JP2006296631A - Raising/lowering table - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a raising/lowering table smoothly raising/lowering a top board and raising/lowering it without moving it in the front/back despite of a simple constitution. <P>SOLUTION: This raising/lowering table is provided with a base frame 1 having a pair of right/left supports 2 and 2 in the back part, a raising/lowering base frame 7 attached along the supports 2 and 2 to be freely raised/lowered, and the top board 4 pivoted to the raising/lowering base frame 7 rotatably around the horizontal axial center. The top board 4 tilts from the horizontal state to the perpendicular state by a top board attitude retaining mechanism A. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lifting table.

2. Description of the Related Art Conventionally, various lifting tables that can adjust the vertical position of a top plate as necessary are known. For example, it is known that a pair of left and right support columns and a top plate are provided, the top plate is supported by a pair of left and right parallel link mechanisms, and is moved up and down while keeping the top plate in parallel (for example, Patent Document 1). reference).
JP 2001-008737 A

However, the elevating table of Patent Document 1 has a problem in that the top plate moves up and down (horizontal) slightly because the top plate moves up and down by the parallel link mechanism. For example, when installed on the bedside and used, the top plate is too close to the bed at a predetermined vertical position of the top plate. In addition, there is a disadvantage that the top plate is too close or too far away depending on the vertical position of the top plate up and down with respect to the position where the weak body is sitting.
In addition, when a weak person or the like wants to draw a picture or read a book, the conventional top plate remains horizontal, so that there is an insufficient point that the user cannot tilt to a convenient angle. Furthermore, there has been a problem that in places such as facilities and schools, the top plate remains horizontal when not in use.

Therefore, the lifting table according to the present invention includes a base frame having a pair of left and right columns at the rear, a lifting frame attached so as to be movable up and down along the columns, and the vicinity of the rear edge with respect to the lifting frame. A top plate pivotally mounted around the shaft center, and the top plate at a predetermined angle within a tilt angle range from a horizontal state to a vertically retracted state through an intermediate tilted state of tilting forward and downward. And a top plate posture holding mechanism for holding the top plate.
In addition, a base frame having a pair of left and right support columns at the rear, an elevating base frame attached so as to be movable up and down along the support columns via a rail and roller guide mechanism, a gas spring, a fixed pulley, a moving pulley, and a wire A lifting biasing mechanism for resiliently biasing the lifting base frame in the upward direction, and a top plate pivotally attached to the lifting base frame so that the vicinity of the rear edge is rotatable about a horizontal axis. And a top plate posture holding mechanism for holding the top plate at a predetermined angle within a tilt angle range from a horizontal state to a vertically retracted state through an intermediate inclined state that is inclined forward and downward, and The ascending urging mechanism sets the ratio of the stroke length of the gas spring to the ascending / descending dimension of the elevating base frame to 1: 2.

The top plate posture holding mechanism has a four semicircular arc guide groove formed around the horizontal axis and a plurality of locking recesses formed along the guide groove on the back surface of the top plate. A fixed guide plate, an operation lever attached to the elevating base frame, a lock rod that can be locked in a lock recess of the guide plate, and an interlock that links the lock rod and the operation lever. A member, and a spring that elastically urges the locking rod or the interlocking member in a direction in which the locking rod engages with the locking recess.
Further, the grip portion of the operation lever is disposed at a lower position near the rear edge of the top plate in a horizontal state when seen in a plan view. The rail / roller guide mechanism includes a rail fixed to the column, a back-and-forth swing prevention roller that rolls relative to the rail, and a left-right shake prevention roller. The locking female member is formed, and a locking male member is attached to the lifting base frame so as to be detachable with respect to the locking female portion, and the operation member provided on the back surface of the front edge of the top plate and the engagement The stop male member was interlocked with a push-pull wire. And it is preferable to form a see-through window part in a part of the top plate.

  The lifting table according to the present invention can be tilted as well as being lifted up and down while having a simple structure, and can be widely used for drawing, reading, and other various uses. In addition, it can be moved up and down with a light force, and the top plate can be tilted and subsequently in a compact storage state (non-use state).

