PH26173A

PH26173A - Lift of boarding bridge

Info

Publication number: PH26173A
Application number: PH30145A
Authority: PH
Inventors: Makoto Awakihara; Hideyuki Shimomura
Original assignee: Mitsubishi Heavy Ind Ltd
Priority date: 1983-01-24
Filing date: 1984-01-23
Publication date: 1992-03-18
Also published as: KR840006145U; JPS59114400U; KR870001612Y1; JPS6337360Y2

Description

This invention relates to a lift of an electrically driven type forming a part of a boarding bridge for the direct transfer of passengers between an aircraft and a terminal building in an airport.

FIG. 1 is an outward view of a typical boarding bridge in use. The numeral 1 indicates a bridge head which can extend toward, and retract away from, an aircraft body, and 2 indicates a tunnel associated with the head 1. A rotunda 4 1s disposed between the tunnel 2 and a terminal building 6.

The end of the tunnel 2 combined with the bridge head 1 is supported to be raised and lowered as desired by a tunnel lift 3. The tunnel 2 is provided with an emergency stairway 5.

FIG. 2 illustrates a conventional lift of an electrically driven type. The lift 3 generally comprises a horizontal top frame 11, a pair of outer cylinders 12, 12' securely suspended vertically from the both end portions, left and right, of the top frame 11, a horizontal support 13 located below, and in parallel to, the top frame 11 to fasten the outer cylinders 12, 12' together in spaced relation, a horizontal bottom - 20 frame 14 laid below, and in parallel to, the support 13, and inner cylinders 15, 15' held upright and secured to the both end portions, left and right, of the bottom frame 14. The outer cylinders 12, 12' are telescopically fitted over the inner cylinders 15, 15', respectively, so that the former can slide upward and downward with respect to the latter through cylindrical guides (not shown).

Inside the top frame ll is housed a set of chain gearing, which comprises a center sprocket wheel 16, a pair of end sprocket wheels 17, and an endless chain 18 wound round these wheels. A motor 19 equipped with a brake is mounted on the central portion of the top frame 11 and is coupled with a reduction gear 20. The sprocket wheel 16 is fixedly mounted on the output shaft of the reduction gear.

The outer cylinders 12, 12' house along their central axes shafts 21 which are externally threaded on the lower portions as male members of ball screws. Each of the shafts 21 is rotatably but not axially slidably journaled at the upper end in the top frame 11. Each sprocket 17 is fixedly monnted on each shaft 21, and a brake 22 is attached to the top of the shaft. - annular plates 23, internally threaded as female members of ball screws adapted to engage the ball screws of the shafts 21, are fixed to the upper portions of the inner cylinders 15, 15' on the opposite ends of the bottom frame 14. As the outer cylinders 12, 12' are first fitted over the inner cylinders 15, 15' for assembling, the shafts 21 are screwed into the annular plates 23 to join the outer and inner cylinders integrally. The top frame 11 and the support 13 have sets of brackets 24, 25, respectively, attached to their front and rear corners so as to secure one ends of the bridge head 1 and the tunnel 2 to the lift 3.

The operation of the lift is as follows. The motor 19 equipped with a brake, when switched on, drives the reduction gear 20, which in turn transmits the power through the chain gearing inside the top frame 11 to the shafts 21 in the left and right outer cylinders 12, 12' for their simultaneous rotation. with the aid of the ball screws on their lower portions the shafts 21 move upward or downward with respect to the annular plates 23 as the fulcrums, thereby raising or lowering the top frame 11. As soon as the motor 19 is switched off, the associated brake works. At the same time, the brakes 22 on the upper ends of the shafts 21 are applied, bringing the top frame 11 to a stop.

The conventional lift, with the construction described above, has the following disadvantages: (1) Driven by a single motor, the lift becomes inoper- ative immediately upon a motor failure. (2) The 1ift, which depends on the chain gearing for power output transmission, needs much maintenance cost because the endless chain has shorter life than the other components. Low chain reliability calls for extended repair time. Moreover, the chain must be kept under proper tension; otherwise it can exert excessive forces on the ball screws, leading to damage of the shafts.

The present invention is aimed at eliminating the disadvantages of the conventional lift as above pointed out.

The aim is achieved, in accordance with the invention, by providing a lift of a boarding bridge including a hori- zontal frame which holds the front end part of the tunnel of the bridge, a pair of outer cylinders suspended vertically from the both end portions of the frame, a pair of inner cylinders telescopically fitted in the outer cylinders to : permit the latter to slide up and down, and externally threaded shafts housed in the outer cylinders along their central axes and engaged with internally threaded annular plates which are housed in the inner cylinders, characterized in that a pair of motors, equipped with a brake each, are mounted on the both end portions of the frame and are drivingly coupled to the externally threaded shafts, and the motor shafts are operatively connected to each other through chain gearings.

The 1ift of the present invention offers the following advantages: (1) In case when either motor fails, the other continues to run for uninterrupted operation. (2) In case of a brake trouble, which will cause the boarding bridge to decline due to unwanted rotation of the ball screws, the chain gearings act as auxiliary units to prevent the decline. (3) The universal joints located between the motor shafts and the shafts having ball screws protect the screws from eccentric loading.

A 1ift of an electrically driven type embodying the invention, forming a part of a boarding bridge, will now be described with reference to the accompanying drawing.

FIG. 1 is a schematic view of a conventional boarding bridge;

FIG. 2 is a perspective view, partly in section, of a lift of the prior art; and

FIG. 3 is a perspective view, partly in section, of a 1ift embodying the invention.

