JPS6318278Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is designed to guide a ladder device movable between a lowered working position and a raised non-working position, especially a ladder connected to a housing, to move between the raised and lowered positions. This invention relates to a retractable ladder device which can be moved to any position with balance by manual movement.

Ships, large vehicles, or moving machinery require ladders for boarding and disembarking. The retractable ladder device of the present invention is used in mining machines having large track pillars used in strip mining operations. Such machines have a removable platform above the caterpillar, which holds the upper part of the machine with the mining section. The cockpit is located above this platform. The cockpit is approached from the platform level by a staircase fixed to the upper part of the machine; the platform is approximately 10-12 m above the ground level.
Reaching this platform at foot level requires a retractable ladder so as not to interfere with the movement of the machine or the rotation of the upper part. The most preferred retracted position of the ladder is with its bottom above the level of the platform and with no portions projecting laterally beyond the platform.

Various other demands have been made for ladder devices, but have not yet been resolved. Conventional lifting devices are in the form of stairs rather than ladders. When ascending and descending using a ladder, it is necessary to grasp the ladder with your hands in order to keep your balance, and there is a drawback that you cannot climb up the ladder while holding tools, etc. In contrast, stairs have sufficiently wide footings and guide rails, making it easy to go up and down while holding heavy tools.

However, in the past, ladders were more commonly used than stairs because stairs were difficult to draw and extend. Stairs are also heavier than ladders, making them difficult to ascend and descend. If a power mechanism is used for raising and lowering the stairs, there is a risk that the stairs will become unusable due to failure of the power device.

U.S. Pat. No. 2,733,86 discloses raising and lowering a heavy ladder or staircase by means of a manually operated winch, but the operation is slow and cumbersome to operate. U.S. Pat. No. 3,737,007 discloses the use of a counterweight that balances the weight of the ladder to facilitate its ascent and descent. However, this or other known counterweight devices have significant drawbacks. If the counterweight is heavier than the ladder or staircase, the ladder will tend to rise beyond its operating position and be permanently restrained in its retracted position; if the ladder is heavier than the counterweight, it will tend to raise the ladder and remain in its raised position. This makes it difficult to restrain the robot from moving downwards, and there is a risk that it will always be restrained downward in that operating position, causing it to collide with the ground.

The retractable ladder described in US Pat. No. 3,737,007 can be raised and lowered from the position of its legs and held in any raised position by means of a locking mechanism that can be operated from below. Ladder systems for mining equipment need to be able to be raised and lowered from both above and below and it is impractical to fix them in either the raised or lowered position.

Compared to ladders, stairs have the troublesome problem of having to change their slope when moving between the retracted position and the operating position. Although the ladder can be raised and lowered in a straight line between these positions, a retractable staircase should extend diagonally in its lower operating position and be as vertical as possible in its retracted position to minimize lateral extension. In the case of stairs, it is not preferable to change the slope manually.

In the previously known staircases used in mining machines and the like, the operating position can only be reached when the platform of the machine is in a predetermined position of its pivoting movement. Such a restriction is undesirable because the ladder or stairs in the retracted position limit the rotation of the upper part of the machine.

It has also been proposed to use springs to counterbalance the weight of retractable stairs to facilitate manual ascent and descent. However, the spring is large, extremely expensive, and difficult to handle, and its structure is complicated. Further, when a spring is used, there is a serious drawback that human beings may be injured if the spring breaks.

The object of the invention is to provide a ladder device in which the ladder is connected to a fixed housing so that the ladder can be moved between a lower operating position where the ladder is inclined and an upper position where the ladder is substantially vertical.

Another object of the invention is to provide a ladder with a spring-free mechanism for balancing the weight of the ladder so that the ladder can be manually raised or lowered with very little force and can be stopped in the raised and lowered positions. You are on your way to getting the equipment.

Another object of the invention is that by simple manual operation the ladder can be started to move from its raised and lowered positions, and then be able to continue to move to the desired position, and when approaching its stopping position, its speed can be increased. There is a reduction in obtaining a gradual stop ladder device.

