JPH028186A - Structure of door for elevator riding spot - Google Patents

Abstract

PURPOSE:To make an opening and closing operation smooth by forming a door in the four sheets structure of the right and left main and sub doors, making the main door and the right and left sub-doors of the other side interlocked with the main door of one part and setting the sub-door moving speed half the main door in the door structure of the elevator for general household. CONSTITUTION:A main door 3a and sub door 3b are freely travelably fitted to the rail 14 for the sub-door and the rail 13 for the main door by upper and lower runners 15 respectively and the subdoor 3b is linked to the main door 3a by the interlocking means B composed by the connection fitting 19 of the subdoor 3b, pinion 21, moving rack 20 and the connection fitting 19 for the main door 3a. On the other hand, a main door interlocking means A is composed by arranging the endless rotary belt 17 fitted with the right and left main doors 3a at the upper part of the rail 13 for main door. The moving speed of the subdoor 3b is then set 1/2 the moving speed of the subdoor 3b. The door opening and closing can be made smooth by this structure.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to elevator equipment installed in general* gardens.
This concerns the structure of the elevator landing door.

[Traditional technique! ] In recent years, home elevators have been proposed. In this domestic elevator, a rlAl self-closing door is provided at the opening of the elevator landing on each floor.

In order to make the door pocket as small as possible, this door is a double door that opens left and right, and the left and right doors are divided into a main door and a DI door, making the door into four doors in total, making the door pocket smaller. There is. The applicant of the present invention has already filed an application for such a door for an elevator hall as U.S. Pat. No. 62-146635.

[Problem to be solved by the invention 1g] However, the method shown in Jitsugan Sho [No. Press Q + j door to move the secondary door together with the main door and store it in the door compartment, and when interfering with the door, first move the main door in the opening direction, and after the main door has moved halfway, close the main door. The secondary door was moved along with the main door by being pulled by the door.

In this way, when opening/closing a door, the main door first moves halfway and then the main door and the sub-door move in conjunction with each other, so the sub-door moves in conjunction with each other from the middle, so when opening/closing the door, the main door moves partway and then moves in conjunction. There was a problem in that it was overloaded and difficult to open and close smoothly.

The present invention was invented in view of the above-mentioned problems, and its object is to operate one of the left and right main doors in a WJFllll door to open the other main door and the left and right sub doors. can be opened and closed in conjunction with each other, and each side door can be opened and closed while each main door is opening and closing.
To provide a structure of an elevator landing door which can be smoothly opened and closed by applying a constant load from beginning to end.

[Means for Solving the Problems 1] The structure of the elevator landing door of the present invention is such that each floor is provided with an opening 2 for entering and exiting from a car 1 that ascends and descends, and a door 3 that can be opened and closed is provided in this opening 2. This door 3 is composed of four doors: left and right main doors 3a and left and right sub-doors 3b. A main door interlocking means A is provided for opening and closing operations of the main door 3a, and a tAll door interlocking means B is provided for opening and closing each side door 3b during the opening and closing operation of each main door 3a in conjunction with the opening and closing operation of each main door 3a. , secondary door 3
The moving speed of the main door 3a is set to 1/2 of the moving speed of the main door 3a, and by adopting such a configuration, the above-mentioned object of the present invention is achieved.

[Function 1] In the present invention, the door pocket can be made smaller by configuring the door 3 with four pieces, the left and right main doors 3a and the left and right sub-doors 3b. A main door interlocking means A is provided so that one of the left and right main doors 3a opens and closes in conjunction with the l1lI quiet operation of either one, and each main door 3a opens and closes in conjunction with the opening and closing operation of each main door 3a. A sub-door interlocking means B is provided so that each side door 3b moves [171 times] during opening/closing operation, and the moving speed of the sub-door 3b is controlled by the main door 3a.
By setting the moving speed to 172, a constant load is applied from the beginning to the end of the opening/closing operation, allowing smooth opening/closing operations.

