BACKGROUND
Traction elevators use a plurality of suspension members to drive an elevator car in an upward and downward direction within opposing guide rails. The suspension members can have various forms, including the non-limiting examples of cables and belts. The suspension members can be driven by various devices including the non-limiting example of a sheaved traction machine.
A well-adjusted traction elevator includes suspension members having equal tension therebetween. Equal tension in the suspension members can extend the working life of the suspension members and the associated equipment, such as the drive sheave of the traction machine. It is known that an amount as little as 10% of unequal tension can reduce the lifetime of the set of suspension members by roughly 30%.
It would be advantageous if the respective tensions in the suspension members could be automatically adjusted as the elevator is operated.
SUMMARY
It should be appreciated that this Summary is provided to introduce a selection of concepts in a simplified form, the concepts being further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of this disclosure, nor is it intended to limit the scope of the suspension member equalization system.
The above objects as well as other objects not specifically enumerated are achieved by a suspension member equalization system configured for use with a plurality of suspension members in an elevator system. The suspension member equalization system includes a plurality of cylinder assemblies, each configured to receive a rod extending from a suspension member socket. The suspension member socket is connected to a suspension member. Each of the plurality of cylinder assemblies has a slidable piston. A manifold block is in fluid communication with the plurality of cylinder assemblies. An incompressible fluid is in simultaneous communication with the plurality of cylinder assemblies and the manifold block. An upper swash plate is received within a cavity formed in a lower portion of each of the plurality of cylinder assemblies and in contact with each of the plurality of cylinder assemblies. A lower swash plate is received within an annular recess of each of the upper swash plates in a manner such that the upper swash plate is rotatable relative to the lower swash plate. The pistons within each of the plurality of cylinder assemblies are configured for movement such as to seek an approximately equal pressure, thereby approximating equal tension in each of the plurality of suspension members.
The above objects as well as other objects not specifically enumerated are also achieved by a method of using a suspension member equalization system for equalizing tension in a plurality of elevator suspension members. The method includes the steps of disposing each of a plurality of upper swash plates into each of a plurality of cavities formed within each of a plurality of cylinder assemblies, disposing each of a plurality of lower swash plates into portions of each of the plurality of upper swash plates in a manner such that each of the plurality of upper swash plates and each of the plurality of lower swash plates are rotatable relative to each other, extending each of a plurality of rods through each of the plurality of cylinder assemblies, through each of the plurality of upper swash plates and through each of the plurality of lower swash plates, each of the plurality of rods extending from each of a plurality of suspension member sockets, each of the suspension member sockets connected to each of a plurality of suspension members, each of the plurality of cylinder assemblies having a slidable piston, fluidly connecting a manifold block to each of the plurality of cylinder assemblies with an incompressible fluid, providing tension in the plurality of suspension members and allowing the sliding pistons to seek an approximately equal pressure, thereby approximating equal tension in each of the plurality of suspension members.
Various aspects of the suspension member equalization system will become apparent to those skilled in the art from the following detailed description of the illustrated embodiments, when read in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of portions of an elevator system including a first and second elevator fixture.
FIG. 2 is a side view, in elevation, of a first fixture of the elevator system of FIG. 1 illustrating a plurality of cylinder assemblies.
FIG. 3 is an exploded perspective view of the first fixture of FIG. 2.
FIG. 4 is a side view of a manifold block of the elevator system of FIG. 1 illustrating fluid connection to a cylinder assembly.
FIG. 5A is a front view, in elevation, of the cylinder assembly of FIG. 2.
FIG. 5B is a cross-sectional view, in elevation, of the cylinder assembly of FIG. 2.
FIG. 6 is an enlarged, cross-sectional view of a lower portion of the cylinder assembly of FIG. 2 shown in relation to an upper and lower swash plate.
FIG. 7 is a top perspective view of the upper and lower swash plates of FIG. 6.
