FR2816300A1 - Safety stop for lift cab using non-metallic rails has roller actuated wedge to engage rail when speed is excessive - Google Patents

Abstract

The safety stop (16) for a lift cab using non-metallic rails (14) has a friction surface (24) mounted on a wedge (20) which is positioned adjacent to a horizontal positioning roller (30). During activation of the wedge, during an excessive speed condition, the rollers press the friction surface of the wedge into contact with the guide rail. The wedge can have a wear resistant surface (22) engaged by the rollers.

Description

<Desc / Clms Page number 1>

SAFETY DEVICE OF AN ELEVATOR CAB WITH RAILS
NON METALLIC
The present invention relates to the elevator industry and passenger transport devices. More specifically, the invention relates to safety devices for an elevator car which stop the movement of an elevator car undergoing an excessive speed condition.

 Typically, elevator systems have steel guide rails to guide elevator cars into elevator shafts. Such rails are reliable and safe and are often used in industry. The safety devices in service with such rails are numerous and varied, all of which work well with regard to the expected goals.

 In an extremely tight market due to the size of the construction and the cost per square meter, as well as the speed of installation and construction of the various elements, alternative non-metallic guide rail structures have been considered, such as concrete guide rail structures. When non-metallic guide rail structures are used, other safety systems are required. Currently, there is no safety system compatible with non-metallic guide rails. Accordingly, there is a need in the art for a safety system capable of arresting the movement of an elevator car which has been subjected to an excessive speed condition on a system of non-metallic guide rails.

 The invention provides a solution to the aforementioned need for a security system intended for an elevator car mounted on a system of non-metallic guide rails. The system of the invention recognizes the fragility of non-metallic guide rail systems, especially concrete, and provides sufficient surface in connection with a high friction contact surface in such a way that a stopping force sufficient can be produced while maintaining the pressure below a level at which concrete damage could occur.

 The device comprises one or more corners of a hard material with a material with a high friction surface mounted on a surface of the corner which comes into contact with the surface of the guide rail, in the case

<Desc / Clms Page number 2>

 where an excessive speed condition occurs.

 It is also envisaged according to the invention to provide the whole corner or a part of the corner devoid of high friction material, in such a way that only a bearing surface should be mounted on the corner and no additional friction material should be mounted on the corner. The wedge is pushed into contact with the guide rail by a component of the slide or roller type arranged at a certain angle relative to the direction of movement of the elevator car on which it is mounted.

 The wedge is preferably connected to a regulator or the like so that at a speed higher than a predetermined maximum speed it cannot move at the same time as the elevator car.

 It should be noted that the electromagnet-type control member can be replaced by an electronic control member, if desired. In the event that an excessive speed condition occurs, the wedge is pulled against the slide or roller type component which gives it a horizontal force and pushes the wedge into contact with the guide rail and at this time braking action is obtained.

 Preferably, the corners will be arranged in pairs on the opposite surfaces of each guide rail. A multitude of corner pairs reduces the area required for each individual corner and can make the system more manageable.

 In another embodiment of the invention, a safety device will brake a falling or descending elevator car.

The invention is illustrated below with the aid of exemplary embodiments described with reference to the appended drawings, in which:
Figure 1 is a perspective view with cutaway of an elevator shaft having an elevator car mounted on concrete guide rails and illustrating the positions of the components of the safety device of the invention;
FIG. 2A is a schematic view of a safety device of the invention in the disengaged position;
Figure 2B is a schematic view similar to Figure 2A but in the engaged position of the safety device;
FIG. 3A is a schematic view of an embodiment of a variant of the invention in which multiple devices

<Desc / Clms Page number 3>

safety are shown acting together and in the disengaged position;
Figure 3B is a schematic view similar to Figure 3A but in the engaged position of the safety devices;
FIG. 4A is a schematic view of a bidirectional security device according to another variant of the invention;
FIG. 4B is a schematic view of the bidirectional safety device of FIG. 4A in an engaged position relative to a first direction, and
Figure 4C is a schematic view of the bidirectional safety device of Figure 4A in an engaged position relative to a second direction.

 Referring to Figure 1, those skilled in the art will recognize an elevator car 10 in an elevator shaft 12. The guide rails 14 illustrated are non-metallic. In the invention, the guide rails 14 are preferably made of a material resistant to high compression, such as concrete. When concrete is used, it is preferably poured together with the elevator shaft.

