GUIDE DEVICE FOR HYDRAULIC ELEVATOR

Abstract: Movement of the cab 12 of an elevator is guided along hoistway guide rails 14 by a guide device that shares loads imposed by the cab between guide shoes 3 and guide rollers 2. There is one guide shoe/guide roller sub-assembly mounted above and below the cab for engagement with each guide rail. In each sub-assembly, the guide shoe 3 and guide roller 2 are mounted on opposite ends of a pivoting arm 5. The guide rollers 2 engage opposite sides of the guide rail blade. The geometry of the system is such that loads are proportionally shared by the guide shoes 3 and guide rollers 2.

Description: The present invention broadly relates to an elevator and, more particularly, to a cantilevered hydraulic elevator in which the cab is suspended at a position deviated from the centroid or centre of gravity thereof so as to be moved up and down along vertical guide rails. The cab of a cantilevered hydraulic elevator is suspended for vertical movement at a point which is horizontally offset from the centroid thereof so that the cab oscillates up and down each time it starts and stops and each time a passenger walks into and out of the cab. In order to eliminate such a vertical oscillation, the elevator is usually equipped with a guide shoe and/or a guide roller. The guide shoe grips the guide rail so as to effectively suppress vertical oscillation of the cab, while the guide roller is effective in suppressing the oscillation in the direction perpendicular to the guide rails. When both a guide shoe and a guide roller are used, it is necessary that the guide roller and the guide shoe suitably share proper proportions of the load. To meet such a demand, a pressing mechanism has been proposed which incorporates spring means designated to enable the guide roller and the guide shoe to share proper portions of the load. Such a mechanism, however, requires a complicated construction and inevitably suffers from age-induced change in the load sharing. It is therefore an object of this invention to provide an improved guide assembly for use in a cantilevered elevator to guide the cab on guide rails in the hoistway. The present invention seeks to provide a guide device for a hydraulic elevator which is simple in construction and which does not suffer substantial age-induced change in the load sharing. Elevator guide devices are known from US 3425516, US 3554327 and CH 662106. In particular, US 3425516 discloses an elevator having a guide device for guiding movement of the elevator cab along guide rails lying in a vertical plane in the elevator hoistway, including a guide device of different structure from the present invention. According to the present invention there is provided a cantilevered hydraulic elevator having a guide device for guiding movement of the elevator cab along two guide rails lying in a vertical plane in the elevator hoistway, characterised by said device comprising: a. a first guide sub-assembly mounted above the cab, said first sub-assembly comprising a first stand fixed with respect to the cab; a first arm mounted on said stand, said first arm being pivotable about an axis which coincides with the vertical plane of the guide rails; a first guide shoe rotatably mounted on one pivoting end of said first arm, said first guide shoe embracing the blade portion of one guide rail; and a first guide roller mounted on an opposite pivoting end of said first arm, said first guide roller engaging one side surface of said guide rail blade portion; and b. a second guide sub-assembly mounted below the cab, said second sub-assembly comprising a second stand fixed with respect to the cab; a second arm mounted on said stand, said second arm being pivotable about an axis which coincides with said vertical plane of the guide rails; a second guide shoe rotatably mounted on one pivoting end of said second arm, said second guide shoe embracing the blade portion of said one guide rail; and a second guide roller mounted on an opposite pivoting end of said second arm, said second guide roller engaging the side surface of said guide rail blade portion opposite to said one side surface thereof. The invention also extends to a guide sub-assembly for a cantilevered hydraulic elevator, comprising a stand fixable to the elevator cab, an arm (5) mounted intermediate its ends to said stand for rotation about an axis which, in use, is horizontal and lies in the vertical plane of the elevator cab guide rails, a guide shoe for embracing a guide rail, the guide shoe being mounted on said arm to one side of said axis of rotation and being rotatable about a parallel axis of rotation, and a guide roller mounted on said arm to the other side of said axis of rotation of said arm to engage, in use, one side of said guide rail and run thereon with vertical movement of said cab. The guide shoe and guide roller may be secured to each arm at such predetermined distances from the fulcrum of the arm that the guide shoe and the guide roller share predetermined defined portions of the cab load. These guide sub-assemblies are mounted on the top and bottom of the cab respectively with the guide shoes embracing the guide rail, and the guide rollers engaging opposite sides of the guide rail. The aforesaid and other objects and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention when taken in conjunction with the accompanying drawings, in which: FIGURE 1 is a somewhat schematic side elevational view of an elevator which is equipped with a guide assembly according to this invention; FIGURE 2 is a sectional view of one of the guide assembly sub-assemblies; and FIGURE 3 is a horizontal sectional view of the rail showing how the guide shoe engages the rail. Referring to the drawings, movement of the cab 12 of an elevator is guided along hoistway guide rails 14 by a guide device that shares loads imposed by the cab between guide shoes 3 and guide rollers 2. There is one guide shoe/guide roller sub-assembly mounted above and below the cab for engagement with each guide rail. In each sub-assembly, the guide shoe 3 and guide roller 2 are mounted on opposite ends of a pivoting arm 5. The guide rollers 2 engage opposite sides of the guide rail blade. Each sub-assembly has a stand 1 which is fixed to the top or bottom plate of the cab. Each stand 1 carries a guide shoe shaft 4, an arm shaft 6, a guide roller shaft 7, a spacer 8, thrust washers 9, and bearings 10. Numeral 13 denotes a main rope. Numeral 11 denotes an inner surface of the guide shoe 3. The guide shoe 3 and the guide roller 2 are secured to the arm 5 at such distances from the axis of the arm shaft 6 of the arm 5 that the guide shoe 3 and the guide roller 2 share portions of load in accordance with the following formulae: P₁ = (W₁ + W₂) L1₁/2H1 P₂ = (W₁ + W₂) L1₂/2H1 where, P₁ represents the portion of the load shared by the guide shoe 3; P₂ represents the portion of the load shared by the guide roller 2; 1 represents the vertical distance between the centre of the guide roller shaft 7 and the centre of the guide shoe shaft 4; 1₁ represents the distance between the axis of the arm shaft 6 and the centre of the guide shoe shaft 4; 1₂ represents the vertical distance between the fulcrum of the arm shaft 6 and the centre of the guide roller shaft 7; L represents the horizontal distance between the centroid of the cab 12 and the suspension centre of the cab 12; H is the distance between the axes of the two arm shafts 6; W₁ represents the weight of the cab 12; and W₂ represents the load on the cab 12. It will be noted that the upper and lower guide rollers 2 contact opposite sides of the blade of the guide rail 14 respectively. The formulae are derived from the following conditions. P₁ + P₂ = (W₁ + W₂) L/2H P₁/1₁ = P₂/1₂ The invention provides a guide device for a hydraulic elevator which is simple in construction and which can realize a proper load sharing without any age-induced change. Since many changes and variations of the disclosed embodiment of the invention may be made without departing from the invention concept, it is not intended to limit the invention otherwise than as required by the appended claims.