FIG. 8 is a bottom perspective view of the upper and lower swash plates of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
The suspension member equalization system for elevators will now be described with occasional reference to the specific embodiments. The suspension member equalization system may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the suspension member equalization system to those skilled in the art.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the suspension member equalization system belongs. The terminology used in the description of the suspension member equalization system herein is for describing particular embodiments only and is not intended to be limiting of the suspension member equalization system. As used in the description of the apparatus and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise indicated, all numbers expressing quantities of dimensions such as length, width, height, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the suspension member equalization system. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the suspension member equalization system are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements.
In accordance with the illustrated embodiments, a suspension member equalization system is provided. Generally, the suspension member equalization system is configured to sense the load incurred by each suspension member. The suspension member equalization system is further configured to adjust the tension in each suspension member to be approximately equal to the tension experienced by the other suspension members. The hydraulic rope equalization system includes cylinder assemblies provided to each suspension member and a common manifold block. The cylinder assemblies and the manifold block are in simultaneous fluid communication with each other. With the suspension members under tension from a load within the elevator car, pistons disposed within the cylinder assemblies are slidable and move to seek an approximately equal pressure, thereby approximating equal tension in each of the plurality of suspension members.
Referring now to the drawings, there is illustrated in FIG. 1 a diagrammatic and simplified view of a traction elevator 10 (hereafter “elevator”). The elevator 10 includes an elevator car 12, configured to move in a substantially vertical direction on opposing car guide rails (not shown for purposes of simplicity). The elevator car 12 and the car guide rails are disposed in an elevator hoistway 14. The hoistway 14 can be defined by hoistway walls or by other structures, assemblies and components, such as the non-limiting example of structural divider beams and the like. The elevator car 12 is supported by a first segment of a plurality of suspension members 16, which are moved with an elevator machine 18. The suspension members 16 may consist of multiple ropes, flat belts or other suitable structures.
Referring again to FIG. 1, a second segment of the one or more suspension members 16 is configured to support a counterweight assembly 20. The counterweight assembly 20 is configured to balance a portion of the weight of the elevator car 12 and the rated capacity of the elevator car 12. The counterweight assembly 20 moves in a substantially vertical direction on opposing counterweight guide rails 22.
Referring again to FIG. 1, the hoistway 14 can be divided vertically into building floors (not shown). The building floors can have entrances (not shown) configured to facilitate ingress into and egress out of the elevator car 12.
Referring again to FIG. 1, a first end 24 of the suspension members 16 can be fixed to a first fixture 26. In a similar manner, a second end 28 of the suspension members 16 can be fixed to a second fixture 30.
While the structures of the first and second fixtures 26, 30 illustrated in FIG. 1 are described in relation to a traction elevator 10 having a 2:1 suspension system, it should be appreciated that the first and second fixtures 26, 30 can be incorporated into traction elevators having other suspension systems, including the non-limiting examples of 1:1, 4:1, 6:1 and underslung suspension systems.
Referring now to FIG. 2, the first fixture 26 is illustrated. The first fixture 26 can be illustrative of the second fixture 30. A plurality of suspension members 16a-16d are illustrated. Each suspension members 16a-16d is attached to a suspension member socket 32a-32d. The suspension member sockets 32a-32d are known in the art. The suspension member sockets 32a-32d include rods 34a-34d having threaded ends 36a-36d. The rods 34a-34d are configured to extend through a mounting plate 38. The mounting plate 38 is designed for minimal deflection and may be fixed to any suitable structural members, including the non-limiting examples of a car or counterweight guide rail, machine beam, hoistway wall, sufficient to support the weight of the car 12. However, in other embodiments, the mounting plate 38 may be eliminated and the suspension member terminations can be attached directly to the other suitable structures.
Referring again to FIG. 2, the first fixture 26 includes a plurality of cylinder assemblies 40a-40d. Each of the cylinder assemblies 40a-40d is axially aligned with the respective rod 34a-34d.