Referring to FIG. 3,the 1ift 3 generally comprises a horizontal top frame 31, a pair of outer eylinders 32, 32' securely suspended vertically from the both ends, left and right, of the top frame, a horizontal support 33 located below, and in parallel to, the top frame 31 to bind the outer cylinders 32, 32° together in spaced relation, a horizontal bottom frame 34 laid below, and in parallel to, the support 33, and inner cylinders 35, 35' held upright and secured to the both ends, left and right, of the bottom frame 34. The outer cylinders 32, 32' are telescopically fitted over the inner cylinders 35, 35', respectively, so that the former can slide upward and downward through cylindrical guides (not shown).

On the both end portions, left and right, of the top frame, there are mounted a pair of motors 39, 39', each of which is equipped with a brake and a reduction gear, at points above the central axes of the outer cylidders 32, 32°.

The output shafts of the motors 39, 39' extend downward into the top frame 31, and sprocket wheels 37, 37' are fixedly mounted on their downward extensions. Although the motors 39, 39' shown are of a vertical type, they may be replaced by a horizontal type.

At a midpoint in the top frame is rotatably supported a vertical spindle 40, on which two sprocket wheels 36 are fixedly mounted, one over the other. Endless chains 38, 38' are wound round these wheels and the sprocket wheels 37, 37' under the motors. The two sets of chain gearings permit the motors 39, 39' to run synchronously.

Shafts 41, 41', externally threaded on the lower portions as male members of ball screws, are housed in the outar cylinders 32, 32' along their central axes. The upper portions of the shafts 41, 41' are rotatably but not axially slidably supported by the top frame 31. The output shafts of the motors 39, 39' are drivingly connected at their lower ends to the upper ends of the shafts 41, 41’, respectively, with universal joints 45, 45'. Thus, the shafts 41, 41' are simultaneously driven by the left and right motors 39, 39'.

Annular plates 43, with internally threaded bores as female members of bhll screws adapted to engage the shafts 4l, -§ -

41' forming the male members of the ball scraws, are fixed in the upper portions of the inner cylinders 35, 35' on the left and right ends of the bottom frame 34. When the outer cylinders 32, 32' are first fitted over the inner cylinders 35, 35', tha shafts 41, 41' are screwed into the respective internally threaded annular plates 43 for integral assembling of the inner and outer cylinders.

The top frame 31 and the support 13 of the lift are provided with brackets 44, 46 on their front and rear corners, for use in securing one and of tha boarding bridge to the lift.

The lift is operated in the following way. The motors 39, 39' on the left and right ends of the top frame 31, each equipped with a brake and a raduction gear, are switched on simultaneously to drive the shafts 41, 41' through the universal joints 45, 45' in the outer cylinders 32, 32'.

With the aid of the ball screws in the lower portions the shafts 41, 41' are parallelly moved upward or downward to raise or lower the top frame 31. During this, the two sete of chain gearings housed in the top frame 31 synchronize the left and right ball screws in motion. They also serve : as auxiliary units to prevent a descent of tha top frame 31 (and hence of the boarding bridge) due to the rotation of either ball screw in case of a malfunction of the motor 39 or 39' or brake failura.

Thus, should either motor of the left develop trouble, the other would continue to work to ensure uninterrupted operation. The chain gearings in the top frame act as auxiliary means to help the 1ift operate properly, adding to its reliability. The universal joints on the shafts in the outer cylinders protect the ball screws against accentric loading,

Claims

Claims: ’ 20 173

1. In a lift of a boarding bridge including a horizontal frame which holds the front end part of the tunnel of the bridge, a pair of outer cylinders suspended vertically from the both end portions of said frame, a pair of inner cylinders telescopically fitted in said outer cylinders to permit the latter to slide therealong, and externally threaded shafts housed in said outer cylinders along the central axes thereof and engaged with internally threaded annular plates housed in said inner cylinders, the improvement comprising motors equipped with a brake each and mounted on the both end portions of said frame, each said motor being drivingly coupled to each said externally threaded shaft.

2. In a lift of a boarding bridge including a horizontal frame which holds the front end part of the tunnel of the bridge, a pair of outer cylinders suspended vertically from the both end portions of said frame, a pair of inner cylinders telescopically fitted in said outer cylinders to permit the latter to slide there along, and externally threaded shafts housed in said outer cylinders } along the central axes thereof and engaged with internally threaded annular plates housed in said inner cylinders, the improvement comprising motors equipped with a brake each and mounted on both end portions of said frame, the output shafts of said motors being operatively connected to each other through chain gearings.

3. In a lift of a boarding bridge including a 34 horizontal frame which holds the front end part of the tunnel of the bridge, a pair of outer cylinders suspended vertically from the both end portions of said frame, a pair of inner cylinders telescopically fitted in said outer cylinders to permit the latter to slide there along, and - g -

oo 26173 externally threaded shafts housed in said outer cylinders along the central axes thereof and engaged with internally threaded annular plates housed in said inner cylinders, the improvement comprising motors equipped with a brake each and mounted on the both end portions of said frame and drivingly coupled to each of said externally threaded shaft, said externally threaded shaft being operatively connected to each other through chain gearings.

4. A lift according to claim 1, wherein each of said motor equipped with a brake is drivingly connected to each said externally threaded shaft through a universal joint.

5. A lift according to claim 2, wherein each of said motor equipped with a brake is drivingly connected to each said externally threaded shaft through a universal joint.

6. A lift according to claim 3, wherein each of said motor equipped with a brake is drivingly connected to each said externally threaded shaft through a universal joint. MAKOTO AWAKIHARA HIDEYUKI SHIMOMURA Inventors