Suitable for double-leaf protective closed partition doors in subway sections and entry and exit lines

Abstract

The present invention discloses a double-leaf protective airtight partition door suitable for subway sections and entrance and exit lines, and suitable for partitions of urban underground rail transit civil air defense projects with one line in a tunnel, and is composed of a door frame, door leaves, movable door sills, track sealing devices, busbar sealing devices, safety devices, locks, hinges, etc. The door leaves are welded structures of steel beams and plates, and the longitudinal steel sections are used as the main load-bearing beams, and the force is evenly applied; the movable door sill is connected to the lower door frame by bolts and bearings, and the force on the door leaves can be transmitted to the door frame by bolts and bearings; ladder-shaped sealing strips are installed on the upper, lower, left, and right sides of the partition door frame, and the door leaves are in close contact with the door frame. The hinges adopt a double-axis hinge structure, which is suitable for single-hole single-line double-leaf protective airtight partition doors, and solves the technical problem of arranging two partition partition doors in a limited space.

Description

Technical Field

[0001] The invention relates to a flood-proof protective closed partition door for subways and civil air defense projects, in particular to a double-leaf protective closed partition door suitable for subway sections and entrance and exit lines. Background Art

[0002] The subway section partition door is an important protective equipment in the subway civil air defense project, and is an extremely important component of the entire subway civil air defense project. It plays the role of separating the protection units, ensuring that the loss of the protection function of one protection unit in wartime will not affect the protection function of other protection units. In wartime, the subway section partition door must first meet the requirements of being able to withstand shock wave loads in both directions. It is mainly used to prevent the shock wave generated by the explosion of nuclear weapons and conventional weapons, and to avoid casualties or equipment damage caused by the entry of the destroyed protection unit into another protection unit. Secondly, since the subway section protection enclosed partition door is generally installed in the section partition protection section on the main line of the tunnel at the station end, under the premise of continuous rigid contact network in wartime, the partition door must be able to ensure the airtightness of the contact network and the track rails when closed to prevent the invasion of various chemical agents.

[0003] At present, the single-leaf or large-and-small-leaf subway partition doors and civil air defense doors for entry and exit sections commonly used in China require a large opening space in front of the door. Generally, the opening space in front of the door needs to be increased by 1.2 meters or more on the basis of the door hole width. However, when the civil construction conditions of individual stations are limited, it is difficult to arrange the partition doors, and the partition doors have to be adjusted to double-leaf form to reduce the width of each door, thereby reducing the opening space requirements. Then, on this basis, the basic requirements of the double-leaf civil air defense door, such as the wartime protective and airtight function and the reliable and fast peacetime-wartime conversion, are guaranteed. Summary of the invention

[0004] Based on the above problems, the present invention provides a double-leaf protective and sealed partition door suitable for subway sections and entrance and exit lines, which effectively solves the problem that there is insufficient reserved space for civil engineering and a single-leaf protective and sealed partition door cannot be set.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A double-leaf protective closed partition door suitable for subway sections and entrance and exit sections, comprising a door frame (1), a door leaf (2), a lock (5), a movable door sill (4) and a hinge mechanism (6); the door frame (1) comprises a lower door frame assembly (302), a right door frame assembly (303), a left door frame assembly and an upper door frame assembly (308); a movable door sill (4) is arranged on the inner side of the lower door frame assembly (302); a bus structure is also arranged in the door leaf (2); the door leaf (2) is characterized in that: the door leaf (2) is connected to the door frame (1) through the hinge mechanism (6); a sealing strip (3) is arranged at the connection between the door leaf (2) and the door frame (1); the door leaf (2) is built with a lock (5) for opening and closing the door leaf (2); the lock (5) is built in the door leaf (2) and is connected to an external hand wheel to realize the opening and closing of the door leaf;

[0007] The door leaf has two leaves, wherein each door leaf comprises a door leaf frame formed by longitudinal channel steels (201) at both ends, a longitudinal channel steel (2015) in the middle, transverse channel steels (208) at both sides, transverse I-beams (202), and longitudinal I-beams (203), and also comprises an inner panel (206) and an outer panel (205) attached to both sides of the door leaf frame, and the lock (5) is accommodated in a cavity formed by the above-mentioned door leaf frame;

[0008] The joints of the lower door frame assembly (302), the right door frame assembly (303), the left door frame assembly and the upper door frame assembly (308) are all installed with ladder-shaped sealing strips.