Referring now to FIG. 3, the suspension member 16a, suspension member socket 32a, rod 34a, threaded end 36a and cylinder assembly 40a are illustrated and are representative of the suspension members 16b-16d, suspension member socket 32b-32d, rods 34b-34d, threaded ends 36b-36d and cylinder assemblies 40b-40d. The suspension member 16a, suspension member socket 32a, rod 34a, threaded end 36a are longitudinally aligned along Axis A-A. As will be explained in more detail below, the cylinder assembly 40a is configured to receive the threaded end 36a of the rod 34a such that the threaded end 36a passes therethrough and the cylinder assembly 40a is also axially aligned with Axis A-A.
Referring again to FIG. 3, the cylinder assembly 40a is secured in place between an upper surface 42a of an upper swash plate 60a and a lower surface 46a of an upper washer 48a by a first nut 50a, a lock nut 52a and cotter pin (not shown). The cylinder assembly 40a is configured to exert an axial force on the rod 34a.
Referring again to FIG. 3, a lower swash plate 62a is positioned between the upper swash plate 60a and the mounting plate 38. The cylinder assembly 40a, upper swash plate 60a and lower swash plate 62a each have annular shapes and respective apertures, thereby allowing the rod 34a to pass therethrough.
Referring again to FIG. 3, a portion of the weight of the elevator car 12 and the rated capacity of the elevator car 12 is borne by the suspension member 16a. The portion of the weight of the elevator car 12 and the rated capacity of the elevator car 12 is sensed by the cylinder assembly 40a, which is compressed in proportion to the load.
Referring again to FIG. 3, the cylinder assembly 40a includes a cylinder port 64a. A first end 65a of a first conduit, shown schematically at 66a, is connected to the cylinder port 64a. The cylinder port 64a is configured for one-way fluid communication from the conduit 66a into an internal cavity 76a. In the illustrated embodiment, the cylinder port 64a has the form of a ball valve. However, in other embodiments, the cylinder port 64a can have other forms sufficient for one-way fluid communication from the conduit 66a into an internal cavity 76a. The first conduit 66a is configured for passage of a fluid therewithin.
Referring now to FIG. 4, a manifold block 68 is illustrated. The manifold block 68 includes a plurality of outer walls configured to define a manifold cavity 70 therewithin. The manifold block 68 includes a first manifold port 72a, a second manifold port 72b, a third manifold port 72c and a fourth manifold port 72d. A second end 67a of the first conduit 66a is connected to the first manifold port 72a in a manner such that the first conduit 66a is in fluid communication with the manifold cavity 70.
Referring again to FIG. 4, a second conduit 66b extends from the cylinder port 64b of the cylinder assembly 40b to the second manifold port 72b, a third conduit 66c extends from the cylinder port 64c of the cylinder assembly 40c to the third manifold port 72c and a fourth conduit 66d extends from the cylinder port 64d of the cylinder assembly 40d to the fourth manifold port 72d. The ports 64a-64d, 72a-72d and conduits 66a-66d are configured such as to allow simultaneous fluid communication between the cylinder assemblies 40a-40d and the manifold cavity 70.
Referring again to FIG. 4, a connector port 74 is attached to the manifold block 68 and configured to facilitate fluid communication between the manifold cavity 70 and an outside source (not shown). As will be explained in more detail below, the connector port 74 is used to supply an incompressible fluid to the manifold block 68, conduits 66a-66d and the cylinder assemblies 40a-40d.
Referring now to FIGS. 5A and 5B, the cylinder assembly 40a is illustrated. The cylinder assembly 40a is in contact with the upper swash plate 60a and the upper swash plate 60a is seated against the lower swash plate 62a. The cylinder assembly 40a includes a housing 75a configured to define the internal cavity 76a. A piston 78a is mounted for slidable axial movement within the internal cavity 76a. The housing 75a is configured to support the cylinder port 64a and an internal passage 80a providing fluid communication between the cylinder port 64 and the internal cavity 76a. As will be explained in more detail below, the internal cavity 76a is configured to receive fluids from the internal passage 80a.