[Examples] The present invention will be described in detail below with reference to Examples shown in the accompanying drawings. *
A car 1 for lifting and lowering people and objects at arbitrary positions indoors is provided so as to be able to rise and fall freely between the downstairs and the upper floors. This cage 1 is raised and lowered by a lifting device (not shown) disposed under the floor below the ladder 1. The basket 1 is covered by a mantle 11. As shown in FIG. 1, the envelope body 11 is constructed by providing an elevator elevating space 11a in a part of the building, and arranging the car 1 in the elevator elevating space 11a so as to be able to move up and down in the vertical direction. The wall of the building may be used as the mantle 11, or a mantle 11 separate from the wall of the building may be provided on the floor. The outer mantle 11 is provided with an opening 2 at each floor. Doors g112 are provided on both sides of the opening 2. A door 3 is arranged in the opening 2 so as to be openable and closable. The door 3 can open on both sides, and is composed of four doors: a left and right main door 3a and a left and right sub-door 3b. In addition, a main door rail 13 and a sub door rail 1 extend from the opening 2 to the door pocket 12.
4 is provided. The main door rail 13 and the sub door rail 14 are provided above and below, respectively, as shown in FIG. In addition, the main door rail 13 and the sub door rail 14
are arranged in front and behind each other. The left and right main doors 3a are movably mounted on the main door rail 13, and the left and right sub doors 3b are movably mounted on the sub-door rail 14, respectively. As shown in FIG. 4, upper and lower runners 15 are provided upwardly from the upper surface of the main door 3a and the secondary door 73b, and the runners 15 are connected to the upper main door rail 13 and the upper secondary door rail 14, respectively. The lower guides 16 protruding downward from the lower surfaces of the main door 3a and the sub door 3b are respectively attached to the lower main door rail 13 and the sub door rail 14 in a freely movable manner. It is. As shown in FIGS. 4, 6, and 8, above the main door rail 13, an endless rotating belt 17 such as an endless belt or an endless chain is arranged. The hook on the pulley 18 is a turn. One of the main doors 3a is connected to the upper part of this endless rotating band 17 by a connecting metal i4:19. r
The other main door 3a is connected to the lower part of r17 by a connecting fitting 19.

With this configuration, when the left and right main doors 3a open one of them, and when the endless rotating belt 17 rotates, the other also opens in conjunction, and when one of them closes, the other also opens. It is designed to close in conjunction with each other. Therefore, the endless rotating belt 17 and the connecting fitting 19 constitute a main door interlocking means A in which when one main door 3a moves, the other main door 3a moves in conjunction. Also, g11 door 3
b is linked to the main door 3a. That is, as shown in FIG. 4), the movable rack 20 is fixed to the connecting fitting 19 of the main door 3a, and the pinion 21 is rotatably attached to the connecting fitting J419 of the sub door 3b.

The pinion 21 is engaged with the fixed rack 22 (the fixed hook 22 does not move) and the movable rack 20. When the main door 3a moves, the movable rack 20 and the binion 21 are engaged, so the main door 3a is moved.
The radius of the nion 21 is set so that the moving speed of the sub door 3b is 1/2 of the moving speed of the main door 3a. In this way, the interlocking metal fitting 19, the moving rack 20, the pinion 21, the fixed rack 22, etc. constitute the sub door interlocking means B. Further, the main door 3a is provided with a handle 25, and the handle 25 is provided with a handle latch (not shown), which engages with a handle latch receiver (not shown) provided on the other main door 3a. When the handle 25 is rotated, the handle latch is removed from the handle latch receiver.

In the present invention, a tenth locking means 4 is provided for locking the door 3 with the opening 2 closed, in addition to the locking device on the handle side comprising the handle latch and the handle latch receiver. be. Then, there is a lock closing means for performing the lock closing operation of the tenth lock operation 4, and a tenth
Lock releasing means 5 for releasing the locking operation of the locking means 4 is provided. That is, as shown in FIG.
The locking means 4 locks one of the left and right main doors 3a.
It is provided at a position facing the other main door 3a of the road opening in the vertical direction. The tenth locking means 4 includes a rotating claw 28 rotatably supported on a rotating shaft 29, and the rotating claw 28 is pressed by a pusher 31 that is pushed down by a spring material 30 such as a tension spring. The rotating claw 28 has a claw portion 32 at the tip of the rotating claw 28 that protrudes outward from the side end surface of one main door 3a, and a metal fitting 33 is provided at the intermediate portion in the vertical direction of the llI end of the adjacent main door 3a. It is designed to be in a locked state when it is latched to. An operating rod 7 is installed inside the main door 3a so as to be movable up and down from the middle part to the upper end. The operating rod 7 is given an upward force by a spring 34, and the lower end of the operating rod 7 is in contact with an operating fitting 35, which is supported by a spring 36 such as a compression spring. . When the operating rod 7 is pulled up, the operating metal fitting 35 is pulled upward by the spring 36 and does not apply an operating force to rotate the rotary claw 28, but when the operating rod 7 is lowered, the operating metal fitting 35 is not operated. The lower end of the rod 7 pushes the operating metal fitting 35 against the spring 36, and the lower end of the operating metal fitting 35 pushes the upper edge of the rotating claw 28, causing the rotating claw 2 to move.
The claw portion 32 of the main door 3a is retracted from the gA end face of the main door 3a to release the lock.

