BACKGROUND OF THE INVENTION Escalators have been in use for the past many years and provide a convenient means for continuously acting passenger conveying device. These have been used commonly where large number of people are required to move continuously from one floor to the other.

These devices have been considered safe, however through an accident the inventors of this invention realized inherent defect in the design and they decided to work on a design to remove this defect to improve the safety factor and with mutual discussion they developed an idea on the basis of which the present invention could be made.

PRIOR ART OF THE INVENTION An escalator is basically a conveyor belt formed by joining individual steps. These steps are guided through wheels attached to its sides two each on either side which run on rails.

These rails are so displaced in relation to one another that each individual steps moves like a carriage. The two wheels on either side form a top pair and a bottom pair, moving on two separate pairs of rails outer rails and inner rails respectively. On the upward journey of the step, the two rails are situated in the same plane, but a short distance past the bottom reversal point the rails are so displaced in relation to one another that the inner rail is below the outer rail. As a result of this arrangement, the steps gradually merge into a flat horizontal surface at the top of the escalator, enabling the passengers to step off easily. Similarly, convenient stepping-on is ensured at the bottom of the upward moving escalator. The moving steps perform the return journey on the rails which are continued on the underside of the escalator. Each step is attached to two endless chains which run on sprocket wheels at the top and bottom of the escalator, the top sprocket wheels are driven by an electric motor whereby the steps can be made to travel upwards or downwards. A rachet wheel is mounted on the driveshaft. Hand rails consist of continuous belts made of rubber and canvas plies incorporated in it, also move with the steps at the synchronized speed so that the passengers can take the support while moving

with the escalator. The principle is explained through figures 1,2, and 3. Now referring to figure 1, a conventional escalator is shown wherein steps (1) of platform in which the steps (1) merged to form a loop (2). The steps lying over a lower roller moving from lower portion of the lower roller upwardly in a belt form. The belt comprising carriages which are linked to one another and capable of forming a stepwise construction when required. When the belt moves over the upper roller, each carriage gradually moves down to form a step. Figure 2 shows inner rail (5), outer rail (6), located over the outer rail (6) are steps (7) and the entire system is moving in the direction (8). Figure 3 shows outer upper wheel (9) located over the outer rail (3) and inner lower wheels (10) and (11) located over inner rails (14). This figure also shows outer rails (3) and (12), step (13), the carriage which forms the step comprising the upper part (16) and a front vertical port (curved) (17).

PROBLEMS AND DIFFICULTIES IN KNOWN PRIOR ART The escalators i. e. the known art have following problem and difficulties: a. the design is very complicated and only a very few companies are able to make it successfully. b. the device is very expensive and therefore not so common. c. heavy metallic structure adds to the cost also metallic steps with sharp edges may cause injury. d. because of heavy metallic structure power cosumption is very high. e. needs high level of maintenance to ensure smooth operations. f. two sets of escalators are necesarry for two-way movement. g. most serious problem with the device is that the steps move in a closed loop in rolling type of motion which if not stopped during emergency situation may lead to the possibilities of crushing although precautionery switches have been provided but this possibility should be eliminated from design itself due to serious consequences. h. the steps on return journey through under side of the escalator do not perform any functions.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS In the drawings accompanying the specification, Figure 1 represents the side view of the escalator system of the prior art.

Figure 2 represents the loading of the steps of the prior art escalator system on to the rails and their movement.

Figure 3 represents the close-up view of a stair mounted on the rails of the prior art escalator system.

Figure 4 represents the top view of the escalator system of the present invention.

Figure 5 shows the perspective view of the escalator system of the present invention.

Figure 6 shows the descending movement of the steps of the escalator system of the present invention.

Figure 7 shows the ascending movement of the steps of the escalator system of the present invention.

Figure 8 shows the rotational motion of the steps in the same horizontal plane on the upper floor level.

Figure 9 represents the close-up view of the hinge developed for connecting the adjacent steps of the escalator.