Referring now to FIG. 5B, the housing 75a has a circular cross-sectional shape and a diameter D. The diameter D is configured such that the cylinder assemblies 40a-40d can fit between the suspension member sockets 32a-32d without interference between adjacent suspension member sockets 32a-32d. In the illustrated embodiment, the diameter D is in a range of from about 2.0 inches (5.08 cm) to about 4.0 inches (10.15 cm). However, in other embodiments, the housing 75a can have other cross-sectional shapes and the diameter D can be less than about 2.0 inches (5.08 cm) or more than about 4.0 inches (10.15 cm), sufficient that the cylinder assemblies 40a-40d can fit between the suspension member sockets 32a-32d without interference between adjacent suspension member sockets 32a-32d.
Referring now to FIGS. 2, 4 and 5B, in operation, a conduit 66a-66d is connected to each of the cylinder assemblies 40a-40d and the manifold ports 72a-72d in a manner such as to allow fluid communication between the cylinder assemblies 40a-40d and the manifold cavity 70. The connector port 74 is also attached to the manifold block 68. In a next step, the connector port 74 is connected to an outside source of incompressible fluid and the incompressible fluid is supplied to the manifold cavity 70, conduits 66a-66d and to the internal cavities 76a-76d of the cylinder assemblies 40a-40d in a manner such as to fill the manifold cavity 70, conduits 66a-66d and to the internal cavities 76a-76d. In the illustrated embodiment, the incompressible fluid is hydraulic fluid. However, in other embodiments, the incompressible fluid can be other fluids. In an optional next step, the system comprising the internal cavities 76a-76d of the cylinder assemblies 40a-40d, conduits 66a-66d and the manifold cavity 70 of the manifold block 68 can be “bled” to remove air trapped with the incompressible fluid.
Referring again to FIGS. 2, 4 and 5B, since all of the incompressible fluid-containing structures, namely the internal cavities 76a-76d of the cylinder assemblies 40a-40d, conduits 66a-66d and the manifold cavity 70 of the manifold block 68 are simultaneous in fluid communication, the pistons 78a-78d within each of the cylinder assemblies 40a-40d will seek an approximately equal pressure and approximate equal tension in each of the suspension members 16a-16d. The equaling of the pressures within the cylinder assemblies 40a-40d and equalization of the tension in each of the suspension members 16a-16d can result in the pistons 78a-78d extending in uneven distances beyond the housings 75a-75d, as is clearly shown in FIG. 2. Without being held to the theory, it is believed the oil-containing structures, namely the internal cavities 76a-76d of the cylinder assemblies 40a-40d, conduits 66a-66d and the manifold cavity 70 of the manifold block 68 operate on the principle of “communicating vessels”, thereby allowing the tension in the suspension members 16a-16d to equalize at any time and not just during non-use of the elevator. The first nuts 50a can be tighten to maintain the pistons 78a in their relative positions.
Referring now to FIGS. 6-8, a lower portion 82a of the cylinder assembly 40a is illustrated along with the upper swash plate 60a and lower swash plate 62a. The cylinder assembly 40a includes an internal circumferential wall 84a and a partition 86a. The internal circumferential wall 84a and the partition 86a cooperate to form a cavity 88a. A plurality of spaced-apart projections 90a extend from the partition 86a of the cylinder assembly 40a. The projections 90a extend in a direction toward the upper swash plate 60a. In the illustrated embodiment, a quantity of three (3) projections 90a are spaced-apart on a consistent radius by equal 120° angles. The consistent radius of the equally spaced-apart projections 90a is configured to define a location for the introduction of force into the cylinder assembly 40a. That is, the cylinder assembly 40a receives the compressive force at defined locations of the partition 86a. Without being held to the theory, it is believed the defined location of the introduction of force into the cylinder assembly 40a contributes to the reliable and repeatable operation of the cylinder assembly 40a. However, in other embodiments, more or less than three (3) projections 90a can be used and the projections 90a can be spaced apart by other angles sufficient to define a location for the introduction of force into the cylinder assembly 40a.