  1 to 11 show an embodiment of a lifting table according to the present invention. This lifting table can raise and lower the top 4 to a desired height according to the posture of the crossbones and the posture seated on a chair, sofa, wheelchair, etc. On the top 4, OA equipment such as a computer, other It can be used for multiple purposes (multipurpose) by placing objects such as machines and tools, tableware and books, and it is also suitable for those with weak physical bodies to draw, read, eat, etc. Is.

  Reference numeral 1 denotes a base frame, which has a pair of left and right support columns 2 and 2 at the rear, and a pair of left and right horizontal members 3 and 3 arranged horizontally and in the front-rear direction. The pillars 2 are connected to each other so that the pillars 2 are erected at the rear ends of the three. Further, the left and right support columns 2 and 2 are connected to each other at the intermediate height position by the left and right connecting members 5. Further, left and right connecting members 5a are added to the lower end position and the like. Reference numeral 6 denotes a moving wheel attached to the lateral member 3.

An elevating base frame 7 is attached along the left and right columns 2 and 2 of the base frame 1 so as to be movable up and down. The top plate 4 is attached to the elevating base frame 7 as a mounting shape. Specifically, the top plate 4 is pivotally attached to the lifting base frame 7 so that the vicinity of the rear edge can be rotated around the horizontal axis L _{1 by the} support shaft 8.
The top plate 4 is moved from a horizontal state (shown in FIG. 1 or 2 and 7) to a vertically retracted state (non-use state) shown in FIG. A top plate posture holding mechanism A that holds the top plate 4 at a predetermined (desired) angle within an inclination angle range θ of about 90 ° is provided.

Further, the top plate 4 and the elevating base frame 7 can be moved up and down along the support column 2 via the rail / roller guide mechanism B. Further, a rising urging mechanism C including a gas spring 9, a fixed pulley 10, a movable pulley 11, a wire 12, and the like is provided along (inside) the support column 2. The elevating base frame 7 (and the top plate 4) is elastically biased in the upward direction by the elastic extension force of the gas spring 9.
The lift urging mechanism C is configured by setting the ratio of the stroke length of the gas spring 9 and the lift dimension of the lift base frame 7 to 1: 2.

  Specifically, the gas spring 9 is provided in the support column 2 in an inverted shape, and is pivotally attached to the upper part of the support column 2 with a support shaft 13, and the movable pulley 11 is attached to the lower end of the rod and is U-shaped. A part (intermediate part) of the wire 12 is suspended, one end 12 a of the wire 12 is fixed to the intermediate height of the support column 2, and the other end 12 b is fixed to the lifting base frame 7. Further, the wire 12 is suspended from the fixed pulley 10 and changed in direction by 180 ° between the other end 12b and the movable pulley 11. A shaft member of the fixed pulley 10 is fixed to the inner surface of the support column 2, and in this fixed pulley 10, a part of the wire 12 has an inverted U shape. In this way, the ratio of the vertical working distance (stroke length) between the gas spring 9 and the lifting base frame 7 is set to 1: 2. When the gas spring 9 is extended by, for example, 170 mm, the lifting base frame 7 (top plate 4) is raised by 340 mm.

The top plate posture holding mechanism A includes a four semicircular arc guide groove 14 formed around the horizontal axis L ₁ , and a plurality of locking recesses 15 formed along the guide groove 14 (on the outer periphery thereof). A guide plate 16 having The guide plate 16 is fixed to the back surface of the top plate 4. Further, the top plate posture holding mechanism A includes an operation lever 17 attached to the elevating base frame 7, a locking rod 18 that can be selectively locked to the locking recess 15 of the guide plate 16, An interlocking member 19 that interlocks and connects the rod 18 and the operation lever 17 and a spring 20 are provided.
The spring 20 is provided on the locking rod 18 or the interlocking member 19 and constantly urges and urges the locking rod 18 in a direction to engage the locking recess 15 of the guide plate 16.

  The grip portion 21 at the tip of the operation lever 17 is disposed at a lower position in the vicinity of the rear end edge 4a of the top plate 4 in the horizontal state when seen in a plan view. In addition, the grip portion 21 is located at the center of the left and right sides of the rear end edge 4a, and is positioned close to the rear end edge 4a so that the grip portion 21 can be easily gripped by hand. As shown in FIG. 4 or FIG. 5, the state in which the locking rod 18 and the locking recess 15 are disengaged and the top plate 4 can be swung (tilted) even if it is swung left or right. Become. That is, since the operation lever 17 may be swung to the left or right, the operation can be performed left-handed or right-handed.