Figure 10 represents a view of the connection portion between two adjacent steps.

Figure 11 represents the close-up view of the connection portion between two adjacent steps wherein the steps are connected using two hinges.

Figure 12 shows the close-up view of the connection portion when the steps are in the ascending or in the descending position.

Figure 13 shows the close-up view of the connection portion when the steps are in the same plane and in the rotational position.

Figure 14 shows the top view of the floor level showing the entrance and the exit portions.

Figure 15 shows the means for driving the escalator in accordance with a first embodiment of the present invention.

OBJECTS OF THE INVENTION The main object of the present invention is to provide movement of steps in the escalator by turning the steps in a horizontal plane or by turning the loop formed by joining the steps in the horizontal plane itself, thereby avoiding rolling motion of steps, which has been found to be dangerous.

Another object of the invention relates to providing two equal and opposite sections of the loop which is arranged to form two parallel arms of the escalator for movement in ascending and descending directions.

Yet another object of the invention relates to an escalator wherein each section is moving in direction opposite to each other and one loop will be sufficient to provide two way movement.

Still further object of the invention relates to providing a simple design for an escalator wherein the loop can be rotated in the plane of motion about an axis perpendicular to the plane in principle.

SUMMARY OF THE INVENTION Accordingly, the present invention relates to an improved construction for escalator based on non-rolling movement which provides two equal and opposite sections of a loop arranged to form two parallel arms of the escalator wherein each section is moving in direction opposite to the other thereby providing two way ascending and descending movement.

DETAILED DESCRIPTION OF THE PRESENT INVENTION Accordingly, the present invention provides an escalator comprising a frame supporting the entire structure, a pair of railings, an end portion disposed at a floor of a lower level serving as an entrance or exit of the passengers, an end portion disposed at a floor of a higher level serving as an exit or entrance thereof, comb plates disposed in the end portions at the floors of different levels for scooping up the passengers, steps connected with each other in an endless fashion such that the steps are movable with respect to each other for transporting the passengers by traveling in a loop, each of the steps comprises a step portion and a riser portion and is supported by a pair of wheels attached to the riser portion, said wheels move in rolling motion over a pair of wheel guide rails, and the steps travel upwardly or'downwardly while the surfaces of the adjacent steps are maintained at different levels, characterized in that the direction of rotation of the loop of steps in the upper and the lower floors is in the plane of direction in which the passengers are travelling.

In an embodiment of the present invention, the loop of escalator is formed such that the steps travel in forward and ascending fashion from the lower floor level to the upper floor

level, in a circular fashion in the upper and the lower floors and in a forward and descending fashion from the upper floor level to the lower floor level.

In another embodiment of the present invention, the two vertical rods are provided on edges of adjacent steps for connecting the same them through a hinge having edges curved insider in semi-cylindrical shape such that in the connected position, the hinges permit sliding of movement and also rotational movement about its axis in the horizontal plane.

In yet another embodiment of the present invention, the adjacent steps are connected via two hinges, one of which is provided at a top portion of the step and the other is provided at a bottom portion of the step.

In still another embodiment of the present invention, the hinges are held releasably at their location through a spring-ball arrangement provided on the rods.

In one more embodiment of the present invention, the steps are in the shape of box.

In a further embodiment of the present invention, the escalator further comprises a driving means for providing power to the escalator.

This invention proposes change in the construction of the escalators and it is this constructional change which the applicants wishes to obtain patented. In the conventional escalators, movement of steps is accomplished by rotation of loop formed by joining the steps in perpendicular to the direction of motion and in the plane in which the passengers are standing (in the plane of paper) as shown in the figure 1 (rolling movement).

However, in the present invention, movement of steps is accomplished by rotating the loop formed by joining the steps in same plane as shown in figures 4 and 5 (as seen from top). Two equal and opposite section of the loop can be arranged to form two parallel arms of the proposed escalator system or pair, for movement in both direction for ascending and descending. As each section will be moving in direction opposite to each other, one loop will be sufficient to provide the pair. for two-way movement. The process is explained through figure 5 and this figure shows the lay out (figures 4 & 5) of loop in principle, however in actual practice the loop can be laid as per convenience formed in the space available. The loop will be rotating (in principle) in the plane of motion about an axis perpendicular to the plane.