[0009] Handles (207) are arranged at intervals on the inner panel (206) and the outer panel (205), a peripheral embedded pressure plate (2010) is arranged at the periphery of the door leaf, and an arc-shaped embedded pressure plate (209) is arranged at the corner.

[0010] The movable door sill (4) is a triangular cross-section composed of a bottom plate (403), a longitudinal steel plate (402) and an end plate (404), wherein a first reinforcing rib (408) is arranged in the triangular cross-section; a pressure plate (406), an oblique flat steel (405) and a bottom rubber strip groove (401) are arranged on the outer side of the longitudinal steel plate (402) in order from top to bottom; a second reinforcing rib (409) and a fixed angle steel (4010) are arranged at the connection between the movable door sill (4) and the lower door frame assembly (302)

[0011] The maximum compression amount of the sealing strip is 10 mm.

[0012] A busbar sealing structure (9) is arranged around the busbar structure, and the busbar sealing structure (9) comprises a box (901), the busbar and the contact network are located in the box (901), a semicircular sealing block (902) is arranged around the busbar and the contact network, an intermediate contour sealing block (903) is arranged inside the busbar and the contact network, and a large sealing block (904) is filled between the semicircular sealing block (902) and the inner wall of the box (901).

[0013] The lock (5) comprises a hand wheel (501), a guide rod (502), a rotating arm assembly (505), a connecting rod (504) and a locking head (503). A connecting head (506) is provided at the end of the connecting rod (504) and is connected with the locking head (503) by a pin shaft (507). The locking head (503) extends into or out of the upper locking seat (508) and the lower locking seat to achieve closing and opening.

[0014] There are 8 locks.

[0015] The hand wheel is provided with a worm reducer and a screw transmission device.

[0016] The hinge mechanism (6) comprises a hinge seat (605), a hinge shaft (603), a bearing cover plate (602), and a hinge plate (607). The hinge plate (607) is sleeved with the hinge shaft (603) and extends outward. A spherical roller bearing (601) is arranged between the hinge seat (605) and the hinge shaft (603).

[0017] The lower locking seat comprises a locking opening formed by two channel steel notches relatively assembled together, an L-shaped angle steel connecting plate is arranged on the side of the channel steel, and the L-shaped angle steel connecting plate and the lower door frame assembly are fixedly connected by bolts.

[0018] The beneficial effects of adopting the above technical solution are:

[0019] a. It adopts double doors, arranged symmetrically on the left and right, with a compact structure and occupies relatively small civil engineering space.

[0020] b. A double-axis hinge solution with relatively simple manufacturing process and relatively light use is adopted. Rolling bearings are used in all relative motion parts of the hinges, and the friction mode of the support seat is rolling friction. It has the characteristics of flexible and light operation and labor-saving when opening and closing the door.

[0021] c. The upper, lower, left and right sides of the partition door frame are all equipped with ladder-shaped sealing strips. The track is specially treated, the door leaf and door frame are in close contact, the sealing strips are evenly compressed, and the maximum compression of the sealing strips is 10mm, which is airtight and reliable;

[0022] d. The lower locking seat is installed during the conversion from war to peace. The two channel steels are welded together with the outer reinforcement plate. The outer reinforcement plate is also used to control the placement depth of the lower locking seat. The inner reinforcement plate is in contact with the locking head to bear the force, making the conversion from war to peace convenient and quick.

[0023] e. The busbar sealing device adopts the form of a continuous rigid contact network. First, two semicircular profiling sealing rubber blocks are used to wrap the busbar. The large sealing rubber blocks on both sides are concave semicircular. The large sealing rubber blocks are squeezed by the busbar sealing drive device to achieve the sealing of the busbar, and can accommodate the left and right ±

[0024] The deviation of 140mm is 50% higher than that of existing partition doors.

[0025] In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention will be further described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1a It is a schematic diagram of the overall structure of the utility model.