The upper end of the operating rod 7 projects upward from the upper end surface of the main door 3a, and a roller 37 is rotatably provided at the upper end of the operating rod 7. When the door 3 is not fully closed, the rollers 37 are in elastic contact with the lower surface of the upper rail 6 due to the spring force of the spring 34, and when the door 3 is fully closed, the rollers 37 are elastically in contact with the recess 8 provided in the upper rail 6. It is designed to be entered. Here, upper rail 6
As shown in the embodiments shown in FIGS. 7 and 8, the main door rail 13 may be used as the upper rail 6, or the upper rail 6 may be provided separately from the main door rail 13. Inside the recess 8, as shown in Fig. 5, @Fig. 1, and Fig. 8, there is a movable member that can move up and down and is pushed upward with the roller 37 at the upper end of the operating rod 7 inserted into the recess 8. Body 9 is arranged.

The movable body 9 has a shaft 38 projecting upward, and the tip of the shaft 38 is inserted into a hole 40 provided on the upper surface of the upper frame 39 of the opening 2.
A horizontal pin 41 is provided at a portion projecting upward from the top. This movable body 9 is given a spring force to be pushed downward by a spring 42, and when the movable body 9 descends, the horizontal pin 41 hits the green of the hole 40, so that it descends only a certain length. . On both sides of the movable body 9, locking claw portions 43 are provided that protrude upward. The connecting metal 14C19 of the main door 3a is provided with an engaging claw portion 44 that protrudes downward, and is engaged when the moving body 9 is pushed up by the roller 37 at the upper end of the operating rod 7 when the door 3 is fully closed. The locking claw portion 43 is engaged with the mating claw portion 44 to be locked.

The locking claw portion 43 and the engaging claw portion 44 constitute a second (seventh) locking means 45.A bearing piece 46 is protruded near the hole 40 on the upper surface of the upper frame 39. , this bearing has 4 pieces
9. The operating piece 47 is rotatably supported at 6.
One end of a loft 48 is rotatably supported on the shaft, and the other end of this loft 48 is inserted through a U-shaped portion 50 of a connecting fitting 49, as shown in FIGS. 5 and 6. , ) character-shaped portion 50
The collar 51 and the U-shaped portion 50 are fixed to the loft 48 inside.
A spring 52, such as a compression spring, is interposed between the two pieces. Further, the rod 48 is provided with a spring force applied by a spring 53 in the direction of arrow A in FIG. A support frame 54 is provided at the end of the upper surface of the upper frame 39, and an electromagnetic clutch 55 is attached to this support frame 54, and a pongee 56 attached to a connecting fitting 49 is connected to a lever 61 fixed at an eccentric position and an electromagnetic clutch 55. The clutch 55 can be engaged freely. Electromagnetic clutch 5
The pongee 57 of 5111Il is provided with an arm 58,
A roller 59 is rotatably provided at the tip of the arm 58. Then, with the car 1 positioned in the opening 2, the roller 59 is rotated in the direction of the arrow in FIG. The operating piece 47 is rotated to push down the horizontal pin 41 and the shaft 38 , and the movable body 9 is lowered to lower the upper layer of the operating rod 7 located in the recess 8 . The lock is released as described above by pushing down the roller 37 and pushing down the operating rod 7. Therefore, the lock release operation section 60, the loft 48, the operation piece 47, etc. serve as a push-down means 10 for pushing down the movable body when the car is located in the opening, and the above-mentioned operation rod 7
, upper rail 6, recess 8, moving body 9, push-down hand #110
The lock release means 5 is constructed as follows.