The present invention is further described in detail in the following paragraphs with reference to the figures.

Figure 4 shows schematic diagram of the proposed escalator pair wherein the steps (13), ascending arm (18), descending arm (19) and the directions of rotation (20) and (21) are shown. Dotted lines in the figures represent the upper and the lower floor levels.

Figure 5 provides a schematic view of the escalator wherein upper floor level (22), lower floor level (23), part of loop on upper floor (24), descending arm (25), ascending arm (26) and their respective directions movements, part of loop in lower floor (27) are shown.

Figure 6 shows the formation of the steps during the descending movement of the escalator. As can be seen, 28 represents the steps which are formed on the upper floor level. These steps are formed at the same level at which the upper floor is located. About two or three steps such steps are located so as facilitate the passenger to mount the escalator. Then the steps start descending downwards and at the same time starts moving forward. The figure shows three such steps (29, 30 and 31) which have descended from the upper floor and have also simultaneously moved forward in the horizontal direction.

Figure 7 shows the formation of the steps during the ascending movement of the escalator. As can be seen, 32 represents the steps which are formed on the lower floor level. These steps are formed at the same level at which the lower floor is located. About two or three steps such steps are located so as facilitate the passenger to mount the escalator. Then the steps start ascending and at the same time starts moving forward. The figure shows three such steps (33,34 and 35) which have moved upward from the lower floor and have also simultaneously moved forward in the horizontal direction.

Figure 8 represents the rotational motion of the steps on the upper floor. About two steps (36) are provided which are formed on the upper floor level itself. These steps facilitate the passenger to de-mount from the escalator. Thereafter, the steps start turning along a curved path formed on the upper floor level itself. These steps are shown by the numerals 37,38 and 39. More particularly, numeral 37 represents the steps which start the curving action, numeral 38 represents the steps which are moving in the turning direction and numeral 39 represents the steps that end the turning action. Once the turning action is complete, once again about two steps (40) are formed on the upper floor level itself.

These steps (40) facilitate the passenger to mount the escalator and descend from the upper floor level to the lower floor level.

Figure 9 shows the hinge which is used to connect adjacent steps. The hinge comprises of two semicylindrical portions (41 and 43) which are connected by a hinge shaft (46). The hinge thus formed can be rotated about the axis (42), Figure 10 shows the steps which are connected using a single hinge. The adjacent steps (52 and 53) are provided with two rods (51 and 54) and the hinge (50) connects these two steps.

Figure 11 shows the close-up view of the connecting portion between two adjacent steps.

The steps here are connected using two hinges. The hinges are held in their position by ball and spring assembly (54,55, 56 and 57). The ball and hinge assembly is also shown, which comprises of a spring (61), a ball (60) and a stopper (62).

Figure 12 shows the close-up view of the connection portion when the steps are ascending of descending. The first step (63) and second step (64) are connected using two hinges (65 and 66). When the steps move in the descending fashion, the hinge 65 shifts from the top location to the bottom on the rod.

Figure 13 shows the close-up view of the connection portion when the steps are moving in a rotational direction in the same plane. The first step (67) and the second step (68) are located in the same plane. The lower hinge (70) and the upper hinge (69) hold their position on the rods (71 and 72). However, the steps turn due to the semi-cylindrical shape of the hinge.

Figure 14 shows the top view of the upper floor. As can be seen, steps 79 is the ascending step and step 78 is the descending step. Comb and groove arrangement (74,75, 76 and 77) are provided at the position where the steps merge with the floor level. Thereafter, the turning portion of the steps is covered using a cover (73).