[0027] Figure 1b for Figure 1a AA section view;

[0028] Figure 1c for Figure 1a BB cross-sectional view;

[0029] Figure 2a This is the main view of the door leaf;

[0030] Figure 2b yes Figure 2a AA section view;

[0031] Figure 2c yes Figure 2a BB cross-sectional view;

[0032] Figure 2d yes Figure 2a CC section view;

[0033] Figure 3a It is the main view of the door frame;

[0034] Figure 3b yes Figure 3a Detailed drawing of location I in the middle;

[0035] Figure 3c yes Figure 3a Middle AA section view;

[0036] Figure 4a It is a top view of the live threshold;

[0037] Figure 4b It is the main view of the live threshold;

[0038] Figure 4c yes Figure 4a Middle AA section view;

[0039] Figure 5a It is the main view of the concealed locking structure;

[0040] Figure 5b yes Figure 5a Middle AA section view;

[0041] Figure 6 It is a detailed drawing of the hinge mechanism;

[0042] Figure 7 It is a sealing diagram of the bottom plate of the door frame and the door leaf;

[0043] Figure 8 This is a detailed view of the lower locking seat;

[0044] Fig. 9 It is a detailed drawing of the busbar sealing structure. DETAILED DESCRIPTION

[0045] The embodiments of the present invention are described in detail below with reference to Figures 1-9 , but the present invention can be implemented in many different ways as defined and covered by the claims.

[0046] Figure 1a It is a schematic diagram of the overall structure of the utility model. Figure 2b for Figure 1a AA section view; Figure 3c for Figure 1a BB cross-sectional view. A double-leaf protective airtight partition door suitable for subway sections and entrance and exit sections, comprising a door frame 1 and a door leaf 2. The door frame 1 is fixed to the surrounding walls, and the door leaf 2 is connected to the door frame 1 through a hinge mechanism 6. A sealing strip 3 is provided at the connection between the door leaf 2 and the door frame 1. The door leaf 2 is equipped with a lock 5 for opening and closing the door leaf 2. The lock 5 is connected to an external hand wheel to realize the opening and closing of the door leaf. A bus structure is also provided in the door leaf 2. To ensure that the bus is not affected by the external environment, a bus sealing structure 9 is provided around the bus structure. A ladder 10 for maintenance is also provided on the door leaf 2. An electrical control box 7 and a door leaf fixing safety device 8 are installed on the walls around the door frame 1.

[0047] Figure 2 Detail of the door leaf, where: Figure 2a This is the main view of the door leaf; Figure 2b yes Figure 2a AA section view; Figure 2c yes Figure 2a BB cross-sectional view; Figure 2d yes Figure 2aThe CC cross-sectional view of the door leaf 2 includes a door leaf frame formed by longitudinal channel steels 201 at both ends, a longitudinal channel steel 2015 in the middle, transverse channel steels 208 at both sides, transverse I-beams 202, and longitudinal I-beams 203, and also includes an inner panel 206 and an outer panel 205 attached to both sides of the door leaf frame, and handles 207 are arranged on the inner panel 206 and the outer panel 205 at intervals, and a peripheral embedded pressure plate 2010 is arranged around the periphery of the door leaf, and an arc-shaped embedded pressure plate 209 is arranged at the corner. At the position where the two longitudinal channel steels 201 in the middle are opposite to each other, the two longitudinal channel steels 201 are located at the position of the inner side plate 206, and the two intermediate embedded pressure plates 2011 form a closed space through the rubber strip groove 2012, and the outer side of the rubber strip groove 2012 is provided with a reinforcing plate 2013. A movable door sill hanger 2014 is fixedly arranged on the inner panel 206. The door leaf structure can withstand shock wave loads in both directions. It is a steel beam-slab structure that can bear bidirectional forces. It is welded into a skeleton with steel sections, and the inner and outer steel plates are welded to it as a whole. The longitudinal steel sections are the main load-bearing beams, the lateral dimensions of a single leaf are relatively small, and the structure is reasonable.