Illustrated on the side of the elevator car 10 is a safety device (security) 16 which is positioned on an elevator car 10 so as to remain at all times close to the guide rail 14.

One embodiment of the invention makes use of a regulator cable 18 to activate the safety device 16 in the event of an excessive speed condition.

 Referring now to Figures 2A and 2B, the safety device of the invention is illustrated in a simplified manner. By first considering FIG. 2A, it will be understood that the device 16 of the invention comprises a corner 20 on which a bearing surface 22 which can be a flat surface, as shown, or curved and a friction material 24 are mounted . The corner 20 is connected to a control member which, as illustrated, may include a regulator cable 18 and a fixing 26. The corner 20 is housed in a housing 28. Also housed in the housing 28 is a positioning member horizontal which comprises at least two rollers 30 (as illustrated) or slides (not shown) with which a bearing surface 22 can be brought into contact. As previously indicated, when the carrier surface 22 is brought into contact with the rollers 30, a horizontal force is generated on

<Desc / Clms Page number 4>

 the corner 20 which pushes it towards the rail 14 (to the right in the illustration). The angles of the horizontal positioner 30, the bearing surface 22 and the friction surface 24 are not critical in themselves but should be chosen to create a force perpendicular to the concrete rails 14. When the corner is still pushed towards the rail 14 by the rollers 30, the friction surface 24 is brought into contact with the rail 14 (see FIG. 2B) in alignment with the latter and acts to decelerate the movement of the cabin 10, with the effect of '' quickly get a complete stop of cab 10.

 In a preferred embodiment of the invention, the wedge 20 is made of a rubbery material and the friction surface 24 is secured to the material of the wedge. In another preferred embodiment, the wedge is made of a different material capable of withstanding the compressive force and the shear force which must be imparted to it during use and it may have a friction surface of the same material or of a different material. In any one of these embodiments, it is preferable to provide, as the carrying surface 22, a material of steel or cast iron to best distribute the load placed on the corner 20 by the rollers 30.

 The friction surface 24 is preferably a relatively high friction material, such as vulcanized rubber (or other material) similar to a tire material for an automobile. The material will preferably have a coefficient of friction of about 1.0. A preferably higher coefficient of friction available for surface 24 which should be used in conventional security for use with a steel guide rail, allows a lower pressure to be used against the concrete rail by the security of the 'invention. It always creates the necessary stopping force.

A larger surface of the friction surface 24 also allows a reduction in the pressure required. The reduction in pressure required is beneficial for non-metallic guide rails since, at least in the case of concrete rails, damage can be easily done to it by higher compressive forces over a smaller area.

 In a first example of the invention, a cab with full load of 1812.4 kg (4000 pounds) with a total suspended weight of approximately 3624.8 kg (8000 pounds) to undergo a safety stop at 1 g

<Desc / Clms Page number 5>

 should require a stopping force of 2 g. (cabin deceleration plus gravity). The total stopping force required is 7,249.6 kg (16,000 pounds). Assuming, for this example, a coefficient of friction in the friction surface 24 of 1.0, a force of 7,249.6 kg (16,000 pounds) against the rail 14 should be sufficient. Pressure of 34.48 N / cm2 (50 psi) or less is desirable to prevent damage to the concrete guide rail. A pressure of 34.48 N / cm2 (50 psi) over approximately 0.207 m2 (320 square inches) produces the desired force against the rail. In a perfect system this could be distributed on at least two opposite friction surfaces on each side of the cabin. A larger area for each is used, however, this avoids a system failure to stop the cab in the event that one side does not work. Since each security 16 includes two corners 20, the area for each in the worst case scenario where only one security operates is 0.103 m2 (160 square inches) provided by each corner. To complete this example, the contact surface of the rail surface must be taken into account, which may preferably be about 0.102 m (four inches) wide. It should be noted that wider rails can be used and that the proposed dimensions are only given by way of example and are not given for the purpose of limitation. Thus, a safety of 1.02 m (40 inches) long and 0.102 m (4 inches) wide should provide the necessary stopping capacity.

 A safety of 1.02 m (forty inches) in length should provide a product that is still effective but not very manageable. It is therefore desired to provide multiple safety devices on each side of the elevator car 10, each having a smaller friction surface 24 that is more easily handled and manufactured.

