a welded joint shown at 40 in Fig, 3. The plate 8 is provided with holes 4| through which the upper ends of the drawbars 5 pass and it also acts as a means for limiting the upward movement of the equalizing bars. For instance if the cable attached to one of the bars breaks, the consequent upward movement of the other bar is limited to a predetermined distance such as three inches. 7

In order to retain the parts of the equalizing units in their assembled position while they are being shipped and handled, a pair of bolts 43 and 44 are disposed in the lower tips of the housing 20 in position to extend through the lower portions of the roller cages and into holes 45 and 46 in the bars 2| and 22. The bolts 43 and 44 will hold the parts in their assembled position until they are installed in the elevator and placed in use, but the bolts must be removed before the equalizers are actually placed in operation.

The equalizing units Is for the counterweight are similar to the units for the car and are mounted in the same manner upon the plate l6.

Although the usual system of roping may be employed in connecting the car and the counterweight by the hoisting cables, I prefer to employ the novel roping arrangement shown diagrammatically in Fig. 6.

In this arrangement, the counterweight ends of the outer cables 50 and are dead-end connected to the counterweight; the car ends of the cables 50 and 5| are individually connected to the cooperating bars 2| and 22 of the equalizing unit la; the counterweight ends of the intermediate cables 5| and 52 are individually connected to the cooperating bars 2| and 22 of the equalizing unit |5a; the car ends of the intermediate cables 52 and 53 are individually connected to the cooperating bars 2| and 22 of the equalizing unit 1b; the counterweight ends of the intermediate cables 53 and 54 are individually connected to the cooperating bars 2| and 22 of the equalizing unit I52); and the car ends of the cables 54 and 55 are individually connected to the cooperating bars 2| and 22 of the equalizing unit To.

By connecting the cables through the equalizing units as described, I secure practically a continuous cable that is laced over the hoisting drum from the counterweight to the car, thereby permitting a particularly accurate automatic adjustment of the load in such manner that an equal proportion of it is borne by each cable.

For instance, if the cable attached to the drawbar 5a in the movable bar 2| stretches, or the groove in which it operates becomes deeply worn, the difference in the force exerted upon the roller 26 by the bars 2| and 22 will force that roller to the left (see Fig. 3), whereupon the bar 22 will move upwardly and the bar 2| will move downwardly until the force exerted by them on the roller 28 is equalized and the bars come to a stop, in which position the tension or pull upon the cables attached thereto will be equal.

Inasmuch as the bars 2| and 22 move vertically on the roller bearings and have a rolling engagement with the roller 26 and the controller in turn has a rolling engagement with the wheel 3|, it will be seen that very little friction arises in the mounting of the parts.

Although I have illustrated and described only one embodiment of my invention, it is to be understood that it may be modified in many ways without departing from the spirit and scope of my invention.

I claim as my invention:

1. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, means for connecting the housing to the load, means for individually connecting the bars to the cables, and an equalizing member mounted in the casing in engagement with the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables.

2. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, means for connecting the housing to the load, means for individually connecting the bars to the cables, and a roller mounted in the casing in engagement with the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables.

3. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, means for connecting the housing to the load, a pair of bars slidably disposed in the housing and having adjacent beveled faces, means for individually connecting the bars to the cables, a roller, means for rotatably and movably supporting the roller in the housing in cooperative engagement with the beveled faces of the bars for permitting relative longitudinal movement thereof in accordance with the tension on the cables.

4. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, means for connecting the housing to the load, apair of bars slidably disposed in said housing and having adjacent beveled faces, means for individually connecting the bars to the cables, a wheel, means for rotatably mounting the wheel in the housing, and a roller disposed in engagement with the periphery of the Wheel and the adjacent beveled faces of the bars to control the relative longitudinal movement of the bars in accordance with the tension of the cables.

5. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, means for connecting the housing to the load, means for individually connecting the bars to the cables, a Wheel, means for rotatably supporting the wheel in the housing, and a roller disposed in engagement with the periphery of the wheel and the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables.

6. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a pair of bars having adjacent beveled faces slidably disposed in said housing, the cooperating sides of said housing and said bars being constructed to prevent lateral movement and more than a predetermined longitudinal movement of said bars, means for connecting said bars to a plurality of hoisting cables, a wheel, a shaft for rotatably mounting said wheel in said casing, an equalizing roller, and means for rotatably and movably supporting said roller from said shaft with the periphery of the roller in cooperative engagement with the periphery of the wheel and the adjacent beveled faces of the bars.

7. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, antifriction elements disposed between the cooperating straight sides of the bars and the housing, means for connecting the housing to the load, means for individually connecting the bars to the cables, and an equalizing member mounted in the casing in engagement with the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables.

8. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, a plurality of rollers disposed between the cooperating straight sides of the bars and the housing, cages for the rollers, means providing lost motion connections of the cages with the bars to maintain the rollers in operative position, means for connecting the housing to the load, means for individually connecting the bars to the cables, and an equalizing member mounted in the casing in engagement with the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables.

'9. An equalizer for connecting a plurality of hoisting cables to a load, comprising a housing, a plurality of bars provided with adjacent beveled faces slidably disposed in said housing, said housing and said bars having cooperating straight sides in planes parallel with the longitudinal axes of the bars for preventing lateral movement thereof, means for connecting the bars to the cables, and an equalizing member mounted in the casing in engagement with the beveled faces of the bars for controlling the relative longitudinal movement of the bars in accordance with the tension of the cables, and removable means for holding the bars in fixed relation to each other and to the housing after they are assembled until the equalizer is placed in operation.

JAMES DUNLOP.

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