  More specifically, the elevating base frame 7 includes, for example, a horizontal cross beam 7a in which a metal material such as a channel material obtained by pressing a metal plate or a square C shape material is disposed in an upper opening shape, and the horizontal girder 7a. It has a mounting portion 7b, 7b that is suspended from the left and right ends of the girder 7a, and has a gate shape with a low front view. The horizontal cross beam 7a has a flat cross section with a small vertical dimension, and the interlocking member 19 and the base of the operation lever 17 are accommodated therein.

  The interlocking member 19 has a multiple link structure as shown in FIGS. In other words, the central link 23 pivotally attached to the left and right center of the cross beam 7a by the vertical spindle 22 and the horizontal upper plate portion of the mounting piece portion 7b connected to the left and right ends of the cross beam 7a The interlocking member 19 is constituted by the swing link 25 pivotally attached to the shaft-shaped support shaft 24, the connecting link 26 connecting the central link 23 and the swing link 25, and the base end of the operation lever 17 is The operation lever 17 and the center link 23 are fixed to the center link 23 to form a T-shaped swing member. In addition, the locking rod 18 (described above) is fixed to the opposite side of the connecting link 26 to the connecting pin 27 with the support shaft 24 therebetween. Reference numeral 48 denotes a pin that pivotally connects the central link 23 and the connecting link 26. By configuring in this way, if the grip part 21 at a slightly lower position in the center of the left and right of the rear end edge 4a of the top plate 4 is gripped by hand and swung left or right (FIG. 3 to FIG. 4 or As shown in FIG. 5, the locking rods 18 and 18 swing around the support shaft 24 via the interlocking member 19 and detach from the locking recess 15 (against the elastic urging force of the spring 20). .

In addition, the planar shape of the top plate 4 has the notch parts 28 and 28 in the left-right corner part of the rear-end edge 4a in the example of the figure, and the interference with the support | pillar 2 is avoided. And the rectangular recessed part 29 is formed in the center of the front-end edge 4b, and it is easy to approach the center of the top plate 4, and is easy to use. The rectangular recess 29 may be an arc-shaped recess.
In addition, as the interlocking member 19 of the above-described top plate posture holding mechanism A, a push-pull wire system (not shown) can be freely used. Further, the spring 20 uses, for example, a tension coil spring to link the connecting link 26 and the swing link 25, and the state of FIG. 3 is the shortest. In FIG. 4 or FIG. Installed to function.

  Next, the rail / roller guide mechanism B will be described. As shown in FIGS. 6 and 10, the rail / roller guide mechanism B includes a rail 30 fixed to the support column 2, and a rail 30. There are provided two upper and lower anti-vibration rollers 31 and 31 that move, and three upper and lower and lower anti-vibration rollers 32, 33, and 32 that roll with respect to the rail 30. For example, as the cross-sectional shape of the rail 30, the U-shaped portion 30a that is open inwardly on the side, and the one-character portion (band plate portion) 30b that extends backward from the opening edge of the U-shaped portion 30a. And consist of

The front and rear run-out prevention rollers 31 and 31 are fitted in a concave groove 49 (vertical direction) formed by a U-shaped portion 30a having a transverse cross section of the rail 30, and contact the front and rear side surfaces of the concave groove 49. Rolling. Further, the left and right shake prevention rollers 32 and 33 are in contact with each other so as to hold the character portion (band plate portion) 30b of the cross section of the rail 30 from the left and right and roll. These rollers 31, 32, 33 are pivotally attached to the attachment piece 7 b of the elevating base frame 7.
The rail 30 is formed with upper and lower multi-stage engaging female portions 34. Specifically, as shown in FIG. 11 and FIG. 6 and the like, square holes are formed through the rear side wall of the U-shaped portion 30a in the cross section in multiple upper and lower portions to form the locking female portion 34. A locking male member 35 is attached to the mounting piece 7b of the elevating base frame 7 so as to be slidable back and forth so that the locking female portion 34 is detachable. In the illustrated example, the locking male member 35 has (for example) three claw pieces and simultaneously engages with the three locking female portions 34. As shown in FIG. 11, the locking male member 35 is always elastically biased rearward by a resilient member (coil spring or the like) 42, and is engaged with the locking female portion 34. Is always energized.