As shown in FIGS. 7 and 8, the upper frame 39 has an opening, and a first opening attached to the upper surface of the upper frame 39
An operating part 73 of the limit switch 72 extends downward from the opening, and when the door 3 is fully closed, an operating member 74 attached to the connecting fitting 19 of the main door 3a operates the operating part 73 and is installed in the elevator control circuit. 1st limit F switch 7
2 is turned on. Further, a second limit switch 75 is provided on the upper surface of the upper frame 39, and when the movable body 9 is pushed upward, the actuating part 76 of the second limit switch 75 is pushed by the horizontal pin 41, and the control circuit of the elevator is activated. The second limit switch 75 provided
is turned on, and when the movable body 9 descends, the suppression of the actuating portion 76 by the horizontal pin 41 is released and the second limit switch 75 is turned off.

Although the elevator control circuit is shown in FIG. 12, the specific configuration will be described later.

In addition, a spring plate 78 attached to the upper surface of the upper frame 39 extends downward from the other three openings of the upper frame, and when the main door 3a is fully closed, the spring plate 78 is rotatably installed in the connection J419 of the main door 3a. When the stopper roller 77 passes over this spring plate 78, the spring plate 78 comes into elastic contact with the rear side of the stopper roller 77, and prevents the spring plate 78 from returning due to the reaction when the main door 3a is closed.

As shown in FIG.
An entrance/exit opening 62 is provided opposite to the opening 62 . In addition, the front part of the car 1 and both fils of the car 1 are provided with openings 62 for entrance and exit.
Although it covers one part, an idle rail 63 is provided, and this
Left and right doors 64 are attached to the idle rail 63 so as to be freely movable. Here, each of the left and right doors 64 is constructed by rotatably connecting a number of narrow door bodies 65 in the left and right direction, and as shown in FIG. The protruding upper running part 66 is movably attached to the upper idle rail 63, and the lower running part 67 protruding downward from the lower surface of R64 is movably attached to the lower idle rail 63. A necessary endless band 68 such as an endless belt or an endless chain is arranged above the upper idle rail 63 along the upper idle rail 63, and this necessary endless band 68 is arranged on the left and right sides as shown in FIG. corner pulley 6
9 is a turn. Then, one of the left and right $64 is attached to the upper part of the required endless band 68, and the other is attached to the lower part using a metal fitting 70.

By doing this, when one of the left and right doors 64 is opened or closed, the other w
fi64 is also designed to open and close. Here left and right R
64, when opened, is pushed into and stored in a position along the left and right sides of the car 1. The door 64 has a handle 7
1 is provided, and this handle 71 may also be provided with a locking means as appropriate.

FIG. 12 shows a control circuit for an elevator according to the present invention, and FIG. 13 shows a flowchart showing the operation.

In Figure 112, 72 is the left and right first limit switch;
75 is a second limit switch, 9o is a push button switch for elevator destination, R3 is a first relay, R, a, R
, b are the normally open contacts of the first relay R1, and R2 is the second
Relays R2a and R2b are respectively the normally open contacts of the second relay R2, T is the timer Ta is the normally closed contact of the timer T,
R3 is the third relay R3a, Rsb is the normally open contact of the third relay R1, R4 is the fourth relay, R<a is the normally open contact of the fourth relay R1, M is the motor circuit for raising and lowering the elevator, and 91 is the normally open contact of the third relay R1. This is a floor detection switch that detects that an elevator car 1 is in a position corresponding to an opening 2.

In the above circuit, the normally open contacts R1a, R,
A self-holding circuit for the relay R1 is formed so that the first relay R is energized even if the push button switch 90 for the destination is released from being pressed after the destination push button switch 90 is turned on. In addition, the normally open contact R3a and the second limit switch 7
5 forms a self-holding circuit for the third relay R1, and when the timer T operation is completed, the normally closed contact Ta of the timer T is
Even if R5 is turned off, the third relay R5 is energized. Here, the operating time of the timer T is slightly longer than the time it takes for the car 1 to move up and down slightly from the position corresponding to the opening 2 and for the lock release operation section 60 to separate from the roller 59 of the arm 58. It is set for a long time.