[0048] Figure 3 shows the door frame details. Figure 3a It is the main view of the door frame; Figure 3b yes Figure 3a Detailed drawing of location I in the middle; Figure 3c yes Figure 3a Middle AA sectional view; the door frame 1 comprises a lower door frame assembly 302, a right door frame assembly 303, a left door frame assembly and an upper door frame assembly 308. A movable door sill 4 is arranged inside the lower door frame assembly 302. In addition to being connected to the lower door frame assembly 302 by bolts, the movable door sill 4 is also connected to the lower door frame assembly 302 by a bearing member, and the force on the door leaf can be transmitted to the door frame by bolts 304 and bearing members 309; ladder-shaped sealing strips are installed on the upper, lower, left and right sides of the partition door frame. The corners where the upper door frame assembly 308 and the left door frame assembly and the upper door frame assembly 308 are connected are provided with arc-shaped oblique flat steel 307, arc-shaped pressure plate 306 and connecting angle steel 305 from outside to inside. The right door frame assembly 303 and the left door frame assembly are provided with hinge bases 3010. The corners, transverse and longitudinal parts of the door frame 1 are provided with temporary horizontal diagonal braces 3011 and temporary corner diagonal braces 3012, respectively. The track is specially treated, the door leaf and door frame are in close contact, the sealing strip is evenly compressed, the maximum compression of the sealing strip is 10mm, and it is airtight and reliable.

[0049] Figure 4 shows the details of the movable threshold, where: Figure 4a It is a top view of the live threshold; Figure 4b It is the main view of the live threshold; Figure 4c yes Figure 4aMiddle AA section view; As shown in FIG4 , the movable threshold 4 includes a triangular section consisting of a bottom plate 403, a longitudinal steel plate 402 and an end plate 404, and a first reinforcing rib 408 is arranged in the triangular section. The outer side of the longitudinal steel plate 402 is provided with a pressure plate 406, an inclined flat steel 405 and a bottom rubber strip groove 401 from top to bottom. A second reinforcing rib 409 and a fixed angle steel 4010 are provided at the connection between the movable threshold 4 and the lower door frame assembly 302, and a hook 407 is provided at the top of the movable threshold 4. The bottom rubber strip groove 401 is parallel to the upper surface of the lower door frame assembly 302. The sealing beam of the movable threshold is composed of a sealing beam and a sealing rubber strip. The sealing measures of the movable threshold are used to seal the lower edge of the door leaf and the track. The movable threshold is used to adjust the gap between the door leaf and the bottom of the door frame to solve the problem of inconsistent roadbed plane when the partition door is in different interval positions. Normally, the threshold is placed on the side close to the hinge and fixed firmly. In wartime, it is connected to the bottom of the door frame to seal the track and achieve sealing with the track bed plane and the track side groove.

[0050] Figure 5 is a detailed diagram of the concealed locking structure. Figure 5a It is the main view of the concealed locking structure; Figure 5b yes Figure 5a Middle AA sectional view; As shown in FIG5 , the concealed locking structure includes a hand wheel 501, a guide rod 502, a rotating arm assembly 505, a connecting rod 504 and a lock head 503. A connector 506 is provided at the end of the connecting rod 504, and the three are connected with the lock head 503 by a pin 507. The lock head 503 extends into or out of the upper locking seat 508 and the lower locking seat to achieve closing and opening. The hand wheel is arranged in the middle, and the locking heads are arranged up and down, and the lock is opened and closed through the worm gear reducer and the connecting rod. The lock has two functions, providing the force for squeezing the sealing strip and bearing the reverse load. In order to make the lock head and the door leaf force uniform and reasonable, 8 lock heads are arranged on the door leaf. In order to make the locking operation easy, a worm gear reducer and a spiral transmission device are provided at the hand wheel to provide sufficient locking force.

[0051] Figure 6 It is a detailed drawing of the hinge mechanism, such as Figure 6As shown, the hinge mechanism 6 includes a hinge seat 605, a hinge shaft 603, a bearing cover plate 602, and a hinge plate 607. The hinge plate 607 is sleeved with the hinge shaft 603 and extends outward. A self-aligning roller bearing 601 is arranged between the hinge seat 605 and the hinge shaft 603. The door hinge seat 604 consists of a vertically arranged steel plate and two horizontal steel plates perpendicular to the vertical steel plate. The outward extending part of the hinge plate 607 extends between the horizontal steel plates and is connected to the two horizontal steel plates by bolts. A sliding gasket 606 is arranged on the contact surface of the two. A single-row needle bearing 608 is arranged between the outward extending part of the hinge plate 607 and the horizontal steel plate. The hinge consists of a door frame hinge seat, a door hinge seat, a hinge shaft, a hinge plate and other parts. Rolling bearings are used in all the relative motion parts of the hinge, and the friction mode of the support seat is rolling friction, which has the characteristics of flexible and light operation and labor-saving when opening and closing the door.