Further, the operation member 36 provided on the back surface of the front end edge 4 b of the top plate 4 and the locking male member 35 are interlocked and connected by a push-pull wire 37. The push-pull wire 37 is provided with a branch portion in the middle so that the pair of left and right engaging male members 35 can be reciprocated by one operating member 36. Further, 38 is a direction changing roller that changes the direction of the operating wire core material of the push-pull wire 37 and connects it to the mounting portion 39 of the locking male member 35.
Preferably, as shown by a two-dot chain line in FIGS. 3 to 5, a transparent window portion 40 is formed in a part of the top plate 4, and the situation of the leg of the weak body and the relation between the wheelchair and the body. And the like can be seen through (observed) from above. Of course, a transparent plate such as an acrylic resin is fixed to the see-through window 40.

As can be seen from FIG. 1, when the top plate 4 is in the highest position, the top 2a of the support column 2 is substantially the same height as the top plate 4 in the highest position, and the overall height is compact. Easy to handle without interfering with other objects.
From the horizontal state of the top plate 4 shown in FIG. 7, the intermediate tilt state of the forward downward tilt shown in FIG. In addition, it is possible to easily switch to the vertical storage state (non-use state) shown in FIG. 9 by this top plate posture holding mechanism A, and two mechanisms are not required as a whole. Thus, simplification of the structure is achieved.

As shown in FIG. 2, when the top plate 4 is in the lowered state, it is easy to use in a tatami or floor (agula) posture (not shown), and from the state of FIG. If tilted, you can easily read, perform various tasks, work, and draw pictures. Further, although not shown in the drawing, a stopper member having a predetermined length is preferably provided so as to protrude slightly above the top surface of the top plate 4 along the bottom of the recess 29 of the top plate 4. It is desirable to be provided so as to be movable up and down so that it can be switched between a protruding shape from the upper surface of the top plate 4 and a non-projecting shape below the same plane. Moreover, according to the attitude | position which seated on the chair, the sofa, or the wheelchair, the raising / lowering mechanism C can raise / lower easily to desired height with moderate lightness. On the top board 4, OA equipment, tableware, food, books, tools, sketchbooks, notebooks and the like can be placed, and can also be used as a bedside table, which can be used for many purposes.
As shown in FIG. 9, the top plate 4 is stored vertically in front of the support column 2. For example, when a plurality of units are used in facilities, schools, etc., the base frame 1 is positioned little by little to the left and right. The whole can be stored compactly. Further, when storing at the bedside, the horizontal member 3 shown in FIG. 9 can be inserted under the bed so as not to get in the way. In particular, the height of the upper surface of the horizontal member 3 can be set low and can be inserted into the lower part of the low floor bed.

  In addition, the lifting table according to the present invention does not move back and forth during lifting as in the conventional (four-section) parallel link mechanism, and the distance (interval) between the person in use and the top changes. The lifting operation is smooth and easy to use. Furthermore, as shown in FIG. 2, the minimum height of the top plate 4 can be set low, and the floor surface can be sufficiently approached.

Further, as shown in FIG. 6, the locking male member 35 reliably engages with the upper and lower multi-stage locking female portions 34 formed on the rail 30 (by the elastic urging force of the elastic member not shown). Since the locking means is provided, it can be easily stopped and held at a desired height. Since the locking female portion 34 is formed on the rail 30 itself (for example, with a rectangular through-hole), the manufacturing is easy, and the structure can be simplified, simplified, and compact.
As the rollers 31, 32, and 33 described with reference to FIGS. 6 and 10 and the like, it is desirable to use bearings as they are, and even when the bearings themselves are used, they are defined as rollers.

Further, the arrangement described in FIGS. 6 and 10 and the like of the rail 30 and the rollers 31, 32, 33 is smooth, and the back-and-forth direction and the left-right direction are not shaken. Therefore, the left and right synchronization (synchronizing mechanism is unnecessary).
The operation member 36 on the back surface in the vicinity of the front edge 4b of the top plate 4 is easy to operate. In addition, the push-pull wire 37 is connected to a stopper male member 35 for locking (for locking), and smooth locking and releasing operations are possible.