Claims: 1. A cantilevered hydraulic elevator having a guide device for guiding movement of the elevator cab (12) along two guide rails (14) lying in a vertical plane in the elevator hoistway, characterised by said device comprising: a. a first guide sub-assembly mounted above the cab, said first sub-assembly comprising a first stand (1) fixed with respect to the cab; a first arm (5) mounted on said stand, said first arm being pivotable about an axis which coincides with the vertical plane of the guide rails; a first guide shoe (3) rotatably mounted on one pivoting end of said first arm, said first guide shoe embracing the blade portion of one guide rail; and a first guide roller (2) mounted on an opposite pivoting end of said first arm, said first guide roller engaging one side surface of said guide rail blade portion; and b. a second guide sub-assembly mounted below the cab, said second sub-assembly comprising a second stand (1) fixed with respect to the cab; a second arm (5) mounted on said stand, said second arm being pivotable about an axis which coincides with said vertical plane of the guide rails; a second guide shoe (3) rotatably mounted on one pivoting end of said second arm, said second guide shoe embracing the blade portion of said one guide rail; and a second guide roller (2) mounted on an opposite pivoting end of said second arm, said second guide roller engaging the side surface of said guide rail blade portion opposite to said one side surface thereof. 2. An elevator according to Claim 1, wherein in each of said sub-assemblies said guide shoes and said guide rollers are mounted to said arms at such distances from the axes of said arms that said guide shoes and said guide rollers share portions of load from the cab in accordance with the following formulae: P₁ = (W₁ + W₂) L1₁/2H1 P₂ = (W₁ + W₂) L1₂/2H1 where for each sub-assembly, P₁ represents the portion of the load shared by said guide shoe, P₂ represents the portion of the load shared by the guide roller, 1 represents the vertical distance between the centre of the guide roller and the centre of the guide shoe, 1₁ represents the distance between said axis of said arm and the centre of said guide shoe, 1₂ represents the vertical distance between said axis of said arm and the centre of said guide roller, L represents the horizontal distance between the centroid of the cab and the suspension centre of said cab, H is the distance between the axes of the first and second arms, W₁ represents the weight of the cab, and W₂ represents the load on the cab. 3. A guide sub-assembly for a cantilevered hydraulic elevator, comprising a stand (1) fixable to the elevator cab, an arm (5) mounted intermediate its ends to said stand for rotation about an axis which, in use, is horizontal and lies in the vertical plane of the elevator cab guide rails, a guide shoe (3) for embracing a guide rail, the guide shoe being mounted on said arm to one side of said axis of rotation and being rotatable about a parallel axis of rotation, and a guide roller (2) mounted on said arm to the other side of said axis of rotation of said arm to engage, in use, one side of said guide rail and run thereon with vertical movement of said cab.

Inventors: NAKANISHI, YOSHINORI NIIDA 445-489
Applicants: OTIS ELEVATOR COMPANY
Application year: 1989
Main classification: B66B7
IPC codes: B66B9, B66B7