 Referring to FIGS. 3A and 3B, a row of multiple safety devices is illustrated in a simplified manner in the disengaged position (FIG. 3A) and in the engaged position (FIG. 3B). This is a possible arrangement to reduce the area required for each individual corner.

By reducing the area required and since the area is obtained or lost mainly in the vertical axis, the necessary height of the corner is reduced. This is a significant advantage in that with a shorter height of the corner, the angle at the side not contacting the corner rail is, therefore, smaller. The corner is then moved

<Desc / Clms Page number 6>

 laterally over a shorter distance of vertical movement. The shorter the vertical displacement required to engage the corner, the shorter the time required to stop the elevator car. In this embodiment of the invention, each corner 20 is actuated by the same regulator cable 18 having simply a plurality of fasteners 26. This embodiment operates in an identical manner to the embodiment described above but simply with multiple safeties . We can have as many safeties as desired, governed by the surface required and the size of the corners used. The safety devices can be mounted above or below the frame of the elevator car if the mounting locations of the frame become a limiting factor.

 In yet another embodiment of this invention, with reference to FIGS. 4A to 4C, a bidirectional safety device 32 is illustrated. The bidirectional safety device of the invention comprises a housing 34 which supports two sets of rollers 36 and 38 oriented in a symmetrical configuration with respect to the rail 14. The angles must simply provide a perpendicular force on the rail to be effective, as described above. The roller 36 pushes the bidirectional corner 40 towards the rail 14 to stop a downward movement of the cabin 10 (see FIG. 4B) while an upward movement of the cabin 10 is stopped by a corner 40 moving in the opposite direction ( see Figure 4C). In this embodiment, two bearing surfaces are used which are identified by the reference numeral 42 and by the reference numeral 44 and interact with the rollers 36 and 38 respectively depending on the fact that the elevator car is in a condition of excessive speed in the upward or downward direction. Braking in the state of excessive speed in the downward direction is illustrated in FIG. 4B, in which the bearing surface 42 is in contact with the rollers 36. In contrast, braking in the state of excessive speed in the upward direction is illustrated in FIG. 4C in which the bearing surface 44 is in contact with the rollers 38. The friction surface 46 is the same in each case and is defined in the same way as in the previous embodiments. In other respects, the invention functions like the previous embodiments.

 Although preferred embodiments have been shown

<Desc / Clms Page number 7>

 and described, numerous modifications and replacements can be carried out there without departing from the spirit or the scope of the invention. Consequently, it will be understood that the present invention has been described by way of illustration and not limitation.

Claims (14)

 CLAIMS 1. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) characterized in that it comprises: a housing (28); a corner (20) disposed in said housing (28); a friction surface (24) disposed on a surface of said corner and aligned to come into contact with a nonmetallic guide rail (14); at least one horizontal positioning member (30); and a control member (18).  2. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 1, characterized in that said corner (20) further comprises a bearing surface (22) made of 'a hard material disposed on a surface of said corner.  3. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 2, characterized in that said bearing surface (22) of the corner (20) is chosen from steel and cast iron.  4. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 1, characterized in that said horizontal positioning member (30) is an arrangement of rollers.  5. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 1, characterized in that said horizontal positioning member (30) is an arrangement of slides.  6. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 1, characterized in that said control member is a regulator cable (18).  7. Safety device (16) on non-metallic guide rails (14) for an elevator car (10) according to claim 1, characterized in that said control member is an electromagnet.  8. Bidirectional safety device (32) on non-metallic guide rails (14) for an elevator car (10), characterized in <Desc / Clms Page number 9>  what it includes: a housing (34); a corner (40) disposed in said housing; a friction material disposed on a surface (46) of said corner (40) and aligned to come into contact with a non-metallic guide rail (14); two horizontal positioners (36,38); and a control member (18).  9. Safety device (32) on non-metallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that said corner (40) further comprises a bearing surface (42,44) made of a hard material disposed at the two surfaces of said corner.  10. Safety device (32) on non-metallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that said bearing surface (42,44) of the corner (40) is chosen from steel and cast iron.  11. Safety device (32) on non-metallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that the two horizontal positioning members (36, 38) each comprise an arrangement of rollers .  12. Safety device (32) on nonmetallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that said two horizontal positioning members (36,38) each comprise an arrangement of slides .  13. Safety device (32) on nonmetallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that said control member is a regulator cable (18).  14. Safety device (32) on non-metallic guide rails (14) for an elevator car (10) according to claim 8, characterized in that said control member is an electromagnet.