As described above, the lifting table according to the present invention includes a base frame 1 having a pair of left and right columns 2, 2 at the rear, a lifting frame 7 attached so as to be movable up and down along the columns 2, 2, A top plate 4 whose rear edge is pivotally attached to the lift base frame 7 so as to be rotatable around a horizontal axis L ₁ , and the top plate 4 is in an intermediate inclined state in which the top plate 4 is inclined forward and downward. Since the top plate posture holding mechanism A for holding the top plate 4 is provided at a predetermined angle within the tilt angle range θ up to the vertically stored state through the structure, the structure is simple and it can be widely used for various applications. If the top plate 4 is tilted to a desired angle and is easy to use according to the application and tilted downward as it is, it can be conveniently stored vertically, and the tilting mechanism and the storage folding mechanism are not required separately.

Further, a base frame 1 having a pair of left and right support columns 2 and 2 at the rear, a lifting base frame 7 attached so as to be movable up and down along the support columns 2 and 2 via a rail / roller guide mechanism B, and a gas spring 9, a fixed pulley 10, a movable pulley 11, and a wire 12, and a lifting biasing mechanism C that elastically biases the lifting base frame 7 in the upward direction, and the rear edge of the lifting base frame 7 has a horizontal axis. A top plate 4 pivotally mounted around the center L ₁ , and within a tilt angle range θ from the horizontal state to a vertically retracted state through an intermediate tilt state of a forward and downward tilt. The top plate posture holding mechanism A that holds the top plate 4 is provided at a predetermined angle, and the upward biasing mechanism C has a ratio of the stroke length of the gas spring 9 and the vertical dimension of the lift base frame 7 to 1. Since it is set to pair 2, the structure is simple, it can be widely used for various applications, and the top 4 is desired If tilted to an angle and easy to use depending on the application and tilted down as it is, it can be conveniently stored vertically, and a tilting mechanism and a storage folding mechanism are not required separately. Furthermore, since the top plate 4 does not move back and forth during the elevation as in the case of the conventional (four-section) parallel link, it is easy to use and the force of the gas spring 9 becomes an appropriate upward biasing force even for the weak. It is easy to adjust (change) the height of the top 4.

Further, the top plate posture holding mechanism A has a semicircular guide groove 14 formed around the horizontal axis L ₁ and a plurality of locking recesses 15 formed along the guide groove 14. A guide plate 16 fixed to the back surface of the top plate 4, an operation lever 17 attached to the elevating base frame 7, a locking rod 18 that can be locked in a locking recess 15 of the guide plate 16, An interlocking member 19 that interlocks and connects the locking rod 18 and the operation lever 17, and the locking rod 18 or the interlocking member 19 is elastically applied in a direction in which the locking rod 18 engages the locking recess 15. Since the spring 20 is provided, the operation is reliable and easy, and the durability is excellent.
Further, since the grip portion 21 of the operation lever 17 is disposed at a position below the rear end edge 4a of the top plate 4 in the horizontal state when viewed in plan, the top plate 4 is touched carelessly. There is no worry that the inclination of the lens suddenly changes, and there is an advantage that it can be easily and surely performed if it is consciously operated.

The rail / roller guide mechanism B includes a rail 30 fixed to the support column 2, front and rear anti-vibration rollers 31 and 31 that roll on the rail 30, and left and right anti-vibration rollers 32, 33, and 32. Further, the rail 30 is formed with a plurality of upper and lower locking female portions 34, and a locking male member 35 is attached to the lifting base frame 7 so as to be detachable with respect to the locking female portion 34. In addition, since the operation member 36 provided on the back surface of the front edge 4b of the top plate 4 and the locking male member 35 are interlocked and connected by the push-pull wire 37, the operation member 36 can be lifted and lowered smoothly without rattling. The desired top plate height can be maintained. In particular, the gas spring 9 having a built-in lock mechanism has a large initial operating load when left for a long time as a characteristic of the gas spring. However, in the present invention, the lock mechanism of the gas spring 9 itself is omitted, and By using the lifting biasing mechanism C, it is possible to reduce the initial operating load when left for a long period of time, and it is possible to release the lock quickly and reliably, and it is easy to use. It can be said that there is.
In addition, by forming the transparent window portion 40 in a part of the top plate 4, the caregiver can check whether the leg portion of the weak body is suffering from pain under the top plate 4, etc. Excellent safety.