Another object of the invention is that there is no need for a power drive mechanism or springs to move the ladder from one defined position to another, but instead a simple counterweight is provided to balance the weight of the ladder and the movement is initiated manually. To obtain an extendable and retractable ladder device which can be moved from each position to a desired direction by moving the ladder device.

Another object of the invention is to mechanically guide the ladder between its retracted and extended positions to change its slope during this movement, and to use this change in slope to automatically control the acceleration and deceleration of the ladder. There is a retractable ladder device to obtain.

Another object of the invention is that it can be moved vertically between a raised retraction position and a lowered operating position, and that it can be easily moved to either of said positions from both above and below, and that the machine can be retracted in any rotational position of the upper part of the machine. and to obtain a retractable ladder device suitable for an extendable mining machine.

The ladder apparatus of the present invention includes a ladder having a pair of elongated parallel ladder girders extending from the top to the bottom and a plurality of laterally extending ladder foot plates connected in a longitudinally spaced manner between the ladder girders. consisting of a fixed housing at the front of the ladder that guides the ladder between a raised inactive position and a lowered activated position;
a first cooperative mechanism provided on the top of the ladder and the housing for vertical movement of the top of the ladder along a path consisting of a vertically extending main straight section, and for rocking the ladder rearward during the descending movement of the ladder; a second cooperative mechanism provided on the ladder at a spaced apart position below the top of the housing and the ladder for rocking forward during its upward movement, and adapted to cooperate with the first cooperative mechanism; a cable connected at one end to said counterweight; a rocking movement of the bottom of the ladder used to connect the other end of said cable to a ladder at a position spaced below its top; a locking mechanism that engages an intermediate portion of said cable and is provided in the housing above and in front of the position of said locking mechanism when the ladder is in its retracted position and when the ladder reaches each of said positions; It is characterized by having a cable guide that guides the cable so that the cable extending relative to the cable is in an inclined state.

The first cooperative mechanism includes a rail mechanism provided on the fixed housing to cooperate with a rail guide at the top of the ladder to move the top of the ladder along the predetermined path, and the path extends from the upper end of the path toward the rear. a vertical passageway extending into a curved section, said curved section being connected to said lowest straight section sloping downwardly and rearwardly, said second cooperation mechanism being engaged by said longitudinally extending surface of said ladder girder; A roller is rotatably supported by an axle fixed to the fixed housing at a position spaced behind the vertical section and below the bottom end of the track.

Embodiments of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 5 indicates a large strip mining machine equipped with a retractable ladder 6 in the apparatus of the present invention. The lower part of this mining machine 5 is the caterpillar 7
, a rotary table 8 , and a platform 9 supported on the rotary table 8 . This platform 9 supports the upper part of the machine. This upper part includes a boom 10 supporting a mining tool (not shown), a housing 11 for mechanically driving the mining tool, and a cockpit 12 fixed to the housing at a height above the level of the platform. . A fixed staircase 14 provided in the housing 11 allows a person to move up and down between the platform 9 and the cockpit 12, the bottom of which is higher than the ground.
The ladder device of the present invention, when in its lowered operating position, allows the operator to ascend toward and descend from the platform.

The device of the present invention is closer to a staircase than a ladder in terms of the ability for people to go up and down it, but since it is retractable, it can be considered a ladder. In the device according to the invention, when in the lowering operating position, the ladder 6 extends from the ground to the bottom of the fixed staircase 14 such that when retracted, its bottom end is at the level of the platform 9 or slightly above it. .

The ladder 6 is comprised of a pair of elongated parallel ladder girders 16 and laterally extending flat ladder foot plates 17 attached to the ladder girders spaced apart in the longitudinal direction of the ladder girders 16. A guardrail 18 is fixed to each ladder girder 16. When the ladder 6 is in the lowering operation position (see Figures 2 and 17), the ladder girder 16 moves forward and upward with respect to the horizontal plane.
Tilt at 60 degrees so that the foot plate 17 is horizontal. In the raised and retracted position (see FIGS. 3 and 14), the ladder is aligned with the vertical wall of the housing 11. When the ladder is in the retracted position, it is more vertical than when it is in the extended position, but about
Make sure it is tilted slightly by 10 degrees.

The ladder 6 and the fixed housing 11 are connected by a pair of guide rail mechanisms 19 provided on the fixed housing. This rail mechanism 19 is formed with a track 24 for guiding the top of the ladder up and down. A pair of counterweights 20 are provided within the guide rail mechanism 19 and are connected to the ladder 6 by cables 21 to act as guides thereof. One end of the cable 21 is connected to the balance weight 20, the other end is connected to the ladder, and the intermediate portion is suspended from a cable guide 22 provided above the top of the ladder. As shown in Fig. 13, each guide rail mechanism 1
9 is provided with a vertically extending box beam 23 serving as a guide for slidingly guiding the balance weight 20 up and down. The two box beams 23 are fixed to a fixed housing so as to be parallel to each other. Guide rail portions for guiding the top of the ladder up and down are formed on adjacent sides of each box beam 23. This guide rail portion is formed with an elongated track 24 that is open on opposite sides. The track 24 is defined by a straight section 25 extending vertically from its top, a rearwardly curved section 26 near its bottom, and a relatively short straight bottom section 27 which slopes downwardly and rearwardly. The straight portion 25 is formed by a pair of L-section pieces 125, and the curved portion 26 and the lowermost portion 27 are grooves formed in a relatively thick plate 126 fixed to a triangular base plate 28 projecting rearward from the fixed housing 11. Formed by

A rail guide mechanism 29 is provided at the top of the ladder and is engaged with the track 24, consisting of a small roller rotatably supported on a horizontal shaft projecting outward from each ladder girder. Bumpers 30 and 3 are provided on the guide rail mechanism to close the upper and lower limits of the rollers along the track 24, respectively.
It is divided by 1.

A guide mechanism 32 consisting of an elongated roller is rotatably supported by a fixed horizontal shaft extending between the triangular base plates 28 and engaged with the front or bottom surface of the ladder girder 16. Due to the weight of the ladder, the ladder girder 16 engages the guide mechanism 32, the guide mechanism 29 engages the track 24, and the guide mechanism 29
guides the ladder up and down, making it possible to control its inclination during each part of this movement.

The guide mechanism 32 is positioned a certain distance below the lower end of the track 24 so as to be substantially in line with the lowest straight sloped portion of the track 24, so that the straight portion 2
so that it is located behind 5. That is, when the ladder is in the retracted or fully raised position, the ladder spar 16 tilts forward and upward, and when the ladder moves downwardly from its retracted position, its bottom end swings rearward in response to the downward movement. Do it like this. When the guide mechanism 29 moves along the curved section 26 of the track, the relative rocking of the ladder girder is reduced, and when the guide mechanism 29 moves along the short sloped lowest section 27, the ladder girder is moved mostly in the longitudinal direction. so that This lowest part of the ladder movement is such that the ladder girder has the greatest upward and forward slope when the ladder is in its fully lowered position.

A beam 33 is provided extending horizontally between the triangular boards slightly above the elongated guide mechanism 32, thereby acting as a support between the boards and as a stop for the forward and downwardly projecting hooks 34 provided on the ladder girder 16. be able to stop at this position.

The cable 21 for connecting the counterweight 20 to the ladder 6 is connected to the center opening 35 of the box beam 23.
The cable guide 22 is disposed within this opening and is rotatably supported by a horizontal shaft extending in the front-rear direction. Each guide 22 separates the two running parts of the cable 21. One of these is a front running section 36 which extends downwardly perpendicular to the balance weight 20, and the other is a rear running section 37 which extends obliquely towards the ladder.

The tension applied to the cable 21 by the counterweight 20 is applied to the front running portion 36 by the vertical movement of the counterweight.
remains approximately constant except for changes due to changes in weight. However, as the ladder moves up and down, the angle of inclination of the rear running section 37 changes, so the tension on the cable changes as the ladder moves between the activated and retracted positions. This change allows you to manually start moving the ladder toward each position.
It can be moved to the other position with a small amount of force, and when it approaches this other position, it can be decelerated and brought to a gentle stop.

This variation is useful for changing the orientation of the ladder as it moves between raised and lowered positions. The rear running portion 37 of the cable 21 is connected to the ladder at the rear portion slightly below the top of the ladder girder 16. This connection is made by a fixing mechanism 39, such as a bracket, which is provided to protrude rearward from the second foot plate 17 counted from the top of the ladder. This fixing mechanism 3
9 is laterally spaced apart from the ladder girder 16 and diverted from the vertical path of the ladder, thus allowing the rear running portions 37 of the cables 21 to run parallel to each other from the fixing mechanism 39 towards the cable guide 22. The connection of the cable 21 to the ladder 6 is such that it takes place in that part of the ladder girder 16 which, when the ladder is in its lowered position (see FIG. 4), is located intermediate between the roller guide mechanisms 29 and 32. .

Rear running part 37 in all positions of the ladder
slopes backwards and downwards. However, due to the change in orientation as the ladder moves up and down, the rear run 37 is most vertical when the ladder is in between its retracted and extended positions, and its slope increases when the ladder is in its retracted and extended positions. do. When the rear running portion 37 is most vertical, the cable exerts the maximum upward force on the ladder, and as the slope increases, the vertical component of the tension decreases and the horizontal component increases.

When the rear running portion 37 is at its most vertical position in the middle of the ladder's range of travel, the vertically upward force exerted on the ladder by the cable is equal to the weight of the ladder. Changes in the length of the running sections 36, 37 and changes in the inclination of the rear running section 37 create a slight unbalance in which the ladder moves in its intermediate range of travel, but this unbalance is small and the ladder can be moved, for example manually, to the desired position. When the ladder is moved in the desired direction, this moving force and the effect of the counterweight cause the ladder to continue moving in the desired direction.

When the ladder approaches its retracted position, the slope of the rear running portion 37 of the cable is as shown in FIGS.
The size increases as shown in Figure 5. As the ladder rises due to this slope change, the reduction in the vertical upward force exerted on the ladder is due to the relative weight of the counterweight due to the increased length of the front running portion 36 and the decreased length of the rear running portion 37 of the cable. compensated by an increase in At the same time, when the ladder is raised, the friction of the guide mechanism 29 increases due to the increase in the horizontal force exerted by the rear running section 37 of the cable, but this is more than offset by the decrease in the friction of the guide mechanism 32. Become. Some force applied to the ladder causes the ladder to decelerate at the end of its upward movement relative to its raised position. The upper vertical component of the force exerted on the ladder by the counterweight at the upper limit of the ladder's motion is slightly less than that which can offset the weight of the ladder, but the frictional force is large enough to restrain the ladder in its retracted position.

When the ladder moves downward from the middle of its travel range as shown in Figures 15 and 16, the bottom of the ladder swings backwards, so that the slope of the rear running portion 37 of the cable gradually increases and is applied to the ladder. The upper component of the force gradually decreases and the ladder begins to overcome the balance caused by the counterweight. However, this imbalance is not very large. When the ladder is lowered, this unbalance component acts to move the ladder to the operating position. The upward acceleration force applied to the ladder during retraction counteracts this imbalance, and as the ladder rises, this imbalance decreases and the ladder continues to rise.

When the roller guide mechanism 29 descends through the curved portion 26 of the track and reaches the lowest sloped portion 27 as shown in FIGS. 16 and 17, the slope of the rear running portion 37 of the cable increases and the top of the ladder begins to move backwards, the path of motion of the ladder becomes aligned with its longitudinal direction, and the counterbalance weight begins to accelerate the deceleration of the ladder. At the same time, when the center of gravity of the ladder moves, the friction between the roller guide mechanisms 29 and 32 increases rapidly, creating a large leverage effect that further suppresses the descending movement of the ladder. The ladder thus comes to a slow stop in the extended position. When the ladder is in this position, the sum of the opposing balance forces tends to cause the ladder to rise from this position, but this can be inhibited by the frictional force of the roller guide mechanism, and this force can prevent inadvertent deflection. This value is large enough to resist the force, but small enough to be easily overcome by manually applied force. As soon as the ladder begins to move toward its retracted position, the frictional force decreases as soon as the roller guide mechanism 29 moves around the curved portion of the track. However, due to the change in the direction of movement of the ladder, the slope of the rear running portion 37 of the cable changes and the forces applied to the ladder are balanced and the ladder continues to rise.

In the device of the present invention, the balance weight 20 and cable 21 are constructed in consideration of the fact that when the balance weight and ladder move up and down, the lengths of the cable running parts 36 and 37 change and the weight on both sides of the cable guide 22 changes. The movement of the ladder can also be favorably controlled.

By connecting a rope or the like to the bottom of the ladder, the ladder in its retracted position can be easily operated from the ground. From the platform 9, the ladder can be moved up and down by grasping the guardrail 18. In order to prevent the ladder from being displaced from its retracted position while the mining machine 5 is being moved, lock bolts 41 are screwed into the triangular base plate 28 and engaged with the sides of the ladder girder 16, as shown in FIG. Make it. According to the device of the present invention, it is possible to obtain a stair ladder which can be climbed up and down like a conventional ladder and which can be raised to a retracted position for storage. At the final stage of reaching , it can be decelerated and manual movement to each position can be started.

[Brief explanation of the drawing]

Fig. 1 is a side view of the strip mining equipment equipped with the ladder device of the present invention, Fig. 2 is a front view of the strip mining equipment with the ladder in its lowered operating position, and Fig. 3 is a view of the strip mining equipment in its raised position. 4 is a side view of a part of the ladder, FIG. 5 is a front view of the upper part of the ladder, FIG. Figures 9 to 12 are cross-sectional views taken along lines -, -, XI-XI, and XII-XII in Figure 3, and Figure 13 is a perspective view of the track section. , 1st
4 to 17 are explanatory diagrams of the moving state of the ladder, respectively. 5... Strip mining machine, 6... Ladder, 7
... Caterpillar, 8 ... Rotating table, 9 ... Platform, 10 ... Boom, 11 ... Housing, 12 ... Control room, 14 ... Fixed staircase, 1
6...Ladder girder, 17...Ladder foot plate, 18...
Guardrail, 19... Rail mechanism, 20... Balance weight, 21... Cable, 22... Cable guide, 23... Box beam, 24... Track, 25... Straight portion, 26... Curved portion,
27... Bottom part, 28... Board, 29, 32...
...Guide mechanism, 33...Beam, 34...Hook, 36...Front running part, 37...Rear running part, 39...Fixing mechanism, 41...Lock bolt,
126...Thick board.

Claims (1)

[Claims for Utility Model Registration] (1) A pair of elongated parallel ladder girders 16 extending from the top to the bottom, and a plurality of laterally extending ladder foot plates 17 connected to and separated from each other in the longitudinal direction between the ladder girders. A fixed housing 11 on the front side of the ladder guiding the ladder between a substantially vertical raised inactive position and an oblique lowered activated position; a rail mechanism 19 provided in said housing 11 to define a track 24 having; B. a rail mechanism 19 engaging said track 24 for linear vertical movement of the top of the ladder as the ladder moves from and towards its raised position; C. A first guide mechanism 29 provided at the top of the ladder to allow the ladder to move; A second portion provided on the housing 11 at a position spaced downward from the straight portion 25 and displaced rearward.
a guide mechanism 32; D a counterweight 2 guided to rise and fall;
0 and; E with a cable 21 connected at one end to said counterweight 20; a fixing mechanism 39 for connecting to the other end of the cable 21;
1 so that the cable 21 extending relative to the fixing mechanism 39 is most vertical when the ladder is in between the positions, and is in an inclined position when the ladder reaches each of the positions. A ladder device comprising: a cable guide 22 for guiding; (2) The track defined by the rail mechanism 19 has a downwardly and backwardly curved portion 26 connected to a lowermost portion 27 which slopes downwardly and backwardly, and the track is located at the final stage of the ladder on which the ladder moves to the operating position. Utility model registration claim 1, characterized in that the ladder moves in the longitudinal direction of the ladder girder.
Ladder device as described in section. (3) The second guide mechanism 32 is comprised of a roller rotatably supported on a horizontal shaft fixed at a position behind the vertical portion 25 of the rail mechanism that is spaced below the lower end of the rail mechanism 19. Claim 1 for utility model registration characterized by
Ladder device as described in section.