Referring again to FIGS. 6-8, the upper swash plate 60a includes an annular race 94a located at an upper surface 96a of the upper swash plate 60a. With the upper swash plate 60a in a seated arrangement within the cavity 88a of the cylinder assembly 40a, the upper surface 96a of the upper swash plate 60a is seated against the partition 86a of the cylinder assembly 40a and the plurality of projections 90a extending from the partition 86a of the cylinder assembly 40a are received by the annular race 94a in the upper swash plate 60a. In this manner, the upper swash plate 60a is radially centered about the cylinder assembly 40a. When seated in the race 94a, the plurality of projections 90a prevent radial sliding of the cylinder assembly 40a relative to the upper swash plate 60a. Without being held to the theory, it is believed the structure of the seated projections 90a within the race 94a contributes to the location of the defined force introduction of the cylinder assembly 40a, which thereby contributes to the accurate, reliable and repeatable operation of the cylinder assembly 40a.
Referring again to FIGS. 6-8, each of the projections 90a has the form of cubes or squares. However, in other embodiments, the projections 90a can have other forms, such as the non-limiting example of a circular structure, sufficient to be received in the race 94a of the upper swash plate 60a and contribute to the location of the defined force introduction of the cylinder assembly 40a. It is also within the contemplation of the suspension member equalization system that the projections 90a can have differing shapes relative to each other.
Referring again to FIGS. 6-8, the upper swash plate 60a includes an annular recess 97a configured to receive a mating annular projection 98a extending from the lower swash plate 62a. With the upper swash plate 60a and the lower swash plate in a nested position, the annular projection 98a is in sliding contact with the annular recess 97a of the upper swash plate 60a. The recess 97a of the upper swash plate 60a and the projection 98a are configured for several functions. First, the recess 97a of the upper swash plate 60a and the projection 98a are configured such that upper swash plate 60a and the lower swash plate 62a can rotate relative to each other in a manner such as to compensate for misalignment of the mounting plate 38 and the rod 34a extending upward through the mounting plate 38. Second, since the recess 97a of the upper swash plate 60a and the projection 98a are configured to rotate relative to each other, the upper swash plate 60a and the lower swash plate 62a cooperate with each other to contribute to the location of the defined force introduction of the cylinder assembly 40a.
Referring again to FIGS. 6-8, the annular recess 97a has the form of a hollow socket and the annular projection 98a has the form of a hollow dome. However, in other embodiments, the annular recess 97a and the annular projection 98a can have other mating forms sufficient for the functions described herein.
Referring again to FIG. 5B, in a nested arrangement, the swash plates 60a, 62a cooperate with the lower portion 82a of the cylinder assembly 40a to provide several unexpected benefits. First, the nested swash plates 60a, 62a align the cylinder assembly 40a such as to be substantially parallel to the rod 34a (shown in phantom for purposes of clarity), even in the circumstance that the rod 34a is arranged at an inclined orientation relative to the mounting plate 38. Without be held to the theory, it is believed that if the swash plates 60a, 62a did not align the cylinder assembly 40a such as to be substantially parallel the rod 34a, then a portion of the tension in the suspension member would act orthogonally on the cylinder assembly 40a, thereby resulting in destruction of the cylinder assembly 40a or the need to use a cylinder assembly 40a having a much larger diameter D. Second, the nested swash plates 60a, 62a provide a defined force introduction location into the cylinder assembly 40a. That is, the cylinder assembly 40a receives the compressive force of the upper swash plate 60a at the defined location of the partition 86a. Without being held to the theory, it is believed the defined force introduction location provides several benefits. First, the defined force introduction location contributes to the reliable and repeatable operation of the cylinder assembly 40a. Second, the defined force introduction location allows the cylinder assembly 40a to be small in diameter, thereby allowing the cylinder assemblies 40a-40d to be permanently mounted in the installation. Finally, the tension in the suspension members 16a-16d equalizes at all times and not just during non-use of the elevator.
The principle and mode of operation of the suspension member equalization system for elevators have been described in certain embodiments. However, it should be noted that the suspension member equalization system for elevators may be practiced otherwise than as specifically illustrated and described without departing from its scope.
Patent Application
20200095093