It is a side view of the top plate rising state which shows one embodiment of the present invention. It is a side view of the top-plate downward state which shows one Embodiment of this invention. It is a top view which shows a latching state. It is a top view which shows a non-locking state. It is a top view which shows a non-locking state. It is a principal part expansion explanatory drawing. It is a side view with a top plate in a horizontal state. It is a side view which shows the inclination state where a top plate inclines forward and downward. It is a side view in which a top plate shows a perpendicular storage state. It is a partial cross section top view of the principal part. It is a partial cross section top view for principal part description.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base frame 2 Support | pillar 4 Top plate 4a Rear end edge 4b Front end edge 7 Lifting base frame 9 Gas spring
10 pulley
11 Moving pulley
12 wires
14 Guide groove
15 Locking groove
16 Guide plate 17 Operation lever 18 Locking rod 19 Interlocking member 20 Spring 21 Grip part 30 Rail 31 Back and forth shake prevention roller
32 Left and right shake prevention roller
33 Left and right runout prevention roller
34 Locking female part
35 Locking male member
36 Operation parts
37 Push-pull wire
40 Perspective window part A Top plate posture holding mechanism B Rail / roller guide mechanism C Lifting biasing mechanism L ₁ Horizontal axis θ Tilt angle range

Claims (6)

A base frame (1) having a pair of left and right support columns (2) and (2) at the rear, an elevating base frame (7) attached so as to be movable up and down along the support columns (2) and (2), and the elevating base A top plate (4) pivotably mounted around the horizontal axis (L ₁ ) in the vicinity of the rear edge with respect to the frame (7), and the top plate (4) is moved forward from the horizontal state. A top plate posture holding mechanism (A) for holding the top plate (4) is provided at a predetermined angle within a tilt angle range (θ) from the intermediate tilt state of the downward tilt to the vertical storage state. Lifting table. A base frame (1) having a pair of left and right columns (2) and (2) at the rear, and a rail and roller guide mechanism (B) are attached along the columns (2) and (2) so as to be movable up and down. It has an elevating base frame (7), a gas spring (9), a fixed pulley (10), a movable pulley (11), and a wire (12), and elastically energizes the elevating base frame (7) in the upward direction. A rising urging mechanism (C), and a top plate (4) pivotably mounted around the horizontal axis (L ₁ ) in the vicinity of the rear edge with respect to the lifting base frame (7), and The top plate (4) is held at a predetermined angle within a tilt angle range (θ) from a horizontal state to a vertically retracted state through an intermediate inclined state that is inclined forward and downward. A mechanism (A), and the upward biasing mechanism (C) has a ratio of the stroke length of the gas spring (9) and the vertical dimension of the lift base frame (7) to 1: 2. Lifting table, characterized in that there was boss. The top plate posture holding mechanism (A) includes a semicircular guide groove (14) formed around the horizontal axis (L ₁ ) and a plurality of latches formed along the guide groove (14). A guide plate (16) having a recess (15) and fixed to the back surface of the top plate (4), an operation lever (17) attached to the elevating base frame (7), and the guide plate (16 ) That can be freely locked in the locking recess (15), an interlocking member (19) that interlocks and connects the locking rod (18) and the operation lever (17), and the locking A spring (20) for resiliently urging the hook (18) or the interlocking member (19) in a direction in which the locking hook (18) engages with the locking recess (15). The lifting table according to 1 or 2.   The grip portion (21) of the operation lever (17) is disposed at a lower position in the vicinity of the rear end edge (4a) of the top plate (4) in a horizontal state when viewed in plan. Lifting table.   The rail / roller guide mechanism (B) includes a rail (30) fixed to the support (2), and a forward / backward swing prevention roller (31, 31) that rolls against the rail (30). Prevention rails (32), (33) and (32), and the rail (30) is formed with upper and lower multi-stage locking female portions (34), and against the locking female portions (34) The locking male member (35) is attached to the lifting base frame (7) so as to be freely detachable, and the operating member (36) provided on the back surface of the front edge (4b) of the top plate (4) and the locking male The elevating table according to claim 1, 2 or 3, wherein the member (35) is interlocked and connected by a push-pull wire (37).   The raising / lowering table of Claim 1, 2, 3, 4 or 5 which formed the transparent window part (40) in a part of said top plate (4).

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