Figure 15 shows the driving means in accordance with a first embodiment of the present invention, the steps (80) are mounted on a rail (81) using supporting wheels (82). Metal strips with uniform gear are attached to a side of the step using screws (87). The driving motion is provided to the steps using a motor, which is provided with a motor shaft with screw type thread. The rotational motion of the motor is transferred to the steps using the gear wheel.

The construction and the working of the escalator of the present invention is further described in detail in the following paragraphs, which are given by way of illustration only and hence, should not be construed to limit the scope of the present invention in any manner.

The key features in constructing the escalator is the construction of the platform or the steps. These should be constructed in such a way that: (a) these can be moved up and down and in relation to one another to form steps in both the directions of motion of the escalator.

(b) these should be joined in such a way that the steps can be turned sideways in the same horizontal plane.

The vertical movement of steps can be made possible by joining the steps on one side with the help of a specifically designed hinge which can permit sliding movement up and down and at the same time rotation about the axis of center of the hinge.

In a simple design the steps can be made in the shape of boxes. These boxes need not have flooring. Size and strength of the boxes may be chosen in such a way that its top surface can be used as a step platform depending on the requirement or the size as used in conventional escalators.

Comb and Groove Arrangement Comb and groove arrangement is desirable to facilitate merger of steps with floor. Hence,. the top surface of the steps should be provided with grooves as are provided in conventional escalators. However, in the present application certain modifications are proposed which would improve the working of the escalators.

In the conventional escalators, the comb teeth are made of metal, which can cause injury if it comes off from its fitting. Although, safety switch is provided to stop the escalators in case this comb plate is moved up accidentally after coming out of the grooves, still it is proposed to make the comb teeth with soft material like hard rubber or rubber lined with thin metal sheet. Use of such materials for constructing the comb teeth along with the safety switch would improve the safety of the escalator.

A thick sheet of such material is laid over the curved portion on side support to allow free movement of the loop. Basically, a small part near the merging point will be used.

However, it may be seen that the comb and groove arrangement is not mandatory for the

escalators of the present invention as the steps are moving in the same plane (i. e. the horizontal plane). The merger can also be done with a sheet with sloping edge placed very close to the level of slope to leave minimum gap possible with soft bristles covering the'gap.

Linking the Steps : As stated earlier, one way to link the steps would be through a specially designed hinge.

This hinge is to be made like a normal hinge used on doors except the difference that its edges should be curved inside to be of semi-cylindrical shape so that it fits properly on two vertical rods attached to the edges of two adjacent steps. When fitted, these hinges will permit sliding of movement and also rotational movement about its axis as shown in figure.

These hinges could be of the size of a few cm and should permit rotation about the XY- axis. The two curved edges can be hooked on to two vertical rods which can be fitted on the two edges of steps thereby permitting sliding movement as well. Two such hinges should be provided one on top of the steps and one on bottom of the step.

These hinges should be held in its place through a spring-ball arrangement provided on the rods. The spring-ball arrangement will hold the hinge at its place at the same time will permit movement with steps when necessary resistance is provided to, the spring-ball arrangement. As shown in figure, when step No. 2 is moving down, the top hinge will move down along with the step and the bottom hinge will retain its position. Whereas, when the step No. 2 is moving up, the top hinge will retain its position and the bottom hinge will move up along with the steps. The above arrangement will ensure that the formation of steps during ascending and descending movement.

This arrangement will also ensure that the linear arrangement of steps can be turned in the same plane about the side facing the reader by splitting as shown in the figure.

Supporting of Steps: The steps may be supported on the two wheels or bearing one on each side fitted at the center of the step, single wheel on either side of the step is sufficient as the step is in the shape of a box and is getting side ward support from other boxes and has the freedom to move only upward and downward. These wheels can be placed on one parallel set of rails

provided on both sides of the steps and laid between the two floors and then all along the curved side. The installation can be done as is being done on conventional escalator.

Drive : The power to the escalator loop may be given from any point of the loop. Consideration may be given to availability of space as motor and gear assembly will need some space.

