KR20050013182A - Conical spring buffer for an elevator - Google Patents

Abstract

The spring shock absorber 26 for the elevator car 12 according to the invention comprises a conical spring coil 32.

Description

Conical Spring Shock Absorber for Elevators {CONICAL SPRING BUFFER FOR AN ELEVATOR}

The use of deceleration shock absorbers located at the extremes of the movement of elevator cars or counterweights is known. Typically such a shock absorber consists of a helical spring or hydraulic damper disposed in the lower elevator pit of the hoistway. If the elevator car moves beyond its normal range, the car stops in a controlled form before it encounters the shock absorber and contacts the hoist floor.

In a traction drive elevator device, the elevator car and the counterweight are connected by one or more ropes moving in the hoistway, and it is common to supply the counterweight with a shock absorber similar to the lower limit of the range of motion. Thus, the passenger car is confined in motion in all directions, up and down by the system, and encounters each shock absorber which provides a controlled stop when overrun. During operation, the requirements for spring shock absorbers are generally limited by local elevator regulations in each market. The rules generally determine the conditions of motion, reduction ratios and load ratings.

To achieve the desired reduction ratio, the shock absorber must make sufficient compression to absorb the energy of the descending car or counterweight at the required ratio. Thus, for helical spring shock absorbers, the uncompressed height of the entire shock absorber is at least the sum of the height of the fully compressed spring and the required compression motion distance. Since the spring buffer is located in the hoist pit, the uncompressed spring buffer height is an element within the required pit depth. As will be apparent to those skilled in the art, increased pit depth and size increase elevator system costs. There is a need for an improved spring buffer design that reduces the required pit depth.

The present invention relates to a spring shock absorber for an elevator car operating in a vertical hoistway.

1 is a schematic cross-sectional view of a traction elevator system disposed in a typical hoistway.

Figure 2 is a side view of the conical spring buffer according to the present invention.

Figure 3a is a side view of a conical spring buffer and elevator car according to the present invention.

FIG. 3B shows the car and shock absorber arrangement of FIG. 3A occurring upon overrun.

4 shows a conical spring buffer according to the invention in a counterweight buffer.

According to the invention, the shock absorber for an elevator car is provided with a spring member having spring coils arranged in conical helix, so that adjacent coils are sized to be received in the next larger coil when the spring is compressed. Thus, the conical spring buffer according to the present invention obtains a sufficiently long stroke between the uncompressed state and the fully compressed state, thereby reducing the elevator car to the required ratio while reducing the uncompressed height of the entire shock absorber.

According to a first embodiment of the invention, the conical spring is arranged in the pit of the elevator hoistway. The spring is in the form of gradually decreasing coil diameter in the upward vertical direction, and the spring end with the smallest diameter is oriented vertically toward the descending elevator car or counterweight. Unlike conventional helical coil springs in which the coils have the same diameter and are axially stacked, the conical spring according to the present invention is a continuous coil that spirals radially inward so that each adjacent coil is disposed entirely within the diameter of the next outward coil. It includes.

By arranging the conical spring according to the invention such that the continuous coils "nest" this way, the overall axial height of the fully compressed spring is smaller than the uncompressed axial height. By selecting the appropriate material, element cross section and diameter, the uncompressed height is further reduced while achieving performance equivalent to conventional helical spring buffers.

According to a second embodiment of the invention, the conical springs described above are further configured to achieve variable spring ratios in different compression stages, so that the force applied to the car or counterweight at overrun can change in response to the contact force.

According to various other embodiments of the invention, the spring coil may be formed of an element having a circular, rectangular or other cross section.

With reference to the drawings, a spring buffer according to the invention is shown in particular in FIG. 1.

FIG. 1 shows a schematic diagram of an elevator hoist for a typical traction device comprising an elevator car 12 suspended by one or more ropes 14 running between a car 12 and a counterweight 16 suspended vertically. . The rope 14 passes through a traction sheave 18 driven by a machine (not shown) that is typically located in the machine room 20 disposed on top of the hoistway 10.

In normal operation, the car 12 operates vertically in the hoistway 10 to stop at certain floors 22a and 22b. As shown in Fig. 1, layer 22a represents the highest floor operated by elevator car 12, and layer 22b represents the lowest floor. The hoistway comprises a pit area 24 in which one or more shock absorbers 26, 28 according to the invention are located.