[0052] Figure 7 The movable threshold 4 is fixed to the bottom plate 3021 in the lower door frame assembly 302 by bolts 401, and the gap formed by the movable threshold 4, the lower bottom plate 3021 of the door frame and the door leaf 2 is filled with a sealing strip 3.

[0053] Figure 8 This is a detailed view of the lower locking seat. The lower locking seat includes a locking mouth formed by two channel steel notches. An L-shaped angle steel connecting plate is set on the side of the channel steel. The L-shaped angle steel connecting plate and the lower door frame assembly are fixedly connected by bolts. To ensure the safety of the locking mouth, a steel plate is used to strengthen the joint position.

[0054] Fig. 9 It is a detailed drawing of the bus sealing structure. The bus sealing structure 9 includes a box 901. The bus and the contact network are located in the box 901. Semicircular sealing blocks 902 are arranged around the bus and the contact network. Intermediate contour sealing blocks 903 are arranged inside the bus and the contact network. Large sealing blocks 904 are filled between the semicircular sealing blocks 902 and the inner wall of the box 901.

[0055] The double-leaf protective closed partition door suitable for subway sections and entrance and exit lines described in the above embodiment has the following specific installation and use process:

[0056] (1) Make sure there are no obstacles on the lower door frame and the lock is in the unlocked position. If the lock is not in the unlocked position, turn the lock hand wheel in the "open" direction until it is unlocked;

[0057] (2) Install the movable door sill and ensure that the joint between the movable door sill and the left and right door frames is well sealed;

[0058] (3) Install the lower locking seat, ensure that the nut is tightened and the locking seat is firmly installed;

[0059] (4) Release the jack to free it from the restraint of the positioning buffer device;

[0060] (5) Pull the handle on the door leaf and close the door leaf with the rubber strip groove in the middle first. When the door leaf is about to close, the closing speed of the door leaf should be reduced so that the door leaf closes gently to avoid the door leaf hitting the door frame vigorously.

[0061] (6) Use the same method to close the other door;

[0062] (7) After the door leaf is fully closed, rotate the hand wheel in the "close" direction until the four longitudinal connecting rods reach the vertical position. At this time, the lock is in the fully closed state;

[0063] (8) The operator climbs up to the operating platform via a ladder and rotates the rocker of the busbar sealing device in the "close" direction to ensure that the busbar is well sealed.

[0064] In the event of a war, follow the above steps to close the single-hole, single-line, double-leaf interval protective enclosed partition door, and follow the reverse order to open it.

[0065] The above embodiments only express several implementation methods of this patent, and the descriptions are relatively specific and detailed, but they cannot be understood as limiting the scope of this patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of this invention shall be based on the attached claims.