Hence, the location may be planned accordingly. While, the horizontal section of the loop may provide convenience of installation, the inclined portion of the escalator may provide ample space below.

Although the power can be given through a single motor, it may be preferable to use more than one motor at different points to distribute the load. Besides distribution, this will also ensure running of the escalator even if one of the motors fail. For example, instead of using one motor of one horse power, two motors of l/2 horse power each may be used. This will also reduce strength requirement for the gear assembly. However, it may not be practical to have power delivered from more than two points.

The size and dimensions of various components of gear assembly should be chosen to provide comfortable and convenient speed of the movement of the loop. Speed of 0.5 meters per second is accepted universally and is provided in conventional escalators.

The basic purpose of the gear assembly is to push the steps or loop laterally by deriving the power from the motor. The power transmission system should not need too many modifications in the basic design as this will not only complicate the design but also reflect on the overall cost of the device.

A number of arrangements are possible, a few of such arrangements are described by way of example below: 1. The arrangement is shown in Figure 15. Here the rotation of the motor is transmitted to the loop through a horizontally mounted gear which will move the loop laterally. This type of arrangement is similar to rack and pinion type. In this type of arrangement, the lower part of the steps on one side may be fitted with metallic strips with sufficient thickness to have parallel grooves and teeth. The width of these strips could be of the order of 2 to 3 inches to provide good grip and sufficient strength. If required, these strips can also be fitted on inner side of the steps but in that case the particular side of the strips will have to be extended

by 2 to 3 inches to accommodate metallic strip. These strips can be fitted on the steps with the help of screws. Two or three screws may be needed for each metallic strip. The holes for these screws may be drilled neatly without disturbing the groove and teeth arrangement. The horizontal gear wheel may also be chosen of thickness equal to the width of the strips and the teeth on this may be cut to match the same with metallic strips fitted on the steps so that the rotation of wheel may push the steps smoothly. This wheel could be given power through a shaft connected to motor having screw type of thread as shown in figure 15. The dimension of wheel and shaft should be chosen to provide desired speed.

2. The other arrangement is shown in figure 16, which may be simpler as no changes or additions are to be done on steps. In this arrangement, the power can be given through a wheel having pushing rods. This can be installed on one side of the steps in such a way that these rods are passing through the gap between the steps and the rail on which steps are supported through wheels or bearings as shown in figure 16. This wheel could be given rotation through a chain driven by motor.

The size of the wheel pushing rod should be chosen in such a way that one of the pushing rod is always in contact with the linking rod of the steps for the smooth movement of the steps.

3. Another arrangement is suggested in figure 17. Here the pushing rods are fitted on a chain which is moving over two geared wheels. One of the gear wheel can be connected to the motor. The gap between pushing rod should be chosen so that each engages itself with supporting link of steps as they move, one after the other.

The length and distance between two wheels should be chosen so that the chain is engaging second step before first one is disengaged for continuous pushing. It may be preferred that one step is always engaged. Figure 17 shows chain engaging third step when the first one is being disengaged. Here the length of the chain has been chosen to accommodate three pushing levers to provide continuous pushing.

Any of the three arrangements described above may be used. However, for simplicity, the second arrangement is more suitable.

ADVANTAGES a. The device of the present invention is based on simple design. b. because of simple design it can be made at very low cost. c. use of heavy metallic parts can be avoided and rubber parts can be used to avoid sharp edges and injuries in case of accidental fall. d. power consumption can be reduced by use of light weight material. e. comparatively lower level of maintenance is required due to simple design. f. two sets of escalators are not necessary as other part of loop can be used for movement in other direction. g. no possibilities of crushing as the loop returns to original position in the same plane. h. as stated in (f) above the steps on return journey can be used for movement in other direction. i. the same parts of the escalator can be used for baggage conveyors, walkalators etc. j. since the steps are getting support from sides by other steps it is necessary to support the steps on two sets of parallel rails via four wheels, as used in the conventional escalators, one rail on either side is sufficient.