If the elevator car 12 exceeds the normal operating range, it will inevitably come into contact with the ceiling 32 of the hoistway 10 or the floor 30 of the pit 24, thereby damaging not only the elevator apparatus but also the surrounding building structure. will be. In addition, passengers in the car may be injured. It is the function of the shock absorbers 26 and 28 to absorb the descending momentum of the car or counterweight and reduce the effect of overrun occurrence by slowing down to a controlled ratio, respectively.

2, a conical spring buffer 26 is shown and described. The structure of the shock absorber 26 according to the present invention is basically the same as the counterweight shock absorber 28.

As shown in Fig. 2, the shock absorber 26 comprises a conical spring coil 32 having the largest base coil 34 spirally formed inward and at the same time vertically upwards and arranged at the bottom, and being continuous Coils 34-1, 34-2, etc. are sized such that the outer radius of the next inward coil is smaller than the inner radius of the previous coil. In the example shown, the outer radius Ro of the coil 34-2 is less than the inner radius Ri of the coil 34-1, so that the coil 34-2 is coiled when the spring is axially compressed. May pass radially inward of (34-1).

As also shown in FIG. 2, the final coil of conical spring 32 is flattened to provide surfaces 36 and 38 perpendicular to central axis 40. The flat surface 38 at the larger end of the conical spring 32 rests on the cylindrical base 41 in the embodiment shown in FIG. The spring 32 is preferably secured to the base by any of a number of evenly corresponding means including welding, bolting, joining, and the like. The base 41 is fixed to the bottom 30 of the hoistway 10 to prevent movement or displacement during operation.

The radius of the coil 34, the diameter d of the coil element, the transverse pitch of the coil and the material form of the conical spring 32 may be determined by the desired spring constants for a particular elevator application as required by elevator regulations or other performance requirements. And to provide an axial stroke. The overall length of the conical spring 32 according to the invention now must not only withstand the required axial deformation but also be sized to have a much larger minimum length when fully compressed due to the axial stacking of spring coils of the same diameter. It is apparent that the size becomes small compared to the conventional spiral spring.

Figure 3a shows a spring shock absorber 26 according to the invention arranged such that the elevator car 12 contacts the lower end of the hoistway 10 during overrun. As shown in FIG. 3B, the elevator 12 moves beyond its normal operating range and is introduced into the pit to contact the conical spring 32 to fully compress the spring.

4 shows an equivalent shock absorber 28 which comes into contact with the counterweight 16 when the car is overrun on top of the hoistway 10. The structure of the counterweight shock absorber 28 according to the present invention is substantially the same as the car shock absorber 26, but of a size required for use with the counterweight. Operation of the counterweight shock absorber 28 excludes that the counterweight shock absorber stops the counterweight at the bottom of the hoistway 10 and thereby prevents damage to the elevator car by removing the upward force on the car 12 by the rope 14. Is the same as the car shock absorber 26.

Although shown for a constant pitch spring with a circular diameter spring element, the conical spring according to the invention may be made of a spring element having an ellipse or rectangular cross section, the coil pitch providing a variable spring constant depending on the degree of compression of the spring. To vary over the length of the spring. Such and other equivalent constructions will be apparent to those skilled in the art upon review of the appended claims and drawings and the foregoing specification.

Claims (7)

In a spring shock absorber for an elevator system disposed at one end of a hoistway of an elevator system in contact with a vertical moving element of an elevator system in an abnormal overrun, the spring shock absorber has a conical coil having a helical coil element whose radius decreases with increasing axial displacement. A spring shock absorber comprising a spring. 2. The conical coil spring of claim 1 wherein the conical coil spring comprises a series of coils, and the outer radius of the subsequent coil is smaller than the inner radius of the previous coil, so that the coil can be compressed axially without radial interference. Spring shock absorber. The spring shock absorber according to claim 2, wherein the cross section of the coil element is circular. 3. A spring shock absorber according to claim 2, wherein the cross section of the coil element is rectangular. 3. The spring shock absorber according to claim 2, wherein the lateral pitch of the coil is constant. The spring shock absorber according to claim 1, wherein the vertical moving element is an elevator car. The spring shock absorber according to claim 1, wherein the vertical moving element is a counterweight.