Claims

1. A double-leaf protective closed partition door suitable for subway sections and entrance and exit sections, comprising a door frame (1), a door leaf (2), a lock (5), a movable door sill (4) and a hinge mechanism (6), wherein the door frame (1) comprises a lower door frame assembly (302), a right door frame assembly (303), a left door frame assembly and an upper door frame assembly (308), wherein the lower door frame assembly (302) is provided with a movable door sill (4) on the inner side, and a busbar structure is further provided in the door leaf (2), wherein: The door leaf (2) is connected to the door frame (1) via a hinge mechanism (6); a sealing strip (3) is provided at the connection between the door leaf (2) and the door frame (1); the door leaf (2) is provided with a built-in lock (5) for opening and closing the door leaf (2); the lock (5) is built into the door leaf (2) and is connected to an external hand wheel to realize the opening and closing of the door leaf; the door leaf is two leaves, wherein each door leaf comprises a door leaf frame formed by longitudinal channel steels (201) at both ends, a middle longitudinal channel steel (2015), transverse channel steels (208) at both sides, a transverse I-beam (202), and a longitudinal I-beam (203); and also comprises an inner panel (206) and an outer panel (205) attached to both sides of the door leaf frame; the lock (5) is accommodated in the door leaf frame. In the cavity formed by the door frame, handles (207) are arranged at intervals on the inner panel (206) and the outer panel (205), a peripheral embedded pressure plate (2010) is arranged around the periphery of the door leaf, and an arc-shaped embedded pressure plate (209) is arranged at the corner; the joints of the lower door frame assembly (302), the right door frame assembly (303), the left door frame assembly and the upper door frame assembly (308) are all installed with ladder-shaped sealing strips, the movable door sill (4) is connected to the lower door frame assembly (302) through bolts and bearings, and the corners where the upper door frame assembly (308) and the left door frame assembly and the right door frame assembly (303) are connected are sequentially provided with arc-shaped inclined flat steel (307), arc-shaped pressure plates (306) and connecting angle steels (305) from the outside to the inside; The movable door sill (4) is a triangular cross-section composed of a bottom plate (403), a longitudinal steel plate (402) and an end plate (404), wherein a first reinforcing rib (408) is arranged in the triangular cross-section; a pressure plate (406), an oblique flat steel (405) and a bottom rubber strip groove (401) are arranged on the outer side of the longitudinal steel plate (402) in order from top to bottom; a second reinforcing rib (409) and a fixed angle steel (4010) are arranged at the connection between the movable door sill (4) and the lower door frame assembly (302); The lock (5) comprises a hand wheel (501), a guide rod (502), a rotating arm assembly (505), a connecting rod (504) and a locking head (503). A connecting head (506) is provided at the end of the connecting rod (504) and is connected with the locking head (503) by a pin shaft (507). The locking head (503) extends into or out of the upper locking seat (508) and the lower locking seat to realize closing and opening. The hinge mechanism (6) comprises a hinge seat (605), a hinge shaft (603), a bearing cover plate (602), and a hinge plate (607); the hinge plate (607) is sleeved with the hinge shaft (603) and extends outward; a self-aligning roller bearing (601) is arranged between the hinge seat (605) and the hinge shaft (603); The hinge mechanism (6) further comprises a door hinge seat (604), a sliding gasket (606), and a single-row needle roller bearing (608); the door hinge seat (604) is composed of a vertical steel plate and two horizontal steel plates perpendicular to the vertical steel plate; the outwardly extending portion of the hinge plate (607) extends between the horizontal steel plates and is connected to the two horizontal steel plates by bolts; the sliding gasket (606) is provided on the contact surface of the two; and the single-row needle roller bearing (608) is provided between the outwardly extending portion of the hinge plate (607) and the horizontal steel plates; The lower locking seat comprises a locking opening formed by two channel steel notches being relatively spliced ​​together, an L-shaped angle steel connecting plate is arranged on the side of the channel steel, the L-shaped angle steel connecting plate and the lower door frame assembly are fixedly connected by bolts, and the splicing position of the two channel steels is reinforced by an outer reinforcing plate and an inner reinforcing plate, the two channel steels are spliced ​​together by the outer reinforcing plate, and the locking head (503) is in contact with the inner reinforcing plate to bear force; A busbar sealing structure (9) is arranged around the busbar structure. The busbar sealing structure (9) comprises a box (901). The busbar and the contact network are located in the box (901). Semicircular sealing blocks (902) are arranged around the busbar and the contact network. An intermediate contour sealing block (903) is arranged inside the busbar and the contact network. A large sealing block (904) is filled between the semicircular sealing block (902) and the inner wall of the box (901). The semicircular sealing block (902) is a semicircular contour sealing rubber block. The busbar is wrapped by two semicircular sealing blocks (902). The large sealing blocks (904) on both sides are concave semicircular. The large sealing blocks (904) are squeezed by a busbar sealing drive device to achieve sealing of the busbar.

2. The double-leaf protective airtight partition door suitable for subway sections and entrance and exit lines according to claim 1 is characterized by: The maximum compression amount of the sealing strip is 10 mm.

3. The double-leaf protective closed partition door suitable for subway sections and entrance and exit lines according to claim 1 is characterized by: There are 8 locks.

4. The double-leaf protective and airtight partition door suitable for subway sections and entrance and exit lines according to claim 1 is characterized in that: The hand wheel is provided with a worm reducer and a screw transmission device.

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