Therefore, when the door 3 is closed with the elevator 1 located at the position corresponding to the opening 2 and the floor detection switch 91 turned on, the left and right first limit switches 2 are turned on. . In this case, when it is confirmed that the first limit switch 72 is turned on and the door 3 is closed, the push button switch 90 for the end of the line is ready to be turned on.
In this state, when the destination push button switch 90 is pressed to turn on, the first relay R1 is energized and the F! 5 contacts R1a
.

R and b are turned on. At this time, Rtax is on, so a self-holding circuit is formed by R, a% R, b. The second relay R2 is energized by turning on the zero-order normally open contacts R, b, and the normally open contact R2a is turned on, the timer T operates, and the operation of the timer T turns on the normally closed contact Ta, energizes the third relay R3, turns on the normally open contact R3m, and energizes the elevator motor circuit M. When the car 1 goes up, the hydraulic pump that raises and lowers the elevator rotates, and when the car 1 goes down, the oil recovery valve opens, thereby causing the car 1 to go up and down.

Then, the car 1 moves and the lock release operation section 60 moves to 7-
At the same time as the loft 48 is removed from the roller 59 of the arm 58, the movable body 9 is pushed upward by the operating rod 7.
When the locking claw portion 43 and the engaging claw portion 44 are engaged with each other, the 20th
When the locking means 45 enters the locked state and the operating rod 7 moves upward, the rotary claw 28 constituting the lock portion 4 is rotated by being pressed by the push metal fitting 31 that is pushed down by the spring material 30, and the tip of the rotary claw 28 is rotated. The claw portion 32 protrudes outward from the I end face of one main door 3a and is attached to the adjacent main door 3a.
(The receiver provided in the vertical middle part of part 111 is the metal fitting 33
It becomes locked. Therefore, the lock portion 4 is also locked.

In addition, in this state, the operating portion 7 of the second limit switch 75 is activated by the horizontal pin 41 provided on the shaft 38 of the moving body 9.
6 is pressed, and the second limit switch 75 is turned on.

Here, if the second limit switch 75 is not turned on before the normally closed contact Ta of the timer T is turned off, the normally closed contact R3a of the third relay R7 is turned off, and the motor circuit M is turned off. The electricity supply is stopped, and the elevator car 1 comes to a stop. Therefore, door 3 is closed while car 1 is moving! ! ! ! (In other words, even if the closed state of the door 3 is detected by the first limit switch 72!! and the normally closed contact Ta of the timer T is in the OFF state, for some reason the lock part 4, the 20th If the locking means 45 is not in the locked state, the car 1 is stopped to maintain safety.On the other hand, if the second limit switch 75 is turned on, the car 1 continues to go up and down to the destination floor. The floor detection switch 91 detects that the car 1 is located in the opening 2 of the destination floor and stops the car 1.

When the car 1 stops at the opening 2, the lock release operation part 6
0, the operating arm 58 is rotated), and the operating arm 58
The loft 48 is moved in the direction of the arrow C in FIG.
1 to push down the shaft 38, and as the movable body 9 lowers, the roller 37 at the upper end of the operating rod 7 located in the recess 8 is pushed down, the operating rod 7 is pushed down, and the f of the operating rod 7 is pushed down.
Push down the operating bracket 35 by pressing the lower end of the operating bracket 35, and push the upper edge of the rotary claw 28 with the lower end of the operating bracket 35 to retract the rotating claw 28 so that the claw portion 32 does not protrude from the side end surface of the main door 3a, and release the lock. It is.

Further, when the movable body 9 is pushed downward, the engagement between the locking claw portion 43 and the engaging claw portion 44 is released, and the wJ20 locking means 45 is unlocked. In this state, the door 3 and the thickness 64 of the car 1 are opened to get out of the car 1. To open the door 3, grab the handle 25 and open one of the main doors 3a, which will open the other main door 31L, and the left and right sub doors 3b will also move with the main door 3a. The left and right main doors 3a and the left and right sub-doors 3b are housed in the left and right door pockets 12, respectively. By the way, when the main door 3a is opened with the rollers 37 at the upper end of the operating rod 7 pushed downward by the movable body 9, the rollers 37 move while being in elastic contact with the lower surface of the upper rail 6, and the operating rod 7 is maintained in a depressed state to maintain unlocking by the lock portion 4. Now get on car 1 again and go to another destination floor (to get back on car 1, fully close door 3 of opening 2, and then go to car 1's door 64.
Fully close the door, press the destination button Ia90, and move up and down to the destination floor using the above operations. In this case, the opening 2 is connected to the door 3.
When fully closed, the roller 37 of the operating rod 7 that was in elastic contact with the lower surface of the upper rail 6 enters the recess 8, but the car 1
In the state where the lock release operation part 60 is pushing the roller 59 of the arm 58, the movable body 9 is pushed down, and therefore the operation rod 7 is also pushed down by the movable body 9. As a result, the lock part 4 and the 20th locking means 45 are both in the unlocked state, but the first limit switch 72 is turned on because the door 3 is in the fully closed state, and therefore, When the destination button of the elevator is pressed in this state, the electric circuit of the elevator is energized and the car 1 moves. The subsequent operation is the same as the operation after pressing the destination push button switch 90 described above.

Incidentally, FIG. 9 shows a device for manually releasing the lock by the lock portion 4 and the twentieth locking means 45. That is, a rotary knob 93 is rotatably provided on the front upper part of the main door 3a, and a rotary knob 93 is rotatably provided in the upper part of the main door 3a.
An eccentric lever 94 fixed to the pongee is provided, and an eccentric operating portion 95 is provided on this eccentric lever 94. When the rotation knob 93 is rotated, the eccentric lever 94 is rotated, and the eccentric actuating section 95 presses the abutting section 96 fixed to the operating rod 7, pushing down the operating rod 7 and locking the opening section 4. It is designed to release the status. Further, when the operating rod 7 is lowered, the movable body 9 is lowered, and the lock of the #20 hand Pi 45 is also released.

[Effect of the invention 1 In the present invention, as described above, the door for opening and closing the opening is composed of four doors, the left and right main doors and the left and right sub-doors. It is effective in places where large spaces are not available, such as houses, and when the left or right main door opens or closes, the other one of the left or right main doors opens and closes. A main door interlocking means is provided to operate the main door, and a sub-door interlocking means is provided so that each side door opens and closes in conjunction with the opening/closing operation of each main door while the main door is opening/closing, thereby controlling the movement speed of the sub-doors. Since the movement speed is 1/2 of the main door, even though the door is composed of four doors: the left and right main doors and the left and right sub-doors, these main doors and 11 doors are opened and closed in conjunction with each other. When opening/closing, the load is constant from the beginning to the end of the opening/closing operation, allowing smooth opening/closing operations.
Especially in the case of domestic elevators whose doors are opened and closed by hand.
It can be opened and closed easily by hand.

[Brief explanation of the drawing]

! Figure #1 is a schematic overall vertical cross-sectional view of the present invention, Figure 2 is a schematic horizontal overall cross-sectional view of the same as above, Figures 3 (a) and (b) are a schematic horizontal cross-sectional view and a schematic rear view of the opening portion of the same, Figure PIIJ4 is a longitudinal sectional view of the same as above, Figure 5 is a partially omitted front view of the same as above, Figure 6 is a horizontal sectional view of the same as above, Figure 7 is an enlarged front sectional view of the 20th hook means part of the same as above, and Figure 8 is The figure is a perspective view of the same as above, seen from the back! Figure #9 (aHb) is a front view and side view of the lock part, Figure 10 is a partially omitted sectional view of the main rail and V sub-rail portions of the same as above, Figure 11 is a schematic front view of the door of the same as above, and Figure 1
2 is a control circuit diagram of the same as above, and FIG. 13 is a 70-chart for explaining the operation of the same as above, in which 1 is a car, 2 is an opening, 3 is a door, 3a is a main door, 3b is a subdoor, A is a main door interlocking means, and B is a subdoor interlocking means. Agent Patent Attorney Ishi 1) Chief 7 Figure 11 Figure 12 Section I

Claims (1)

[Claims] (1) An opening is provided on each floor for entry and exit from the car that goes up and down, and a door that can be opened and closed is provided in this opening. A main door interlocking means is provided so that one of the left and right main doors opens and closes in conjunction with the opening and closing operation of either one of the main doors, and each main door opens and closes in conjunction with the opening and closing operation of each main door. A sub-door interlocking means is provided so that each sub-door opens and closes during operation, and the movement speed of the sub-door is set to 1/2 of the movement speed of the main door.
An elevator landing door structure characterized by comprising: